JP2000018736A - Air-conditioning device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool a cold storage unit and to cool a nap room by alternately supplying a refrigerant to a main evaporator and a cold storage unit forcibly when the thermal load of a compressor is larger than a specific value. SOLUTION: In a process where a compressor 9 is turned on and off, a first solenoid valve 12 and a second solenoid valve 16 are alternately opened. As a result, when the compressor 9 is on, a refrigerant is alternately supplied to a main evaporator 14 and a cold storage unit 6. More specifically, when operation is made for 30 minutes when a cold storage switch 28 is turned on in a normal cold storage operation, the second solenoid valve 16 is opened and a refrigerant is supplied to the cold storage unit 16 when temperature at the side of the main evaporator is equal to or less than a specific temperature, thus cooling the cold storage unit 16 without affecting the cooling of an operation chamber and cooling a nap room.

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, and more particularly to a control for cooling a regenerative unit.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 7-329556
The vehicle air conditioner disclosed in the above publication supplies the refrigerant from the main evaporator to the cold storage unit to cool the cold storage unit, and the cold storage unit cools the nap room of the truck. . In this case, when the temperature on the main evaporator side is equal to or lower than a predetermined temperature, the refrigerant from the compressor is supplied to the cool storage unit. Thus, the refrigerant from the compressor is supplied to the cold storage unit when the main evaporator is sufficiently cooled, so that the cooling on the driver's seat side is not significantly affected.

[0003]

However, conventionally, since the refrigerant of the compressor is supplied to the cool storage unit and cooled only when the temperature of the main evaporator is lower than a predetermined temperature, for example, in the summer, If the heat load of the compressor is large, such as when operating under the scorching sun, the temperature of the main evaporator does not easily fall below the predetermined temperature, so that the refrigerant from the compressor cannot be supplied to the cold storage unit. Therefore, the cold storage unit is not cooled forever, and therefore, when taking a nap by stopping the operation of the automobile, the nap room is not cooled by the cold storage unit, so that the nap is hindered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. Even when the heat load is large and the temperature of the main evaporator does not drop below a predetermined temperature, the refrigerant from the compressor is supplied to the regenerator unit. The above-mentioned drawbacks are eliminated by making it possible to cool the regenerative storage unit and to make it possible to cool the nap room.

[0005]

According to a first aspect of the present invention, there is provided a forced cold storage operation function for forcibly supplying a refrigerant to a main evaporator and a cold storage unit alternately when a heat load of a compressor is larger than a predetermined value. Set to.

According to the second aspect of the present invention, the case where the operation time of the compressor is longer than the predetermined time is regarded as the case where the heat load of the compressor is larger than the predetermined value, and the forced cold storage operation function is set.

According to the third aspect of the present invention, in the forced cold storage operation function, the time during which the refrigerant is supplied to the main evaporator is set longer than the time during which the refrigerant is supplied to the cold storage unit.

According to the fourth aspect of the invention, the setting of the forced cold storage operation function is performed at predetermined time intervals.

According to the fifth aspect of the present invention, when the cold storage switch is turned on before the forced cold storage operation function is set, the normal cold storage operation function is set for a fixed time.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 and 2 are a side view and a circuit diagram, respectively, showing an embodiment of a vehicle air conditioner according to the present invention. In each of the drawings, reference numeral 1 denotes a truck. A nap room 4 is provided via the partitioning section 3, and a cool storage unit 6 is installed below a bed 5 provided in the nap room 4. An air conditioner 8 constituting a vehicle air conditioner according to the present invention is provided inside a dashboard 7 of the driver's cab 2. As shown in FIG. 2, the air conditioner 8 has a main cooling system including a condenser 10 to which a refrigerant from a compressor 9 is supplied, a receiver tank 11, a first solenoid valve 12, an expansion valve 13, and a main evaporator 14. Cycle 15 is provided.
Further, it includes a second solenoid valve 16 to which the refrigerant is supplied from the receiver tank 11 side, an expansion valve 17, a subcooling cycle 19 including the cold storage unit 6, and a check valve 18.

