JP3629754B2 - Fuel injection rate control device for diesel engine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a control device that changes a fuel injection rate of a diesel engine according to a warm-up state.
[0002]
[Prior art]
Examples of variably controlling the combustion injection rate of a diesel engine include those disclosed in Japanese Patent Laid-Open No. 63-1754 or Japanese Patent Laid-Open No. 2-283840.
[0003]
All of these attempt to reduce combustion noise and NOx in the exhaust by changing the fuel injection rate according to the operating conditions.
[0004]
[Problems to be solved by the invention]
However, in either case, no particular consideration is given to the combustion noise when the engine is cold before the engine is sufficiently warmed up. Therefore, the fuel injection rate (initial injection rate) during warm-up is high and the combustion noise is high. There was a problem that was large.
[0005]
When the initial fuel injection rate is lowered, the combustion noise during cold operation is reduced, but combustion after warm-up tends to be insufficient, and the generation of HC and particulates increases.
[0006]
The present invention has been proposed to solve such a problem. By controlling the initial fuel injection rate in accordance with the warm-up state of the engine, the combustion noise during warm-up can be reduced, and after the warm-up. The purpose is to satisfy the improvement of the combustion characteristics of
[0007]
[Means for Solving the Problems]
As shown in FIG. 14, the first invention comprises means 111 for varying the initial injection rate of fuel supplied from the fuel injection nozzle to the engine at a time set according to the engine speed and load, and the warming of the engine. A means 112 for detecting the engine state, and a control means 113 for lowering the initial fuel injection rate during the warm-up of the engine as compared to after the warm-up. The control means performs the initial injection as the engine warms up. Increase the rate.
[0009]
In a second aspect based on the first aspect , the warm-up state detecting means detects the coolant temperature of the engine.
[0010]
In a third aspect based on the first aspect , the warm-up state detection means detects the oil temperature of the engine.
[0011]
The fourth invention is the first invention, the means for the initial injection rate in the variable was interposed leak passage connecting the pressurizing chamber and the low pressure chamber of the fuel injection pump for supplying fuel to the engine variable The orifice and the control means are each composed of a thermo wax that controls the opening of the variable orifice so that the opening of the variable orifice decreases as the coolant temperature rises and is fully closed above a predetermined temperature .
[0012]
Fifth invention, in the first aspect, the electromagnetic the means for the initial injection rate in the variable was interposed leak passage connecting the pressurizing chamber and the low pressure chamber of the fuel injection pump for supplying fuel to the engine valve, said control means, an opening degree of the solenoid valve decreases as the coolant temperature rises, hand stage, in each composed that controls the fully closing so at a predetermined temperature or higher.
[0013]
A sixth invention is the first aspect, the means for the initial injection rate in the variable is adjusted piston the volume of the pressure chamber of a fuel injection pump for supplying fuel and variable in engine, and the regulating piston An electrostrictive actuator that drives in a volume expansion direction in synchronization with a pump compression stroke, and the control means reduces the expansion amount of the pressurizing chamber volume as the cooling water temperature increases during engine warm-up. Each means is configured to control energization .
[0015]
[Action]
In the first aspect of the invention, during the warm-up of the engine, the initial fuel injection rate is controlled to be low according to the warm-up state. This prevents an increase in combustion noise when the engine is cold. When the warm-up is completed, the initial injection rate is increased to a normal state, the combustion conditions are kept optimal, and HC and particulates in the exhaust gas are reduced.
[0016]
Further, since the initial injection rate is increased as the engine warms up, combustion noise can be suppressed and combustion stability can be maintained in accordance with the warmed up state.
[0017]
In the second invention, the warm-up state of the engine is detected based on the coolant temperature.
[0018]
In the third invention, the warm-up state of the engine is detected based on the engine oil temperature.
[0019]
In the fourth aspect of the invention, part of the high-pressure fuel escapes to the low-pressure side according to the opening of the variable orifice during the pump compression stroke while the engine is warming up. Increase in combustion noise when the engine is cold is prevented.
[0020]
The opening of the variable orifice decreases as the warm-up progresses, and when the warm-up ends, the high-pressure fuel leak stops and returns to the normal initial injection rate and injection pressure to ensure combustion stability.
