A TP adhesion mechanism

Abstract

The present invention discloses a TP adhesion mechanism, comprising at least two groups of adhesion components connected by a connecting piece and a driving device connected to the connecting piece to drive all adhesion components to rise and fall simultaneously, the adhesion component comprises a connecting rod and an adhesion block connected to one end of the connecting rod through a buffer portion, the end of the adhesion block away from the connecting rod is a smooth surface that can adhere to TP, and the ends of the connecting rods of all adhesion components away from the adhesion block pass through a mounting plate and are sealed and fixed to the mounting plate through a sealing fixing member. The present invention drives multiple groups of adhesion components to adhere TP simultaneously through a driving device, which can completely resist the force when the upper and lower cavities are closed and vacuumed. Compared with the traditional vacuum adsorption of TP, the closed cavity can avoid TP from being offset or falling after vacuuming, thereby ensuring the fitting accuracy of TP. In addition, the setting of the buffer portion can prevent the adhesion block from crushing and damaging TP.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal panel assembly, and particularly relates to a TP adhesion mechanism. Background Art

[0002] In the production process of liquid crystal panels, one of the links is the bonding of a TP (Touch Panel) and an LCD (Liquid Crystal Display) / LCM (LCD Module) in a vacuum environment between hard substrates. There is an upper cavity template that vacuum-sucks the TP and a lower cavity template that sucks the LCD / LCM. After alignment by the vision system, the upper and lower cavities are closed, and then the air in the cavity is evacuated for bonding.

[0003] When the cavity is closed and evacuated, the air in the upper cavity template will be pumped out. Since the force of vacuum-sucking the TP on the upper cavity template is much smaller than the force of evacuating the vacuum when the cavity is closed, the TP will be offset or dropped, affecting the bonding accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a TP adhesion mechanism that can avoid the offset or dropping of the TP when the cavity is closed and evacuated, and ensure the bonding accuracy of the TP.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] Provide a TP adhesion mechanism, including at least two sets of adhesion components connected by a connecting member and a driving device connected to the connecting member to drive all the adhesion components to lift and lower simultaneously. The adhesion component includes a connecting rod and an adhesion block connected to one end of the connecting rod through a buffer part. The end of the adhesion block away from the connecting rod is a smooth surface that can adhere to the TP. The ends of the connecting rods of all the adhesion components away from the adhesion blocks pass through a mounting plate and are hermetically fixed to the mounting plate through a sealing fixing member.

[0007] As a preferred solution of the TP adhesion mechanism, the buffer part includes a guide cylinder and a spring installed in the guide cylinder. The adhesion block is fixed to one end of a floating block. The end of the floating block away from the adhesion block is inserted into the guide cylinder and connected to the spring. The end of the guide cylinder away from the adhesion block is connected to the connecting rod.

[0008] As a preferred solution of the TP adhesion mechanism, mounting holes are respectively formed on two opposite sides of the guiding cylinder. The mounting holes have a first end face close to the adhesion block and a second end face opposite to the first end face along the axial direction of the guiding cylinder. The buffer portion further includes a gasket located inside the guiding cylinder and connected to the spring. Two sides of the gasket extend into the mounting holes. The gasket can move along the length direction of the mounting holes, and the spring makes the gasket always tend to move towards the first end face. The floating block is movably mounted inside the guiding cylinder.

[0009] As a preferred solution of the TP adhesion mechanism, the floating block includes a first floating column and a second floating column connected coaxially. The outer diameter of the first floating column is smaller than that of the second floating column. A connecting flange fixedly connected to one end of the guiding cylinder close to the adhesion block is sleeved outside the first floating column. The second floating column is inserted into the guiding cylinder and fixedly connected to the gasket. One end of the first floating column far from the second floating column is fixedly connected to the adhesion block through an intermediate connecting member.

[0010] As a preferred solution of the TP adhesion mechanism, a mounting groove for inserting and matching with the connecting rod and a connecting hole coaxial with the mounting groove are formed at one end of the guiding cylinder far from the adhesion block. The connecting hole is located inside the mounting groove. The connecting rod is threadedly connected with a screw inserted into the connecting hole.

