JP3048285B2 - Fuel injection valve drive control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control apparatus for a fuel injection valve of an internal combustion engine, and more particularly to a drive control apparatus for a fuel injection valve for an internal combustion engine using a piezoelectric actuator.

[0002]

2. Description of the Related Art Recently, a fuel injection valve device for an internal combustion engine using a piezoelectric element actuator has been receiving particular attention because of its high speed operation. FIG. 6 is a conceptual configuration diagram showing an example of a configuration of a fuel injection valve device for an internal combustion engine using such a piezoelectric element.
Inside, a piezoelectric element 101 is used as a driving actuator. That is, when the pressure of the hydraulic oil 103 becomes lower than the pressure of the pressure receiving surface 106 when the piston 102 rises in accordance with the contraction of the piezoelectric element 101, the push rod 104
Rises, and the fuel in the pressure chamber 105 is pressurized and injected from the injection holes 108. In addition, when the piezoelectric element 101 is expanded, the pressure of the hydraulic oil 103 increases, and the injection holes 108 are closed by an action opposite to that at the time of compression. The injection stops. In order to reliably open and close the valve by the above operation, for example, a disc spring 107 is disposed in the hydraulic oil chamber.

[0003] Incidentally, as a fuel injection valve using a piezoelectric element actuator, there is a type which injects fuel when the piezoelectric element is expanded and inhales when contracted, contrary to the one shown in the figure. The amount of fuel injection is determined by the duration of the contraction or extension of the piezoelectric element.
There is also a fuel injection valve having a structure in which fuel is pumped by a piston that moves up and down in accordance with expansion and contraction of a piezoelectric element to inject fuel. It will be.

FIG. 7 is a circuit diagram showing a basic configuration of a flyback type driving circuit suitable as a piezoelectric element driving circuit in the fuel injection valve as shown in FIG.
Is a piezoelectric element (PZT) corresponding to the piezoelectric element 101 as a driving actuator in FIG. 6, 202 is a flyback transformer, 203 is a driving transistor, 204 is a charging switch, 205 is a reverse current prevention diode for charging,
06 is a discharge switch, 207 is a backflow prevention diode for discharge, 208 is a discharge coil, and 210 is an electronic control unit E.
CU. FIG. 8 shows operation waveforms during normal operation of the drive circuit.

The principle of operation of this flyback type drive circuit is that the flyback transformer 202 is connected to the secondary side by flyback energy generated on the secondary side of the transformer when the current flowing through the primary coil of the flyback transformer 202 is cut off. The piezoelectric element (PZT) 201 is charged, the piezoelectric element 201 is expanded, the injection is stopped, and the electric charge of the piezoelectric element 201 is discharged through the discharge coil 208, and the piezoelectric element 201 is contracted to inject fuel. The piezoelectric element 201
Is in a contracted state during the period from discharge to the next charge, and the fuel injection amount is determined by the time width.

[0006] In the operation waveforms shown in FIG.
Reference numerals 2, 213, and 214 denote an injection signal, a coil energization signal (hereinafter, also referred to as a dwell signal, as will be described later), a PZT discharge signal, and a PZT charge signal, respectively.
In the electronic control unit ECU 210, a coil energizing signal for supplying a necessary amount of energy to the piezoelectric element 201, that is, a dwell signal 21 is supplied from a fuel injection signal 211 indicating a fuel injection time calculated in accordance with the operating state of the engine.
2. PZT discharge signal 213 and PZT charge signal 21 synchronized with rising and falling of injection signal 211, respectively.
4 are formed.

The coil energization signal, that is, the dwell signal 212
Has its fall coincident with the fall of the injection signal 211, and its rise is a constant time during which a constant charge energy can be supplied to the piezoelectric element 201, that is, an energizing time between rise and fall, that is, a dwell time. Width, eg 4-5
Milliseconds. As a result, the amount of expansion of the piezoelectric element 201 becomes constant, and the degree of change in the operating oil pressure is made constant. As a result, the fuel injection amount per time, that is, the fuel injection rate is made constant, thereby enabling uniform fuel injection control. Things. Further, the PZT discharge signal 213 and the PZT charge signal 214 are respectively
1 is an on / off control signal of the discharge switch 206 and the charge switch 204 for instantaneously achieving the discharge and charge of 1. Both of the on periods have a time width of, for example, about 200 microseconds.

