Check valves and refrigeration cycle systems

Abstract

To provide a check valve capable of smoothing the opening / closing movement of a valve body, and a refrigeration cycle system.SOLUTION: A check valve 1 comprises an outer pipe part 2, a valve body 3, and a valve element 4. The valve body 3 has a cylindrical valve holder 5 that supports the valve element 4, a valve seat part 6, and a valve port 7. The valve element 4 is provided in the valve holder 5 so as to be axially movable between a valve closed position where it is seated on the valve seat part 6 and a valve open position P1 away from the valve seat part 6. The valve holder 5 is provided with a communication hole 21 that penetrates a cylindrical peripheral surface and communicates the inside of the outer pipe part 2 with the valve port 7. The outer peripheral surface of the valve element 4 and the inner peripheral surface of the valve holder 5 are configured to be in slide contact via contact parts that are in contact with each other and non-contact parts that are separated without contact with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a check valve and a refrigeration cycle system. [Background technology]

[0002] A conventional check valve is known that includes a valve body provided inside an outer pipe and a valve element provided inside the valve body, the valve body having a valve seat that forms a valve port and a cylindrical valve holder (valve case) that movably houses the valve element (see, for example, Patent Document 1). In this check valve, the valve holder is provided with a communication hole that connects the inside of the outer pipe with the valve port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-200552 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional check valves such as those described in Patent Document 1 are installed in the refrigerant flow path of a refrigeration cycle system. Many such refrigerants contain refrigeration oil for lubrication. If refrigeration oil is present between the outer circumferential surface of the valve disc and the inner circumferential surface of the valve holder, the surface tension of the refrigeration oil can cause resistance to the movement of the valve disc. In this case, the larger the contact area between the outer circumferential surface of the valve disc and the inner circumferential surface of the valve holder, the greater the resistance to movement, which can cause problems with opening and closing the valve disc.

[0005] An object of the present invention is to provide a check valve and a refrigeration cycle system that can smooth the opening and closing movement of a valve element. [Means for solving the problem]

[0006] The check valve of the present invention is a check valve comprising a cylindrical outer tube portion extending in the axial direction, a valve body built into the outer tube portion, and a valve element provided in the valve body, wherein the valve body has a cylindrical valve holder that supports the valve element, a valve seat portion on which the valve element can be seated, a valve port that is closed by the valve element seated on the valve seat portion, and a valve stopper that is fixed to the valve holder and regulates the opening degree of the valve element, and the valve element is seated on the valve seat portion within the valve holder. The valve holder is provided so as to be movable in the axial direction between a valve closed position and a valve fully open position where it abuts against the valve stopper, and the valve holder is provided with a communication hole that penetrates the cylindrical peripheral surface and communicates the inside of the outer tube portion with the valve port, and the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder are configured to be in sliding contact with each other via a contact portion that contacts them and a non-contact portion that is spaced apart and does not contact them, and any elastic member that urges the valve body in the valve closing direction is provided within the valve holder. The non-contact portion is a groove formed on the outer peripheral surface of the valve body, and when the valve body is separated from the valve seat portion to the valve fully open position, the groove and the communication hole communicate with each other. It is characterized by: The check valve is a check valve comprising a cylindrical outer tube portion extending in the axial direction, a valve body built into the outer tube portion, and a valve element provided in the valve body, wherein the valve body has a cylindrical valve holder that supports the valve element, a valve seat portion on which the valve element can be seated, a valve port that is closed by the valve element seated on the valve seat portion, and a valve stopper that is fixed to the valve holder and regulates the opening degree of the valve element, and the valve element has a valve closing position in the valve holder where it sits on the valve seat portion, and a valve fully open position where it abuts against the valve stopper, the valve holder is provided with a communication hole that penetrates the cylindrical peripheral surface and communicates the inside of the outer tube portion with the valve port, the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder are configured to be in sliding contact with each other via a contact portion that contacts them and a non-contact portion that is spaced apart and does not contact them, and the valve body can be in a state where it does not contact other members between the valve closed position and the valve fully open position. The non-contact portion is a groove formed on the outer peripheral surface of the valve body, and when the valve body is separated from the valve seat portion to the valve fully open position, the groove and the communication hole communicate with each other. It is characterized by:

[0007] According to the present invention, the contact area at the contact portion is kept small by providing a non-contact portion between the outer peripheral surface of the valve disc and the inner peripheral surface of the valve holder. As a result, even if refrigeration oil is present between the outer peripheral surface of the valve disc and the inner peripheral surface of the valve holder, the movement resistance due to the surface tension of the refrigeration oil is reduced, and the outer peripheral surface of the valve disc does not stick to the inner peripheral surface of the valve holder, thereby enabling smooth opening and closing movement of the valve disc.

[0008] In this case, it is preferable that the non-contact portion is constituted by a plurality of grooves formed on at least one of the outer peripheral surface of the valve disc and the inner peripheral surface of the valve holder, and that the plurality of grooves are arranged in positions that are line-symmetrical with respect to the central axis of the valve disc. With this configuration, the non-contact portion is effectively constituted by the plurality of grooves, and the plurality of grooves are arranged in positions that are line-symmetrical with respect to the central axis of the valve disc, so that movement resistance is uniformly distributed around the central axis, thereby further facilitating the opening and closing movement of the valve disc. Furthermore, by providing grooves on the valve disc as the non-contact portion, the valve disc becomes lighter and the pressure difference required to open the valve is reduced, making it easier to open the valve.

[0009] Furthermore, it is preferable that the plurality of grooves are formed to be equal in size. With this configuration, the weight distribution around the central axis of the valve body is made uniform, thereby further smoothing the opening and closing movement of the valve body.

[0010] Furthermore, it is preferable that each of the plurality of grooves is formed to extend in the valve disc axial direction along the central axis of the valve disc, and that the cross-sectional shape of a cross section intersecting the valve disc axial direction be constant in the valve disc axial direction or that the cross-sectional shape gradually changes in the valve disc axial direction. With this configuration, the grooves constituting the non-contact portions extend in the valve disc axial direction, so that the remaining contact portions also extend in the valve disc axial direction, further facilitating the opening and closing movement of the valve disc along the valve disc axial direction. Furthermore, because the cross-sectional shape of the grooves intersecting the valve disc axial direction is constant or gradually changes in the valve disc axial direction, the weight distribution in the valve disc in the valve disc axial direction is uniform or changes gradually, further facilitating the opening and closing movement of the valve disc.