[0011] As a preferred solution of the TP adhesion mechanism, the sealing and fixing member includes a first fixing member, a second fixing member and a sealing member sleeved on the connecting rod. The sealing member includes an O-ring and a Y-ring. The first fixing member is fixed to the mounting plate by screws. An annular groove is formed at one end of the first fixing member close to the adhesion block. The O-ring is mounted in the groove and partially protrudes from the surface of the first fixing member. The Y-ring is fixed between the first fixing member and the second fixing member.

[0012] As a preferred solution of the TP adhesion mechanism, the number of the Y-rings is two. The sealing member further includes an annular supporting portion sleeved on the connecting rod and located between the two Y-rings.

[0013] As a preferred solution of the TP adhesion mechanism, the connecting member includes an I-shaped connecting plate and a locking portion for locking the connecting rod. The number of the adhesion assemblies is four groups. The four groups of adhesion assemblies are respectively fixed to four ends of the connecting plate through one locking portion. The driving device includes two lifting cylinders, and the two lifting cylinders are respectively connected to two sides of the connecting plate.

[0014] As a preferred solution of the TP adhesion mechanism, the locking part includes a fixing ring sleeved on the connecting rod and fixedly connected to the surface of the connecting plate away from the adhesion block, a screw rod passing through the fixing ring and threadedly connected to the connecting rod, and a nut cooperating with the screw rod. The nut is located on the surface of the fixing ring away from the connecting plate;

[0015] The fixing ring is provided with an expansion notch along its thickness direction. The expansion notch communicates with the through hole of the fixing ring for inserting the connecting rod, and the opening of the expansion notch is located on the outer side wall of the fixing ring. Two locking holes communicating with the expansion notch are opened on the fixing ring, and the two locking holes are connected by bolts.

[0016] As a preferred solution of the TP adhesion mechanism, the locking part further includes a portal bracket and a locking cap fixed on the fixing ring and located above the screw rod. The portal bracket has an upper end plate and two side plates at both ends of the upper end plate. The nut has two opposite and parallel side edges, and the distance between the two side edges is equal to the distance between the inner side walls of the two side plates. The locking cap includes a connecting part, a pressing part spaced and fixed on the connecting part, and a locking cap body. The connecting part is threadedly connected to the screw rod, the pressing part abuts against the lower surface of the upper end plate, and the distance between the pressing part and the locking cap body is not less than the thickness of the upper end plate.

[0017] Advantages of the present invention: In the present invention, the sealing and fixing member can ensure that the upper and lower cavities always have good sealing performance when the driving device drives the adhesion assembly to move up and down. The surface of the adhesion block is a smooth surface, and after it comes into surface contact with the equally smooth TP surface, the two are adhered together. By driving multiple groups of adhesion assemblies to adhere to the TP simultaneously through the driving device, the acting force of vacuum pumping after the upper and lower cavities are closed can be completely resisted. Compared with the traditional vacuum adsorption of TP, the TP can be prevented from shifting or falling when the closed cavity is pumped with vacuum, thereby ensuring the fitting accuracy of the TP. Moreover, the setting of the buffer part can prevent the adhesion block from pressing or damaging the TP. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of the TP adhesion mechanism according to an embodiment of the present invention.

[0020] Figure 2It is a partial exploded view of the adhesion component and the connection plate according to an embodiment of the present invention.

[0021] Figure 3 It is a schematic structural view of the locking part according to an embodiment of the present invention.

[0022] Figure 4 It is a side view of the locking part according to an embodiment of the present invention.