First, the electronic control unit ECU 210
By the supplied coil energizing signal 212, t₁At the time
Drive transistor 203 is turned on, and the flyback
Primary current I to the primary coil of the transformer 202₁215
Flows. At this time, the primary current I ₁Is the primary in of the transformer
Ductance is L₁Then dI₁/ Dt = V_B/ L ₁
(V_B: Power supply voltage). Soshi
At the end of the coil energization period, that is, the coil energization signal
The falling t of 212_ThreeThe primary current at the time is I_DTo be
And the flyback transformer 202 has 1/2 (L₁・ I
_D ^Two) Will be stored. This
During t₁~ T_ThreeInitially, the charging switch 204
And the discharge switch 206 are both in the off state.
In addition, the piezoelectric element 201 was charged in the previous charging cycle.
It is stretched in the state where it was put. The piezoelectric element 2 at this time
01, that is, the PZT voltage 216_C= I
_D・ √ (L₁/ C) (C: capacitance of the piezoelectric element 201)
Value, for example, reaches a value of about +600 V
I do.

After energizing the flyback coil, the injection signal 2
11, that is, at time t ₂ , a PZT discharge signal 213 is applied from the electronic control unit ECU 210 to the discharge switch 206, the discharge switch 206 is turned on, and the electric charge of the piezoelectric element 201 is discharged through the discharge coil 208. Is done. As a result, the piezoelectric element 201 contracts, opens the injection hole 108 of the fuel injection valve 100 in FIG. 6, and starts fuel injection. During this transition, a resonance circuit is formed by the capacitance C of the piezoelectric element 201 and the discharge coil 208, and a resonance current flows and the piezoelectric element 201
Is discharged instantaneously, and the terminal voltage PZT voltage 216 drops sharply. Then, the resonance current is cut off by the backflow prevention diode 207, and the discharge ends. This transient change is about 100 microseconds, and ends within about 200 microseconds of the PZT discharge signal width. For this reason, the PZT voltage 216 has its swing in the plus direction cut off as shown by the dotted line, and
For example, the voltage drops to -200 V, and the piezoelectric element 201 stays in the contracted state corresponding to this state. At this time,
The fuel injection at a constant rate is continued as shown by the fuel injection rate 217 in FIG. 8 depending on the contraction state of the piezoelectric element or according to the valve opening determined mechanically. .

Next, when the falling of the injection signal 211, that is, the time t ₃ is reached, the coil energizing signal 212 falls,
The drive transistor 203 is turned off, and the PZT charge signal 214 is applied from the electronic control unit ECU 210 to the charge switch 204 to be turned on. When the drive transistor 203 is turned off, the primary current I ₁ is cut off, a flyback pulse is generated on the secondary side of the flyback transformer 202, and the energy stored during the above-described energization period, that is, during the dwell time, is released. At this time, since the charging switch 204 is turned on, the piezoelectric element 201 is charged by the flyback energy. In a transient state, the secondary side inductance of the flyback transformer 202 and the capacitance C of the piezoelectric element 201 constitute a resonance circuit, and a resonance current flows, and the piezoelectric element 201 is instantaneously charged and expanded by flyback energy. . As in the case of discharging, the reverse resonance current is
5, the piezoelectric element 201 is maintained in a charged state by flyback energy, that is, an expanded state corresponding to the energy amount. as a result,
The terminal voltage of the piezoelectric element 201, that is, the PZT voltage 216
As shown in FIG. 8, the voltage rapidly rises in the positive direction to reach the above-described E _C, that is, +600 V, for example, and is maintained at that voltage. The secondary side inductance of the flyback transformer 202 is set to be substantially the same as that of the discharge coil 208.
Microseconds, and ends within about 200 microseconds of the PZT charging signal width. Thus, the fuel injection rate 2
17 also, as shown in the drawing, the injection is rapidly stopped, and the injection valve is closed.