[0011] Preferably, the non-contact portion is a groove formed on the outer peripheral surface of the valve disc, and the groove and the communication hole communicate with each other when the valve disc is fully open and has moved away from the valve seat to the fully open position. With this configuration, the communication between the groove and the communication hole functions as a relief hole for refrigeration oil present at the contact portion, preventing refrigeration oil from accumulating in the groove, thereby suppressing the retention of surface tension of the refrigeration oil at the contact portion and further smoothing the opening and closing movement of the valve disc. Furthermore, it is preferable that the primary side end face of the valve body has a seal surface that seats on the valve seat, the inner peripheral edge of the seal surface is larger than the inner diameter of the valve port, and the area between the outer peripheral edge of the valve body and the inner peripheral edge of the seal surface is a ring-shaped area that is thinner in the axial direction of the valve body than other areas.

[0012] Furthermore, the valve opening end face of the valve disc and the valve seat end face of the valve stopper are preferably configured to contact and separate via an axial contact portion where they contact each other and an axial non-contact portion where they are separated and not contact each other. Generally, in a structure in which the valve is positioned when the valve is opened by contacting the valve stopper as described above, refrigeration oil may also enter between the valve opening end face of the valve disc and the valve seat end face of the valve stopper. In this case, the refrigeration oil that has entered between the valve opening end face of the valve disc and the valve seat end face of the valve stopper may adhere these two faces due to surface tension, creating resistance to movement of the valve disc from the valve open position in contact with the valve stopper to the valve closed position. The greater the contact area between the valve opening end face of the valve disc and the valve seat end face of the valve stopper, the greater the resistance to movement. If the valve opening end face of the valve disc remains attached to the valve seat end face of the valve stopper, the valve may not close. In contrast, according to the preferred configuration described above, the valve opening end face of the valve disc and the valve seat end face of the valve stopper contact each other via the axial contact portion and the axial non-contact portion, thereby minimizing the contact area between the valve opening end face and the valve seat end face. This reduces the resistance to movement of refrigeration oil due to the surface tension of the refrigeration oil, preventing the valve opening end face of the valve disc from sticking to the valve seat end face of the valve stopper, and enabling smooth opening and closing movement of the valve disc.

[0013] Furthermore, the valve stopper is preferably a C-shaped retaining ring. With this configuration, the area of ​​the valve seat side end face of the valve stopper can be kept smaller than when, for example, the valve seat side end face is circular. In other words, the contact area between the valve opening side end face and the valve seat side end face is kept small even on the valve stopper side, further reducing sticking between the valve opening side end face of the valve disc and the valve seat side end face of the valve stopper, further facilitating the opening and closing movement of the valve disc. Furthermore, with the above configuration, a C-shaped retaining ring, which is inexpensive and easy to install, can be used as the valve stopper, thereby reducing manufacturing costs.

[0014] The valve body preferably has a non-through hole formed therein that extends to a predetermined depth in the axial direction of the valve body along the central axis of the valve body. This configuration makes it possible to prevent the occurrence of sink marks, air bubbles, etc. when the valve body is formed from resin. Furthermore, the formation of the hole reduces the weight of the valve body, which in turn reduces the valve opening pressure difference, making it easier to open the valve and further facilitating the opening and closing movement of the valve body.

[0015] Furthermore, it is preferable that the valve body is formed of a resin material that does not contain reinforcing fibers. According to this configuration, the valve body is formed of a resin material that does not contain reinforcing fibers and therefore has a low elastic modulus and is easily deformed, so that even if the flatness of the sealing surface is low, the sealing surface can deform and come into close contact with the valve port, thereby suppressing valve leakage.

[0016] Furthermore, it is more preferable that the resin material is a PEEK material. According to this configuration, the valve body is formed from a PEEK material that has little plastic deformation and excellent resistance to harsh usage environments such as high temperatures and high pressures. By using such a PEEK material as the resin for forming the valve body, it is possible to achieve good shape recovery by suppressing plastic deformation after the back pressure is released. Furthermore, it is possible to impart excellent resistance to the above-mentioned harsh usage environment to the valve body.

[0017] The refrigeration cycle system of the present invention is characterized by including any one of the check valves described above.

[0018] According to the present invention, the check valve described above is employed in a refrigeration cycle system, so that the opening and closing movement of the valve element in the check valve can be made smoother. [Effects of the Invention]

[0019] According to the check valve and refrigeration cycle system of the present invention, the opening and closing movement of the valve element can be made smoother. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is an overall cross-sectional view showing a cross section along an axial direction of a check valve according to a first embodiment. [Figure 2] 2 is an enlarged cross-sectional view showing a main part of the check valve shown in FIG. 1. FIG. [Figure 3] 3A and 3B are a top view of the valve body shown in FIGS. 1 and 2, a cross-sectional view taken along line V0-V1 in the figure, and a cross-sectional view taken along line V0-V2 in the figure. [Figure 4] 4A and 4B are a top view and a side view of the valve body shown in FIGS. 1 to 3. [Figure 5] FIG. 5 is a diagram showing a refrigeration cycle system according to a first embodiment, which is provided with the check valve shown in FIGS. 1 to 4. [Figure 6] FIG. 10 is an overall cross-sectional view showing a cross section along the axial direction of a check valve according to a second embodiment. [Figure 7] 7A and 7B are a top view and a cross-sectional view of the valve body shown in FIG. 6 along line V14-V14 in the figure, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0021] A check valve according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG.

[0022] FIG. 1 is an overall cross-sectional view showing a cross section along the axial direction of a check valve according to a first embodiment, and FIG. 2 is an enlarged cross-sectional view showing a main part of the check valve shown in FIG. 1.

[0023] A check valve 1 according to the first embodiment is installed in a refrigerant flow path in a refrigeration cycle system, as will be described in detail later. Refrigerant containing lubricating refrigerating machine oil flows through the check valve 1. As shown in FIG. 1, the check valve 1 is a valve device that allows fluid flow (forward flow) from the primary side (lower side in FIG. 1) to the secondary side (upper side in FIG. 1) and prohibits fluid flow (backflow) from the secondary side to the primary side. The check valve 1 includes a cylindrical outer tube 2 extending in the axial direction along an axis L, a valve body 3 housed in the outer tube 2, and a valve element 4 provided in the valve body 3. The valve body 3 is a member made of brass or the like, integrally formed with a cylindrical valve holder 5 that supports the valve element 4 and a valve seat 6 on which the valve element 4 can be seated. The valve seat 6 has a valve port 7 that is closed by the seated valve element 4. As shown in Figure 2, the valve element 4 is arranged within the valve holder 5 so as to be movable axially between a valve closed position P2 where it sits on the valve seat portion 6 and a valve open position P1 where it is spaced apart from the valve seat portion 6.

