Switching valve and manufacturing method thereof

Abstract

A switching valve (100) including a valve body (1), a valve seat (2), and a first connecting pipe (3), wherein the valve body (1) is provided with a notch (11), the valve seat (2) is located in a valve chamber (101) of the valve body (1), the upper surface of the valve seat (2) is flat, and the lower surface of the valve seat (2) includes a weld (201) that matches the shape of the notch (11) of the valve body (1), the inner edge (201) of the weld (201) is located in the notch (11), and the outer edge ( a welded portion (212) located in the valve body (1), the welded portion (211) and the cylindrical wall of the valve body (1) at the edge of the notch (11) are welded in a closed-loop manner, the dimension of the notch (11) is larger than the outer diameter of the first connecting pipe (3), a first valve seat hole (20) is provided in the valve seat (2), and the first connecting pipe (3) passes through the notch (11) and is inserted into the first valve seat hole (20) and welded to the valve seat (2),

Description

[Technical Field]

[0001] Related Applications This application claims priority to a Chinese patent application filed on September 30, 2022, bearing application number 202211208351.2 and entitled "Switching valve and manufacturing method thereof," the entire text of which is incorporated herein by reference.

[0002] The present application relates to the technical field of refrigeration equipment, and more particularly to a switching valve and a manufacturing method thereof. [Background technology]

[0003] In an air conditioning system, a switching valve is usually used to realize switching between cooling and heating functions.

[0004] A switching valve in the related art typically includes a valve disc 01, a valve seat 02, and a connecting pipe 03, the valve disc 01 having a valve disc hole, the valve seat 02 having a valve seat hole, the connecting pipe 03 passing through the valve disc hole and then attached to the valve seat hole of the valve seat 02. During manufacturing, a welding ring is first inserted into the valve seat hole, and then the valve disc hole and the valve seat hole are aligned one-to-one. Then, the connecting pipe 03 is inserted into the valve seat hole through the valve disc hole to bring the connecting pipe 03 and the welding ring into contact with each other. The welding ring is then heated to melt, and the molten welding material fills the gap between the connecting pipe 03 and the valve seat 02 by capillary action, and simultaneously fills the gap between the valve seat 02 and the valve disc 01. At the same time, the welding material flows between the valve disc 01 and the connecting pipe 03, connecting the connecting pipe 03 and the valve disc 01.

[0005] However, the following phenomenon often occurs during the welding process of switching valves. (1) The spacing between adjacent valve body holes does not match the spacing between adjacent valve seat holes, making it difficult to install the connecting pipe 03. (2) The contact area between the arc-shaped surface of the valve disc 01 and the arc-shaped surface of the valve seat 02 is large, making it impossible to ensure that the welding material fills the entire gap between the valve seat 02 and the valve disc 01. This makes it easy for the refrigerant to flow out of the valve disc 01 through the gap where there is no welding material. In particular, after the valve disc 01 or the valve seat 02 is deformed by processing, the gap between the arc-shaped surface of the valve disc 01 and the arc-shaped surface of the valve seat 02 becomes large, making it more difficult to effectively weld with the welding material. (3) Furthermore, some of the molten welding material is likely to flow onto the upper surface of the valve seat 02, which also increases the process flow of polishing the upper surface of the valve seat 02. Summary of the Invention

[0006] According to various embodiments of the present application, a diverter valve and a method for manufacturing the same are provided.

[0007] The present application uses the following technical aspects: The switching valve includes a valve body, a valve seat, and a first connecting pipe. The valve body has a cylindrical wall with a notch. The valve body has a valve chamber inside. The valve seat is located within the valve chamber. The upper surface of the valve seat is flat. The lower surface of the valve seat has a weld that matches the shape of the notch in the valve body. The inner edge of the weld is located in the notch, and the outer edge is located within the valve body. The weld and the cylindrical wall of the valve body at the edge of the notch are welded together in a closed loop manner. The dimension of the notch is larger than the outer diameter of the first connecting pipe. The valve seat has a first valve seat hole. The first connecting pipe passes through the notch and is inserted into the first valve seat hole and welded to the valve seat.

[0008] In one embodiment, a flow restricting structure is provided in the first valve seat hole, and the flow restricting structure is used to prevent the welding material between the first connecting pipe and the valve seat from flowing onto the upper surface of the valve seat.

