Switching valve

Abstract

A switching valve, comprising a valve body (100), a piston assembly (200) and an elastic member, wherein the valve body (100) comprises an inner cavity (101) having valve ports; the piston assembly (200) is movably arranged in the inner cavity (101) and is configured to block or open the valve ports; and the elastic member is configured to keep the piston assembly (200) in an equilibrium state. The equilibrium state is defined as follows: in the absence of a fluid impact, the piston assembly (200) remains stationary relative to the valve body (100); and a throttling channel communicating with the valve ports is formed between the piston assembly (200) and a cavity wall of the inner cavity (101), wherein when the piston assembly (200) is in the equilibrium state, the ratio of the maximum flow area of the throttling channel to the maximum flow area of each valve port is less than or equal to 3 / 10.

Description

Switching valve

[0001] Cross-reference to related applications

[0002] The present disclosure claims priority to Chinese Patent Application No. 202411047213.X, filed on July 31, 2024, entitled “Switching Valve and Refrigeration System”, Chinese Patent Application No. 202421834340.X, filed on July 31, 2024, entitled “Switching Valve and Refrigeration System”, Chinese Patent Application No. 202421841966.3, filed on July 31, 2024, entitled “Switching Valve and Refrigeration System”, and Chinese Patent Application No. 202422838717.5, filed on November 20, 2024, entitled “Switching Valve”, the contents of all four Chinese Patent Applications are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of fluid control, and in particular, to a switching valve. BACKGROUND

[0004] The switching valve in the related art can move in the valve cavity of the valve body under the drive of fluid pressure. If the pressure of the fluid acting on the switching valve is small, the switching valve will not have high actuation capability, and sometimes the valve cannot be completely closed or completely opened, which affects the reliability of the valve. SUMMARY

[0005] The present disclosure provides a switching valve, comprising a valve body, a piston assembly and an elastic member, the valve body comprising an inner cavity with a valve port; the piston assembly is movably arranged in the inner cavity and used for blocking or opening the valve port; the elastic member is used for keeping the piston assembly in a balanced state; the balanced state refers to that the piston assembly remains stationary relative to the valve body under no fluid impact; a throttling passage in communication with the valve port is formed between the piston assembly and the cavity wall of the inner cavity; wherein the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is ≤3 / 10 when the piston assembly is in the balanced state. BRIEF DESCRIPTION OF DRAWINGS

[0006] FIG. 1 shows an exploded schematic view of the switching valve of the first embodiment of the present disclosure.

[0007] FIG. 2 shows a top view schematic view of the switching valve of the first embodiment of the present disclosure.

[0008] FIG. 3 shows a sectional view along the A-A sectional line in FIG. 2.

[0009] FIG. 4 shows a flow area curve of the switching valve when the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is >3 / 10 when the piston assembly is in the balanced state.

[0010] Figure 5 shows a flow area curve of the switching valve when 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 is in the balanced state.

[0011] Figure 6 shows a flow resistance curve of the switching valve when 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 is in the balanced state.

[0012] Figure 7 shows a flow resistance curve of the switching valve when 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 is in the balanced state.

[0013] Figure 8 shows a cross-sectional view of the switching valve according to the second embodiment of the present disclosure.

[0014] Figure 9 shows a cross-sectional view of the switching valve according to the third embodiment of the present disclosure.

[0015] Figure 10 shows a cross-sectional view of the switching valve according to the fourth embodiment of the present disclosure.

[0016] Figure 11 shows a cross-sectional view of the switching valve according to the fifth embodiment of the present disclosure.

[0017] Figure 12 shows a perspective view of the piston assembly of the switching valve according to the fifth embodiment of the present disclosure.

[0018] Figure 13 shows an exploded view of the switching valve according to the sixth embodiment of the present disclosure.

[0019] Figure 14 shows a cross-sectional view of the switching valve according to the sixth embodiment of the present disclosure.

[0020] Figure 15 shows a curve of the elastic resultant force of a pair of first elastic members acting on the piston assembly when the free length of the first elastic member is in three different intervals in the switching valve according to the sixth embodiment of the present disclosure.

[0021] Figure 16 shows a curve of the elastic resultant force of a pair of first elastic members and a pair of second elastic members acting on the piston assembly simultaneously.

[0022] Figure 17 shows an exploded view of the switching valve according to the seventh embodiment of the present disclosure.

[0023] Figure 18 shows a cross-sectional view of the switching valve according to the seventh embodiment of the present disclosure.

[0024] Figure 19 shows an exploded view of an exemplary embodiment of the switching valve according to the eighth embodiment of the present disclosure.

[0025] Figure 20 shows a longitudinal cross-sectional view of an exemplary embodiment of the switching valve according to the eighth embodiment of the present disclosure.

[0026] Fig. 21 shows a schematic view of a longitudinal section of another exemplary embodiment of the switching valve according to the eighth embodiment of the present disclosure;

[0027] Fig. 22 shows a schematic view of a piston assembly in an exemplary embodiment of the switching valve according to the eighth embodiment of the present disclosure;

[0028] Fig. 23 shows a schematic view of a valve body in an exemplary embodiment of the switching valve according to the eighth embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings; however, these embodiments should not be construed as limiting the present disclosure, but merely as illustrating

[0030] It is to be understood that the terms "including", "comprising", "having" and variations thereof herein are intended to cover the case where non-excluded elements are included, without limitation. For example, a process, method, system, product, or apparatus that comprises a list of steps or elements is not necessarily limited to the listed steps or elements, but can include additional steps or elements not expressly listed or inherent to such process, method, system, product, or apparatus.

[0031]

Embodiment One

[0032] As shown in Figs. 1-3, the switching valve according to the embodiments of the present disclosure comprises a valve body 100, a piston assembly 200, and an elastic member. The valve body 100 comprises an inner cavity 101 having valve ports (102a, 102b); the piston assembly 200 is movably arranged in the inner cavity 101 for blocking or opening the valve ports; and the elastic member is used to keep the piston assembly 200 in an equilibrium state; wherein when the piston assembly 200 is in the equilibrium state, a throttling passage is formed between the piston assembly 200 and the cavity wall of the inner cavity 101, and the throttling passage is in communication with the valve ports. The ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve ports is ≤ 3 / 10, so that the piston assembly can be driven by a relatively large driving force of the fluid from the equilibrium state to the range in which the valve ports are completely closed, which is beneficial to improve the action capability of the switching valve.

[0033] The valve port includes a first valve port 102a and a second valve port 102b, which are arranged at intervals along the movement direction of the piston assembly 200. The piston assembly 200 is used to block the first valve port 102a and the second valve port 102b, respectively. The maximum flow area of the first valve port 102a is S11, and the maximum flow area of the second valve port 102b is S12.

[0034] The maximum flow area of the valve port refers to the fluid flow cross-sectional area when the valve port is fully open, that is, the opening area of the valve port. The flow area of the throttling channel refers to the opening area of the flow area.

[0035] The elastic member includes a pair of first elastic members 310, which are defined as a first elastic part 310a and a second elastic part 310b, respectively. The first elastic part 310a and the second elastic part 310b are used to maintain the stability of the piston assembly in the balanced state. And the first elastic part 310a is used to provide the piston assembly 200 with a first elastic force moving towards the position of blocking the second valve port 102b, and the second elastic part 310b is used to provide the piston assembly 200 with a second elastic force moving towards the position of blocking the first valve port 102a.

[0036] In an embodiment, when the piston assembly 200 is in the balanced state, the resultant force of the elastic force of the first elastic part 310a and the second elastic part 310b acting on the piston assembly 200 and the gravity of the piston assembly 200 is zero.

[0037] As shown in FIG. 1 and FIG. 3, the valve body 100 can include a valve seat 120 having an inner cavity 101 and a valve cover 130 connected to the valve seat 120. Wherein the connection mode of the valve cover 130 and the valve seat 120 is not limited by the present disclosure, for example, threaded connection, welding, interference fit, etc. Or the valve cover 130 and the valve seat 120 are integrally provided.

[0038] The valve cover 130 has a first opening 131 which communicates with the inner cavity 101. The valve seat 120 has a second opening 121 which communicates with the inner cavity 101. Wherein when the piston assembly 200 blocks the first valve port 102a, the first opening 131 and the second opening 121 are not communicated; when the piston assembly 200 blocks the second valve port 102b, the first opening 131 and the second opening 121 are communicated. The first opening 131 can serve as the fluid inlet of the switching valve, which communicates with the outlet of the compressor. The second opening 121 can serve as the fluid outlet of the switching valve, which communicates with the inlet of the compressor. The end of the valve seat 120 away from the valve cover 130 can serve as another fluid inlet of the switching valve, which can communicate with the outlet of the compressor. Therefore, the switching valve can be a three-way valve, including two fluid inlets and one fluid outlet.

[0039] As shown in FIG. 3, the piston assembly 200 includes a plug rod 210, a first piston 220 and a second piston 230. The first piston 220 is connected to one end of the plug rod 210 for blocking the first valve port 102a. The second piston 230 is connected to the other end of the plug rod 210 for blocking the second valve port 102b.

