JPS60240849A - Engine control device - Google Patents

Abstract

PURPOSE:To stably maintain good operational performance of an engine for a long period, by equipping a deterioration detecting means, which detects deterioration of the engine, and correcting a preset operational region for controlling the engine in accordance with the deterioration of the engine. CONSTITUTION:A control unit 18, which actuates an injector 12 to be controlled by receiving an output signal from a speed sensor 13, throttle valve opening sensor 14, intake air temperature sensor 15 and a water temperature sensor 16, equips an operational region setting means 19 setting an operational region map for controlling supply of fuel from an engine speed and a throttle valve opening. While the control unit 18 equips a control means 20 which controls an engine 1 in accordance with an operational region through the above described means 19 by inputting the output signal from each sensor 13-16. Further the control unit 18 provides a correcting means 22, which corrects the operational region of the above described means 19 in accordance with an output signal from a negative pressure sensor 21 used as a deterioration detecting means detecting deterioration of the engine 1, in this way, good operational performance of the engine is stably maintained over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention detects the operating state of an engine, compares it with preset operating ranges for various controls, and controls the engine based on the operating range. The present invention relates to an engine W control device that controls engine power consumption, and particularly to a measure for correcting the above-mentioned operating range in accordance with engine deterioration.

(Prior Art) Conventionally, as a device for controlling an engine according to the operating state of the engine, for example, as shown in Japanese Patent Publication No. 56-38781, there has been a device that controls the amount of fuel supplied according to the operating state of the engine. an arithmetic circuit that generates an injection pulse with a predetermined time width; an injection valve that opens according to the injection pulse of the arithmetic circuit and injects fuel into the engine; and an injection valve that instructs fuel cutoff during deceleration and generates the injection pulse. a cut circuit that prevents generation of the signal; and a recovery compensation circuit that generates a compensation signal that gradually changes after the command signal of the cut circuit disappears, and uses the compensation signal to gradually increase the time width of the injection pulse of the arithmetic circuit. It is equipped with a timing signal synchronized with engine rotation and a logic circuit that uses various parameters such as intake negative pressure, throttle opening, intake air temperature, and cooling water temperature as signals that indicate the operating state of the engine in synchronization with the timing signal. The logic circuit outputs an injection pulse signal with a predetermined time width to control the amount of fuel injected from the injector via the drive circuit, while cutting fuel when the engine operating state is in a predetermined operating range. It is determined whether or not the condition is met, and if the cut condition is met, the fuel supply from the above injection valve is cut off, and immediately after that, the fuel supplied to the engine is gradually increased to the fuel supply amount according to the engine operating state. There are known methods that allow for increased recovery.

However, in the above-mentioned conventional engine, since the preset operating range for fuel supply control is constant, the engine deteriorates with long-term use and the air intake capacity decreases.
Even if the very low-speed torque of the engine becomes weak, the above operating range is used as is to control the injection amount from the fuel injection valve. 9-c, ENG>, >lfi stop □hi, -c.

(Problems to be Solved by the Invention) The present invention has been made in view of the above points, and its purpose is to change the operating range for engine control described above so as to cope with engine deterioration. The purpose is to make it possible to always perform engine operation control based on an appropriate operating range even if the engine deteriorates by appropriately correcting the above.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention is as follows:
As shown in the figure, an operating state detecting means 17 for detecting the operating state of the engine, an operating region setting means 19 for setting an operating region based on at least one of engine speed or load, and a signal from the operating state detecting means 17. In an engine control device comprising a control means 20 for controlling the engine in accordance with the operating range determined by the operating range setting means 19 by inputting a a deterioration detecting means 21 for detecting deterioration of the engine; and a signal from the deterioration detecting means 21 is inputted to determine the operating range setting means 19 according to the deterioration of the engine.
and a correction means 22 for correcting the operating range.

(Function) Accordingly, in the present invention, the actual engine operating state detected by the operating state detection means 19 is compared with a preset operating range, and the engine is adjusted to correspond to the operating range. While performing this basic control, the deterioration detection means 21 detects engine deterioration and corrects the above operating range according to the deterioration to prevent a decrease in air suction capacity due to deterioration, etc. This is to compensate for the impact.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of an embodiment of the present invention, where 1 is an engine equipped with a combustion chamber 5 surrounded by a cylinder 2, a cylinder head 3, and a piston 4, and 6 is an engine that supplies intake air to the combustion chamber 5. 7 is an exhaust passage for discharging exhaust gas from the combustion chamber 5, 8 is an intake valve, and 9 is an exhaust valve. an air flow meter 10 that detects the amount of intake air taken into the combustion chamber 5 of the engine 1; a throttle valve 11 that controls the amount of intake air that is supplied to the combustion chamber 5; and an injector 12 that injects fuel into the engine 1. is thinly coated.

