SMT chip mounter applied to electronic component processing

Abstract

The invention relates to the technical field of chip mounters, and discloses an SMT chip mounter applied to electronic component processing, which comprises a thread rotation type moving mechanism and a cache type pressure control mechanism, the hollow shell is installed on one side of the movable base block and is in a hollow state, the built-in valve plate can control the pressure of liquid flowing into the movable base block, the spiral spring plays an elastic acting force on the built-in valve plate, and the elastic air bag can generate a buffering and pre-storing effect on the liquid flowing into the movable base block. According to the SMT chip mounter applied to electronic component processing, a threaded structure between an adjusting lead screw and a movable base block is used for achieving directional driving of a mounting head module, and in the moving process of the movable base block, lubricating oil located in the movable base block can cover the threaded structure and the periphery of a horizontal limiting rod in a buffering mode; therefore, the degree of damage caused by friction of relative movement of parts is reduced, and the effective operation time of equipment is prolonged.

Description

Technical Field

[0001] This invention relates to the field of pick and place machine technology, specifically to an SMT pick and place machine applied to the processing of electronic components. Background Technology

[0002] SMT (Surface Mount Technology) pick-and-place machines, also known as "mounting machines" or "surface mount systems," are installed after dispensing machines or screen printers in the production line. They are devices that accurately place surface mount components onto PCB pads by moving the placement head. Fully automatic pick-and-place machines are used to achieve high-speed, high-precision, and fully automated placement of components. They are the most critical and complex equipment in the entire SMT production process. Pick-and-place machines are the main equipment in the SMT production line. They have evolved from early low-speed mechanical pick-and-place machines to high-speed optical alignment pick-and-place machines, and are developing towards multi-functionality, flexible connection, and modularity.

[0003] For example, Chinese patent publication number "CN216565775U" discloses "an SMT placement machine," whose main structure includes a worktable assembly fixedly connected to the ground. Y-axis motion components are fixedly connected to both sides of the upper surface of the worktable assembly, and placement motion components are fixedly connected to the upper surfaces of the Y-axis motion components. The worktable assembly includes a workpiece table, and a placement box is fixedly connected to the upper surface of the workpiece table. A mounting groove is formed on the upper surface of the workpiece table, and two motion slide rails are fixedly connected to the bottom inner side of the mounting groove. Motion screws are movably sleeved on both sides of the mounting groove, and the output shaft of a first motor is fixedly connected to the end of the shaft of the motion screw. This SMT placement machine can adjust the distance between the placement nozzles by adjusting the rotation of the screw, thereby achieving the placement effect of components with different spacing solder joints on PCB pads. Furthermore, this SMT placement machine can reduce the placement error of traditional SMT placement machines.

[0004] It is obvious that when the adjusting screw drives the first adjusting block, it moves by means of the threaded structure between the screw and the adjusting block. During the movement, friction is generated between the threaded structures, which can damage the threaded structure. Prolonged and rapid movement will lead to a decrease in the accuracy of the equipment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an SMT placement machine for electronic component processing. It utilizes a threaded structure between an adjusting screw and a moving base block to achieve directional drive of the placement head module. During the movement of the moving base block, the lubricating oil inside it acts as a buffer, covering the threaded structure and the outer periphery of the horizontal limit rod, thereby reducing the degree of damage caused by relative friction between components and increasing the effective operating time of the equipment, thus solving the aforementioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an SMT placement machine for processing electronic components, comprising a placement head module mounting substrate for mounting the placement head module in the placement machine, and a threaded rotary moving mechanism, which internally comprises a hollow moving base block capable of moving the placement head module mounting substrate, an adjusting screw connected to the moving base block via a threaded structure, a horizontal limiting rod capable of preventing the moving base block from rotating, a first liquid flow hole capable of preventing lubricating oil from leaking outward along the gap between the moving base block and the adjusting screw, and a sealing cap capable of preventing lubricating oil from leaking outward along the gap between the moving base block and the horizontal limiting rod; and a buffered pressure control mechanism, which internally comprises a hollow shell mounted on one side of the moving base block, an internally hollow shell capable of controlling the pressure of liquid flowing into the moving base block, a helical spring that provides elastic force to the internally hollow valve plate, and an elastic airbag capable of buffering and pre-storing the liquid flowing into the moving base block.