[0023] In the figure:

[0024] 1. Connecting piece; 11. Connection plate; 12. Fixed ring; 121. Expansion notch; 122. Locking hole; 13. Screw; 14. Nut; 15. Gate-shaped bracket; 16. Connecting part; 17. Tightening part; 18. Locking cap body;

[0025] 2. Adhesion component; 21. Connecting rod; 22. Buffer part; 221. Guide cylinder; 222. Spring; 223. Installation hole; 224. Gasket; 23. Adhesive block; 24. Sealing and fixing piece; 241. First fixing piece; 242. Second fixing piece; 243. O-ring; 244. Y-ring; 245. Supporting part; 25. Floating block; 251. First floating column; 252. Second floating column; 253. Connection flange; 254. Intermediate connecting piece;

[0026] 3. Driving device. Detailed implementation manners

[0027] The technical solution of the present invention will be further described below with reference to the drawings and through specific implementation manners.

[0028] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to this patent; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of actual products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0030] In the description of the present invention, unless otherwise clearly specified and defined, if terms such as "connection" are used to indicate the connection relationship between components, such terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] As Figure 1 and Figure 2 shown, this embodiment provides a TP adhesion mechanism, which includes at least two groups of adhesion components 2 connected by a connecting member 1 and a driving device 3 connected to the connecting member 1 to drive all the adhesion components 2 to lift and lower simultaneously. The adhesion component 2 includes a connecting rod 21 and an adhesion block 23 connected to one end of the connecting rod 21 through a buffer portion 22. The end of the adhesion block 23 away from the connecting rod 21 is a smooth surface for adhering to the TP. The ends of the connecting rods 21 of all the adhesion components 2 away from the adhesion blocks 23 pass through a mounting plate and are hermetically fixed to the mounting plate through a sealing fixing member 24.

[0032] In this embodiment, the sealing fixing member 24 can ensure that the upper and lower cavities always have good sealing performance when the driving device 3 drives the adhesion component 2 to lift and lower. The surface of the adhesion block 23 is a smooth surface, and after it comes into surface contact with the equally smooth TP surface, the two adhere together. By driving multiple groups of adhesion components 2 to adhere to the TP simultaneously through the driving device 3, the acting force of vacuum pumping after the upper and lower cavities are closed can be completely resisted. Compared with the traditional vacuum adsorption of the TP, the TP can be prevented from shifting or falling when the closed cavity is evacuated, thereby ensuring the fitting accuracy of the TP. Moreover, the setting of the buffer portion 22 can prevent the adhesion block 23 from pressing and damaging the TP.

[0033] Specifically, the buffer portion 22 includes a guide cylinder 221 and a spring 222 installed in the guide cylinder 221. The adhesion block 23 is fixed to one end of a floating block 25. The end of the floating block 25 away from the adhesion block 23 is inserted into the guide cylinder 221 and connected to the spring 222. The end of the guide cylinder 221 away from the adhesion block 23 is connected to the connecting rod 21.

[0034] The guiding cylinder 221 guides the telescopic direction of the spring 222, preventing the spring 222 from bending during the telescopic process and affecting the adhesion of the adhesion assembly 2 to the TP. When the driving device 3 drives the adhesion assembly 2 to move downward until the adhesion block 23 contacts the TP, the adhesion block 23 is subjected to the resistance of the TP, causing the floating block 25 to push up the spring 222. The spring 222 contracts, thereby realizing the buffering effect when the adhesion block 23 adheres to the TP. Similarly, after the driving device 3 drives the adhesion block 23 to adhere to the TP and then descend and fit on the LCD / LCM, the buffer portion 22 also provides a certain buffering force for this fitting process.

[0035] Further, mounting holes 223 are respectively formed on two opposite sides of the guiding cylinder 221. The mounting holes 223 have a first end face close to the adhesion block 23 and a second end face opposite to the first end face along the axial direction of the guiding cylinder 221. The buffer portion 22 further includes a gasket 224 located inside the guiding cylinder 221 and connected to the spring 222. Both sides of the gasket 224 extend into the mounting holes 223. The gasket 224 can move along the length direction of the mounting holes 223, and the spring 222 always makes the gasket 224 tend to move towards the first end face. The floating block 25 is movably installed inside the guiding cylinder 221.

