Cleaning machine for wafer processing

Abstract

The invention relates to the field of wafer processing, in particular to a cleaning machine for wafer processing, which comprises a mounting frame and further comprises a cleaning box, and a sliding notch is formed in the side wall of the cleaning box; the megasonic cleaning mechanism comprises a liquid adding pipe, a cleaning pipe is arranged on the liquid adding pipe, and the cleaning pipe is connected with a megasonic cleaning head; the reciprocating driving assembly is arranged on the cleaning box, the rotary clamping mechanism comprises a fixing frame, a reciprocating moving plate is arranged on the fixing frame, and a second rack plate is arranged at the bottom of the reciprocating moving plate; a second mounting frame is further included, a connecting notch is formed in the second mounting frame, an outer gear slides on the connecting notch, and the outer gear is in meshed connection with the second rack plate; the interior of the external gear is connected with the wafer body through an elastic clamping assembly. According to the wafer cleaning machine, the wafers can be synchronously cleaned in batches, so that the cleaning efficiency of the cleaning machine is improved, and the use of the cleaning machine is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wafer processing, and particularly relates to a cleaning machine for wafer processing. BACKGROUND

[0002] Wafer processing is a core link of semiconductor manufacturing, which refers to a process of manufacturing a silicon wafer containing thousands of integrated circuits through a series of precise and complex process steps. The whole process can be divided into three stages of front-end process, middle-end process and back-end process, each stage containing dozens or even hundreds of subdivided steps, which requires high precision of environment and equipment.

[0003] In the wafer processing process, a cleaning machine is needed to clean the wafer. However, in order to ensure clean cleaning of the wafer and prevent pollution between wafers, the current cleaning machine often processes a single wafer, so the cleaning machine cannot realize batch synchronous cleaning of multiple wafers, thereby affecting the wafer cleaning efficiency of the cleaning machine. SUMMARY

[0004] The present application aims to provide a cleaning machine for wafer processing to solve the problems in the background.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0006] A cleaning machine for wafer processing, comprising a mounting frame, further comprising: a cleaning tank, the cleaning tank is placed on the mounting frame, a plurality of sliding notches are evenly arranged on the side walls at both ends of the cleaning tank; a megasonic cleaning mechanism, the megasonic cleaning mechanism comprises a liquid feeding pipe, a plurality of cleaning pipes are evenly arranged on the liquid feeding pipe, the cleaning pipes pass through the sliding notches and are connected with the megasonic cleaning head; further comprising a reciprocating driving assembly, the reciprocating driving assembly is placed on the outer wall of the cleaning tank and is used to drive the cleaning pipes to realize reciprocating movement; a rotating clamping mechanism, the rotating clamping mechanism comprises symmetrically arranged fixed frames, a reciprocating moving plate is slidably arranged on the fixed frame, a second rack plate is arranged at the bottom of the reciprocating moving plate; further comprising a second mounting frame, the second mounting frame is fixedly arranged at the center of the top end of the cleaning tank; a plurality of connecting notches are evenly arranged on the second mounting frame, an external gear is slidably arranged on the connecting notch, the external gear is meshed and connected with the second rack plate; the external gear is clamped and connected with the wafer body through a plurality of elastic clamping assemblies inside the external gear; the megasonic cleaning head is placed on both sides of the wafer body.

[0007] Preferably, the front end of the mounting frame is connected with an operator through a first mounting frame.

[0008] Preferably, a processor and a power supply are fixedly arranged on the inner wall of the mounting frame.

[0009] Preferably, the cleaning tank is internally provided with a flow guide groove, the bottom of the flow guide groove is provided with a cleaning liquid storage cylinder, and the bottom of the cleaning liquid storage cylinder is in contact connection with the cleaning tank.

[0010] Preferably, the cleaning tank is internally provided with a flow guide groove, the bottom of the flow guide groove is provided with a cleaning liquid storage cylinder, and the bottom of the cleaning liquid storage cylinder is in contact connection with the cleaning tank.