[0040] In an embodiment, the first elastic part 310a and the second elastic part 310b are compression springs and are sleeved on the outer periphery of the plug rod 210.

[0041] As shown in FIG. 3, the valve seat 120 includes two first valve sleeves 122 and a second valve sleeve 123 connected between the two first valve sleeves 122, and the first valve sleeves 122 and the second valve sleeve 123 are coaxially arranged. The two ends of the second valve sleeve 123 form the first valve port 102a and the second valve port 102b, respectively.

[0042] In the case where the piston assembly 200 blocks the first valve port 102a, one of the first valve sleeves 122 is sleeved on the outer periphery of the first piston 220; in the case where the piston assembly 200 blocks the second valve port 102b, the other of the first valve sleeves 122 is sleeved on the outer periphery of the second piston 230.

[0043] Of course, in other embodiments, the valve seat 120 can also not include the first valve sleeve 122 but have the second valve sleeve 123.

[0044] As shown in FIG. 3, the inner cavity 101 is provided with a partition 110, which separates the first valve port 102a and the second valve port 102b; the first elastic part 310a is located between the first piston 220 and the partition 110, and one end of the first elastic part 310a abuts against the partition 110 and the other end abuts against the first piston 220. The second elastic part 310b is located between the second piston 230 and the partition 110, and one end of the second elastic part 310b abuts against the partition 110 and the other end abuts against the second piston 230.

[0045] In an embodiment, the partition 110 includes a partition ring 111 and a guide sleeve 112, the partition ring 111 is fixedly connected to the inner periphery of the second valve sleeve 123 and surrounds the outer periphery of the guide sleeve 112, and the guide sleeve 112 has a guide hole 110a, and the plug rod 210 movably penetrates the guide hole 110a of the guide sleeve 112.

[0046] In the embodiments of the present disclosure, the plug rod 210 and the guide sleeve 112 are guided and matched, which improves the stability of the movement of the plug rod 210 and further improves the reliability of the valve action.

[0047] In other embodiments, the partition 110 can also include the partition ring 111, and the partition ring 111 surrounds the guide hole 110a.

[0048] As shown in FIG. 3, the partition ring 111 has a first annular surface 1111 and a second annular surface 1112, which are arranged opposite to each other along the movement direction of the piston assembly 200; the portion of the guide sleeve 112 extending out of the first annular surface 1111 is defined as a first section 112a, and the first elastic portion 310a is sleeved on the outer periphery of the first section 112a; the portion of the guide sleeve 112 extending out of the second annular surface 1112 is defined as a second section 112b, and the second elastic portion 310b is sleeved on the outer periphery of the second section 112b.

[0049] As shown in FIG. 3, the throttle passage includes a first throttle passage 410 communicating with the first valve port 102a and a second throttle passage 420 communicating with the second valve port 102b, the maximum flow area of the first throttle passage 410 is S21, and the maximum flow area of the second throttle passage 420 is S22; when the piston assembly 200 is in the balanced state, S21 / S11≤3 / 10, and S22 / S12≤3 / 10.

[0050] In the embodiment of the present disclosure, the first throttle passage 410 is formed between the outer peripheral surface of the first piston 220 and the inner peripheral surface of one of the first valve sleeves 122, and the second throttle passage 420 is formed between the outer peripheral surface of the second piston 230 and the inner peripheral surface of the other first valve sleeve 122.

[0051] The stroke of the piston assembly 200 from the valve port flow area being zero to the valve port being the maximum flow area is S1; the stroke of the piston assembly 200 between the valve port flow area being zero and the valve port being the maximum flow area is S2, and the valve port can be the first valve port 102a or the second valve port 102b. The abscissa in FIGS. 4 and 5 represents the value of S2 / S1 of the switching valve, i.e., the opening degree. The ordinate in FIGS. 4 and 5 represents the ratio of the valve port flow area to the maximum valve port flow area when the switching valve is at different opening degrees. The fluid flows into the valve port through the opening between the piston assembly 200 and the inner wall of the valve seat 120, and before the opening area reaches the valve port opening area, the valve port flow area is equal to the opening area between the piston assembly 200 and the inner wall of the valve seat 120. With the movement of the piston assembly 200, when the opening area between the piston assembly 200 and the inner wall of the valve seat 120 is reduced to a certain extent, the opening area between the piston assembly 200 and the inner wall of the valve seat 120 is the throttle passage area in the embodiment.

[0052] The high pressure fluid enters the valve port through the throttling passage, and the fluid becomes low pressure fluid after throttling, and the low pressure fluid flows out from the second opening 121, and the piston assembly 200 is subjected to the pressure difference of the fluid before and after the valve port. Or the high pressure fluid directly enters the throttling passage in the valve port and becomes low pressure fluid, and the low pressure fluid flows out from the second opening 121, and the piston assembly 200 is subjected to the pressure difference of the fluid before and after the valve port. When the flow area of the valve port is zero, the piston assembly 200 is subjected to the pressure difference F1 of the fluid before and after the valve port. When the flow area of the valve port is between zero and the maximum flow area of the valve port, the piston assembly 200 is subjected to the pressure difference F2 of the fluid before and after the valve port. The abscissa in FIGS. 6 and 7 represents the opening of the switching valve. The ordinate in FIGS. 6 and 7 represents the value of F2 / F1 corresponding to different openings of the switching valve.

[0053] For convenience of description, the following description of FIGS. 4 to 7 takes the first valve port 102a as an example. For example, 0% in the abscissa of FIGS. 4 to 7 represents the position of the piston assembly 200 when the piston assembly 200 blocks the first valve port 102a. 100% in the abscissa represents the position of the piston assembly 200 when the first valve port 102a is fully open.

[0054] In FIGS. 4 and 6, when the piston assembly 200 is in the balance state, the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is >3 / 10. As can be seen from FIG. 4, when the first valve port 102a is switched from the closed state to the fully open state, the flow area gradually and steadily increases with the increase of the opening. When the opening of the piston assembly 200 reaches 50%, the flow area of the throttling passage is smaller than the maximum flow area of the valve port. At this time, the flow area of the valve port is equal to the flow area of the throttling passage, and the ratio of the flow area of the valve port to the maximum flow area of the valve port is slightly higher than 60%, and the value of F2 / F1 at this time is about 25%.

[0055] In the balance state of the piston assembly 200, the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is ≤3 / 10 in FIG. 5 and FIG. 7. As can be seen from FIG. 5, when the first valve port 102a is switched from the closed state to the fully open state, the valve port flow area remains substantially unchanged as the opening of the piston assembly 200 reaches the range of 50%, and when the opening of the piston assembly 200 reaches 55%, the flow area of the throttling passage is smaller than the maximum flow area of the valve port. At this time, the valve port flow area is equal to the flow area of the throttling passage, and the ratio of the valve port flow area to the maximum flow area of the valve port is about 8%, while the value of F2 / F1 is about 95%. Therefore, it can be seen that when the opening of the piston assembly 200 reaches the range of 55%, the piston assembly 200 is driven by the increased fluid pressure difference before and after the valve port, which is beneficial to improve the action ability of the valve. The fluid pressure difference driving force not only overcomes the elastic force applied to the piston assembly 200 by the elastic member, but also enables the piston assembly 200 to quickly switch between different working conditions. When the closing operation of the first valve port 102a is performed, the piston assembly 200 can have a larger fluid pressure difference driving force when it reaches the balance state, which ensures the smooth closing of the first valve port 102a.

[0056] As shown in FIG. 5, since the first throttling passage 410 is formed between the outer circumferential surface of the first piston 220 and the inner circumferential surface of the first valve sleeve 122, and S21 / S11≤3 / 10, the flow area of the first valve port 102a of the switching valve is small in the opening range of 0% to 55%. When the valve opening stroke is in the range of 55% to 100%, the flow area of the first valve port 102a of the switching valve gradually increases. A larger fluid pressure difference driving force is generated in the opening range of 0% to 55%.

[0057] As can be seen from FIG. 6, during the switching process of the first valve port 102a from the closed state to the fully open state, F2 quickly and gradually decreases, which is not conducive to improving the action ability of the valve.

[0058] As can be seen from FIG. 7, since the first throttling passage 410 is formed between the outer circumferential surface of the first piston 220 and the inner circumferential surface of the first valve sleeve 122, and S21 / S11≤3 / 10, F2 remains at a large value in the opening range of 0% to 55%, and F2 only gradually decreases when the opening is in the range of 55% to 100%, which is conducive to pushing the piston assembly 200 from the balance state to the fully closed state.

[0059] Therefore, the switching valve can maintain a large flow resistance value within a certain valve opening stroke when performing switching action, which is beneficial to improve the action capability of the switching valve and reduce the action pressure difference.

[0060] Embodiment Two

[0061] As shown in FIG. 8, the second embodiment of the present disclosure is the same as the first embodiment, and the differences are as follows:

[0062] When the piston assembly 200 is in the balanced state, the throttling passage further includes a third throttling passage 430 communicated with the first valve port 102a and a fourth throttling passage 440 communicated with the second valve port 102b. The maximum flow area of the third throttling passage 430 is S31, and the maximum flow area of the fourth throttling passage 440 is S32. S31 / S11≤3 / 10, and S32 / S12≤3 / 10.