[0036] In this embodiment, the mounting holes 223 are formed on two opposite sides of the guiding cylinder 221, facilitating the installation of the gasket 224 and the fixation of the spring 222 inside the guiding cylinder 221. At the same time, both sides of the gasket 224 extend to the positions of the mounting holes 223 and are flush with the outer periphery of the guiding cylinder 221, which can further guide the telescopic direction of the spring 222 and limit the telescopic limit of the spring 222, preventing the spring 222 from being deformed due to excessive contraction or excessive stretching and being unable to recover.

[0037] In this embodiment, the floating block 25 includes a first floating column 251 and a second floating column 252 connected coaxially. The outer diameter of the first floating column 251 is smaller than that of the second floating column 252. A connecting flange 253 fixedly connected to one end of the guiding cylinder 221 close to the adhesion block 23 is sleeved outside the first floating column 251. The second floating column 252 is inserted into the guiding cylinder 221 and fixedly connected to the gasket 224. One end of the first floating column 251 away from the second floating column 252 is fixedly connected to the adhesion block 23 through an intermediate connecting member 254.

[0038] Specifically, the first floating column 251 and the connecting flange 253 are in clearance fit, and the second floating column 252 and the inner wall of the guiding cylinder 221 are in clearance fit, so that the floating block 25 can move smoothly along the axial direction of the guiding cylinder 221. The connecting flange 253 in this embodiment is equivalent to a limiting plate, preventing the floating block 25 from detaching from the guiding cylinder 221.

[0039] One end of the guiding cylinder 221 away from the adhesion block 23 is provided with a mounting groove for inserting and mating with the connecting rod 21 and a connecting hole coaxial with the mounting groove. The connecting hole is located within the mounting groove. The connecting rod 21 is threadedly engaged with a screw inserted into the connecting hole, thereby fixedly connecting the connecting rod 21 to the guiding cylinder 221. The design of the mounting hole 223 on the guiding cylinder 221 also facilitates the quick connection between the connecting rod 21 and the guiding cylinder 221.

[0040] In this embodiment, the sealing and fixing member 24 includes a first fixing member 241, a second fixing member 242 sleeved on the connecting rod 21, and a sealing member. The sealing member includes an O-ring 243 and a Y-ring 244. The first fixing member 241 is fixed to the mounting plate by screws. One end of the first fixing member 241 close to the adhesion block 23 is provided with an annular groove. The O-ring 243 is installed in the groove and partially protrudes from the surface of the first fixing member 241. The Y-ring 244 is fixed between the first fixing member 241 and the second fixing member 242.

[0041] Among them, the O-ring 243 seals between the first fixing member 241 fixed to the mounting plate and the mounting plate. The Y-ring 244 is fixed between the first fixing member 241 and the connecting rod 21 through the second fixing member 242, providing a good sealing effect between the first fixing member 241 and the connecting rod 21.

[0042] Further, the number of Y-rings 244 is two. The sealing member further includes an annular supporting portion 245. The supporting portion 245 is sleeved on the connecting rod 21 and located between the two Y-rings 244.

[0043] In this embodiment, in order to further strengthen the sealing effect between the first fixing member 241, the second fixing member 242 and the connecting rod 21, two Y-rings 244 are required, and the supporting portion 245 serves to support the two Y-rings 244.

[0044] The connecting member 1 includes an I-shaped connecting plate 11 and a locking portion for locking the connecting rod 21 to the connecting plate 11. The number of adhesion assemblies 2 is four groups. The four groups of adhesion assemblies 2 are respectively fixed to the four ends of the connecting plate 11 through a locking portion. The driving device 3 includes two lifting cylinders, and the two lifting cylinders are respectively connected to both sides of the connecting plate 11.

[0045] In this embodiment, an adhesion assembly 2 is installed adjacent to each of the four ends of the I-shaped connecting plate 11, which can further improve the adhesion stability and fitting flatness of the TP adhesion mechanism to the TP. Moreover, both sides of the I-shaped connecting plate 11 are respectively connected to a lifting cylinder, which can improve the force uniformity of the four groups of adhesion assemblies 2, enabling the four adhesion blocks 23 to stably float and adhere to the TP.

