Switching valve

Abstract

The present application provides a switching valve. The switching valve comprises a main valve and a pilot valve. An annular flange is provided on the side wall of the main valve, and a mounting hole is defined by the annular flange. The pilot valve comprises a valve pipe, the valve pipe comprises a pipe body and a mounting end which are connected to each other, and the mounting end is directly connected or indirectly connected to the annular flange. The mounting end is provided with an end wall, the end wall is provided with a flow channel hole, and the flow channel hole is communicated with a cavity in the main valve.

Description

Switching valve

[0001] The present application claims priority to the patent application No. 2024226597624 filed on October 31, 2024 in the China National Intellectual Property Office and entitled "Switching valve"; the present application claims priority to the patent application No. 2024211032912 filed on May 20, 2024 in the China National Intellectual Property Office and entitled "Switching valve"; the present application claims priority to the patent application No. 2024211065920 filed on May 20, 2024 in the China National Intellectual Property Office and entitled "Switching valve". TECHNICAL FIELD

[0002] The present application relates to the field of valves, in particular, to a switching valve. BACKGROUND

[0003] Switching valves, such as four-way valves, are used to change the direction of fluid flow. The switching valve mainly includes a main valve, a pilot valve, a connecting pipe, a capillary tube and the like. For the connection mode of the pilot valve and the main valve, a special bracket is previously used to connect the pilot valve and the main valve, that is, the bracket is installed on the main valve, and the pilot valve is installed on the bracket, and the pilot valve and the main valve are spaced apart. This solution has many parts and high cost. With the development of technology, the bracket is cancelled, and the pilot valve and the main valve are directly connected. However, after the pilot valve and the main valve are connected, the pilot valve is long, and in the use process, the pilot valve is prone to deflection, resulting in a leak between the pilot valve and the main valve, which affects the normal work of the switching valve.

[0004] SUMMARY

[0005] The present application provides a switching valve to at least solve the problem of poor reliability of the connection between the pilot valve and the main valve.

[0006] To solve the above problems, the present application adopts the following technical solution: a switching valve is provided, which includes a main valve and a pilot valve. The side wall of the main valve has an annular flange, and the annular flange surrounds to form a mounting hole. The pilot valve includes a valve pipe, which includes a pipe body and a mounting end connected to each other, and the mounting end is directly or indirectly connected to the annular flange. The mounting end has an end wall, and the end wall has a flow passage hole, which is in communication with a cavity in the main valve.

[0007] In some embodiments, a space is provided between the end face of the annular flange and the valve pipe, and the space is used to set a first welding ring before welding.

[0008] In some embodiments, the mounting end has an end side wall connected to the end wall, the height of the annular flange is H, the thickness of the side wall of the main valve is T, the height of the mounting end is h, the thickness of the end side wall of the mounting end is t, and the diameter of the welding wire of the first welding ring is a, wherein 3t≤h-a≤H+T.

[0009] In some embodiments, the pipe body and the mounting end are an integral structure.

[0010] In some embodiments, the pipe body and the mounting end are a split structure.

[0011] In some embodiments, the valve pipe further comprises a connecting pipe, one end of the connecting pipe has an annular protruding edge extending into the interior of the connecting pipe, the annular protruding edge is connected to the mounting end, the pipe body extends into the other end of the connecting pipe and is fixedly connected with the connecting pipe.

[0012] In some embodiments, the pipe body and the connecting pipe are welded, and the end of the connecting pipe away from the mounting end is used to set a second welding ring.

[0013] In some embodiments, the pipe body abuts against the annular protruding edge.

[0014] In some embodiments, the connecting pipe and the mounting end are an integral structure.

[0015] In some embodiments, a filter is further included, the filter is arranged on the side of the end wall facing the pipe body and shields the flow passage hole.

