A contrastive explanation board for Chinese education

Abstract

The application relates to the technical field of teaching aids, in particular to a contrast explanation board for Chinese education for foreigners, which comprises a bottom shell, a fixed plate is welded on the side wall of each rotating disc, a sliding rail is welded between every two adjacent fixed plates, two movable plates are slidably arranged on each sliding rail, a second spring is arranged around each sliding rail, a connecting rod is welded between every two adjacent movable plates, and a partition plate is welded between every two adjacent connecting rods. The device is configured with movable partition plates at the bottom of the writing board to form a precise suction air flow field in cooperation with a negative pressure fan, so that dust scattered in the writing process can be efficiently captured. In view of the problem that chalk heads and chalk fragments may be stuck in the gap between adjacent partition plates during the reset stage of the partition plates, the automatic cleaning of the stuck sundries can be realized by the self-driving characteristics of the mechanical structure, so that the device can adapt to harsh working conditions with high dust, and has practicability and economy.

Description

Technical Field

[0001] This invention relates to the field of teaching aids technology, specifically a comparative explanation board for teaching Chinese as a foreign language. Background Technology

[0002] In teaching Chinese as a foreign language, comparative explanation boards are indispensable teaching aids. They typically combine electronic display with traditional chalk writing functions, providing intuitive comparisons of Chinese characters, pinyin, definitions, and example sentences, while also meeting teachers' needs for real-time blackboard explanations and interactive demonstrations. They are widely used in various Chinese language classrooms. However, the process of writing and erasing with chalk easily generates a large amount of fugitive dust. This dust not only permeates the teaching space, harming the respiratory health of teachers and students when inhaled, but also irritates the eye mucosa, affecting the comfort of teaching activities. Simultaneously, the fugitive dust easily adheres to the electronic components, display screen, and surrounding teaching equipment surfaces. Long-term accumulation can lead to equipment malfunctions and reduce equipment lifespan. Existing comparative explanation boards generally lack targeted dust control mechanisms, relying solely on traditional chalk trays or simple wiping tools, which cannot solve the dust emission problem at its source. This makes dust pollution a prominent pain point in teaching Chinese as a foreign language, affecting the health of teachers and students and the teaching experience. Therefore, this invention provides a comparative explanation board for teaching Chinese as a foreign language. Summary of the Invention

[0003] The purpose of this invention is to provide a comparative explanation board for teaching Chinese as a foreign language, so as to solve the problems mentioned in the background art.

[0004] The technical solution of this invention is: a comparative explanation board for teaching Chinese as a foreign language, comprising a base shell, a writing board fixedly mounted on the top of the base shell, a plurality of turntables rotatably connected to the inner cavity of the base shell, a fixed plate welded to the side wall of each turntable, a slide rail welded between each pair of adjacent fixed plates, two movable plates slidably mounted on each slide rail, a second spring wound around each slide rail, and a plurality of second springs respectively located between corresponding movable plates and corresponding fixed plates, a connecting rod welded between each pair of adjacent movable plates, a partition welded between each pair of adjacent connecting rods, a pre-dust filter and a post-HEPA filter provided in the inner cavity of the base shell, a plurality of negative pressure fans provided on the back of the base shell, and a collection bin fixedly mounted to the bottom of the base shell by screws. This device connects to the bottom of the writing board. Equipped with movable partitions and relying on a linkage drive structure, the partitions synchronously rotate to a preset angle during writing operations. This, combined with a negative pressure fan, creates a precise adsorption airflow field, efficiently capturing dust emitted during writing and preventing dust spread that could harm personnel's health. To address the issue of chalk tips and fragments getting stuck between adjacent partitions during the partition reset phase, the device features a flexible, redundant buffer structure. The elastic deformation of the partitions themselves resolves the stuck stress, effectively avoiding the risk of structural wear or failure caused by debris. Furthermore, the device does not rely on high-precision sensors or an additional power source; its self-driving mechanical structure enables automatic cleaning of stuck debris. This makes it suitable for harsh, high-dust operating conditions while significantly reducing manufacturing and maintenance costs, combining practicality and economy.

