Accessory for rotary switching valve, manufacturing method, and rotary switching valve

Abstract

An accessory for a rotary switching valve, a manufacturing method, and a rotary switching valve. The accessory (1, 2) for a rotary switching valve is attached to a corresponding mating member in the rotary switching valve, and can relatively and rotatably mate with the mating member by means of taking the normal line of an attachment surface of the two as a rotation axis, so as to realize turning on and off of the rotary switching valve. The accessory comprises an accessory body (10) and a coating (20), the accessory body being provided with a mating surface (102); and the coating is at least arranged on the mating surface, the coating comprising a first transition bonding layer (21) near the accessory body and a wear-resistant layer (23) located on the side of the first transition bonding layer away from the accessory body, the hardness of the first transition bonding layer being greater than that of the accessory body, and the hardness of the first transition bonding layer being smaller than that of the wear-resistant layer.

Description

Accessories for rotary switching valve and preparation method thereof, rotary switching valve Technical Field

[0001] The present disclosure relates to the technical field of switching valves, and in particular to accessories for rotary switching valves, a preparation method thereof, and a rotary switching valve. Background Art

[0002] A rotary switching valve typically consists of a fixed stator and a rotatable rotor. The stator and rotor fit snugly against each other, and the rotation of the rotor causes them to rotate relative to each other, opening and closing the valve. Over time, the mating surfaces of the stator and rotor in a rotary switching valve can wear, potentially leading to fluid leakage. Summary of the Invention

[0003] The present disclosure provides an accessory for a rotary switching valve, which is fitted with a corresponding mating piece in the rotary switching valve and can be relatively rotated with the mating piece with a normal line of the mating surfaces of the two as a rotation axis to realize the on-off switching of the rotary switching valve. The accessory comprises: an accessory body having a mating surface; a coating provided at least on the mating surface, the coating comprising a first transition bonding layer close to the accessory body and a wear-resistant layer located on a side of the first transition bonding layer facing away from the accessory body; wherein the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer.

[0004] In some embodiments, the accessory body is made of austenitic stainless steel, and the first transition bonding layer is made of metal.

[0005] In some embodiments, the wear-resistant layer is made of diamond-like carbon; and the wear-resistant layer has a thickness of 1 μm to 10 μm.

[0006] In some embodiments, the material of the first transition bonding layer is a metal material, at least one of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten; the thickness of the first transition bonding layer is 1 μm to 10 μm.

[0007] In some embodiments, the coating further comprises a second transition bonding layer located between the first transition bonding layer and the wear-resistant layer, wherein the hardness of the second transition bonding layer is greater than the hardness of the first transition bonding layer, and the hardness of the second transition bonding layer is less than the hardness of the wear-resistant layer.

[0008] In some embodiments, the material of the second transition bonding layer is at least one of tungsten and tungsten carbide; and the thickness of the second transition bonding layer is 1 μm to 10 μm.

[0009] In some embodiments, one side of the accessory body in the thickness direction has a protruding structure in the middle, and the outermost surface of the protruding structure is the mating surface.

[0010] In some embodiments, the accessory serves as a fixing part fixed in the rotary switching valve; the accessory has a plurality of through holes that pass through the accessory in the thickness direction, one end opening of the plurality of through holes is located on the side surface of the accessory body away from the protruding structure, and the other end opening is located on the mating surface of the protruding structure; a part of the plurality of through holes are inlet holes, and the other part are outlet holes that can correspond to the inlet holes; when the accessory is rotated and matched with the mating part, the rotary switching valve can be in an open state or a closed state; when the rotary switching valve is in an open state, the inlet hole is connected to the corresponding outlet hole; when the rotary switching valve is in a closed state, the inlet hole is disconnected from the corresponding outlet hole.

