JP2021032178A - Electromagnetic actuator controller, high-pressure fuel pump and injector - Google Patents

Abstract

To provide a method for detecting valve closing even in a holding current period, controlling a suction valve based on the detection, and realizing noise reduction.SOLUTION: An electromagnetic actuator controller comprises a calculation unit that controls a mover by controlling a current flowing through a coil so as to change within a certain range. The calculation unit controls the current flowing through the coil so that the frequency of the current flowing through the coil is equal to or higher than a setting value and the timing of change falls within a setting range.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electromagnetic actuator control device, a high pressure fuel pump and an injector.

Internal combustion engines of automobiles are required to have high efficiency, low exhaust, and high output. Direct-injection internal combustion engines have long been popular as a means to solve these problems in a well-balanced manner. Automakers and suppliers have been constantly striving to improve their product value, and one of the important issues is to reduce the noise of high-pressure fuel pumps. In order to reduce the noise of the high-pressure fuel pump, the current may be reduced, but if the current is reduced too much, the high-pressure fuel pump cannot discharge fuel. The optimum amount of current applied for noise reduction depends on the individual high-pressure fuel pump. Therefore, we would like to detect individual differences in the high-pressure fuel pump and adjust the amount of current applied accordingly to achieve optimum noise reduction. The movement of the valve body can be considered as an individual difference of the high-pressure fuel pump to be detected.

As an example thereof, the plunger described in claim 1 of Patent Document 1 "reciprocally moving with the rotation of the rotating shaft to change the volume of the pressurizing chamber and the fuel suction passage communicating with the pressurizing chamber are arranged. It is applied to a high-pressure pump having a valve body and a control valve for supplying and shutting off fuel to the pressurizing chamber by axially shifting the valve body by energization control for an electromagnetic part. A high-pressure pump control device that adjusts the fuel discharge amount of the high-pressure pump by switching between opening and closing of the control valve by the energization control. A high-pressure pump control device including a motion detecting means for detecting the movement of the valve body and an operation determining means for performing an operation determining of the high-pressure pump based on the detection result of the motion detecting means. " Can be mentioned.

Among them, in particular, claim 3 of Patent Document 1 states that "the motion detecting means detects the motion of the valve body in response to the drive command by detecting the change in the current flowing through the electromagnetic portion, and at that time. The invention of the high-pressure pump control device according to claim 1 or 2, which detects that a switch between an increasing tendency and a decreasing tendency of the current occurs as a change in the current is disclosed.

Japanese Unexamined Patent Publication No. 2015-31203

We also faced the need to detect the closing timing of the intake valve of the high-pressure fuel pump while working to reduce the noise of the high-pressure fuel pump, but it turned out that there are situations that cannot always be covered by the above-mentioned background technology. It was. As will be described later in the embodiment of the present invention, the suction valve of the high-pressure fuel pump is performed by controlling the current flowing through the solenoid. This control current is divided into a peak current that gives energy to start moving the valve body that is stationary in the valve open state and a holding current that holds the valve body in the valve closed state. In the method introduced in the background technology, when the valve is closed during the period when the peak current is flowing, the counter electromotive force generated in the solenoid causes the peak current that is increasing to decrease once and then increase, and the valve is closed. Is detected. Here, the inflection point at which the peak current switches from decreasing to increasing is detected as the valve closing timing. However, we faced the need for control to close the valve while the holding current was flowing. Therefore, the present invention provides a method of detecting valve closure even during the holding current period, controlling the intake valve based on the detection, and realizing noise reduction.

In order to solve the above problems, the present invention is an electromagnetic actuator control device including an arithmetic unit that controls a mover by controlling the current flowing through the coil so as to change within a certain range after applying a peak current. The arithmetic unit is characterized in that the frequency of the current flowing through the coil is controlled to be equal to or higher than a set value and the current flowing through the coil is controlled so that the timing of change falls within the set range.

The present inventors have discovered that the frequency of the current flowing through the solenoid changes by a set value or more at the timing when the valve closing is completed. Furthermore, the present inventors have found that there is a current saturation region (setting range) in which the speed of the mover immediately before the completion of valve closing does not decrease any more even if the current flowing through the solenoid is reduced. The fact that the speed of the mover immediately before the completion of valve closing does not decrease any more means that the impact and noise at the time of valve closing, which are controlled by this speed, do not decrease any more. Therefore, according to the above invention, the valve closing timing can be set within the above setting range, and it is possible to reduce the noise of the electromagnetic actuator while suppressing the failure of valve closing. is there.

