JPS60201035A - Method of controlling electronically controlled engine - Google Patents

Abstract

PURPOSE:To prevent delay of response and occurrence of knocking, by correcting the detected value of the pressure in an intake pipe or the quantity of intake air in case that the opening and closing speed of a throttle valve is higher than a predetermined value. CONSTITUTION:The opening and closing speed of a throttle valve is detected at a step 1. At a step 2, judgement is made whether the opening and closing speed of the throttle valve is higher than a predetemined value or not. In case of YES, the detected value of the pressure in an intake pipe or the quantity of intake air is corrected at a step 3. Further, at a step 4, the injection quantity of fuel and the ignition timing are calculated by use of the pressure in the intake pipe or the quantity of intake air. By empolying such a method, it is enabled to prevent delay of response or occurrence of knocking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a control method for an electronically controlled engine, and in particular,
Suitable for use in automobile engines where accelerator response is important, the fuel injection amount and/or ignition timing is controlled according to engine operating conditions including at least intake pipe pressure or intake air amount. 1111 improvements have been made to the control method of electronically controlled engines. [Prior Art] One method of controlling combustion in an internal combustion engine such as an automobile engine is to arrange one injector in the throttle body or several engine cylinders in the intake manifold to inject fuel into the engine. By electronically controlling the valve opening time of the injector according to the engine operating state, for example, the engine load and engine rotation speed detected from the intake pipe pressure or the amount of intake air per engine rotation,
There is one in which an air-fuel mixture with a predetermined air-fuel ratio is supplied to the engine combustion chamber and is ignited at an appropriate time in synchronization with engine rotation. However, in controlling the fuel injection time and ignition timing in such an electronically controlled engine, the intake pipe pressure (or intake air amount), which is the reference for determining this, is affected by sensor response delays and calculations. Therefore, although it is possible to take an appropriate value in steady state, during transient times such as acceleration and deceleration,
There was a problem that accurate correspondence with the required value could not be established. As a result, for example, during acceleration, the amount of fuel injected becomes insufficient, and the ignition timing shifts to the advanced side, causing problems such as poor accelerator response and knocking. was causing Furthermore, even during deceleration, the air-fuel ratio deviates from an appropriate value, causing problems such as deterioration of fuel efficiency and generation of NOx. [Object of the Invention] The present invention has been made to solve the above-mentioned conventional problems, and it solves the problem of deterioration of responsiveness and knocking caused by delay in detection and calculation of intake pipe pressure or intake air amount during acceleration and deceleration. An object of the present invention is to provide a control method for an electronically controlled engine that can prevent such occurrence. [Configuration 1 of the Invention The present invention provides an electronic control system (super engine control method) that controls fuel injection amount and/or ignition timing in accordance with engine operating conditions that meet at least intake pipe pressure or intake air amount. As shown in Fig. 1, the thrower i
- A procedure for detecting the opening/closing speed of the valve, a procedure for correcting the detected value of the intake pipe pressure or intake air amount when the opening/closing speed exceeds a set value, and a procedure for correcting the detected value of the intake pipe pressure or intake air amount based on the detected value after the correction. The above object is achieved by including a procedure for measuring the injection amount and/or ignition timing. Further, in an embodiment of the present invention, the detected value of the intake pipe pressure angle or the intake air amount is corrected in accordance with the opening/closing speed of the throttle valve, so that an appropriate amount corresponding to the degree of acceleration/deceleration is corrected. This is so that corrections can be made. Furthermore, another example of the present invention is that when the corrected detected value exceeds the set limit value, the limiter process that replaces the corrected detected value with the set limit value is stopped. The correction process prevents abnormal values from appearing. [Operation of the Invention] The present invention detects the transient state in which the engine operating state deviates from the steady state by detecting the opening/closing speed of the throttle valve. In addition, when the opening/closing speed of the throttle valve is equal to or higher than the set value, the detected value of intake pipe pressure or intake air amount is corrected. Fuel injection amount control and/or ignition timing control is performed. Therefore, the accelerator response is good even during transient times, and there is no risk of knocking. [Example 1] Referring to the drawings below, An embodiment of an automobile engine equipped with an intake pipe pressure sensing type electronically controlled fuel control device and an ignition timing control device, in which the control method of the controlled engine is adopted, will be described in detail. As shown in FIG.