[0007] Preferably, the threaded rotary moving mechanism includes two opposing vertical support base plates, which are fixedly connected at their opposing ends by a horizontal limiting rod. Each vertical support base plate has a shaft mounting hole with open ends at its top. A rotating shaft is mounted in each shaft mounting hole via a bearing. An adjusting screw is fixedly mounted on each of the two rotating shafts at their opposing ends. A coupling is fixedly mounted on the end of one of the rotating shafts. The moving base has an internal threaded hole that is threaded around the adjusting screw. The moving base also has a mechanism that allows movement along water... The horizontal sliding hole of the horizontal limit rod has a lubrication chamber on the outer periphery of the middle area of ​​the internal threaded hole and the horizontal sliding hole of the moving base block. The two lubrication chambers are connected by a first liquid flow hole. The interior of the moving base block has a second liquid flow hole that connects one side of the moving base block to the first liquid flow hole. The moving base block has a first liquid flow hole at both ends of the internal threaded hole to prevent lubricating oil from leaking outward along the gap between the moving base block and the adjusting screw. The moving base block has sealing caps at both ends of the horizontal sliding hole to prevent lubricating oil from leaking outward along the gap between the moving base block and the horizontal limit rod.

[0008] Preferably, during operation, the coupling is connected to the rotor of the servo motor in the pick-and-place machine.

[0009] Preferably, during operation, the vertical support base plate is fixedly installed on the driven end of the track of the chip mounter.

[0010] Preferably, the thread structure includes an internal thread structure disposed on the inner wall of the internal thread hole and an external thread structure disposed on the adjusting screw body, and the internal thread structure and the external thread structure are matched.

[0011] Preferably, the cross-sectional shape of the horizontal sliding hole is consistent with the cross-sectional shape of the horizontal limiting rod, both being polygonal structures, and the structural dimensions of the cross-sectional shape of the horizontal sliding hole match the structural dimensions of the cross-sectional shape of the horizontal limiting rod.

[0012] Preferably, the buffer-type pressure control mechanism includes a component movable cavity disposed inside a hollow shell. One end of the hollow shell is provided with an integral flow tube, and the end of the flow tube is provided with a docking flange fixedly installed on the side of the movable base. The interior of the flow tube is provided with a third liquid flow hole connecting one end of the component movable cavity and a second liquid flow hole. The other end of the hollow shell is provided with a rod through hole and a fourth liquid flow hole connecting the external space and the other end of the component movable cavity. An elastic airbag is fixedly installed on the body of the flow tube by a fixing ring. The interior of the flow tube is provided with an overflow port connecting the inner cavity of the elastic airbag and the third liquid flow hole. The movable cavity of the component houses an internal valve plate capable of axial movement. The outer circumferential surface of the internal valve plate has a concave liquid flow groove. The end of the internal valve plate facing the third liquid flow hole has a concave annular embedding groove, in which an annular sealing ring is installed. The other end of the internal valve plate is fitted with a compressed helical spring. The end of the internal valve plate is fitted with a horizontal telescopic rod integral with it and passing through a hole in the rod body. The internal parts of the horizontal telescopic rod and the internal valve plate have a fifth liquid flow hole with open ends, and a valve is installed inside the fifth liquid flow hole.

[0013] Preferably, the structural shape of the perforated cross section of the rod is consistent with the structural shape of the cross section of the horizontal telescopic rod, both being polygonal structures, and the structural dimensions of the perforated cross section of the rod match the structural dimensions of the cross section of the horizontal telescopic rod.

[0014] Preferably, the elastic strength of the helical spring is greater than the elastic deformation strength of the elastic airbag in the taut state.

[0015] Preferably, the depth of the annular embedded groove is less than the thickness of the annular sealing ring, the structural radius of the inner ring of the annular sealing ring is greater than the structural radii of the No. 3 liquid flow hole and the No. 5 liquid flow hole, and the structural radius of the outer ring of the annular sealing ring is less than the distance between the liquid flow groove and the centerline of the built-in valve plate.

