JP4969611B2 - High pressure fuel pump control device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine device mounted on an automobile or the like, and more particularly to a high pressure fuel supply device including a high pressure fuel pump.

  Current automobiles are required to reduce exhaust gas substances such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) contained in automobile exhaust gas from the viewpoint of environmental conservation. In-cylinder injection engines have been developed for the purpose of reducing this. An in-cylinder injection engine performs fuel injection by a fuel injection valve directly into a combustion chamber of a cylinder, promotes combustion of injected fuel by reducing the particle size of fuel injected from the fuel injection valve, and emits exhaust gas. It aims to reduce substances and improve engine output.

  Here, in order to reduce the particle size of the fuel injected from the fuel injection valve, a means for increasing the pressure of the fuel is required, and various proposals have been made on the technology of a high-pressure fuel pump that pumps high-pressure fuel to the fuel injection valve. Has been.

  For example, Patent Document 1 proposes a technique related to a high-pressure fuel pump provided with a normally closed electromagnetic valve.

JP 2006-250086 A

  A high-pressure fuel pump equipped with a normally-closed solenoid valve calculates an appropriate energization start / end request phase in the high-pressure fuel pump control unit phase calculation unit, and starts energization according to the required phase in the control unit drive signal output unit. , Unintended pressure increase / decrease in the accumulator chamber (hereinafter referred to as common rail) will occur unless it is terminated. Combustion stability and exhaust gas will not be the target fuel pressure to achieve optimal combustion. Incurs performance degradation.

  The present invention has been made in view of such a problem, and an object of the present invention is to appropriately start energization in a control unit phase calculation unit in a high-pressure fuel pump device including a normally closed electromagnetic valve. The internal combustion engine contributes to stabilization of the fuel system, stabilization of combustion, and improvement of exhaust gas performance by calculating the end request phase and starting and stopping energization according to the required phase in the drive signal output unit in the control device. A high-pressure fuel pump control device is provided.

A suction passage of the fluid, and a discharge passage of the fluid, the compression chamber connecting said discharge passage and said suction passage, a pressure member for pumping fluid in the pressure chamber to the discharge passage, the discharge passage and provided with a discharge valve, wherein provided in the suction passage, the control apparatus for controlling a pump having a solenoid valve which opens when energized, demand values for the drive signal of the solenoid valve, oN signal output and / or Provided is a high-pressure fuel pump control device for an internal combustion engine, wherein a required value for the drive signal is calculated again before a predetermined timing of an OFF signal output scheduled phase.

  The high-pressure fuel pump control device for an internal combustion engine according to the present invention calculates an appropriate energization start / end request phase in the in-control device phase calculation unit, and the energization start / end in accordance with the requested phase in the in-control device drive signal output unit. Since it can be implemented, it can contribute to stabilization of the fuel system, stabilization of combustion, and improvement of exhaust gas performance.

1 is an overall configuration diagram of an engine including a high-pressure fuel pump control device for an internal combustion engine according to an embodiment. FIG. The internal block diagram of the engine control apparatus of FIG. The whole block diagram of the fuel system provided with the high-pressure fuel pump of FIG. FIG. 4 is a longitudinal sectional view of the high pressure fuel pump of FIG. 3. The operation | movement timing chart of the high pressure fuel pump of FIG. FIG. 6 is a supplementary explanatory diagram of the operation timing chart of FIG. 5. The control block diagram of this invention by the internal combustion engine control apparatus of FIG. The control block diagram of this invention by the internal combustion engine control apparatus of FIG. The control block diagram of this invention by the internal combustion engine control apparatus of FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. The control block diagram of this invention by the internal combustion engine control apparatus of FIG. The discharge amount characteristic of the high-pressure fuel pump of FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. The control state transition diagram of the present invention by the internal combustion engine control device of FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. The control block diagram of this invention by the internal combustion engine control apparatus of FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. FIG. 2 is a control time chart of the present invention by the internal combustion engine control device of FIG. 1. FIG. The figure explaining an example of the effect of this invention by the internal combustion engine control apparatus of FIG.

  Hereinafter, an embodiment of a high pressure fuel supply control apparatus for an internal combustion engine according to the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of the control system of the direct injection engine 507 of the present embodiment. The in-cylinder injection engine 507 has four cylinders, and here, one of them will be described. The air introduced into the cylinder 507b is taken from the inlet of the air cleaner 502, passes through an air flow meter (air flow sensor 503), passes through a throttle body 505 in which an electric throttle valve 505a for controlling the intake flow rate is accommodated, and a collector 506. to go into. The air sucked into the collector 506 is distributed to the intake pipes 501 connected to the cylinders 507b of the in-cylinder injection engine 507, and then guided to the combustion chamber 507c formed by the piston 507a, the cylinder 507b, and the like. The airflow sensor 503 outputs a signal representing the intake air flow rate to an engine control device (control unit 515) having the high-pressure fuel pump control device of the present embodiment. Further, a throttle sensor 504 for detecting the opening degree of the electric throttle valve 505 a is attached to the throttle body 505, and its signal is also output to the control unit 515.

