Check valve and refrigeration cycle system

Abstract

The invention provides a check valve, which adopts a valve core centripetal mechanism and can eliminate the conventional problem point (decline of valve opening performance) even if the differential pressure in the valve opening direction is relatively small. A check valve is provided with: an outer pipe section (10); a valve body (20) having a valve seat portion (21) having a valve seat (21B) and a valve port (21A), and a valve holder portion (22) having a cylindrical side wall portion (22A) defining a valve chamber and standing from the outer peripheral side of the valve seat; a valve body (30A) having a valve body side surface (32A) capable of coming into contact with the side wall part, a seal part (31Aa) provided only on one end surface (31A) of the valve body, and a tapered part (33A) connected to the seal part (31Aa) by reducing the diameter from the valve body side surface; and a valve body centripetal mechanism that, in a slightly open state, introduces a primary side pressure into an annular tapered section space (St) defined by the tapered section (33A), the radially extended line of the seal section (31Aa), and the side wall section, and that is movable in a direction orthogonal to the axis of the valve body.

Description

Technical Field

[0001] The present invention relates to a check valve having a valve core centrifugal mechanism that centers the valve core axis relative to the valve body axis, and a refrigeration circulation system using the check valve. Background Technology

[0002] For check valves, in the closed state, in addition to reliably preventing the backflow of fluid from the secondary side piping to the primary side piping, it is also required that even when the differential pressure between the primary side pressure and the secondary side pressure in the opening direction is small, the valve can quickly switch from the closed state to the open state to allow the fluid to flow smoothly.

[0003] For example, in patent document 1, such as Figure 11 As shown in (a) and (b), a longitudinally arranged check valve (hereinafter referred to as "conventional check valve") 1100 is described, which includes: a cylindrical outer tube portion 1110 extending along the axis L from a primary opening portion 1111C to a secondary opening portion 1112C; a valve body 1120 housed in the outer tube portion 1110; and a valve core 1130 disposed in the valve body 1120.

[0004] The valve body 1120 is composed of a valve seat portion 1121 and a valve support portion 1122. The valve seat portion 1121 includes a valve seat 1121B on which the valve core 1130 can sit, and a valve port 1121A that defines the inner periphery of the valve seat 1121B and extends to one end. The valve support portion 1122 includes a cylindrical sidewall portion 1122A that is erected from the outer periphery of the valve seat 1121B and supports the valve core 1130 for contact; and a plurality of through holes 1122B that penetrate the sidewall portion 1122A in the radial direction and are evenly arranged in the circumferential direction. Furthermore, a valve limiter 1140 is provided on the inner circumferential surface of the other end of the valve support portion 1122 to restrict the movement of the valve core 1130 towards the other end in the direction of axis L.

[0005] Thus, in the existing check valve 1100, the valve core 1130 is configured within the valve holder 1122 to move freely along the axis L between a closed state (sitting on the valve seat 1121B) and an open state (leaving the valve seat 1121B). Here, regardless of the mounting orientation of the outer tube 1110 (e.g., longitudinal arrangement of the outer tube 1110 along the direction of gravity, transverse arrangement along a direction orthogonal to gravity, etc.), as... Figure 11 As shown in (b), in the closed state, the axis L1130 of the valve core 1130 is not coaxial with the axis L of the valve body 1120. When the side surface 1132A of the valve core is in contact with the inner circumferential surface 1122Aa of the side wall, the static friction and dynamic friction of the valve core 1130 relative to the side wall 1122A are relatively large.

[0006] Therefore, under such circumstances, when the primary side pressure P1 is slightly greater than the secondary side pressure P2, and the valve core 1130 generates a relatively small differential pressure in the opening direction, the contact between the valve core side surface 1132A and the inner circumferential surface 1122Aa of the side wall generates relatively large resistance (static friction and dynamic friction). Therefore, there is a concern that the valve core may not move from the closed state to the open state, or that it may take time to move from the closed state to the open state (hereinafter referred to as "the previous problem point (decrease in valve opening performance)").

[0007] Furthermore, in the conventional check valve 1100, when it is horizontally positioned and in the closed state, the valve core side surface 1132A contacts the inner circumferential surface 1122Aa of the side wall (making... Figure 11 In (b) the case of rotating 90° clockwise, the self-weight of the valve core 1130 is applied to the inner circumferential surface 1122Aa of the side wall, thereby increasing the static and dynamic friction forces further compared to the longitudinal configuration, and making the previous problem (decrease in valve opening performance) more significant.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2022-159975 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The purpose of this invention is to provide a check valve that, by employing a valve core centrifugal mechanism that centers the valve core axis toward the valve body axis, is independent of longitudinal or transverse configurations. Even with relatively small differential pressure in the valve opening direction, it can eliminate previous problems (decrease in valve opening performance) and improve reliability.

[0013] Solution for solving the problem

[0014] To address the aforementioned issues, a check valve is provided, comprising: an outer tube extending along an axial direction and having a cylindrical shape; a valve body housed within the outer tube; a valve core configured to abut against the valve body; and a valve core radial mechanism that centers the axis of the valve core relative to the axis of the valve body. The valve body includes: a valve seat having a valve seat and a valve port; and a valve support having a cylindrical sidewall defining a valve chamber and erected vertically from the outer periphery of the valve seat. The valve core includes: a valve core sidewall capable of abutting against the sidewall; and a sealing portion disposed only on the valve core. One end face; and a tapered portion, which is connected to the valve core from the side of the valve core toward the sealing portion by a reduced diameter. The valve core is configured to move freely along the axial direction between a closed valve state in which the sealing portion abuts against the valve seat and an open valve state in which the sealing portion is separated from the valve seat and the valve port communicates with the secondary side internal space of the outer tube portion. The valve core centripetal mechanism introduces primary side pressure into the annular tapered space defined by the tapered portion, the radial extension line of the sealing portion, and the side wall portion in the slightly open state when the valve chamber and the valve port begin to communicate, thereby enabling the valve core to move in a direction orthogonal to the axis.

[0015] Alternatively, in the aforementioned check valve, the valve core centripetal mechanism may be configured such that the axial length of the cone is greater than the radial length of the cone.

[0016] Alternatively, in the aforementioned check valve, the valve core centripetal mechanism may move the valve core along the axial direction by a length that is more than half the axial length of the cone portion from the closed valve state to the upcoming open valve state.

[0017] Alternatively, in the aforementioned check valve, a non-through weight-reducing hole may be formed in the valve core, extending along the axial direction of the valve core.

[0018] Alternatively, in the aforementioned check valve, a mortar-shaped recess is formed on one end face of the valve core, which is coaxial with the valve core and faces the other end in a mortar-like shape, and the sealing portion is formed between the mortar-shaped recess and the cone portion.

[0019] Alternatively, in the aforementioned check valve, a mountain-shaped protrusion is formed on one end face of the valve core, which protrudes in a mountain shape coaxially with the valve core toward one end, and an annular recess is formed around the mountain-shaped protrusion, which is coaxially with the valve core toward the other end, with the sealing portion formed between the annular recess and the cone portion.

[0020] Alternatively, in the aforementioned check valve, the axial length of the side wall portion may be greater than the axial length of the valve core. Multiple connecting holes are provided at the position on the side wall portion separated from the valve seat, connecting the secondary side internal space of the outer tube portion and the valve chamber in the radial direction. From the closed valve state to the soon-to-open valve state, the multiple connecting holes are arranged opposite to the side of the valve core.

[0021] Alternatively, in the above-mentioned check valve, when the valve core is coaxially arranged with the valve body in the open state, the intersection of the inner surface of the side wall portion and the other end of the plurality of connecting holes is located on the inner side of an imaginary frustum-shaped structure formed by imaginary extension of the cone portion to the other end, regardless of the axial direction of the valve core.

[0022] Alternatively, in the aforementioned check valve, the axial length of the sidewall portion may be smaller than the axial length of the valve core, and in the closed state, when viewed from a direction orthogonal to the axis, the other end face of the sidewall portion may be positioned to overlap with the side face of the valve core.

[0023] Alternatively, a refrigeration circulation system may also be equipped with the aforementioned check valve.

[0024] Invention Effects

[0025] According to the present invention, a check valve is provided that, by employing a valve core centrifugal mechanism that centers the valve core axis toward the valve body axis, regardless of whether the valve is arranged longitudinally or transversely, can eliminate previous problems (decrease in valve opening performance) and improve reliability, even with relatively small differential pressure in the valve opening direction. Attached Figure Description

[0026] Figure 1 This is a longitudinal sectional view of the check valve (closed state) according to the first embodiment of the present invention. (a) is an overall view, and (b) is a partial enlarged view of the valve body and valve core in (a) (outer tube omitted).

[0027] Figure 2 Is Figure 1 In the region enclosed by dashed lines IIa, IIb, IIc, and IId shown in (a), the gap is exaggerated and magnified. (a) represents the closed valve state, (b) represents the slightly open valve state, (c) represents the valve about to open valve state, and (d) represents the open valve state.

[0028] Figure 3 yes Figure 1 The diagram illustrates the centripetal action of the annular conical space in the check valve shown. (a) shows a partial enlarged view of the valve body and valve core (outer tube omitted). Figure 1The corresponding diagram to (b), (b) represents a magnified view of the area enclosed by the dashed line IIIb shown in (a), where the gap is exaggerated. Figure 2 (The corresponding diagram of (b)).

