JP2012036886A - Control method and control device of high pressure fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce operation noise of a high pressure fuel supply pump comprising a normally-closed type solenoid actuated intake valve.SOLUTION: The high-pressure fuel supply pump 100 comprises a normally-closed type solenoid actuated intake valve 110 configured to be opened or kept open by a magnetic force. The control current IC of the solenoid actuated intake valve 110 is controlled for opening the solenoid actuated intake valve 110 by applying a control voltage VC to the solenoid actuated intake valve 110. The control of the control current IC of the solenoid actuated intake valve 110 includes a step for increasing the control current IC to a first control current value IC1 for energizing the solenoid actuated intake valve 110. The control of a control current IC of the solenoid actuated intake valve 110 for opening the solenoid actuated intake valve 110 further includes a step for reducing the control current IC from the first control current value IC1 to a second control current value IC2 lower than the first control current value IC1.

Description

  The present invention relates to a control method for a high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine, and a control device that controls the high-pressure fuel supply pump. Furthermore, the present invention relates to a computer program product including computer program code for configuring a control device such as an engine control unit to control a high pressure fuel supply pump.

  Specifically, the present invention relates to a high pressure fuel supply pump having a normally closed electromagnetic intake valve that is opened and / or held open by a magnetic force by energizing a solenoid of a normally closed electromagnetic intake valve. The present invention relates to a control method and a control apparatus. This is distinguished from a high pressure fuel supply pump comprising a normally open electromagnetic intake valve that is closed and / or held closed by magnetic force by energizing the normally open electromagnetic intake valve.

  The present invention relates to controlling a control current of an electromagnetic intake valve to open the electromagnetic intake valve by applying a control voltage or a control current, and the control of the control current of the electromagnetic intake valve is applied to the electromagnetic intake valve. Increasing to the first control current value for energization, in particular, the compression plunger reciprocating between top dead center (TDC) and bottom dead center (BDC) in the compression chamber of the high pressure fuel supply pump is compressed Including increasing the control current to a first control current value for energizing the electromagnetic intake valve before reaching BDC at the end of the intake stroke of the plunger.

  A high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine can be used in a fuel supply system based on a direct injection operation in which fuel is directly injected into a combustion chamber of an internal combustion engine by an injector. The pressurized fuel that is directly injected into the combustion chamber of the internal combustion engine is pressurized by a high-pressure fuel supply pump.

  For example, in Patent Document 1, a high-pressure fuel supply system for supplying pressurized fuel to an internal combustion engine, which is opened or kept open by a magnetic force generated by energization of a solenoid of an electromagnetic intake valve, is normally closed. 2. Description of the Related Art A supply system including a type electromagnetic intake valve is known. Here, the normally closed valve means a closed type valve when the shut-off state, that is, when the control current / control voltage is not applied to the solenoid of the electromagnetic intake valve.

  Patent Document 1 addresses the problem of reducing operation noise of a normally closed electromagnetic intake valve, and before energizing the solenoid of the electromagnetic intake valve, the upstream side and the downstream side of the valve for opening the valve by fluid force It was proposed to use the fluid pressure difference between the two. However, efforts are continuing to find further optimization strategies and optimization methods to further reduce the operating noise of normally closed electromagnetic intake valves and enable reliable operation.

  In the prior art, the control supplied to the solenoid to avoid thermal overload of the solenoid by reducing the control current after the electromagnetic intake valve has already opened, i.e. after the electromagnetic intake valve has already reached the fully open position. There are technologies that reduce the current. In such a control method, the control current is not yet reduced in the step of controlling the control current to open the electromagnetic intake valve, and the normally closed electromagnetic intake valve is already fully closed by the magnetic force during the operation stroke. For example, the control current is reduced only during the process of outputting the pressurized fuel through the discharge valve of the high-pressure fuel supply pump (see, for example, Patent Document 2).

EP1898085A2 publication DE102004016554A1 publication

  In conventional high-pressure fuel supply systems, when the motor is in a low rotational speed condition, for example, during idling of an internal combustion engine, the main operating noise is noise emitted from the electromagnetic intake valve, and this noise especially opens and closes the valve. For example, this occurs when the intake valve member of the electromagnetic intake valve comes into contact with the valve seat in the fully closed position of the valve. Therefore, it is desirable to provide a fuel supply system having an electromagnetic intake valve that can reduce operating noise.

  It is an object of the present invention to reduce the operating noise of a high pressure fuel supply pump that is configured to supply pressurized fuel to an internal combustion engine and that is normally opened or held open, with a normally closed electromagnetic intake valve. It is to reduce.

[1] According to the first aspect of the present invention, a method for controlling a high-pressure fuel supply pump for controlling a high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine is proposed. The high-pressure fuel supply pump opens and / or holds the electromagnetic intake valve open, so that it is opened by magnetic force and / or held open especially when a control voltage or control current is applied to the electromagnetic intake valve On the other hand, when the fluid pressure does not act on the electromagnetic intake valve and no control voltage or control current is applied to the electromagnetic intake valve, the electromagnetic intake valve remains closed by the biasing member. A type electromagnetic intake valve is provided.

  According to the present invention, a method for controlling a high pressure fuel supply pump includes controlling a control current of an electromagnetic intake valve to open the electromagnetic intake valve by applying a control voltage or a control current to the electromagnetic intake valve, The control current of the valve is controlled by increasing the control current to a first control current value for energizing the electromagnetic intake valve, in particular, reciprocating between BDC and TDC in the compression chamber of the high pressure fuel supply pump. Including increasing the control current to a first control current value for energizing the electromagnetic intake valve before the compression plunger reaches the BDC at the end of the intake stroke of the compression plunger.

  According to the present invention, controlling the control current of the electromagnetic intake valve to open the electromagnetic intake valve means that the compression plunger reciprocating between BDC and TDC in the compression chamber of the high pressure fuel supply pump Including reducing the control current from a first control current value to a lower second control current value before reaching BDC at the end of the stroke.

  Therefore, in order to reduce the operation noise of the electromagnetic intake valve, the control current for opening the normally closed electromagnetic intake valve first increases to the first control current value for energizing the electromagnetic intake valve, and then Control is performed so as to be reduced again to a lower second control current value. Since the magnetic force acting on the electromagnetic intake valve is reduced by reducing the control current in the solenoid of the electromagnetic intake valve, the urging force of the normally closed electromagnetic intake valve urging member acting in the closing direction of the electromagnetic intake valve is reduced. By using it, the movement of the electromagnetic intake valve in the opening direction can be decelerated.

  Decreasing the speed of the electromagnetic intake valve when it hits the mechanical locking part such as a restricting member, stopper, or valve seat in the fully open position in the fully open position by slowing down the moving speed of the electromagnetic intake valve to the open position Therefore, the generated impact noise can be further reduced. In other words, the movement of the electromagnetic intake valve in the opening direction is decelerated (or at least acceleration toward the fully opened position is performed so that the electromagnetic intake valve can smoothly land on a mechanical locking portion such as a valve seat, for example. Impact noise can be greatly reduced.

  In order to open the electromagnetic intake valve, reducing operating noise by first increasing to a first control current value and then controlling the control current to decrease to a lower second control current value is It has the advantage that operating noise can be reduced by simply modifying the applied current control without requiring modification of the mechanical design of the high pressure fuel supply pump. Changes and modifications to the mechanical design are usually very expensive and laborious to develop or implement, so reducing the noise by modifying the solenoid current control is more than modifying the mechanical design. Significant cost savings. This is particularly advantageous when considering the large number of productions in the mass production of parts in the automotive industry.

  In particular, today's high pressure fuel supply pumps are generally automatically controlled by an electronic engine controller, so that the current controller has been optimized by reprogramming or configuring the engine controller, for example by software modifications. The algorithm can be implemented in the control of existing high pressure fuel supply pumps.

  In addition, by precisely controlling the control current applied to the solenoid of the electromagnetic intake valve, the amount of energy supplied to the solenoid is precisely controlled to accelerate and / or decelerate the electromagnetic intake valve during movement in the open direction. can do. In other words, since it becomes possible to directly influence the amount of the magnetic biasing force generated by the control current control, for example, based on the increase or decrease of the fluid force acting on the electromagnetic intake valve, the increase of the magnetic biasing force and / or Or the reduction can be controlled.

  “Current control” in the sense of the present invention can be realized by various methods of current control such as PWM control or threshold current control. The basic concept of the present invention is to first increase the control current to a first control current value for energizing the solenoid, and then move the control current to the electromagnetic intake valve, particularly before the electromagnetic intake valve reaches the fully open position. As long as the control current is controlled to open the electromagnetic intake valve by slowing down or at least reducing it to a lower second control current value to reduce its acceleration, The configuration is not limited.

  For example, the control current can be controlled by applying a PWM control voltage to the solenoid of the electromagnetic intake valve, wherein the value and / or change of the control current in the solenoid depends on the duty cycle of the PWM control voltage signal. Can be controlled.

  Further, the control current applied to the solenoid can be controlled by changing the frequency of the PWM control signal. Therefore, it is possible to use PWM control to control the control current by combining the duty cycle of the PWM voltage control signal and changing the frequency of the PWM control.

  In addition to being able to control the control current using PWM voltage control, for example, controlling either the control voltage or the control current using a continuously applied control voltage, for example, using an amplifier to control analogly The current can also be controlled directly. For example, current control can be achieved using threshold current control in which the current is adjusted to a specific threshold without requiring modulation such as pulse width modulation of the voltage signal. The value of the control current can also be adjusted directly using an integrated circuit.

  In contrast to these prior arts, according to the present invention, the reduction of the control current from the first control current value to the lower second control current value controls the control current to open the electromagnetic intake valve. Thus, it is performed in a step that enables reduction of operation noise of the high-pressure fuel supply pump.

On the other hand, in the control method described in Patent Document 1, the control current is reduced only after the electromagnetic intake valve has already reached the fully open position, and the valve seat or the mechanical / mechanical locking in which the valve is in the fully open position. Since the impact at the end of the opening operation of the electromagnetic intake valve at the time of contact with the part has already occurred, it is not at all suitable for reducing operation noise.
[2] Preferably, before the electromagnetic intake valve is fully opened, the control current is applied before the compression plunger that reciprocates between BDC and TDC in the compression chamber of the high-pressure fuel supply pump reaches BDC at the end of the intake stroke. The first control current value is reduced to the second control current value.
[3] According to the present invention, the second control current value may be a non-zero current value lower than the first control current value and lower than the first control current value.

Alternatively, in order to ensure that the electromagnetic intake valve is fully opened before the compression plunger reaches BDC, the compression plunger that reciprocates between BDC and TDC in the compression chamber of the high-pressure fuel supply pump reaches BDC at the end of the intake stroke. Previously, the control current may be reduced to zero or nearly zero.
[4] According to one embodiment of the present invention, the current control of the electromagnetic intake valve for opening the electromagnetic intake valve further increases the control current from the second control current value before the compression plunger reaches the BDC. Including increasing to a third control current value. According to this aspect, it is possible to greatly reduce the operation noise of the standard mass-produced high-pressure fuel supply pump and the electromagnetic intake valve, and in particular, even when there is a variation due to mass production, the compression stroke A series of mass-produced products can be controlled to ensure that the fully open position is reached before the start of.

  That is, the high-pressure fuel supply pump and the electromagnetic intake valve that form the basis of the present invention are generally composed of standard mass-produced products that are produced in large quantities. For such mass-produced products, there may be at least a small production variation between the products. According to the present invention, it is possible to optimize the control of the control current of the electromagnetic intake valve based on, for example, a standard electromagnetic intake valve of a mass-produced product. In the above-described aspect of the present invention, including increasing to a third control current value higher than the control current value of 2, in consideration of the possibility of variations due to small-scale mass production between mass-produced products Even if it exists, the reliability of operation control can be improved more.

  For example, a minimum control current value may be sufficient to open a mass produced standard electromagnetic intake valve before the compression plunger reaches the BDC, rather than the compression plunger begins to move upward again toward the TDC. Before, control so that the mass production standard electromagnetic intake valve can reach the fully open position. That is, the first control current value is set so that the compression stroke for pressurizing the fuel in the compression chamber starts after the electromagnetic intake valve is actually in the fully open position, and the electromagnetic intake valve can be held open in the fully open position. It is possible to control the minimum control current value to a lower second control current value.

  If the electromagnetic plunger is not already in the fully open position when the compression plunger begins to pressurize the fuel in the compression chamber when the compression plunger starts to move from BDC to TDC, the fuel when the compression plunger is moving toward TDC Since the pressure acts on the electromagnetic intake valve in the closing direction opposite to the magnetic force of the electromagnetic intake valve, the minimum control current value for a standard electromagnetic intake valve is not sufficient to keep the electromagnetic intake valve fully open and open. There may not be.

  Specifically, as the speed of the compression plunger increases, the fuel pressure in the compression chamber may increase, and the fuel leaks from the partially opened electromagnetic intake valve. For example, the magnetic force may be reduced due to the gap between the core and anchor of the partially open electromagnetic intake valve, and the magnetic force may not be sufficient to hold the electromagnetic intake valve open.

  In this case, in order to enable highly reliable control of the operation of the high-pressure fuel supply pump in consideration of the variation that may occur in the mass-produced product, the lower second control current value due to the variation due to mass production is reduced by electromagnetic intake. If it is not sufficient to fully open the valve, the electromagnetic intake valve is fully opened before the start of the compression stroke by increasing the magnetic force by increasing the control current from the second to the third control current value. In order to ensure, it is preferred that the control current is increased from the second control current value to a third control current value higher than the second control current value.

Therefore, the electromagnetic intake valve, which is a standard mass-produced product that is the basis for setting the second control current value, can be operated with greatly reduced operation noise, and there are variations due to mass production. However, the electromagnetic intake valve made of mass-produced products can be reliably opened to the fully open position.
[5] Preferably, the high pressure fuel supply pump further includes a BDC in the compression chamber to pressurize the fuel in the compression chamber when the compression chamber and the electromagnetic intake valve are fully closed and the compression plunger moves toward the TDC. And a compression plunger that reciprocates between the TDC and the TDC.

Preferably, in order to ensure that the electromagnetic intake valve is fully opened before the compression plunger reaches the BDC, an increase in the control current from the second control current value to the third control current value causes the compression plunger to change to the BDC. Done before reaching. Therefore, it can be ensured that the electromagnetic intake valve is in the fully open position before the start of the compression stroke in which the compression plunger moves from the BDC toward the TDC.
[6] According to one embodiment of the present invention, the third control current value is a target control current value for keeping the electromagnetic intake valve fully open, and in particular, the third control current value is a compression value. This is a target control current value for keeping the electromagnetic intake valve fully opened after the plunger reaches BDC. Thus, the third control current value holds the electromagnetic intake valve in the fully open position until it is closed to initiate an output stroke in which pressurized fuel is discharged through the discharge valve of the high pressure fuel supply pump to the common rail of the internal combustion engine. This is the target control current value that is maintained to be performed.

  Depending on the pump design, the step of increasing the control current to the third control current value may counter the increase in fuel pressure during the compression stroke (ie, after the compression plunger reaches the BDC and begins moving again toward the TDC). This ensures that the electromagnetic intake valve is held open.

  Alternatively, the control of the control current of the electromagnetic intake valve is held with the electromagnetic intake valve fully opened in order to reduce energy consumption, so that the third control current value is changed from the third control current value to the target control current value after the electromagnetic intake valve is fully opened. The control of the control current of the electromagnetic intake valve includes reducing the third control current after the compression plunger reaches the BDC because the electromagnetic intake valve is held fully open after the compression plunger reaches the BDC. Including reducing the value to a target control current value after the electromagnetic intake valve is fully opened.

  In order to reduce energy consumption, the target control current value is lower than the third control current value and is preferably electromagnetic during the compression stroke (ie, after the compression plunger reaches BDC and starts moving again toward TDC). It is sufficient to ensure that the intake valve remains open.

  Therefore, as described above, the third control current value, which is an increased control current value to ensure that the electromagnetic intake valve reaches the fully open position before the compression plunger reaches the BDC, Is again reduced to a lower target control current value, which is maintained to remain fully open until the electromagnetic intake valve should be closed to initiate the output stroke discharged from the compression chamber via the discharge valve .

  This makes it possible to reduce the energy consumption of the high-pressure fuel supply pump, since the target control current value maintained during the spill phase is lower than the third control current value. The target control current value may be equal to the second control current value. Further, after the compression plunger reaches BDC, the control current is reduced again from the third control current value to the target control current value, so that the thermal overload of the solenoid can be efficiently avoided.

Here, the leakage stroke means that when the compression plunger has already moved toward the TDC in the compression stroke, the electromagnetic intake valve is held in the fully opened position, and the fuel is moved from the compression chamber through the electromagnetic intake valve. It refers to the operating stroke through which the fuel is not pressurized and thereby the pressurized fuel is not released through the discharge valve of the electromagnetic intake valve.
[7] The control current of the electromagnetic intake valve is controlled by controlling the duty cycle of the PWM voltage signal supplied to the electromagnetic intake valve and controlling the duty cycle and frequency of the PWM voltage signal supplied to the electromagnetic intake valve. Alternatively, it may be performed by controlling the value of the PWM voltage signal supplied to the electromagnetic intake valve, for example, by directly controlling the value of the PWM voltage signal supplied to the electromagnetic intake valve using an amplifier means.

  As described above, the basic idea of the present invention relates to controlling the control current supplied to the solenoid of the electromagnetic intake valve, and the duty cycle of the PWM voltage signal is controlled when the electromagnetic intake valve is controlled by PWM control. It can be realized in various ways of controlling the control current by controlling or by controlling the frequency and duty cycle of the PWM voltage signal of the PWM control.

  In addition to being able to control the voltage signal using PWM control, the control current can also be controlled directly by directly adjusting the control voltage and / or control current, for example using an amplifier and / or integrated circuit. The control current can be directly controlled by voltage threshold control, and the control current is directly controlled by, for example, an integrated circuit.

Although direct adjustment of the control current by an amplifier or integrated circuit can precisely control the current, PWM control can lead to ripple in the gradual change of the control current due to the on / off switching of the PWM voltage signal. However, the influence of the ripple of the control current controlled by the PWM voltage signal can be effectively reduced by increasing the frequency of the PWM voltage signal. Another advantage of PWM control is that it can be easily implemented, and a common electronic engine controller has already been manufactured to supply the PWM control signal, for example by software and / or hardware modifications. Can be easily configured.
[8] Preferably, the control of the control current of the electromagnetic intake valve further comprises applying an initial voltage pulse to increase the control current to the first control current value, preferably rapidly, and the control current to the first Applying the first PWM voltage signal after applying the initial voltage pulse includes reducing the control current value to the second control current value.

  The initial voltage pulse can be embodied by a short applied constant voltage signal that embodies the initial voltage pulse or as an initial PWM voltage signal that embodies the initial voltage pulse, where the duty cycle of the initial PWM voltage signal is: Preferably it is greater than the duty cycle of the first PWM voltage signal. In particular, the duty cycle of the initial PWM voltage signal may be 100% or at least approximately 100%.

According to this embodiment, PWM control is used to control the control current supplied to the electromagnetic intake valve. Initially, in order to increase the control current to the first control current value, an initial voltage pulse for increasing the control current can be applied. When using PWM control, the initial voltage pulse may be realized by a PWM voltage signal pulse having a duty cycle of 100% or at least approximately 100%. After applying this initial voltage pulse, a first PWM voltage signal having a duty cycle of preferably less than 100% (especially less than the duty cycle of the initial voltage pulse) is applied, in particular applied to the solenoid of the electromagnetic intake valve. The control current can be reduced from the first control current value to the lower second control current value.
[9] Preferably, the control of the control current of the electromagnetic intake valve further increases the control current from the second control current value to a third control current value higher than the second control current value. Including applying the second PWM voltage signal after applying the PWM voltage signal, in particular, the first PWM voltage signal has a smaller duty cycle than the second PWM voltage signal. The second PWM voltage signal may have a duty cycle of 100% or less, or approximately 100% or less.

  According to this embodiment, even if there is a variation due to mass production, for example, the second control current value is used to ensure that the electromagnetic intake valve reaches the fully open position before the compression plunger reaches the BDC. In order to control the control current so as to increase again from 1 to the third control current value, a further second PWM voltage signal having a duty cycle greater than the first PWM voltage signal is used to increase the voltage current again. Can be applied.

