Valve and manufacturing method thereof

Abstract

The present invention provides a valve and a manufacturing method thereof. The valve comprises a valve body, a prefabricated ring, and a valve core. The inner wall of the prefabricated ring is formed with a sealing surface that abuts against an abutting surface on the valve core. The valve core can abut against the sealing surface of the prefabricated ring to achieve a seal within the valve body. The sealing surface formed on the prefabricated ring, combined with the assembly of the prefabricated ring in the valve body, is achieved by electron beam welding. This effectively solves the problem of a welding torch being unable to enter a small internal space for cladding welding, resulting in the inability to form a high-quality sealing surface. This ensures that the valve sealing surface meets high hardness and wear resistance requirements, effectively improving the overall stability and reliability of the valve.

Description

Technical Field

[0001] The present invention relates to the technical field of valve and metal structural part processing, and in particular to a valve and a manufacturing method thereof. Background Art

[0002] In order to ensure the quality and service life of valves, the industry has high requirements for the hardness and wear resistance of valve sealing surfaces.

[0003] Currently, the common practice is to cast the valve body from conventional materials and then weld a layer of cemented carbide on the sealing surface to meet the above requirements. For valves with larger nominal diameters, conventional methods such as automatic argon arc welding, gas metal arc welding, and arc welding can be used to weld the sealing surface. After welding, machining is performed to produce a sealing surface that meets the requirements.

[0004] However, for valves with smaller nominal diameters, especially those with sealing surfaces smaller than DN40, apertures smaller than 30mm, and depths greater than 50mm, the welding gun cannot enter the interior for welding due to the size limitations of the welding equipment. Even if it can barely penetrate deep enough, it is impossible to operate the welding gun and observe the operation process, and a reliable quality cemented carbide welding surface cannot be effectively formed. This will result in the valve sealing surface being unable to meet the higher hardness and wear resistance requirements, and the overall reliability of the valve is poor. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem in the prior art that, for valves with smaller nominal diameters, due to size limitations, it is impossible to form a reliable quality cemented carbide surfacing surface, resulting in the valve sealing surface being unable to meet the requirements of higher hardness and wear resistance, and the overall reliability of the valve being poor.

[0006] In order to solve the above technical problems, the present invention provides a method for manufacturing a valve, which comprises the following steps:

[0007] Processing the valve body, forming a communicating inlet and outlet on the valve body, and forming a receiving position inside the valve body;

[0008] Processing a prefabricated ring, the size of the prefabricated ring can be adapted to the size of the accommodation position, and assembling the prefabricated ring to the accommodation position so that the valve body and the prefabricated ring form an assembled structure;

[0009] The assembled structure is welded by electron beam welding so that the outer wall of the prefabricated ring is welded and fixed to the inner wall of the valve body corresponding to the receiving position;

[0010] A sealing surface is then processed on the inner wall of the prefabricated ring, and the sealing surface can abut against the abutting surface of the end of the valve core to form a seal.

[0011] In some embodiments of the present application, the accommodating position is a groove-shaped structure, and the depth of the accommodating position is not less than 4 mm; the inner diameter of the accommodating position is a negative tolerance, and the tolerance range is -0.05 mm-0 mm.

[0012] In some embodiments of the present application, the prefabricated ring is made of cemented carbide powder by casting, and the cemented carbide powder is a cobalt-based alloy;

[0013] In terms of weight percentage, the cobalt-based alloy includes the following components: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%;

[0014] The outer diameter of the prefabricated ring is a positive tolerance, and the tolerance range is 0mm-0.05mm.

[0015] In some embodiments of the present application, after the processing of the prefabricated ring is completed, before the prefabricated ring is assembled with the valve body, the prefabricated ring is first frozen, and then the frozen prefabricated ring is assembled into the accommodating position to create an interference fit between the prefabricated ring and the valve body.

[0016] In some embodiments of the present application, before the assembly structure is welded by electron beam welding, the assembly structure is first placed in a vacuum chamber for vacuuming to ensure that the vacuum degree is no greater than 0.01 Pa.

[0017] In some embodiments of the present application, the thickness of the prefabricated ring at the sealing surface is not less than 1 mm, and the hardness of the prefabricated ring at the sealing surface is 38HRC-45HRC.

