JPS62642A - Electric load idle control system for engine - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an engine stop, by a method wherein, when a high electric load is suddenly produced at a battery, the opening of an idle speed control valve is increased by a specified amount and for a specified time. CONSTITUTION:A voltage drop rate measuring means 107 is attached to a battery 103 charged by a generator 102 driven by an engine 101. When a battery drop rate exceeds a given value, the opening of an idle speed control valve 106 is increased by a specified amount and for a specified time.

Description

[Detailed description of the invention] [Summary] Electrical load is supplied from the luhatchiri, which is charged by a generator connected to the internal combustion engine, and the idle speed is kept constant by setting bypass + i + i + to a constant value using the idle speed control valve. In an internal combustion engine that is configured to keep the idle speed control valve constant, the rate of decrease in battery voltage is measured, and when it exceeds a certain value, a Q signal is generated to increase the opening of the idle speed control valve by a certain amount and for a certain period of time. Therefore, it is possible to effectively prevent a drop in the internal combustion engine rotational speed and engine stalling due to a sudden increase in electrical load during idling.

[Industrial application field]

The present invention relates to an idle control method for an engine (internal combustion engine), and in particular to an engine idle control method for preventing a decrease in engine speed or engine stall when the internal combustion engine is loaded with an electrical load during idling. This invention relates to an electric load idle control method.

In recent years, with the advancement of electronics in automobiles, the electrical load on automobile generators (alternators) has been rapidly increasing. Engines for one-way vehicles are becoming increasingly smaller and lighter, and as a result of the inertia of rotating parts becoming smaller, they tend to become more susceptible to external disturbances (loads).

Therefore, if a large electrical load is applied to the alternator when the engine is idling, for example due to the operation of the headlights or power windows, the load will be placed on the engine, causing a drop in engine speed, and in the worst case scenario, the engine will stall. will occur.

FIG. 6 shows the general configuration of an electronic control system of an automobile. In the figure, reference numeral 1 indicates an engine body including a piston 2, etc., and a combustion chamber 3 above the piston has an intake valve 4.
through an exhaust valve 5 respectively an intake pipe 6. It is connected to the exhaust pipe 7. The intake pipe 6 includes an intake air amount sensor 8. Intake pipe pressure sensor that measures negative pressure in the intake pipe9. Intake temperature sensor 10
．． A throttle opening sensor 11 for measuring the opening of the throttle valve is provided, and the exhaust pipe 7 is provided with an 02 sensor 12 for measuring the amount of residual oxygen in the exhaust gas.

The engine 1 is provided with a coolant temperature sensor 13 and a crank angle sensor 1 that measures the engine speed.
4 are provided. The processing unit 15 has signals from each of these sensors added to it, as well as a start signal from the starter 16. By processing each of these signals, the processing unit 15 performs each operation including startup. The optimum fuel supply amount and ignition timing are determined for the operating condition, and the fuel injection valve (injector) 17 is controlled to inject the required fuel, and the ignition timing of the ignition plug 18 is controlled.

In addition, for idling operation, the difference between the idling rotation speed and the target rotation speed is detected, and the idling speed control (ISC) valve 19 is controlled to adjust the bypass amount of the throttle valve 20, thereby controlling the target rotation speed. Feedback control is performed to maintain the idling speed at a predetermined value.

Furthermore, a battery 21 is provided, and an electric load 22 for the entire automobile is provided.
At the same time, alternating current generated by an alternator connected to the engine 1 is supplied to the battery 21 through voltage rectification and a regulator 24 for charging. The voltage of the battery 21 is constantly monitored by the processing unit 15.

The present invention is applicable to such a system, and can reduce engine speed drop or engine stall due to electrical load during idling.
The aim is to enable effective prevention.

[Conventional technology]

FIG. 7 illustrates idle control during electrical load in the system shown in FIG. 6 in a conventional control method.

The electrical load is now at time 1. When this occurs, the battery voltage decreases with a slight delay, reaches a minimum at time t2, and then settles down to a certain value. The engine load starts to increase almost simultaneously with the decrease in battery voltage, reaches a maximum value after a certain time, and then settles down to a certain value. On the other hand, due to the inertia of the rotating parts, the engine speed starts to decrease after a certain period of time has passed after the engine load increases, reaches the lowest value at time t3, and then gradually recovers and settles down to a certain value.

In the conventional electric load idle control method, a fixed threshold value V is set for each of the battery voltage and engine speed.
th and Rth are provided, and when both the battery voltage and the engine speed drop below the threshold, this is detected and the opening of the ISC valve is increased to increase the amount of intake air and the amount of fuel injection. By increasing the torque, the engine speed was prevented from decreasing.

[Problem that the invention seeks to solve]

When such a conventional control method is used, the time delay from when an electrical load is generated to when the opening of the ISO valve increases is large (in other words, in Fig. 7, the engine speed has reached the threshold value). At time t4 when the speed becomes lower than Rth, this is detected and control is performed to open the ■SC valve, but at this time the engine speed has already decreased, while the IS
Even when the O-valve is opened, the engine speed does not recover immediately, but continues to decrease until it reaches the lowest value, which poses a problem in that the engine speed becomes unstable around this point, making the engine more likely to stall.

[Means for solving problems]

FIG. 1 is a diagram showing the basic configuration of the system of the present invention.

101 is an internal combustion engine, and a generator 1 coupled to it
02 charges the battery 103, and the battery 103
supplies the electrical load. The internal combustion engine 101 has an intake pipe section 10
The idle speed control valve 106 that bypasses the throttle valve 105 provided at 4 maintains the idle speed constant.

