Switching valve

Abstract

The switching valve comprises a valve body and a piston assembly, the valve body comprises a valve cavity, and the valve cavity is provided with a first valve port and a second valve port; the piston assembly is movably arranged in the valve cavity and comprises a piston rod, a first piston and a second piston, the first piston and the second piston are connected to the two opposite ends of the piston rod respectively, the first valve port and the second valve port are arranged in the movement direction of the piston assembly at intervals, and the first piston is used for blocking the first valve port. The second piston is used for blocking the second valve port; at least one of the first piston and the second piston is formed through injection molding. According to the switching valve, the weight and the manufacturing cost of the switching valve can be controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valves, in particular to a switching valve. BACKGROUND

[0002] The multi-way switching valve in the prior art includes a piston and multiple valve ports, and different valve ports are opened and closed by moving the piston to different positions, thereby achieving the effect of switching the flow path. However, the material of the piston in the prior art is metal, which is relatively high in cost.

[0003] How to reduce the cost of the switching valve is a technical problem to be solved by the present application. CONTENT OF THE UTILITY MODEL

[0004] The purpose of the present disclosure is to provide a switching valve, which can reduce abnormal sound during the operation of the switching valve and improve the mute effect of the switching valve.

[0005] The present disclosure provides a switching valve, comprising:

[0006] a valve body comprising a valve cavity, the valve cavity having a first valve port and a second valve port;

[0007] a piston assembly movably arranged in the valve cavity, the piston assembly comprising a plug rod, a first piston and a second piston, the first piston and the second piston being respectively connected to opposite ends of the plug rod, the first valve port and the second valve port being arranged at intervals along the movement direction of the piston assembly, the first piston being used for blocking the first valve port, and the second piston being used for blocking the second valve port;

[0008] At least one of the first piston and the second piston is injection molded.

[0009] In an exemplary embodiment of the present disclosure, the plug rod comprises a metal material, the first piston comprises a plastic material, the first piston is integrally injection molded with the plug rod as a metal insert; or, the plug rod comprises a plastic material, the first piston comprises a plastic material, and the plug rod and the first piston are integrally injection molded.

[0010] In an exemplary embodiment of the present disclosure, when the plug rod comprises a metal material, the plug rod is fixedly connected with the second piston comprising a metal material; or, the plug rod is fixedly connected with the second piston comprising a plastic material; when the plug rod comprises a plastic material, the plug rod is fixedly connected with the second piston comprising a metal material; or, the plug rod is fixedly connected with the second piston comprising a plastic material.

[0011] In an exemplary embodiment of the present disclosure, when the plug rod comprises a metal material, the first piston comprises a metal material, the second piston comprises a plastic material, the first piston is fixedly connected with the plug rod, and the second piston is integrally injection molded with the plug rod as a metal insert; or, when the plug rod comprises a plastic material, the first piston is fixedly connected with the plug rod, and the second piston is integrally injection molded with the plug rod.

[0012] In an example embodiment of the present disclosure, the valve body comprises a valve seat and a valve cover, the valve seat has a valve cavity, and the valve cover is connected to the valve seat. The valve cover is made of a metal material, and the valve seat is made of a metal material or a plastic material.

[0013] In an example embodiment of the present disclosure, the valve seat has a third opening arranged along the radial direction of the valve seat and communicating with the valve cavity. The valve cover partially extends into the third opening or partially covers the third opening. One end of the valve seat with the third opening is provided with a riveting portion connected to the valve cover. Or, one end of the valve cover close to the valve seat is provided with a riveting portion connected to the valve seat.

[0014] In an example embodiment of the present disclosure, the valve seat has a third opening arranged along the radial direction of the valve seat and communicating with the valve cavity. The valve cover has a fitting segment extending into the third opening, and the outer circumferential surface of the fitting segment is in interference fit with the inner circumferential surface of the third opening. Or, the valve cover has a fitting segment covering the third opening, and the inner circumferential surface of the fitting segment is in interference fit with the outer circumferential surface of the third opening.

[0015] In an example embodiment of the present disclosure, the valve seat comprises a first valve sleeve and a second valve sleeve arranged coaxially and connected. The two ends of the second valve sleeve form a first valve port and a second valve port, respectively. The maximum value of the outer diameter of the second valve sleeve is less than the maximum value of the outer diameter of the first valve sleeve.