[0063] The first piston 220 and the second piston 230 each have an insertion part 240. When the piston assembly 200 is in the balanced state, the insertion part 240 of the first piston 220 extends into the first valve port 102a, and a third throttling passage 430 is formed between the outer peripheral surface of the insertion part 240 of the first piston 220 and the hole wall of the first valve port 102a. The insertion part 240 of the second piston 230 extends into the second valve port 102b, and a fourth throttling passage 440 is formed between the insertion part 240 of the second piston 230 and the hole wall of the second valve port 102b.

[0064] In the embodiments of the present disclosure, when the piston assembly 200 is in the balanced state, not only the first throttling passage 410 and the second throttling passage 420 are provided, but also the third throttling passage 430 and the fourth throttling passage 440 are provided, which further improves the action capability of the switching valve.

[0065] Of course, it can be understood that in other embodiments, the switching valve can only be provided with the third throttling passage 430 and the fourth throttling passage 440, and not provided with the first throttling passage 410 and the second throttling passage 420.

[0066] Embodiment Three

[0067] As shown in FIG. 9, the third embodiment of the present disclosure is the same as the first embodiment, and the differences are as follows:

[0068] During the process of plugging the valve port, the flow area of the throttling passage formed between the inner peripheral surface of the first valve sleeve 122 and the piston assembly 200 gradually decreases.

[0069] In the embodiment of the present disclosure, the flow area of the first throttling passage 410 gradually decreases during the process that the piston assembly 200 blocks the first valve port 102a, and the flow area of the second throttling passage 420 gradually decreases during the process that the piston assembly 200 blocks the second valve port 102b. In this way, the fluid force generated by throttling gradually increases as the piston assembly 200 gradually blocks the valve ports, and the elastic force of the first elastic portion 310a gradually increases as the piston assembly 200 gradually blocks the valve ports, so that the gradually increasing elastic force can be overcome to further improve the valve action capability.

[0070] As shown in FIG. 9, the inner circumferential surface of the first valve sleeve 122 has an inner conical surface 1221. By arranging the inner conical surface 1221, not only the valve action capability can be further improved, but also the piston assembly 200 can be prevented from being stuck in the first valve sleeve 122 due to the too narrow throttling passage.

[0071] Embodiment Four

[0072] As shown in FIG. 10, the fourth embodiment of the present disclosure is the same as the third embodiment, and the differences are as follows:

[0073] The outer circumferential surface of the first piston 220 and the outer circumferential surface of the second piston 230 of the piston assembly 200 both have a first outer conical surface 250.

[0074] Embodiment Five

[0075] As shown in FIG. 11, the fifth embodiment of the present disclosure is the same as the above embodiments, and the differences are as follows:

[0076] The piston assembly 200 includes a plug rod 210, a first piston 220 and a second piston 230, the first piston 220 and the second piston 230 are connected to the plug rod 210 and are arranged in the axial direction of the plug rod 210. The valve body 100 has a guide portion 132, and the plug rod 210 is in guided cooperation with the guide portion 132. In the embodiment of the present disclosure, the guide portion 132 can guide the movement of the plug rod 210, thereby avoiding the deflection of the plug rod 210 during the movement and affecting the sealing performance of the piston in blocking the valve port. The guided cooperation means that there is a small gap between the plug rod 210 and the guide portion 132.

[0077] In an embodiment, the valve body 100 includes a valve cover 130 and a valve seat 120, the valve seat 120 has an inner cavity 101, and the valve cover 130 is connected to the valve seat 120. The guide portion 132 is integrally formed on the valve cover 130.

[0078] Further, the first piston 220 is arranged close to the valve cover 130, and the plug rod 210 has a guide section 211 arranged on the side of the first piston 220 away from the second piston 230. The guide section 211 is guided by the guide portion 132.

[0079] In an embodiment, the guide portion 132 can be a hole, and the guide section 211 is guided by the inner wall surface of the hole.

[0080] As shown in FIG. 12, the first piston 220 and the second piston 230 each include a first piston sheet 260, a second piston sheet 270, and a third piston sheet 280. The second piston sheet 270 is arranged between the first piston sheet 260 and the third piston sheet 280. The second piston sheet 270 can be made of rubber material, and the first piston sheet 260 and the third piston sheet 280 can be made of metal material.

[0081] When the piston blocks the valve port, the first piston sheet 260 of the piston extends into the valve port. In the embodiment of the present disclosure, when the first piston 220 blocks the first valve port 102a, the first piston sheet 260 of the first piston 220 extends into the first valve port 102a, and the second piston 230 is located outside the second valve port 102b; when the second piston 230 blocks the second valve port 102b, the first piston sheet 260 of the second piston 230 extends into the second valve port 102b, and the first piston 220 is located outside the first valve port 102a.

[0082] In an embodiment, the second piston sheet 270 has a second outer conical surface 271 that is sealingly matched with the valve port. By sealingly matching the second outer conical surface 271 with the valve port, the sealing performance of the piston when blocking the valve port can be improved.

[0083] As shown in FIG. 12, the outer circumferential surface of the first piston sheet 260 has an outer cylindrical surface 261 and two third outer conical surfaces 262 symmetrically connected to the two ends of the outer cylindrical surface 261 along the movement direction of the piston assembly 200. The diameter of the outer cylindrical surface 261 is slightly smaller than the diameter of the valve port.

[0084] In the embodiment of the present disclosure, the outer circumferential surface of the first piston sheet 260 has the outer cylindrical surface 261 and the two third outer conical surfaces 262. On the one hand, the first piston sheet 260 can be prevented from being stuck at the edge of the valve port during the opening and closing of the valve; on the other hand, since the two third outer conical surfaces 262 are symmetrically connected to the two ends of the outer cylindrical surface 261 along the movement direction of the piston assembly 200, the front or back of the first piston sheet 260 does not need to be considered when assembling the first piston sheet 260, and the assembly efficiency is improved.

[0085] It can be understood that the guide portion 132, the second outer conical surface 271, the outer cylindrical surface 261, and the two third outer conical surfaces 262 in the embodiment are applicable to the switching valve of any of the above-mentioned embodiments, which will not be listed one by one here.

[0086] Embodiment Six

[0087] As shown in FIGS. 13 and 14, the sixth embodiment of the present disclosure is the same as the above-described embodiments, and the difference is that:

[0088] The switching valve of the embodiment of the present disclosure comprises a valve body 100, a piston assembly 200, and elastic members. The elastic members can comprise a pair of first elastic members 310. The pair of first elastic members 310 are used to make the piston assembly 200 in a balanced state.

[0089] In an embodiment, the first elastic members 310 are compression springs, and are sleeved on the outer periphery of the plug rod 210.

[0090] As shown in FIG. 14, the inner cavity 101 is provided with a partition 110, which separates the first valve port 102a and the second valve port 102b, and has a guide hole 110a; the plug rod 210 movably penetrates the guide hole 110a. One of the first elastic members 310 is located between the first piston 220 and the partition 110, and one end of the one of the first elastic members 310 abuts against the partition 110, and the other end abuts against the first piston 220. The other of the first elastic members 310 is located between the second piston 230 and the partition 110, and one end of the other of the first elastic members 310 abuts against the partition 110, and the other end abuts against the second piston 230.

[0091] As shown in FIG. 14, the partition ring 111 has a first annular surface 1111 and a second annular surface 1112, which are oppositely arranged along the movement direction of the piston assembly 200; the part of the guide sleeve 112 extending out of the first annular surface 1111 is defined as a first section 112a, and the one of the first elastic members 310 is sleeved on the outer periphery of the first section 112a; the part of the guide sleeve 112 extending out of the second annular surface 1112 is defined as a second section 112b, and the other of the first elastic members 310 is sleeved on the outer periphery of the second section 112b.

[0092] Wherein, when the piston assembly 200 blocks one of the first valve port 102a and the second valve port 102b, the lengths of the pair of first elastic members 310 are L1 and L2 respectively, L1 is greater than L2, the free length of the first elastic member 310 is L', L2 < L' ≤ (L1 + L2) / 2, or L' ≥ L1. Wherein, the "free length" refers to the length value when the both ends of the spring are not subjected to any external force.

[0093] As shown in FIG. 15, a pair of first elastic members 310 exerts elastic force on the piston assembly 200 when the free length of the first elastic member 310 is in three different intervals, respectively. The three different intervals are: L'≥L1(curve 1), (L1+L2) / 2

[0094] In FIG. 15, the abscissa represents the opening of the switching valve, and the ordinate represents the ratio of the elastic force corresponding to different openings of the switching valve to the maximum elastic force. The maximum elastic force refers to the elastic force exerted by a pair of first elastic members 310 on the piston assembly 200 when the piston assembly 200 blocks one of the first valve port 102a and the second valve port 102b. The maximum elastic force exerted by the three pairs of different first elastic members 310 on the piston assembly 200 is equal, i.e., curve 1, curve 2 and curve 3 have the same starting point and the same ending point.