It is a figure which shows the structure of the internal combustion engine. It is a figure which shows the structure of the high pressure fuel pump. It is a figure which shows the time chart of the operation of a high pressure fuel pump. It is a figure which shows the variation of the individual characteristic of a pump. It is a figure which shows the saturation of the valve closing speed with respect to the integral value of Denryu of a pump. It is a figure which shows the valve closing speed and the valve closing displacement of a suction valve when the peak current is changed. It is a figure which shows the relationship between the valve closing speed and the valve closing timing. It is a figure which shows the electric current at the time of completion of valve closing. It is a figure which shows the method of detecting the valve closing completion timing. It is a figure which shows the differentiating circuit. It is a figure which shows the absolute value circuit. It is a figure which shows the filter which captures the frequency change of the switching current by closing a valve. It is a figure which shows the signal at each stage which detects the completion of valve closing. It is a figure which shows the filter which captures the frequency change of the switching current by closing a valve. It is a figure which shows the processing flow for detecting the valve closing. It is a figure which shows the structure of an injector. It is a figure which shows the time chart of the operation of an injector.

Hereinafter, an embodiment of the present invention will be described, but the present embodiment is not limited to the embodiments described in the drawings. The present embodiment provides an electromagnetic actuator capable of detecting the valve closing completion timing.

FIG. 1 shows an outline of the direct injection internal combustion engine 10. In the direct injection internal combustion engine 10, the fuel stored in the fuel tank 101 is pressurized to about 0.4 MPa by the feed pump 102, and further pressurized to several tens of MPa by the high pressure fuel pump 103. The pressurized fuel is injected from the direct injection injector 105 into the cylinder 106 of the internal combustion engine via the high-pressure pipe 104.

The injected fuel is mixed with the air sucked into the cylinder 106 by the operation of the piston 107. This air-fuel mixture is ignited by a spark generated by the spark plug 108 and explodes. The heat generated by the explosion causes the air-fuel mixture in the cylinder 106 to expand, pushing down the piston 107. The force pushing down the piston 107 passes through the link mechanism 109 and rotates the crankshaft 110. The rotation of the crankshaft 110 is transmitted to the wheels through the mission and becomes a force to move the vehicle.

Internal combustion engines are mainly required to have low fuel consumption, high output, and exhaust gas purification, but as additional value, noise and vibration reduction are required. In a high-pressure fuel pump, noise is generated due to a collision between a valve body or a mover (which may be called an anchor) and a stopper when opening and closing the suction valve. Each automobile manufacturer and supplier is making a lot of efforts to reduce the noise.

FIG. 2 shows the structure of the high-pressure fuel pump 103. The high-pressure fuel pump 103 moves the plunger 202 that moves up and down by the rotation of the cam 201 attached to the camshaft of the internal combustion engine 10, the suction valve 203 that opens and closes in synchronization with the vertical movement of the plunger 202, and the suction valve 203. An electromagnetic actuator 200 (solenoid) for controlling is provided. The electromagnetic actuator 200 (solenoid) is a device that converts electrical energy into mechanical energy via electromagnetic energy. The details will be described later, but the electromagnetic actuator 200 (solenoid) is attracted to the stator 206 (magnetic core) by the electromagnetic force generated by the current flowing through the coil 205, the stator 206 (magnetic core), and the coil 205. , Mainly composed of a mover 204 that controls the operation of the suction valve 203.

The high-pressure fuel pump 103 is surrounded by a casing 223, and a pressurizing chamber 211 is arranged inside. Fuel flows from the low-pressure pipe 111 side into the pressurizing chamber 211 through the inflow port 225 and the communication port 221. The fuel that has flowed into the pressurizing chamber is discharged to the high-pressure pipe 104 side through the outlet 222. The outlet 222 is opened and closed by the discharge valve 210. The discharge valve 210 is constantly urged by the spring portion 226 in the direction of closing the outlet 222, and when the pressure in the pressurizing chamber exceeds the spring force, the discharge port opens and fuel is injected.

In the electromagnetic actuator 200 of the high-pressure fuel pump 103, the operation of the mover 204 in the axial direction (left-right direction in FIG. 2) is controlled by controlling the on / off of the energization of the coil 205. When the coil 205 is off, the mover 204 is constantly urged in the valve opening direction by the first spring 209 to keep the suction valve 203 in the valve opening position. Such a high-pressure fuel pump 103 is called a normally open type high-pressure fuel pump, and although the normally open type will be described in this embodiment, it can also be applied to the normally closed type by replacing the valve opening and the valve closing.
When the energization of the coil 205 is turned on, an electromagnetic attraction force is generated between the stator 206 (magnetic core) and the mover 204. As a result, the mover 204 provided on the proximal end side of the suction valve 203 is sucked in the valve opening direction (left direction in FIG. 2) against the spring force of the first spring 209. When the mover 204 is sucked by the stator 206, the suction valve 203 is a check valve that opens and closes based on the differential pressure between the upstream side and the downstream side and the urging force of the second spring 215. Therefore, the suction valve 203 moves in the valve closing direction as the pressure on the downstream side of the suction valve 203 increases. When the suction valve 203 moves by the lift amount set in the valve closing direction, it is seated on the seat portion 207, the suction valve 203 is closed, and the fuel in the pressurizing chamber cannot flow back to the low pressure piping side.