[0016] In an example embodiment of the present disclosure, the switching valve comprises a first elastic member and a second elastic member. The valve cavity is provided with a partition portion separating the first valve port and the second valve port. The first elastic member is sleeved on the plug rod and located between the first piston and the partition portion. The opposite ends of the first elastic member are in abutment with the first piston and the partition portion, respectively. The second elastic member is sleeved on the plug rod and located between the second piston and the partition portion. The opposite ends of the second elastic member are in abutment with the second piston and the partition portion, respectively.

[0017] When the piston assembly is in a balanced state, the resultant force of the elastic force of the first elastic member and the second elastic member acting on the piston assembly and the gravity of the piston assembly is zero. The balanced state refers to that, under no fluid impact, the piston assembly remains stationary relative to the valve body.

[0018] A throttling passage communicating with the valve port is formed between the piston assembly and the inner wall of the valve cavity. When the piston assembly is in a balanced state, the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is ≤3 / 10.

[0019] In an example embodiment of the present disclosure, during the process of plugging the valve port, the flow area of the throttling passage gradually decreases.

[0020] In an exemplary embodiment of the present disclosure, the throttling passage comprises a first throttling passage, the first throttling passage being formed between the outer circumferential surface of the first piston and the first valve port, and the ratio of the maximum flow area of the first throttling passage to the maximum flow area of the first valve port is ≤ 3 / 10.

[0021] In an exemplary embodiment of the present disclosure, the throttling passage comprises a second throttling passage, the second throttling passage being formed between the outer circumferential surface of the second piston and the second valve port, and the ratio of the maximum flow area of the second throttling passage to the maximum flow area of the second valve port is ≤ 3 / 10.

[0022] In an exemplary embodiment of the present disclosure, the first piston comprises a first body and a first sealing ring sleeved on the outer circumference of the first body, when the first piston blocks the first valve port, the first sealing ring is compressed between the first body and the first valve port to seal the first valve port; the valve body has a first end face, the first end face being located at the end of the first valve port away from the second valve port, and the first piston has a first limiting face for abutting against the first end face when the first piston blocks the first valve port.

[0023] In an exemplary embodiment of the present disclosure, the second piston comprises a second body and a second sealing ring sleeved on the outer circumference of the second body, when the second piston blocks the second valve port, the second sealing ring is compressed between the second body and the second valve port to seal the second valve port; the valve body has a second end face, the second end face being located at the end of the second valve port away from the first valve port, and the second piston has a second limiting face for abutting against the second end face when the second piston blocks the second valve port.

[0024] In an exemplary embodiment of the present disclosure, the valve cover is provided with a guide hole, one end of the plug rod connected with the first piston passes through the first piston and extends into the guide hole, and the plug rod is movably arranged in the guide hole.

[0025] In an exemplary embodiment of the present disclosure, the switching valve further comprises a mounting seat, the valve body is externally provided with a limiting table and a threaded connection part, and after the threaded connection part is threadedly connected with the mounting seat, the limiting table abuts against the mounting seat.

[0026] The switching valve of the present disclosure, the injection-molded first piston and / or second piston are beneficial to control the weight and cost of the switching valve. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings incorporated into the specification and constituting a part of the specification show embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.

[0028] For a better understanding of the present disclosure, reference can be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale, and related elements can be omitted in order to emphasize and clarify the technical features of the present disclosure. In addition, related elements or components can have different settings as known in the art. Furthermore, in the drawings, the same reference numerals represent the same or similar components throughout the various drawings. Among them:

[0029] Figure 1 Exploded view of an exemplary embodiment of a switching valve of the present disclosure;

[0030] Figure 2 Longitudinal sectional view of an exemplary embodiment of a switching valve of the present disclosure along the plunger rod;

[0031] Figure 3 Longitudinal sectional view of another exemplary embodiment of a switching valve of the present disclosure along the plunger rod;

[0032] Figure 4 Schematic view of a piston assembly in an exemplary embodiment of a switching valve of the present disclosure;

[0033] Figure 5 Schematic view of a valve body in an exemplary embodiment of a switching valve of the present disclosure.

[0034] The reference numerals are explained as follows:

[0035] 10, valve body; 101, first valve port; 102, second valve port; 11, valve cavity; 111, first throttling passage; 112, second throttling passage; 12, valve seat; 121, second opening; 122, third opening; 123, first valve sleeve; 1241, first end face; 124, second valve sleeve; 1242, second end face; 125, partition; 13, valve cover; 131, first opening; 132, abutting section; 133, guide hole; 20, piston assembly; 21, plunger rod; 22, first piston; 221, first body; 222, first sealing ring; 223, first limit surface; 23, second piston; 231, second body; 232, second sealing ring; 233, second limit surface; 31, first elastic member; 32, second elastic member. DETAILED DESCRIPTION

[0036] The technical solutions in the example embodiments of the present disclosure will be described clearly and completely below in combination with the drawings in the example embodiments of the present disclosure. The example embodiments described herein are only for illustrative purposes, and are not intended to limit the protection scope of the present disclosure, so it should be understood that various modifications and changes can be made to the example embodiments without departing from the protection scope of the present disclosure.

