A high-performance glass fiber drawing device

Abstract

The application belongs to the field of centrifugal devices, and particularly relates to a high-performance glass fiber drawing equipment, which comprises a cylinder, a centrifugal cylinder arranged at a central position in the cylinder, an opening at the top of the centrifugal cylinder, a main shaft connected to the bottom of the cylinder and rotatable by a centrifugal driving device, a cylinder wall of the centrifugal cylinder, a plurality of drawing nozzles arranged on the cylinder wall, the cylinder wall being in a wave shape, a trough being a slag channel, the drawing nozzles being arranged at wave crests, a funnel-shaped bottom of the cylinder, a leakage nozzle arranged at the central position of the bottom of the cylinder, a circle of glass fiber cooling impellers arranged outside the cylinder above a drawing area of the drawing nozzles, and a plurality of material falling conveying belts with negative pressure adsorption function arranged on the inner wall of the cylinder, all the material falling conveying belts being vertically arranged and having consistent running linear speeds. The high-speed rotation of the centrifugal cylinder generates a centrifugal effect, so that impurities are removed while drawing, temperature attenuation of glass liquid is avoided when flowing through a long path, and additional heating energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the drawing and forming of glass fibers, and more specifically to a high-performance glass fiber drawing device. Background Technology

[0002] With the increasing power output of wind turbines and the widespread adoption of offshore wind power and large-blade turbines for low wind speeds, blade sizes continue to break through limitations. Larger blades place higher demands on material performance: a significant increase in modulus is needed while reducing the weight percentage of the fabric. Although carbon fiber offers superior overall performance, its high cost limits its large-scale application. Therefore, the wind power industry is shifting its focus to developing high-performance glass fiber fabrics, aiming to achieve a balance between blade size and economic efficiency through breakthroughs in material performance.

[0003] Impurity removal is crucial in the glass fiber forming process. Currently, the commonly used production process for glass fiber is the furnace drawing process. In this process, the batch material is heated at high temperature in a furnace to form a uniform molten glass. The molten glass then flows through the main channel (i.e., the pool) for clarification and impurity removal, before flowing into a liquid tank. Under gravity, it flows out through multiple rows of porous platinum sprues, drawing into fibers. Finally, it is wound into twisted or untwisted yarn bobbins by a rotating winding machine. During this process, due to the relatively long pool, the molten glass experiences a significant temperature drop as it passes through for impurity removal. Therefore, the molten glass is heated to superheated levels in the furnace before the pool to offset the temperature drop during the pool process and to meet the final drawing temperature. Alternatively, during drawing, the molten glass is electrically heated again through a platinum-rhodium drawing nozzle to achieve the final drawing temperature. Both of these processes generate significant energy consumption. The glass melting furnace is the most energy-intensive thermal equipment in a factory, typically accounting for about 80% of the total energy consumption.

[0004] In addition, the gravity drawing technology used in the present technology has low pressure, and the drawn glass fiber material does not have better toughness and is easy to break, which will increase the defect rate of finished glass fiber products for wind turbine blades. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a high-performance glass fiber drawing equipment to reduce the energy consumption of glass fiber production and improve the toughness of glass fiber products.

[0006] The high-performance glass fiber drawing equipment of the present invention includes a vertically oriented cylindrical body with openings at the top and bottom. A centrifugal cylinder is located at the center of the cylindrical body, with an opening at the top. A main shaft connected to the bottom of the cylindrical body is located at the center of the centrifugal cylinder, and the main shaft can be driven to rotate by a centrifugal drive device. Several drawing nozzles are arranged on the cylinder wall, which is inclined and wavy, with slag accumulation channels at the troughs and drawing nozzles located at the crests. The bottom of the cylinder is funnel-shaped, with a drain nozzle located at the center of the bottom. A ring of glass fiber cooling impellers is arranged outside the cylinder body above the drawing zone where the drawing nozzles are located. Several material feeding conveyor belts with negative pressure adsorption function are densely arranged on the inner wall of the cylindrical body. All material feeding conveyor belts are arranged vertically and have the same linear speed.

[0007] The centrifuge cylinder has a raised internal nozzle on its inner wall, which is connected to the wire-drawing nozzle, and the internal nozzle and the wire-drawing nozzle correspond one-to-one.