FIG. 3 is a time chart illustrating the operation of the high-pressure fuel pump 103. The suction valve 203 detects the rotation angle of the camshaft 201 so that it opens and closes in synchronization with the top and bottom of the plunger 202, and cams, for example, an angle (P_ON timing) determined from top dead center (TDC: Top Dead Center). After the shaft rotates, a voltage V is started to be applied to both ends of the coil 205 (timing t1). Due to this voltage V, the current I flowing through the coil 205 is LdI / dt = V-RI ... (Equation 1).
It increases according to. Here, L and R are the inductance and resistance of the coil 205 and the wiring, respectively. As the current I increases, the magnetic attraction force Fmag that the stator 206 (magnetic core) attracts the mover 204 also increases.

When the magnetic attraction force Fmag becomes larger than the force Fsp of the first spring 209, the mover 204 pressed by the spring force Fsp starts moving toward the stator 206 (timing t2). When the mover 204 moves, it is pushed by the fuel pressurized by the rise of the plunger 202, and the suction valve 203 also follows the mover 204 and moves toward the stator 206.

Eventually, the protrusion of the suction valve 203 collides with the seat portion 207 and is seated. Due to this collision, the fuel flow path (dotted line in FIG. 2) is blocked, the fuel pressurized by the rise of the plunger 202 cannot return to the low pressure pipe 111 side, and the pressure of the pressurizing chamber 211 rises. (Timing t4)

When the pressure in the pressurizing chamber 211 becomes larger than the spring force Fsp_out that suppresses the discharge valve 210, the discharge valve 210 opens, and the fuel pressurized by the rise of the plunger 202 is discharged to the high-pressure pipe 104. After that, when the drive pulse is turned off at the timing t5, a reverse voltage is applied to the coil 205, whereby the holding current supplied to the coil 205 is cut off.

When the cam angle passes the top dead center and the plunger starts to descend (timing t6), the fuel pressure of the pressurizing chamber 211 decreases, and when this becomes smaller than the spring force Fsp_out, the discharge valve 210 closes and the fuel discharge ends.

Further, due to the decrease in the fuel pressure of the pressurizing chamber 211, the mover 204 moves from the valve closed position to the valve open position together with the suction valve 203 (timing t7 to t8).

By such an operation, the high-pressure fuel pump 103 sends fuel from the low-pressure pipe 111 to the high-pressure pipe 104. In this process, when the mover 204 collides with the stator 206 and the valve closing is completed (timing t4 in FIG. 3), the mover 204 and the suction valve 203 collide with the stopper 208 and the valve opening is completed (FIG. 3). Noise is generated at the timing t8). This noise can be offensive to drivers, especially when idle, and automakers and high-pressure fuel pump suppliers are competing to reduce it. The present embodiment aims to reduce noise when the valve is closed.

The current for driving the electromagnetic actuator 200 of the high-pressure fuel pump 103 is roughly divided into two. The peak current (hatched portion of the current waveform in FIG. 3) and the holding current (horizontal portion of the current waveform in FIG. 3). The peak current gives momentum for closing the suction valve 203 and the mover 204, which are pressed by the first spring 209 and are stationary at the valve opening position. On the other hand, the holding current attracts the mover 204 approaching the stator 206 until it collides with the stator 206, and maintains the contact state. If the amount of peak current applied is reduced, the momentum of valve closing is weakened and noise can be reduced. However, if it is reduced too much, valve closing will fail. Therefore, it is desired to reduce the peak current application amount as much as possible within the valve closing range. As shown in FIG. 3, the maximum current value of the peak current is Im, and the maximum current value of the holding current is Ik.

The problem is that the peak current application amount at the limit of valve closing depends on the individual characteristics of the high-pressure fuel pump 103. In FIG. 4, for the standard spring force Fsp, the upper limit of the manufacturing variation, and the lower limit, the average velocity v_ave (average value from the start to the completion of the valve closing) and the peak current integral value II at the time of valve closing are shown. Show the relationship. In this embodiment, the peak current application amount is the integral value of the current, but the same thing can be achieved by replacing it with the integral value of the square of the current or the integral value of the product of the current and the voltage. From this figure, it can be seen that the relationship between the peak current integral value II and the average velocity v_ave varies depending on the spring force Fsp. Unfortunately, when the valve closing limit current for the lower limit product of the spring force Fsp is given to the upper limit product of the spring force Fsp, the magnetic attraction force generated by the coil loses to the spring force and the valve closing fails. On the contrary, if the lower limit product of the spring force Fsp is controlled by the valve closing limit current with respect to the upper limit product of the spring force Fsp, an excessive magnetic attraction force is applied as compared with the spring force, so the valve is closed at almost the maximum speed. That is, the noise level is maximized.