[0018] The present invention further provides a valve, which is manufactured by the above-mentioned manufacturing method, and comprises:

[0019] The valve body is provided with an inlet and an outlet connected to each other, and a receiving position is provided inside the valve body;

[0020] a prefabricated ring, disposed in the accommodation position, wherein the inner wall of the prefabricated ring is formed with a sealing surface;

[0021] The valve core is movably arranged on the valve body, and the end of the valve core can extend into the interior of the valve body, and the end of the valve core is formed with an abutment surface; the valve core moves relative to the valve body so that the end of the valve core can extend into the prefabricated ring and the abutment surface abuts against the sealing surface to form a seal.

[0022] In some embodiments of the present application, the sealing surface is an inclined surface, and the inner diameter of the prefabricated ring tends to gradually decrease in the direction in which the valve core extends into the valve body;

[0023] The abutting surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the outer diameter of the end portion of the valve core where the abutting surface is formed tends to gradually decrease.

[0024] In some embodiments of the present application, the prefabricated ring includes a ring base and a ring body, both of which are annular and connected, and the outer surfaces of the ring base and the ring body are flush; the inner wall of the ring body constitutes the sealing surface, and the inner wall of the ring base and the sealing surface are arranged at an obtuse angle.

[0025] In some embodiments of the present application, the accommodating position is a groove-shaped structure opened inside the valve body, and the outer wall of the prefabricated ring and the inner wall of the valve body corresponding to the accommodating position are welded and fixed by electron beam welding.

[0026] In some embodiments of the present application, the prefabricated ring is a prefabricated alloy part, and the prefabricated ring is cast from cemented carbide powder.

[0027] In some embodiments of the present application, the cemented carbide powder adopts a cobalt-based alloy, and the cobalt-based alloy includes the following components in weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0028] In some embodiments of the present application, the valve further includes a valve cover, which is arranged on the valve body and has a mounting hole; the valve core includes a valve stem and a valve flap connected to the end of the valve stem, and the end of the valve stem facing away from the valve flap is movably inserted into the mounting hole of the valve cover; the end surface of the valve flap away from the valve stem is formed with the abutment surface.

[0029] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: in the valve and its manufacturing method of the present invention, the valve includes a valve body, a prefabricated ring, and a valve core. The inner wall of the prefabricated ring is formed with a sealing surface that abuts against the abutting surface on the valve core. The valve core can abut against the sealing surface of the prefabricated ring to achieve a seal within the valve body. The sealing surface formed on the prefabricated ring, combined with the assembly of the prefabricated ring in the valve body, is achieved by electron beam welding. This effectively solves the problem of a welding gun being unable to enter a small internal space for cladding and thus failing to form a high-quality sealing surface. This ensures that the valve sealing surface meets the requirements of high hardness and wear resistance, effectively improving the overall stability and reliability of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural cross-sectional view of an embodiment of a valve of the present invention.

[0031] Figure 2 It is a structural schematic diagram of an embodiment of a valve of the present invention.

[0032] Figure 3 It is a cross-sectional view of an embodiment of a valve of the present invention.

[0033] Figure 4 It is a flow chart of the steps of the manufacturing method of the valve of the present invention.

[0034] Figure 5 It is a schematic diagram of the welding operation of the prefabricated ring and the valve body during the manufacturing process of the valve of the present invention.

[0035] Figure 6 It is a schematic diagram of the connection structure after the prefabricated ring and the valve body are welded during the manufacturing process of the valve of the present invention.

[0036] The description of the accompanying numbers is as follows: 100, valve; 10, valve body; 11, inlet; 12, outlet; 13, accommodating position; 14, circulation channel; 15, installation port; 16, installation channel; 20, prefabricated ring; 201, sealing surface; 21, ring base; 22, ring body; 30, valve core; 31, valve stem; 32, valve disc; 321, disc body; 322, abutment part; 200, electron beam welding equipment; 300, electron beam. DETAILED DESCRIPTION

[0037] Typical embodiments embodying the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention is capable of various variations in different embodiments without departing from the scope of the present invention, and that the descriptions and illustrations herein are intended to be illustrative rather than limiting.

