JPH05171987A - Fuel injection amount controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To compensate fuel injection amount exactly according to a change in engine speed with a structure by setting compensation amount per a factor which generates variation in the fuel injection amount on a different criterion. CONSTITUTION:The running condition of an internal combustion engine is detected by a running condition detection means, and a signal generation means generates a signal according to the rotational phase of a cam which drives the plunger of a fuel force feed pump. A control means opens an electromagnetic valve at a prescribed timing based on the running condition to control fuel injection. The first electric signal regulation means outputs an angle compensation signal corresponding to an offset from the rotational phase of the cam, and the second electric signal regulation means outputs a timing compensation signal which compensates the response time of the electromagnetic valve. Based on these compensation signals, the electromagnetic valve control of the control means is compensated exactly for a change in engine speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection amount control device for an internal combustion engine, and more particularly to an electromagnetic valve provided in a passage connecting a high pressure pump chamber and a low pressure pump chamber pressurized by a plunger of a fuel pressure pump. The present invention relates to a fuel injection amount control device for an internal combustion engine using a so-called solenoid valve spill metering method in which pressurized fuel overflows to a low pressure side by opening a valve at a predetermined time to control a fuel injection amount.

[0002]

2. Description of the Related Art Since it is necessary to precisely control the fuel injection amount of an internal combustion engine in order to purify exhaust gas and improve fuel efficiency, a conventional fuel injection pump that mechanically controls the fuel injection amount by a spill ring is used. There has been proposed a fuel supply device for an internal combustion engine using a fuel injection pump of a solenoid valve spill metering system that controls the end of fuel injection by opening a solenoid valve. (For example, JP-B-51-34936.) In such a fuel injection control device, the fuel injection amount varies among the devices.
Factors that cause such variations in fuel injection amount are differences in the responsiveness of solenoid valves that control fuel injection, errors in the mounting angle of the sensor that detects the cam phase, the amount of fuel leak in each part of the fuel injection pressure feeding system, or There are variations in manufacturing the cam profile.

Japanese Patent Laid-Open No. 168030/1982 discloses a correction resistor for changing the electrical characteristic of the control unit in order to correct these factors and obtain a desired fuel injection amount characteristic. The technique disclosed in this publication includes a plurality of resistors for setting the correction amount for each rotation speed in order to set the correction amount in accordance with the change in the engine rotation speed.

[0004]

However, in the prior art as described above, a large number of correction resistors are provided and the respective resistance values are set in order to perform accurate correction over the entire operating range of the engine. It was necessary and the setting was complicated.

The present invention has been made in view of the above problems, and it is easy to set the correction amount for each factor that causes the variation of the fuel injection amount, and to set them according to different criteria. It is an object of the present invention to provide a fuel injection amount control device for an internal combustion engine, which is capable of performing accurate correction even if the engine speed changes even though it has such a configuration.

[0006]

In order to achieve the above object, the present invention, as shown in FIG. 1, exemplifies an operating state detecting means for detecting an operating state of an internal combustion engine, and a fuel pressure pump in a fuel injection pump. A solenoid valve that is provided in a passage that connects the signal generation means for generating a signal corresponding to the rotation phase of a cam driving the plunger of the pump and the high pressure side and the low pressure side pressurized by the plunger, and opens and closes the passage. And a fuel pressurized by the plunger by opening the solenoid valve at a predetermined time based on the operating state of the internal combustion engine detected by the operating state detecting means with reference to the signal from the signal generating means. In a fuel injection amount control device for an internal combustion engine, which comprises a control means for controlling the fuel injection amount by spilling the fuel to the low pressure side and terminating the fuel injection. A first electric signal adjusting means for outputting an angle correction signal corresponding to a deviation of the cam with respect to the rotational phase, which is set so as to obtain a predetermined fuel injection amount when a regulated reference solenoid valve is used; A second correction signal that outputs a time correction signal that corrects a deviation in response time of the solenoid valve, which is set to obtain a predetermined fuel injection amount when an actually used solenoid valve is used instead of the reference solenoid valve An internal combustion engine comprising: an electric signal adjusting unit; and a correcting unit that corrects a predetermined timing when the solenoid valve is opened by the control unit based on the angle correction signal and the time correction signal. The gist is the fuel injection amount control device of the engine.

