JPS58200057A - Engine speed controlling device - Google Patents

Abstract

PURPOSE:To prevent erroneous actions at the time of any trouble in an idling switch by controlling the opening degree of a throttle bypass valve to a target value stored in a memory in correspondence to the temperature of water in the engine for a predetermined period of time, and carrying out the engine speed feedback control in a slow frequency at the time of discriminating the idling. CONSTITUTION:A control device 8 which receives detected values of suction pipe negative pressure sensor 4, and a water temperature sensor 5 and input signals such as engine speed signals and the like from an ignition coil 7 introduces atmospheric air or negative pressure into a throttle bypass valve 66 and a control chamber 64 through electromagnetic valves 62 and 63 to thereby carry out an opening degree control. The control device 8 stores the target value of the valve 66 in the memory in accordance with the water temperature and controls electromagnetic valves 62 and 63 for a predetermined period of time so that the value of the opening degree position sensor 61 of the valve 66 becomes equivalent to the target value. When the idling switch 23 is turned ON, the electromagnetic valves 62 and 63 are contolled in a frequency slower than the above described value to carry out an engine speed feedback control, and the correction of the target value is carried out by integrated information upon this occasion.

Description

[Detailed description of the invention] In the present invention, the idle speed of the internal combustion engine is set to a predetermined value.

In cases where the amount of fuel in an internal combustion engine is electrically controlled, the intake air amount is usually measured by measuring the intake air amount of the engine, or alternatively, the intake air amount is calculated from the engine's intake stomach pressure and rotational speed, and this intake air amount is When controlling the idle speed of such an engine,
A method of controlling the air by a bypass valve;

As a method of controlling the above bypass 1<rub, a vacuum motor using the intake pipe pressure of the internal combustion engine is used, and the pressure of the vacuum motor is controlled by a solenoid valve. It is conceivable to control the position of the valve.In this case, since the solenoid valve has leakage, a control cycle of about 20H2 is required.

In addition, even if the air-fuel mixture is increased in an internal combustion engine, the engine speed and rotational speed do not change, resulting in a response delay of about 100 msec.If the control gain for rotational speed is made too fast, it may cause hunting in the control, resulting in poor stability. becomes worse. Additionally, if the idle state can always be detected correctly, the position of the bypass valve can be controlled so that the internal combustion engine's rotation speed always matches the target revolution speed at idle, but if the idle state cannot be detected, e.g. If the switch that detects the fully closed position of the throttle valve malfunctions, the bypass valve will normally be in the fully closed position and idling operation will no longer be possible.

The present invention compensates for leakage of the control solenoid by controlling the target position of the bypass valve at a relatively fast cycle, and easily reduces the control gain by controlling the rotation speed at a slow cycle close to the response speed of the internal combustion engine. This prevents excessive control and enables stable idle rotation control. Also, the target position of the bypass valve is set in advance, and during idle, this target position is corrected according to the deviation between the target rotation speed and the internal combustion engine rotation speed. The invention is intended to control the position of the bypass valve to a predetermined position even when the idle state cannot be detected.Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings.