The flyback type driving circuit shown in FIG. 7 operates as described above to drive and control the fuel injection of the fuel injection valve in accordance with the injection signal having an injection time corresponding to the operating state of the engine, thereby achieving the target idle Fuel injection control such as fuel ratio control can be realized. FIG. 9 is a circuit block diagram showing a principle configuration of a fuel injection valve drive control system of a four-cycle four-cylinder engine to which a fuel injection valve using a piezoelectric element driven by the above flyback type drive circuit is applied. . Here, one flyback transformer section 220 is used in common, and the piezoelectric elements for operating the fuel injection valves for four cylinders are selectively formed in a predetermined order and driven by forming a flyback drive circuit. The piezoelectric element circuit portions 221 to 224, which are the remaining portions of the flyback drive circuit, are similarly configured and provided for four cylinders, as shown. The components of the flyback transformer section 220 and the piezoelectric element circuit sections 221 to 224 are the same as those in FIG. 7. For example, the flyback transformer 202, the drive switch (transistor) 203, and the reverse current for charging are used. The protection diode 205 is provided in a common flyback transformer section 220.

FIG. 10 is a time chart schematically showing an operation signal waveform for each of the cylinders # 1 to # 4 in the fuel injection valve drive control system for the four-cylinder engine. In the drawing, a signal 231 is a coil energization signal for storing energy in a coil of a flyback transformer in a drive circuit, that is, a coil energization signal for charging energy, that is, a dwell signal, a signal 232 is an ejection signal, and a signal 233 is a dwell signal 2
31 and the terminal voltage of the piezoelectric element driven based on the ejection signal 232, that is, the PZT voltage _VPZT . Each of these signals for each cylinder is assigned a cylinder number, and the operation sequence of each cylinder follows the ignition sequence of a normal four-cylinder internal combustion engine.

FIG. 11A shows a schematic configuration of an example of an actual four-cylinder piezoelectric element drive circuit, in which one flyback transformer A or B uses four cylinders #.
Piezoelectric element # 1PZT for driving fuel injection valve for # 1 to # 4
# 4PZT are driven in common, and for each cylinder, in the intake stroke so as to generate a good air-fuel mixture,
Further, a flyback transformer A for the intake stroke and a flyback transformer B for the compression stroke are provided to perform two fuel injections in the compression stroke so as to form a rich mixture around the plug at the time of ignition. I have. FIG. 11 (2)
Is the drive waveform of each flyback transformer in that case (1
4 is a time chart showing the relationship between the secondary current) and the crank rotation angle ( _CA ).

FIG. 12 is a time chart showing the timing of intake and compression stroke injection for four cylinders # 1 to # 4 in more detail.
210) PZT injection signals for intake and compression injections as output signals of (2) and a flyback energization signal, ie, a dwell signal (3), which is an energization signal to the primary coils of the flyback transformers A and B. The resulting PZ
The T voltage waveform (1) is shown clarifying the time relationship. Here, a case is shown where both the intake injection and the compression injection are executed for each cylinder and the intake injection time is slightly long. In this case, the control is performed when the engine load is a medium load, that is, when the engine load is a medium load. For other engine loads, from the required fuel injection amount and the generation state of the air-fuel mixture, for example, at light load, fuel injection is performed only in the compression stroke, and at high load, Means that fuel injection is executed only during the intake stroke.

In the fuel injection valve drive control device for an internal combustion engine of an automobile as described above, the operation of the engine is controlled according to the operating state of the engine.
The fuel injection amount is constantly and widely controlled,
A parameter indicating the operating state of the engine, for example, accelerator opening
Controls the timing and time of fuel injection by forming an injection signal according to the fuel injection amount Q _INJ determined by ACCP and engine speed NE, and adjusting the dwell signal and PZT discharge and charge signals based on the injection signal Thus, the actual fuel injection amount for each cylinder of the engine is controlled.