[0007]

In the present invention, the operating state detecting means detects the operating state of the internal combustion engine, and the signal generating means generates a signal corresponding to the rotational phase of the cam driving the plunger of the fuel pressure pump in the fuel injection pump. Then, the control means communicates the high pressure side and the low pressure side pressurized by the plunger at a predetermined time based on the operating state of the internal combustion engine detected by the operating state detecting means with reference to the signal from the signal generating means. The fuel injection amount is controlled by opening the electromagnetic valve provided in the passage for causing the fuel pressurized by the plunger to overflow to the low pressure side and ending the fuel injection.

Then, the first electric signal adjusting means with respect to the rotation phase of the cam set so as to obtain a predetermined fuel injection amount when the reference solenoid valve whose response is adjusted beforehand is used as the solenoid valve. An angle correction signal corresponding to the deviation is output, and the second electric signal adjusting means is set to obtain a predetermined fuel injection amount when an actually used solenoid valve is used instead of the reference solenoid valve, A time correction signal for correcting the response time of the solenoid valve is output, and the correction unit corrects a predetermined time when the control unit opens the solenoid valve based on the angle correction signal and the time correction signal.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 is a schematic configuration diagram showing a fuel injection amount control device for an internal combustion engine as one embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a control circuit.

In FIG. 2, reference numeral 1 is a solenoid valve spill metering type fuel injection pump (hereinafter referred to as fuel injection pump) based on a known Bosch type distributed fuel injection pump, and 2 is a crankshaft of an internal combustion engine. The drive shaft is connected and rotates the vane feed pump 3. The vane type feed pump 3 introduces the fuel in the fuel tank (not shown) from the suction port 4 through A through a filter, pressurizes this fuel and regulates it to the pressure set by the regulation valve 5, and then the fuel injection pump. The fuel is supplied to the fuel chamber 6 formed inside 1.

The drive shaft 2 drives a plunger 8 via a coupling 7. The coupling 7 integrally rotates the plunger 8 in the rotation direction, but when the plunger 8 reciprocates in the axial direction, the movement in the axial direction is allowed freely. A face cam 9 is integrally provided on the plunger 8. The face cam 9 is pressed against the cam roller 11 by the spring 10, and due to the sliding contact between the face cam 9 and the cam roller 11, the cam ridges of these face cams 9 are formed.
Plunger 8 is reciprocated when riding on. The plunger 8 is reciprocated during one rotation by a rotation (four times in this case) according to the number of cylinders of an engine (not shown).

The plunger 8 is slidably and precisely fitted to a head 12 attached to the fuel injection pump 1, and the head 12 and the end face of the plunger 8 form a pump chamber 13. A suction groove 14 is formed on the peripheral surface of the end of the plunger 8, and one of these suction grooves 14 is formed during the suction stroke of the plunger 8, that is, during the movement to the left in FIG. When communicating with the suction port 15 provided in the head 12, fuel is sucked from the fuel chamber 6 into the pump chamber 13.

During the compression stroke of the plunger 8, that is, during the movement to the right in FIG. 2, the fuel pressurized in the pump chamber 13 passes through the communication passage 19 and the distribution port 16 to the injection passage 17. It is pumped and injected from B through the discharge valve 18 into the combustion chamber of the engine by an injection valve (not shown).

