JPH09277820A - Air-conditioning device for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability and quietness of a compressor by starting a motor-driven compressor after opening a bypass opening and closing a valve for a specified time in starting it. SOLUTION: In operating air conditioner in a vehicle room, an opening and closing valve 12 is opened to thereby allow refrigerant to flow in a bypass circuit 11, and after the lapse of a specified time the valve 12 is closed to thereby prevent the refrigerant from flowing in the circuit 11. Under the condition where the refrigerant flows in the circuit 11, there is no difference between the discharge pressure and suction pressure of a motor-driven compressor 1. Accordingly the start-up can be made from the equalized pressure condition, there is less load on the compressor 1 to thereby assure a smooth operation, resulting in improvement in the reliability and quietness of the compressor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-conditioning control system for an electric vehicle that air-conditions the interior of the electric vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 2, an air conditioner control device for an electric vehicle according to a conventional embodiment has an electric compressor 1.
A refrigerant expansion device 4, a vehicle exterior air heat exchanger 2, a vehicle exterior air heat exchanger blower 3, a vehicle interior air heat exchanger blower 6, and the vehicle interior air heat exchanger blower 6. A ventilation circuit 9 connecting the vehicle interior air outlets 8, a vehicle interior air heat exchanger 10 arranged in the ventilation circuit 9, the electric compressor 1, the vehicle exterior air heat exchanger 2, and the vehicle interior air A refrigerant pipe 5 connecting the heat exchanger 10 and the refrigerant expansion device 4, and a bypass circuit 1 connecting the discharge side and the suction side of the electric compressor 1.
1 and an on-off valve 12 arranged in the bypass circuit 11
And an air conditioning control means 7 for controlling the number of rotations of the electric compressor 1 and the on-off valve 12.

FIG. 3 is a flow chart for performing differential pressure activation prevention control of the compressor in the conventional electric vehicle air conditioning control device of FIG.

In FIG. 3, when the air conditioning in the passenger compartment is stopped (step 201), the electric compressor 1 is first stopped (step 202), and the on-off valve 12 is driven to bypass the bypass circuit 1.
1 is opened (step 203).

By this control, the pressure difference between the discharge pressure and the suction pressure can be eliminated when the air conditioning in the room is stopped, so that when the electric compressor 1 is restarted, it can be started in a state where there is no pressure difference.

[0006]

When air-conditioning an electric vehicle, there is a large pressure difference between the discharge pressure and the suction pressure immediately after the electric compressor is stopped. There is no difference. If left unattended, it will take 1-2 hours.

When the electric compressor is started, if there is a pressure difference between the discharge pressure and the suction pressure of the electric compressor, the electric compressor may be loaded and may not be started. Further, even if it can be started, it is forcibly driven, so there is a possibility that the internal mechanism of the electric compressor may be damaged.

Further, since the inside of the electric compressor is a sliding component and is most easily worn and damaged, which leads to poor cooling, it is necessary to ensure the reliability of the electric compressor. Furthermore, since electric vehicles are driven by motors, the interior space is quite quiet, and quietness is required even when driving air-conditioning parts.

However, in the case of the control for eliminating the pressure difference when the air conditioning is stopped as in the above-mentioned conventional case, when the key peculiar to the vehicle is removed and both the air conditioning and the vehicle are stopped, the control power supply is lost thereafter, so that the electric compressor Although it stops, the on-off valve for bypassing cannot be controlled and the pressure difference cannot be eliminated.

[0010] In the case of a car, it may frequently occur that the engine is restarted after a few minutes, but in such a case, the pressure difference is still left, so the electric compressor should be turned on. Difficult to start.

Further, immediately after the compressor is stopped, there is a large pressure difference between discharge and suction. If the on-off valve is opened in this state to equalize the pressure, the high-pressure refrigerant abruptly flows into the low-pressure state, and a considerably loud noise is generated. The sound is transmitted to the indoor heat exchanger and is heard in the room.

[0012] The present invention solves the above-mentioned conventional problems, and improves the reliability of the compressor, and at the same time, it can realize the improvement of the comfort in the passenger compartment while measuring the quietness. The purpose is to provide a device.

[0013]

In order to solve the above problems, the present invention has a control means for starting the electric compressor after opening the bypass opening / closing valve only for a predetermined time when starting the electric compressor. It is a thing.

