Traumatic postoperative exercise device
The rehabilitation device addresses the challenge of adjusting training intensity and providing assistance based on patient condition by using integrated sensors and electromagnets to ensure safe and effective post-surgery rehabilitation.
Patent Information
- Application Number
- CN202510623266.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-15
- Publication Date
- 2025-07-15
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing devices for post-surgery rehabilitation of lower limb injuries fail to automatically adjust training intensity or provide assistance based on the patient's changing physical condition, leading to suboptimal training outcomes.
A rehabilitation device with integrated sensors and a central processor that adjusts training intensity and provides assistance by monitoring patient weight and exercise parameters, using electromagnets to alter resistance and provide additional support when needed.
Ensures personalized and effective rehabilitation by dynamically adjusting resistance and providing assistance, ensuring safety and effectiveness of the training process.
Smart Images
Figure CN120305632A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of medical devices, and specifically to a postoperative exercise device for trauma. Background Art
[0002] With the progress of modern medical technology, postoperative rehabilitation treatment has become a key link for patients to restore function and improve the quality of life; during the postoperative rehabilitation process, leg muscle exercise for patients with lower limb trauma is particularly important, which not only helps prevent complications such as muscle atrophy and joint stiffness, but also promotes blood circulation and accelerates wound healing.
[0003] For patients with leg trauma or after surgery, early rehabilitation training is crucial for restoring muscle strength, joint range of motion, and preventing complications; the foot exercise device, as a common rehabilitation training tool, is widely used in the rehabilitation treatment after lower limb trauma surgery. The foot-operated postoperative exercise device for leg trauma enables patients to directly perform foot stepping training through the device by adding a foot stepping training function, thereby shortening the rehabilitation time.
[0004] Currently, during the active training process of patients, when the physical strength or power of patients decreases, some existing devices are difficult to automatically sense the state changes of patients and accordingly adjust the training intensity or provide an assisted exercise mode, resulting in possibly unsatisfactory training effects, being difficult to meet the training needs in various situations, and reducing the exercise effect. Therefore, we propose a postoperative exercise device for trauma. Summary of the Invention
[0005] The purpose of the present invention is to provide a postoperative exercise device for trauma to solve the problem that during the active training process of patients, when the physical strength or power of patients decreases, some existing devices are difficult to automatically sense the state changes of patients and accordingly adjust the training intensity or provide an assisted exercise mode, resulting in possibly unsatisfactory training effects, being difficult to meet the training needs in various situations, and reducing the exercise effect as mentioned in the above background art.
[0006] To achieve the above purpose, the present invention provides the following technical solution: A postoperative exercise device for trauma, including a foot exercise device and a display screen, and further including: an exercise adjustment component, a detection component, and an electromagnet I; The display screen is arranged on the front side of the foot exercise device. A central processor is arranged inside the foot exercise device, and the central processor is electrically connected to the display screen, the exercise adjustment component, and the detection component; Both the exercise adjustment component and the detection component are arranged inside the foot exercise device. The detection component detects the exercise speed of the patient and adjusts the training intensity through the exercise adjustment component. The electromagnet I is installed on one side inside the foot exercise device.
[0007] Among them, the exercise adjustment component includes a mounting seat installed inside the foot exercise device and an internal guide rod connected to the foot exercise device. One side inside the mounting seat is installed with a first motor, and the power driving end of the first motor is connected to a lead screw. The lead screw is movably connected to the inside of the mounting seat through a bearing. A moving seat is connected to the outside of the lead screw. Limit plates are installed on both sides outside the moving seat. Limit grooves are opened on both sides inside the mounting seat. The limit plates are slidably connected to the inside of the limit grooves. A connecting seat is installed on the top of the limit plates.
[0008] Among them, the top of the connecting seat is connected to a mounting frame. A second motor is installed on one side of the mounting frame. The power driving end of the second motor is connected to a positioning rod. A number of anti-slip particles are arranged on the outside of the positioning rod in a circumferential distribution. A connecting shaft is connected to the inside of the connecting seat. A positioning groove is opened in the inside of the connecting shaft. A first synchronous pulley is connected to the outside of the connecting shaft.