A battery voltage drop rate measuring means 107 measures the battery voltage drop rate, and when it exceeds a certain value, generates a signal to control the idle speed control valve.

[For production]

When it is detected that the battery voltage drop rate exceeds a certain value, control is performed to increase the opening of the idle speed control valve by a certain amount and for a certain period of time. This prevents the engine from stalling due to a drop in rotational speed.

〔Example〕

FIG. 2 shows the configuration of a processing section in an embodiment of the present invention. In the figure, 31 is a battery, 32 is a power window, 33 is a headlight, 34 is a processing section, in the processing section 34, 35 is an input interface section, A is an analog-digital (A/D) converter, 3
7 is a microcomputer, and 38 is an output interface section.

As mentioned above, the battery 31 includes a power window 32,
An electrical load is generated by the headlights 33 and the like. The voltage of the battery 31 is applied to the processing section 34 and input via the input interface section 35 . A/D converter 3
6 converts the input battery voltage into a digital signal and inputs it to the microcomputer 37. The microcomputer 37 processes the read battery voltage signal to determine its rate of change, and generates an output when the rate of change is greater than a predetermined value. This signal is output as a control signal to the ISO valve via the output interface section 38, and thereby the ISO valve increases its opening degree by a certain amount and for a certain period of time.

FIG. 3 is a flowchart explaining the control method of the present invention, and shows a routine every 100 m5 in the processing section 34.

The A/D converter 36 A/D converts the voltage of the battery 31 input via the input interface unit 35,
The microcomputer 37 thereby receives the measured value BA of the battery voltage.
Read T (step Sl). Next, calculate the rate of change Δ0B by taking the difference between the previous battery voltage holding value BATo and the current measured value BAT.Step S2)
, the held value BATo is replaced by the current measured value BAT (step S3).

It is checked whether the calculated rate of change Δ0B is smaller than a predetermined level (step S4), and if it is smaller, the value CNT of the counter in the microcomputer 37 is updated to +1 (step S5); if it is not smaller, it is checked. The counter value CNT is cleared (step S6).

Next, check whether the counter value CNT is smaller than 10 seconds (step S7), and if it is not smaller,
The control output signal l5Cout for the valve is replaced by the previous output value ISC (step output value I
The SC plus 10% is output (step S9). The counter shall count up to 90 seconds, and after that, it will hold 90 seconds.

FIG. 4 shows signals of various parts in the control system of the present invention.

As shown in the figure, when the battery voltage element B is normal, the counter value CNT holds 90 seconds, and the control output signal l5Cou to the ISC valve
t is maintained at a normal value rsc. When the battery voltage decreases due to the electrical load and the rate of change becomes greater than a predetermined value, the counter is cleared and starts counting from Osec, and at the same time the control output signal l5C to the ISO valve is
The value obtained by adding 10% to the normal value ISC is output as out. When 10 seconds have elapsed since the count started, ■Control output signal l5Cout for SC valve
returns to the normal value ISC, but the counter continues counting and reaches 90.
After reaching sec, 90 sec is held.

FIG. 5 illustrates the effect of implementing the method of the present invention. Due to the generation of electrical load at time t, the battery voltage drops at time t2, and at about the same time the engine load increases, but as mentioned above, by adjusting the rate of change in battery voltage, it is possible to time t5
Since control is performed to increase the opening degree of the ISC valve by a certain amount and for a certain period of time, the timing of increasing the opening degree of the ISC valve is earlier by the illustrated time T than time t4 in the case of the conventional control method. In this case, the engine speed changes as shown by the solid line, and there is no drop unlike in the conventional case shown by the dotted line, so the engine does not stall.

〔Effect of the invention〕

As explained above, according to the control method of the present invention, when a large electrical load suddenly occurs on the battery, the idle speed control valve opening degree is increased by a certain amount for a certain period of time to prevent a drop in engine speed. Therefore, it is possible to prevent the rotational speed from dropping due to a sudden increase in electrical load during idling, and to effectively prevent the engine from stalling due to this.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle configuration of the system of the present invention, FIG. 2 is a diagram showing the configuration of a processing section in an embodiment of the invention, FIG. 3 is a flowchart explaining the control system of the present invention, Figure 4 is a diagram showing the signals of each part in the control method of the present invention, Figure 5 is a diagram explaining the effect when implementing the method of the present invention, and Figure 6 is a diagram showing the general configuration of the electronic control system of an automobile. , FIG. 7 is a diagram illustrating idle control during electrical load in a conventional system. 31-Battery, 32-Power window, 33-Headlight, 34-Processing section, 35...-Human power interface section, 3G/-Analog-digital (A,/D) converter, 37--Microcomputer, 38-Output interface Department Patent Applicant Fujitsu Ten Ltd. Company Agent
Patent attorney Gobe Tamamushi (one other person) A flowchart explaining the control method of the present invention 3. Each of the control methods of Japanese inventions! Nichika showing I3 signal 4
Figure 5 is a diagram explaining the effects of implementing the method of the present invention.

Claims (1)

[Claims] An idle speed control valve is provided in the intake pipe section, which includes a battery that is charged by a generator coupled to the internal combustion engine, supplies the electric load, and bypasses the throttle valve, and adjusts the idle speed by setting the idle speed control valve. In an internal combustion engine that is kept constant, the method includes means for measuring the rate of decrease in the battery voltage and generating a signal when the measured value exceeds a certain value, and controlling the opening degree of an idle speed control valve of the internal combustion engine when the signal is generated. An engine electric load idle control method that increases the idle load by a certain amount for a certain period of time.