[0016] From the above technical solution, the advantages and positive effects of the switching valve proposed in the present application are that:

[0017] In the switching valve, the annular flange is arranged on the side wall of the main valve, the annular flange is arranged to form a mounting hole, the valve pipe of the pilot valve is provided with a mounting end with a diameter smaller than that of the pipe body, the mounting end extends into the mounting hole and is fixedly connected with the annular flange, the reliable connection of the pilot valve and the main valve can be achieved, the risk of fluid leakage is greatly reduced, and no other structures except the main valve and the pilot valve such as supports or reinforcing members are needed, the structure is simple, the parts are few, the reliability is high, and the service life is long. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the present application. The use of the same reference numbers in different drawings and / or discussion indicates similar or identical items. In the drawings:

[0019] Fig. 1 is a schematic view of the switching valve in an embodiment;

[0020] Fig. 2 is a perspective view of the pilot valve in an embodiment;

[0021] Fig. 3 is a front view of Fig. 2;

[0022] Fig. 4 is a sectional view of Fig. 3 at position A-A;

[0023] Fig. 5 is a perspective view of the main valve in an embodiment;

[0024] Fig. 6 is a front view of Fig. 5;

[0025] Fig. 7 is a schematic view of a first welding ring in an embodiment;

[0026] Fig. 8 is a schematic view of a switching valve in an embodiment;

[0027] Fig. 9 is a perspective view of a connection pipe and a mounting end as an integrated structure in Fig. 8;

[0028] Fig. 10 is a schematic view of a filter in Fig. 8;

[0029] Fig. 11 is a schematic view of a connection circuit of a switching valve in an embodiment;

[0030] Fig. 12 is a schematic view of a switching valve in an embodiment;

[0031] Fig. 13 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0032] Fig. 14 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0033] Fig. 15 is a schematic view of a filter in Fig. 14;

[0034] Fig. 16 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0035] Fig. 17 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0036] Fig. 18 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0037] Fig. 19 is a schematic view of a limiting member in Fig. 18;

[0038] Fig. 20 is a schematic view of a connection region of a main valve and a pilot valve in a switching valve in an embodiment;

[0039] Fig. 21 is a schematic view of a limiting member in Fig. 20;

[0040] Fig. 22 is a schematic view of a switching valve in an embodiment;

[0041] Fig. 23 is a schematic view of a connection region of a main valve and a pilot valve in an embodiment;

[0042] Fig. 24 is a schematic view of a sleeve in Fig. 2;

[0043] Fig. 25 is a schematic view of a connection region of a main valve and a pilot valve in an embodiment;

[0044] Fig. 26 is a schematic view of a sleeve in Fig. 25;

[0045] Fig. 27 is a schematic view of a connection region of a main valve and a pilot valve in an embodiment;

[0046] Fig. 28 is a schematic view of the sleeve in Fig. 27;

[0047] Fig. 29 is a schematic view of the filter in Fig. 27.

[0048] Wherein, the above-mentioned drawings include the following reference signs: 1, first capillary; 2, second capillary; 3, third capillary; 4, D connector; 5, E connector; 6, C connector; 7, S connector; 10, main valve; 101, annular flange; 12, mounting hole; 104, inner cavity; 20, pilot valve; 21, valve pipe; 201, space; 202, connecting port; 210, pipe body; 212, mounting end; 2121, end wall; 2122, flow passage hole; 2123, end side wall; 23, inner flange; 30, first welding ring; 40, connecting pipe; 401, annular convex edge; 50, sleeve; 51, annular end plate; 52, outer cylinder; 53, annular transition plate; 54, inner cylinder; 55, limiting structure; 80, filter; 90, limiting piece; 91, annular plate; 92, limiting cylinder. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0050] As shown in Figs. 1 to 7, the switching valve includes a main valve 10 and a pilot valve 20, the side wall of the main valve 10 has an annular flange 101, the annular flange 101 surrounds to form a mounting hole 12; the pilot valve 20 includes a valve pipe 21, the valve pipe 21 includes a pipe body 210 and a mounting end 212 connected with each other, the mounting end 212 is directly or indirectly connected with the annular flange 101, the mounting end has an end wall 2121, the end wall 2121 has a flow passage hole 2122, the flow passage hole 2122 is communicated with the cavity in the main valve 10.