On the other hand, fuel such as gasoline is primarily pressurized from a fuel tank 50 by a low-pressure fuel pump 51 and regulated to a constant pressure (for example, 3 kg / cm ² ) by a fuel pressure regulator 52, and also by a high-pressure fuel pump 1 described later. Secondary pressure is applied to a higher pressure (for example, 50 kg / cm ² ), and the fuel is injected into the combustion chamber 507 c from a fuel injection valve (hereinafter referred to as an injector 54) provided in each cylinder 507 b via the common rail 53. The fuel injected into the combustion chamber 507 c is ignited by the ignition plug 508 by the ignition signal that has been increased in voltage by the ignition coil 522.

  A crank angle sensor (hereinafter referred to as a position sensor 516) attached to the crankshaft 507d of the direct injection engine 507 outputs a signal representing the rotational position of the crankshaft 507d to the control unit 515. A cam angle sensor (hereinafter referred to as a phase sensor 511) attached to a cam shaft (not shown) provided in a mechanism for changing the opening / closing timing of the exhaust valve 526 receives an angle signal indicating the rotational position of the cam shaft. In addition to being output to the control unit 515, an angle signal indicating the rotational position of the pump drive cam 100 of the high-pressure fuel pump 1 that rotates with the rotation of the cam shaft of the exhaust valve 526 is also output to the control unit 515.

  The main part of the control unit 515 is shown in FIG. The control unit 515 includes an MPU 603, an EP-ROM 602, a RAM 604, an I / O LSI 601 including an A / D converter, and the like, and includes a position sensor 516, a phase sensor 511, a water temperature sensor 517, an accelerator sensor (not shown), an air-fuel ratio sensor. 518, an airflow sensor 503, a fuel pressure sensor 56, and signals from various sensors including an ignition switch (not shown) are input as inputs. Thereafter, predetermined calculation processing is executed, and various control signals calculated as the calculation results are sent to the high-pressure pump solenoid 200, the low-pressure fuel pump 51, each injector 54, the ignition coil 522, the electric throttle valve 505a, etc., which are actuators. The fuel supply amount is controlled, the fuel injection amount is controlled, the ignition timing is controlled, and the like.

  FIG. 3 is an overall configuration diagram of a fuel system including the high-pressure fuel pump 1, and FIG. 4 is a longitudinal sectional view of the high-pressure fuel pump 1.

  The high-pressure fuel pump 1 pressurizes fuel from the fuel tank 50 and pumps high-pressure fuel to the common rail 53, and a fuel intake passage 10, a fuel discharge passage 11, and a fuel pressurization chamber 12 are formed. In the fuel pressurizing chamber 12, a plunger 2 as a pressurizing member is slidably held. The fuel discharge passage 11 is provided with a fuel discharge valve 6 in order to prevent the high-pressure fuel on the downstream side from flowing back into the pressurizing chamber. The fuel intake passage 10 is provided with an electromagnetic valve 8 that controls the intake of fuel. The electromagnetic valve 8 is a normally closed type electromagnetic valve, and a force acts in the valve closing direction when not energized, and a force acts in the valve opening direction when energized.

  The fuel is led from the fuel tank 50 to the fuel inlet (connected to the fuel intake passage 10) of the high-pressure fuel pump 1 by the low-pressure fuel pump 51, with the fuel pressure regulator 52 regulating the pressure. Thereafter, the pressure is increased by the high-pressure fuel pump 1 and is fed from the fuel discharge port to the common rail 53 through the fuel discharge passage.

  The common rail 53 is provided with injectors 54 (four in this embodiment), a fuel pressure sensor 56, and a pressure adjustment valve (hereinafter referred to as a relief valve 55). The relief valve 55 is opened when the fuel pressure in the common rail 53 exceeds a predetermined value, and prevents damage to the high-pressure piping system.

  The injector 54 is attached to each cylinder of the engine, and injects fuel according to a drive current (control signal) given from the control unit 515. The fuel pressure sensor 56 outputs the acquired pressure data to the control unit 515. The control unit 515 calculates an appropriate fuel injection amount, fuel pressure, etc. based on engine state quantities (for example, crank rotation angle, throttle opening, engine speed, fuel pressure, etc.) obtained from various sensors, and the pump 1 or injector 54 is controlled.

  The plunger 2 reciprocates through the lifter 3 pressed against the pump drive cam 100 that rotates as the cam shaft of the exhaust valve 526 in the engine 507 rotates, thereby changing the volume of the fuel pressurizing chamber 12. When the plunger 2 descends and the volume of the pressurizing chamber 12 increases, the electromagnetic valve 8 opens and fuel flows into the pressurizing chamber 12 from the fuel suction passage 10. Hereinafter, the stroke in which the plunger 2 descends is referred to as an intake stroke. When the plunger 2 is raised and the electromagnetic valve 8 is closed, the fuel in the pressurizing chamber 12 is pressurized, and the fuel discharge valve 6 is pushed open to be pumped to the common rail 53. The fuel discharge valve 6 is a check valve and has a structure in which fuel does not flow from the common rail 53 toward the fuel discharge passage. Hereinafter, the stroke in which the plunger 2 moves up is referred to as a compression stroke.

