JPH1148770A - Air-conditioning device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-conditioning device for an automobile to further completely suppress the occurrence of blur of a window glass due to a stop of a compressor effected to prevent freezing of an evaporator under operation according to a manual of an internal air circulation mode (REC mode). SOLUTION: In a car air compressor 1 having a refrigerating cycle, when a stop of a compressor 10 to compress a refrigerant at a refrigerating cycle is inputted to a microcomputer 20, it is decided by the microcomputer 20 whether or not blur occurs on the window glass of an automobile and when it is decided that the blur occurs, after completion of counting of a prescribed time starting from introduction of outside air in a car room, the compressor 10 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to an air conditioner for a vehicle having a function of preventing a window glass in a vehicle compartment from fogging.

[0002]

2. Description of the Related Art At present, an air conditioner for a vehicle (hereinafter referred to as a car air conditioner) generally has a refrigeration cycle for cooling air while changing the state of refrigerant such as evaporation, compression, condensation and expansion. . In the refrigeration cycle, compression of the refrigerant is performed by a compressor. When the compressor sucks and compresses the refrigerant, the pressure in the evaporator on the suction side decreases, and the refrigerant in the evaporator is in a state where it is more likely to evaporate.

It is desirable that the evaporator has a low temperature in order to absorb as much heat of the passing air as possible. However, when the temperature of the evaporator becomes 0 ° C. or less, moisture in the air passing around the radiation fin freezes. . The frozen ice adheres around the fins and impedes the flow of air through the evaporator, which also reduces the heat exchange efficiency in the evaporator. If the efficiency of heat exchange in the evaporator is reduced, in the worst case, the refrigerant may pass through the evaporator in a liquid state and be sucked into the compressor, and the compressor may be damaged.

[0004] In order to prevent such a situation, the car air conditioner detects the temperature of the outside air or the air at the outlet, and when the detected temperature of the evaporator falls below a predetermined value, the compressor is turned off to compress the refrigerant. Many are configured to stop.

[0005] Stopping the compressor to prevent the evaporator from freezing can prevent the heat exchange efficiency of the evaporator from deteriorating and also cause fogging of the window glass.
That is, when the car air conditioner is operated in the inside air circulation mode (REC mode), if heat exchange in the evaporator is stopped, the temperature of the evaporator surface rises, and frost attached to the evaporator surface is melted into water, It blows out into the cabin together with air to increase the humidity inside the cabin. When the humidity in the vehicle interior increases, fogging of the window glass may occur depending on the difference between the outside air temperature and the inside air temperature.

Meanwhile, there is a so-called auto air conditioner that detects the inside air temperature, the outside air temperature, the amount of solar radiation, and the like, and automatically realizes a temperature desired by a user based on the detected information. In such an auto air conditioner, when the car air conditioner detects that the compressor is stopped in the REC mode to prevent the evaporator from freezing, the car air conditioner is automatically switched to the outside air introduction mode (FRE mode) and the outside air is introduced into the room. And introduce
Some are configured to prevent fogging of the window glass.

[0007]

Even in an automatic air conditioner having a configuration for preventing fogging of a window glass, if a user manually sets a REC mode (manual REC mode), the compressor is turned off. It is necessary to cancel the manual REC mode by the detection and to set the automatic mode. At this time, the air intake of the car air conditioner is switched to the FRE mode, and the actuator of the intake door for switching between the inside air intake and the outside air intake is driven.

However, the process of driving the actuator in order to cancel the manual REC mode when it has been set and to switch to the auto mode to switch to the FRE mode is different from the process of directly switching from the auto mode to the FRE mode. It takes time. For this reason, if the compressor is turned off when the manual REC mode is set, the car air conditioner turns off the compressor and enters the REC mode for a few seconds, and there is a possibility that the window glass in the vehicle compartment may become fogged even for a very short time. is there. The occurrence of such fogging on the window glass is not preferable from the viewpoint of securing the visibility of the driving even for a short time.

The present invention has been made in view of the above circumstances, and provides an air conditioner for an automobile which completely suppresses fogging of a window glass due to stoppage of a compressor for preventing evaporator freezing. The purpose is to do.