[0024] The outer pipe portion 2 is an integrally molded member made of copper and includes a primary joint portion 11 on the primary side, a secondary joint portion 12 on the secondary side, a first expanded diameter portion 13 that is larger in diameter than the primary joint portion 11, and a second expanded diameter portion 14 that is larger in diameter than the first expanded diameter portion 13 and continues to the secondary joint portion 12. The primary joint portion 11 has a primary opening portion 11A that is connected to a primary pipe (not shown), a cylindrical primary cylindrical portion 11B that is continuous with the primary opening portion 11A, and a first connecting portion 11C that expands in diameter from the primary cylindrical portion 11B toward the first expanded diameter portion 13. The secondary joint portion 12 has a secondary opening portion 12A that is connected to a secondary pipe (not shown), a cylindrical secondary cylindrical portion 12B that is continuous with the secondary opening portion 12A, and a second connecting portion 12C that expands in diameter from the secondary cylindrical portion 12B toward the second expanded diameter portion 14. The secondary opening portion 12A has a diameter slightly larger than that of the secondary cylindrical portion 12B.

[0025] The first enlarged diameter portion 13 holds the valve seat 6 press-fitted therein, and four fixing portions 13A are formed on its circumferential surface, which deform radially inward to fix the valve seat 6. These fixing portions 13A are crimped and deformed by a punch in a press machine, and bite into the annular recess 25 of the valve seat 6, thereby fixing the valve seat 6 at a predetermined position inside the outer tube portion 2. The second enlarged diameter portion 14 is cylindrical, with its inner circumferential surface facing the outer circumferential surface of the valve holder 5 with a predetermined gap between them, and has an inner diameter large enough to allow smooth fluid flow through this gap. A step 14A, which narrows toward the first enlarged diameter portion 13, is provided at the boundary between the second enlarged diameter portion 14 and the first enlarged diameter portion 13.

[0026] The valve holder 5 of the valve body 3 has four communication holes 21 that penetrate the cylindrical circumferential surface in the radial direction. These communication holes 21 connect the interior of the valve holder 5 to the interior of the second enlarged diameter section 14 of the outer tube section 2. The communication holes 21 are circular in side view. That is, the communication holes 21 are formed by drilling orthogonally to the axis of the valve holder 5. A substantially annular valve stopper 22 made of stainless steel is attached to the inner surface near the secondary end of the valve holder 5. When the valve disc 4 moves to the valve open position P1 shown in FIGS. 1 and 2, it abuts against the valve stopper 22, thereby restricting the valve disc 4 from moving downstream beyond the valve open position P1. Specifically, a C-shaped retaining ring is used as the valve stopper 22. That is, the valve open position P1 is a position where the valve disc 4 is separated from the valve seat 6 and is in contact with the valve stopper 22, thereby restricting the movement of the valve disc 4 to the secondary side beyond the valve stopper 22 (the maximum position in the secondary side direction in the valve stroke). In Figure 2, the valve disc 4 located at the valve open position P1 within the valve holder 5 is shown in the upper part of the drawing.

[0027] The valve seat 6 has a cylindrical portion 23 extending toward the primary side. The inner surface of the secondary-side (valve holder 5-side) end of the cylindrical portion 23 is provided with a stepped valve seat surface 24. The valve disc 4, when moved to the valve-closed position P2 shown in the lower part of Figure 2, seats on the valve seat surface 24. The outer surface of the cylindrical portion 23 near the primary-side end is formed with an annular recess 25 into which the fixing portion 13A of the outer tube portion 2 is fitted. The outer surface of the secondary-side end of the valve seat 6 is formed with a radially protruding annular protrusion 26. This annular protrusion 26 abuts against the inner surface of the stepped portion 14A of the outer tube portion 2, thereby positioning the valve body 3 relative to the outer tube portion 2. When used with ultra-high pressure refrigerants such as CO2 refrigerants, the force acting on the valve seat 6 in the valve-closing direction when the valve is closed can be borne by the inner surface of the stepped portion 14A, preventing misalignment of the valve seat 6. The annular protrusion 26 is formed with a D-cut portion 27, which is a notch cut out from its circumferential portion. Here, the annular protrusion 26 of the valve seat 6 abuts against the inner surface of the stepped portion 14A of the outer pipe 2, forming a liquid seal, which is a minute gap, between them. If the refrigerant, which is a fluid, enters and accumulates in this liquid seal and is suddenly exposed to high temperatures after cooling and liquefying, the liquid refrigerant will suddenly expand in volume. However, because the D-cut portion 27 is in communication with the liquid seal, the expanded refrigerant is able to escape into the outer pipe 2. Therefore, damage or deformation of the outer pipe 2 and the valve seat 6 due to the expansion pressure of the refrigerant can be prevented.

[0028] Figure 3 is a top view of the valve disc shown in Figures 1 and 2, a cross-sectional view taken along line V0-V1 in the figure, and a cross-sectional view taken along line V0-V2 in the figure. Also, Figure 4 is a top view and a side view of the valve disc shown in Figures 1 to 3. The shaded area in the top view of the valve disc 4 indicates the contact portion with the valve stopper 22, and the shaded area in the side view indicates the contact portion with the inner peripheral surface of the valve holder 5 above the lateral hole 21.

[0029] 2 to 4, the valve disc 4 is a resin member formed such that four grooves 43 are provided in the valve disc axial direction D11 on the outer peripheral surface of a cylinder, and the cross section intersecting the valve disc axial direction D11 is substantially cross-shaped. The outer diameter of the valve disc 4 is slightly smaller than the inner diameter of the valve holder 5, and the valve disc 4 is provided along the inner peripheral surface of the valve holder 5 so as to be able to move axially within the valve holder 5. The valve disc 4 has the four grooves 43 formed on the outer peripheral surface of the cylinder, leaving four feather-shaped ribs 41 around the central axis 4A and a bottom plate portion 42 on the primary side that abuts against the valve seat surface 24.

