JP2600498Y2 - Idle control device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to idle control means for controlling an idle speed of an engine in a vehicle equipped with a cooling circuit (car cooler). It relates to the one using a machine.

(Conventional technology) In a vehicle equipped with a cooling circuit, the engine load increases during cooling operation, the idle speed decreases, and knocking occurs at the time of starting, because the compressor of the cooling circuit is driven by the engine. The engine may stop.

Normally, to prevent this decrease in idle speed,
The throttle valve of the fuel carburetor is slightly opened (idle-up) from the idle position in synchronization with the operation of the compressor, and the idle speed is adjusted to a specified value.

FIG. 8 shows a conventional idle adjustment mechanism for performing idle adjustment during cooling operation.

In the figure, 71 is a fuel carburetor, 72 is an intake pipe, and 73 is an actuator.

The actuator 73 is of a negative pressure operation type, and is a fuel vaporizer.
A diaphragm 73a spring-biased to the 71 side, a negative pressure chamber 73b defined on one side of the diaphragm 73a, and a diaphragm 73
and an operating rod 73c connected to a. The negative pressure chamber 73b of the actuator 73 communicates with the intake pipe 72 via a negative pressure pipe 75 having a normally closed solenoid valve 74.
73c is connected to the operation lever 71b of the throttle valve 71a of the fuel carburetor 71.

That is, in the above idle adjustment mechanism, the solenoid valve 74 is opened by a control circuit (not shown) in synchronization with the operation of the compressor of the cooling circuit, and the diaphragm 73a is moved to the negative pressure chamber 73b by the negative pressure transmitted through the negative pressure pipe 75. By deforming to the side,
By driving the operating lever 71b through the operating rod 73c, the throttle valve 71a can be slightly opened from the idle position (see a two-dot chain line in the figure).

(Problems to be Solved by the Invention) By the way, recent cooling circuits include a variable displacement compressor capable of adjusting a discharge capacity according to a heat load, for example, according to a low pressure circuit pressure between an evaporator and a compressor. Some compressors use a compressor in which a high-pressure gas compressed by a compressor is bypassed to a low-pressure side to change a discharge capacity.

In the above-described compressor, the discharge capacity is changed in accordance with the heat load, so that the load on the engine, that is, the idle speed of the engine is changed in accordance with the change in the discharge capacity.

However, when the above-described idle control is performed in the cooling circuit, the following problem occurs.

That is, as shown in FIG.
In the case of using a variable displacement compressor that changes in the range of, even if the idle-up is performed in synchronization with the operation of the compressor, the discharge capacity of the compressor decreases with a decrease in the heat load. The load on the engine decreases, the idle speed increases, and the engine speed greatly deviates from the specified idle speed.

This increase in idling speed not only causes the driver to feel uneasy, but also causes an accident, particularly in an auto-matched car, when the car suddenly jumps out when starting.

The present invention has been made in view of the above problems, and its purpose is to provide a vehicle equipped with a cooling circuit using a variable displacement compressor capable of adjusting a discharge capacity according to a heat load. It is an object of the present invention to provide a vehicle idle control device capable of maintaining a constant idle speed regardless of the displacement of a compressor.

(Means for Solving the Problems) In order to achieve the above object, claim (1) is a variable displacement type having a built-in capacity adjusting mechanism driven by an engine and capable of adjusting a discharge capacity according to a heat load by itself. An idle control device for a vehicle provided with a cooling circuit including a compressor, an engine speed detecting means for detecting an engine speed,
Valve opening means for opening the throttle valve of the fuel carburetor based on the idle position, and idle control means for adjusting the opening of the throttle valve in inverse proportion to the fluctuation of the engine speed to keep the engine idle at a constant value. It is characterized by having.

According to a second aspect of the present invention, in the vehicle idle control device according to the first aspect, the opening degree of the throttle valve by the valve opening means is changed stepwise.