[0029] Figure 4 It means Figure 1 The longitudinal sectional view of the check valve (open state) shown is shown in (a) as an overall view. Figure 1 (a) is the corresponding figure, (b) is a magnified view of the part surrounded by the dashed line IVb shown in (a), and (c) is a cross-sectional view of IVc-IVc shown in (a).

[0030] Figure 5 This is a diagram illustrating the refrigeration cycle system of the present invention.

[0031] Figure 6 This is an explanatory diagram of a modified valve core example (closed valve state) according to the first embodiment. Figure 1 The corresponding diagrams for (b) are shown. (a) represents valve core deformation example 1 (mortar-shaped recess), and (b) represents valve core deformation example 2 (mountain-shaped protrusion and annular recess).

[0032] Figure 7 This is a longitudinal sectional view showing the check valve (closed state) according to the second embodiment of the present invention, (a) showing the overall view ( Figure 1 (b) represents the bottom view of the valve core shown in (a), (c) represents the side view of the valve core shown in (a), and (d) represents the top view of the valve core shown in (a).

[0033] Figure 8 Is Figure 7 (a) shows an exaggerated magnified view of the gaps within the region enclosed by dashed lines VIIIa, VIIIb, VIIIc, and VIIId. Figure 2 The corresponding diagrams are as follows: (a) represents the closed valve state, (b) represents the slightly open valve state, (c) represents the valve about to open valve state, and (d) represents the open valve state.

[0034] Figure 9 It means Figure 7 The longitudinal sectional view of the check valve shown (open position) Figure 4 (Corresponding diagram of (a)).

[0035] Figure 10 This is an explanatory diagram of a modified valve core example (closed valve state) according to the second embodiment. Figure 6 The corresponding diagrams are as follows: (a) represents valve core deformation example 1 (mortar-shaped recess), and (b) represents valve core deformation example 2 (mountain-shaped protrusion and annular recess).

[0036] Figure 11The figures are longitudinal sectional views of a prior art check valve (closed state), (a) is an overall view, and (b) is a partial enlarged view enclosed by the dashed line XIb shown in (a). Detailed Implementation

[0037] Reference Figures 1 to 10 The embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein.

[0038] <Regarding terminology>

[0039] In this specification and the claims, "left," "right," "upper," and "lower" indicate... Figures 1-3 , Figure 4 (a), (b) Figure 6 , Figure 7 (a), (c) Figures 8-10The directions shown. In this specification and claims, "one end" and "the other end" refer to the "lower end" and "upper end" in the drawings. In this specification and claims, "longitudinal configuration" means "an arrangement in which the axial direction of the outer tube is along the direction of gravity." In this specification and claims, "transverse configuration" means "an arrangement in which the axial direction of the outer tube is along a direction orthogonal to the direction of gravity." In this specification and claims, "valve core centripetal mechanism" means "a mechanism that makes the axis of the valve core centripetal relative to the axis of the valve body." In this specification and claims, "annular" means "whether it is a circular shape or not, it also includes a shape that is continuously closed in the circumferential direction, such as a polygon." In this specification and claims, "annular conical space" means "an annular space defined by the conical portion of the valve core, the radial extension line of the sealing portion of the valve core, and the side wall portion of the valve body." In this specification and claims, "closed valve state" means "the state in which the sealing part of the valve core abuts against the valve seat of the valve body and the flow of fluid stops." In this specification and claims, "slightly open state" means "the state in which the sealing part of the valve core separates from the valve seat of the valve body, and the valve chamber begins to communicate with the valve port." In this specification and claims, "about to open valve state" means "the state in which the sealing part of the valve core separates from the valve seat of the valve body, and the valve chamber is about to communicate with the secondary internal space of the outer tube via the connecting hole or directly." In this specification and claims, "open valve state" means "the state in which the sealing part of the valve core separates from the valve seat of the valve body, and the valve port communicates with the secondary internal space of the outer tube via the valve chamber and the connecting hole or directly from the valve chamber." In this specification and claims, "mortar-shaped" means "not only conical, but any shape recessed into a mortar shape, therefore also including a polygonal pyramidal shape with a polygonal base." In this specification and the claims, "mountain shape" means "not only a conical shape, but any shape that protrudes into a mountain shape, and therefore also includes a polygonal pyramidal shape with a polygonal base."

[0040] (First Implementation)

[0041] <About the structure of check valves>

[0042] use Figure 1The check valve 100A according to the first embodiment of the present invention will be described. The check valve 100A consists of an outer tube portion 10, a valve body 20 housed in the secondary side internal space, i.e., the housing chamber HC, within the outer tube portion 10, and a valve core 30A disposed within the valve body 20 in a manner that allows it to slide along the axis L. Hereinafter, the structure of each component of the check valve 100A will be described sequentially. In the check valve 100A of the first embodiment, for the sake of explanation, a longitudinal configuration is used as an example, but it is not limited to this, and other configurations such as a transverse configuration are also included. Furthermore, in the transverse configuration, the only difference from the longitudinal configuration is that the self-weight of the valve core 30A acts in a direction orthogonal to the axis L, so the description here is omitted.

[0043] Details will be described later, but in the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular cone space), regardless of whether the configuration is longitudinal or transverse, even a relatively small differential pressure in the valve opening direction can eliminate previous problems (decrease in valve opening performance) and improve reliability.

[0044] <About the Foreign Exchange Administration>

[0045] The outer tube 10 is made of a metal material such as copper and has a cylindrical shape extending along the axis L. It is integrally formed by deep drawing or other processes. The outer tube 10 includes a primary connector 11 extending to one end, a secondary connector 12 extending to the other end, and a valve body housing 13 continuously connected between the primary connector 11 and the secondary connector 12.

[0046] The primary connector 11 has a cylindrical primary cylindrical portion 11A, a first connecting portion 11B that expands from the primary cylindrical portion 11A, and a primary opening portion 11C that is connected to a primary piping (not shown) and is introduced with a primary side pressure P1.

[0047] The secondary connector 12 has a cylindrical secondary cylindrical portion 12A, a second connecting portion 12B that expands from the secondary cylindrical portion 12A, and a secondary opening portion 12C that is connected to a secondary piping (not shown) and is introduced with secondary side pressure P2.

[0048] The valve body receiving portion 13 has: a first diameter expansion portion 13A, which continuously expands from the primary connector portion 11; a second diameter expansion portion 13B, which expands in diameter compared to the first diameter expansion portion 13A and is continuous with the secondary connector portion 12; and a step portion 13C, which is located at the boundary portion between the first diameter expansion portion 13A and the second diameter expansion portion 13B.

[0049] The first expansion section 13A is a portion that holds the valve body 20 disposed inside. Multiple portions of the valve body 20 are formed on its circumferential surface, with fixing portions 13D that deform inward in the radial direction to fix the valve body 20. As will be described in detail later, the fixing portions 13D are riveted and deformed by a punch of a stamping device, engaging with the throttling portion 21C of the valve body 20, thereby fixing the valve body 20 to a predetermined position inside the outer tube section 10.

[0050] Furthermore, in the first embodiment, the primary connector 11, the secondary connector 12, and the valve body housing 13 are integrally formed, but this is not a limitation. For example, they can be assembled by threading or welding after being formed separately. In addition, in the first embodiment, when fixing the valve body 20 inside the outer tube 10, press-fitting and riveting are used, but this is not a limitation. For example, press-fitting alone, riveting alone, threading, welding, or adhesive bonding can also be used.

[0051] <About the valve body>

[0052] The valve body 20 is made of metal materials such as brass and is formed through machining processes. For example... Figure 1 As shown in (b), the valve body 20 includes a valve seat portion 21 and a valve bracket portion 22.

[0053] The valve seat portion 21 includes: a valve port 21A having a circular cross-section extending along the axis L; and a valve seat 21B formed flatly on the periphery of the other end of the valve port 21A, allowing the valve core 30A to be seated. Additionally, an annular throttling portion 21C is formed on the outer surface of one end of the valve seat portion 21, and a flange portion 21D protruding radially is formed on the outer surface of the other end of the valve seat portion 21. By pressing the valve body 20 into the first enlarged diameter portion 13A until the flange portion 21D abuts against the inner surface of the stepped portion 13C of the outer tube portion 10, the valve body 20 is positioned relative to the outer tube portion 10, and is fixed relative to the outer tube portion 10 by engaging the fixing portion 13D of the outer tube portion 10 with the annular throttling portion 21C.

[0054] Furthermore, in the first embodiment, the valve port 21A has a circular cross-sectional shape, but it is not limited to this. For example, it can also have an elliptical cross-sectional shape, a polygonal cross-sectional shape, etc.