[0008] Molten glass in the glass furnace flows into a centrifugal cylinder through a feed channel. Under the centrifugal force of high-speed rotation, particulate impurities with a density greater than that of the molten glass gradually move away from the center and are thrown into the slag accumulation channel on the inner wall of the centrifugal cylinder, while impurities such as air bubbles with a density less than that of the molten glass gradually gather towards the center. The pure molten glass in the middle zone is then ejected at high speed through a protruding internal nozzle and drawn into fibers. The high speed and centrifugal force generate strong extrusion pressure, thereby improving the toughness of the glass fibers and thus increasing the pass rate of glass fibers for wind turbine blades. Simultaneous centrifugal drawing and impurity removal can be carried out without passing through an impurity removal channel, thus avoiding the temperature decay and overheating in the furnace that were common in previous impurity removal processes; alternatively, the molten glass can be electrically heated again through a platinum-rhodium drawing nozzle, effectively reducing energy consumption by 10% to 15%.

[0009] After the glass fiber is drawn and thrown out, it is immediately cooled by the powerful airflow blown by the high-speed rotating glass fiber cooling impeller above the drawing zone. Because the glass fiber is very thin, it can be cooled and shaped instantly. The shaped glass fiber is thrown onto the unloading conveyor belt on the inner wall of the cylinder and is attracted by the unloading conveyor belt, forming multiple spiral lines throughout the inner wall area of ​​the cylinder. As the unloading conveyor belt moves, it is gradually output from the bottom outlet of the cylinder.

[0010] Because the particulate impurities are denser and heavier, they gradually sink in the slag channel due to inertia under the rotation of the centrifuge cylinder, eventually accumulating at the bottom of the cylinder and dripping down from the leak in the center of the bottom.

[0011] The main shaft has an internal suction channel. Multiple low-density component suction ports are located around the top of the main shaft, and multiple high-density component suction ports are located around the bottom of the main shaft. Because a small amount of molten glass continuously drips from the central drain at the bottom of the cylinder, denser particulate impurities are drawn in by the high-density component suction ports at the bottom of the main shaft and discharged from the drain. Meanwhile, less dense impurities such as air bubbles enter the low-density component suction ports at the top of the main shaft, and some descend through the internal suction channel and are discharged from the drain.

[0012] In addition, a solution cooling impeller is installed outside the bottom of the tank below the drawing zone. After the molten glass containing impurities drips from the drain at the bottom of the tank, it is immediately cooled by the powerful airflow blown out by the high-speed rotating solution cooling impeller at the bottom of the tank, forming amorphous solids of inconsistent volume that fall down.

[0013] Furthermore, a collector is suspended below the centrifuge cylinder, and the top of the collector has a solution receiving funnel, which is vertically aligned with the nozzle at the center of the bottom of the cylinder. Falling amorphous solids will enter the collector through the solution receiving funnel.

[0014] Furthermore, the collector is equipped with a side door. Rapidly cooled amorphous solids will not adhere to the inside of the collector, and can be cleaned through the door during periodic equipment shutdowns for maintenance.

[0015] The feeding conveyor belt is installed on the reversing support rollers at the upper and lower ends of the plate-shaped support frame. The plate-shaped support frame has a cavity inside, and the side of the plate-shaped support frame facing the centrifuge cylinder is densely covered with several vertical fine holes, which are connected to the cavity. The feeding conveyor belt is closely attached to this side of the plate-shaped support frame, and the feeding conveyor belt is densely covered with several micropores. All cavities inside the plate-shaped support frame are connected to the annular negative pressure main pipeline outside the cylinder. The annular negative pressure main pipeline is connected to the vacuum pump station, thereby providing a negative pressure adsorption function for the feeding conveyor belt, so that the thrown glass fibers fall in an orderly manner.

[0016] At least one of the unloading conveyor belts is equipped with an unloading drive device, and the reversing support rollers of adjacent unloading conveyor belts are connected by universal joints. Even when glass fiber is adsorbed, the unloading conveyor belts are basically in an unloaded state, so multiple unloading conveyor belts can share a single drive system, thereby reducing energy consumption.