To explain the control system for controlling the operation of the injector 12, 13 is a rotation sensor that detects the rotation speed of the engine 1, and 14 is the throttle valve 1.
1 is a throttle opening sensor that detects the load condition of the engine 1 by the opening of 1; 15 is an intake air temperature sensor that detects the temperature of intake air taken into the engine 1; and 16 is a water temperature sensor that detects the temperature of the engine cooling water. The above-mentioned sensors 13 to 16 constitute an operating state detection means 17 that detects the actual operating state of the engine 1.

In addition, 18 receives output signals from each of the sensors 13 to 16 (operating state detection means 17) and operates the injector 12.
This control unit 18 includes an operating range setting means 19 that sets an operating range map for controlling fuel supply based on the engine speed and the throttle opening as a load. and a control means 20 that inputs signals from the sensors 13 to 16 (operating state detection means 17) to control the engine.

That is, the operating range setting means 1 of the control unit 18
For example, as shown in FIG. 3, the operating range map set in 9 includes a low-speed high-load range z1 in which the engine is operated at low-speed and high-load operation, and a low-speed high-load range z1 in which the engine is operated at low speed and high load, using the engine speed and throttle opening as parameters. Feedback of the fuel supply amount based on the idle region Z2 in which idle operation is performed, the high rotation high load region Z3 in which the engine is operated at high speed and high load, and the oxygen concentration in the exhaust gas by the 02 sensor 23, that is, the air-fuel ratio of the engine 1. Feedback area z for control
4, a light (load region Z5) in which the engine is operated under a light load, a fuel cut region Z6 in which fuel supply is cut when the engine decelerates, and fuel restored during transition from the fuel cut region Z6 to the above-mentioned idle region Z2. It is divided in advance into each area including an idle return increase area Z7 where the amount is increased.

Furthermore, as a feature of the present invention, a negative pressure sensor 21 is disposed in the intake passage 6 to detect the intake negative pressure at a position directly downstream of the throttle valve 11 during engine idling. A deterioration detection means for detecting deterioration is configured.

The control unit 18 also controls the negative pressure sensor 21 (
The correction means 22 receives an output signal from the deterioration detection means (deterioration detection means), that is, an intake negative pressure signal indicating the degree of deterioration of the engine, and corrects the operating range map according to the intake negative pressure signal. The operation of the correction means 22 will be explained with reference to the flowchart shown in FIG. Based on the opening signal, it is determined whether the engine operating state is in the idle region (Z2). If the determination is YES in the idle region (Z2), a second step S2 determines whether the engine has warmed up sufficiently, that is, if the cooling water temperature detected by the water temperature sensor 16 is, for example, 70"C. If the determination is YES because the cooling water temperature is 70°C or higher, the process proceeds to a third step S3, and the rotation sensor 1
For example, if the engine rotation speed detected in step 3 is 600±10r
It is determined whether or not it has settled within the range of pIll.

If this determination is YES because the engine speed is within the above range, the process moves to a fourth step S4, where it is determined whether or not the engine is igniting at the initially set regular ignition timing. If this determination is YES due to the normal state of the ignition timing, the intake negative pressure is measured based on the signal from the intake negative pressure sensor 21 in the fifth step $5, and the process moves to the sixth step S6. Then, the operating range map is corrected and corrected according to the degree of engine deterioration indicated by the intake negative pressure. That is, as shown in FIGS. 5 and 6, the control unit 18 controls the engine speed A, which indicates the boundary between the fuel cut region Z6 and the idle return increase region z7, and the maximum throttle opening in the light load region Z5. The minimum engine speed C, the throttle opening B at a predetermined engine speed on the boundary line between the fuel cut region 76 and the light load region z5, and the throttle that indicates the boundary between the low rotation high load region Z+ and the idle region Z2. A map is stored for setting the opening degree and opening degree according to the intake negative pressure (engine deterioration), and as the degree of engine deterioration increases, the engine speed A is changed to a higher engine speed. A′, engine speed C
By shifting the engine speed C' to a lower engine speed C', the operating range map includes the idle return increase area 11iZy up to a higher engine speed and the light load area Z5 up to a larger throttle opening. Expand. In addition, with increasing engine deterioration,
The above throttle openings B and D are set to a larger opening B'
, D' respectively, the fuel cut region Z6 and the idle region Z2 are set in the operating region map.
are expanded to include larger throttle openings.