As described above, the control for eliminating the pressure difference when operating the air conditioner can always start the electric compressor from the pressure equalized state.

[0015]

A first aspect of the present invention is an electric compressor, a bypass circuit connecting a discharge side and a suction side of the electric compressor, an opening / closing valve arranged in the bypass circuit, Air-conditioning control means for controlling the drive of the electric compressor and for controlling the opening / closing valve, and control means for starting the electric compressor after opening the bypass opening / closing valve only for a predetermined time when starting the electric compressor. Is provided.

Therefore, the electric compressor can be brought into a pressure equalizing state at the time of starting.

[0017]

An embodiment of the present invention will be described below with reference to the drawings.

The block diagram of the air-conditioning control device for an electric vehicle according to the present invention is the same as the block diagram of the prior art shown in FIG. 2, and therefore its explanation is omitted and the control contents of the air-conditioning control means 7 will be explained.

FIG. 1 is a control flow chart for performing differential pressure activation prevention control of a compressor of an embodiment in an electric vehicle air conditioning control device.

In FIG. 1, when the air conditioning in the room is operated (step 101), the on-off valve 12 is opened so that the refrigerant flows to the bypass circuit 11 (step 10).
2) It is determined whether or not a predetermined time has passed (step 103). If the predetermined time has not passed, the on-off valve 12 is continuously opened, and if the predetermined time has passed, the on-off valve 12 is turned on. As a closed state, the bypass circuit 11
Then, the refrigerant does not flow (step 104), and then the electric compressor 1 is driven.

Therefore, before the electric compressor 1 is driven to drive the air conditioning in the room, the on-off valve 12 is always opened so that the refrigerant flows through the bypass circuit 11. There is no pressure difference between the discharge pressure and the suction pressure of the machine 1. In other words, even when the key is removed to stop the air conditioning and the engine is restarted after a few minutes, the operation can be started from the pressure equalized state.

Therefore, since the load on the electric compressor 1 is reduced and the electric compressor 1 can be operated smoothly, the reliability of the electric compressor 1 can be improved.

Further, the pressure equalization is not performed immediately after the electric compressor 1 is stopped, but at least after some time has passed, or after a considerable time has passed, the pressure difference becomes small. It is in a state of being. Therefore, since the refrigerant does not suddenly flow from the discharge of the electric compressor 1 to the suction, noise is less likely to be generated and quieter air conditioning control can be realized.

[0024]

As is apparent from the above-mentioned embodiment, claim 1
In the invention described in (1), since the on-off valve is always opened and the refrigerant flows to the bypass circuit before the electric compressor is driven to operate the air conditioning in the room, the discharge pressure and the suction pressure of the electric compressor are There will be no pressure difference.

In other words, remove the key to stop air conditioning, and
The operation can be started from the pressure equalized state even when the engine is restarted after a lapse of minutes. Therefore, the load on the electric compressor is reduced and it can be operated smoothly,
The reliability of the electric compressor can be improved.

Further, the pressure equalizing state is not set immediately after the electric compressor is stopped, but at least after some time has passed or after a considerable time has passed and the pressure difference is small. Is. Therefore, since the refrigerant does not suddenly flow from the discharge to the suction of the electric compressor, noise is less likely to be generated and quieter air conditioning control can be realized.

[Brief description of drawings]

FIG. 1 is a flowchart of control of an air conditioning control device for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an air-conditioning control device for an electric vehicle in a conventional example.

FIG. 3 is a flowchart of control of an air-conditioning control device for an electric vehicle in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric compressor 2 Air-heat exchanger outside vehicle compartment 3 Air blower for air heat exchanger outside vehicle 4 Refrigerant expansion device 5 Refrigerant piping 6 Air blower for air heat exchanger in vehicle interior 7 Air conditioning control unit 8 Air outlet for vehicle 9 Ventilation circuit 10 vehicle Indoor air heat exchanger 11 Bypass circuit 12 Open / close valve

Claims (1)

[Claims] 1. An electric compressor, a bypass circuit connecting a discharge side and a suction side of the electric compressor, an on-off valve arranged in the bypass circuit, a drive of the electric compressor, and the opening / closing. An electric vehicle, comprising: an air conditioning control means for controlling a valve; and a control means for starting the electric compressor after opening the bypass opening / closing valve only for a predetermined time when starting the electric compressor. Air conditioning control device.