[0009] In one embodiment, the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located within the first hole segment, there is a limiting surface between the first hole segment and the second hole segment to block the end of the insert segment, the flow limiting structure is a groove provided on the inner wall of the first hole segment, and a weld ring accommodating chamber is formed between the groove and the outer wall of the insert segment.

[0010] In one embodiment, the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located within the first hole segment, there is a limiting surface between the first hole segment and the second hole segment that blocks the end of the insert segment, the flow limiting structure is a groove provided on the limiting surface, and a weld ring accommodating chamber is formed between the groove and the end of the insert segment.

[0011] In one embodiment, the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located within the first hole segment, a limiting surface is located between the first hole segment and the second hole segment to block an end of the insert segment, a weld ring receiving chamber is formed between the limiting surface and the end of the insert segment, and the flow limiting structure is a stepped inner wall of the second hole segment.

[0012] In one embodiment, the first hole segment and the second hole segment are both straight hole segments.

[0013] In one embodiment, the welded portion and the cylindrical wall of the valve body at the edge of the notch are tightly welded together.

[0014] In one embodiment, the shape of the notch is a rectangle, and the rectangle has two first sides and two second sides, the two first sides are opposite and parallel to each other, and both extend along the axial direction of the valve body, and the two first sides are connected by an arc-shaped second side.

[0015] In one embodiment, the valve seat has a D-shaped cross section along its longitudinal direction, and if the arc length from the first side of the starting side where the D-shaped arc surface and the valve body are in close contact is L1, the projected length value D1 of L1 in the cross section along the axial direction of the first connecting pipe is greater than 1 mm, and if the shortest straight-line distance from the second side of the end of the D-shaped arc surface is L2, the length value of L2 is greater than 1 mm.

[0016] In one embodiment, the switching valve further includes a second connecting pipe and a third connecting pipe, and the valve seat is provided with a second valve seat hole connected to the second connecting pipe and a third valve seat hole connected to the third connecting pipe, respectively, and the second valve seat hole and the third valve seat hole have the same structure as the first valve seat hole.

[0017] In one embodiment, the number of notches is one, and the first connecting pipe, the second connecting pipe and the third connecting pipe are spaced apart within the notch and all pass through the notch before connecting to the valve seat.

[0018] In one embodiment, one or more of the valve seat, the valve body, the first connecting pipe, the second connecting pipe and the third connecting pipe are stainless steel members.

[0019] In one embodiment, the switching valve further includes a fourth connecting pipe, and the fourth connecting pipe is attached to the connecting pipe hole segment in the cylindrical wall of the valve body.

[0020] The present application further provides a method for manufacturing a switching valve, including the following steps. S1: A valve body and a first connecting pipe are manufactured, and a notch having an inner diameter larger than the outer diameter of the first connecting pipe is machined in the cylindrical wall of the valve body. S2: The valve seat is manufactured and installed in the valve body so that the notch is located on the underside of the valve body, and the area where the valve seat and the valve body are welded is designated as a weld, with the inner edge of the weld located in the notch and the outer edge located inside the valve body. S3: The welded portion and the cylindrical wall of the valve body at the edge of the notch are welded in a closed-loop manner. S4: After the welding material is placed in the first seat hole of the valve seat, the insert segment of the first connecting pipe is inserted into the first seat hole through the notch to form a pre-welded assembly. S5: The temporary welding assembly is heated to heat and then melt the welding material, and the welding material is filled between the inner wall of the first valve seat hole and the outer wall of the first connecting pipe.

[0021] In one embodiment, step S3 comprises: S31: selecting a plurality of welding points on the edge of the notch, and temporarily fixing the arc surface of the valve seat and the valve body located on the edge of the notch at the welding points using a laser; S32: Laser welding the outer edge of the arcuate surface of the valve seat and the valve element located at the edge of the notch all around, or filling welding paste between the outer edge of the arcuate surface of the valve seat and the valve element located at the edge of the notch.

[0022] The details of one or more embodiments of the application are set forth in the drawings and description below. Other features, objects, and advantages of the application will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0023] In order to more clearly explain the technical aspects of the embodiments of the present application or the prior art, the drawings necessary for the description of the embodiments or the prior art will be briefly introduced below. However, the drawings in the following description are merely embodiments of the present application, and it is obvious to those skilled in the art that other drawings can be obtained based on the disclosed drawings without any creative effort.

