JPS5939950A - Idling speed controller of automotive engine - Google Patents

Abstract

PURPOSE:To prevent an engine from temporarily rising or dropping in its idling speed by providing both a control means which regulates an idling speed to a target value and a transmission gear actuating means which transmits an engine output to or cuts it from engine accessories. CONSTITUTION:A relay switch 5 and a transistor 6 are provided so as to actuate a compressor magnet clutch 4 at a time when a certain lapse passed after a control circuit 100 generated an output to turn an air conditioner switch 3 on or off. Since the air conditioner shall not be operated until the power of an engine is increased to a certain extent, there is no possibility that the idling speed of the engine may be temporarily reduced immediately after the air conditioner switch 3 is turned on. Once the air conditioner switch 3 is turned off, the control circuit 100 sends an output to the base terminal of the transistor 6 after a lapse of a specified time counted from the point of the turning on. Meanwhile, since the air conditioner is kept in operation during this period, temporary rise in idling speed may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an idle rotation speed control device for an automobile engine, and more particularly to an idle rotation speed control device when an auxiliary device such as an air conditioner or a cooler is operating.

It is necessary to improve the drivability of an automobile engine by stably controlling its idle rotational speed to a predetermined value. Such control differs greatly between when the auxiliary equipment is activated and when it is not activated. When the auxiliary equipment is activated, it is necessary to increase the amount of fuel or mixture to increase output and prevent the idle rotation speed from decreasing. .

An example of an idle rotation speed control device that takes this point into consideration is shown in FIG. In the figure, power output from a battery 1 is transmitted to a control circuit 1 via an ignition switch 2.
00, and by turning on an auxiliary device such as the air conditioner switch 3 for operating the air conditioner, power is released to a transmission device such as the compressor magnetic clutch 4 that transmits engine output to the air conditioner or cuts it off. The fact that the force was pressed is input to the control circuit 1oo.

On the other hand, as shown in FIG. 2, the automobile engine 200 includes:
An engine rotation speed sensor 201 such as a crank angle sensor that detects engine crank angular rotation speed, a water temperature sensor 202 that detects engine-related temperatures such as engine cooling water temperature, and a throttle valve opening provided in the engine intake passage that is below a predetermined value. a throttle switch 203 that detects the vehicle speed, and a vehicle speed sensor 20 that detects the vehicle speed
4.) Various engine state detection means such as a transmission switch 205 for detecting that the transmission is in the neutral position are provided, and these detection signals are manually input to the control circuit 100, respectively.

The control circuit 100 outputs a control signal to the idle rotation speed control section 206 of the engine 200 in response to the detection signals inputted from each of the engine state detection means. That is, throttle switch 203, vehicle speed sensor 204,)
The transmission transmission switch 205 alone or a combination thereof detects that the engine is at idle rotation, and according to these human power conditions, a preset basic idle rotation speed is read by the arithmetic circuit 1D5,
A target idle rotation speed is calculated by correcting and controlling the engine cooling water temperature, the air conditioner operating state input from the air conditioner switch 3, and the basic idle rotation speed.

Then, an electric signal corresponding to the target idle rotation speed is output to the idle rotation speed control section 206 of the engine to maintain control at a predetermined idle rotation speed. Although not shown, the idle rotation speed control section 206 provides, for example, a bypass intake passage that bypasses a throttle valve installed in the intake passage of the engine, and an idle control flow rate control valve is installed in the bypass intake passage to perform the control. The control signal pressure of the valve is adjusted by performing duty control that repeatedly turns on and off using a solenoid valve, and controls idle intake air etc. when the throttle valve is fully closed.

Increases and decreases in the idle intake air amount are measured by an intake air amount measuring means (measuring the total amount of air taken into the engine) (not shown), and the engine output is increased by injecting fuel according to the measured value from the fuel injection valve. Increase/decrease control. Therefore, when the engine coolant temperature drops or when the air conditioner operates and the engine load increases, the engine output is increased as described above to prevent engine malfunctions due to a drop in idle speed. There is.