(Operation) In the vehicle idle control device according to claim (1), when the heat load is large and the compressor is operated at the maximum capacity, and the load applied to the engine increases and the engine speed decreases, the fuel carburetor is activated. The throttle valve is released from the idle position, and the idle speed is kept constant. Also, when the discharge capacity of the compressor decreases with a decrease in heat load, the load on the engine decreases, and the engine speed increases, the opening of the throttle valve of the fuel carburetor decreases, and the idle speed increases. Is kept constant.

In the idle control device for a vehicle according to the present invention, the opening degree of the throttle valve is changed stepwise by the valve opening means, and the above-described adjustment of the idle speed is performed.

(Embodiment) FIGS. 1 to 7 show one embodiment of the present invention.
1 is a cross-sectional view of an idle adjusting mechanism, FIGS. 2 and 3 are explanatory diagrams of the operation of the idle adjusting mechanism, FIG. 4 is a configuration diagram of an idle control circuit, and FIG. 5 is a capacity adjustment built in a compressor. FIG. 6 is a time chart of the idle control, and FIG. 7 is a flowchart of the idle control.

First, a configuration of an idle adjustment mechanism capable of performing two-stage idle-up will be described with reference to FIG.

In the figure, 1 is a fuel carburetor, 2 is an intake pipe, and 3 and 4 are first and second actuators of a negative pressure operation type.

The first actuator 3 includes a hollow disk-shaped main body 3a, a diaphragm 3b arranged to divide the inside of the main body 3a into two,
A spring 3c for urging the diaphragm 3b toward the fuel carburetor 1;
Stopper 3d supporting the spring-biased diaphragm 3b
And a negative pressure chamber 3e defined on the left side of the diaphragm 3b, and an operating rod 3f connected to the diaphragm 3b and protruding into the fuel carburetor 1. The negative pressure chamber 3e of the first actuator 3 is connected to a negative pressure pipe 6 which communicates the negative pressure chamber 3e with one end of the normally closed first solenoid valve 5.

The second actuator 4 includes a main body 4a of the same shape connected to the main body 3a of the first actuator 3, a diaphragm 4b arranged so as to divide the inside of the main body 4a into two, and a diaphragm 4b.
4c for urging the first actuator 3 side, a stopper 4d for supporting a spring-biased diaphragm 4b, a negative pressure chamber 4e defined on the left side of the diaphragm 4b, and a first cylinder connected to the diaphragm 4b. The actuator 3 includes a stopper pin 4f projecting into the negative pressure chamber 3e of the actuator 3 and an adjustment screw 4g attached to the main body 4a. The negative pressure chamber 4e of the second actuator 4 is connected to a negative pressure pipe 8 that communicates the negative pressure chamber 4e with one end of a normally closed second solenoid valve 7.

Although not shown, the first and second actuators 3, 4
The negative pressure chambers 3e and 4e are both formed airtight using a sealing material or the like.

The other ends of the first and second solenoid valves 5 and 7 are connected to a negative pressure induction port 2 a of the intake pipe 2 via a collective negative pressure pipe 9.

On the other hand, a throttle valve 1a that opens and closes an internal flow path, a fuel supply pipe 1b, and an idle port (not shown) are provided inside the fuel carburetor 1. An operating lever 1c for rotating the throttle valve 1a is connected to the throttle valve 1a, and the operating lever 3f of the first actuator 3 is connected to the operating lever 1c.

Here, the operation of the idle adjustment mechanism will be described with reference to FIGS.

When opening the throttle valve 1a by one stage from the idle position, only the first solenoid valve 5 is opened in the state shown in FIG. As a result, as shown in FIG. 2, a negative pressure acts on the negative pressure chamber 3e of the first actuator 3 through the negative pressure pipes 6, 9, and the diaphragm 3b resists the urging force of the spring 3c, and the second actuator 4 side. The operating rod 3f is retracted into the main body 3a and the throttle valve 1a rotates by a predetermined angle in the opening direction.