[0011] In some embodiments, the accessory serves as a rotating part rotatably arranged in the rotary switching valve, and at least the middle area of ​​the one side surface of the accessory in the thickness direction is the mating surface, and the accessory is provided with one or more spaced connecting grooves recessed from the mating surface; when the accessory rotates and rotates with the mating part, the rotary switching valve can be in an open state or a closed state; the mating part has a corresponding one or more groups of inlet holes and outlet holes, and when the rotary switching valve is in an open state, each of the connecting grooves is opposite to a corresponding group of inlet holes and outlet holes in the mating part, so that the corresponding inlet holes and outlet holes are connected; when the rotary switching valve is in a closed state, each of the connecting grooves is staggered with at least one of the corresponding group of inlet holes and outlet holes, so that the corresponding inlet holes and outlet holes are disconnected.

[0012] The present disclosure further provides a rotary switching valve, which includes a fixed part and a rotating part. The fixed part and the rotating part are arranged in close contact with each other and can rotate relative to each other with a normal line of the contact surface of the two as the rotation axis to realize the opening and closing of the rotary switching valve; wherein, the fixed part is the accessory as described above; and / or, the rotating part is the accessory as described above.

[0013] The present disclosure further provides a method for preparing an accessory for a rotary switching valve, wherein the accessory can be fitted with a corresponding mating piece in the rotary switching valve, and can be relatively rotated with the mating piece with a normal of the mating surfaces of the two as a rotation axis to realize the on and off of the rotary switching valve. The preparation method includes: providing an accessory body, wherein the accessory body has a mating surface; arranging a coating on the mating surface of the accessory body; the coating includes a first transition bonding layer close to the accessory body and a wear-resistant layer located on a side of the first transition bonding layer away from the accessory body; wherein the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer.

[0014] In some embodiments, providing a coating on the mating surface of the accessory body includes: providing the first transition bonding layer on the mating surface of the accessory body by vapor deposition; and providing the wear-resistant layer on the side of the first transition bonding layer away from the accessory body by vapor deposition.

[0015] In some embodiments, the coating further includes a second transition bonding layer located between the first transition bonding layer and the wear-resistant layer. The hardness of the second transition bonding layer is greater than that of the first transition bonding layer, and the hardness of the second transition bonding layer is less than that of the wear-resistant layer. Accordingly, providing the coating on the mating surface of the accessory body includes: providing the first transition bonding layer on the mating surface of the accessory body by vapor deposition; providing the second transition bonding layer on the side of the first transition bonding layer facing away from the accessory body by vapor deposition; and providing the wear-resistant layer on the side of the second transition bonding layer facing away from the accessory body by vapor deposition.

[0016] The above-mentioned accessories for rotary switching valves and preparation methods, as well as rotary switching valves, provided in the embodiments of the present disclosure, are provided with a coating at least on the mating surface of the accessory body, and the coating is provided to include a first transition bonding layer close to the accessory body and a wear-resistant layer located on the side of the first transition bonding layer away from the accessory body; and the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer, which can greatly improve the wear resistance of the accessories. At the same time, based on the transitional matching of the first transition bonding layer, the wear-resistant layer can be more firmly arranged on the mating surface of the accessory through the first transition bonding layer, thereby improving the stability of the wear-resistant layer and facilitating increasing the service life of the accessories.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] FIG1 is a schematic structural diagram of an accessory for a rotary switching valve provided in one embodiment of the present disclosure.

[0020] FIG2 is a partial cross-sectional schematic diagram of an accessory for a rotary switching valve provided in one embodiment of the present disclosure.

[0021] FIG3 is a schematic structural diagram of another rotary switching valve accessory provided in an embodiment of the present disclosure.

[0022] FIG4 is a cross-sectional view of a rotary switching valve provided in accordance with an embodiment of the present disclosure.

[0023] FIG5 is a side view of the rotary switching valve shown in FIG4 .

[0024] FIG6 is a flow chart of a method for preparing an accessory for a rotary switching valve provided in one embodiment of the present disclosure.