[0030] The four grooves 43 are positioned symmetrically about the central axis 4A of the valve disc 4, specifically, at four positions spaced at 90° intervals around the central axis 4A. Each of the four grooves 43 extends in the valve disc axial direction D11 along the central axis 4A of the valve disc 4. Each groove 43 has a constant cross-section portion 43A, which is a sector-shaped constant cross-section portion with a central angle of approximately 90°, extending partway along the secondary side of the valve disc axial direction D11. From the primary-side end of the constant cross-section portion 43A to the bottom plate portion 42, the groove 43 forms a varying cross-section portion 43B, whose cross-sectional shape gradually changes in the valve disc axial direction D11 while forming an arc with a central angle of approximately 90° and gradually decreasing in depth. Each of the four grooves 43 has a constant cross-section portion 43A and a varying cross-section portion 43B, which are equal in size and shape.

[0031] The bottom plate portion 42 of the valve disc 4 has a flattened conical shape that connects the groove bottom surfaces of the cross-section-changing portions 43B of the groove 43 in the circumferential direction. An umbrella-shaped recess 42A is formed on the primary side of this bottom plate portion 42, and in the valve closed position P2 shown in Fig. 2, the peripheral edge of this recess 42A is seated so as to abut against the valve seat surface 24. The valve disc 4 is seated in this manner in the valve closed position P2, thereby closing the valve port 7 and preventing backflow of fluid from the secondary side to the primary side.

[0032] When the valve is open, the normal flow of fluid flows out of the valve port 7. The recess 42A in the bottom plate 42 effectively receives the fluid, pushing the valve element 4 upward toward the secondary side and opening the valve. The secondary-side end (i.e., the valve-opening-side end face) of the valve element 4 forms a cross-shaped end face 41B formed by the secondary-side edges of the four feather-like ribs 41. At the valve-opening position P1 shown in FIG. 2, the four radially outward ends 41B-1 of this cross-shaped end face 41B, i.e., the portions indicated by diagonal lines in the upper diagram of FIG. 4, contact the valve-seat-side end face 22A of the valve stopper 22, restricting its movement. At this time, the cross-shaped end face 41B (valve-opening-side end face) of the valve element 4 and the valve-seat-side end face 22A of the valve stopper 22 come into contact with and separate from each other via the axial contact portion 4E and the axial non-contact portion 4F described below. The axial contact portion 4E is a portion formed by the four end portions 41B-1 of the cross-shaped end face 41B of the valve body 4. The axial non-contact portion 4F is a portion formed by the valve-opening side end portions 43C of the four grooves 43 between the four end portions 41B-1.

[0033] In the present embodiment, the valve body 4 is formed with a non-through hole 44 that extends from the center of the end face on the valve open position P1 side, i.e., the cross-shaped end face 41B, to a predetermined depth in the valve body axial direction D11. Note that, unlike the hole 44 of the present embodiment, a non-through hole may be provided that opens in the opposite direction from the center of the recess 42A in the bottom plate portion 42 in the valve body axial direction D11.

[0034] Here, in the valve disc 4 in which four grooves 43 are formed and four blade-shaped ribs 41 and the primary-side bottom plate portion 42 remain, the leading edges 41A of the four blade-shaped ribs 41 form contact portions 4B that come into contact with the inner circumferential surface 5A of the valve holder 5. In addition, the four grooves 43 form non-contact portions 4C that are separated from the inner circumferential surface 5A of the valve holder 5 without coming into contact with it. The valve disc 4 is configured to come into sliding contact with the inner circumferential surface 5A of the valve holder 5 via these contact portions 4B and non-contact portions 4C.

[0035] 2, the four grooves 43 constituting the non-contact portion 4C are configured so that when the valve is fully open and the valve element 4 is separated from the valve seat 6 to the valve open position P1, the primary side ends of the four grooves 43 communicate with the four communication holes 21 in the valve holder 5. As a result, when the valve is in the valve open position P1, a passage is formed between the non-contact portion 4C of the valve element 4 (i.e., the four grooves 43) and the outer space of the valve holder 5. In this embodiment, this passage functions as a relief hole 4D for discharging refrigeration oil when this refrigeration oil is present in the contact portion 4B.

[0036] The check valve 1 described with reference to Figures 1 to 4 operates as follows when used in the upright position shown in Figure 1. First, when a fluid flows in the normal direction from the primary side to the secondary side while the valve disc 4 is seated in the valve closed position P2, the valve disc 4 is pushed by the fluid flowing out of the valve port 7 and moves to the valve open position P1 where it abuts against the valve stopper 22. When the normal flow stops, the valve disc 4 falls under its own weight and moves to the valve closed position P2 where it seats on the valve seat 6.

[0037] Furthermore, when the check valve 1 is used in a horizontal position or in a vertical position, which is upside down from that shown in Figure 1, it operates as follows. First, in the valve closed position P2, the pressure on the secondary side is set higher than that on the primary side, and the differential pressure at this time presses the valve disc 4 against the valve seat 6, maintaining it in a seated state. When fluid flows normally from the primary side to the secondary side in this state, the valve disc 4 is pressed by the fluid flowing out of the valve port 7 and moves to the valve open position P1, which is the farthest from the valve seat that abuts against the valve stopper 22. Then, when the valve is closed, the pressure on the secondary side is made higher than that on the primary side, and this differential pressure causes the valve disc 4 to move to the valve closed position P2, where it seats on the valve seat 6.

[0038] This check valve 1 is installed in the middle of a refrigerant flow path in a refrigeration cycle system and used as described below.

[0039] FIG. 5 is a diagram showing a refrigeration cycle system according to the first embodiment, which is provided with the check valve shown in FIGS.

[0040] 5 is used in, for example, an air conditioner such as a commercial air conditioner. This refrigeration cycle system 50 includes an indoor heat exchanger 51, an outdoor heat exchanger 52, an expansion valve 53, a four-way valve 54, and three compressors 55 connected in parallel, all connected by piping. In order to prevent backflow of refrigerant to each compressor 55, a check valve 1 is connected between the discharge (high-pressure output) side of each compressor 55 and the four-way valve 54, with the compressor 55 serving as the primary side and the four-way valve 54 serving as the secondary side.

