JPH0610733A - Fuel injection device - Google Patents

Abstract

PURPOSE:To improve the fuel injection quantity control at the time of acceleration, and improve the acceleration feeling. CONSTITUTION:A basic injection quantity computing means 101 computes the basic injection quantity on the basis of the detecting signal from an operation condition detecting means 100. An instantaneous rotating speed difference computing means 103 computes a difference of the instantaneous rotating speed of the explosion process and the instantaneous rotating speed of the compression process in the next air cylinder continued to the explosion process, which are computed by the instantaneous rotating speed computing means 102. Next, a basic injection quantity correcting means 104 corrects the basic injection quantity in response to the difference of the instantaneous rotating speeds so as to reduce the difference of the instantaneous rotating speeds. At this stage, when the acceleration condition is detected by an acceleration condition detecting means 105, a fuel injection quantity computing means 106 corrects the correction basic injection quantity. Since this correction basic injection quantity is regarded as the fuel injection quantity to the next air cylinder, the fuel injection quantity control at the time of acceleration is improved to improve the acceleration feeling of a vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device, and more particularly to a fuel injection device for controlling injection timing.

[0002]

2. Description of the Related Art Conventionally, in a "fuel injection device" (Japanese Patent Application No. 3-67941) for which we have previously applied for a patent, the basic injection amount is calculated from various detection signals such as engine speed and accelerator opening. ing.

When the engine condition is steady, a measurement position is set such that the instantaneous rotation speed during the explosion stroke during one fuel injection is equal to the instantaneous rotation speed during the compression stroke in the next cylinder. The measurement position is determined by the output pulse from the rotation speed sensor that is counted a predetermined number from the reference position signal. Then, a difference occurs between the two instantaneous rotation speeds, and when this difference is equal to or greater than a predetermined value, it is determined that the engine rotation fluctuation is occurring. Therefore, a correction coefficient corresponding to the instantaneous rotational speed difference is calculated so as to suppress this variation, the basic injection amount is corrected, and the corrected basic injection amount is injected to the next cylinder.

Therefore, the correction based on the difference between the instantaneous rotation speeds in the explosion stroke and the compression stroke during one injection can be reflected in the injection amount of the fuel injection performed immediately after the compression stroke. Therefore, the correction of the fuel injection amount is performed with high response, and the engine rotation fluctuation is quickly suppressed.

Therefore, when the vehicle is started, for example, when the clutch is engaged or when an engine load is applied such as when the braking is applied, the fluctuation of the engine rotation is suppressed and becomes stable.

[0006]

However, when the engine speed increases as the driver tries to accelerate,
Since the engine rotation fluctuation is quickly suppressed by the above control, the fuel injection amount may be reduced so as to reduce the engine rotation speed. Therefore, even when the driver wants to accelerate, sufficient acceleration cannot be obtained, and there is a problem that the feeling of acceleration becomes poor.

In view of the above problems, it is an object of the present invention to improve the fuel injection amount control during acceleration and to improve the acceleration feeling of the vehicle.

[0008]

In order to achieve the above object, the present invention, as shown in FIG. 1, includes an operating state detecting means 100 for detecting an operating state of an engine and a detection signal from the operating state detecting means 100. A basic injection amount calculation means 101 for calculating a basic injection amount, an instantaneous rotation speed calculation means 102 for calculating an instantaneous rotation speed in an explosion stroke and an instantaneous rotation speed in a compression stroke in the next cylinder, and the instantaneous rotation. An instantaneous rotational speed difference calculating means 103 for calculating a difference between the two instantaneous rotational speeds calculated by the speed calculating means 102, and the basic injection according to the instantaneous rotational speed difference so as to reduce the instantaneous rotational speed difference. Basic injection amount correction means 104 for correcting the amount, and acceleration state detection means 1 for detecting the acceleration state
05, the corrected basic injection amount calculated by the basic injection amount correction unit 104 is corrected when the acceleration state is detected by the acceleration state detection unit 105, and the corrected basic injection amount correction amount is used as the fuel for the next cylinder. A technical means called a fuel injection device characterized by including a fuel injection amount calculation means 106 for setting an injection amount.