[0017] The material feeding drive device consists of a material feeding motor and a drive roller. The material feeding motor drives the drive roller to rotate, and the drive roller drives the material feeding conveyor belt to move. The material feeding motor and drive roller are located outside the cylinder through a fixed window opened on the cylinder body. The reversing support roller of this material feeding conveyor belt then drives the reversing support rollers of other material feeding conveyor belts to rotate through a universal joint.

[0018] The driven material feeding conveyor belt has end plates on both sides of its plate-shaped support frame. The end plates are placed outside the cylinder through mounting slots opened on the cylinder body. A connecting plate is installed between the end plates on both sides to fix the material feeding conveyor belt to the inner wall of the cylinder body.

[0019] The beneficial effects of this invention compared to the prior art are:

[0020] 1. Reduce energy consumption and avoid temperature decay and overheating:

[0021] In the process of drawing glass fibers, traditional methods require heating to offset the temperature drop of the molten glass as it flows through the impurity removal channel, or the molten glass needs to be electrically heated again during drawing to meet the drawing temperature. This invention utilizes the centrifugal force generated by the high-speed rotation of a centrifugal cylinder to achieve impurity removal simultaneously with drawing, avoiding the temperature drop that occurs when the molten glass flows through a long channel, thereby reducing additional heating energy consumption.

[0022] 2. Improve the toughness of glass fiber products:

[0023] During the centrifugal drawing process, due to the high-speed rotation of the centrifugal cylinder, the pure glass liquid in the middle area generates strong extrusion pressure when it is thrown out at high speed, which helps to improve the toughness of the glass fiber, making it more durable and thus improving the quality and pass rate of the glass fiber end products for wind turbine blades.

[0024] 3. Small footprint:

[0025] The high-performance glass fiber drawing equipment of this invention features a compact design and a relatively small footprint, which helps save production space and reduce production costs. The vertical layout and optimized structural design of the equipment ensure that the glass fibers are immediately absorbed and collected by the discharge conveyor belt after being thrown out, preventing them from being thrown far. It can achieve efficient glass fiber drawing, impurity removal, and output processes within a limited space, thus improving space utilization. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram showing the connection between the present invention and the melting furnace;

[0028] Figure 3 This is a sectional view of the internal structure of the cylinder;

[0029] Figure 4 This is a schematic diagram of the centrifuge cylinder and its drive device;

[0030] Figure 5 This is a cross-sectional view of the centrifuge cylinder;

[0031] Figure 6 This is a sectional view of the main axis;

[0032] Figure 7 This is a schematic diagram showing the positional relationship between the wire drawing nozzle, the slag collection channel, and the internal nozzle;

[0033] Figure 8 This is a schematic diagram of the arrangement of the material feeding conveyor belt inside the cylinder;

[0034] Figure 9 yes Figure 8 A magnified view of part A in the middle;

[0035] Figure 10 yes Figure 9 A magnified view of part B in the middle;

[0036] Figure 11 This is a schematic diagram of the active unloading conveyor belt;

[0037] Figure 12 This is a schematic diagram of the structure of the adsorption surface of the material feeding conveyor belt;

[0038] Figure 13 This is a schematic diagram of the plate-shaped support frame of the material unloading conveyor belt and the fine strip holes on its surface;

[0039] Figure 14 This is a schematic diagram of the driven material feeding conveyor belt;

[0040] Figure 15 This is a schematic diagram of the cylinder structure.

[0041] In the diagram: 1. Centrifugal motor; 2. Gearbox; 3. Material channel; 4. Cylinder; 5. Feeding motor; 6. Annular negative pressure main pipeline; 7. Glass fiber; 8. Winding machine; 9. Gathering roller; 10. Impurity collector; 11. Vacuum pump station; 12. Maintenance ladder; 13. Melting furnace; 14. Shaft support; 15. Main shaft; 16. Thrust bearing; 17. Cage; 18. Glass fiber cooling impeller; 19. Centrifugal cylinder; 20. Solution cooling impeller; 21. Feeding conveyor. 22. Feeding belt; 23. Solution receiving funnel; 24. Tank door; 25. Nozzle; 26. Wire drawing nozzle; 27. Slag accumulation channel; 28. Internal nozzle; 29. ​​Low-density component suction port; 30. High-density component suction port; 31. Suction flow channel; 32. Protective cover; 33. Drive roller; 34. End plate; 35. Connecting plate; 36. Reversing support roller; 37. Universal joint; 38. Micro-hole; 39. Plate-shaped support frame; 40. Fine strip hole; 41. Fixing window; 42. Mounting groove. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments.

