JPH0221965B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is equipped with an internal combustion engine as a driving force,
The present invention relates to a car air conditioner control device applied to a car air conditioner that obtains the driving force of a refrigerant compressor of an air cooling system through an intermittent coupling device from the internal combustion engine and is used as at least an air conditioner, and particularly relates to an internal combustion engine. The aim is to appropriately control the idle rotational speed of an internal combustion engine according to the operating state of a refrigerant compressor that is a load on the engine.

[Conventional technology]

Conventionally, a typical car air conditioner control device has a refrigerant compressor that is connected intermittently via a coupling device, and is configured to operate the air cooling device intermittently. In this case, as in Japanese Patent Publication No. 56-21895, mechanical load is applied to the internal combustion engine when the compressor is in operation, so the mixture supply system of the internal combustion engine is activated in conjunction with the energization of the coupling device. It is customary to additionally provide a so-called idle-up mechanism which acts to increase the idle speed.

On the other hand, as disclosed in Japanese Patent Publication No. 56-7079, it is also generally known to use a compressor that can change the compression capacity in stages, and to change this compressor according to the load required for the refrigeration cycle. was.

The present applicant previously proposed a refrigeration cycle control device for automobiles using such a stepwise variable capacity compressor in Japanese Patent Application No. 112427/1983.

[Problem to be solved by the invention]

However, when the above-mentioned stepwise variable capacity compressor is driven by an internal combustion engine for driving an automobile, the following problems occur.

In other words, in conventional car air conditioners, the idle rotational speed is increased when the coupling device that connects the compressor and internal combustion engine is energized (when they are connected), so the compressor operates at a small capacity in this idle up state. In this case, a large cooling effect is not required to begin with (compressor rotational speed does not need to be that high), and even though the power required to drive the compressor is small, the idle rotational speed may be increased more than necessary. This caused the fuel consumption of the internal combustion engine to deteriorate.

On the other hand, if the rotation speed is lowered in the idle state, a large cooling effect is required when the compressor is operating at a large capacity, and the power required to drive the compressor is also large. However, the idle rotation speed was not sufficiently increased, resulting in insufficient cooling and engine stalling.

In view of these problems, the present invention electrically controls the stepwise capacity switching of the variable capacity compressor and the intermittent connection of the coupling device, and also controls the idle rotation speed in steps according to the capacity of the compressor. The purpose of this invention is to provide a car air conditioner control device that can control the air conditioner and obtain an appropriate cooling effect even in an idling state, and does not cause deterioration in fuel efficiency or stalling of an internal combustion engine.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a compressor that supplies refrigerant to an air cooling device that cools air supplied into a vehicle interior, and whose compression capacity can be switched to at least two stages, large capacity and small capacity; a coupling device for intermittent transmission of power from a running internal combustion engine to the compressor; and a coupling device for controlling the idle rotational speed of the internal combustion engine to a first rotational speed greater than a base rotational speed and a second rotational speed greater than the first rotational speed. an idle adjustment device that selectively increases speed; and an idle adjustment device that electrically controls on/off of power transmission by the coupling device and switching between a large capacity and a small capacity of the compressor; control means for controlling the idle adjustment device to select the second rotational speed when a capacity is selected and to select the first rotational speed when the small capacity is selected.

Adopt technical means.

[Effect]

According to the configuration of the present invention described above, the coupling device and the idle adjustment device for the compressor are controlled by the control means.

Here, the control means increases the rotational speed of the internal combustion engine to a first rotational speed when the compressor has a small capacity while power is being transmitted by the coupling device, and increases the rotational speed of the internal combustion engine to a first rotational speed when the compressor has a small capacity. The compressor is rotated at a rotation speed that generates torque suitable for driving and provides a cooling effect suitable for a small capacity.

The control means increases the rotational speed of the internal combustion engine to a second rotational speed that is higher than the first rotational speed when the compressor has a large capacity while the power is being transmitted by the coupling device. Generates torque suitable for driving the compressor at capacity.