Further, when the acceleration state is detected by the acceleration state detecting means, the basic injection amount correction executed by the basic injection amount correcting means is invalidated, and the basic injection amount is set to the fuel injection amount for the next cylinder. The fuel injection amount calculation means may be provided.

[0010]

In the fuel injection system of the present invention, the basic injection amount calculation means 1 is based on the detection signal from the operating state detection means 100.
The basic injection amount is calculated at 01. In addition, the difference between two instantaneous rotation speeds, such as the instantaneous rotation speed in the explosion stroke calculated by the instantaneous rotation speed detection means 102 and the instantaneous rotation speed in the compression stroke in the next cylinder, is calculated in the instantaneous rotation speed difference calculation means 102. It is calculated. Then, the basic injection amount correction means 104 corrects the basic injection amount according to the instantaneous rotation speed difference so as to reduce this instantaneous rotation speed difference. Here, when the acceleration state detection means 105 detects the acceleration state, the fuel injection amount calculation means 106 further corrects the corrected basic injection amount. Since this corrected basic injection amount correction amount is injected as the fuel injection amount for the next cylinder, the fuel injection amount control during acceleration is improved,
The acceleration feeling of the vehicle is improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A diesel engine to which the present invention is applied will be described below with reference to the drawings. FIG. 2 is a schematic diagram of a diesel engine equipped with an electromagnetic spill type distributed fuel injection pump. The electromagnetic spill type distribution type fuel injection pump is provided with a solenoid valve in a communication passage that connects a high pressure chamber formed by an inner wall surface of a cylinder and a tip end surface of a plunger to a low pressure chamber (pump chamber) in the pump. The fuel injection amount is controlled by shutting off and communicating the communication passage by controlling the on / off of the.

The fuel passed through the filter is a vane type feed pump (9 driven by the drive shaft 2).
After being expanded by 0 ° and shown in FIG. 4), it is guided from the oil supply port 6 to the pressure regulating valve 8 and the pressure is adjusted by the pressure regulating valve 8. Then, the pump chamber 1 which is a low pressure chamber in the pump housing 10
Filled within 2. The fuel filled in the pump chamber 12 lubricates the operating portion in the pump chamber 12, and at the same time,
It is sent to the high pressure chamber 18 formed at the tip of the plunger 16 via the suction port 14. A part of the fuel is circulated from the overflow valve 20 back to the fuel tank for discharging excess fuel and cooling the operating part.

Intake grooves 22 of the same number as the number of cylinders are formed at the tip of the plunger 16, and a cam plate 28 is fixed to the tail end of the plunger 16, and a roller ring 30 is fitted on the cam plate 28. The same number of rollers 32 as the number of combined cylinders are in contact with each other. This plunger 16
Is inserted into the cylinder 34 from the tip side, and the plunger 1
6 and the inner wall surface of the cylinder 34, the high pressure chamber 18
Is formed. The intake port 14 is formed in the cylinder 34, and the delivery valve 3 is inserted from the inner surface of the cylinder.
The distribution passages 38 are formed in the same number as the number of cylinders communicating with the six cylinders. The pump housing 10 has a communication passage 40.
A solenoid valve 44 for connecting and disconnecting is attached. The communication passage 40 connects the high pressure chamber 18 and the pump chamber 12 with each other. When the solenoid 46 is turned on, the solenoid valve 44 projects the valve body 42 to shut off the communication passage 40, and when the solenoid 46 is turned off, the solenoid valve 44 sucks the valve body 42 to communicate the communication passage 40.

The drive shaft 2 projects toward the pump chamber 12 and is connected to a cam plate 28 via a coupling. The cam plate 28 is fixed to the plunger 16 and is pressed against the roller 32 by the spring 50. Therefore, when the roller 32 rides on the cam crest on the cam plate 28 that rotates depending on the contact state between the roller 32 and the cam plate 28, the plunger 16 is reciprocated the number of times equal to the number of cylinders during one rotation.