[0024] [Figure 1] FIG. 1 is a structural diagram of a switching valve according to a related art. [Figure 2] 1 is a diagram illustrating the overall structure of a switching valve according to some embodiments. [Figure 3] FIG. 1 is a side view of a diverter valve according to some embodiments. [Figure 4] 1 is a structural diagram of a valve disc according to some embodiments. [Figure 5]FIG. 10 is an assembly diagram of a valve disc and a valve seat according to some embodiments. [Figure 6] FIG. 10 is a top view of a valve disc and valve seat assembly according to some embodiments. [Figure 7] 10A and 10B are schematic diagrams illustrating the contact length between the valve disc and the valve seat in some embodiments. [Figure 8] 1 illustrates a flow restriction structure according to some embodiments. [Figure 9] 1 illustrates a flow restriction structure according to some embodiments. [Figure 10] 1 illustrates a flow restriction structure according to some embodiments.

[0025] 01 valve body, 02 valve seat, 03 connecting pipe, 100 switching valve, 1 valve body, 101 valve chamber, 102 connecting pipe hole segment, 11 notch, 111 first edge, 112 second edge, 2 valve seat, 201 welded portion, 211 inner edge, 212 outer edge, 202 flow limiting structure, 203 weld ring accommodating chamber, 20 first valve seat hole, 40 second valve seat hole, 50 third valve seat hole, 21 first hole segment, 22 second hole segment, 23 recessed groove, 24 limiting surface, 3 first connecting pipe, 31 insert segment, 4 second connecting pipe, 5 third connecting pipe, 6 fourth connecting pipe, 7 weld ring, 8 tack welded assembly. DETAILED DESCRIPTION OF THE INVENTION

[0026] The technical aspects of the embodiments of the present application will be described below clearly and completely with reference to the drawings in the embodiments of the present application, but it is clear that the described embodiments are only some of the embodiments of the present application and do not represent all of the embodiments. Based on the embodiments of the present application, all other embodiments that can be obtained by a person skilled in the art without creative efforts shall fall within the scope of protection of the present application.

[0027] It should be noted that, for ease of description and simplicity of description, "up" refers to one end or side of the valve body of the switching valve that is perpendicular to the valve body, and "down" refers to the opposite position or direction. This does not indicate or imply that the devices or elements shown necessarily have a particular orientation, or are configured and operated in a particular orientation, and should not be understood as limiting the present application.

[0028] As shown in FIGS. 2 to 6 , this embodiment provides a switching valve 100, which includes a valve disc 1, a valve seat 2, and a first connecting pipe 3. The valve disc 1 has a notch 11 in its cylindrical wall, and the interior of the valve disc 1 is a valve chamber 101. The valve seat 2 is located within the valve chamber 101, and its upper surface is flat. The lower surface of the valve seat 2 includes a weld 201 that matches the shape of the notch 11 in the valve disc 1. The inner edge 211 of the weld 201 is located in the notch, and the outer edge is located within the valve disc 1. The weld 201 and the cylindrical wall of the valve disc 1 at the edge of the notch 11 are welded in a closed loop manner. The notch 11 is larger in size than the outer diameter of the first connecting pipe 3. The valve seat 2 has a first valve seat hole 20, and the first connecting pipe 3 passes through the notch 11 and is inserted into the first valve seat hole 20 and welded to the valve seat 2. In this embodiment, the dimension of the notch 11 is at least larger than the outer diameter of the first connecting pipe 3 so as to reduce the cylindrical wall area of ​​the valve disc 1. When welding the valve disc 1 and the valve seat 2, it is sufficient to firmly weld the welded portion 201 of the valve seat 2 to the cylindrical wall of the valve disc 1 located at the edge of the notch 11. Even if the valve seat 2 or the valve disc 1 deforms, it is relatively easy to weld the valve disc 1 and the valve seat 2 from the notch 11, so the robustness of the weld between the valve disc 1 and the valve seat 2 is not affected, and at the same time, the risk of weld cracking between the valve seat 2 and the valve disc 1 is reduced. The weld area between the valve disc 1 and the valve seat 2 is closed-ring type, and the notch 11 is arranged on the surface of the valve disc 1 in an open type. Therefore, in this embodiment, when welding the valve seat 2 and the valve body 1, the welded portion 201 of the valve seat 2 can be directly welded to the valve body 1 at the edge of the notch 11 through the notch 11, and since the welding area is a closed-ring type, the operation during welding is simplified and the welding time is significantly reduced.