[0055] The valve holder portion 22 has: a cylindrical sidewall portion 22A, which is erected from the outer periphery of the valve seat 21B to the other end, and defines the valve chamber VC on the inner side (see reference). Figure 4(a)); a plurality of (e.g., two, etc.) connecting holes 22B that penetrate the sidewall portion 22A radially at a position separated from the valve seat 21B; and an annular groove portion 22C provided at the other end of the inner circumferential surface 22Aa (inner circumferential surface of the sidewall portion). Viewed from the axis L direction, the plurality of connecting holes 22B are arranged axially symmetrically. Furthermore, the length of the sidewall portion 22A in the axis L direction is greater than the length of the valve core 30A in the axis L direction. And, a valve limiter 40 (see reference 22C) is provided in the annular groove portion 22C to restrict the movement of the valve core 30A to the other end. Figure 4 (a)). The valve limiter 40 is made of stainless steel and has a retaining ring (e.g., a C-ring) shape. After being temporarily compressed radially and inserted into the annular groove 22C, the valve limiter 40 is released from compression and stored in the annular groove 22C. In addition, the outer diameter of the valve holder 22 is set to be smaller than the inner diameter of the second expansion portion 13B so that the fluid flows along the axial direction L through the radial gap between the valve holder 22 and the second expansion portion 13B.

[0056] Furthermore, in the first embodiment, such as Figure 4 As shown in (a), two connecting holes 22B are arranged symmetrically, but not limited to this, and the number and arrangement can be changed as needed.

[0057] <About the valve core>

[0058] The valve core 30A is made of a high-strength resin material such as polyetheretherketone (PEEK) and has a generally cylindrical shape centered on an axis L30A parallel to the axis L. This structure allows for a lighter valve core 30A compared to metal materials while maintaining strength. The valve core 30A has: one end face 31A, which has a flat, circular plate shape; and a side face 32A, which is a cylindrical outer curved surface.

[0059] The valve core has a sealing portion 31Aa formed by a flat annulus on its outer peripheral edge in the radial direction at one end face 31A. This sealing portion 31Aa abuts against the valve seat 21B, which is also formed by a flat annulus. Therefore, the outer diameter of the valve core end face 31A is set to be larger than the inner diameter of the valve seat 21B, i.e., the inner diameter of the valve port 21A. In addition, the outer diameter of the valve core side surface 32A is set to be slightly smaller than the inner diameter of the inner peripheral surface 22Aa of the side wall portion 22A, so that the valve core 30A can slide along the axis L within the side wall portion 22A. Therefore, in the refrigeration cycle system 1000 described later, when the check valve 100A is located immediately after the compressor 600 or immediately after a curved pipe, even if there is a swirling component in the fluid, it can prevent the swirling flow from flowing into the space between the inner circumferential surface 22Aa of the side wall and the side surface 32A of the valve core, suppress the rotation of the valve core 30A, and reduce the generation of abnormal noise and wear of the valve core caused by the rotation of the valve core 30A.

[0060] In addition, such as Figure 2 As shown in (a), the valve core 30A has a tapered portion 33A that is connected to the sealing portion 31Aa by reducing its diameter from the valve core side 32A to the sealing portion 31Aa.

[0061] Furthermore, in the first embodiment, the longitudinal cross-sectional shape of the cone portion 33A is a straight shape, but it is not limited to this. For example, it may also be a curved longitudinal cross-sectional shape that narrows from the valve core side 32A to the sealing portion 31Aa.

[0062] <About the Refrigeration Cycle System>

[0063] like Figure 5 As shown, the check valve 100A can be used in a refrigeration cycle system 1000 (e.g., an air conditioner such as a commercial air conditioner).

[0064] The refrigeration cycle system 1000 is connected via piping to an indoor heat exchanger 200, an outdoor heat exchanger 300, an expansion valve 400, a four-way valve 500, and three compressors 600 connected in parallel. A check valve 100A is used to prevent refrigerant backflow into each compressor 600. It connects the compressor 600 as the primary side and the four-way valve 500 as the secondary side between the discharge (high-pressure) side of each compressor 600 and the four-way valve 500. Furthermore, the accumulator, pressure sensor, temperature sensor, etc., are not shown in the diagram.

[0065] The refrigeration cycle flow path is switched between two modes by the four-way valve 500: one for cooling operation and one for heating operation. During cooling operation (refer to...). Figure 5 (Solid arrow in the image) The refrigerant compressed by the compressor 600 circulates through the check valve 100A from the four-way valve 500 in the following order: outdoor heat exchanger 300, expansion valve 400, indoor heat exchanger 200, four-way valve 500, and compressor 600. The outdoor heat exchanger 300 functions as a condenser, and the indoor heat exchanger 200 functions as an evaporator.

[0066] On the other hand, during heating operation (refer to...) Figure 5 (The dashed arrow in the image shows the refrigerant compressed by the compressor 600, which circulates sequentially through the four-way valve 500 via the check valve 100A in the indoor heat exchanger 200, expansion valve 400, outdoor heat exchanger 300, four-way valve 500, and compressor 600. The indoor heat exchanger 200 functions as a condenser, and the outdoor heat exchanger 300 functions as an evaporator.)

[0067] Here, for example, under conditions of high cooling load, all three compressors 600 operate simultaneously, so each of the three check valves 100A is fully open. Conversely, under conditions of low cooling load, only one compressor 600 needs to operate, so the other two compressors 600 do not operate. In this case, the secondary side pressure of the two check valves 100A is higher than the primary side pressure, resulting in backflow from the secondary side, and the two check valves 100A are closed.

[0068] Furthermore, in this embodiment, an air conditioner such as a commercial air conditioner is used as the refrigeration cycle system, but it is not limited to this. It can also be a household air conditioner or other air conditioner. It is not limited to air conditioners and can also be applied to various types of refrigeration units.

[0069] <Regarding the operation of check valves>

[0070] use Figure 1 (a) and Figure 4 (a) describes the operation of check valve 100A. Here, as... Figure 5 As shown, a compressor 600, serving as a pressure supply source, is connected to the primary connector 11, and an indoor heat exchanger 200 and an outdoor heat exchanger 300, serving as heat loads, are connected to the secondary connector 12 via a four-way valve 500. Initially, the primary side pressure P1 is less than the secondary side pressure P2 (P1 < P2). For ease of explanation, a longitudinally positioned check valve 100A is used here, but it is not limited to this; other configurations, such as a transverse configuration, are also included. Furthermore, this explanation focuses on the force acting on the valve core 30A in both the longitudinal and transverse configurations—the differential pressure in the opening / closing direction—and therefore omits the explanation of the effect of the valve core 30A's own weight. Moreover, in the first embodiment, since there is no force-applying component that applies force to the valve core 30A in the closing direction, the valve opening performance is improved even with a relatively small differential pressure in the opening direction (P1-P2).

[0071] First, such as Figure 1 As shown in (a), when the valve core 30A is seated on the valve seat 21B and the sealing part 31Aa abuts against the valve seat 21B, if a primary side pressure P1 and a secondary side pressure P2 (<P1) are applied to one end and the other end of the valve core 30A respectively, a differential pressure (P1-P2) in the valve core 30A in the opening direction will be generated.

[0072] If the differential pressure (P1-P2) in the valve opening direction exceeds a predetermined threshold, then... Figure 4As shown in (a), the valve core 30A separates from the valve seat 21B, becoming an open valve. In this open valve state, the fluid flowing into the valve chamber VC from the primary opening 11C via the valve port 21A temporarily branches into multiple connecting holes 22B provided on the side wall 22A. Furthermore, the branched fluids pass through the radial gap between the outer peripheral surface of the valve holder 22 and the inner peripheral surface of the outer tube 10, and then re-converge in the receiving chamber HC of the outer tube 10 before flowing towards the other end in the direction of the axis L, namely the secondary opening 12C.

[0073] In this open valve state, when the differential pressure (P1-P2) in the opening direction of the valve core 30A is relatively large, such as Figure 4 As shown in (a), the valve core 30A continues to move to the other end within the valve holder 22, but eventually the other end face of the valve core 30A abuts against the valve limiter 40, thereby restricting the movement to the other end.

[0074] Subsequently, when the pressure on the primary side P1 is less than the pressure on the secondary side P2 (P1 < P2) due to a decrease in the pressure of the pressure supply source, a differential pressure (P2 - P1) in the valve core 30A in the valve closing direction is generated. The valve core 30A returns to the closed valve state, sitting on the valve seat 21B, to prevent backflow from the secondary opening 12C to the primary opening 11C.

[0075] <Regarding previous issues (decrease in valve opening performance)>

[0076] As mentioned above, in Figure 11 In the conventional check valve 1100 shown in (b), when the valve core 1130 generates a relatively small differential pressure in the opening direction, the valve core side 1132A generates a relatively large resistance (static friction and dynamic friction) due to the contact between the valve core side 1132A and the inner circumferential surface 1122Aa of the side wall, thus exhibiting the conventional problem of (decrease in valve opening performance).

[0077] In contrast, in the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular cone space), regardless of whether the valve is arranged longitudinally or transversely, even a relatively small differential pressure in the valve opening direction can eliminate previous problems (decrease in valve opening performance) and improve reliability.

[0078] <Regarding the valve core radial mechanism (1) (introducing primary lateral pressure into the annular conical space>

[0079] use Figure 2 as well as Figure 3 The valve core centripetal mechanism 1 (which introduces primary lateral pressure into the annular conical space) will be explained here. Figure 2 As shown in (a), in the closed state, the valve core side 32A is positioned in contact with the side wall portion 22A. Additionally, Figure 2(b) to (d) and Figure 3 The gaps between the valve seat 21B and the sealing portion 31Aa, and between the inner circumferential surface 22Aa of the side wall and the side surface 32A of the valve core, shown in (b) are exaggerated for better understanding. Furthermore, in Figure 2 (b) to (c) and Figure 3 As shown in (b), from the slightly open state to the state about to open the valve, the fluid velocity is extremely slow, so the static pressure becomes dominant compared to the dynamic pressure.