At the lower part of the fuel injection pump, the drive shaft 2 and the plunger 16 are utilized by utilizing the change of the fuel feeding pressure.
There is provided a hydraulic timer (developed by 90 °) 52 that changes the fuel injection timing by changing the phase with the cam plate 28 that drives the. The hydraulic chamber 5 of this timer 52
3, a spring 54 is provided at one end of the timer piston 56 and biases the timer piston 56 in the injection delay direction. The hydraulic chamber 53 communicates with the fuel filler port 6, and the hydraulic chamber 55 formed at the other end of the timer piston 56 communicates with the pump chamber 12. Then, as the engine speed increases, the oil feed pressure increases, so the pressure in the hydraulic chamber 55 becomes higher than the pressure in the hydraulic chamber 53, and the timer piston 56 resists the urging force of the spring 54 and moves in the direction of the hydraulic chamber 53. Move to. Then, the roller ring 30 is rotated in the direction opposite to the rotation direction of the injection pump via the rod 58, and the fuel injection timing is advanced in proportion to the oil pressure. Further, a communication passage 57 is formed between the hydraulic chamber 53 and the hydraulic chamber 55, and a timing control valve 59 (hereinafter TCV) is provided in the communication passage 57.
Will be provided). The TCV 59 is controlled by the duty ratio, connects and disconnects the communication passage 57, and controls the fuel injection timing.

Next, a signal rotor 60 is fixed to the tip of the drive shaft 2 coaxially with the drive shaft 2, and a pickup 62 is attached to the roller ring 30 so as to face the peripheral surface of the signal rotor 60. . The signal rotor 60 and the pickup 62 are
It acts as a rotation speed sensor that detects the engine rotation speed. The signal rotor 60 has a predetermined angle (for example, 5.
A plurality of convex teeth are arranged every 625 °), and the convex teeth are cut out at equal intervals as the number of cylinders to form toothless portions. That is, in the case of a 4-cylinder diesel engine, as shown in FIG.
A plurality of convex teeth 60α, 60β ... Are arranged for each (corresponding to ° CA), and toothless portions 60a to 60d are formed for each 90 ° (corresponding to 180 ° CA).
Therefore, when the signal rotor 60 rotates, the convex teeth move toward and away from the pickup 62, so that the pulse signal shown in FIG. 4 is output from the pickup 62 by electromagnetic induction. The wide valley portion of this pulse signal acts as a reference position signal, and the other portions act as rotation angle signals. Further, the pickup 62 and the signal rotor 60 are arranged such that one of the toothless portions approaches the pickup 62 before the plunger 16 is pushed in the direction in which the high pressure chamber is contracted, that is, before the plunger 16 is lifted.
The relative position is determined so that the reference position signal is output from 2, that is, the width of the valley portion of the pulse signal is widened.

The pulse signal output from the pickup 62 is input to a microcomputer 82, which will be described later, to calculate the engine average rotation speed Na and the instantaneous rotation speed Nei. The engine average rotation speed Na is calculated, for example, from the time from the pulse appearing by the convex tooth 60α to the pulse appearing by the convex tooth 60γ shown in FIG. 3, that is, from the time corresponding to 180 ° CA in this embodiment. There is. On the other hand, the instantaneous rotation speed Nei
Is calculated from one pulse time output when one convex tooth approaches and separates from the pickup 62, that is, a time corresponding to 11.25 ° CA in this embodiment.

Due to the above configuration of the rotation speed sensor, the timer 5
When the roller ring 30 rotates by the operation of 2, the pickup 62 also rotates by the same phase as the roller ring 30. For this reason, the reference position signal output from the pickup 62 also shifts by the same phase, so that the operation timing of the solenoid valve 44 changes. That is, since the spill timing also changes in accordance with the amount of deviation of the reciprocating movement of the plunger 16, the injection amount does not change.

Further, a fuel injection cut valve 64 for stopping fuel injection by shutting off the intake port 14 is attached to the pump housing 10. The delivery valve 36 is connected to a fuel injection valve 68 mounted so as to project into the sub fuel chamber of the diesel engine 66. A glow plug 70 is attached to this sub fuel chamber. Further, a throttle valve 88 is arranged in the intake passage, and a venturi 90 is configured including the throttle valve 88.

Incidentally, 74 is an accelerator sensor for detecting the accelerator opening, 76 is a pressure sensor for detecting the intake pipe pressure,
Reference numeral 78 is a water temperature sensor for detecting the engine cooling water temperature, 80 is a glow relay, and 92 is a vehicle speed sensor. Further, 84 is a signal rotor fixed to the crankshaft and having a projection at the top dead center position of the specific cylinder, 86 is a top dead center sensor that outputs a top dead center signal as the projection passes, and 94 is a shift position. It is a switch. Microcomputer 82
In addition to the accelerator sensor 74, a pickup 62, a pressure sensor 76, a water temperature sensor 78, a vehicle speed sensor 92, a shift position switch 94, and a top dead center sensor 86 are connected to the.