[0025] 7 to 10 are a set of process diagrams for preparing a rotary switching valve accessory according to a method for preparing the rotary switching valve accessory provided in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0027] In conventional rotary switching valves, a coating significantly harder than the stator or rotor surface is typically added to the stator or rotor surface to improve wear resistance. However, due to the significant physical property differences between the coating and the stator or rotor surface materials, the coating is poorly matched to the stator or rotor surface, resulting in high internal stress in the coating, poor adhesion between the stator or rotor surface and the coating, and severe coating peeling.

[0028] To this end, the present disclosure provides an accessory for a rotary switching valve, a preparation method, and a rotary switching valve. The accessory for a rotary switching valve is fitted with a corresponding mating part in the rotary switching valve and can rotate relative to the mating part with a normal line of the mating surface of the two as the rotation axis to realize the on and off of the rotary switching valve. The accessory includes an accessory body and a coating. The accessory body has a mating surface; the coating is provided at least on the mating surface, and the coating includes a first transition bonding layer close to the accessory body and a wear-resistant layer located on the side of the first transition bonding layer facing away from the accessory body; wherein the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer. The above-mentioned accessory for the rotary switching valve is provided with a coating at least on the mating surface of the accessory body, and the coating is provided to include a first transition bonding layer close to the accessory body and a wear-resistant layer located on the side of the first transition bonding layer away from the accessory body; and the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer, which can greatly improve the wear resistance of the accessory. At the same time, based on the transitional fit of the first transition bonding layer, the wear-resistant layer can be more firmly arranged on the mating surface of the accessory through the first transition bonding layer, thereby improving the stability of the wear-resistant layer and facilitating increasing the service life of the accessory.

[0029] The following describes in detail the accessories for the rotary switching valve, the preparation method, and the rotary switching valve provided by the present disclosure in conjunction with Figures 1 to 5.

[0030] Please refer to Figure 1 and, if necessary, Figure 2. The present disclosure provides an accessory 1 for a rotary switching valve, which fits with the corresponding mating piece in the rotary switching valve and can rotate relative to the mating piece with a normal line of the mating surface of the two as the rotation axis to realize the on and off of the rotary switching valve.

[0031] The fitting 1 for a rotary switching valve includes a fitting body 10 and a coating 20 . The fitting body 10 has a mating surface 102 .

[0032] The coating 20 is provided at least on the mating surface 102. The coating 20 includes a first transition bonding layer 21 adjacent to the fitting body 10 and a wear-resistant layer 23 located on a side of the first transition bonding layer 21 facing away from the fitting body 10. The hardness of the first transition bonding layer 21 is greater than that of the fitting body 10, and the hardness of the first transition bonding layer 21 is less than that of the wear-resistant layer 23.

[0033] When the coating 20 is bonded to the corresponding mating component in the rotary switching valve, the surface of the coating 20 provided on the bonding surface 102 is bonded to the corresponding mating component.

[0034] In some embodiments, the coating 20 further includes a second transition bonding layer 22 located between the first transition bonding layer 21 and the wear-resistant layer 23; wherein the hardness of the second transition bonding layer 22 is greater than the hardness of the first transition bonding layer 21, and the hardness of the second transition bonding layer 22 is less than the hardness of the wear-resistant layer 23.

[0035] In some embodiments, the wear-resistant layer 23 is made of diamond-like carbon (DLC).

[0036] In some embodiments, the wear-resistant layer 23 has a thickness of 1 μm to 10 μm.

[0037] In some embodiments, the accessory body 10 is made of austenitic stainless steel, and the first transition bonding layer 21 is made of metal.

[0038] The first transition bonding layer 21 utilizes the structural characteristics of metal materials with large grains and small pores to strengthen the bonding force with the second transition bonding layer 22 and the wear-resistant layer 23, thereby improving the bonding force between the base material (i.e., the accessory body) and the wear-resistant layer 23.

[0039] In some embodiments, the material of the first transition bonding layer 21 is at least one of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten.