[0016]

SUMMARY OF THE INVENTION A compressed line as described above
Of the internal combustion engine of the double injection system
In the fuel injection valve drive control device, as shown in FIG.
In addition, for example, the end timing of the compression stroke injection of cylinder # 1 and
End timing of intake stroke injection of other # 3 cylinders approaches
Then, the charge to the piezoelectric elements in the fuel injection valves of both cylinders
Both piezoelectric elements are charged at the same time during the
Current I flowing simultaneously in the element_PZT(# 1) and I _PZT(# 3)
The distribution is skewed, for example, as shown_PZT(# 1)
And I_PZTDistortion may occur to reduce (# 3)
You. As a result, the PZT voltage V_{PZ T}As seen in
And V_PZT(# 1) is big by getting energy from # 3 cylinder
Become, V_PZT(# 3) is energy taken by the # 1 cylinder
Will be smaller.

When the end timings of the compression stroke injection and the intake stroke injection of the two different cylinders overlap each other, the energy supply source of the intake injection flyback coil and the compression stroke injection flyback coil corresponding to each injection is increased. As a result, the energy distribution will be impossible,
In a cylinder provided with a fuel injection valve driven by a piezoelectric element on the side where the amount of energy supplied is small, the amount of fuel injected is reduced, which causes a problem that engine misfire occurs.

According to the present invention, in order to solve such a problem, a correction is made so as to avoid overlapping of the dwell-off times for the compression stroke injection and the intake stroke injection in the cylinders having the adjacent ignition sequences. It is an object of the present invention to provide a fuel injection valve drive control device for an internal combustion engine that can be used.

[0019]

According to the present invention, as schematically shown in FIG. 1, a piezoelectric element is connected to a secondary coil of a transformer, and a current flowing through the primary coil at a predetermined timing. By shutting off, a flyback energy is generated in the secondary coil to charge the piezoelectric element, and the piezoelectric element is discharged at a predetermined timing,
(B) for controlling opening and closing of a fuel injection valve operated by the piezoelectric element, wherein a plurality of fuel injection valves (1, 2,..., N) for injecting fuel into a plurality of cylinders are provided in a predetermined manner. In a fuel injection valve drive control device for an internal combustion engine, which performs opening / closing control (D) in order and controls (A) each fuel injection valve to inject a plurality of times in an intake stroke and a compression stroke in one cycle, a specific cylinder When the compression stroke injection end timing and the intake stroke injection end timing of another cylinder are close to each other, the injection timing is corrected (C) so that at least one of the injection timings is shifted.
This correction of the injection timing is made so that the intake stroke injection end timing is shifted away from the compression stroke injection end timing.

[0020]

According to the above arrangement, the injection end timing of the intake stroke injection and the injection end timing of the compression stroke injection do not overlap.
The energy charged in the piezoelectric elements in each injector is evenly distributed, and the fuel injection amount in each injector can be controlled to a desired value.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel injection valve drive control device for an internal combustion engine according to the present invention will be described below with reference to a configuration for avoiding the above-described overlapping injection. The configuration shown in FIG. 11 is used as the PZT drive circuit. As described above, the flyback coil A is responsible for the intake stroke injection of the # 1 to # 4 cylinders, and the flyback coil B is used for the compression. I am in charge of stroke injection. In the double injection control system in which injection is required in the intake stroke and the compression stroke, # 1 → # 3
In the process in which the combustion progresses from # 4 to # 2, the end time of the compression stroke injection of the preceding cylinder, for example, # 1, and the intake stroke injection of the succeeding cylinder, for example, # 3, overlap between consecutive cylinders. Occurs.

