JPH032689Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement of an idle speed control device for an internal combustion engine.

Prior Art When a load is applied to an internal combustion engine in an idling state by equipment such as power steering or an air conditioner, it is necessary to maintain a high idling speed. However, such necessity is not constant, and during normal idling, it is desirable to maintain the idling speed as low as possible from the standpoint of fuel consumption. Therefore, the rotation speed is controlled by changing the amount of intake air supplied to the internal combustion engine according to the magnitude of the deviation signal that is the result of comparing the speed signal that detects the rotation speed of the internal combustion engine and the idle rotation speed setting signal. However, an idle rotation speed control device that performs negative feedback control so that the deviation signal becomes zero has been conventionally used. For example, Japanese Patent Application Laid-Open No. 54-81421,
This is the idle speed control device described in Japanese Patent Application Laid-open No. 54-95892.

However, since the above-mentioned idle speed control device controls the speed by changing the amount of intake air supplied to the internal combustion engine, the response time from when the control operation is performed to when a change in the speed appears is long. However, when a sudden load is applied to the engine, such as when an air conditioner is activated, the system may not be able to respond adequately.

Problems to be solved by this invention In order to solve this problem, for example, as described in Japanese Patent Application Laid-Open No. 1989-19981, an ignition timing adjustment method that controls the engine rotational speed by adjusting the ignition timing of the engine is proposed. It is conceivable that this method may be used for control to match the actual engine speed to a correspondingly determined target value. However, with this type of system, the additional output torque of the engine obtained by changing the ignition timing is not that large;
It had the disadvantage that it could not adequately handle the large load that was applied to the engine during idling. These drawbacks become noticeable when various loads are applied to the engine at the same time when the engine is idling.

The present invention was developed against the background of the above-mentioned circumstances, and its main points are (a) a rotation speed detection means that generates a speed signal representing the rotation speed of an internal combustion engine, and (b) an idling state (c) at least one of the plurality of types of output signals from the load state detection device;
(d) generating a deviation signal corresponding to the difference between the speed signal and the setting signal; (e) an arithmetic control circuit that determines the ignition timing and intake air amount based on the deviation signal and generates control signals corresponding to those values; and (f) an arithmetic control circuit that determines the internal combustion according to the control signal. an ignition timing adjustment device that increases or decreases the rotation speed of the internal combustion engine by adjusting the ignition timing of the engine; and an ignition timing adjustment device that increases or decreases the rotation speed of the internal combustion engine by adjusting the amount of intake air supplied to the internal combustion engine according to the control signal. and a rotational speed control means equipped with an intake air amount adjusting device that increases or decreases the intake air amount.

Effects of operation and invention With this arrangement, the arithmetic control circuit calculates the basic ignition timing and basic intake air amount of the internal combustion engine according to the speed signal and the output signal of the load condition detection device, and also calculates the idling speed. The basic ignition timing and basic intake air amount are corrected according to the deviation between the target value and the actual rotational speed, and a control signal representing the corrected ignition timing and intake air amount is generated. Then, according to this control signal, the ignition timing adjustment device adjusts the ignition timing of the internal combustion engine, and
By adjusting the amount of intake air supplied to the internal combustion engine by the intake air amount adjusting device, the engine rotational speed during idling is controlled to a target value.
Therefore, the ignition timing adjustment device, which has a relatively high responsiveness, and the intake air amount adjustment device, which can obtain a relatively large additional output torque, are operated to match the engine speed at idle with the target value. Even if a load is suddenly applied or a large load is applied due to multiple types of loads being applied, it can be adequately coped with, and the idle rotation speed can be suitably controlled.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In Fig. 1, the crankshaft of an internal combustion engine 1 is provided with a disk 2 having tooth-shaped protrusions on its circumference in order to detect the rotational speed, and is generally located at a position where the proximity of the protrusions can be detected. A crank angle sensor 3 composed of a proximity switch is attached to the crank angle sensor 3, and an output signal SS of the crank angle sensor 3 is supplied to a control circuit section 4. The distributor 5 is provided with a cylinder discrimination sensor 6 for detecting the ignition timing and the cylinder to be ignited, and its output signal is
ST is supplied to the control circuit section 4. In addition, there are signal groups SA, SW, etc. that indicate the status of the vehicle and internal combustion engine, such as the air conditioner electromagnetic clutch and water temperature sensor (not shown).
SP, SH, SV, and SD are input. The output signal SI of the control circuit 4 is supplied to the igniter 31 as an ignition signal, and the cylinders of the internal combustion engine 1 are ignited and rotated by the high voltage generated in the igniter 31.