[0051] In the switching valve, the pilot valve 20 is connected with the main valve 10, and the valve pipe 21 of the pilot valve 20 is provided with the mounting end 212, the mounting end 212 is directly or indirectly connected with the annular flange 101, the connection is firm, compact and reliable, does not need intermediate parts such as a bracket, does not need to use reinforcing parts, the structure is simple, can prevent fluid leakage, and avoids the pilot valve 20 from being deviated in the use process.

[0052] As shown in FIG. 1, the diameter of the mounting end 212 is smaller than the diameter of the pipe body 210, the mounting end 212 extends into the mounting hole 12 and is fixedly connected with the annular flange 101. The mounting end 212 and the annular flange 101 can be connected by welding. The valve pipe 21 of the pilot valve 20 and the side wall of the main valve 10 can be made of stainless steel, which has high strength and is easy to weld.

[0053] In some embodiments, the mounting end 212 has an end side wall 2123 connected with the end wall 2121, the height of the annular flange 101 is H, the thickness of the side wall of the main valve 10 is T, the height of the mounting end 212 is h, the thickness of the end side wall 2123 of the mounting end 212 is t, and the diameter of the welding wire of the first welding ring 30 is a, wherein 3t≤h-a≤H+T. h-a≤H+T can avoid the mounting end 212 of the valve pipe 21 of the pilot valve 20 extending into the inside of the side wall of the main valve 10, which can block the fluid in the main valve 10 and make the fluid flow not smooth, which is not conducive to quickly switching the fluid passage. 3t≤h-a can make the length of the mounting end 212 of the valve pipe 21 extending into the annular flange 101 of the side wall of the main valve 10 sufficient, which can enhance the connection firmness of the main valve 10 and the pilot valve 20 and improve the use reliability of the switching valve.

[0054] In some embodiments, the pipe body 210 and the mounting end 212 are an integral structure. The integral structure is convenient to manufacture, has simple process and low cost, and only needs to weld the mounting end 212 and the annular flange 101.

[0055] In some embodiments, referring to FIGS. 1 and 7, the end of the annular flange 101 and the valve pipe 21 have a space 201, and the space 201 is used to set the first welding ring 30 before welding. The first welding ring 30 is set in the space 201 between the end face of the annular flange 101 and the valve pipe 21, which can firmly weld the annular flange 101 and the valve pipe 21 and prevent liquid leakage.

[0056] In some embodiments, the switching valve of the present application further comprises a filter 80, which is arranged on the side of the end wall 2121 facing the pipe body 210 and shields the flow passage hole 2122. The arrangement of the filter 80 can filter the fluid flowing into the flow passage hole 2122, which avoids impurities entering the pilot valve 20 and affecting the normal operation of the pilot valve 20. In other embodiments, the filter 80 can also be arranged on the side of the end wall 2121 facing the main valve 10. The filter 80 can be arranged by welding. FIG. 10 shows the structure of the filter 80 of the present application, wherein the filter 80 is a circular sheet-shaped filter screen.

[0057] FIG. 8 shows another embodiment of the switching valve of the present application, which has substantially the same structure as the switching valve of the embodiment of FIGS. 1-7 in the basic configuration. Therefore, in the following description of the switching valve of this another embodiment, the structures that have been described in the embodiment of FIGS. 1-7 will not be repeated. In addition, the same reference numerals are used to designate the structures that are the same as those of the switching valve described in the embodiment of FIGS. 1-7. Therefore, in the following description of this embodiment, mainly the differences from the switching valve of the embodiment of FIGS. 1-7 will be described.

[0058] As shown in FIG. 8, in the another embodiment of the switching valve of the present application, the pipe body 210 and the mounting end 212 are in a split structure. The split structure can allow the designer to select different materials for the pipe body 210 and the mounting end 212 according to the actual needs.

[0059] In some embodiments, the valve pipe 21 further comprises a connecting pipe 40, one end of the connecting pipe 40 has an annular protrusion 401 extending into the interior of the connecting pipe 40, the annular protrusion 401 connects the mounting end 212, the pipe body 210 extends into the other end of the connecting pipe 40 and is fixedly connected with the connecting pipe 40. The provision of the connecting pipe 40 can achieve the fixed connection of the pipe body 210 and the mounting end 212, and the extension of the pipe body 210 into the connecting pipe 40 and the fixed connection with the connecting pipe 40 can enhance the connection sealing performance of the pilot valve 20 and the main valve 10, preventing fluid leakage.