A solenoid valve spill type fuel metering mechanism 20 is connected to the pump chamber 13. That is, the pump chamber 13 is communicated with the fuel chamber 6 through the overflow passages 21 and 22, and the overflow passage 21 is opened and closed by the solenoid valve 23. The electromagnetic valve 23 includes a needle valve 24 and an electromagnetic coil 2
When the electromagnetic coil 25 is energized, the needle valve 24 is lifted and the pump chamber 13 is opened to the overflow passage 21. Therefore, when the solenoid valve 23 is operated during the compression stroke of the plunger 8, the pump chamber 13
Since the fuel pressurized inside is released to the low pressure side fuel chamber 6 via the overflow passages 21 and 22, the injection passage 17
The fuel injection is stopped. This controls the fuel injection amount to be supplied to the engine side. A part of the fuel overflowing into the fuel chamber 6 is returned from C to a fuel tank (not shown).

The energization start timing of the solenoid valve 23 is performed by the electronic control circuit 26 equipped with a microcomputer. The configuration and operation of the electronic control circuit 26 will be described later. The cam roller 11 described above is held by the roller ring 27. The roller ring 27 is operated by a fuel injection timing adjusting mechanism (timer) 30. The fuel injection timing adjusting mechanism 30 includes a timer piston 31.
The fuel pressure in the fuel chamber 6 acts on one end surface of the timer piston 31. The fuel pressure in the fuel chamber 6 changes according to the engine rotation speed, that is, the rotation speed of the feed pump 3. When the fuel pressure in the fuel chamber 6 acts on one end surface of the timer piston 31, the timer piston 31
2 against the force of the spring 32 acting on the other end surface.
Is moved to the left of. Such reciprocating movement of the timer piston 31 is transmitted to the roller ring 27 via the pin 33.

In FIG. 2, the timer piston 31 is shown in a posture orthogonal to the actual case, and in reality, the timer piston 31 is mounted with the axis of the timer piston 31 oriented in a direction orthogonal to the plane of the drawing. Therefore, the reciprocating movement of the timer piston 31 causes the roller ring 27 to be rotationally displaced about the drive shaft 2. Therefore, the cam roller 11 and the face cam 9
And are relatively displaced in the circumferential direction, the timing at which the cam lobe of the face cam 9 rides on the cam roller 11 is deviated, and the phase of the reciprocating motion of the plunger 8 relative to the drive shaft 2 changes. As a result, the communication timing between the distribution port 16 and the injection passage 17 changes, so the fuel injection timing is automatically adjusted.

A timing detector 35 of, for example, an electromagnetic pickup type, a hall element type or an optical angle detecting type is attached to the roller ring 27, while a pulsar 36 is fixed to the drive shaft 2. ing.
The protrusion 37 formed on the pulsar 36 by the rotation of the drive shaft 2
When one of them crosses the timing detector 35, this timing detector 35 generates a signal. This signal is sent to the electronic control unit 26. In the electronic control unit 26,
When receiving the output signal from the timing detector 35,
This signal is used as a reference signal, and after a predetermined time, a power signal for instructing the solenoid valve 23 to operate is output. The timing detector 35 corresponds to signal generating means for generating a signal according to the rotation phase of the cam.

When the roller ring 27 is rotated by the operation of the timer 30, the timing detector 35 is also rotated by the same phase as the roller ring 27. Therefore,
When the fuel injection timing is adjusted, the reference signal sent to the electronic control unit 26 also shifts by the same phase, so the operation timing of the solenoid valve 23 changes, and the overflow timing also changes by the shift in the reciprocating timing of the plunger 8. , The injection amount is not changed.

As shown in FIG. 3, the electronic control circuit 26 includes
It comprises a well-known CPU 51, ROM 52, RAM 53, and data bus 55 as main parts, and has an input port 57 and a pulse input port 5 in order to perform input / output with the outside.
8 and an output port 60, and each element is connected to each other by a data bus 55.

The input port 57 has an A / D conversion function, and various sensors for detecting the operating state of the engine, such as an accelerator pedal sensor 70 for detecting the position (depression amount) of the accelerator pedal 68 and the engine. A rotation speed sensor (not shown) for detecting the rotation angle of the engine, an intake air temperature sensor, or the like is connected, and two sets of voltage signals from the resistance adjusting circuit 90 as the first and second electric signal adjusting means are also input. There is.