[0040] In some embodiments, the thickness of the first transition bonding layer 21 is 1 μm to 10 μm;

[0041] In some embodiments, the material of the second transition bonding layer 22 is at least one of tungsten and tungsten carbide. In some embodiments, the thickness of the second transition bonding layer 22 is 1 μm to 10 μm.

[0042] Based on the above description, the wear-resistant layer 23 is a diamond-like carbon (DLC) layer, and the contact portion between the second transition bonding layer 22 and the wear-resistant layer is mainly composed of tungsten carbide (WC 1-x, x is a number less than 1 and greater than or equal to 0) is embedded in the amorphous DLC coating (i.e., the wear-resistant layer 23) in the form of nanocrystals, which alleviates the distortion degree of sp3 hybridization of carbon atoms in the wear-resistant layer 23 and reduces the internal stress of the wear-resistant layer 23. Under appropriate tungsten content, tungsten and carbon atoms combine to form WC1-x, which not only plays a role in dispersion strengthening, but also makes the wear-resistant layer 23 have a higher proportion of sp3 bonds. Although the sp3 bond ratio in the wear-resistant layer 23 increases, the sp2 bond specific gravity decreases, and the friction coefficient of the coating as a whole increases. However, as the temperature rises during the friction process, some sp3 bonds in the wear-resistant layer 23 undergo graphitization and are converted into sp2 bonds of carbon atoms, which plays a role in lubrication and friction reduction. Therefore, the W element in the second transition bonding layer 22 improves the wear resistance of the coating. That is, the provision of the second transition bonding layer 22, while increasing the bonding force with the wear-resistant layer 23, ensures the lubricity and wear resistance of the wear-resistant layer 23.

[0043] Austenitic stainless steel has a hardness of approximately 200 HV. The first transition layer can have a hardness of 700-900 HV, the second transition layer can reach 2600 HV, and the DLC layer has a hardness of 2600-2800 HV. As can be seen, the coating 20 achieves a gradient hardness transition from the accessory body 10 to the first transition layer 21, the second transition layer 22, and the DLC layer. This gradient hardness improves the substrate's support and effectively hinders crack propagation in the coating 20.

[0044] The bonding strength between the coating 20 and the accessory body 10 of the present disclosure can reach HF1 level (a higher level in the bonding strength evaluation method).

[0045] It should be noted that, in other embodiments, only one transition bonding layer may be provided inside the wear-resistant layer. The transition bonding layer may be a material layer doped with at least one of metallic tungsten and tungsten carbide.

[0046] As shown in FIG1 , the accessory body 10 has a protruding structure 12 in the middle on one side in the thickness direction. The outermost surface of the protruding structure 12 is the mating surface 102 .

[0047] In some embodiments, the rotary switching valve accessory 1 is used as a fixing member fixed in the rotary switching valve.

[0048] The rotary switching valve accessory 1 has multiple through-holes 101 extending through the accessory in the thickness direction. One end of each through-hole 101 opens on the side of the accessory body 10 facing away from the raised structure 12, and the other end opens on the mating surface 102 of the raised structure 12. Some of the through-holes 101 serve as inlet holes, while others serve as outlet holes that correspond to the inlet holes.

[0049] For example, the rotary switching valve accessory 1 shown in FIG1 may include six through holes evenly distributed on a circle. These six through holes can be divided into three pairs of through holes. Each pair of through holes can serve as an inlet hole and a through hole. For example, one through hole 1011 and the adjacent through hole 1012 can serve as an inlet hole and the other as an outlet hole.

[0050] When the accessory 1 is rotationally engaged with the mating part (i.e., the rotating part), the rotary switching valve can be in an open state or a closed state; when the rotary switching valve is in the open state, the inlet hole is connected to the corresponding outlet hole; when the rotary switching valve is in the closed state, the inlet hole is disconnected from the corresponding outlet hole.