[0037] Unless otherwise defined, or specified herein, technical terms used in the present disclosure shall have the meanings as commonly understood by one of ordinary skill in the art to which the present disclosure pertains. For example, "connected" can be direct or indirect connection, or integral connection, or detachable connection, or can be directly connected, or indirectly connected through an intermediate medium. The terms "comprising" and "having" are used to mean open-ended including the possibility that additional elements / components / etc. can be present in addition to those listed; the terms "first" and "second" etc. are used as labels, and are not intended to denote a quantity limitation.

[0038] Further, it needs to be understood that the orientation words such as "top / bottom", "upper / lower", "inner / outer" and the like described in the example embodiments of the present disclosure are merely for convenience, for example, according to the angle shown in the drawings, or according to the general understanding of the switching valve in the art, and should not be understood as a limitation on the example embodiments of the present disclosure.

[0039] According to an aspect of the present disclosure, a switching valve is provided, comprising a valve body 10 and a piston assembly 20. The valve body 10 comprises a valve cavity 11 having a first valve port 101 and a second valve port 102; the piston assembly 20 is movably arranged in the valve cavity 11, and comprises a plug rod 21, a first piston 22 and a second piston 23, the first piston 22 and the second piston 23 are respectively connected to opposite ends of the plug rod 21, the first valve port 101 and the second valve port 102 are arranged at intervals along the movement direction of the piston assembly 20, the first piston 22 is used to block the first valve port 101, and the second piston 23 is used to block the second valve port 102; wherein at least one of the first piston 22 and the second piston 23 is injection molded.

[0040] The switching valve of the present disclosure, the injection molded first piston 22 and / or the second piston 23 are beneficial to control the weight and cost of the switching valve. In addition, during the movement of the piston assembly 20 in the valve cavity 11, the injection molded first piston 22 and / or the second piston 23 can reduce the friction and impact noise with the inner wall of the valve cavity 11 and the first valve port 101 and the second valve port 102, thereby improving the mute effect of the switching valve.

[0041] Specifically, referring to Figures 1 to 5 As shown in the figure, the valve body 10 can comprise a valve seat 12 and a valve cover 13, the valve seat 12 has the valve cavity 11, and the valve cover 13 is connected to the valve seat 12. Wherein the valve cover 13 is made of metal material, and the valve seat 12 can be made of metal material or plastic material, the valve seat 12 made of plastic material is light and beneficial to save cost.

[0042] In one embodiment, the valve cover 13 has a first opening 131 passing through the valve cover 13 to communicate with the valve cavity 11, and the valve seat 12 has a second opening 121 passing through the valve seat 12 to communicate with the valve cavity 11. When the first piston 22 blocks the first valve port 101, the first opening 131 is not communicated with the second opening 121; when the second piston 23 blocks the second valve port 102, the first opening 131 is communicated with the second opening 121. In some embodiments, the first opening 131 can be used as a fluid inlet of the switching valve, and can be communicated with an outlet of the compressor. The second opening 121 can be used as a fluid outlet of the switching valve, and can be communicated with an inlet of the compressor. An end of the valve seat 12 away from the valve cover 13 can be used as another fluid inlet of the switching valve, and can be communicated with an inlet of the compressor. When the first piston 22 blocks the first valve port 101, the second opening 121 is communicated with the fluid inlet. That is, the switching valve of the present disclosure can be a three-way valve, including two fluid inlets and one fluid outlet.

[0043] In another embodiment, the valve cover 13 has a first opening 131 passing through the valve cover 13 to communicate with the valve cavity 11, and the valve seat 12 has a second opening 121 passing through the valve seat 12 to communicate with the valve cavity 11. That is, the first opening 131 and the second opening 121 are both provided in the valve seat 12. When the first piston 22 blocks the first valve port 101, the first opening 131 is not communicated with the second opening 121; when the second piston 23 blocks the second valve port 102, the first opening 131 is communicated with the second opening 121.

