JPH0547754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a four-way reversing valve used for switching between cooling and heating in a heating and cooling air conditioner.

Conventional technology A conventional differential pressure driven four-way reversing valve has three chambers: a high pressure chamber, a low pressure chamber, and a pressure conversion chamber, or a high pressure chamber and two pressure conversion chambers, using a pair of pistons or the like within the cylindrical reversing valve body. In most cases, the pressure conversion chamber is switched by a pilot three-way solenoid valve or the like to move a piston and a valve body connected to the piston for switching the flow path.

Problems to be Solved In the above conventional technology, both the reversing four-way valve and the pilot solenoid valve have complex structures and a large number of mutually communicating conduits, creating a bottleneck in miniaturization. Since the control by operation involves passive pressure reduction and active pressurization of the pressure conversion chamber, it has disadvantages such as not being suitable for fine electronic control.

The present invention focuses on the above points, and divides the inside of the reversing valve body into two chambers, a high pressure chamber and a pressure conversion chamber, by a piston, and opens and closes the pressure conversion chamber by an on-off valve to operate the piston or the flow path switching valve. By adopting a movable configuration, we have achieved a simpler and more compact structure.
Furthermore, the control of the pressure conversion chamber by the opening/closing valve is an opening/closing operation for a refrigerant flow in a fixed direction from the pressure conversion chamber to the suction side of the compressor, thereby enabling fine electronic control.

Means for Solving the Problems In order to achieve the above object, in the present invention,
The cylindrical reversing valve body is divided into a high pressure chamber and a pressure conversion chamber by a single piston having substantially the same pressure receiving part on both sides in the axial direction, and the high pressure chamber has a connection port for the compressor discharge pipe and a compressor. A connection port for the suction pipe and a connection port for the two heat exchanger conduits are provided across the connection port, and a series of switching valve seats is provided from the connection port for the suction pipe to the connection port for the two heat exchanger conduits. a slide valve that is in sliding contact with the switching valve seat is connected to the piston, and the slide valve selectively communicates the connection port for the suction pipe with the connection port for the two heat exchanger conduits; Connecting ports for the two heat exchanger conduits are selectively communicated with the high pressure chamber, a pressure equalizing hole is formed in the piston to constantly communicate the high pressure chamber and the pressure conversion chamber, and the piston is attached in the direction of the high pressure chamber. A pressure relief hole communicating with the suction side of the compressor is provided in the pressure conversion chamber, and an electromagnetic opening/closing valve is provided in the pressure relief hole to close the pressure relief hole when electricity is not applied. By forming the diameter to be larger than the diameter of the pressure equalization hole, and opening the pressure relief hole by energizing the electromagnetic on-off valve when starting the compressor, the differential pressure between the high pressure chamber and the pressure conversion chamber is reduced by the spring. The piston and the slide valve are moved from the high pressure chamber side operating position to the pressure conversion chamber side operating position against the pressure, and in the pressure conversion chamber side operating position, the electromagnetic on-off valve is de-energized and placed in the high pressure chamber. The differential pressure between the high and low pressures inside and outside the slide valve presses the slide valve against the switching valve seat, thereby overcoming the elasticity of the spring and moving the piston and slide valve to the pressure conversion chamber side operating position. It is characterized by being fixed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In the drawings, reference numeral 1 denotes a cylindrical reversing valve body, and plugs 2 and 3 are welded and fixed to both ends. A discharge pipe 5 of a compressor 4 is connected to the plug body 2, and a compressor 4 is connected to the reversing valve body 1 in the axial direction.
Two conduits 7 and 8 are connected with a suction pipe 6 between them. The conduits 7, 8 are connected to two heat exchangers 9, 10 which are used reciprocally as condensers or evaporators. The inner ends of the suction pipe 6 and conduits 7 and 8 are connected to the reversing valve body 1.
A series of smooth surfaces 11d are formed on the inside of the valve seat 11, which are connected to three through holes 11a, 11b, and 11c of the switching valve seat 11 fixed therein.

Inside the reversing valve main body 1, a piston 12 having substantially the same pressure receiving portions A and B on both sides in the axial direction is slidably provided between the valve seat 11 and the stopper 3, and the piston 12 has substantially the same pressure receiving portions A and B on both sides in the axial direction. ₁ and pressure conversion chamber
Plot into R ₂ . A compression spring 13 is provided between the piston 12 and the stopper 3, and the piston 12 is connected to a high pressure chamber.
R Constantly biased in _one direction. A pressure equalization hole 12a is formed in the piston 12, and the pressure equalization hole 12a is formed in the plug body 3 to constantly communicate the high pressure chamber _R1 and the pressure conversion chamber _R2 .
A pressure relief hole 3a having a larger diameter than the pressure relief hole 3a is formed, and a conduit 14 leading to the suction pipe 6 is connected to the pressure relief hole 3a.