[0041] During cooling operation, as indicated by solid arrow D51, the refrigerant that has absorbed heat in indoor heat exchanger 51 flows through four-way valve 54 to compressor 55, is compressed by compressor 55, passes through check valve 1 and four-way valve 54, and reaches outdoor heat exchanger 52. After discharging heat in outdoor heat exchanger 52, the refrigerant passes through expansion valve 53 and returns to indoor heat exchanger 51. During heating operation, as indicated by dotted arrow D52, the refrigerant that has discharged heat in indoor heat exchanger 51 passes through expansion valve 53 and reaches outdoor heat exchanger 52. After absorbing heat in outdoor heat exchanger 52, the refrigerant passes through four-way valve 54 to compressor 55, is compressed by compressor 55, and returns to indoor heat exchanger 51 through check valve 1 and four-way valve 54. The refrigeration cycle system 50 repeats these cycles to cool or heat the room.

[0042] Here, for example, under conditions of high cooling load, three compressors 55 are operated simultaneously, and each of the three check valves 1 is fully open. On the other hand, under conditions of low cooling load, operation of only one compressor 55 is sufficient, and the other two compressors 55 are not operated. In this case, the secondary pressure of the two check valves 1 becomes higher than the primary pressure, causing backflow from the secondary side, and the two check valves 1 are closed.

[0043] According to the check valve 1 and refrigeration cycle system 50 of the first embodiment described above, the contact area at the contact portion 4B is kept small by providing the non-contact portion 4C between the outer peripheral surface of the valve element 4 and the inner peripheral surface 5A of the valve holder 5. As a result, even if refrigeration oil is present between the outer peripheral surface of the valve element 4 and the inner peripheral surface 5A of the valve holder 5, the movement resistance due to the surface tension of the refrigeration oil is reduced, and the outer peripheral surface of the valve element 4 does not stick to the inner peripheral surface 5A of the valve holder 5, thereby enabling smooth opening and closing movement of the valve element 4.

[0044] Here, in this embodiment, the non-contact portion 4C is configured by four grooves 43 formed on the outer peripheral surface of the valve element 4, and these four grooves 43 are provided at positions that are line-symmetrical with respect to the central axis 4A of the valve element 4. With this configuration, the non-contact portion 4C is effectively configured by the four grooves 43, and the four grooves 43 are provided at positions that are line-symmetrical with respect to the central axis 4A of the valve element 4, so that movement resistance is uniformly distributed around the central axis 4A, further facilitating the opening and closing movement of the valve element 4. Furthermore, by providing the grooves 43 in the valve element 4 as the non-contact portion 4C, the valve element 4 becomes lighter and the pressure difference required to open the valve is reduced, making it easier to open the valve.

[0045] Furthermore, in this embodiment, the four grooves 43 are formed to be equal in size to one another. With this configuration, the weight distribution around the central axis 4A of the valve body 4 is made uniform, which further facilitates the opening and closing movement of the valve body 4.

[0046] In this embodiment, each of the four grooves 43 extends in the valve element axial direction D11 along the central axis 4A of the valve element 4. Each groove 43 has a constant cross-sectional area 43A, whose cross-sectional shape intersecting the valve element axial direction D11 is constant along the valve element axial direction D11, and a gradually changing cross-sectional area 43B. With this configuration, the grooves 43 constituting the non-contact portion 4C extend in the valve element axial direction D11, so that the remaining contact portion 4B also extends in the valve element axial direction D11, further facilitating the opening and closing movement of the valve element 4 along the valve element axial direction D11. Furthermore, because the cross-sectional shape of each groove 43 intersecting the valve element axial direction D11 is constant or gradually changes along the valve element axial direction D11, the weight distribution of the valve element 4 in the valve element axial direction D11 is uniform or gradually changes. This configuration also further facilitates the opening and closing movement of the valve element 4.

[0047] Furthermore, in this embodiment, when the valve is fully open and the valve disc 4 is separated from the valve seat 6 to the valve open position P1, the groove 43 communicates with the communication hole 21 of the valve holder 5. With this configuration, the portion where the groove 43 communicates with the communication hole 21 functions as a relief hole 4D for the refrigeration oil present in the contact portion 4B, preventing the refrigeration oil from accumulating in the groove 43. This suppresses the retention of surface tension of the refrigeration oil at the contact portion 4B, prevents the outer peripheral surface of the valve disc 4 from sticking to the inner peripheral surface 5A of the valve holder 5, and further smooths the opening and closing movement of the valve disc 4.

[0048] In this embodiment, the cross-shaped end surface 41B (valve-opening end surface) and the valve-seat-side end surface 22A of the valve stopper 22 are configured to come into contact with and separate from each other via the axial contact portion 4E and the axial non-contact portion 4F. Generally, in a structure in which the valve is positioned when the valve is opened by abutting against the valve stopper 22 as described above, refrigeration oil may also enter between the cross-shaped end surface 41B of the valve disc 4 and the valve-seat-side end surface 22A of the valve stopper 22. In this case, the refrigeration oil that has entered between the cross-shaped end surface 41B of the valve disc 4 and the valve-seat-side end surface 22A of the valve stopper 22 acts to adhere these two surfaces together due to surface tension. This action may cause movement resistance when the valve disc 4, which is in contact with the valve stopper 22 at the valve-opening position P1, attempts to move away from the valve stopper 22 to the valve-closing position P2.

[0049] Here, consider a structure that differs from this embodiment, for example, in which the valve disc is formed into a simple cylindrical shape and the circular surface on the valve opening side is in contact with the valve stopper 22, thereby increasing the contact area between the valve opening side end face of the valve disc 4 and the valve seat side end face 22A of the valve stopper 22. In such a structure, the movement resistance due to the above-mentioned sticking increases, and there are cases in which the valve opening side end face of the cylindrical valve disc sticks to the valve seat side end face 22A of the valve stopper 22 and cannot be separated, preventing the valve from closing.

[0050] In contrast, according to the present embodiment, the cross-shaped end face 41B (valve opening side end face) of the valve disc 4 and the valve seat side end face 22A of the valve stopper 22 come into contact with and separate from each other via the axial contact portion 4E and the axial non-contact portion 4F, thereby minimizing the contact area between the cross-shaped end face 41B and the valve seat side end face 22A. As a result, even if refrigeration oil is present between these two surfaces, the movement resistance due to the surface tension of the refrigeration oil is reduced, and the cross-shaped end face 41B of the valve disc 4 will not stick to the valve seat side end face 22A of the valve stopper 22, allowing for smooth opening and closing movement of the valve disc 4.

