JP2002310542A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent concentration of carbon dioxide from increasing in a car. SOLUTION: A concentration detecting means 13 detects concentration of carbon dioxide in a car. A control means 14 begins processing for suppressing the concentration when the concentration of carbon dioxide detected by the concentration detecting means 13 exceeds a set level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, in a vehicle air conditioner, carbon dioxide having a lower global warming potential than R134a has been used as a refrigerant circulated in a refrigeration cycle.

[0003]

[Problems to be solved by the invention] However,
If the refrigerant in the refrigeration cycle leaks into the vehicle, the carbon dioxide concentration may increase. It is said that if the concentration of carbon dioxide exceeds 7%, the consciousness becomes unconscious in about 15 minutes.

Accordingly, an object of the present invention is to provide a vehicle air conditioner that prevents an increase in the concentration of oxygen dioxide in a vehicle.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a vehicle air conditioner provided with a refrigeration cycle using carbon dioxide as a refrigerant. And a control means for starting a concentration suppression process for suppressing the carbon dioxide concentration in the vehicle when the carbon dioxide concentration detected by the concentration detection means exceeds a set concentration.

As the concentration suppression processing, for example, the power window is automatically opened, the intake door is switched to the outside air introduction mode to increase the air flow,
A method for stopping the operation of the compressor is included.

[0007] With this configuration, by starting the concentration suppression processing, the concentration of carbon dioxide in the vehicle can be forcibly suppressed, so that there is no problem for the occupant.

[0008] A relief valve is provided in the middle of a pipe located outside the vehicle of the refrigeration cycle, and the control means opens the relief valve when the concentration of carbon dioxide detected by the concentration detecting means exceeds a set concentration, and releases the carbon dioxide. The concentration suppression process may be started by discharging carbon out of the vehicle.

Further, a temperature detecting means for detecting a refrigerant temperature is provided at an outlet side of the compressor of the refrigeration cycle, and the control means determines that the carbon dioxide concentration detected by the concentration detecting means does not exceed a set concentration. Also, it is preferable that the compressor be stopped if the refrigerant temperature detected by the temperature detecting means exceeds a set temperature.

[0010] It is preferable that a display unit is provided, and that the control unit, when starting the concentration suppression processing, display a failure on the display unit, stop driving the compressor, and prohibit restarting the compressor.

[0011] After the repair of the faulty part is completed,
By operating the release means, the compressor may be restartable.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a vehicle air conditioner according to this embodiment. In this vehicle air conditioner, a blower fan 2, an inboard heat exchanger 3, an air mix door 4, and a heater core 5 are sequentially arranged from the upstream side in an air conditioning unit 1 in the front part of the vehicle. The rotation speed of the blower fan 2 can be adjusted by switching the voltage applied to the blower motor 6 stepwise. The vehicle interior heat exchanger 3 is connected in the middle of the refrigeration cycle. In the refrigeration cycle, the compressor 7
, That is, carbon dioxide, which is discharged from the compressor, returns to the compressor 7 via the vehicle exterior heat exchanger 8, the throttle valve 9, the vehicle interior heat exchanger 3, and the accumulator 10. A temperature sensor 11 for detecting a refrigerant temperature is provided near the discharge port of the compressor 7. Further, a relief valve 12 located outside the vehicle is provided near the outlet of the heat exchanger 8 on the outside of the vehicle. By opening the relief valve 12, carbon dioxide in the refrigeration cycle can be released outside the vehicle.

The blower motor 6, the throttle valve 9, the compressor 7 and the like are controlled by a control device 14 based on input signals from a temperature sensor 11, a concentration detection sensor 13 provided at a front portion inside the vehicle for detecting the concentration of carbon dioxide in the vehicle, and the like. Drive controlled. Various information such as the concentration of carbon dioxide in the vehicle is displayed on a display unit 15 disposed in a front portion of the vehicle.

Next, a description will be given of a concentration suppressing process by the vehicle air conditioner having the above-described configuration.

When an air conditioner switch (not shown) is operated, the amount of air to be blown, the temperature of the air to be blown, and the mode of air to be blown are determined based on the inside air temperature, the outside air temperature, the amount of solar radiation and the like, and the air conditioning in the vehicle is started.

When the in-vehicle air conditioning is started, the in-vehicle carbon dioxide concentration C detected by the concentration detection sensor 13 is read (step S1). Then, it is determined whether or not the detected carbon dioxide concentration C exceeds the set value Cs (step S2). Here, a value (for example, 7%) estimated to cause an occupant to malfunction is used as the set concentration Cs.

The detected carbon dioxide concentration C is equal to the set value Cs.
Is exceeded, there is a possibility that carbon dioxide may leak into the vehicle from the refrigeration cycle, so the power window is driven to open the window (step S3). Further, the intake door 16 is rotated as shown by the solid line in FIG. 1 to set the outside air introduction mode (step S4). Further, the relief valve 12 is opened to release carbon dioxide as a refrigerant to the outside of the vehicle (step S5). Further, the compressor 7 is stopped so that the carbon dioxide as the refrigerant does not flow inside the vehicle (step S6). As a result, the concentration of carbon dioxide in the vehicle is suppressed, and there is no possibility that the occupant becomes unconscious. Then, the restart of the compressor 7 is prohibited (step S7), and the display unit 15 is caused to display a failure (step S8).