[0080] First of all, Figure 2 In the closed valve state, where the sealing portion 31Aa abuts against the valve seat 21B as shown in (a), a continuous annular conical space St is defined in the circumferential direction when viewed from the axis L by the conical portion 33A, the radial extension line of the sealing portion 31Aa of the valve core 30A, and the side wall portion 22A. Furthermore, if the axis L30A of the valve core 30A is coaxial with the axis L of the valve body 20, then the same radial gap is formed between the valve core side surface 32A and the side wall portion 22A in the circumferential direction. Here, as... Figure 1 As shown in (b), the valve core 30A is eccentric relative to the valve body 20. The right side of the valve core side 32A is in contact with the inner circumferential surface 22Aa of the side wall, while the left side of the valve core side 32A is separated from the inner circumferential surface 22Aa of the side wall.

[0081] Next, in Figure 2 In the slightly open state where the valve chamber VC and valve port 21A are initially connected, as shown in (b), the valve core centripetal mechanism (1) (introducing primary side pressure into the annular conical space) introduces primary side pressure P1 into the annular conical space St via the valve chamber VC, and discharges a small amount of fluid from the annular conical space St to the secondary side. The valve core centripetal mechanism (1) (introducing primary side pressure into the annular conical space) will be described in detail below, enabling the application of a pressing force (radial pressing force Ftr) to the valve core 30A in a direction orthogonal to the axis L.

[0082] First, such as Figure 3 As shown in (a), when viewed from the axis L direction, the radial gap GL region (refer to) has a relatively large radial gap between the valve core 30A and the side wall portion 22A. Figure 3 In (a), the fluid pressure is easily released to the secondary side, thus the annular cone space St becomes locally low pressure. On the other hand, in the small radial clearance region GS (refer to) where the radial clearance between the valve core 30A and the side wall portion 22A is relatively small (or zero), the pressure is low. Figure 3 In (a)), the fluid pressure is difficult to release to the secondary side, thus the annular conical space St becomes locally high-pressure. Therefore, in the annular conical space St, when viewed from the axis L direction, a non-uniform pressure distribution is generated along the circumference.

[0083] Here, as Figure 3 As shown in (a) and (b), in the cone 33A, the fluid pressure in the annular cone space St generates a pressing force Ft that presses against the cone 33A in the vertical direction. This pressing force Ft can be divided into an axial pressing force Ftl towards the axis L and a radial pressing force Ftr towards the radial direction.

[0084] Therefore, as Figure 3 As shown in (a), due to the uneven pressure distribution in the circumferential direction generated in the annular conical space St, a centripetal force Ftr, which is relatively large in the radial direction, is generated in the small radial direction gap region GS compared with the large radial direction gap region GL.

[0085] As a result, the centripetal force, which is the sum of the radially unevenly generated pressure Ftr in the circumferential direction, acts on the valve core 30A in a manner that is uniform in the circumferential direction with respect to the radial gap between the valve core 30A and the side wall portion 22A, i.e., the axis L30A of the valve core 30A is coaxial with the axis L of the valve body 20. Here, since the axially uneven pressure Ftl acts on the valve core 30A, the valve core 30A moves in the opening direction while being centripetal in the radial direction (refer to...). Figure 2 (M1 in (b)).

[0086] Furthermore, due to the uneven pressure distribution in the circumferential direction generated in the annular conical space St, a larger axial pressing force Ftl is generated in the region GS with a small radial gap compared to the region GL with a large radial gap. However, as Figure 3 As shown in (a), in the region of valve core 30A opposite to valve port 21A on one end face 31A of valve core, a primary side pressure P1 is applied, generating an upward axial pressing force that is significantly greater than the sum of the axial pressing forces Ftl generated throughout the annular conical space St. Therefore, the effect caused by the axial pressing force Ftl generated throughout the annular conical space St can be ignored.

[0087] Furthermore, in Figure 2 In the state of about to open the valve, where the annular conical space St is connected to the connecting hole 22B as shown in (c), the valve core 30A moves radially inward and towards the opening direction, still through the valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular conical space). Additionally, in Figure 2 In (c), during the period from the slightly open state to the state about to open, the axis L30A of the valve core 30A is coaxial with the axis L of the valve body 20. Therefore, the valve core 30A moves in the opening direction in a non-contact state with the side wall portion 22A (refer to...). Figure 2 (M2 in (c)).

[0088] Furthermore, in Figure 2 In the open valve state, where the annular conical space St disappears and the valve chamber VC and the receiving chamber HC are connected via the connecting hole 22B, the fluid flowing into the valve chamber VC from the valve port 21A flows through the gap between the cone 33A and the inner circumferential surface 22Aa of the side wall towards the multiple connecting holes 22B evenly arranged in the circumferential direction. At this time, the annular conical space St disappears, and the centripetal force generated by the radial pressure Ftr disappears. However, since a primary lateral pressure P1 is still loaded on one end face 31A of the valve core, the valve core 30A can continue to move in the valve opening direction (refer to...). Figure 2 (d) of M3).

[0089] Here, as Figure 4 As shown in (a), when the differential pressure (P1'-P2') on the valve core 30A in the opening direction is relatively large, the valve core 30A continues to move towards the other end within the valve holder 22, but eventually the other end face of the valve core 30A abuts against the valve limiter 40, thereby restricting the movement towards the other end. At this time, as Figure 4 As shown in (b) and (c), when the axis L30A of the valve core 30A and the axis L of the valve body 20 are coaxially arranged, the intersection point P of the inner circumferential surface 22Aa of the side wall and the other end 22Bb of the multiple connecting holes 22B is all located in an imaginary frustum-shaped cone formed by imaginarily extending the cone 33A to the other end (see reference). Figure 4 The inner side of the single-dotted line extending from 33A in (b). Thus, in the open state, when the fluid collides with one end face 31A of the valve core and moves outward in the radial direction, the fluid is guided along the cone 33A, and therefore easily flows smoothly into the radial gap between the outer peripheral surface of the valve holder 22 and the inner peripheral surface of the outer tube 10 without passing through the flow path that generates pressure loss (the intersection P becomes the gap between the inner peripheral surface 22Aa of the inlet sidewall and the side surface 32A of the valve core) (see reference). Figure 4 (b) In addition, when there is a swirling component in the fluid, it can prevent the swirling flow from flowing into the space between the inner circumferential surface 22Aa of the side wall and the side surface 32A of the valve core, suppress the rotation of the valve core 30A, and further reduce the generation of abnormal noise and wear of the valve core caused by the rotation of the valve core 30A.

[0090] Thus, in the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular conical space), during the period from the slightly open state to the state about to open the valve, the axis L30A of the valve core 30A is coaxial with the axis L of the valve body 20, and the valve core 30A can move in the valve opening direction in a non-contact state with the side wall portion 22A, thereby eliminating the previous problem point (decrease in valve opening performance) and improving reliability.

[0091] In addition, through in-depth research, the inventors attempted to make the axis L30A of the valve core 30A more reliably oriented toward the axis L of the valve body 20 by further adopting at least one of the following: valve core centripetal mechanism (2) (increased pressure in the radial direction), valve core centripetal mechanism (3) (larger movement length caused by pressure in the radial direction), and valve core centripetal mechanism (4) (lighter valve core).

[0092] <Regarding the valve core radial mechanism (2) (radial direction according to the increase of pressure)>

[0093] Valve core centripetal mechanism (2) (radial direction according to the increase of pressure) such as Figure 2 As shown in (a), the length a in the axial direction L of the cone 33A is made greater than the radial length b of the cone 33A (1 < a / b), that is, the angle θ between the cone 33A and the axis L (refer to) Figure 2 (a) is smaller than 45° (θ < 45°).

[0094] Therefore, as Figure 3 As shown in (b), the direction of the pressing force Ft applied to the cone 33A can be more actively directed towards the radial direction, that is, the radial pressing force Ftr can be greater than the axial pressing force Ftl. Therefore, the sum of the radial pressing forces Ftr acting on the valve core 30A, i.e., the centripetal force, can be increased. Thus, during the period from the slightly open state to the almost open state, the axis L30A of the valve core 30A can be more reliably centripetal to the axis L of the valve body 20. In addition, in order to reliably increase the radial pressing force Ftr, it is preferable to set it to 5 ≤ a / b.

[0095] <Regarding the valve core radial mechanism (3) (the radial direction is determined by the greater distance the pressure causes to move)>

[0096] Valve core radial mechanism (3) (the radial direction is based on the greater movement length under pressure) such as Figure 2 As shown in (a), the length c by which the valve core 30A moves along the axis L from the closed valve state to the soon-to-open valve state is more than half (0.5 ≤ c / a) of the length a of the cone portion 33A along the axis L. Furthermore, the length c by which the valve core 30A moves along the axis L from this closed valve state to the soon-to-open valve state is, in other words, the length along the axis L between the other end of the cone portion 33A and one end 22Ba of the connecting hole in the closed valve state.