The output port of the microcomputer 82 is connected to the glow plug 70 via the glow relay 80, and is also connected to the solenoid 46 of the solenoid valve 44 and the solenoid of the fuel injection cut valve 64. Further, it is connected to the TCV 59 provided in the timer 52 and outputs a duty signal to the TCV 59. The microcomputer 82 is composed of a CPU, a RAM, a ROM, an AD converter, etc., and the AD converter sequentially converts the signals from the accelerator sensor 74, the pressure sensor 76, and the water temperature sensor 78 into digital signals in accordance with instructions from the CPU. Further, the ROM of the microcomputer 82 stores in advance the fuel injection timing determined by the basic injection amount Q and the average engine rotation speed Na calculated by the accelerator opening α and the average engine rotation speed Na.

The fuel injection control in the first embodiment having the above construction will be described with reference to the flow chart showing the main routine of FIG. 5 and the time chart of FIG. The fuel injection control is realized by the process executed by the CPU according to the control program stored in the ROM of the microcomputer 82. When the process starts, in step 200, the engine average rotation speed Na, accelerator opening α, engine cooling water temperature, vehicle speed, etc. are fetched as engine parameters.

In step 201, the engine injection speed command value Q, which is the basic injection amount, and the injection timing target value T are calculated from the engine average rotational speed Na and accelerator opening α acquired in step 200.
Etc. are calculated.

In step 202, 2 during one injection
The two instantaneous rotation speeds Ne _i-1 and Nc _i are fetched. The instantaneous rotation speeds Ne _i-1 and Nc _i are calculated by the predetermined pulse time from the reference position signal of the output signal from the rotation speed sensor composed of the signal rotor 60 and the pickup 62, respectively. The number of this predetermined pulse is the instantaneous rotation speed N when the engine state is steady.
It is determined that e _i−1 and Nc _i are equal (FIG. 6A).

Next, at step 203, this instantaneous rotational speed difference ΔN _i = Ne _i-1 −Nc _i is calculated. Step two
At 04, the predicted correction coefficient KF corresponding to this instantaneous rotational speed difference ΔN _i is obtained from the characteristic map of FIG. 7.

In step 205, the accelerator opening change amount Δα = | α _{i- 1} −α _i | is calculated in order to detect the acceleration state. The accelerator opening is detected at regular intervals,
α _i-1 is the accelerator opening measured last time, and α _i is the accelerator opening measured this time. Then, in step 206, it is determined whether or not the accelerator opening change amount Δα is equal to or larger than a predetermined value A. When the accelerator opening change amount Δα is equal to or larger than the predetermined value A, in step 207, the predicted correction correction coefficient KD corresponding to the throttle opening change amount Δα is corrected in FIG. 8 in order to correct the fuel injection amount decrease in the acceleration state. It is calculated by the characteristic map of. If the accelerator opening change amount Δα is not greater than or equal to the predetermined value A, the prediction correction correction is not performed in step 208, and the prediction correction correction coefficient KD = 1.0 is reset.

Then, in step 209, step 20
4 and the prediction correction coefficient KF calculated in step 208
Then, the predicted correction coefficient KD is multiplied by the basic injection amount Q calculated in step 201 to correct the fuel injection amount Q _OUT = Q × KF × KD to be injected into the next cylinder. Next, in step 210, Q _OUT is set to the output port.

Thereafter, the process returns to step 200 again and the above control is repeated. Therefore, when the engine load is applied, such as when the vehicle is started and the clutch is engaged, or when the braking is applied, the fluctuation of the engine rotation is suppressed and becomes stable.