The idle rotation control device used in the above system has a circuit configuration as shown in the block diagram of FIG. That is, the rotation speed detection device 8, the load state detection device 9, the deviation circuit 10, the target value setting circuit 11, and the intake air amount ignition timing calculation control circuit 3
0, an igniter 3 that functions as an ignition timing adjustment device for the rotation speed control means.
1 and an intake device 32 that functions as an intake air amount adjusting device for the rotation speed control means.

In the rotation speed detection device 8, the crank angle sensor 3 is used to convert a pulse signal of a frequency proportional to the speed of the crankshaft of the internal combustion engine 1 outputted by the crank angle sensor 3 into a voltage signal SS proportional to the speed.
The output terminal of the frequency/voltage conversion circuit (F/V conversion circuit) 13 is connected to the input terminal of the frequency/voltage conversion circuit 13, while the output terminal of the frequency/voltage conversion circuit 13 is connected to the deviation circuit 1.
0 and the input terminal of the intake air amount ignition timing calculation control circuit 30.

The load state detection device 9 detects multiple types of loads applied to the internal combustion engine 1 during idling, generates multiple types of output signals representing these loads, and supplies them to the control circuit 4, and detects multiple types of loads applied to the internal combustion engine 1 during idling. Sensor 14, water temperature sensor 15 and its voltage conversion circuit 1
6, a power steering oil pressure sensor 17 and its voltage conversion circuit 18, and an altitude sensor 19 and its voltage conversion circuit 20. Further, the internal combustion engine 1 is provided with a cylinder discrimination sensor 6 and its waveform shaping circuit 21, a negative pressure sensor 22 and its voltage conversion circuit 23, and an idle switch 24. The air conditioner operation sensor 14 is for supplying a signal representing the operation of the air conditioner to the target value setting circuit 11, and is a voltage signal representing the operation of the electromagnetic clutch or electric motor that drives the compressor of the air conditioner. Generate SA. The water temperature sensor 15 is provided in the internal combustion engine 1 and is a general temperature/electrical signal conversion element such as a resistance temperature detector or a thermistor, in order to detect the temperature of the cooling water and to detect the warm-up state of the internal combustion engine 1. By being connected to the voltage conversion circuit 16, a voltage signal SW representing the water temperature is generated. The power steering oil pressure sensor 17 is composed of a general pressure/electrical signal conversion element such as a diaphragm to which a strain gauge is attached, in order to detect the state of oil pressure for driving the power steering, and the voltage conversion circuit 18 is connected to generate a voltage signal SP representing the state of the power steering oil pressure. The altitude sensor 19 is composed of a general pressure/electrical signal conversion element such as a strain gauge attached to a bellows that is activated by fluctuations in atmospheric pressure, and is connected to the voltage conversion circuit 20. This generates a voltage signal SH representing atmospheric pressure.

The signal groups SA, SW, SP, and SH correspond to multiple types of loads applied to the internal combustion engine 1 in an idle state, and the signal groups SA, SW, SP,
When SH occurs, the idle speed must be changed accordingly, so the air conditioner operation sensor 14 and the voltage conversion circuit 1
The output terminals 6, 18, and 20 are connected to the corresponding input terminals of the target value setting circuit 11, respectively. That is, the target value setting circuit 11 receives the input signal
A setting signal SK representing the idle rotation target value according to SA, SW, SP, and SH is output, but the load on the internal combustion engine 1, such as when the air conditioner is running, when the engine is low temperature, when the power steering is switched to the stationary position,
A target idle rotation speed suitable for each state during high-altitude driving is determined from a pre-stored relationship. Therefore, the target value setting circuit 11 corresponds to the target value setting means of this embodiment.

The cylinder discrimination sensor 6 is composed of an ignition cylinder and a coil that detects the position of the rotor by generating an induced electromotive force in order to detect the ignition timing, and is connected to the waveform shaping circuit 21 to generate a signal. Generates ST. The negative pressure sensor 22 is attached to the intake system of the internal combustion engine 1, and is configured with the same pressure/electrical signal conversion element as the above-mentioned pressure/electrical signal conversion element in order to detect the degree of negative pressure.
3 to generate a voltage signal SV representing the degree of negative pressure. The idle switch 24 is
Consists of a switch that detects whether or not the internal combustion engine 1 is in an idle state, and outputs an idle signal SD.
occurs.

The signal groups ST, SV, and SD are signals for determining the basic ignition timing together with the speed signal SS, and the output terminals of the waveform shaping circuit 21, voltage conversion circuit 23, and idle switch 24 correspond to the intake air amount. It is connected to an input terminal of the ignition timing calculation control circuit 30.