The temperature of the main evaporator 14 is detected by a thermoswitch 20.
Is supplied to the air conditioner control unit 21. The air conditioner control unit 21 includes an outside air temperature sensor 22, an inside air temperature sensor 23, a solar temperature sensor 24, and a temperature setting unit 25.
And the like, as well as signals from the engine start switch 26, the front air conditioner switch 27, the cool storage switch 28, and the like. The air conditioner control section 21 controls the electromagnetic clutch 29 of the compressor 9 on and off so as to control the compressor 9 on and off so that the vehicle interior temperature becomes the temperature set by the temperature setting device 25. The air-conditioning control unit 21 also controls the cold storage control unit 3 based on a signal from the thermo switch 20.
By controlling 0, the cool storage control unit 30 turns on and off the first solenoid valve 12 and the second solenoid valve 16 to control opening and closing. The cold storage unit 6 is also provided with a thermoswitch 32, and the thermoswitch 32 controls the cold storage control unit 30.

The regenerative unit 6 is constituted by, for example, meandering a pipe constituting a refrigerant flow path and covering the entire circumference of the pipe with a cold insulator. Based on the refrigerant supplied through the pipe 16 flowing through the pipe, the cold insulator is cooled and cold storage is performed. The cold insulator is cooled, and cool air is supplied to the nap room 4 from a cool storage unit blower (not shown).
Thereby, the lower part of the bed 5 and the entire nap room 4 are cooled.

The operation of the vehicle air conditioner having the above configuration will be described below with reference to FIGS. In the flowchart of FIG. 3, the engine start switch 26 is turned on in step 33, and the front air conditioner switch 27 is turned on in step 34.
Based on the operation of the air conditioner control unit 21, the compressor 9 is operated to perform air conditioning. As described above, air conditioning is performed based on the operation of the air conditioner control unit 21. The air conditioner control unit 21 fetches signals from the outside air temperature sensor 22, the inside air temperature sensor 23, the solar radiation temperature sensor 24, and the temperature setting unit 25, On / off control of the compressor 9 is performed so that the temperature in the vehicle interior becomes the set temperature.

In this state, when the driver turns on the cold storage switch 28 in step 35, the vehicle air conditioner
In step 36, the normal cold storage operation function is set for a predetermined time (for example, 30 minutes in this example). In this normal cold storage operation, as shown in FIG.
The first solenoid valve 12 and the second solenoid valve 16 are alternately opened based on the on / off operation of the thermo switch 20 to supply the refrigerant from the compressor 9 to the main evaporator 14 and the cold storage unit 6 alternately. That is, based on the on / off control of the compressor 9 as shown in FIG. 7 (a), the temperature of the main evaporator 14 follows the on / off and is set in advance as shown in FIG. 7 (b). It changes upward and downward with reference to the range of the off level and the on level that has been set. In this case, as shown in FIG. 4, the off level is, for example, 7 ° C., and the on level is, for example, 4 ° C.
And a hysteresis H is provided between the off level and the on level. As a result, as shown in FIG.
Is turned on when the temperature on the front side of the main evaporator 14 is lower than a predetermined level, and turned off when the temperature on the front side of the main evaporator 14 is high. Here, in the cold storage control unit 30, when the thermo switch 20 is off, the first solenoid valve 12
Is turned on, the second solenoid valve 16 is turned off, and when the thermoswitch 20 is on, the first solenoid valve 12 is turned off, the second solenoid valve 16 is turned on, and the first solenoid valve 12 and the second solenoid valve are turned on. The valves 16 are alternately opened.

As described above, when the compressor 9 is on / off controlled, the first solenoid valve 12 and the second solenoid valve 1 are controlled.
When the compressor 9 is turned on, the refrigerant is alternately supplied to the main evaporator 14 and the cold storage unit 6 within the range shown by the hatched portions in FIGS. 7D and 7E. Become. That is, in the present invention, the normal cold storage operation of step 36 is performed for 30 minutes when the cool storage switch 28 is turned on, so that when the temperature on the main evaporator side is equal to or lower than the predetermined temperature, the second solenoid valve 16 is activated. When opened, the refrigerant is supplied to the cool storage unit 6, so that the cool storage unit 6 can be cooled without affecting the cooling of the cab 2 and the nap room 4 can be cooled.