[0005] Preferably, a drive motor is fixedly installed in the inner cavity of the bottom shell, and a drive gear is fixedly installed at the output end of the drive motor. Driven gears are welded to the side walls of several turntables. A transmission chain is wound between the drive gear and the driven gears. When the teacher writes with chalk, the writing dust suction mode of this device can be activated. At this time, the drive motor drives the drive gear to rotate, and the drive gear drives the driven gear to rotate through the transmission chain. The driven gear drives the turntable, fixed plate, second spring, movable plate, connecting rod and partition to rotate. At this time, the partition rotates 45 degrees, so that an airflow channel is formed between two adjacent partitions. Then the negative pressure fan operates, and the dust scattered when the teacher writes with chalk enters the inner cavity of the bottom shell through the airflow channel formed between two adjacent partitions. Then the airflow carrying dust passes through the pre-dust filter and the post-HEPA filter in sequence and is discharged into the inner cavity of the bottom shell. The dust carried in the airflow is intercepted by the pre-dust filter and the post-HEPA filter.

[0006] Preferably, each of the partitions has several fan housings fixedly installed at its bottom, each fan housing has an impeller rotatably connected to its inner cavity, and each fan housing has a guide plate at its air inlet.

[0007] Preferably, each impeller has a rotating housing welded to its bottom, and each rotating housing has several pressure rods circumferentially slidably arranged at equal intervals on its outer ring surface. Each pressure rod has a circular plate welded to one side of the corresponding rotating housing, and each pressure rod has a first spring wound around its body. Several first springs are respectively connected between the corresponding circular plate and the inner cavity wall of the corresponding rotating housing.

[0008] Preferably, a sealed housing is fixedly installed at the bottom of each of the fan housings, and several rotating housings are respectively located in the inner cavity of the corresponding sealed housing. An air supply pipe connects every three adjacent sealed housings, and the air supply pipes are respectively connected to two corresponding slide rails. After the teaching task is completed, the device is turned off, and the drive motor drives the partition to reset, closing the airflow channel between adjacent partitions, thereby preventing dust from escaping when the device is idle. It should be noted that after the device is turned off, the controller on the power supply line will continue to supply power to the negative pressure fan, allowing it to continue... After running for a period of time; if the chalk breaks or shatters while the teacher is writing, and the broken pieces of chalk happen to get stuck in the airflow channel between two adjacent partitions; when the drive motor resets the partitions, all partitions except the two blocked by the chalk pieces have returned to their initial positions; due to the delayed operation of the negative pressure fan, and because all partitions except the two blocked by the chalk pieces have completed their reset, the airflow channels that were originally dispersed between several partitions converge at the two partitions blocked by the chalk pieces, and the airflow at the two partitions blocked by the chalk pieces suddenly increases.

[0009] Preferably, each slide rail cavity is slidably provided with a movable block, each movable block has an arc-shaped rod welded to its side wall, each arc-shaped rod has a push plate welded to the side away from the corresponding movable block, and each push plate has two symmetrical extension plates welded to its two sides.

[0010] Preferably, each slide rail cavity is divided into a pressurizing cavity and a sliding cavity, with several movable blocks located in the corresponding pressurizing cavity and several push plates located in the corresponding sliding cavity. Since the movable plates are slidably mounted on the slide rail, and a second spring is wound around the slide rail, the gas flowing into the pressurizing cavity will push the movable blocks, arc rods, push plates, and extension plates to move. With the help of the extension plates, the movable plates are pushed to rotate clockwise along the slide rail and compress the second spring. During this process, the partitions that are blocked by the chalk block and maintained at 45 degrees gradually flip to 90 degrees, so that the airflow channel between two adjacent partitions gradually increases, and the chalk block stuck at the two partitions falls smoothly into the inner cavity of the bottom shell under its own gravity and the push of the high-speed airflow. After the chalk block is processed, the movable plates are driven to reset the corresponding partitions under the action of the second spring.

