JPH0113620Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to an engine protection device for an automobile equipped with a cooling device, and in particular, to prevent engine overload by a fast idling device.

(Conventional Example) Conventionally, as this type of device, for example,
As shown in Publication No. 48649, there is a fast idling device that increases the speed of the engine, and an acceleration cut device that stops the compressor for compressing refrigerant when the engine speed is increased by the accelerator pedal. A device equipped with this has already become publicly known. If the accelerator pedal is depressed for a long time, stopping the compressor will reduce the air conditioning feeling, so it is also recommended to stop the compressor only for a predetermined period of time from the time the accelerator pedal is depressed. 47−29307
It is already publicly known in the publication No.

(Problems to be Solved by the Invention) However, in the above conventional example, since the fast idling device and the accelerated cutting device are connected in series to the power supply, when accelerated cutting is performed, The fast idling device also stops along with the compressor.

Therefore, during such accelerated cutting,
For example, when the accelerator pedal is released to change gears, the engine speed becomes idling. In this state, when the compressor returns to normal operation, the engine speed drops below the idling speed, causing problems such as malfunction and stalling of the engine.

Therefore, this invention solves the conventional problem caused by treating compressor stop due to acceleration cut as the same as stop in other cases, as described above, and properly performs fast idle according to the compressor stop conditions. The object of the present invention is to provide a device that can control the engine and protect the engine more reliably.

(Means for Solving the Problem) The gist of this invention is that a compressor for compressing refrigerant is connected to a driving engine whose output torque increases or decreases depending on the position of the accelerator pedal via an intermittent means. For connected cars,
an acceleration switch that operates in conjunction with the accelerator pedal;
an acceleration cut means for outputting a disconnection signal to the intermittent means to stop the compressor for a predetermined period of time after the output of the acceleration switch is applied; a command means for outputting to the intermittent means to instruct driving of the compressor; The engine protection device for an automobile equipped with a cooling device includes a fast idle means for accelerating the engine regardless of whether or not the acceleration cut means is activated when an output from the command means is received.

(Function) Therefore, even if the compressor is stopped due to acceleration cut, the first idle means operates to increase the speed of the engine while the command means outputs. Therefore, even if the accelerator pedal is released, the engine speed does not become insufficient, and the above-mentioned problem can therefore be achieved.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

In Figure 2, 1 is a driving engine, 2
is a carburetor that supplies air-fuel mixture to the engine 1 via the intake manifold 3. The carburetor 2 has a slot valve 4, and the amount of air-fuel mixture supplied to the engine 1 is adjusted by the opening degree of the slot valve 4. The amount of depression of an accelerator pedal 5 is transmitted to the slot valve 4 via an operating shaft 6, so that the opening degree can be adjusted.

Further, a fast idling device 7 constituting a fast idling means is connected to the throttle valve 4 via the operating shaft 6, and apart from the accelerator pedal 5, the opening of the throttle valve 4 is Adjustments are being made. This fast idling device 7 uses, for example, an electromagnet to increase the opening degree of the throttle valve 4 by a certain amount via a movably provided plunger due to the operation of the electromagnet, thereby increasing the opening degree of the throttle valve 4 by a certain amount.
This increases the speed of the engine.

An acceleration switch 8 is provided near the accelerator pedal 5, and outputs a signal to the control circuit 9 when the accelerator pedal 5 is depressed beyond a predetermined value (the position indicated by the two-dot chain line in FIG. 2). This control circuit 9 is provided immediately after an air conditioning switch 10 that turns on and off the air conditioner, a blower switch 11 that turns on and off a blower 15 (described later), and an evaporator 16 (described later), and detects the temperature of air passing through the evaporator 16. , the output signals of the thermoswitch 12, which outputs signals below a predetermined value, are inputted to control the electromagnetic clutch 13 and the fast idling device 7, which constitute the disconnection means.