[0021]
In the fifth aspect of the invention, during the warming up of the engine, part of the high pressure fuel escapes to the low pressure side in accordance with the opening of the solenoid valve during the pump compression stroke, so the injection pressure decreases with the initial fuel injection rate. This prevents an increase in combustion noise when the engine is cold.
[0022]
The opening degree of the solenoid valve decreases as the warm-up progresses, and when the warm-up ends, the high-pressure fuel leak stops and returns to the normal initial injection rate and injection pressure.
[0023]
In the sixth aspect of the invention, during the warming up of the engine, the volume of the pressurizing chamber is increased by the movement of the adjustment piston in the pump compression stroke, and thus the compression pressure is reduced, and the initial fuel injection rate and the injection pressure are reduced. This prevents an increase in combustion noise when the engine is cold.
[0024]
In addition, the volume expansion amount by the adjustment piston decreases as the warm-up progresses, the initial injection rate and the injection pressure gradually increase, and the volume expansion amount becomes zero at the end of the warm-up, and the normal initial injection rate and injection Return to pressure.
[0025]
【Example】
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0026]
In FIG. 1, reference numeral 10 denotes a fuel injection pump in which the fuel injection timing and the fuel injection amount are electronically controlled. The fuel pumped from the fuel injection pump 10 is guided to the injection nozzle 52 through the pipe 51.
[0027]
Reference numeral 53 denotes an intake passage, 54 denotes an exhaust passage, 55 denotes a filter that collects particulates and the like in the exhaust, and 56 denotes an exhaust muffler that reduces exhaust noise.
[0028]
Reference numeral 57 denotes an EGR passage that recirculates exhaust through the exhaust passage 54 and the intake passage 53. Reference numeral 58 denotes a diaphragm EGR valve that controls the amount of exhaust recirculation in response to the control negative pressure.
[0029]
A negative pressure control valve 59 is supplied to the EGR valve 58 and adjusts the constant negative pressure from the vacuum pump 61 in three stages according to the duty signal from the control unit 60. For example, when the OFF duty to the negative pressure regulating valve 59 (OFF period ratio of a constant cycle) is the maximum value and the constant negative pressure is introduced into the EGR valve 58 as it is, it is set so that 50% of the exhaust gas is recirculated. To do. The EGR rate (= EGR amount / fresh air amount) at this time corresponds to 100%. When the OFF duty is reduced stepwise, the EGR valve opening is reduced stepwise due to a decrease in the negative control pressure to the EGR valve 27, and the EGR flow rate is reduced. That is, every time the OFF duty is reduced, the EGR rate is reduced to 60% and 30%.
[0030]
The three-stage EGR rate thus obtained is set as shown in FIG. 2 with respect to the operating conditions. In the figure, the EGR rate is 100% in the medium speed medium load range and the low speed full load range. On the other hand, in the high speed and high load region, the combustion period is long and the generation of smoke cannot be completely suppressed. Therefore, the intake air temperature rises due to the rise of the exhaust gas temperature and the EGR flow rate, and the NO _The EGR rate is gradually reduced to 60% and 30% because the effect of _X reduction is reduced.
[0031]
In order to control the EGR rate in accordance with engine operating conditions, a control unit 60 comprising a microcomputer is provided. In the control unit 60, an intake passage is provided via an air cleaner 62 and a sensor for detecting an accelerator opening (accelerator pedal opening). The EGR flow rate is controlled stepwise based on the signal from the air flow meter 63 that detects the intake air amount Q taken into 53 and the reference pulse and scale pulse related to the rotation speed signal.
[0032]
In order to obtain the characteristics of the EGR rate (target EGR rate) shown in FIG. 2 with respect to the torque generated by the engine and the engine speed, the accelerator opening (amount corresponding to the engine load) Acc and the engine speed Ne are used as parameters. A map (not shown) to be set is set, the map is looked up, and the target EGR rate at that time is obtained. From this and the air flow meter flow rate (fresh air flow), the EGR flow rate is calculated by EGR flow rate = air flow meter flow rate × target EGR rate, and the OFF duty to the negative pressure control valve 59 is determined so that the EGR gas of this flow rate flows. It is.
[0033]
Means for generating a swirl in the intake air flowing into the combustion chamber 71 is shown in FIGS. 3 and 4 (not shown in FIG. 1). A so-called helical-type intake port 81 (formed by a substantially straight intake passage 81a and a spiral passage 81b around the intake valve shaft) is located near a spiral passage 81b and is rotatably provided. And a link mechanism (not shown) connected to the blade 82 and an actuator (not shown) for driving the link mechanism, and the swirl ratio can be adjusted at the rotational position of the blade 82.
