JPS6026144A - Fuel injection timing control device for fuel injection pump - Google Patents

Abstract

PURPOSE:To prevent the engine from generating abnormal sound and vibration to satisfy the driveability, by providing a deviation computing means for computing the deviation between the actual fuel injection timing value and the desired injection timing value, and a compensating means for setting a compensating value as the fuel injection timing value. CONSTITUTION:In a control circuit 20, a desired fuel injection timing computing means A receives the operating condition of the engine from an engine sensor 30, and calculates the desired fuel injection timing value. A deviation computing means B receives data from an actual injection timing sensor 11, and computes the deviation between the actual fuel injection timing value and the desired fuel injection timing value. A setting value computing means C computes a setting value in accordance with an operating condition signal from the engine sensor 30. A compensating means D compensates such that the setting value is added to or subtracted from the actual fuel injection timing value, and delivers the thus obtained compensated value as the fuel injection timing value to a timer control valve 10. Thus, the engine is prevented from generating abnormal sound and vibration, and therefore, the driveability including the abilities of acceleration and deceleration, etc. may be satisfactorily sustained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides P! A fuel injection f
The fuel injection timing control device of the lJ pump, especially when there is a sudden change in the unbalanced injection timing, changes gradually in stages depending on the operating condition. The present invention relates to a combustion engine injection timing control device that prevents this.

Recently, in diesel engines, the operating state of the engine is detected electrically, the fuel I injection timing (injection start timing) of the fuel injection pump is calculated based on this detection signal, and the °ζ ivy is calculated based on this injection timing data. An electronic fuel injection timing control device that adjusts four mechanisms has been realized.

This type of fuel injection timing control device generally uses an engine sensor including a rotation speed sensor that detects the rotation speed of the diesel engine and a load sensor that detects the engine load, and based on calculated fuel injection timing data. The optimum fuel injection timing is determined based on a timer control valve that controls a timer mechanism, an actual injection timing sensor that detects the actual injection timing, at least rotation speed data from a rotation speed sensor, and load data from a load sensor. The engine is equipped with a control circuit that calculates the fuel injection timing and outputs an injection timing control signal to the timer control valve based on the fuel injection timing data, thereby optimizing the fuel injection timing of the engine according to the operating state.

However, in general, the control circuit inputs rotation speed data sent from a rotation speed sensor and calculates the optimum fuel injection timing from a data map for the engine rotation speed and load written in advance in the ROM. Fuel injection timing data is calculated by correcting the injection timing based on other engine data such as intake air temperature data from an intake air temperature sensor and cooling water temperature data from a water temperature sensor that detects engine cooling water temperature. Based on the timing data, a corresponding control signal is output to the timer controller I/roll valve to control the timer position of the timer mechanism. Therefore, if the engine speed changes suddenly or greatly, or if the engine load changes significantly due to a large and sudden operation of the accelerator, the fuel injection timing will be calculated to be significantly advanced or retarded. The timer position of the timer mechanism is controlled by this, and the fuel injection timing changes rapidly, which may cause abnormal engine noise and vibration such as abnormal changes in combustion noise, and changes in acceleration, deceleration, etc. There was a problem that the drivability deteriorated.

The present invention has been made to solve the above problems, and when the fuel injection R1 timing suddenly changes due to fluctuations in engine data such as engine speed and engine load, the change in fuel injection timing is reflected in the operating state. Fuel injection timing control is carried out step by step by value within a predetermined range to prevent abnormal engine noise and vibration and maintain good drivability such as acceleration and deceleration. The purpose is to provide equipment.

First, the overall configuration of the present invention is ff! This will be explained with reference to Figure 6.

In the control circuit 20, ζ and A are target injection timing calculation outputs, and the engine operating state including the rotation speed and negative <::f is manually input from the engine sensor 30 to calculate the target injection timing. B is a deviation calculating means, which calculates the deviation between the actual injection timing value from the actual injection timing sensor 11 and the target injection timing value. C is a set value calculation stage 1, which calculates a set value corresponding to a permissible injection timing change according to the operating state signal from the engine sensor 36. D is a correction means, which performs correction by comparing the color deviation value with the color deviation value and adding or subtracting the set value from the actual injection timing value when this difference is larger than the set value;
This correction value is output to the timer control valve 10 as a fuel injection timing value.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a timer mechanism 1 built into a fuel injection pump for a diesel engine. 2 is a roller ring in which a plurality of rollers 2a corresponding to the number of cylinders are provided on the circumference, and a coupling 3 is attached to a drive shaft (not shown).
When the υ-ra 2a comes into contact with the cam surfaces of the cam plays 1 and 3' that are connected and rotated through the
The pump plunger (not shown), which rotates together with the bolt 3', has reciprocating motion in the axial direction! 4. By changing the angular position of the roller ring 2, the time for the reciprocating water qi movement of the pump plunger changes, and the fuel injection timing (injection start timing) is adjusted. 4 is a slide bin connected to the roller ring 2 to change its angle a) γ position, and the lower ring of the slide bin 4 is connected to the pump housing 5.
The roller ring 2 is connected to a timer piston 6 installed in the lower part thereof in a direction perpendicular to the axial direction of the drive shaft, and the angular position of the roller ring 2 is adjusted by sliding the timer piston 6 through the slide bin 4. Timer Bis I・N6
is inserted into the cylinder chamber 8 in the pump housing 5 from the left side in the drawing while being pushed to the right by the coil spring 7, and the coil spring 7 is compressed by the hydraulic pressure in the cylinder chamber 8 on the right side in the drawing. be moved by

