Rib rolling assembly of rib rolling machine
The adjustable rolling wheel and edge-rolling assembly design solves the flexibility problem of the rolling assembly, enabling efficient processing and diverse adaptability of the inner cylinder, and improving the flexibility of the rolling machine and the support strength of the inner cylinder.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGDAO HUIHAO MOULD EQUIP CO LTD
- Filing Date
- 2025-06-07
- Publication Date
- 2026-05-05
AI Technical Summary
Existing rib rolling assemblies, due to their fixed-shape roller design, cannot flexibly adjust the shape and size of the reinforcing ribs according to different product requirements, and their efficiency in working with edge rolling equipment is low, resulting in poor component flexibility.
The adjustable rolling wheel and edge-rolling assembly are used. The combination of motor, cylinder and threaded rod realizes the vertical movement of the rolling wheel and the edge-rolling operation. Combined with the design of guide groove and elastic element, the replacement and installation of the rolling wheel is convenient, improving the flexibility of the assembly and working efficiency.
It enables flexible replacement and precise installation of the rolling wheels, improves the processing efficiency of the rolling machine and its ability to adapt to different inner cylinder models, and enhances the support strength and processing accuracy of the inner cylinder.
Smart Images
Figure CN224195682U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of inner cylinder manufacturing technology, and in particular to a rolling assembly for a rolling machine. Background Technology
[0002] As a core washing component, the structure of the washing machine drum directly affects the washing effect and the lifespan of the equipment. In order to increase the support strength of the drum body, ribs are pressed into the surface of the drum body using a rib rolling assembly. These ribs are evenly distributed on the surface of the drum, which can effectively disperse the stress borne by the drum during operation and enhance the overall resistance to deformation of the drum.
[0003] The existing cylindrical rib rolling assembly precisely and securely fixes the cylinder to be rolled onto a specially designed operating table. After the inner cylinder is fixed in place on the operating table, the motor starts and drives the inner cylinder to rotate. At the same time, the cylinder drives the roller mold to move and contact the inner cylinder, applying pressure to the inner cylinder. Under the action of pressure, the metal material of the inner cylinder will undergo plastic deformation, forming inwardly concave ribs. By increasing the local thickness of the cylinder wall and changing the stress distribution, the ribs enable the inner cylinder to withstand greater internal pressure or external load, thereby improving the service life of the inner cylinder.
[0004] Regarding the aforementioned technologies, the rib-rolling assembly uses rollers of a fixed shape. When these fixed-shape rollers press against the surface of the inner cylinder, due to the uniformity of the roller shape, they can only form a fixed type of reinforcing rib on the inner cylinder surface. The shape, size, and texture of these reinforcing ribs are strictly limited by the shape of the rollers, and cannot be flexibly adjusted according to different product needs and design requirements. Furthermore, some inner cylinders require edge rolling after the rib-rolling process is completed. However, due to the design of its fixed-shape rollers, the aforementioned rib-rolling assembly cannot work efficiently and accurately with the edge rolling equipment, and cannot meet the manufacturing needs of different models of inner cylinder bodies, resulting in poor flexibility of the assembly. Utility Model Content
[0005] To improve the flexibility of using the rolling assembly of the rolling machine, this application provides a rolling assembly for the rolling machine.
[0006] This application provides a rolling assembly for a rolling machine, which adopts the following technical solution:
[0007] A rolling assembly for a rolling machine includes a base, a support frame at the upper end of the base, motors at both ends of the support frame, two threaded rods corresponding to the motors inside the support frame, the threaded rods being vertically arranged and located on the same axis, the threaded rods being rotatably connected to the support frame, and the threaded rods being coaxially fixed to their corresponding motors, a movable block being provided on the outer side of the threaded rods, the threaded rods being threadedly connected to the movable block, a cylinder being fixedly provided on one side of the movable block, a connecting block being fixedly provided at the output end of the cylinder, the connecting block being hollow, a rolling wheel being provided inside the connecting block, a connecting member being provided between the connecting block and the rolling wheel, the connecting member being used to connect the connecting block and the rolling wheel, a rotating assembly being provided at the upper end of the base, the rotating assembly being used to drive the inner cylinder to rotate, and a curling assembly being provided on one side of the support frame, the curling assembly being used to curl the inner cylinder.
