A rotary switching valve

Abstract

The application discloses a rotary switching valve and relates to the technical field of switching valves, which comprises a valve body, a valve rod, a pipe orifice, a valve ball, a valve seat and a pressing unit, two of which are arranged at the two ends of the inner cavity of the valve body respectively, the pressing unit gives the valve seat potential energy to move towards the valve ball, and the surface of the valve ball is in abutment with the wall surface of the sealing groove; when the valve rod rotates, the pressing unit is triggered to act and the pressing force of the pressing unit on the valve ball is first reduced and then increased; in use, the valve rod is rotated to trigger the pressing unit to act, so that the pressing force of the pressing unit on the valve ball is first reduced; at this time, the friction resistance between the inner wall of the sealing groove of the valve seat and the surface of the valve ball is reduced, the friction and abrasion of the valve seat by the valve ball when the valve ball rotates are reduced, and the abrasion of the valve seat and the valve ball can be reduced; when the valve rod rotates to 90 degrees, the pressing unit increases the pressing force of the valve seat on the valve ball, so that the valve ball and the valve seat are more closely attached, and the sealing effect of the valve seat and the valve ball is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of switching valves, in particular to a rotary switching valve. BACKGROUND

[0002] Valves are used to open and close pipelines, control flow direction, adjust and control the parameters of the conveying medium. Valves are control components in fluid conveying systems, with functions such as shut-off, regulation, flow direction, anti-backflow, pressure stabilization, flow distribution, or overflow pressure relief. Valves used in fluid control systems range from the simplest shut-off valve to the most complex self-control system, with a wide variety of types and specifications.

[0003] As disclosed in Chinese Patent No. CN212273225U, a rotary switching valve is disclosed, which comprises a valve body, a cavity is formed in the inside of the valve body, pipe bodies are fixedly inserted into the two side surfaces of the valve body, the inside of the pipe body is in communication with the inside of the cavity, a rotor is movably inserted into the inside of the cavity, through grooves are formed in the two side surfaces of the rotor, and a rotating rod is rotatably connected to the bottom of the inner wall of the cavity. The rotary switching valve facilitates the operation of the driving gear through the rotation of the movable rod, achieves the effect of controlling the rotation of the driven gear, contacts the larger driven gear with the inner tooth groove to achieve the labor-saving effect, facilitates the rotation of the hand wheel, fixes the driven gear through the stabilizing rod to ensure the stable rotation of the driven gear, and uses the annular block and the limiting block to achieve the effect of stabilizing the rotating plate and the movable rod, so that the hand wheel can stably control the operation of the rotor.

[0004] The existing rotary switching valve is rotated by the staff during use, the valve stem is rotated, the valve ball is rotated, the flow channel on the valve ball corresponds to the throttling port of the valve body, the opening and closing of the valve body is realized, in order to ensure the sealing of the switching valve, the valve ball and the valve seat are generally tightly connected, which causes the valve ball to have a large friction and wear on the surface of the valve seat during rotation, and the service life of the valve ball and the valve seat is reduced over a long period of time. SUMMARY

[0005] In view of the problems existing in the prior art, the present application is proposed. Therefore, the present application aims to provide a rotary switching valve, which solves the problem that the existing rotary switching valve is rotated by the staff during use, the valve stem is rotated, the valve ball is rotated, the flow channel on the valve ball corresponds to the throttling port of the valve body, the opening and closing of the valve body is realized, in order to ensure the sealing of the switching valve, the valve ball and the valve seat are generally tightly connected, which causes the valve ball to have a large friction and wear on the surface of the valve seat during rotation, and the service life of the valve ball and the valve seat is reduced over a long period of time.