A method of controlling near the valve closing limit is considered by repeating the control of gradually reducing the peak current integrated value II when the valve closing is successful and increasing the peak current integrated value II when the valve closing is unsuccessful. Be done. However, with this method, valve closing failure occurs at a certain frequency. When the characteristics of the pump were investigated in order to avoid such valve closing failure, the inventors found that the relationship between the peak current integral value II and the velocity vel_Tb immediately before the valve closing was completed had a dead zone 500 as shown in FIG. I found. This figure shows the relationship between the peak current integral value II and the velocity vel_Tb immediately before the completion of valve closing. The peak current integrated value II indicates the integrated value of the current from the peak current supply start timing t1 to the peak current reduction start timing t3 in FIG.
The view of FIG. 6 will be described later, but as shown in the middle part of this figure, the speed of the mover 204 during valve closing is not constant. The noise level is dominated by the speed of the mover 204 immediately before the valve closure is completed (immediately before the mover 204 collides with the stator 206). Looking at FIG. 5, as expected so far, when the peak current integral value II becomes smaller, the velocity vel_Tb immediately before the completion of valve closing tends to become smaller, but when the peak current integral value II becomes smaller than a certain value, it closes. It can be seen that there is a region (dead zone 500) in which the decrease in the velocity vel_Tb of the mover 204 immediately before the completion of the valve is saturated.

The reason why the dead zone 500 exists will be considered based on the current supplied to the coil 205, the speed of the mover 204, and the displacement of the mover 204 with reference to FIG. The upper part of FIG. 6 shows the current applied to the coil 205, the middle part shows the speed of the mover 204, and the lower part shows the displacement of the mover 204. In addition, there are four lines in each of the upper, middle, and lower figures, and these have a time width (peak current width Th) of 1.095, 1 from the time when the maximum current value Im of the peak current is supplied until it is cut off. It is a value when it is set to .1, 1.11, 1.15, and 1.35 ms.

When the maximum current value Im of the peak current is given for a sufficiently long time (for example, when the peak current width shown by the solid line is 1.35 ms), the mover 204 is always accelerated, but the peak current width is 1.15 ms. , 1.11 ms, 1.1 ms, 1.095 ms, the mover 204 decelerates from the timing when the maximum current value Im of the peak current is cut off (around 0.03 s to 0.0301 s). Then, it coasts toward the stator 206 at a small speed. The coasting section is up to around 0.0306, 0.031, and 0.0316s, respectively.

Then, when the mover 204 approaches the stator 206, it is accelerated again by the magnetic attraction generated by the holding current (for example, in the case of the peak current width of 1.15 ms shown by the broken line, 0.0306s to 0. Near 03075s). When re-accelerated by the magnetic force of the holding current from the state of almost zero speed, the valve closes at a nearly constant speed regardless of the way of movement up to that point. This is the reason why there is a dead zone 500 of the velocity vel_Tb of the mover 204 immediately before the completion of valve closing with respect to the peak current integral value II.

Since it was found that there is a dead zone 500 in the relationship between the peak current integral value II and the velocity vel_Tb of the mover 204 immediately before the valve closing is completed, the horizontal axis is replaced with the valve closing completion timing Tb from the peak current integrated value II. The valve closing completion timing Tb is the timing at which the mover 204 collides with the stator 206. Then, as shown in FIG. 7, it can be seen that there is a dead zone between the valve closing completion timing Tb and the speed vel_Tb of the mover 204 immediately before the valve closing is completed. Even more thankfully, when the relationship between the valve closing completion timing Tb and the speed vel_Tb immediately before the valve closing is completed by changing the set spring force to the standard, the upper limit and the lower limit of the manufacturing variation, all of them are shown by the broken lines. It can be seen that there is a saturation region Tr of the valve closing completion timing Tb in which the high-pressure fuel pump of the above is in a dead zone.
Returning to FIG. 5, even if the current flowing through the coil 205 is further reduced from the dead zone 500, the speed of the mover 204 immediately before the valve closing is completed (that is, immediately before the mover 204 collides with the stator 206) is further increased. It cannot be made smaller, but rather the valve closing may fail. Since the dead zone 500 with respect to the current integral value II in FIG. 5 corresponds to the saturation region Tr of the valve closing completion timing Tb in FIG. 7, the speed of the mover 204 is reduced even if an attempt is made to delay the valve closing completion timing Tb in FIG. As described above, it can be said that the valve cannot be reduced, but rather the valve closing may fail.
That is, the speed of the mover 204 immediately before the completion of valve closing can be minimized by setting the valve closing completion timing Tb (the timing at which the mover 204 collides with the stator 206) to the saturation region Tr (setting range). Therefore, by setting the valve closing completion timing Tb to the saturation region Tr (setting range), it is possible to minimize the impact or noise between the mover 204 and the stator 206 at the time of valve closing while suppressing the valve closing failure. it can.
As mentioned above, there is no peak current integrated value II that can silently control all high-pressure fuel pumps, and it was necessary to adjust according to the characteristics of the high-pressure fuel pump. By controlling Tb so as to enter the common saturation region Tr, all the high-pressure fuel pumps 103 can be made quiet.

As described above, in order to realize the control of keeping the valve closing completion timing Tb in the common saturation region Tr, it is necessary to detect the valve closing completion timing Tb. Therefore, from here on, a method of detecting the valve closing timing Tb from the current driving the coil 205 will be described.