[0008] By adopting the above technical solution, the rotating component starts and drives the inner cylinder to rotate. The edge-rolling component contacts the inner cylinder to roll the inner cylinder edge. The support frame supports the threaded rod. When the motor starts, it drives the threaded rod to rotate. The support frame limits the movement block. The rotation of the threaded rod drives the movement block to move vertically. The vertical movement of the movement block drives the cylinder to move vertically. The movement of the cylinder drives the vertically rolling wheel to move. Then, the cylinder starts and pushes the rolling wheel to contact the inner cylinder, causing the rolling wheel to move vertically and press the reinforcing ribs of the inner cylinder. The two rolling wheels work simultaneously, which helps to improve the working efficiency of the component. At the same time, by controlling the operation of one rolling wheel, reinforcing ribs are formed in different areas of the inner cylinder. When it is necessary to replace the rolling wheel with a different shape, the rolling wheel can be replaced through the connector to meet the needs of different inner cylinders, which helps to improve the flexibility of the component.
[0009] Optionally, the edge-rolling assembly includes cylinder two, roller one, cylinder three, and roller two. Cylinder two is fixed to the upper end of the base. Roller one is coaxially fixed with the output end of cylinder two. Roller one is located inside the inner cylinder and is used to lift the surface of the inner cylinder. Cylinder three is located on one side of cylinder two. Roller two is coaxially fixed with the output end of cylinder three and is used to press the raised edge of the inner cylinder.
[0010] By adopting the above technical solution, cylinder two starts and drives roller one to move and contact the edge of the inner cylinder. Driven by cylinder two, pressure is applied to the surface of the inner cylinder, causing it to curl upward and form a preliminary rolled edge shape. Cylinder three starts and drives roller two to contact the curled edge of the inner cylinder. Roller two presses the curled edge further to fit the inner cylinder wall or form a specific arc by flat pressure, thus realizing the rolled edge of the inner cylinder.
[0011] Optionally, the connector includes a connecting rod, two fixing blocks, and two push rods. The connecting rod is located inside the connecting block and is slidably connected to the connecting block in the lateral direction. The connecting rod passes through the rolling wheel and is fixedly connected to the rolling wheel. The two fixing blocks are respectively fixed at both ends of the connecting block. The push rods correspond one-to-one with the fixing blocks. The push rods are located inside the fixing blocks and are slidably connected to the fixing blocks in the lateral direction. Both ends of the connecting rod have slots. The push rods are inserted into the slots and engage with the inner wall of the slots.
[0012] By adopting the above technical solution, the connecting rod is pushed into the connecting block, the fixing block supports the push rod, and after the connecting rod enters the connecting block, the push rod slides laterally to insert into the slot and engage with the inner wall of the slot, thereby realizing the connection between the roller and the connecting block. At the same time, it is convenient to disassemble and replace rollers of different shapes, improving the flexibility of component use.
[0013] Optionally, the connecting rod includes a vertical rod, two locking rods, and two elastic elements. The vertical rod is coaxially fixed with the rolling wheel. The two locking rods are located at both ends of the vertical rod, and the vertical rod is inserted into the locking rods. The vertical rod is slidably connected to the locking rods in the vertical direction. The elastic elements are fixed between the vertical rod and the locking rods and are used to drive the locking rods to move vertically.
[0014] By adopting the above technical solution, one end of the connecting rod is first brought into contact with the connecting block, and then the vertical rod at the other end is pressed. The vertical rod moves vertically, at which point the elastic element is compressed. Then the other end of the connecting rod is pushed into the connecting block, and the elastic element is in a normal state. The locking rod is engaged with the inner wall of the connecting block, which makes it easy to push the connecting rod into the connecting block and improves the convenience of using the component.
[0015] Optionally, guide grooves are provided at both ends of the connecting block in the transverse direction, and the connecting rod is slidably connected to the connecting block along the length of the guide groove.
[0016] By adopting the above technical solution, the guide groove enables the connecting rod to slide and connect with the connecting block along the length of the guide groove, thereby guiding the connecting rod and ensuring the stability and accuracy of the connecting rod sliding laterally within the connecting block, thus ensuring the stability of the installation and operation of the roller wheel.