[0011] Preferably, the liquid pumping assembly comprises a liquid pumping pump fixedly connected with the inner wall of the cleaning tank, the liquid pumping pump is inserted into the inside of the cleaning liquid storage cylinder through a liquid pumping pipe, and a filter cover is arranged in the inside of the cleaning liquid storage cylinder outside the liquid pumping pipe; the liquid pumping assembly further comprises a liquid discharging pipe in communication connection at one end with the liquid supplying pipe and in connection at the other end with the liquid pumping pump.

[0012] Preferably, the reciprocating driving assembly comprises a multi-section reciprocating driving screw rotatably installed on the outer wall of the cleaning tank; the reciprocating driving assembly further comprises a plurality of sliding blocks in screw connection with the multi-section reciprocating driving screw, and the sliding blocks are connected with the cleaning pipe through connecting rods.

[0013] Preferably, a guide notch is formed in the second mounting frame on the two sides of the connecting notch, and a guide ring is arranged at the outer end of the external gear and inserted into the inside of the guide notch.

[0014] Preferably, the elastic clamping assembly comprises a connecting cylinder arranged on the inner wall of the external gear, a sliding rod slidingly arranged on the connecting cylinder, and the sliding rod is connected with the inner wall of the connecting cylinder through a clamping spring; the elastic clamping assembly further comprises an arc-shaped clamping block, the inner end of the arc-shaped clamping block is provided with a rubber protection pad, and the arc-shaped clamping block is connected with the sliding rod.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] 1. By arranging the megasonic cleaning mechanism at the two ends of the cleaning tank, cooperating with the rotating clamping mechanism arranged at the top of the cleaning tank to drive the clamped wafers to rotate synchronously, and cooperating with the reciprocating movement of the megasonic cleaning head, the cleaning efficiency is significantly improved, and each wafer surface can be uniformly and dead-angle-free cleaned, realizing the unification of batch processing and cleaning quality.

[0017] 2. The elastic clamping assembly is used to elastically clamp the wafer body, the second rack plate is driven to move by the reciprocating moving plate, the external gear arranged on the second mounting frame is driven to rotate synchronously by the second rack plate, and the wafer body clamped in the external gear is realized synchronous rotation processing.

[0018] 3. This invention uses a reciprocating drive assembly to drive the cleaning tubes at both ends to move the megasonic cleaning head back and forth for megasonic cleaning. Combined with the rotating wafer body, it can achieve symmetrical batch megasonic cleaning of wafers, thereby improving the wafer cleaning efficiency of the cleaning machine and facilitating its use. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a cleaning machine for wafer processing provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the liquid extraction component in a wafer processing cleaning machine provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the connection between the processor and the power supply in a wafer processing cleaning machine provided by the present invention.

[0022] Figure 4 This is a schematic diagram of the connection between the reciprocating drive component and the cleaning tube in a wafer processing cleaning machine provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the structure of a reciprocating moving plate and an external gear meshing in a wafer processing cleaning machine provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the connection between the second mounting frame and the external gear in a wafer processing cleaning machine provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the structure of the second mounting frame in a wafer processing cleaning machine provided by the present invention.

[0026] Figure 8 This is a schematic diagram of the connection between the external gear and the wafer body in a cleaning machine for wafer processing provided by the present invention.

[0027] Figure 9 This is a cross-sectional view of the external gear in a wafer processing cleaning machine provided by the present invention.

[0028] Figure 10 for Figure 9 A schematic diagram of the elastic clamping component at point A.

[0029] Label: 1, installation frame; 2, cleaning box; 3, megasonic cleaning mechanism; 4, rotating clamping mechanism; 5, wafer body; 11, support leg; 12, universal wheel; 13, first installation frame; 14, operator; 15, processor; 16, power supply; 21, flow guide groove; 22, cleaning liquid storage cylinder; 23, sliding notch; 31, liquid supply pipe; 32, liquid pumping assembly; 321, liquid pumping pump; 322, liquid pumping pipe; 323, filter cover; 324, liquid discharge pipe; 33, connecting pipe; 34, liquid filling pipe; 35, connecting hose; 36, cleaning pipe; 361, sliding sleeve; 37, megasonic cleaning head; 38, reciprocating driving assembly; 381, multi-section reciprocating driving screw; 382, sliding block; 383, connecting rod; 41, fixed frame; 42, reinforcing plate; 43, reciprocating moving plate; 431, first rack plate; 432, second rack plate; 44, driving gear; 45, second installation frame; 46, connecting notch; 461, guide notch; 47, external gear; 48, guide ring; 49, elastic clamping assembly; 491, connecting cylinder; 492, sliding rod; 493, clamping spring; 494, arc-shaped clamping block; 495, rubber protection pad. DETAILED DESCRIPTION