[0011] This invention provides an improved version of a comparative explanation board for teaching Chinese as a foreign language, which has the following improvements and advantages compared with the prior art: In summary, this device, by incorporating movable partitions at the bottom of the writing board and relying on a linkage drive structure, allows the partitions to synchronously rotate to a preset angle during writing operations. This, combined with a negative pressure fan, creates a precise adsorption airflow field, efficiently capturing dust emitted during writing and preventing dust spread that could harm personnel's health. Addressing the issue of chalk tips and fragments potentially getting stuck between adjacent partitions during the partition reset phase, the device innovatively designs a flexible redundant buffer structure. This structure uses the elastic deformation of the partitions themselves to release the stuck stress, effectively avoiding the risk of structural wear or failure caused by debris getting stuck. Furthermore, this device does not rely on high-precision sensors or an additional power source; it achieves automatic cleaning of stuck debris through the self-driving characteristics of its mechanical structure. This makes it suitable for harsh operating conditions with high dust levels while significantly reducing manufacturing and maintenance costs, demonstrating both practicality and economy. Attached Figure Description

[0012] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the partition structure of the present invention; Figure 3 This is the present invention. Figure 2 Enlarged schematic diagram of part A; Figure 4 This is a schematic diagram of the gas pipeline structure of the present invention; Figure 5 This is the present invention. Figure 4 Enlarged schematic diagram of section B structure; Figure 6 This is a schematic diagram of the impeller structure of the present invention; Figure 7 This is a schematic diagram of the turntable structure of the present invention; Figure 8 This is the present invention. Figure 7 Enlarged schematic diagram of section C Figure 9 This is a schematic diagram of the inner cavity structure of the bottom shell of the present invention.

[0013] Explanation of reference numerals in the attached figures: 1. Bottom shell; 2. Writing board; 3. Turntable; 4. Fixed plate; 5. Slide rail; 6. Movable plate; 7. Connecting rod; 8. Partition plate; 9. Pre-filter; 10. Rear HEPA filter; 11. Negative pressure fan; 12. Collection bin; 13. Drive motor; 14. Drive gear; 15. Driven gear; 16. Transmission chain; 17. Fan housing; 18. Impeller; 19. Guide plate; 20. Rotating housing; 21. Pressure rod; 22. Circular plate; 23. First spring; 24. Sealing housing; 25. Air supply pipe; 26. Movable block; 27. Arc rod; 28. Push plate; 29. ​​Extension plate; 30. Pressurization chamber; 31. Sliding chamber; 32. Second spring. Detailed Implementation

[0014] The present invention will now be described in detail, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention provides an improved comparative explanation board for teaching Chinese as a foreign language. The technical solution of this invention is as follows: like Figures 1-9As shown, a comparative explanation board for teaching Chinese as a foreign language includes a base shell 1, a writing board 2 fixedly installed on the top of the base shell 1, several turntables 3 rotatably connected to the inner cavity of the base shell 1, a fixed plate 4 welded to the side wall of each turntable 3, a slide rail 5 welded between each pair of adjacent fixed plates 4, two movable plates 6 slidably arranged on each slide rail 5, a second spring 32 wound around each slide rail 5, and several second springs 32 respectively located between the corresponding movable plate 6 and the corresponding fixed plate 4, a connecting rod 7 welded between each pair of adjacent movable plates 6, and a partition 8 welded between each pair of adjacent connecting rods 7, a pre-dust filter 9 and a post-HEPA filter 10 provided in the inner cavity of the base shell 1, several negative pressure fans 11 provided on the back of the base shell 1, a collection bin 12 fixedly installed at the bottom of the base shell 1 by screws, a drive motor 13 fixedly installed in the inner cavity of the base shell 1, a drive gear 14 fixedly installed at the output end of the drive motor 13, and driven gears 14 welded to the side walls of each of the turntables 3. 5. A transmission chain 16 is wound between the driving gear 14 and several driven gears 15. When the teacher writes with chalk, the writing dust suction mode of this device can be turned on. At this time, the drive motor 13 drives the driving gear 14 to rotate. The driving gear 14 drives several driven gears 15 to rotate through the transmission chain 16. The driven gears 15 drive the turntable 3, the fixed plate 4, the second spring 32, the movable plate 6, the connecting rod 7 and the partition 8 to rotate. At this time, the partition 8 rotates 45 degrees, so that an airflow channel is formed between two adjacent partitions 8. Then the negative pressure fan 11 operates. When the teacher writes with chalk, the dust flying out enters the inner cavity of the bottom shell 1 through the airflow channel formed between two adjacent partitions 8. Then the airflow carrying dust passes through the pre-dust filter 9 and the post-HEPA filter 10 in sequence and is discharged into the inner cavity of the bottom shell 1. The dust carried in the airflow is intercepted by the pre-dust filter 9 and the post-HEPA filter 10.