[0051] Furthermore, in this embodiment, when the valve element 4 is in the valve open position P1, the groove 43 and the communication hole 21 of the valve holder 5 communicate with each other to form the relief hole 4D, as described above. Therefore, refrigeration oil between the cross-shaped end face 41B of the valve element 4 and the valve seat side end face 22A of the valve stopper 22 can also be released to the outside of the valve holder 5 via the groove 43 and the relief hole 4D, which also facilitates the opening and closing movement of the valve element 4.

[0052] Furthermore, in this embodiment, a C-shaped retaining ring is used as the valve stopper 22. With this configuration, the area of ​​the valve seat-side end face 22A of the valve stopper 22 is kept small compared to when, for example, the valve seat-side end face is circular, unlike in this embodiment. In other words, the contact area between the cross-shaped end face 41B of the valve body 4 and the valve seat-side end face 22A of the valve stopper 22 is also kept small on the valve stopper 22 side. As a result, sticking between the cross-shaped end face 41B of the valve body 4 and the valve seat-side end face 22A of the valve stopper 22 is further reduced, further facilitating the opening and closing movement of the valve body 4. Furthermore, with the above configuration, a C-shaped retaining ring, which is inexpensive and easy to install, is used as the valve stopper 22, thereby reducing manufacturing costs.

[0053] In this embodiment, the valve element 4 is formed with a non-through hole 44 that extends from the end face on the valve open position P1 side to a predetermined depth in the valve element axial direction D11. This configuration makes it possible to prevent sink marks, air bubbles, and the like from occurring when the valve element 4 is formed from resin. Furthermore, the formation of the hole 44 reduces the weight of the valve element 4, which in turn reduces the valve opening pressure difference, making it easier to open the valve and further facilitating the opening and closing movement of the valve element 4.

[0054] Next, a second embodiment will be described. This second embodiment differs from the first embodiment described above in the shape of the valve body of the check valve, etc. Below, the check valve according to the second embodiment will be described with reference to Figures 6 and 7, focusing on the differences from the first embodiment. On the other hand, the refrigeration cycle system is the same as that of the first embodiment, so illustrations and descriptions thereof will be omitted.

[0055] Fig. 6 is an overall cross-sectional view showing a cross section along the axial direction of a check valve according to a second embodiment, and Fig. 7 is a top view of the valve body shown in Fig. 6 and a cross-sectional view along line V14-V14 in the figure. In Fig. 6, components equivalent to the components of the check valve 1 of the first embodiment shown in Fig. 1 are assigned the same reference numerals as in Fig. 1, and redundant explanations of these equivalent components will be omitted below.

[0056] The check valve 100 of the second embodiment is a valve device similar to the check valve 1 of the first embodiment, and has a valve body 3 built into an outer tube portion 2 along an axis L, and a valve element 140 is provided in the valve body 3 and supported by a cylindrical valve holder 5. The valve element 140 is provided so as to be movable in the axial direction between a valve closed position P2 where it seats on a valve seat portion 6 to close the valve port 7, and a valve open position P1 where it is spaced apart from the valve seat portion 6.

[0057] In this embodiment, the leading edges 141A of the four feather-like ribs 141 of the valve disc 140 constitute the contact portion 140B, and the four grooves 143 constitute the non-contact portion 140C, which is the same as in the first embodiment. Also in this embodiment, the cross-shaped end face 141B (the valve-opening-side end face) and the valve-seat-side end face 22A of the valve stopper 22 are configured to come into contact with and separate from each other via the axial contact portion 140E and the axial non-contact portion 140F. The axial contact portion 140E is formed by the four end portions 141B-1 of the cross-shaped end face 141B, and the axial non-contact portion 140F is formed by the valve-opening-side end portions 143C of the four grooves 143. Unlike the first embodiment, each groove 143 forms a cross-sectionally changed portion 143B that rises obliquely from the bottom plate portion 142 without passing through a flat end portion. The inclination is steeper than the cross-sectionally changed portion 43B of the first embodiment shown in FIG. 3. As a result, in this embodiment, the constant cross-section portion 143A of the groove 143 on the cross-shaped end face 141B side has a shorter length in the valve element axial direction D141 along the central axis 140A than the constant cross-section portion 43A of the first embodiment. Furthermore, in this embodiment, as shown in the cross-sectional view of Figure 7, the lightening hole 144 is a tapered hole with a round bottom that tapers in the valve element axial direction D141. In addition, the cross-shaped end face 141B has one ejector pin hole 141C formed in the end face portion of each of the four feather-like ribs 141 to hold the valve element 140 when attaching or detaching it.

[0058] In this embodiment, the valve body 140 is formed of a resin material that does not contain reinforcing fibers. Examples of such resin materials include high-strength materials such as PEEK (polyether ether ketone), PI (polyimide), and PPS (polyphenylene sulfide). These high-strength materials are resin materials that exhibit little plastic deformation and have excellent resistance to harsh operating environments, such as high temperatures and high pressures. In this embodiment, among these high-strength materials, PEEK, which has particularly high strength, is used. The valve body 140 is formed using PEEK without containing reinforcing fibers such as CF (carbon fiber) or GF (glass fiber). This results in little plastic deformation and high resistance, but a low elastic modulus, which gives the valve body 140 a wide elastic deformation range and easy deformation (ease of stretching) within the elastic range. In the first embodiment described above, the valve body 4 was simply described as a resin member. However, the valve body 4 may also be formed of PEEK material that does not contain reinforcing fibers, as in the second embodiment.

[0059] It goes without saying that the second embodiment described above also makes it possible to smooth the opening and closing movement of the valve body 140, similar to the first embodiment described above.

[0060] Furthermore, in this embodiment, the valve element 140 is formed from a resin material that does not contain reinforcing fibers. According to this configuration, as described above, the valve element 140 is formed from a resin material that does not contain reinforcing fibers, and therefore has a low elastic modulus and is easily deformed. Here, in a valve element 140 that operates in a harsh operating environment such as that described above, a decrease in flatness may be observed on the sealing surface. It is desirable for the valve element 140 to suppress valve leakage during back pressure even in such cases. In this case, according to this embodiment, since the valve element 140 is endowed with the properties of a low elastic modulus and easy deformation, even if the flatness of the sealing surface is low, the sealing surface can deform and come into close contact with the valve port 7, thereby suppressing valve leakage.

[0061] In this embodiment, PEEK, which has little plastic deformation and excellent resistance to harsh operating environments such as high temperatures and high pressures, is used as the resin material for forming the valve element 140. This configuration provides advantages such as good shape recovery after the back pressure is removed and excellent resistance to the operating environment, even for the valve element 140, which has a low elastic modulus and is prone to deformation as described above.