The output of the above-mentioned timing detector 35 is connected to the pulse input port 58, which is combined with the pulser 36 to detect the pulse signal corresponding to the rotational phase of the face cam 9 of the fuel injection pump as described above. Is configured to. The output port 60 is provided with a counter for setting the fuel injection time τ, and electric power for exciting the electronic coil 25 of the connected solenoid valve 23 after the time set by the CPU 51 for the counter elapses. It outputs a signal and opens and closes it.

Next, a method for detecting the pulse signal from the above-mentioned timing detector 35 to detect the rotational phase of the face cam 9 (here, the rotational phase of the drive shaft 2) will be described. The detection of the timing with respect to the rotation of the drive shaft 2 performed using the timing detector 35 means the detection of the reference point in the fuel injection amount control, and the control of the fuel injection amount (fuel injection time) described below is performed by this control. It is performed by the reference point.

FIG. 4 is a sectional view taken along the line aa 'of FIG.
This is for explaining the relationship between the timing detector 35 and the pulser 36. As shown in the drawing, the pulsar 36 is provided with a protrusion 37 that divides the circumference into four equal parts. The pulsar 36
These projections 37 are the closest to the timing detector 35 and pass through the detection end at the bottom dead center of each cam 9 that drives the plunger 8 that injects fuel into each cylinder of the four-cylinder engine. It is press-fitted / fitted onto the drive shaft 2 at an angle. Therefore, a pulse signal is generated in the timing detector 35 when the pressurization for fuel injection by the plunger 8 is started.

These timings are shown in the timing chart of FIG. In FIG. 5, (I) is the plunger 8.
And the DP indicates its bottom dead center. (II) shows a voltage signal generated in the timing detector 35 when the protrusion 37 of the pulsar 36 passes,
(III) shows a pulse signal after the signal is waveform-shaped by the pulse input port 58 of the electronic control circuit 26. (IV) shows the timing at which the solenoid valve 23 is energized and opened at a predetermined rotation angle θ with this pulse signal indicating the bottom dead center of the plunger 8 as a reference point (rotation angle θ = 0). ..

When the needle valve 24 of the solenoid valve 23 is opened, the pressurized fuel overflows to the low pressure side through the overflow passages 21 and 22, and the fuel injection is completed. In (I), the shaded portions q and q'represent the range in which fuel injection is performed by pressurization of the plunger 8. Therefore, as will be described later, in the electronic control circuit 26, the accelerator opening is detected by the accelerator sensor 70 to obtain the fuel injection amount,
If the engine speed is detected and the fuel injection time is calculated and the solenoid valve 23 is operated to open at the predetermined rotation angle θ as described above, the fuel injection amount control apparatus using the solenoid valve spill metering system is provided. Will function as.

Next, the configuration of the resistance adjusting circuit 90 will be described with reference to FIG. In FIG. 6, reference numerals 91 to 94 are fixed resistors for equalizing resistance values, and 95 and 96 are adjusting resistors. Further, Vcc indicates a constant voltage (here, 5V) supplied to the resistance adjusting circuit 90. Therefore, between the adjustment voltage output terminals 97 and 98 and the ground terminal 99, the divided voltage Vτ by the resistors 91 and 92 and the adjustment resistor 95 and the divided voltage by the resistors 93 and 94 and the adjustment resistor 96, respectively. The voltage Vθ is output. The resistance values of the adjusting resistors 95 and 96 may be adjusted by a variable resistor, but in consideration of conditions for mounting on a vehicle, adjustment by exchanging a fixed resistor or laser trimming of a film resistor is performed. It may be adjusted. The divided voltage Vτ corresponds to the time correction signal, and the divided voltage Vθ corresponds to the angle correction signal.