〔Example〕

The present invention will be described below with reference to embodiments shown in the accompanying drawings. In FIG. 1 showing the overall configuration of this device, reference numeral 1 denotes a variable capacity refrigerant compressor, which is equipped with a mechanism 2 that adjusts the refrigerant discharge capacity per stroke into two stages: large capacity and small capacity. . The adjustment mechanism 2 sets the compressor 1 to full capacity (first capacity) when a solenoid valve provided in a bypass passage (not shown) of the compressor is deenergized and closed, and when the solenoid valve is energized and opened. It is configured to have half the capacity (second capacity). Reference numeral 3 denotes a connecting device, which is a so-called electromagnetic clutch, which connects the rotational force of an output shaft of an internal combustion engine (not shown) to the compressor 1 via a V-belt when energized.

To explain an air cooling system having a compressor 1, the refrigerant discharged from the compressor 1 passes through a condenser 4, a receiver 5, an expansion valve 6, and an evaporator 7, and returns to the compressor 1 through a refrigerant circulation cycle (refrigeration cycle). It circulates, and in this circulation process, it is compressed and expanded, and the heat of vaporization is removed in the evaporator 7, thereby lowering the surface temperature of the evaporator 7 and the surrounding temperature.

The evaporator 7 is disposed across the interior of the air conditioning unit 8 and placed in an air stream directed toward the passenger compartment, generated by a blower 9 energized by an electric motor 10 . Although the air conditioning unit 8 functions as a cooling device as shown, it can also be used as a temperature control device with a dehumidifying function by providing an air mic type heating amount adjustment mechanism downstream of the evaporator 8 if necessary.

In this apparatus, a variable capacity compressor 1 is provided with an electric control circuit 11 so that its capacity is adjusted according to the degree of cooling of the evaporator 7.
For this purpose, the electric control circuit 11 is connected to a temperature sensor 12 that responds to the temperature of the air blown from the evaporator 7 (the surface temperature may be used if necessary), and in response to the detection signal of the temperature sensor 12, the connecting device 3 is attached. A first output signal S1 indicating energization or deenergization, and a second output signal S2 indicating the stage of compressor capacity are output. The temperature sensor 12 is made of, for example, a temperature-dependent resistance element such as a thermistor. The electric control circuit 11 energizes this resistance element and compares the voltage generated at both ends with a plurality of preset reference voltages, thereby generating the first output signal S1 and the second output signal S1.
produces an output signal S2. Although detailed electrical processing in the electrical control circuit 11 is omitted, it can be realized using ordinary electronic technology.

Therefore, the electric control circuit 11 is connected to the temperature sensor 12.
The detection signal deactivates the first output signal S1 when the temperature of the evaporator 7 is lower than the set value indicating the lowest reference temperature (for example, 0° C. to 4° C.), and when the temperature has risen above it, the detection signal deactivates the first output signal S1. Activate the first output signal S1.
Further, the electric control circuit 11 deactivates the second output signal S2 when the detection signal of the temperature sensor 12 indicates that the temperature of the evaporator 7 is lower than a set value indicating an intermediate reference temperature (for example, 7° C. to 11° C.).

Therefore, when comparing the operation of the variable displacement compressor 1 with the degree of cooling of the evaporator 7, if the temperature of the evaporator 7 rises above the intermediate reference temperature,
Since the coupling device 3 is energized and the solenoid valve of the regulating mechanism 2 is deenergized, the compressor 1 is operated at full capacity and cools the evaporator 7 at its maximum capacity. If the temperature of the evaporator 7 is below the intermediate reference temperature and above the minimum reference temperature, the coupling device 3 is energized and the solenoid valve of the regulating mechanism 2 is energized. Therefore, the compressor 1 is operated at half capacity and cools the evaporator 7 at an intermediate capacity. Further, when the temperature of the evaporator 7 falls below the minimum reference temperature, the coupling device 3 is deenergized and disconnected from the internal combustion engine, and the evaporator 7 stops its cooling action.

Power is supplied to the electric control circuit 11 from a DC battery 13 mounted on the vehicle to a switch 14 linked to a key switch.
and a switch 15 that is linked to the operating switch of the car air conditioner.

Next, a description will be given of an adjustment device for raising the idle rotational speed of the internal combustion engine above the base rotational speed. Reference numeral 16 denotes a flow rate adjustment valve, and a bypass passage 17 bypasses a throttle valve (not shown) of the internal combustion engine.
It is located in The opening degree of the control valve 16 is determined by a link mechanism 18B that moves in response to the displacement of the output rod of the negative pressure actuator 18. The negative pressure actuator 18 is configured to be capable of suctioning the output rod in two stages from a specified position (extended state). Therefore, when the output rod is now at the specified position, the flow rate regulating valve 16 is at the base opening degree, and the idle rotational speed of the internal combustion engine is the base rotational speed.