[0043] However, the description of the present invention is merely a structural or even functional description of the embodiments, and the scope of the present invention is not limited by the embodiments described herein.

[0044] For example, multiple embodiments may have various modifications and forms, and it should be understood that the scope of the present invention includes equivalents that can realize the technical concept.

[0045] This embodiment is achieved through the following technical solution:

[0046] like Figures 1-15 As shown, this embodiment is achieved through the following technical solution: a cylindrical body 4 with vertical openings at the top and bottom, a centrifugal cylinder 19 located in the center of the cylindrical body 4, an opening at the top of the centrifugal cylinder 19, a main shaft 15 connected to the bottom of the cylinder body located in the center of the centrifugal cylinder 19, the top of the main shaft 15 suspended on a shaft bracket 14, a thrust bearing 16 and a retainer 17 for sharing the weight of the centrifugal cylinder 19 on the outer ring of the centrifugal cylinder 19, the retainer 17 being connected and fixed to the cylindrical body 4, and the main shaft 15 being driven to rotate by a centrifugal drive device; the centrifugal drive device in this embodiment is a centrifugal motor 1 and a gearbox 2 connected to it, the gearbox 2 being fixed to the top of the shaft bracket 14, and a maintenance ladder 12 for inspecting and repairing the centrifugal motor 1 and the gearbox 2 located outside the cylindrical body 4.

[0047] The main shaft 15 has an internal suction channel 30. Multiple low-density component suction ports 28 are located around its upper circumference, and multiple high-density component suction ports 29 are located around its bottom circumference. Several drawing nozzles 25 are arranged on the wall of the centrifuge cylinder 19, and protruding internal nozzles 27 are located on the inner wall of the centrifuge cylinder 19, with each internal nozzle 27 corresponding to a drawing nozzle 25. The cylinder wall is a sloping, wavy shape (when the centrifuge cylinder 19 is designed to rotate clockwise from a top-down angle, the wave direction when viewed from the front of the centrifuge cylinder 19 is upper left and lower right, i.e., as shown). Figure 4 As shown; when the centrifuge cylinder 19 is designed to rotate counterclockwise, the wave direction is from right to left (the trough is the slag accumulation channel 26, and the drawing nozzle 25 is located at the crest of the wave); the bottom of the cylinder is funnel-shaped, and a nozzle 24 is provided in the center of the bottom of the cylinder, which is connected to the suction channel 30; a ring of glass fiber cooling impellers 18 is provided on the outside of the cylinder above the drawing zone where the drawing nozzle 25 is located; a solution cooling impeller 20 is provided on the outside of the bottom of the cylinder below the drawing zone.

[0048] A collector 10 is suspended below the centrifuge cylinder 19. The collector 10 has a side door 23 and a solution receiving funnel 22 on the top. The solution receiving funnel 22 is vertically aligned with the leak 24 at the center of the bottom of the cylinder.

[0049] The inner wall of the cylinder 4 is densely covered with several material feeding conveyor belts 21 with negative pressure adsorption function on their surfaces. All material feeding conveyor belts 21 are arranged vertically and have the same linear speed. The material feeding conveyor belts 21 are mounted on the reversing support rollers 35 at the upper and lower ends of the plate-shaped support frame 38. The plate-shaped support frame 38 has a cavity inside. The side of the plate-shaped support frame 38 facing the centrifuge cylinder 19 is densely covered with several vertical fine strip holes 39, which communicate with the cavity. The material feeding conveyor belts 21 are closely attached to this side of the plate-shaped support frame 38, and the material feeding conveyor belts 21 are densely covered with several micropores 37. All cavities inside the plate-shaped support frame 38 are connected to the annular negative pressure main pipeline 6 outside the cylinder 4. The annular negative pressure main pipeline 6 is connected to the vacuum pump station 11.

[0050] One of the unloading conveyor belts 21 is equipped with an unloading drive device, and the reversing support rollers 35 of adjacent unloading conveyor belts 21 are connected by universal joints 36. Even when glass fiber is adsorbed, the unloading conveyor belt is basically in an unloaded state, so multiple unloading conveyor belts can share a single drive system, thereby reducing energy consumption.