[0016] Furthermore, each partition 8 has several fan housings 17 fixedly installed at its bottom. Each fan housing 17 has an impeller 18 rotatably connected to its inner cavity. Each fan housing 17 has a guide plate 19 at its air inlet. Each impeller 18 has a rotating shell 20 welded to its bottom. Each rotating shell 20 has several pressure rods 21 circumferentially slidably arranged at equal intervals on its outer ring surface. Each pressure rod 21 has a circular plate 22 welded to one side of its corresponding rotating shell 20. Each pressure rod 21 has a first spring 23 wound around its rod body, and the first springs 23 are respectively connected between the corresponding circular plate 22 and the inner wall of the corresponding rotating shell 20. Each fan housing 17 has a sealing device fixedly installed at its bottom. The device consists of a housing 24, with several rotating housings 20 located within the corresponding sealed housing 24 cavities. Each set of three adjacent sealed housings 24 is connected by an air supply pipe 25, which is connected to two corresponding slide rails 5. Each slide rail 5 cavity is divided into a pressurizing chamber 30 and a sliding chamber 31. Several movable blocks 26 are located within the corresponding pressurizing chamber 30, and several push plates 28 are located within the corresponding sliding chamber 31. After completing the teaching task, the device is turned off, and the drive motor 13 resets the partition 8, closing the airflow channels between adjacent partitions 8 and preventing dust from escaping when the device is idle. It should be noted that after the device is turned off… The controller on the power transmission line will continue to supply power to the negative pressure fan 11, allowing it to run for a delayed period. If the chalk breaks or shatters while the teacher is writing, and a piece of chalk falls off and gets stuck in the airflow channel between two adjacent partitions 8, when the drive motor 13 resets the partitions 8, all partitions 8 except the two blocked by the chalk pieces have returned to their initial positions. Due to the delayed operation of the negative pressure fan 11, and because all partitions 8 except the two blocked by the chalk pieces have completed their reset, the airflow channels that were originally dispersed among several partitions 8 converge at the two partitions 8 blocked by the chalk pieces. At this time, the airflow at the two partitions 8 blocked by the chalk pieces... The flow suddenly increases; the high-speed airflow enters the fan housing 17 under the guidance of the guide plate 19, and is discharged through the air outlet on the side of the fan housing 17 away from the guide plate 19; during this process, the high-speed airflow will drive the impeller 18 in the fan housing 17 to rotate, the impeller 18 will drive the rotating housing 20 to rotate, and the rotating housing 20 will drive the pressure rod 21 on its outer ring surface to rotate, so that the pressure rod 21 slides into the sealing housing 24 under the action of centrifugal force, and then the sliding pressure rod 21 compresses the space inside the sealing housing 24, so that the gas in the space inside the sealing housing 24 flows into the pressurization chamber 30 of the slide rail 5 through the gas delivery pipe 25.

[0017] Furthermore, each slide rail 5 has a movable block 26 slidably mounted inside its cavity. Each movable block 26 has an arc-shaped rod 27 welded to its side wall. Each arc-shaped rod 27 has a push plate 28 welded to the side away from the corresponding movable block 26. Each push plate 28 has two symmetrical extension plates 29 welded to its two sides. Since the movable plate 6 is slidably mounted on the slide rail 5 and a second spring 32 is wound around the slide rail 5, the gas flowing into the pressurization chamber 30 will push the movable block 26, the arc-shaped rod 27, the push plate 28, and the extension plate 29 to move. With the help of the extension plate 29, the movable plate 6 is pushed to rotate clockwise along the slide rail 5 and compress the second spring 32. During this process, the partition 8, which is blocked by the chalk block and maintained at 45 degrees, gradually flips to 90 degrees, so that the airflow channel between the two adjacent partitions 8 gradually increases, and the chalk block stuck at the two partitions 8 falls smoothly into the inner cavity of the bottom shell 1 under its own gravity and the push of the high-speed airflow. After the chalk block is processed, the movable plate 6 is driven by the second spring 32 to reset the corresponding partition 8.