[0044] In one exemplary embodiment of the present disclosure, as shown in Figure 1 , Figure 2 , the valve seat 12 has a third opening 122 passing through the valve seat 12 to communicate with the valve cavity 11, and a portion of the valve cover 13 extends into the third opening 122 or the valve cover 13 is sleeved on the third opening 122. To facilitate the connection between the valve cover 13 and the valve seat 12, an end of the valve seat 12 having the third opening 122 is provided with a riveting portion, and the riveting portion is connected with the valve cover 13. Alternatively, an end of the valve cover 13 close to the valve seat 12 is provided with a riveting portion, and the riveting portion is connected with the valve seat 12.

[0045] In one exemplary embodiment of the present disclosure, as shown in Figure 2 , the valve cover 13 has a fitting section 132 extending into the third opening 122, and an outer circumferential surface of the fitting section 132 is in interference fit with an inner circumferential surface of the third opening 122. For example, an outer diameter of the fitting section 132 before the valve cover 13 is connected with the valve seat 12 is greater than an outer diameter of the fitting section 132 after the valve cover 13 is connected with the valve seat 12. Alternatively, as shown in Figure 3 , the valve cover 13 has a fitting section 132 sleeved on the third opening 122, and an inner circumferential surface of the fitting section 132 is in interference fit with an outer circumferential surface of the valve seat 12 at a position of the third opening 122.

[0046] In an example embodiment of the present disclosure, the valve cover 13 and the valve seat 12 can also be connected in a threaded connection, or welded together as a whole, or, in some example embodiments, the valve cover 13 and the valve seat 12 can also be integrally formed.

[0047] In an example embodiment of the present disclosure, referring to Figures 1 to 4 As shown, the switching valve includes a first elastic member 31 and a second elastic member 32, and the valve cavity 11 is provided with a partition 125 that separates the first valve port 101 and the second valve port 102; the first elastic member 31 is sleeved on the plug rod 21 and located between the first piston 22 and the partition 125, and the opposite ends of the first elastic member 31 abut against the first piston 22 and the partition 125, respectively; the second elastic member 32 is sleeved on the plug rod 21 and located between the second piston 23 and the partition 125, and the opposite ends of the second elastic member 32 abut against the second piston 23 and the partition 125, respectively.

[0048] The first elastic member 31 and the second elastic member 32 are used to maintain the stability of the piston assembly 20 in the balanced state. The balanced state of the present disclosure refers to the state that the piston assembly 20 remains stationary relative to the valve body 10 under no fluid impact. The first elastic member 31 is used to apply an elastic force to the piston assembly 20 to move the second piston 23 to the position of blocking the second valve port 102, and the second elastic member 32 is used to apply an elastic force to the piston assembly 20 to move the first piston 22 to the position of blocking the first valve port 101. In an example embodiment, when the piston assembly 20 is in the balanced state, the resultant force of the elastic force of the first elastic member 31 and the second elastic member 32 acting on the piston assembly 20 and the gravity of the piston assembly 20 is zero.

[0049] In an example embodiment of the present disclosure, the first elastic member 31 can be a compression spring, and the second elastic member 32 can also be a compression spring.

[0050] Please refer to Figures 1 to 3 As shown, in an example embodiment of the present disclosure, the valve seat 12 includes a first valve sleeve 123 and a second valve sleeve 124 coaxially arranged and connected. The valve cover 13 is connected with the first valve sleeve 123, the second valve sleeve 124 is connected with the first valve sleeve 123, and the two ends of the second valve sleeve 124 form the first valve port 101 and the second valve port 102, respectively. The first valve sleeve 123 and the second valve sleeve 124 can be integrally formed. For example, the first opening 131 can be arranged on the peripheral side wall of the first valve sleeve 123, and the second opening 121 can be arranged on the second valve sleeve 124. In other embodiments, the valve seat 12 can also not include the first valve sleeve 123 and have the second valve sleeve 124, and the first opening 131 can be arranged on the valve cover 13.

[0051] In one exemplary embodiment of this disclosure, the valve seat 12 may further include a third valve sleeve, which is coaxially disposed with and connected to the second valve sleeve 124 on the side of the second valve sleeve 124 away from the first valve sleeve 123. The first valve sleeve 123, the second valve sleeve 124, and the third valve sleeve may be integrally formed. The fluid inlet at the end of the valve seat 12 away from the valve cover 13 may be disposed on the peripheral sidewall of the third valve sleeve.