[0017] Optionally, the rotating assembly includes a second motor, a turntable, several arc-shaped plates, and a pusher. The second motor is fixed to the upper end of the base, the turntable is coaxially fixed with the output shaft of the second motor, several arc-shaped plates are located at the lower end of the turntable, the arc-shaped plates are evenly distributed along the circumference of the turntable, and the arc-shaped plates are slidably connected to the turntable in the horizontal direction. The turntable pusher is located at the lower end of the turntable and is used to drive the arc-shaped plates to slide in the horizontal direction.
[0018] By adopting the above technical solution, the pusher pushes the arc plate to move horizontally, so that the arc plate is in close contact with the inner wall of the inner cylinder. The second motor starts and drives the turntable to rotate. The rotation of the turntable drives the arc plate to rotate, and the rotation of the arc plate drives the inner cylinder to rotate, so that the component processes the inner cylinder.
[0019] Optionally, a support plate is fixed to the upper end of the base, and the inner cylinder is located at the upper end of the support plate. Push blocks are fixed to both ends of the support plate, and the push blocks are used to limit the movement of the inner cylinder.
[0020] By adopting the above technical solution, the support plate supports the inner cylinder, and the push block constrains the position of the inner cylinder, reducing the probability of displacement of the inner cylinder during processing and improving processing accuracy and stability.
[0021] Optionally, the push block has a groove, the inner cylinder is inserted into the groove, and the push block has an arc-shaped surface that fits against the outer wall of the inner cylinder.
[0022] By adopting the above technical solution, the groove allows the inner cylinder to be inserted, and the arc-shaped surface fits against the outer wall of the inner cylinder, increasing the contact area and making the positioning more stable. This ensures that the inner cylinder remains stable during processing and does not deviate from the rotation trajectory, which is beneficial for the precise execution of operations such as rolling and edge curling.
[0023] In summary, this application includes at least one of the following beneficial technical effects:
[0024] 1. When the cylinder moves, it drives the vertical rolling wheel to move. Then, when the cylinder is activated, it pushes the rolling wheel to contact the inner cylinder, causing the rolling wheel to move vertically and press the reinforcing ribs of the inner cylinder. The two rolling wheels work at the same time, which helps to improve the working efficiency of the component. At the same time, by controlling the operation of one rolling wheel, reinforcing ribs are formed in different areas of the inner cylinder. When it is necessary to replace the rolling wheel with a different shape, the rolling wheel can be replaced through the connector to meet the needs of different inner cylinders, which helps to improve the flexibility of the component.
[0025] 2. The guide groove allows the connecting rod to slide along the length of the guide groove and connect with the connecting block, thus guiding the connecting rod and ensuring the stability of the connecting rod sliding laterally within the connecting block;
[0026] 3. Place one end of the connecting rod into the connecting block, then press the vertical rod at the other end. The vertical rod moves vertically, compressing the elastic element. Then push the other end of the connecting rod into the connecting block. The elastic element is in its normal state, and the locking rod engages with the inner wall of the connecting block, making it easier to push the connecting rod into the connecting block and improving the convenience of using the component. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the overall structure of the rolling assembly of a rolling machine.
[0028] Figure 2This is a schematic diagram designed to highlight the connection structure of the curved plates.
[0029] Figure 3 This is a schematic diagram designed to highlight the connection structure of the connecting blocks.
[0030] Figure 4 This is a cross-sectional schematic diagram designed to highlight the connection structure of the rollers.
[0031] Explanation of reference numerals in the attached drawings: 1. Base; 11. Support frame; 111. Motor 1; 112. Threaded rod; 113. Moving block; 114. Cylinder 1; 115. Connecting block; 1151. Fixing block; 1152. Push rod; 1153. Slot; 1154. Vertical rod; 1155. Locking rod; 1156. Elastic element; 1157. Guide groove; 1158. Rolling wheel; 12. Edge curling assembly; 121. Cylinder 2; 122. Roller 1; 123. Cylinder 3; 124. Roller 2; 13. Rotating assembly; 131. Motor 2; 132. Turntable; 133. Arc plate; 134. Pushing element; 14. Support plate; 141. Push block; 142. Groove; 143. Arc surface; 2. Inner cylinder. Detailed Implementation
[0032] The present application will be further described in detail below with reference to all the accompanying drawings.
