JP3535882B2 - Vehicle air-conditioning control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioning control method. 2. Description of the Related Art A heat pump cycle is used in an air conditioner of an electric vehicle because engine cooling water cannot be used unlike an automobile equipped with a water-cooled engine. As shown in FIG. 2, the heat pump cycle includes an outside heat exchanger 1 disposed in a front part of a vehicle body, an inside heat exchanger 3 disposed in a unit 2 in a front part inside the vehicle, and a compressor 4.
, A four-way valve 5, a capillary tube 6, etc.
A heat exchange medium is circulated. When the interior of a vehicle is heated by the vehicle air conditioner, a heat exchange medium is circulated in a heating cycle. That is, the control device 8 switches the four-way valve 5 as shown by the solid line in FIG. 2 and drives the compressor 4 to set the heat exchange medium to a high temperature and a high pressure. As shown by the solid line arrow in FIG. After the heat is radiated by the heat exchanger 3 on the inside of the vehicle, the pressure is reduced by the capillary tube 6 and the heat is absorbed from the outside air by the heat exchanger 1 on the outside of the vehicle. As a result, the air sucked into the unit 2 is heated by the heat exchanger 3 on the inside of the vehicle, becomes hot air, and is blown into the vehicle. When the interior of the vehicle is cooled by the vehicle air conditioner, a heat exchange medium is circulated in a cooling cycle. That is, the four-way valve 5 is switched as shown by a dotted line in FIG. 2, and the compressor 4 is driven to make the heat exchange medium a high temperature and a high pressure as described above, and the four-way valve 5 is switched through the four-way valve 5 as shown by the dotted arrow in FIG. The heat is radiated by the heat exchanger 1 outside the vehicle, the pressure is reduced by the capillary tube 6, the heat is absorbed from the air passing through the unit 2 by the heat exchanger 3 inside the vehicle, and the heat is returned to the compressor 4 via the four-way valve 5 and circulated. As a result, the air sucked into the unit 2 is cooled by the heat exchanger 3 on the inside of the vehicle, becomes cool air, and is blown into the vehicle. While the heat exchange medium is circulated in this way, the blower 9 is driven to control the temperature of the air taken into the unit 2 by the heat exchanger 3 on the inside of the vehicle. To blow. That is, at the time of heating, the dampers 10, 11, 12 are turned to rotate the heat duct 13.
Heat mode or heat duct 1 with only opening
The vent mode is a bi-level mode in which both the vent duct 3 and the vent duct 14 are opened, and the vent mode in which only the vent duct 14 is opened in cooling. Further, according to the occupant's preference, the inside / outside air switching damper 16 is rotated to change to the inside air mode for circulating inside air or the outside air mode for taking in outside air. By the way, in the vehicle air conditioner, heat is absorbed from outside air by the outside heat exchanger 1 during heating.
Frost may form when the outside air temperature is very low. This frost prevents heat absorption of the heat exchanger 1 on the outside of the vehicle and lowers the heating performance of the heat exchanger 3 on the inside of the vehicle. For this reason, based on the detected temperature from the temperature sensor 7 provided in the vicinity of the outside heat exchanger 1, the controller 8 detects the frost formation state of the outside heat exchanger 1 and if frost formation is detected. In addition, the heating cycle is switched to the cooling cycle. As a result, the heat is radiated and defrosted in the vehicle-side heat exchanger 1. However, in the air conditioning control method for the vehicle air conditioner, immediately after the return from the heating operation, one of the dampers 10, 11, 12 is rotated to send the air to the air blowing mode. The air supplied into the unit 2 by the rotation of the blower 9 may collide with any of the rotating dampers 10, 11, 12 to generate an unpleasant noise. is there. The present invention has been made in view of the above problems, and has as its object to provide a vehicle air conditioning control method capable of preventing generation of abnormal noise immediately after returning to a heating operation from a defrosting operation. According to the present invention, in order to achieve the above object, a heat exchange medium is circulated by a compressor, an outside heat exchanger, and an inside heat exchanger disposed in a unit inside the vehicle. A heat pump cycle is configured to perform the heating operation or the cooling operation by changing the circulation direction of the heat exchange medium and switching to the heating cycle or the cooling cycle, and frost is formed on the vehicle-side heat exchanger during the heating operation. If this occurs, for vehicles that stop the compressor and switch from the heating cycle to the cooling cycle, stop the blower and prohibit airflow into the vehicle, and then start the defrosting operation by driving the compressor again. In the air conditioning control method, when returning from the defrosting operation to the heating operation, the compressor is stopped and the cooling cycle is switched to the heating cycle. After a predetermined time delay, the blower driving is restarted. Next, an embodiment of the present invention will be described with reference to the accompanying drawings. The vehicle air conditioner to which the vehicle air conditioning control method according to the present invention is applied has the same configuration as the conventional example shown in FIG. 2, and the control operation by the control device 8 is the same except for the defrosting control method during heating. Therefore, the defrost control will be described below with reference to the flowchart of FIG. First, in step S1, the four-way valve 5 is switched as shown by the solid line in FIG. 2 to drive the compressor 4, thereby starting a normal heating operation. This heating operation
As in the prior art, the temperature is adjusted by adjusting the air blowing temperature based on various conditions (inside air temperature, outside air temperature, amount of solar radiation, set temperature, etc.) inside and outside the vehicle. Then, it is determined in step S2 whether frost has occurred. Defrosting is determined based on whether the temperature detected by the temperature sensor 7 provided in the vicinity of the heat exchanger 1 on the outside of the vehicle is equal to or lower than a set temperature. If not, the heating operation is continued. Subsequently, if it is determined in step S2 that frost has occurred, the flow proceeds to step S3 to start the defrosting operation, and the blower 9 is temporarily stopped in step S4. Then, it is determined whether or not the defrosting operation has been completed in step S5, that is, whether or not the temperature detected by the temperature sensor 7 has exceeded the set temperature. If it does not exceed, the defrosting operation is continued, and if it has exceeded, the process shifts to step S6 to temporarily stop the compressor 4 and then switches from the cooling cycle to the heating cycle by the four-way valve 5 in step S7. Thereafter, in step S8, the compressor 4 is started again to circulate the heat exchange medium in the heating cycle.
Then, in step S9, by turning each damper 10, 11, or 12 based on various conditions inside and outside the vehicle, a desired blow port 13, 14, or 15 is opened to switch the blow mode. Thus, the damper 10, 11 or 1
When the rotation of 2 is completed, the process returns to step S1 to adjust the number of revolutions of the compressor 4 and the voltage applied to the blower 9 to restart the heating operation. It is preferable that the return to step S1 be delayed for a predetermined time so that the switching of the blowing mode is completely performed and the blowing temperature rises to a desired temperature. As described above, before returning from the defrosting operation to the heating operation and restarting the operation of the blower 9, the dampers 10, 11
Or 12 is rotated to change the air blowing mode, so that the air blown by the blower 9 collides with the rotating damper 10, 11 or 12, as in the related art, and is unpleasant for passengers. Does not generate sound. As is apparent from the above description, according to the vehicle air-conditioning control method of the present invention, after the compressor is stopped to switch from the cooling cycle to the heating cycle, and to switch the blowing mode, Since the blower volume is increased by the blower, the heating operation can be restarted in a state where the heat exchanger inside the vehicle is warm, and the blower temperature can be prevented from lowering.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart of air conditioning control. FIG. 2 is a schematic diagram of a vehicle air conditioner. [Description of Signs] 1 ... Outside heat exchanger, 3 ... Inside heat exchanger, 4 ... Compressor, 5 ... Four-way valve, 7 ... Temperature sensor, 8 ... Control device,
9 ... Blower, 10,11,12 ... Damper.

