JPS6018822B2 - Automatic no-load speed control device for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic no-load rotation speed control device for an internal combustion engine (particularly an automobile engine).

Recently, in order to improve the exhaust purification performance, fuel efficiency, etc. of automobiles, it has become necessary to precisely control the rotational speed of the engine during no-load (idling).

Hence the microphone. An arithmetic circuit using a computer or the like is provided, and the actual no-load rotation speed is compared with a value stored in advance in the memory of the arithmetic circuit using the arithmetic circuit to determine whether the actual rotation speed is greater than or equal to the memorized value. In the case of , it outputs a signal to decrease the air supply amount, and in the opposite case, it outputs a signal to increase it,
A method has been developed to control the air supply amount using the signal. Note that since the amount of fuel supplied to the engine (for example, the amount of fuel injection) is determined according to the amount of air supplied, the rotation speed can be controlled by controlling the amount of air supplied. However, the above-described conventional feedback control method has a problem in that the response to a small load change of 4.0 mm during no-load is slow. In other words, in the case of a car, even when there is no load (when the vehicle is not being driven), the shift position of the automatic transmission (the load changes between the neutral position and the drive position), the compressor for the cooler (
Some load fluctuations occur depending on whether or not bucket machines such as car cooler compressors are operating.

In the conventional feedback control method, the control amount changes only when the rotational speed changes due to load fluctuations, so the deviation from the target rotational speed until the rotational speed stabilizes is large and the response is slow. Furthermore, if the gain of feedback control is increased in order to speed up the response, there are problems such as unstable control. The present invention detects minute load fluctuations, predicts rotation speed changes due to them, and adds predictive control to slave feedback control.
It is an object of the present invention to provide an automatic rotation speed control device during no-load operation that suppresses rotation speed fluctuations during minute load fluctuations.

The present invention will be explained in detail below based on the drawings.

FIG. 1 is a block diagram showing the overall configuration of the present invention.
In Fig. 1, 100 is a rotation sensor that detects the engine speed, 101 is a sensor that detects engine operating variables other than the engine speed (engine temperature, etc.), and 102 is a sensor that detects the automatic transmission, which causes minute load fluctuations in the engine. This is a detection means that detects changes in the gear shift position and the presence or absence of operation of auxiliary equipment (such as a car cooler).

The deviation detection means 103 detects the deviation between the actual rotation speed detected by the rotation sensor 100 and the target rotation speed given from the target rotation speed setting means 107 (details will be described later).

The control means 104 outputs a constant control amount when the deviation is less than a predetermined set value, and outputs control according to the deviation when the deviation is greater than or equal to the set value.

That is, when the deviation is smaller than the set value, the control amount is fixed and feedback control is stopped, and when the deviation is greater than the set value, normal feedback control is performed. The correction means 105 is the detection means 10
2 detects a cause of variation, retrieves a correction control amount corresponding to the cause of variation from storage means 108 (details will be described later),
A value obtained by adding the corrected control amount to the control amount of the control means 104 is output, and the opening degree of the air supply V supply valve 106 is controlled thereby. The target rotation speed setting means 107 is normally set to sensor 1.
The target rotational speed is set according to the output of 01, for example, the engine temperature. When the detection means 102 detects the occurrence of a cause of variation, the target rotational speed corresponding to the cause of variation is read from the storage means 108 and set.

The storage means 108 stores in advance a target rotational speed corresponding to the cause of variation and a correction control amount that increases or decreases by a value corresponding to the amount of load variation caused by each cause of variation.

With the above configuration, when a minute load fluctuation occurs, the control amount is changed by the sum of the corrected control amount that has a value corresponding to each cause of fluctuation, so the amount of load fluctuation varies depending on the cause of fluctuation. In addition to being able to perform well-adapted corrections, even when multiple causes of variation occur simultaneously,
Load fluctuations caused by this can be effectively compensated for.

In addition, since it is configured to perform corrections corresponding to increases and decreases in load, accurate rotational speed control can always be performed whether the load increases or decreases. Additionally, when the deviation between the actual rotation speed and the target rotation speed is less than the set value, the control amount is fixed to keep the air supply valve relationship constant, eliminating rotational fluctuations around the target rotation. , stability is improved. Hereinafter, the present invention will be explained based on Examples.