[0033] This application discloses a rolling assembly for a rolling machine. Example
[0034] Reference Figure 1 and Figure 2 A rolling assembly for a rolling machine includes a base 1, a support plate 14 fixedly mounted on the upper end of the base 1, and two push blocks 141 fixedly mounted on the upper end of the support plate 14. The two push blocks 141 are located at both ends of the support plate 14. A groove 142 is formed in the push block 141, and an inner cylinder 2 is inserted into the groove 142. The inner wall of the groove 142 limits the inner cylinder 2, reducing the probability of displacement of the inner cylinder 2 during processing and improving the stability of the assembly in processing the inner cylinder 2. The push block 141 is provided with an arc-shaped surface 143, which fits against the outer wall of the inner cylinder 2, increasing the contact area between the push block 141 and the inner cylinder 2, further improving the stability of the assembly and facilitating subsequent rolling and edge curling operations.
[0035] Reference Figure 1 and Figure 2The inner cylinder 2 is equipped with a second motor 131 at its upper end. A turntable 132 is fixedly mounted on the output shaft of the second motor 131. Several arc-shaped plates 133 are provided at the lower end of the turntable 132. The arc-shaped plates 133 are evenly distributed around the turntable 132. A pusher 134 is fixedly mounted on the end of the turntable 132 away from the second motor 131. The pusher 134 pushes the arc-shaped plates 133 to move horizontally, so that the arc-shaped plates 133 are in close contact with the inner cylinder 2. When the second motor 131 is started, it drives the turntable 132 to rotate. The rotation of the turntable 132 drives the arc-shaped plates 133 to rotate. The rotation of the arc-shaped plates 133 drives the inner cylinder 2 to rotate, which facilitates the processing of the inner cylinder 2.
[0036] Reference Figure 3 The base 1 has a support frame 11 at its upper end. Both ends of the support frame 11 are equipped with motors 111. Two threaded rods 112 are installed inside the support frame 11, rotatably connected to the support frame 11. Each threaded rod 112 corresponds to one of the motors 111, and the threaded rod 112 is coaxially fixed to the output shaft of its corresponding motor 111. A moving block 113 is located on the outer side of each threaded rod 112. When the motor 111 starts, it drives the threaded rod 112 to rotate. The support frame 11 limits the movement of the moving block 113. As the threaded rod 112 rotates, the moving block 113 moves vertically. A cylinder 114 is located on one side of the moving block 113, causing the moving block 113 to move vertically. The cylinder 114 moves vertically, and a connecting block 115 is fixed at the output end of the cylinder 114. A rib-rolling wheel 1158 is provided inside the connecting block 115, and a connecting member is provided between the connecting block 115 and the rib-rolling wheel 1158. When the cylinder 114 is activated, it pushes the rib-rolling wheel 1158 to contact the inner cylinder 2 and presses the inner cylinder 2 to form reinforcing ribs. The vertical movement of the cylinder 114 facilitates the operation of the entire inner cylinder 2, and the simultaneous operation of the two rib-rolling wheels 1158 is beneficial to improving the working efficiency of the component. Alternatively, by controlling the operation of one rib-rolling wheel 1158, reinforcing ribs can be formed in different areas of the inner cylinder 2, which is beneficial to improving the flexibility of the component.
[0037] Reference Figure 3 and Figure 4The connector includes a connecting rod, two fixing blocks 1151, and two push rods 1152. The connecting rod is located inside the connecting block 115 and is slidably connected to the connecting block 115 in the transverse direction. The connecting rod passes through the rolling wheel 1158 and is fixedly connected to the rolling wheel 1158. The two fixing blocks 1151 are respectively fixed at both ends of the connecting block 115. The push rods 1152 correspond one-to-one with the fixing blocks 1151 and are located inside the fixing blocks 1151. The fixing blocks 1151 support the push rods 1152. After the connecting rod enters the connecting block 115, the push rod 1152 slides in the transverse direction. Both ends of the connecting rod have slots 1153, which allow the push rod 1152 to be inserted into the slots 1153 and engaged with the inner wall of the slots 1153, thereby connecting the rolling wheel 1158 to the connecting block 115. This also facilitates the disassembly and replacement of rolling wheels 1158 of different shapes, improving the flexibility of the component.