FIG. 8 shows the current 213 supplied to the coil 205 and the output signal 214 of the vibration sensor arranged side by side. There is a timing when the amplitude of the output signal 214 of the vibration sensor is rapidly increasing, and this is the valve closing completion timing Tb. Correspondingly, it can be seen that the density of the switching waveform of the current 213 (the number of lines per unit time) is changing. When this change is enlarged, it becomes as shown in the enlarged view at the bottom of FIG. 8, and the change in the frequency of the current switching is changed. That is, the arithmetic unit 1133 (CPU or MPU) of the electromagnetic actuator control device 113 of the present embodiment controls the current flowing through the coil 205 based on the timing at which the frequency of the current flowing through the coil 205 changes by a set value or more. Specifically, the arithmetic unit 1133 vibrates the current 213 supplied to the coil 205 within a certain range by switching the voltage applied to the coil 205. The mover 204 is controlled by the coil current controlled in this way. The change in the frequency of the current switching described above is because when the mover 204 approaches the stator 206, the magnetic inductance of the magnetic circuit formed by the mover 204 and the stator 206 decreases. Switching voltage _V +, V _- between the current I,
L × dI / dt = V ₊ −RI ・ ・ ・ (Equation 2)
L × dI / dt = V ₋ −RI ・ ・ ・ (Equation 3)
As L becomes smaller, the slope of I becomes steeper. Equation 2 shows the relationship between _{the switching voltage V +} and the current I when the current I rises. Equation 3 shows the relationship between _{the switching voltage V −} and the current I at the falling edge of the current I. This is the reason why the switching frequency is changing. In the control of the normal high-pressure fuel pump 103, V ₊ is 14V at the battery voltage and V ₋ is 0V at the ground voltage.
In this way, the frequency of the current switching of the current 213 supplied to the coil 205 changes according to the valve closing completion timing Tb. Then, in the present embodiment, the timing of the change in the frequency of the current switching corresponding to the valve closing completion timing Tb is controlled so as to belong to the intersection Tr of the saturation region. That is, the arithmetic unit 1133 (CPU or MPU) of the electromagnetic actuator control device 113 of the present embodiment controls so that the switching frequency of the current 213 is equal to or higher than the set value and the timing of change falls within the set range (intersection Tr of the saturation region). To do. In other words, in the high-pressure fuel pump 103 of the present embodiment, the electromagnetic actuator 200 in which the current that changes in a certain range, the frequency is equal to or higher than the set value, and the timing of the change falls within the set range (intersection Tr of the saturation region) flows through the coil 205. It is equipped with.
Here, this setting range is the saturation region of the relationship between the current flowing through the coil 205 and the speed of the mover 204 when the valve is closed (the timing when the mover 204 collides with the stator 206) (dead zone 500 in FIG. 5). Is set to be. As a result, the noise caused by the collision of the mover 204 and the suction valve 203 can be reduced, and all the high-pressure fuel pumps 103 can be made quiet. The speed of the mover 204 when the valve is closed (the timing when the mover 204 collides with the stator 206) and the impact between the mover 204 and the stator 206 when the valve is closed, or the mover 204 and the stator 206. There is a correlation with the noise caused by the collision with. Therefore, the above-mentioned setting range (intersection Tr of the saturation region) may be set to be the saturation region (dead zone 500 in FIG. 5) of the relationship between the current flowing through the coil 205 and the impact at the time of valve closing. Alternatively, the above setting range may be set to be a saturation region (dead zone 500 in FIG. 5) of the relationship between the current flowing through the coil 205 and the noise when the valve is closed.
Specifically, the current flowing through the coil 205 is the integrated current value from the start of supply of the peak current (timing t1) to the start of reduction (timing t3) in FIG. 3, the maximum current value of the peak current, or the maximum current. It indicates the period during which the value is passed (peak current width Th). Therefore, the arithmetic unit 1133 flows the current integral value from the start of supply (timing t1) to the start of reduction (timing t3) flowing through the coil 205, the maximum current value Im of the peak current, or the period (peak current width) of flowing the maximum current value Im. It is desirable to control the peak current so that Th) enters the saturation region (dead zone 500 in FIG. 5). As a result, the noise caused by the collision of the mover 204 and the suction valve 203 can be reduced, and all the high-pressure fuel pumps 103 can be made quiet.

As described above, it was found that the noise can be reduced by controlling the peak current application amount based on the change in the switching frequency. The next issue is how to detect this change in switching frequency. In order to capture the change in the switching frequency, the process is performed according to the flow shown in FIG.
First, the switching current is converted into a voltage by a shunt resistor or the like. This voltage signal is differentiated by a differentiating circuit 301 as shown in FIG. The output is as shown in FIG. 9 (2). Since the differential result differs between rising and falling, if a sample is taken near the end of the rising in synchronization with switching, a value corresponding to the frequency can be obtained, but this sampling imposes a load on the microcomputer (arithmetic unit 1133). The absolute value is taken in the absolute value circuit 302 as shown in FIG. Then, it becomes as shown in FIG. 9 (3).