  FIG. 5 shows an operation timing chart of the high-pressure fuel pump 1. The actual stroke (actual position) of the plunger 2 driven by the pump drive cam 100 is a curve as shown in the lower diagram of FIG. 6, but in order to make the positions of the top dead center and the bottom dead center easy to understand, Hereinafter, the stroke of the plunger 2 is expressed linearly as shown in the upper diagram of FIG.

  If the electromagnetic valve 8 is closed during the compression stroke, the fuel sucked into the pressurizing chamber 12 during the suction stroke is pressurized and discharged to the common rail 53 side. Further, since the pressure in the fuel intake passage 10 is lower than the pressure in the common rail 53, if the electromagnetic valve 8 is opened during the compression stroke, the fuel is pushed back toward the intake passage 10 during that time, and the pressure is increased. The fuel in the chamber 12 is not discharged to the common rail 53 side. Thus, the fuel discharge of the pump 1 is operated by opening and closing the electromagnetic valve 8. Opening and closing of the electromagnetic valve 8 is controlled by the control unit 515.

  The electromagnetic valve 8 includes a valve body 5, a spring 92 that biases the valve body 5 in the valve closing direction, a solenoid 200, and an anchor 91 as components. When a current flows through the solenoid 200, an electromagnetic force is generated in the anchor 91 and is drawn to the right side in the figure, and the valve body 5 formed integrally with the anchor 91 is opened. When no current flows through the solenoid 200, the valve body 5 is closed by the spring 92 that biases the valve body 5 in the valve closing direction. The electromagnetic valve 8 is a valve having a structure that closes in a state where no driving current flows, and is therefore referred to as a normally closed electromagnetic valve.

  During the intake stroke, the pressure in the fuel pressurizing chamber 12 becomes lower than the pressure in the fuel intake passage 10, and the fuel in the intake passage 10 pushes the valve body 5 open by the pressure difference, and the fuel enters the pressurizing chamber 12. Inhaled. At this time, the spring 92 is installed so that the valve body 5 is pulled in the valve closing direction, but it is designed so that the fuel can push the valve body open by a pressure difference. In this case, the valve body 5 becomes easier to open.

  On the other hand, the pressure in the pressurizing chamber 12 is higher than that in the suction passage 10 during the compression stroke, so that the valve body 5 receives a force in the valve closing direction due to the pressure difference. Here, if the drive current does not flow through the solenoid 200, the valve body 5 is closed by a spring force or the like that biases the valve body 5 in the valve closing direction. On the other hand, if a driving current flows through the solenoid 200 and a sufficient magnetic attractive force is generated, the valve element 5 is opened by the magnetic attractive force.

  Therefore, when the drive current starts to be applied to the solenoid 200 of the electromagnetic valve 8 during the intake stroke and continues to be applied even during the compression stroke, the valve body 5 is held in the opened state. Meanwhile, the fuel in the pressurizing chamber 12 flows back into the fuel intake passage 10, so that the fuel is not pumped into the common rail. On the other hand, when the drive current is stopped at a certain timing during the compression stroke, the valve body 5 is closed and the fuel in the pressurizing chamber 12 is pressurized and discharged to the discharge passage 11 side. When the timing to stop applying the drive current is early, the volume of the pressurized fuel is large, and when the timing is late, the volume of the pressurized fuel is small. Therefore, the control unit 515 can control the discharge flow rate of the pump 1 by controlling the closing timing of the valve body 5.

  Further, the control unit 515 calculates an appropriate energization OFF timing based on the signal from the fuel pressure sensor 56, and controls the solenoid 200, so that the pressure of the common rail 53 can be feedback controlled to the target value.

  FIG. 7 is an example of a control block diagram of the high-pressure fuel pump 1 implemented by the MPU 603 of the control unit 515 having the high-pressure fuel pump control device. The high-pressure fuel pump control device filters the signal from the fuel pressure sensor 56 to output the actual fuel pressure, fuel pressure input processing means 701, and calculates the target fuel pressure that calculates the optimum target fuel pressure for the operating point from the engine speed and load. Means 702, pump control angle calculation means 703 for calculating a phase parameter for controlling the pump discharge flow rate from the actual fuel pressure and the target fuel pressure, and a parameter of the duty signal which is a pump drive signal from the battery voltage and the engine speed. From the pump control DUTY calculating means 704 to calculate, the pump state transition judging means 705 for judging the state of the in-cylinder injection engine 507 and making a transition to the pump control mode, and the solenoid driving means 706 for giving the current generated from the duty signal to the solenoid 200 Composed.

  FIG. 8 shows an aspect of the pump control angle calculation unit 703. The pump control angle calculation unit 703 includes an energization start angle calculation unit 801 and an energization end angle calculation unit 802.

  FIG. 9 shows one mode of the energization start angle calculation means 801. The basic energization start angle STANGMAP is calculated from the basic energization start angle calculation map 901 with the engine speed and the battery voltage as inputs, and the energization start angle is corrected by correcting the phase difference EXCAMADV by the variable valve timing mechanism of the pump drive camshaft. Calculate STANG.

  The correction of the phase difference by the variable valve timing mechanism is performed by subtracting when operating on the advance side with respect to the operating angle 0 position, and adding if the variable valve timing mechanism operating on the retard side. In this embodiment, a variable valve timing mechanism that operates on the retard side is assumed. Hereinafter, in the pump control phase parameter, the part that requires the phase difference correction by the variable valve timing mechanism has the same concept.