[0062] The first and second embodiments described above merely show typical forms of the present invention, and the present invention is not limited thereto. That is, various modifications can be made without departing from the gist of the present invention. As long as such modifications still include the configuration of the check valve and refrigeration cycle system of the present invention, they are of course included in the scope of the present invention.

[0063] For example, in the first and second embodiments described above, the check valve 1,100 used in an air conditioner such as a commercial air conditioner was exemplified. However, the check valve may be used not only in commercial air conditioners but also in residential air conditioners, and not only in air conditioners but also in various freezers, refrigerators, and the like. Furthermore, in the various refrigeration cycle systems described above, the check valve is not limited to being installed on the discharge side of the compressor as in the refrigeration cycle system 50 shown in FIG. 5 , but can be applied to prevent backflow in various locations in various refrigeration cycle systems. Furthermore, there are a wide variety of refrigerants available for each refrigeration cycle system (e.g., various fluorocarbon-based refrigerants, hydrocarbon-based refrigerants, and natural refrigerants such as CO2 and ammonia). The check valve of the present invention can be applied to refrigeration cycle systems compatible with any of these refrigerants.

[0064] In the above-described first and second embodiments, the communicating holes 21 are provided at four locations radially penetrating the cylindrical circumferential surface of the valve holder 5. However, the number of locations is not limited to four, and the number of locations may be one, two, or more. In addition, the communicating holes 21 have been described as holes formed in a circular shape in side view, but the shape is not limited to a circular shape in side view and may be elliptical, for example. In addition, in the above-described first and second embodiments, a check valve has been described in which the outer tube portion 2 (the coupling member and the main body member) is an integrally formed copper member. However, the present invention can also be applied to a check valve in which the inlet and outlet copper pipe coupling members and the main body member accommodating the valve element are separate members.

[0065] In the first and second embodiments described above, the non-contact portion 4C, 140C is exemplified as an example of the non-contact portion, which is configured by four grooves 43, 143 formed on the outer peripheral surface of the valve body 4, 140. However, the non-contact portion is not limited to this, and may be configured by a plurality of grooves formed on the inner peripheral surface of the valve holder, or may be configured by a plurality of grooves formed on both the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder. Furthermore, the non-contact portion is not limited to being configured by such grooves, and may be, for example, a plurality of recesses formed on at least one of the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder. Furthermore, the groove may be a spiral groove extending in the axial direction.

[0066] Furthermore, in the above-described first and second embodiments, as an example of a non-contact portion configured with a plurality of grooves, a non-contact portion 4C, 140C configured with four grooves 43, 143 arranged at positions that are line-symmetrical with respect to the central axis 4A, 140A of the valve disc 4, 140 is exemplified. However, the non-contact portion is not limited to this, and the number and positions of the grooves can be set as appropriate. Therefore, the number of grooves may be a number other than one or four. However, as described above, by configuring the non-contact portion 4C, 140C with four grooves 43, 143 arranged at positions that are line-symmetrical with respect to the central axis 4A, 140A of the valve disc 4, 140, the opening and closing movement of the valve disc 4, 140 can be further smoothed.

[0067] Furthermore, in the first and second embodiments described above, four grooves 43, 143 formed to be equal in size are exemplified as an example of the plurality of grooves constituting the non-contact portion. However, the plurality of grooves constituting the non-contact portion is not limited to this, and may be formed to be different in size. However, as described above, by forming the non-contact portion 4C, 140C from four grooves 43, 143 formed to be equal in size, the opening and closing movement of the valve body 4, 140 can be further smoothed.

[0068] In the first and second embodiments described above, the grooves 43, 143 are exemplified as examples of grooves constituting the non-contact portion. The grooves 43, 143 have both a constant cross-sectional area 43A, 143A and a gradually changing cross-sectional area 43B, 143B in a cross section intersecting the valve element axial direction D11, D141. However, the grooves constituting the non-contact portion are not limited to this, and the cross-sectional area of ​​the grooves may be set to any shape. However, as described above, the opening and closing movement of the valve element 4, 140 can be further smoothed by forming the non-contact portion 4C, 140C with a groove 43, 143 whose cross-sectional area is constant in the valve element axial direction D11, D141 or whose cross-sectional area gradually changes in the valve element axial direction D11, D141. The grooves may be formed only with a constant cross-sectional area or only with a gradually changing cross-sectional area.

[0069] Furthermore, in the first and second embodiments described above, as an example of a non-contact portion formed by a groove, the non-contact portions 4C, 140C formed by the grooves 43, 143 that communicate with the communication holes 21 of the valve holder 5 when the valve is fully open are exemplified. However, the non-contact portion is not limited to this, and the communication portion may be blocked from the communication hole when the valve is fully open. However, as described above, by forming the non-contact portions 4C, 140C by the grooves 43, 143 that communicate with the communication holes 21 of the valve holder 5 when the valve is fully open, accumulation of refrigeration oil in the grooves 43, 143 can be prevented, thereby further facilitating the opening and closing movement of the valve body 4, 140.

[0070] Furthermore, in the first and second embodiments described above, an example of the valve disc is the valve disc 4, 140 whose valve opening side end face is a cross-shaped end face 41B, 141B and which comes into contact with and separates from the valve seat side end face 22A of the valve stopper 22 via an axial contact portion 4E, 140E and an axial non-contact portion 4F, 140F. However, the valve disc is not limited to this. For example, the valve disc may have a circular opening side end face that comes into contact with the valve stopper at the circular plane. However, as described above, the valve disc 4, 140 comes into contact with and separates from the valve seat side end face 22A of the valve stopper 22 via the axial contact portion 4E, 140E and the axial non-contact portion 4F, 140F, so that the valve disc 4, 140 can easily separate from the valve stopper 22, thereby facilitating the opening and closing movement of the valve disc 4, 140. Furthermore, the shape of the valve opening end face is not limited to the above-mentioned shape, and as long as the axial contact area is small, it may be a cross shape or a shape other than a circular flat surface, and the surface roughness of the axial contact portion may be made rough, and similar effects will be obtained.

[0071] Furthermore, in the first and second embodiments described above, a C-shaped retaining ring valve stopper 22 is used as an example of the valve stopper. However, the valve stopper may be, for example, a disk-shaped member, or the like, as long as it is fixed to the valve holder and restricts the opening degree of the valve disc, and the specific form of the member is not important. However, as described above, using a C-shaped retaining ring valve stopper 22 can further smooth the opening and closing movement of the valve disc 4, 140 and can also reduce manufacturing costs.