[0034]
For example, the blade 82 has a high swirl ratio at the position shown in FIG. 3, but a low swirl ratio when the blade 82 reaches the position shown in FIG. This rotating blade system has a quick response and can control a wide range of swirl ratios. Therefore, it is suitable for controlling HC that reacts sensitively to the swirl ratio.
[0035]
When the characteristic of the swirl ratio with respect to the operating conditions is shown in FIG. 5, the swirl ratio is increased in the engine low speed range. On the other hand, in the high speed range, the volume (intake charging) efficiency decreases significantly with the high swirl ratio, and the improvement in combustion by increasing the injection pressure weakens the need for swirl. The swirl ratio is reduced.
[0036]
The variable swirl actuator is a diaphragm type actuator with a two-stage spring (not shown), and a negative pressure that creates a control negative pressure in three stages by diluting the atmosphere to a constant negative pressure from a negative pressure source. It consists of a control valve.
[0037]
Next, FIG. 6 shows details of the fuel injection pump 10. In FIG. 6, the fuel injection pump 10 includes a plunger 2 that compresses fuel in the pressurizing chamber 10 a while reciprocating while rotating with a cam roller in an injection pump body 1 that forms a pump housing. A control sleeve 3 that adjusts the fuel injection amount by opening and closing a cut-off port 2 a formed on the plunger 2 is slidably fitted to the outer periphery of the plunger 2, and a rotary that drives the control sleeve 3. A solenoid 4 is provided.
[0038]
The fuel discharged from the feed pump 6 attached to the pump drive shaft lubricates the inside of the pump and accumulates pressure in the pump chamber 7, and is sucked into the pressurizing chamber 10a from here.
[0039]
In order to control the fuel injection timing, a timer piston 8 is provided as an injection timing control member that moves the phase of the cam roller while engaging the cam roller that drives the plunger 2. The position of the timer piston 8 is controlled by a timing control valve 9 (see FIG. 7) that controls the flow rate of fuel leaked from the high-pressure chamber at one end to the low-pressure chamber, thereby leading or retarding the fuel injection timing. Or make it horn.
[0040]
A control unit 18 is provided to control the fuel injection amount, injection timing, and the like. The control unit 18 includes positions of various sensors constituting the operation state detection means, that is, the nozzle lift sensor 12 and the control sleeve 3 as actual injection timing detection means mounted on the fuel injection nozzle 11 and actually measuring the injection timing. A sleeve position sensor 5 that detects the fuel injection amount (a representative value of the load), a water temperature sensor 13 that detects the cooling water temperature, a rotational speed sensor 14 that detects the engine rotational speed, a fuel temperature sensor 15 that detects the fuel temperature, Signals from various sensors from a start switch 16 for recognizing an engine start command, a starter 17 as cranking means for cranking the engine, and the like are input, and based on these, the fuel injection amount and the injection timing are controlled as described later. To do.
[0041]
FIG. 8 shows a control block diagram of the fuel injection amount.
[0042]
S11 is a drive Q control circuit that sets a target injection amount based on the fuel injection characteristics set by the engine speed N and the water temperature Tw during normal operation, and S12 is in addition to the drive Q control during idle operation. The circuit compares the target engine speed with the actual engine speed and increases or decreases the target fuel injection amount by PID control according to the deviation. S13 is a limiting circuit that limits the maximum injection amount based on the water temperature Tw, the supercharging pressure, and the like for the drive Q set in the standard state.
[0043]
On the other hand, when the engine is started, the target fuel injection amount is increased by the start increase control circuit S14 based on the engine speed N and the water temperature Tw. Since the fuel injection amount at the position of the same control sleeve 3 varies depending on the fuel temperature detected by the fuel temperature sensor 11, the correction circuit S15 is used for the target fuel injection amount determined by the circuits S11 to S14. Add correction by fuel temperature. Then, the circuit S16 searches the pump characteristic map for the relationship between the position of the control sleeve 3 and the fuel injection amount, and determines the position of the target control sleeve 3 with respect to the target fuel injection amount.
[0044]
Further, in the circuit S17, the target control sleeve position is compared with the actually measured control sleeve position, the amount of movement of the control sleeve 3 is obtained by PID processing, and is output to the rotary solenoid 4.