Next, the control of the fuel injection amount performed with the above configuration will be described with reference to the flowchart shown in FIG. When the engine is started and the control of the fuel injection amount in the steady operation is started, the electronic control circuit 2
6 repeatedly executes this control routine together with other necessary control routines not shown. This control routine is started from A, and in step 110, first, a process of reading the output of the accelerator sensor 70 corresponding to the depression amount of the accelerator pedal 68, the engine speed and the like as the operating state of the engine from the input port is performed.

In the following step 120, step 110
The fuel injection amount is obtained from the depression amount of the accelerator pedal 68 read in step 3, and the fuel injection time corresponding to the fuel injection amount is calculated from the engine speed. The amount of fuel discharged by one stroke of the plunger 8 is fixed, and the same amount of fuel is discharged as the engine speed increases.
Since the time required for injection becomes shorter, the fuel injection time τ1 can be obtained from the accelerator depression amount and the engine speed.

In the following step 130, the resistance adjusting circuit 9
A process of reading the voltage signals Vτ and Vθ respectively adjusted by the adjusting resistors 95 and 96 from 0 is performed. In the next step 140, the correction amounts Δτ and Δθ corresponding to the fuel injection amount to be corrected are obtained from the voltage signals Vτ and Vθ read in step 130, and the fuel injection time realized by actually driving the solenoid valve 23 is obtained. The process of obtaining τ is performed. Here, the voltage signals Vτ and Vθ are voltages determined by an adjustment operation described later, the voltage signal Vτ is a response delay time Δτ of the solenoid valve 23, and the voltage signal Vθ is a pulse generated by the timing detector 35. Of the plunger 8 with respect to the bottom dead center of the rotation angle Δθ. Vτ and △
The correspondence relationship with τ, Vθ, and Δθ is defined by a map stored in the ROM 52, for example, as shown in FIG.
(B) shows an example of each.

Of these, the correction amount of the fuel injection time to be corrected by the deviation Δθ in the rotation angle is a function of the engine speed, so that the engine speed N read in step 110 is used to calculate f It is calculated as (Δθ, N). Therefore, the fuel injection time f (Δθ, N) to be corrected, which is calculated from the rotational angle Δθ to be corrected obtained from the voltage signal Vθ of the resistance adjusting circuit 90 using the engine rotational speed N, is the same as The fuel injection time Δτ to be corrected corresponding to the response delay time of the solenoid valve 23 obtained from the voltage signal Vτ and the fuel injection time τ1 obtained in step 120 are added to determine the fuel injection determined by the operating state of the engine. That is, the timing τ of the valve opening signal given to the solenoid valve 23 in order to realize the fuel injection in the quantity is calculated.

In the following step 150, step 140
After setting the timing τ obtained in step 1 in the counter of the output port 60, the process goes to step B to end the present control routine. In this control routine, the timing τ set in the counter of the output port 60 is used to operate the counter of the output port (countdown) based on the pulse signal detected by the timing detector 35 by the fuel injection control routine (not shown). When the counter value becomes zero, a drive signal is output to the solenoid valve 23, the needle valve 24 is opened to overflow the fuel to the low pressure side, and the fuel injection amount is controlled.

Therefore, the response delay time Δτ of the solenoid valve 23 and the deviation Δθ in the rotation angle of the pulse signal generated by the timing detector 35 with respect to the bottom dead center of the plunger 8 are corrected. Resistance adjustment circuit 9
If the voltage signals Vτ and Vθ of 0 are adjusted, the solenoid valve 2
The valve opening timing of 3 is corrected according to the above error,
Accurate control of the fuel injection amount can be performed.