[0046] Specifically, asFigure 3 and Figure 4 As shown in Figure 4 , the locking part includes a fixing ring 12 sleeved on the connecting rod 21 and fixedly connected to the surface of the connecting plate 11 away from the adhesive block 23, a screw rod 13 passing through the fixing ring 12 and threadedly connected to the connecting rod 21, and a nut 14 cooperating with the screw rod 13. The nut 14 is located on the surface of the fixing ring 12 away from the connecting plate 11;

[0047] An expansion notch 121 is formed in the fixing ring 12 along its thickness direction. The expansion notch 121 communicates with the through hole of the fixing ring 12 for inserting the connecting rod 21, and the opening of the expansion notch 121 is located on the outer side wall of the fixing ring 12. Two locking holes 122 communicating with the expansion notch 121 are formed in the fixing ring 12, and the two locking holes 122 are connected by bolts.

[0048] Among them, the design of the expansion notch 121 enables the fixing ring 12 to adapt to the connecting rod 21 floating within a certain size range, and the connecting rod 21 and the fixing ring 12 are locked by bolts passing through the two locking holes 122. The nut 14 is designed on the upper surface of the fixing ring 12 for convenient screwing and fixing.

[0049] The locking part further includes a portal bracket 15 fixed on the fixing ring 12 and located above the screw rod 13 and a locking cap. The portal bracket 15 has an upper end plate and two side plates at both ends of the upper end plate. The nut 14 has two opposite and parallel side edges, and the distance between the two side edges is equal to the distance between the inner side walls of the two side plates. The locking cap includes a connecting part 16, a pressing part 17 spaced and fixed on the connecting part 16, and a locking cap body 18. The connecting part 16 is threadedly connected to the screw rod 13, the pressing part 17 abuts against the lower surface of the upper end plate, and the distance between the pressing part 17 and the locking cap body 18 is not less than the thickness of the upper end plate.

[0050] The two side plates of the portal bracket 15 and the two side edges of the nut 14 are in contact, which can prevent the nut 14 from rotating and loosening, enable the fixing ring 12 to be stably installed on the connecting plate 11, prevent the bolts from loosening and affecting its stability, avoid affecting the stable adhesion of the adhesive block 23 to the TP, and prevent the fitting forces of the four groups of adhesive assemblies 2 after adhering to the TP from being inconsistent.

[0051] Furthermore, the portal bracket 15 further includes two connecting cross plates respectively connected to the lower ends of one of the side plates. The connecting cross plates are located outside the side plates, and arc-shaped notches are respectively formed on one side of the connecting cross plates and one side of the upper end plate. The connecting cross plates are fixedly connected to the fixing ring 12 by screws inserted into the arc-shaped notches. The design of the arc-shaped notches can facilitate the disassembly and assembly of the portal bracket 15 and the locking cap.

[0052] It should be noted that the above specific embodiments are only the preferred embodiments of the present invention and the technical principles applied. Those skilled in the art should understand that various modifications, equivalent replacements, changes, etc. can also be made to the present invention. However, as long as these transformations do not deviate from the spirit of the present invention, they should be within the protection scope of the present invention. In addition, some terms used in the specification and claims of this application are not restrictive, but are only for the convenience of description.