The output terminal of the target value setting circuit 11 is connected to the positive input terminal of the deviation circuit 10 in order to supply the idle rotation speed setting signal SK, and the deviation circuit is connected to the positive input terminal of the deviation circuit 10 in order to supply the deviation signal SE to the intake air amount ignition timing calculation control circuit 30. The output terminal 10 is connected to the input terminal of the intake air amount ignition timing calculation control circuit 30. The output terminal of the intake air amount ignition timing calculation control circuit 30 is the igniter 31
and is supplied to the intake device 32.

The intake air amount ignition timing calculation control circuit 30, which corresponds to the calculation control circuit of this embodiment, calculates not only the ignition timing but also the intake air amount of the internal combustion engine to control the idle rotation speed, and generates the ignition signal SI and the intake air amount signal SC. The engine is configured to generate an ignition signal SI and an intake air amount signal SC to the igniter 31 and intake device 32, which constitute rotational speed control means, respectively. The igniter 31 adjusts the ignition timing of the internal combustion engine 1 according to the ignition signal SI, which is a control signal supplied from the intake air amount ignition timing calculation control circuit 30, and also adjusts the ignition timing of the internal combustion engine 1.
adjusts the intake air amount supplied to the internal combustion engine 1 in accordance with the intake air amount signal SC, which is a control signal supplied from the intake air amount ignition timing calculation control circuit 30. Here, the intake device 32 is a device that determines the air flow rate of the intake mixture of the internal combustion engine, and controls the amount of air passing through the carburetor part in a type of internal combustion engine with a carburetor, and the air flow meter in a fuel injection type internal combustion engine. Refers to the throttle valve part.

The operation of this embodiment will be explained below.

When the output signal SK of the target value setting circuit 11 is constant, idle rotation speed control as shown in FIG. 3 is performed. In other words, as shown in section A, when the speed signal SS representing the idle rotation speed is larger than the setting signal SK, a negative deviation signal SE proportional to the difference between the speed signal SS and the setting signal SK indicates the intake air amount ignition. The signal is supplied to the timing calculation control circuit 30.
In the intake air amount ignition timing calculation control circuit 30, the speed signal
In addition to calculating the basic intake air amount signal and basic ignition signal calculated based on SS, cylinder discrimination signal ST, negative pressure signal SV, and idle signal SD, the deviation signal is calculated so that the deviation signal SE disappears.
The basic intake air amount signal and basic ignition signal are corrected in proportion to the magnitude of SE, and the resulting control signals are the intake air amount signal SC and the ignition signal.
SI is supplied to the intake device 32 and the igniter 31, respectively, and the rotation of the internal combustion engine 1 is slowed down. Conversely, as shown in section B, when the speed signal SS representing the idle rotation speed is smaller than the setting signal SK, a positive deviation signal SE proportional to the difference between the speed signal SS and the setting signal SK is generated during intake air. The intake air amount ignition timing calculation control circuit 30 receives the cylinder discrimination signal as described above.
ST, negative pressure signal SV, idle signal SD, speed signal
A correction is added to the basic intake air amount signal and the basic ignition signal calculated based on SS in proportion to the magnitude of the deviation signal SE so that the deviation signal SE is eliminated, and the control obtained in this way is The intake air amount signal SC and the ignition signal SI, which are signals, are transmitted to the intake device 32.
and are supplied to the igniter 31, respectively, to speed up the rotation of the internal combustion engine 1. In this way, the idle speed is controlled so that it always matches the target idle speed represented by the setting signal SK.

Next, a signal input to the target value setting circuit 11,
For example, when the signal SA indicating that the air conditioner has been activated is generated, the target idle speed is determined from pre-stored data and corresponds to the relatively high target idle speed necessary for the operation of the air conditioner. The setting signal SK to be set is the deviation circuit 1.
0. The deviation circuit 10 immediately generates a positive deviation signal SE in response to the sudden input of the setting signal SK representing a high target idle speed, and supplies it to the intake air amount ignition timing calculation control circuit 30.
In the intake air amount ignition timing calculation control circuit 30, the deviation signal
Based on the magnitude of SE, the basic intake air amount signal and the basic ignition signal are corrected in a direction that eliminates the deviation signal SE, and the corrected intake air amount signal SC
The ignition signal SI is then supplied to the intake device 32 and the igniter 31, and the internal combustion engine 1 is driven to rapidly increase its rotation. That is, the control response shown at time C in FIG. 4 is obtained, and the control of this embodiment, which includes control based on electrical ignition timing, is better than the response time of the conventional idle speed control device that only adjusts the amount of intake air. The response of the device is faster.

