JP3501839B2 - Electric vehicle air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle air conditioner. 2. Description of the Related Art In recent years, with the development of electric vehicles, various inventions have also been made on air conditioners for electric vehicles mounted on the electric vehicles. In such an electric vehicle air conditioner, when cooling the inside of a vehicle, generally, by circulating a refrigerant in a refrigeration cycle, the air passing through the heat exchanger inside the vehicle is cooled to supply cool air into the vehicle. I have. That is, in the refrigeration cycle, the refrigerant which has become high temperature and high pressure by driving the compressor flows into the outside heat exchanger disposed in the front of the vehicle, is cooled, and is easily vaporized by the capillary tube. After being vaporized when passing through the inside heat exchanger disposed in the air conditioning unit in the front part of the vehicle, it is liquefied by the accumulator and circulated back to the compressor. In addition, cold air can be blown into the vehicle by removing heat of vaporization from inside air or outside air that passes when the refrigerant is vaporized in the vehicle-side heat exchanger. [0004] However, in the air conditioner for an electric vehicle that has been proposed in the past, since the vertical relationship between the inside and outside temperature of the vehicle differs depending on the presence or absence of solar radiation during parking, for example, the cooling operation starts in summer. If the inside air circulation mode is selected immediately after that, the inside air having a considerably higher temperature than the outside air passes through the heat exchanger inside the vehicle, and the cooling is not sufficiently performed. In this case, since the temperature of the refrigerant itself is also very high, the refrigerant vaporized in the heat exchanger inside the vehicle is overheated and flows into the compressor. ), Which increases the possibility of failure. The present invention has been made in view of the above problems, and has as its object to provide an air conditioner for an electric vehicle that can perform appropriate in-vehicle air conditioning while preventing failure of a compressor. [0006] In order to achieve the above object, the present invention achieves the above object by driving a compressor to circulate a heat exchange medium in the order of an outer heat exchanger and an inner heat exchanger. In an air conditioner for an electric vehicle that cools air passing through an inside heat exchanger and supplies cold air to the inside of the vehicle, an outside temperature detection sensor that detects outside temperature and a temperature near the inside heat exchanger If the temperature detected by both sensors is compared before and after the compressor is driven, switch to the inside air circulation mode if the outside temperature is higher, and switch to the inside air circulation mode if the outside temperature is lower. During the outside air introduction mode, the difference between the temperatures detected by the two sensors is equal to or greater than a predetermined value, while the operation is switched to the outside air introduction mode. And an inside / outside air mode switching control means for switching to an air circulation mode. According to the present invention, the inside / outside air mode switching means reads the temperatures detected by the outside temperature detection sensor and the inside heat exchanger sensor or the inside temperature detection sensor. , The lower temperature of the inside air or the outside air is taken in and passed through the inside heat exchanger. An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a schematic diagram of an air conditioner for an electric vehicle,
An inside / outside air switching damper 2, a blower fan 3, and an in-vehicle heat exchanger 4 are sequentially arranged from the upstream side in an air-conditioning unit 1 disposed in the front part of the vehicle, and open at a predetermined position in the vehicle at the most downstream part. Heat / vent / diff switch damper 5 for opening / closing the heat / vent / diff outlets 5, 6 and 7, respectively
a, 6a and 7a are provided rotatably. The inside / outside air switching damper 2 is opened and closed by driving an actuator 2a to close either the inside air circulation port 1a or the outside air introduction port 1b. The driving of the actuator 2a is controlled by an inside / outside air switching control device. 8 is controlled by a signal from The inside / outside air switching control device 8 includes an outside temperature detection sensor 9 provided in the middle of the outside air introduction passage, an inside temperature detection sensor 10 provided in the front portion inside the vehicle, and the inside heat exchanger 4.