Since this absolute value also changes depending on the timing, it is smoothed by the filter 303 having a time constant longer than the switching period. Then, the signal as shown in FIG. 9 (4) is obtained, and the change as shown by the arrow in the figure appears at the valve closing completion timing Tb. If this change is extracted by a method such as threshold value determination, the valve closing timing Tb can be specified. As described above, the electromagnetic actuator control device 113 of the present embodiment shown in FIG. 2 has a differentiating circuit 301 that differentiates the current, an absolute value circuit 302 that takes an absolute value of the output of the differentiating circuit 301, and an absolute value circuit 302. A smoothing circuit 303 that smoothes with a time constant longer than the switching frequency is provided. Then, the arithmetic unit 1133 of the electromagnetic actuator control device 113 extracts the change point of the output of the smoothing circuit 303.

In this method, an analog circuit is used up to the point of smoothing, and the waveform after smoothing as shown in FIG. 9 (4) is converted to AD (Analog / Digital) and imported into a microcomputer (arithmetic unit 1133) to respond to changes in frequency. If the function of identifying the changed point is realized by the microcomputer, the processing load of the microcomputer can be reduced. On the other hand, since it is necessary to realize a differentiating circuit and an absolute value circuit with an analog circuit, the cost of the circuit element and the area of the base on which the element is mounted increase.

Therefore, an embodiment in the case where the processing capacity of the microcomputer (arithmetic unit 1133) has a margin is shown. In this embodiment, a filter 304 having a frequency-gain characteristic as shown in FIG. 12 is used. Comparing the gain for the frequency f_bef before the collision with g_bef and the gain for the frequency f_aft after the collision g_aft,
g_bef> g_aft ... (Equation 4)
Note that. When a switching current signal before and after the collision as shown in FIG. 13 (1) is input to the filter 304, the output becomes as shown in FIG. 13 (2). As shown in FIG. 13 (1), the amplitude of the switching current is the same before and after the collision, but the filter output changes before and after the collision as shown in FIG. 13 (2) due to the change in the frequency of the switching current before and after the collision. Please note that.

The amplitude of the switching current input to the filter 304 is almost the same before and after the collision, but the amplitudes a_bef and a_aft before and after the collision of the output signal are
a_bef> a_aft ... (Equation 5)
There is a relationship. This is because, as described above, the gain of the filter 304 is different before and after the collision, so if a signal having the same amplitude is input to the filter, the difference in gain becomes the difference in output.

When the absolute value of this output signal is taken and smoothed with a filter having a cutoff frequency smaller than the switching frequency, a change in the frequency of the output signal shown in FIG. 13 (3) appears. By specifying the timing of this change point, the valve closing timing Tb can be specified.

Further, in the embodiments described so far, the gain before and after the collision is
g_bef> g_aft ... (Equation 4)
However, this is g_bef <g_aft ... (Equation 6)
It may be. Further, the frequencies before and after the collision may be distributed in a certain range as shown in FIG. 14 depending on the conditions such as temperature. Then, in the frequency domain before and after the collision, the frequency change due to the collision can be detected by using the filter 304 in which the gain monotonically increases or decreases monotonically.
In this way, when the suction valve 203 of the high-pressure fuel pump 103 is closed, the inductance in the magnetic circuit between the mover 204 and the stator 206 changes. As a result, the slope of the switching current flowing through the coil 205 changes as shown in FIG. This appears in the change in the switching frequency of the switching current. Since the amplitude of the switching current is controlled to be constant before and after the valve is closed, if a filter with a different gain is used for the switching frequency before and after the valve is closed, the amplitude of the switching current after filtering will be before and after the valve is closed. Is different. Therefore, in the present embodiment, the valve closing completion timing of the electromagnetic actuator 200 can be detected by extracting this amplitude and specifying the change point thereof.

Therefore, as shown in FIG. 15, the valve closing detection device (electromagnetic actuator control device 113) of the present embodiment closes the valve with the current measuring means (S1) for measuring the current flowing through the coil 205 and the measured current signal. It is provided with an amplitude extraction unit (S3) that filters (S2) with a filter 304 having different gains at a later frequency and a frequency before valve closing, and extracts an amplitude component from the filtering result. Specifically, the electromagnetic actuator control device 113 inputs the filter 304 having different gains and the current flowing through the coil 205 to the filter 304 with respect to the frequencies before and after the timing when the mover 204 collides with the stator 206. It is provided with an amplitude extraction unit for extracting the amplitude of the obtained output. Then, the arithmetic unit 1133 estimates the timing at which the mover 204 collides with the stator 206 based on the change in the amplitude output by the amplitude extraction unit. Thereby, the valve closing timing of the electromagnetic actuator 200 can be detected.

Further, as described with reference to FIG. 5, if the current applied to the high-pressure fuel pump 103 is reduced, the speed vel_Tb and noise immediately before the completion of valve closing can be reduced, but this is saturated when the current is reduced to some extent. I understood. Examination of the relationship between the valve closing timing Tb and the speed vel_Tb immediately before the valve closing and noise revealed that there is a common saturation region Tr even if the individual characteristics of the high-pressure fuel pump 103 vary, as shown in FIG.