[0045]
Next, FIG. 9 shows a control block diagram of injection timing control.
[0046]
S21 is a circuit for determining the fuel injection timing based on the rotation-load characteristic of the injection timing set by the engine speed N and the load (represented by the fuel injection amount and the accelerator opening) during normal operation, S22 is a circuit for determining the fuel injection timing based on the start injection timing advance characteristic set by the engine speed N and the water temperature Tw when the engine is started.
[0047]
Then, the control circuit S23 compares the target injection timing with the actually measured injection timing actually measured by the nozzle lift sensor 12, obtains the movement amount of the timer piston 8 by PID processing, and obtains an actuator command signal (timing control valve 9). And the fuel injection timing is thereby controlled.
[0048]
FIG. 10 shows a configuration for controlling the initial fuel injection rate according to the warm-up state of the engine in such a fuel injection pump 10.
[0049]
FIG. 10 is a cross-sectional view of a part of FIG. 1 and is provided with a leak passage 40 that connects the pressurizing chamber 10a and the pump chamber 7, and the leak passage 40 has a variable orifice 42 that expands and contracts the flow passage cross section. Is installed.
[0050]
The variable orifice 42 having a through hole 42a in the middle of the piston 42b is driven by a thermowax 41 to change the degree of communication between the through hole 42a and the leak passage 40. The thermowax 41 communicates with an engine coolant passage (not shown). It expands according to the temperature of the cooling water introduced by the cooling water introduction pipe 44 to be moved, thereby moving the piston 42b against the return spring 43, and when the warm-up operation is completed, the through hole 42a and the leak passage 40 Block communication.
[0051]
It is comprised as mentioned above, Next, an effect | action is demonstrated.
[0052]
As the engine rotates, the pressurized fuel sent to the pump chamber 7 by the feed pump 6 is sucked into the pressurizing chamber 10a by the reciprocating motion of the plunger 2 and pumped from the pressurizing chamber 10a to the delivery valve 20. The fuel is injected directly from the fuel injection valve of each cylinder into the combustion chamber.
[0053]
By the way, when the engine is cold immediately after starting the engine, the coolant temperature is low, the thermowax 41 is contracted, the piston 42b is pushed by the return spring 43, and the opening area of the variable orifice 42 is fully open.
[0054]
In this state, in the compression stroke of the plunger 2, part of the fuel in the pressurizing chamber 10 a escapes from the leak passage 40 to the low-pressure pump chamber 7 according to the area of the variable orifice 42. However, since the opening area of the variable orifice 42 is very small, only a part of the fuel compressed by the plunger 19 leaks, and the rest is injected and supplied to the combustion chamber of each cylinder.
[0055]
However, when a part of the high-pressure fuel escapes from the leak passage 40 in this way, in particular, the initial injection rate of the fuel is lowered and the injection pressure is also relatively lowered. For this reason, combustion noise is significantly reduced with a decrease in the initial injection rate, such as when the engine is cold.
[0056]
During the warm-up, the coolant temperature rises as the warm-up progresses, and the thermowax 41 expands little by little (see FIG. 11A). In response to this, the piston 42b is pushed back against the return spring 43, and the opening area of the variable orifice 42 gradually decreases. By reducing the opening area of the variable orifice 42, the amount of high-pressure fuel escaping from the pressurizing chamber 10a to the leak passage 40 is reduced, and the initial injection rate is gradually increased.
[0057]
Therefore, the initial fuel injection rate does not change abruptly during the warm-up, and combustion stability and smooth warm-up operation are ensured.
[0058]
When the warm-up is completed, the variable orifice 42 is fully closed and the amount of fuel leaking from the pressurizing chamber 10a becomes zero (see FIG. 11B). In this state, the fuel initial injection rate and injection pressure rise to values required during normal operation.
[0059]
For this reason, the combustion characteristics after warm-up are stabilized, and HC and particulates in the exhaust are effectively suppressed.
[0060]
In addition, stable combustion can be ensured by high initial injection rate and high-pressure fuel injection, such as when NOx and particulates are reduced and the fuel injection timing is retarded together with exhaust gas recirculation after warm-up.
[0061]
In this embodiment, the thermowax 41 is controlled by the cooling water temperature, but the expansion of the thermowax 41 can also be controlled by the oil temperature of the engine.