[0009] Among them, a second synchronous pulley is installed on the outside of the guide rod. A synchronous belt is jointly arranged on the outside of the first synchronous pulley and the second synchronous pulley. Connecting frames are connected to both sides outside the guide rod. One ends of the two connecting frames are respectively connected to fixed seats.
[0010] Among them, pressure sensors one are installed at the four corners inside each fixed seat. A first spring is installed on the top of each pressure sensor one. A foot pedal is jointly installed on the top of each first spring. An elastic band is arranged on the top of the foot pedal. A sliding rod is installed on the bottom of the foot pedal.
[0011] Among them, a sliding groove is opened on the top of the connecting seat. An electromagnet two and an electromagnet three are respectively installed on both sides inside the sliding groove. A ferromagnetic sliding seat is connected to the inside of the sliding groove. The top of the ferromagnetic sliding seat is connected to the mounting frame.
[0012] Among them, a first fixing plate and a second fixing plate are respectively installed inside the mounting seat. A tension sensor is installed on the outside of one side of the first fixing plate. One end of the tension sensor is connected to a tension rope. One end of the tension rope is connected to the moving seat. The tension rope is located inside the second fixing plate.
[0013] Among them, the detection component includes mounting plates installed on one side inside the foot exercise device. There are several groups of mounting plates. Fixed cylinders are installed inside each of the several groups of mounting plates. A pressure sensor two is installed on one side inside the fixed cylinder. A second spring is installed at one end of the pressure sensor two. A connecting rod is installed at one end of the second spring. The connecting rod is located inside the fixed cylinder. An arc-shaped plate is installed at one end of the connecting rod. An installation cylinder is installed on the outside of the guide rod. A positive electrode plate and a negative electrode plate are respectively arranged inside the installation cylinder. An electromagnet four is installed on the outside of one side of the installation cylinder.
[0014] Among them, a sleeve is sleeved outside the guide rod. The sleeve is made of iron. Several groups of arc-shaped plates are distributed in a circular shape with the sleeve as the center. A connecting cylinder is installed outside the sleeve. A third spring is installed inside the connecting cylinder, and a sphere is installed at the top of the third spring.
[0015] The present invention has at least the following beneficial effects: When the present invention is in use, the device can real-time monitor the pressure change on the foot pedal when the patient steps on it through a plurality of first pressure sensors arranged below the foot pedal, and analyze through the central processing unit to obtain the patient's weight condition (overweight, underweight or normal). According to the weight condition, the initial training intensity is automatically adjusted. For overweight patients, the initial intensity is appropriately increased, and for underweight patients, the initial intensity is appropriately reduced to ensure the safety and effectiveness of the training and meet the personalized training needs of patients with different weights; during the patient's exercise process, the detection component precisely senses the patient's exercise speed and intensity through the extrusion of the arc-shaped plate by the centrifugal force of the sphere and the monitoring of the pressure change by the second pressure sensor. The central processing unit analyzes the patient's exercise state and physical strength level according to the feedback data, and adjusts the training intensity through the exercise adjustment component, changing the distance between the first synchronous pulley and the second synchronous pulley to make the synchronous belt in a loose or tight state, thereby increasing or decreasing the resistance of the foot pedal and realizing precise resistance adjustment to ensure the rationality and effectiveness of the training; when the patient's physical strength permits, the device is in the autonomous exercise mode, and the patient relies on his own strength to step on the foot pedal for exercise. The exercise adjustment component adjusts the resistance in real time according to the patient's state to help the patient exercise better; when the patient's physical strength is severely insufficient, the central processing unit can start the assisted exercise mode to provide additional assistance to the patient to help the patient complete the exercise, avoiding exercise interruption or ineffective exercise due to physical exhaustion and improving the exercise effect. Description of the Drawings
[0016] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is an internal view of the first perspective of the structure of the present invention; Figure 3 is an internal view of the second perspective of the structure of the present invention; Figure 4 is a schematic diagram of the exercise adjustment component of the present invention; Figure 5 is an internal view of the first perspective of the exercise adjustment component of the present invention; Figure 6 is an internal view of the second perspective of the exercise adjustment component of the present invention; Figure 7 is a semi-exploded view of the exercise adjustment component of the present invention; Figure 8 is a schematic diagram of the detection component of the present invention; Figure 9 is an internal view of the detection component of the present invention.