In addition, in FIG. 2, 101 and 103 are A/D converters, 1
02 and 104 are pulse counters, and 106 is an output circuit.

The idle rotational speed of the engine controlled in this way is detected by the engine rotational speed sensor 201, and the idle rotational speed of the engine controlled in this way is detected by the engine rotational speed sensor 201. It is input to J circuit 105.

FIG. 3 is a flowchart showing a control example of the control circuit 100, in which when the air conditioner is on, the basic idle rotation speed ft
As a result, the target idle rotational speed is corrected to a constant value, for example, 800 rpm or more, as much as possible, and when the air conditioner is off, the basic idle rotational speed is not corrected.

However, such conventional idle rotation speed control devices for automobile engines have the following drawbacks. That is, as shown in FIG. 4, when the air conditioner switch 3 is turned on, power is immediately supplied to the compressor magnetic clutch 4, which transmits power to the air conditioner compressor, and the compressor magnetic clutch 4 is activated, while the idle rotation speed is controlled by the operation command of the control circuit 100. In order to activate the section 206 and increase the engine output, the time constant at the stability 1 is required, therefore, as shown in Fig. 4(D).
As shown in FIG. 2, the actual idle rotational speed temporarily decreases when the air conditioner switch 3 is turned on, which causes an inconvenience.

Conversely, when the air conditioner switch 3 is turned off, power is no longer transmitted to the air conditioner compressor immediately, so the actual idle rotation speed temporarily increases when the air conditioner switch 2 is turned off.

The present invention has been made in view of the drawbacks of such conventional devices, and provides an idle rotation speed control device for an automobile engine that prevents the idle rotation speed from temporarily decreasing or increasing when turning on/off an auxiliary machine. The purpose is to

In order to achieve such an object, the present invention provides a control means for adjusting the engine output to a target idle rotation speed by increasing or decreasing the engine output based on an input signal of an auxiliary equipment operation switch, and a control means for adjusting the engine output to a target idle rotation speed after the start of adjustment by the control means. A transmission device operating means for transmitting or cutting off the transmission to the machine is provided.

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

FIG. 5 is a diagram showing a first embodiment of the present invention. All elements that are the same as those of the conventional device shown in FIG. In the figure, the parts that differ from Figure 1 are as follows:
By providing a relay switch 5 and a transistor 6, instead of directly driving the compressor magnetic clutch 4 with the air conditioner switch 3, the compressor is activated after a predetermined period of time has elapsed after the air conditioner switch 3 is turned on and off by the output of the control circuit 100. This is to operate the magnetic clutch 4.

That is, the control circuit 100 includes an ignition switch 2
The on/off signal of the air conditioner switch 3 and the on/off signal of the air conditioner switch 3 are input directly. Also, ignition switch 2
are connected in series to the compressor magnet clutch (device for transmitting engine output to the compressor of the air conditioner) 4 through the relay switch 5'kR, and also connected in series to the coil 5a of the relay switch 5. A compressor magnetic clutch operating circuit is constructed by connecting the terminal of the relay coil 5a opposite to the ground to the collector terminal of a transistor 6 whose emitter is grounded, and the base terminal of the transistor 6 to the output terminal of the control circuit 1oO. 9. The control circuit 100 includes an output circuit 107 that outputs an activation or deactivation signal for the compressor magnetic clutch 4 to the base terminal of the transistor 6 after the ON signal of the air conditioner switch 3 is inputted and after the start of the idle rotation speed control. The transmission device actuating means as used in the present invention includes the output circuit 107 of the control circuit in addition to the compressor magnetic clutch actuating circuit.

The compressor magnetic clutch operating circuit is configured to demagnetize the relay coil 5a by turning on the transistor 6 and grounding the voltage applied to the relay coil 5a when the control circuit 100 outputs a high level signal. .

