JPS6218488Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a vehicle air conditioner, and prevents the cooling function from stopping due to engine revving when the refrigerant is in a high pressure state by operating the air conditioner during idling. It relates to a vehicle air conditioner.

Fig. 1 shows a conventional example of a cooling device for a vehicle air conditioner, where 1 is an ignition switch, 3 is an ignition switch, and 3 is an ignition switch.
is an air conditioner switch, 5 is an air conditioner relay that operates when the ignition switch 1 and air conditioner switch 3 are on, 7 is an evaporator, 9 is an expansion valve, 11 is a compressor, and 13 is a condenser ( 15 is a condenser fan (air blower) for cooling the condenser 13, 17 is a compressor 11, condenser 1
3. Detect that the pressure of the refrigerant in the high-pressure pipe between the expansion valves 9 has reached a predetermined pressure (for example, about 15 kg/cm ² G), turn on the contact 17-a, and rotate the condenser fan 15. A high pressure switch 19 is used to adjust the pressure of the refrigerant in the high pressure pipe to a predetermined pressure (for example,
This is a liquid tank with a built-in safety device that detects when the temperature reaches 38 kg/cm ² G) and opens the refrigeration cycle consisting of a compressor 11, a condenser 13, an expansion valve 9, and an evaporator 7. Note that 21 is a battery.

In the operation of the above-described vehicle while the vehicle is running, the gaseous refrigerant compressed by the compressor 11 to a high temperature and high pressure is sent to the condenser 13,
It is cooled and liquefied by the wind generated by the condenser fan 15 due to the operation of the high-pressure switch 17 and the outside air introduced by the running of the vehicle. Note that the condenser fan 15 has a refrigerant pressure of 15 kg/
When the pressure exceeds cm ² G, the high voltage switch 17 is turned on and the electric current is supplied from the battery 21 to rotate. The liquefied refrigerant is once stored in the liquid tank 19 and cleaned, and then sent to the expansion valve 9, where the pressure is reduced and the refrigerant becomes a low-temperature, low-pressure atomized state. The atomized refrigerant is blown into the evaporator 7, absorbs heat from the outside, and is vaporized. Here, when the air inside the vehicle is passed between the pipes of the evaporator 7 using a blower motor (not shown), the heat is removed from the air by the evaporator 7 and it turns into cold air, thereby cooling the interior of the vehicle. be able to. On the other hand, the vaporized refrigerant is recovered and sent to the compressor 11, where it is adiabatically compressed and becomes a high-temperature, high-pressure gas state.
3, where it is liquefied and used for air conditioning (Nissan Motor Co., Ltd. Service Bulletin, Nissan Sedrick, Gloria, June 1973, No. 337, pp. 181-182).

The above configuration is well known as a cooling device for a vehicle, and can cool the interior of a vehicle using the latent heat of evaporation when the refrigerant evaporates as a low heat source. On the other hand,
When the interior of the vehicle is cooled while idling, the condenser is naturally cooled, so the heat dissipation in the condenser is not sufficient, and the pressure of the refrigerant gradually increases. Cooling capacity decreases. In addition, when the refrigerant pressure increases, for example, if you start the engine to stabilize engine rotation, or to charge the battery when the battery's electromotive force is low, , the pressure of the refrigerant rises rapidly due to the operation of the compressor, so the high pressure switch operates when the pressure of the refrigerant reaches 15 kg/cm ² G, but due to the time delay of the switch, the condenser fan rotates and cools the condenser. However, before the pressure of the refrigerant can be lowered, the pressure of the refrigerant reaches 38 kg/cm ² G or higher, and a safety device built into the liquid tank is activated, opening the refrigeration cycle and stopping the cooling action. Sometimes. In order to prevent such a stoppage of the cooling action, the objective can be achieved, for example, by providing another pressure switch in series with the high pressure switch, but this is time consuming and causes an increase in costs.

Therefore, when the vehicle interior is being cooled during idling, it is necessary to lower the pressure of the refrigerant.

This idea was created in view of the above, and prevents the safety valve from operating and stopping the cooling when the engine is idling and cooling due to a sudden increase in refrigerant pressure due to engine revving. Therefore, when the idling state of the engine is detected, the cooling fan is operated to lower the refrigerant pressure.