FIG. 1 shows the configuration of the present invention. An internal combustion engine 1 is a known four-stroke spark ignition internal combustion engine mounted on an automobile. Combustion air is taken in through an air cleaner 22° throttle valve (2). do. Further, fuel is supplied from a fuel system (not shown) via an electromagnetic injection valve 8 provided upstream of the throttle valve 21. A pressure sensor 4 for detecting the pressure in the intake pipe 2 is connected downstream of the throttle valve 21 . The pressure sensor 4 is, for example, a known semiconductor pressure sensor that converts the absolute pressure in the intake pipe 2 into voltage and outputs it. The water temperature sensor 6 detects the temperature of the cooling water of the internal combustion engine 1, and the ignition coil 7 (not shown) is installed in each cylinder of the internal combustion engine 1. Supplies high voltage to the spark plug. The idle switch 28 is turned on when the throttle valve is fully closed, and turned off otherwise. The vehicle speed switch 9 is built into a speedometer (not shown) and is set to kI per hour.
It turns on only at I/h or lower. The idle control valve 6 controls bypass air that bypasses the throttle valve 21 and is supplied downstream of the throttle valve 21. The idle control valve 6 is a valve 6 provided in a bypass passage 68.
6, a diaphragm 66 to which the valve 66 is connected,
It is composed of a negative pressure chamber 64 equipped with a spring 67 that biases the diaphragm 65, and the amount of the bypass air is changed by changing the lift amount of the valve 66 by the diaphragm 66 according to the increase or decrease of the negative pressure introduced into the negative pressure chamber 64. control. The valve 66 is connected to the position sensor 61, and the resistance value of the position sensor 61 changes depending on the position of the valve 66. This negative pressure chamber 6
4 communicates with the throttle valve downstream of the intake pipe 2 via the VAC solenoid valve 68, and
It communicates with the atmosphere via a solenoid valve 62. Therefore, by opening and closing the VAC solenoid valve 6 and the VENT solenoid Palflo 2, the negative pressure in the negative pressure chamber 64 is changed and the lift amount of the valve 66 is controlled. Close the VENT solenoid valve 62 and close the vAC solenoid valve C.
8, the pressure in the negative pressure chamber 64 gradually approaches the pressure downstream of the throttle valve 21 in the intake pipe 2, and the pressure in the negative pressure chamber 64 gradually approaches the pressure downstream of the throttle valve 21 in the intake pipe 2.
6 moves in the direction of increasing the bypass air, and VE
When the NT solenoid vibe 62 is opened and the VAC solenoid valve 68 is closed, the negative pressure in the negative pressure chamber 64 gradually approaches atmospheric pressure, and the valve 66 moves in a direction to reduce the bypass air. The control device 8 receives signals from the pressure sensor 4, water temperature sensor 6, position sensor 61, ignition coil 7, etc., and controls the electromagnetic injection valve 8, the VENT solenoid valve 62. Controls the VAC solenoid valve 68, etc. FIG. 2 shows the configuration of the control device 8. The control device 8 is a microcomputer 8 having a built-in R&M 97 for storing control programs and a RAM 9g for temporarily storing data.
It is structured around 0. The low-pass filter 81 smoothes the output of the pressure sensor 4, the filter 82 removes noise in the output voltage of the position sensor 61, the interface 88 converts the resistance change of the water temperature sensor 6 into a voltage change, and the low-pass filter 81, the filter 82, the output of interface 88 is connected to multiplexer 99. The multiplexer 99 sequentially selects the three signals inputted to the multiplexer 99 based on the output signal of the microcomputer 80 and outputs them to the AD converter 84. The AD converter 84 converts the input voltage into a digital value (
(hereinafter referred to as AD conversion) and outputs the digital value to the microcomputer.

The AD converter 84 starts the AD conversion operation based on the output signal of the microcomputer 80, and after a predetermined time, the
Complete the D conversion operation. The comparator 85 converts the voltage of the primary coil of the ignition coil 7 into a logic level signal, and
It is output to the clock terminal of the flip-flop 86. The output of the D flip-flop 86 becomes "L" in synchronization with the generation of high voltage by the ignition coil 7, and becomes rHJ due to the output signal of the microcomputer 80. The output signal of the D flip-flop 86 is connected to the gate terminal of the counter 87 and to the first interrupt terminal of the microcomputer 80. The counter 87's glue lock terminal is connected to the output of the oscillator 88, and the counter 87 counts the output of the oscillator 88 during the period when the output signal is rHJ.

The microcomputer 80 has the first interrupt terminal rL.
When it reaches J, the count value of the counter 87 is read, the counter 87 is cleared, and then the D flip-flop 86 is set and its output is set to rHJ.

Therefore, the count value of the counter 87 is a numerical value corresponding to the ignition cycle of the internal combustion engine 1. Timer 79 is 6 m5e
An interrupt signal is output to the second interrupt terminal of the microcomputer 80 every c. The digital interface 89 is
The on/off signals of the idle switch 28 and the on/off signals of the vehicle speed switch 9 are converted into logic level signals and output to the microcomputer 80. timer 90.91
．． 92 counts the output signal of the oscillator 98,
It starts counting down the numerical value set by the microcomputer 80 in response to a trigger signal from the microcomputer 80, and outputs the rHJ signal from when the trigger signal is input until the count value becomes zero.