An electromagnetic on-off valve 16 is attached to the plug body 3 via a plunger pipe 15, and a needle valve body 18 provided at the tip of the plunger 17 approaches and separates from a valve seat 3b provided in the middle of the pressure relief hole 3a to relieve the pressure. Hole 3a
Open and close. A compression spring 20 is provided between the plunger 17 and the suction core 19, and the needle valve body 18 is biased in the direction of contacting the valve seat 3b.

A slide valve 21 having a communication bore 21a is provided on the valve seat 11, and the slide valve 21 is connected to the piston 12 by a connecting rod 22. The slide valve 21 selectively communicates the through hole 11a for the suction pipe 6 in the valve seat 11 with the through holes 11b and 11c for the heat exchanger conduits 7 and 8 on both sides of the slide valve 21 through its inner cavity 21a.

In the above configuration, when the compressor 4 is stopped, the piston 12 is pushed by the spring 13 and is in the high pressure chamber side operating position in contact with the valve seat 11;
In the electromagnetic on-off valve 16 in a non-energized state, the plunger 17 is pushed by the spring 20 and the needle valve body 18
closes the pressure relief hole 3a (FIG. 1).

When the compressor is operated in this state, the high pressure from the discharge pipe 5 is sent to the pressure conversion chamber R ₂ via the high pressure chamber R ₁ and the pressure equalization hole 12a, and both chambers R ₁ and R ₂ have the same pressure.
By holding the piston 12 in the same position, the slide valve 21 opens the through hole 11a.
Since it is connected to 1c, the refrigerant is transferred to compressor 4→
Discharge pipe 5 → conduit 7 → outdoor heat exchanger 9 → throttle means 2
3→Indoor heat exchanger 10→Conduit 8→Suction pipe 6→Compressor 4 The air conditioner is in a cooling operation state (first
figure).

When the compressor 4 is stopped and the electromagnetic on-off valve 16 is energized and the compressor 4 is started, the plunger 17 is attracted, the needle valve body 18 opens the pressure relief hole 3a, and the inside of the pressure conversion chamber R ₂ is compressed. Connect to the low pressure on the suction side of machine 4. As a result, in the pressure conversion chamber _R2 , refrigerant escapes from the pressure relief hole 3a to the suction side, and at the same time, refrigerant is supplied from the high pressure chamber _R1 through the pressure equalization hole 12a, and at this time, the diameter of the pressure relief hole 3a increases. Since the diameter of the pressure equalization hole 12a is larger and the amount of refrigerant discharged is larger than the amount of refrigerant supplied, the pressure conversion chamber _R2 has a low pressure, and there is a pressure difference between the chambers _R1 and _R2 that overcomes the elasticity of the compression spring 13. occurs, and the second
As shown in the figure, the piston 12 to the slide valve 21 are moved in the direction of the stopper 3 to the pressure conversion chamber side operating position. Since the slide valve 21 allows the through hole 11a to communicate with the through hole 11b,
The refrigerant flows through the compressor 4 → discharge pipe 5 → conduit 8 → outdoor heat exchanger 10 → throttle means 23 → outdoor heat exchanger 9 → conduit 7
The air circulates through the path of → suction pipe 6 → compressor 4, resulting in heating operation.

When the differential pressure normally exceeds about 2 kg/cm ² after a certain period of time after the piston 12 or the entire body 21 is switched and moved, the electromagnetic on-off valve 16 is de-energized. In this state, the slide valve 21 is pressed and fixed to the valve seat 11 due to the differential pressure between the low pressure inside the communication lumen 21a of the slide valve 21 and the high pressure outside the slide valve 21, and the elasticity of the compression spring 13 Overcome and hold the position.

As described above, in the operating state of the compressor, the differential pressure between the inside and outside of the slide valve 2 has a positioning locking effect for the slide valve 2, so that the switching to the above-mentioned heating operating state is performed using the slide valve when the compressor is started. This is achieved by energizing the electromagnetic on-off valve 16 to open the pressure relief hole 3a in a state where no differential pressure is generated between the inside and outside of the valve.

When the compressor 4 is stopped by the thermostat, the electromagnetic on-off valve 16 is energized to open the pressure relief hole 3a to forcibly equalize the pressure and shorten the pressure equalization time.
The air conditioner is switched to the cooling state by the elasticity of the compression spring 13. After quickly switching to the cooling state during the heating operation in this way, the defrosting operation is performed in response to the defrosting start signal.