Continuing on the front page (72) Inventor Hiroshi Hamamoto 5658 Yoshikawa, Hachihonmatsu-cho, Higashi-Hiroshima-shi, Hiroshima Japan Climate Systems Co., Ltd. (72) Inventor Toru Fujiwara 5658 Yoshikawa, Hachi-Honmatsu-cho, Higashihiroshima-shi, Hiroshima Japan (56) References JP-A-62-186157 (JP, A) JP-A-4-251150 (JP, A) JP-A-61-59110 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B60H 1/00-3/06

Claims (1)

(57) [Claims 1] A heat pump cycle in which a heat exchange medium is circulated by a compressor, an outside heat exchanger, and an inside heat exchanger disposed in a unit inside the vehicle, wherein the heat pump cycle is formed. By changing the circulation direction of the exchange medium and switching to the heating cycle or the cooling cycle, the heating operation or the cooling operation is enabled, and when frost is formed on the outside heat exchanger during the heating operation, the compressor is stopped. The air conditioning control method for a vehicle, wherein the defrosting operation is started by switching from the heating cycle to the cooling cycle, stopping the blower and prohibiting air blowing into the vehicle, and then starting the defrosting operation by driving the compressor again. When returning to the heating operation from the above, the compressor is stopped, the cooling cycle is switched to the heating cycle, and the ventilation mode is switched, An air conditioning control method for a vehicle, wherein the drive of the blower is restarted after a time delay.