FIG. 2 is a diagram showing an embodiment of the automatic control device of the present invention, and FIG. 3 is a flowchart of control. In Figure 2,
1 is a temperature sensor that detects the engine temperature and outputs a temperature signal S. As the temperature sensor, a thermistor or the like that detects, for example, cooling water temperature, combustion chamber wall temperature, lubricating oil temperature, exhaust gas temperature, engine outer wall temperature, etc. can be used. Further, 2 is a rotation sensor that detects the engine rotation speed. The rotation sensor 2 includes, for example, a magnetic gear that rotates in synchronization with the crankshaft, and a magnetic detector that outputs a pulse every time the teeth of the gear pass, and outputs a pulse signal with a frequency proportional to the number of rotations. A device that outputs can be used. Further, 3 is a cooler operation sensor, which is, for example, a switch that is turned on when the compressor of the cooler is operated. Reference numeral 4 denotes a shift position sensor, which is a switch that is turned on when the shift position of the transmission is in the drive position (including forward and reverse) and turned off when it is in other positions (neutral, parking, etc.). Reference numeral 5 is a remote sensor that determines whether the vehicle is running or stopped, and is, for example, a switch that is turned on when the vehicle is stopped and turned off when it is running. Further, 6 is a throttle opening sensor, which is, for example, a switch that is turned on when the throttle valve (or accelerator pedal) is in a fully open position (during idling) and turned off at other times. Further, the A-D converter 7 converts the analog temperature signal S outputted from the temperature sensor 1 into a digital temperature signal S2.

In addition, 8 is a microcomputer (hereinafter abbreviated as MUCOM), 9 is an input/output device, and 1 is a central processing position (hereinafter referred to as C
(abbreviated as PU), 11 is a memory.

The French-COM 8 inputs the signals of the above-mentioned sensors 1 to 6 via the input/output device 9, and outputs a control signal S3 corresponding to their states. On the other hand, the upstream and downstream parts of the throttle valve 13 provided in the intake pipe 12 of the engine are connected by a side passage via an air supply valve 14.

Further, the solenoid valve 18 intermittently disconnects the atmospheric pipe 19 and the negative pressure pipe 20 according to the opening and closing of the valve. Therefore, the pressure in the air chamber 15 of the air supply valve 14 connected between the negative pressure pipe 20 and the solenoid valve 18 changes depending on the opening/closing time of the solenoid valve 18 (the longer the opening time is, the higher the pressure is; the shorter the opening time is, the higher the pressure is). Accordingly, the diaphragm 16 and the valve 17 connected thereto move up and down, thereby changing the amount of air supplied to the engine via the air supply valve 14. Therefore, by changing the duty ratio of the pulse signal (hereinafter referred to as control pulse) that controls the electromagnetic valve 18, the air supply amount can be freely controlled. As this control pulse, the control signal S
3, it becomes possible to control the air supply amount (therefore, the rotational speed) during no-load by using MuCOW8. Note that the memory 11 in FIG. 1 contains, depending on the content to be stored,
Various different memories, i.e. memory for target rotational speed data for engine temperature, target rotational speed memory, c memory for engine temperature, memory for cooler operating status, e memory for control pulse width, and control pulse for engine temperature. memory for width,
It includes a memory for the current rotational speed, a memory for accumulating the number of control cycles, a memory for the shift position, etc.

Next, the contents of calculations in the Yamaichi COM8 will be explained with reference to the flowchart shown in FIG. In this flowchart, the flowchart symbols ``■'' to ``■'' marked on the left represent one cycle of control, and the control is performed in synchronization with the rotation of the engine, for example, one cycle per revolution. When the engine starts and the calculation of COM8 starts, the temperature signal S2 is first input (■), and this temperature signal S2 is stored in the memory 11 (memory for target rotation data for engine temperature). The engine target rotation speed NN is calculated from the target rotation speed data corresponding to each temperature, and it is stored in the memory 11 along with the temperature value (NN is stored in the memory for the target rotation speed) (■) .

Note that the idling speed takes different values depending on the engine temperature; for example, when warming up immediately after starting, the speed is set to a higher value than during normal times, and as the temperature rises, it gradually approaches the normal value. It looks like this. Next, check the operation of the cooling machine compressor (◎). While the compressor is operating, the load on the engine increases somewhat, and in order to fully utilize the compression capacity of the compressor, it is necessary to increase the no-load rotational speed by a certain value. Therefore, when the cooler operation sensor 3 indicates "operation", the value of the target rotation speed NM stored in the memory 11 (the above-mentioned target rotation speed memory) is increased by a certain value. The above constant value uses a value stored in the memory in advance. Also, since the response will be slow if this is done alone, the control amount is changed in advance by an amount commensurate with the load fluctuation (predictive control).
There is a need. Therefore, judging from the signal of the cooler operation sensor 3 and the signal of the cooler operation sensor 3 of the previous calculation cycle stored in memory 1 (memory for the second cooler operation state), it is switched from "stop" to "operation". When the calculation is performed up to the previous cycle, it is stored in memory 11 (mouth control pulse width memory).
The control pulse width stored in the control pulse width is increased by a certain value, and when switching from "operation" to "stop", the same value is decreased. Also, the information stored in the memory 11 (control pulse width memory) is updated at this point. (■,■. For the above constant values, use the values stored in advance by Memo Kawako.Next, check whether the engine is in a no-load state using the shift position sensor 4, vehicle distance sensor 5, and throttle opening. It is determined from the signal of the temperature sensor 6 (■, ■, ■, ■, ■.