[0006] In order to achieve the above object, the present application provides the following technical scheme: A rotary switching valve, comprising a valve body, a valve rod, a pipe opening, further comprising:

[0007] A valve ball is coaxially fixed to the valve rod and has two axial flow channels that are orthogonal to each other, and the opening part of the flow channel corresponds to the pipe opening;

[0008] Two valve seats are provided and are slidingly engaged in the two ends of the valve body, and the opposite ends of the two valve seats are provided with sealing grooves that are matched with the profile of the valve ball;

[0009] Two abutting units are provided and are arranged in the two ends of the inner cavity of the valve body, the abutting unit gives the potential energy of the valve seat moving towards the valve ball, and the surface of the valve ball is abutted with the wall surface of the sealing groove, when the valve rod rotates, the abutting unit is triggered to act, and the abutting force of the abutting unit on the valve ball first decreases and then increases;

[0010] By rotating the valve rod, the valve ball is rotated, so that the opening part of the flow channel on the valve ball can be alternately corresponded with the pipe opening, the flow through the pipe opening is adjusted, when the valve ball rotates, the valve rod rotates and triggers the abutting unit to act, so that the abutting force of the abutting unit on the valve ball first decreases, at this time, the friction resistance between the inner wall of the sealing groove of the valve seat and the surface of the valve ball will decrease, under the premise of ensuring the sealing effect of the valve seat and the valve ball, the friction and wear of the valve seat by the valve ball during rotation is reduced, and the wear of the valve seat and the valve ball is reduced.

[0011] As a preferred scheme of the rotary switching valve of the present application, wherein: the abutting unit comprises a sliding ring slidingly sleeved on the periphery of the valve rod, the sliding ring is connected to the valve rod by a key, a compression spring is arranged between the sliding ring and the valve seat, the elastic force direction of the compression spring is elastically abutted with the sliding ring and the valve seat respectively, and the valve rod is provided with a variable resistance assembly for moving the sliding ring away from the valve ball first and then moving the sliding ring towards the valve ball during the rotation of the valve rod by 90 degrees;

[0012] By rotating the valve rod, the variable resistance assembly is triggered to act, and the sliding ring is driven to move away from the valve ball first, and when the sliding ring moves, the compression force of the valve seat on the valve ball is reduced, so that the resistance of the valve ball during rotation is smaller, and when the valve rod is rotated to the position, the sliding ring moves towards the valve ball, so that the compression force of the valve seat on the valve ball is increased, and the mechanical sealing effect of the valve ball and the valve seat is improved, and the leakage is reduced.

[0013] As a preferred scheme of the rotary switch valve, the variable resistance assembly comprises a fixed seat installed in the valve body, a cylindrical portion is connected to the end face of the fixed seat, a plurality of rolling grooves are arranged on the end face of the sliding ring, and the rolling ball is rotatably embedded in the end of the cylindrical portion away from the fixed seat.

[0014] When the valve rod is rotated, the rolling ball at the end of the cylindrical portion first rolls on the end face of the sliding ring and then rolls into the rolling groove, so that the extrusion force of the compression spring on the valve seat is reduced, and the abutting force of the valve seat on the valve ball is also reduced, thereby reducing the mechanical wear of the valve seat and the valve ball when the valve ball rotates.

[0015] As a preferred scheme of the rotary switch valve, the included angle between the two adjacent rolling grooves and the axis of the sliding ring is 45°.

[0016] Through the above arrangement, during the rotation of the valve rod by 90°, the rolling ball can roll from the end face of the sliding ring to the rolling groove and then roll from the rolling groove to the end face of the sliding ring, and the structure is simple.

[0017] As a preferred scheme of the rotary switch valve, the plurality of rolling grooves are arranged in an array along the axial direction of the sliding ring.

[0018] Through the above arrangement, the movement process of the rolling ball on the sliding ring is consistent whether the valve rod is rotated forward or backward.

[0019] As a preferred scheme of the rotary switch valve, the end face of the fixed seat is fixedly connected with a mounting seat, the mounting seat is hollow and slidably connected with a sliding block, the end of the cylindrical portion away from the sliding ring is fixedly connected to the sliding block, and the cylindrical portion slides out of the mounting seat, the valve rod is provided with a variable pressure unit, and the variable pressure unit is driven to move towards the sliding ring based on the pressure change of the fluid medium in the valve body.