[0095] For convenience of description, the first valve port 102a is taken as an example. For example, 0% in the abscissa of FIG. 15 represents the position of the piston assembly 200 when the piston assembly 200 blocks the first valve port 102a and the second valve port 102b is fully open. 100% in the abscissa represents the position of the piston assembly 200 when the first valve port 102a is fully open and the piston assembly 200 blocks the second valve port 102b. When the abscissa is 50%, it means that the piston assembly 200 is in a balanced state, i.e., the elastic force exerted by a pair of first elastic members 310 on the piston assembly 200 is zero.

[0096] It should be noted that 0% to 50% in the abscissa represents the movement of the piston assembly 200 from the first position (blocking the first valve port 102a) to the balanced state, and 50% to 100% represents the movement of the piston assembly 200 from the balanced state to the second position (blocking the second valve port 102b).

[0097] When switching the working condition, at the position of 0% on the horizontal coordinate, the first valve port 102a is completely closed, the compressor is not stopped, and the high-pressure fluid flows into the bottom of the second piston 230. At this time, the pressure of the high-pressure fluid in the first valve port 102a has not started to decrease, and the force for pushing the piston assembly 200 to open the first valve port 102a is mainly the sum of the elastic forces of the pair of first elastic members 310. The greater the sum of the elastic forces of the pair of first elastic members 310, the greater the ability to instantaneously open the first valve port 102a, that is, the size of the elastic force of the first elastic member 310 is the key factor to determine whether the first valve port 102a can be successfully opened; in the range of 0% to 50% on the horizontal coordinate, the first valve port 102a is opened first, and the second valve port 102b is in an open state at the same time, the first valve port 102a, the second valve port 102b and the inner cavity 101 of the valve body 100 are communicated, the old high-pressure fluid pressure in the first valve port 102a gradually decreases, and the new high-pressure fluid flows from the bottom of the second piston 230. The pressure difference formed by the pressure difference between the high-pressure fluid and the fluid in the inner cavity 101 acts on the piston assembly 200, and the fluid pressure and the sum of the elastic forces of the pair of first elastic members 310 push the piston assembly 200 to move to the position where the balance state is located. The direction of the fluid pressure is the same as the direction of the sum of the elastic forces of the pair of first elastic members 310.

[0098] Then, in the range of 50% to 100% on the horizontal coordinate, the direction of the fluid pressure is opposite to the direction of the sum of the elastic forces of the pair of first elastic members 310. The piston assembly 200 needs to overcome the sum of the elastic forces of the pair of first elastic members 310 to move to the position where the second valve port 102b is in a closed state. Therefore, the sum of the elastic forces of the pair of first elastic members 310 not only serves as the driving force for opening the first valve port 102a, but also serves as the resistance for closing the second valve port 102b. Since the maximum sum of the elastic forces of the pair of first elastic members 310 corresponding to the curve 1, the curve 2 and the curve 3 are all equal, the disclosure analyzes the elastic force that needs to be overcome by the switching valve during switching.

[0099] As can be seen from FIG. 15, in the range of 50% to 100% on the horizontal coordinate, the elastic force corresponding to the curve 1 and the elastic force corresponding to the curve 2 are both smaller than the elastic force corresponding to the curve 3 at the same horizontal coordinate value. Therefore, it can be known that, during switching of the switching valve, the resistance that needs to be overcome by the flow resistance in the curve 1 and the resistance that needs to be overcome by the flow resistance in the curve 2 are both smaller than the resistance that needs to be overcome by the flow resistance in the curve 3.

[0100] Therefore, the switching valve in the embodiment of the disclosure has the free length L' of the first elastic member 310 satisfying L2 < L' ≤ (L1 + L2) / 2 or L' ≥ L1, so that the resistance that needs to be overcome by the valve during switching is smaller, and the action ability of the valve is effectively improved.

[0101] As shown in FIG. 14, the switching valve of the embodiment of the present disclosure further comprises a pair of second elastic members 320 for enabling the piston assembly 200 to be in a balanced state.

[0102] In an embodiment, the second elastic member 320 is a compression spring and is sleeved on the outer periphery of the plug rod 210.

[0103] The pair of second elastic members 320 are respectively located on both sides of the partition portion 110 along the movement direction of the piston assembly 200; further, one end of the pair of second elastic members 320 respectively abuts against the guide sleeve 112, and the other end respectively abuts against the first piston 220 and the second piston 230; still further, the guide sleeve 112 has a first limiting surface 1121 and a second limiting surface 1122, the first limiting surface 1121 and the second limiting surface 1122 are arranged opposite to each other along the axial direction of the plug rod 210; one end of the pair of second elastic members 320 respectively abuts against the first limiting surface 1121 and the second limiting surface 1122. As an example, the first elastic member 310 is sleeved on the outer periphery of the second elastic member 320.

[0104] In an embodiment, the first segment 112a has the first limiting surface 1121 at one end thereof which is opposite to the second segment 112b, and the second segment 112b has the second limiting surface 1122 at one end thereof which is opposite to the first segment 112a.

[0105] When the piston assembly 200 blocks one of the first valve port 102a and the second valve port 102b, the second elastic force provided by the second elastic member 320 to the piston assembly 200 is greater than the first elastic force provided by the first elastic member 310 to the piston assembly 200.

[0106] As an example, when the piston assembly 200 blocks one of the first valve port 102a and the second valve port 102b, the length of the pair of second elastic members 320 is respectively L3 and L4, L3 is greater than L4, the free length of the second elastic member 320 is L”, L4 < L” < (L3 + L4) / 2, and L’ ≥ L1. Wherein, L” can be less than L’.

[0107] It should be noted that, as shown in FIG. 15, the curve 2 (L2 < L’ ≤ (L1 + L2) / 2) has a stroke (for example, 40% ~ 60% of the horizontal coordinate) with zero elastic force, and in this interval, the piston assembly 200 is prone to unstable and up-and-down swinging due to zero elastic force, thereby causing noise vibration. When L’ ≥ L1, the piston assembly 200 is always in contact with the pair of second elastic members 320, the pair of second elastic members 320 supports the piston assembly 200, and the piston assembly 200 stably operates throughout the process and does not swing.

[0108] In addition, the elastic resultant force corresponding to curve 1 is greater than the elastic resultant force corresponding to curve 2 in the same abscissa in FIG. 15, so that the piston assembly 200 is subjected to a greater elastic force in the entire movement formation, which is not conducive to improving the action capability.

[0109] Based on this, the switching valve of the embodiment of the present disclosure is provided with a pair of first elastic members 310 and a pair of second elastic members 320, the free length of the first elastic member 310 is designed as L'≥L1, the free length of the second elastic member 320 is designed as L4<L''<(L3+L4) / 2, and the elastic resultant forces of the pair of first elastic members 310 and the pair of second elastic members 320 form two curves respectively in the entire movement stroke of the piston assembly 200, and the two curves form a curve as shown in FIG. 16 after coupling. The maximum elastic resultant force that the piston assembly 200 is subjected to in the entire movement stroke in FIG. 16 is equal to the maximum elastic force that the piston assembly 200 is subjected to in the entire movement stroke shown in FIG. 4, and when the piston assembly blocks one of the first valve port and the second valve port, the second elastic force provided by the second elastic member to the piston assembly is greater than the first elastic force provided by the first elastic member to the piston assembly, so that the piston assembly 200 moves to the position where the balance state is located under the action of the greater second elastic force. That is, the second elastic member with greater elastic force effectively improves the action capability of the valve, and the greater elastic force of the second elastic member can smoothly open the first valve port 102a.

[0110] As can be seen from FIG. 16, in the interval of 10% to 90% of the abscissa, only the elastic resultant force provided by the pair of first elastic members 310 acts on the piston assembly 200, and the elastic resultant force is small, so that the resistance to be overcome during valve switching is small, thereby effectively improving the action capability of the valve; in addition, L'≥L1, and the pair of first elastic members can stabilize the piston assembly to prevent the piston assembly 200 from generating noise vibration.

[0111] Therefore, the switching valve of the embodiment of the present disclosure can take into account the problems of improving the action capability of the valve and preventing the piston assembly 200 from generating noise vibration.

[0112] It can be understood that the design of the embodiment can be applied to the switching valve of any of the above-mentioned embodiments, which will not be listed one by one here.

[0113]

Embodiment Seven

[0114] As shown in FIGS. 17 and 18, the seventh embodiment of the present disclosure has the same parts as the above-mentioned embodiments, which will not be repeated, and the different parts are as follows:

[0115] The switching valve of the embodiment of the present disclosure comprises a valve body 100, a piston assembly 200, and an elastic member, wherein the elastic member comprises a pair of first elastic members 310. The valve body 100 has an inner cavity 101, wherein the inner cavity 101 has a first passage 102 and a second passage 103; the piston assembly 200 is movably arranged in the inner cavity 101 and used for blocking the first passage 102 and / or the second passage 103; wherein the first passage 102 and the second passage 103 are arranged along the movement direction of the piston assembly 200. The elastic member is used for enabling the piston assembly 200 to be in a balanced state. When the piston assembly 200 is in the balanced state, the piston assembly 200 simultaneously blocks the first passage 102 and the second passage 103.