[0017] In the figure: 1. Foot exercise device; 2. Exercise adjustment component; 3. Detection component; 4. Display screen; 5. Electromagnet I; 21. Mounting seat; 22. Motor I; 23. Lead screw; 24. Moving seat; 25. Limiting plate; 26. Limiting groove; 27. Connecting seat; 28. Motor II; 29. Positioning rod; 210. Connecting shaft; 211. Positioning groove; 212. Synchronous pulley I; 213. Guide rod; 214. Synchronous pulley II; 215. Timing belt; 216. Connecting frame; 217. Fixed seat; 218. Pressure sensor I; 219. Spring I; 220. Foot pedal; 221. Elastic band; 222. Chute; 223. Electromagnet II; 224. Electromagnet III; 225. Iron guide slide; 226. Mounting frame; 227. Fixed plate I; 228. Fixed plate II; 229. Tensile sensor; 230. Tensile rope; 231. Slide bar; 31. Mounting plate; 32. Fixed cylinder; 33. Pressure sensor II; 34. Spring II; 35. Connecting rod; 36. Arc plate; 37. Mounting cylinder; 38. Positive electrode plate; 39. Negative electrode plate; 310. Electromagnet IV; 311. Sleeve; 312. Connecting cylinder; 313. Spring III; 314. Sphere. Detailed implementation manners
[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0019] Embodiment 1 Please refer to Figures 1 to 9 , the present invention provides a technical solution: a post-traumatic exercise device, including a foot exercise device 1 and a display screen 4, further including: an exercise adjustment component 2, a detection component 3 and an electromagnet I 5; The display screen 4 is arranged on the front side of the foot exercise device 1. A central processor is arranged inside the foot exercise device 1, and the central processor is electrically connected to the display screen 4, the exercise adjustment component 2 and the detection component 3; The display screen 4 is arranged on the front side of the foot exercise device 1 for displaying exercise data, mode information, etc.; a central processor is arranged inside the foot exercise device 1, and the central processor is electrically connected to the display screen 4, the exercise adjustment component 2 and the detection component 3 for controlling the operation of the device, processing data and feeding it back to the display screen 4; Both the exercise adjustment component 2 and the detection component 3 are arranged inside the foot exercise device 1. The detection component 3 detects the exercise speed of the patient and adjusts the training intensity through the exercise adjustment component 2. The electromagnet I 5 is installed on one side inside the foot exercise device 1; The exercise adjustment component 2 includes a mounting base 21 installed inside the foot exercise device 1 and an internal guide rod 213 connected to the foot exercise device 1. One side inside the mounting base 21 is equipped with a first motor 22. The power driving end of the first motor 22 is connected to a lead screw 23. The lead screw 23 is movably connected to the inside of the mounting base 21 through a bearing. The outside of the lead screw 23 is connected to a moving seat 24. Both sides outside the moving seat 24 are equipped with limit plates 25. Limit grooves 26 are respectively opened on both sides inside the mounting base 21. The limit plates 25 are slidably connected to the inside of the limit grooves 26. The top of the limit plate 25 is equipped with a connecting seat 27; The top of the connecting seat 27 is connected to a mounting frame 226. One side of the mounting frame 226 is equipped with a second motor 28. The power driving end of the second motor 28 is connected to a positioning rod 29. A number of anti-slip particles are arranged on the outside of the positioning rod 29 and are distributed in a circular shape. The inside of the connecting seat 27 is connected to a connecting shaft 210. A positioning groove 211 is opened inside the connecting shaft 210. The outside of the connecting shaft 210 is connected to a first synchronous pulley 212. A second synchronous pulley 214 is installed on the outside of the guide rod 213. A synchronous belt 215 is jointly arranged on the outside of the first synchronous pulley 212 and the second synchronous pulley 214. Both sides outside the guide rod 213 are connected to connecting frames 216. One end of