14 is an air conditioning duct, and the air conditioning duct 14 is provided with a blower 15 and an evaporator 16. Air blown by the blower 15 passes through the evaporator 16 and is sent to the downstream side. The evaporator 16 constitutes a cooling cycle with a compressor 17, a condenser, a liquid receiver, etc. (not shown).

The compressor 17 is connected to the drive shaft 1a of the engine 1 via a belt transmission device 18 when the electromagnetic clutch 13 is turned on and off.

In FIG. 1, the acceleration switch 8 has one end connected to a power source 19 and the other end connected to one end of a resistor 20. The other end of the resistor 20 is connected to an A output terminal of a multivibrator circuit 22, which will be described later, and a capacitor 21, and the other end of the capacitor 21 is grounded. Further, a blower switch 11, an air conditioning switch 10, and a thermoswitch 12 are connected in series to the power source 19, and constitute command means. And thermo switch 12
The other end is connected to the electromagnet 7a of the fast idling device 7 and a fixed contact 23 of a relay 23, which will be described later.
c.

The thermoswitch 12 is disposed immediately after the evaporator 16, and opens and closes its contacts depending on the temperature of the air passing through the evaporator 16. For example, it has a normally open contact when not in operation.

The multivibrator circuit 22 is, for example, a dedicated
It is composed of an IC, and input terminals A,
In response to the input signal of B, a signal having a predetermined time width Tw determined by the time constant of the externally connected resistor 24 and capacitor 25 is output to the output terminal Q. This multivibrator circuit 22 is retriggerable, and when a predetermined input signal is input during output, the output signal is retriggered with a time width Tw.
It is to be extended and output. In addition, the terminal CD is
When an "L" signal is input, the output terminal Q is forcibly set to "L", and the terminals T ₁ and T ₂ are the connections between the resistor 24 and capacitor 25 that set the time width Tw of the output signal. This is a terminal for

The input terminal B and the terminal CD are connected between the air conditioning switch 10 and the thermoswitch 12,
It is always held in the "H" state when the power is turned on.
Further, a capacitor 25 is connected between the terminals T1 and T2, and a diode 26 is connected to the terminal T1.
The anode of is connected to the terminal T2, and a resistor 24 is connected to the terminal T2, forming a time constant circuit. The other end of these resistors 24 and the diode 26
The cathodes of both are connected between the air conditioning switch 10 and the thermoswitch 12.

On the other hand, the output terminal Q is connected to the base of a transistor 28 via a resistor 27, and the base is grounded via a resistor 29. Furthermore, the collector of the transistor 29 is connected to the diode 26.
The emitter is connected to one end of the excitation coil 23a of the relay 23, and the other end of the excitation coil 23a is grounded.

In the relay 23, fixed contacts 23c and 23d are closed by a moving contact 23b when the excitation coil 23a is de-energized.The fixed contact 23c is connected to the thermoswitch 12, and the fixed contact 23d is connected to the electromagnetic clutch 13. When the fixed contacts 23c and 23d are opened by excitation of the excitation coil 23a, the excitation coil 13a of the electromagnetic clutch 13 becomes de-energized and the compressor 17 stops operating. I'm starting to do that.

On the other hand, one end of the electromagnet 7a of the fast idling device 7 is connected to the fixed contact 23c of the relay 23.
The electromagnet 7a is also connected to one end of the thermoswitch 12, and the other end of the electromagnet 7a is grounded. Then, the air conditioning switch 10, the blower switch 1
1. It starts operating when all thermoswitches 12 are closed.

In the above structure, the operation will be explained based on FIG. 3. First, the air conditioning switch 10 and the blower switch 11 are turned on.