  FIG. 10 shows a method for setting the basic energization start angle STANGMAP. The basic energization start angle STANGMAP is equal to the energization start angle STANG when the phase difference due to the variable valve timing mechanism is zero. Since this pump is of a normally closed type, if there is no force that can open the solenoid valve 8 by the bottom dead center of the pump plunger, the solenoid valve 8 is closed and full discharge is performed.

  When the timing at which the fuel in the fuel pressurizing chamber 12 is pressurized by the plunger 2 is earlier than the timing at which the valve is opened, the force between the fuel pressurizing chamber 12 and the fuel intake passage 10 is greater than the force by which the valve is opened by the drive current. Since the force for closing the valve is increased due to the pressure difference (especially when the fuel is gasoline, the pressure in the fuel pressurizing chamber 12 immediately increases due to the rise of the plunger 2), the valve cannot be opened. This is because the force for opening the valve by the drive current cannot be increased so much. Under such circumstances, regardless of the fuel discharge amount calculated by the control unit 515, all of the fuel sucked into the fuel pressurizing chamber by raising the plunger 2 opens the discharge valve and flows into the common rail 53. become.

  For this reason, if the energization start angle is not accurately controlled in accordance with the operating state of the internal combustion engine, an unintended boosted state occurs, leading to deterioration of the combustion state and exhaust gas performance. For this reason, the inventor pays attention to means for improving the control accuracy of the energization start angle. Also, if the energization start angle is not made variable and energization is started from the top dead center of the pump plunger, it will give more electromagnetic valve opening force generation time than necessary, increasing the power consumption of the pump solenoid, This leads to an increase in the calorific value.

  The force capable of opening the valve increases in proportion to the rotational speed, and is a force that is superior to the force that works in the valve closing direction before the pressure in the fuel pressurizing chamber 12 is increased by the plunger 2. It is. Therefore, since the force generated in the solenoid is proportional to the current, it is necessary that a current greater than a certain value flows in the solenoid 200 before the pump bottom dead center. The time until the constant value is reached depends on the voltage of the battery that is a power source for the solenoid 200, and the constant value depends on the rotational speed. Therefore, the basic energization start angle calculation map 901 includes the engine rotational speed and the battery. Input the voltage.

  In addition, the time required for the current flowing through the solenoid 200 to reach a certain value is required to be within the suction stroke period in view of the operating characteristics of the pump. Therefore, the energization start angle range, that is, the angle range required to output the ON signal is basically within the pump suction stroke.

  In addition, the pump drive cam has phase variations during assembly. For this reason, even when the pump has a variation on the most advanced angle side, by setting so that a current of a certain value or more flows through the solenoid 200 by the bottom dead center of the pump, an unintended boosting even when the cam assembly has a variation. The state can be avoided. As a setting method considering variation, there is a method of setting the basic energization start angle STANGMAP by including variation.

  FIG. 11 shows an aspect of the energization end angle calculation unit 802. The discharge amount of this pump is controlled by changing the energization end angle. A basic angle BASANG is calculated from a basic angle map 1101 with the injection amount from the injector and the engine speed as inputs. BASANG sets the valve closing angle corresponding to the discharge required discharge amount in the steady operation state.

  FIG. 12 shows a method for setting the basic angle BASANG. FIG. 12 is a diagram showing the discharge amount of the high-pressure fuel pump with respect to the valve closing timing. In this pump, the discharge amount decreases as the solenoid valve closing timing approaches the top dead center of the plunger. Further, the discharge amount of the high-pressure fuel pump changes because the discharge efficiency varies depending on the engine speed. Therefore, the basic angle BASANG changes depending on the rotation speed. For this reason, it is possible to improve control responsiveness by calculating the basic angle BASANG from a map in which the injection amount by the injector and the engine speed are input.

  The fuel pressure F / B control calculation unit 1102 calculates the reference angle REFANG by adding the F / B component calculated from the target fuel pressure and the actual fuel pressure to the basic angle BASANG. The reference angle REFANG indicates an angle at which the electromagnetic valve 8 from the reference REF is desired to be closed when it is assumed that there is no variable valve timing operation. Here, the reference REF is a position serving as a reference point for phase control. In the control unit 515, it is necessary to set a reference point in order to output the requested phase.

  The energization end angle OFFANG is calculated by adding / subtracting the valve closing delay PUMDLY and the variable valve timing operating angle calculated from the valve closing delay calculation map 1103 to which the REFANG and the engine speed are input to the reference angle REFANG. The reason why REFANG and the engine speed are used for the valve closing delay PUMDLY is that the fluid force generated in the pump differs depending on the valve closing timing and the engine speed.

  OFFANG has an output forcible end angle CPOFFANG as an upper limit value. CPOFFANG is a value obtained by adding the variable valve timing operating angle from the map value having the rotational speed and the battery voltage as inputs.