[0060] In some embodiments, the pipe body 210 and the connecting pipe 40 are welded, and the end of the connecting pipe 40 away from the mounting end 212 is used to provide a second welding ring before welding. The use of the second welding ring to weld the pipe body 210 and the connecting pipe 40 has good sealing performance, firm and reliable connection, and can prolong the service life of the switching valve.

[0061] In some embodiments, the pipe body 210 abuts against the annular protrusion 401. The abutment of the pipe body 210 against the annular protrusion 401 can make the fluid flow passage smooth, while making the connection length of the pipe body 210 and the connecting pipe 40 longer, improving the connection firmness and stability, and avoiding the inclination or deviation of the pipe body 210.

[0062] In some embodiments, as shown in FIG. 9, the connecting pipe 40 and the mounting end 212 are in an integral structure. The integral structure is convenient to manufacture and has simple process.

[0063] Figure 11 shows the overall connection circuit of the switching valve, wherein the pilot valve 20 connects the first capillary tube 1, the second capillary tube 2 and the third capillary tube 3 through the connection port 202, wherein the first capillary tube 1 is connected to the right end of the main valve, the second capillary tube 2 is connected to the S port 7 of the main valve 10, and the third capillary tube 3 is connected to the left end of the main valve. After the D port 4 of the main valve 10 enters the fluid, the fluid flows into the pilot valve 20 through the flow channel hole 2122 on the mounting end 212 of the pilot valve 20, and then flows into the right end of the main valve 10 through the capillary tube 1, thereby pushing the valve core of the main valve to move to the left, as shown in Figure 11, so that the D port 4 is in communication with the C port 6 of the main valve 10, and the E port 5 and the S port 7 of the main valve 10 are in communication. Alternatively, after the D port 4 enters the fluid, the fluid flows into the pilot valve 20 through the flow channel hole 2122 on the mounting end 212 of the pilot valve 20, and then flows into the left end of the main valve 10 through the capillary tube 3, thereby pushing the valve core of the main valve to move to the right, so that the D port 4 is in communication with the E port 5, and the C port 6 and the S port 7 are in communication.

[0064] As shown in Figure 12, the embodiment of the utility model provides a switching valve, which comprises a main valve 10, a pilot valve 20 and a filter 80, the side wall of the main valve 10 is provided with an outward annular flange 101, the annular flange 101 is formed with a mounting hole 12, the pilot valve 20 is provided with a valve tube 21, one end of the valve tube 21 is a mounting end, the mounting end is fixedly connected with the annular flange 101, the mounting end is provided with an end wall 2121, the end wall 2121 is provided with a flow channel hole 2122, the flow channel hole 2122 is in communication with the cavity in the main valve 10, and the filter 80 is matched with the end wall 2121 and shields the flow channel hole 2122.

[0065] The connection of the main valve 10 and the pilot valve 20 is realized by the connection of the mounting end of the pilot valve 20 and the annular flange, the communication of the main valve 10 and the pilot valve 20 is realized by the flow channel hole 2122 on the end wall 2121, and since the filter 80 is arranged to shield the flow channel hole 2122, the fluid flowing from the main valve 10 into the flow channel hole 2122 can be filtered, thereby avoiding impurities from entering the pilot valve 20, so that the impurities do not affect the normal work of the pilot valve 20. The end wall 2121 is arranged to facilitate the assembly of the filter 80.

[0066] As shown in Figures 13 to 15, in some embodiments, the mounting end penetrates into the mounting hole 12 and is welded with the inner wall of the annular flange 101. That is, the reliable connection of the pilot valve 20 and the annular flange 101 is realized by directly welding the outer wall of the pilot valve 20 and the inner wall of the annular flange 101.

[0067] As shown in Figure 13, in one embodiment, the filter 80 is located on the side of the end wall 2121 facing the inside of the main valve 10 and is welded with the end wall 2121. That is, the reliable connection of the end wall 2121 and the filter 80 is realized by welding.