Therefore, the electromagnetic actuator control device 113 reduces the current applied to the coil 205 of the high-pressure fuel pump 103, and when the valve closing completion timing Tb is delayed, the speed vel_Tb at the time of valve closing completion or the noise is saturated. The current that drives the coil 205 is controlled so that the result detected by the valve closing completion timing Tb detection device described above belongs to the common portion Tr that does not depend on the variation in the individual characteristics of the saturation region. As a result, the high-pressure fuel pump 103 can be made quieter.

The control of the high-pressure fuel pump based on the change in the frequency of the switching current flowing through the electromagnetic actuator (solenoid) has been described above. The change in switching frequency due to the movement of the valve body and mover is not limited to the pump, but the coil, the mover (anchor and valve body) controlled by the magnetic attraction generated by this, and the stator (core) that attracts the mover. ) Is included in the electromagnetic actuator (solenoid). In order to show that the present invention can be generally applied to electromagnetic actuators other than high-pressure fuel pumps, a mode in which the present invention is applied to an injector will be disclosed.

Since this embodiment corresponds to a modified example of the first embodiment, the differences from the first embodiment will be mainly described. An embodiment of the present invention in the injector 105b will be described with reference to FIG. The injector 105b is surrounded by a casing 223b, and a space 211b is arranged inside. Fuel flows into the space 211b from the high-pressure pipe 104 side through the inflow port 225b. When the suction valve 203b is opened, the fuel that has flowed into the space 211b is injected from the injection port 222b into the combustion chamber of the cylinder 106. The opening / closing operation of the suction valve 203b is controlled by the electromagnetic actuator 200b.

The electromagnetic actuator 200b (solenoid) is a device that converts electrical energy into mechanical energy via electromagnetic energy. The details will be described later, but the electromagnetic actuator 200b (solenoid) is attracted to the stator 206b (magnetic core) by the electromagnetic force generated by the current flowing through the coil 205b, the stator 206b (magnetic core), and the coil 205b. , Mainly composed of a mover 204b that controls the operation of the suction valve 203b. When the mover 204b is sucked into the stator 206b, the suction valve 203b moves in the valve opening direction.

When the coil 205b is off, the mover 204b is constantly urged in the valve closing direction by the spring 209b to keep the suction valve 203b in the valve closing position. Such an injector 105b is called a normally closed type injector, and the normally closed type will be described in the present embodiment.

The arithmetic unit (power supply control unit 1133) of the electromagnetic actuator control device 113b controls the mover 204b by changing the current supplied to the coil 205b within a certain range by switching the voltage applied to the coil 205b. The electromagnetic actuator 200b moves the suction valve 203b by controlling the mover 204b provided on the proximal end side of the suction valve 203b. As a result, the suction valve 203b opens and closes the injection port 222b on the tip side. The suction valve 203b is constantly urged in the valve closing direction by the spring 209b. The coil 205b moves the suction valve 203b in the valve closing direction by sucking the mover 204b against the spring force of the spring 209b.

The electromagnetic actuator control device 113b controls the current supplied to the coil 205b by controlling the power supply 112. More specifically, the arithmetic unit (power supply control unit 1133) of the electromagnetic actuator control device 113b controls the current supplied to the coil 205b by switching and controlling the voltage applied to the coil 205b. As shown in FIG. 16, the electromagnetic actuator control device 113b includes a voltage measuring unit 1131, a detecting unit 1135, and a power supply control unit 1133. The detection unit 1135 includes, for example, a differentiating circuit 301, an absolute value circuit 302, and a smoothing circuit 303. The detection unit 1135 detects the valve opening timing of the injector 105b from the current supplied to the coil 205b. The detection unit 1135 may include a filter 304 and an amplitude extraction unit 305.

When the voltage shown in the lower part of FIG. 17 is applied to the coil 205b of the injector 105b, the current shown in the middle part flows through the coil 205b, whereby the suction valve 203b is lifted as shown in the upper part. Since fuel is injected while the intake valve 203b is being lifted, the fuel injection amount can be controlled by controlling the time difference between valve opening and valve closing by applying a voltage.

Although the change in frequency switching current during closing completion case of the high-pressure fuel pump appeared, the injector, when the valve opening completion, the frequency of the switching current, such as a timing t _open the middle diagram of FIG. 17 Changes appear. The method of this detection is the same as the method of detecting the completion of valve closing of the high-pressure fuel pump 103 described above. Further, when the injector 105b is closed, an inflection point appears in the drive voltage of the coil 205b as _{shown in the timing t close in the middle diagram of FIG.} The method of this detection is described in JP-A-2014-214738 and the like. In this way, since the valve opening timing to _open and the valve closing timing to _close of the injector 105b can be detected, a value having a correlation with the fuel injection amount can be obtained from these time differences. Therefore, the fuel injection amount of the injector is controlled by controlling the voltage applied to the solenoid so that this time difference matches the target value.
As described above, the injector 105b of the present embodiment is an electromagnetic actuator 200b in which a current that changes in a certain range, the frequency is equal to or higher than the set value, and the timing of the change falls within the set range (intersection Tr of the saturation region) flows through the solenoid 400. Equipped with. Further, as in the case of the high-pressure fuel pump, it is desirable that this setting range is set to be a saturation region (dead zone 500 in FIG. 5) of the relationship between the current flowing through the injector 105b and the speed at the time of valve closing. Others are the same as in the case of the high-pressure fuel pump, so the description will be omitted.