[0010]

An air conditioner for a vehicle according to the present invention is an air conditioner for a vehicle having a refrigeration cycle, and a compressor stop instruction means for instructing a stop of a compressor for compressing a refrigerant in the refrigeration cycle. And window fogging determining means for determining whether or not window fogging occurs on the window glass of the vehicle when the compressor stop is instructed by the compressor stop instructing means, and it is determined that the window fogging is generated by the window fogging determining means. When, outside air introduction means to start the introduction of outside air into the vehicle interior and outside air introduction timing means to time a predetermined time, and compressor stop control means to stop the compressor after the end of the time measurement of the outside air introduction time, characterized by having Is what you do.

With the above arrangement, when it is instructed to stop the compressor and when it is determined that the vehicle is fogged, the outside air is introduced and the compressor is stopped after a predetermined time has elapsed. Can be controlled. Therefore, sufficient time to drive the actuator for introducing outside air can be secured before the compressor is stopped, and the compressor is turned off after the state in which the outside air can be completely introduced. The fogging of the window glass can be prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

FIG. 1 is a diagram for explaining the overall configuration of a car air conditioner 1 according to the present invention. The illustrated car air conditioner 1 is roughly divided into an air conditioning execution unit 100 having a mechanical configuration and a control unit 200 that controls the air conditioning execution unit.

The air-conditioning execution unit 100 includes a car air conditioner 1
An intake unit 2 for taking air into the air conditioner, a cooler unit 4 for cooling the air taken in, and a heater unit 6 for heating the air flowing from the cooler unit 4. The intake unit 2 is provided with an outside air intake 3 for taking in outside air and an inside air intake 8 for taking in inside air, and the outside air intake 3 and the inside air intake 8 are selectively switched by the intake door 5. The intake unit 2 has a fan F rotated by a motor M.
Is provided, and when the fan F rotates, the outside air intake 3
Alternatively, air is taken into the intake unit 2 from the inside air inlet 8.

The air taken in by the intake unit 2 flows into the cooler unit 4. An evaporator 7 is provided in the cooler unit 4. The evaporator 7 is an evaporator in a refrigeration cycle (only a part is shown) of the car air conditioner 1. The evaporator 7 introduces a gas-liquid mixed refrigerant depressurized by an expansion valve (not shown) and evaporates the refrigerant by exchanging heat with air. I have. The evaporated and vaporized refrigerant exits the evaporator 7 and is sucked into the compressor 10, where it is compressed by the compressor to become liquid again and circulates through the refrigeration cycle.

The evaporator 7 of the present embodiment includes:
An evaporator temperature sensor 9 for detecting the temperature of the air immediately after passing through the evaporator 7 is provided.

The air cooled by the cooler unit 4 flows into the heater unit 6 and is blown out of one of the vent outlet 17, the differential outlet 19 and the foot outlet 15 into the vehicle interior.

The control unit 200 for controlling the air conditioning execution unit 100 described above includes an outside air temperature sensor 21 for detecting the temperature of the outside air, an inside air temperature sensor 22 for detecting the temperature of the inside air,
It has a solar radiation sensor 23 for detecting the solar radiation, a microcomputer 20 connected to the evaporator temperature sensor 9, and an operation panel 30 for setting a desired air conditioning condition to the microcomputer 20 and displaying the air conditioning condition to the user. I have.

The car air conditioner 1 according to the present embodiment comprises an outside air temperature sensor 21, an inside air temperature sensor 22, and a solar radiation sensor 23.
An automatic air conditioner that automatically realizes air conditioning conditions desired by the user based on detected values such as the above, and the microcomputer 20 is configured to be shared with control of processing for this purpose. The microcomputer 20 includes an intake door actuator 5a for driving the intake door 5, a mixed door actuator 11a, an actuator 18a for driving the vent door 18, the differential door 12, and the foot door 13, respectively, according to the air conditioning conditions input from the operation panel 30. 12a and 13a are controlled. In addition, it is connected to the compressor 10 so that an ON / OFF instruction is input to the compressor 10 and an ON / OFF signal is also input from the compressor 10.

FIG. 2 is a diagram for explaining transmission and reception of signals according to the present embodiment performed by control unit 200 described with reference to FIG.