  FIG. 13 shows a method for setting the forced output end angle CPOFFANG. The purpose of CPOFFANG is to stop energization in an angular region where no discharge occurs even when energization is stopped, thereby reducing power consumption and preventing the solenoid 200 from generating heat. For this reason, it is necessary to accurately control the output forced end angle CPOFFANG according to the operating conditions. As shown in FIG. 13, even if the drive signal is stopped before the top dead center, there is a valve closing delay, so that the valve is opened to the vicinity of the top dead center, and the pump is in a non-discharge operation.

  The output forced end angle CPOFFANG is also used at the time of fuel cut where pump non-discharge operation is required, and the energization to the solenoid is ended at this angle. As a result, it is possible to reduce power consumption and prevent the solenoid 200 from generating heat compared to creating a non-discharge operation state by controlling all energization of the solenoid 200.

  FIG. 14 is a state transition diagram showing an aspect of the pump state transition determination unit 705. The control block includes A control, B control, feedback control (hereinafter referred to as F / B control), and fuel cut control (hereinafter referred to as F / C control).

  The A control is a default control, and if the engine is rotating at start-up, the pump performs full discharge. The purpose of the B control is to prevent a boost before the REF signal is recognized when the residual pressure in the common rail is high. The F / B control is aimed at controlling to the target fuel pressure, and the F / C control is stopped for the purpose of preventing the common rail internal combustion pressure from being raised during F / C.

  First, when the ignition switch is switched from OFF to ON and the MPU 603 of the control unit 515 is reset, the A control block 1402 enters the non-energized control state, the pump state variable: PUMPMD = 0, and the solenoid 200 is energized. I will not.

  Next, when the starter switch is turned on, the engine 507 is in the cranking state, the crank angle signal CRANK is detected, and the fuel pressure in the common rail 53 is high, the condition 1 is satisfied and the B control block 1403 is set at equal intervals. A transition is made to the energization control state, and the pump state variable: PUMPMD = 1. Here, the B control block 1403 detects the pulse of the crank angle signal CRANK, but has not yet recognized the stroke of the plunger 2 as the REF signal, and has not yet performed the crank angle signal CRANK and the cam angle signal CAM. That is, the plunger phase of the high-pressure fuel pump 1 is not recognized at the bottom dead center position.

  Then, when the cranking state starts from the initial stage to the middle stage, the plunger phase of the crank angle signal CRANK and the cam angle signal CAM is determined, and the operation state in which the reference REF can be generated is established, the condition 3 is satisfied and the F / B control is performed. Transition is made to block 1404, and a pump state variable: PUMPMD = 2 is set, and a solenoid control signal is output so that the actual fuel pressure calculated by the fuel pressure input processing means 701 becomes the target fuel pressure calculated by the target fuel pressure calculating means 702 To do. FIG. 19 shows an example of a reference REF generation method. The crank angle sensor signal has a tooth missing portion (a portion having a wider interval than a normal crank angle sensor signal interval). The crank angle sensor from the time when the engine is started until the first missing tooth is recognized as the reference REF, and thereafter, the reference REF is generated from the crank angle sensor value at every fixed angle. Missing tooth recognition is determined from the crank angle sensor input interval.

  If the plunger phase is not determined during the B control and the REF signal cannot be generated, the condition 2 is satisfied, and the process proceeds to the A control.

  In addition, when the starter switch is turned on, the engine 507 is in a cranking state, and the fuel pressure in the common rail 53 is low, boosting is promoted by performing A control, the pump reference REF is generated, and If the target fuel pressure and the common rail internal combustion pressure are converging, the condition 4 is satisfied, and the process proceeds to the F / B control block 1404. This is because even when the pump reference REF is generated, if the common rail internal combustion pressure is significantly lower than the target fuel pressure, the pump will fully discharge if the A control is continued, so that boosting is promoted. This is because it becomes possible.

  Thereafter, the F / B control block 1404 continues unless an engine stall occurs. However, in the F / B control block 1404, when a fuel cut occurs due to vehicle deceleration or the like, the fuel injection from the injector 54 is not performed, and there is no decrease in the amount of fuel from the common rail 53, so Condition 5 is satisfied. A transition is made to the control block 1405 during F / C, the pump state variable: PUMPMD = 3, and fuel pumping from the high-pressure fuel pump 1 to the common rail 53 stops. Note that, from the F / C control block 1405, the condition 6 is satisfied by the end of the fuel cut, and the process shifts to the F / B control block 1404 to return to the normal feedback control.

  If the control unit 515 recognizes the engine stall during the F / B control or the F / C control, the condition 7 is satisfied, and the A control block 1402 is entered.

  FIG. 15 shows a time chart of the energization signal to the solenoid 200 during the F / B control. An open current control duty is output from the energization start angle STANG to the energization end angle OFFANG. The open current control duty includes an initial energization time TPUMON and a duty after the initial energization. Here, the initial energization time TPUMON and the duty ratio PUMDTY after the initial energization are calculated in the pump control DUTY calculation means 704. FIG. 18 shows an example of calculation in the pump control DUTY calculation means 704. The initial energization time TPUMON is calculated from a map of the battery voltage and the engine speed (block 1801).

  The duty ratio PUMDTY is calculated from a map of the rotational speed and the battery voltage (block 1802).

  The initial energization time TPUMON and the duty ratio PUMDTY are calculated from the rotation speed and the battery voltage, which are parameters indicating the operating state. For this reason, in order to improve the control accuracy, it is necessary to use the latest value that can always be set because it is necessary to accurately grasp the operating state.