Drivers 94, 95, 96 each have timers 90, 91
．． Out of 92 1, connected to force. The driver 94 is connected to the electromagnetic injection valve 8 and drives the electromagnetic injection valve 8 during the period when the output of the timer 90 is rHJ. The driver 96 is connected to the VAC solenoid 68, and drives the VAC solenoid 68 during the period when the output of the timer 91 is rHJ, thereby communicating the negative pressure chamber 64 and the intake pipe 2. driver 96
is connected to the VENT solenoid 62, and the output of the timer 92 drives the VENT solenoid 62 after a period of rHj, thereby communicating the negative pressure chamber 64 with the atmosphere.3 The microcomputer 80 connects the timer 79 to the second interrupt terminal. 5 more
When an interrupt signal is input every m5ec, the multiplexer 99 sends the low-pass filter 81 . Filter 82.
The output signals of the interface 88 are sequentially selected and the AD converter 8
4, the pressure sensor 49 position sensor 61. water temperature sensor b
AD converts the data and stores it in RAM9g. The microcomputer 80 also sends an interrupt signal (generated when the ignition coil 7 generates a high voltage) to the first interrupt terminal.
When input, the count value of the counter 87 is read and stored in the register A built in the microcomputer 80, the counter 87 is cleared to zero, the D flip-flop 86 is set, and the output of the D flip-flop 86 is set to r.
Make it HJ. Next, the calculation /T is performed using the data T in the register A and the numerical value set in advance in the R&M 97 to calculate the 1-1 rotation number Nt, and the result is stored in the RAM 9g. Next, the pressure sensor 4 calculates the time width for driving the electromagnetic injection valve 8 from the rotational speed N, presets the value in the timer 90, and inputs a trigger signal to the timer 90. Therefore, the 14Ea injection valve 8 is driven for a period of time determined by the pressure sensor 4 and the rotational speed N at intervals of ignition of the internal combustion engine 1.

Next, the idle u rotation speed control of the microcomputer 80 will be described. Microcomputer 80 R&M97
The target idle speed of the internal combustion engine 1 shown in FIG. 8 is stored using the water temperature of the internal combustion engine 1 as a parameter. Further, the target position of the valve 66 that can almost give the target idle speed shown in FIG. 8 is as shown in FIG.
The water temperature is stored in the R&M97 as a parameter. FIG. 5 is a flowchart for controlling the idle rotation speed of the microcomputer 80. The process shown in Fig. 6 is performed by setting the timer 7 to the interrupt terminal shown in Fig. 42 above every 6 m5ec.
From 9 onwards, this is done every time the dispatch signal is manually input. When the above interrupt signal is input, in step 100, the pressure sensor 4,
Position sensor 61. The information of the water temperature sensor 5 is AD converted, and R
Recorded on AM 98. At this time, the pressure sensor 49 position sensor 61. PB each result of AD conversion of water temperature sensor 5
Let AD + P AD, WAD. Step 10
1, determine whether 200m sec has elapsed, and
If 5ec has elapsed, the process moves to step 102; otherwise, the process moves to step 105. The judgment of 200m5ec is
Data that counts down every 5m5ec is provided in the RAM98, and 200m5ec is counted down depending on whether the data reaches zero or not.
The value is determined to be 40 and the value is preset to 40 each time the value becomes zero. Every time this 200 m5 elapses, the state of the idle switch 2B is determined in step 102, and if it is on, that is, the throttle valve is fully open, the process moves to step 108, and if it is tr, the process moves to step 105. In step 108, the state of the vehicle speed switch 9vt)9 is determined, and if the on-speed speed is less than 5 b/h, the process moves to step 104, and if not, the process moves to 106.

Therefore, step 104 is performed every 200 m5ec when the throttle valve 21 is in the fully closed position and the speed is 6kV'h.
It will be done. In step 104, the target rotational speed No. determined as shown in FIG. 8 from the water temperature WAD, the rotational speed Nt when performing this process, the correction coefficient K, and the calculation of PH0(No-Nt)XK from the valve position correction data PH. and use this as new valve position mix positive data. Therefore, internal combustion engine 1
If the idle rotation speed is lower than the target rotation speed NO determined from the water temperature WAD, the value of the valve position correction data P)I will gradually increase; if the opposite is true,
It gradually becomes smaller. That is, the valve position correction data PH is information obtained by integrating the rotational deviation (No-Nt) by sequentially adding or subtracting it every 200 m5.

In step 106, it is determined whether 60 m5ec has elapsed. If 50 m5ec has elapsed, the process moves to step 106; otherwise, the process moves to step 115. 50m5ec
The determination is made in the same manner as in step 101, but the data to be preset is 10. In step 106, the position of the valve 66 [P] determined from the water temperature WAD as shown in FIG.
.