[0016] Compared with the prior art, the present invention provides an SMT placement machine for electronic component processing, which has the following beneficial effects: The mounting head module is driven directionally by the threaded structure between the adjusting screw and the moving base block. During the movement of the moving base block, the lubricating oil inside it can cover the threaded structure and the horizontal limit rod in a buffering manner, thereby reducing the damage caused by the relative movement friction of the components and thus improving the effective operating time of the equipment. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present invention; Figure 2 This is a three-dimensional cross-sectional view of the present invention; Figure 3 This is a perspective view of the threaded rotary moving mechanism in this invention; Figure 4 This is a three-dimensional cross-sectional view of the threaded rotary moving mechanism in this invention; Figure 5 This is a three-dimensional cross-sectional view of the movable base block in this invention; Figure 6 This is a perspective view of the buffer-type pressure control mechanism in this invention; Figure 7 This is a three-dimensional cross-sectional view of the buffer-type pressure control mechanism in this invention.

[0018] Among them: 1. Threaded rotary moving mechanism; 11. Vertical support base plate; 12. Horizontal limit rod; 13. Shaft mounting hole; 14. Rotating shaft; 15. Adjusting screw; 16. Coupling; 17. Moving base block; 18. Internal threaded hole; 19. Horizontal sliding hole; 110. Lubrication cavity; 111. No. 1 liquid flow hole; 112. No. 2 liquid flow hole; 113. Sealing nut; 114. Sealing cap; 2. Buffer-type pressure control mechanism; 21. Hollow shell; 2 2. Flow tube; 23. Connecting flange; 24. Component moving cavity; 25. No. 3 liquid flow hole; 26. Overflow port; 27. Rod body through hole; 28. No. 4 liquid flow hole; 29. ​​Built-in valve plate; 210. Liquid flow groove; 211. Annular embedded groove; 212. Annular sealing ring; 213. Helical spring; 214. No. 5 liquid flow hole; 215. Elastic airbag; 216. Fixing ring; 217. Horizontal telescopic rod; 3. Mounting base plate for mounting head module. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 and Figure 2 An SMT placement machine for processing electronic components includes a placement head module mounting substrate 3 for mounting the placement head module in the placement machine. During installation, the coupling 16 is connected to the rotor of the servo motor in the placement machine, and the vertical support substrate 11 is fixedly mounted on the driven end of the track of the placement machine.

[0021] To implement directional driving of the placement head module, please refer to [link / reference]. Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A threaded rotating moving mechanism 1 is required, which includes a hollow moving base block 17 that can move the mounting base 3 of the placement head module, an adjusting screw 15 connected to the moving base block 17 via a threaded structure, a horizontal limiting rod 12 that prevents the moving base block 17 from rotating, a first liquid flow hole 113 that prevents lubricating oil from leaking outward along the gap between the moving base block 17 and the adjusting screw 15, and a sealing cap 114 that prevents lubricating oil from leaking outward along the gap between the moving base block 17 and the horizontal limiting rod 12. When the servo motor is started, the rotor will drive the adjusting screw 15 to rotate in a specific direction. Due to the threaded connection, the adjusting screw 15 will cause the moving base block 17 to move in a specific direction, thereby achieving directional drive of the placement head module. During the rotation of the adjusting screw 15, the lubricating oil located inside the lubrication cavity 110 will effectively lubricate the threaded structure and the horizontal limiting rod 12.