each of the two connecting frames 216 is respectively connected to a fixed seat 217. Pressure sensors 218 are installed at the four corners inside the fixed seat 217. A first spring 219 is installed on the top of each pressure sensor 218. A foot pedal 220 is jointly installed on the top of each first spring 219. An elastic band 221 is arranged on the top of the foot pedal 220. A sliding rod 231 is installed at the bottom of the foot pedal 220. A chute 222 is opened on the top of the connecting seat 27. An electromagnet 223 and an electromagnet 224 are respectively installed on both sides inside the chute 222. An iron guide sliding seat 225 is connected to the inside of the chute 222. The top of the iron guide sliding seat 225 is connected to the mounting frame 226. A first fixing plate 227 and a second fixing plate 228 are respectively installed inside the mounting base 21. A tension sensor 229 is installed on one side outside the first fixing plate 227. One end of the tension sensor 229 is connected to a tension rope 230. One end of the tension rope 230 is connected to the moving seat 24. The tension rope 230 is located inside the second fixing plate 228; The outside of the positioning rod 29 is provided with a plurality of groups of anti-skid particles distributed in a circumferential shape. When the positioning rod 29 and the anti-skid particles are located inside the positioning groove 211, the motor 28 can drive the connecting shaft 210 to rotate, and the connecting shaft 210 drives the synchronous wheel 1 212 to rotate. At this time, the synchronous wheel 214 is driven to rotate by the synchronous belt 215, so as to achieve auxiliary exercise. The anti-skid particles increase the tightness of the connection between the positioning rod 29 and the positioning groove 211; the synchronous belt 215 is elastic. When the synchronous wheel 1 212 and the synchronous wheel 214 are close to each other, the synchronous belt 215 is in a relaxed state, and the resistance becomes small. When the synchronous wheel 1 212 and the synchronous wheel 214 are far apart, the synchronous belt 215 is in a tight state, and the resistance becomes large. The resistance value is detected by setting the tension rope 230 and the tension sensor 229; The detection assembly 3 includes a mounting plate 31 mounted on one side of the pedal exercise device 1. The mounting plate 31 is provided with a plurality of groups. A fixing cylinder 32 is installed inside each of the plurality of mounting plates 31. A pressure sensor 2 33 is installed on one side of the fixing cylinder 32. A spring 2 34 is installed at one end of the pressure sensor 2 33. A connecting rod 35 is installed at one end of the spring 2 34. The connecting rod 35 is located inside the fixing cylinder 32. An arc plate 36 is installed at one end of the connecting rod 35. The guide rod 213 is installed outside the fixing cylinder 32. A mounting cylinder 37 is installed, and a positive electrode sheet 38 and a negative electrode sheet 39 are respectively arranged inside the mounting cylinder 37. An electromagnet 310 is installed on one side of the outside of the mounting cylinder 37. A sleeve 311 is sleeved on the outside of the guide rod 213, and the sleeve 311 is made of iron. A plurality of groups of arc plates 36 are distributed in a circular shape with the sleeve 311 as the center. A connecting cylinder 312 is installed outside the sleeve 311, and a spring 313 is installed inside the connecting cylinder 312. A sphere 314 is installed on the top of the spring 313. When the electromagnet four 310 is attracted to the iron sleeve 311, the installation tube 37 can drive the sleeve 311 to rotate when it rotates. When the electromagnet four 310 is powered off, the sleeve 311 is attracted to the electromagnet one 5. At this time, the sleeve 311 is in a stationary state. The electromagnet four 310 is energized through the positive electrode sheet 38, the negative electrode sheet 39 and the coil. When the detection component 3 detects the patient's speed and adjusts the resistance value, the detection component 3 continues to detect and adjust the resistance after the patient has exercised for a certain period of time.