When the throttle valve 1a is opened two stages from the idle position, the first and second solenoid valves 5, 7 are both opened in the state shown in FIG. As a result, as shown in FIG. 3, a negative pressure also acts on the negative pressure chamber 4e of the second actuator 4 through the negative pressure pipes 6, 9, and the diaphragm 4b resists the urging force of the spring 4c, and the adjustment screw 4g side. The stopper pin 4f is drawn into the main body 4a. This stopper pin
4f moves the diaphragm of the first actuator 3
3b further deforms the movement, the operating rod 3f is retracted into the main body 3a, and the throttle valve 1a rotates at a larger angle in the opening direction.

As described above, in the idle adjustment mechanism, the throttle valve 1a can be opened one stage from the idle position by opening only the first solenoid valve 5, and the first and second solenoid valves 5, 7 can both be opened. Thus, the throttle valve 1a can be opened two stages from the idle position. That is, by selectively opening the first and second solenoid valves 5 and 7, the throttle valve 1a of the fuel carburetor 1 can be opened in two stages from the idle position.

Next, the configuration of the idle control circuit will be described with reference to FIG.

In the figure, 11 is an operation switch of a cooling circuit mounted on a vehicle, 12 is a temperature setter for setting a cooling temperature made up of a variable resistor, 13 is a temperature sensor for detecting the temperature inside the car made up of a thermistor, and 14 is an engine speed. Detecting section, 15 is a shift position detecting section, 16 is a control section having a microcomputer configuration, 17 is an electric clutch for connecting the engine E and the variable displacement compressor C, and 18 is a driving section for supplying driving power to the electric clutch 17. Reference numeral 19 denotes a drive unit for supplying drive power to the first and second solenoid valves 5 and 7.

The engine speed detector 14 can transmit the engine speed to the control unit 16 as a predetermined electric signal, for example, a voltage value, based on an ignition signal obtained from an ignition unit of the engine E.

Further, the shift position detecting unit 15 sends a signal to the control unit 16 for distinguishing whether the shift position is in the P, N range or other range based on the detection signal from the position sensor provided in the shift unit S of the automatic vehicle. It can be sent.

The control unit 16 stores an idle control program in a memory, and includes an operation switch 11, a temperature setting unit 12, a temperature sensor 13, an engine speed detection unit 14, and a shift position detection unit 1.
Based on the operation signal or the detection signal of 5, a control signal is sent to each of the driving units 18 and 19 according to a program described in detail later.

On the other hand, the variable displacement compressor C is of a scroll type,
It has a built-in capacity adjustment mechanism Ca that can adjust the discharge capacity by itself within the range of 100 to 40% according to the heat load.

Here, the configuration and operation of the capacity adjusting mechanism Ca will be described with reference to FIG.

The capacity adjusting mechanism Ca is disposed between the suction chamber and the discharge chamber of the scroll compressor C, and is arranged in the adjustment chamber Ca1 with a spring bias toward the discharge chamber as shown in FIG. 5 (a). Piston-type control valve Ca2, a hollow Ca3 formed through the inside of the control valve Ca2, an expandable bellows Ca4 with a lower end fixed to the hollow Ca3, and a bellows side at the top of the hollow Ca3. And a ball valve Ca5 which is arranged to be urged by a spring and opened by extension of the bellows Ca4.

In the capacity adjusting mechanism Ca, as shown in FIG. 5 (a), when the heat load is large with respect to the rotation speed of the compressor C and the suction pressure is larger than the set pressure, the bellows Ca4 contracts, and the ball valve Ca5 The control valve Ca2 is closed to increase the pressure above the control valve Ca2, and the depressing force due to the pressure overcomes the spring urging force of the control valve Ca2 to close the bypass passage and operate at the maximum capacity. On the other hand, as shown in FIG. 5 (b), when the heat load is small with respect to the rotation speed of the compressor C and the suction pressure becomes lower than the set force, the bellows Ca4 expands, and the ball valve Ca5 is pushed up by the bellows Ca4. Can be As a result, the high-pressure gas filling the upper portion of the control valve Ca2 leaks to the suction chamber side through the cavity Ca3 of the control valve Ca2, and the spring urging force of the control valve Ca2 overcomes the control valve Ca2.
Opens to bypass the high pressure gas and reduce the discharge capacity.
When the heat load is further reduced, the ball valve Ca5 and the control valve Ca are greatly opened, the bypass amount is increased, and the discharge capacity is further reduced.