[0116] The switching valve of the embodiment of the present disclosure, when the piston assembly 200 is in the balanced state, the first passage 102 and the second passage 103 are both in a closed state, at this time, the fluid driving force applied to the piston assembly 200 by throttling when the fluid passes through the switching valve is the largest, thus the action ability of the switching valve is maximized, and the reliability of the action of the switching valve is improved. For example, the piston assembly can be switched from a state of blocking the first passage 102 and opening the second passage 103 to a state of blocking the second passage 103 and opening the first passage 102. In the process of switching from the state of blocking the first passage 102 and opening the second passage 103 to the state of blocking the first passage 102 and blocking the second passage 103, the force for driving the piston assembly 200 to move is the elastic force of the elastic member and the fluid force. When switching from the state of blocking the first passage 102 and blocking the second passage 103 to the state of blocking the second passage 103 and opening the first passage 102, the elastic force of the elastic member needs to be overcome, and at this time, the fluid driving force generated by throttling due to the blocking of the second passage 103 can just overcome the elastic force of the elastic member. In an embodiment, the elastic member comprises a pair of first elastic members 310. For the convenience of description, the pair of first elastic members 310 are defined as a first elastic part 310a and a second elastic part 310b, respectively. The pair of first elastic members 310 can ensure the stability of the piston assembly 200 in the balanced state. In addition, the first elastic part 310a is used for providing the piston assembly 200 with a first elastic force for moving toward the position of blocking the second passage 103; and the second elastic part 310b is used for providing the piston assembly 200 with a second elastic force for moving toward the position of blocking the first passage 102.

[0117] As shown in FIG. 18, the inner cavity 101 is provided with a partition 110, wherein the partition 110 divides the inner cavity 101 into the first passage 102 and the second passage 103; the first elastic part 310a is located in the first passage 102, and the second elastic part 310b is located in the second passage 103.

[0118] The piston assembly 200 comprises a plug rod 210, a first piston 220 and a second piston 230. The first piston 220 is connected to an axial end of the plug rod 210 and used to block the first channel 102. One end of a first elastic part 310a is in abutment with the partition 110, and the other end is in abutment with the first piston 220. The second piston 230 is connected to the other axial end of the plug rod 210 and used to block the second channel 103. One end of a second elastic part 310b is in abutment with the partition 110, and the other end is in abutment with the second piston 230.

[0119] In the embodiment of the present disclosure, one end of the first elastic part 310a is in abutment with the partition 110, and the other end is in abutment with the first piston 220. The first elastic force provided by the first elastic part 310a is used to make the first piston 220 have a tendency to open the first channel 102. One end of the second elastic part 310b is in abutment with the partition 110, and the other end is in abutment with the second piston 230. The second elastic force provided by the second elastic part 310b is used to make the second piston 230 have a tendency to open the second channel 103.

[0120] In an embodiment, the first elastic part 310a and the second elastic part 310b can be compression springs and are sleeved on the outer periphery of the plug rod 210.

[0121] The first piston 220 comprises a first body 221 and a first sealing ring 222. The first body 221 is connected to the axial end of the plug rod 210, and the first sealing ring 222 is sleeved on the outer periphery of the first body 221 and used to seal with the first channel 102. The first body 221 and the plug rod 210 can be connected by screwing, interference fit, welding or the like.

[0122] The second piston 230 comprises a second body 231 and a second sealing ring 232. The second body 231 is connected to the other axial end of the plug rod 210, and the second sealing ring 232 is sleeved on the outer periphery of the second body 231 and used to seal with the second channel 103. The second body 231 and the plug rod 210 can be connected by screwing, interference fit, welding or the like.

[0123] The partition 110 comprises a partition ring 111 and a guide sleeve 112. The partition ring 111 is fixedly connected to the cavity wall of the inner cavity 101 and surrounds the outer periphery of the guide sleeve 112. The plug rod 210 is movably arranged in the guide sleeve 112.

[0124] In the embodiment of the present disclosure, the plug rod 210 and the guide sleeve 112 are in guiding cooperation, which improves the stability of the movement of the plug rod 210 and further improves the reliability of the valve action.

[0125] As shown in FIG. 18, the guide sleeve 112 has a first limiting surface 1121 and a second limiting surface 1122 at two axial ends thereof, and the first limiting surface 1121 and the second limiting surface 1122 are arranged opposite to each other along the movement direction of the piston assembly 200. The first limiting surface 1121 is configured to abut against the first piston 220 of the piston assembly 200 when the piston assembly 200 blocks the first passage 102 and moves to a first limit position, and the second limiting surface 1122 is configured to abut against the second piston 230 of the piston assembly 200 when the piston assembly 200 blocks the second passage 103 and moves to a second limit position. In other words, when the piston assembly 200 is located at the first limit position, the first limiting surface 1121 abuts against the first piston 220, and the second passage 103 is in a maximum open state; when the piston assembly 200 is located at the second limit position, the second limiting surface 1122 abuts against the second piston 230, and the first passage 102 is in a maximum open state.

[0126] In the embodiments of the present disclosure, by arranging the first limiting surface 1121 and the second limiting surface 1122, the piston assembly 200 can be limited at the first limit position and the second limit position.

[0127] As shown in FIG. 18, the partition ring 111 has a first ring surface 1111 and a second ring surface 1112, and the first ring surface 1111 and the second ring surface 1112 are arranged opposite to each other along the movement direction of the piston assembly 200; a portion of the guide sleeve 112 extending out of the first ring surface 1111 is defined as a first segment 112a, and the first elastic portion 310a is sleeved on the outer periphery of the first segment 112a; a portion of the guide sleeve 112 extending out of the second ring surface 1112 is defined as a second segment 112b, and the second elastic portion 310b is sleeved on the outer periphery of the second segment 112b.

[0128]

Embodiment Eight

[0129] The eighth embodiment of the present disclosure is the same as the above-mentioned embodiments, and the difference lies in that:

[0130] As shown in FIGS. 19 and 20, the switching valve of the embodiments of the present disclosure includes a valve body 10c and a piston assembly 20c. The valve body 10c includes an inner cavity 11c having a first valve port 101c and a second valve port 102c; the piston assembly 20c is movably arranged in the inner cavity 11c, and includes a plug rod 21c, a first piston 22c and a second piston 23c, the first piston 22c and the second piston 23c are respectively connected to opposite ends of the plug rod 21c, the first valve port 101c and the second valve port 102c are arranged at intervals along the movement direction of the piston assembly 20c, the first piston 22c is used for blocking the first valve port 101c, and the second piston 23c is used for blocking the second valve port 102c; wherein at least one of the first piston 22c and the second piston 23c is injection molded.

[0131] The injection-molded first piston 22c and / or the injection-molded second piston 23c of the switching valve of the present disclosure are advantageous for controlling the weight and cost of the switching valve. In addition, the injection-molded first piston 22c and / or the injection-molded second piston 23c can reduce the friction and impact noise with the inner wall of the inner cavity 11c and the first valve port 101c and the second valve port 102c during the movement of the piston assembly 20c in the inner cavity 11c, thereby improving the mute effect of the switching valve.

[0132] Specifically, referring to FIGS. 19-23, the valve body 10c can include a valve seat 12c having an inner cavity 11c and a valve cover 13c connected to the valve seat 12c. The valve cover 13c is made of a metal material, and the valve seat 12c can be made of a metal material or a plastic material. The valve seat 12c made of a plastic material is light and advantageous for saving cost.

[0133] In an embodiment, the valve cover 13c has a first opening 131c passing through the valve cover 13c to communicate with the inner cavity 11c, and the valve seat 12c has a second opening 121c passing through the valve seat 12c to communicate with the inner cavity 11c. When the first piston 22c blocks the first valve port 101c, the first opening 131c and the second opening 121c are not communicated. When the second piston 23c blocks the second valve port 102c, the first opening 131c and the second opening 121c are communicated. In some embodiments, the first opening 131c can serve as a fluid inlet of the switching valve and can be communicated with an outlet of the compressor. The second opening 121c can serve as a fluid outlet of the switching valve and can be communicated with an inlet of the compressor. An end of the valve seat 12c away from the valve cover 13c can serve as another fluid inlet of the switching valve and can be communicated with an inlet of the compressor. When the first piston 22c blocks the first valve port 101c, the second opening 121c 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.

[0134] In another embodiment, the valve seat 12c has a first opening 131c passing through the valve seat 12c to communicate with the inner cavity 11c, and the valve seat 12c has a second opening 121c passing through the valve seat 12c to communicate with the inner cavity 11c. That is, the first opening 131c and the second opening 121c are both provided on the valve seat 12c. When the first piston 22c blocks the first valve port 101c, the first opening 131c and the second opening 121c are not communicated. When the second piston 23c blocks the second valve port 102c, the first opening 131c and the second opening 121c are communicated.

[0135] In an exemplary embodiment of the present disclosure, referring to FIGS. 19 and 20, the valve seat 12c has a third opening 122c which is arranged along the radial direction of the valve seat 12c and communicates with the inner cavity 11c; the valve cover 13c extends into the third opening 122c or is sleeved on the third opening 122c. To facilitate the connection between the valve cover 13c and the valve seat 12c, the valve seat 12c is provided with a riveting portion at one end of the third opening 122c, and the riveting portion is connected with the valve cover 13c. Alternatively, the valve cover 13c is provided with a riveting portion at one end close to the valve seat 12c, and the riveting portion is connected with the valve seat 12c.