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

FIG. 2 shows an embodiment of this invention, and its features include an engine rotation detector 23 that detects and outputs the idling state of the engine, and when the detector 23 is outputting an output, the blower The condenser fan 15 constituting the refrigerant is rotated to cool the condenser (condenser) and lower the pressure of the refrigerant in the high-pressure piping. Note that the same reference numerals as in FIG. 1 indicate the same parts.

The engine rotation detector 23 constitutes a blower operation control means, and inputs an ignition pulse to a comparator (not shown) built in the detector 23 for comparison, and determines the engine rotation speed. When the speed is below the set value (for example 1400rpm), battery 2
A built-in switch (not shown) is turned on so as to supply the current from 1 to the capacitor fan 15. Note that the engine rotation detector 23 can also be used for correcting engine rotation during idling.

Next, the operation of this embodiment will be explained.

When the ignition switch 1 is turned on while the air conditioner switch 3 is on, ignition pulses begin to be input to the engine rotation detector 23. The engine rotation detector 23 detects the engine rotation speed based on the ignition pulse, for example.
When a state of 1400 rpm or less is detected, a built-in switch is turned on to allow current from the battery 21 to flow to the capacitor fan 15, thereby causing the capacitor fan 15 to rotate. Therefore, when the vehicle interior is being cooled in an idling state, the condenser fan 15 rotates to cool the condenser 13 and radiate heat.
As the pressure of the refrigerant decreases, the pressure of the refrigerant in the high-pressure pipe between the compressor 11, the condenser 13, and the expansion valve 9 also decreases.
Therefore, when the engine is revved under such conditions, the pressure of the refrigerant by the compressor 11 increases to a pressure (for example, 38 kg/cm ² G) sufficient to activate the safety device in the liquid tank 19. Never.

When the vehicle starts running, the switch in the engine rotation detector 23 is turned off due to the increase in engine rotation speed, and the rotation of the condenser fan 15 is stopped. However, the condenser 13 is cooled by the running wind. The interior of the vehicle continues to be cooled without the pressure of the refrigerant in the high-pressure pipe increasing. Then, the cooling capacity of the condenser 13 due to the running wind becomes insufficient, and the pressure of the refrigerant increases.
When the pressure reaches 15 kg/cm ² G, the high pressure switch 17 is activated, and the current from the battery 21 is transferred to the air conditioner relay 5 and the contact 17-a of the high pressure switch 17.
Since the condenser 13 is cooled by the wind generated by the rotation of the condenser fan 15 and the traveling wind, the cooling capacity of the condenser 13 is restored, and the refrigerant is Pressure also decreases.

According to this embodiment, when the vehicle interior is being cooled while idling, the condenser fan is rotated to cool the condenser and reduce the pressure of refrigerant in the high-pressure pipe between the compressor, condenser, and expansion valve. As a result, the cooling function of the air conditioner will not stop due to the refrigeration cycle becoming open due to the pressure increase of the refrigerant due to engine revving, and the cooling function of the air conditioner will not stop when the engine is idling. Cooling capacity will also be improved.

This invention is in accordance with the scope of the above-mentioned utility model registration claim, so that when the engine is idling and cooling, the safety valve is activated due to a sudden increase in refrigerant pressure due to the engine revving, and the cooling is stopped. You can prevent it from getting stowed away.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example of a vehicle air conditioner, and FIG. 2 shows an embodiment of this invention. Explanation of the symbols representing the main parts of the figure: 7...evaporator, 11...compressor, 9...expansion valve, 13...condenser, 15...condenser fan, 23...engine rotation detector.

Claims (1)

[Scope of utility model registration request] In a device for cooling a vehicle interior by a refrigeration cycle having an evaporator, a compressor, an expansion valve, a condenser, and a blower for cooling the condenser, a high-pressure switch is interposed in the blower for the condenser, and the high-pressure switch An engine idling detector is interposed in parallel with the first circuit means for rotating the air blower when a state of a predetermined pressure or higher in the refrigeration cycle is detected by the refrigeration cycle, and a second circuit means for rotating the air blower when the engine idling is detected by the detector. An air conditioner for a vehicle, characterized in that a circuit means is connected thereto.