[0051] As shown in Figure 3, and in conjunction with Figure 2 as needed, accessory 2 also comprises a fitting body and a coating. The mating surface of the fitting body of this accessory 2 can be a flat surface. This flat surface is provided with a coating 20 similar to that of the aforementioned accessory 1, at least in the area where the mating surface is located. The material of the fitting body of this accessory 2 is similar to that of the fitting body of the aforementioned accessory 1. For details, please refer to the relevant description above. Unlike the aforementioned accessory 1, this accessory 2 is a rotating member rotatably disposed within the rotary switching valve, mating with a fixed member similar to the aforementioned accessory 1.

[0052] At least the middle area of ​​one side surface of the accessory 2 in the thickness direction is the mating surface 102 . The accessory 2 is provided with one or more communicating grooves 201 that are recessed from the mating surface 102 and are spaced apart.

[0053] The mating surface 102 may be the area corresponding to the dotted line 2001 shown in FIG. 3 .

[0054] The connecting groove 201 does not penetrate the accessory 2. That is, the depth of the connecting groove 201 in the direction perpendicular to the thickness of the accessory 2, which is perpendicular to the mating surface 102, is less than the thickness of the accessory 2 in that direction. When the accessory 2 rotates to engage with a mating component (such as a fixed component), the rotary switching valve can be in an open or closed state. The mating component, similar to the aforementioned accessory 1, has one or more corresponding sets of inlet and outlet holes. When the rotary switching valve is in the open state, each connecting groove 201 is aligned with a corresponding set of inlet and outlet holes in the mating component, connecting the corresponding inlet and outlet holes. When the rotary switching valve is in the closed state, each connecting groove 201 is offset from at least one of the corresponding sets of inlet and outlet holes, disconnecting the corresponding inlet and outlet holes.

[0055] As shown in FIG3 , corresponding to the outlet hole and the inlet hole of the fitting similar to that shown in FIG1 , the communicating groove 201 here can be configured as three arc-shaped slots evenly distributed on the same circumference.

[0056] It is understood that when the rotary switching valve is in an open state, the orthographic projections of each of the communication grooves 201 and a corresponding set of inlet holes in the mating component on the mating surface between the fitting 2 and the mating component at least partially overlap, and the orthographic projections of each of the communication grooves 201 and a corresponding set of outlet holes in the mating component on the mating surface between the fitting 2 and the mating component at least partially overlap, thereby enabling communication between the corresponding inlet holes and outlet holes through the communication grooves 201. Accordingly, when the rotary switching valve is in a closed state, the orthographic projection of each of the communication grooves 201 on the mating surface between the fitting 2 and the mating component does not overlap with the orthographic projection of at least one of the corresponding set of inlet holes and outlet holes on the mating surface between the fitting 2 and the mating component, thereby preventing communication between the corresponding inlet holes and outlet holes.

[0057] The fitting surface between the accessory 2 and the mating component can be the outer surface of the coating provided on the mating surface 102 of the accessory 2 .

[0058] It is understandable that the specific number and arrangement of the outlet holes and inlet holes on the fixed part, and the connecting grooves on the rotating part can be set according to specific circumstances, and the present disclosure does not limit this.

[0059] 4 and 5 , and in combination with FIG. 1 to FIG. 3 when necessary, the present disclosure further provides a rotary switching valve 100 , which includes a fixed member 1 ′ and a rotating member 2 ′. The fixed member 1 ′ and the rotating member 2 ′ are fitted together and can rotate relative to each other with a normal line OO′ of a fitting surface S of the fixed member 1 ′ as the rotation axis, thereby realizing the on-off switching of the rotary switching valve 100 .

[0060] In some embodiments, the fixed part is the accessory 1 described above, and the rotating part is the accessory 2 described above, which can ensure that both the rotating part and the fixed part are not easily worn.

[0061] Since rotating parts are more cost-effective than fixed parts, preferably, the fixed part is the accessory 1 as described above, and the surface of the rotating part is not provided with a coating 20, which is beneficial for ensuring the sealing of the two while better controlling product costs.