On the other hand, when the detected carbon dioxide concentration C is equal to or less than the set value Cs, it is determined whether or not the elapsed time Tm from the start of driving the compressor 7 has exceeded the set time Tms (step S9). As the set time Tms, a time sufficient for stabilizing the refrigerant temperature from the start of driving of the compressor 7 is used. Then, when the set time Tms has elapsed, it is determined whether or not the refrigerant temperature Te has exceeded the set temperature Tes (step S10). As the set temperature Tes, a value that greatly exceeds the expected increased refrigerant temperature is used. If the refrigerant temperature Te is equal to or lower than the set temperature Tes, normal air-conditioning control is continued. Further, if the refrigerant temperature Te exceeds the set temperature Tes, it is determined that the refrigerant circulation in the refrigeration cycle has a problem even if the detected carbon dioxide concentration in the vehicle has not increased, Similarly, the compressor 7 is stopped (step S6), its restart is prohibited (step S7), and the display unit 15 is displayed as a failure (step S8).

As described above, according to the vehicle air conditioner of the embodiment, it is possible to prevent not only the rise of the carbon dioxide concentration in the vehicle, but also the occurrence of a malfunction of the refrigeration cycle. Therefore, it can be used with confidence.

In the above embodiment, the concentration of carbon dioxide in the vehicle is suppressed by opening the window, switching to the outside air introduction mode, and opening the relief valve 12. However, the amount of air blown by the blower fan 2 is further increased ( Preferably,
Maximum) or by fully closing the throttle valve 9,
This is preferable in that the concentration of carbon dioxide in the vehicle can be suppressed. Also, valves may be provided in pipes located outside the vehicle on the entrance side and the exit side of the vehicle interior heat exchanger 3, and when the carbon dioxide concentration exceeds the set concentration, both valves may be closed and the compressor may be stopped. Good. Thereby, inflow of carbon dioxide to the inside of the vehicle is prevented, and at the maximum, it can be suppressed only by outflow of carbon dioxide in the piping on the inside of the vehicle including the heat exchanger 3 on the inside of the vehicle.

By providing a release switch,
After the repair, the compressor 7 may be restarted. As a result, it is possible to deal with the problem only by repairing only the failed part without replacing the control device.

[0023]

As is apparent from the above description, according to the present invention, the concentration suppression process is started when the carbon dioxide concentration in the vehicle exceeds the set concentration.
The carbon dioxide concentration in the vehicle does not increase and does not cause any trouble to the occupants.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a density suppression process performed by the control device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Air conditioning unit 2 ... Blower 6 ... Blower motor 7 ... Compressor 8 ... Outside heat exchanger 11 ... Temperature sensor 12 ... Relief valve 13 ... Concentration detection sensor 14 ... Control device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 1/00 395 F25B 1/00 395Z (72) Inventor Shinji Watanabe No. 3 Yoshikawa Industrial Park in Higashihiroshima City, Hiroshima Prefecture No. 11 Japan Climate Systems Co., Ltd.

Claims (5)

[Claims] 1. A vehicle air conditioner comprising a refrigeration cycle using carbon dioxide as a refrigerant, a concentration detecting means for detecting the concentration of carbon dioxide in the vehicle, and wherein the concentration of carbon dioxide detected by the concentration detecting means is equal to a set concentration. A control unit for starting a concentration suppression process for suppressing the carbon dioxide concentration in the vehicle when the air conditioner exceeds the limit. 2. A relief valve is provided in the middle of a pipe located outside the vehicle of the refrigeration cycle, wherein the control means opens the relief valve when the concentration of carbon dioxide detected by the concentration detection means exceeds a set concentration. The vehicle air conditioner according to claim 1, wherein the concentration control process is started by discharging carbon dioxide of the refrigerant to the outside of the vehicle. 3. A temperature detecting means for detecting a refrigerant temperature at an outlet side of a compressor of the refrigeration cycle, wherein the control means controls a temperature of the refrigerant even if a carbon dioxide concentration detected by the concentration detecting means does not exceed a set concentration. If the refrigerant temperature detected by the temperature detecting means exceeds a set temperature,
The vehicle air conditioner according to claim 1 or 2, wherein the compressor is stopped. 4. When the concentration suppression process is started, the control unit displays a failure on the display unit, stops driving the compressor, and prohibits restart of the compressor. The vehicle air conditioner according to any one of claims 1 to 3, wherein: 5. The vehicle air conditioner according to claim 4, further comprising a releasing unit, wherein after the repair of the failed part is completed, the compressor can be restarted by operating the releasing unit.