[0020] Through the arrangement of the variable pressure unit, when the pressure of the fluid medium in the valve body is large, the pressure of the fluid medium will trigger the variable pressure unit to act, so that the variable pressure unit drives the sliding block to move towards the sliding ring, thereby increasing the extrusion force of the rolling ball on the sliding ring and increasing the stroke of the sliding ring moving towards the valve ball, and the mechanical sealing degree of the valve ball and the valve seat is improved, and leakage of the valve ball and the valve seat is prevented when the pressure of the fluid medium in the valve body is too large.

[0021] As a preferred scheme of the rotary switch valve, the variable pressure unit comprises a short column fixed to the other end of the sliding block, the short column is used to make the sliding block and the surface of the fixed seat have a gap, the valve rod is provided with a fluid hole penetrating the through flow channel, and the valve rod periphery and the surface of the mounting seat are provided with a hose to make the fluid hole and the gap penetrate through each other.

[0022] When the fluid medium pressure in the fluid hole is large, the fluid medium will enter the gap from the hose, and a thrust force is generated on the sliding block, so that the sliding block moves away from the fixed seat, the extrusion force of the ball on the sliding ring is increased, and the compression degree of the sliding ring on the compression spring is increased, so that the mechanical sealing degree of the valve seat and the valve ball is improved.

[0023] As a preferred scheme of the rotary switch valve, the valve seat is provided with a storage cavity for storing sealing grease, the valve seat is provided with a capillary hole penetrating the sealing groove and the storage cavity, and the storage cavity is provided with a lubricating sealing unit.

[0024] When the sliding ring moves towards the valve ball, the lubricating sealing unit is triggered to inject the sealing grease between the sealing groove and the valve ball wall surface, so that the valve seat and the valve ball can be lubricated to a certain extent when the extrusion force of the valve seat on the valve ball is increased and the valve rod is in a rotating state, the wear of the valve seat and the valve ball surface is reduced, and on the other hand, the sealing grease can fill the abutting surface of the valve seat and the valve ball, so that the gap between the two abutting surfaces is filled, and the sealing effect of the valve seat and the valve ball is improved.

[0025] As a preferred scheme of the rotary switch valve, the lubricating sealing unit comprises an annular part coaxially and slidingly fitted in the storage cavity, a connecting rod is fixed to the end face of the annular part, the connecting rod slidingly penetrates the valve seat, and one end of the connecting rod penetrating the valve seat is fixed to the end face of the sliding ring.

[0026] When the sliding ring moves towards the valve ball, the connecting rod drives the annular part to move towards the valve ball, so that the annular part extrudes the sealing grease in the storage cavity to the capillary hole, and the sealing grease is injected into the abutting surface of the valve seat and the valve ball from the capillary hole.

[0027] As a preferred scheme of the rotary switch valve, the annular part is fixedly sleeved with a sealing ring on the periphery.

[0028] The sealing ring is provided to improve the sealing effect of the annular part and the inner wall of the storage cavity, and to reduce the leakage of the sealing grease from the annular part and the inner wall of the storage cavity.

[0029] The present application includes at least the following advantages:

[0030] 1、The present application, by rotating the valve rod, further driving the valve ball to rotate, so that the flow passage opening on the valve ball can be alternately corresponding to the pipe opening, realizing the adjustment of the pipe opening flow, when the valve ball rotates, by rotating the valve rod, and triggering the abutting unit to act, so that the abutting unit reduces the abutting force of the valve ball, at this time, the friction resistance between the inner wall of the sealing groove of the valve seat and the surface of the valve ball will be reduced, under the premise of ensuring the sealing effect of the valve seat and the valve ball, reducing the friction and wear of the valve seat when the valve ball rotates, and further reducing the wear of the valve seat and the valve ball, when the valve rod rotates to 90°, the abutting unit increases the abutting force of the valve seat to the valve ball, so that the valve ball and the valve seat are more closely attached, and the sealing effect of the valve seat and the valve ball is improved.