[0038] In the description of this application, it should be understood that in the embodiments illustrated in the accompanying drawings, indications of directions or positional relationships (such as up, down, left, right, front, and back) are provided solely for the purpose of facilitating the description of this application and simplifying the description. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. These descriptions are appropriate when these components are in the positions shown in the accompanying drawings. If the descriptions of the positions of these components change, these directional indications will also change accordingly.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0040] See Figures 1 to 3 An embodiment of the present application provides a valve 100 , which is manufactured by the manufacturing method of the present application. The valve 100 includes a valve body 10 , a prefabricated ring 20 and a valve core 30 .

[0041] Specifically, the valve body 10 has an inlet 11 and an outlet 12 that communicate with each other, and a receiving space 13 within the valve body 10. A preformed ring 20 is positioned within the receiving space 13 and welded to the valve body 10. A sealing surface 201 is formed on the inner wall of the preformed ring 20. A valve core 30 is movably mounted on the valve body 10. The end of the valve core 30 is capable of extending into the interior of the valve body 10, and an abutment surface is formed on the end of the valve core 30. The valve core 30 moves relative to the valve body 10, allowing the end of the valve core 30 to extend into the preformed ring 20, whereupon the abutment surface abuts against the sealing surface 201, forming a seal.

[0042] In one embodiment of the present application, a flow channel 14 is formed inside the valve body 10 for medium circulation. An inlet 11 and an outlet 12 are also formed at both ends of the valve body 10, and both the inlet 11 and the outlet 12 are connected to the flow channel 14.

[0043] In some examples, a mounting port 15 is further provided on the side of the valve body 10 , and a mounting channel 16 is formed inside the valve body 10 corresponding to the mounting port 15 . The mounting port 15 is communicated with the circulation channel 14 through the mounting channel 16 .

[0044] In some embodiments of the present application, the valve 100 may further include a valve cover, which is fixed to the mounting opening 15 of the valve body 10 to close the mounting opening 15. In some examples, the valve cover may be fixed to the valve body 10 by fasteners, such as screws or pins.

[0045] Furthermore, the valve core 30 is disposed on the valve body 10 , and the valve core 30 can move relative to the valve body 10 , so that the end of the valve core 30 can extend into the interior of the circulation channel 14 , thereby controlling the on-off state of the circulation channel 14 .

[0046] In some embodiments of the present application, the valve core 30 includes a valve stem 31 and a valve flap 32, and the valve flap 32 is connected to the end of the valve stem 31. The valve stem 31 can be connected to the valve body 10 through a valve cover. The valve cover is provided with a mounting hole for connecting the valve stem 31 to the valve cover.

[0047] This mounting hole can be either a blind hole or a through hole. The end of the valve stem 31, distal from the valve disc 32, is inserted into the mounting hole. The valve disc 32 is housed in the flow passage 14. The valve stem 31 is movable relative to the valve cover. Under external force, the valve stem 31 drives the valve disc 32 to rise and fall along its axis, thereby controlling the flow passage 14.

[0048] In some embodiments of the present application, the valve flap 32 may include a flap body 321 and an abutment portion 322 connected to the flap body 321. The flap body 321 and the abutment portion 322 may be integrally formed. The end surface of the flap body 321 may have an assembly opening, through which the flap body 321 is sleeved onto the end of the valve stem 31 and connected to the valve stem 31 via a locking member. The locking member may be a screw or a pin, etc.

[0049] In some examples, the locking member can be eliminated, and an internal thread can be provided on the inner wall of the assembly opening, and an external thread can be provided on the end of the valve stem 31. The valve flap 32 is fixed to the valve stem 31 through the screw connection between the internal and external threads. In other examples, the assembly opening on the flap body 321 can be eliminated, and the flap body 321 can be directly fixed to the end of the valve stem 31 through a locking member or a clamping structure.

[0050] The abutment portion 322 is disposed at the end of the valve body 321 facing away from the valve stem 31, and the outer surface of the abutment portion 322 forms the abutment surface of the valve core 30. In some embodiments of the present application, the abutment surface of the abutment portion 322 is an inclined surface, and the outer diameter of the abutment portion 322 gradually decreases in the direction in which the valve core 30 extends into the valve body 10.