On the other hand, if any of the first to fourth steps 81 to S4 is NO, that is, the operating state of the engine is not in the idle region Z2, the cooling water temperature is less than 70°C, and the engine speed is 600°C. If the rotational speed is outside the range of ±10 rpm, or if the ignition timing of the engine has been changed from the normal ignition timing, the routine is terminated without correcting the operating range map.

Therefore, according to the above embodiment, engine deterioration is detected by the intake negative pressure under predetermined operating conditions of the engine,
The operating range map for fuel supply control is corrected according to the intake negative pressure, so even if pressure leaks in the combustion chamber or part of the intake system due to engine deterioration and the air intake capacity decreases, The operating range map can be changed in accordance with the degree of deterioration of the engine, and as a result, the engine 1 can always be operated stably and well.

In other words, in response to engine deterioration, the idle return increase region z7 is expanded to include higher engine speeds, so in older engines, when transitioning from the fuel cut region 76 to the idle region Z2, Fuel is restored from a relatively high engine speed, making it possible to prevent engine stalling due to a decrease in very low-speed torque.

In addition, as the engine deteriorates, the idle area wAZ2 is expanded to include a larger throttle opening, so the fuel will not become lean due to a decrease in the engine's suction capacity during idling operation. Therefore, engine stall can be effectively prevented.

Furthermore, as the engine ages and deteriorates, the light load region z5 shifts from the fuel cut region Z6 to the feedback region Z4 side due to an increase in the throttle opening degree B and a decrease in the engine speed C. In other words, at the same engine speed, the intake air Since the throttle opening degree is corrected to be slightly open in order to secure the amount, the light load region Z5 can be made to correspond accurately to engine deterioration, and therefore, engine stalling due to engine deterioration in the light load region Z5 can be prevented. At the same time,
Fuel consumption can be reduced by expanding the fuel cut region Z6.

In the above embodiment, the operating range for controlling the fuel supply to the engine is corrected in accordance with the deterioration of the engine, but the present invention also corrects the operating range for controlling the exhaust gas recirculation and the control for knocking. It can also be applied to the case where the operating range for performing Sendai type control is corrected according to the deterioration of the engine, such as the operating range for controlling the ignition timing by dividing it into a non-knocking range.

Further, in the above embodiment, the operating range of the engine is set by a computer, but the present invention can also employ a control device in which the operating range is set by an electric circuit having a resistor, a capacitor, etc.

(Effects of the Invention) As described above, according to the present invention, the degree of deterioration of the engine is detected and the preset operating range is appropriately corrected according to the degree of deterioration of the engine. Regardless of the deterioration of the engine, the operation of the engine can always be controlled based on the optimum operating range, and therefore good operating performance of the engine can be stably maintained over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the present invention, Figs. 2 to 6 show an embodiment of the invention, Fig. 2 is a general schematic diagram, and Fig. 3 is a control of fuel supply to the engine. FIG. 4 is a control system flowchart, and FIGS. 5 and 6 are explanatory diagrams showing the degree of correction of the limit rotation speed and limit load in a predetermined region of the operation region map, respectively. be. 1...Engine, 10...Air flow meter, 1
2... Injector, 13... Rotation sensor, 14.
... Throttle opening sensor, 15... Intake air temperature sensor, 16... Water temperature sensor, 17... Operating state detection means, 18... Control unit, 19... Operating region setting means, 20. ...control means, 21...deterioration detection means,
22...Correction means. Fig. 3 Fig. 5 Fig. 6

Claims (1)

[Claims] (1) An operating state detecting means for detecting the operating state of the engine, an operating region setting means for setting an operating range based on at least one of engine speed or load, and a signal from the operating state detecting means being input to perform the above operation. In an engine control device comprising a control means for controlling the engine according to an operating region by a region setting means, a deterioration detecting means for detecting engine deterioration and a signal from the deterioration detecting means are inputted to control the deterioration of the engine. 1. A control device for an engine, comprising: correcting means for correcting the operating range of the operating range setting means accordingly.