[0022] For the specific structure of the threaded rotary moving mechanism 1, please refer to [link / reference]. Figure 3 , Figure 4 and Figure 5The system includes two opposing vertical support base plates 11, which are fixedly connected at their opposing ends by a horizontal limiting rod 12. Each vertical support base plate 11 has a shaft mounting hole 13 with both ends open at its top. A rotating shaft 14 is mounted in each shaft mounting hole 13 via a bearing. An adjusting screw 15 is fixedly mounted at the opposing ends of the two rotating shafts 14. A coupling 16 is fixedly mounted at the end of one of the rotating shafts 14. The moving base block 17 has an internally threaded hole 18 that is threaded around the adjusting screw 15. The moving base block 17 also has a horizontal sliding hole 19 that can slide horizontally along the horizontal limiting rod 12. A lubrication cavity 110 is located around the middle area of ​​the internally threaded hole 18 and the horizontal sliding hole 19. The two lubrication cavities 110 are connected by a first liquid flow hole 111. The moving base block 17 also has a second lubrication cavity 110 that connects one side of the lubrication cavity 111 to the first liquid flow hole 111. Liquid flow hole 112, the movable base block 17 is equipped with a first liquid flow hole 113 at both ends of the internal thread hole 18 to prevent lubricating oil from leaking outward along the gap between the movable base block 17 and the adjusting screw 15, the movable base block 17 is equipped with a sealing cap 114 at both ends of the horizontal sliding hole 19 to prevent lubricating oil from leaking outward along the gap between the movable base block 17 and the horizontal limit rod 12, during operation, the coupling 16 is connected to the rotor of the servo motor in the pick and place machine, during operation, the vertical support base plate 11 is fixedly installed on the driven end of the track of the pick and place machine, the thread structure includes an internal thread structure set on the inner wall of the internal thread hole 18 and an external thread structure set on the lever body of the adjusting screw 15, and the internal thread structure matches the external thread structure, the cross-sectional shape of the horizontal sliding hole 19 is consistent with the cross-sectional shape of the horizontal limit rod 12, both are polygonal structures, and the cross-sectional dimensions of the horizontal sliding hole 19 match the cross-sectional dimensions of the horizontal limit rod 12.

[0023] To achieve pressure control and buffering function of the lubricating oil, please refer to [link / reference]. Figure 1 , Figure 2 , Figure 6 and Figure 7A buffer-type pressure control mechanism 2 needs to be set up. Inside, there is a hollow shell 21 installed on one side of the movable base 17, an internal valve plate 29 that controls the pressure of the liquid flowing into the movable base 17, a helical spring 213 that provides elastic force to the internal valve plate 29, and an elastic airbag 215 that buffers and stores the liquid flowing into the movable base 17. Using a lubricating oil injection device, lubricating oil is injected into the third liquid flow hole 25 through the fifth liquid flow hole 214. Due to the connection, the lubricating oil eventually accumulates inside the lubrication chamber 110. Simultaneously, the liquid pressure causes the elastic airbag 215 to expand, giving the lubricating oil a certain flow pressure. This pressure allows the lubricating oil to enter the gaps in the threaded structure. When the lubricating oil pressure exceeds the elastic strength of the helical spring 213, the internal valve plate 29 will move, and the lubricating oil will overflow along the gaps in the internal valve plate 29 and the fourth liquid flow hole 28. When this phenomenon is observed, the injection of lubricating oil should be stopped immediately.

[0024] For details regarding the specific structure of the buffered pressure control mechanism 2, please refer to [link / reference]. Figure 6 and Figure 7The system includes a component movable cavity 24 disposed inside a hollow shell 21. One end of the hollow shell 21 is provided with an integrally structured flow tube 22. The end of the flow tube 22 is provided with a docking flange 23 fixedly installed on the side of the movable base block 17. Inside the flow tube 22 is a third liquid flow hole 25 connecting one end of the component movable cavity 24 and a second liquid flow hole 112. The other end of the hollow shell 21 is provided with a rod through hole 27 and a fourth liquid flow hole 28 connecting the external space and the other end of the component movable cavity 24. The tube of the flow tube 22... An elastic airbag 215 is fixedly installed within the component via a retaining ring 216. An overflow port 26, connecting the inner cavity of the elastic airbag 215 and the third liquid flow hole 25, is provided inside the flow tube 22. An internal valve plate 29, capable of axial movement, is housed inside the movable cavity 24 of the component. The outer circumferential surface of the internal valve plate 29 has a concave liquid flow groove 210. At the end of the internal valve plate 29 facing the third liquid flow hole 25, a concave annular embedding groove 211 is provided, and an annular seal is installed in the annular embedding groove 211. Circle 212, the other end of the built-in valve plate 29 is equipped with a compressed helical spring 213, and the end of the built-in valve plate 29 is provided with a horizontal telescopic rod 217 integral with it and passing through the rod body through hole 27. The horizontal telescopic rod 217 and the built-in valve plate 29 are provided with a No. 5 liquid flow hole 214 with both ends open, and a valve is installed inside the No. 5 liquid flow hole 214. The cross-sectional shape of the rod body through hole 27 is consistent with the cross-sectional shape of the horizontal telescopic rod 217, both being polygonal structures, and the rod body through... The structural dimensions of the cross-section of hole 27 match the structural dimensions of the cross-section of the horizontal telescopic rod 217. The elastic strength of the helical spring 213 is greater than the elastic deformation strength of the elastic airbag 215 in the taut state. The depth of the annular embedded groove 211 is less than the thickness of the annular sealing ring 212. The structural radius of the inner ring of the annular sealing ring 212 is greater than the structural radii of the third liquid flow hole 25 and the fifth liquid flow hole 214. The structural radius of the outer ring of the annular sealing ring 212 is less than the distance between the centerline of the liquid flow groove 210 and the built-in valve plate 29.