As described above, according to the present embodiment, the ignition timing control, which has relatively high responsiveness, and the intake air amount control, which can obtain a relatively large additional output torque, are used to make the engine speed at idle match the target value. Therefore, even if a load is suddenly applied, sufficient response characteristics can be obtained by the ignition timing control, and even if a large load is applied, such as when multiple types of loads overlap, sufficient output can be obtained by the intake air amount control described above. This can be done by changing the torque, and the idle speed can be suitably controlled under a wide range of conditions. That is, since the idle rotation control of the internal combustion engine 1 is performed including control to change the ignition timing, the response time is short, and the internal combustion engine 1 due to sudden load changes is
It is possible to reduce fuel consumption during idling without causing the engine to stop. At the same time, since the idle rotation control of the internal combustion engine 1 includes control that changes the intake air amount, the output torque is significantly increased to respond to large loads that cannot be handled by ignition timing control. It is possible. In short, this embodiment combines both the intake air amount control method with a relatively wide control range and the ignition timing control method with good response characteristics, so it is possible to provide an idle speed control device with an extremely wide practical range.

What has been described in detail above is one embodiment of the present invention, and various changes may be made without departing from the spirit of the present invention.

For example, in the embodiments described above, an analog control method using voltage signal processing is used, but a digital control method using digital signal processing may also be used.
In the case of digital control method, each voltage conversion circuit
Each circuit 10, 1 is replaced with a D conversion circuit.
1, 30, etc. are composed of digital elements, and the idle speed control device is highly reliable against temperature changes and disturbances. Further, most of the circuit configuration of the digital control system can be configured by a microcomputer, and can be made small and inexpensive.

Although the control operation in the above-described embodiment was proportional control, differential control for improving response characteristics and integral control for eliminating offset may also be added to the operation of the intake air amount ignition timing calculation control circuit 30. The present invention is also applicable to a stepwise control method as shown in FIG. 5, rather than a continuous control method. This step control system has the advantage that since the control operation is stepwise, it is possible to more easily prevent the rotational speed of the internal combustion engine from decreasing when a sudden load is applied.

Further, in the target value setting circuit 11, a signal representing the actual rotation speed is supplied as one of the signals representing the operating state of the internal combustion engine, and the target rotation speed is substantially set based on the moving average of this rotation speed. At the same time as the target rotation speed is determined, the target rotation speed may be increased and corrected using the signals SA, SW, SP, SH, etc., and the setting signal SK representing the target rotation speed determined in this way may be output.

Moreover, each sensor of the load state detection device 9 may be added or deleted depending on the purpose.

Furthermore, although the rotational speed control means of the above embodiment includes a method in which the igniter 31 is used and the ignition is ignited according to the timing of the ignition signal SI, a device equipped with a mechanical advance angle adjustment device may also be used. The present invention may include a method in which a signal representing the amount of advance is supplied from the arithmetic control circuit to the tributary, and the ignition timing is controlled based on this signal.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of the present invention.
FIG. 2 is a block diagram showing the circuit configuration of an embodiment of the present invention. 3 and 4 are explanatory views of the operation of the embodiment shown in FIG. 2. FIG. 5 is an explanatory diagram of the operation of another embodiment of the present invention. 1: Internal combustion engine, 8: Rotation speed detection device (rotation speed detection means), 9: Load state detection device, 10: Deviation circuit (deviation detection means), 11: Target value setting circuit (target value setting means), 30: Intake air amount ignition timing calculation control circuit (calculation control circuit), 31: Igniter (ignition timing adjustment device), 32: Intake device (intake amount adjustment device), SS: Speed signal, SK: Setting signal, SE: Deviation signal, SI , SC: control signal, SV: voltage signal.

Claims (1)

[Claims for Utility Model Registration] A rotational speed detection means for generating a speed signal representing the rotational speed of an internal combustion engine; and a load state for generating a plurality of types of output signals representing a plurality of types of loads applied to the internal combustion engine in an idle state. a detection device; and a target value setting means for determining a target value of the idle rotation speed according to at least one of a plurality of types of output signals from the load state detection device and generating a setting signal representing the target value. , a deviation detection means for generating a deviation signal corresponding to the difference between the speed signal and the setting signal; and determining an ignition timing and an intake air amount based on the deviation signal, and generating a control signal corresponding to those values. an arithmetic control circuit; an ignition timing adjustment device that increases or decreases the rotational speed of the internal combustion engine by adjusting the ignition timing of the internal combustion engine according to the control signal; 1. An idle speed control device comprising: a rotation speed control device including an intake air amount adjusting device that increases or decreases the rotation speed of the internal combustion engine by adjusting the intake air amount.