A throttle valve 16 that controls the flow rate of intake air in conjunction with
, a throttle body 18 for detecting the opening degree of the throttle valve 16, and a surge tank 2 for preventing intake air interference.
In order to intermittently inject pressurized fuel toward the intake boats of each cylinder of the engine 10, which are arranged in the intake pipe pressure sensor 22 for detecting the pressure of intake air in the engine 10 and the intake manifold 24, an injector 26, an ignition coil 30 with an igniter, a distributor 34 that distributes the high-voltage secondary ignition signal generated by the ignition coil 30 to the spark plugs 32 of each cylinder of the engine 10, and a distributor 34 built in the distributor 34. Also, distributor shaft 34A
a crank angle sensor 36 for detecting the rotational state of the engine 10 from the rotational state of the engine 10, a water temperature sensor 38 disposed in the cylinder block IOA of the engine 10 for detecting the engine cooling water temperature, and the intake pipe pressure sensor. 2
The ignition timing of the spark plug 32 is adjusted according to the engine load detected from the two outputs and the engine rotation speed determined from the output of the crank angle sensor 36, and the injection time of the injector 26 is determined. It is comprised of an electronic control unit (hereinafter referred to as ECU) 44 that outputs a corresponding valve opening time signal to the injector 26 and an ignition command signal to the ignition coil 30. In the figure, 46 is an exhaust manifold. As shown in detail in FIG. 3, the ECU 44 stores central processing units 1 to 44A (hereinafter referred to as "CPU") consisting of, for example, a microprocessor for performing various arithmetic processing, control programs, various data, etc. a read-only memory 44B for temporarily storing data calculated by the CPU 44A, a random access memory 44C for temporarily storing data calculated by the CPU 44A, and analog signals input from the intake temperature sensor 12, intake pipe pressure sensor 22, water temperature sensor 38, etc. Analog-to-digital converter 44E with multiplexer function for converting into digital signals and sequentially capturing them.
The digital signals inputted from the thrower 1 to the throttle sensor 18, the crank angle sensor 36, etc. are taken in, and the CP 1. , I44A, the input/output capos 1 to 44F for outputting control signals to the injector 26, ignition coil 30, etc., and each of the component devices are connected to transfer data and instructions. It consists of a common bus 44G for The effects of the embodiment will be explained below. Fuel injection control in this embodiment is executed according to a routine as shown in FIG. That is, first, in step 110, it is determined whether or not the opening speed DELTA of the thrower valves 1 to 16, which is determined based on the outputs of the thrower valves 1 to 18, is greater than or equal to a set value TΔS. When it is determined that the opening speed DELTA is an acceleration rate greater than or equal to the constant value TAS, the process proceeds to step 112, where the value PM obtained by A/D converting the detected value of the intake pipe pressure is calculated as shown in the following equation.
Add the value obtained by multiplying the opening speed DELTA by the constant K to AD, and use the correction value after addition as the standard A/D conversion 1!
P M. PM(-PMAo+*DELTA...(1) On the other hand, in step 110 mentioned above, the opening speed D of the throttle valve 16 is
If it is determined that ELTA is in a steady state or deceleration state where ELTA is below a certain value TAS, the process proceeds to step 114, and the A/D conversion value P of the intake pipe pressure is changed to A/D which should be used as the reference.
It is adopted as the D conversion value PM. A that should be the reference in step 112 or step 114
, -'D variation 11m P M is detected, the process proceeds to step 116, and limiter processing is performed to eliminate and cover the abnormal value of A/D conversion #iPM. That is, A reduced by 1q,
−'D conversion value P M A D is the limit value P M guar
It is determined in step 116 whether or not the value is larger than d. When it is determined that the limit value P M guard is large, the process proceeds to step 118 and the A/D change 1fAW that the limit value P M guard should be used as a reference is determined.
1P Iv+. On the other hand, when it is determined that the A/D conversion value P M obtained in step 116 is smaller than Ptvlguard, the A/D conversion value P M is directly used as the reference. After the limiter processing in steps 116 and 118 is performed, the process proceeds to step 120, and the A, -'D changes obtained in the flow up to this point! The ignition timing is calculated in the same manner as in the conventional method based on IIIPM, and then the process proceeds to step 122, where the valve opening time of the injector 26 which determines the fuel injection 61 is calculated, and the routine is closed. FIG. 5 shows a diagram comparing the conventional example and the above embodiment. When the opening degree of the throttle valve 16 changes as shown by the solid line in the figure, the intake pipe pressure, required fuel injection 01, and required ignition timing change as shown by the solid line A, respectively. However, conventionally,
As shown by broken line B, sensor response delay and ECU4
4, the rise of the A/D conversion value PMAC is delayed compared to the actual intake pipe pressure, and as a result, the fuel injection amount becomes smaller than the request, and the ignition timing shifts to the advance side compared to the request. was. On the other hand, in this embodiment, as shown by the two-point IC in the figure, a correction corresponding to the throttle valve opening speed DELTA is added.