The second PWM voltage signal is an electromagnetic intake valve so that the control current reaches the target control current value, or in order to pressurize the fuel in the compression chamber and discharge the pressurized fuel via the discharge valve of the high-pressure fuel supply pump. Set to reach a current greater than the final target control current to hold the electromagnetic intake valve in the fully open position during the leakage stroke in which the compression plunger moves upward on the upward stroke toward TDC can do.
[10] The first PWM voltage signal may be switched to the second PWM control voltage signal. According to another embodiment of the present invention, the first PWM voltage signal may be changed to the second PWM voltage signal by stepwise PWM control. Next, at least a third PWM voltage signal may be applied after the first PWM voltage signal and before the second PWM voltage signal. As a result, the duty cycle of the third PWM voltage signal may be greater than the duty cycle of the first PWM control voltage signal and smaller than the duty cycle of the second PWM control voltage signal.

  According to yet another embodiment of the present invention, the duty cycle of the first PWM voltage signal may be increased continuously or repetitively to the second PWM control voltage signal by incremental PWM control.

  If the control current is rapidly increased from the second control current value to the third control current value, the standard mass-produced high pressure fuel supply pump is either in the process of applying the second control current value or At least immediately after that, the fully-open position has already been reached, but the electromagnetic intake valve has not reached the fully-open position due to variations due to mass production, and the control current is increased from the second to the third control current value. The situation of full opening may occur. If this increase from the second to the third control current value is made rapidly, the electromagnetic intake valve hits the valve seat or the mechanical locking part at high speed, which rarely causes undesirable impact noise.

  However, according to the above-described embodiment in which the increase of the control current from the second to the third control current value is performed more slowly and smoothly by the stepwise or incremental PWM control, even in such a situation, Since the electromagnetic intake valve reaches the fully open position at a low speed, the impact noise can be greatly reduced even in a rare case where the electromagnetic intake valve is not fully opened by the control current corresponding to the second control current value.

  According to one embodiment utilizing stepped PWM control, after applying the first PWM voltage signal, the duty cycle of the PWM control voltage is repeated to increase the control current more slowly to the third control current value. Therefore, it is possible to apply a plurality of PWM control signals each having a duty cycle increased as compared with the previous duty cycle of each PWM control signal.

  According to an alternative embodiment, the PWM current is increased by utilizing incremental PWM control in which the duty cycle of the applied PWM voltage signal increases continuously or repeatedly to increase the control current to a third control current value. Control can be performed. This is achieved, for example, in that the duration of the PWM control in the on state increases continuously or repeatedly and / or the duration of the PWM control in the off state decreases continuously or continuously. be able to.

  Furthermore, the substantially continuous increase of the control current from the second control current value to the third control current value also changes the frequency of the PWM control signal continuously or repetitively, or the PWM voltage signal It may also be achieved by a combination of continuous or repetitive changes in duty cycle and continuous or repetitive changes in the frequency of the PWM voltage signal.

For example, in the case of the direct current control by the above threshold current control using an amplifier and / or an integrated circuit, the control current is, for example, at the timing when the compression plunger reaches the BDC or almost at that timing (preferably before or just before). It can be increased with a smaller slope to reach a control current value of 3.
[11] Preferably, the control of the control current of the electromagnetic intake valve further sets the timing for starting application of the initial voltage pulse, sets the duration for applying the initial voltage pulse, and the first PWM voltage. It may include at least one of setting a timing for applying the signal and / or a duration for applying the first PWM voltage signal. The timing and duration of the initial voltage pulse and the first PWM voltage signal are set according to the fluid force acting in the opening direction of the electromagnetic intake valve and the urging force acting in the closing direction of the electromagnetic intake valve. This may be done to control the magnetic force of the valve.

  When using PWM control to control the control current, the control can be easily performed, a plurality of control parameters are set to optimize the control and / or the electromagnetic intake valve reaches the fully closed position It can be optimized to limit the impact noise. The control parameters preferably energize the electromagnetic intake valve in a direction that closes the magnetic force (ie, the magnetic force generated by energizing the solenoid of the electromagnetic intake valve) and the normally closed electromagnetic intake valve. Biasing force (i.e., fluid force generated by the pressure difference upstream and downstream of the electromagnetic intake valve when the compression plunger is in a downward stroke toward the BDC, thereby increasing the volume of the compression chamber and Optimized to reduce the impact noise when the electromagnetic intake valve reaches the fully open position, reducing pressure and generating fluid force against the electromagnetic intake valve acting in the opening direction of the electromagnetic intake valve) It is set as follows.

  For example, the amplitude of the fluid force generally depends on the speed of movement of the compression plunger in the compression chamber, and the compression plunger first accelerates while moving from TDC until it decelerates again when approaching bottom dead center, ie , The movement speed of the compression plunger corresponds approximately to a periodic function that depends on the profile of the rotating cam that drives the compression plunger, for example a sine wave, and the maximum speed may reach approximately halfway between TDC and BDC (sinusoidal wave). The maximum speed occurs halfway between TDC and BDC).

  On the other hand, the magnetic force generated by energizing the solenoid of the electromagnetic intake valve generally depends on the applied control current and the distance between components attracted by the magnetic force, such as the anchor and core of the electromagnetic intake valve. On the other hand, the biasing force depends on the position of the electromagnetic intake valve, and may generally increase linearly from the fully closed position to the fully open position.

  The movement of the electromagnetic intake valve is obtained by the sum of the aforementioned forces, i.e. the sum of the biasing force, fluid force and magnetic force. Fluid force and magnetic force may act in the opening direction of the electromagnetic intake valve, and for example, an urging force such as a spring force may act in the closing direction of the electromagnetic intake valve.

  Preferably, when the compression plunger moves from TDC to BDC, the temporal change in magnetic force is balanced with the temporal change in fluid force, in which case the method according to the invention preferably initiates, for example, an increase in control current Including setting a control parameter, such as setting a timing, setting a timing to reach a first control current value, and / or setting a value of the first control current value.

  For example, when utilizing PWM control, the fluid force and magnetic force preferably include additional balancing of the fluid force and magnetic force with a biasing force that increases linearly while displacing the electromagnetic intake valve toward the fully open position. In order to balance the temporal change of the first voltage pulse, at least one of the time when the application of the initial voltage pulse is started, the duration of the application of the initial voltage pulse, and the timing and / or the duration of the application of the first PWM voltage signal is determined. Can be set.

  By setting the timing and / or duration described above, the average impact speed when reaching the fully open position is minimized (ie, the electromagnetic intake valve in the fully open position) so as to reduce operating noise of the high pressure fuel supply pump. To ensure a soft landing). In addition, pump design parameters, such as cam profile and low pressure fuel feed pressure supplied to the high pressure fuel supply pump, can affect fluid forces and their behavior, so they are optimized May be considered for.

  Preferably, the timing and duration settings described above are such that the resultant force, which is the sum of fluid force, magnetic force, and biasing force, is a threshold force value suitable for holding the electromagnetic intake valve in the fully open position (e.g., a large amount After the general standard electromagnetic intake valve of the product reaches the fully open position, the resultant force should be higher than the force that is sufficient to hold the valve open. Done.

  It can be seen that the fluid force has a maximum value at the point when the moving speed of the compression chamber during the downward stroke is maximum, that is, approximately in the middle between TDC and BDC, and thereafter the fluid force decreases overall again. Sometimes it is necessary to consider. As a result, the electromagnetic intake valve has reached the fully open position when the fluid force acting in the opening direction of the electromagnetic intake valve decreases again due to a decrease in the moving speed of the compression plunger toward the BDC due to variations due to mass production, for example. If not, a larger magnetic force is required to still move the electromagnetic intake valve to the fully open position.

  According to one embodiment, even in such a situation, if the timing of applying the initial voltage pulse is set to an earlier value, for example, the timing before the fluid force reaches the maximum value, Reduced impact speed and reduced impact noise can be achieved.

Thus, at an early point during the downward stroke of the compression plunger, the fluid force acting in the opening direction of the electromagnetic intake valve is at this timing during the stroke when the compression plunger is approximately halfway between TDC and BDC. Because it is large, a smaller magnetic force may be sufficient to move the electromagnetic intake valve to the fully open position.
[12] Preferably, the control of the control current of the electromagnetic intake valve may further include setting a timing for applying the second PWM voltage signal and / or a duration for applying the second PWM voltage signal. Setting the timing and duration of the initial voltage pulse, the first PWM voltage signal, and the second PWM voltage signal may be performed to control the magnetic force according to the fluid force and the biasing force.

By setting the timing and / or duration of applying the second PWM voltage signal to increase the control current again from the second control current value to the third control current value, and / or Even when there is variation due to mass production of electromagnetic intake valves, it is possible to ensure that the electromagnetic intake valves always reach the fully open position.
[13] Preferably, the timing of applying the initial voltage pulse may be set before the maximum fluid force acting in the opening direction of the electromagnetic intake valve is generated. In other words, the timing of applying the initial voltage pulse may be set before the maximum speed of movement of the compression plunger that reciprocates in the compression chamber of the high-pressure fuel supply pump in the direction toward the BDC occurs.

  The timing and duration settings for the above parameters are preferably such that the timing to reach the fully open position occurs when the fluid force is at a maximum value, for example, at a timing at which the moving speed of the compression plunger toward the BDC is approximately maximum. Is set. The timing of applying the initial voltage pulse is set to the timing before the fluid force reaches the maximum value, in other words, before the moving speed of the compression plunger toward the BDC becomes maximum.

Furthermore, the duration of application of the initial voltage pulse (and / or the time of application of the first PWM voltage signal as described below) is at the point where the fluid force is at a maximum value, or in other words, the compression plunger towards the BDC. The electromagnetic intake valve is set so as to approach the fully open position at the timing when the movement reaches the maximum value during the stroke. Thereafter, the control current is reduced by applying a first PWM control signal (the control current can be reduced to zero or nearly zero), whereby the magnetic force generated by the solenoid is reduced by a decrease in the control current. Thus, the resultant force acting on the electromagnetic intake valve is varied so that the speed toward the fully open position is reduced or the acceleration is greatly reduced.
[14] Preferably, the setting of the timing and duration of the initial voltage pulse and the first PWM voltage signal or the first and second PWM voltage signals is applied to the electromagnetic intake valve, for example, when the PWM control is in a low current condition The electromagnetic intake valve is set to reach its fully open state at the timing when the PWM signal is turned off. This is for low frequency PWM control, for example most commonly used in single switch PWM control (eg, PWM control in the range of about 100-1000 Hz, preferably 200-600 Hz, preferably about 400 Hz). This is particularly advantageous (in frequency).

When the control signal is controlled by PWM control, at least when low-frequency PWM control is used, the switching of the PWM voltage signal may cause a ripple in the gradual change of the control current, preferably at that time The setting of the timing and duration of the initial voltage pulse and the first PWM voltage signal or the first and second PWM voltage signals is such that the ripple of the control current is a low current condition, that is, the control current is average controlled by PWM control. At a timing lower than the current average value, which is a condition slightly lower than the current value, in other words, when the PWM signal applied to the solenoid is substantially OFF, the electromagnetic intake valve is set to reach the fully open position. .
[15] Preferably, the timing to start increasing the control current to the first control current value to energize the electromagnetic intake valve is the timing before the maximum fluid force acting in the opening direction of the electromagnetic intake valve is generated. Set to This is accomplished by setting the timing and duration of the initial voltage pulse as described above for another type of current control, such as PWM control, or directly adjusting current control as described above, such as current threshold control. be able to.

This is for low frequency PWM control, for example most commonly used in single switch PWM control (e.g. PWM in the range of about 100-1000 Hz, preferably 200-600 Hz, more preferably about 400 Hz). This is particularly advantageous (at the control frequency).
[16] According to one embodiment, the electromagnetic intake valve includes an intake valve member and an intake valve plunger formed as a unit body, that is, an intake valve member and an intake valve plunger that are fixed to each other or integrally formed. And an integrated electromagnetic intake valve. According to an alternative embodiment, the electromagnetic intake valve can also be a separate electromagnetic intake valve having an intake valve member and an intake valve plunger formed as separate members. As a result, the magnetic force of the electromagnetic intake valve preferably acts on the intake valve plunger.

  In the case of a separate type electromagnetic intake valve, the timing at which the control current starts to increase to the first control current value to energize the electromagnetic intake valve is determined by the fluid force acting in the opening direction of the intake valve member. Is set at a timing after the movement starts, and in particular, the intake valve plunger comes into contact with the intake valve member when the intake valve member moves in the opening direction of the intake valve member.

  In the integrated electromagnetic intake valve, the magnetic force preferably acts on the intake valve plunger, but may also act on the intake valve member in the opening direction of the electromagnetic intake valve, while closing the integrated solenoid electromagnetic intake valve The biasing force may act on the intake valve plunger and / or the intake valve member in the closing direction of the electromagnetic intake valve, and the fluid force may mainly act on the intake valve member. The resultant force obtained by the magnetic force, the fluid force, and the urging force is applied to the single body including the intake valve member and the intake valve plunger that are integrally formed, or to the single body including the intake valve plunger and the intake valve member that are fixed to each other. It may act. Therefore, the resultant force may act so that the intake valve member and the intake valve plunger move together.

  According to an alternative embodiment, the invention is also applied to control a separate electromagnetic intake valve having an intake valve plunger and an intake valve member as separate members that can be displaced independently of each other. Can do. In such a separate electromagnetic intake valve, fluid force generally acts on the intake valve member, and magnetic force generally acts on the intake valve plunger in the direction of opening the electromagnetic intake valve. At least a biasing member that biases the intake valve member in the closing direction may be provided, and another biasing member may act on the intake valve plunger. The urging member acting on the intake valve plunger can be configured to generate an urging force that acts in either the closing direction or the opening direction of the electromagnetic intake valve.

  Since the separation type electromagnetic intake valve is realized as a normally closed electromagnetic intake valve according to the present invention, when the urging member acts on the intake valve member, an urging force acting in the direction of opening the valve may be generated. When the urging member acting on the intake valve plunger acts in the opening direction, the urging member acting on the intake valve member generates a large urging force (particularly larger than the urging force acting on the intake valve plunger), As a result, the intake valve member and the intake valve plunger are in contact with each other, and in the situation where there is no fluid force or magnetic force, the entire urging force acts in the closing direction, and the intake valve member It may be configured to be held in the fully closed position.

  In the case of a separate electromagnetic intake valve, the fluid force generally acts only on the intake valve member as described above, and as a result, the intake valve member moves in the opening direction of the electromagnetic intake valve. In particular, in the case of a separated electromagnetic intake valve configuration in which the urging force acts on the intake valve plunger in the direction of closing the valve, the timing at which the control current starts to increase is set by, for example, setting the timing of the initial voltage pulse. The timing may be set after the intake valve member has already started moving in the direction to open the valve due to physical strength. Thereby, the intake valve plunger which is moved in the direction of opening the valve by the increasing magnetic force comes into contact with the intake valve member when the intake valve member has already been moved in the opening direction by the fluid force.

Therefore, in such a separate electromagnetic intake valve, it is possible to significantly reduce the first impact noise that is generally generated when the intake valve plunger contacts the intake valve member. The second impact noise generated when the intake valve member reaches the fully open position together with the intake valve plunger controls the control current applied to the solenoid of the electromagnetic intake valve according to at least one of the above-described aspects of the present invention. Can be greatly reduced.
[17] According to the second aspect of the present invention, a control device for controlling a high-pressure fuel supply pump for supplying pressurized fuel to an internal combustion engine is proposed. The control device according to the second aspect of the present invention is configured to control the control current of the electromagnetic intake valve for opening the electromagnetic intake valve according to at least one of the above-described embodiments according to the first aspect of the present invention. The

  Specifically, the control device of the present invention is configured to control a high-pressure fuel supply pump that supplies pressurized fuel to the internal combustion engine. The high pressure fuel supply pump is opened or held open by magnetic force, particularly when applying a control voltage to the electromagnetic intake valve to open or hold the electromagnetic intake valve, while the fluid pressure Does not act on the electromagnetic intake valve, and when the control voltage is not applied to the electromagnetic intake valve, the electromagnetic intake valve comprises a normally closed electromagnetic intake valve that remains closed by the biasing member.

  According to the present invention, the control device of the present invention is configured to control the control current of the electromagnetic intake valve in order to open the electromagnetic intake valve by applying a control voltage to the electromagnetic intake valve. The control device according to the second aspect of the present invention is configured to control the control current of the electromagnetic intake valve so that the control current is increased to a first control current value for energizing the electromagnetic intake valve. .

  In particular, the control current is applied to the electromagnetic intake valve before the compression plunger reciprocating between BDC and TDC in the compression chamber of the high pressure fuel supply pump reaches bottom dead center (BDC) at the end of the intake stroke of the compression plunger. Is increased to a first control current value for energizing.

  The control device of the present invention is particularly suitable for the BDC in the compression chamber of the high-pressure fuel supply pump so that the control current is reduced from the first control current value to the second control current value lower than the first control current value. And the compression plunger reciprocating between TDC and TDC so that the control current is reduced from the first control current value to the second control current value before reaching the BDC at the end of the intake stroke of the compression plunger. It is configured to control the control current of the electromagnetic intake valve to open the valve.

Furthermore, the control device of the present invention may be further configured to control the control current of the electromagnetic intake valve according to at least one of the above-described embodiments of the first aspect of the present invention.
[18] According to a third aspect of the present invention, the control device may be configured to open the electromagnetic intake valve to open the electromagnetic intake valve according to at least one of the embodiments described in connection with the first aspect of the present invention. A computer program product is proposed, comprising computer program code for configuring the control device, in particular the engine control device, to be configured to control the control current. That is, the computer program product comprises computer program code that configures the control device, particularly the engine control device, so that the control device embodies the control device as described above in connection with the second aspect of the invention.

  The above-mentioned features and aspects of the method according to the invention, as well as preferred features and aspects thereof, also apply to the control device and the computer program product described above, and the advantages as described in the method aspects also apply, which Omitted for brevity. The preferred features and aspects described above can be modified or combined in any manner.

The present invention includes a normally closed electromagnetic intake valve that is opened or held open by a magnetic force, and includes a step of controlling a control current of the electromagnetic intake valve to open the electromagnetic intake valve. In the control method of the high pressure fuel supply pump for supplying pressurized fuel to the internal combustion engine, the step of controlling the control current of the method includes the step of increasing the control current to a first control current value for energizing the electromagnetic intake valve The step of controlling the control current of the electromagnetic intake valve to open the electromagnetic intake valve further reduces the control current from the first control current value to a second control current value lower than the first control current value. By including
By reducing the moving speed of the electromagnetic intake valve to the open position, it is possible to reduce the speed of the electromagnetic intake valve when hitting the mechanical locking portion at the fully open position, so that the generated impact noise can be greatly reduced. .

The schematic diagram which shows an example of a fuel supply system provided with the high pressure fuel supply pump for supplying a high pressure fuel to an internal combustion engine provided with a normally closed electromagnetic intake valve. The schematic diagram which shows an example of the normally closed electromagnetic intake valve in a fully closed position. The schematic diagram which shows the normally closed electromagnetic intake valve of FIG. 2A in a fully open position. Explanatory drawing which shows an example of the normally closed electromagnetic intake valve of a prior art example. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the control method of the high pressure fuel supply pump provided with a normally closed electromagnetic intake valve of a prior art example. The circuit diagram which shows the system | strain which has two switches for the PWM control applied to a solenoid. The time chart which shows the PWM control signal supplied to the solenoid of FIG. 5A, and the control current obtained from it. The circuit diagram which shows the system | strain which has one switch for the PWM control applied to a solenoid. The time chart which shows the PWM control signal and control current which are supplied to the solenoid of FIG. 6A. 4 is a time chart showing a gradual change of the voltage control signal VC and a gradual change of the control current IC by the method according to the first embodiment of the present invention. FIG. 3 is a schematic diagram showing a gradual change in control current IC and valve movement according to the first embodiment of the present invention. The time chart which shows the gradual change of the voltage control signal VC and the gradual change of the control current IC by the 2nd Embodiment of this invention. Schematic showing the gradual change of control current and valve movement according to the second embodiment of the present invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the 3rd Embodiment of this invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the 4th Embodiment of this invention. Schematic which shows the gradual change of the control electric current IC and valve movement by the 4th Embodiment of this invention. The time chart which compares the conventional control method and one Embodiment of this invention. The schematic diagram which shows an example of a separation-type electromagnetic intake valve. Schematic which shows an example of the normally closed electromagnetic intake valve regarding the separation type electromagnetic intake valve of a prior art example. Schematic showing the gradual change of the control current IC and valve movement according to the fifth embodiment of the present invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the method by the 6th Embodiment of this invention. The time chart which shows the gradual change of the alternative example of a PWM voltage control signal.