[0068] Or, as shown in Fig. 14, in another embodiment, the filter 80 is located on the side of the end wall 2121 facing outside the main valve 10 and is welded with the end wall 2121.

[0069] As shown in Figs. 16-21, in some embodiments, the outer diameter of the mounting end is larger than the outer diameter of the annular flange 101, the mounting end has an inwardly turned step 23 facing inside the pilot valve 20, the bottom wall of the inwardly turned step 23 forms the end wall 2121, and the annular side wall of the inwardly turned step 23 is welded with the outer wall of the annular flange 101. In this way, the annular flange 101 penetrates into the inwardly turned step 23, and a reliable connection is achieved by welding.

[0070] As shown in Fig. 16, in one embodiment, the filter 80 is clamped between the side of the end wall 2121 facing inside the main valve 10 and the end face of the annular flange 101. In this way, the filter 80 can be reliably fixed. In this embodiment, the filter 80 does not need to be welded, or the filter 80 can be spot-welded with the annular flange 101.

[0071] As shown in Fig. 17, in one embodiment, in the case of the inwardly turned step 23, the filter 80 is located on the side of the end wall 2121 facing outside the main valve 10 and is welded with the end wall 2121.

[0072] In the above embodiments, the filter 80 can be a circular disc-shaped filter screen, which is simple in structure and easy to process.

[0073] As shown in Figs. 18-21, in some embodiments, the switching valve further comprises a limiting member 90, the limiting member 90 is in limiting cooperation with the end face of the annular flange 101, and the filter 80 is arranged between the end wall 2121 and the limiting member 90. In this way, the filter 80 can be limited by the limiting member 90, and the fixation of the filter 80 is achieved.

[0074] As shown in Figs. 18 and 19, the limiting member 90 is an annular plate 91, the hole diameter of the annular plate 91 is smaller than the diameter of the mounting hole 12, the hole of the annular plate 91 corresponds to the flow passage hole 2122, and the filter 80 is a circular disc-shaped filter screen, the diameter of the filter 80 is larger than the hole diameter of the annular plate 91. The filter 80 is a circular disc-shaped filter screen, which is simple in structure, easy to process, and low in cost. Through the above size limitation, the annular plate 91 can better support the filter 80, improve the reliability, and prevent the filter 80 from deforming.

[0075] As shown in FIGS. 20 and 21, in some embodiments, the limiting member 90 includes an annular plate 91 and a limiting cylinder 92, the annular plate 91 is clamped between the end face of the annular flange 101 and the end wall 2121, one end of the limiting cylinder 92 is connected with the inner periphery of the annular plate 91, and the other end of the limiting cylinder 92 has an opening, the filter 80 is limited in the limiting cylinder 92, the filter 80 is a filter screen with grooves, and the opening of the filter 80 faces the flow passage hole 2122. In this way, the filter 80 is limited by the limiting cylinder 92. The filter 80 adopts the filter screen with grooves, and the filtering area is large.

[0076] Alternatively, in some embodiments, the opening of the filter 80 faces the opening of the limiting cylinder 92.

[0077] Specifically, the opening of the limiting cylinder 92 is formed into a tapered necking structure, the filter 80 is semispherical, and the necking structure limits the filter 80. Alternatively, the opening of the limiting cylinder 92 is formed into an annular flat plate structure, the filter 80 is a barrel shape, and the flat plate structure limits the filter 80. Through the necking structure or the flat plate structure, the filter 80 can be reliably limited.

[0078] As shown in FIGS. 22 to 29, in some embodiments, the switching valve includes the main valve 10, the pilot valve 20, the sleeve 50, and the filter 80, the side wall of the main valve 10 has an outward annular flange 101, the annular flange 101 is formed with a mounting hole 12, the two ends of the sleeve 50 are fixedly connected with the pilot valve 20 and the annular flange 101 respectively, one end of the pilot valve 20 has an end wall 2121, the end wall 2121 has a flow passage hole 2122, the flow passage hole 2122 is communicated with the cavity in the main valve 10, and the filter 80 cooperates with the end wall 2121 and shields the flow passage hole 2122.