[0051] In addition, in some embodiments of the present application, the valve 100 may further include an elastic tube body, which may be a bellows and may be made of an elastic material that is resistant to aging and corrosion, such as polytetrafluoroethylene.

[0052] An elastic tube is sleeved around the outer periphery of the valve stem 31. One end of the elastic tube is sealed to the inner side of the valve cover, and the other end is sealed to the end surface of the valve disc 32 facing the valve cover. In some examples, the valve 100 may further include a spring sleeved around the outer periphery of the valve stem 31 and housed within the elastic tube. The ends of the spring are respectively fixed to the valve cover and the valve disc 32.

[0053] Furthermore, in some embodiments of the present application, a receiving position 13 is provided inside the valve body 10, and the receiving position 13 is provided corresponding to the installation opening 15 of the valve body 10. The receiving position 13 is a groove-shaped structure, which is recessed on the inner wall of the valve body 10.

[0054] When the valve body 10 is processed, such as by casting or forging, a groove-shaped receiving area 13 can be reserved at a set position. The depth of the receiving area 13 is not less than 4 mm, and the inner diameter of the receiving area 13 has a negative tolerance within a tolerance range of -0.05 mm to 0 mm.

[0055] Valve 100 also includes a preformed ring 20, which is positioned in accommodation position 13. A sealing surface 201 is formed on the inner wall of preformed ring 20. When valve core 30 moves relative to valve body 10, valve flap 32 can partially extend into preformed ring 20. The abutment surface on abutment portion 322 can abut against sealing surface 201 of preformed ring 20, forming a seal.

[0056] In some embodiments of the present application, the sealing surface 201 of the prefabricated ring 20 is an inclined surface, and the inner diameter of the prefabricated ring 20 tends to gradually decrease in the direction in which the valve core 30 extends into the valve body 10 .

[0057] This arrangement can be adapted to the abutting portion 322 on the valve core 30 , whose outer diameter tends to gradually decrease, so that the abutting surface and the sealing surface 201 form an effective sealing fit, thereby ensuring the sealing performance of the cooperation between the two.

[0058] In some examples, the prefabricated ring 20 may include a ring base 21 and a ring body 22 that are connected in an annular shape. The outer surfaces of the ring base 21 and the ring body 22 are flush. The ring body 22 is arranged on the side of the ring base 21 facing the installation opening 15. The inner wall of the ring body 22 forms a sealing surface 201, and the inner wall of the ring base 21 and the sealing surface 201 are arranged at an obtuse angle.

[0059] When the end of the valve core 30 extends into the preformed ring 20, the abutment portion 322 of the valve flap 32 first contacts the ring body 22 of the preformed ring 20. The abutment surface of the abutment portion 322 slides against the sealing surface 201 of the ring body 22 until the two abut and form a seal. When the abutment surface and the sealing surface 201 form a seal, the outer end of the valve flap 32 can abut against the connection between the ring base 21 and the ring body 22. In other words, the connection between the ring base 21 and the ring body 22 provides a limit to the travel of the valve core 30.

[0060] In some embodiments of the present application, the prefabricated ring 20 is a prefabricated alloy part, and the prefabricated ring 20 is cast from cemented carbide powder to ensure the hardness and wear resistance of the prefabricated ring 20, thereby effectively ensuring the sealing of the valve core 30 and the valve body 10.

[0061] In some examples, the cemented carbide powder used to make the preformed ring 20 can be a cobalt-based alloy, which includes the following components by weight: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0062] In other examples, the prefabricated ring 20 may also be made of other materials with good hardness and wear resistance, which are not limited here, as long as the prefabricated ring 20 can meet the actual use requirements.

[0063] In some embodiments of the present application, the preformed ring 20 can be manufactured by casting. The thickness of the preformed ring 20 at the sealing surface 201 is not less than 1 mm, and the hardness of the preformed ring 20 is 38HRC-45HRC. To ensure that the preformed ring 20 is effectively fixed in the receiving position 13, the outer diameter of the preformed ring 20 has a positive tolerance within a tolerance range of 0mm-0.05mm. This ensures that the preformed ring 20 can fit tightly with the valve body 10 when placed in the receiving position 13.