  Preferred embodiments of the invention are described below with reference to the drawings. The features and aspects of the embodiments may be modified or combined to form further embodiments of the invention. In the description of the preferred embodiment, control currents and PWM voltage signals that generate such control currents are exemplarily shown. However, PWM control or DC control can be used by using any method for current control.

The actual current profile may exhibit characteristics such as current ripple (particularly associated with PWM control) or current drop when the electromagnetic intake valve collides with the mechanical locking part. It is omitted and only the average current is shown.
[First Embodiment]
FIG. 1 shows an example of a fuel supply system including a high-pressure fuel supply pump including a normally closed electromagnetic intake valve. The high-pressure fuel supply pump 100 is configured to supply high-pressure fuel to the internal combustion engine in order to inject the pressurized fuel directly into the combustion chamber of the internal combustion engine.

  The fuel supply system includes a fuel tank 600 and a low-pressure fuel pump 200 in order to supply low-pressure fuel from the fuel tank to the high-pressure fuel supply pump 100 via the intake pipe 300. After pressurizing the fuel in the high-pressure fuel supply pump 100, the pressurized fuel is supplied to the common rail 800 via the discharge pipe 400, and then the internal combustion engine using the four injectors 810a, 810b, 810c, and 810d. Directly injected into the compression chamber.

  The present invention is not limited to a fuel supply system having four injectors, and is generally applicable to a fuel supply system having at least one common rail each having at least one injector.

  The high-pressure fuel supply pump includes a normally closed electromagnetic intake valve 110, a compression chamber 120, and a compression plunger 130 that reciprocates between TDC and BDC in the compression chamber 120.

  The high-pressure fuel supply pump further includes a discharge valve 140 including a discharge valve seat 140a, a discharge valve member 140b, and a discharge valve spring 140c that generates a biasing force that acts on the discharge valve member 140b in the closing direction of the discharge valve 140. When the discharge valve 140 is fully closed, the discharge valve member 140b is in contact with the discharge valve seat 140a.

  The reciprocating motion of the compression plunger 130 is driven by the rotation of the cam 500. As the compression plunger moves from TDC toward BDC, the volume of the compression chamber 120 increases, and after reaching the BDC, the compression plunger 130 starts moving again toward the TDC, thereby reducing the volume of the compression chamber 120 again. When the compression plunger 130 reaches the TDC, it becomes the minimum.

  The low-pressure fuel is put into the compression chamber 120 from the low-pressure fuel pipe 300 via the normally closed electromagnetic intake valve 110, and discharged at high pressure through the high-pressure fuel pipe 400 by the discharge valve 140. The amount and timing of the pressurized fuel discharged is controlled by controlling a control current applied to the solenoid of the electromagnetic intake valve 110 controlled by the engine control device 700.

  2A and 2B show different states of an example of a normally closed electromagnetic intake valve 110.

  In FIG. 2A, the electromagnetic intake valve 110 is in a fully closed state, that is, no control voltage or control current is applied to the solenoid 112 and the electromagnetic intake valve 110 is in a shut-off state, so there is no magnetic force acting on the electromagnetic intake valve, Since there is no pressure difference with the downstream, the fluid force does not act on the valve. As a result, the electromagnetic intake valve 110 is held closed by an urging force generated by an urging member such as a spring 113 and acting in the closing direction of the electromagnetic intake valve.

  In FIG. 2B, the electromagnetic intake valve 110 is shown in an open state when a control voltage or control current is applied to the solenoid 112, for example because the valve is held in a fully open position.

  2A and 2B includes an intake valve plunger 111a and an intake valve member 111e. 2A and 2B, the intake valve plunger 111a and the intake valve member 111e are exemplarily formed as a single body, but may be formed as separate bodies (see, for example, FIG. 15).

  The anchor 111b is provided at the other end of the intake valve plunger 111a and at the end of the intake valve plunger 111a opposite to the intake valve member 111e. When current is applied to the solenoid 112, the solenoid valve anchor 111b and the core 114 are attracted to each other by magnetic force, so that the intake valve plunger 111a opens the valve until the anchor 111b and the core 114 come into contact and the displacement is limited. Displace in the direction. The position of the electromagnetic intake valve where the anchor 111b and the core 114 are in contact and thereby the displacement of the intake valve plunger 111a is limited is called the fully open position because the electromagnetic intake valve cannot be opened any further.

  As long as current is applied to the solenoid 112, the anchor 111b and the core 114 are attracted to each other in contact, so that the valve can be held open, and the intake valve member 111e moves away from the intake valve seat 111d. Retained. Therefore, as indicated by the arrow, the low pressure fuel can be taken out from the low pressure system via the intake passage 117 and fed to the compression chamber 120 of the high pressure fuel supply pump via the intake port 118.

  As long as the valve is held open by applying an electric current to the solenoid 112, when the compression plunger 130 in the compression chamber 120 is in an upward stroke that reduces the volume of the compression chamber 120, unpressurized fuel is In some cases, the air leaks from the intake port 118 to the low-pressure fuel system through the intake passage 117 in the reverse direction.

  When no current is applied to the solenoid 112, the spring 113 biases the intake valve plunger 111a until the intake valve member 111e contacts the intake valve seat 111d to close the valve as shown in FIG. 2A. Therefore, in the upward stroke of the compression plunger 130 in the compression chamber 120, the fuel cannot leak through the intake port 118, and the fuel is pressurized in the compression chamber 120 and discharged at a high pressure through the discharge valve 140. .

  On the other hand, when no current is applied to the solenoid 112 and the compression plunger 130 is in the intake stroke (downward stroke) to increase the volume of the compression chamber 120, the fuel pressure in the compression chamber 120 is low. Since the pressure is reduced as compared with the pressure of the fuel in the intake passage 117 connected to the fuel system, the intake valve member 111e is opened in the direction to open the valve against the urging force of the spring 113 even when no current is applied to the solenoid 112. A fluid force is generated that causes a displacement of. The fluid force is a displacement that does not lead to a sufficient displacement of the intake valve plunger 111a and / or the intake valve member 111e until the anchor 111b contacts the core 114 or a sufficient displacement until the anchor 111b contacts the core 114. Can be generated.

  Thereafter, when a current is applied to the solenoid 112, the valve is opened and / or held open by magnetic force. In particular, in the configuration as shown in FIGS. 2A and 2B, the intake valve plunger 111a is displaced with the intake valve member 111e before the current is applied to the solenoid 112, and the noise level and the electromagnetic intake valve 110 during operation. Vibration can be efficiently reduced. Here, the intake valve plunger 111a and the intake valve member 111e are integrally formed.

The intake valve plunger 111a and the intake valve member 111e may be formed as separate main bodies fixed to each other. Alternatively, when the intake valve member 111e is displaced in a direction to open the valve by fluid force, the intake valve plunger 111a and the intake valve member 111e are urged in the direction to close the valve by the urging mechanism, and the intake valve plunger 111a opens the valve. It can also be formed as a separate body that is further biased in the direction of the intake valve member 111e so as to be displaced in the direction.
[Control method of conventional high-pressure fuel supply pump]
FIG. 3 shows conventional control of the high-pressure fuel supply pump 100 that includes the normally closed electromagnetic intake valve 110. In the uppermost row of FIG. 3, the time change (plunger lift) of the movement of the compression plunger 130 is shown. The compression plunger 130 operates similar to a sine wave (or other periodic function) and reciprocates between TDC and BDC. Therefore, as shown in the second row from the top of FIG. 3, the speed of the compression plunger 130 is zero when the compression plunger 130 is at TDC or BDC.

  The maximum speed of operation of the compression plunger 130 is obtained in the middle of the stroke of the compression plunger 130, and the compression plunger 130 is moved by a sine wave in this embodiment, so that it is between TDC and BDC or between BDC and TDC. Reach the maximum speed in the middle. The movement of the compression plunger 130 between the TDC and the BDC is referred to as the downward stroke or the intake stroke, and the movement of the compression plunger 130 between the BDC and the TDC is referred to as the upward stroke, the output stroke, or the discharge stroke.

  As shown in the second column from the bottom of FIG. 3, the electromagnetic intake valve 110 is opened and held open at the start of the discharge stroke, so that the compression plunger 130 reaches the BDC in the downward stroke (FIG. 3). The voltage control signal VC (referred to herein as “ON”) is applied, thereby reducing the volume of the compression chamber 120 (without substantially pressurizing the fuel in the compression chamber 120), so that the fuel is supplied to the electromagnetic intake valve 110. Through the compression chamber 120.

  In the lowermost row of FIG. 3, a temporal change in valve movement of the electromagnetic intake valve 110 (particularly, the intake valve member 111e) is shown. Immediately after the compression plunger 130 reaches TDC and begins to move again toward the BDC, the volume of the compression chamber 120 is reduced, thereby creating a pressure difference between the upstream and downstream of the intake valve member 111e of the electromagnetic intake valve 110. As soon as the fluid force generated by the pressure difference exceeds the biasing force of the spring 113, the fluid force acts to open the electromagnetic intake valve 110 by displacing the intake valve member 111 e in the opening direction of the electromagnetic intake valve 110. .

  The amplitude of the fluid force depends on the moving speed of the compression plunger 130 and increases until the maximum value of the moving speed of the compression plunger 130 is reached, but then the fluid force decreases again and is supplied to the solenoid 112 of the electromagnetic intake valve 110. Until the control voltage signal is turned on and energized, the fluid force decreases and the biasing force of the spring 113 causes the intake valve member 111e to be displaced again in the direction of closing the valve.

  When the voltage control signal VC is turned on, the control current of the solenoid 112 generates a magnetic force that acts on the electromagnetic intake valve 110. Due to the generated magnetic force, the intake valve member 111 is displaced to the fully open position where the intake valve member 111e comes into contact with the intake valve seat 111d. Impact noise, which is the main noise in the operation of the high-pressure fuel supply pump having the intake valve 110, is generated.

  The electromagnetic intake valve 110 is held in the fully open position by the magnetic force that attracts the anchor 111b and the core 114, and the fuel in the combustion chamber 120 is fully open until the control voltage VC supplied to the solenoid 112 is switched off. It leaks out from the compression chamber 120 through 110. Thereafter, the electromagnetic intake valve is closed by the urging force in the closing direction of the electromagnetic intake valve 110 generated by the spring 113 and the fluid force.

  When the electromagnetic intake valve 110 reaches the fully closed position, an output stroke for discharging pressurized fuel from the compression chamber 120 to the internal combustion engine via the discharge valve 140 starts. Specifically, the compression plunger 130 is still moving toward the TDC, and the volume of the compression chamber 120 is further reduced, but the pressure of the fuel in the compression chamber 120 acts in the closing direction of the discharge valve 140. The pressure increases until the urging force of the discharge valve spring 140 c is overcome, thereby opening the discharge valve 140, so that pressurized fuel can be fed to the common rail 800 via the discharge valve 140 and the discharge pipe 400.

  The output stroke of discharging pressurized fuel through the discharge valve 140 ends as soon as the compression plunger 130 reaches TDC. As soon as the compression plunger 130 starts moving again in the direction of the BDC, the next intake stroke begins.

  FIG. 4 shows a conventional PWM control for opening the normally closed electromagnetic intake valve before the compression plunger 130 reaches the bottom dead center BDC as shown in FIG. The upper column of FIG. 4 shows that the control voltage signal VC applied to the solenoid of the electromagnetic intake valve switches on and off between the minimum and maximum control voltage values (the minimum value may be zero and the maximum value). Lower non-zero values).

  The lower column of FIG. 4 shows the gradual change of the control current IC corresponding to the control voltage signal VC in the upper column of FIG. First, the initial voltage pulse IVP is turned on at timing t1, and is applied to the solenoid 112 of the electromagnetic intake valve 110 until time t2. Here, t1 and t2 are times before the time when the compression plunger 130 reaches the BDC. By time t2, the PWM control signal VCF is applied with a duty cycle of less than 100%, and the control current IC continues to be supplied to the solenoid 112 of the electromagnetic intake valve 110 at a substantially constant current control target value IT, which is then , Used to generate a substantially constant magnetic force to hold the electromagnetic intake valve 110 in the fully open position during the above-described leakage stroke.

Here, an initial voltage pulse signal IVP (for example, a PWM signal having a duty cycle of 100% or almost 100%) applied between times t1 and t2 energizes the solenoid at a high speed, while the solenoid's thermal excess is detected. The PWM voltage signal VCF is applied with a duty cycle of less than 100% to avoid increasing the control current to an amplitude that may lead to waste of load and possibly electrical energy.
[PWM control method]
FIG. 5A shows a general system for PWM control of the solenoid 112 of the electromagnetic intake valve 110. The PWM control system includes two switches S1 and S2 controlled by signals 1 and 2 output from the CPU 710 which is a processing device of the engine control device 700. The switches S1 and S2 may be embodied by, for example, an electronic switch that can be switched by applying a voltage signal to a gate electrode of a field effect transistor (FET), ie, a field effect transistor controlled by the CPU 710. FIG. 5B shows signals 1 and 2 and the solenoid current.

  In general, such a PWM control system with two switches is usually a high frequency of pulse width modulated PWM (generally in the range of 1-10 kHz, preferably in the range of 2-6 kHz, most commonly Is controlled by about 4 kHz), and one switch (S2 in FIG. 5A) is used to turn on and off the PWM signal applied to the solenoid 112 by the necessary pulse width modulation. The system may be connected to a battery (battery voltage VBAT) and ground potential (GND), or may be connected to two poles of the battery. The switch S1 is used for PWM control, and the switch S2 is used for shutting off the solenoid at high speed, that is, for quickly and constantly lowering the voltage.

  FIG. 6A shows an alternative general system for PWM control of solenoid 112 of electromagnetic intake valve 110. The PWM control system includes one switch S1 that is controlled by a signal 1 from the processing device 710 (for example, CPU) of the engine control device 700. The switch S1 may be embodied by, for example, a field effect transistor (FET), ie, an electronic switch that can be switched by applying a voltage signal to the gate electrode of the field effect transistor controlled by the CPU 710. FIG. 6B shows signal 1 and solenoid current.

  In general, such a PWM control system with one switch is usually the low frequency of pulse width modulated PWM (typically in the range of 100-1000 Hz, preferably in the range of 200-600 Hz, most commonly Is controlled at about 400 Hz). The system may be connected to a battery (battery voltage VBAT) and ground potential (GND), or may be connected to two poles of the battery.

  FIG. 7 shows control of the control current IC of the electromagnetic intake valve 110 by the control method of the high-pressure fuel supply pump according to the first embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

  At the first point of time t1, before the compression plunger 130 reaches BDC and until time t2 (t2−t1 = ΔT1), the control current IC is supplied to the electromagnetic intake valve 110 to open the valve. To increase to the value IC1, an initial voltage signal IVP is supplied to the solenoid 112 of the electromagnetic intake valve 110 (eg, a PWM voltage signal having a 100% duty cycle).

  From time t2, the solenoid 112 of the electromagnetic intake valve 110 has a duty cycle of less than 100%, in particular such that the control current is reduced from the control current value IC1 to a lower control current value IC2, and the valve is fully opened. Therefore, the PWM voltage signal VCF having a duty cycle set so that the control current IC is substantially held at the control current value IC2 is applied.

  At the start of the compression stroke in which the compression plunger 130 starts moving from BDC toward TDC, the electromagnetic intake valve is held fully open, so that the control current value IC2 is maintained, that is, in the first embodiment of the present invention. The control current value IC2 is obtained after the compression plunger 130 reaches BDC at the start of the compression stroke so that fuel can escape from the compression chamber 120 of the high pressure fuel supply pump 100 through the fully open electromagnetic intake valve 110. This represents a target control current value IT for holding the valve 110 in the fully opened position.

  FIG. 8 shows a comparison between the current control according to the first embodiment and the current control of the conventional example described in FIG. As described above, according to the conventional current control (see the broken line in FIG. 8), the control current IC is first increased to the target control value IT, and is then held substantially constant at the target control current IT. In contrast, according to the present invention, the control current IC is increased to the current control value IC1 and then decreased again to the control current value IC2 which is the target control current value IT.

  In particular, in FIG. 8, the control current IC is reduced from the control current IC1 to the control current value IC2 after the electromagnetic intake valve starts to move from the fully closed position toward the fully open position. However, as can be seen in the lower row of FIG. 8, by reducing the control current IC, the moving speed of the electromagnetic intake valve toward the fully open position is reduced compared to the valve movement by the conventional current control. Thus, when the intake valve member 111e contacts the intake valve seat 111d at time N2, a softer landing in the fully open position can be achieved. After time N2, the electromagnetic intake valve is held in the fully closed position by the magnetic force induced by the control current IC2 of the solenoid 112.

According to the conventional current control, the intake valve member 111e hits the valve seat 111d at a higher speed at the initial time N1, thereby generating significantly larger impact noise. According to the control according to the first embodiment, it is possible to effectively reduce impact noise that occurs when the intake valve member 111e reaches the fully open position (when it contacts the valve seat 111d).
[Second Embodiment]
FIG. 9 shows control of the control current IC of the electromagnetic intake valve 110 by the control method of the high-pressure fuel supply pump according to the second embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

  Similar to the first embodiment, at time t1 until time t2, an initial voltage pulse IVP for increasing the control current IC of the solenoid 112 to the control current value IC1 is supplied. Similar to the first embodiment, a PWM voltage control signal VC1 for reducing the control current IC to the control current value IC2 is applied starting from time t2. This has the effect that the movement of the intake valve member 111e toward the fully open position is decelerated after time t2, or at least its acceleration is reduced.

  In order to achieve optimum deceleration of the movement of the intake valve member 111e toward the fully open position, the control current IC2 is sufficient to open and hold the standard electromagnetic intake valve 110 from mass production (open and open). That is, the duty cycle of the voltage control signal VC1 can be set so that a standard mass-produced electromagnetic intake valve is at a substantially minimum value (suitable for holding the valve open during the compression stroke). .

  At that time, due to variation due to mass production, the magnetic force acting in the opening direction of the electromagnetic intake valve may become too small, the fluid force acting in the opening direction will soon become too small and / or acting in the closing direction. Since the urging force to be increased becomes too large, a situation occurs in which the voltage control signal VC1 and the control current value IC2 are not sufficient to move the intake valve member 111e to the fully open position before the time when the compression plunger 130 reaches BDC. Sometimes.

  As a result, when the magnetic force begins to move upward again toward the TDC due to a gap that may occur between the anchor 111b and the core 114 when the compression plunger 130 reaches the BDC, the electromagnetic intake valve 110 May not be enough to be held open. Fluid force acting on the intake valve member 111e in the closing direction as soon as fuel flows through the intake port 118 toward the intake valve member 111e and thereby leaks out of the compression chamber 120 through the intake port 118 and intake passage 117. Can occur.

  In the second embodiment, at time t3, a further PWM voltage control signal VCF with a higher duty cycle compared to the PWM voltage control signal VC1 causes the control current IC to reach a higher control current value before the compression plunger 130 reaches BDC. Applied to increase again to IC3. Thereby, before the compression plunger 130 reaches BDC, the electromagnetic intake valve 110 is fully opened.

  In the case of a mass-produced standard electromagnetic intake valve 110, the control current IC2 is already sufficient to smoothly land the intake valve member 111e on the valve seat 111d in the fully open position during the stroke between times t2 and t3. Thus, it may be set so that there is no gap between the anchor 111b and the core 114. As a result, even when the fluid force acting in the opening direction is reduced again before the compression plunger 130 reaches BDC, the magnetic force generated by the control current IC2 of the solenoid 112 is maintained with the electromagnetic intake valve fully opened. Enough. In such a standard configuration, by increasing the control current IC from the control current value IC2 to the control current value IC3, the electromagnetic intake valve 110 is further held in the fully opened position, and thereby no impact noise is generated.