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that, in the embodiments of the present application, many technical details are presented in order to make the readers better understand the present application. However, the technical solutions claimed by the present application can be realized even without these technical details and based on various changes and modifications of the following embodiments.

[0032] The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0033] Reference Figures 1-10 In the embodiments of the present application, a cleaning machine for wafer processing includes an installation frame 1, and further includes:

[0034] A cleaning box 2 is arranged on the installation frame 1, and a plurality of sliding notches 23 are arranged on the side walls at both ends of the cleaning box 2 at equal intervals. The cleaning box 2 is used for cleaning and processing the wafer, and the sliding notches 23 are arranged to facilitate the sliding connection between structures.

[0035] Megasonic cleaning mechanism 3, megasonic cleaning mechanism 3 includes liquid adding pipe 34, a plurality of cleaning pipes 36 are arranged at equal intervals on the liquid adding pipe 34, the cleaning pipe 36 is connected with the megasonic cleaning head 37 through the sliding notch 23, the megasonic cleaning head 37 is used to realize megasonic cleaning treatment to the wafer, so that high-precision cleaning is realized;

[0036] Further comprising reciprocating drive assembly 38, which is arranged on the outer wall of the cleaning tank 2, for driving the cleaning pipe 36 to realize reciprocating movement;

[0037] Rotary clamping mechanism 4, the rotary clamping mechanism 4 includes symmetrically arranged fixed frame 41, the fixed frame 41 is slidably provided with reciprocating moving plate 43, and the bottom of the reciprocating moving plate 43 is provided with second rack plate 432;The fixed frame 41 at both ends realizes the limiting guide of the reciprocating moving plate 43;

[0038] Further comprising second mounting frame 45, which is fixedly arranged at the top center of the cleaning tank 2;

[0039] A plurality of connecting notches 46 are arranged at equal intervals on the second mounting frame 45, and an external gear 47 is slidably arranged on the connecting notch 46, the external gear 47 is in meshing connection with the second rack plate 432, and the reciprocating moving plate 43 drives the second rack plate 432 to move synchronously during reciprocating movement, and the second rack plate 432 drives the meshing connected external gear 47 to reciprocate;

[0040] The external gear 47 is clamped and connected with the wafer body 5 through a plurality of elastic clamping assemblies 49 inside the external gear 47;

[0041] The megasonic cleaning head 37 is arranged on both sides of the wafer body 5, and the megasonic cleaning head 37 is used for realizing symmetric cleaning treatment to the wafer body 5.

[0042] Referring to Figure 1 In an embodiment of the present application, the mounting frame 1 is provided with supporting legs 11 at the bottom of the four corners, and universal wheels 12 are installed on the supporting legs 11, so that the universal wheels 12 can be conveniently used for adjusting the moving direction of the machine.

[0043] Referring to Figure 1 In an embodiment of the present application, the mounting frame 1 is connected with an operator 14 through the first mounting frame 13 at the front end, and the operator 14 is used for operating the work of the whole cleaning machine.

[0044] Referring to Figure 3 In an embodiment of the present application, the mounting frame 1 is fixedly provided with a processor 15 and a power supply 16 on the inner wall, and the processor 15 and the power supply 16 can realize the control of the work and power supply of the whole cleaning machine.