[0031] 2、The present application, by setting the pressure changing unit, when the fluid medium pressure in the valve body is larger, the pressure of the fluid medium will trigger the pressure changing unit to act, so that the pressure changing unit drives the sliding block to move towards the sliding ring, and further increases the extrusion force of the sliding ring by the rolling balls, so that the sliding ring moves towards the valve ball, and the mechanical sealing degree of the valve ball and the valve seat is improved, preventing the valve ball and the valve seat from leaking due to excessive fluid medium pressure in the valve body.

[0032] 3、The present application, by setting the lubricating sealing unit, when the sliding ring moves towards the valve ball, the lubricating sealing unit will be triggered to act, and further the sealing grease can be injected between the sealing groove and the valve ball wall surface, on the one hand, when the extrusion force of the valve seat to the valve ball increases and the valve rod is in a rotating state, the abutting surface of the valve seat and the valve ball can be lubricated to a certain extent, reducing the wear of the valve seat and the valve ball, on the other hand, after the valve seat and the valve ball abut, the sealing grease can fill the abutting surface of the valve seat and the valve ball, and further the gap between the two abutting surfaces can be filled, so that the sealing effect of the abutting surface of the valve seat and the valve ball is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0034] Figure 1 It is a perspective view of a rotary switching valve in the present application;

[0035] Figure 2 It is a perspective view of a rotary switching valve in the present application; Figure 1 It is a schematic view of the position relationship after part of the structure is cut open;

[0036] Figure 3 Figure 1 is a schematic view of the position relationship in the first perspective view in the embodiment of the present application; Figure 1 Figure 2 is a schematic view of the position relationship in the second perspective view in the embodiment of the present application;

[0037] Figure 4 Figure 3 is a schematic view of the position relationship in the embodiment of the present application after the valve seat, the valve ball and the valve rod are assembled;

[0038] Figure 5 Figure 4 is a schematic view of the position relationship in the third perspective view in the embodiment of the present application; Figure 4

[0039] Figure 5 is a schematic view of the position relationship in the fourth perspective view in the embodiment of the present application; Figure 6 Figure 4 Figure 6 is a schematic view of the position relationship in the fifth perspective view in the embodiment of the present application;

[0040] Figure 7 is a schematic view of the position relationship in the sixth perspective view in the embodiment of the present application; Figure 7 Figure 6 Figure 8 is a schematic view of the enlarged view of the local structure at A in the embodiment of the present application;

[0041] Figure 9 is a schematic view of the exploded view of the structure in the embodiment of the present application. Figure 8 Figure 4 Figure 10 is a schematic view of the exploded view of the structure in the embodiment of the present application.

[0042] Figure 1 is a schematic view of the position relationship in the first perspective view in the embodiment of the present application;Figure 2 is a schematic view of the position relationship in the second perspective view in the embodiment of the present application; Figure 3 is a schematic view of the position relationship in the embodiment of the present application after the valve seat, the valve ball and the valve rod are assembled; Figure 4 is a schematic view of the position relationship in the third perspective view in the embodiment of the present application; Figure 5 is a schematic view of the position relationship in the fourth perspective view in the embodiment of the present application; Figure 6 is a schematic view of the position relationship in the fifth perspective view in the embodiment of the present application; Figure 7 is a schematic view of the position relationship in the sixth perspective view in the embodiment of the present application; Figure 8 is a schematic view of the enlarged view of the local structure at A in the embodiment of the present application; Figure 9 is a schematic view of the exploded view of the structure in the embodiment of the present application. Figure 10 is a schematic view of the exploded view of the structure in the embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0044] The embodiment of the present application discloses a rotary switching valve.