[0025] During use and installation, the coupling 16 is connected to the rotor of the servo motor in the pick-and-place machine, and the vertical support base plate 11 is fixedly installed on the driven end of the track of the pick-and-place machine. A lubricating oil injection device is used to inject lubricating oil into the liquid flow hole 25 through the fifth liquid flow hole 214. Due to the connection, the lubricating oil eventually accumulates inside the lubrication chamber 110. Simultaneously, the liquid pressure causes the elastic airbag 215 to expand, giving the lubricating oil a certain flow pressure. This pressure allows the lubricating oil to enter the gaps in the threaded structure. When the lubricating oil pressure exceeds the elasticity of the coil spring 213... When the pressure is high, the built-in valve plate 29 will move, and the lubricating oil will overflow outward along the moving gap of the built-in valve plate 29 and the fourth liquid flow hole 28. When this phenomenon is observed, the injection of lubricating oil should be stopped in time. Start the servo motor, and the rotor will drive the adjusting screw 15 to rotate in a direction. Due to the threaded connection, the adjusting screw 15 will cause the moving base block 17 to drive the placement head module to move in a direction, thereby realizing the directional drive of the placement head module. During the rotation of the adjusting screw 15, the lubricating oil located inside the lubrication cavity 110 will effectively lubricate the threaded structure and the horizontal limit rod 12.

[0026] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An SMT placement machine for processing electronic components, comprising a placement head module mounting substrate (3) for mounting a placement head module in the placement machine, characterized in that: It also includes, The threaded rotating moving mechanism (1) is provided with a moving base block (17) that can drive the mounting base plate (3) of the mounting head module to move and is hollow inside, an adjusting screw (15) connected to the moving base block (17) by a threaded structure, a horizontal limiting rod (12) that can prevent the moving base block (17) from rotating, a first liquid flow hole (113) that can prevent lubricating oil from leaking outward along the gap between the moving base block (17) and the adjusting screw (15), and a sealing cap (114) that can prevent lubricating oil from leaking outward along the gap between the moving base block (17) and the horizontal limiting rod (12). And a buffer-type pressure control mechanism (2), which is provided with a hollow shell (21) installed on one side of the moving base (17) and hollow inside, an internal valve plate (29) that can control the pressure of liquid flowing into the moving base (17), a helical spring (213) that provides elastic force to the internal valve plate (29), and an elastic airbag (215) that can buffer and store the liquid flowing into the moving base (17).

2. The SMT placement machine for electronic component processing according to claim 1, characterized in that: The threaded rotary moving mechanism (1) includes two opposing vertical support base plates (11). The two vertical support base plates (11) are fixedly connected at their opposing ends by a horizontal limiting rod (12). Each vertical support base plate (11) has a shaft mounting hole (13) with both ends open at its top. Each shaft mounting hole (13) is fitted with a rotating shaft (14) through a bearing. An adjusting screw (15) is fixedly installed at the opposing ends of the two rotating shafts (14). A coupling (16) is fixedly installed at the end of one of the rotating shafts (14). The moving base block (17) has an internal threaded hole (18) that is threaded around the adjusting screw (15). The moving base block (17) also has a horizontal sliding mechanism that can slide horizontally along the horizontal limiting rod (12). The movable base (17) has a lubrication cavity (110) located in the middle area of ​​the internal threaded hole (18) and the horizontal sliding hole (19). The two lubrication cavities (110) are connected by a first liquid flow hole (111). The movable base (17) has a second liquid flow hole (112) inside that connects one side of it to the first liquid flow hole (111). The movable base (17) has a first liquid flow hole (113) installed at both ends of the internal threaded hole (18) to prevent lubricating oil from leaking outward along the gap between the movable base (17) and the adjusting screw (15). The movable base (17) has a sealing cap (114) installed at both ends of the horizontal sliding hole (19) to prevent lubricating oil from leaking outward along the gap between the movable base (17) and the horizontal limit rod (12).