The car air conditioner 1 of the present embodiment is an air conditioner for a vehicle having a refrigeration cycle, and a control unit 200 that controls the air conditioner 1 instructs the compressor 10 to stop the compressor 10 for compressing the refrigerant in the refrigeration cycle. Stop instruction means, which is a window fogging determining means for determining whether or not window fogging occurs on the window glass of the vehicle when the stop of the compressor 10 is instructed. It has a microcomputer 20 which is an outside air introduction means for starting introduction of outside air into the room and an outside air introduction timing means for measuring a predetermined time, and a compressor stop control means for stopping the compressor after the completion of the time measurement.

That is, the microcomputer 20 comprises an outside air temperature sensor 21, an inside air temperature sensor 22, and an evaporator temperature sensor 7.
, A signal for transmitting the detected information is input, and a signal for transmitting the operation state is input from the compressor 10 and the operation panel 30, and a signal for instructing the operation is output to the compressor 10 and the intake door actuator 5a. The microcomputer 20 includes a CPU 27 for calculating and processing the temperatures detected by the outside air temperature sensor 21, the inside air temperature sensor 22, and the evaporator temperature sensor 9, compressor stop data 25a, evaporator temperature frozen data 25b, and window glass fogging used for the calculation performed by the CPU 27. It has a memory 25 for storing the generated data 25c and a timer 29 for measuring a predetermined time.

The compressor stop data 25a indicates that the evaporator 7 may be frozen.
Temperature data of the outside air and evaporator temperature frozen data 25b which are the criteria for determining whether to stop the operation of the compressor are temperature data of the evaporator 7 which determines that it is necessary to stop the compressor 10 in preference to fogging of the window glass, and data of fogging of the window glass. 25c is an outside air temperature sensor 21, an inside air temperature sensor 2
2 is reference difference temperature data for determining whether or not the window glass of the automobile is fogged when the compressor 10 is stopped, based on the difference between the outside air temperature and the inside air temperature detected respectively in Step 2.

In the microcomputer 20, first, the outside air temperature sensor 2
1. The detected outside air temperature is compared with the compressor stop data, and if this value is equal to or less than the outside air temperature data of the compressor stop data 25a, it is determined to stop the compressor. In the present embodiment, the value of the outside air temperature data is
It was about 2 ° C.

Further, a difference between the temperatures of the outside air temperature sensor 21 and the inside air temperature sensor 22 is calculated, and this value is compared with the window glass fogging occurrence data. If the difference between the temperature of the outside air temperature sensor 21 and the temperature of the inside air temperature sensor 22 is equal to or greater than the difference temperature data of the window glass fogging occurrence data, it is determined that fogging occurs on the window glass by stopping the compressor 10,
It is determined whether or not the manual REC mode has been set on the operation panel 30. If the manual REC mode has been set, the manual REC mode is cancelled, and the intake door actuator 5a is instructed to take the air intake into the outside air. Drive.

In this embodiment, at the same time, the manual REC mode is cancelled, switching to the outside air intake is started, and the timer 29 starts measuring a predetermined time, and the control is performed so that the compressor 10 is turned off after the time measurement is completed. doing. The predetermined time measured by the timer 29 is set to a time that is deemed necessary for the intake door actuator 5a to drive the intake door 5 to switch to the FRE mode after canceling the manual REC mode.

Therefore, at the time when the compressor 10 is stopped, the intake door 5 completely opens the outside air intake 3, and even for a short time, the car air conditioner 1 stops the compressor 10 and stops introducing the outside air. There is no situation that it is not done.

FIG. 3 is a flow chart for explaining the processing for preventing the fogging of the window glass from occurring due to the above-described turning off of the compressor.

The flowchart of this embodiment is started when the car air conditioner 1 is turned on (S1). When the car air conditioner 1 is turned on, first, it is determined whether or not the setting of the car air conditioner 1 is in the manual mode (S2). If the auto mode is set, the compressor 10 for preventing the evaporator 7 from freezing in the auto mode. The process enters an auto mode subroutine for controlling the prevention of fogging of the window glass due to the stop (S13). On the other hand, if the result of the determination in step 2 is that the car air conditioner 1 is in the manual mode, it is further determined whether the car air conditioner 1 is set to the REC mode (S3), and as a result, the REC mode is set. If the car air conditioner 1 is a manual REC
Mode is set.