[0052] In one exemplary embodiment of this disclosure, reference is made to Figure 2 As shown, the maximum value of the outer diameter of the second valve sleeve 124 is less than the maximum value of the outer diameter of the first valve sleeve 123. Alternatively, the maximum value of the outer diameter of the second valve sleeve 124 may be less than the maximum value of the outer diameter of the first valve sleeve 123, and the maximum value of the outer diameter of the third valve sleeve may be less than the maximum value of the outer diameter of the first valve sleeve 123.

[0053] In one exemplary embodiment of this disclosure, reference is made to Figure 1 As shown, the first piston 22 includes a first body 221 and a first sealing ring 222 sleeved on the outer periphery of the first body 221. When the first piston 22 blocks the first valve port 101, the first sealing ring 222 is compressed between the first body 221 and the first valve port 101 to seal the first valve port 101. The second piston 23 includes a second body 231 and a second sealing ring 232 sleeved on the outer periphery of the second body 231. When the second piston 23 blocks the second valve port 102, the second sealing ring 232 is compressed between the second body 231 and the inner wall of the second valve port 102 to seal the second valve port 102. The first sealing ring 222 and the second sealing ring 232 can be made of elastic material, such as rubber. The first body 221 and the plug rod 21 can be connected by screwing, interference fit, welding, injection molding, etc.; the second body 231 and the plug rod 21 can be connected by screwing, interference fit, welding, injection molding, etc.

[0054] Those skilled in the art should understand that "at least one of the first piston 22 and the second piston 23" as described in this disclosure refers to at least one of the first body 221 and the second body 231 being injection molded, and does not mean that the first sealing ring 222 is also injection molded with the first body 221, or that the second sealing ring 232 is also injection molded with the second body 231.

[0055] refer to Figure 2 , Figure 3As shown, the valve body 10 has a first end face 1241, preferably the second valve sleeve 124 has the first end face 1241, the first end face 1241 is located at one end of the first valve port 101 close to the valve cover 13, the first piston 22 has a first limiting face 223 for abutting the first end face 1241 when the first piston 22 blocks the first valve port 101. When the first limiting face 223 abuts the first end face 1241, the first piston 22 moves to the limit position in the direction of the first valve port 101, and the first body 221 and the compressed first sealing ring 222 seal and block the first valve port 101. Exemplarily, the valve body 10 has a second end face 1242, preferably the second valve sleeve 124 has the second end face 1242, the second end face 1242 is located at one end of the second valve port 102 away from the valve cover 13, the second piston 23 has a second limiting face 233 for abutting the second end face 1242 when the second piston 23 blocks the second valve port 102. When the second limiting face 233 abuts the second end face 1242, the second piston 23 moves to the limit position in the direction of the second valve port 102, and the second body 231 and the compressed second sealing ring 232 seal and block the second valve port 102.

[0056] In an exemplary embodiment of the present disclosure, the plug rod 21 can comprise a metal material, for example, the plug rod 21 does not comprise a non-metal material. The first piston 22 can be a plastic material. The first piston 22 can be integrally injection molded with the plug rod 21 as a metal insert. The second piston 23 can comprise a metal material and be formed by mechanical processing and can be mechanically connected with the plug rod 21. The second piston 23 can also be the same metal material as the plug rod 21. Or the second piston 23 can be a plastic material.

[0057] For another example, the plug rod 21 is a plastic material, the first piston 22 can be a plastic material, and the plug rod 21 can be integrally injection molded with the first piston 22. The second piston 23 can comprise a metal material and be formed by mechanical processing and can be mechanically connected with the plug rod 21. For another example, the first piston 22 and the second piston 23 can both be plastic materials.

[0058] The valve cover 13 can be made of a metal material, for example, comprising an aluminum alloy. For example, the valve cover 13 is made of an aluminum alloy material. In an exemplary embodiment of the present disclosure, the valve cover 13 which can be an aluminum alloy material cooperates with the injection molded valve seat 12, or the valve cover 13 which can be an aluminum alloy material cooperates with the valve seat 12 made of a metal material.

[0059] For example, in an embodiment, the valve cover 13 and the valve seat 12 can be made of aluminum alloy material. The valve cover 13 and the valve seat 12 can be connected by thread connection, welding, interference fit, etc. The plug rod 21, the first body 221 and the second body 231 can be respectively processed and formed, and then connected by screwing, interference fit, welding, injection molding, etc. Alternatively, the first body 221 and the plug rod 21 are integrally formed, and the second body 231 is mechanically connected with the plug rod 21; or the second body 231 and the plug rod 21 are integrally formed, and the first body 221 is mechanically connected with the plug rod 21; or the first body 221 and the second body 231 are integrally formed with the plug rod 21. Figure 3 As shown, the first opening 131 is arranged on the valve cover 13, so that the length of the valve seat 12 can be relatively shortened, and the metal machining of the valve seat 12 is facilitated.