Then, a method of adjusting the fuel injection amount control device for the internal combustion engine having the above-mentioned structure will be described below. First, the solenoid valve 23 is removed from the main body of the fuel injection pump 1 of the solenoid valve spill metering system used in the fuel injection amount control device for an internal combustion engine having the above-mentioned configuration, and the response speed when the valve is opened is accurate as a master for adjustment. Install a solenoid valve for adjustment controlled by. Since an adjustment solenoid valve whose response speed is controlled is attached as the solenoid valve 23, Vτ of the voltage signal of the resistance adjustment circuit 90 is a reference value (here, 2.
5V). In this state, the fuel injection amount control device for the internal combustion engine is operated at a predetermined rotation speed and load, and the fuel discharge amount is measured and adjusted. For example, rotation speed 1000 rp
m, the operation is performed with the accelerator pedal half-opened, and the adjustment resistor 96 of the resistance adjuster 90 is adjusted to change the voltage signal Vθ so that the discharge amount becomes the calculated set value of 8.8 cc / stroke. Adjust the injection amount. By this operation, the deviation Δθ in the rotation angle of the pulse signal generated by the timing detector 35 with respect to the bottom dead center of the plunger 8 is corrected.

Next, the solenoid valve for adjustment is removed, the solenoid valve 23, which is the original fuel injection amount control device for the internal combustion engine, is attached, and the fuel injection amount is adjusted in the same manner as described above.
Is adjusted to change the voltage signal Vτ. By this adjustment, the variation in the response speed of the solenoid valve 23 with respect to the solenoid valve for adjustment is corrected.

By the above simple adjustment, the variation in the response speed of the solenoid valve 23 (Δτ) and the variation in the rotation angle of the bottom dead center detection of the plunger 8 by the timing detector 35 (Δθ) are corrected. Therefore, the fuel injection amount control apparatus for the internal combustion engine according to the present embodiment uses the above-described fuel injection amount control routine (shown in FIG. 7) to perform the entire engine operating range,
That is, it is possible to realize fuel injection with an accurate injection amount over the entire range of the rotation speed and the fuel injection amount.

Further, the resistance adjusting circuit 90 for correcting the fuel injection amount requires only a few resistors and realizes the correction of the fuel injection amount with a simple structure. As a result, It also has the advantage of excellent reliability and durability. It should be noted that if an attempt is made to correct a deviation factor such as a mounting angle error of the timing detector 35 for detecting the cam phase with a correction signal indicating time, the length of the deviation time caused by the mounting error is due to a change in the engine speed. Since it changes, it is not possible to follow this change in engine speed with a fixed time correction signal, and the solenoid valve 2
If an attempt is made to correct a shift factor such as the variation in response of No. 3 with a correction signal indicating an angle, the response of the solenoid valve 23 is constant irrespective of the engine speed, and therefore the correction amount changes in engine speed. As it shifts, accurate correction cannot be performed. In the present embodiment, as described above, the variation in the response speed of the solenoid valve 23 (Δτ) and the variation in the rotation angle of the bottom dead center detection of the plunger 8 by the timing detector 35 (Δθ) are separately corrected. Therefore, accurate correction is performed over the entire operating range of the engine regardless of the engine speed.

In the above embodiment, the electronic control circuit 26 has a C
Although the PU 51 is configured as a main part and is digitally controlled, the PU 51 may be configured by an ordinary electronic control circuit as shown in FIG. 9 without any problem. In FIG. 9, 26 'is an electronic control circuit, and 201 is an accelerator sensor (first
(Corresponding to 70 of the embodiment), 203 is an engine speed detection sensor, and 205 is a solenoid valve spill metering fuel injection pump 1.
Solenoid valve (corresponding to the first embodiment 23), 207 is a timing detector (corresponding to 35 of the first embodiment) for detecting the rotational phase of the drive shaft 2 of the fuel injection pump, and 210 is a resistance adjusting circuit (the first embodiment). (Corresponding to 90 in the embodiment).