[0045] See Figure 2 In one embodiment of the present invention, the cleaning tank 2 is provided with a flow guide 21 inside, and a cleaning fluid storage cylinder 22 is provided at the bottom of the flow guide 21. The bottom of the cleaning fluid storage cylinder 22 is in contact with the cleaning tank 2. The flow guide 21 and the cleaning fluid storage cylinder 22 are used to store and process the cleaning fluid.

[0046] See Figures 1-4 In one embodiment of the present invention, the megaphonic cleaning mechanism 3 further includes a liquid supply pipe 31, which is placed outside the cleaning tank 2;

[0047] The liquid supply pipe 31 is connected to the cleaning liquid storage cylinder 22 via the liquid extraction assembly 32;

[0048] The top two ends of the liquid supply pipe 31 are connected to the liquid addition pipe 34 via connecting pipe 33 and connecting hose 35.

[0049] The cleaning fluid inside the cleaning fluid storage cylinder 22 is drawn into the liquid supply pipe 31 by the liquid extraction component 32, and the liquid is added to the liquid addition pipe 34 through the connecting pipe 33 and the connecting hose 35.

[0050] See Figure 2 In one embodiment of the present invention, the liquid extraction assembly 32 includes a liquid extraction pump 321, which is fixedly connected to the inner wall of the cleaning tank 2. The liquid extraction pump 321 is inserted into the cleaning liquid storage cylinder 22 through a liquid extraction pipe 322, and a filter cover 323 is provided inside the cleaning liquid storage cylinder 22 located outside the liquid extraction pipe 322.

[0051] It also includes a drain pipe 324, one end of which is connected to the supply pipe 31 and the other end is connected to the pump 321.

[0052] The pump 321 operates, and the pumping pipe 322 draws the cleaning solution filtered by the filter cover 323 into the supply pipe 31 through the drain pipe 324 for liquid supply treatment.

[0053] See Figure 4 In one embodiment of the present invention, a sliding sleeve 361 is fixedly provided on the cleaning tube 36, and the sliding sleeve 361 is slidably connected to the sliding recess 23. The provision of the sliding sleeve 361 can realize the slidable connection between the sliding recess 23 and the cleaning tube 36.

[0054] See Figure 1 and Figure 8 In one embodiment of the present invention, the reciprocating drive assembly 38 includes a multi-segment reciprocating drive screw 381, which is rotatably mounted on the outer wall of the cleaning tank 2.

[0055] It also includes several sliders 382, ​​which are threadedly connected to a multi-segment reciprocating drive screw 381, and the sliders 382 are connected to the cleaning tube 36 through a connecting rod 383;

[0056] The multi-segment reciprocating drive screw 381 drives the threaded slider 382 to reciprocate. The slider 382 drives the cleaning tube 36 to reciprocate synchronously for megasonic cleaning treatment via the connecting rod 383.

[0057] The multi-segment reciprocating drive screw 381 has fixed blocks at both ends. The fixed blocks are connected to the cleaning machine, and a drive motor is installed on the fixed blocks. The drive motor is connected to the multi-segment reciprocating drive screw 381, and the drive motor drives the multi-segment reciprocating drive screw 381 to perform forward and reverse rotation.

[0058] The multi-segment reciprocating drive screw 381 includes several threaded segments with the same direction of rotation. When the multi-segment reciprocating drive screw 381 rotates at a constant speed in both directions, the slider (382) that cooperates with it can achieve reciprocating motion within its stroke.

[0059] See Figure 2 In one embodiment of the present invention, the bottom of the fixed frame 41 is connected to the cleaning tank 2 by a reinforcing plate 42. The reinforcing plate 42 can achieve the fixed connection of the fixed frame 41.

[0060] See Figures 1-2 In one embodiment of the present invention, a first rack plate 431 is provided at the top of the reciprocating moving plate 43, and a drive gear 44 is installed on the fixed frame 41. The drive gear 44 is meshed with the first rack plate 431, and the first rack plate 431 is driven to move by the drive gear 44. The first rack plate 431 drives the reciprocating moving plate 43 to perform reciprocating movement.

[0061] The drive gear 44 is connected to the fixed frame 41 via a mounting bracket. A drive motor is mounted on the fixed frame 41, and the motor shaft of the drive motor is connected to the drive gear 44. The drive motor is used to control the drive gear to perform forward and reverse rotation.