[0060] For example, in an embodiment, the valve cover 13 and the plug rod 21 can be made of aluminum alloy material. The valve seat 12 is injection molded by plastic material, and the valve cover 13 and the valve seat 12 can be riveted or connected by interference fit. The forming and connecting mode of the plug rod 21, the first body 221 and the second body 231 can refer to the foregoing embodiment. Figure 2 As shown, the first opening 131 can be arranged on the valve seat 12, specifically on the first valve sleeve 123, so that the length of the valve cover 13 can be relatively shortened, and the metal machining of the valve cover 13 is facilitated.

[0061] For example, in an embodiment, the valve cover 13 is made of metal material, for example, can be made of aluminum alloy material. The valve seat 12 is injection molded by plastic material, and the valve cover 13 and the valve seat 12 can be riveted or connected by interference fit. The plug rod 21 is made of metal material, for example, can be made of aluminum alloy material. The first piston 22 can be plastic material, and the first piston 22 is integrally injection molded with the plug rod 21 as an insert. The second piston 23 includes metal material, and is formed by mechanical machining and can be mechanically connected with the plug rod 21. Alternatively, the second piston 23 can be plastic material, and the second piston 23 is integrally injection molded with the plug rod 21 as an insert. The first piston 22 includes metal material, and is formed by mechanical machining and can be mechanically connected with the plug rod 21. Figure 2 As shown, the first opening 131 can be arranged on the valve seat 12, specifically on the first valve sleeve 123, so that the length of the valve cover 13 can be relatively shortened, and the metal machining of the valve cover 13 is facilitated.

[0062] In an exemplary embodiment of the present disclosure, the throttle passage is formed between the piston assembly 20 and the valve port, wherein the ratio of the maximum flow area of the throttle passage to the maximum flow area of the valve port is ≤ 3 / 10 when the piston assembly 20 is in the balanced state. The throttle passage allows the fluid to generate a relatively large driving force on the piston assembly 20 from the balanced state to the fully closed range of the valve port, which is beneficial to improve the action capability of the switching valve.

[0063] Specifically, the maximum flow area of the valve port of the present disclosure refers to the fluid flow cross-sectional area when the valve port is fully open, i.e., the opening area of the valve port. The flow area of the throttle passage refers to the opening area of the throttle passage.

[0064] For example, the throttle passage includes a first throttle passage 111 formed between the outer circumferential surface of the first piston 22 and the first valve port 101, and the ratio of the maximum flow area of the first throttle passage 111 to the maximum flow area of the first valve port 101 is ≤ 3 / 10. For example, the throttle passage can also include a second throttle passage 112 formed between the outer circumferential surface of the second piston 23 and the second valve port 102, and the ratio of the maximum flow area of the second throttle passage 112 to the maximum flow area of the second valve port 102 is ≤ 3 / 10. The first throttle passage 111 and the second throttle passage 112 can improve the action capability of the switching valve during operation and reduce the action pressure difference.

[0065] Please refer to Figures 2 to 3 As shown, the first valve port 101 has an inner conical surface that shrinks in the direction of the second valve sleeve 124. The first sealing ring 222 is compressed between the first body 221 and the first valve port 101 to seal the first valve port 101. The inner conical surface can form the inner wall of the first throttle passage 111. During the process of blocking the first valve port 101 by the first piston 22, the flow area of the first throttle passage 111 gradually decreases, the fluid force generated by throttling gradually increases as the first piston 22 gradually blocks the first valve port 101, and the elastic force of the first elastic member 31 gradually increases. In this way, the valve action capability can be further improved by overcoming the gradually increasing elastic force as the first valve port 101 closes. In addition, the inner conical surface shrinking in the direction of the second valve sleeve 124 can also avoid the piston assembly 20 being stuck due to the first throttle passage 111 being too narrow and the first sealing ring 222 being excessively compressed.

[0066] Exemplarily, the second valve port 102 also has an inner conical surface which is tapered towards the second valve sleeve 124. The second sealing ring 232 is compressed between the second body 231 and the inner wall of the second valve port 102. When the second valve port 102 is sealed, the inner conical surface can form a second throttling passage 112. During the process that the second piston 23 blocks the second valve port 102, the flow area of the second throttling passage 112 gradually decreases, the fluid force generated by throttling gradually increases as the second piston 23 gradually blocks the second valve port 102, and the elastic force of the second elastic member 32 gradually increases. In this way, the elastic force which gradually increases as the second valve port 102 is closed can be overcome, so as to further improve the valve action capability. In addition, the inner conical surface tapered towards the second valve sleeve 124 can also avoid the situation that the second throttling passage 112 is too narrow and the second sealing ring 232 is excessively compressed, resulting in the piston assembly 20 being stuck.