[0045] Embodiment 1: refer to Figures 1-8For the first embodiment of the present application, a rotary switching valve is provided, which comprises a valve body 1, a valve rod 3, and three ports 2, two of which are coaxial, and the other port 2 is located between the other two ports 2 and perpendicular to the axial direction of the other two ports 2. The valve body 1 is hollow inside and has two sealing end covers at both ends. The valve rod 3 is rotatably connected to the two sealing end covers and can rotate freely. The other sealing end cover can be provided with a damping state to make the resistance of the valve rod 3 rotation larger, preventing the valve rod 3 from rotating by itself. The valve rod 3 penetrates the valve body 1 and is coaxially fixed with a valve ball 6. The valve ball 6 is located between the three ports 2, and the surface of the valve ball 6 is provided with two flow channels that do not penetrate the valve ball 6. The axial directions of the two flow channels are orthogonal, and the openings of the two flow channels correspond to the two ports 2, respectively. Two valve seats 5 are installed in the valve body 1, and the two valve seats 5 are located on the opposite sides of the valve body 1 and are located on the opposite sides of the valve ball 6 in the radial direction. The valve seat 5 is coaxially fitted in the valve body 1 and can rotate freely in the valve body 1. The opposite ends of the two valve seats 5 are provided with sealing grooves that match the contour of the valve ball 6, i.e., the sealing grooves are coaxially fitted with the contour of the valve ball 6. When the sealing grooves are fitted with the valve ball 6, the abutting surface of the valve seat 5 and the valve ball 6 has a sealing effect.

[0046] The valve rod 3 is slidably sleeved with a sliding ring 8, which is keyed to the valve rod 3. An extrusion spring 11 is provided between the sliding ring 8 and the valve seat 5. The elastic force direction of the extrusion spring 11 is elastically abutted against the sliding ring 8 and the valve seat 5, respectively. The extrusion spring 11 has an elastic abutting force on the valve seat 5, which makes the extrusion spring 11 have a large extrusion force on the valve seat 5, so that the valve seat 5 and the valve ball 6 are tightly fitted. The two sealing end covers in the valve body 1 are each screw-connected with a fixed seat 4. The fixed seat 4 is connected with a cylindrical portion 17 at the end face. The cylindrical portion 17 is rotatably embedded with a ball 16 at the end away from the fixed seat 4. The end face of the sliding ring 8 is provided with a plurality of rolling grooves 18 for the ball 16. Specifically, the included angle between the two adjacent rolling grooves 18 and the sliding ring 8 is 45°. The plurality of rolling grooves 18 are arranged along the axial direction of the sliding ring 8. When the valve rod 3 rotates, the ball 16 at the end of the cylindrical portion 17 first rolls on the end face of the sliding ring 8 and then rolls into the rolling groove 18, so that the extrusion force of the extrusion spring 11 on the valve seat 5 is reduced, and the abutting force of the valve seat 5 on the valve ball 6 is also reduced, thereby reducing the mechanical wear of the abutting surface of the valve seat 5 and the valve ball 6 when the valve ball 6 rotates. As the valve rod 3 continues to rotate, the ball 16 will roll from the rolling groove 18 to the end face of the sliding ring 8, and the compression degree of the sliding ring 8 on the extrusion spring 11 will increase, so that the extrusion force of the extrusion spring 11 on the valve seat 5 will increase, and the abutting degree of the valve seat 5 on the valve ball 6 will also increase, so that the mechanical sealing degree of the valve seat 5 and the valve ball 6 is better.