  If the electromagnetic intake valve 110 does not fully open during the stroke between times t2 and t3 due to variations due to mass production, the intake valve member is increased by increasing the control current from the control current value IC2 to the control current value IC3. The magnetic force that attracts the anchor 111b and the core 114 is increased so that 111e is displaced to the fully open position. This may lead to greater impact noise compared to the standard electromagnetic intake valve 110 that is already fully open between times t2 and t3 and has no variation due to mass production.

  However, in the second embodiment, it is possible to ensure that the electromagnetic intake valve 110 reaches the fully open position before the compression plunger 130 reaches the BDC, so that it opens even when there is a variation due to mass production. Can be retained.

  FIG. 10 schematically illustrates a gradual change in control current and valve movement according to a second embodiment of the present invention. FIG. 10 shows that the control current IC is first increased to the control current value IC1, then decreased to the control current value IC2 after the start of the electromagnetic intake valve movement, and further compressed before the compression plunger 130 reaches BDC. The current control is again increased to the current control value IC3 which is the final target control current value IT for holding the electromagnetic intake valve in the fully open position after the plunger 130 reaches the bottom dead center BDC.

  In the lower row of FIG. 10, during the stroke of applying the control current value IC2 (between times t2 and t3 in FIG. 9), the fluid force is reduced just before the compression plunger 130 reaches BDC. The valve movement for the electromagnetic intake valve moving again towards the fully closed position is shown. However, immediately before the compression plunger 130 reaches BDC, the control current IC increases from the current control value IC2 to the control current value IC3, so that it can still be displaced to the fully open position. Here, at time N3, impact noise is generated when the electromagnetic intake valve reaches the fully open position. However, even if there is variation due to mass production, it can be ensured that the electromagnetic intake valve is held in the fully open position after the compression plunger 130 reaches the BDC.

  As shown in FIG. 10, even when using the control according to the second embodiment, the standard mass-produced electromagnetic intake valve 110 exhibits the same behavior as shown in FIG. Due to the decrease of the control current IC from the control current value IC1 to the control current value IC2, it is possible to significantly reduce the impact noise and achieve the soft landing at the fully open position at time N2. The broken line in FIG. 10 also corresponds to the conventional current control as described in FIG.

As described above, according to the current control according to the second embodiment, when there is a variation due to mass production, the electromagnetic intake valve 110 is not fully opened by the reduced current control value IC2, and then the control current IC is changed again. Since it is fully opened by increasing it to a high target control current value IT, in some cases, a larger impact noise is generated, but the reliability of control is increased.
[Third Embodiment]
FIG. 11 shows control of the control current IC of the electromagnetic intake valve 110 by the control method of the high-pressure fuel supply pump according to the third embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

  According to the third embodiment, the increase of the control current IC from the current control value IC2 to the final target control current value IT for keeping the electromagnetic intake valve fully opened after the compression plunger 130 reaches BDC is as follows. Even if there is a variation due to mass production as described above in the second embodiment, it is increased only gradually in order to ensure soft landing at the fully open position.

According to the third embodiment, as shown in the upper column of FIG. 11, the plurality of PWM voltage controls VC1, VC2, VC3, and VCF are applied to the initial voltage pulse IVP at times t2, t3, t4, t5. It is applied later. Here, the duty cycle of the plurality of PWM voltage control signals from the PWM voltage control signal VC1 to the final voltage control signal VCF is to keep the electromagnetic intake valve 110 fully opened after the compression plunger 130 reaches BDC. In order to continuously increase the control current IC from the control current value IC2 to the control current value IC3, to the control current value IC4, and to the final target control current value IT, the control current IC is gradually increased by stepwise PWM control.
[Fourth Embodiment]
FIG. 12 shows control of the control current IC of the electromagnetic intake valve 110 by the control method of the high-pressure fuel supply pump according to the fourth embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

  According to FIG. 12, the control current IC is increased from the control current value IC2 to the final target control current value IT. However, unlike the third embodiment described above with reference to FIG. 11, the duty cycle of the PWM voltage control signal VC1 is between the initial voltage pulse IVP and the final PWM voltage control signal VCF before the compression plunger 130 reaches BDC. Then, the time t2 and the time t3 are increased so as to continuously increase the control current value IC2 to the final target control current value IT (or repeatedly increase the duration of the ON state and / or decrease the duration of the OFF state). It is continuously increased between (t3−t2 = ΔT2).

  The influence of control of the control current IC of the solenoid 112 of the electromagnetic intake valve 110 according to the fourth embodiment of the present invention is shown in FIG. FIG. 13 shows in the upper row that the control current value IC2 is continuously increased to the final target control current value IT. The broken line still points to the conventional control as shown in FIG. The bottom row of FIG. 13 shows that the mass produced standard electromagnetic intake valve 110 behaves similarly to that described above in FIG.

  However, if there is a variation due to mass production, the second control current value IC2 may not be enough to fully open the electromagnetic intake valve 110, the control current is continuously increased, so that the compression plunger 130 becomes BDC. Before reaching, it is ensured that at time N4, the electromagnetic intake valve still reaches the fully open position and the impact velocity is lower than in the second embodiment.

  The continuous increase of the control current value from the control current value IC2 to the target control current value IT enables a smooth landing at the time N4 of the intake valve member 111e in the intake valve seat 111d, thereby resulting in mass production. Even when there is a variation, it is possible to significantly reduce the impact noise. Since the increase of the control current from the control current value IC2 to the target control current value IT is performed at a lower speed than in the case of the second embodiment, using stepped PWM voltage control has a similar advantage.

FIG. 14 shows a comparison between the conventional control method as shown in FIG. 3 and the control method according to the fourth embodiment of the present invention. The dashed curve labeled “A” in FIG. 14 shows a standard mass production valve movement that is controlled to land smoothly with significantly reduced impact noise in the fully open position. As shown in FIGS. 12 and 13, the control current value IC2 decreases, so that the moving speed of the electromagnetic intake valve before reaching the fully open position can be reduced. The broken curve indicated by “B” is not fully opened yet by the reduced control current value IC2, but immediately after that, the electromagnetic intake valve is fully opened by increasing the control current to the target control current value IT. The valve movement is shown.
[Separate plunger type electromagnetic intake valve]
FIG. 15 schematically shows an example of the separation type electromagnetic intake valve 210. Unlike the electromagnetic intake valve 110 shown in FIGS. 2A and 2B, the intake valve member 211e and the intake valve plunger 211a of the electromagnetic intake valve 210 are formed as separate bodies that can move independently. The intake valve plunger 211a is urged in the closing direction by an urging member, for example, a spring 213a, and the intake valve member 211e is urged in the closing direction by another urging member, for example, a spring 213b.

  The anchor 211b is provided at one end of the intake valve plunger 211a, that is, at the end of the intake valve plunger 211a opposite to the side on which the intake valve plunger 211a can contact the intake valve member 211e. When current is applied to the solenoid 212, the solenoid valve anchor 211b and the core 214 are attracted to each other by magnetic force, so that the anchor valve 211b and the core 214 come into contact with each other, and the intake valve plunger 2111a is moved until the displacement is limited. Displaced in the direction of opening the valve. In this position, the intake valve plunger 211a can hold the intake valve member 211e in the fully open position against the urging force of the springs 213a and 213b.

  As long as current is applied to the solenoid 212, the anchor 211b and the core 214 remain attracted to each other so that they remain in contact, thereby allowing the valve to remain open and the intake valve member 211e is It is held away from the intake valve seat 211d. Thus, as indicated by the arrow, the low pressure fuel is removed from the low pressure system via the intake passage 217 and fed to the compression chamber 120 of the high pressure fuel supply pump via the intake port 218 as further indicated by the arrow. Can do.

  As long as the valve is held open by applying an electric current to the solenoid 212, the unpressurized fuel is present when the compression plunger 130 in the compression chamber 120 is in an upward stroke that reduces the volume of the compression chamber 120. In some cases, the air may leak from the intake port 218 to the low-pressure fuel system through the intake passage 217 in the reverse direction.

  However, when no current is applied to the solenoid 212, the springs 213a and 213b cause the intake valve plunger 211a and intake valve member 213b to valve until the intake valve member 211e contacts the intake valve seat 211d to close the valve. Energize in the closing direction. The intake valve plunger 211a may be further displaced in the closing direction by the biasing force of the spring 213a.

  In the upward stroke of the compression plunger 130 in the compression chamber 120, the fuel cannot be leaked through the intake port 218, and the fuel is pressurized in the compression chamber 120 so as to be discharged at a high pressure through the discharge valve 140. The On the other hand, when no current is applied to the solenoid 212 and the compression plunger 130 is in the intake stroke (downward stroke) so as to increase the volume of the compression chamber 120, the fuel pressure in the compression chamber 120 is low. Since the pressure is reduced as compared with the pressure of the fuel in the intake passage 217 connected to the fuel system, the intake valve member 211e is opened in the direction to open the valve against the biasing force of the spring 213b even when no current is applied to the solenoid 212. A fluid force is generated that can cause a displacement of. The fluid force can cause a sufficient displacement of the intake valve member 211e or an insufficient displacement of the intake valve member 211e to the fully open position.

  When a current is applied to the solenoid 212 and energized, the intake valve plunger 211a is displaced by the magnetic force in the valve opening direction. As a result, generally, according to the conventional control of such a separate electromagnetic intake valve, two impact noises are generated. The first impact noise is generated when the intake valve plunger 211a hits the intake valve member 211e, and the second impact noise is generated when the electromagnetic intake valve reaches the fully open position.

  FIG. 16 shows an example of conventional control of a normally closed electromagnetic intake valve related to the background of the present invention for a separate electromagnetic intake valve. The top row shows the movement of the compression plunger between TDC and BDC. The second row from the top shows the gradual change of the control current IC, and the bottom row shows the corresponding movement of the intake valve member 211e and the intake valve plunger 211a. FIG. 16 shows the occurrence of two impact noises generated continuously at times N5 and N6.

The impact noise at time N6, ie when the electromagnetic intake valve reaches the fully open position, can be greatly reduced by current control according to the invention as described above, in particular according to any of the embodiments described above. Furthermore, in the following, another embodiment will be described which additionally makes it possible to reduce the first impact noise generated when the intake valve plunger 211a hits the intake valve member 211e.
[Fifth Embodiment]
FIG. 17 schematically illustrates a gradual change in control current IC and valve movement according to a fifth embodiment of the present invention. The top row shows the movement of the compression plunger between TDC and BDC. The second row from the top shows the gradual change of the control current IC (the broken line corresponds to the conventional control described above in FIG. 16), and the bottom row shows the corresponding movement of the intake valve member 111e and the intake valve plunger 111a. .

  Before the compression plunger 130 reaches the BDC, the control current is increased to the control current value IC1, then decreased to the control current value IC2, and then the final target control current value, similar to the control current according to the second embodiment. Increased to IT again. Alternatively, the control current according to the first, third or fourth embodiment can be used.

Further, for example, as described above, the timing of starting the increase of the control current IC by setting the timing of the initial voltage pulse IVP is after the intake valve member 111e has already started its movement in the opening direction by the fluid force. The timing is set. As shown in FIG. 17, the timing of starting the increase of the control current IC is the intake air when the intake valve plunger 111a, which has been displaced in the opening direction by the increase of the magnetic force, has already moved in the opening direction by the fluid force. It is set so as to come into contact with the valve member 111e. Therefore, the first impact noise that is generally generated when the intake valve plunger 111a hits the intake valve member 111e can be greatly reduced.
[Sixth Embodiment]
FIG. 18 shows a control method for controlling the control current of the solenoid 112 according to the sixth embodiment of the present invention. The control before the time when the compression plunger 130 reaches BDC in FIG. 18 completely corresponds to the control as described in FIG. 9 with respect to the second embodiment of the present invention.

  However, when the compression plunger 130 reaches the BDC and then moves up again toward the TDC, the control method according to the sixth embodiment is further illustrated in FIG. 18 at time t4 after the compression plunger 130 reaches the BDC. The control current IC3 is reduced to a lower target control current value IT that is still sufficient to hold the electromagnetic intake valve in the fully open position even during the compression stroke when the compression plunger 130 moves toward TDC. Applying a final PWM control signal VCF having a smaller duty cycle than the previously applied PWM voltage control signal VC2.

  In addition to the advantages of the second embodiment, the sixth embodiment results in a reduced target control current value IT that reduces energy consumption and maintains the electromagnetic intake valve to be held in the fully open position. Further, it becomes possible to further avoid the thermal overload of the solenoid 112.

  FIG. 19 shows a gradual change of an alternative example of the PWM voltage control signal. In the embodiments described above, PWM control of the solenoid (s) has been exemplarily achieved by single switch or dual switch PWM control. When single switch control is used, the PWM frequency is generally very low, typically 100-800 Hz, preferably 300-600 Hz, more preferably equal to 400 Hz or at least about 400 Hz (equivalent to a period of 2.5 ms). ).

  Since this is relatively slow compared to the mechanical operation of the electromagnetic intake valve, the electromagnetic intake valve generally reaches the mechanical lock after the first few PWM cycles. In such a case, “soft landing” of the electromagnetic intake valve in the fully open position (that is, there is almost no impact noise by reducing the impact speed to almost zero) can also be realized. This uses a different duty cycle for the first few cycles and then increases the duty cycle before reaching the BDC to ensure that the electromagnetic intake valve reaches the fully open position before the compression stroke begins. Can be achieved.

  The actual value of the first PWM period is determined by taking into account the so-called P_ON timing (i.e., the time at which initial energization of the solenoid (s) relative to the time of the TDC of the pump) and the engine speed are taken into account. It can be determined for operating conditions. In order to minimize noise generation, the electromagnetic intake valve preferably reaches the mechanical lock during the time when the PWM voltage control signal is in the off state or at the start of the pulse.

  The method described above can be used during the calibration process to allow determination of the moment when the electromagnetic intake valve in the fully open position will land. Under any conditions, switching to a higher PWM duty cycle (between BDC and TDC) prior to the start of the compression cycle will cause electromagnetic changes regardless of any changes in operating conditions or variations due to mass production. It is ensured that the intake valve reaches the fully open position.

  The calibration procedure may involve determining several distinct PWM duty cycles (for the first few cycles). FIG. 10 exemplarily shows four duty cycles “Duty 1”, “Duty 2”, “Duty 3”, and “Duty 4” (displayed as “Initial PWM”). Generally, the electromagnetic intake valve can reach the fully open position within the first two, three, or four cycles unless the value is too low, and if the value is low, a sufficiently high duty cycle, It is moved to the fully open position by a final PWM duty cycle, preferably having a duty cycle of about 95%.

  Thus, one possible configuration is to use stepped PWM control, and for the duration of the entire initial PWM, “Duty1” = “Duty2” = “Duty3” = “Duty4” (eg, 75% Duty cycle). Also, the final PWM duty cycle is about 95% (or another sufficiently high value of 85% to 100% duty cycle, preferably 90% to 100% duty cycle).

  Another possible configuration is a constant increase in the PWM voltage signal duty cycle in the initial PWM duration, or a large initial duty cycle (such as an initial voltage pulse) followed by a second period (Duty2). Such as those using a low duty cycle. A large duty cycle should be used before reaching the BDC to ensure that the electromagnetic intake valve is fully open before the start of the compression stroke. This algorithm can be generalized as follows.

Duty1
Duty2 = Duty1 + a
Duty3 = Duty2 + b
Duty4 = Duty3 + c
Where a, b, c,... Can be determined during the calibration process (typically ± about 5%). Next, a constant large duty cycle is used before the BDC is reached.

Duty final = DutyF (eg, 95% duty cycle)
The structural features, components, and specific details of the embodiments described above can be interchanged or combined to form further embodiments optimized for individual applications. To the extent that such modifications are apparent to those skilled in the art, it is intended to be implicitly disclosed by the above description without explicitly specifying every possible combination.

100: high-pressure fuel supply pump 110: electromagnetic intake valve 111a: intake valve plunger 111e: intake valve member 120: compression chamber 130: compression plunger 700: control device IC: control current IC1: first control current value IC2: second Control current value IC3: third control current value IT: target control current value TDC: top dead center BDC: bottom dead center VC: voltage signal IVP of electromagnetic intake valve: initial voltage pulse VC1: first PWM voltage signal VC2; VC3; VCF: second PWM voltage signal ΔT1: duration of applying an initial voltage pulse (IVP) ΔT2: duration of applying a first PWM voltage signal (VC1) t1: applying an initial voltage pulse (IVP) Start timing t2: Timing (ΔT2) timing t3; t4; t5: Second PWM voltage signal for applying the first PWM voltage signal (VC1) Applying a timing .DELTA.T3; .DELTA.T4: duration for applying the second PWM voltage signal

  The present invention relates to a control method for a high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine, and a control device that controls the high-pressure fuel supply pump. Furthermore, the present invention relates to a computer program product including computer program code for configuring a control device such as an engine control unit to control a high pressure fuel supply pump.

Specifically, the present invention provides a high-pressure fuel supply pump comprising opened by magnetic force energizing the solenoid of the normally closed solenoid inlet valve and retained / or open while the solenoid suction valve normally closed The present invention relates to a control method and a control apparatus. It is kept closed by magnetic force and / or closed by energizing the normally open electromagnetic intake valve is distinguished from the high-pressure fuel supply pump comprising a normally open type solenoid inlet valve.

The present invention relates to controlling the control current to the electromagnetic intake valve to open the solenoid inlet valve by applying a control voltage or control current, the control of the control current of the solenoid suction valve, a control current to the electromagnetic intake valve Increasing to the first control current value for energization, in particular, the compression plunger reciprocating between top dead center (TDC) and bottom dead center (BDC) in the compression chamber of the high pressure fuel supply pump is compressed Including increasing the control current to a first control current value for energizing the electromagnetic suction valve before reaching BDC at the end of the plunger suction stroke.

  A high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine can be used in a fuel supply system based on a direct injection operation in which fuel is directly injected into a combustion chamber of an internal combustion engine by an injector. The pressurized fuel that is directly injected into the combustion chamber of the internal combustion engine is pressurized by a high-pressure fuel supply pump.

For example, in Patent Document 1, a high-pressure fuel supply system that supplies pressurized fuel to an internal combustion engine, which is opened or held open by a magnetic force generated by energization of a solenoid of an electromagnetic intake valve. 2. Description of the Related Art Supply systems that include electromagnetic suction valves of the type are known. Here, the normally closed valve means a closed type valve when the shut-off state, that is, when the control current / control voltage is not applied to the solenoid of the electromagnetic intake valve.

Patent Document 1 addresses the problem of reducing the operation noise of a normally closed electromagnetic suction valve. Before energizing the solenoid of the electromagnetic suction valve, upstream and downstream sides of the valve for opening the valve by fluid force It was proposed to use the fluid pressure difference between the two. However, there are ongoing efforts to find further optimization strategies and optimization methods to further reduce the operating noise of normally closed electromagnetic suction valves and enable reliable operation.

In the prior art, the control supplied to the solenoid to avoid thermal overload of the solenoid by reducing the control current after the electromagnetic suction valve has already opened, i.e. after the electromagnetic suction valve has already reached the fully open position. There are technologies that reduce the current. In such a control method, in the step of controlling the control current to open the electromagnetic suction valve, the control current is not yet reduced, and the normally closed electromagnetic suction valve is already fully closed by the magnetic force during the operation stroke. For example, the control current is reduced only during the process of outputting the pressurized fuel through the discharge valve of the high-pressure fuel supply pump (see, for example, Patent Document 2).

EP1898085A2 publication DE102004016554A1 publication

In conventional high-pressure fuel supply systems, when the motor is in a low rotational speed condition, for example, when the internal combustion engine is idling, the main operating noise is noise emitted from the electromagnetic suction valve, and this noise especially opens and closes the valve. For example, this occurs when the intake valve member of the electromagnetic intake valve comes into contact with the valve seat in the fully closed position of the valve. Therefore, it is desirable to provide a fuel supply system having an electromagnetic intake valve that can reduce operating noise.

It is an object of the present invention to reduce the operating noise of a high pressure fuel supply pump that is configured to supply pressurized fuel to an internal combustion engine and that is normally opened or held open, with a normally closed electromagnetic intake valve. It is to reduce.