[0067] Please refer to Figures 2 to 3 As shown in the figure, the valve cover 13 is provided with a guide hole 133, and the end of the plug rod 21 connected with the first piston 22 penetrates through the first piston 22 and extends into the guide hole 133. The plug rod 21 is movably arranged in the guide hole 133, so as to guide the reciprocating movement of the piston assembly 20 and support the plug rod 21, thereby increasing the support rigidity of the plug rod 21.

[0068] In an exemplary embodiment of the present disclosure, the valve body 10 is installed into a mounting seat (not shown in the figure) as a plug-in valve. The valve body 10 is externally provided with a limiting table, and the outer periphery of the valve body 10 is provided with a threaded connection part which is threadedly connected with the mounting seat. When the threaded connection part is threadedly connected with the mounting seat, the limiting table abuts against the mounting seat. The limiting table and the threaded connection part jointly realize the limiting of the valve body 10. The limiting table prevents the valve body 10 from moving downward, and the threaded connection part can prevent the valve body from moving upward.

[0069] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The present disclosure is intended to cover any and all variations of the present disclosure which become apparent to those skilled in the art from the reading and understanding of the specification and examples included herein. The specification and examples are intended to be exemplary only and the true scope and spirit of the present disclosure should be indicated by the appended claims.

[0070] It should be understood that the present disclosure is not limited to the precise construction which has been described above and shown in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the present disclosure. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A switching valve characterized by comprising: The valve body (10) comprises a valve cavity (11) having a valve port, the valve port comprising a first valve port (101) and a second valve port (102); a piston assembly (20) movably arranged in the valve cavity (11), the piston assembly (20) comprising a plug rod (21), a first piston (22) and a second piston (23), the first piston (22) and the second piston (23) being respectively connected to opposite ends of the plug rod (21), the first valve port (101) and the second valve port (102) being arranged at intervals along a movement direction of the piston assembly (20), the first piston (22) being used for blocking the first valve port (101), and the second piston (23) being used for blocking the second valve port (102); wherein at least one of the first piston (22) and the second piston (23) is injection molded. The plug rod (21) comprises a metal material, and the first piston (22) comprises a plastic material; the first piston (22) is integrally injection molded with the plug rod (21) as a metal insert; or the plug rod (21) comprises a plastic material, the first piston (22) comprises a plastic material, and the plug rod (21) and the first piston (22) are integrally injection molded. When the plug rod (21) comprises a metal material, the plug rod (21) is fixedly connected with the second piston (23) comprising a metal material; or the plug rod (21) is fixedly connected with the second piston (23) comprising a plastic material. When the plug rod (21) comprises a plastic material, the plug rod (21) is fixedly connected with the second piston (23) comprising a metal material; or the plug rod (21) is fixedly connected with the second piston (23) comprising a plastic material.

2. The switching valve according to claim 1, characterized by When the plug rod (21) comprises a metal material, the first piston (22) comprises a metal material, the second piston (23) comprises a plastic material, the first piston (22) is fixedly connected with the plug rod (21), and the second piston (23) is integrally injection molded with the plug rod (21) as a metal insert; or when the plug rod (21) comprises a plastic material, the first piston (22) comprises a metal material, the second piston (23) comprises a plastic material, the first piston (22) is fixedly connected with the plug rod (21), and the second piston (23) is integrally injection molded with the plug rod (21).

3. The switching valve according to claim 2, characterized by The valve body (10) comprises a valve seat (12) having the valve cavity (11) and a valve cover (13) connected to the valve seat (12); wherein the valve cover (13) is made of a metal material, and the valve seat (12) is made of a metal material or a plastic material. The valve seat (12) has a third opening (122) arranged along a radial direction of the valve seat (12) and communicating with the valve cavity (11); and the valve cover (13) partially extends into the third opening (122) or partially covers the third opening (122) outside.

4. The switching valve of claim 1, wherein ​ 5. The switching valve of claim 1, wherein ​ ​ 6. The switching valve according to claim 5, characterized by ​ ​ The valve seat (12) has a riveting portion at one end of the third opening (122), and the riveting portion is connected with the valve cover (13); or the valve cover (13) has a riveting portion at one end close to the valve seat (12), and the riveting portion is connected with the valve seat (12).