As will be explained in detail later with reference to FIG. 3, the negative pressure actuator 18 is separated into two systems, each connected to a solenoid valve 1.
When the solenoid valve 19 is energized and opened, the output rod is sucked into the first stage, and when both the solenoid valves 19 and 20 are energized and opened, the output rod is further pulled into the first stage. It is configured to suck in two stages. Then, by the energization of the solenoid valve 19, the flow rate adjustment valve 16 is opened by one step from the base state, and furthermore, both the solenoid valves 19, 2
0, the flow rate regulating valve 16 is further opened by one step, so by selectively energizing the solenoid valves 19 and 20, the flow rate of the bypass passage can be selected in three steps including the base value. Can be done.

Reference numeral 22 indicates a connection circuit between the electric control circuit 11 and the electromagnetic valves 19 and 20. In this connection circuit 22, the energizing circuit of the solenoid valve 19 is used to energize the coupling device 3,
It is connected at a node C1 to a transmission line for a first output signal S1 that determines de-energization. Also, the solenoid valve 20
The energizing circuit is connected to the energizing circuit of the solenoid valve 19 via a normally closed relay contact 23. The relay contact 23 is opened by energizing a relay coil 24, and the relay coil 24 is connected in parallel so that it is energized and deenergized under the same conditions as the second output signal. Note that the connection circuit 22 can be housed together with the electrical control circuit 11 in a common electrical circuit package.

The structural feature of this device is that the electric control circuit 11
The first output signal S1 and the second output signal
According to the output signal S2, the coupling device 3 is switched on and off;
Furthermore, the solenoid valves 19 and 20 are selectively energized by the connection circuit 22 at the same time as the capacity of the compressor 1 is adjusted in two stages. For this reason, the opening degree of the flow rate adjustment valve 16 is adjusted depending on whether the compressor 1 is operating at full capacity or at half capacity.
It is possible to open the valve in two further stages from the base state, thereby increasing the idle rotation speed by two stages.

That is, when the degree of cooling detected by the temperature sensor 12 indicates a sufficiently cooled state, the coupling device 3 is deenergized by the first output signal S1, and in this case both the solenoid valves 19 and 20 are also deenergized. , the idle rotation speed is the base rotation speed.

Next, when the degree of cooling is approximately intermediate, the first output signal S1 energizes the coupling device 3, and at the same time, the solenoid valve 19 is energized. Furthermore, the solenoid valve of the adjustment mechanism 2 is energized by the second output signal S2, and the compressor 1 is operated at half capacity. In this case, the solenoid valve 20 remains deenergized because the relay coil 24 is also energized and the relay contact 23 is opened. Therefore, the opening degree of the flow rate regulating valve 16 becomes a value corresponding to the first stage suction of the negative pressure actuator 18, and the idle rotational speed of the internal combustion engine is increased to the first stage.

Next, when the degree of cooling is completely insufficient, the second output signal S2 is deenergized while the coupling device 3 is energized by the first output signal S1, and the solenoid valve of the adjustment mechanism 2 is deenergized. Therefore, the compressor 1 is operated at full capacity. In this case, relay coil 24 is deenergized, so that relay contacts 23 are closed, so that solenoid valves 19 and 20 are energized. Therefore, the opening degree of the flow rate regulating valve 16 becomes a value corresponding to the second stage suction of the negative pressure actuator 18, and the idle rotational speed of the internal combustion engine is increased to the second stage.

In the above embodiment, it is naturally possible for the electric control circuit 11 to set hysteresis when setting the lowest reference temperature and the intermediate reference temperature, and the second
The figure shows the operating characteristics of this device when hysteresis is set. t1 and t2 are the lowest reference temperatures, and t
3, q4 indicates the intermediate reference temperature.