[0079] The pilot valve 20 and the sleeve 50 are connected, the sleeve 50 and the annular flange 101 are connected, so that the connection between the main valve 10 and the pilot valve 20 is realized; the communication between the main valve 10 and the pilot valve 20 is realized through the flow passage hole 2122 on the end wall 2121, and since the filter 80 is arranged to shield the flow passage hole 2122, the fluid flowing from the main valve 10 into the flow passage hole 2122 can be filtered, so that impurities are prevented from entering the pilot valve 20, thereby avoiding that the impurities affect the normal work of the pilot valve 20. The end wall 2121 is arranged to facilitate the installation of the filter 80.

[0080] The inner wall of the sleeve 50 is welded with the pilot valve 20, and the outer wall of the sleeve 50 is welded with the annular flange 101. Alternatively, the end wall 2121 is formed with a step recessed into the pilot valve 20, the outer wall of one end of the sleeve 50 facing the pilot valve 20 is welded with the step surface, and the other end of the sleeve 50 is welded with the annular flange 101. The connection by welding is reliable. The materials of the welding positions of the sleeve 50, the pilot valve 20, and the annular flange 101 can all adopt stainless steel, the welding strength is high, and the sleeve 50, the pilot valve 20, and the annular flange 101 can be welded by furnace welding, which is efficient.

[0081] The filter 80 is located between the end wall 2121 and the sleeve 50. In this way, the filter 80 can be reliably fixed.

[0082] As shown in FIGS. 23 and 24, in some embodiments, the sleeve 50 has a ring-shaped end plate 51, the opening of the ring-shaped end plate 51 corresponds to the flow passage hole 2122, the filter 80 is a circular filter screen, and the filter 80 is clamped between the ring-shaped end plate 51 and the end wall 2121. With this arrangement, the structure is simple, the connection is reliable, and the filter 80 is not easily deformed.

[0083] The filter 80 can be welded or not welded with the ring-shaped end plate 51 and the end wall 2121 in contact.

[0084] In some embodiments, the sleeve 50 is a barrel, the sleeve 50 penetrates the mounting hole 12, the outer diameter of the pilot valve 20 is smaller than the diameter of the mounting hole 12, and the end wall 2121 and the filter 80 are located in the mounting hole 12. The sleeve 50 is in the form of a barrel, which is easy to process.

[0085] As shown in FIGS. 25 to 29, in some embodiments, the sleeve 50 includes an outer cylinder 52, a ring-shaped transition plate 53, and an inner cylinder 54 connected in sequence, the outer diameter of the outer cylinder 52 is greater than the inner diameter of the ring-shaped flange 101, the inner cylinder 54 penetrates the mounting hole 12, one end of the pilot valve 20 penetrates the outer cylinder 52 and is fixedly connected with the outer cylinder 52, the outer diameter of the pilot valve 20 is greater than the diameter of the mounting hole 12, the ring-shaped transition plate 53 limits the axial direction of the pilot valve 20, the ring-shaped transition plate 53 and the end surface of the ring-shaped flange 101 are limitedly matched, and the outer wall of the inner cylinder 54 is fixedly connected with the inner wall of the ring-shaped flange 101.

[0086] With the above arrangement, the design of the pilot valve 20 is not limited by the size of the mounting hole 12, and the axial direction of the pilot valve 20 can be limited by the ring-shaped transition plate 53, which can improve the installation accuracy during assembly. In addition, the inner wall and the end surface of the sleeve 50 and the ring-shaped transition plate 53 are connected, the contact area is large, and the connection strength is high.

[0087] As shown in FIG. 25, in some embodiments, the filter 80 is a circular filter screen, the diameter of the filter 80 is greater than the diameter of the inner cylinder 54, and the filter 80 is clamped between the end wall 2121 and the ring-shaped transition plate 53. In this way, the filter 80 can be reliably limited, and the filter 80 is not easily deformed. In this embodiment, the structure in contact with the filter 80 can be welded or not welded.