Therefore, according to this configuration, when the air conditioner switch 3 is turned on, the control circuit ioo that receives the signal becomes aware of the increase in engine load and creates the idle rotation speed control section 206 to increase the engine output. After a predetermined time has elapsed, the high level air conditioner operation stop signal input to the base terminal of the transistor 6 is changed to the low level operation signal and output. Therefore, when the transistor 6 is turned off, the relay coil 5a is excited, turning on the relay switch 5, connecting the compressor magnetic clutch 4, and operating the air conditioner. Since the air conditioner is activated after the engine output has been increased to some extent, there is no possibility that the engine idle rotational speed will be temporarily lowered immediately after the air conditioner switch 3 is turned on.

Also, when the air conditioner switch 3 is turned off, the control circuit 100
outputs a command signal to reduce the output of the engine, and then outputs a high level to the base terminal of the transistor 6 after a predetermined period of time has elapsed. Therefore, the transistor 6 is turned on, the relay coil 5a is demagnetized, and the relay switch 5 is turned off, cutting off the power transmission to the compressor magnetic seat clutch 4 and stopping the air conditioner operation. Here, the output reduction of the zero engine becomes stable after a predetermined period of time has elapsed after the control circuit 100 outputs the output reduction signal, and since the air conditioner continues to operate during this time, the idle rotation speed temporarily decreases immediately after the air conditioner switch 3 is turned off. can be prevented from rising.

FIG. 6 shows the control circuit 100 in the embodiment shown in FIG.
3 is a flowchart showing the operation of FIG. In the control circuit 100, first, it is determined whether the air conditioner switch 3 is on or off. If it's on.

An engine output enhancement correction corresponding to a 5% rotational speed increase is added to the target idle rotational speed.

Next, it is determined whether or not the target rotational speed exceeds a certain value (for example, 800 rpm), and if it does not, it is raised to a certain value.

Next, it is determined whether the flag is "]" or "()". The flag Ilt&l means that the air conditioner switch 3 was off the last time this routine was processed, and 7lag 0" means that it was on. If the flag is ``I'', it means that the air conditioner switch 3 has just been turned on, so the flag is set to ``1'' and the count value of the counter is reset to zero. If it is determined that the magnet clutch 4 is still off (1) - flag is "0", the count value of the counter is counted up and the time since the air conditioner switch 3 was turned on is measured.

Then, it is determined whether or not the value has reached a predetermined value, and only when the value has reached the predetermined value is it determined that the engine output has been sufficiently increased and the compressor magnetic clutch 4 is activated to operate the air conditioner. If the air conditioner switch 3 is off, the correction value is set to 0% of the basic idle rotational speed, and no correction is made, so it is determined whether the flag is '1' or '0'. If the flag is 0'', it means that the air conditioner switch 3 has just been turned off, so the flag is set to 1xll and the count value of the counter is set to zero.

Then, the compressor magnetic clutch 4 is kept in the on state. If the flag is determined to be ``1'', the count value of the counter is counted up, and only when the count value reaches a predetermined value is the compressor magnetic clutch 4 turned off to stop the air conditioner.

FIG. 7 is a flowchart showing the operation of each part when controlled according to the flowchart shown in FIG. 6. As shown in the figure, according to this embodiment, even if the air conditioner switch 3 is turned on or off, the compressor magnetic clutch is connected or disconnected after the counter counts for a predetermined period of time, so that the engine output increases or decreases to some extent. The air conditioner will start or stop at that point. Therefore, as shown in the figure, the actual idle rotational speed of the engine is prevented from temporarily decreasing or increasing immediately after the air conditioner switch 3 is turned on or off.