The configuration of the negative pressure actuator 18 will be explained with reference to FIG. 25, 26, 27 are metal cases,
Two diaphragms 28 and 29 are caulked and fixed. The diaphragms 28 and 29 are made of polyester fiber or the like covered with a rubber-like elastic material. 30 is a coil spring for returning the first diaphragm 28;
1 is a coil spring for returning the second diaphragm 29; Also, 32 and 33 are the diaphragms 2, respectively.
A movable member 34 is fixed to the support member 32 and slidable with respect to the support member 33. A movable member 34 is provided between the support members 32 and 33. A space partitioned by the first diaphragm 28 and the case 27 constitutes a first negative pressure member 35, and the first diaphragm 28, the case 26, and the second diaphragm 29
The space partitioned by the second negative pressure space 36
, and each negative pressure medium communicates with the electromagnetic valves 19 and 20 via conduits 37 and 38.

In the above configuration, when the electromagnetic valve 19 is opened, the first negative pressure chamber 35 is opened as shown in FIG.
Negative pressure is introduced into the first diaphragm 28, and the output rod 18A is moved by a first stroke St1. Furthermore, when the solenoid valve 20 is also opened, negative pressure is introduced into both the first negative pressure chamber 35 and the second negative pressure chamber 36, as shown in FIG. Both diaphragms 29 are attracted and the output rod 18A is moved by the second stroke St1. In this case, by sliding the movable member 34 with the support member 33, the acting forces of the two negative pressure chambers can be applied in two stages.

In the above-mentioned embodiments, the variable capacity compressor has been described as having the full capacity when the adjustment mechanism is de-energized, but the present invention can also be applied to a variable-capacity compressor that attains the full capacity when the adjustment mechanism is energized. For example, in the configuration shown in FIG. 1, if the adjustment mechanism 2 is set to full capacity when energized, the relay setting 23 is set to the relay coil 2.
It is only necessary to use a normally closed contact that closes when energized in step 4.

Further, in the present invention, it is not important how much the capacitance is reduced, and it goes without saying that it can be set to an appropriate value. Further, the control parameter for adjusting the capacity is not limited to the temperature of the evaporator 7, but may be a means that responds to the evaporation pressure, such as a pressure switch, or may be made to depend on the air temperature in each room or the outside air temperature. .

〔Effect of the invention〕

As described above, according to the present invention, the idle rotation speed of the internal combustion engine that drives the variable displacement compressor can be adjusted according to the compression capacity of the variable displacement compressor, and the cooling effect can be improved in the idle state of the internal combustion engine. This has the excellent effect of not causing excess or deficiency of fuel, and preventing deterioration of fuel efficiency or engine stalling.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of its operation, and FIG. 3 is a sectional view showing the configuration of a negative pressure actuator 18. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Adjustment mechanism, 3... Connection device, 7... Evaporator, 11... Electric control circuit, 16... Flow rate adjustment valve, 18... Negative pressure actuator,
22... Connection circuit.

Claims (1)

[Scope of Claims] 1. A compressor for supplying refrigerant to an air cooling device that cools air supplied into a vehicle interior, and capable of switching the compression capacity into at least two stages of large capacity and small capacity, and for use in driving an automobile. a coupling device for intermittent transmission of power from an internal combustion engine to the compressor; an idle adjustment device for increasing the speed; and electrically controlling on/off of power transmission by the coupling device and switching between large capacity and small capacity of the compressor, and selecting the large capacity while transmitting power by the coupling device. and control means for controlling the idle adjustment device to select the second rotation speed when the small capacity is selected, and select the first rotation speed when the small capacity is selected. Device. 2. The control means includes a detection means for detecting the degree of cooling of the evaporator that is supplied with refrigerant by the compressor and cools the air; and a detection means for detecting the degree of cooling of the evaporator that cools the air by supplying refrigerant by the compressor; cut off the transmission,
a first control means for continuing power transmission by the coupling device when the degree of cooling exceeds the first degree of cooling, and lowers the capacity of the compressor to exceed the second degree of cooling when the degree of cooling exceeds the first degree of cooling and falls below a second degree of cooling set in advance; when the second control means increases the capacity of the compressor; and when the second control means decreases the capacity of the compressor in a state where the first control means continues power transmission by the coupling device; and third control means for controlling the idle adjustment device to select the first rotation speed and to select the second rotation speed when the compressor has a large capacity. A car air conditioner control device according to scope 1. 3. The third control means selects the first rotation speed when the first control means continues power transmission by the coupling device, and selects the first rotation speed when the second control means increases the capacity of the compressor. 3. The car air conditioner control device according to claim 2, wherein the device is configured to control the idle adjustment device to select two rotational speeds.