[0029] A flow restricting structure 202 is provided in the first valve seat hole 20, and the flow restricting structure 202 is used to prevent the welding material between the first connecting pipe 3 and the valve seat 2 from flowing onto the upper surface of the valve seat 2. The valve seat 2 is made of a metal material, and a slider (not shown) can slide back and forth on the upper surface of the valve seat 2 to control the direction switching between the first connecting pipe 3 and other connecting pipes of the switching valve 100.

[0030] Because the outer wall of the first connecting pipe 3 and the edge of the notch 11 are not in contact with each other but are spaced apart, there is no need to consider welding the first connecting pipe 3 to the valve disc 1. When installing the first connecting pipe 3, it is only necessary to consider the engagement between the first connecting pipe 3 and the first valve seat hole 20, which simplifies installation of the first connecting pipe 3. Furthermore, in this embodiment, a flow restricting structure 202 is provided in the first valve seat hole 20 to prevent welding material from flowing onto the upper surface of the valve seat 2 when welding the valve seat 2 to the valve disc 1. Therefore, in this embodiment, by utilizing the cooperation between the notch 11 and the flow restricting structure 202, there is less likely to be a poorly welded area between the valve seat 2 and the valve disc 1, and there is no welding material on the upper surface of the valve seat 2, making the overall welding process of the switching valve 100 more efficient.

[0031] As shown in Figures 6 and 8, the first valve seat hole 20 in this embodiment includes a first hole segment 21 and a second hole segment 22. The inner diameter of the first hole segment 21 is larger than that of the second hole segment 22. The first connecting pipe 3 includes an insert segment 31 located within the first hole segment 21. Between the first hole segment 21 and the second hole segment 22, there is a limiting surface 24 that blocks the end of the insert segment 31. The limiting surface 24 is a stepped surface located between the first hole segment 21 and the second hole segment 22. The flow limiting structure 202 is a groove 23 provided in the inner wall of the first hole segment 21. A weld ring receiving chamber 203 is formed between the groove 23 and the outer wall of the insert segment 31. The first hole segment 21 and the second hole segment 22 are both straight hole segments. The welding material is a weld ring 7. Before welding, the welding ring 7 is first placed in the groove 23, and then the insert segment 31 of the first connecting pipe 3 is inserted into the first hole segment 21 so that the outer wall of the insert segment 31 is tightly engaged with the inner wall of the first hole segment 21 and the end of the insert segment 31 abuts against the stepped surface. The welding ring 7 is melted by heating, such as furnace brazing, and after melting, it moves downward by capillary action to fill the gap between the first connecting pipe 3 and the valve seat 2. The abutment of the end of the insert segment 31 against the stepped surface inhibits the flow of welding material to a certain extent, preventing the welding material from moving upward to the upper surface of the valve seat 2.

[0032] As shown in FIG. 9 , the flow restricting structure 202 in this embodiment may be a groove 23 formed in the stepped surface, with a weld ring receiving chamber 203 defined between the groove 23 and the end of the insert segment 31. Before welding, a weld ring 7 is first placed between the stepped surface and the end of the insert segment 31. Then, the insert segment 31 of the first connecting pipe 3 is inserted into the first hole segment 21, firmly engaging the outer wall of the insert segment 31 with the inner wall of the first hole segment 21 and abutting the end of the insert segment 31 against the weld ring 7. The weld ring 7 is melted by heating, such as furnace brazing, and then moves downward by capillary action to fill the gap between the first connecting pipe 3 and the valve seat 2. The groove 23 in the stepped surface can accommodate some of the weld material, preventing it from migrating upward to the upper surface of the valve seat 2.

[0033] As shown in FIG. 10 , the flow restricting structure 202 in this embodiment may be the stepped inner wall of the second hole segment 22. Before welding, a weld ring 7 is first placed between the stepped surface and the end of the insert segment 31. Then, the insert segment 31 of the first connecting pipe 3 is inserted into the first hole segment 21 so that the outer wall of the insert segment 31 is tightly engaged with the inner wall of the first hole segment 21, and the end of the insert segment 31 is abutted against the weld ring 7. The weld ring 7 is melted by a heating method such as furnace brazing, and after melting, it moves downward by capillary action to fill the gap between the first connecting pipe 3 and the valve seat 2. The stepped inner wall of the second hole segment 22 increases the flow length of the weld material and prevents it from moving upward to the upper surface of the valve seat 2.