[0047] The fixed seat 4 is fixedly connected with a mounting seat 9 in the end face. The mounting seat 9 is hollow and slidably connected with a sliding block 19. The cylindrical part 17 is fixedly connected with the sliding block 19 at the end away from the sliding ring 8 and slides out of the mounting seat 9. The other end of the sliding block 19 is fixedly connected with a short column 20. The short column 20 is used to make the sliding block 19 and the surface of the fixed seat 4 have a gap 7. The valve rod 3 is provided with a fluid hole 15 penetrating the flow channel. The valve rod 3 and the surface of the mounting seat 9 are provided with a hose 12, so that the fluid hole 15 and the gap 7 are communicated. When the fluid medium in the valve body 1 has a large pressure, the pressure of the fluid medium enters the hose 12 from the fluid hole 15 and then enters the gap 7 from the hose 12. The fluid medium generates a thrust to the sliding block 19 in the direction away from the fixed seat 4, so that the sliding block 19 moves towards the sliding ring 8. The sliding ring 8 is further pressed by the ball 16, so that the sliding ring 8 moves towards the valve ball 6 with an increased stroke. Therefore, the mechanical sealing degree of the valve ball 6 and the valve seat 5 is improved, so that the valve ball 6 and the valve seat 5 do not leak due to the large pressure of the fluid medium in the valve body 1. The valve seat 5 is provided with a storage cavity for storing sealing grease. The valve seat 5 is provided with a capillary hole 14 penetrating the sealing groove and the storage cavity. The storage cavity is coaxially and slidably connected with an annular part 10. Further, the annular part 10 is fixedly sleeved with a sealing ring (not shown in the figure) at the periphery. The annular part 10 is fixedly connected with a connecting rod 13 at the end face. The connecting rod 13 slides out of the valve seat 5 and is fixedly connected with the end face of the sliding ring 8.

[0048] The working principle of the embodiment is as follows:

[0049] When the valve body 1 is opened or closed, the valve rod 3 is rotated by the worker. When the valve rod 3 rotates, the sliding ring 8 is rotated. Since the fixed seat 4 is fixedly installed on the valve body 1, the sliding ring 8 moves relative to the ball 16. The rotation of the valve rod 3 makes the ball 16 at the end of the cylindrical part 17 first roll on the end face of the sliding ring 8 and then roll into the rolling groove 18. The compression of the compression spring 11 on the valve seat 5 is reduced, so that the pressing force of the valve seat 5 on the valve ball 6 is reduced. Therefore, the mechanical wear of the valve seat 5 and the valve ball 6 is reduced when the valve ball 6 rotates. With the continuous rotation of the valve rod 3, the ball 16 rolls from the rolling groove 18 to the end face of the sliding ring 8. The compression degree of the sliding ring 8 on the compression spring 11 is increased, so that the compression of the compression spring 11 on the valve seat 5 is increased. Therefore, the pressing degree of the valve seat 5 on the valve ball 6 is increased, so that the mechanical sealing degree of the valve seat 5 and the valve ball 6 is better.

[0050] When the sliding ring 8 moves towards the valve ball 6, the sliding ring 8 will drive the connecting rod 13 to move, the connecting rod 13 will push the annular part 10 to slide in the storage cavity, and the annular part 10 will extrude the sealing grease in the storage cavity to the capillary hole 14, and then to the abutting surface of the valve ball 6, on the one hand, when the extrusion force of the valve seat 5 to the valve ball 6 increases, and the valve stem 3 is in a rotating state, the abutting surface of the valve seat 5 and the valve ball 6 can be lubricated to a certain extent, reducing the wear of the surfaces of the valve seat 5 and the valve ball 6, on the other hand, when the valve stem 3 is rotated to the position, and the valve seat 5 and the valve ball 6 are tightly abutted, the sealing grease can fill the abutting surface of the valve seat 5 and the valve ball 6, and then the gap of the abutting surface of the valve seat 5 and the valve ball 6 can be filled, so that the sealing effect of the abutting surface of the valve seat 5 and the valve ball 6 is improved;