The detected temperature is input from the vehicle interior heat exchanger sensor 11 provided in the. A thermistor can be used for each of the sensors 9, 10 and 11. The blower fan 3 is rotated by the drive of the blower motor 3a, draws inside air or outside air into the air conditioning unit 1 and blows the air into the vehicle from predetermined outlets 5, 6, or 7. The heat exchanger 4 cools or heats the air passing through the heat exchanger 4 in the vehicle interior heat exchanger 4. The heat exchange medium circulates through a heating cycle H indicated by a solid line in FIG. 1 and a cooling cycle C indicated by a dotted line by switching the four-way valve 12. That is, in the heating cycle H, by driving the compressor 13, the four-way valve 12, the inside heat exchanger 4, the flow regulating valve 14, the outside heat exchanger 15, the four-way valve 12 and the accumulator 16 are provided. Compressor 1
Return to 3 and cycle. In the cooling cycle C, the refrigerant returns to the compressor 13 via the four-way valve 12, the outside heat exchanger 15, the flow regulating valve 14, the inside heat exchanger 4, the four-way valve 12, and the accumulator 16 to circulate. The in-vehicle heat exchanger 4 has a structure in which flat tubes and fins are alternately stacked, and headers are provided on both sides, so that the heat exchange medium flows from the header through each flat tube while meandering. The outside heat exchanger 15 has substantially the same configuration. The four-way valve 12 has a configuration in which a pair of passages formed in a cylindrical body rotating inside is positioned at one of a solid line and a dotted line by rotating the cylindrical body.
The rotation speed of the compressor 13 is adjusted by a change in the operating frequency from the inverter 13a, and the compressor 13 discharges the heat exchange medium in a high temperature and high pressure state. The accumulator 1
Reference numeral 6 denotes a gas-liquid diversion device for not sending the heat exchange medium, which could not be vaporized, to the compressor 13, which is conventionally known. The flow control valve 14 changes the opening of the flow passage by driving the motor 14a.
Is driven and controlled by a signal from the flow controller 17.
The detected temperature information from the sensors 9, 10, and 11 is input to the flow control device 17 from the inside / outside air switching control device 8. (First Embodiment) In the first embodiment, the air conditioning control immediately after the start of the cooling operation is performed according to the flowchart shown in FIG. That is, if the cooling operation is started in step S1, the temperature outside the vehicle is read in step S2, and the temperature inside the vehicle is read in step S3. In step S4, the outside temperature and the inside temperature are compared. If the outside temperature is high, the mode is switched to the inside air circulation mode in step S5, and if the temperature is low, the mode is switched to the outside air introduction mode in step S6. As described above, according to the first embodiment, the lower temperature air can be supplied to the in-vehicle heat exchanger 4 by comparing the outside temperature and the inside temperature. As a result, the heat exchange medium is prevented from being overheated in the in-vehicle heat exchanger 4,
The superheated heat exchange medium does not flow into the compressor 13 without being completely liquefied by the accumulator 16. (Second Embodiment) In the second embodiment, the air conditioning control immediately after the start of the cooling operation is performed according to the flowchart shown in FIG. That is, first, if the cooling operation is started in step S11, the outside temperature input from the outside temperature detection sensor 9 is read in step S12, and the process proceeds to step S1.
In step 3, the temperature near the inside heat exchanger 4 input from the inside heat exchanger sensor 11 is read. Next, in step S14, the two sensors 9,
If the outside temperature is higher than the temperature detected in step S11, the process proceeds to step S15. If the outside temperature is lower, the process proceeds to step S16.
Respectively. In order to allow low-temperature air to pass through the inside heat exchanger 4, the mode is switched to the outside air introduction mode in step S15, and to the inside air circulation mode in step S16. Then, in step S17, the compressor 13
To start the cooling operation. Subsequently, in step S18, it is determined again whether the mode is the inside air circulation mode. This is because even if the mode is switched to the outside air introduction mode in step S15, the mode may be switched to the inside air circulation mode by the operation of the occupant. In the case of the inside air circulation mode, the air conditioning control immediately after the start of the cooling operation ends, and the process shifts to the normal air conditioning control. If the mode is not the inside air circulation mode,
The temperature outside the vehicle is read in step S19, and the heat exchange temperature inside the vehicle is read in step S20. In step S21, it is determined whether or not the temperature difference between them is larger than a predetermined value a (for example, a = 15 deg). The reason why the predetermined value a is taken into consideration is that the heat exchanger 4 inside the vehicle is considerably cooled by the flow of the heat exchange medium, so that the heat exchanger sensor 11 inside the vehicle is susceptible to the influence. This is because the temperature to be reduced becomes lower than the temperature of the air passing through the heat exchanger 4 inside the vehicle. Then, when the temperature difference becomes larger than the predetermined value a, the mode is switched to the inside air circulation mode in step S22, and thereafter, the process shifts to normal air conditioning control. As described above, according to the second embodiment,