[0034] In this embodiment, the first valve seat hole 20 further includes a first valve orifice segment, which is located at the upper end of the valve seat 2, i.e., close to the upper surface of the valve seat 2. The valve chamber 101 can communicate with the first connecting pipe 3 located in the first orifice segment 21 through the first valve orifice segment 22 in order.

[0035] To ensure robust welding performance, the weld 201 in this embodiment is tightly welded to the cylindrical wall of the valve body 1 at the edge of the notch 11. As shown in Figure 4, the notch 11 in this embodiment has a rectangular shape, with two first sides 111 and two second sides 112. The two first sides 111 are parallel to each other and extend along the axial direction of the valve body 1, and are connected by an arc-shaped second side 112. A smooth transition between the first side 111 and the second side 112 is achieved by an arc-shaped chamfer. In order to verify the optimal shape of the notch 11, in this embodiment, the notch 11 is made into several other different shapes, and the notches of different shapes are constantly tested and verified. After performing force analysis, calculations, and derivations for the valve body 1 having notches of different shapes, it was found that unless the notch 11 is set into the shape shown in Figure 4, not only will smooth cutting by the laser cutting machine be impossible, but the amount of deformation of the structure of the valve body 1 will also be impossible to minimize.

[0036] 3 and 7, the valve seat 2 has a D-shaped cross section along its longitudinal direction, and if the arc length from a first side 111 at the start of the D-shaped cross section where the arc surface of the D-shaped cross section and the valve disc 1 are in close contact is L1, then in order to ensure the welding strength between the valve disc 1 and the valve seat 2, the value D1 of the projected length of L1 in the cross section along the axial direction of the first connecting pipe 3 is greater than 1 mm. If the shortest linear distance from a second side 112 at the end of the arc surface of the D-shaped cross section is L2, then in order to ensure the welding length between the valve disc 1 and the valve seat 2, the value of L2 is greater than 1 mm.

[0037] The switching valve 100 of this embodiment further includes a second connecting pipe 4 and a third connecting pipe 5. The valve seat 2 is provided with a second valve seat hole connected to the second connecting pipe 4 and a third valve seat hole connected to the third connecting pipe 5, respectively. The second valve seat hole and the third valve seat hole have the same structure as the first valve seat hole 20. This embodiment has only one notch 11. The first connecting pipe 3, the second connecting pipe 4, and the third connecting pipe 5 are spaced apart within the notch 11 and pass through the notch 11 before connecting to the valve seat 2. The valve seat 2, valve body 1, the first connecting pipe 3, the second connecting pipe 4, and the third connecting pipe 5 of this embodiment are all made of stainless steel. This embodiment also includes a fourth connecting pipe 6, which is attached to a connecting pipe hole segment in the cylindrical wall of the valve body 1.

[0038] The present application further provides a method for manufacturing the diverter valve 100, which includes the following steps. S1: The valve body 1 and the first connecting pipe 3 are manufactured, and a notch having an inner diameter larger than the outer diameter of the first connecting pipe 3 is machined in the cylindrical wall of the valve body 1. S2: The valve seat 2 is manufactured and attached to the valve body 1 so that the notch 11 is positioned on the underside of the valve body 1, and the area where the valve seat 2 and the valve body 1 are welded is designated as the weld 201, with the inner edge 211 of the weld 201 positioned in the notch 11 and the outer edge 212 positioned within the valve body 1. S3: The welded portion 201 and the cylindrical wall of the valve body 1 at the edge of the notch 11 are welded together by a ring-closing method. S4: After the welding material is placed in the first valve seat hole 20 of the valve seat 2, the insert segment 31 of the first connecting pipe 3 is inserted into the first valve seat hole 20 through the notch 11 to form a pre-welded assembly 8. S5: The temporary welding assembly 8 is heated to heat and melt the welding material, and the welding material is filled between the inner wall of the first valve seat hole 20 and the outer wall of the first connecting pipe 3.

[0039] Step S1 further includes manufacturing the second connecting pipe 4, the third connecting pipe 5 and the fourth connecting pipe 6, by pre-machining small holes in the valve body 1 and using a punching pipe to pierce the small holes, then machining connecting pipe hole segments connected to the fourth connecting pipe 6 in the cylindrical wall of the valve body 1, and then machining notches 11 covering the small hole areas.