FIG. 8 is a flowchart showing another embodiment of the 10 control circuits shown in FIG. The correction value is set to 3% when the air conditioner switch is on, and 2% when the air conditioner switch is off. be done. Due to the above-mentioned 3% correction, the actual engine idle speed increases after a predetermined period of time has passed after the air conditioner is turned on, and when this value does not exceed the predetermined value, the compressor magnetic clutch 4 is turned off, and when it exceeds the predetermined value, the compressor magnetic clutch 4 is turned off. The correction value is increased by 2% to 5%, the engine output is increased accordingly, and the compressor magnetic clutch 4 is turned on.

The reason for controlling the engine output increase in two stages in this way is
The 3% correction in the first stage is set so that the idling rotation speed does not decrease much even if the shared air conditioner is activated, and the output of the second stage is increased at the same time as the air conditioner is activated to maintain the actual idle rotation speed. This is done to ensure that the value is maintained.

Even when it is determined that the air conditioner switch 3 is off, the correction value of the target idle rotational speed is changed from 5% to 2% in the same manner as described above. Furthermore, in case the actual idle rotational speed falls below a predetermined value, two-step control is performed in which the correction value is set to 0%. Therefore, according to such control, actual idle rotation speed control is performed smoothly as shown in FIG. 9(E).

FIG. 9 is a time chart showing the operation of each part when controlled by this flowchart.

FIG. 1O is a flowchart showing another embodiment of the control circuit 100. This flowchart is a variation of the flowchart shown in FIG. 8 in which the two-stage control is performed in one stage. That is, after the air conditioner switch 3 is turned on or off, it is detected whether the actual engine idle speed has become higher or lower than a predetermined value, and based on this, the compressor magnetic clutch 4 is turned on or off. It is something that makes you

In the above embodiment, an air conditioner is shown as an example of an auxiliary machine, but it is obvious that the present invention can be similarly applied to other auxiliary machines that increase the load on the engine, such as a cooler. Further, the combrezza magneto switch is an example of a transmission device that transmits or interrupts engine output to an auxiliary machine. In the embodiment, the transmission device operating means for transmitting the operation of the transmission device with a delay from the input signal of the auxiliary equipment operation switch detects the delay time or the engine idling speed, but it is possible to detect elements such as intake air amount. As is clear from the above explanation, according to the present invention, after the auxiliary equipment operating switch is turned on or off, the auxiliary equipment is not activated immediately, but the auxiliary equipment is automatically activated. Because the engine is activated after the engine output is able to respond to the auxiliary equipment operation after a delay, the idle rotation speed does not suddenly drop or increase temporarily immediately after the auxiliary equipment starts or stops, and the idle rotation speed smoothly increases. Can be controlled.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of a conventional idle rotation speed control device for an automobile engine, Fig. 2 is a block diagram showing an example of the control circuit same as the above, and Fig. 3 shows the operation of the control circuit shown in Fig. 1. 4 is a time chart showing the operation of the conventional automobile engine idle speed control device shown in FIG. 1, FIG. 5 is a configuration diagram showing an embodiment of the present invention, and FIG. 6 is the same as above. 7 is a time chart of each part that operates according to the flowchart shown in FIG. 6, FIG. 8 is a 70-chart showing another embodiment of the control circuit, and FIG. A time chart of each part that operates according to the flowchart shown in the figure,
FIG. 1O is a flowchart showing another embodiment of the control circuit. DESCRIPTION OF SYMBOLS 1... Battery, 2... Ignition switch, 3... Air conditioner switch, 4... Compressor magnetic clutch, 5... Relay switch, 6... Transistor, 100... Control circuit, 107... Output circuit, 206... Idle rotation speed control section. Patent applicant: Nissan Motor Co., Ltd., patent attorney Fujio Sasashima

Claims (1)

[Claims] an auxiliary equipment operation switch, a transmission device that transmits engine output to the auxiliary equipment or cuts it off, a control means that increases or decreases the engine output based on an input signal of the auxiliary equipment operation switch to adjust it to a target idle rotation speed; 1. An idle rotation speed control device for an automobile engine, comprising: a transmission device actuating device that performs transmission or cutoff of the transmission device with a delay in the start of adjustment of the control device.