JPH0194016A - Air conditioning system for vehicle - Google Patents

Abstract

PURPOSE:To improve the operation of refrigerating cycle in cold weather by suspending both refrigerating cycle and an electric fan when pressure in the refrigerating cycle deviates out of the specified pressure range, and suspending the electric fan when outside air temperature is less than a specified one. CONSTITUTION:When the pressure within refrigerating cycle is either lower than No.1 set pressure (for example, 2.1kg/cm<2>) or equal to or more than No.2 set pressure (for example, 27kg/cm<2>), a pressure switch 430 is turned on. This causes an electromagnetic clutch 213 and an electric fan 221 to be suspended since a cooler control circuit 420 is de-energized even if the cooler switch 410 is turned on. In addition, when outside air temperature which is thermally interchanged with an outside heat exchanger is lower than specified one, the electric fan 221 is suspended with a temperature switch 450 turned off. This constitution prevents the electric fan from being failed because of the shortage of refrigerant and from being refrigerated because of cold weather, thereby enabling it to be operable even in cold weather.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle cooling system that is provided so that the operation of the refrigeration cycle is stopped when the refrigeration cycle runs out of refrigerant.

[Prior Art] This type of vehicle cooling system is equipped with, for example, a pressure switch on the high-pressure side of the refrigeration cycle that is turned ON at a predetermined pressure or higher, and is provided so that the refrigeration cycle does not operate when the pressure switch is OFF. was.

The setting pressure of the pressure switch of the refrigeration cycle in a normal vehicle is set at the saturation pressure of the refrigerant when the outside temperature (outside air) of the vehicle is approximately 0°C (for the refrigerant R-12 normally used), so that dehumidifying heating can be performed even in cold weather. 2.1N9/cI
I).

[Problems to be Solved by the Invention] However, in the above case, the refrigeration cycle operates even when the outside temperature is around 1°C, so if the electric fan installed in the outdoor heat exchanger of the refrigeration cycle freezes, The electric fan is also energized.

As a result, there is a possibility that the fuse in the current path of the electric fan may blow, the motor portion of the electric fan may generate heat, and the resin fan may fall off the motor shaft, or the motor may burn out.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a cooling system for a vehicle that can operate a refrigeration cycle without causing problems due to freezing of an electric fan even in cold weather.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a refrigeration system for vehicles equipped with an outdoor heat exchanger that exchanges heat between the air outside the vehicle interior and the refrigerant flowing inside the vehicle; an electric fan for forcibly exchanging heat between the outdoor heat exchanger and the air outside the vehicle; and detecting the pressure within the refrigeration cycle, when the pressure within the refrigeration cycle is lower than a first set pressure; Alternatively, a refrigeration cycle control means that stops the operation of the refrigeration cycle and the electric fan when the pressure is higher than a second set pressure that is set higher than the first set pressure, and a temperature of the outside air of the vehicle is detected. However, when the temperature of the air outside the vehicle is lower than a predetermined temperature, the above-mentioned function? ) + electric fan control means for stopping the operation of the fan.

[Operations and Effects of the Invention] According to the present invention having the above configuration, when the pressure in the refrigeration cycle is between the first set pressure and the second set pressure and the temperature outside the vehicle compartment is higher than the predetermined temperature, Since the refrigeration cycle control means does not stop the operation of the refrigeration cycle and the electric fan, and the electric fan control means does not stop the operation of the electric fan, the refrigeration cycle and the electric fan can be operated.

When the pressure inside the refrigeration cycle is between the first set pressure and the second set pressure and the temperature outside the vehicle is lower than a predetermined temperature, the refrigeration cycle control means stops the upward movement of the refrigeration cycle and the electric fan. However, the electric fan control means stops the operation of the electric fan. As a result, even if the electric fan freezes, the electric fan will stop operating, preventing damage to the electric fan and blowing out the fuse, and also preventing the electric fan from operating because the outside air temperature is sufficiently low. Both can cool the refrigerant passing through the outdoor heat exchanger. As a result, the conventional problems can be eliminated and the vehicle interior can be cooled or dehumidified even at outside temperatures where the electric fan may freeze.