The electronic control circuit 26 'includes a delay circuit 220,
225, an amplification circuit 230, and a division circuit 240. The amplifying circuit 230 amplifies the output A of the accelerator sensor 201, converts it into the fuel injection time according to the output signal N of the rotation speed detecting sensor 203, and then delays the signal according to the accelerator depression amount. First delay amount control terminal D1
Output to. On the other hand, the division circuit 240 is connected to the resistance adjustment circuit 21.
One voltage signal Vθ of 0 is divided by the output signal N of the rotation speed detection sensor 203, and the deviation in the rotation angle of the timing detector is converted into a correction amount in the fuel injection time.
The output of the division circuit 240 is input to another delay amount control terminal D2 of the delay circuit 220, and the delay circuit 220
The voltage of the output terminal OUT changes from the low level after a predetermined time based on the signals input to the delay amount control terminals D1 and D2 from the time when the pulse signal from the timing detector 207 is input to the trigger terminal CLK. Invert to high level. The delay circuit 225 at the next stage receiving this signal
Is the resistance adjustment circuit 21 input to the delay amount control terminal D3.
After a time corresponding to another voltage signal Vτ of 0, the output terminal OUT is activated, the electronic valve 205 is opened, and the fuel injection is ended.

An electronic control circuit 26 'constructed as shown in FIG.
By using, it is possible to perform the same control as in the first embodiment and obtain the same effect. When a fuel injection amount control device for an internal combustion engine is configured using a normal electronic control circuit 26 'as shown in FIG. 9, the configuration of the electronic control circuit 26' can be somewhat simplified because a CPU or the like is not used. The cost can be kept low.

Further, in the first embodiment, in order to detect the rotation phase of the drive shaft 2, the pulsar 36 provided with the projections 37 by the number (4) equal to the number of cylinders is used. For more precise control, see, for example, FIG.
Alternatively, a pulsar 36 'and a timing detector 35 whose cross section is shown in FIG.

FIG. 10 corresponds to a sectional view taken along the line aa ′ of FIG. 2 (FIG. 4 of the first embodiment), but in FIG. 10, 56 protrusions 37 ′ having four missing teeth on the outer periphery as a pulsar. The pulsar 36 'provided with is used. The four incisor parts are located exactly at the bottom dead center of the plunger 8.

FIG. 11 is a timing chart showing an output signal and the like of the timing detector 35 in the above configuration. In FIG. 11, (I ') indicates the stroke of the plunger 8, and DP means the time of the bottom dead center (start of pressurization). (II ') is the electromotive force signal generated in the timing detector 35, (III') is the pulse signal after its waveform shaping, and (IV ') is this pulse signal indicating the bottom dead center of the plunger 8. As a reference point (rotation angle θ = 0), the timing at which the solenoid valve 23 is energized and opened at a predetermined rotation angle θ is shown.

The bottom dead center (DP) of the plunger 8 is detected as the trailing edge of a pulse having a large pulse width generated in the toothless portion, and the timing detector 35 is used with this point as a reference.
If the rotation angle of the drive shaft 2 is detected more accurately by counting the number of pulses representing a minute angle, the rotation angle of the drive shaft 2 can be known more accurately. The fuel injection amount control by the fuel injection pump can be performed more precisely.

In the above embodiment, the resistance adjusting circuit 9
Since 0 is composed of several resistors, it can be manufactured in an extremely small size, and it has the advantage that the mounting location is not restricted by its shape. Therefore, it can be mounted on the fuel injection pump 1. In this case, the machine difference of the fuel injection pump 1 is the voltage signals Vτ and Vθ of the resistance adjusting circuit 90.
This can be regarded as being compensated for the electronic control circuit 26, and the compatibility of the fuel injection pump 1 alone is ensured, which is preferable.

Further, in the above embodiment, the resistance adjusting circuit 90 is used as the electric signal adjusting means. However, even if the resistance adjusting circuit 90 is not used, the state of the electric signal (voltage, frequency, binary code) is externally applied. Etc.), it does not matter at all. It is needless to say that a method of fixing the corrected value on the memory may be used, and the correction may be performed in an optimum mode according to the fuel injection amount control device of the internal combustion engine to be applied.