[1] According to the first aspect of the present invention, a method for controlling a high-pressure fuel supply pump for controlling a high-pressure fuel supply pump that supplies pressurized fuel to an internal combustion engine is proposed. The high-pressure fuel supply pump opens and / or holds the electromagnetic intake valve open, so that it is opened by magnetic force and / or held open especially when a control voltage or control current is applied to the electromagnetic intake valve is configured to be, on the other hand, does not act the fluid pressure to the electromagnetic intake valve, and when the control voltage or the control current is not applied to the electromagnetic intake valve, normally closed remains electromagnetic intake valve is closed by the urging member A type electromagnetic intake valve is provided.

According to the present invention, a control method of the high-pressure fuel supply pump, the method comprising controlling the control current to the electromagnetic intake valve for opening the electromagnetic intake valve by applying a control voltage or control current to the electromagnetic intake valve, the electromagnetic intake The control current of the valve is controlled by increasing the control current to a first control current value for energizing the electromagnetic suction valve, particularly, reciprocating between BDC and TDC in the compression chamber of the high-pressure fuel supply pump. Including increasing the control current to a first control current value for energizing the electromagnetic suction valve before the compression plunger reaches the BDC at the end of the compression plunger suction stroke.

According to the present invention, by controlling the control current of the solenoid inlet valve for opening the electromagnetic intake valve, the compression plunger reciprocates between the BDC and TDC in the compression chamber of the high-pressure fuel supply pump, the suction of the compression plunger Including reducing the control current from a first control current value to a lower second control current value before reaching BDC at the end of the stroke.

Therefore, in order to reduce the operating noise of the electromagnetic intake valve, the control current for opening the electromagnetic intake valve of normally closed initially increases to the first control current value for energizing the electromagnetic inlet valve, thereafter, Control is performed so as to be reduced again to a lower second control current value. Since the magnetic force acting on the electromagnetic intake valve is reduced by reducing the control current in the solenoid of the solenoid inlet valve, the biasing force of the biasing member normally closed solenoid inlet valve acting in the closed direction of the electromagnetic intake valve By using it, the movement of the electromagnetic suction valve in the opening direction can be decelerated.

Reduce the speed of the electromagnetic suction valve when it hits the mechanical locking part such as a restricting member, stopper, or valve seat in the fully open position in the fully open position by slowing down the moving speed of the solenoid intake valve to the open position Therefore, the generated impact noise can be further reduced. In other words, for example, the mechanical locking portions such as the valve seat to allow the electromagnetic intake valve is smoothly landing, the acceleration toward moving to decelerate (or fully opened position in the opening direction of the electromagnetic intake valve least Impact noise can be greatly reduced.

Reducing operating noise by controlling the control current to first increase to a first control current value and then decrease to a lower second control current value to open the electromagnetic suction valve, It has the advantage that operating noise can be reduced by simply modifying the applied current control without requiring modification of the mechanical design of the high pressure fuel supply pump. Changes and modifications to the mechanical design are usually very expensive and laborious to develop or implement, so reducing the noise by modifying the solenoid current control is more than modifying the mechanical design. Significant cost savings. This is particularly advantageous when considering the large number of productions in the mass production of parts in the automotive industry.

  In particular, today's high pressure fuel supply pumps are generally automatically controlled by an electronic engine controller, so that the current controller has been optimized by reprogramming or configuring the engine controller, for example by software modifications. The algorithm can be implemented in the control of existing high pressure fuel supply pumps.

Furthermore, by precisely controlling the control current applied to the solenoid of the electromagnetic intake valve, the amount of energy supplied to the solenoid is precisely controlled to accelerate and / or decelerate the electromagnetic intake valve while moving in the open direction. can do. In other words, since it becomes possible to directly influence the amount of the magnetic biasing force generated by the control current control, for example, based on the increase or decrease of the fluid force acting on the electromagnetic suction valve, the increase of the magnetic biasing force and / or Or the reduction can be controlled.

“Current control” in the sense of the present invention can be realized by various methods of current control such as PWM control or threshold current control. The basic concept of the present invention is to first increase the control current to a first control current value for energizing the solenoid, and then move the control current to the electromagnetic suction valve, especially before the electromagnetic suction valve reaches the fully open position. As long as the control current is controlled to open the electromagnetic suction valve by slowing down or at least reducing it to a lower second control current value to reduce its acceleration, The configuration is not limited.

For example, the control current can be controlled by applying a PWM control voltage to the solenoid of the electromagnetic suction valve, wherein the value and / or change of the control current in the solenoid depends on the duty cycle of the PWM control voltage signal. Can be controlled.

  Further, the control current applied to the solenoid can be controlled by changing the frequency of the PWM control signal. Therefore, it is possible to use PWM control to control the control current by combining the duty cycle of the PWM voltage control signal and changing the frequency of the PWM control.

  In addition to being able to control the control current using PWM voltage control, for example, controlling either the control voltage or the control current using a continuously applied control voltage, for example, using an amplifier to control analogly The current can also be controlled directly. For example, current control can be achieved using threshold current control in which the current is adjusted to a specific threshold without requiring modulation such as pulse width modulation of the voltage signal. The value of the control current can also be adjusted directly using an integrated circuit.

In contrast to these prior arts, according to the present invention, the reduction of the control current from the first control current value to the lower second control current value controls the control current to open the electromagnetic suction valve. Thus, it is performed in a step that enables reduction of operation noise of the high-pressure fuel supply pump.

On the other hand, in the control method described in Patent Document 1, the control current is reduced only after the electromagnetic suction valve has already reached the fully open position, and the valve seat or the mechanical mechanical lock in which the valve is in the fully open position. Since the impact at the end of the opening operation of the electromagnetic suction valve when contacting the part has already occurred, it is not at all suitable for reducing the operation noise.
[2] Preferably, the control current is applied before the compression plunger reciprocating between BDC and TDC in the compression chamber of the high-pressure fuel supply pump reaches BDC at the end of the intake stroke before the electromagnetic intake valve is fully opened. The first control current value is reduced to the second control current value.
[3] According to the present invention, the second control current value may be a non-zero current value lower than the first control current value and lower than the first control current value.

Alternatively, in order to ensure that the electromagnetic intake valve is fully opened before the compression plunger reaches the BDC, the compression plunger that reciprocates between the BDC and the TDC in the compression chamber of the high-pressure fuel supply pump reaches the BDC at the end of the intake stroke. Previously, the control current may be reduced to zero or nearly zero.
[4] According to one embodiment of the present invention, the current control of the electromagnetic suction valve for opening the electromagnetic suction valve further increases the control current from the second control current value before the compression plunger reaches the BDC. Including increasing to a third control current value. According to this aspect, it is possible to greatly reduce the operation noise of the standard mass-produced high-pressure fuel supply pump and the electromagnetic suction valve, and in particular, even when there is a variation due to mass production, the compression stroke A series of mass-produced products can be controlled to ensure that the fully open position is reached before the start of.

That is, the high-pressure fuel supply pump and the electromagnetic suction valve that are the basis of the present invention are generally composed of standard mass-produced products that are produced in large quantities. For such mass-produced products, there may be at least a small production variation between the products. According to the present invention, it is possible to optimize the control current of the electromagnetic suction valve based on, for example, a standard electromagnetic suction valve of a mass-produced product, and the control current can be optimized from the second control current value. In the above-described aspect of the present invention, including increasing to a third control current value higher than the control current value of 2, the possibility of variation due to small-scale mass production between mass-produced products is considered. Even if it exists, the reliability of operation control can be improved more.

For example, a minimum control current value may be sufficient to open a mass produced standard solenoid intake valve before the compression plunger reaches the BDC, rather than the compression plunger begins to move upward again toward the TDC. Before, control the mass production standard electromagnetic intake valve to reach the fully open position. That is, the first control current value is set so that the compression stroke of pressurizing the fuel in the compression chamber starts after the electromagnetic intake valve is actually in the fully open position, and the electromagnetic intake valve can be held open at the fully open position. It is possible to control the minimum control current value to a lower second control current value.

Once started pressurizes the fuel in the compression chamber when the compression plunger starts moving to TDC from BDC, when the electromagnetic intake valve is not already fully open position, when the compression plunger is moving toward the TDC, the fuel since pressure acts in the closing direction of the magnetic force in the opposite direction from the electromagnetic intake valve to the electromagnetic intake valve, the minimum control current value for the standard solenoid inlet valve is sufficient to remain open to fully open the electromagnetic intake valve There may not be.

Specifically, the fuel pressure in the compression chamber may increase as the speed of the compression plunger increases, and the fuel leaks from the partially opened electromagnetic intake valve. For example, the magnetic force may be reduced due to the gap between the core and anchor of the partially open electromagnetic intake valve, and the magnetic force may not be sufficient to hold the electromagnetic intake valve open.

In this case, in order to enable highly reliable control of the operation of the high-pressure fuel supply pump in consideration of variations that may occur in mass-produced products, the lower second control current value is electromagnetically sucked due to variations due to mass production. If it is not sufficient to fully open the valve, the electromagnetic suction valve is fully opened before the start of the compression stroke by increasing the control current from the second to the third control current value to increase the magnetic force. In order to ensure, it is preferred that the control current is increased from the second control current value to a third control current value higher than the second control current value.

Therefore, the electromagnetic suction valve, which is a standard mass-produced product that is the basis for setting the second control current value, can be operated with greatly reduced operation noise, and there is a variation due to mass production. However, the electromagnetic suction valve made of mass-produced products can be opened to the fully open position with high reliability.
[5] Preferably, the high pressure fuel supply pump further includes a BDC in the compression chamber to pressurize the fuel in the compression chamber when the compression chamber and the electromagnetic suction valve are fully closed and the compression plunger moves toward the TDC. And a compression plunger that reciprocates between the TDC and the TDC.

Preferably, in order to ensure that the electromagnetic suction valve is fully opened before the compression plunger reaches the BDC, the increase in the control current from the second control current value to the third control current value causes the compression plunger to change to the BDC. Done before reaching. Therefore, it can be ensured that the electromagnetic suction valve is in the fully open position before the start of the compression stroke in which the compression plunger moves from the BDC toward the TDC.
[6] According to one embodiment of the present invention, the third control current value is a target control current value for keeping the electromagnetic suction valve fully open, and in particular, the third control current value is a compression value. This is the target control current value for holding the electromagnetic intake valve fully opened after the plunger reaches BDC. Therefore, the third control current value holds the electromagnetic suction valve in the fully open position until it is closed to initiate the output stroke through which the pressurized fuel is discharged through the discharge valve of the high pressure fuel supply pump to the common rail of the internal combustion engine. This is the target control current value that is maintained to be performed.

Depending on the pump design, the step of increasing the control current to the third control current value may counter the increase in fuel pressure during the compression stroke (ie, after the compression plunger reaches the BDC and begins moving again toward the TDC). This ensures that the electromagnetic intake valve is held open.

Alternatively, the control of the control current of the solenoid inlet valve is to be kept fully opened electromagnetic intake valve in order to reduce energy consumption, the third control current value after the electromagnetic intake valve is fully opened to the target control electric current value The control of the control current of the electromagnetic suction valve includes reducing the third control current after the compression plunger reaches the BDC because the electromagnetic suction valve is held fully open after the compression plunger reaches the BDC. Including reducing the value to a target control current value after the electromagnetic suction valve is fully opened.

In order to reduce energy consumption, the target control current value is lower than the third control current value and is preferably electromagnetic during the compression stroke (ie, after the compression plunger reaches BDC and starts moving again toward TDC). It is sufficient to ensure that the intake valve remains open.

Therefore, as described above, the third control current value, which is an increased control current value to ensure that the electromagnetic suction valve reaches the fully open position before the compression plunger reaches BDC, Is again reduced to a lower target control current value, which is maintained to remain fully open until the electromagnetic suction valve should be closed to initiate the output stroke discharged from the compression chamber through the discharge valve .

This makes it possible to reduce the energy consumption of the high-pressure fuel supply pump, since the target control current value maintained during the spill phase is lower than the third control current value. The target control current value may be equal to the second control current value. Further, after the compression plunger reaches BDC, the control current is reduced again from the third control current value to the target control current value, so that the thermal overload of the solenoid can be efficiently avoided.

Here, the leakage stroke, when the compressed plunger in the compression stroke is already moving towards TDC, the fuel is held electromagnetic intake valve is in the fully opened position the electromagnetic intake valve from the compression chamber through the electromagnetic intake valve It refers to the operating stroke in which the fuel is leaking through, thereby preventing pressurized fuel from being discharged through the discharge valve of the electromagnetic intake valve.
[7] the control of the control current to the electromagnetic intake valve, by controlling the duty cycle of the PWM voltage signal to be supplied to the electromagnetic intake valve, controls the duty cycle and frequency of the PWM voltage signal supplied to the electromagnetic intake valve or, by controlling the value of the PWM voltage signal to be supplied to the electromagnetic inlet valve, for example, the amplifier means may be performed by directly controlling the value of the PWM voltage signal to be supplied to the electromagnetic intake valve is used.

As described above, the basic idea of the invention relates to controlling the control current supplied to the solenoid of the solenoid inlet valve, the duty cycle of the PWM voltage signal when the electromagnetic intake valve is controlled by the PWM control It can be realized in various ways of controlling the control current by controlling or by controlling the frequency and duty cycle of the PWM voltage signal of the PWM control.

  In addition to being able to control the voltage signal using PWM control, the control current can also be controlled directly by directly adjusting the control voltage and / or control current, for example using an amplifier and / or integrated circuit. The control current can be directly controlled by voltage threshold control, and the control current is directly controlled by, for example, an integrated circuit.

Although direct adjustment of the control current by an amplifier or integrated circuit can precisely control the current, PWM control can lead to ripple in the gradual change of the control current due to the on / off switching of the PWM voltage signal. However, the influence of the ripple of the control current controlled by the PWM voltage signal can be effectively reduced by increasing the frequency of the PWM voltage signal. Another advantage of PWM control is that it can be easily implemented, and a common electronic engine controller has already been manufactured to supply the PWM control signal, for example by software and / or hardware modifications. Can be easily configured.
[8] Preferably, the control of the control current of the electromagnetic suction valve further comprises applying an initial voltage pulse to increase the control current to the first control current value, preferably rapidly, and the control current to the first Applying the first PWM voltage signal after applying the initial voltage pulse includes reducing the control current value to the second control current value.

  The initial voltage pulse can be embodied by a short applied constant voltage signal that embodies the initial voltage pulse or as an initial PWM voltage signal that embodies the initial voltage pulse, where the duty cycle of the initial PWM voltage signal is: Preferably it is greater than the duty cycle of the first PWM voltage signal. In particular, the duty cycle of the initial PWM voltage signal may be 100% or at least approximately 100%.

According to this embodiment, PWM control is used to control the control current supplied to the electromagnetic intake valve. Initially, in order to increase the control current to the first control current value, an initial voltage pulse for increasing the control current can be applied. When using PWM control, the initial voltage pulse may be realized by a PWM voltage signal pulse having a duty cycle of 100% or at least approximately 100%. After applying this initial voltage pulse, a first PWM voltage signal having a duty cycle of preferably less than 100% (especially smaller than the duty cycle of the initial voltage pulse) is applied, in particular applied to the solenoid of the electromagnetic intake valve. The control current can be reduced from the first control current value to the lower second control current value.
[9] Preferably, the control of the control current of the electromagnetic suction valve further increases the control current from the second control current value to a third control current value higher than the second control current value. Including applying the second PWM voltage signal after applying the PWM voltage signal, in particular, the first PWM voltage signal has a smaller duty cycle than the second PWM voltage signal. The second PWM voltage signal may have a duty cycle of 100% or less, or approximately 100% or less.

According to this embodiment, even if there is a variation due to mass production, for example, the second control current value is used to ensure that the electromagnetic suction valve reaches the fully open position before the compression plunger reaches the BDC. In order to control the control current so as to increase again from 1 to the third control current value, a further second PWM voltage signal having a duty cycle greater than the first PWM voltage signal is used to increase the voltage current again. Can be applied.

The second PWM voltage signal is an electromagnetic intake valve so that the control current reaches a target control current value, or in order to pressurize the fuel in the compression chamber and discharge the pressurized fuel through the discharge valve of the high-pressure fuel supply pump. Set to reach a current greater than the final target control current to hold the electromagnetic suction valve in the fully open position during the leakage stroke in which the compression plunger moves upward on the upward stroke toward TDC can do.
[10] The first PWM voltage signal may be switched to the second PWM control voltage signal. According to another embodiment of the present invention, the first PWM voltage signal may be changed to the second PWM voltage signal by stepwise PWM control. Next, at least a third PWM voltage signal may be applied after the first PWM voltage signal and before the second PWM voltage signal. As a result, the duty cycle of the third PWM voltage signal may be greater than the duty cycle of the first PWM control voltage signal and smaller than the duty cycle of the second PWM control voltage signal.

  According to yet another embodiment of the present invention, the duty cycle of the first PWM voltage signal may be increased continuously or repetitively to the second PWM control voltage signal by incremental PWM control.

If the control current is rapidly increased from the second control current value to the third control current value, the standard mass-produced high pressure fuel supply pump is either in the process of applying the second control current value or At least immediately after that, the fully-open position has already been reached, but the electromagnetic suction valve has not reached the fully-open position due to variations due to mass production, and the control current is increased from the second to the third control current value. The situation of full opening may occur. If this increase from the second to the third control current value takes place quickly, the electromagnetic suction valve hits the valve seat or the mechanical locking part at high speed, which rarely causes undesirable impact noise.

However, according to the above-described embodiment in which the increase of the control current from the second to the third control current value is performed more slowly and smoothly by the stepwise or incremental PWM control, even in such a situation, Since the electromagnetic suction valve reaches the fully open position at a low speed, the impact noise can be greatly reduced even in a rare case where the electromagnetic suction valve is not fully opened by the control current corresponding to the second control current value.

  According to one embodiment utilizing stepped PWM control, after applying the first PWM voltage signal, the duty cycle of the PWM control voltage is repeated to increase the control current more slowly to the third control current value. Therefore, it is possible to apply a plurality of PWM control signals each having a duty cycle increased as compared with the previous duty cycle of each PWM control signal.

  According to an alternative embodiment, the PWM current is increased by utilizing incremental PWM control in which the duty cycle of the applied PWM voltage signal increases continuously or repeatedly to increase the control current to a third control current value. Control can be performed. This is achieved, for example, in that the duration of the PWM control in the on state increases continuously or repeatedly and / or the duration of the PWM control in the off state decreases continuously or continuously. be able to.

  Furthermore, the substantially continuous increase of the control current from the second control current value to the third control current value also changes the frequency of the PWM control signal continuously or repetitively, or the PWM voltage signal It may also be achieved by a combination of continuous or repetitive changes in duty cycle and continuous or repetitive changes in the frequency of the PWM voltage signal.

For example, in the case of the direct current control by the above threshold current control using an amplifier and / or an integrated circuit, the control current is, for example, at the timing when the compression plunger reaches the BDC or almost at that timing (preferably before or just before). It can be increased with a smaller slope to reach a control current value of 3.
[11] Preferably, the control of the control current of the electromagnetic suction valve further sets the timing for starting the application of the initial voltage pulse, sets the duration for applying the initial voltage pulse, and the first PWM voltage. It may include at least one of setting a timing for applying the signal and / or a duration for applying the first PWM voltage signal. Timing and duration setting of the initial voltage pulse and the first PWM voltage signal, the fluid force acting in the opening direction of the electromagnetic inlet valve, depending on the urging force which acts in the closing direction of the electromagnetic inlet valve, an electromagnetic suction This may be done to control the magnetic force of the valve.

When using PWM control to control the control current, the control can be easily performed, a plurality of control parameters are set to optimize the control and / or the electromagnetic intake valve reaches the fully closed position It can be optimized to limit the impact noise. Control parameter, preferably, the magnetic force (i.e., the magnetic force generated by energization of the solenoid of the solenoid inlet valve) and biases the solenoid inlet valve in the direction for closing the valve as is common in a normally closed solenoid inlet valve Biasing force (ie, the fluid force generated by the pressure difference upstream and downstream of the electromagnetic suction valve when the compression plunger is in the downward stroke toward the BDC, thereby increasing the volume of the compression chamber and reducing the pressure, fluid force balanced to) the generator to the electromagnetic intake valve which acts in the open direction of the electromagnetic inlet valve, is optimized in order to reduce the impact noise when the electromagnetic intake valve reaches the full open position Is set as follows.