[0062] As shown in Figure 4, the fixed part 1' is the accessory 1 described above, and the rotating part 2' is not provided with the coating 20 as an example. The rotating part 2' is similar to the accessory 2 described above without the coating, and is also provided with a connecting groove.

[0063] As shown in Figure 4, the rotary switching valve 100 also includes a shell 3 having an inner cavity 301. The shell 3 has two opposite openings 3001 and 3002. The fixed part 1' can be fixed to the opening 3002 by a fixed structural part 4. The rotating part 2' is arranged in the inner cavity 301 and is rotatably attached to the inner side of the fixed part 1' through a rotating shaft assembly. The rotating shaft assembly includes a rotating shaft 8, an elastic part 5, a bearing 6 and a baffle 7. A mounting portion 81 is provided at the inner end of the rotating shaft 8. The rotating part 2' is fixed to the mounting portion 81 and can rotate under the rotation of the rotating shaft 8 to achieve relative rotational cooperation with the fixed part 1'. The rotating shaft 8 is partially inserted into the opening 3001. The elastic part 5 is sleeved on the rotating shaft 8, with one end abutting against the mounting portion 81 and the other end abutting against the baffle 7. The bearing 6 is arranged between the baffle 7 and the shell at the opening 3001.

[0064] In this embodiment, the normal line OO′ is also the axis of the rotation shaft 8 .

[0065] Based on the above description, when the rotary switching valve 100 is in the open state, the communicating groove of each rotating part 2' is opposite to a group of corresponding inlet holes and outlet holes in the fixed part 1', so that the corresponding inlet holes and outlet holes are connected; when the rotary switching valve 100 is in the closed state, the communicating groove of each rotating part 2' is staggered with at least one of the corresponding group of inlet holes and outlet holes in the fixed part 1', so that the corresponding inlet holes and outlet holes are disconnected.

[0066] It should be noted that the rotary switching valve 100 can be used in a chromatograph, such as a gas chromatograph or a liquid chromatograph. The rotary switching valve 100 can be used to control the flow of fluid being analyzed in the chromatograph. Similarly, the rotary switching valve 100 can also be used in a mass spectrometer to control the flow of fluid in the chromatograph.

[0067] As shown in FIG6 , the present disclosure further provides a method for preparing an accessory for a rotary switching valve. The accessory can be fitted with a corresponding mating component in the rotary switching valve and can rotate relative to the mating component with a normal line of the mating surfaces of the two being used as a rotation axis to realize the on / off switching of the rotary switching valve. The preparation method includes the following steps S101 and S103:

[0068] In step S101 , an accessory body 10 is provided, wherein the accessory body 10 has a mating surface 102 ;

[0069] In step S103, a coating 20 is provided on the mating surface 102 of the accessory body; the coating 20 includes a first transition bonding layer 21 close to the accessory body 10 and a wear-resistant layer 23 located on a side of the first transition bonding layer 21 facing away from the accessory body 10; wherein the hardness of the first transition bonding layer 21 is greater than the hardness of the accessory body 10, and the hardness of the first transition bonding layer 21 is less than the hardness of the wear-resistant layer 23.

[0070] 7 to 10 , the following description will be made by taking an example where the coating 20 includes a second transition bonding layer 22 located between the first transition bonding layer 21 and the wear-resistant layer 23 .

[0071] The hardness of the second transition bonding layer 22 is greater than the hardness of the first transition bonding layer 21 , and the hardness of the second transition bonding layer 22 is less than the hardness of the wear-resistant layer 23 .

[0072] As shown in FIG. 7 , in step S101 , an accessory body 10 is provided. The accessory body 10 has a mating surface 102 .

[0073] In some embodiments, the step S101 of providing the coating 20 on the mating surface 102 of the accessory body includes the following steps S1011 to S1013:

[0074] As shown in FIG. 8 , in step S1011 , the first transition bonding layer 21 is provided on the mating surface 102 of the accessory body by vapor deposition.