[0136] In an exemplary embodiment of the present disclosure, referring to FIG. 20, the valve cover 13c has a fitting section 132c extending into the third opening 122c, and the outer circumferential surface of the fitting section 132c is in interference fit with the inner circumferential surface of the third opening 122c. For example, the outer diameter of the fitting section 132c before the valve cover 13c is combined with the valve seat 12c is greater than the outer diameter of the fitting section 132c after the valve cover 13c is combined with the valve seat 12c. Alternatively, referring to FIG. 21, the valve cover 13c has a fitting section 132c sleeved on the third opening 122c, and the inner circumferential surface of the fitting section 132c is in interference fit with the outer circumferential surface of the valve seat at the position of the third opening 122c.

[0137] In an exemplary embodiment of the present disclosure, the valve cover 13c and the valve seat 12c can also be connected in a threaded connection manner, or welded and fixed as a whole, or in some exemplary embodiments, the valve cover 13c and the valve seat 12c can also be integrally formed.

[0138] In an exemplary embodiment of the present disclosure, referring to FIGS. 19 to 22, the elastic member includes a first elastic portion 31c and a second elastic portion 32c, and the inner cavity 11c is provided with a partition portion 125c which separates the first valve port 101c and the second valve port 102c; the first elastic portion 31c is sleeved on the plug rod 21c and located between the first piston 22c and the partition portion 125c, and the opposite ends of the first elastic portion 31c abut against the first piston 22c and the partition portion 125c, respectively; the second elastic portion 32c is sleeved on the plug rod 21c and located between the second piston 23c and the partition portion 125c, and the opposite ends of the second elastic portion 32c abut against the second piston 23c and the partition portion 125c, respectively.

[0139] The first elastic part 31c and the second elastic part 32c are used to maintain the stability of the piston assembly 20c in the balanced state. The balanced state in the present disclosure refers to the state that the piston assembly 20c is kept stationary relative to the valve body 10c under no fluid impact. The first elastic part 31c is used to apply an elastic force to the piston assembly 20c to move the second piston 23c to the position of blocking the second valve port 102c, and the second elastic part 32c is used to apply an elastic force to the piston assembly 20c to move the first piston 22c to the position of blocking the first valve port 101c. In an exemplary embodiment, when the piston assembly 20c is in the balanced state, the resultant force of the elastic forces of the first elastic part 31c and the second elastic part 32c acting on the piston assembly 20c and the gravity of the piston assembly 20c is zero.

[0140] In an exemplary embodiment of the present disclosure, the first elastic part 31c can be a compression spring, and the second elastic part 32c can be a compression spring.

[0141] Please refer to FIGS. 19-21. In an exemplary embodiment of the present disclosure, the valve seat 12c includes a first valve sleeve 123c and a second valve sleeve 124c coaxially arranged and connected. The valve cover 13c is connected with the first valve sleeve 123c, the second valve sleeve 124c is connected with the first valve sleeve 123c, and the two ends of the second valve sleeve 124c form the first valve port 101c and the second valve port 102c, respectively. The first valve sleeve 123c and the second valve sleeve 124c can be integrally formed. Exemplarily, the first opening 131c can be arranged on the peripheral side wall of the first valve sleeve 123c, and the second opening 121c can be arranged on the second valve sleeve 124c. In other embodiments, the valve seat 12c can not include the first valve sleeve 123c but have the second valve sleeve 124c, and the first opening 131c can be arranged on the valve cover 13c.

[0142] In an exemplary embodiment of the present disclosure, the valve seat 12c can further include a third valve sleeve coaxially arranged with the second valve sleeve 124c and connected to the side of the second valve sleeve 124c away from the first valve sleeve 123c. The first valve sleeve 123c, the second valve sleeve 124c, and the third valve sleeve can be integrally formed. The fluid inlet at the end of the valve seat 12c away from the valve cover 13c can be arranged on the peripheral side wall of the third valve sleeve.

[0143] In an exemplary embodiment of the present disclosure, referring to FIG. 20, the maximum value of the outer diameter of the second valve sleeve 124c is less than the maximum value of the outer diameter of the first valve sleeve 123c. Exemplarily, the maximum value of the outer diameter of the second valve sleeve 124c can be less than the maximum value of the outer diameter of the first valve sleeve 123c, and the maximum value of the outer diameter of the third valve sleeve can be less than the maximum value of the outer diameter of the first valve sleeve 123c.

[0144] In one example embodiment of the present disclosure, referring to FIG. 19, the first piston 22c comprises a first body 221c and a first sealing ring 222c sleeved on the outer periphery of the first body 221c. When the first piston 22c blocks the first valve port 101c, the first sealing ring 222c is compressed between the first body 221c and the first valve port 101c to seal the first valve port 101c. The second piston 23c comprises a second body 231c and a second sealing ring 232c sleeved on the outer periphery of the second body 231c. When the second piston 23c blocks the second valve port 102c, the second sealing ring 232c is used to be compressed between the second body 231c and the inner wall of the second valve port 102c to seal the second valve port 102c. The first sealing ring 222c and the second sealing ring 232c can be made of elastic material, such as rubber. The first body 221c and the plug rod 21c can be connected by screwing, interference fit, welding, injection molding, etc. The second body 231c and the plug rod 21c can be connected by screwing, interference fit, welding, injection molding, etc.

[0145] Those skilled in the art should understand that the "at least one of the first piston 22c and the second piston 23c is injection molded" in the present disclosure means that at least one of the first body 221c and the second body 231c is injection molded, and does not mean that the first sealing ring 222c is also injection molded with the first body 221c, or the second sealing ring 232c is also injection molded with the second body 231c.

[0146] Referring to FIGS. 20 and 21, the valve body 10c has a first end face 1241c, preferably the second valve sleeve 124c has the first end face 1241c, the first end face 1241c is located at one end of the first valve port 101c close to the valve cover 13c, the first piston 22c has a first limiting face 223c for abutting against the first end face 1241c when the first piston 22c blocks the first valve port 101c. When the first limiting face 223c abuts against the first end face 1241c, the first piston 22c moves to the limit position in the direction of the first valve port 101c, and the first body 221c and the compressed first sealing ring 222c seal and block the first valve port 101c. For example, the valve body 10c has a second end face 1242c, preferably the second valve sleeve 124c has the second end face 1242c, the second end face 1242c is located at one end of the second valve port 102c away from the valve cover 13c, the second piston 23c has a second limiting face 233c for abutting against the second end face 1242c when the second piston 23c blocks the second valve port 102c. When the second limiting face 233c abuts against the second end face 1242c, the second piston 23c moves to the limit position in the direction of the second valve port 102c, and the second body 231c and the compressed second sealing ring 232c seal and block the second valve port 102c.

[0147] In an exemplary embodiment of the present disclosure, the plug rod 21c can comprise a metal material, for example, the plug rod 21c does not comprise a non-metal material. The first piston 22c can be made of plastic. The first piston 22c can be integrally injection molded with the plug rod 21c as a metal insert. The second piston 23c can comprise a metal material, formed by mechanical processing, and can be mechanically connected with the plug rod 21c. The second piston 23c can also be the same metal material as the plug rod 21c. Or the second piston 23c can be made of plastic.

[0148] For another example, the plug rod 21c is made of plastic, the first piston 22c can be made of plastic, and the plug rod 21c can be integrally injection molded with the first piston 22c. The second piston 23c can comprise a metal material, formed by mechanical processing, and can be mechanically connected with the plug rod 21c. For another example, the first piston 22c and the second piston 23c can both be made of plastic.

[0149] The valve cover 13c can be made of a metal material, for example, comprising an aluminum alloy. For example, the valve cover 13c is made of an aluminum alloy material. In an exemplary embodiment of the present disclosure, the valve cover 13c which can be made of an aluminum alloy material can be matched with the injection molded valve seat 12c, or the valve cover 13c which can be made of an aluminum alloy material can be matched with the valve seat 12c made of a metal material.

[0150] For example, in an embodiment, the valve cover 13c, the valve seat 12c, and the plug rod 21c can all be made of an aluminum alloy material. The valve cover 13c and the valve seat 12c can be connected by thread connection, welding, interference fit, etc. The plug rod 21c, the first body 221c, and the second body 231c can be respectively processed and formed, and then connected by screwing, interference fit, welding, injection molding, etc. Alternatively, the first body 221c and the plug rod 21c are integrally formed, and the second body 231c is mechanically connected with the plug rod 21c; or the second body 231c and the plug rod 21c are integrally formed, and the first body 221c is mechanically connected with the plug rod 21c; or the first body 221c and the second body 231c are both integrally formed with the plug rod 21c. Referring to FIG. 21, the first opening 131c is provided on the valve cover 13c, so that the length of the valve seat 12c can be relatively shortened, facilitating the metal mechanical processing of the valve seat 12c.