Next, control of the idle speed (idle control) during the cooling operation will be described with reference to FIG. 6 and FIG.

First, at the same time when the operation switch 11 of the cooling circuit is turned on, it is determined whether the shift position of the shift unit S is the P, N range or any other range based on the detection signal from the shift position detection unit 15 (steps 1 and 2). .

If it is determined in step 2 that the shift position is in the P, N range, then the electric clutch 17 is operated to connect the compressor C and the engine E (step 3), and the first and second idle adjustment mechanisms are started. The second solenoid valves 5 and 7 are both opened to open the throttle valve 1a of the fuel carburetor 1 from the idle position by two stages (step 4).

That is, since the heat load is large immediately after the start of cooling and the compressor C operates at the maximum capacity, the throttle valve 1a is opened in two stages in anticipation of the load applied to the engine E at this time, and the engine speed is kept at a specified value. To do. Actually, the engine speed is slightly increased by the above idle up, for example,
It rises from 850 rpm to around 900 rpm.

Since the discharge capacity of the compressor C gradually decreases in accordance with the heat load by the function of the capacity adjusting mechanism Ca, the load on the engine E decreases, and the engine speed increases in inverse proportion.

After the throttle valve 1a is opened by two stages, it is determined whether or not the rotation speed Ne of the engine E has become, for example, 1400 rpm or more based on the detection signal from the engine rotation speed detection unit 14 (step 5).

When the rotation speed Ne of the engine E becomes 1400 rpm or more due to the opening of the throttle valve 1a in two stages, only the first solenoid valve 5 of the idle adjustment mechanism is opened and the throttle valve 1a of the fuel carburetor 1 is opened in one stage. It is returned to the position and its opening is reduced (step 6).

That is, when the engine speed is excessively increased due to the two-stage idle-up, the opening degree of the throttle valve 1a is reduced to keep the engine speed Ne at a specified value.

In step 5, the rotation speed Ne of the engine E is 1400 rpm.
If not, the process proceeds to step 8 described later.

After returning the throttle valve 1a to the one-stage open position, based on a detection signal from the engine speed detector 14,
It is determined whether or not the rotation speed Ne of the engine E is less than, for example, 900 rpm (step 7).

If the rotation speed Ne of the engine E drops to less than 900 rpm in the one-stage idle-up state, the process returns to step 4 to adjust the engine rotation speed Ne.

If the rotation speed Ne of the engine E is equal to or higher than 900 rpm in step 7, then the in-vehicle temperature t detected by the temperature sensor 13 is reduced to the lower limit value TL of the set temperature (the set temperature −0.5 ° C. set by the temperature setter 12). Are compared (step 8).

If the vehicle interior temperature t is higher than the set temperature lower limit value TL,
Returning to step 2, the same idle control as described above is performed.

If the in-vehicle temperature t is equal to or lower than the lower limit value TL of the set temperature, the electric clutch 15 is released to stop the operation of the compressor C, and the throttle valve 1a is returned to the idle position (steps 9, 10). ).

Thereafter, it is determined whether or not the interior temperature t is equal to or higher than the upper limit value TH of the set temperature (the set temperature set by the temperature setting device 12 + about 0.5 ° C.) (step 11), and the interior temperature t is set. If the temperature is equal to or higher than the upper limit value TL, the process returns to step 2
The same idle control as described above is performed.

If it is determined in step 2 that the shift position is in a range other than the P and N ranges, then the electric clutch 17 is operated to connect the compressor C and the engine E, and the fuel carburetor The first throttle valve 1a is opened two stages from the idle position (steps 12 and 13), and the routine proceeds to step 8.