Next, it is determined whether or not an instruction to turn off the compressor 10 from the on state to the off state has been input (S
4). The indication of turning off or on this compressor is
This is output by the process shown in another flowchart for controlling the evaporator freeze prevention process.

When an instruction to turn off the compressor 10 is given,
For example, it is determined whether or not the window glass is fogged when the compressor 10 is stopped by a method of comparing the difference between the outside air temperature and the inside air temperature with the window glass fogging occurrence data 25c (S5). As a result of this determination, when it is determined that fogging occurs in the window glass (S6), the REC mode set in the manual mode is canceled and switched to the FRE mode (S7).

Next, it is determined whether or not the evaporator temperature TE detected by the evaporator temperature sensor 9 is 1 ° C. or more (S8). If TE is equal to or higher than 1 ° C., the timer 29 starts measuring time immediately (S9), and after the time TW measured by the timer 29 reaches T (S10), the compressor 10 is turned off (S11). In this embodiment, the time T is set to approximately 10 to 12 seconds.

On the other hand, if it is determined in step 8 that TE is 1 ° C. or less, it is considered that the evaporator 7 may freeze in a very short time. Stop the compressor immediately (S1
1).

After the above processing is performed, it is determined whether or not the car air conditioner 1 has been turned off (S12). If the car air conditioner 1 has not been turned off, the process returns to step 2; The process ends.

As described above, in the present embodiment, when the car air conditioner 1 is operating in the manual REC mode, the stop of the compressor is instructed to prevent the evaporator 7 from freezing, and the window fogging is instructed to the automobile. Is determined to occur, the outside air is introduced and the compressor 10 is controlled to stop after a predetermined time has elapsed.

Therefore, even if it takes a relatively long time to switch from the manual REC cancellation to the FRE mode by the automatic mode, the compressor is turned off after the switching to the FRE mode is completely completed. The fogging of the glass can be prevented.

In this embodiment, the fogging of the window glass is determined by using the difference between the outside air temperature and the inside air temperature. However, the present invention is not limited to such an example. It is also conceivable to provide a humidity sensor and determine window fogging in consideration of this value and the temperature of the outside air.

[0038]

According to the air conditioner for a vehicle of the present invention, when the stop of the compressor is instructed and it is determined that the window fogging occurs in the vehicle while the car air conditioner is operated by the manual REC, the outside air conditioner is controlled. After the introduction of the compressor, the compressor is controlled to stop after a predetermined period of time, thereby preventing the fogging of the window glass of the automobile even for a moment and stopping the compressor to prevent the evaporator from freezing. It is possible to provide an automotive air conditioner that more completely suppresses fogging of window glass due to the above.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an entire car air conditioner according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating transmission and reception of signals in a control unit in FIG. 1;

FIG. 3 is a flowchart illustrating a process for preventing occurrence of fogging of a window glass by turning off a compressor according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Car air conditioner (air conditioner for vehicles) 5 ... Intake door (outside air introduction means) 5a ... Intake door actuator (outside air introduction means) 7 ... Evaporator 9 ... Evaporator temperature detection sensor 10 ... Compressor 20 ... Microcomputer (compressor stop instruction means) , Window fogging determination means, outside air introduction means, compressor stop control means) 21 ... outside air temperature sensor (window fogging determination means) 22 ... inside air temperature sensor (window fogging determination means) 29 ... timer (outside air introduction timing means)

Claims (1)

[Claims] 1. A vehicle air conditioner (1) having a refrigeration cycle, comprising: compressor stop instruction means (20) for instructing a stop of a compressor (10) for compressing a refrigerant in the refrigeration cycle; Window fogging determining means (20, 21, 22) for determining whether or not window fogging occurs in a window glass of an automobile when the stop of the compressor (10) is instructed by the instructing means (20); When the determination means (20) determines that window fogging occurs, the external air introduction means (5, 5a, 20) for starting introduction of outside air into the vehicle interior and the external air introduction timing means (29) for timing a predetermined time. And a compressor stop control means (20) for stopping the compressor (10) after completion of the timing of the outside air introduction timing means (29). Automotive air conditioning system.