In addition, during operation of the refrigeration cycle, if the condensing capacity of the outdoor heat exchanger becomes insufficient due to high-speed driving, etc., and the pressure within the refrigeration cycle becomes higher than the second set temperature, the refrigeration cycle control means Since the operation of the cycle is stopped, damage to piping etc. due to pressure increase within the refrigeration cycle is prevented.

Furthermore, when the pressure within the refrigeration cycle is lower than a predetermined pressure, the refrigeration cycle control means stops the operation of the refrigeration cycle and the electric fan. As a result, the vehicle interior cannot be cooled or dehumidified.

[Example] Next, a vehicle cooling device of the present invention will be described based on an example shown in the drawings.

FIG. 2 shows a schematic diagram of a refrigerant circuit of a refrigerated Nicle to which the present invention is applied.

A refrigerant compressor 210 of a refrigeration cycle 200 is connected to a driving engine 110 of the vehicle 100. This refrigerant compressor 210 is connected to the output shaft of the engine 110 and the V-belt 2.
11, connected via a pulley 212, refrigerant compression ta
By energizing the electromagnetic clutch 213 of 210,
It is provided so that the power of the engine 110 is transmitted to the refrigerant compressor 210.

The refrigeration cycle 200 is installed in the front grill of the vehicle at a position where heat is exchanged with the outside air when the vehicle is running, and is equipped with an electric fan 221 that forcibly exchanges heat with the outside air. Heat exchanger 22
0, a receiver 230, a refrigerant depressurizer@240, an indoor heat exchanger 250 installed in the air conditioner 300 in the vehicle interior, connected by a refrigerant pipe 260, and an internal cooling 1R
-12 is filled in a predetermined amount.

The electromagnetic clutch 213 of the refrigerant compressor 210 and the electric fan 221 of the outdoor heat exchanger 220 are energized and controlled by an electric circuit 400 shown in FIG.

The electric circuit 400 includes a cooler control circuit 420 that becomes operable only when a cooler switch 410 provided on a power supply panel or the like is turned on.

This cooler switch 410 and cooler control circuit 420
A pressure switch 430, which is the refrigeration cycle control means of the present invention, is connected in series between. This pressure switch 430, as shown in FIG.
Refrigerant piping 26 between receiver 230 and pressure reducing device 240
Since the pressure inside the refrigeration cycle 200 is lower than the first set pressure (for example, 2.1 to 9/cai), the second set pressure (for example, 27 to 9/cai) is set. /aj) so that it becomes 0 [F].

The cooler control circuit 420 controls energization of the electromagnetic clutch 213 using a temperature adjustment volume, a vehicle interior temperature sensor, etc. (not shown). This electromagnetic clutch 213 has a relay coil 4 for energizing the electric fan 221 in parallel.
40 are connected. This relay coil 440 has
Temperature switch 450 which is electric fan control means of the present invention
are connected in series. This humidity switch 450 is
It is installed upstream of the outdoor heat exchanger 220 and turns off at a predetermined temperature (5° C.) or lower.

In addition, 460 shown in the figure is a battery which is a power source for the vehicle;
470 is a fuse.

Next, the operation of the above embodiment will be explained.

b) The pressure inside the refrigeration cycle 200 is set to the first set pressure (2
, 1Kg/cd) and the second set pressure (27 to 5F/i)
When the temperature of the outside air that is heat exchanged with the outdoor heat exchanger 220 is higher than the predetermined temperature (5° C.), the pressure switch 430 of the refrigeration cycle control means is in the ON state, so the cooler switch 410 is turned ON. As a result, the cooler control circuit 420 is energized and controls the energization of the electromagnetic clutch 213. Furthermore, since the temperature switch 450 of the electric fan control means is also in the ON state, when the electromagnetic clutch 213 is energized, the relay coil 440 is energized, the normally open switch 441 is closed, and the electric fan 221 is energized.

This causes the cooler control circuit 420 to control the electromagnetic clutch 2.
13 is energized, the refrigerant compressor 210 is driven by the engine 110, and the refrigerant mlt cycle 200 is operated.