[0040] In the present application, the outer wall of the first connecting pipe 3 does not come into contact with the edge of the notch, and the first connecting pipe 3 only needs to be attached to the valve seat 2, which simplifies the installation process. There is no poor welding area between the valve seat 2 and the valve body 1. In the present application, the connecting pipe hole segment is pre-drilled using a small hole, which avoids the structural deformation of the valve body 1 that would occur if the notch were drilled directly, and further avoids the influence of the structural deformation of the valve body 1 on the setting position of the fourth connecting pipe 6.

[0041] Step S2 includes: S21: machining a first valve seat hole 20 in the valve seat 2, the first valve seat hole 20 including a first hole segment 21 and a second hole segment 22, the inner diameter of the first hole segment 21 being larger than that of the second hole segment 22, the first connecting pipe 3 including an insert segment 31 located in the first hole segment 21, and a limiting surface 24, which is a step surface between the first hole segment 21 and the second hole segment 22 and blocks the end of the insert segment 31; S22: Forming a groove 23 on the inner wall of the first hole segment 21 and placing a welding ring 7 between the groove 23 and the outer wall of the insert segment 31, or forming a groove 23 on a stepped surface and placing a welding ring 7 between the groove 23 and the end of the insert segment 31, or processing the inner wall of the second hole segment 22 to form a stepped shape.

[0042] Step S2 further includes machining a second valve seat hole and a third valve seat hole in the valve seat 2, each having the same structure as the first valve seat hole 20. By machining the inner wall of the first hole segment 21 into a groove 23, or machining a stepped surface into the groove 23, or machining the second hole segment 22 to have a stepped inner wall, all of these can block the flowing welding material to a certain extent, preventing the welding material from moving upward to the upper surface of the valve seat 2. No welding material exists on the upper surface of the valve seat 2.

[0043] Step S3 includes the steps of: S31: selecting a plurality of welding points on the edge of the notch, and temporarily fixing the arc surface of the valve seat 2 and the valve element 1 located on the edge of the notch at the welding points using a laser; S32: Laser welding the outer edge of the arc surface of the valve seat 2 and the valve body 1 located at the edge of the notch 11 all around, or filling a welding paste between the outer edge of the arc surface of the valve seat 2 and the valve body 1 located at the edge of the notch 11.

[0044] Step S3 further includes using a tooling device to temporarily fasten the valve body 1 and the valve seat 2 together, and then temporarily fixing the valve body 1 and the valve seat 2 by laser spot welding, thereby avoiding a gap between the valve body 1 and the valve seat 2 being too large and affecting the effect of the laser spot welding.

[0045] Step S4 further includes: after placing the welding material in the second valve seat hole of the valve seat 2, inserting the insert segment 31 of the second connecting pipe 4 into the second valve seat hole through the notch; and after placing the welding material in the third valve seat hole of the valve seat 2, inserting the insert segment 31 of the third connecting pipe 5 into the third valve seat hole through the notch.

[0046] The valve body 1 and valve seat 2 filled with the welding paste, and the entire switch valve 100 after assembly are placed in a brazing furnace for brazing.

[0047] The technical features of the above-described embodiments can be combined in any desired manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, any combination should be considered within the scope described in this specification.

[0048] The above examples merely illustrate some embodiments of the present application, and although the descriptions are relatively specific and detailed, they should not be understood as limiting the scope of the patent claims of the present application. It should be noted that those skilled in the art can make some modifications and improvements without departing from the spirit of the present application, and all of these are within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be determined according to the scope of the attached claims.

Claims

1. a valve body, a valve seat, and a first connecting pipe; A notch is provided in the cylindrical wall of the valve body, and the inside of the valve body is a valve chamber, a valve seat located in the valve chamber, the upper surface of the valve seat being flat, and the lower surface of the valve seat including a weld portion matching the shape of the notch in the valve disc, the inner edge of the weld portion being located in the notch, and the outer edge of the weld portion being located in the valve disc, the weld portion being welded to the cylindrical wall of the valve disc at the edge of the notch in a closed-loop manner; A switching valve, wherein the dimension of the notch is larger than the outer diameter of the first connecting pipe, a first valve seat hole is provided in the valve seat, and the first connecting pipe passes through the notch and is inserted into the first valve seat hole and welded to the valve seat.

2. 2. The switching valve according to claim 1, wherein a flow restricting structure is provided in the first valve seat hole, and the flow restricting structure is used to prevent welding material between the first connecting pipe and the valve seat from flowing onto an upper surface of the valve seat.

