JPH0767884B2 - Air conditioner for vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle air conditioner having a wide control range of cooling capacity and high efficiency.

[Conventional technology]

FIG. 5 is a block diagram showing a conventional vehicle air conditioner, in which 11 is a smoothing capacitor connected between the output terminals of the main circuit power supply 12, and 5 is applied from the main circuit power supply 12. A first inverter 6 for converting a DC voltage into a three-phase AC of a variable voltage variable frequency (VVVF), 6 is a variable voltage variable DC voltage applied from the main circuit power source 12, similar to the first inverter 5. It is the second inverter that converts the frequency (VVVF) into three-phase AC.

Reference numeral 4 is a control circuit for controlling the output frequencies of the first and second inverters 5 and 6, 7 is a compressor for refrigerant compression connected to the output side of the first inverter 5, and 8 is a second inverter 6. An indoor fan for a cooler connected to the output side, 9 is an outdoor fan for condensing the refrigerant compressed by the compressor 7, and the outdoor fan 9 is an electromagnetic contactor that is closed only when the compressor operates. It is connected to the output side of the second inverter 6 via a main contact 10 (not shown). Reference numeral 13 is an operation command unit of the control circuit 4, 14 is a control power source of the control circuit 4, and 15 is an in-vehicle temperature detector.

Next, the operation will be described. The detection signal of the vehicle interior temperature detector 15 is input to the control circuit 4, and by controlling the output frequency of the first inverter 5 by the output of this control circuit 4, the rotation speed of the compressor 7 is changed and the cooling capacity is improved. Have control. In this case, the indoor fan 8 and the outdoor fan 9 received the output of the second inverter 6 and were in continuous operation at a constant frequency of 60 Hz.

[Problems to be Solved by the Invention]

Since the conventional vehicle air conditioner is configured as described above, especially in the rainy season when the inside of the vehicle is in a high humidity environment, by operating with the cooling capacity reduced, moisture is condensed on the cooler. Although it has an effect of lowering the humidity inside the vehicle, there is a problem that the dehumidifying effect is reduced because the airflow is passed with the dew condensation water adhering to the cooler, and the inside of the vehicle is too cold due to the large air volume.

Further, since the operation control of the first inverter 5 that drives the compressor 7 is performed by the detection signal of only the vehicle interior temperature detector 15, the cooling is performed to improve the high humidity uncomfortable environment at the time when the temperature is relatively low. Even if it is attempted to start the engine, it may not be possible to operate because the detected temperature is lower than the set temperature of cooling. Therefore, the set temperature should be lowered or the operation command unit 13
There was a problem such as driving by manual operation.

The present invention has been made in order to solve the above problems, and even in the air conditioning at a time when the temperature is relatively low, it is possible to prevent overcooling and to keep the dehumidifying effect of the cooler at the maximum, An object is to obtain a vehicle air conditioner capable of improving comfort.

[Means for Solving the Problems]

An air conditioner for a vehicle according to the present invention includes a first inverter that drives a compressor at a variable voltage variable frequency, a second inverter that drives an indoor fan at a variable voltage variable frequency, and a temperature detector inside a vehicle. A humidity detector and a boarding rate detector, and respective detection values of these detectors are input and arithmetically processed, and an intermittent operation area is set by the temperature and relative humidity, and the boarding rate detector in the intermittent operation area is set. And a control circuit for independently changing the output frequency and the intermittent operation time of the first and second inverters according to the detected value.

[Action]

The control circuit according to the present invention sets the intermittent operation region according to the temperature and relative humidity inside the vehicle, and independently changes the output frequency and the intermittent operation time of the first and second inverters according to the boarding rate detection value in the intermittent operation region. By doing so, the operating states of the compressor and the indoor fan are independently controlled, and even when the temperature is relatively low and high humidity, the dew condensation water adhering to the cooler is encouraged to drop and the air volume is reduced to dehumidify. It is possible to enhance the effect.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 5 is a block diagram showing the device of the present invention in which the same parts as those in FIG. 5 are designated by the same reference numerals, and FIG.

In FIGS. 1 and 2, 16 is a relative humidity detector, which is mounted on the inner wall of the vehicle or on the wall. Reference numeral 17 is a occupancy rate detector, and shows an example in which a variable load atmospheric pressure switch for detecting the air pressure of an air spring on the bogie of the vehicle is used.