At this time, the electric fan 221 is energized and starts operating.
The refrigerant passing through the outdoor heat exchanger 220 is transferred to the electric fan 221.
forced cooling. The forcedly cooled refrigerant then removes latent heat from the air inside the vehicle in the indoor heat exchanger 250.
Perform air conditioning or dehumidification operation inside the vehicle.

2) The pressure inside the refrigeration cycle 200 is the first set pressure (2
, Ikg/cd) and the second set pressure (27Kg/cd)
When the temperature of the outside air that is heat exchanged with the outdoor heat exchanger 220 is lower than the predetermined temperature (5° C.), the pressure switch 430 of the refrigeration cycle control means is in the ON state, so the cooler switch 410 is turned ON. As a result, the cooler control circuit 420 is energized and controls the energization of the electromagnetic clutch 213. Furthermore, since the temperature switch 450 of the electric fan control means is in the OFF state, even if the electromagnetic clutch 213 is energized, the relay coil 440 is de-energized, and the energization of the electric fan 221 is stopped.

This causes the cooler 111111 circuit 420 to
When the magnetic clutch 213 is energized, the refrigerant compression 9210 is driven by the engine 110, and the refrigeration Nicle 200 is activated. At this time, the electric fan 221 is de-energized and stops operating, so even if the electric fan 221 freezes due to a drop in outside temperature, damage to the electric fan 221 and blowing of the fuse can be prevented.

Furthermore, at this time, since the temperature of the outside air is sufficiently low, the refrigerant passing through the outdoor heat exchanger 220 can be cooled without operating the electric fan. The cooled refrigerant then removes latent heat from the air inside the vehicle in the indoor heat exchanger 250.
Perform air conditioning or dehumidification operation inside the vehicle.

c) There is a lack of refrigerant in the refrigeration cycle 200 or the outside temperature is 0.
If the pressure inside the refrigeration cycle 200 is lower than the first set pressure (2,1 to 9/Ci), or if the above-mentioned refrigeration cycle is running at high speed, etc. The condensing capacity of the heat exchanger 220 is insufficient,
The pressure inside the refrigeration cycle 200 is less than the second set pressure
'j/d), the pressure switch 430 of the refrigeration cycle control means enters the F state, so even if the cooler switch 410 is turned ON, the cooler control circuit 420 is not energized, and the N magnetic latch 213 is not energized. Electric fan 221 is not energized. As a result, the refrigerant compression Ia 210 may be damaged due to refrigerant shortage, and the cold 111i! due to abnormal pressure inside the refrigeration cycle 200! & tube 26
0 etc. damage is prevented.

In the above embodiment, a dual type pressure switch is used as the refrigeration cycle control means, but a low pressure side pressure switch and a high pressure side pressure switch may be provided independently.

In addition, the pressure switch of the refrigeration cycle control means,
In this example, the temperature switch of the transmission fan control means is connected in series with the functional parts of the electric circuit, but the pressure inside the refrigeration cycle and the outside temperature are detected by the sensor, and the energization of the refrigeration cycle and electric fan is controlled by the computer. It's okay.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electric circuit diagram for controlling a refrigeration cycle, and FIG. 2 is a refrigerant circuit diagram of the refrigeration cycle. In the figure 200... Refrigeration cycle 220... Outdoor heat exchanger 221... Electric fan 430... Pressure switch (refrigeration cycle control means) 450...
Temperature switch (electric fan control means)

Claims (1)

[Scope of Claims] (a) A refrigeration cycle for a vehicle that includes an outdoor heat exchanger that exchanges heat between the air outside the vehicle interior and a refrigerant flowing inside the vehicle; (c) detecting the pressure within the refrigeration cycle, and detecting the pressure within the refrigeration cycle when the pressure within the refrigeration cycle is lower than a first set pressure, or the first set pressure; (d) detecting the temperature of the outside air of the vehicle; and (d) detecting the temperature of the outside air of the vehicle; A vehicle cooling device comprising an electric fan control means for stopping the operation of the electric fan when the temperature of the air is lower than a predetermined temperature.