[0020] The patient sits in front of the post-traumatic exercise device, places both feet on the footrest 220, and fixes them with the elastic band 221 to ensure stability during the exercise. The patient turns on the display screen 4. When the patient steps on the footrest 220, a certain resistance is generated under the combined action of several groups of the first springs 219. At this time, several groups of the first pressure sensors 218 installed at the four corners inside the fixed seat 217 monitor the pressure changes on the footrest 220 in real time. These first pressure sensors 218 transmit the data to the central processor. After receiving the data from multiple first pressure sensors 218, the central processor calculates and analyzes the patient's weight situation (overweight, underweight or normal). According to the patient's weight situation, the central processor automatically adjusts the initial training intensity. For example, for overweight patients, the initial intensity is appropriately increased; for underweight patients, the initial intensity is appropriately decreased to ensure the safety and effectiveness of the training. The guide rod 213 guides the footrest 220 to ensure the smoothness of its movement. During the patient's exercise, the electromagnet four 310 attracts the sleeve 311, and the detection component 3 starts to work. It rotates with the stepping on of the footrest 220, driving the sleeve 311 to rotate. When the sleeve 311 rotates, the sphere 314 in the connecting cylinder 312 outside it is thrown out under the action of the centrifugal force generated by the third spring 313 and squeezes the arc plate 36. At this time, the connecting rod 35 slides in the fixed cylinder 32, further compressing the second spring 34. When the second pressure sensor 33 monitors this pressure change, it further accurately senses the patient's exercise speed and intensity. The central processor analyzes the patient's exercise status and physical strength level according to the data fed back by the detection component 3. When the detection component 3 detects that the patient's physical strength has declined or the strength is insufficient, the central processor adjusts the training intensity through the exercise adjustment component 2. The central processor controls the motor one 22 to drive the lead screw 23 to rotate. The moving seat 24 moves along the mounting seat 21 under the guidance of the limit plate 25 and the limit groove 26. This movement changes the position of the connecting seat 27, thereby affecting the resistance of the footrest 220. When the first synchronous pulley 212 approaches the second synchronous pulley 214, the synchronous belt 215 is in a slack state. At this time, the resistance of the footrest 220 is reduced. After the resistance is reduced, when the tension sensor 229 detects that the tension value reaches a certain value, it controls the electromagnet four 310 to separate from the sleeve 311, and the electromagnet one 5 is energized to attract the sleeve 311. At this time, the sleeve 311 stops rotating. When the patient exercises for a certain period of time, the electromagnet one 5 stops being energized, and the electromagnet four 310 is energized to attract the sleeve 311 to continue detecting the patient's speed. When the patient's physical strength is severely insufficient, the central processing unit can activate the assisted exercise mode. When the electromagnet two 223 is energized and attracted to the iron guide slider 225, and when the iron guide slider 225 moves, the positioning rod 29 and the anti-slip particles provided externally are located in the positioning groove 211. At this time, the motor two 28 is started, and the motor two 28 drives the synchronous pulley one 212 to rotate. At this time, additional assistance can be provided to the patient to help the patient complete the exercise.
[0021] Embodiment 2 In the second embodiment, other structures remain unchanged. Different from the first embodiment, when the moving seat 24 moves, it drives the tension rope 230 to move. One end of the tension rope 230 is connected to the tension sensor 229. At this time, the tension sensor 229 can detect the resistance value generated by the synchronous belt 215 and reflect it on the display screen 4 through the central processing unit. The fixing plate two 228 provides a lifting effect on the tension rope 230; the resistance value is judged by the tension value displayed by the tension sensor 229, so as to control the electromagnet one 5 and the electromagnet four 310. When the resistance value detected by the tension sensor 229 reaches an appropriate value, the sleeve 311 does not rotate. After the patient exercises for a certain time, the sleeve 311 rotates again for detection.
[0022] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.
[0023] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A postoperative exercise device for trauma, comprising a foot exercise device (1) and a display screen (4), characterized in that: It further includes: An exercise adjustment component (2), a detection component (3), and an electromagnet I (5); The display screen (4) is arranged on the front side of the foot exercise device (1). A central processor is arranged inside the foot exercise device (1), and the central processor is electrically connected to the display screen (4), the exercise adjustment component (2), and the detection component (3); Both the exercise adjustment component (2) and the detection component (3) are arranged inside the foot exercise device (1). The detection component (3) detects the exercise speed of the patient, and adjusts the training intensity through the exercise adjustment component (2). The electromagnet I (5) is installed on one side inside the foot exercise device (1).