[0062] See Figure 7 and Figure 8 In one embodiment of the present invention, a guide recess 461 is provided on the second mounting frame 45 located on both sides of the connecting recess 46. A guide ring 48 is provided at the outer end of the external gear 47. The guide ring 48 is inserted into the guide recess 461. During the rotation of the external gear 47, the guide ring 48 rotates synchronously inside the guide recess 461, which can ensure that the external gear 47 rotates smoothly.

[0063] See Figure 9 and Figure 10In one embodiment of the present invention, the elastic clamping assembly 49 includes a connecting cylinder 491, the connecting cylinder 491 is placed on the inner wall of the external gear 47, and a sliding rod 492 is slidably disposed on the connecting cylinder 491, the sliding rod 492 being connected to the inner wall of the connecting cylinder 491 through a clamping spring 493;

[0064] It also includes an arc-shaped clamping block 494, the inner end of which is provided with a rubber protective pad 495, and the arc-shaped clamping block 494 is connected to the sliding rod 492;

[0065] By placing the wafer body 5 inside the rubber protective pad 495, the clamping spring 493 is stretched to generate elastic force, thereby achieving adaptive clamping of the wafer body 5.

[0066] In one embodiment of the present invention, the control system of the wafer processing cleaning machine includes a processor 15 and a power supply 16, wherein the power supply 16 is electrically connected to the processor 15, and the processor 15 is connected to an operator 14 and a drive motor respectively via wires.

[0067] The operator 14 is used to control the entire machine to work and to control the processor 15 to start.

[0068] The processor (15) is configured to: control the drive motor of the rotating clamping mechanism (4) to make the wafer body (5) rotate at a constant speed; at the same time, control the drive motor of the reciprocating drive assembly (38) to make the mega-sound cleaning head (37) reciprocate along the wafer radius direction, thereby achieving uniform cleaning of the entire wafer surface.

[0069] In one embodiment of the present invention, the working principle of a wafer processing cleaning machine is as follows:

[0070] 1. By placing the wafer body 5 inside the rubber protective pad 495, the clamping spring 493 is stretched to generate elastic force. The elastic force drives the arc-shaped clamping block 494 and the rubber protective pad 495 through the sliding rod 492 to achieve adaptive sequential clamping of the wafer body 5.

[0071] 2. The pump 321 operates, and the pumping assembly 32 draws the cleaning solution into the supply pipe 31. The liquid is added to the filling pipe 34 through the connecting pipe 33 and the connecting hose 35. The filling pipe 34 supplies liquid to the mega-sound cleaning head 37 through the cleaning pipe 36. The mega-sound cleaning head 37 performs cleaning on the clamped wafer body 5.

[0072] 3. During the mega-sound cleaning process, the mega-sound cleaning head 37 drives the slider 382 to move back and forth through the multi-stage reciprocating drive screw 381. The slider 382 drives the cleaning tube 36 to move synchronously inside the sliding recess 23 through the connecting rod 383. The cleaning tube 36 synchronously drives the mega-sound cleaning head 37 to move and clean.

[0073] 4. The first rack plate 431 is driven to reciprocate by the drive motor 44. The first rack plate 431 drives the reciprocating moving plate 43 to move. The reciprocating moving plate 43 drives the second rack plate 432 to move. The second rack plate 432 drives the meshing external gear 47 to rotate synchronously. The external gear 47 drives the clamped wafer body 5 to rotate. In conjunction with the moving megasonic cleaning head 37, the wafer body 5 is synchronously and symmetrically cleaned, which facilitates the wafer processing.