First, when the throttle opening sensor 6 indicates "open", the throttle opening sensor 6 indicates "fully closed", the shift position sensor 4 indicates "drive position", and the vehicle remote sensor 5 indicates "driving". If it shows, it is judged that there is no no-load condition, and the engine temperature at that time stored in the memory 11 (C memory for engine temperature) and the engine temperature stored in the memory 11 (C memory for control pulse width for engine temperature) are stored. The initial value of the control pulse width is calculated from the data of the control pulse corresponding to each engine temperature, and the value is stored in memory 1 again as the control pulse width.
1 (E control pulse width memory). Further, if the throttle related sensor 6 indicates "fully closed", the shift position sensor 4 indicates "drive position", and the vehicle remote sensor 5 indicates "stopped", or the throttle opening sensor 6 indicates "
"fully closed" and the shift position sensor 4 is in the "neutral position"
If it shows, it is judged as a no-load state, but in this state, the signal of the shift position sensor changes from "drive position" to "
If it changes to “neutral position” or vice versa,
The load changes somewhat due to resistance changes within the transmission.

Therefore, when the control pulse width stored in the memory 11 (E control pulse width memory) changes from the "neutral position" to the "drive position" (the shift value of the previous calculation cycle stored in the shift position memory) (Judging from the signal of the position sensor 4) is increased by a certain amount, and vice versa, it is decreased by the same amount (judging from the signal of the shift position sensor 4 of the previous control cycle stored in the memory 11 and the signal of the current control cycle). (judged based on the signal from the shift position sensor 4), predictive control is performed. The above-mentioned fixed amount uses a value stored in the memory in advance. Further, the throttle related sensor 6 indicates "fully closed" and the shift position sensor 4 indicates "
When the throttle related sensor 6 indicates "fully closed," the shift position sensor 4 indicates the "drive position," and the vehicle remote sensor 5 indicates "stopped." It is determined that there is no load, and the control pulse width is determined by performing feedback control in the following pairwise order.

First, data on the rotation speed N given from the rotation sensor 2 is stored in the memory 11 (memory for the current rotation speed) (■
).

Next, the target rotation speed NN already stored in the memory 11 (a memory for target rotation speed data for the engine temperature) and the actual rotation speed N stored in the memory 11 (memory for the current rotation speed data) It is determined whether or not it is significant, that is, whether the deviation between NM and N is greater than or equal to a predetermined set value No (■).

If there is no significant difference, the control pulse width is maintained at the previous value and the opening degree of the air supply valve is fixed. If there is a significant difference, if the actual rotation speed N is larger, the memory 11
Increase the value of the cumulative number of control cycles in (memory for cumulative number of control cycles) by 1 (■, ◎. When this increased value reaches K (usually about 5 to 1 mouse), the control cycle Return the cumulative value to 0, reduce the control pulse width by a certain amount, and store it in memory 11 (E control pulse width memory) again (■).On the other hand, if the actual rotation speed N is smaller, the control pulse width is The cumulative number of cycles is decreased by 1, and when the decreased value reaches -K, the cumulative number of control cycles is returned to 0, the control pulse width is increased by a certain amount, and it is stored in the memory 11 (memory for uncontrolled pulse width). Correct (■,■◎.

With the above operation, the control pulse width is corrected if the actual rotation speed is higher or lower than the target rotation speed K times in a row (or every K rotations if the control cycle is synchronized with the rotation speed). Ru.

In addition, if no-load operation is not performed, if there is no significant difference between the actual rotation speed and the target rotation speed, or if the magnitude relationship between the actual rotation speed and the target rotation speed is reversed, the cumulative control cycle will be 0. be returned. Through the above calculations, the control pulse width is calculated and stored in the memory 11 (control pulse width memory) both in the case of no-load operation and in other cases.

Then, a control signal S3 with a pulse width corresponding to that value is outputted via the input/output device 9 and sent to the solenoid valve 18 (■
). As described above, according to the control device of the present invention, minute load fluctuations are detected by the signals of the cooler operation sensor 3 and the shift position sensor 4, and predictive control corresponding to the load fluctuation is performed, so that control at the time of minute load fluctuations is performed. improves responsiveness.