[0051] The material feeding drive device consists of a material feeding motor 5 and a drive roller 32. The drive roller 32 is located inside the protective cover 31. The material feeding motor 5 drives the drive roller 32 to rotate, and the drive roller 32 drives the material feeding conveyor belt 21 to move. The material feeding motor 5 and the drive roller 32 are located outside the cylinder 4 through a fixed window 40 opened on the cylinder 4. The driven material feeding conveyor belt 21 has end plates 33 on both sides of its plate-shaped support frame 38. The end plates 33 are located outside the cylinder 4 through mounting grooves 41 opened on the cylinder 4. A connecting plate 34 is installed between the end plates 33 on both sides, thereby fixing the material feeding conveyor belt 21 to the inner wall of the cylinder 4.

[0052] Molten glass in the furnace 13 flows into the centrifugal cylinder 19 through the feed channel 3. Under the centrifugal force of the high-speed rotation of the centrifugal cylinder 19, particulate impurities with a density greater than that of the molten glass gradually move away from the center and are thrown into the slag accumulation channel 26 on the inner wall of the centrifugal cylinder 19, while impurities such as bubbles with a density less than that of the molten glass gradually gather towards the center. Due to their higher density and greater mass, the particulate impurities gradually sink in the slag accumulation channel 26 due to inertia under the rotation of the centrifugal cylinder 19, and finally accumulate at the bottom of the cylinder, dripping down from the leak 24 in the center of the bottom of the cylinder. Since a small amount of molten glass continuously drips from the leak 24 in the center of the bottom of the cylinder, the higher density particulate impurities are sucked in by the high-density component suction port 29 at the bottom of the main shaft 15 and discharged from the leak 24; while the lower density impurities such as bubbles enter the low-density component suction port 28 at the top of the main shaft 15, and some of them descend through the suction flow channel 30 inside the main shaft 15 and are discharged from the leak 24. Molten glass containing impurities drips from the drain 24 at the bottom of the cylinder and is immediately cooled by the powerful airflow from the high-speed rotating solution cooling impeller 20 at the bottom of the cylinder, condensing into amorphous solids of varying sizes that fall down. The falling amorphous solids enter the impurity collector 10 through the solution receiving funnel 22. The rapidly cooled amorphous solids do not adhere, and can be cleaned through the chamber door 23 during periodic shutdown maintenance. The connecting pipe between the solution receiving funnel 22 and the impurity collector 10 can be a lifting telescopic pipe, which is raised and lowered by a motor-driven gear and rack mechanism. After the impurity collector 10 descends and extends out of the bottom outlet of the cylinder 4, the chamber door 23 is opened for cleaning.

[0053] The pure molten glass in the middle zone is ejected at high speed through the protruding built-in nozzle 27 and drawn into fibers from the drawing nozzle 25. The high speed and centrifugal force generate strong extrusion pressure, thereby improving the toughness of the glass fiber and thus increasing the yield of the finished glass fiber products for wind turbine blades. Simultaneous centrifugal drawing and impurity removal can be performed without passing through a separate impurity removal channel, thus avoiding the temperature decay and overheating in the furnace that were common in previous impurity removal processes. Alternatively, the molten glass can be electrically heated again through a platinum-rhodium drawing nozzle, effectively reducing energy consumption by 10% to 15%.

[0054] After the glass fibers are drawn and thrown out, they are immediately cooled by the powerful airflow blown by the high-speed rotating glass fiber cooling impeller 18 above the drawing zone. The solution cooling impeller 20 also enhances the downward flow of air inside the cylinder. Because the glass fibers are very fine, they can be cooled and shaped instantly. The shaped glass fibers are thrown onto the unloading conveyor belt 21 on the inner wall of the cylinder 4 and are attracted by the unloading conveyor belt 21, so that the thrown glass fibers form multiple spirals in the entire inner wall area of ​​the cylinder 4, falling in an orderly manner. With the movement of the unloading conveyor belt 21, they are gradually output from the bottom outlet of the cylinder 4. Finally, the glass fibers 7 can be wound into a yarn bobbin by the rotating winding machine 8 through the spindle-shaped gathering roller 9.