[0097] This creates a circular conical space St, which increases the length of the valve core 30A moving along the axis L under the action of pressure Ftr in the radial direction, i.e., from the slightly open state to the state about to open (refer to...). Figure 2 (b) and Figure 2The length by which the valve core 30A moves along the axis L up to (c) allows the axis L30A of the valve core 30A to be more reliably centered on the axis L of the valve body 20. Furthermore, if the length by which the valve core 30A moves along the axis L under the action of pressure Ftr in the radial direction is too long, the time from the closed state to the open state will increase, potentially leading to a decrease in responsiveness. Therefore, it is preferable to set it to 0.5 ≤ c / a ≤ 0.9.

[0098] <Regarding the valve core centripetal mechanism (4) (Valve core lightweighting)>

[0099] Valve core centripetal mechanism (4) (Valve core lightweighting) such as Figure 1 As shown in (b), a weight-reducing hole 34A is provided on the valve core 30A along its axis L30A in a manner that reduces weight by not penetrating from the center of the other end face toward one end side. This weight reduction of the valve core 30A allows the axis L30A of the valve core 30A to be more reliably centered on the axis L of the valve body 20 during the transition from a slightly open state to a state about to open. This is achieved even when a small centripetal force generated by a relatively small differential pressure (P1'-P2') in the opening direction acts on the valve core 30A.

[0100] Thus, in the first embodiment, in addition to the valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular cone space), at least one of the valve core centripetal mechanism (2) (increasing the pressure in the radial direction), the valve core centripetal mechanism (3) (larger movement length caused by the pressure in the radial direction), and the valve core centripetal mechanism (4) (lightening of the valve core) is also adopted, thereby enabling the axis L30A of the valve core 30A to be more reliably centripetal towards the axis L of the valve body 20.

[0101] (Example of valve core deformation)

[0102] Here, use Figure 6 The following describes valve core modifications 1 and 2 of the first embodiment. Valve core modifications 1 and 2 differ from the first embodiment in that the shape of one end face 31A', 31A" of the valve core is not a flat surface, but the other basic structures are the same as the first embodiment. Here, the same symbols are used to indicate the same structures, and repeated descriptions are omitted.

[0103] <Regarding concerns (smooth movement caused by valve spool tilting during valve spool centering)>

[0104] In the valve core 30A of the first embodiment, since one end face 31A of the valve core is a flat surface, it may be affected by considerable dynamic pressure. Specifically, during the period from the slightly open state to the state about to open (refer to...), Figure 2(b) and (c) If the fluid collides with the valve core end face 31A, which is composed of a flat surface, through the valve port 21A, three-dimensional turbulence is generated in the fluid after the collision. Therefore, the load on the valve core end face 31A is accompanied by unstable changes and becomes a non-uniformly distributed dynamic pressure when viewed from the axis L direction. Therefore, due to this dynamic pressure, assuming that the axis L30A of the valve core 30A is eccentric relative to the axis L of the valve body 20, and in the case of tilting, the outer periphery of the other end of the valve core 30A is stuck in the inner periphery of the side wall 22Aa. Therefore, it is possible to suppress the smooth movement of the valve core 30A in the radial direction and the valve opening direction based on centripetal action (hereinafter referred to as "concern (suppression of smooth movement of valve core tilted when the valve core is centripetal)").

[0105] In contrast, in the valve core modification example of the first embodiment, the valve core centrifugal mechanism (5) of the valve core modification example 1 (suppressing valve core tilting when the valve core is centrifuged: concave portion) or the valve core centrifugal mechanism (6) of the valve core modification example 2 (suppressing valve core tilting when the valve core is centrifuged: concave portion and convex portion) is further adopted, thereby eliminating concerns (suppressing smooth movement caused by valve core tilting when the valve core is centrifuged).

[0106] <Regarding the valve core centrifugal mechanism (5) (Valve core tilting when suppressing valve core centrifugation: concave part)>

[0107] use Figure 6 (a) The valve core centrifugal mechanism (5) (valve core tilting when suppressing valve core centrifugation: recess) of the valve core modification example 1 of the first embodiment will be described. This valve core centrifugal mechanism (5) (valve core tilting when suppressing valve core centrifugation: recess) has a mortar-shaped recess 31Ab' formed on one end face 31A' of the valve core, which is coaxial with the valve core 30A' and faces the other end in a mortar-shaped recess. A sealing portion 31Aa' is formed between the mortar-shaped recess 31Ab' and the cone portion 33A. As a result, at least during the period when the centrifugal action on the valve core 30A' is in effect (at least from the slightly open state to the state about to open the valve), the fluid in the mortar-shaped recess 31Ab' is stagnant. Therefore, the static pressure at one end face 31A' of the valve core has a stable change and is uniformly distributed when viewed from the axis L direction, thus suppressing the tilt of the axis of the valve core 30A' relative to the axis L of the valve body 20. As a result, concerns (suppressing the smooth movement caused by the tilt of the valve core when it is concentric) can be eliminated.

[0108] Furthermore, the mortar-shaped recess 31Ab' in the valve core deformation example 1 is composed of a conical shape with a round bottom surface, but it is not limited to this. As long as the recess is mortar-shaped, it can be a polygonal pyramidal shape with a polygonal bottom surface, for example.

[0109] <Regarding the valve core centrifugal mechanism (6) (Valve core tilting when suppressing valve core centrifugation: concave and convex parts)>

[0110] use Figure 6 (b) will be explained regarding the valve core centrifugal mechanism (6) (valve core tilting when suppressing valve core centrifugality: concave and convex portions) of the valve core deformation example 2 of the first embodiment. The valve core centripetal mechanism (6) (which suppresses valve core tilting during centripetal movement: concave and convex portions) has a mountain-shaped convex portion 31Ac” that protrudes in a mountain shape and is coaxial with the valve core 30A” towards one end face 31A”, and an annular concave portion 31Ab” that is coaxial with the valve core 30A” towards the other end face. A sealing portion 31Aa’ is formed between the annular concave portion 31Ab” and the conical portion 33A. Thus, at least during the period when the centripetal action of the valve core 30A” is in effect (at least from the slightly open state to the state about to open the valve), if the fluid collides with the valve core end face 31A” via the valve port 21A, the fluid after the collision flows smoothly outward in the radial direction due to the rectifying effect of the mountain-shaped convex portion 31Ac”. Therefore, the dynamic pressure is uniformly distributed in the circumferential direction when viewed from the axis L, with a stable change in load on one end face 31A” of the valve core. Furthermore, due to the fluid stagnation within the annular recess 31Ab”, the static pressure is uniformly distributed in the circumferential direction when viewed from the axis L, with a stable change in load on one end face 31A” of the valve core. This suppresses the tilting of the valve core 30A” relative to the axis L of the valve body 20, thus eliminating concerns about smooth movement caused by valve core tilting during centripetal movement.

[0111] Furthermore, the mountain-shaped protrusion 31Ac” in the valve core deformation example 2 is composed of a conical shape with a circular bottom surface, but it is not limited to this. As long as it protrudes in a mountain shape, it can be, for example, a polygonal pyramidal shape with a polygonal bottom surface.

[0112] As described above, in the first embodiment and valve core modification examples 1 and 2, by employing the valve core centripetal mechanism 1 (which introduces primary lateral pressure into the annular cone space), regardless of whether the arrangement is longitudinal or transverse, even with a relatively small differential pressure in the valve opening direction, the previous problem (decrease in valve opening performance) can be eliminated, thus improving reliability.

[0113] Furthermore, in the first embodiment and valve core modification examples 1 and 2, by further employing at least one of the valve core centripetal mechanism (2) (increased pressure in the radial direction), valve core centripetal mechanism (3) (larger movement length due to pressure in the radial direction), and valve core centripetal mechanism (4) (lighter valve core), the axis L30A of the valve cores 30A, 30A', and 30A'” can be more reliably centripetal towards the axis L of the valve body 20.

[0114] Furthermore, by allowing the valve core 30A to slide within the side wall portion 22A along the axis L, the outer diameter of the valve core side surface 32A is made slightly smaller than the inner diameter of the inner circumferential surface 22Aa of the side wall portion 22A. This prevents swirling flow from entering between the side wall portion 22A and the valve core side surface 32A, suppresses the rotation of the valve core 30A, and reduces the generation of abnormal noise and wear of the valve core caused by the rotation of the valve core 30A.

[0115] Furthermore, in the first embodiment and valve core modification examples 1 and 2, when the valve cores 30A, 30A', and 30A'' are coaxially arranged with the axis L30A of the valve cores 30A, 30A', and 30A'', and the axis L of the valve body 20, the intersection point P of the inner circumferential surface 22Aa of the side wall and the other end 22Bb of the multiple connecting holes 22B is all located inside the imaginary frustum-shaped structure formed by the cone portion 33A. As a result, the fluid is guided along the cone portion 33A, thus allowing it to flow smoothly without passing through a flow path that generates pressure loss. Additionally, it prevents swirling flow from flowing between the side wall portion 22A and the valve core side surface 32A, suppresses the rotation of the valve core 30A, and further reduces the generation of abnormal noise and wear of the valve core caused by the rotation of the valve core 30A.

[0116] Furthermore, by further employing the valve core centrifugal mechanism (5) in valve core deformation example 1 (suppressing valve core tilting during valve core centrifugation: concave portion) or the valve core centrifugal mechanism (6) in valve core deformation example 2 (suppressing valve core tilting during valve core centrifugation: concave portion and convex portion), concerns (suppressing smooth movement caused by valve core tilting during valve core centrifugation) can be eliminated.