[0075] As shown in FIG9 , in step S1012 , the second transition bonding layer 22 is formed on the side of the first transition bonding layer 21 away from the accessory body 10 by vapor deposition;

[0076] As shown in FIG. 10 , in step S1013 , the wear-resistant layer 23 is provided on the side of the second transition bonding layer 22 away from the accessory body 10 by vapor deposition.

[0077] Of course, in other embodiments, if there is only the first transition bonding layer 21 between the wear-resistant layer 23 and the accessory body 10, step S101 of providing the coating 20 on the mating surface 102 of the accessory body may include the following steps S1011 and S1013:

[0078] In step S1011, the first transition bonding layer 21 is provided on the mating surface 102 of the accessory body by vapor deposition;

[0079] In step S1013 , the wear-resistant layer 23 is provided on the side of the first transition bonding layer 21 away from the accessory body 10 by vapor deposition.

[0080] In some embodiments, the accessory body 10 is made of austenitic stainless steel, and the first transition bonding layer 21 is made of metal.

[0081] In some embodiments, the wear-resistant layer 23 is made of diamond-like carbon and has a thickness of 1 μm to 10 μm.

[0082] In some embodiments, the material of the first transition bonding layer 21 is at least one of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten.

[0083] The thickness of the first transition bonding layer 21 may be 1 μm to 10 μm;

[0084] In some embodiments, the material of the second transition bonding layer 22 is at least one of tungsten and tungsten carbide. The thickness of the second transition bonding layer 22 may be 1 μm to 10 μm.

[0085] In addition, before step S103, the preparation method may further include the following steps S102 and S104:

[0086] In step S102 , the accessory body 10 is ultrasonically cleaned to remove dust, oil, and other foreign matter on the surface.

[0087] In step S104 , Ar ion etching is performed on the accessory body 10 to remove surface oxides and increase the adhesion of the substrate to the coating.

[0088] The other structures of the coating 20 and the accessories for the rotary switching valve can refer to the above-mentioned related descriptions and will not be described in detail here.

[0089] In the present disclosure, the structural embodiments and method embodiments may complement each other if they do not conflict.

[0090] In the present disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The terms "plurality" and "several" refer to two or more, unless otherwise clearly defined.

[0091] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0092] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An accessory (1, 2) for a rotary switching valve, which fits with a corresponding mating piece in the rotary switching valve and can rotate relative to the mating piece with a normal line of the mating surfaces of the two as a rotation axis to realize the on-off switching of the rotary switching valve, comprising: an accessory body (10) having a mating surface (102); A coating (20) is provided at least on the mating surface, the coating comprising a first transition bonding layer (21) close to the accessory body and a wear-resistant layer (23) located on a side of the first transition bonding layer away from the accessory body; The hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer.

2. The accessory for a rotary switching valve according to claim 1, wherein: The material of the accessory body is austenitic stainless steel. The first transition bonding layer is made of metal.

3. The accessory for a rotary switching valve according to claim 1 or 2, wherein: The material of the wear-resistant layer is diamond-like carbon; The thickness of the wear-resistant layer is 1 μm to 10 μm.

4. The accessory for a rotary switching valve according to any one of claims 1 to 3, wherein: The material of the first transition bonding layer is a metal material, at least one of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten; The thickness of the first transition bonding layer is 1 μm to 10 μm.

5. The accessory for a rotary switching valve according to any one of claims 1 to 4, wherein: The coating further comprises a second transition bonding layer (22) located between the first transition bonding layer and the wear-resistant layer; The hardness of the second transition bonding layer is greater than the hardness of the first transition bonding layer, and the hardness of the second transition bonding layer is less than the hardness of the wear-resistant layer.

6. The accessory for a rotary switching valve according to claim 5, wherein: The material of the second transition bonding layer is at least one of tungsten and tungsten carbide; The thickness of the second transition bonding layer is 1 μm to 10 μm.

7. The accessory for a rotary switching valve according to any one of claims 1 to 6, wherein: The accessory body has a raised structure (12) located in the middle on one side in the thickness direction, and the outermost surface of the raised structure is the mating surface (102).