FIG. 2 shows such a # 1 compression stroke injection and #
9 is a time chart for explaining a correction control method according to the present invention for avoiding the overlap when the end timings of the three intake stroke injections overlap. To avoid duplication, the intake stroke injection is for producing a good mixture, and the compression stroke injection is for forming a rich mixture around the plug just before ignition, and Since the stroke injection is relatively insensitive to combustion, the intake stroke injection is shifted on the advance side or the retard side in anticipation of the margin time Tc according to the close condition.

As shown in FIGS. 2A and 2B, a dwell signal and an injection signal for the compression stroke injection of the # 1 cylinder, and #
The dwell signal and the injection signal for the intake stroke injection of the three cylinders are approaching almost at the same time. Here, for simplicity, the time parameter in those signals is # 2
It is shown based on TDC timing. That is, regarding the dwell signal for the compression stroke injection of the # 1 cylinder, the dwell time: TDWLS # 1, the dwell time: TDWL,
Dwell-off time: TDWLE # 1 For the injection signal for the compression stroke injection of # 1 cylinder,
Injection start time: TAINJ # 1, Injection time: TINJ # 1, and #
Regarding the dwell signal for the intake stroke injection of the three cylinders,
Dwell time: TDWLS # 3, dwell time: TDWL, dwell off time: TDWLE # 3 Regarding the injection signal for the intake stroke injection of # 3 cylinder,
The injection start time is represented by TAINJ # 3, and the injection time is represented by TINJ # 3.

Therefore, in the correction control according to the present invention, first, the dwell-off time for the compression stroke of the # 1 cylinder and the # 3
The difference from the dwell time for the intake stroke of the cylinder is taken. That is, ΔT = TDWLE # 1-TDWLE # 3 is calculated. Next, whether or not the dwell-off times for both injections are close to each other and the condition of the proximity, that is, the direction of the proximity, are determined based on the magnitude relationship between the dwell-off time difference ΔT and the allowance time Tc and the sign thereof, as follows. Take appropriate measures. In addition, as the allowance time Tc, for example,
As described above, a PZT charging signal having a time width of about
That is, about 200 microseconds can be used.

Countermeasure: When Tc ≧ ΔT ≧ 0, that is, when # 3 is close to # 1 on the advance side, as shown in FIG. 2C, the dwell-off time of # 3 is set to # 1. The angle is advanced by an amount corresponding to the time Tc. That is, TDWLE # 3 = TDWLE # 1−Tc = TDWLE # 3− (Tc−ΔT), and is shifted to the advance side. Similarly, the dwell-on time and the injection start time of # 3 are also shifted to the advance side. That is, TDWLS # 3 = TDWLS # 3− (Tc−ΔT) TAINJ # 3 = TAINJ # 3− (Tc−ΔT).

Measures: When 0> ΔT ≧ −Tc, that is, when # 3 is close to # 1 on the retard side, as shown in FIG. 2D, the dwell-off time of # 3 is set to # It is retarded by an amount corresponding to the Tc time from 1. That is, TDWLE # 3 = TDWLE # 1 + Tc = TDWLE # 3 + Tc + .DELTA.T, and is shifted to the retard side. Similarly, the dwell-on time and the injection start time of # 3 are also shifted to the retard side. That is, TDWLS # 3 = TDWLS # 3 + Tc + ΔT TAINJ # 3 = TAINJ # 3 + Tc + ΔT.

By the above measures, the dwell-off time for the compression stroke injection of the # 1 cylinder and the dwell-off time for the intake stroke injection of the # 3 cylinder can be shifted so as to have a Tc time interval. Of the piezoelectric element charging time can be completely avoided. FIG. 3 is a timing chart for explaining the operation of the embodiment of the fuel injection valve drive control device for an internal combustion engine according to the present invention, and FIGS. 4 and 5 are flowcharts showing an example of software for realizing the operation. is there. Here, a case where the compression stroke injection of the # 4 cylinder and the intake stroke injection of the # 2 cylinder are close to each other will be described as an example.