[0064] After the preformed ring 20 is placed in the receiving position 13, the outer wall of the preformed ring 20 is welded to the inner wall of the valve body 10 corresponding to the receiving position 13 by electron beam welding. Electron beam welding uses an accelerated and focused electron beam 300 to bombard the welding surface between the preformed ring 20 and the valve body 10, melting the welded surface and achieving welding.

[0065] Electron beam welding is used to fusion weld the prefabricated ring 20 and the valve body 10. The maximum thickness of the weldable prefabricated ring 20 can reach 200 mm, the weld width can be no more than 1 mm, and the heat-affected zone is extremely narrow. This can effectively solve the problems of the welding connection causing the welding fusion zone to lose its fine microstructure, unable to achieve optimal toughness, and reduced wear resistance due to carbide decarburization.

[0066] Furthermore, vacuum electron beam welding is used to weld the prefabricated ring 20 and the valve body 10 , which has high welding quality and can ensure high connection strength, thereby effectively improving the stability of the overall structure of the valve body 10 .

[0067] In addition, in response to the dilemma that the welding gun of the existing cladding equipment cannot weld valves 100 with smaller nominal diameters, the technical solution of the present application uses a prefabricated ring 20 to form a sealing surface 201, and combines electron beam welding to perform fusion welding between the prefabricated ring 20 and the valve body 10. This can be effectively applied to the formation of sealing structures in valves 100 with smaller nominal diameters, especially the sealing structures of valves 100 with a diameter less than DN40, an aperture less than 30 mm, and a depth greater than 50 mm.

[0068] See Figure 4 One embodiment of the present application further provides a method for manufacturing a valve 100, which can be used to manufacture the valve 100 having the above structure. The manufacturing method includes the following steps:

[0069] S10: Processing the valve body 10, forming a communicating inlet 11 and outlet 12 on the valve body 10, and forming a receiving position 13 inside the valve body 10;

[0070] S20: Processing the prefabricated ring 20, wherein the size of the prefabricated ring 20 is adapted to the size of the accommodating position 13, and assembling the prefabricated ring 20 to the accommodating position 13, so that the valve body 10 and the prefabricated ring 20 form an assembled structure;

[0071] S30: Welding the assembled structure by electron beam welding to fix the outer wall of the prefabricated ring 20 to the inner wall of the valve body 10 corresponding to the accommodating position 13;

[0072] S40: A sealing surface 201 is then processed on the inner wall of the prefabricated ring 20 . The sealing surface 201 can abut against the abutting surface of the end of the valve core 30 to form a seal.

[0073] In step S10, when the valve body 10 is processed, such as by casting or forging, a groove-shaped receiving area 13 may be reserved at a predetermined position. The depth of the receiving area 13 is not less than 4 mm, and the inner diameter of the receiving area 13 has a negative tolerance within a tolerance range of -0.05 mm to 0 mm.

[0074] During processing, a flow channel 14 is formed inside the valve body 10 , an inlet 11 and an outlet 12 are formed at both ends of the valve body 10 , and a mounting port 15 is formed on the side of the valve body 10 .

[0075] In step S20, the prefabricated ring 20 is cast from cemented carbide powder to ensure the hardness and wear resistance of the prefabricated ring 20, thereby effectively ensuring the sealing between the valve core 30 and the valve body 10. The hardness of the prefabricated ring 20 is 38HRC-45HRC.

[0076] The cemented carbide powder used to make the preformed ring 20 can be a cobalt-based alloy, which includes the following components in weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0077] In other examples, the prefabricated ring 20 may also be made of other materials with good hardness and wear resistance, which are not limited here, as long as the prefabricated ring 20 can meet the actual use requirements.

[0078] After the prefabricated ring 20 is cast and passes flaw detection, it is then machined to the dimensions of the receiving portion 13 in the valve body 10. The outer diameter of the prefabricated ring 20 has a positive tolerance within a range of 0 mm to 0.05 mm. This ensures that the prefabricated ring 20 fits tightly against the valve body 10 when placed in the receiving portion 13.

[0079] After the prefabricated ring 20 is processed, it can be frozen with ice water or liquid nitrogen, and then placed in the accommodating position 13 to form an assembled structure with the valve body 10 and the prefabricated ring 20.