FIG. 3 is a comparison diagram of responsiveness during load fluctuations.

In the figure, in the case of only conventional feedback control, if the load a changes at a certain point, then after the rotation speed c changes,
Control is performed only after this change is detected, and the air supply valve function b changes. Therefore, as shown in the figure, the rotational speed c varies greatly when the load changes. On the other hand, in the present invention, since predictive control is performed to change the air supply valve function d when the load fluctuates, fluctuations in the rotational speed e can be made extremely small.

As explained above, the present invention is configured to detect the cause of minute load fluctuations and add a correction control amount that increases or decreases by a value corresponding to the amount of load fluctuation caused by the cause of the fluctuations, so that minute load fluctuations are prevented. The amount of deviation from the target rotational speed when this occurs can be reduced, and the time required to return to the target rotational speed can be shortened.

In addition, since the control amount is changed by the sum of the correction control amount that has a value corresponding to each cause of variation, it is possible to make corrections that are well suited to the amount of load variation that differs depending on the cause of variation, and to compensate for multiple causes of variation. Even if they occur at the same time, the resulting load fluctuations can be effectively compensated for. Furthermore, since the system is configured to perform corrections corresponding to increases and decreases in load, accurate rotational speed control can always be performed whether the load increases or decreases. Further, by configuring the target rotation speed to be set according to the cause of variation, the rotation speed during no-load operation can be controlled to a desired value depending on the presence or absence of a minute load. In addition, when the deviation between the actual rotation speed and the target rotation speed is less than a predetermined setting value, the control amount is fixed and the opening degree of the air supply valve is kept constant. This eliminates this problem, improving rotational stability and exhaust composition.

In addition, when the deviation is greater than the set value, feedback control is performed according to the deviation, so if the actual rotational speed deviates significantly from the target rotational speed, it can be quickly brought closer to the target rotational speed, resulting in noise reduction. , vibration and fuel efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the overall configuration of the present invention, Fig. 2 is an embodiment of the invention, Fig. 3 is an embodiment of a flowchart showing calculations in the invention, and Fig. 4 is load fluctuation. FIG. Explanation of symbols 1...Temperature sensor, 2...Rotation sensor, 3...Cooler operation sensor, 4...
...Shift position sensor, 5...Vehicle speed sensor, 6
...Throttle relationship sensor, 7...A
-D converter, 8...Microcomputer, 9
...Input/output device, 10...Central calculation position,
11...Memory, 12...Intake pipe, 1
3... Throttle valve, 14... Air supply valve, 15. ．． ...Air chamber, 16...Diaphragm, 17. ．．・．． ．．・Valve, 18...Solenoid valve, 19...Atmospheric pipe, 20...Negative pressure pipe, 100...Rotation sensor, 101...Air related Sensor for detecting a rotational variable, 102... detection means, 103... deviation detection means, 104...
... Control means, 105 ... Correction means, 106 ...
- Air supply valve, 107...Target rotation speed setting means, 108...Storage means. Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] 1 Compare the actual rotation speed with the target rotation speed at no-load, which is preset according to the temperature of the internal combustion engine, etc., and calculate the control amount so that the actual rotation speed matches the target rotation speed. , in an automatic no-load speed control device for an internal combustion engine that performs feedback control of the opening degree of an air supply valve that adjusts the amount of air supplied to the internal combustion engine according to the control amount, which causes minute load fluctuations in the internal combustion engine. A detection means for detecting at least one of a change in the shift position of an automatic transmission and the presence or absence of operation of auxiliary equipment, a target rotation speed corresponding to each of the causes of variation above, and load fluctuations caused by each cause of variation. a storage means that stores in advance a correction control amount that increases or decreases by a value corresponding to the amount; a deviation detection means that detects a deviation between a target rotation speed and an actual rotation speed; In this case, the control means fixes the control amount and stops the feedback control, and when the deviation is greater than the set value, performs feedback control and outputs the control amount according to the deviation, and the detection means detects the occurrence of the cause of the fluctuation. target rotation speed setting means for reading from the storage means and setting the target rotation speed to a value corresponding to the cause of variation when the detection means detects occurrence of the cause of variation; and correction corresponding to the cause of variation when the detection means detects the occurrence of the cause of variation. A correction means that adds a controlled amount to the controlled amount of the control means and outputs the result, compensates for the response delay of the control system during minute load fluctuations during no-load conditions, and when the rotational speed deviation is less than a set value. An automatic no-load speed control device for an internal combustion engine characterized by fixing a control amount and keeping the opening degree of an air supply valve constant.