[0055] Of course, the above description is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the embodiments of the present invention. The present invention is also not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of the present invention should fall within the patent coverage of the present invention.

Claims

1. A high-performance glass fiber drawing apparatus characterized by, The cylinder (4) includes vertical up and down openings, a centrifugal cylinder (19) is arranged at the central position in the cylinder (4), the top of the centrifugal cylinder (19) is open, a main shaft (15) is arranged at the central position of the centrifugal cylinder (19) and is connected to the bottom of the cylinder, and the main shaft (15) can be driven to rotate by a centrifugal driving device; A plurality of wire drawing nozzles (25) are arranged on the cylinder wall of the centrifugal cylinder (19), the cylinder wall is in a wave shape, the wave trough is a slag accumulation channel (26), and the wire drawing nozzles (25) are arranged at the wave crest; the bottom of the cylinder is in a funnel shape, a leakage nozzle (24) is arranged at the central position of the bottom of the cylinder; a circle of glass fiber cooling impellers (18) is arranged outside the cylinder above the wire drawing area of the wire drawing nozzles (25); A plurality of blank conveying belts (21) with negative pressure adsorption function are arranged on the inner wall of the cylinder (4), all the blank conveying belts (21) are arranged vertically and have consistent running linear speeds; The inside of the main shaft (15) is provided with an inhalation flow channel (30), a plurality of low-density component suction inlets (28) are arranged around the upper part of the main shaft (15), and a plurality of high-density component suction inlets (29) are arranged around the bottom of the main shaft (15).

2. The high-performance glass fiber draw equipment of claim 1, wherein, A protruding built-in nozzle (27) is arranged on the inner wall of the centrifugal cylinder (19), and the built-in nozzle (27) corresponds to the wire drawing nozzle (25) one by one.

3. The high-performance glass fiber draw equipment of claim 1, wherein, A solution cooling impeller (20) is arranged outside the bottom of the cylinder below the wire drawing area.

4. The high-performance glass fiber draw equipment of claim 3, wherein, The centrifugal cylinder (19) is suspended below the collector (10), the top of the collector (10) is provided with a solution receiving hopper (22), and the solution receiving hopper (22) is vertically aligned with the leakage nozzle (24) at the central position of the bottom of the cylinder.

5. The high-performance glass fiber draw equipment of claim 4, wherein, The collector (10) is provided with a warehouse door (23) opened on the side.

6. The high-performance glass fiber draw equipment of claim 1, wherein, The blank conveying belt (21) is installed on the reversing support roller (35) at the upper and lower ends of the plate-shaped support frame (38), the inside of the plate-shaped support frame (38) is provided with a cavity, one side of the plate-shaped support frame (38) facing the centrifugal cylinder (19) is densely provided with a plurality of vertical thin strip holes (39), the thin strip holes (39) are communicated with the cavity, the blank conveying belt (21) is closely arranged on the side of the plate-shaped support frame (38), a plurality of micropores (37) are densely arranged on the blank conveying belt (21), and the cavities in the interiors of all the plate-shaped support frames (38) are connected with an annular negative pressure main pipeline (6) outside the cylinder (4), and the annular negative pressure main pipeline (6) is connected with a vacuum pump station (11).

7. The high-performance glass fiber draw equipment of claim 6, wherein, At least one blank conveying belt (21) is provided with a blank driving device, and the reversing support rollers (35) of adjacent blank conveying belts (21) are connected through universal joints (36).

8. The high-performance glass fiber draw equipment of claim 7, wherein, The blank driving device is a blank motor (5) and a driving roller (32), the blank motor (5) drives the driving roller (32) to rotate, the driving roller (32) drives the blank conveying belt (21) to move, and the blank motor (5) and the driving roller (32) are arranged outside the cylinder (4) through a fixed window (40) arranged on the cylinder (4).

9. The high-performance glass fiber draw equipment according to claim 7 or 8, characterized in that End plates (33) are arranged on both sides of the plate-shaped support frame (38) of the driven blank conveying belt (21), the end plates (33) are arranged outside the cylinder (4) through an installation slot (41) arranged on the cylinder (4), and a connecting plate (34) is arranged between the two end plates (33).

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