Although some embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be carried out in various modes without departing from the scope of the present invention. Of course you can get it.

[0047]

As described in detail above, according to the present invention,
The response of the fuel injection device is adjusted in advance to the factors such as the change in the engine rotational speed such as the cam angle detection sensor mounting angle error that changes the length of the deviation time caused by the mounting error. When the solenoid valve is connected and operated, the fuel discharge amount is measured, and the angle correction signal is set so that the desired discharge amount is obtained, and the angle correction signal is used for correction. Therefore, accurate correction is performed over the entire operating range of the engine without being affected by changes in the engine speed.

On the other hand, for factors such as variations in response of the solenoid valve that cause a constant deviation time even if the engine speed changes, the solenoid valve actually used is connected to the fuel injection device. Measure the fuel discharge amount when operated by
The time correction signal is set so that a desired ejection amount is obtained, and the time correction signal is used for correction. For this reason, accurate correction is performed over the entire operating range of the engine regardless of the engine speed.

As described above, in the present invention, the correction signal is set for each of the factors that cause the variation in the fuel discharge amount among the fuel injection devices, one of which is set with the angle as a reference, and the other of which is set with the time as a reference. Therefore, accurate correction is performed even if the engine speed changes.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram of a fuel injection amount control device for an internal combustion engine of the present embodiment.

FIG. 3 is a block diagram showing a configuration of an electronic control circuit of this embodiment.

FIG. 4 is a cross-sectional view taken along line aa ′ shown in FIG.

FIG. 5 is a timing chart showing the relationship between the output pulse of the timing detector and the timing of fuel injection.

FIG. 6 is a circuit diagram showing a configuration of a resistance adjustment circuit.

FIG. 7 is a flowchart showing an example of control of a fuel injection amount.

FIG. 8 is a graph showing the relationship between the voltage output Vτ of the resistance adjustment circuit and the correction amount Δτ of the delay time of the solenoid valve, and the relationship between the voltage output Vθ and the correction amount Δθ.

FIG. 9 is a sectional view showing another embodiment of the electronic control circuit.

FIG. 10 is a cross-sectional view showing another embodiment of the pulsar.

11 is a timing chart showing the timing of output pulses and fuel injection amount control when the pulser shown in FIG. 10 is used.

[Explanation of symbols]

1 ... Fuel injection pump 8 ... Plunger 9 ... Face cam 23 ... Electromagnetic valve 26, 26 '... Electronic control circuit 35 ... Timing control circuit 36, 36' ... Pulser 51 ... CPU 70 ... Accelerator sensor 90 ... Resistance adjustment circuit

Claims (1)

[Claims] 1. A driving state detecting means for detecting a driving state of an internal combustion engine, a signal generating means for generating a signal according to a rotational phase of a cam driving a plunger of a fuel pressure pump in a fuel injection pump, and the plunger. An internal combustion engine detected by the operating state detecting means with reference to a signal from the signal generating means and an electromagnetic valve provided in a passage connecting the high pressure side and the low pressure side, which are pressurized by A control means for controlling the fuel injection amount by opening the solenoid valve at a predetermined time based on the operating state of the fuel cell, causing the fuel pressurized by the plunger to overflow to the low pressure side and terminating the fuel injection. In a fuel injection amount control device for an internal combustion engine, the setting is made so that a predetermined fuel injection amount can be obtained when a reference solenoid valve whose response is adjusted in advance is used as the solenoid valve. Further, when a first electric signal adjusting means for outputting an angle correction signal corresponding to a deviation of the cam with respect to the rotational phase and a solenoid valve which is actually used instead of the reference solenoid valve, a predetermined fuel injection amount is used. The second electric signal adjusting means for outputting a time correction signal for correcting the deviation of the response time of the solenoid valve, which is set so as to obtain a predetermined time when the solenoid valve is opened by the control means. A fuel injection amount control device for an internal combustion engine, comprising: a correction unit that corrects based on the angle correction signal and the time correction signal.