[0072] Furthermore, in the first and second embodiments described above, the valve body 4, 140 having the lightening holes 44, 144 formed therein is shown as an example of the valve body. However, the valve body is not limited to this, and may have a solid structure without any lightening holes formed therein. However, as described above, by providing the lightening holes 44, 144 in the valve body 4, 140, it is possible to suppress the occurrence of sink marks, air bubbles, etc. during resin molding, and the lighter weight of the valve body 4, 140 makes it possible to further smooth the opening and closing movement of the valve body 4, 140.

[0073] In the second embodiment described above, the valve element 140 is formed from a resin material that does not contain reinforcing fibers. However, the valve element is not limited to this, and may be formed from a resin material that contains reinforcing fibers or other materials. However, as described above, forming the valve element 140 from a resin material that does not contain reinforcing fibers can suppress valve leakage during back pressure.

[0074] In the second embodiment described above, a PEEK material containing no reinforcing fibers is used as an example of the resin material containing no reinforcing fibers that forms the valve body. However, the resin material containing no reinforcing fibers that forms the valve body is not limited to this, and other resins such as the above-mentioned PI material, PPS material, or PA (polyamide) material may be used as long as they do not contain reinforcing fibers. However, as described above, the use of a PEEK material containing no reinforcing fibers can provide particularly excellent effects in terms of shape recovery after the release of back pressure and durability to the usage environment.

[0075] The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configurations are not limited to these embodiments, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention. [Explanation of symbols]

[0076] 1,100 check valve 2 Outer tube part 3 Valve body 4,140 valve bodies 4A,140A center axis 4B,140B Contact part 4C,140C Non-contact part 4D relief hole 4E,140E Axial contact part 4F,140F Axial non-contact part 5 Valve holder 6 Valve seat 7. Orifice 21 Communication hole 22 Valve stopper 22A Valve seat side end surface 41,141 Pinnate ribs 41A,141A Tip edge 41B, 141B Cross-shaped end face (valve opening side end face) 43,143 grooves 50 Refrigeration cycle system

Claims

1. A check valve comprising a cylindrical outer tube portion extending in an axial direction, a valve body housed in the outer tube portion, and a valve element provided in the valve body, The valve body includes a cylindrical valve holder that supports the valve element, a valve seat portion on which the valve element can be seated, a valve port that is closed by the valve element seated on the valve seat portion, and a valve stopper that is fixed to the valve holder and that regulates the opening degree of the valve element, the valve disc is provided in the valve holder so as to be movable in the axial direction between a valve closed position in which the valve disc is seated on the valve seat portion and a valve fully open position in which the valve disc is in contact with the valve stopper, The valve holder is provided with a communication hole that penetrates a cylindrical peripheral surface and communicates the inside of the outer tube portion with the valve port, the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder are configured to be in sliding contact with each other via a contact portion where they come into contact with each other and a non-contact portion where they are spaced apart without coming into contact with each other, No elastic member is provided in the valve holder to bias the valve body in a valve closing direction, a non-contact portion formed on the outer peripheral surface of the valve body, the non-contact portion being a groove that communicates with the communication hole when the valve body is fully open and has moved away from the valve seat to the fully open position.

2. A check valve comprising a cylindrical outer tube portion extending in an axial direction, a valve body housed in the outer tube portion, and a valve element provided in the valve body, The valve body includes a cylindrical valve holder that supports the valve element, a valve seat portion on which the valve element can be seated, a valve port that is closed by the valve element seated on the valve seat portion, and a valve stopper that is fixed to the valve holder and that regulates the opening degree of the valve element, the valve disc is provided in the valve holder so as to be movable in the axial direction between a valve closed position in which the valve disc is seated on the valve seat portion and a valve fully open position in which the valve disc is in contact with the valve stopper, The valve holder is provided with a communication hole that penetrates a cylindrical peripheral surface and communicates the inside of the outer tube portion with the valve port, the outer peripheral surface of the valve body and the inner peripheral surface of the valve holder are configured to be in sliding contact with each other via a contact portion where they come into contact with each other and a non-contact portion where they are spaced apart without coming into contact with each other, the valve element can be in a state where it does not come into contact with other members between the valve closed position and the valve fully open position, a non-contact portion formed on the outer peripheral surface of the valve body, the non-contact portion being a groove that communicates with the communication hole when the valve body is fully open and has moved away from the valve seat to the fully open position.

3. A check valve as described in claim 1 or 2, characterized in that the non-contact portion is composed of a plurality of grooves formed on at least one of the outer surface of the valve body and the inner surface of the valve holder, and the plurality of grooves are arranged in positions that are linearly symmetrical with respect to the central axis of the valve body.

4. 4. The check valve according to claim 3, wherein the plurality of grooves are formed to have equal sizes.

5. The check valve according to claim 3 or 4, characterized in that each of the plurality of grooves is formed to extend in a valve body axial direction along the central axis of the valve body, and the cross-sectional shape of a cross section intersecting the valve body axial direction is constant in the valve body axial direction, or the cross-sectional shape gradually changes in the valve body axial direction.

6. The primary end surface of the valve body has a seal surface that seats on the valve seat, The inner periphery of the sealing surface is larger than the inner diameter of the valve port, 3. The check valve according to claim 1, wherein the area between the outer peripheral edge of the valve body and the inner peripheral edge of the sealing surface is a ring-shaped area that is thinner in the axial direction of the valve body than other areas.

7. The check valve according to any one of claims 1 to 6, characterized in that the valve opening side end face of the valve body and the valve seat side end face of the valve stopper are configured to come into contact with and separate from each other via an axial contact portion in which they come into contact with each other and an axial non-contact portion in which they are separated without coming into contact with each other.

8. 8. The check valve according to claim 7, wherein the valve stopper is a C-shaped retaining ring.

9. The check valve according to any one of claims 1 to 8, characterized in that the valve body has a non-through hole formed therein that extends to a predetermined depth in the valve body axial direction along the central axis of the valve body.

10. 10. The check valve according to claim 1, wherein the valve body is made of a resin material that does not contain reinforcing fibers.

11. 11. The check valve according to claim 10, wherein the resin material is a PEEK material.

12. A refrigeration cycle system comprising the check valve according to any one of claims 1 to 11.

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