[0038] Reference Figure 1 and Figure 2 The upper end of the base 1 is provided with a curling assembly 12, which includes a second cylinder 121, a first roller 122, a third cylinder 123, and a second roller 124. The second cylinder 121 is fixed to the upper end of the base 1. The first roller 122 is coaxially fixed with the output end of the second cylinder 121 and is located inside the inner cylinder 2. When the second cylinder 121 is activated, it drives the first roller 122 to move and contact the edge of the inner cylinder 2. Through the drive of the second cylinder 121, pressure is applied to the surface of the inner cylinder 2. The cylinder 123 is located on one side of the cylinder 121. The roller 124 is coaxially fixed with the output end of the cylinder 123. The roller 124 is used to press the raised edge of the inner cylinder 2. When the cylinder 123 is started, it drives the roller 124 to contact the raised edge of the inner cylinder 2. The roller 124 presses the raised edge further to fit the inner cylinder 2 wall or form a specific arc by flat pressing, thus realizing the edge rolling of the inner cylinder 2.
[0039] Reference Figure 3 Both ends of the connecting block 115 are provided with guide grooves 1157 along the transverse direction. The connecting rod is slidably connected to the connecting block 115 along the length direction of the guide groove 1157. The guide groove 1157 allows the connecting rod to slide along the length direction of the guide groove 1157 and connect to the connecting block 115, thus guiding the connecting rod and ensuring the stability and accuracy of the transverse sliding of the connecting rod within the connecting block 115. This, in turn, ensures the stability of the installation and operation of the roller 1158.
[0040] Reference Figure 4The connecting rod includes a vertical rod 1154, two locking rods 1155, and two elastic elements 1156. The vertical rod 1154 is coaxially fixed with the rolling wheel 1158. The two locking rods 1155 are located at both ends of the vertical rod 1154, and the vertical rod 1154 is inserted into the locking rods 1155. The vertical rod 1154 is slidably connected to the locking rods 1155 in the vertical direction. The elastic elements 1156 are fixed between the vertical rod 1154 and the locking rods 1155. The elastic elements 1156 are used to drive the locking rods 1155 to move vertically. When installing the roller 1158, first place one end of the connecting rod in contact with the inner wall of the guide groove 1157, then press the other end of the vertical rod 1154. The vertical rod 1154 moves vertically, at which point the elastic element 1156 is compressed. Then push the other end of the connecting rod into the connecting block 115. The elastic element 1156 is in its normal state, and the locking rod 1155 engages with the inner wall of the connecting block 115, making it easier to push the connecting rod into the connecting block 115 and improving the convenience of connecting the roller 1158 and the connecting block 115.
[0041] The implementation principle of the rolling assembly of the rolling machine in this application embodiment is as follows: Cylinder 114 starts and drives the rolling wheel 1158 to move, causing the rolling wheel 1158 to contact the inner cylinder 2. Motor 111 starts and drives the threaded rod 112 to rotate. The rotation of the threaded rod 112 drives the moving block 113 to move vertically. The vertical movement of the moving block 113 drives the cylinder 114 to move vertically. The vertical movement of the cylinder 114 drives the rolling wheel 1158 to move vertically, so that the rolling wheel 1158 contacts various parts of the inner cylinder 2. The two rollers 1158 can be processed separately. Working simultaneously improves work efficiency. At the same time, different areas of the inner cylinder 2 can be processed by controlling the operation of one roller 1158. When it is necessary to replace the roller 1158, the push rod 1152 is moved laterally to separate the push rod 1152 from the slot 1153. Then the connecting rod is moved laterally to separate the connecting rod from the connecting block 115. This makes it easy to replace rollers 1158 of different shapes to meet the needs of different inner cylinders 2 and improve the flexibility of component use.
