JPH0718494B2 - Four-way valve for refrigeration cycle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refrigeration cycle, and more particularly to a four-way valve for a refrigeration cycle used for switching between cooling and heating of a heat pump type air conditioner.

2. Description of the Related Art In recent years, the demand for four-way valves for refrigeration cycles has increased rapidly as the use of air conditioners as heat pumps has increased, and there is a strong demand for cost reduction, reliability improvement, miniaturization, and the like.

An example of the conventional four-way valve for a refrigeration cycle described above will be described below with reference to the drawings.

FIG. 4 shows a sectional view of a conventional four-way valve for a refrigeration cycle. Reference numeral 1 is a compressor, 2 is an accumulator, and an indoor coil 4, an expander 5 and an outdoor coil 6 via a four-way valve 3.
And a known heat pump type refrigerant circuit. The four-way valve 3 is composed of a valve body 7 and a bilot valve 8, and the valve body 7 has two pistons.
It is divided into three spaces 11, 12, 13 by 9, 10, and the two pistons 9, 10 are connected by a connecting rod 14 and simultaneously move left and right in FIG. A slide valve 15 is mounted on the connecting rod 14, and when the pistons 9 and 10 move, the slide valve 15 also moves. 4 conduits in the area between the pistons 9 and 10
16, 17, 18, 19 are connected, the discharge pipe 16 of the compressor 1 is always in communication with the space 12, and the suction pipe 17 of the compressor 1 is a slide valve 15
And always communicates with a space 21 formed by the valve seat 20. The conduits 18 and 19 are connected to the indoor coil 4 and the outdoor coil 6, respectively, and communicate with the space 12 or the space 21 depending on the position of the slide valve 15. The pistons 9 and 10 are provided with pressure balance holes 22 and 23. Next, the structure of the pilot valve 8 will be described. Two spaces 24 and 25 are provided in the pilot valve 8 and have communication holes 29 which are alternately closed by needle valves 27 and 28 which are operated by a solenoid coil 26. The needle valves 27 and 28 in FIG. 4 show a heating operation state in which the solenoid coil 26 is energized. 30 is the communication hole 29 and the suction pipe 17
An extraction pipe that connects the space 11 and the space 24, and an extraction pipe 32 that connects the space 13 and the space 25. Next, the operation of the four-way valve 3 having the above configuration will be described.

Fig. 4 shows the heating operation state. Each space 11, 12, 13, 2
The pressure of 4,25 is as follows. The gas discharged from the compressor 1 causes the space 12 to have a high pressure and tries to maintain the space 11 and the space 13 at a high pressure through the pressure balancing holes 22 and 23 provided in the pistons 9 and 10. However, since the needle valve 27 in the pilot valve 8 closes the communication hole 29, the space 13 communicates with the suction pipe 17 through the extraction pipe 32, the space 25, the communication hole 29, and the extraction pipe 30, and has a low pressure. . Therefore, a pressure difference is generated between the space 11 and the space 13 via the pistons 9 and 10, and the pistons 9 and 10 and the slide valve 15 are pressed rightward in FIG. 4 to maintain a predetermined heating operation state. Next, the operation of the four-way valve 3 when the heating operation is stopped, the defrosting operation is started, or the cooling operation is started will be described. 3 above
In one of the operating states, the solenoid coil 3 is de-energized. Therefore, the needle valves 27 and 28 move to the left in FIG. 4, so that the needle valve 28 closes the communication hole 29 and the bleed pipe 30 communicates with the space 24. Therefore, the space 11 that had a high pressure during heating was bleed pipe 31, space 2
4, It communicates with the suction pipe 17 through the bleed pipe 30 and suddenly becomes a low pressure. Therefore, the piston 9 is pushed out and a pressure difference is generated between the space 12 and the space 11, and the pistons 9 and 10 and the slide valve 15 are pressed leftward in FIG. 4 by this pressure difference. Therefore, the discharge pipe 16 communicates with the conduit 19, and the conduit 18 has a space 21.
Through the suction pipe 17.