Note that the right side of the cylinder chamber 8 is connected to the discharge side of a feed pump (not shown) built into the fuel injection pump.
The left side of the cylinder chamber 8, that is, the coil spring 7 side, is connected to the suction side of the feed pump, and furthermore, there is a bypass passage between the discharge side and the suction side of the feed pump, that is, the right side chamber and the left side chamber of the cylinder chamber 8. 1? δ9 is connected in communication, and a timer control valve IO is interposed in this pipe passage 9. Then, by controlling the timer control valve 10 in the direction of closing, the pressure on the right side of the cylinder chamber 8, that is, on the feed pump discharge side, increases, pushing the timer piston 6 in the direction of compressing the coil spring 7, and thereby compressing the roller ring 2. It operates by rotating clockwise to advance the fuel injection timing. timer control valve l
O is controlled by inputting an injection timing control signal based on duty ratio control from a control circuit 20, which will be described later in FIG. On the other hand, 11 is a differential transformer type timer position sensor that detects the position of the timer piston 6, and is disposed on the left side of the timer screw I/N 6, and detects the actual position of the timer piston 6, that is, the actual fuel injection timing. , the detection signal is sent from the timer position sensor 1 to the control circuit 20 for feedback control.

FIG. 2 shows a block configuration diagram consisting of a control circuit 20, an engine sensor 30, and the like. The control circuit 20 is composed of a microcomputer, and includes a microprocessor unit (Ml) 21 that performs various wandering processes. Read-only memory that stores constants and data maps required for calculations
(ROM) 22, a memory (RAM) 23 for temporarily storing detected data and calculation results, an input buffer 24, and an output sofa 25. M I) tJ 21 is R
The 'ζ process is executed in accordance with a program stored in the OM 22 in advance.

30 is an engine sensor that detects the operating state of the diesel engine. This engine sensor 3o is a rotation speed sensor 31 that detects the rotation speed (speed) of a diesel engine. A load sensor 32 detects the load on the engine, for example, a potentiometer detects the amount of depression of the accelerator pedal, and a thermistor-type coolant temperature sensor 33 detects the engine coolant temperature. Sensors, oil temperature sensors, etc. are used. The detection signal of each sensor is control 1iTI II820 human cover sofa 2
It is connected so that it is sent to 4. In addition, the hippo sofa 2
An evening/immediate position sensor 11 is connected to 4 so that actual position data indicating the actual injection timing is input. On the other hand, the timer control valve 10 is connected to the outgoing cover sofa 25 via its drive circuit 1?812, and the outgoing cover sofa 25
An injection timing control signal corresponding to the fuel injection timing is output from.

Next, refer to the flowchart shown in FIG.
Fuel injection time! +Explain the operation of the control.

This fuel injection timing control processing routine, for example, has a cycle of τ0.
is executed at intervals of First, execute step 100,
The rotation speed N is read from the rotation speed sensor 31. Next, step 101 is executed, and the rotational speed data read in step 100 is previously stored in the ROM 2.2. For example, by using a data map of the rotational speed N and the set value α as shown in FIG. 4, an allowable advance angle change amount (hereinafter referred to as the set value α) at this rotational speed is searched. Next, step 102 is executed, and the actual position data from the timer position sensor 11, that is, the current actual injection time 1311'.

(timer advance angle) is read into the RAM 23.

Next, step 103 is executed, and based on the rotation speed data read in step 100 and the load data from the load sensor 32, the basic injection timing is set using the rotation speed and load stored in the ROM 22 in advance as parameters. At this point using the data map for 4? Furthermore, is this basic injection timing based on other engine data such as cooling water temperature data from the cooling water temperature sensor 33 or intake air temperature data from the intake air temperature sensor? df
iE, and the target injection timing TI is calculated.

Then, the process proceeds to step 104, where the difference ΔT between the target injection time 'I'1 calculated in step 103 and the actual injection timing To is calculated.

Next, the process proceeds to step 105, where the target injection timing 'I'1 calculated in step 101 and the actual injection timing T are calculated.

A determination is made as to whether or not the difference T is smaller than the set value α set in step 101 above. At this time, the engine load increases due to accelerator operation, etc., and the target injection timing 1
゛1 is larger than the actual injection timing 1"0, and the difference Δ'
If F is abnormal to the set value α, the judgment result is “NO”
And then, Ste.