Effects of the Invention As described above, the present invention divides the inside of a cylindrical reversing valve body into a high pressure chamber and a pressure conversion chamber by a single piston having substantially the same pressure receiving portion on both sides in the axial direction, and compresses the air into the high pressure chamber. A connection port for the discharge pipe of the compressor, a connection port for the suction pipe of the compressor, and a connection port for two heat exchanger conduits are provided across the connection port, and two heat exchanger conduits are provided from the connection port for the suction pipe. A series of switching valve seats are provided across the connection ports to the switching valve seats, and a slide valve that is in sliding contact with the switching valve seats is connected to the piston, and the slide valves connect the connection ports to the suction pipes to the two heat exchanger conduits. A pressure equalization hole is provided in the piston, which selectively communicates with the connection port and selectively communicates the connection port for the two heat exchanger conduits with the high pressure chamber, and allows the piston to constantly communicate the high pressure chamber and the pressure conversion chamber. A spring is provided to bias the piston toward the high pressure chamber, a pressure relief hole is provided in the pressure conversion chamber that communicates with the suction side of the compressor, and the pressure relief hole is closed when the pressure relief hole is not energized. Equipped with an electromagnetic on-off valve,
The diameter of the pressure relief hole is formed larger than the diameter of the pressure equalization hole, and when the compressor is started, the electromagnetic on-off valve is energized to open the pressure relief hole, thereby reducing the pressure between the high pressure chamber and the pressure conversion chamber. The differential pressure moves the piston and the slide valve from the high pressure chamber side operating position to the pressure conversion chamber side operating position against the spring, and the electromagnetic on-off valve is de-energized in the pressure conversion chamber side operating position. The differential pressure between the high and low pressures inside and outside of the slide valve located in the high pressure chamber presses the slide valve against the switching valve seat, overcomes the elasticity of the spring, and causes the piston and slide valve to convert the pressure. (a) It is separated from the high pressure chamber by a single piston and communicates with the high pressure chamber through a pressure equalizing hole formed in the piston. The pressure inside the pressure conversion chamber in the state of By shutting off, the pressure can be converted to high or low pressure, and the overall structure including the solenoid valve can be simplified, and fine heating and cooling control can be performed by electronically opening and closing the solenoid valve. (b) Due to the pressure difference between the inside and outside due to the constant low pressure in the communication bore of the slide valve located in the high pressure chamber, the slide valve comes into pressure contact with the valve seat and has a locking effect on the piston, and this locking effect causes the piston to lock. Since the piston and slide valve can be fixed at the operating position on the pressure conversion chamber side by overcoming the elasticity of the spring, the operating position can be stabilized even against differential pressure fluctuations in the refrigeration circuit, and the electromagnetic on-off valve can be energized. Even if the electromagnetic on-off valve is shut off after the piston and slide valve are moved to the pressure conversion chamber side operating position, it is possible to maintain the conversion chamber side operating position by the above-mentioned locking action, thereby achieving energy saving. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention;
FIG. 2 is an operating state diagram of the same as above. 1... Reversing valve body, R ₁ ... High pressure chamber, R ₂ ... Pressure conversion chamber, 3a... Pressure relief hole, 4... Compressor,
5... Discharge pipe, 6... Suction pipe, 7, 8... Heat exchanger conduit, 11... Switching valve seat, 12... Piston, 12a... Equalizing hole, 13... Spring, 16
...Opening/closing valve, 21...Slide valve.

Claims (1)

[Claims] 1 The cylindrical reversing valve body is divided into a high pressure chamber and a pressure conversion chamber by a single piston having substantially the same pressure receiving part on both sides in the axial direction, and the high pressure chamber has a connection port for the discharge pipe of the compressor and a compression chamber. A connection port for the suction pipe of the machine and a connection port for two heat exchanger conduits are provided across the connection port, and a series of switching valve seats is provided from the connection port for the suction pipe to the connection ports for the two heat exchanger conduits. a slide valve that is in sliding contact with the switching valve seat is connected to the piston, and the slide valve selectively communicates the connection port for the suction pipe with the connection port for the two heat exchanger conduits, and Connecting ports for the two heat exchanger conduits are selectively communicated with the high pressure chamber, a pressure equalizing hole is formed in the piston to constantly communicate the high pressure chamber and the pressure conversion chamber, and the piston is directed toward the high pressure chamber. A biasing spring is provided, a pressure relief hole communicating with the suction side of the compressor is provided in the pressure conversion chamber, and an electromagnetic opening/closing valve is provided in the pressure relief hole to close the pressure relief hole when electricity is not applied, and the pressure relief hole The diameter of the pressure equalizing hole is larger than that of the pressure equalizing hole, and when the compressor is started, the electromagnetic on-off valve is energized to open the pressure relief hole, thereby reducing the pressure difference between the high pressure chamber and the pressure conversion chamber. The piston and the slide valve are moved from the high pressure chamber side operating position to the pressure conversion chamber side operating position against the spring, and the electromagnetic on-off valve is de-energized in the pressure conversion chamber side operating position, and the valve is moved to the high pressure chamber. The differential pressure between high and low pressure inside and outside the slide valve presses the slide valve against the switching valve seat, overcomes the elasticity of the spring, and moves the piston and slide valve to the pressure conversion chamber side operating position. A four-way reversing valve for reversible refrigeration cycles, which is characterized by being fixed to.