[0151] For example, in an embodiment, the valve cover 13c and the plug rod 21c can be made of aluminum alloy material. The valve seat 12c is injection molded by plastic material, and the valve cover 13c and the valve seat 12c can be riveted or connected by interference fit. The plug rod 21c, the first body 221c and the second body 231c can be formed and connected in the manner as described in the foregoing embodiment. Referring to FIG. 20, the first opening 131c can be provided on the valve seat 12c, specifically on the first valve sleeve 123c, so that the length of the valve cover 13c can be relatively shortened, facilitating the metal machining of the valve cover 13c.

[0152] For example, in an embodiment, the valve cover 13c is made of metal material, for example, can be made of aluminum alloy material. The valve seat 12c is injection molded by plastic material, and the valve cover 13c and the valve seat 12c can be riveted or connected by interference fit. The plug rod 21c is made of metal material, for example, can be made of aluminum alloy material. The first piston 22c can be made of plastic material, and the first piston 22c is integrally injection molded with the plug rod 21c as an insert. The second piston 23c includes metal material and is formed by machining and can be mechanically connected with the plug rod 21c. Alternatively, the second piston 23c can be made of plastic material, and the second piston 23c is integrally injection molded with the plug rod 21c as an insert. The first piston 22c includes metal material and is formed by machining and can be mechanically connected with the plug rod 21c. Referring to FIG. 20, the first opening 131c can be provided on the valve seat 12c, specifically on the first valve sleeve 123c, so that the length of the valve cover 13c can be relatively shortened, facilitating the metal machining of the valve cover 13c.

[0153] In an exemplary embodiment of the present disclosure, a throttling passage is formed between the piston assembly 20c and the valve port, wherein the ratio of the maximum flow area of the throttling passage to the maximum flow area of the valve port is ≤3 / 10 when the piston assembly 20c is in the balanced state. The throttling passage enables the piston assembly 20c to generate a relatively large driving force 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.

[0154] 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 throttling passage refers to the opening area of the throttling passage.

[0155] For example, the throttling passage includes a first throttling passage 111c formed between the outer circumferential surface of the first piston 22c and the first valve port 101c, and the ratio of the maximum flow area of the first throttling passage 111c to the maximum flow area of the first valve port 101c is ≤ 3 / 10. For example, the throttling passage can also include a second throttling passage 112c formed between the outer circumferential surface of the second piston 23c and the second valve port 102c, and the ratio of the maximum flow area of the second throttling passage 112c to the maximum flow area of the second valve port 102c is ≤ 3 / 10. The first throttling passage 111c and the second throttling passage 112c can improve the action capability of the switching valve during operation and reduce the action pressure difference.

[0156] Referring to FIGS. 20 and 21, the first valve port 101c has an inner conical surface that narrows in the direction of the second valve sleeve 124c. The first sealing ring 222c is compressed between the first body 221c and the first valve port 101c to seal the first valve port 101c. When the first valve port 101c is sealed, the inner conical surface can constitute the inner wall of the first throttling passage 111c. During the process of blocking the first valve port 101c by the first piston 22c, the flow area of the first throttling passage 111c gradually decreases, the fluid force generated by throttling gradually increases as the first piston 22c gradually blocks the first valve port 101c, and the elastic force of the first elastic portion 31c gradually increases. In this way, the gradually increasing elastic force as the first valve port 101c closes can be overcome to further improve the valve action capability. In addition, the inner conical surface narrows in the direction of the second valve sleeve 124c, which can also avoid the first sealing ring 222c being excessively compressed due to the first throttling passage 111c being too narrow, thereby preventing the piston assembly 20c from being stuck.

[0157] For example, the second valve port 102c also has an inner conical surface that narrows in the direction of the second valve sleeve 124c. The second sealing ring 232c is compressed between the second body 231c and the inner wall of the second valve port 102c to seal the second valve port 102c. When the second valve port 102c is sealed, the inner conical surface can constitute the second throttling passage 112c. During the process of blocking the second valve port 102c by the second piston 23c, the flow area of the second throttling passage 112c gradually decreases, the fluid force generated by throttling gradually increases as the second piston 23c gradually blocks the second valve port 102c, and the elastic force of the second elastic portion 32c gradually increases. In this way, the gradually increasing elastic force as the second valve port 102c closes can be overcome to further improve the valve action capability. In addition, the inner conical surface narrows in the direction of the second valve sleeve 124c, which can also avoid the second sealing ring 232c being excessively compressed due to the second throttling passage 112c being too narrow, thereby preventing the piston assembly 20c from being stuck.

[0158] Please refer to FIGS. 20-21, the valve cover 13c is provided with a guide hole 133c, the plug rod 21c passes through the first piston 22c from one end connected with the first piston 22c and extends into the guide hole 133c, the plug rod 21c is movably arranged in the guide hole 133c to guide the reciprocating movement of the piston assembly 20c and can support the plug rod 21c to increase the support rigidity of the plug rod 21c.

[0159] In an exemplary embodiment of the present disclosure, the valve body 10c is installed into a mounting seat (not shown in the figure) as an insertion valve. The valve body 10c is externally provided with a limiting table, and the valve body 10c is externally 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 10c, the limiting table prevents the valve body 10c from moving downward, and the threaded connection part can prevent the valve body from moving upward.

[0160] Another aspect of the present disclosure also provides a refrigeration system comprising the switching valve of any one of the above. Since the refrigeration system of the present disclosure comprises the switching valve of any one of the above, the refrigeration system of the present disclosure comprises all the advantages and beneficial effects of any one of the above, which will not be repeated here.

[0161] It can be understood that the various embodiments / embodiments provided by the present disclosure can be combined with each other without contradiction, which will not be illustrated one by one here.

[0162] In the embodiments of the present disclosure, the terms "first", "second", "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; the term "multiple" refers to two or more, unless otherwise explicitly limited. The terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, "connecting" can be fixed connection, can also be detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0163] In the description of the embodiments of the present disclosure, it should be understood that the terms "upper", "lower", "left", "right", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings, and are only used for the purpose of facilitating the description of the embodiments of the present disclosure and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or units referred to must have a particular direction, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present disclosure.

[0164] In the description of the application, the terms "one embodiment", "some embodiments", "certain embodiments", etc. indicate that the described features, structures, materials, or characteristics are included in at least one embodiment of the application. The illustrative examples of the above terms are not necessarily mutually exclusive and are not necessarily mutually inclusive. Moreover, the described features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0165] The above merely provides preferred embodiments of the application, and is not intended to limit the application. The application can have various modifications and changes without departing from the spirit and principles thereof. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A switching valve, wherein, include: Valve body, including an inner cavity with a valve port; A piston assembly is movably disposed within the inner cavity for sealing or opening the valve port; An elastic element is used to keep the piston assembly in a balanced state; the balanced state means that the piston assembly remains stationary relative to the valve body under no fluid impact. A throttling channel communicating with the valve port is formed between the piston assembly and the cavity wall of the inner cavity; wherein, when the piston assembly is in the equilibrium state, the ratio of the maximum flow area of ​​the throttling channel to the maximum flow area of ​​the valve port is ≤3 / 10.

2. The switching valve according to claim 1, wherein, When the piston assembly is in the equilibrium state, the throttling channel is formed between the inner circumferential surface of the valve port and the piston assembly.

3. The switching valve according to claim 2, wherein, The piston assembly has a second outer conical surface for sealing and engaging with the valve port.

4. The switching valve according to claim 2, wherein, The piston assembly includes a first piston plate for extending into the valve port; The piston assembly further includes a second piston plate and a third piston plate, the second piston plate being sandwiched between the first piston plate and the third piston plate, and the second piston plate having a second outer conical surface that seals with the valve port.

5. The switching valve according to claim 1, wherein, The valve body includes a first valve sleeve and a second valve sleeve arranged coaxially, and the second valve sleeve has the valve port; The throttling channel is formed between the inner circumferential surface of the first valve sleeve and the piston assembly and / or between the inner circumferential surface of the second valve sleeve and the piston assembly.

6. The switching valve according to claim 5, wherein, During the process of the piston assembly blocking the valve port, the flow area of ​​the throttling channel formed between the inner circumferential surface of the first valve sleeve and the piston assembly gradually decreases.

7. The switching valve according to claim 6, wherein, The inner circumferential surface of the first valve sleeve has an inner conical surface, or the outer circumferential surface of the piston assembly has a first outer conical surface.

8. The switching valve according to claim 1, wherein, The valve port includes a first valve port and a second valve port. One end of the piston assembly is sealed to the first valve port, and the other end is sealed to the second valve port. The maximum flow area of ​​the first valve port is S11, and the maximum flow area of ​​the second valve port is S12. When the piston assembly is in the equilibrium state, the throttling channel includes a first throttling channel communicating with the first valve port and a second throttling channel communicating with the second valve port. The maximum flow area of ​​the first throttling channel is S21, and the maximum flow area of ​​the second throttling channel is S22; S21 / S11≤3 / 10, S22 / S12≤3 / 10.

9. The switching valve according to claim 8, wherein, The first throttling channel is located outside the first valve port, and the fluid flows through the first throttling channel to the first valve port; the second throttling channel is located outside the second valve port, and the fluid flows through the second throttling channel to the second valve port.