  For example, the amplitude of the fluid force generally depends on the speed of movement of the compression plunger in the compression chamber, and the compression plunger first accelerates while moving from TDC until it decelerates again when approaching bottom dead center, ie , The movement speed of the compression plunger corresponds approximately to a periodic function that depends on the profile of the rotating cam that drives the compression plunger, for example a sine wave, and the maximum speed may reach approximately halfway between TDC and BDC (sinusoidal wave). The maximum speed occurs halfway between TDC and BDC).

On the other hand, the magnetic force generated by energizing the solenoid of the electromagnetic suction valve generally depends on the applied control current and the distance between the components attracted by the magnetic force, such as the anchor and core of the electromagnetic suction valve. On the other hand, the biasing force depends on the position of the electromagnetic suction valve, and may generally increase linearly from the fully closed position to the fully open position.

The movement of the electromagnetic suction valve is obtained by the sum of the aforementioned forces, ie the sum of the biasing force, the fluid force and the magnetic force. Fluid force and magnetic force may act in the opening direction of the electromagnetic suction valve. For example, an urging force such as a spring force may act in the closing direction of the electromagnetic suction valve.

  Preferably, when the compression plunger moves from TDC to BDC, the temporal change in magnetic force is balanced with the temporal change in fluid force, in which case the method according to the invention preferably initiates, for example, an increase in control current Including setting a control parameter, such as setting a timing, setting a timing to reach a first control current value, and / or setting a value of the first control current value.

For example, when utilizing PWM control, the fluid force and magnetic force preferably include additional balancing of the fluid force and magnetic force with a biasing force that increases linearly while displacing the electromagnetic suction valve toward the fully open position. In order to balance the temporal change of the first voltage pulse, at least one of the time when the application of the initial voltage pulse is started, the duration of the application of the initial voltage pulse, and the timing and / or the duration of the application of the first PWM voltage signal is determined. Can be set.

By setting the timing and / or duration described above, the average impact speed when reaching the fully open position is minimized (ie, the electromagnetic intake valve in the fully open position) so as to reduce operating noise of the high pressure fuel supply pump. To ensure a soft landing). In addition, pump design parameters, such as cam profile and low pressure fuel feed pressure supplied to the high pressure fuel supply pump, can affect fluid forces and their behavior, so they are optimized May be considered for.

Preferably, the timing and duration settings described above are such that the resultant force, which is the sum of fluid force, magnetic force, and biasing force, is a threshold force value suitable for holding the electromagnetic suction valve in the fully open position (e.g., a large amount The product's general standard electromagnetic intake valve should have a resultant force that acts in the direction of opening the valve, which is higher than the force sufficient to hold the valve open after reaching the fully open position. Done.

It can be seen that the fluid force has a maximum value at the point when the moving speed of the compression chamber during the downward stroke is maximum, that is, approximately in the middle between TDC and BDC, and thereafter the fluid force decreases overall again. Sometimes it is necessary to consider. As a result, due to variation e.g. by mass production, when the fluid force acting in the opening direction of the electromagnetic intake valve by reducing the moving speed of the compression plunger towards the BDC is reduced again, it has electromagnetic intake valve reaches the full open position If not, a greater magnetic force is required to still move the electromagnetic suction valve to the fully open position.

  According to one embodiment, even in such a situation, if the timing of applying the initial voltage pulse is set to an earlier value, for example, the timing before the fluid force reaches the maximum value, Reduced impact speed and reduced impact noise can be achieved.

Thus, at an initial point during the downward stroke of the compression plunger, the fluid force acting in the opening direction of the electromagnetic suction valve is at this timing during the stroke when the compression plunger is approximately halfway between TDC and BDC. Because it is large, a small magnetic force may be sufficient to move the electromagnetic suction valve to the fully open position.
[12] Preferably, the control of the control current of the electromagnetic suction valve may further include setting a timing for applying the second PWM voltage signal and / or a duration for applying the second PWM voltage signal. Setting the timing and duration of the initial voltage pulse, the first PWM voltage signal, and the second PWM voltage signal may be performed to control the magnetic force according to the fluid force and the biasing force.

By setting the timing and / or duration of applying the second PWM voltage signal to increase the control current again from the second control current value to the third control current value, and / or even if there are variations due to mass production of the electromagnetic intake valve, it is possible to ensure that the electromagnetic intake valve is always reaches the fully open position.
[13] Preferably, the timing of applying the initial voltage pulse may be set before the maximum fluid force acting in the opening direction of the electromagnetic suction valve is generated. In other words, the timing of applying the initial voltage pulse may be set before the maximum speed of movement of the compression plunger that reciprocates in the compression chamber of the high-pressure fuel supply pump in the direction toward the BDC occurs.

  The timing and duration settings for the above parameters are preferably such that the timing to reach the fully open position occurs when the fluid force is at a maximum value, for example, at a timing at which the moving speed of the compression plunger toward the BDC is approximately maximum. Is set. The timing of applying the initial voltage pulse is set to the timing before the fluid force reaches the maximum value, in other words, before the moving speed of the compression plunger toward the BDC becomes maximum.

Furthermore, the duration of application of the initial voltage pulse (and / or the time of application of the first PWM voltage signal as described below) is at the point where the fluid force is at a maximum value, or in other words, the compression plunger towards the BDC. The electromagnetic suction valve is set so as to approach the fully open position at the timing when the movement reaches the maximum value during the stroke. Thereafter, the control current is reduced by applying a first PWM control signal (the control current can be reduced to zero or nearly zero), whereby the magnetic force generated by the solenoid is reduced by a decrease in the control current. Thus, the resultant force acting on the electromagnetic intake valve is varied such that the speed toward the fully open position is reduced or the acceleration is greatly reduced.
[14] Preferably, the setting of the timing and duration of the initial voltage pulse and the first PWM voltage signal or the first and second PWM voltage signals is applied to a low current condition, for example, an electromagnetic suction valve. The electromagnetic suction valve is set to reach its fully open state at the timing when the PWM signal is turned off. This is for low frequency PWM control, for example most commonly used in single switch PWM control (eg, PWM control in the range of about 100-1000 Hz, preferably 200-600 Hz, preferably about 400 Hz). This is particularly advantageous (in frequency).

When the control signal is controlled by PWM control, at least when low-frequency PWM control is used, the switching of the PWM voltage signal may cause a ripple in the gradual change of the control current, preferably at that time The setting of the timing and duration of the initial voltage pulse and the first PWM voltage signal or the first and second PWM voltage signals is such that the ripple of the control current is a low current condition, that is, the control current is average controlled by PWM control. At a timing lower than the current average value, which is a condition slightly lower than the current value, in other words, when the PWM signal applied to the solenoid is substantially OFF, the electromagnetic intake valve is set to reach the fully open position. .
[15] Preferably, the timing to start increasing the control current for energizing the solenoid suction valve to the first control current value before the maximum fluid forces acting in the opening direction of the electromagnetic intake valve occurs timing Set to This is accomplished by setting the timing and duration of the initial voltage pulse as described above for another type of current control, such as PWM control, or directly adjusting current control as described above, such as current threshold control. be able to.

This is for low frequency PWM control, for example most commonly used in single switch PWM control (e.g. PWM in the range of about 100-1000 Hz, preferably 200-600 Hz, more preferably about 400 Hz). This is particularly advantageous (at the control frequency).
According to [16] one embodiment, the electromagnetic intake valve, the intake valve member and the intake valve plunger are formed as a unit body, i.e., the intake valve member and the intake valve plunger is formed integrally with or secured to each other This is an integrated electromagnetic intake valve. According to an alternative embodiment, it is possible solenoid inlet valve also has a suction valve member and the intake valve plunger are formed as a separate member, the separation solenoid suction valve. As a result, the magnetic force of the electromagnetic suction valve preferably acts on the suction valve plunger.

For isolation solenoid intake valve, timing to start increasing to the first control current value of the control current for energizing the solenoid suction valve, suction valve member by the fluid force acting in the opening direction of the intake valve member There is set to a timing after the start of the movement, in particular whereby the suction valve plunger, the intake valve member is moved in the opening direction of the inlet valve member, it comes into contact with the suction valve member.

In integrated electromagnetic inlet valve of the magnetic force is preferably acts on the intake valve plunger may act to suction valve member in the opening direction of the electromagnetic intake valve while closing the integrated solenoid electromagnetic intake valve The biasing force may act on the suction valve plunger and / or the suction valve member in the closing direction of the electromagnetic suction valve, and the fluid force may mainly act on the suction valve member. The resultant force obtained by the magnetic force, the fluid force, and the urging force is applied to a single body including the integrally formed suction valve member and the suction valve plunger, or to a single body including the suction valve plunger and the suction valve member fixed to each other. It may act. Therefore, the resultant force may act so that the suction valve member and the suction valve plunger move together.

According to an alternative embodiment, the present invention also includes a suction valve plunger and the suction valve member as a separate member which can be displaced independently of one another, be applied to control the separation-type solenoid inlet valve Can do. In such a separate electromagnetic intake valve, fluid force generally acts on the intake valve member, and magnetic force generally acts on the intake valve plunger in the direction of opening the electromagnetic intake valve. At least a biasing member that biases the suction valve member in the closing direction may be provided, and another biasing member may act on the suction valve plunger. The biasing member acting on the suction valve plunger can be configured to generate a biasing force that acts in either the closing direction or the opening direction of the electromagnetic suction valve.

Since the separation type electromagnetic intake valve is realized as a normally closed electromagnetic intake valve according to the present invention, when the urging member acts on the intake valve member, an urging force acting in the direction of opening the valve may be generated. When the biasing member acting on the intake valve plunger acts in the opening direction, the biasing member acting on the suction valve member generates a large bias force (particularly, greater than the biasing force acting on the suction valve plunger), As a result, the suction valve member and the suction valve plunger come into contact with each other, and in the situation where there is no fluid force or magnetic force, the entire biasing force acts in the closing direction, and the suction valve member counters the biasing force acting on the suction valve plunger. It may be configured to be held in the fully closed position.

In the case of a separate type electromagnetic intake valve, the fluid force generally acts only on the intake valve member as described above, and as a result, the intake valve member moves in the opening direction of the electromagnetic intake valve. In particular, in the case of a separation type electromagnetic suction valve configuration in which the biasing force acts on the suction valve plunger in the direction of closing the valve, the timing at which the control current starts to increase is set by, for example, setting the timing of the initial voltage pulse. The timing may be set after the intake valve member has already started moving in the direction of opening the valve by physical strength. Thereby, the intake valve plunger is moved in the direction of opening the valve by magnetic force increases when the inlet valve member has already moved in the opening direction by the fluid force, comes into contact with the suction valve member.

Therefore, in such a separate electromagnetic intake valve, the first impact noise generally generated when the intake valve plunger comes into contact with the intake valve member can be significantly reduced.
The second impact noise generated when the intake valve member reaches the fully open position together with the intake valve plunger controls the control current applied to the solenoid of the electromagnetic intake valve according to at least one of the above aspects of the present invention. Can be greatly reduced.
[17] According to the second aspect of the present invention, a control device for controlling a high-pressure fuel supply pump for supplying pressurized fuel to an internal combustion engine is proposed. Control apparatus according to the second aspect of the present invention, by at least one of the embodiments described above according to the first aspect of the present invention, is configured to control the control current of the solenoid inlet valve for opening the electromagnetic intake valve The

Specifically, the control device of the present invention is configured to control a high-pressure fuel supply pump that supplies pressurized fuel to the internal combustion engine. The high-pressure fuel supply pump is opened or held open by magnetic force, especially when applying a control voltage to the electromagnetic intake valve to open or hold the electromagnetic intake valve, while the fluid pressure There does not act on the solenoid inlet valve, when the control voltage is not applied to the electromagnetic intake valve, the electromagnetic intake valve remain closed by the urging member comprises an electromagnetic inlet valve of the normally closed.

According to the present invention, the control apparatus of the present invention, for opening the electromagnetic intake valve by applying a control voltage to the electromagnetic inlet valve configured to control the control current of the solenoid inlet valve. The control device according to the second aspect of the present invention is configured to control the control current of the electromagnetic intake valve such that the control current is increased to a first control current value for energizing the electromagnetic intake valve. .

In particular, the control current is applied to the electromagnetic intake valve before the compression plunger reciprocating between BDC and TDC in the compression chamber of the high pressure fuel supply pump reaches bottom dead center (BDC) at the end of the compression plunger intake stroke. Is increased to a first control current value for energizing.

The control device of the present invention is particularly suitable for the BDC in the compression chamber of the high-pressure fuel supply pump so that the control current is reduced from the first control current value to the second control current value lower than the first control current value. Electromagnetic suction so that the compression plunger that reciprocates between TDC and TDC is reduced in control current from the first control current value to the second control current value before reaching the BDC at the end of the suction stroke of the compression plunger. It is configured to control the control current of the electromagnetic intake valve to open the valve.

Furthermore, the control device of the present invention may be further configured to control the control current of the electromagnetic suction valve according to at least one of the above-described embodiments of the first aspect of the present invention.
According to a third aspect of the 18 present invention, the control device, by at least one of the first embodiment described in connection with the embodiment of the present invention, the electromagnetic intake valve to open the electromagnetic intake valve A computer program product is proposed, comprising computer program code for configuring the control device, in particular the engine control device, to be configured to control the control current. That is, the computer program product comprises computer program code that configures the control device, particularly the engine control device, so that the control device embodies the control device as described above in connection with the second aspect of the invention.

  The above-mentioned features and aspects of the method according to the invention, as well as preferred features and aspects thereof, also apply to the control device and the computer program product described above, and the advantages as described in the method aspects also apply, which Omitted for brevity. The preferred features and aspects described above can be modified or combined in any manner.

The present invention has a normally closed solenoid inlet valve to be held while being or open opened by magnetic force, comprising the step of controlling the control current of the solenoid inlet valve to open the electromagnetic intake valve, the electromagnetic intake valve In the control method of the high-pressure fuel supply pump for supplying pressurized fuel to the internal combustion engine, the step of controlling the control current of the method includes the step of increasing the control current to a first control current value for energizing the electromagnetic suction valve The step of controlling the control current of the electromagnetic suction valve to open the electromagnetic suction valve further reduces the control current from the first control current value to a second control current value lower than the first control current value. By including
By reducing the moving speed of the electromagnetic suction valve to the open position, it is possible to reduce the speed of the electromagnetic suction valve when it hits the mechanical locking portion at the fully open position, so that the generated impact noise can be greatly reduced. .

The schematic diagram which shows an example of a fuel supply system provided with the high pressure fuel supply pump for supplying a high pressure fuel to an internal combustion engine provided with a normally closed electromagnetic suction valve. The schematic diagram which shows an example of the normally closed electromagnetic suction valve in a fully closed position. The schematic diagram which shows the normally closed electromagnetic suction valve of FIG. 2A in a fully open position. Explanatory drawing which shows an example of the normally closed electromagnetic suction valve of a prior art example. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the control method of the high pressure fuel supply pump provided with a normally closed electromagnetic suction valve of a prior art example. The circuit diagram which shows the system | strain which has two switches for the PWM control applied to a solenoid. The time chart which shows the PWM control signal supplied to the solenoid of FIG. 5A, and the control current obtained from it. The circuit diagram which shows the system | strain which has one switch for the PWM control applied to a solenoid. The time chart which shows the PWM control signal and control current which are supplied to the solenoid of FIG. 6A. 4 is a time chart showing a gradual change of the voltage control signal VC and a gradual change of the control current IC by the method according to the first embodiment of the present invention. FIG. 3 is a schematic diagram showing a gradual change in control current IC and valve movement according to the first embodiment of the present invention. The time chart which shows the gradual change of the voltage control signal VC and the gradual change of the control current IC by the 2nd Embodiment of this invention. Schematic showing the gradual change of control current and valve movement according to the second embodiment of the present invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the 3rd Embodiment of this invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the 4th Embodiment of this invention. Schematic which shows the gradual change of the control electric current IC and valve movement by the 4th Embodiment of this invention. The time chart which compares the conventional control method and one Embodiment of this invention. The schematic diagram which shows an example of a separation-type electromagnetic suction valve. Schematic which shows an example of the normally closed electromagnetic suction valve regarding the separation-type electromagnetic suction valve of a prior art example. Schematic showing the gradual change of the control current IC and valve movement according to the fifth embodiment of the present invention. The time chart which shows the gradual change of voltage control signal VC and the gradual change of control current IC by the method by the 6th Embodiment of this invention. The time chart which shows the gradual change of the alternative example of a PWM voltage control signal.

  Preferred embodiments of the invention are described below with reference to the drawings. The features and aspects of the embodiments may be modified or combined to form further embodiments of the invention. In the description of the preferred embodiment, control currents and PWM voltage signals that generate such control currents are exemplarily shown. However, PWM control or DC control can be used by using any method for current control.

The actual current profile may exhibit characteristics such as current ripple (particularly associated with PWM control) or current drop when the electromagnetic suction valve collides with the mechanical locking part. It is omitted and only the average current is shown.
[First Embodiment]
FIG. 1 shows an example of a fuel supply system including a high-pressure fuel supply pump including a normally closed electromagnetic intake valve. The high-pressure fuel supply pump 100 is configured to supply high-pressure fuel to the internal combustion engine in order to inject the pressurized fuel directly into the combustion chamber of the internal combustion engine.

The fuel supply system includes a fuel tank 600 and a low-pressure fuel pump 200 in order to supply low-pressure fuel from the fuel tank to the high-pressure fuel supply pump 100 via the suction pipe 300. After pressurizing the fuel in the high-pressure fuel supply pump 100, the pressurized fuel is supplied to the common rail 800 via the discharge pipe 400, and then the internal combustion engine using the four injectors 810a, 810b, 810c, and 810d. Directly injected into the compression chamber.

  The present invention is not limited to a fuel supply system having four injectors, and is generally applicable to a fuel supply system having at least one common rail each having at least one injector.

The high-pressure fuel supply pump includes a normally closed electromagnetic suction valve 110, a compression chamber 120, and a compression plunger 130 that reciprocates between TDC and BDC in the compression chamber 120.

  The high-pressure fuel supply pump further includes a discharge valve 140 including a discharge valve seat 140a, a discharge valve member 140b, and a discharge valve spring 140c that generates a biasing force that acts on the discharge valve member 140b in the closing direction of the discharge valve 140. When the discharge valve 140 is fully closed, the discharge valve member 140b is in contact with the discharge valve seat 140a.

  The reciprocating motion of the compression plunger 130 is driven by the rotation of the cam 500. As the compression plunger moves from TDC toward BDC, the volume of the compression chamber 120 increases, and after reaching the BDC, the compression plunger 130 starts moving again toward the TDC, thereby reducing the volume of the compression chamber 120 again. When the compression plunger 130 reaches the TDC, it becomes the minimum.

The low-pressure fuel is put into the compression chamber 120 from the low-pressure fuel pipe 300 via the normally closed electromagnetic suction valve 110 and discharged at high pressure through the high-pressure fuel pipe 400 by the discharge valve 140. The amount and timing of the pressurized fuel discharged is controlled by controlling the control current applied to the solenoid of the electromagnetic intake valve 110 controlled by the engine control device 700.

2A and 2B show different states of an example of a normally closed electromagnetic suction valve 110.

In FIG. 2A, the electromagnetic suction valve 110 is in a fully closed state, that is, no control voltage or control current is applied to the solenoid 112 and the electromagnetic suction valve 110 is in a shut-off state, so there is no magnetic force acting on the electromagnetic suction valve. Since there is no pressure difference with the downstream, the fluid force does not act on the valve. As a result, the electromagnetic intake valve 110 is held closed by an urging force that is generated by an urging member such as a spring 113 and acts in the closing direction of the electromagnetic intake valve.

In FIG. 2B, the electromagnetic suction valve 110 is shown in an open state when a control voltage or control current is applied to the solenoid 112, for example because the valve is held in a fully open position.

Electromagnetic intake valve 110 of FIGS. 2A and 2B is provided with a suction valve plunger 111a and the suction valve member 111e. 2A and 2B, the suction valve plunger 111a and the suction valve member 111e are exemplarily formed as a single body, but may be formed as separate bodies (see, for example, FIG. 15).