[0051] In addition, when the fluid medium pressure in the valve body 1 is large, the pressure of the fluid medium will enter the soft tube 12 from the fluid hole 15, and then enter the gap 7 from the soft tube 12, the fluid medium will generate a pushing force to the sliding block 19 in the direction away from the fixed seat 4, so that the sliding block 19 moves in the direction of the sliding ring 8, and then the extrusion force of the ball 16 to the sliding ring 8 increases, so that the stroke of the sliding ring 8 moving in the direction of the valve ball 6 increases, and then the mechanical sealing degree of the valve ball 6 and the valve seat 5 can be improved, so as to prevent the leakage of the abutting surface of the valve ball 6 and the valve seat 5 due to the excessive pressure of the fluid medium in the valve body 1.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A rotary switching valve, comprising a valve body (1), a valve stem (3), and a port (2), characterized in that, Also includes: The valve ball (6) is coaxially fixed to the valve stem (3) and has two orthogonal flow channels, the openings of which correspond to the pipe opening (2). Two valve seats (5) are provided and are slidably engaged at both ends of the valve body (1). The two valve seats (5) have sealing grooves that are adapted to the contour of the valve ball (6) at their opposite ends. Two clamping units are provided and are respectively located at both ends of the inner cavity of the valve body (1). The clamping units give the valve seat (5) the potential energy to move toward the valve ball (6) and make the surface of the valve ball (6) abut against the wall of the sealing groove. When the valve stem (3) rotates, it triggers the clamping unit to act and makes the clamping unit's pushing force on the valve ball (6) first decrease and then increase. The clamping unit includes a sliding ring (8) that is slidably fitted around the valve stem (3). The sliding ring (8) is keyed to the valve stem (3). A compression spring (11) is provided between the sliding ring (8) and the valve seat (5). The compression spring (11) elastically abuts the sliding ring (8) and the valve seat (5) at both ends in the direction of its elastic force. The valve stem (3) is provided with a variable resistance assembly for moving the sliding ring (8) away from the valve ball (6) first and then towards the valve ball (6) during the 90° rotation of the valve stem (3). The variable resistance assembly includes a fixed seat (4) installed in the valve body (1), a cylindrical part (17) connected to the end face of the fixed seat (4), a ball (16) is rotatably embedded at the end of the cylindrical part (17) away from the fixed seat (4), and a plurality of rolling grooves (18) for the ball (16) to engage are opened on the end face of the sliding ring (8).

2. The rotary switching valve according to claim 1, characterized in that, The angle between the line connecting the axis of two adjacent rolling grooves (18) and the axis of the sliding ring (8) is 45°.

3. The rotary switching valve according to claim 1, characterized in that, Multiple rolling grooves (18) are arranged in an array along the axial direction of the sliding ring (8).

4. The rotary switching valve according to claim 1, characterized in that, The mounting base (9) is fixedly connected to the end face of the fixed base (4). The mounting base (9) is hollow inside and is slidably engaged with a sliding block (19). The end of the cylindrical part (17) away from the sliding ring (8) is fixedly connected to the sliding block (19), and the cylindrical part (17) slides out of the mounting base (9). The valve stem (3) is provided with a pressure changing unit. The pressure changing unit drives the sliding block (19) to move toward the sliding ring (8) based on the pressure change of the fluid medium in the valve body (1).

5. The rotary switching valve according to claim 4, characterized in that, The transformer unit includes a short column (20) fixed to the other end of the sliding block (19). The short column (20) is used to create a gap (7) between the sliding block (19) and the surface of the fixed seat (4). A fluid hole (15) is provided in the valve stem (3) to pass through the flow channel. A hose (12) is provided around the valve stem (3) and on the surface of the mounting seat (9) to make the fluid hole (15) and the gap (7) communicate.

6. The rotary switching valve according to claim 1, characterized in that, The valve seat (5) has a storage cavity for storing sealing grease. The valve seat (5) has a capillary hole (14) that penetrates the sealing groove and the storage cavity. The storage cavity is provided with a lubrication sealing unit. The lubrication sealing unit is used to inject sealing grease from the capillary hole (14) into the space between the sealing groove and the wall of the valve ball (6) when the sliding ring (8) moves toward the valve ball (6).

7. The rotary switching valve according to claim 6, characterized in that, The lubrication and sealing unit includes an annular portion (10) that is coaxially and slidably engaged in the storage cavity. A connecting rod (13) is fixedly connected to the end face of the annular portion (10). The connecting rod (13) slidably passes through the valve seat (5), and one end of the connecting rod (13) that passes through the valve seat (5) is fixedly connected to the end face of the sliding ring (8).

8. The rotary switching valve according to claim 7, characterized in that, A sealing ring is fixedly fitted around the periphery of the annular portion (10).

Images