[0088] As shown in FIGS. 27-29, in some embodiments, the sleeve 50 further comprises a limiting structure 55, which is connected to the inner cylinder 54 away from the annular transition plate 53, the filter element 80 is located in the inner cylinder 54, and the limiting structure 55 limits the filter element 80. That is, in this embodiment, the annular transition plate 53 directly limits the end wall 2121, and the filter element 80 is limited by the inner cylinder 54 and the limiting structure 55.

[0089] Wherein, the annular transition plate 53 can be in direct contact with the end wall 2121, or can not be in contact, for example, there is an outward portion at the opening of the filter element 80, which is clamped between the annular transition plate 53 and the end wall 2121.

[0090] In some embodiments, the limiting structure 55 is a ring-shaped flat plate structure, and the filter element 80 is a barrel shape, and the flat plate structure limits the filter element 80. Alternatively, in some embodiments, the limiting structure 55 is a tapered necking structure, and the filter element 80 is a semispherical shape, and the necking structure limits the filter element 80. In the above schemes, reliable limiting of the filter element 80 can be achieved.

[0091] The above only describes some embodiments of the present scheme and is not intended to limit the present scheme. For those skilled in the art, the present scheme can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present scheme shall be included in the protection scope of the present scheme.

Claims

1. A switching valve characterized by comprising: The valve includes a main valve (10) and a pilot valve (20), the main valve (10) has a ring-shaped flange (101) on the side wall, the ring-shaped flange (101) surrounds the mounting hole (12); the pilot valve (20) includes a valve pipe (21), the valve pipe (21) includes a pipe body (210) and a mounting end (212) connected with each other, the mounting end (212) is directly or indirectly connected with the ring-shaped flange (101), the mounting end has an end wall (2121) with a flow passage hole (2122) communicating with the cavity in the main valve (10).

2. The switching valve according to claim 1, characterized by The diameter of the mounting end (212) is smaller than the diameter of the pipe body (210), the mounting end (212) extends into the mounting hole (12) and is fixedly connected with the ring-shaped flange (101).

3. The switching valve according to claim 2, characterized by The space (201) between the end face of the ring-shaped flange (101) and the valve pipe (21) is used for arranging a first welding ring (30) before welding; the pipe body (210) and the mounting end (212) are integrated or separated; the mounting end (212) has an end side wall (2123) connected with the end wall (2121), the height of the ring-shaped flange (101) is H, the thickness of the side wall of the main valve (10) is T, the height of the mounting end (212) is h, the thickness of the end side wall (2123) of the mounting end (212) is t, and the diameter of the welding wire of the first welding ring (30) is a, wherein 3t≤h-a≤H+T.

4. The switch valve according to claim 2, characterized by The valve pipe (21) further includes a connecting pipe (40), one end of the connecting pipe (40) has a ring-shaped convex edge (401) extending into the connecting pipe (40), the ring-shaped convex edge (401) is connected with the mounting end (212), the pipe body (210) extends into the other end of the connecting pipe (40) and is fixedly connected with the connecting pipe (40); the pipe body (210) and the connecting pipe (40) are welded, and the end of the connecting pipe (40) away from the mounting end (212) is used for arranging a second welding ring before welding; the pipe body (210) and the connecting pipe (40) are integrated; the pipe body (210) abuts against the ring-shaped convex edge (401).

5. The switching valve of claim 1, wherein Further including a filter (80), the filter (80) cooperates with the end wall (2121) and shields the flow passage hole (2122).

6. The switching valve according to claim 5, characterized by The mounting end penetrates into the mounting hole (12) and is welded with the inner wall of the ring-shaped flange (101), the filter (80) is a circular filter screen; the filter (80) is located on the side of the end wall (2121) facing the inside of the main valve (10) and is welded with the end wall (2121), or the filter (80) is located on the side of the end wall (2121) facing the outside of the main valve (10) and is welded with the end wall (2121).

7. The switching valve according to claim 5, characterized by The outer diameter of the mounting end is greater than the outer diameter of the annular flange (101), the mounting end has an inwardly turned step (23) towards the pilot valve (20), the bottom wall of the inwardly turned step (23) forms the end wall (2121), and the annular side wall of the inwardly turned step (23) and the outer wall of the annular flange (101) are welded.