The anchor 111b is provided at the other end of the suction valve plunger 111a at the end of the suction valve plunger 111a opposite to the suction valve member 111e. When current is applied to the solenoid 112, the solenoid valve anchor 111b and the core 114 are attracted to each other by magnetic force, so that the intake valve plunger 111a opens the valve until the anchor 111b and the core 114 come into contact and the displacement is limited. Displace in the direction. Contacting the anchor 111b and core 114, the position of the electromagnetic intake valve displacement of the intake valve plunger 111a is limited thereby, since it can not be opened electromagnetic intake valve is more, called fully open position.

As long as current is applied to the solenoid 112, the anchor 111b and the core 114 are attracted to each other in contact, thereby allowing the valve to be held open, and the intake valve member 111e moves away from the intake valve seat 111d. Retained. Therefore, as indicated by the arrow, the low-pressure fuel can be taken out from the low-pressure system via the suction passage 117 and fed to the compression chamber 120 of the high-pressure fuel supply pump via the suction port 118.

As long as the valve is held open by applying an electric current to the solenoid 112, when the compression plunger 130 in the compression chamber 120 is in an upward stroke that reduces the volume of the compression chamber 120, unpressurized fuel is In some cases, leakage from the suction port 118 to the low-pressure fuel system may occur in the reverse direction via the suction passage 117.

When no current is applied to the solenoid 112, the spring 113, the intake valve member 111e to close the valve as shown in Figure 2A until the contact with the suction valve seat 111d, it urges the suction valve plunger 111a. Therefore, in the upward stroke of the compression plunger 130 in the compression chamber 120, the fuel cannot leak through the suction port 118, and the fuel is pressurized in the compression chamber 120 and discharged at a high pressure through the discharge valve 140. .

On the other hand, when no current is applied to the solenoid 112 and the compression plunger 130 is in the suction stroke (downward stroke) so as to increase the volume of the compression chamber 120, the fuel pressure in the compression chamber 120 is low. Since the pressure is reduced as compared with the pressure of the fuel in the suction passage 117 connected to the fuel system, the suction valve member 111e is opened in the direction to open the valve against the urging force of the spring 113 even when no current is applied to the solenoid 112. A fluid force is generated that causes a displacement of. The fluid force is a displacement that does not reach a sufficient displacement of the suction valve plunger 111a and / or the suction valve member 111e until the anchor 111b contacts the core 114 or a sufficient displacement until the anchor 111b contacts the core 114. Can be generated.

Thereafter, when a current is applied to the solenoid 112, the valve is opened and / or held open by magnetic force. In particular, in the construction as shown in FIGS. 2A and 2B, the suction valve plunger 111a is displaced with the suction valve member 111e before the current is applied to the solenoid 112, and the noise level and the electromagnetic suction valve 110 during operation. Vibration can be efficiently reduced. Here, the suction valve plunger 111a and the suction valve member 111e are integrally formed.

The suction valve plunger 111a and the suction valve member 111e can also be formed as separate bodies fixed to each other. Alternatively, when the suction valve member 111e is displaced in a direction to open the valve by fluid force, the suction valve plunger 111a and the suction valve member 111e are biased in the direction to close the valve by the biasing mechanism, and the suction valve plunger 111a opens the valve. It can also be formed as a separate body that is further biased in the direction of the intake valve member 111e so as to be displaced in the direction.
[Control method of conventional high-pressure fuel supply pump]
FIG. 3 shows the conventional control of the high-pressure fuel supply pump 100 with the normally closed electromagnetic suction valve 110. In the uppermost row of FIG. 3, the time change (plunger lift) of the movement of the compression plunger 130 is shown. The compression plunger 130 operates similar to a sine wave (or other periodic function) and reciprocates between TDC and BDC. Therefore, as shown in the second row from the top of FIG. 3, the speed of the compression plunger 130 is zero when the compression plunger 130 is at TDC or BDC.

The maximum speed of operation of the compression plunger 130 is obtained in the middle of the stroke of the compression plunger 130, and the compression plunger 130 is moved by a sine wave in this embodiment, so that it is between TDC and BDC or between BDC and TDC. Reach the maximum speed in the middle. The movement of the compression plunger 130 between the TDC and the BDC is referred to as the downward stroke or the suction stroke, and the movement of the compression plunger 130 between the BDC and the TDC is referred to as the upward stroke, the output stroke, or the discharge stroke.

As shown in the second column from the bottom of FIG. 3, the electromagnetic suction valve 110 is opened and held open at the start of the discharge stroke, so that the compression plunger 130 reaches the BDC in the downward stroke (FIG. 3). The voltage control signal VC (referred to herein as “ON”) is applied, thereby reducing the volume of the compression chamber 120 (without substantially pressurizing the fuel in the compression chamber 120), so that the fuel is supplied to the electromagnetic intake valve 110. Through the compression chamber 120.

The lowermost row in FIG. 3 shows a temporal change in valve movement of the electromagnetic suction valve 110 (particularly, the suction valve member 111e). Immediately after the compression plunger 130 reaches TDC and begins to move again toward the BDC, the volume of the compression chamber 120 is reduced, thereby creating a pressure difference between the upstream and downstream of the intake valve member 111e of the electromagnetic intake valve 110. As soon as the fluid force generated by the pressure differential exceeds the biasing force of the spring 113, by displacing the inlet valve member 111e in the opening direction of the electromagnetic intake valve 110, the fluid force acts to open the solenoid inlet valve 110 .

The amplitude of the fluid force depends on the moving speed of the compression plunger 130, but increases until it reaches a maximum value of the moving speed of the compression plunger 130, since then the fluid force decreases again supplied to the solenoid 112 of the solenoid inlet valve 110 Until the control voltage signal is turned on and energized, the fluid force decreases and the biasing force of the spring 113 causes the suction valve member 111e to be displaced again in the direction of closing the valve.

When the voltage control signal VC is turned on, the control current of the solenoid 112 generates a magnetic force that acts on the electromagnetic suction valve 110. By the generated magnetic force, suction valve member 111e is displaced suction valve member 111 to the fully open position that comes into contact with the suction valve seat 111d, thereby, at low rotational speed condition of the internal combustion engine such as idling conditions, normally closed solenoid Impact noise, which is the main noise in the operation of the high-pressure fuel supply pump having the intake valve 110, is generated.

Electromagnetic intake valve 110 is held at the fully open position by magnetic force to attract the anchor 111b and core 114, until the control voltage VC supplied to the solenoid 112 is switched off, the electromagnetic intake valve of the fuel fully open state of the combustion chamber 120 It leaks out from the compression chamber 120 through 110. Thereafter, the closing direction force of the force of the solenoid inlet valve 110 generated by the spring 113, the electromagnetic intake valve is closed by the fluid force.

When the electromagnetic suction valve 110 reaches the fully closed position, an output stroke for discharging pressurized fuel from the compression chamber 120 to the internal combustion engine via the discharge valve 140 starts. Specifically, the compression plunger 130 is still moving toward the TDC, and the volume of the compression chamber 120 is further reduced, but the pressure of the fuel in the compression chamber 120 acts in the closing direction of the discharge valve 140. The pressure increases until the urging force of the discharge valve spring 140 c is overcome, thereby opening the discharge valve 140, so that pressurized fuel can be fed to the common rail 800 via the discharge valve 140 and the discharge pipe 400.

The output stroke of discharging pressurized fuel through the discharge valve 140 ends as soon as the compression plunger 130 reaches TDC. As soon as the compression plunger 130 begins to move again in the direction of the BDC, the next suction stroke begins.

FIG. 4 shows a conventional PWM control for opening the normally closed electromagnetic intake valve before the compression plunger 130 reaches the bottom dead center BDC as shown in FIG. The upper row of FIG. 4 shows that the control voltage signal VC applied to the solenoid of the electromagnetic suction valve switches on and off between the minimum and maximum control voltage values (the minimum value may be zero and the maximum value). Lower non-zero values).

The lower column of FIG. 4 shows the gradual change of the control current IC corresponding to the control voltage signal VC in the upper column of FIG. First, the initial voltage pulse IVP is turned on at timing t1, and is applied to the solenoid 112 of the electromagnetic suction valve 110 until time t2. Here, t1 and t2 are times before the time when the compression plunger 130 reaches the BDC. By time t2, the PWM control signal VCF is applied with a duty cycle of less than 100%, and the control current IC continues to be supplied to the solenoid 112 of the electromagnetic intake valve 110 at a substantially constant current control target value IT, which is then , Used to generate a substantially constant magnetic force to hold the electromagnetic suction valve 110 in the fully open position during the leakage stroke described above.

Here, an initial voltage pulse signal IVP (for example, a PWM signal having a duty cycle of 100% or almost 100%) applied between times t1 and t2 energizes the solenoid at a high speed, while the solenoid's thermal excess is detected. The PWM voltage signal VCF is applied with a duty cycle of less than 100% to avoid increasing the control current to an amplitude that may lead to waste of load and possibly electrical energy.
[PWM control method]
FIG. 5A shows a general system for PWM control of the solenoid 112 of the electromagnetic intake valve 110. The PWM control system includes two switches S1 and S2 controlled by signals 1 and 2 output from the CPU 710 which is a processing device of the engine control device 700. The switches S1 and S2 may be embodied by, for example, an electronic switch that can be switched by applying a voltage signal to a gate electrode of a field effect transistor (FET), ie, a field effect transistor controlled by the CPU 710. FIG. 5B shows signals 1 and 2 and the solenoid current.

  In general, such a PWM control system with two switches is usually a high frequency of pulse width modulated PWM (generally in the range of 1-10 kHz, preferably in the range of 2-6 kHz, most commonly Is controlled by about 4 kHz), and one switch (S2 in FIG. 5A) is used to turn on and off the PWM signal applied to the solenoid 112 by the necessary pulse width modulation. The system may be connected to a battery (battery voltage VBAT) and ground potential (GND), or may be connected to two poles of the battery. The switch S1 is used for PWM control, and the switch S2 is used for shutting off the solenoid at high speed, that is, for quickly and constantly lowering the voltage.

FIG. 6A shows an alternative general system for PWM control of solenoid 112 of electromagnetic intake valve 110. The PWM control system includes one switch S1 that is controlled by a signal 1 from the processing device 710 (for example, CPU) of the engine control device 700. The switch S1 may be embodied by, for example, a field effect transistor (FET), ie, an electronic switch that can be switched by applying a voltage signal to the gate electrode of the field effect transistor controlled by the CPU 710. FIG. 6B shows signal 1 and solenoid current.

  In general, such a PWM control system with one switch is usually the low frequency of pulse width modulated PWM (typically in the range of 100-1000 Hz, preferably in the range of 200-600 Hz, most commonly Is controlled at about 400 Hz). The system may be connected to a battery (battery voltage VBAT) and ground potential (GND), or may be connected to two poles of the battery.

FIG. 7 shows control of the control current IC of the electromagnetic suction valve 110 by the control method of the high-pressure fuel supply pump according to the first embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

At the first point of time t1, before the compression plunger 130 reaches BDC and until time t2 (t2−t1 = ΔT1), the control current IC is supplied to the electromagnetic suction valve 110 to open the valve. To increase to the value IC1, an initial voltage signal IVP is supplied to the solenoid 112 of the electromagnetic intake valve 110 (eg, a PWM voltage signal having a 100% duty cycle).

From time t2, the solenoid 112 of the electromagnetic suction valve 110 has a duty cycle of less than 100%, in particular such that the control current is reduced from the control current value IC1 to a lower control current value IC2, and the valve is fully opened. Therefore, the PWM voltage signal VCF having a duty cycle set so that the control current IC is substantially held at the control current value IC2 is applied.

At the start of the compression stroke in which the compression plunger 130 starts to move from BDC toward TDC, the electromagnetic suction valve is held fully open, so that the control current value IC2 is maintained, that is, in the first embodiment of the present invention. control current value IC2, as can be the fuel leaking from the compression chamber 120 of the high-pressure fuel supply pump 100 through a solenoid inlet valve 110 fully open, after the compressed plunger 130 at the start of the compression stroke reaches BDC, the electromagnetic intake This represents a target control current value IT for holding the valve 110 in the fully opened position.

  FIG. 8 shows a comparison between the current control according to the first embodiment and the current control of the conventional example described in FIG. As described above, according to the conventional current control (see the broken line in FIG. 8), the control current IC is first increased to the target control value IT, and is then held substantially constant at the target control current IT. In contrast, according to the present invention, the control current IC is increased to the current control value IC1 and then decreased again to the control current value IC2 which is the target control current value IT.

In particular, in FIG. 8, the reduction of the control current IC from the control current IC1 to the control current value IC2 is performed after the electromagnetic suction valve starts to move from the fully closed position toward the fully open position. However, as can be seen in the lower row of FIG. 8, by reducing the control current IC, the moving speed of the electromagnetic suction valve toward the fully open position is reduced compared to the valve movement by the conventional current control. Thereby, when the suction valve member 111e contacts the suction valve seat 111d at time N2, a softer landing in the fully open position can be achieved. After time N2, the electromagnetic suction valve is held in the fully closed position by the magnetic force induced by the control current IC2 of the solenoid 112.

According to conventional current control, the intake valve member 111e hits the valve seat 111d at a higher speed at the initial time N1, thereby generating a significantly larger impact noise. According to the control according to the first embodiment, it is possible to effectively reduce the impact noise generated when the intake valve member 111e reaches the fully open position (when it comes into contact with the valve seat 111d).
[Second Embodiment]
FIG. 9 shows control of the control current IC of the electromagnetic suction valve 110 by the control method of the high-pressure fuel supply pump according to the second embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

Similar to the first embodiment, at time t1 until time t2, an initial voltage pulse IVP for increasing the control current IC of the solenoid 112 to the control current value IC1 is supplied. Similar to the first embodiment, a PWM voltage control signal VC1 for reducing the control current IC to the control current value IC2 is applied starting from time t2. This has the effect that the movement of the suction valve member 111e toward the fully open position is decelerated after time t2, or at least its acceleration is reduced.

In order to achieve an optimum deceleration of the movement of the suction valve member 111e towards the fully open position, the control current IC2 is sufficient to open and hold the standard electromagnetic suction valve 110 from mass production (open and open). That is, the duty cycle of the voltage control signal VC1 can be set so that a standard mass production electromagnetic intake valve is at a substantially minimum value (suitable for holding the valve open during the compression stroke). .

At that time, due to variations due to mass production, the magnetic force acting in the opening direction of the electromagnetic suction valve may become too small, the fluid force acting in the opening direction will soon become too small and / or acting in the closing direction. Since the urging force to be applied becomes too large, a situation occurs in which the voltage control signal VC1 and the control current value IC2 are not sufficient to move the suction valve member 111e to the fully open position before the time when the compression plunger 130 reaches BDC. Sometimes.

As a result, the electromagnetic suction valve 110 when the magnetic force begins to move upward again toward the TDC due to a gap that may occur between the anchor 111b and the core 114 when the compression plunger 130 reaches the BDC. May not be enough to be held open. Fuel flows toward the suction valve member 111e through the suction port 118, thereby as soon as leaking from the compression chamber 120 through the suction port 118 and the suction passage 117, the fluid force acting on the intake valve member 111e in the closing direction Can occur.

In the second embodiment, at time t3, a further PWM voltage control signal VCF with a higher duty cycle compared to the PWM voltage control signal VC1 causes the control current IC to reach a higher control current value before the compression plunger 130 reaches BDC. Applied to increase again to IC3. As a result, the electromagnetic intake valve 110 is fully opened before the compression plunger 130 reaches the BDC.

In the case of a mass-produced standard electromagnetic suction valve 110, the control current IC2 is already sufficient to smoothly land the suction valve member 111e on the valve seat 111d in the fully open position during the stroke between times t2 and t3. Thus, it may be set so that there is no gap between the anchor 111b and the core 114. As a result, even when the fluid force acting in the opening direction is reduced again before the compression plunger 130 reaches the BDC, the magnetic force generated by the control current IC2 of the solenoid 112 is held with the electromagnetic suction valve fully opened. Enough. In such a standard configuration, by increasing the control current IC from the control current value IC2 to the control current value IC3, the electromagnetic suction valve 110 is further held in the fully opened position, and thereby no impact noise is generated.

If the electromagnetic suction valve 110 is not fully opened during the stroke between the times t2 and t3 due to variations due to mass production, the suction valve member is increased by increasing the control current from the control current value IC2 to the control current value IC3. The magnetic force that attracts the anchor 111b and the core 114 is increased so that 111e is displaced to the fully open position. This may lead to a greater impact noise compared to the standard electromagnetic suction valve 110 which is already fully open between times t2 and t3 and has no variation due to mass production.

However, in the second embodiment, it is possible to ensure that the electromagnetic suction valve 110 reaches the fully open position before the compression plunger 130 reaches the BDC, so that it opens even when there is variation due to mass production. Can be retained.

FIG. 10 schematically illustrates a gradual change in control current and valve movement according to a second embodiment of the present invention. FIG. 10 shows that the control current IC is first increased to the control current value IC1, then decreased to the control current value IC2 after the start of the movement of the electromagnetic suction valve, and further compressed before the compression plunger 130 reaches BDC. The current control is again increased to the current control value IC3 which is the final target control current value IT for holding the electromagnetic suction valve in the fully open position after the plunger 130 reaches the bottom dead center BDC.

In the lower row of FIG. 10, during the process of applying the control current value IC2 (between times t2 and t3 in FIG. 9), the fluid force is reduced just before the compression plunger 130 reaches BDC. The valve movement for the electromagnetic suction valve moving again towards the fully closed position is shown. However, immediately before the compression plunger 130 reaches BDC, the control current IC increases from the current control value IC2 to the control current value IC3, so that it can still be displaced to the fully open position. Here, at time N3, impact noise is generated when the electromagnetic suction valve reaches the fully open position. However, even when there is variation due to mass production, it can be ensured that the electromagnetic suction valve is held in the fully open position after the compression plunger 130 reaches the BDC.

As shown in FIG. 10, even when using the control according to the second embodiment, the standard mass-produced electromagnetic intake valve 110 shows the same behavior as shown in FIG. Due to the decrease of the control current IC from the control current value IC1 to the control current value IC2, it is possible to significantly reduce the impact noise and achieve the soft landing at the fully open position at time N2. The broken line in FIG. 10 also corresponds to the conventional current control as described in FIG.

As described above, according to the current control according to the second embodiment, when there is a variation due to mass production, the electromagnetic suction valve 110 is not fully opened by the reduced current control value IC2, and then the control current IC is changed again. Since it is fully opened by increasing it to a high target control current value IT, in some cases, a larger impact noise is generated, but the reliability of control is increased.
[Third Embodiment]
FIG. 11 shows control of the control current IC of the electromagnetic suction valve 110 by the control method of the high-pressure fuel supply pump according to the third embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

According to the third embodiment, the increase of the control current IC from the current control value IC2 to the final target control current value IT for keeping the electromagnetic suction valve fully open after the compression plunger 130 reaches BDC is as follows. Even if there is a variation due to mass production as described above in the second embodiment, it is increased only gradually in order to ensure soft landing at the fully open position.

According to the third embodiment, as shown in the upper column of FIG. 11, the plurality of PWM voltage controls VC1, VC2, VC3, and VCF are applied to the initial voltage pulse IVP at times t2, t3, t4, t5. It is applied later. Here, the duty cycle of the plurality of PWM voltage control signals from the PWM voltage control signal VC1 to the final voltage control signal VCF is to keep the electromagnetic suction valve 110 fully opened after the compression plunger 130 reaches BDC. In order to continuously increase the control current IC from the control current value IC2 to the control current value IC3, to the control current value IC4, and to the final target control current value IT, the control current IC is gradually increased by stepwise PWM control.
[Fourth Embodiment]
FIG. 12 shows control of the control current IC of the electromagnetic suction valve 110 by the control method of the high-pressure fuel supply pump according to the fourth embodiment of the present invention. The upper row shows the PWM control voltage signal VC for controlling the control current IC as in the lower row of FIG.

  According to FIG. 12, the control current IC is increased from the control current value IC2 to the final target control current value IT. However, unlike the third embodiment described above with reference to FIG. 11, the duty cycle of the PWM voltage control signal VC1 is between the initial voltage pulse IVP and the final PWM voltage control signal VCF before the compression plunger 130 reaches BDC. Then, the time t2 and the time t3 are increased so as to continuously increase the control current value IC2 to the final target control current value IT (or repeatedly increase the duration of the ON state and / or decrease the duration of the OFF state). It is continuously increased between (t3−t2 = ΔT2).