Next, 30 minutes after the cold storage switch 28 is turned on, in step 37, the operation rate of the compressor 9 for the previous two minutes (operation (on) per unit time).
Time Ts) is determined. FIG. 7A shows the ON time Ts per unit time 60 seconds as the operation rate of the compressor 9.
In the case of 40 seconds (40/60 × 100 ≒ 67%) or less as shown in FIG. 7, since it can be determined that the heat load of the compressor 9 is not so large, the temperature of the main evaporator is
As shown in FIG.
As shown in (d) and (e), the first solenoid valve 12 and the second solenoid valve 16 are opened alternately, and the cool storage unit 6 is cooled. In this case, the normal cold storage operation based on step 38 is performed. That is, based on the normal cold storage operation 38, the refrigerant is supplied to the cold storage unit 6 in accordance with the operation shown in FIGS. Next, in step 37, as shown in FIG. 8A, when the ON time Ts per unit time 60 seconds of the compressor 9 is as long as 40 seconds (67%) or more, the vehicle is driven under the hot summer weather. When the heat load under the hot sun is large, the temperature of the main evaporator 14 does not decrease to the ON level as shown in FIG. 8B. In such a case, the thermoswitch 20 remains off as shown in FIG. 8 (c), whereby the second solenoid valve 16 is turned on while the first solenoid valve 12 remains on. Is turned off, and the refrigerant from the compressor 9 is not supplied to the cool storage unit 6 at all.

However, when the operating time Ts per unit time of the compressor 9 is long, such as 40 seconds or more (when the operating rate is as high as 67% or more), the process proceeds to step 39 in the present embodiment. Then, the operation is set to the forced cold storage operation control, and as shown in FIG. 6, the cold storage control unit 30 causes the first solenoid valve 12 and the second solenoid valve 16 to connect the main evaporator 1 to the main evaporator 1.
4 forcibly and alternately regardless of the operation of the thermoswitch 20. In the present embodiment, the first solenoid valve 12
Is turned on for 30 seconds (per unit time 60 seconds), the second solenoid valve 16 is closed for 30 seconds (per unit time 60 seconds), and the first solenoid valve 12 is closed for 20 seconds (per unit time 60 seconds).
The second solenoid valve 16 is turned off for 2 seconds.
It is assumed that it is turned on for 0 seconds (per unit time of 60 seconds) and opened. As described above, by forcibly opening the first solenoid valve 12 and the second solenoid valve 16 alternately, the refrigerant from the compressor 9 can be forcibly supplied to the cold storage unit 6. Thermo switch 20
Can be supplied to the cold storage unit 6 even if it remains off when the heat load is large, so that the cold storage unit 6 can be cooled.

As in the present embodiment shown in FIG. 6, the opening time of the first solenoid valve 12 is set to 30 seconds per 60 seconds during the forced cold storage operation, and is slightly longer than the opening time of the second solenoid valve 16. Thus, there is no possibility that the cooling of the main evaporator 14 will be affected so much. In this case, when performing the forced cold storage operation of step 39, the forced cold storage operation may be performed for a predetermined time Tm as shown in FIG.

In this embodiment, the operation time Ts of the compressor per unit time is detected, and the operation time Ts is determined to be longer or shorter than 40 seconds (the operation rate is 67%).
Although it has been described that the thermal load of the compressor is determined, the magnitude of the thermal load is determined by determining the magnitude of the signal from the outside air temperature sensor 22 as a method of detecting the thermal load. It may be detected. Step 36 when the cool storage switch 28 is turned on
The operation time of the normal cold storage operation is not limited to 30 minutes, and may be set to be long or short in consideration of the capacity of the cold storage unit 6 and the like. Further, the operation time per unit time of the compressor that determines the switching between the normal cold storage operation in step 38 and the forced cold storage operation in step 39 is not limited to 40 seconds, and the most preferable time can be appropriately obtained by experiments or the like. . Various operating times of the first solenoid valve 12 and the second solenoid valve 16 shown in FIG. 6 are conceivable in design. Further, the case where the thermoswitch 20 is not turned off after the set time may be regarded as the case where the heat load is larger than a predetermined value. Further, the operating rate of the compressor may be obtained by detecting the off-time per unit time of the compressor, or may be obtained by detecting the ratio of the on-time to the off-time. Further, when the compressor is of a capacity control type, it does not perform on / off control. However, the magnitude of the capacity may be detected, and the forced cold storage operation may be switched according to the magnitude of the capacity.