[0074] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A cleaning machine for wafer processing comprising a mounting frame (1), characterized in that, Also include: The cleaning tank (2) is placed on the mounting frame (1), and a plurality of sliding notches (23) are evenly arranged on the side walls at both ends of the cleaning tank (2); The rotating clamping mechanism (4) comprises a fixed frame (41) symmetrically arranged, a reciprocating moving plate (43) is slidably arranged on the fixed frame (41), and a second rack plate (432) is arranged at the bottom of the reciprocating moving plate (43); Also include a second mounting frame (45), the second mounting frame (45) is fixedly arranged at the top center of the cleaning tank (2); A plurality of connecting notches (46) are evenly arranged on the second mounting frame (45), an external gear (47) is slidably arranged on the connecting notch (46), and the external gear (47) is in meshing connection with the second rack plate (432); The external gear (47) is internally connected with the wafer body (5) through a plurality of elastic clamping assemblies (49); The megasonic cleaning mechanism (3) comprises a liquid adding pipe (34), a plurality of cleaning pipes (36) are evenly arranged on the liquid adding pipe (34), and the cleaning pipes (36) are connected with the megasonic cleaning head (37) through the sliding notches (23); Also include a reciprocating drive assembly (38), the reciprocating drive assembly (38) is arranged on the outer wall of the cleaning tank (2), and is used for driving the cleaning pipe (36) and the megasonic cleaning head (37) to reciprocate along the radial direction of the wafer body (5); The megasonic cleaning head (37) is arranged in pairs and located on both sides of each wafer body (5).

2. The wafer processing cleaning machine according to claim 1, wherein The front end of the mounting frame (1) is connected with the operator (14) through the first mounting frame (13).

3. The wafer processing cleaning machine according to claim 1, wherein The inner wall of the mounting frame (1) is fixedly provided with a processor (15) and a power supply (16).

4. The wafer processing cleaning machine according to claim 1, wherein The cleaning tank (2) is internally provided with a flow guide groove (21), and the bottom of the flow guide groove (21) is provided with a cleaning liquid storage cylinder (22), and the bottom of the cleaning liquid storage cylinder (22) is in contact connection with the cleaning tank (2).

5. The wafer processing cleaning machine according to any one of claims 1 to 4, characterized by, The megasonic cleaning mechanism (3) further comprises a liquid supply pipe (31), and the liquid supply pipe (31) is arranged outside the cleaning tank (2); The liquid supply pipe (31) is connected with the cleaning liquid storage cylinder (22) through the liquid pumping assembly (32); The top of the liquid supply pipe (31) is connected with the liquid adding pipe (34) through the connecting pipe (33) and the connecting hose (35).

6. The wafer processing cleaning machine according to claim 5, wherein The liquid pumping assembly (32) comprises a liquid pumping pump (321), the liquid pumping pump (321) is fixedly connected with the inner wall of the cleaning tank (2), the liquid pumping pump (321) is inserted into the cleaning liquid storage cylinder (22) through the liquid pumping pipe (322), and the cleaning liquid storage cylinder (22) outside the liquid pumping pipe (322) is provided with a filter cover (323); Further include a drain pipe (324), one end of the drain pipe (324) is in communication connection with the liquid supply pipe (31), and the other end is connected with the liquid pumping pump (321).

7. The wafer processing cleaning machine according to claim 1, wherein The reciprocating drive assembly (38) comprises a multi-section reciprocating drive screw (381), and the multi-section reciprocating drive screw (381) is rotatably installed on the outer wall of the cleaning tank (2); A plurality of sliders (382) are threadedly connected with the multi-section reciprocating drive screw (381), and the sliders (382) are connected with the cleaning pipe (36) through connecting rods (383).

8. The wafer processing cleaning machine according to claim 1, wherein A guide notch (461) is formed in the second mounting frame (45) located on both sides of the connecting notch (46), and the outer end of the external gear (47) is provided with a guide ring (48) inserted into the guide notch (461).

9. The wafer processing cleaning machine according to claim 1, wherein The elastic clamping assembly (49) comprises a connecting cylinder (491) arranged on the inner wall of the external gear (47), and a sliding rod (492) is slidably arranged on the connecting cylinder (491) and connected with the inner wall of the connecting cylinder (491) through a clamping spring (493). An arc-shaped clamping block (494) is further included, the inner end of the arc-shaped clamping block (494) is provided with a rubber protection pad (495), and the arc-shaped clamping block (494) is connected with the sliding rod (492).

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