When the car is running without the engine 1 being accelerated, the acceleration switch 8 is open, so the input terminal A of the multivibrator circuit 22
“L” signal is input to output terminal Q.
An “L” signal is also output to the transistor 28.
becomes non-conductive. Therefore, the fixed contacts 23c and 23d of the relay 23 are closed, and if the temperature of the air passing through the evaporator 16 has not reached a predetermined value or less, the thermoswitch 12 is closed, so the excitation coil 13a is closed. is energized and the compressor 17 can continue operating. At the same time, the electromagnet 7a of the fast idling device 7 is also excited, and during idling, the engine 1
acts to protect against overload. In this case, when the temperature of the air passing through the evaporator 16 reaches a predetermined value or less, the thermoswitch 12 is opened.
Both the compressor 17 and the fast idling device 7 stop operating.

Next, when the engine 1 is accelerated to a predetermined value or more, the acceleration switch 8 is closed, and an "H" signal is input to the input terminal A of the multivibrator circuit 22 as shown in FIG. (Figure 3)
_A1 ).

The multivibrator circuit 22 detects the rising edge of the input signal and simultaneously outputs "H" to the output terminal Q.
The signal is output for a time width Tw (see output terminal Q in FIG. 3). Therefore, the transistor 28 becomes conductive (see Tr in FIG. 3), the exciting coil 23a of the relay 23 is excited, and the fixed contacts 23c, 23d
will be opened. Therefore, compressusa17
stops operating for a time width Tw (see Figure 3).
(See Comp.)

In this case, the electromagnet 7a of the fast idling device 7 is energized unless the thermoswitch 12 is opened, so the fast idling device 7 continues to operate and acceleration of the engine 1 is stopped while the compressor 17 is stopped. When this occurs, the rotational speed of the engine 1 is increased from the conventional idling rotational speed, and thereafter, when the compressor 17 starts operating, the engine rotational speed becomes close to the conventional idling rotational speed.

Furthermore, when the acceleration switch 8 is closed again while the compressor 17 is not operating, the multivibrator circuit 22 outputs an output signal for an additional time width Tw from the latest input signal (input signal A ₄ in FIG. 3). is output for an extended period of time, and during this period, the compressor 17 also continues to stop operating. Note that even when the compressor 17 is stopped, the fast idling device 7
continues to operate unless thermoswitch 12 is opened.

(Effects of the invention) As described above, according to this invention, after the acceleration of the engine is detected by the acceleration switch linked to the accelerator pedal, the electromagnetic clutch is disconnected for a predetermined period of time to stop the compressor operation. Although a cutting device is provided, the speed of the engine driven only by the command means is increased regardless of whether or not the acceleration cutting device is in operation. Therefore, even if the accelerator pedal is loosened to change gears while the compressor is stopped, the engine speed can be prevented from decreasing. Therefore, even if the compressor starts operating immediately after that, the engine speed will not be insufficient, so there will be less shock at the start of operation, the car will run smoothly, and the engine will not rotate smoothly or stall. It has the effect of disappearing.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a specific circuit example of the engine protection device according to this invention, Fig. 2 is a schematic diagram of the engine protection device according to this invention, and Fig. 3 shows the operation of the main parts of the same engine protection device. FIG. 2... Carburetor, 4... Throttle valve, 5... Accelerator pedal, 7... Fast idling device, 8... Acceleration switch, 13...
Electromagnetic clutch, 22...multivibrator circuit, 23...relay.

Claims (1)

[Scope of utility model registration request] In an automobile in which a compressor for compressing refrigerant is connected via an intermittent means to a driving engine whose output torque increases or decreases depending on the position of the accelerator pedal, there is provided an acceleration switch that interlocks with the accelerator pedal, and an acceleration switch that operates in conjunction with the accelerator pedal. an acceleration cut means for outputting a disconnection signal to the intermittent means to stop the compressor for a predetermined time from when the output is applied; a command means for outputting to the intermittent means to instruct driving of the compressor; and an output of the command means. 1. An engine protection device for an automobile equipped with a cooling device, characterized in that the engine protection device includes a first idle means for increasing the speed of the engine regardless of whether or not the acceleration cut means is activated when the engine is heated.