[0062]
Next, the embodiment of FIG. 12 will be described. Here, the opening area of the leak passage 40 is controlled according to the warm-up state by the electromagnetic valve 45 instead of the variable orifice 42.
[0063]
The solenoid valve 45 is duty-controlled by a signal from a controller (not shown). The lower the coolant temperature is, the larger the opening area is. As the warm-up proceeds, the area decreases, and when the warm-up ends, the solenoid valve 45 is fully closed. It has become.
[0064]
Also in this case, as in the above-described embodiment, the initial fuel injection rate can be reduced when the engine is cold, and the fuel injection rate can be gradually increased as the warm-up progresses. A high initial injection rate is maintained so that combustion noise is effectively reduced and stable combustion characteristics are obtained after warm-up.
[0065]
On the other hand, in the embodiment of FIG. 13, only in the compression stroke of the plunger 2, the volume of the pressurizing chamber 10a is variably controlled to change the initial fuel injection rate and the injection pressure.
[0066]
A volume adjusting piston 48 is inserted into the pressurizing chamber 10a from the side opposite to the plunger 19, the position of the adjusting piston 48 is changed by a compression stroke, the volume of the pressurizing chamber 10a is temporarily expanded, and the compression pressure of the fuel Lower.
[0067]
The volume expansion amount of the pressurizing chamber 10a by the adjustment piston 48 gradually decreases as the warm-up progresses, and returns to the normal state after the warm-up is completed. However, the adjustment piston 48 moves immediately after the transition to the compression stroke, and the adjustment piston 48 is returned to the initial position at the moment when the compression is finished. In order to control the position of the adjustment piston 48 in this way, an electrostrictive actuator 47 is provided, and the electrostrictive actuator 47 drives the adjustment piston 48 in accordance with the amount of current supplied. The electrostrictive actuator 47 expands and contracts simultaneously with the energization control. The energization amount is controlled according to the coolant temperature, the engine oil temperature, and the like by a controller (not shown), and the energization timing is controlled in synchronization with the reciprocation of the plunger 2. Is done.
[0068]
Therefore, the electrostrictive actuator 47 is energized with the start of the compression stroke by the plunger 2 such as when the engine is cold, thereby driving the adjustment piston 48 and expanding the volume of the pressurizing chamber 10a. For this reason, the compression pressure decreases, the initial fuel injection rate decreases, and the injection pressure relatively decreases, reducing combustion noise.
[0069]
When the compression stroke is completed, the energization to the electrostrictive actuator 47 is interrupted, the adjustment piston 48 is returned to the initial position (the pressure chamber volume is reduced), and the suction stroke is performed by the plunger 2 in this state.
[0070]
The volume expansion amount by the adjustment piston 48 decreases as the warm-up progresses. When the warm-up is completed, the energization control to the electrostrictive actuator 47 is stopped, and the adjustment piston 48 is held in the initial state. For this reason, after the warm-up, both the initial fuel injection rate and the injection pressure are kept high, and the combustion characteristics after the warm-up are stabilized.
[0071]
【The invention's effect】
According to the first aspect of the invention, the initial fuel injection rate is kept low, such as when the engine is cold, thereby reducing the combustion noise of the engine. When the warm-up is completed, the initial fuel injection rate and the injection pressure are normal. It can be raised to the state, the combustion conditions are kept optimal, and HC and particulates in the exhaust can be effectively reduced.
[0072]
Since the initial injection rate is increased as the engine warms up, the combustion stability during warm-up, smooth operation and suppression of combustion noise can be achieved.
[0073]
According to the second invention, it is possible to appropriately detect the warm-up state of the engine based on the coolant temperature.
[0074]
According to the third aspect of the invention, the warm-up state of the engine can be detected appropriately based on the engine oil temperature.
[0075]
According to the fourth aspect of the invention, during the warming up of the engine, part of the high-pressure fuel escapes to the low-pressure side in accordance with the opening of the variable orifice during the pump compression stroke, thereby reducing the injection pressure together with the initial fuel injection rate. The combustion noise of the engine can be reduced, and the opening of the variable orifice decreases with the progress of warming up. At the end of warming up, the leakage of high pressure fuel stops and returns to the normal initial injection rate and injection pressure. This ensures the stability of combustion and reduces the generation of HC and particulates.