[0018] Working principle: When the teacher writes with chalk, the writing dust suction mode of this device can be turned on. At this time, the drive motor 13 drives the active gear 14 to rotate. The active gear 14 drives several driven gears 15 to rotate through the transmission chain 16. The driven gears 15 drive the turntable 3, fixed plate 4, second spring 32, movable plate 6, connecting rod 7 and partition 8 to rotate. At this time, the partition 8 rotates 45 degrees, so that an airflow channel is formed between two adjacent partitions 8. Then the negative pressure fan 11 operates. When the teacher writes with chalk, the dust flying out enters the inner cavity of the bottom shell 1 through the airflow channel formed between two adjacent partitions 8. Then the airflow carrying dust passes through the pre-dust filter 9 and the post-HEPA filter 10 and is discharged into the inner cavity of the bottom shell 1. The dust carried in the airflow is intercepted by the pre-dust filter 9 and the post-HEPA filter 10. After the teaching assignment is completed, the device is turned off. The drive motor 13 drives the partition 8 to reset, closing the airflow channel between adjacent partitions 8 and preventing dust from escaping when the device is idle. It should be noted that after the device is turned off, the controller on the power supply line continues to supply power to the negative pressure fan 11, allowing it to run for a delayed period. If the teacher uses chalk and the chalk breaks or shatters, and a piece of chalk gets stuck in the airflow channel between two adjacent partitions 8, when the drive motor 13 drives the partitions 8 to reset, all partitions 8 except the two blocked by the chalk pieces will have returned to their initial positions. Due to the delayed operation of the negative pressure fan 11, and because all partitions 8 except the two blocked by the chalk pieces will have returned to their initial positions, the negative pressure fan 11 will continue to operate. The reset operation has been completed, causing the airflow channels originally dispersed among several partitions 8 to converge at the two partitions 8 blocked by the chalk block. At this time, the airflow at the two partitions 8 blocked by the chalk block suddenly increases. The high-speed airflow enters the fan housing 17 under the guidance of the guide plate 19 and is discharged through the air outlet on the side of the fan housing 17 away from the guide plate 19. During this process, the high-speed airflow will drive the impeller 18 in the fan housing 17 to rotate. The impeller 18 will drive the rotating housing 20 to rotate. The rotating housing 20 will drive the pressure rod 21 on its outer ring surface to rotate. Under the action of centrifugal force, the pressure rod 21 slides into the sealing housing 24, thereby compressing the space inside the sealing housing 24 with the help of the sliding pressure rod 21. This allows the gas inside the sealed housing 24 to flow through the gas supply pipe 25 into the pressurization chamber 30 of the slide rail 5. Since the movable plate 6 is slidably mounted on the slide rail 5, and a second spring 32 is wound around the slide rail 5, the gas flowing into the pressurization chamber 30 pushes the movable block 26, the arc-shaped rod 27, the push plate 28, and the extension plate 29 to move. The extension plate 29 then pushes the movable plate 6 to rotate clockwise along the slide rail 5, compressing the second spring 32. During this process, the partition 8, which is maintained at 45 degrees due to the chalk block, gradually rotates to 90 degrees, gradually increasing the airflow channel between adjacent partitions 8. This allows the chalk block, which is engaged with the two partitions 8, to fall smoothly into the inner cavity of the bottom housing 1 under its own weight and the force of the high-speed airflow. After processing, the movable plate 6, under the action of the second spring 32, drives the corresponding partition 8 to reset; the dust and chalk blocks entering the bottom shell 1 are intercepted by the pre-dust filter 9 and the post-HEPA filter 10, and under the action of their own gravity, they gradually fall through the discharge hole at the bottom of the bottom shell 1 into the collection bin 12 at the bottom of the bottom shell 1; during cleaning, the staff only needs to disassemble the collection bin 12 to complete the cleaning of the collection bin 12; this device, by configuring the movable partition 8 at the bottom of the writing board 2, and relying on the linkage drive structure, makes the partition 8 rotate synchronously to the preset angle during writing operations, and forms a precise adsorption airflow field with the negative pressure fan 11, which efficiently captures the dust that is dispersed during the writing process, and avoids the harm to personnel health caused by dust diffusion from the source;To address the issue of chalk tips and fragments potentially getting stuck in the gaps between adjacent partitions 8 during the partition 8 reset phase, the device is designed with an elastic redundant buffer structure. The device resolves the stuck stress through the elastic deformation of the partition 8 itself, effectively avoiding the risk of structural wear or failure caused by debris getting stuck. Simultaneously, this device does not rely on high-precision sensors or an additional power source; it achieves automatic cleaning of stuck debris through the self-driving characteristics of its mechanical structure. This makes it suitable for harsh operating conditions with high dust levels, while significantly reducing manufacturing and maintenance costs, thus combining practicality and economy.