That is, when the shift position is in a range other than the P and N ranges, unlike the case where the shift position is in the P and N ranges, the throttle valve 1a of the fuel carburetor 1 is synchronized with the operation of the compressor C. The idle control is performed in a state in which is opened two stages from the idle position.

As described above, in the above embodiment, when the heat load is large and the compressor C operates at the maximum capacity, and the load on the engine increases and the rotation speed of the engine E decreases, the fuel carburetor 1
By opening the throttle valve 1a two stages from the idle position, the idle speed can be kept almost constant, and the discharge capacity of the compressor decreases as the heat load decreases, and the load on the engine decreases. When the engine speed increases, the opening of the throttle valve 1a of the fuel carburetor 1 can be made smaller than the above to keep the idle speed substantially constant.

That is, even when the discharge capacity of the compressor C changes arbitrarily in accordance with the heat load and the load applied to the engine fluctuates, the throttle valve 1a of the fuel carburetor 1 operates in accordance with the fluctuation in the engine speed due to the load fluctuation. By adjusting the opening, the idle speed can be kept substantially constant. Therefore, it is possible to eliminate the driver's feeling of anxiety due to the abnormal increase in the idling speed, and to surely prevent sudden start of the auto-matching vehicle.

In the embodiment, the throttle valve is configured to be opened in two stages from the idle position as the idle adjustment mechanism. However, a throttle valve that can be opened in three or more stages or steplessly is employed, and the engine speed is varied. It may be possible to perform an idle-up adapted to the above. Also,
The scroll-type compressor shown as a variable-capacity compressor capable of adjusting the discharge capacity according to the heat load may be replaced with another compressor having the same function. Further, in the embodiment, the content of the idle control is changed according to the shift position. However, the same idle control may be performed regardless of the shift position. Furthermore, in the embodiment, an example in which the present invention is applied to an auto-matching vehicle is shown.
Similar effects can be obtained with other vehicles of the manual specification.

(Effects of the Invention) As described in detail above, according to the vehicle idle control device described in claim (1) or (2), the discharge capacity of the compressor changes arbitrarily in accordance with the heat load, and the engine is controlled. Even when the load fluctuates, the idle speed can be kept substantially constant by adjusting the opening of the throttle valve of the fuel carburetor according to the fluctuation of the engine speed due to the load fluctuation.

[Brief description of the drawings]

1 to 7 show an embodiment of the present invention. FIG. 1 is a sectional view of an idle adjusting mechanism, FIGS. 2 and 3 are explanatory views of the operation of the idle adjusting mechanism, and FIG. FIG. 5 is a configuration diagram of an idle control circuit, FIG. 5 is an operation explanatory diagram of a capacity adjusting mechanism built in the compressor, FIG. 6 is a time chart of idle control, and FIG. 7 is a flowchart of idle control. 8 and 9 show a conventional example. FIG. 8 is a schematic diagram of an idle adjustment mechanism, and FIG. 9 is a time chart of idle control. In the drawing, 1 ... fuel carburetor, 1a ... throttle valve, 3 ... first actuator, 4 ... second actuator, 5 ... first
Solenoid valve, 7: second solenoid valve, 14: engine speed detection unit,
16: control unit, 18, 19: drive unit, E: engine, C: compressor, Ca: capacity adjustment mechanism.

Claims (2)

(57) [Scope of request for utility model registration] An idle control device for a vehicle including a cooling circuit including a variable displacement compressor driven by an engine and having a capacity adjusting mechanism capable of adjusting a discharge capacity according to a heat load. An engine speed detecting means for detecting an engine speed; a valve opening means capable of opening a throttle valve of a fuel carburetor based on an idle position; and an opening degree of a throttle valve in inverse proportion to a change in engine speed. Idle control means for adjusting the idle rotation of the engine to a constant value by adjusting the idle speed of the engine. 2. The idle control device for a vehicle according to claim 1, wherein the opening degree of the throttle valve is changed stepwise by the valve opening means.