The influence of control of the control current IC of the solenoid 112 of the electromagnetic suction valve 110 according to the fourth embodiment of the present invention is shown in FIG. FIG. 13 shows in the upper row that the control current value IC2 is continuously increased to the final target control current value IT. The broken line still points to the conventional control as shown in FIG. The bottom row of FIG. 13 shows that the mass produced standard electromagnetic suction valve 110 behaves in the same manner as described above in FIG.

However, if there is a variation due to mass production, the second control current value IC2 may not be sufficient to fully open the electromagnetic suction valve 110, the control current is continuously increased, so that the compression plunger 130 becomes BDC. Before reaching, it is ensured that at time N4, the electromagnetic suction valve still reaches the fully open position and the impact velocity is lower than in the second embodiment.

The continuous increase of the control current value from the control current value IC2 to the target control current value IT enables a smooth landing at the time N4 of the suction valve member 111e in the suction valve seat 111d, thereby resulting in mass production. Even when there is a variation, it is possible to significantly reduce the impact noise. Since the increase of the control current from the control current value IC2 to the target control current value IT is performed at a lower speed than in the case of the second embodiment, using stepped PWM voltage control has a similar advantage.

FIG. 14 shows a comparison between the conventional control method as shown in FIG. 3 and the control method according to the fourth embodiment of the present invention. The dashed curve labeled “A” in FIG. 14 shows a standard mass production valve movement that is controlled to land smoothly with significantly reduced impact noise in the fully open position. As shown in FIGS. 12 and 13, the control current value IC2 decreases, so that the moving speed of the electromagnetic suction valve before reaching the fully open position can be reduced. The broken-line curve labeled “B” is not yet fully opened by the reduced control current value IC2, but immediately after that, the electromagnetic suction valve is fully opened by increasing the control current to the target control current value IT. The valve movement is shown.
[Plunger separation type electromagnetic suction valve]
FIG. 15 schematically shows an example of the separation type electromagnetic intake valve 210. Unlike the electromagnetic suction valve 110 shown in FIGS. 2A and 2B, the suction valve member 211e and the suction valve plunger 211a of the electromagnetic suction valve 210 are formed as separate bodies that can move independently. The suction valve plunger 211a is biased in the closing direction by a biasing member, for example, a spring 213a, and the suction valve member 211e is biased in the closing direction by another biasing member, for example, a spring 213b.

Anchor 211b is at one end of the intake valve plunger 211a, i.e., the intake valve plunger 211a is provided at the end of the suction valve plunger 211a on the opposite side to the side that can contact the intake valve member 211e. When current is applied to the solenoid 212, the solenoid valve anchor 211b and the core 214 are attracted to each other by magnetic force, so that the anchor 211b and the core 214 come into contact with each other and the intake valve plunger 2111a is moved until the displacement is limited. Displaced in the direction of opening the valve. In this position, the suction valve plunger 211a can hold the suction valve member 211e in the fully open position against the urging force of the springs 213a and 213b.

As long as the current is applied to the solenoid 212, the anchor 211b and core 214 remain attracted to each other to remain in contact, thereby it can be kept open the valve, the intake valve member 211e is It is held away from the suction valve seat 211d. Thus, as indicated by the arrow, the low pressure fuel is removed from the low pressure system via the intake passage 217 and fed to the compression chamber 120 of the high pressure fuel supply pump via the intake port 218 as further indicated by the arrow. Can do.

As long as the valve is held open by applying an electric current to the solenoid 212, the unpressurized fuel is present when the compression plunger 130 in the compression chamber 120 is in an upward stroke that reduces the volume of the compression chamber 120. In some cases, the air may leak from the suction port 218 to the low-pressure fuel system through the suction passage 217 in the reverse direction.

However, when the current is not applied to the solenoid 212, the spring 213a and 213b until the suction valve member 211e to close the valve is in contact with the suction valve seat 211d, the valve intake valve plunger 211a and the suction valve member 213b Energize in the closing direction. The suction valve plunger 211a may be further displaced in the closing direction by the biasing force of the spring 213a.

In the upward stroke of the compression plunger 130 in the compression chamber 120, the fuel cannot be leaked through the suction port 218, and the fuel is pressurized in the compression chamber 120 so as to be discharged at a high pressure through the discharge valve 140. The On the other hand, when no current is applied to the solenoid 212 and the compression plunger 130 is in the suction stroke (downward stroke) so as to increase the volume of the compression chamber 120, the fuel pressure in the compression chamber 120 is low. Since the pressure is reduced as compared with the pressure of the fuel in the suction passage 217 connected to the fuel system, even if no current is applied to the solenoid 212, the suction valve member 211e is opened in the direction to open the valve against the biasing force of the spring 213b. A fluid force is generated that can cause a displacement of. Fluid forces, a sufficient displacement of the intake valve member 211e, or can be generated not sufficient displacement of the suction valve member 211e to the fully open position.

When a current is applied to the solenoid 212 and energized, the suction valve plunger 211a is displaced in the valve opening direction by the magnetic force. As a result, generally, according to the conventional control of such a separation type electromagnetic suction valve, two impact noises are generated. The first impact noise occurs when the intake valve plunger 211a hits the intake valve member 211e, and the second impact noise occurs when the electromagnetic intake valve reaches the fully open position.

FIG. 16 shows an example of conventional control of a normally closed electromagnetic intake valve related to the background of the present invention for a separate electromagnetic intake valve. The top row shows the movement of the compression plunger between TDC and BDC. The second row from the top shows the gradual change of the control current IC, and the bottom row shows the corresponding movement of the suction valve member 211e and the suction valve plunger 211a. FIG. 16 shows the occurrence of two impact noises generated continuously at times N5 and N6.

The impact noise at time N6, i.e. when the electromagnetic suction valve reaches the fully open position, can be greatly reduced by current control according to the invention as described above, in particular according to any of the embodiments described above. Furthermore, in the following, another embodiment will be described which additionally makes it possible to reduce the first impact noise generated when the intake valve plunger 211a hits the intake valve member 211e.
[Fifth Embodiment]
FIG. 17 schematically illustrates a gradual change in control current IC and valve movement according to a fifth embodiment of the present invention. The top row shows the movement of the compression plunger between TDC and BDC. The second row from the top shows a gradual change in the control current IC (the broken line corresponds to the conventional control described above in FIG. 16), and the bottom row shows the corresponding movement of the suction valve member 111e and the suction valve plunger 111a. .

  Before the compression plunger 130 reaches the BDC, the control current is increased to the control current value IC1, then decreased to the control current value IC2, and then the final target control current value, similar to the control current according to the second embodiment. Increased to IT again. Alternatively, the control current according to the first, third or fourth embodiment can be used.

Further, for example, as described above, the timing of starting the increase of the control current IC by setting the timing of the initial voltage pulse IVP is after the suction valve member 111e has already started its movement in the opening direction by the fluid force. The timing is set. As shown in FIG. 17, the timing of starting the increase in the control current IC is suction valve plunger 111a being displaced in the opening direction by the increase of the magnetic force, suction when already moving in the opening direction by the fluid force It is set so as to come into contact with the valve member 111e. Therefore, the first impact noise that is generally generated when the intake valve plunger 111a hits the intake valve member 111e can be greatly reduced.
[Sixth Embodiment]
FIG. 18 shows a control method for controlling the control current of the solenoid 112 according to the sixth embodiment of the present invention. The control before the time when the compression plunger 130 reaches BDC in FIG. 18 completely corresponds to the control as described in FIG. 9 with respect to the second embodiment of the present invention.

However, when the compression plunger 130 reaches the BDC and then moves up again toward the TDC, the control method according to the sixth embodiment is further illustrated in FIG. 18 at time t4 after the compression plunger 130 reaches the BDC. The control current IC3 is reduced to a lower target control current value IT which is still sufficient to hold the electromagnetic suction valve in the fully open position even during the compression stroke in which the compression plunger 130 moves toward TDC. Applying a final PWM control signal VCF having a smaller duty cycle than the previously applied PWM voltage control signal VC2.

In addition to the advantages of the second embodiment, the sixth embodiment results in a reduced target control current value IT that reduces energy consumption and maintains the electromagnetic suction valve to be held in the fully open position. Further, it becomes possible to further avoid the thermal overload of the solenoid 112.

  FIG. 19 shows a gradual change of an alternative example of the PWM voltage control signal. In the embodiments described above, PWM control of the solenoid (s) has been exemplarily achieved by single switch or dual switch PWM control. When single switch control is used, the PWM frequency is generally very low, typically 100-800 Hz, preferably 300-600 Hz, more preferably equal to 400 Hz or at least about 400 Hz (equivalent to a period of 2.5 ms). ).

Since this is relatively slow compared to the mechanical operation of the electromagnetic inlet valve, generally electromagnetic intake valve reaches the mechanical locking portions after PWM cycle the first few times. In such a case, “soft landing” of the electromagnetic suction valve in the fully open position (that is, there is almost no impact noise by reducing the impact speed to almost zero) can be realized. That this is to use a duty cycle different for the first few cycles, then to ensure that the electromagnetic intake valve reaches the full open position before the compression stroke starts, to increase the duty cycle prior to reaching BDC Can be achieved.

The actual value of the first PWM period is determined by taking into account the so-called P_ON timing (i.e., the time at which initial energization of the solenoid (s) relative to the time of the pump TDC) and engine speed are It can be determined for operating conditions. In order to minimize noise generation, the electromagnetic suction valve preferably reaches the mechanical lock during the time when the PWM voltage control signal is in the off state or at the start of the pulse.

The method described above can be used during the calibration process to allow determination of the moment when the electromagnetic suction valve in the fully open position lands. Under any conditions, switching to a higher PWM duty cycle (between BDC and TDC) prior to the start of the compression cycle will cause electromagnetic changes regardless of any changes in operating conditions or variations due to mass production. It is ensured that the intake valve reaches the fully open position.

The calibration procedure may involve determining several distinct PWM duty cycles (for the first few cycles). FIG. 10 exemplarily shows four duty cycles “Duty 1”, “Duty 2”, “Duty 3”, and “Duty 4” (displayed as “Initial PWM”). In general, the electromagnetic intake valve can reach the fully open position within the first 2, 3, or 4 cycles unless the value is too low, and if the value is low, a sufficiently high duty cycle, It is moved to the fully open position by a final PWM duty cycle, preferably having a duty cycle of about 95%.

  Thus, one possible configuration is to use stepped PWM control, and for the duration of the entire initial PWM, “Duty1” = “Duty2” = “Duty3” = “Duty4” (eg, 75% Duty cycle). Also, the final PWM duty cycle is about 95% (or another sufficiently high value of 85% to 100% duty cycle, preferably 90% to 100% duty cycle).

Another possible configuration is a constant increase in the PWM voltage signal duty cycle in the initial PWM duration, or a large initial duty cycle (such as an initial voltage pulse) followed by a second period (Duty2). Such as those using a low duty cycle. A large duty cycle should be used before the BDC is reached to ensure that the electromagnetic intake valve is fully open before the start of the compression stroke. This algorithm can be generalized as follows.

Duty1
Duty2 = Duty1 + a
Duty3 = Duty2 + b
Duty4 = Duty3 + c
Where a, b, c,... Can be determined during the calibration process (typically ± about 5%). Next, a constant large duty cycle is used before the BDC is reached.

Duty final = DutyF (eg, 95% duty cycle)
The structural features, components, and specific details of the embodiments described above can be interchanged or combined to form further embodiments optimized for individual applications. To the extent that such modifications are apparent to those skilled in the art, it is intended to be implicitly disclosed by the above description without explicitly specifying every possible combination.

100: High pressure fuel supply pump 110: Electromagnetic suction valve 111a: Suction valve plunger 111e: Suction valve member 120: Compression chamber 130: Compression plunger 700: Control device IC: Control current IC1: First control current value IC2: Second Control current value IC3: third control current value IT: target control current value TDC: top dead center BDC: bottom dead center VC: electromagnetic suction valve voltage signal IVP: initial voltage pulse VC1: first PWM voltage signal VC2; VC3; VCF: second PWM voltage signal ΔT1: duration of applying an initial voltage pulse (IVP) ΔT2: duration of applying a first PWM voltage signal (VC1) t1: applying an initial voltage pulse (IVP) Start timing t2: Timing (ΔT2) timing t3; t4; t5: Second PWM voltage signal for applying the first PWM voltage signal (VC1) Applying a timing .DELTA.T3; .DELTA.T4: duration for applying the second PWM voltage signal

Claims (19)

A normally closed electromagnetic intake valve that is opened or held open by a magnetic force, and comprising controlling a control current of the electromagnetic intake valve to open the electromagnetic intake valve; Control of a high pressure fuel supply pump for supplying pressurized fuel to an internal combustion engine, wherein the step of controlling a control current includes the step of increasing the control current to a first control current value for energizing the electromagnetic intake valve In the method
The step of controlling the control current of the electromagnetic intake valve to open the electromagnetic intake valve further reduces the control current from the first control current value to a second control current value lower than the first control current value. And a control method for the high-pressure fuel supply pump.   2. The method of controlling a high-pressure fuel supply pump according to claim 1, wherein the control current is reduced from the first control current value to the second control current value before the electromagnetic intake valve is fully opened. A control method for a high-pressure fuel supply pump.   3. The method for controlling a high-pressure fuel supply pump according to claim 1, wherein the second control current value is a non-zero current value lower than the first control current value, or the second control current. A control method for a high-pressure fuel supply pump, characterized in that the value is zero or at least approximately zero.   The control method of the high pressure fuel supply pump according to any one of claims 1 to 3, wherein the control current of the electromagnetic intake valve for opening the electromagnetic intake valve is the second control current. The method for controlling a high-pressure fuel supply pump further comprising the step of increasing the control current value to a third control current value higher than the second control current value. 5. The method of controlling a high pressure fuel supply pump according to claim 4, wherein the high pressure fuel supply pump reciprocates between the bottom dead center and the top dead center in the compression chamber, and the electromagnetic chamber. A compression plunger that pressurizes fuel in the compression chamber when moving to top dead center when the intake valve is fully open;
The step of increasing the control current from the second control current value to the third control current value in order to ensure that the electromagnetic intake valve is fully opened before the compression plunger reaches the bottom dead center. The method for controlling the high-pressure fuel supply pump is performed before the compression plunger reaches the bottom dead center. 6. The control method for a high-pressure fuel supply pump according to claim 4 or 5, wherein the third control current value to be held holds the electromagnetic intake valve fully open after the compression plunger reaches the bottom dead center. Is the target control current value to be
Since the step of controlling the control current of the electromagnetic intake valve is held with the electromagnetic intake valve fully opened, the third control current value is reduced to the target control current value after the electromagnetic intake valve is fully opened. Steps,
The third control voltage value after the compression plunger has reached the bottom dead center is held at the electromagnetic intake valve since the electromagnetic intake valve is held fully open after the compression plunger has reached the bottom dead center. Further comprising reducing to a target control current value after the valve is fully open,
A control method for a high-pressure fuel supply pump, wherein the target control current value is lower than the third control current value in order to reduce energy consumption.   7. The method for controlling a high-pressure fuel supply pump according to claim 1, wherein the step of controlling the control current of the electromagnetic intake valve is a duty cycle of a PWM voltage signal supplied to the electromagnetic intake valve. And controlling the duty cycle and the frequency of the PWM voltage signal supplied to the electromagnetic intake valve.     The method for controlling a high-pressure fuel supply pump according to any one of claims 1 to 6, wherein the step of controlling the control current of the electromagnetic intake valve controls a value of a voltage signal of the electromagnetic intake valve. A control method for a high-pressure fuel supply pump. The method for controlling the high-pressure fuel supply pump according to any one of claims 1 to 8, wherein the step of controlling the control current of the electromagnetic intake valve comprises:
Applying an initial voltage pulse to increase the control current to the first control current value;
Applying the first PWM voltage signal after applying the initial voltage pulse to reduce the control current from the first control current value to the second control current value. Control method for high pressure fuel supply pump. The method for controlling the high-pressure fuel supply pump according to claim 9, wherein the step of controlling the control current of the electromagnetic intake valve comprises:
In order to increase the control current from the second control current value to a third control current value higher than the second control current value, a second PWM voltage signal is applied after applying the first PWM voltage signal. Further comprising applying
The method of controlling a high-pressure fuel supply pump, wherein the first PWM voltage signal has a smaller duty cycle than the second PWM voltage signal. The method for controlling a high-pressure fuel supply pump according to claim 10, wherein the first PWM voltage signal is switched to the second PWM voltage signal.
The first PWM voltage signal is changed to the second PWM voltage signal by stepped PWM control, and at least a third PWM after the first PWM voltage signal and before the second PWM voltage signal. A voltage signal is applied,
The high-pressure fuel is characterized in that a duty cycle of the third PWM voltage signal is larger than a duty cycle of the first PWM voltage signal and smaller than a duty cycle of the second PWM control voltage signal. Control method of supply pump. The method for controlling a high-pressure fuel supply pump according to claim 10, wherein the first PWM voltage signal is switched to the second PWM voltage signal.
The first PWM voltage signal is changed to the second PWM voltage signal by stepped PWM control, and at least a third PWM after the first PWM voltage signal and before the second PWM voltage signal. A voltage signal is applied,
A method for controlling a high pressure fuel supply pump, wherein the duty cycle of the first PWM voltage signal is increased continuously or repetitively to the duty cycle of the second PWM voltage signal by incremental PWM control. . The method for controlling the high-pressure fuel supply pump according to any one of claims 9 to 12, wherein the step of controlling the control current of the electromagnetic intake valve comprises:
Setting a timing t1 to start applying the initial voltage pulse;
Setting a duration ΔT1 for applying the initial voltage pulse;
At least one of applying the first PWM voltage signal and / or setting a timing t2 of a duration ΔT2 of applying the first PWM voltage signal;
The step of setting the timing and duration of the initial voltage pulse and the first PWM voltage signal is applied to the fluid force acting in the opening direction of the electromagnetic intake valve and the biasing force acting in the closing direction of the electromagnetic intake valve. And a control method for the high-pressure fuel supply pump, wherein the control is performed to control the magnetic force of the electromagnetic intake valve. The method of controlling a high pressure fuel supply pump according to claim 13, wherein the control current of the electromagnetic intake valve is controlled.
Further comprising setting a timing for applying the second PWM voltage signal and / or a duration for applying the second PWM voltage signal;
The step of setting the timing and duration of the initial voltage pulse, the first PWM voltage signal, and the second PWM voltage signal controls the magnetic force depending on the fluid force and the biasing force. The method for controlling the high-pressure fuel supply pump is characterized in that:   15. The control method for a high-pressure fuel supply pump according to claim 13 or 14, wherein the timing for applying the initial voltage pulse is set before the maximum fluid force acting in the opening direction of the electromagnetic intake valve is generated. A control method for a high-pressure fuel supply pump.   16. The method of controlling a high pressure fuel supply pump according to any one of claims 13 to 15, wherein the initial voltage pulse and the timing and duration of the first PWM voltage signal or the first and second PWM voltage signals. The step of setting is set so that the electromagnetic intake valve reaches its fully open position at a timing when the PWM control is in a low current condition. 17. The control method for a high-pressure fuel supply pump according to claim 1, wherein the electromagnetic intake valve has an intake valve member and an intake valve plunger formed as separate members. And the magnetic force of the electromagnetic intake valve acts on the intake valve plunger,
The timing at which the control current starts to increase to the first control current value in order to energize the electromagnetic intake valve is the timing after the intake valve member starts to move in the opening direction due to fluid force. A method for controlling a high-pressure fuel supply pump, wherein a plunger is set so as to come into contact with the intake valve member.   The control method of the high pressure fuel supply pump according to any one of claims 1 to 17, wherein the control device is configured to control a control current of the electromagnetic intake valve to open the electromagnetic intake valve. A control device for controlling a high-pressure fuel supply pump, characterized by supplying pressurized fuel to an internal combustion engine.   The control method of the high pressure fuel supply pump according to any one of claims 1 to 17, wherein the control device is configured to control a control current of the electromagnetic intake valve to open the electromagnetic intake valve. A computer program product comprising computer program code, characterized in that it is a control device, in particular comprising an engine control device.

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