  FIG. 16 shows parameters used for the energization start angle STANG and the energization end angle OFFANG of the solenoid control signal for the control of the fuel pressure by the control unit 515.

  The energization start angle STANG and the energization end angle OFFANG of the solenoid signal are set from the reference REF generated based on the CRANK signal and the CAM signal and the stroke of the plunger 2. First, the energization start angle STANG is as shown in FIG. Further, calculation is performed by correcting the phase difference caused by the variable valve timing mechanism of the pump drive camshaft to a map value having the engine speed and battery voltage as inputs.

  Further, the energization end angle OFFANG can be obtained as shown in Equation 1.

OFFANG = REFANG + EXCAMADV-PUMDLY (Formula 1)
Here, REFANG is a reference angle and can be obtained as shown in Equation 2.

REFANG = BASANG + FBGAIN (Formula 2)
Here, BASANG is a basic angle, and is calculated by a basic angle map 1101 (FIG. 11) based on the operating state of the engine 507. EXCAMADV is a cam operation angle and corresponds to an operation angle of variable valve timing. PUMDLY is a pump delay angle, and FBGAIN is a feedback amount.

  FIG. 17 shows energization signals for the solenoid 200 in each control state. During the A control, the solenoid 200 is not energized. During the B control, the open current control duty is output from the time when the B control is permitted to the initial reference REF. During the F / B control, an open current control duty is output from the energization start angle STANG to the energization end angle OFFANG. During the F / C control, the open current control duty is output from the energization start angle STANG to the forced energization end angle CPOFFANG.

  As described in the description of FIG. 10, it is important to accurately control the energization start angle. The following measures are necessary to improve the control accuracy of the energization start angle.

(1) Improve the calculation accuracy of the energization start angle STANG.
(2) The error between the energization start angle STANG calculated as the required value and the actual output start angle is reduced.

  FIG. 20 shows a first embodiment corresponding to the above (1). FIG. 20 shows the relationship between the reference REF and the plunger displacement. Arranging the reference REF on the crank angle signal immediately before the energization start angle setting range (the most advanced angle phase) improves the calculation accuracy. This is because, in the reference REF, the energization start angle request value based on the operation state at that time is determined. Therefore, if the reference REF is away from the energization start angle setting range, the operation state is easily changed. This is because there is a possibility that the operating state has changed (the required value has changed). The reason why it is arranged on the crank angle signal is that it is always based on the same phase without being affected by fluctuations in the rotational speed. In addition, by arranging the cam angle sensor output at the top dead center of the pump drive cam, it is possible to maintain the control accuracy of the energization start angle by using the cam angle sensor output even when the crank angle sensor fails. Become.

  In the present embodiment, it has been found that the system performance is improved by handling the energization start position as an important parameter, and for that purpose, it is necessary to arrange the reference REF in the compression stroke of the pump.

  The energization start angle setting range is a range obtained by adding the variable valve timing maximum operating angle and the sensor and cam mounting variation in addition to the range required from the pump operating characteristics. FIG. 23 shows the energization start angle setting range and the output forced end angle setting range required from the pump operating characteristics. The energization start angle setting range is basically a range determined in accordance with the operation state after the top dead center of the plunger in terms of pump operation characteristics. On the other hand, the output forced end angle setting range is a range determined according to the operation state from before the top dead center of the plunger due to the pump operation characteristics.

  In addition, in order to improve accuracy, it is preferable that the energization start requested phase range falls within the reference REF. If the reference REF exists in the middle of the energization start requested phase range, the range advanced from the reference REF must use the decision value of the reference REF from the previous one, and the control accuracy is lowered. In addition, in the reference REF, it is necessary to control whether the required value from the previous REF or the current reference REF is switched, which imposes a calculation load on the control unit and lowers the control accuracy.

  FIG. 21 is a diagram showing a case where the cam in which the variable valve timing moves to the advance side and the pump drive cam are in the same system. In this case as well, the energization start angle setting range is a range obtained by adding the variable valve timing maximum operating angle and the sensor and cam mounting variation in addition to the range required from the pump characteristics. It is preferable to arrange it on the crank angle signal immediately before the angle setting range (the most advanced angle phase), and the reference REF is on the compression stroke.

  Similarly, the fact that it is necessary to improve the calculation accuracy for the forced output end angle is described in the explanation for FIG. An embodiment of the means for improving the output forced end angle calculation accuracy is shown in FIG. FIG. 22 shows the relationship between the reference REF and the plunger displacement. Arranging the reference REF immediately before the output forced end angle setting range (the most advanced angle phase) improves the calculation accuracy. This is because, in the reference REF, the output forced end angle request value is determined based on the operation state at that time. Therefore, if the reference REF and the output forcible end angle setting range are separated from each other, the operation state is likely to be changed. This is because there is a possibility that the operating state has changed (the required value has changed) at the time of forced termination.

  The output forced end angle setting range is a range obtained by adding the variable valve timing maximum operating angle range in addition to the range required from the pump operating characteristics. Also, sensor and cam mounting variation may be taken into consideration.