Proceed to step 106. Then, in step 106, a process is performed in which the fuel injection timing 1 and 2, which are the final data, are set to a value obtained by adding, for example, a set value α to the actual injection timing To. That is, when the target injection timing TI is sufficiently larger than the actual injection timing 'l''0, the set value α is added to the actual injection timing T ( ) instead of the target injection timing T1, and is used as the fuel injection timing T2.

On the other hand, in the determination step 105, if the difference ΔT is smaller than the zero value α, the determination is r Y E S J, and the process then proceeds to step 107, in which "1 target injection timing T1
Processing is then performed to finally set the fuel injection timing to 1 and 2.

The data of the fuel injection timing 'I'2 extracted in step 106 or step 107 is outputted from the output buffer 25 of the control circuit 20 to the drive amount 11A 12 in the next step 106, and from the drive amount 11A 12, Injection timing'1
The pulse signal of the debt ratio generated according to 2 is sent as an injection timing control signal to the timer control valve 10 of the C timer mechanism 1, and the opening degree of the timer 1 control varso IO is controlled. As a result, the pressure in the cylinder chamber 8 of the timer mechanism 1 is adjusted, and the timer piston 6
By adjusting the position of the roller ring 2, the angular position of the roller ring 2 is adjusted. If step 107 is executed here, advance control is performed on the target injection timing Go 1 relative to I, t, while if step 106 is executed, the injection timing 41 is adjusted to the set value α. Advance 1 l By mouth (I (control is performed.

In this way, when the processing routine of the flowchart in FIG. 3 is repeated every calculation cycle τ0, for example, as shown in FIG. 5, when the difference between the actual injection timing 'I' 0 and the target injection timing TI is large, , the fuel injection timing will be increased step by step by the set value α according to the operating condition for each operation period τ0, and even in the case of operation with sudden changes in the injection timing,
Smooth acceleration can be achieved without producing abnormal engine noise such as abnormal changes in combustion noise.

In the above embodiment, the case where the injection timing is advanced is explained, but the same applies to the case where the injection timing is retarded, and in this case, the actual injection timing is advanced from the target injection timing. If the difference between the actual injection timing and the target injection timing is large, the injection timing is controlled so that the fuel injection timing is delayed stepwise by a preset value. here,
The set value during retard angle control is a negative value, and its absolute value is set larger than the set value α during advance angle control.

As explained above, in the fuel injection timing control device for a diesel engine, the present invention compares the difference between the actual injection timing and the target injection timing with a setting value set according to the operating state, and The present invention is characterized in that a value obtained by adding or subtracting the set value from the actual injection timing value is set as the fuel injection timing value. Therefore, according to the present invention, when the difference between the actual injection timing and the target injection timing is larger than a preset value, the value obtained by adding or subtracting the set value to the actual injection timing is added to or subtracted from the actual injection timing. Since the injection timing is controlled in this way, even if engine data such as engine speed and engine load suddenly change and the target injection timing differs greatly from the actual injection timing, the injection timing will be controlled in accordance with the operating conditions. Since the engine can gradually advance or retard the angle in a stepwise manner, it is possible to always prevent abnormal engine noise and vibration from occurring, provide smooth acceleration or deceleration, and ensure good drivability.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, Fig. 1 is a sectional view of a timer mechanism built into a fuel injection pump, Fig. 2 is a block diagram of a fuel injection timing control device, and Fig. 3 shows the operation of the device. Flowchart, FIG. 4 is a graph showing changes in set value α depending on rotational speed N, FIG. 5 is a graph showing temporal changes in fuel injection timing, and FIG. 6 is an overall diagram to clearly demonstrate the implementation of the present invention. It is a complete drawing. DESCRIPTION OF SYMBOLS 1... Timer ta structure, i o... Timer control valve, 11... Timer position sensor, 20... Control circuit, 30... Engine sensor, 31... Rotation speed sensor, 32... - Load sensor, A... Target injection timing calculation means, B... Deviation calculation means, C... Set value calculation means, D... Correction means. Representative Patent Attorney Takashi Okabe Figure 1 Figure 2

Claims (1)

[Claims] An engine sensor that detects the operating state of a diesel engine, a timer control valve that controls the position of a timer mechanism built into the fuel injection pump, and an actual engine sensor that detects the actual injection timing by the fuel injection pump. an injection timing sensor; and a control circuit that receives engine data from the engine sensor, calculates a target fuel injection timing value, and outputs an injection timing control signal to the timer control valve for the fuel injection timing control device. In the fuel injection timing control device equipped with the above-mentioned fuel injection timing control device, the above-mentioned 11 control laws include: 1. A deviation calculation for calculating the deviation between the actual injection timing value of the actual injection timing sensor and 2. the target injection timing based on the engine data. a set value calculation means for calculating a set value for determining the magnitude of the deviation according to the engine data; A fuel injection pump characterized by comprising: correction means for correcting or subtracting the set value from the actual injection timing value when the value is larger than the set value, and making this correction value a "secondary fuel injection timing value". fuel injection timing control device.