The delay in the A/D conversion value PMxo has been corrected, and the fuel injection range and ignition timing calculated based on the corrected A/D conversion value PM are extremely close to the required fuel injection interval and required ignition timing, respectively. . As a result, in the past, sluggishness and sluggishness sometimes occurred at the point indicated by arrow X, which corresponds to the time when the engine speed begins to rise, but in this embodiment, such symptoms are no longer observed. Note that the set value TAS is a comparison level for not making corrections during gentle acceleration, but it may be applied to all accelerations by setting TΔS=0. Furthermore, in the embodiment described above, the detected value of the intake pipe pressure is corrected by an amount proportional to the opening speed of the throttle valve, but the present invention is not limited to this method, and the correction can be made more precisely. The correction may be performed using a map, or a simple correction such as a fixed amount of correction may be performed in a stepwise manner. In the above embodiment, the correction is made only when the throttle valve 16 opens, that is, when accelerating, but the present invention improves fuel efficiency and improves the air-fuel ratio by making the same correction even when decelerating. It is possible to optimize the Further, in the above embodiment, both the fuel injection amount and the ignition timing are controlled, but even if only one of them is controlled, a corresponding effect of 1q can be obtained. Further, in the above embodiment, the present invention is applied to an automobile engine equipped with an electronically controlled fuel injection device and an ignition timing control device that sense intake pipe pressure, but the scope of application of the present invention is limited to this. However, the present invention can be similarly applied to automobile engines equipped with an intake air amount sensing type electronic control device and general electronically controlled engines. Furthermore, the present invention can meet conditions such as detecting several holes (or several hundred meters) where the idle switch changes from on to off, where the change in intake pipe pressure (or intake air amount) is large, and making corrections only during this period. It is clear that this technology can be developed to enable more rational engine control. [Effects of the Invention] As explained above, according to the present invention, it is possible to supply a sufficient amount of fuel to achieve an optimal air-fuel ratio even during transient times such as acceleration and deceleration, and/or to perform ignition at the optimal time. This has the excellent effect of preventing knocking and poor responsiveness caused by delays in detection and calculation of intake pipe pressure or intake air direction during acceleration and deceleration.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the gist of the control method for an electronically controlled engine according to the present invention, and FIG. 2 shows an intake pipe pressure sensing type electronically controlled fuel injection device and ignition timing control device to which the present invention is adopted. FIG. 3 is a block diagram showing the configuration of the electronic control unit used in the embodiment, and FIG. Similarly, FIG. 5, a flowchart showing a routine for determining ignition timing and injector opening time, compares the results of the above embodiment and the conventional example with the required values (ideal values). FIG. DESCRIPTION OF SYMBOLS 10... Engine, 22... Intake pipe pressure sensor, 26... Injector, 36... Crank angle sensor, 44... Electronic control unit 1- (ECU), DELTA
... Opening speed, TAS... Setting value, PMAD... A/D conversion value, p iv+... A/D conversion value after correction, PM gu
ard...Setting limit value. Agent Takaya Ron (and 1 other person) Figure 1 Figure 4 Figure 2 1Uha Figure 3

Claims (3)

[Claims] (1) In a method for controlling an electronically controlled engine that controls the fuel injection amount and/or ignition timing according to engine operating conditions including at least intake pipe pressure or intake air amount, the opening/closing speed of a throttle valve is detected. a procedure for correcting the detected value of the intake pipe pressure or intake air amount when the opening speed is equal to or higher than a set value; A method for controlling an electronically controlled engine, comprising: a procedure for calculating . (2) The method for controlling an electronically controlled engine according to claim 1, wherein the detected value is corrected in accordance with the opening/closing speed of the throttle valve. (3) The corrected detected value is subjected to limiter processing in which it is replaced with the set limit value when the detected value exceeds the set limit value, or The method for controlling an electronically controlled engine according to item 2.