As in the first embodiment, by passing air having a lower temperature through the in-vehicle heat exchanger, it is possible to prevent the heat exchange medium from being overheated. (Third Embodiment) In the third embodiment, in addition to supplying the lower temperature of the inside air or the outside air to the in-vehicle heat exchanger 4, the inflow to the in-vehicle heat exchanger 4 is also performed. The overheat state of the heat exchange medium is avoided by increasing the flow rate of the heat exchange medium. That is, drive control of the compressor 13 is performed by a compressor control device (not shown) in accordance with the flowchart of FIG. First, in step S31, the temperature near the heat exchanger 4 inside the vehicle is set to a predetermined temperature (for example, 20
° C) or more. If the temperature is lower than the predetermined temperature, the compressor 13 is driven at a normal driving frequency (for example, 90 Hz). If the temperature is higher than the predetermined temperature, the compressor 13 is corrected to a higher driving frequency (for example, 100 Hz). This control may be performed, for example, immediately before step S17 in the second embodiment. As described above, according to the third embodiment, if the temperature in the vicinity of the heat exchanger 4 inside the vehicle is higher than the predetermined temperature and the heat exchange medium flowing in the interior is likely to be overheated, the driving of the compressor 13 is started. Raise the frequency to heat exchanger 4 inside the car
Since the heat exchange performance is enhanced by increasing the flow rate of the heat exchange medium in step (1), it is possible to prevent the heat exchange medium from flowing into the compressor 13 in an overheated state. In the third embodiment, the compressor 13
Is controlled based on whether the temperature in the vicinity of the in-vehicle heat exchanger 4 is higher than a predetermined temperature, but may be performed steplessly in accordance with the detected temperature or may be performed in multiple steps by providing a plurality of set temperatures. May be. Further, in the third embodiment, the drive control of the compressor 13 is performed based on the temperature in the vicinity of the heat exchanger 4 inside the vehicle. However, the drive control is performed simply by detecting whether or not the mode is switched to the outside air introduction mode. It may be. That is, immediately after the start of the cooling operation, if the mode is switched to the outside air introduction mode by the air conditioning control of the first or second embodiment, the drive frequency of the compressor 13 is corrected upward. As is apparent from the above description, according to the present invention, immediately after the start of cooling, the temperature outside the vehicle is compared with the temperature inside the vehicle or the temperature near the heat exchanger inside the vehicle, and the internal air circulation mode or By selecting the outside air introduction mode, air with lower temperature can be supplied to the heat exchanger inside the vehicle, so the heat exchange medium flowing in the heat exchanger inside the vehicle becomes overheated and flows into the compressor. Can be prevented, and the compressor can be prevented from causing a failure. [0031]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an electric vehicle air conditioner according to an embodiment. FIG. 2 is a flowchart illustrating air conditioning control according to the first embodiment. FIG. 3 is a flowchart illustrating air conditioning control according to a second embodiment. FIG. 4 is a flowchart illustrating air conditioning control according to a third embodiment. [Description of Signs] 2 ... inside / outside air switching damper, 4 ... inside heat exchanger, 8 ... inside / outside air switching control device, 9 ... outside temperature detection sensor, 10 ... inside temperature detection sensor, 11 ... inside heat exchange. Container sensor, 1
3 ... Compressor, 14 ... Flow control valve, 15 ... Outside heat exchanger.

Continuation of the front page (72) Inventor Yuki Maebobo 5658 Yoshikawa, Hachihonmatsu-cho, Higashihiroshima-shi, Hiroshima Japan Climate Systems Co., Ltd. -1011 (JP, U) Actually open 58-29515 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60H 1/00-3/06

Claims (1)

(57) [Claims 1] The compressor is driven to circulate the heat exchange medium in the order of the heat exchanger outside the vehicle and the heat exchanger inside the vehicle, thereby passing through the heat exchanger inside the vehicle. An air conditioner for an electric vehicle that cools air and supplies cool air to the inside of the vehicle. An outside temperature detection sensor that detects outside temperature and an inside heat exchange temperature detection sensor that detects temperature near a heat exchanger inside the vehicle. And, before driving the compressor, comparing the temperature detected by the two sensors, if the outside temperature is higher, switch to the inside air circulation mode, if it is low, switch to the outside air introduction mode, If after the start of driving of the compressor, in the outside air introduction mode, the inside / outside air mode is switched to the inside air circulation mode when the difference between the temperatures detected by the two sensors becomes a predetermined value or more. Electric car air-conditioning system, characterized in that a control means.