  Further, as shown in FIG. 22, the reference REF is arranged immediately before the output forced end angle setting range (the most advanced angle phase), and the same signal is used for the reference REF of the energization start angle and the energization end angle, thereby It is possible to place the energization start angle setting range and the output forced end angle setting range that require accuracy in the vicinity. By using the same signal, the pump control method can be simplified, and the calculation load can be reduced. Reduction can be achieved.

  FIG. 24 shows a second embodiment corresponding to the above (1). It is a time chart which showed the energization start angle calculation method. At the time of the reference REF, the energization start angle (temporary value) and the energization start angle recalculation timing are set. Here, the energization start angle (temporary value) is an energization start angle calculated at a fixed cycle (for example, 10 ms cycle) timing before the reference REF. The energization start angle recalculation timing is calculated from the energization start angle (temporary value). The purpose of setting the energization start angle recalculation timing is to recognize the operating state immediately before the energization start time. For this reason, the energization start angle recalculation timing is set before the energization start angle (temporary value). The interval between the energization start angle (temporary value) and the energization start angle recalculation timing is set to be equal to or longer than the time when the maximum calculation is completed before the energization start angle (temporary value). A crank angle signal may be used instead of time.

  Next, the energization start angle is calculated and set again at the energization start angle recalculation timing. By this calculation, it is possible to reflect the energization start angle calculated at a fixed period (for example, 10 ms period) after the reference REF, and it is possible to improve the calculation accuracy of the energization start angle.

  By performing the same control for the energization end angle calculation, it is possible to improve the calculation accuracy at the energization end angle.

  FIG. 25 shows the case where the recalculated energization end angle is the energization end angle when the recalculated energization start angle is the requested value before the energization start angle recalculation timing and at the energization end angle recalculation timing. It is a time chart when it is a required value before the end angle recalculation timing. When the energization start angle calculated again at the energization start angle recalculation timing is a request value before the energization start angle recalculation timing, energization is immediately started. When the energization end angle calculated again at the energization end angle recalculation timing is a request value before the energization end angle recalculation timing, energization is immediately terminated.

An embodiment corresponding to the above (2) is shown in FIG. In order to reduce the error between the energization start angle STANG calculated as the required value and the actual output start angle, angle + time control is performed. An explanation of the angle + time control is shown in FIG. In the angle + time control, the control angle is set based on a crank signal (for example, 10 deg) output at a predetermined crank angle interval from the crank angle sensor. FIG. 27 shows a control method when the energization start angle STANG = 33 deg is requested at the time of the reference REF. Counter counted up for each crank signal: When ONCANT becomes 3 (= 30 deg from the reference REF), the remaining 3 deg is set to 3 deg from the time A in ONCNT = 2. . That is, in this embodiment, 3 deg = time A × 0.3 (formula 3)
It becomes. A setting method using a counter that counts up for each crank signal is referred to as angle control, and a setting method for 3 deg is referred to as time control. The angle + time control has higher control accuracy at the time of sudden change in the rotation speed than the time control alone.

In the high-pressure fuel pump 1 equipped with the normally closed intake valve, the control accuracy of the energization end angle is also necessary. For this reason, angle + time control is also performed for energization end control. That is, the energization start and energization end of the high-pressure fuel pump are controlled by angle + time control. In addition, the energization start angle and the forced output end angle are important in the control of the high pressure fuel pump. Therefore, as shown in FIG. 28, the crank angle sensor signal and the pump drive cam phase are arranged so that there is no tooth missing on the energization start angle setting range and the output forced end angle setting range.
This is because when there is no tooth, there is no crank angle signal, the time control period becomes longer, and the control accuracy is lowered.

  FIGS. 32 and 33 show an embodiment in which only the energization start angle is set to angle + time control and the energization end angle is set to time control. In this embodiment, only the energization start angle, which is the most important parameter, is set to angle + time control to ensure control accuracy. When it is desired to suppress the calculation load of the MPU 603 in the control unit 515, the embodiments shown in FIGS. 32 and 33 are suitable.

  FIG. 29 shows a time chart when a reference REF, which is a pump control angle setting timing, enters during energization. Scene 1 is a case where the request for the energization end angle OFFANG at the time of the next reference REF is a value equal to or less than the reference REF interval. In this case, energization is immediately terminated at the reference REF in order to satisfy the request.

  Scene 2 is when the request for the energization end angle OFFANG used for setting is a value equal to or greater than the reference REF interval at the next reference REF. In this case, an angle of (OFFANG-reference REF interval (for example, 90 deg)) is set. As a result, the latest operation state can be reflected, and the control accuracy can be improved.

  As shown in FIG. 29, when the next reference REF is input during energization, it can be determined at the time of the initial setting reference REF. Therefore, at the time of the initial setting reference REF, the time + angle control setting for the end of energization is performed. do not do. With this method, even when there are many reference REFs, it is sufficient to set each one of the energization start timing and the energization end timing, which contributes to simplification of the control logic and reduction of the calculation load.

  FIG. 30 is a time chart showing a countermeasure when the setting is reversed when each of the energization start timing and the energization end timing is set by angle + time control from the reference REF. When two angle + time controls are used together, the control start order may be reversed due to the noise of the crank angle signal or the like. In the state shown in FIG. 30, the energization end time exists before the energization start time. When an energization end request is input between the energization start timing and the next reference REF, the request is determined to be erroneous control due to noise or the like, and the energization end request is not accepted. The reason for not accepting the energization end request is that there is a possibility of full discharge when the pump is not energized.