FIG. 3 is an operation pattern diagram showing the relationship between the vehicle interior temperature and the vehicle interior relative humidity, which is programmed in advance in the storage device (not shown) of the control circuit 4. Third
In the figure, the area A indicates the compressor 7 and the indoor fan 8 by 60.
Hz continuous operation, region a is 50Hz continuous operation of the compressor 7, indoor fan 8 is 60Hz continuous operation, region c is 40Hz continuous operation of the compressor 7, indoor fan 8 is 60Hz continuous operation, region d is the compressor 7 Is continuously operated for 30 Hz, the indoor fan 8 is continuously operated for 60 Hz, the compressor 7 and the indoor fan 8 are intermittently operated in the area E, and neither the compressor 7 nor the indoor fan 8 is operated in the area C.

FIG. 4 shows the operating frequency of the indoor fan 8 and the compressor 7 and the ON duration time (T _ON ) during intermittent operation and the OFF duration time (T
It is an operation pattern diagram showing the relationship of ( _OFF ).

Next, the operation will be described. In the operation pattern diagram shown in FIG. 3, the range surrounded by points ABCD is the area (e), and the relationship value between the vehicle interior temperature and the vehicle interior relative humidity is within the area (e). Under the conditions, the indoor fan and the compressor turn on at their respective operating frequencies and at the time of intermittent operation according to the operation pattern for changes in the occupancy rate shown in FIG.
Operation is controlled by automatically changing the duration (T _ON ) and OFF duration (T _OFF ).

The control circuit 4 sets an intermittent operation area, and lowers the output frequency of the first inverter 5 to the lower limit value of 30 Hz or 40 Hz, for example, according to the boarding detection value in this intermittent operation area,
The output frequency of the second inverter 6 is reduced to 30 Hz and the intermittent operation time is changed.

As a result, the operating states of the compressor 7 and the indoor fan 8 are independently controlled, and comfortable vehicle air conditioning is performed even when the temperature is relatively low and the humidity is high.

In the above embodiment, the operation pattern diagram shown in FIG. 3 shows the operation pattern based on 26 ° C., 50% R, H as an example, but this operation pattern can be changed by changing the reference value. it can.

In addition, the operation pattern diagram shown in Fig. 4 shows an example where the operating frequency of the indoor fan is 30Hz, and T _ON time and T _OFF
The time was repeated, but this was performed at 40Hz during the T _ON time and 30Hz without stopping the indoor fan during the T _OFF time.
By controlling the operation so as to perform the operation, it is possible to eliminate the change in noise caused by the ON-OFF of the indoor fan. In this case, the operating frequency of T _ON time and T _OFF time of the indoor fan can be set arbitrarily.
Not limited to this.

〔The invention's effect〕

As described above, according to the present invention, the intermittent operation area is set on the basis of the vehicle interior temperature and the vehicle relative humidity, and the compressor and the indoor fan are driven by the boarding rate detection value in the intermittent operation area. Since it was configured to change the output frequency and intermittent operation time of the inverter independently of each other, the air conditioner can be lowered to the minimum dose during low load such as the middle period, and the intermittent operation operation can be automatically performed. Since there is no need for detailed manual operation for preventing excessive coldness and the dehumidification effect can be enhanced, there is an effect that comfort in the intermediate period can be significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a vehicle air conditioner according to an embodiment of the present invention, FIG. 2 is a diagram showing the device configuration of the present invention, and FIG. 3 is an operation pattern diagram showing the relationship between temperature and humidity, FIG. 4 is an operation pattern diagram showing the relationship between the operating frequency and the intermittent operating time with respect to changes in the passenger ratio, and FIG. 5 is a block diagram of a conventional vehicle air conditioner. Reference numeral 4 is a control circuit, 5 and 6 are inverters, 7 is a compressor, 8 is an indoor fan, 15 is an in-vehicle temperature detector, 16 is an in-vehicle relative humidity detector, and 17 is a passenger rate detector. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first inverter that drives a compressor for compressing a refrigerant at a variable voltage variable frequency, a second inverter that drives an in-vehicle fan at a variable voltage variable frequency, a temperature detector installed in the vehicle, and Relative humidity detector, occupancy rate detector for detecting the occupancy rate of the vehicle, and intermittent operation area of the compressor and the in-vehicle fan by inputting the detection signal of each of the detectors and the correlation between the in-vehicle temperature and the in-vehicle relative humidity. And the vehicle air having a control circuit for independently setting the output frequency and the intermittent operation time of the first inverter and the second inverter according to the detection value of the passenger factor detector in the intermittent operation region. Harmony device.