JPS6316017B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention is a so-called multi-type vehicle for use in which evaporators are connected in parallel, each evaporator is installed at an appropriate position in the vehicle, and the temperature of each evaporator can be controlled individually. This relates to air conditioning equipment.

If temperature control is to be performed in an automobile air conditioner equipped with multiple evaporators, it is not possible to adopt the conventional method of turning the compressor on and off. It's compressusa
This is because if they are turned on and off, refrigerant will no longer be supplied to all evaporators, making it impossible to control the temperature individually.

Therefore, in this invention, an evaporation pressure control valve is provided in the outlet pipe of the evaporator, and this evaporation pressure control valve is driven by the discharge side pressure of the compressor.
The supply control of the discharge side pressure is performed by a solenoid valve installed in the pressure supply pipe leading the discharge side pressure, and the solenoid valve is operated by the output from the thermoswitch, which allows the capacity of each evaporator to be controlled. It is designed so that it can be controlled.

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

In Fig. 1, compressor 1 for compressing refrigerant
Although not shown, is driven and rotated by a driving engine or the like. When a cooler switch (not shown) is closed, this compressor 1 for compressing refrigerant continues to be driven until it is opened. The discharge side of the compressor 1 is connected to a condenser 3 via a pipe 2a, and the refrigerant pressurized by the compressor 1 is condensed and liquefied in the condenser 3. The condensed and liquefied refrigerant flows through the pipe 2b and the pipe 2b' branched from the pipe 2b to the evaporators 4a and 4b provided in parallel, respectively.
It is evaporated within a and 4b. Evaporator 4
For example, one of a and 4b is attached below the instrument panel of the driver's seat of the vehicle, and the other one is attached to the ceiling of the vehicle. Expansion valves 5a and 5b are provided on the inflow sides of the evaporators 4a and 4b.

The refrigerant evaporated and vaporized in the evaporators 4a, 4b flows out from the pipes 2c, 2c' on the outlet side of the evaporators 4a, 4b.
An evaporation pressure control valve 6 is provided at the end of the circuit 2c', and the evaporation pressure control valve 6 opens and closes the flow path and collects the superheated refrigerant to the suction side of the compressor 1 via the collection outlet pipe 2d. Connected.

An example of the evaporation pressure control valve 6 is shown in FIG. 2, and has a structure in which two evaporation pressure control valves respectively provided in two pipes 2c and 2c' are combined.

The evaporation pressure control valve 6 has a body 7 having a space 10 therein, and caps 9a and 9b having connectors 8a and 8b are fitted to both ends of the body 7 by brazing. Further, to this body 7, pipes 2c and 2c' are connected from the center to the end portion side, and a collection outlet pipe 2d is connected to the center.

Further, within the space 10 of this body 7, pistons 11a and 11b are provided at both ends thereof,
The pistons 11a and 11b are pushed toward both ends by springs 12 and 12b.
When pressure chambers 13a and 13b consisting of caps 9a and 9d are not supplied with discharge side pressure, they are at both end positions as shown in the figure. That is, the pipes 2c, 2c' are communicated with the collective outlet pipe 2d via the space 10 of the body 7.

The pistons 11a and 11b have an annular groove 1 on their outer periphery.
4 is formed, and a small diameter hole 15 is drilled in the radial direction. In addition, the pistons 11a and 11b
The spring seats 20a, 20b of the springs 12a, 12b that press the springs 12a, 12b are engaged with protrusions 21 formed on the body 7 to determine their positions.

A pressure supply pipe 1 is provided in the pressure chambers 13a and 13b.
6a and 16b are connected, and the pressure supply pipe 16
a, 16b (pressure on the discharge side is approximately 14
Kg/cm ² ) is supplied, the pistons 11a, 11
b is displaced against the springs 12a, 12b to close the openings of the pipes 2c, 2c', and the pipes 2c, 2c' are closed.
2c' and the collective outlet pipe 2d are cut off.

Furthermore, the pressure inside the pipes 2c and 2c' is approximately 2Kg/cm ²
Since the pressure difference between the pressure (14 kg/cm ² ) and the pressure applied to the pistons 11a and 11b is large, it is reliably and immediately closed.

Returning to FIG. 1, pressure supply pipes 16a, 16
One end of b is connected between the discharge side of the compressor 1 and the condenser 3, and the other end is connected to the connectors 8a and 8b protruding from both ends of the evaporation pressure control valve 6, as described above. The pressure supply pipes 16a, 16b are provided with so-called electromagnetic valves 17a, 17b, which are valves that are opened and closed by electromagnetic force. These solenoid valves 17a, 17b are
It is opened and closed by the output of thermo switches 18a and 18b, which will be described below.

The thermoswitches 18a, 18b have their heat sensitive parts 19 provided on the blowing sides of the respective evaporators 4a, 4b, and
This is to control the temperature of the cold air from B so that it does not fall below the set temperature of the thermoswitch.When the heat load becomes small and the temperature of the cold air falls below the set temperature,
From thermo switches 18a and 18b to solenoid valve 17
Current flows through the pipes 16a and 17b, opening the passage, and the pressure on the discharge side (approximately 14Kg/cm ² ) increases to the pressure supply pipes 16a and 16a.
It is supplied to the evaporation pressure control valve 6 described above via 6b.