[0080] When the prefabricated ring 20 and the valve body 10 are assembled, they can be pressed in appropriately to ensure that the prefabricated ring 20 is in close contact with the inner wall of the accommodating position 13 of the valve body 10 without any obvious gap.

[0081] Combine Figure 5 In step S30, after the prefabricated ring 20 and the valve body 10 are assembled, the assembled structure is placed in a vacuum chamber for high-energy electron beam welding after returning to room temperature, and the vacuum chamber is evacuated to a vacuum degree below 0.01 Pa.

[0082] Electron beam welding is then performed using extremely fine, high-energy electrons. The electron beam welding equipment is placed on the outside of the valve body 10. The electron beam 300 heats and melts the outer wall of the prefabricated ring 20 and the inner wall of the corresponding receiving position 13 of the valve body 10 through the mounting opening 15 of the valve body 10 and along the inner wall of the receiving position 13 of the valve body 10, thereby welding the prefabricated ring 20 and the valve body 10 into a single piece.

[0083] Electron beam welding is used to fusion weld the prefabricated ring 20 and the valve body 10. The maximum thickness of the weldable prefabricated ring 20 can reach 200 mm, the weld width can be no more than 1 mm, and the heat-affected zone is extremely narrow. This can effectively solve the problems of the welding connection causing the welding fusion zone to lose its fine microstructure, unable to achieve optimal toughness, and reduced wear resistance due to carbide decarburization.

[0084] Furthermore, vacuum electron beam welding is used to weld the prefabricated ring 20 and the valve body 10 , which has high welding quality and can ensure high connection strength, thereby effectively improving the stability of the overall structure of the valve body 10 .

[0085] In addition, in response to the dilemma that the welding gun of the existing cladding equipment cannot weld valves 100 with smaller nominal diameters, the technical solution of the present application uses a prefabricated ring 20 to form a sealing surface 201, and combines electron beam welding to perform fusion welding between the prefabricated ring 20 and the valve body 10. This can be effectively applied to the formation of sealing structures in valves 100 with smaller nominal diameters, especially the sealing structures of valves 100 with a diameter less than DN40, an aperture less than 30 mm, and a depth greater than 50 mm.

[0086] Combine Figure 6 In step S40, after the prefabricated ring 20 is welded to the valve body 10, a sealing surface 201 is machined on the inner wall of the prefabricated ring 20 by machining, such as mechanical grinding, to meet the dimensional requirements. The sealing surface 201 is used to abut against the abutting surface at the end of the valve core 30 to form a seal.

[0087] The processing step of the sealing surface 201 on the prefabricated ring 20 is located after the step of welding the prefabricated ring 20 to the valve body 10. This setting can avoid the deformation of the sealing surface 201 caused by high temperature and high heat in the welding operation, and can effectively ensure the accuracy of the sealing surface 201 in the prefabricated ring 20.

[0088] The thickness of the processed prefabricated ring 20 at the sealing surface 201 is not less than 1 mm, and the hardness of the prefabricated ring 20 at the sealing surface 201 is 38HRC-45HRC.

[0089] In addition, for other components in the valve 100, such as the valve cover, valve stem 31, elastic tube body, spring, etc., after completing step S40, the valve cover, valve stem 31, elastic tube body, spring, etc. can be assembled on the valve body 10 according to the assembly order of each component, thereby completing the production of the valve 100.

[0090] The valve and its manufacturing method disclosed herein include a valve body, a prefabricated ring, and a valve core. The inner wall of the prefabricated ring is formed with a sealing surface that abuts against an abutting surface on the valve core. The valve core can abut against the sealing surface of the prefabricated ring to achieve a seal within the valve body. The sealing surface formed on the prefabricated ring, combined with its placement within the valve body, is achieved through electron beam welding. This effectively resolves the problem of a welding torch being unable to enter a smaller internal space for cladding and thus failing to form a high-quality sealing surface. This ensures that the valve's sealing surface meets high hardness and wear resistance requirements, effectively improving the overall stability and reliability of the valve.