First, in the base routine of FIG. 4, basic injection output data and dwell output data for the compression stroke injection and the intake stroke injection are calculated in advance at a constant cycle of, for example, every 5 milliseconds. That is, in the calculation step a, for the compression stroke injection (A2) and for the intake stroke injection (A1)
Basic injection output data, that is, injection start timing TAIN
Calculate JA1, TAINJA2 and injection time TINJA1, TINJA2 based on accelerator opening ACCP and engine speed NE: TAINJA1 = f (ACCP, NE) TAINJA2 = f (ACCP, NE) TINJA1 = f (ACCP, NE) TINJA2 = f (ACCP, NE) Next, in the calculation step b, for the compression stroke injection (A2)
And basic dwell output data for intake stroke injection (A1),
That is, dwell start times TDWLSA1, TDWLSA2, dwell time TDWL, and reference 30 ( _CA ) angular position CASET are calculated: TDWLSA1 = f (TAINJA1, TINJA1, NE) TDWLSA2 = f (TAINJA2, TINJA2, NE) CASET = f (TDWLSA2 , NE) TDWL = constant (ms ) FIG. 5 is a 30 _(CA) interrupt routine for shifting the Doeruofu time is executed every 30 _(CA). FIG. 3 shows the time relationship of the data handled there. First, in step c, it is determined whether or not it is time to output the injection and dwell signals (CASET?). If Yes, in step d, among the dwell data for the fuel injection valves of the cylinders in the adjacent injection order,
The difference ΔT between the dwell-off time TDWLEA2 for the compression stroke injection for the fuel injection valve of the preceding cylinder and the dwell-off time TDWLEA1 for the intake stroke injection for the fuel injection valve of the following cylinder is calculated. Next, in step e, Δ
It is determined whether T is a positive direction equal to or greater than zero. In addition,
When ΔT is equal to or longer than the margin time Tc, the correction according to the present invention is unnecessary, but a flow for that is not particularly shown.

If the determination in step e is Yes, the process proceeds to step f, in which the dwell on / off times TDWLEA1 / TDWLSA1 and the injection start time TAIN for the fuel injection valves of the subsequent cylinders are set.
With respect to JA1, advance correction processing for a margin time Tc is executed from that for the fuel injection valve of the preceding cylinder. At this time, the injection time TINJA1 is not changed. That is, the correction process is performed as follows.

TDWLEA1 (i) = TDWLEA1 (i)-(Tc-ΔT) TDWLSA1 (i) = TDWLSA1 (i)-(Tc-ΔT) TAINJA1 (i) = TAINJA1 (i)-(Tc-ΔT) TINJA1 ( i) = TINJA1 (i) If the determination in step e is No, the process proceeds to step g, where the dwell on / off time TDWLEA1 / TDWLSA1 and the injection start time TAINJA1 for the fuel injection valve of the succeeding cylinder are determined for the preceding cylinder. A delay angle correction process for a margin time Tc from the fuel injection valve is executed. At this time, the injection time TINJA1 is not changed. That is, the correction process is performed as follows.

TDWLEA1 (i) = TDWLEA1 (i) + Tc + ΔT TDWLSA1 (i) = TDWLSA1 (i) + Tc + ΔT TAINJA1 (i) = TAINJA1 (i) + Tc + ΔT TINJA1 (i) = TINJA1 (i) On the basis of the obtained dwell data and injection data and the engine speed NE, in step h, the reference angle 30 ( _CA ) for the adjacent injection, that is, the set dwell-on times TA1 and TA2 from CASET, and the set injection start times TDA1 and TDA2 are calculated. calculate. Thereafter, in step j, the calculated data is output together with the injection time TINJ and the dwell time TDWL.

[0032]

As described above, according to the fuel injection valve drive control apparatus for an internal combustion engine of the present invention, the injection end of the intake stroke injection of the succeeding cylinder and the compression stroke injection of the preceding cylinder in the cylinder whose ignition order is adjacent is completed. Because there is no overlapping time,
The energy charged in the piezoelectric elements in each fuel injection valve is evenly distributed, and the fuel injection amount in each fuel injection valve can be correctly controlled to a desired value.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a fuel injection valve drive control device for an internal combustion engine according to the present invention.