10 Direct injection internal combustion engine 101 Fuel tank 102 Feed pump 103 High pressure fuel pump 104 High pressure piping 105 Direct injection injector 106 Cylinder 107 Piston 108 Spark plug 109 Link mechanism 110 Crank shaft 111 Low pressure piping 112 Power supply 113 Electromagnetic actuator control device 1131 Voltage measuring unit 1133 Power control unit

200 Electromagnetic actuator 201 Cam 202 Plunger 203 Suction valve 204 Movable 205 Coil 206 Stator 207 Seat part 208 Stopper 209 Spring 210 Discharge valve 211 Pressurizing chamber 212 Flow path 221 Communication port 222 Outlet 223 Casing 225 Inflow port 226 Spring part 301 Differentiating circuit 302 Absolute value circuit 303 Smoothing circuit

Claims (13)

In an electromagnetic actuator control device equipped with an arithmetic unit that controls a mover by controlling the current flowing through the coil so as to change within a certain range.
The arithmetic unit is an electromagnetic actuator control device that controls the current flowing through the coil based on the timing at which the frequency of the current flowing through the coil changes by a set value or more. In an electromagnetic actuator control device equipped with an arithmetic unit that controls a mover by controlling the current flowing through the coil so as to change within a certain range.
The arithmetic unit is an electromagnetic actuator control device that controls the current flowing through the coil so that the frequency of the current flowing through the coil is equal to or higher than a set value and the timing of change falls within the set range. In an electromagnetic actuator control device equipped with an arithmetic unit that controls a mover by controlling the current flowing through the coil so as to change within a certain range.
The arithmetic unit is an electromagnetic actuator control device that controls the current flowing through the coil so as to enter a saturation region of the relationship between the current flowing through the coil and the speed at the time of valve closing. In the electromagnetic actuator control device according to claim 2,
A control device for an electromagnetic actuator, wherein the setting range is set to be a saturation region of the relationship between the current flowing through the coil and the speed of the mover when the valve is closed. In the electromagnetic actuator control device according to claim 2,
A control device for an electromagnetic actuator, wherein the setting range is set so as to be a saturation region of the relationship between the current flowing through the coil and the impact at the time of valve closing. In the electromagnetic actuator control device according to claim 2,
A control device for an electromagnetic actuator, wherein the setting range is set so as to be a saturation region of the relationship between the current flowing through the coil and the noise when the valve is closed. In the electromagnetic actuator control device according to claim 3,
The arithmetic unit has the peak current so that the integrated current value from the start of supply of the peak current flowing through the coil to the start of reduction, the maximum current value of the peak current, or the period of flowing the maximum current value falls within the saturation region. An electromagnetic actuator control device characterized by controlling an electric current. In the electromagnetic actuator control device according to claim 1,
Filters with different gains for frequencies before and after the timing at which the mover collides with the stator,
In the amplitude extraction unit and the arithmetic unit that input the current flowing through the coil to the filter and extract the amplitude of the output obtained, the mover becomes the stator based on the change in the amplitude output by the amplitude extraction unit. An electromagnetic actuator control device characterized by estimating the timing of collision. In the electromagnetic actuator control device according to claim 1,
A differentiating circuit that differentiates the current and
An absolute value circuit that takes the absolute value of the output of the differentiating circuit and an absolute value circuit
A smoothing circuit that smoothes the output of the absolute value circuit with a time constant longer than the switching frequency is provided.
The arithmetic unit is an electromagnetic actuator control device characterized by extracting a change point of an output of the smoothing circuit. A valve body that opens and closes the inflow port where fuel flows into the pressurizing chamber on the tip side,
A mover provided on the base end side of the valve body and
In a high-pressure fuel pump provided with a stator that sucks the mover by energizing the coil.
A high-pressure fuel pump characterized by being provided with an electromagnetic actuator in which a current that changes in a certain range and whose frequency is equal to or higher than a set value and the timing of the change falls within the set range flows through the coil. In the high-pressure fuel pump according to claim 10.
The high-pressure fuel pump is characterized in that the set range is set to be a saturation region of the relationship between the current flowing through the coil and the speed at the time of valve closing. A valve body that opens and closes the injection port where fuel is injected on the tip side,
A mover provided on the base end side of the valve body and
A spring portion that constantly urges the mover in the valve closing direction, and
A coil that moves in the valve opening direction by sucking the mover against the spring force of the spring portion,
With
An injector characterized by comprising an electromagnetic actuator in which a current that changes in a certain range and whose frequency is equal to or higher than a set value and whose timing of change falls within the set range flows through the coil. In the injector according to claim 12,
The injector is characterized in that the setting range is set to be a saturation region of the relationship between the current flowing through the coil and the speed at the time of valve closing.

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