8. The accessory for a rotary switching valve according to claim 7, wherein: The accessory (1) serves as a fixing member fixed in the rotary switching valve; The accessory has a plurality of through holes (101) that pass through the accessory in the thickness direction, one end opening of the plurality of through holes is located on a side surface of the accessory body away from the protruding structure, and the other end opening is located on a mating surface of the protruding structure; a portion of the plurality of through holes are inlet holes, and another portion are outlet holes that can correspond to the inlet holes; When the accessory is rotationally engaged with the mating piece, the rotary switching valve can be in an open state or a closed state; when the rotary switching valve is in the open state, the inlet hole is connected to the corresponding outlet hole; when the rotary switching valve is in the closed state, the inlet hole is disconnected from the corresponding outlet hole.

9. The accessory for a rotary switching valve according to any one of claims 1 to 6, wherein: The accessory (2) is a rotating part rotatably arranged in the rotary switching valve, at least the middle area of ​​one side surface of the accessory in the thickness direction is the mating surface, and the accessory is provided with one or more spaced communicating grooves (201) recessed from the mating surface; When the accessory rotates and rotates with the mating piece, the rotary switching valve can be in an open state or a closed state; the mating piece has a corresponding one or more groups of inlet holes and outlet holes, and when the rotary switching valve is in an open state, each of the communicating grooves is opposite to a corresponding group of inlet holes and outlet holes in the mating piece, so that the corresponding inlet holes and outlet holes are connected; when the rotary switching valve is in a closed state, each of the communicating grooves is staggered with at least one of the corresponding group of inlet holes and outlet holes, so that the corresponding inlet holes and outlet holes are disconnected.

10. A rotary switching valve (100), characterized in that: It comprises a fixed part (1') and a rotating part (2'), wherein the fixed part and the rotating part are arranged in close contact with each other and can rotate relative to each other with a normal line of the contact surface of the two as a rotation axis, thereby realizing the on-off switching of the rotary switching valve; Wherein, the fixing member is the accessory according to claim 7 or 8; and / or the rotating member is the accessory according to claim 9.

11. A method for preparing an accessory for a rotary switching valve, wherein the accessory (1, 2) can be fitted with a corresponding mating piece (1, 2) in the rotary switching valve and can be relatively rotated with the mating piece about a normal line of the mating surfaces of the two as a rotation axis to realize the on-off switching of the rotary switching valve, the method comprising: Providing (S101) an accessory body (10), wherein the accessory body has a mating surface (102); A coating is provided (S103) on the mating surface of the accessory body; the coating (20) comprises a first transition bonding layer (21) close to the accessory body and a wear-resistant layer (23) located on a side of the first transition bonding layer facing away from the accessory body; wherein the hardness of the first transition bonding layer is greater than the hardness of the accessory body, and the hardness of the first transition bonding layer is less than the hardness of the wear-resistant layer.

12. The method for preparing the accessory for a rotary switching valve according to claim 11, wherein: Providing a coating on the mating surface of the accessory body includes: The first transition bonding layer is provided on the mating surface of the accessory body by vapor deposition; The wear-resistant layer is provided on the side of the first transition bonding layer away from the accessory body by vapor deposition.

13. The method for preparing the accessory for a rotary switching valve according to claim 11, wherein: The coating further includes a second transition bonding layer located between the first transition bonding layer and the wear-resistant layer; wherein the hardness of the second transition bonding layer is greater than the hardness of the first transition bonding layer, and the hardness of the second transition bonding layer is less than the hardness of the wear-resistant layer; and providing the coating on the mating surface of the accessory body includes: The first transition bonding layer is provided on the mating surface of the accessory body by vapor deposition; The second transition bonding layer is provided on the side of the first transition bonding layer away from the accessory body by vapor deposition; The wear-resistant layer is provided on the side of the second transition bonding layer away from the accessory body by vapor deposition.

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