[0117] (Second Implementation)

[0118] use Figure 7 The check valve 100B according to the second embodiment will be described. The main differences between the check valve 100B and the check valve 100A according to the second embodiment are the structure of the valve holder portion 22' of the valve body 20' and the valve core 30B, and the fact that a valve limiter 40' is provided in the outer tube portion 10. However, the other basic structures are largely the same as those of the first embodiment. Here, identical symbols are used to denote identical structures, and repeated descriptions are omitted.

[0119] <Concerns regarding reduced responsiveness due to burrs>

[0120] In the first embodiment, such as Figure 1As shown in (b), a connecting hole 22B is provided in the side wall portion 22A, communicating with the storage chamber HC, which serves as the secondary side internal space. This connecting hole 22B is formed by drilling the side wall portion 22A in a direction orthogonal to the axis L using a drill bit or the like. As a result, burrs protruding inward in the radial direction are generated at the inner edge of the connecting hole 22B. Therefore, deburring is performed on the connecting hole 22B, but from a microscopic perspective, some undulations may remain at the inner edge of the connecting hole 22B after deburring.

[0121] Therefore, in the closed state, when the valve core 30A is in contact with the side wall portion 22A containing the connecting hole 22B, due to the influence of the microscopic undulations remaining in the inner edge of the connecting hole 22B, the static friction force and dynamic friction force of the valve core 30A relative to the side wall portion 22A increase slightly, and there is a concern that the responsiveness of the transition from the closed state to the open state is reduced (hereinafter referred to as "concern (reduced responsiveness due to the influence of burrs)").

[0122] In contrast, in the second embodiment, similar to the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular conical space), regardless of longitudinal or transverse configuration, even a relatively small differential pressure in the valve opening direction can eliminate previous problems (decrease in valve opening performance) and improve reliability. Furthermore, details will be described later, but by omitting the connecting hole and making the length of the side wall portion 22A' in the axial direction L smaller than the length of the valve core 30B in the axial direction L, and by positioning the other end face 22Ab' of the side wall in the closed state, when viewed from a direction orthogonal to the axial direction L, overlapping with the side face 32B of the valve core, concerns (reduced responsiveness due to burrs) are eliminated.

[0123] <About the structure of check valves>

[0124] The check valve 100B comprises an outer tube 10, a valve body 20' housed within the secondary side internal space (i.e., the housing chamber HC) of the outer tube 10, and a valve core 30B configured to slide along the axis L within the outer tube 10 and the valve body 20'. The structures of each component of the check valve 100B will be described below. Furthermore, the second embodiment, like the first embodiment, includes not only a longitudinal arrangement but also other arrangements such as a transverse arrangement.

[0125] <About the Foreign Exchange Administration>

[0126] The outer tube 10 has the same structure as in the first embodiment, so its description is omitted. Furthermore, the inner circumferential surface of the second connecting part 12B functions as a valve limiter 40' that restricts the movement of the valve core 30B toward the other end in the direction of the axis L.

[0127] Furthermore, in the second embodiment, similar to the first embodiment, the primary connector 11, the secondary connector 12, and the valve body housing 13 are integrally formed, but this is not a limitation. For example, they can be assembled by threading or welding after being formed separately. Additionally, in the second embodiment, similar to the first embodiment, when fixing the valve body 20' inside the outer tube 10, press-fitting and riveting are used, but this is not a limitation. For example, press-fitting alone, riveting alone, threading, welding, or adhesive bonding can be used. Furthermore, in the second embodiment, by setting the inner circumferential surface of the second connecting portion 12B as the valve limiter 40', the number of parts can be reduced compared to the first embodiment, and the assembly operation can be simplified.

[0128] <About the valve body>

[0129] The valve body 20' is made of a metal material such as brass and is formed by machining. The valve body 20' includes a valve seat portion 21 and a valve support portion 22'. In addition, the valve seat portion 21 has the same structure as in the first embodiment, so the valve support portion 22' will be described here.

[0130] Furthermore, in the second embodiment, the valve port 21A has a circular cross-sectional shape, but is not limited to this; for example, it can also have an elliptical cross-sectional shape, a polygonal cross-sectional shape, etc.

[0131] Valve bracket portion 22' is erected from the outer periphery of valve seat 21B to the other end, and has a demarcated valve chamber VC on its inner side (see reference). Figure 9 The cylindrical sidewall portion 22A' has a length in the L direction of its axis that is smaller than the length in the L direction of its axis that is smaller than that of the valve core 30B. Furthermore, the outer peripheral surface of the sidewall portion 22A' abuts against the outer tube portion 10.

[0132] <About the valve core>

[0133] like Figure 7 As shown in (b) to (d), the valve core 30B is made of a high-strength resin material such as polyetheretherketone (PEEK) and centered on an axis L30B parallel to the axis L. This structure allows for a lighter valve core 30A while maintaining strength, compared to metal materials. The valve core 30B includes: a valve core end face 31B with a flat, circular plate shape; a valve core side face 32B (side face) as a cylindrical outer peripheral curved surface; a frustum-shaped portion 36B continuous with the other end face 32B; and multiple (e.g., three) legs 35B evenly arranged in the circumferential direction and extending from the valve core side face 32B and the frustum-shaped portion 36B to the other end.

[0134] The valve core has a sealing portion 31Ba formed by a flat annulus at one end face 31B in the radial direction at its outer peripheral edge. This sealing portion 31Ba abuts against the valve seat 21B, which is also formed by a flat annulus. Therefore, the outer diameter of the valve core end face 31B is set to be larger than the inner diameter of the valve seat 21B, i.e., the inner diameter of the valve port 21A. In addition, the outer diameter of the valve core side surface 32B is set to be slightly smaller than the inner diameter of the inner peripheral surface 22Aa' of the side wall portion 22A', so that the valve core 30B can slide along the axis L within the side wall portion 22A'. Furthermore, in order to enable the valve core 30B to slide along the axis L within the valve body receiving portion 13 of the outer tube portion 10, the outer diameter of the imaginary outer peripheral edge of the leg portion 35B (refer to...) is... Figure 7 The (d) is set to be slightly smaller than the inner diameter of the valve body receiving part 13 of the outer tube part 10.

[0135] In addition, such as Figure 8 As shown in (a), the valve core 30B has a tapered portion 33B that is connected between the valve core side 32B and the sealing portion 31Ba, which is narrowed from the valve core side 32B to the sealing portion 31Ba.

[0136] Furthermore, in the second embodiment, such as Figure 7 As shown in (c), the valve core 30B has a cylindrical valve core side surface 32B and a frustum-shaped conical portion 36B, but is not limited thereto; for example, it may also have a cylindrical valve core side surface and a hemispherical portion. Furthermore, in the second embodiment, the longitudinal cross-sectional shape of the cone portion 33B is a straight line shape, but is not limited thereto; for example, it may also have a curved longitudinal cross-sectional shape that narrows from the valve core side surface 32B towards the sealing portion 31Ba.

[0137] <Regarding the operation of check valves>

[0138] use Figure 7 and Figure 9 Explain the operation of check valve 100B. Here, the connection status of check valve 100B with external equipment is described (refer to...). Figure 5 The initial pressure state (P1 < P2) is the same as in the first embodiment.

[0139] First, such as Figure 7 As shown, when the valve core 30B is seated on the valve seat 21B and is in the closed state with the sealing part 31Ba abutting against the valve seat 21B, if a primary side pressure P1 and a secondary side pressure P2 (<P1) are applied to one end and the other end of the valve core 30B respectively, a differential pressure (P1-P2) in the opening direction will be generated in the valve core 30B.

[0140] If the differential pressure (P1-P2) in the valve opening direction exceeds a predetermined threshold, then... Figure 9As shown, the valve core 30B separates from the valve seat 21B, becoming an open valve. In this open valve state, the fluid flowing from the primary opening 11C through the valve port 21A into the valve chamber VC passes through the radial gap between the valve core side 32B and the inner circumferential surface of the outer tube 10, and the adjacent legs 35B, and then merges again in the receiving chamber HC of the outer tube 10 before flowing towards the other end of the axis L, namely the secondary opening 12C.

[0141] In this open valve state, when the differential pressure (P1-P2) in the opening direction of the valve core 30B is relatively large, such as Figure 9 As shown, the valve core 30B slides and contacts the inner circumferential surface of the outer tube 10 while continuing to move to the other end within the outer tube 10. However, the other end of the leg 35B eventually comes into contact with the valve limiter 40', which serves as the inner circumferential surface of the second connecting part 12B, thereby restricting the movement to the other end.

[0142] Subsequently, when the pressure on the primary side P1 is less than the pressure on the secondary side P2 (P1 < P2) due to a decrease in the pressure of the pressure supply source, a differential pressure (P2 - P1) in the valve core 30B in the valve closing direction is generated. The valve core 30B returns to the closed valve state, sitting on the valve seat 21B, to prevent backflow from the secondary opening 12C to the primary opening 11C.

[0143] <Regarding the valve core radial mechanism (1) (introducing primary lateral pressure into the annular conical space>

[0144] The valve core radial mechanism (1) of the second embodiment (which introduces primary lateral pressure into the annular conical space) is the same as that of the first embodiment, therefore it is used here. Figure 8 To put it simply, Figure 8 The gaps shown in (b) to (d) are exaggerated to enhance understanding. Additionally, in Figure 8 As shown in (b) to (c), from the slightly open state to the state about to open the valve, the fluid velocity is extremely slow, so the static pressure becomes dominant compared to the dynamic pressure.