Problems to be Solved by the Invention However, in the above configuration, since the slide valve 15 is driven by the pilot method using the high and low pressure difference of the refrigerant gas, an extremely large number of parts are required and the structure is complicated. However, there is a problem in that the number of assembling steps also increases. Furthermore, since there are many minute openings in the structure such as the extraction pipes 30, 31, 32, the pressure balance holes 22, 23, the communication holes 28, 29 of the pilot valve 8, etc., they are blocked by foreign matter in the refrigerant circuit and the switching operation is performed. There was a problem in that it was unstable in terms of reliability, such as the possibility that it would be impossible.

On the other hand, as a recent trend of air conditioners, in order to eliminate impact noise due to collision of high pressure refrigerant and low pressure refrigerant at the time of switching four-way valve, the compressor operation is stopped before and after defrosting or when switching between cooling and heating to eliminate the pressure difference between the four directions. Since the control system for switching the valves is becoming mainstream, the high bottom pressure difference at the time of switching tends to be reduced, and the switching force of the slide valve 15 tends to be greatly reduced compared to the conventional one. , It is heading in a direction where switching is possible.

In view of the above problems and changes in the environment in which four-way valves are used due to recent trends in air conditioners, the present invention aims to eliminate pilot valves, simplify the structure, improve assembly workability, reduce costs, and perform switching operations. A four-way valve for a refrigeration cycle having improved reliability is provided.

Means for Solving the Problems In order to solve the above problems, a four-way valve for a refrigeration cycle according to the present invention is a cylinder having a valve body and having an inlet, and an outlet and a guide which are fixed to the inner wall of the cylinder. A valve seat in which first and second openings are arranged side by side in the axial direction of the cylinder on both sides of the outlet, and a recess serving as a flow path for selectively communicating the outlet and the first or second opening. Cap type slide valve, a solenoid fixedly attached to the center of a lid provided at one end of the cylinder to reciprocate the slide valve, and a return of the solenoid interposed between the lid and the slide valve. In a four-way valve for a refrigeration cycle equipped with a spring, a slide seat ring made of a highly slidable material for sealing the inside and outside of the cap-type slide valve is fixed, A spring is interposed between the outer surface of the valve and the inner wall of the cylinder to urge the slide seat ring to constantly contact the valve seat surface by urging it toward the valve seat.

The present invention has the above-described structure, and thus even if the pressure difference of the system is applied to the inside and the outside of the slide valve, the sealing position with the valve seat surface is the innermost position that can secure the required flow passage cross-sectional area as the four-way valve. The area that receives the differential pressure of the system is minimized, the load applied to the sealing surface of the Teflon seat ring can be reduced, and the slide seat ring uses a high sliding material such as fluororesin with a low friction coefficient. The switching force required to move the return spring in the cylinder axis direction can be significantly reduced, and the return spring for the solenoid is not provided between the plunger and the fixed core, so there is no need for a hole to store the return spring. A large suction cross section can be obtained, and a larger suction force can be obtained. The slide seat ring is always in contact with the spring valve seat surface by the spring interposed between the outer surface of the slide valve and the inner wall of the cylinder.