3. The SMT placement machine for electronic component processing according to claim 2, characterized in that: During operation, the coupling (16) is connected to the rotor of the servo motor in the pick-and-place machine.

4. The SMT placement machine for electronic component processing according to claim 3, characterized in that: During operation, the vertical support base plate (11) is fixedly installed on the driven end of the track of the chip mounter.

5. The SMT placement machine for electronic component processing according to claim 4, characterized in that: The threaded structure includes an internal thread structure located on the inner wall of the internal threaded hole (18) and an external thread structure located on the body of the adjusting screw (15), and the internal thread structure matches the external thread structure.

6. The SMT placement machine for electronic component processing according to claim 5, characterized in that: The cross-sectional shape of the horizontal sliding hole (19) is consistent with the cross-sectional shape of the horizontal limiting rod (12), both being polygonal structures, and the structural dimensions of the cross-sectional shape of the horizontal sliding hole (19) match the structural dimensions of the cross-sectional shape of the horizontal limiting rod (12).

7. The SMT placement machine for electronic component processing according to claim 6, characterized in that: The buffer-type pressure control mechanism (2) includes a component movable cavity (24) disposed inside a hollow shell (21). One end of the hollow shell (21) is provided with an integral flow tube (22). The end of the flow tube (22) is provided with a docking flange (23) fixedly installed on the side of the movable base block (17). The interior of the flow tube (22) is provided with a third liquid flow hole (25) connecting one end of the component movable cavity (24) and the second liquid flow hole (112). The other end of the hollow shell (21) is provided with a rod through hole (27) and a fourth liquid flow hole (28) connecting the external space and the other end of the component movable cavity (24). An elastic airbag (215) is fixedly installed on the tube body of the flow tube (22) by a fixing ring (216). The interior of the flow tube (22) is provided with an overflow port connecting the inner cavity of the elastic airbag (215) and the third liquid flow hole (25). (26) The inner cavity (24) of the component is equipped with an internal valve plate (29) that can move along its axial direction. The outer circumferential surface of the internal valve plate (29) is provided with a concave liquid flow groove (210). The end of the internal valve plate (29) facing the third liquid flow hole (25) is provided with a concave annular embedding groove (211). An annular sealing ring (212) is installed in the annular embedding groove (211). A coil spring (213) in a compressed state is installed at the other end of the internal valve plate (29). The end of the internal valve plate (29) is provided with a horizontal telescopic rod (217) that is integral with it and passes through the rod body through hole (27). The interior of the horizontal telescopic rod (217) and the internal valve plate (29) is provided with a fifth liquid flow hole (214) with both ends open. A valve is installed inside the fifth liquid flow hole (214).

8. The SMT placement machine for electronic component processing according to claim 7, characterized in that: The cross-sectional shape of the rod through hole (27) is consistent with the cross-sectional shape of the horizontal telescopic rod (217), both being polygonal structures, and the structural dimensions of the cross-sectional shape of the rod through hole (27) match the structural dimensions of the cross-sectional shape of the horizontal telescopic rod (217).

9. The SMT placement machine for electronic component processing according to claim 8, characterized in that: The elastic strength of the helical spring (213) is greater than the elastic deformation strength of the elastic airbag (215) in the taut state.

10. An SMT placement machine for electronic component processing according to claim 9, characterized in that: The depth of the annular embedded groove (211) is less than the thickness of the annular sealing ring (212). The structural radius of the inner ring of the annular sealing ring (212) is greater than the structural radius of the No. 3 liquid flow hole (25) and the No. 5 liquid flow hole (214). The structural radius of the outer ring of the annular sealing ring (212) is less than the distance between the centerline of the liquid flow groove (210) and the built-in valve plate (29).

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