8. The switching valve according to claim 7, characterized by The filter (80) is clamped between the side of the end wall (2121) towards the main valve (10) and the end face of the annular flange (101).

9. The switching valve of claim 7, wherein The switching valve further comprises a limiting member (90), the limiting member (90) and the end face of the annular flange (101) are in limiting cooperation, and the filter (80) is arranged between the end wall (2121) and the limiting member (90).

10. The switching valve according to claim 9, characterized by The limiting member (90) is an annular plate (91), the hole diameter of the annular plate (91) is smaller than the diameter of the mounting hole (12), the hole of the annular plate (91) corresponds to the flow channel hole (2122); the filter (80) is a circular sheet-shaped filter screen, and the diameter of the filter (80) is greater than the hole diameter of the annular plate (91).

11. The switching valve of claim 9, wherein The limiting member (90) comprises an annular plate (91) and a limiting cylinder (92), the annular plate (91) is clamped between the end face of the annular flange (101) and the end wall (2121), one end of the limiting cylinder (92) is connected with the inner periphery of the annular plate (91), the other end of the limiting cylinder (92) has an opening, the filter (80) is limited in the limiting cylinder (92), the filter (80) is a filter screen with a groove, and the opening of the filter (80) faces the flow channel hole (2122) or the opening of the limiting cylinder (92); the opening of the limiting cylinder (92) forms a tapered necking structure, the filter (80) is semispherical, the necking structure limits the filter (80); or, the opening of the limiting cylinder (92) forms an annular flat plate structure, the filter (80) is a circular barrel, and the flat plate structure limits the filter (80).

12. The switching valve of claim 1, wherein Further comprising a sleeve (50) and a filter (80), the two ends of the sleeve (50) are fixedly connected with the pilot valve (20) and the annular flange (101) respectively, and the filter (80) cooperates with the end wall (2121) and shields the flow channel hole (2122).

13. The switching valve of claim 12, wherein The inner wall of the sleeve (50) is welded with the guide valve (20), the outer wall of the sleeve (50) is welded with the annular flange (101); the filter (80) is located between the end wall (2121) and the sleeve (50); or, the sleeve (50) has an annular end plate (51), the opening of the annular end plate (51) corresponds to the flow passage hole (2122), the filter (80) is a circular sheet-shaped filter screen, the filter (80) is clamped between the annular end plate (51) and the end wall (2121), the sleeve (50) is a circular barrel, the sleeve (50) penetrates into the mounting hole (12), the outer diameter of the guide valve (20) is smaller than the diameter of the mounting hole (12), and the end wall (2121) and the filter (80) are located in the mounting hole (12).

14. The switching valve of claim 12, wherein The sleeve (50) comprises an outer cylinder (52), an annular transition plate (53) and an inner cylinder (54) connected in sequence, the outer diameter of the outer cylinder (52) is greater than the inner diameter of the annular flange (101), the inner cylinder (54) penetrates into the mounting hole (12), one end of the guide valve (20) penetrates into the outer cylinder (52) and is fixedly connected with the outer cylinder (52), the outer diameter of the guide valve (20) is greater than the diameter of the mounting hole (12), the annular transition plate (53) limits the axial direction of the guide valve (20), the annular transition plate (53) and the end face of the annular flange (101) are limitedly matched, and the outer wall of the inner cylinder (54) is fixedly connected with the inner wall of the annular flange (101).

15. The switching valve of claim 14, wherein The filter (80) is a circular sheet-shaped filter screen, the diameter of the filter (80) is greater than the diameter of the inner cylinder (54), and the filter (80) is clamped between the end wall (2121) and the annular transition plate (53); or, the sleeve (50) further comprises a limiting structure (55), the limiting structure (55) is connected to the end of the inner cylinder (54) away from the annular transition plate (53), the filter (80) is located in the inner cylinder (54), the limiting structure (55) limits the filter (80), the limiting structure (55) is an annular flat plate structure, the filter (80) is a circular barrel, and the flat plate structure limits the filter (80); or, the limiting structure (55) is a tapered necking structure, the filter (80) is a semispherical shape, and the necking structure limits the filter (80).

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