[0091] While the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are intended to be illustrative and exemplary rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. All changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A method for manufacturing a valve, characterized in that: The steps include: A valve body is processed to form a communicating inlet and outlet on the valve body, and a receiving position is formed inside the valve body; a mounting opening is provided on a side of the valve body, and a mounting channel is formed in the valve body corresponding to the mounting opening, wherein the mounting opening is connected to the receiving position through the mounting channel; the receiving position is a groove-shaped structure, and the depth of the receiving position is not less than 4 mm; the inner diameter of the receiving position has a negative tolerance within a tolerance range of -0.05 mm to 0 mm; Processing a prefabricated ring: Casting a prefabricated alloy part from cemented carbide powder to obtain a prefabricated ring; the size of the prefabricated ring is adapted to the size of the receiving position; freezing the prefabricated ring, and then assembling the frozen prefabricated ring into the receiving position, so that the prefabricated ring and the valve body have an interference fit to form a gap to be welded between the prefabricated ring and the valve body, and the valve body and the prefabricated ring form an assembled structure; Electron beam welding is used to weld the assembly structure in a manner such that the electron beam corresponds to the gap to be welded formed between the prefabricated ring and the valve body, so that the outer wall of the prefabricated ring and the inner wall of the valve body corresponding to the receiving position are welded and fixed, thereby forming a weld with a width of no more than 1 mm between the prefabricated ring and the valve body; A sealing surface is then machined on the inner wall of the prefabricated ring. The thickness of the prefabricated ring at the sealing surface is not less than 1 mm. The sealing surface can abut against the abutting surface of the valve core end to form a seal.

2. The method for manufacturing a valve according to claim 1, wherein: The prefabricated ring is made of cemented carbide powder by casting, and the cemented carbide powder is a cobalt-based alloy; The cobalt-based alloy comprises the following components in weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, W: 3.5%-5.5%; The outer diameter of the prefabricated ring is a positive tolerance, and the tolerance range is 0mm-0.05mm.

3. The method for manufacturing a valve according to claim 1, wherein: Before welding the assembled structure by electron beam welding, the assembled structure is first placed in a vacuum chamber for vacuuming to ensure that the vacuum degree is no greater than 0.01 Pa.

4. The method for manufacturing a valve according to claim 1, wherein: The hardness of the prefabricated ring at the sealing surface is 38HRC-45HRC.

5. A valve, characterized in that: The valve is manufactured by the manufacturing method according to any one of claims 1 to 4, and the valve comprises: The valve body is provided with an inlet and an outlet connected to each other, and a receiving position is provided inside the valve body; a prefabricated ring, disposed in the accommodation position, wherein the inner wall of the prefabricated ring is formed with a sealing surface; The valve core is movably arranged on the valve body, and the end of the valve core can extend into the interior of the valve body, and the end of the valve core is formed with an abutment surface; the valve core moves relative to the valve body so that the end of the valve core can extend into the prefabricated ring and the abutment surface abuts against the sealing surface to form a seal.

6. The valve according to claim 5, characterized in that The sealing surface is an inclined surface, and the inner diameter of the prefabricated ring tends to gradually decrease in the direction in which the valve core extends into the valve body; The abutting surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the outer diameter of the end portion of the valve core where the abutting surface is formed tends to gradually decrease.

7. The valve according to claim 6, characterized in that The prefabricated ring includes a ring base and a ring body, both of which are annular and connected. The outer surfaces of the ring base and the ring body are flush; the inner wall of the ring body constitutes the sealing surface, and the inner wall of the ring base and the sealing surface are arranged at an obtuse angle.

8. The valve according to claim 5, characterized in that The accommodating position is a groove-shaped structure opened inside the valve body, and the outer wall of the prefabricated ring and the inner wall of the valve body corresponding to the accommodating position are welded and fixed by electron beam welding.

9. The valve according to claim 5, characterized in that The cemented carbide powder used to prepare the prefabricated ring is a cobalt-based alloy. In terms of weight percentage, the cobalt-based alloy includes the following components: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, W: 3.5%-5.5%.

10. The valve according to claim 5, characterized in that The valve also includes a valve cover, which is arranged on the valve body and has a mounting hole. The valve core includes a valve stem and a valve disc connected to the end of the valve stem, and the end of the valve stem away from the valve disc is movably inserted into the mounting hole of the valve cover. The end surface of the valve disc away from the valve stem is formed with the abutment surface.

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