In the above configuration, when the compressor 1 is driven, the refrigerant is supplied to the evaporators 4a, 4b, and the evaporators 4a, 4b start cooling action, and the air passing through the evaporators 4a, 4b is turned into cold air and sent to a predetermined outlet. It is blown out into the passenger compartment. In such a state, the solenoid valves 17a, 1
7b is closed, the evaporation pressure control valve 6 is opened, and the pipes 2c, 2c' and the collective outlet pipe 2d are in communication.

The interior of the vehicle is gradually cooled, and the thermo switch 18
When the cold air temperature falls to the set value a, a driving current is passed from the thermoswitch 18a to the solenoid valve 17a, and the solenoid valve 17a is opened. For this,
The pressure on the discharge side of the compressor 1 is supplied to the pressure chamber 13a of the evaporation pressure control valve 6 via the pressure supply pipe 16a.
is supplied to the piston 1 at this pressure.
1a is moved against the spring 12a, and the pipe 2c is closed. Therefore, evaporator 4
The refrigerant no longer flows out from the evaporator 4a, the internal pressure increases, and the capacity of the evaporator 4a decreases to the extent that it is in a stopped state. In addition, even in such a case, since the small diameter hole 15 exists, a minimum amount of refrigerant flows to lubricate the oil and prevent vacuum operation.

Even if the pistons 11a and 11b are both closed, the pressure on the suction side of the compressor 1 will be approximately 0.5
It is maintained at around Kg/ ^cm2 .

When the temperature of the cold air rises and reaches the set value of the thermoswitch 18a, the energization to the solenoid valve 17a is stopped, the supply of discharge side pressure is stopped, and the pressure in the pressure chamber 13a of the evaporation pressure control valve 6 is discharged. and decreases. For this purpose, the piston 11a has a spring 1
2a is pushed back, the pipe 2c of the evaporator 4a is opened, and the refrigerant begins to flow out.
As the pressure inside the evaporator 4a decreases, the capacity increases and the temperature of the cold air decreases, thus acting to cope with the rise in temperature inside the vehicle.

In addition, in this embodiment, the evaporation pressure control valve 6
Although the two evaporation pressure control valves are integrated, the present invention is not limited to this, and individual evaporation pressure control valves may be provided in the pipes 2c and 2c'.

As explained above, according to the present invention, the evaporation pressure control valve is provided in the pipe on the outlet side of the evaporator, the evaporation pressure control valve uses the discharge side pressure of the compressor as a driving source, and the supply control of the discharge side pressure is performed on the discharge side. This is done by a solenoid valve installed in the pressure supply pipe that guides the side pressure, and the solenoid valve is operated by the output from a thermoswitch.This makes it possible to control the capacity of each evaporator, and Since the discharge side pressure of the compressor is used as the drive source for the evaporation pressure control valve, it has the advantage of being able to operate reliably and immediately. Furthermore, the evaporation pressure control valve has a structure in which two evaporation pressure control valves are combined, and has the advantage of being structurally simple.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a cooling cycle of an automobile hot water air conditioner according to the present invention, and FIG. 2 is a sectional view of an evaporation pressure control valve. 1... Compressor for refrigerant compression, 2c, 2c'...
...Pipe, 3...Condenser, 4a, 4b...Evaporator 6...Evaporation pressure control valve, 7...Body, 11a, 11b...Piston, 13a, 13
b...Pressure chamber, 16a, 16b...Pressure supply pipe, 17a, 17b...Solenoid valve, 18a, 18b
...Thermo switch.

Claims (1)

[Claims] 1. In a cooling cycle having at least one compressor 1 and a plurality of evaporators 4a, 4b connected in parallel, the evaporators 4a, 4
The pipes 2c and 2c' on the outlet side of b
An evaporation pressure control valve 6 is provided to open and close the passages 2c and 2c'.
a, 16b to move the evaporation pressure control valve 6 and close the passages of the pipes 2c, 2c'. Valve 17a, 1
7b, and the opening and closing of the electromagnetic valves 17a and 17b are operated by outputs from thermoswitches 18a and 18b. 2. The evaporation pressure control valve 6 has pipes 2c and 2 connected to the ends from the center of the body 7, which has a space inside.
c' and the central outlet pipe 2d.
The structure is such that the refrigerant flows from the pipes 2c and 2c' to the collecting pipe 2d by connecting the two pistons 11a and 11b.
are springs 12a and 12b toward both ends, respectively.
The piston 1 is arranged so as to be pressed by the
Pressure chambers 13a, 13 that introduce pressure to move 1a, 11b against springs 12a, 12b
pressure is introduced into the pressure chambers 13a, 13b, and the pistons 11a, 11b are moved by the spring 1.
When moved against the pipes 2a and 12b, the pipe 2c,
2. The control device for an air conditioner for an automobile according to claim 1, wherein the air conditioner 2c' is closed. 3. The control device for an air conditioner for an automobile according to claim 2, wherein an annular groove 14 is formed on the outer peripheral surface of the pistons 11a and 11b. 4. The control device for an air conditioner for an automobile according to claim 2, wherein the pistons 11a and 11b are formed with small diameter holes 15 in the radial direction.