JPH07266848A - Air conditioner for electric vehicle - Google Patents

Abstract

PURPOSE:To substantially shorten time in which high pressure balances with low pressure in a refrigerant circuit to enable a compressor to be restarted in a short time after stopping the compressor by providing a four-way valve controlling means for changing over the four-way valve to a reversing cycle for a certain time after the stop of the compressor. CONSTITUTION:When a compressor stopping signal 30 generated according to the operation of a running switch, running mode change-over switch or the like, the operation of a high pressure cut switch or the like is inputted to a four-way valve controlling means 31, a control signal for changing over the four-way valve 2 in the opposite direction to the prior cycle direction, i.e., the reverse direction is outputted by an on-off determining means 32 to a delaying means 33. Then, after a delaying time, for example 30secs, set to the delaying means 33 previously elapses, a solenoid coil 34 is electrified to change over the four-way valve 2 to the reverse direction over the set time of a timer 35. Thus, high pressure gas in a refrigerant circuit communicates to low pressure gas through the four-way valve 2 so that the high pressure balances quickly with the low pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an electric vehicle.

[0002]

2. Description of the Related Art A schematic configuration of a conventional air conditioner for an electric vehicle is shown in FIG. An inside air inlet 13 and an outside air inlet 14 are formed on the upstream side of a casing 12 of the air conditioner, and a face outlet 20, a foot outlet 24, and a defrost outlet 23 are formed on the downstream side.

The inside air inlet 13 and the outside air inlet 14 are opened and closed by an inside air / outside air switching damper 15. The face outlet 20 is opened and closed by a damper 25, the foot outlet 24 is opened and closed by a damper 26, and the defrost outlet 23 is opened and closed by a damper 27.

A blower 16, an indoor heat exchanger 3, a PTC heater 28, etc. are arranged in the casing 12. The indoor heat exchanger 3 constitutes a heat pump cycle by connecting to the compressor 1, the four-way valve 2, the outdoor heat exchanger 5, the accumulator 6, the expansion means 4 such as an expansion valve, etc. via the refrigerant pipe, and the expansion valve 4 An electromagnetic valve 7 is interposed in a bypass pipe 8 that connects a refrigerant pipe that connects the heat exchanger 5 with the outdoor heat exchanger 5 and a discharge pipe of the compressor 1.

Outdoor air is blown to the outdoor heat exchanger 5 from an outdoor fan 9 driven by a motor 10. The compressor 1 is driven by a motor 29 incorporated therein, and this motor 29
Is driven to rotate by electricity supplied from the battery 11 via the inverter 17.

During cooling operation, the four-way valve 2 is switched as shown by the broken line in the figure, so that the refrigerant is compressed by the compressor 1, the four-way valve 2, the outdoor heat exchanger 5, the expansion valve 4, as shown by the broken line in the figure.
The indoor heat exchanger 3, the four-way valve 2, and the accumulator 6 are passed in this order and returned to the compressor 1.

During the heating operation, since the four-way valve 2 is switched as shown by the solid line in the figure, the refrigerant discharged from the compressor 1 is shown by the solid line arrow in the figure, the four-way valve 2, the indoor heat exchanger 3, The expansion valve 4, the outdoor heat exchanger 5, the four-way valve 2, and the accumulator 6 are returned to the compressor 1 in this order.

When the outdoor heat exchanger 5 is frosted by the heating operation, the defrost operation is performed by opening the solenoid valve 7. During this defrost operation, a part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 5 through the bypass pipe 8 and the solenoid valve 7 as shown by the alternate long and short dash line, and then reaches the surface thereof. Melt and remove the attached frost.

When the blower 16 is driven by the motor 21, the inside air or the outside air is sucked into the casing 12 from the inside air inlet 13 or the outside air inlet 14 selected by switching the inside / outside air switching damper 15, and the blower 16 After being energized, it is cooled or heated by passing through the indoor heat exchanger 3, and then heated by the PTC heater 28 to become conditioned air of a predetermined temperature.

This conditioned air is supplied to the blower mode switching damper 2
It is blown into the vehicle compartment from the face outlet 20, the foot outlet 24, and the defrost outlet 23 selected by opening and closing 5, 26, 27.

During the heating operation, when the outside air temperature is relatively high and the coefficient of performance of the air conditioner is 1 or more, the air is heated only by the indoor heat exchanger 3, but is conditioned air blown into the passenger compartment. When the temperature is low, it is heated by the indoor heat exchanger 3 and the PTC heater 28 in order to improve the air conditioning filling.

When the coefficient of performance of the air conditioner falls below 1 due to the decrease in outside air temperature, the air is
It is heated only by the TC heater 28.

An indoor heat exchanger temperature sensor for detecting the temperature of the indoor heat exchanger 3, an outdoor heat exchanger temperature sensor for detecting the temperature of the outdoor heat exchanger 5, and an outlet for detecting the temperature of air blown into the vehicle interior. Detection values of an air temperature sensor, a refrigerant pressure sensor that detects the refrigerant pressure at the inlet of the compressor 1, a solar radiation sensor, an outside air temperature sensor, and the like are input to the controller.

