JPH0661526U - Vehicle air conditioner - Google Patents

Abstract

(57) [Summary] [Purpose] Defrosting is completed even if the main switch for the vehicle is turned off during the defrosting operation. [Structure] The heat pump cycle consists of a compressor 4,
It is composed of a heat exchanger 1 on the outside of the vehicle and a heat exchanger 3 on the inside of the vehicle arranged inside the unit 2, and a heat exchange medium is circulated. Then, the circulation direction of the heat exchange medium is changed to a heating cycle or a cooling cycle to heat or cool the inside heat exchanger 3. When the vehicle exterior heat exchanger 1 is frosted during heating, the defrost control means 7 switches to the defrost cycle and radiates heat in the vehicle exterior heat exchanger 1 to defrost, and the defrosting operation is started. Then, the defrosting is completed regardless of the on / off state of the vehicle main switch 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle air conditioner.

[0002]

[Prior art]

 Electric vehicles cannot use the heat source of the engine cooling water for air conditioning inside the vehicle, so an air conditioner using a heat pump cycle is used. As shown in FIG. 4, this heat pump cycle includes an exterior heat exchanger 1 provided in the front portion of the vehicle body, an interior heat exchanger 3, a compressor 4, a four-way valve 5 provided in a unit 2 in the front portion of the vehicle. The heat exchange medium is circulated by the capillary tube 6 and the like.

In the air conditioner, when heating the inside of the vehicle, the four-way valve 5 is switched to establish a heating cycle. In this heating cycle, by driving the compressor 4, the heat exchange medium first flows through the four-way valve 5 into the heat exchanger 3 inside the vehicle to radiate heat, and after being decompressed by the capillary tube 6, the heat exchanger 1 outside the vehicle It absorbs heat and returns to the compressor 4 via the four-way valve 5 and circulates. As a result, the air sucked into the unit 2 is overheated by the heat exchanger 3 inside the vehicle, and hot air is supplied into the vehicle.

When cooling the inside of the vehicle, the four-way valve 5 is switched to establish a cooling cycle. In this cooling cycle, the heat exchange medium flows into the vehicle exterior heat exchanger 1 by driving the compressor 4 to radiate the heat, and after being decompressed by the capillary tube 6, it absorbs heat in the vehicle interior heat exchanger 3 and again the four-way valve. It returns to the compressor 4 via 5 and circulates. As a result, the air sucked into the unit 2 is cooled by the heat exchanger 3 inside the vehicle, and cold air is supplied into the vehicle.

By the way, since the heat exchanger 1 outside the vehicle absorbs heat during the heating, frost formation may occur when the outside air temperature is very low. This frost reduces the amount of heat absorbed in the vehicle exterior heat exchanger 1 and reduces the amount of heating in the vehicle interior heat exchanger 3, resulting in a decrease in heating capacity. When the detected temperature from 8 becomes lower than the predetermined temperature, it is judged that frost has formed, and the four-way valve 5 switches from the heating cycle to the cooling cycle and heat is dissipated by the heat exchanger 1 outside the vehicle to defrost. Drive.

[0006]

[Problems to be solved by the device]

 However, as shown in FIG. 6, in the vehicle air conditioner, when the vehicle main switch is turned off during the defrosting operation, the compressor 4 also stops, so that the heat exchange medium does not circulate and the defrosting operation is performed. Suspended. For this reason, when the vehicle is parked once and the main switch is turned on again, the exterior heat exchanger 1 still remains frosted, so the defrosting operation is performed first and the inside of the vehicle is defrosted. The cold air blows off and gives an occupant discomfort. In view of the above problems, the present invention aims to provide a vehicle air conditioner capable of completing defrosting even when the vehicle main switch is turned off during defrosting operation.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention constitutes a heat pump cycle in which a heat exchange medium is circulated by a compressor, a heat exchanger outside the vehicle, and a heat exchanger inside the vehicle arranged in a unit inside the vehicle. By changing the circulation direction and switching to a heating cycle or a cooling cycle, heating or cooling can be performed, and if frost forms on the exterior heat exchanger during heating, it is switched to the defrost cycle to defrost. The vehicle air conditioner described above is provided with defrost control means for completing defrosting regardless of the on / off state of the vehicle main switch when the defrosting operation is started.