Here, when the accelerator opening α in FIG. 6 (b) becomes large and the vehicle is accelerated, the value of the prediction correction coefficient KF in FIG. 6 (c) becomes 1 or less unless the conventional prediction correction correction is performed. Become. Therefore, the fuel injection amount is reduced as indicated by the alternate long and short dash line in FIG. 6 (e), and the engine speed does not sufficiently increase as indicated by the alternate long and short dash line in FIG. 6 (a). However, the fuel injection amount reduction is suppressed by the predicted correction correction coefficient KD of the present embodiment shown in FIG. 6D, and the fuel injection amount is required as shown by the solid line in FIG. (E) Middle broken line). As a result, FIG.
(A) As indicated by the solid line, the engine speed also rises, and the vehicle can be sufficiently accelerated when it is desired to accelerate it. Therefore, acceleration feeling can be improved.

Next, another embodiment will be described with reference to the flowchart shown in FIG. The basic injection amount Q and the injection timing target value T etc. are calculated from the engine parameters fetched in steps 301 and 302.

Then, in step 304, it is detected from the accelerator opening change amount Δα calculated in step 303 whether or not the vehicle is in an accelerating state. The control for obtaining the similar prediction correction coefficient KF is performed in step 30.
6, 307 and 308. On the other hand, when the vehicle is accelerated, the prediction correction coefficient KF = 1 is set in step 305, and the prediction correction is stopped. Then, in step 309, the output command value Q _OUT = Q × KF is calculated, and in step 210 Q
Set _OUT to output port.

By this control, the fuel injection amount is not reduced by the predictive control during acceleration, so that the vehicle can be sufficiently accelerated when desired. Therefore, acceleration feeling can be improved.

In the above embodiment, the acceleration state determination is made based on the change amount of the accelerator opening α, but the acceleration state determination may be made from the change amount of the engine average rotation speed Na.

[0034]

As described above, the fuel injection device of the present invention further corrects the corrected basic injection amount during acceleration.
As a result, it is possible to prevent the fuel injection amount from being reduced at the time of acceleration due to the control for suppressing the engine rotation fluctuation, and the acceleration performance from being impaired. Since the corrected basic injection amount correction amount is the fuel injection amount for the next cylinder, the fuel injection amount control during acceleration can be improved, and the acceleration feeling of the vehicle can be improved.

[Brief description of drawings]

FIG. 1 is a complaint correspondence diagram.

FIG. 2 is a schematic diagram of a first embodiment to which the present invention is applied.

FIG. 3 is a plan view of a signal rotor.

FIG. 4 is a pulse signal waveform output from the pickup.

FIG. 5 is a flowchart showing injection control of the first embodiment.

FIG. 6 is a time chart showing the effect of the first embodiment.

FIG. 7 is a characteristic diagram for obtaining a prediction correction coefficient KF.

FIG. 8 is a characteristic diagram for obtaining a prediction correction correction coefficient KD.

FIG. 9 is a flowchart showing injection control of the second embodiment.

[Explanation of symbols]

 52 timer 60 signal rotor 62 pickup 74 accelerator sensor 82 microcomputer 100 operating state detecting means 101 basic injection amount calculating means 102 instantaneous rotational speed detecting means 103 instantaneous rotational speed difference calculating means 104 basic injection amount correcting means 105 acceleration state detecting means stage 106 Fuel injection amount calculation means

Claims (2)

[Claims] 1. An operating state detecting means for detecting an operating state of an engine, a basic injection amount calculating means for calculating a basic injection amount from a detection signal from the operating state detecting means, and an instantaneous rotation speed in an explosion stroke and a continuous value. An instantaneous rotation speed calculation means for calculating the instantaneous rotation speed in the compression stroke in the next cylinder, and an instantaneous rotation speed difference calculation means for calculating the difference between the two instantaneous rotation speeds calculated by the instantaneous rotation speed calculation means. , A basic injection amount correction means for correcting the basic injection amount according to the instantaneous rotation speed difference, an acceleration state detection means for detecting an acceleration state, and the acceleration state detection means When the acceleration condition is detected by
A fuel injection amount calculating means for correcting the corrected basic injection amount calculated by the basic injection amount correcting means, and using the corrected basic injection amount correction amount as a fuel injection amount for the next cylinder. apparatus. 2. The basic injection amount correction executed by the basic injection amount correction unit when the acceleration state is detected by the acceleration state detection unit is invalidated, and the basic injection amount is set to the fuel injection amount for the next cylinder. 2. The fuel injection device according to claim 1, further comprising a fuel injection amount calculation means for performing the operation.