[0020]

According to the first aspect of the present invention, when the heat load of the compressor is larger than a predetermined value, the forced cold storage operation function is set so that the refrigerant is forcibly and alternately supplied to the main evaporator and the cold storage unit. Therefore, even when the heat load is large, the regenerator unit is cooled, so that the nap room can be cooled, and the feeling of the nap person can be improved.

According to the second aspect of the present invention, the case where the operation rate of the compressor is larger than the predetermined value is regarded as the case where the heat load of the compressor is larger than the predetermined value, and the forced cold storage operation function is set. Therefore, it is easy to determine the magnitude of the heat load, and the switching between the normal cold storage operation function and the forced cold storage operation function is ensured.

According to the third aspect of the present invention, the time during which the refrigerant is supplied to the main evaporator is set to be longer than the time during which the refrigerant is supplied to the cold storage unit, so that the cooling of the main evaporator is not significantly impaired. The unit can be cooled.

According to the fourth aspect of the present invention, the setting of the forced cold storage operation function is performed at predetermined time intervals. This also allows the cold storage operation by the main evaporator without significantly impairing the refrigerant in the operation room. The unit can be cooled.

According to the fifth aspect of the present invention, the normal cold storage operation function is set for a fixed time after the cold storage switch is turned on. Therefore, even when the heat load is large, the main evaporator is operated for a fixed time. Since the refrigerant is supplied, the cooling of the main evaporator is not impaired. Also,
After a certain period of time, even if the thermal load is large, the forced cold storage operation function is set, so that the cold storage unit can be continuously cooled, and there is no possibility that the comfort of the occupant when taking a nap is impaired.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart showing a vehicle air conditioner according to one embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 5 is a time chart for explaining the operation of the embodiment of the present invention;

FIG. 6 is a time chart for explaining the operation of the embodiment of the present invention;

FIG. 7 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 8 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 9 is a time chart showing another embodiment of the present invention.

[Explanation of symbols]

1 truck, 2 cab, 3 partition, 4 nap room, 5 bed, 6 cold storage unit, 10 condenser, 11 receiver tank, 12 first solenoid valve, 13
Expansion valve, 14 main evaporator, 15 main cooling cycle, 16 second solenoid valve, 17 expansion valve, 18 check valve, 20 thermoswitch, 21 air conditioner control unit, 2
8 Cold storage switch, 30 cold storage control units.

Claims (5)

[Claims] 1. A vehicle air conditioner comprising a main evaporator and a cold storage unit, and having a normal cold storage operation function for supplying a refrigerant from a compressor to the cool storage unit when the temperature on the main evaporator side is equal to or lower than a predetermined value. When the heat load of the compressor is larger than a predetermined value, instead of the normal cold storage operation function, the forced cold storage operation function for forcibly supplying the refrigerant to the main evaporator and the cold storage unit alternately is set. Characteristic vehicle air conditioner. 2. The forced cold storage operation function is set as a case where the operating rate of the compressor within a predetermined time is larger than a predetermined value, when the heat load of the compressor is larger than a predetermined value. Item 4. The vehicle air conditioner according to Item 1. 3. In the forced cold storage operation function, the time during which the refrigerant is supplied to the main evaporator is set longer than the time during which the refrigerant is supplied to the cold storage unit.
2. The vehicle air conditioner according to claim 1. 4. The vehicle air conditioner according to claim 1, wherein the setting of the forced cold storage operation function is performed at predetermined time intervals. 5. A vehicle comprising a main evaporator, a cold storage unit, and a cold storage switch, and having a normal cold storage operation function of supplying a refrigerant from a compressor to the cold storage unit when the temperature on the main evaporator side is equal to or lower than a predetermined value. In the air conditioner for use, after the normal cold storage operation function is set for a certain period of time after the cold storage switch is turned on, when the heat load of the compressor is larger than a predetermined value, refrigerant is mainly used instead of the normal cold storage operation function. An air conditioner for a vehicle, wherein the air conditioner is set to a forced cold storage operation function for forcibly supplying an evaporator and a cold storage unit alternately.