FIG. 2 is a time chart for explaining a control method for avoiding duplication based on the present invention.

FIG. 3 is a timing chart for explaining the operation of the fuel injection valve drive control device for an internal combustion engine according to the present invention.

FIG. 4 is a flowchart showing an example of software for realizing a fuel injection valve drive control device for an internal combustion engine according to the present invention.

FIG. 5 is a flowchart showing an example of software for realizing a fuel injection valve drive control device for an internal combustion engine according to the present invention.

FIG. 6 is a conceptual configuration diagram illustrating a configuration of an example of a fuel injection valve device for an internal combustion engine using a piezoelectric element.

FIG. 7 is a circuit diagram showing a basic configuration of a flyback type piezoelectric element driving circuit.

8 is a time chart showing operation signal waveforms of the flyback type piezoelectric element drive circuit of FIG.

FIG. 9 is a circuit block diagram showing a basic configuration of a fuel injection valve drive control system of a four-cycle four-cylinder engine to which a fuel injection valve using a piezoelectric element driven by a flyback drive circuit is applied.

FIG. 10 is a time chart for explaining the operation of the fuel injection valve drive control system of the four-cycle four-cylinder engine of FIG. 9;

FIG. 11 is an explanatory view conceptually showing a configuration of an example of an actual four-cylinder piezoelectric element drive circuit.

12 is a time chart showing timings of intake and compression stroke injection in the four-cylinder piezoelectric element drive circuit of FIG. 14;

FIG. 13 is a time chart for explaining a state in which dwell-off times overlap in a fuel injection valve drive control system of a four-cycle four-cylinder engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 100 ... Fuel injection valve 101, 201 ... Piezoelectric element 103 ... Hydraulic oil 104 ... Push rod 105 ... Pressure chamber 108 ... Injection hole 202 ... Flyback transformer 203 ... Driving transistor 204 ... Charge switch 205, 207 ... Backflow prevention diode 206 ... Discharge Switch 208 ... Discharge coil 210 ... Electronic control unit 211 ... Injection signal 212 ... Coil energization signal 213 ... PZT discharge signal 214 ... PZT charge signal 215 ... Primary current 216 ... PZT voltage 217 ... Fuel injection rate 221,222,223,224 ... Flyback drive circuit 231 ... Dwell signal 232 ... Ejection signal 233 ... PZT voltage

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiji Morino 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside of Denso Co., Ltd. (72) Inventor ▲ Yoshihiro Tani 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Denso Co., Ltd. (56) References JP-A-4-309273 (JP, A) JP-A-2-176121 (JP, A) JP-A-62-2659 (JP, A) JP-A-63-9656 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/34 F02D 41/40 F02M 51/06

Claims (2)

(57) [Claims] 1. A piezoelectric element is connected to a secondary coil of a transformer, and a current flowing through the primary coil is interrupted at a predetermined timing to generate flyback energy in the secondary coil to charge the piezoelectric element. Discharging the piezoelectric element at a predetermined timing to control the opening and closing of a fuel injection valve operated by the piezoelectric element, wherein a plurality of fuel injection valves for injecting fuel into a plurality of cylinders are arranged in a predetermined order. In the internal combustion engine fuel injection valve drive control device, which controls each fuel injection valve to perform multiple injections during an intake stroke and a compression stroke within one cycle, a compression stroke of a specific cylinder is controlled. A state in which the injection end timing is close to the intake stroke injection end timing of another cylinder is determined, and at least one of the injection timings is shifted. A fuel injection valve drive control device for an internal combustion engine, comprising an injection timing correction means for performing correction as described above. 2. The fuel injection valve drive control device for an internal combustion engine according to claim 1, wherein the injection timing correction means shifts the intake stroke injection end timing in a direction away from the compression stroke injection end timing.