[0145] First of all, Figure 8 In the closed valve state shown in (a), the annular conical space St, which is continuous in the circumferential direction when viewed from the axis L, is defined by the radial extension line of the cone portion 33B, the sealing portion 31Ba of the valve core 30B, and the side wall portion 22A'. Here, as Figure 7As shown in (a), the valve core 30B is eccentric relative to the valve body 20'. The right side of the valve core side 32B is in contact with the inner circumferential surface 22Aa' of the side wall, while the left side of the valve core side 32B is separated from the inner circumferential surface 22Aa' of the side wall. At this time, the length of the side wall portion 22A' in the L direction is smaller than the length of the valve core 30B in the L direction, and when viewed from a direction orthogonal to the L direction, the other end face 22Ab' of the side wall is positioned overlapping with the valve core side 32B. In addition, the outer periphery of the leg portion 35B is not in contact with the inner circumferential surface of the valve body receiving portion 13.

[0146] Next, in Figure 8 As shown in (b) and (c), from the slightly open state to the almost open state, as the valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular conical space), primary lateral pressure P1 is introduced into the annular conical space St via the valve chamber VC. Thus, similar to the first embodiment, a non-uniform pressure distribution is generated along the radial direction of the circumferential direction according to the pressure Ftr (refer to...). Figure 8 The sum of (b) becomes the centripetal force, which acts on the valve core 30B in a manner coaxial with the axis L30B of the valve core 30B and the axis L of the valve body 20'. At this time, the radial clearance between the leg 35B and the outer tube 10 is set to be larger than the clearance between the valve core side 32B and the inner circumferential surface 22Aa' of the side wall. As a result, the valve core 30B moves towards the valve opening direction while being centripetal in the radial direction, without contacting the side wall 22A' and the outer tube 10 (see reference). Figure 8 (M1' and M2' in (b) and (c)).

[0147] Furthermore, in Figure 8 The differential pressure (P1'-P2') on valve core 30B in the opening direction under the valve opening state shown in (d) (refer to) Figure 9 ), valve core 30B moves in the valve opening direction (refer to) Figure 2 (d) M3'), so that the fluid flowing from the valve port 21A into the valve chamber VC flows to the receiving chamber HC of the outer pipe section 10.

[0148] Thus, in the second embodiment, similar to the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular conical space), during the period from the slightly open state to the state about to open the valve, the axis L30B of the valve core 30B is coaxial with the axis L of the valve body 20'. The valve core 30B can move in the valve opening direction in a non-contact state with the side wall portion 22A'. Therefore, regardless of the longitudinal or transverse configuration, even a relatively small differential pressure in the valve opening direction can eliminate previous problems (decrease in valve opening performance) and improve reliability.

[0149] In addition, in order to omit the connecting hole, the length of the side wall portion 22A' in the L direction of the axis is smaller than the length of the valve core 30B in the L direction of the axis. Furthermore, in the closed state, when viewed from a direction orthogonal to the axis L, the other end face 22Ab' of the side wall is positioned to overlap with the side face 32B of the valve core. This eliminates concerns about reduced responsiveness due to the influence of burrs.

[0150] Moreover, in the second embodiment, similar to the first embodiment, by further employing at least one of the valve core centripetal mechanism (2) (increased pressure in the radial direction), valve core centripetal mechanism (3) (larger movement length due to pressure in the radial direction), and valve core centripetal mechanism (4) (lighter valve core), the axis L30B of the valve core 30B can be more reliably centripetal towards the axis L of the valve body 20'.

[0151] <Regarding the valve core radial mechanism (2) (radial direction according to the increase of pressure)>

[0152] Valve core centripetal mechanism (2) (radial direction according to the increase of pressure) such as Figure 8 As shown in (a), the length a' of the cone 33B along the axis L is made greater than the length b' of the cone 33B along the radius (1 < a' / b'), that is, the angle θ' of the cone 33B relative to the axis L is made greater than the length b' of the cone 33B along the radius (refer to...). Figure 8 (a) is smaller than 45° (θ < 45°). Therefore, as Figure 8 As shown in (b), the sum of the radial pressing force Ftr acting on the valve core 30B, i.e., the centripetal force, can be increased. Therefore, during the period from the slightly open state to the state about to open the valve, the axis L30B of the valve core 30B can be more reliably centripetal to the axis L of the valve body 20'. In addition, in order to reliably increase the radial pressing force Ftr, it is preferable to set it to 5 ≤ a' / b'.

[0153] <Regarding the valve core radial mechanism (3) (the radial direction is determined by the greater distance the pressure causes to move)>

[0154] Valve core radial mechanism (3) (the radial direction is based on the greater movement length under pressure) such as Figure 8 As shown in (a), the length c' that moves the valve core 30B from the closed state to the almost open state along the axis L is more than half (0.5 ≤ c' / a') of the length a' of the cone portion 33B along the axis L. Therefore, the distance from the slightly open state to the almost open state can be increased (see reference). Figure 8 (b) and Figure 8The length by which the valve core 30A moves along the axis L in (c) allows the axis L30B of the valve core 30B to reliably align with the axis L of the valve body 20'. Furthermore, if the length by which the valve core 30A moves along the axis L in the radial direction under the action of pressure Ftr is too long, the time from the closed state to the open state becomes longer, potentially leading to a decrease in responsiveness. Therefore, it is preferable to set it to 0.5 ≤ c' / a' ≤ 0.9.

[0155] <Regarding the valve core centripetal mechanism (4) (Valve core lightweighting)>

[0156] Valve core centripetal mechanism (4) (Valve core lightweighting) such as Figure 7 As shown in (c), a weight-reducing hole 34B is provided on the valve core 30B along the axis L30B of the valve core 30B from the center of the other end face of the truncated cone portion 36B toward one end side in a non-through manner to reduce weight. Through this weight reduction of the valve core 30B, even if a small centripetal force acts on the valve core 30B due to a relatively small differential pressure (P1'-P2') in the valve opening direction during the transition from a slightly open state to a state about to open, the axis L30B of the valve core 30B can be more reliably centered on the axis L of the valve body 20'.

[0157] Thus, in the second embodiment, similar to the first embodiment, in addition to the valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular cone space), at least one of the valve core centripetal mechanism (2) (increasing the pressure in the radial direction), the valve core centripetal mechanism (3) (larger movement length caused by the pressure in the radial direction), and the valve core centripetal mechanism (4) (lightening of the valve core) is also adopted, thereby enabling the axis L30B of the valve core 30B to be more reliably centripetal towards the axis L of the valve body 20'.

[0158] (Example of valve core deformation)

[0159] Here, use Figure 10 The valve core modifications 1 and 2 of the second embodiment are described below. The valve core modifications 1 and 2 differ from the second embodiment in that the shape of one end face 31B', 31B" of the valve core is not a flat surface, but the other basic structures are the same as those of the second embodiment. Here, the same symbols are used to denote the same structures, and repeated descriptions are omitted.

[0160] <Regarding concerns (smooth movement caused by valve spool tilting during valve spool centering)>

[0161] In the valve core 30B of the second embodiment, similarly to the first embodiment, one end face 31B of the valve core is flat, and therefore may be affected by considerable dynamic pressure. Specifically, during the period from the slightly open state to the state about to open (refer to...) Figure 8(b) and (c) If the fluid collides with one end face 31B of the valve core, three-dimensional turbulence is generated. Therefore, when viewed from the axis L, the load on one end face 31B of the valve core is unevenly distributed dynamic pressure. Therefore, there are concerns caused by this dynamic pressure (suppressing the smooth movement caused by the valve core tilting when the valve core is centripetal).

[0162] In contrast, in the valve core modification example of the second embodiment, the same as the valve core modification example of the first embodiment, the valve core centrifugal mechanism (5) of the valve core modification example 1 (suppressing valve core tilting when the valve core is centrifugal: concave portion) or the valve core centrifugal mechanism (6) of the valve core modification example 2 (suppressing valve core tilting when the valve core is centrifugal: concave portion and convex portion) can eliminate concerns (suppressing smooth movement caused by valve core tilting when the valve core is centrifugal).

[0163] <Regarding the valve core centrifugal mechanism (5) (Valve core tilting when suppressing valve core centrifugation: concave part)>

[0164] use Figure 10 (a) will be explained in the description of the valve core centrifugal mechanism (5) (valve core tilting during valve core centrifugation: recess) of the valve core modification example 1 of the second embodiment. This valve core centrifugal mechanism (5) (valve core tilting during valve core centrifugation: recess) has a mortar-shaped recess 31Bb' formed on one end face 31B' of the valve core, which is coaxial with the valve core 30B' and faces the other end side in a mortar-shaped recess. A sealing portion 31Ba' is formed between the mortar-shaped recess 31Bb' and the cone portion 33B. As a result, at least during the period when the centrifugal action on the valve core 30B' is in effect, the fluid in the mortar-shaped recess 31Bb' is stagnant, and a static pressure that is uniformly distributed when viewed from the axis L direction is applied to one end face 31B' of the valve core. Therefore, concerns (smooth movement caused by valve core tilting during valve core centrifugation) can be eliminated.