Claims

1. A TP adhesion mechanism, characterized in that: The invention comprises at least two groups of adhesive components connected by connecting members and a driving device connected to the connecting members to drive all the adhesive components to rise and fall simultaneously, wherein the adhesive components comprise a connecting rod and an adhesive block connected to one end of the connecting rod through a buffer portion, wherein one end of the adhesive block away from the connecting rod is a smooth surface that can be adhered to TP, and one end of the connecting rod of all the adhesive components away from the adhesive block passes through a mounting plate and is sealed and fixed to the mounting plate through a sealing fixing member; The buffer part includes a guide cylinder and a spring installed in the guide cylinder, the adhesive block is fixed to one end of a floating block, the end of the floating block away from the adhesive block is inserted into the guide cylinder and connected to the spring, and the end of the guide cylinder away from the adhesive block is connected to the connecting rod; The sealing fixing member includes a first fixing member, a second fixing member and a sealing member which are sleeved on the connecting rod, the sealing member includes an O-ring and a Y-ring, the first fixing member is fixed to the mounting plate by screws, an annular groove is provided at one end of the first fixing member close to the adhesive block, the O-ring is installed in the groove and partially protrudes from the surface of the first fixing member, and the Y-ring is fixed between the first fixing member and the second fixing member.

2. The TP adhesion mechanism according to claim 1, characterized in that: The guide cylinder is provided with mounting holes on opposite sides thereof, and the mounting hole has a first end face close to the adhesive block and a second end face opposite to the first end face along the axial direction of the guide cylinder. The buffer portion also includes a gasket located in the guide cylinder and connected to the spring, and both sides of the gasket extend into the mounting hole. The gasket can move along the length direction of the mounting hole, and the spring makes the gasket always have a tendency to move toward the first end face. The floating block is movably installed in the guide cylinder.

3. The TP adhesion mechanism according to claim 2, characterized in that: The floating block includes a first floating column and a second floating column that are coaxially connected. The outer diameter of the first floating column is smaller than the outer diameter of the second floating column. The outer sleeve of the first floating column is provided with a connecting flange fixedly connected to one end of the guide cylinder close to the adhesive block. The second floating column is inserted into the guide cylinder and fixedly connected to the gasket. The end of the first floating column away from the second floating column is fixedly connected to the adhesive block through an intermediate connecting piece.

4. The TP adhesion mechanism according to claim 1, characterized in that: The end of the guide cylinder away from the adhesive block is provided with a mounting groove plugged with the connecting rod and a connecting hole coaxial with the mounting groove. The connecting hole is located in the mounting groove, and the connecting rod is screwed to the screw inserted into the connecting hole.

5. The TP adhesion mechanism according to claim 1, characterized in that: The number of the Y-shaped sealing rings is two, and the sealing member further comprises an annular supporting portion, which is sleeved on the connecting rod and located between the two Y-shaped sealing rings.

6. The TP adhesion mechanism according to claim 1, characterized in that: The connecting member includes an I-shaped connecting plate and a locking portion for locking the connecting rod. The number of the adhesive components is four groups, and the four groups of adhesive components are respectively fixed to the four ends of the connecting plate through one of the locking portions. The driving device includes two lifting cylinders, and the two lifting cylinders are respectively connected to the two sides of the connecting plate.

7. The TP adhesion mechanism according to claim 6, characterized in that: The locking part comprises a fixing ring sleeved on the connecting rod and fixedly connected to a side of the connecting plate away from the adhesive block, a screw rod passing through the fixing ring and screwed to the connecting rod, and a nut matched with the screw rod, wherein the nut is located on a side of the fixing ring away from the connecting plate; The fixing ring has an expansion notch along its thickness direction, the expansion notch is connected to the through hole of the fixing ring for inserting the connecting rod, and the opening of the expansion notch is located on the outer side wall of the fixing ring. The fixing ring has two locking holes connected to the expansion notch, and the two locking holes are connected by bolts.

8. The TP adhesion mechanism according to claim 7, characterized in that: The locking portion also includes a door-shaped bracket and a locking cap fixed on the fixing ring and located above the screw rod, the door-shaped bracket has an upper end plate and two side plates located at both ends of the upper end plate, the nut has two side edges that are opposite to each other and parallel, and the distance between the two side edges is equal to the distance between the inner walls of the two side plates, the locking cap includes a connecting portion, a tightening portion fixed on the connecting portion at intervals, and a locking cap body, the connecting portion is screwed to the screw rod thread, the tightening portion is in abutment with the lower surface of the upper end plate, and the distance between the tightening portion and the locking cap body is not less than the thickness of the upper end plate.

Images