7. The switching valve according to claim 5, characterized by The valve seat (12) has a third opening (122) arranged along the radial direction of the valve seat (12) and connected with the valve cavity (11). The valve cover (13) has a fitting segment (132) extending into the third opening (122), and the outer circumferential surface of the fitting segment (132) is in interference fit with the inner circumferential surface of the third opening (122); or the valve cover (13) has a fitting segment (132) sleeved outside the third opening (122), and the inner circumferential surface of the fitting segment (132) is in interference fit with the outer circumferential surface of the third opening (122).

8. The switching valve according to claim 5 or 6, characterized by The valve seat (12) comprises a first valve sleeve (123) and a second valve sleeve (124) arranged coaxially and connected, wherein the two ends of the second valve sleeve (124) form the first valve port (101) and the second valve port (102) respectively, and the maximum value of the outer diameter of the second valve sleeve (124) is smaller than the maximum value of the outer diameter of the first valve sleeve (123).

9. The switching valve of claim 1, wherein The switching valve comprises a first elastic member (31) and a second elastic member (32), the valve cavity (11) is provided with a separation portion (125) for separating the first valve port (101) and the second valve port (102); the first elastic member (31) is sleeved on the plug rod (21) and located between the first piston (22) and the separation portion (125), and the opposite ends of the first elastic member (31) are in abutment with the first piston (22) and the separation portion (125) respectively; the second elastic member (32) is sleeved on the plug rod (21) and located between the second piston (23) and the separation portion (125), and the opposite ends of the second elastic member (32) are in abutment with the second piston (23) and the separation portion (125) respectively. When the piston assembly (20) is in a balanced state, the resultant force of the elastic force of the first elastic member (31) and the second elastic member (32) acting on the piston assembly (20) and the gravity of the piston assembly (20) is zero; the balanced state refers to that, under no fluid impact, the piston assembly (20) remains stationary relative to the valve body (10). A throttling passage in communication with the valve port is formed between the piston assembly (20) and the inner wall of the valve cavity (11), wherein when the piston assembly (20) is in the balanced state, the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is ≤3 / 10.

10. The switching valve of claim 9, wherein In the process of the piston assembly (20) blocking the valve port, the flow area of the throttling passage gradually decreases.

11. The switching valve of claim 9, wherein The throttle channel includes a first throttle channel (111) formed between the outer circumferential surface of the first piston (22) and the first valve port (101), and a ratio of a maximum flow area of the first throttle channel (111) to a maximum flow area of the first valve port (101) is less than or equal to 3 / 10; and / or, the throttle channel includes a second throttle channel (112) formed between the outer circumferential surface of the second piston (23) and the second valve port (102), and a ratio of a maximum flow area of the second throttle channel (112) to a maximum flow area of the second valve port (102) is less than or equal to 3 / 10.

12. The switching valve of claim 1, wherein The first piston (22) includes a first body (221) and a first sealing ring (222) sleeved on the outer periphery of the first body (221), and when the first piston (22) blocks the first valve port (101), the first sealing ring (222) is compressed between the first body (221) and the first valve port (101) to seal the first valve port (101); the valve body (10) has a first end face (1241) located at one end of the first valve port (101) away from the second valve port (102), and the first piston (22) has a first limiting face (223) for abutting against the first end face (1241) when the first piston (22) blocks the first valve port (101); and / or; The second piston (23) includes a second body (231) and a second sealing ring (232) sleeved on the outer periphery of the second body (231), and when the second piston (23) blocks the second valve port (102), the second sealing ring (232) is compressed between the second body (231) and the second valve port (102) to seal the second valve port (102); the valve body (10) has a second end face (1242) located at one end of the second valve port (102) away from the first valve port (101), and the second piston (23) has a second limiting face (233) for abutting against the second end face (1242) when the second piston (23) blocks the second valve port (102).

13. The switching valve according to claim 5 or 6, characterized by The valve cover (13) is provided with a guide hole (133), one end of the plug rod (21) connected with the first piston (22) passes through the first piston (22) and extends into the guide hole (133), and the plug rod (21) is movably arranged in the guide hole (133).

14. The switching valve of claim 1, wherein The switching valve further includes a mounting seat; the valve body (10) is externally provided with a limiting table and a threaded connection part; after the threaded connection part is threadedly connected with the mounting seat, the limiting table abuts against the mounting seat.

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