[0165] Furthermore, the mortar-shaped recess 31Bb' in the valve core deformation example 1 is composed of a conical shape with a round bottom surface, but it is not limited to this. As long as the recess is mortar-shaped, it can be a polygonal pyramidal shape with a polygonal bottom surface, for example.

[0166] <Regarding the valve core centrifugal mechanism (6) (Valve core tilting when suppressing valve core centrifugation: concave and convex parts)>

[0167] use Figure 10(b) will be used to explain the valve core centrifugal mechanism (6) of the valve core deformation example 2 of the second embodiment (valve core tilting when the valve core is centrifuged: concave and convex portions). The valve core centripetal mechanism (6) (which suppresses valve core tilting during centripetal movement: concave and convex portions) has a mountain-shaped convex portion 31Bc” that protrudes in a mountain shape and is coaxial with the valve core 30B” towards one end face 31B”. Around the mountain-shaped convex portion 31Bc”, an annular recess 31Bb” that is coaxial with the valve core 30B” towards the other end face is formed. The sealing portion 31Ba’ is formed between the annular recess 31Bb” and the cone portion 33B. Thus, at least during the period when the centripetal action of the valve core 30B” is in effect (at least from the slightly open state to the state about to open the valve), the fluid flows smoothly outward in the radial direction due to the rectifying effect of the mountain-shaped convex portion 31Bc” and then stagnates in the annular recess 31Bb”. Therefore, when viewed from the axis L direction at one end face 31B” of the valve core, the load is uniformly distributed in the circumferential direction, with dynamic pressure at the center and static pressure at the periphery, thus eliminating concerns (smooth movement caused by valve core tilting when the valve core is concentric).

[0168] Furthermore, the mountain-shaped protrusion 31Bc” in the valve core deformation example 2 is composed of a conical shape with a round bottom surface, but it is not limited to this. As long as it protrudes in a mountain shape, it can be a polygonal pyramidal shape with a polygonal bottom surface, for example.

[0169] As described above, in the second embodiment and valve core modification examples 1 and 2, similar to the first embodiment, by employing a valve core centripetal mechanism (1) (introducing primary lateral pressure into the annular cone space), regardless of whether it is a longitudinal or transverse configuration, even a relatively small differential pressure in the valve opening direction can eliminate previous problems (decrease in valve opening performance) and improve reliability.

[0170] Furthermore, in the second embodiment and valve core modification examples 1 and 2, since the connecting hole is omitted, concerns (reduced responsiveness due to the influence of burrs) can be eliminated.

[0171] Furthermore, in the second embodiment and valve core modification examples 1 and 2, similar to the first embodiment, by further employing at least one of the valve core centripetal mechanism (2) (increased pressure in the radial direction), valve core centripetal mechanism (3) (larger movement length due to pressure in the radial direction), and valve core centripetal mechanism (4) (lighter valve core), the axis L30B of the valve cores 30B, 30B', and 30B'” can be more reliably centripetal towards the axis L of the valve body 20'.

[0172] Furthermore, the valve core centrifugal mechanism (5) in valve core deformation example 1 (suppressing valve core tilting when the valve core is centrifuged: concave portion) or the valve core centrifugal mechanism (6) in valve core deformation example 2 (suppressing valve core tilting when the valve core is centrifuged: concave portion and convex portion) is the same as the valve core deformation example 1 or valve core deformation example 2 of the first embodiment, thus eliminating concerns (smooth movement caused by valve core tilting when the valve core is centrifuged).

[0173] <Other>

[0174] The check valves 100A and 100B of this embodiment can, of course, be applied to all fluid devices and fluid circuits, including refrigeration circuits. Furthermore, this invention is not limited to the embodiments described above, and appropriate modifications and variations can be made without departing from the technical concept of this invention.

[0175] Symbol Explanation

[0176] 100A, 100B—Check valve; 10—Outer pipe section; 11—Primary connector section; 11A—Primary cylindrical section; 11B—First connecting section; 11C—Primary opening section; 12—Secondary connector section; 12A—Secondary cylindrical section; 12B—Secondary connecting section; 12C—Secondary opening section; 13—Valve body housing section; 13A—First expansion section; 13B—Second expansion section; 13C—Stepped section; 13D—Fixing section; 20, 20'—Valve body; 21—Valve seat section; 21A—Valve port; 21B—Valve seat; 21C—Throttling section; 21D—Flange portion; 22, 22'—Valve frame portion; 22A, 22A'—Side wall portion; 22Aa, 22Aa'—Inner circumferential surface of side wall (inner circumferential surface of side wall portion); 22Ab'—Other end face of side wall (other end face of side wall portion); 22B—Connecting hole; 22Ba—One end of connecting hole; 22Bb—Other end of connecting hole; 22C—Annular groove portion; 30A, 30A', 30A'', 30B, 30B'', 30B''—Valve core; 31A, 31A', 31A'', 31B, 31B'', 31B'' —One end face of the valve core (one end face of the valve core); 31Aa, 31Aa', 31Ba, 31Ba'—Sealing part; 31Ab', 31Bb'—Mortar-shaped recess; 31Ab'', 31Bb''—Annular recess; 31Ac'', 31Bc''—Mountain-shaped protrusion; 32A, 32B—Side of the valve core; 33A, 33B—Conical part; 34A, 34B—Weight reduction hole; 35B—Leg part; 36B—Frustum conical part; 40, 40'—Valve limiter; 200—Indoor heat exchanger; 300—Outdoor heat exchanger Components: 400—Expansion valve; 500—Four-way valve; 600—Compressor; 1000—Refrigeration cycle system; Ft—Pressing pressure; Ftl—Pressing pressure in the axial direction; Ftr—Pressing pressure in the radial direction; GL—Large clearance area in the radial direction; GS—Small clearance area in the radial direction; HC—Receiving chamber (internal space on the secondary side); L—Axis; L30A, L30B—Axis center; P—Intersection point; P1, P1'—Primary side pressure; P2, P2'—Secondary side pressure; St—Annular conical space; VC—Valve chamber; θ, θ'—Angles.

Claims

1. A check valve, comprising: The outer tube extends along the axial direction and has a cylindrical shape; The valve body is housed within the outer tube section; Valve core, configured to abut against the valve body; and A valve core centripetal mechanism that makes the axis of the valve core centripetal relative to the axis of the valve body. The check valve is characterized in that... The valve body includes: a valve seat portion having a valve seat and a valve port; and a valve support portion having a cylindrical sidewall portion that defines a valve chamber and is erected from the outer periphery of the valve seat. The valve core includes: a valve core side surface that abuts against the side wall portion; a sealing portion disposed only on one end face of the valve core; and a tapered portion that tapers in diameter from the valve core side surface toward the sealing portion. The valve core is configured to move freely along the axial direction between a closed valve state in which the sealing part abuts against the valve seat, and an open valve state in which the sealing part is separated from the valve seat and the valve port communicates with the secondary side internal space of the outer tube. When the valve chamber and the valve port are in a slightly open state, the valve core radial mechanism introduces primary lateral pressure into the annular conical space defined by the radial extension line of the conical portion, the sealing portion, and the side wall portion, thereby enabling the valve core to move in a direction orthogonal to the axis.

2. The check valve according to claim 1, characterized in that, The valve core centripetal mechanism makes the axial length of the cone greater than the radial length of the cone.

3. The check valve according to claim 1, characterized in that, The valve core centripetal mechanism moves the valve core along the axial direction by a length that is more than half the axial length of the cone portion from the closed valve state to the upcoming open valve state.

4. The check valve according to claim 1, characterized in that, The valve core has a non-through weight reduction hole that extends along the axial direction of the valve core.

5. The check valve according to claim 1, characterized in that, A mortar-shaped recess is formed on one end face of the valve core, coaxial with the valve core and facing the other end. The sealing portion is formed between the mortar-shaped recess and the conical portion.

6. The check valve according to claim 1, characterized in that, A mountain-shaped protrusion is formed on one end face of the valve core, protruding in a mountain shape and coaxial with the valve core toward one end; and an annular recess is formed around the mountain-shaped protrusion, coaxial with the valve core and protruding toward the other end. The sealing portion is formed between the annular recess and the conical portion.

7. The check valve according to claim 1, characterized in that, The axial length of the sidewall portion is greater than the axial length of the valve core. At the location on the side wall where it separates from the valve seat, there are multiple connecting holes that connect the secondary side internal space of the outer tube section and the valve chamber in the radial direction. From the closed valve state to the valve about to open state, the plurality of connecting holes are arranged opposite to the side of the valve core.

8. The check valve according to claim 7, characterized in that, In the open valve state, when the axis of the valve core is coaxial with the axis of the valve body, the intersection of the inner surface of the side wall portion and the other end of the plurality of connecting holes is located on the inner side of an imaginary frustum formed by imaginary extension of the cone portion to the other end, regardless of the axial direction of the valve core.

9. The check valve according to claim 1, characterized in that, The axial length of the sidewall portion is smaller than the axial length of the valve core. In the closed valve state, when viewed from a direction orthogonal to the axis, the other end face of the side wall portion is positioned to overlap with the side face of the valve core.

10. A refrigeration cycle system, characterized in that, The check valve is provided with any one of claims 1 to 9.

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