[0076]
According to the fifth invention, during engine warm-up, part of the high-pressure fuel escapes to the low-pressure side in accordance with the opening of the solenoid valve during the pump compression stroke, so the injection pressure decreases with the initial fuel injection rate, The combustion noise of the engine can be reduced, and the opening of the solenoid valve decreases with the progress of warming up. At the end of warming up, the leak of high-pressure fuel stops and returns to the normal initial injection rate and injection pressure. Ensures combustion stability and reduces the generation of HC and particulates.
[0077]
According to the sixth aspect of the invention, during the warming up of the engine, the adjustment piston moves in the pump compression stroke, so that the volume of the pressurizing chamber is increased, so that the compression pressure is reduced, and the initial fuel injection rate and the injection pressure are reduced. In addition, engine combustion noise can be reduced.
[0078]
In addition, the volume expansion amount by the adjustment piston decreases as the warm-up progresses, the initial injection rate and the injection pressure gradually increase, and the volume expansion amount becomes zero at the end of the warm-up, and the normal initial injection rate It is possible to return to the injection pressure, thereby ensuring the stability of combustion and reducing the generation of HC and particulates.
[Brief description of the drawings]
FIG. 1 is an overall schematic configuration diagram showing an embodiment of the present invention.
FIG. 2 is a control characteristic diagram of an exhaust gas recirculation rate.
FIG. 3 is an explanatory diagram of swirl generating means.
FIG. 4 is an explanatory view showing the operating state of the same.
FIG. 5 is a control characteristic diagram of a swirl ratio.
FIG. 6 is a cross-sectional view of a fuel injection pump.
FIG. 7 is a partial cross-sectional view of the same.
FIG. 8 is a block diagram of a fuel injection amount control circuit.
FIG. 9 is a block diagram of a fuel injection timing control circuit.
FIG. 10 is a cross-sectional view of a main part of a fuel injection rate control part.
11A and 11B are explanatory views showing the operating state, wherein FIG. 11A shows the variable orifice half open, and FIG. 11B shows the fully closed state.
FIG. 12 is a cross-sectional view of a main part showing a second embodiment.
FIG. 13 is a cross-sectional view of a main part showing a third embodiment.
FIG. 14 is a configuration diagram of the present invention.
[Explanation of symbols]
10 Fuel injection pump 40 Leak passage 41 Thermo wax 42 Variable orifice 45 Electromagnetic valve 47 Electrostrictive actuator 48 Adjusting piston

Claims (6)

Means for varying the initial injection rate of fuel supplied to the engine from the fuel injection nozzle at a time set according to the engine speed and load, means for detecting the warm-up state of the engine, and during engine warm-up And a control means for lowering the initial fuel injection rate as compared to after warm-up, wherein the control means increases the initial fuel injection rate as the engine warms up. Control device. The fuel injection rate control device for a diesel engine according to claim 1, wherein the warm-up state detection means detects a cooling water temperature of the engine. The diesel engine fuel injection rate control apparatus according to claim 1, wherein the warm-up state detection means detects an oil temperature of the engine. A variable orifice interposed in a leak passage connecting a pressurizing chamber and a low pressure chamber of a fuel injection pump for supplying fuel to the engine;
2. The diesel engine according to claim 1, wherein the control means includes a thermo wax that controls the opening degree of the variable orifice so that the opening degree of the variable orifice decreases as the coolant temperature increases and is fully closed at a predetermined temperature or higher. Fuel injection rate control device. A solenoid valve interposed in a leak passage connecting a pressurizing chamber and a low-pressure chamber of a fuel injection pump for supplying fuel to the engine;
2. The fuel for a diesel engine according to claim 1, wherein each of the control means is configured to control the opening degree of the electromagnetic valve so that the opening degree of the solenoid valve decreases as the coolant temperature increases and is fully closed at a predetermined temperature or higher. Injection rate control device. The means for varying the initial injection rate is an adjustment piston that makes the volume of the pressurization chamber of the fuel injection pump that supplies fuel to the engine variable, and the adjustment piston is driven in the volume expansion direction in synchronization with the pump compression stroke. Electrostrictive actuator,
2. The control unit according to claim 1, wherein the control unit is configured to control energization of the electrostrictive actuator so that the amount of expansion of the pressurizing chamber volume is reduced as the cooling water temperature increases while the engine is warming up. Fuel injection rate control device for diesel engines.

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