  On the other hand, in the state shown in FIG. 31, the energization end timing exists after the energization start timing. If an energization start request is input between the energization end control and the next reference REF, the request is determined to be erroneous control due to noise or the like, but an energization start request is accepted. This is for avoiding all discharges due to non-energization.

  Further, as another response to the above (2), it is possible to suppress the calculation amount of the MPU 603 at the time of the reference REF. If the amount of calculation at the time of the reference REF is large, it may take time until the angle is set, and it may not be in time for the requested output start time. For this reason, the energization start angle STANG, the energization end angle OFFANG, the initial energization time TPUMON, the duty ratio PUMDTY, and the like, which are required values for the pump drive signal, are calculated at regular intervals (for example, 10 ms), so that the MPU 603 at the time of the reference REF interrupt Reduce the amount of computation.

  As described above, the embodiment of the present invention exhibits the following functions by the above configuration.

  The control unit 515 of the present embodiment is an in-cylinder having an injector 54 provided in a cylinder 507b, a high-pressure fuel pump 1 including a normally closed suction valve that pumps fuel to the injector 54, a common rail 53, and a fuel pressure sensor 56. The high-pressure fuel pump control device of the injection engine 507 calculates an appropriate energization start / end request phase in the in-control device phase calculation unit, and starts and ends energization in accordance with the requested phase in the in-control device drive signal output unit. By doing so, it is possible to stabilize the fuel system, stabilize the combustion, and improve the exhaust gas performance.

  An example of the effect of the present embodiment will be described with reference to FIG. FIG. 34 is a time chart of the control device and the prior art in the present embodiment. In the prior art, the interval between the energization start angle and the reference REF is large, and the operation state recognized at the reference REF, which is the angle set point, may be different from the operation state at the start of energization (in FIG. 34, the battery voltage is illustrated as an example. ). At this time, an unintended boost may occur.

  In the present embodiment, the operation state recognized at the time of the reference REF and the operation state at the start of energization can be made substantially the same by bringing the reference REF close to the energization start timing, and the discharge amount can be controlled stably until the high rotation speed. I can do it. The fuel system can be further stabilized, combustion can be stabilized, and exhaust gas performance can be improved.

  Although the present embodiment has been described in detail above, the present invention is not limited to these embodiments, and various changes can be made in the design without departing from the spirit of the present invention described in the claims. Is.

DESCRIPTION OF SYMBOLS 1 High pressure fuel pump 2 Plunger 3 Lifter 4 Lowering spring 5 Valve body 6 Fuel discharge valve 8 Solenoid valve 10 Fuel intake passage 11 Fuel discharge passage 12 Fuel pressurization chamber 50 Fuel tank 51 Low pressure fuel pump 52 Fuel pressure regulator 53 Common rail 54 Injector 55 Relief Valve 56 Fuel pressure sensor 91 Anchor 92 Spring 100 Pump drive cam 200 Solenoid 502 Air cleaner 503 Air flow sensor 504 Throttle sensor 505 Throttle body 505a Electric throttle valve 506 Collector 507 In-cylinder injection engine 507a Piston 507b Cylinder 507c Combustion chamber 507d Crankshaft 508 Ignition plug 511 Phase sensor 515 Control unit 516 Position sensor 522 Ignition coil 526 Exhaust valve 601 I / OLSI
602 EP-ROM
603 MPU
604 RAM
701 Fuel pressure input processing means 702 Target fuel pressure calculation means 703 Pump control angle calculation means 704 Pump control duty calculation means 705 Pump state transition determination means 706 Solenoid drive means 801 Energization start angle calculation means 802 Energization end angle calculation means 1101 Basic angle map 1102 Fuel pressure F / B control operation unit 1402 A control block 1403 B control block 1404 F / B control block 1405 F / C middle control block

Claims (3)

A fluid suction passage; a fluid discharge passage; a pressurization chamber connecting the suction passage and the discharge passage; a pressurization member that pumps fluid in the pressurization chamber to the discharge passage; and In a control device for controlling a pump having a provided discharge valve and an electromagnetic valve provided in the suction passage and opened when energized,
The control device generates a reference signal that is a reference for performing output at a requested phase, and based on the reference signal,
ON signal output and / or OFF signal output planned phase;
Energization start angle recalculation timing for recalculating the ON signal output scheduled phase and / or
Set the energization end angle recalculation timing to recalculate the OFF signal output scheduled phase,
And the energization start angle recalculation timing is before the ON signal output scheduled phase,
The energization end angle recalculation timing is before the OFF signal output scheduled phase,
Controller characterized that you set to terminate the recalculation. The said pump has a spring which urges | biases the said electromagnetic valve to a valve closing direction so that it may open by the pressure difference of the said suction passage and the said pressurization chamber in the suction stroke of the said pump. control device as claimed. The pump control apparatus according to claim 1 or 2 any one claim, characterized in that said a pump for adjusting the discharge amount by returning the fluid to the suction passage from the pressure chamber.

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