Po+1'H is calculated from the valve position correction data PH, and deviations PT and -PAD are calculated from the target position PTI and the actual position PAD of the position sensor 61 to obtain PT2. Therefore, the positional deviation PT2 is the deviation between the target position PTI and the actual position of the valve 66 at the water temperature WAD.

In step 108, if the polarity of the deviation PT2 is positive, that is, if the target position PTI is larger than the actual position of Palfluoro, the process proceeds to step 109; otherwise, step 11
Processing moves to 2. At step 109, a constant KA is added to the deviation PT2, and a numerical value TA corresponding to the driving time of the VAC solenoid 68 is calculated. At step 110, the numerical value TA is set in the timer 91.

In step 111, the timer 91 is triggered to drive the VAC solenoid 68 for a period of time corresponding to the number i'FA.

In step 112, a constant KE is set to the absolute value of the deviation PT2.
A numerical value TE corresponding to the driving time of the VENT solenoid 62 is calculated by multiplying by the value TE. In step 118, the numerical value TE is set in the timer 92. At step 114 the timer 92
is triggered to drive the VENT solenoid 62 for a time corresponding to the value 'I'E.

After the processing of steps 111 and 114, the process moves to step 115 and the processing of FIG. 5 is completed. Therefore, through the processing from step 106 to step 114, the valve position is feedback-controlled so that the position of the valve 66 coincides with the target position PTI. Further, if the throttle valve 21 is in a fully closed state in the almost stopped state where the vehicle speed of the automatic rate is 6 kv'h or less, the rotation speed of the internal combustion engine 1 matches the target rotation speed NO by the process of step 104. The valve position correction data PH is corrected so that valve 6
6 is controlled, the rotation speed b is feedback-controlled so that the rotation speed of the internal combustion engine 1 matches the target rotation speed No. Further, if the idle state of the internal combustion engine 1 cannot be detected due to a poor contact of the idle switch 28, for example, the process of step 104 will not be performed, and the rotation speed feedback control function will be lost, but the predetermined control function shown in FIG. Since the position of the valve 66 is controlled to match the position of the valve 66, the rotational speed is controlled to approximately the same as shown in FIG.

As described above, according to the present invention, the VAC solenoid valve 68. VENT solenoid valve 62, for example, 50 m
Control is performed at a relatively fast cycle of 5 ec, and feedback control is performed so that the valve 66 matches the target position, so even if there is a leak in the solenoid, the valve 66 can be controlled to the target position. For example, 20Gm
Since the rotational deviation is sequentially added and subtracted at a relatively slow cycle of s and integrated, and the target position is extracted and feedback control is performed, it is possible to easily keep the feedback control gain of the rotation speed small and prevent excessive control. can. Also,
R&M9 in advance? Since the position of 66 is controlled based on the target position stored in , even if the idle state cannot be detected, the rotation speed can be controlled to approximately the target rotation speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of the control device shown in FIG. 1, FIG. 8 is a characteristic diagram of water temperature and rotation speed, and FIG. Position characteristic diagram, Figure 6 is the second
This is a flowchart showing the processing of the microcomputer 80 shown in the figure. 1- internal combustion engine, 2- intake pipe, 8- electromagnetic injection valve. 4-pressure sensor, 5-water temperature sensor, 6-idle control valve, 7-ignition coil, 8-control device, 9-vehicle speed switch,
21-throttle valve, 28-idle switch,
61-position sensor, 62-VENT solenoid valve, 68-VAC solenoid valve, 80-microcomputer, 81-low-pass filter. 82-filter, 88.89-interface, 8
5-Comparator, 86-D flip-flop, 87-
Counter, 84-AD converter, '88.98-Oscillator, 79° 90-92-Timer, 94-96-Driver, 97-RAM, 98-RAM Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A throttle valve installed in the middle of an intake pipe of an internal combustion engine, a bypass valve that controls air that bypasses this throttle valve, a position sensor that detects the position of this bypass valve, and a target position of the bypass valve that is adjusted to the water temperature of the engine. a memory for storing the information, and means for feedback controlling the bypass valve at a predetermined period so that the output of the position sensor matches the target position;
means for detecting that the engine is in an idle state, receiving an output from the means and sequentially integrating the deviation between the rotational speed of the internal combustion engine and the target rotational speed at a period slower than the predetermined period when the engine is idling; A rotation speed control device comprising means for correcting the target position according to the integral information.