Embodiment A four-way valve for a refrigeration cycle according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are sectional views showing a four-way valve for a refrigerating cycle according to an embodiment of the present invention when not energized. Reference numeral 33 is a cylinder forming a valve body, and an inlet port 34a of a discharge pipe 34 connected to the discharge side of the compressor is opened on the side surface. Reference numeral 35 is a lid fitted and welded to one end of the cylinder 33. A valve seat 36 is fixed to the inner wall of the cylinder 33 and has a seat surface 36a on the side opposite to the fixed side. The valve seat 36 has three openings 36b in the axial direction of the cylinder 33.
36c and 36d are arranged side by side. The central opening 36b of the valve seat 36 is a lead-out port to which a suction pipe 37 connected to the suction side of the compressor is connected. Further, the openings 36c and 36d on both sides of the outlet 36b are connected to the outdoor coil and the first and second conduits 38 and 39 connected to the indoor coil which reversibly function as a condenser or an evaporator, respectively. These are the first and second gateways. Four
0 is a slide seat ring 41 made of a highly slidable material such as a fluororesin having a low friction coefficient that abuts against the seat surface 36a of the valve seat 36 and seals the valve seat 36 at the innermost position of the opening end 40a. A recess that fixes the contact sheet surface 41a so that it is positioned and forms a flow path inside
It is a cap-type slide valve having 40b. Reference numeral 42 denotes a leaf spring interposed between the outer surface 40c of the slide valve 40 and the inner wall of the cylinder 33.
Is urged toward the valve seat 36 to constantly apply contact pressure between the contact seat surface 41a of the slide seat ring 41 and the valve seat surface 36a. 43 is a lid that closes the other end of the cylinder 33. Reference numeral 44 denotes an operation solenoid fixedly attached to the center of the lid 43, and a fixed iron core 45, an electromagnetic coil 46, and a plunger 47 in which the slide valve 40 is fitted and connected to a ring portion 47a on the side opposite to the suction side. When the electromagnetic coil 46 is energized, the plunger 47 is attracted to the fixed iron core 45, and the slide valve 40 slides in the slide 33 in the right direction in the drawing. Reference numeral 48 is a return spring interposed between the lid 43 and the slide valve 40, and slides the plunger 47 and the slide valve 40 to the left in the figure when the electromagnetic coil 46 is de-energized. The position of the slide seat ring 41 fixed to the opening end of the slide valve 40 is the same as the outlet 36b at the first position of the slide valve 40 shown in FIGS. 1 and 2 (the electromagnetic coil 46 is not energized). The first through hole 36c is communicated with the inner recess 40b of the slide valve 40 as a flow path, and the plunger 47 and the slide valve 40 are energized by energizing the electromagnetic coil 46.
The outlet 36 at the second position (FIG. 3) where the
It is designed so that b and the second passage 36d communicate with each other.

The operation of the four-way valve for a refrigeration cycle configured as described above will be described below with reference to FIGS. 1 to 3. First
FIG. 2 and FIG. 2 show a state in which the electromagnetic coil 46 is not energized. The plunger 47 is urged to the left side of the drawing by the action of the return spring 48, and the tip of the ring portion 47a is moved to the lid 35. Abut and stop. As a result, the slide seat ring 41 is used as a sealing surface and the inner recess 40b of the slide valve 40 is used as a flow path to connect the outlet port 36b and the first communication port 36c.
The introduction port 34a and the second communication port 36d are also communicated with each other through the inside of the cylinder 33. Therefore, the refrigerant gas becomes a compressor → discharge pipe 34 → first conduit 38 → outdoor coil → expansion valve → indoor coil → second conduit 39 → suction pipe 37 → compressor cooling cycle circuit or defrost cycle circuit. .

Next, when the electromagnetic coil 46 is energized (Fig. 3), the plunger 47 is attracted to the fixed iron core 45 and comes into contact with it to stop. As a result, the outlet 36b and the second passage 36d are communicated with each other through the flow path formed by the inner recess 40b of the slide valve 40, and the inlet 34a and the first passage 36c are also passed through the inside of the cylinder 33. Communicated. Therefore, the refrigerant gas is compressed from the compressor to the discharge pipe 34.
→ second conduit 39 → indoor coil → expansion valve → outdoor coil → first conduit 38 → suction pipe 37 → compressor heating cycle circuit.