[0008]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a vehicle air conditioner, and the same members as those in the conventional example are designated by the corresponding symbols. In this vehicle air conditioner, a vehicle main switch 11 for detecting an on / off state by a key operation is provided near the steering wheel 10, and the detection signal is input to the control device 7. Has become. In the control device 7, the heating, cooling and defrosting operations are performed in the same manner as in the conventional example, and the air conditioner is stopped by the detection signal from the main switch 11 as described below.

The air conditioning control when the main switch 11 is turned off during the heating operation will be described below with reference to the flowchart of FIG. First, in step S1, it is determined whether the main switch 11 is on. If it is off, the process proceeds to step S6 and the heating operation is not performed. If it is in the ON state, the heating operation is started by switching to the heating cycle by the four-way valve 5 and driving the compressor 4 in step S2.

Then, in step S3, it is determined whether or not there is frost on the exterior heat exchanger 1, that is, whether or not the temperature detected by the temperature sensor 8 has dropped below a predetermined temperature. If there is no frost, the operation is returned to step S1 and the above operation is repeated. If frost is found, the compressor 4 is temporarily stopped in step S4, the heating cycle is switched to the cooling cycle by the four-way valve 5, and then the compressor 4 is restarted. The defrosting operation is started by driving the heat exchanger 1 to dissipate heat in the heat exchanger 1 outside the vehicle.

Then, in step S5, it is determined whether the defrosting operation is completed, that is, whether the temperature detected by the temperature sensor 8 has risen above a predetermined temperature. If the defrosting is not completed, the operation waits in step S5 to continue the defrosting operation. If the defrosting is completed, the procedure returns to step S1 to repeat the above operation.

As described above, since the on / off state of the main switch 11 is not judged during the defrosting operation, even if the main switch 11 is turned off by the key operation during the defrosting operation. However, the compressor 4 does not stop and the defrosting operation can be continued until the defrosting is completed.

[0013]

[Effect of device]

 As is clear from the above description, according to the vehicle air conditioner of the present invention, the defrosting operation is performed regardless of whether the main switch for the vehicle is on or off. Defrosting can be completed even if the main switch for the vehicle is turned off during operation, and heating operation can be started even if the main switch for the vehicle is turned on again. Is never blown out.

[Submission date] March 1, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

In the air conditioner, when heating the inside of the vehicle, the four-way valve 5 is switched to establish a heating cycle. In this heating cycle, by driving the compressor 4, the heat exchange medium first flows through the four-way valve 5 into the heat exchanger 3 inside the vehicle to radiate heat, and after being decompressed by the capillary tube 6, the heat exchanger 1 outside the vehicle It absorbs heat and returns to the compressor 4 via the four-way valve 5 and circulates. As a result, the air sucked into the unit 2 is heated by the vehicle interior heat exchanger 3, and hot air is supplied into the vehicle interior.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vehicle air conditioner according to an embodiment.

FIG. 2 is a flow chart showing air conditioning control of the vehicle air conditioner according to the present embodiment.

FIG. 3 is a graph showing the relationship between the heating and defrosting operations and the on / off state of the main switch during vehicle operation.

FIG. 4 is a schematic diagram of a vehicle air conditioner according to a conventional example.

FIG. 5 is a graph showing a relationship between heating and defrosting operations during continuous operation and ON / OFF states of a main switch.

FIG. 6 is a graph showing a relationship between heating and defrosting operations and a main switch ON / OFF state during vehicle operation according to a conventional example.

[Explanation of symbols]

1 ... Exterior heat exchanger, 3 ... Interior heat exchanger, 4 ... Compressor, 7 ... Control device, 11 ... Main switch.

[Procedure amendment]

[Submission date] March 1, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Scope of utility model registration request

[Correction method] Change

[Correction content]

[Scope of utility model registration request]

Claims (1)

[Scope of utility model registration request] 1. A heat pump cycle in which a heat exchange medium is circulated by a compressor, a heat exchanger outside the vehicle, and a heat exchanger inside the vehicle arranged in a unit inside the vehicle, and the circulation direction of the heat exchange medium is changed. In a vehicle air conditioner that enables heating or cooling by switching to a defrost cycle, and switches from a heating cycle to a cooling cycle to defrost when frost forms on the exterior heat exchanger during heating. If the defrosting operation is started,
An air conditioner for a vehicle, comprising defrost control means for completing the defrost regardless of whether the main switch for the vehicle is on or off.