2. The postoperative exercise device for trauma according to claim 1, wherein: The exercise adjustment component (2) includes a mounting seat (21) installed inside the foot exercise device (1) and a guiding rod (213) connected inside the foot exercise device (1). A motor I (22) is installed on one side inside the mounting seat (21). The power driving end of the motor I (22) is connected to a lead screw (23). The lead screw (23) is movably connected inside the mounting seat (21) through a bearing. A moving seat (24) is connected to the outside of the lead screw (23). Limiting plates (25) are installed on both outer sides of the moving seat (24). Limiting grooves (26) are opened on both sides inside the mounting seat (21). The limiting plates (25) are slidably connected inside the limiting grooves (26). A connecting seat (27) is installed on the top of the limiting plate (25).
3. The postoperative exercise device for trauma according to claim 2, wherein: The top of the connecting seat (27) is connected to a mounting frame (226). A motor II (28) is installed on one side of the mounting frame (226). The power driving end of the motor II (28) is connected to a positioning rod (29). A number of anti-slip particles are arranged on the outside of the positioning rod (29) in a circumferential distribution. A connecting shaft (210) is connected inside the connecting seat (27). A positioning groove (211) is opened inside the connecting shaft (210). A synchronous pulley I (212) is connected to the outside of the connecting shaft (210).
4. The postoperative exercise device for trauma according to claim 3, wherein: A synchronous pulley II (214) is installed on the outside of the guiding rod (213). A synchronous belt (215) is jointly arranged on the outside of the synchronous pulley I (212) and the synchronous pulley II (214). Connecting frames (216) are connected to both outer sides of the guiding rod (213). One ends of the two connecting frames (216) are respectively connected to a fixed seat (217).
5. The postoperative exercise device for trauma according to claim 4, characterized in that: Pressure sensors I (218) are installed at the four corners inside the fixed seat (217). A spring I (219) is installed on the top of each pressure sensor I (218). A foot pedal (220) is jointly installed on the top of each spring I (219). An elastic band (221) is arranged on the top of the foot pedal (220). A sliding rod (231) is installed on the bottom of the foot pedal (220).
6. The postoperative trauma exercise device according to claim 3, characterized in that: A chute (222) is formed at the top of the connection base (27). Electromagnets II (223) and III (224) are respectively installed on both sides inside the chute (222). An iron guide slider (225) is connected inside the chute (222). The top of the iron guide slider (225) is connected to the mounting bracket (226).
7. The postoperative trauma exercise device according to claim 2, wherein: A fixing plate I (227) and a fixing plate II (228) are respectively installed inside the mounting base (21). A tension sensor (229) is installed on one outer side of the fixing plate I (227). One end of the tension sensor (229) is connected to a tension rope (230). One end of the tension rope (230) is connected to the moving base (24). The tension rope (230) is located inside the fixing plate II (228).
8. The postoperative trauma exercise device according to claim 2, characterized in that: The detection assembly (3) includes mounting plates (31) installed on one side inside the pedal exercise device (1). There are several groups of the mounting plates (31). A fixed cylinder (32) is installed inside each of the several groups of mounting plates (31). A pressure sensor II (33) is installed on one side inside the fixed cylinder (32). One end of the pressure sensor II (33) is installed with a spring II (34). One end of the spring II (34) is installed with a connecting rod (35). The connecting rod (35) is located inside the fixed cylinder (32). One end of the connecting rod (35) is installed with an arc-shaped plate (36). An installation cylinder (37) is installed on the outer part of the guide rod (213). A positive electrode plate (38) and a negative electrode plate (39) are respectively arranged inside the installation cylinder (37). An electromagnet IV (310) is installed on one outer side of the installation cylinder (37).
9. The postoperative exercise device for trauma according to claim 8, wherein: A sleeve (311) is sleeved on the outer part of the guide rod (213). The sleeve (311) is made of iron. The several groups of arc-shaped plates (36) are distributed in a circular shape centered on the sleeve (311). A connecting cylinder (312) is installed on the outer part of the sleeve (311). A spring III (313) is installed inside the connecting cylinder (312). A sphere (314) is installed on the top of the spring III (313).