As described above, according to this embodiment, the valve seat 36 having the outlet 36b and the first and second passages 36c and 36d arranged on both sides of the outlet 36b is provided in the cylinder 33 forming the valve body. A cap-type slide valve 4 having a recess 40b inside which a slide seat ring 41 made of a highly slidable material that abuts and seals against the valve seat 36 is fixed at the position closest to the opening end 40a.
By moving 0 in the axial direction of the cylinder 33 by a solenoid 44 fixedly attached to the center of a lid 43 provided at one end of the cylinder 33, communication ports 36c, 36 communicating with the outlet 36 are provided.
By selecting d, the refrigerant circuit is configured to be switched, and the return spring 48 of the solenoid 44 is interposed between the lid 43 and the slide valve 40. Even if added, the seal position with the valve seat surface 36a is set to the innermost position that can secure the required flow passage cross-sectional area as a four-way valve, so the system pressure difference receiving area of the slide valve 40 is minimized and the seal of the Teflon seat ring 41 is minimized. Since the load applied to the surface 41a can be reduced and the slide seat ring 41 is made of a highly slidable material such as a fluororesin having a low friction coefficient, the switching force required to move the slide valve 40 in the axial direction of the cylinder 33. Of the solenoid 44 is not provided between the plunger 47 and the fixed iron core 45. Since the hole for accommodating the valve 48 is not required, the suction cross-sectional area of the plunger 47 can be made large, and a larger suction force can be obtained. It is possible to switch, so that the cost can be significantly reduced, the size can be reduced, and the operational reliability can be improved.

EFFECTS OF THE INVENTION As described above, in the four-way valve for the refrigeration cycle of the present invention, the pressure receiving area that receives the system pressure difference of the slide valve is minimized, and it is added to the seat surface of the seat ring. Since the load can be reduced and the slide seat ring is made of a highly slidable material having a low friction coefficient, the switching force required to move the slide valve in the cylinder axis direction can be significantly reduced. Furthermore, since the return spring for the solenoid is not provided between the plunger and the fixed iron core, the hole for accommodating the return spring is unnecessary, and the suction cross-sectional area of the plunger can be increased, resulting in a larger suction force. Therefore, it is possible to directly switch the valves by the solenoid without using a pilot valve as in the conventional case, and it is possible to significantly reduce the cost, make the device compact, and improve the operation reliability. The slide seat ring is urged by the spring so as to always contact the valve seat surface, and the slide seat ring and the valve seat surface are kept airtight.

[Brief description of drawings]

FIG. 1 is a sectional view showing a four-way valve for a refrigerating cycle in one embodiment of the present invention, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 shows a heating state of FIG. A sectional view and FIG. 4 are sectional views of a conventional four-way valve for a refrigeration cycle. 33 …… Cylinder, 34a …… Inlet port, 36 …… Valve seat, 36b …… Outlet port, 36c, 36d …… First and second through holes, 40
…… Slide valve, 41 …… Slide seat ring, 44
...... Solenoid, 48 ...... Return spring.

Claims (1)

[Claims] Claim: What is claimed is: 1. A cylinder having a valve body and having an introduction port; a cylinder fixed to an inner wall of the cylinder; a discharge port; and first and second through holes arranged on both sides of the discharge port in the axial direction of the cylinder. A valve seat, a cap-type slide valve having a recess serving as a flow path for selectively communicating the outlet and the first or second passage, and a cap fixed to the center of a lid provided at one end of the cylinder. A four-way valve for a refrigeration cycle equipped with a solenoid for reciprocating the slide valve attached to the lid, and a return spring for the solenoid interposed between the lid and the slide valve, wherein an opening edge of the cap-type slide valve A slide seat ring made of a highly slidable material that abuts the valve seat to seal the inside and outside of the slide valve is fixed to the innermost position of the portion, and the slide bar is fixed. Refrigeration cycle four-way valve, characterized in that interposed a spring the between the outer surface and the inner wall of the cylinder to energize the valve seat side is always in contact with the sliding seat ring to the valve seat surface of the probe.