3. 3. The switching valve according to claim 2, wherein the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located in the first hole segment, and a limiting surface is provided between the first hole segment and the second hole segment to block an end of the insert segment, and the flow limiting structure is a groove provided on the inner wall of the first hole segment, and a weld ring receiving chamber is formed between the groove and the outer wall of the insert segment.

4. 3. The switching valve according to claim 2, wherein the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located in the first hole segment, a limiting surface is provided between the first hole segment and the second hole segment to block an end of the insert segment, the flow limiting structure is a groove provided in the limiting surface, and a weld ring receiving chamber is formed between the groove and the end of the insert segment.

5. 3. The switching valve according to claim 2, wherein the first valve seat hole includes a first hole segment and a second hole segment, the inner diameter of the first hole segment is larger than that of the second hole segment, the first connecting pipe includes an insert segment located in the first hole segment, a limiting surface is located between the first hole segment and the second hole segment to block an end of the insert segment, a weld ring accommodating chamber is formed between the limiting surface and the end of the insert segment, and the flow limiting structure is a stepped inner wall of the second hole segment.

6. The diverter valve according to claim 3 , wherein the first hole segment and the second hole segment are both straight hole segments.

7. 2. The switching valve according to claim 1, wherein the welded portion and the cylindrical wall of the valve body at the edge of the notch are welded in close contact with each other.

8. 8. The switching valve according to claim 7, wherein the shape of the notch is a rectangle, the rectangle having two first sides and two second sides, the two first sides being opposite and parallel to each other and both extending along the axial direction of the valve body, and the two first sides being connected by an arc-shaped second side.

9. 9. The switching valve according to claim 8, wherein the valve seat has a D-shaped cross section along its longitudinal direction, and when an arc length from a first side of a starting side where the arc surface of the D-shaped cross section and the valve body are in close contact with each other is defined as L1, a value D1 of a projected length of L1 in a cross section along the axial direction of the first connecting pipe is greater than 1 mm, and when a shortest linear distance from a second side of an end of the arc surface of the D-shaped cross section is defined as L2, the value of L2 is greater than 1 mm.

10. 2. The switching valve according to claim 1, further comprising a second connecting pipe and a third connecting pipe, wherein the valve seat is provided with a second valve seat hole connected to the second connecting pipe and a third valve seat hole connected to the third connecting pipe, respectively, and the second valve seat hole and the third valve seat hole have the same structure as the first valve seat hole.

11. 11. The switching valve according to claim 10, wherein the number of the notches is one, and the first connecting pipe, the second connecting pipe, and the third connecting pipe are spaced apart within the notch, and all pass through the notch before being connected to the valve seat.

12. The switching valve according to claim 10, wherein one or more of the valve seat, the valve body, the first connecting pipe, the second connecting pipe, and the third connecting pipe are made of stainless steel.

13. The switching valve according to claim 10 , further comprising a fourth connecting pipe, the fourth connecting pipe being attached to a connecting pipe hole segment in a cylindrical wall of the valve body.

14. S1: manufacturing a valve body and a first connecting pipe, and forming a notch in a cylindrical wall of the valve body, the notch having an inner diameter larger than an outer diameter of the first connecting pipe; S2: manufacturing a valve seat, and installing the valve seat in the valve body, with the notch positioned on the underside of the valve body, and the area where the valve seat and the valve body are welded together forming a weld, with the inner edge of the weld positioned in the notch and the outer edge positioned inside the valve body; S3: welding the welded portion and the cylindrical wall of the valve body at the edge of the notch in a closed-loop manner; S4: After placing the welding material in the first valve seat hole of the valve seat, inserting an insert segment of the first connecting pipe into the first valve seat hole through the notch to form a pre-welded assembly; S5: Heating the temporary welding assembly to heat and melt the welding material, and filling the welding material between the inner wall of the first valve seat hole and the outer wall of the first connecting pipe; A method for manufacturing a switching valve, comprising:

15. Step S3 is S31: Selecting a plurality of welding points on the edge of the notch, and temporarily fixing the arc surface of the valve seat and the valve body located on the edge of the notch at the welding points using a laser; S32: Laser welding the outer edge of the arcuate surface of the valve seat and the valve element located on the edge of the notch all around, or filling a welding paste between the outer edge of the arcuate surface of the valve seat and the valve element located on the edge of the notch.

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