[0019] The foregoing description enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A comparative explanation board for teaching Chinese as a foreign language, comprising a base shell (1), characterized in that: A writing board (2) is fixedly installed on the top of the bottom shell (1). Several turntables (3) are rotatably connected to the inner cavity of the bottom shell (1). A fixed plate (4) is welded on the side wall of each turntable (3). A slide rail (5) is welded between each two adjacent fixed plates (4). Two movable plates (6) are slidably arranged on each slide rail (5). A second spring (32) is wound around each slide rail (5). Several second springs (32) are respectively located between the corresponding movable plate (6) and the corresponding fixed plate (4). A connecting rod (7) is welded between each two adjacent movable plates (6). A partition plate (8) is welded between each two adjacent connecting rods (7). A pre-dust filter (9) and a rear HEPA filter (10) are provided in the inner cavity of the bottom shell (1). Several negative pressure fans (11) are provided on the back of the bottom shell (1). A collection bin (12) is fixedly installed at the bottom of the bottom shell (1) by screws.

2. The comparative explanation board for teaching Chinese as a foreign language according to claim 1, characterized in that: A drive motor (13) is fixedly installed in the inner cavity of the bottom shell (1). A drive gear (14) is fixedly installed at the output end of the drive motor (13). A driven gear (15) is welded on the side wall of several turntables (3). A transmission chain (16) is wound between the drive gear (14) and several driven gears (15).

3. The comparative explanation board for teaching Chinese as a foreign language according to claim 1, characterized in that: Each of the partitions (8) has several fan housings (17) fixedly installed at its bottom. Each fan housing (17) has an impeller (18) rotatably connected to its inner cavity. Each fan housing (17) has a guide plate (19) installed at its air inlet.

4. A comparative explanation board for teaching Chinese as a foreign language according to claim 3, characterized in that: Each impeller (18) has a rotating housing (20) welded to its bottom. Each rotating housing (20) has several pressure rods (21) circumferentially slidably arranged at equal intervals on its outer ring surface. Each pressure rod (21) has a circular plate (22) welded to one side of the corresponding rotating housing (20). Each pressure rod (21) has a first spring (23) wound around its rod body. Several first springs (23) are respectively connected between the corresponding circular plate (22) and the inner cavity wall of the corresponding rotating housing (20).

5. A comparative explanation board for teaching Chinese as a foreign language according to claim 4, characterized in that: Each of the fan housings (17) has a sealed housing (24) fixedly installed at the bottom, and several rotating housings (20) are located in the inner cavity of the corresponding sealed housing (24). Each three adjacent sealed housings (24) are connected by an air supply pipe (25), and several air supply pipes (25) are connected to two corresponding slide rails (5).

6. A comparative explanation board for teaching Chinese as a foreign language according to claim 1, characterized in that: Each slide rail (5) has a movable block (26) slidably disposed in its inner cavity. Each movable block (26) has an arc-shaped rod (27) welded on its side wall. Each arc-shaped rod (27) has a push plate (28) welded on the side away from the corresponding movable block (26). Each push plate (28) has two symmetrical extension plates (29) welded on both sides.

7. A comparative explanation board for teaching Chinese as a foreign language according to claim 1, characterized in that: Each slide rail (5) has an inner cavity divided into a pressurizing cavity (30) and a sliding cavity (31), and several movable blocks (26) are located in the corresponding pressurizing cavity (30), and several push plates (28) are located in the corresponding sliding cavity (31).

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