Further, an operation switch arranged on the control operation panel in front of the driver's seat, a target temperature setting device, a blowout mode selection switch, a defrost switch, an inside / outside air mode selection switch, an operation mode selection switch, and a blower air volume. Outputs of a selection switch, an auto switch for switching control automatically or manually, a display switch, a heater switch, etc. are also input to the controller.

The output of this controller is an inverter 17,
Drive motor 29 for compressor 1 and drive motor 1 for outdoor fan 9
0, drive motor 21 for blower 16, drive motor for inside / outside air switching damper 15 and blower mode switching dampers 25, 26, 27, PTC
Heater 28, solenoid of four-way valve 2, coil of on-off valve 7,
It is sent to a display device or the like to control these operations.

[0016]

In the conventional air conditioner described above, once the compressor 1 is stopped, the high pressure and the low pressure in the refrigerant circuit are balanced and then the compressor 1 is restarted. There is a problem that it takes a long time (3 to 5 minutes) to restart the compressor 1.

[0017]

The present invention has been invented to solve the above-mentioned problems, and the gist thereof is to provide a compressor driven by electricity supplied from a battery, a cooling / heating system. In an air conditioner for an electric vehicle equipped with a heat pump cycle consisting of a switching four-way valve, an outdoor heat exchanger, an expansion means, an indoor heat exchanger, etc., the four-way valve is switched to a reverse cycle for a certain time after the compressor is stopped. An air conditioner for an electric vehicle, characterized by comprising four-way valve control means.

The four-way valve control means may have a delay means for switching the four-way valve after a lapse of a predetermined delay time after the stop signal of the compressor is input.

[0019]

In the present invention, after the compressor is stopped, the four-way valve control means switches the four-way valve to the reverse cycle for a certain period of time. It is also possible to switch the four-way valve to the reverse cycle after a predetermined delay time has elapsed after the input of the compressor stop signal.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the present invention is shown in FIGS. The stop signal 30 of the compressor based on the operation of the operation switch, the operation mode changeover switch, etc., the operation of the high pressure cut switch, the inverter switch, the system switch, etc. is input to the on / off determination means 32 of the four-way valve control means 31. Then, the on / off decision means 32 decides to switch the four-way valve in the direction opposite to the cycle direction up to that point, that is, in the reverse cycle (from on to off or from off to on), and at the same time outputs it to the delay means 33. . Then, after a delay time provided in advance in the delay means 33, for example, 30 seconds has elapsed, this determination is output to the electromagnetic coil 34 and simultaneously to the timer 35. When a predetermined time set in the timer 35, for example, 30 seconds, the on / off determination means 32 determines to switch the reverse cycle to the previous cycle direction by a signal from this, and this determination is output to the electromagnetic coil 34. To be done.

Thus, after inputting the compressor stop signal 30,
After the elapse of a predetermined delay time, the four-way valve 2 is switched to the reverse cycle for a certain time, so that the high pressure gas and the low pressure gas in the refrigerant circuit communicate with each other via the four-way valve 2, and as shown in FIG. Quickly equilibrates.

Therefore, the time required for equilibrating the high pressure and the low pressure can be remarkably shortened as compared with the conventional one shown by the broken line in FIG.

If the four-way valve 2 is switched after the delay time has elapsed after the input of the compressor stop signal, the moving speed of the high-pressure gas can be reduced, so that the four-way valve 2 can be prevented from generating noise. .

[0024]

According to the present invention, since the four-way valve is switched to the reverse cycle for a certain period of time after the compressor is stopped, the time for the high pressure and the low pressure in the refrigerant circuit to equilibrate can be greatly shortened as compared with the conventional case. . Therefore, the compressor can be restarted in a short time after the stop. After inputting the compressor stop signal,
If the four-way valve is switched to the reverse cycle after the lapse of a predetermined delay time, the moving speed of the high-pressure gas can be suppressed, so that noise can be prevented from being generated from the four-way valve.

[Brief description of drawings]

FIG. 1 is a control block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a temporal change of pressure in the above-mentioned embodiment.

FIG. 3 is a schematic configuration diagram of a conventional air conditioner for an electric vehicle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yokoyama Kominori Aichi Prefecture Nishi-Kasugai-gun Nishibiwajima-cho, Asahi-cho 3-chome 1 Mitsubishi Heavy Industries, Ltd. Air-conditioner factory (72) Inventor Shigeki Hayashi Aichi Prefecture Nishibashijima-cho Asahi-cho 3-chome 1 Air-conditioning factory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Futa Furuta Iwazuka-cho, Nakamura-ku, Nagoya-shi 1 Highway, Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Tetsuo Kanie Chiyoda-ku, Tokyo 2-5-1, Marunouchi Sanryo Heavy Industries Co., Ltd.

Claims (2)

[Claims] 1. An electric vehicle having a heat pump cycle including a compressor driven by electricity supplied from a battery, a four-way valve for switching between cooling and heating, an outdoor heat exchanger, an expansion means, an indoor heat exchanger, etc. An air conditioner for an electric vehicle, comprising: a four-way valve control means for switching the four-way valve to a reverse cycle for a certain period of time after the compressor is stopped. 2. The air for an electric vehicle according to claim 1, wherein the four-way valve control means has a delay means for switching the four-way valve after a lapse of a predetermined delay time after the stop signal of the compressor is input. Harmony device.