[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A rolling assembly for a rolling machine, comprising a base (1), characterized in that: The upper end of the base (1) is provided with a support frame (11), and both ends of the support frame (11) are provided with motors (111). Inside the support frame (11) are two threaded rods (112) corresponding to the motors (111). The threaded rods (112) are vertically arranged, and the two threaded rods (112) are located on the same axis. The threaded rods (112) are rotatably connected to the support frame (11), and the threaded rods (112) are coaxially fixed with the corresponding motors (111). A moving block (113) is provided on the outside of the threaded rods (112). The threaded rods (112) and the moving block (113) are threadedly connected. A cylinder (114) is fixedly mounted on one side of the base (1). A connecting block (115) is fixedly mounted on the output end of the cylinder (114). The connecting block (115) is hollow and has a rolling wheel (1158) inside. A connector is provided between the connecting block (115) and the rolling wheel (1158). The connector is used to connect the connecting block (115) and the rolling wheel (1158). A rotating component (13) is provided at the upper end of the base (1). The rotating component (13) is used to drive the inner cylinder (2) to rotate. A curling component (12) is provided on one side of the support frame (11). The curling component (12) is used to curl the inner cylinder (2).
2. The rolling assembly of a rolling machine according to claim 1, characterized in that: The edge-rolling assembly (12) includes cylinder two (121), roller one (122), cylinder three (123) and roller two (124). Cylinder two (121) is fixed to the upper end of the base (1). Roller one (122) is coaxially fixed with the output end of cylinder two (121). Roller one (122) is located inside the inner cylinder (2) and is used to lift the surface of the inner cylinder (2). Cylinder three (123) is located on one side of cylinder two (121). Roller two (124) is coaxially fixed with the output end of cylinder three (123) and is used to press the rolled edge of the inner cylinder (2).
3. The rolling assembly of a rolling machine according to claim 1, characterized in that: The connector includes a connecting rod, two fixing blocks (1151) and two push rods (1152). The connecting rod is located inside the connecting block (115) and is slidably connected to the connecting block (115) in the transverse direction. The connecting rod passes through the roller (1158) and is fixedly connected to the roller (1158). The two fixing blocks (1151) are respectively fixed at both ends of the connecting block (115). The push rods (1152) correspond one-to-one with the fixing blocks (1151). The push rods (1152) are located inside the fixing blocks (1151) and are slidably connected to the fixing blocks (1151) in the transverse direction. Both ends of the connecting rod have slots (1153). The push rods (1152) are inserted into the slots (1153) and are engaged with the inner wall of the slots (1153).
4. The rolling assembly of a rolling machine according to claim 3, characterized in that: The connecting rod includes a vertical rod (1154), two locking rods (1155) and two elastic elements (1156). The vertical rod (1154) is fixed coaxially with the roller (1158). The two locking rods (1155) are located at both ends of the vertical rod (1154) and the vertical rod (1154) is inserted into the locking rods (1155). The vertical rod (1154) is slidably connected to the locking rods (1155) in the vertical direction. The elastic elements (1156) are fixed between the vertical rod (1154) and the locking rods (1155) and are used to drive the locking rods (1155) to move in the vertical direction.
5. The rolling assembly of a rolling machine according to claim 1, characterized in that: The connecting block (115) has guide grooves (1157) at both ends in the transverse direction, and the connecting rod is slidably connected to the connecting block (115) along the length direction of the guide groove (1157).
6. The rolling assembly of a rolling machine according to claim 1, characterized in that: The rotating assembly (13) includes a second motor (131), a turntable (132), several arc-shaped plates (133), and a pusher (134). The second motor (131) is fixed to the upper end of the base (1). The turntable (132) is coaxially fixed with the output shaft of the second motor (131). Several arc-shaped plates (133) are located at the lower end of the turntable (132). The several arc-shaped plates (133) are evenly distributed around the circumference of the turntable (132), and the arc-shaped plates (133) are slidably connected to the turntable (132) in the horizontal direction. The pusher (134) of the turntable (132) is located at the lower end of the turntable (132) and is used to drive the arc-shaped plates (133) to slide in the horizontal direction.
7. The rolling assembly of a rolling machine according to claim 1, characterized in that: The base (1) is fixed with a support plate (14) at its upper end. The inner cylinder (2) is located at the upper end of the support plate (14). Push blocks (141) are fixed at both ends of the support plate (14). The push blocks (141) are used to limit the inner cylinder (2).
8. The rolling assembly of a rolling machine according to claim 7, characterized in that: The push block (141) has a groove (142) inside, the inner cylinder (2) is inserted into the groove (142), and the push block (141) has an arc-shaped surface (143) that fits against the outer wall of the inner cylinder (2).