10. The switching valve according to claim 8 or 9, wherein, When the piston assembly is in the equilibrium state, the throttling channel further includes a third throttling channel communicating with the first valve port and a fourth throttling channel communicating with the second valve port. The maximum flow area of ​​the third throttling channel is S31, and the maximum flow area of ​​the fourth throttling channel is S32. Part of the piston assembly extends into the first valve port and forms the third throttling channel between itself and the orifice wall of the first valve port. Part of the piston assembly extends into the second valve port and forms the fourth throttling channel between itself and the orifice wall of the second valve port. Furthermore, S31 / S11≤3 / 10, S32 / S12≤3 / 10.

11. The switching valve according to claim 1, wherein, The elastic element includes a first elastic part and a second elastic part, and the valve port includes a first valve port and a second valve port; The inner cavity is provided with a partition, which separates the first valve port and the second valve port; The first elastic portion and the second elastic portion are respectively located on both sides of the separator along the movement direction of the piston assembly. One end of the first elastic portion abuts against the separator and the other end abuts against one end of the piston assembly; one end of the second elastic portion abuts against the separator and the other end abuts against the other end of the piston assembly.

12. The switching valve according to claim 11, wherein, The partition includes a partition ring and a guide sleeve. The partition ring is fixedly connected to the cavity wall of the inner cavity and surrounds the outer periphery of the guide sleeve. The piston assembly is movably inserted into the guide sleeve.

13. The switching valve according to claim 1, wherein, The piston assembly includes a piston rod and a piston, the piston being connected to the piston rod for sealing the valve port; The valve body includes a valve cover and a valve seat connected together. The valve seat has an inner cavity, and the valve cover has a guide portion. The plug rod is guided and engaged with the guide portion.

14. The switching valve according to claim 13, wherein, The piston includes a first piston and a second piston arranged axially spaced along the piston rod, and the valve port includes a first valve port and a second valve port. The first piston is used to block or open the first valve port, and the second piston is used to block or open the second valve port. The piston rod has a guide section located on the side of the first piston facing away from the second piston, and the guide section is guided and engaged with the guide portion.

15. The switching valve according to claim 1, wherein, The inner cavity has a first channel and a second channel; the piston assembly is used to block the first channel and / or the second channel; When the piston assembly is in the equilibrium state, the piston assembly simultaneously blocks the first channel and the second channel.

16. The switching valve according to claim 15, wherein, The inner cavity is provided with a partition, which divides the inner cavity into the first channel and the second channel; The elastic element includes a first elastic portion and a second elastic portion; The first elastic part is located within the first channel, with one end abutting against the partition and the other end abutting against one end of the piston assembly; the second elastic part is located within the second channel, with one end abutting against the partition and the other end abutting against the other end of the piston assembly; the first elastic part and the second elastic part are used to keep the piston assembly in a balanced state.

17. The switching valve according to claim 16, wherein, The partition has a guide hole that extends through the partition along the movement direction of the piston assembly; the piston assembly is movably disposed within the guide hole.

18. The switching valve according to claim 17, wherein, The partition includes a partition ring and a guide sleeve. The partition ring is fixedly connected to the cavity wall of the inner cavity and surrounds the outer periphery of the guide sleeve. The guide sleeve has the guide hole.

19. The switching valve according to claim 18, wherein, The guide sleeve has a first limiting surface and a second limiting surface at both axial ends, and the first limiting surface and the second limiting surface are arranged opposite to each other along the movement direction of the piston assembly; The first limiting surface is configured to abut against the piston assembly when the piston assembly blocks the first channel and moves to the first extreme position, and the second limiting surface is configured to abut against the piston assembly when the piston assembly blocks the second channel and moves to the second extreme position.

20. The switching valve according to claim 18, wherein, The separator ring has a first annular surface and a second annular surface, and the first annular surface and the second annular surface are arranged opposite to each other along the movement direction of the piston assembly; The portion of the guide sleeve extending beyond the first annular surface is defined as the first segment, and the first elastic part is sleeved on the outer periphery of the first segment; the portion of the guide sleeve extending beyond the second annular surface is defined as the second segment, and the second elastic part is sleeved on the outer periphery of the second segment.

21. The switching valve according to claim 16, wherein, The piston assembly includes: A stopper rod is movably inserted through the partition. A first piston, connected to one axial end of the piston rod, is used to block the first channel; the other end of the first elastic part abuts against the first piston; and The second piston is connected to the other axial end of the piston rod and is used to block the second channel. The other end of the second elastic part abuts against the second piston.

22. The switching valve according to claim 21, wherein, The first elastic part and the second elastic part are sleeved on the outer periphery of the plug rod.

23. The switching valve according to claim 21, wherein, The first piston includes a first body and a first sealing ring. The first body is connected to one axial end of the piston rod, and the first sealing ring is sleeved on the outer periphery of the first body for sealing cooperation with the first channel. The second piston includes a second body and a second sealing ring. The second body is connected to the other axial end of the piston rod, and the second sealing ring is sleeved on the outer periphery of the second body for sealing cooperation with the second channel.

24. The switching valve according to claim 1, wherein, The valve port includes a first valve port and a second valve port; The piston assembly includes a piston rod, a first piston, and a second piston. The first piston and the second piston are respectively connected to opposite ends of the piston rod. The first valve port and the second valve port are arranged at intervals along the movement direction of the piston assembly. The first piston is used to block the first valve port, and the second piston is used to block the second valve port. Wherein, at least one of the first piston and the second piston is injection molded.

25. The switching valve according to claim 24, wherein, The plunger rod is made of metal, and the first piston is made of plastic; the first piston is integrally injection molded with the plunger rod as a metal insert; or, the plunger rod is made of plastic, the first piston is made of plastic, and the plunger rod and the first piston are integrally injection molded.

26. The switching valve according to claim 25, wherein, When the stopper rod comprises a metal material, the stopper rod is fixedly connected to the second piston, which comprises a metal material; or, the stopper rod is fixedly connected to the second piston, which comprises a plastic material. When the stopper rod comprises a plastic material, the stopper rod is fixedly connected to the second piston, which comprises a metal material; or, the stopper rod is fixedly connected to the second piston, which comprises a plastic material.

27. The switching valve according to claim 24, wherein, When the stopper rod is made of metal, the first piston is made of metal and the second piston is made of plastic. The first piston and the stopper rod are fixedly connected, and the second piston is integrally injection molded with the stopper rod as a metal insert. Alternatively, when the stopper rod is made of plastic, the first piston is made of metal and the second piston is made of plastic. The first piston and the stopper rod are fixedly connected, and the second piston is integrally injection molded with the stopper rod.

28. The switching valve according to claim 24, wherein, The valve body includes a valve seat and a valve cover, the valve seat having the inner cavity, and the valve cover being connected to the valve seat; The valve cover is made of metal, and the valve seat is made of metal or plastic.

29. The switching valve according to claim 28, wherein, The valve seat has a third opening, which is arranged radially along the valve seat and communicates with the inner cavity; The valve cover portion extends into the third opening or the valve cover portion is fitted outside the third opening; The valve seat has a riveting part at one end with the third opening, and the riveting part is connected to the valve cover; or the valve cover has a riveting part at one end near the valve seat, and the riveting part is connected to the valve seat.

30. The switching valve according to claim 28, wherein, The valve seat has a third opening, which is arranged radially along the valve seat and communicates with the inner cavity; The valve cover has a fitting section extending into the third opening, the outer peripheral surface of the fitting section being press-fitted with the inner peripheral surface of the third opening; or the valve cover has a fitting section sleeved outside the third opening, the inner peripheral surface of the fitting section being press-fitted with the outer peripheral surface of the third opening.

31. The switching valve according to claim 24, wherein, The elastic element includes a first elastic portion and a second elastic portion. The inner cavity is provided with a partition portion that separates the first valve port and the second valve port. The first elastic portion is sleeved on the stopper rod and located between the first piston and the partition portion. The opposite ends of the first elastic portion abut against the first piston and the partition portion, respectively. The second elastic portion is sleeved on the stopper rod and located between the second piston and the partition portion. The opposite ends of the second elastic portion abut against the second piston and the partition portion, respectively. When the piston assembly is in equilibrium, the resultant force of the elastic force exerted on the piston assembly by the first elastic part and the second elastic part and the gravity of the piston assembly is zero.

32. The switching valve according to claim 24, wherein, The first piston includes a first body and a first sealing ring sleeved on the outer periphery 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 located at the end of the first valve port away from the second valve port. The first piston has a first limiting surface for abutting against the first end face when the first piston blocks the first valve port. The second piston includes a second body and a second sealing ring sleeved on the outer periphery 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 located at the end of the second valve port away from the first valve port. The second piston has a second limiting surface for abutting against the second end face when the second piston blocks the second valve port.

33. The switching valve according to claim 28 or 29, wherein, The valve cover is provided with a guide hole. One end of the plug rod connected to the first piston passes through the first piston and extends into the guide hole. The plug rod is movably disposed within the guide hole.

34. The switching valve according to claim 24, wherein, The switching valve also includes a mounting base; the valve body is provided with a limiting platform and a threaded connection part; after the threaded connection part is threadedly connected to the mounting base, the limiting platform abuts against the mounting base.

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