Product surface polishing device
By introducing an adjustment mechanism and a clamping mechanism into the polishing device, adjusting the polishing angle and contact pressure is solved, and the problem of limited application scope of existing devices is improved, and the polishing ability of metal products of different shapes and sizes is improved.
Patent Information
- Application Number
- CN202421185737.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-05-28
AI Technical Summary
The existing polishing device design is mostly specific metal products or application scenarios, and it is difficult to adapt to metal products of different shapes and sizes, resulting in limited application scope and inability to effectively contact and polish different parts of metal products.
A polishing device including an adjustment mechanism and a clamping mechanism is designed. By changing the angle between the adjustment frame A and the adjustment frame B, the meshing of the gear and the connecting rod drive the grinding disc to rotate, thereby realizing the adjustment of the grinding angle; the clamping mechanism is carried out through The rotation of the knob and double-segment screw changes the distance and contact pressure between the metal product and the grinding disc, and is suitable for products of different volumes.
It improves the scope of application of polishing devices, can accurately contact and polish metal products in different parts, and enhances the adaptability and polishing effect to different volumes of products.
Smart Images
Figure CN222327767U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of polishing devices, in particular to a product surface polishing device. Background Art
[0002] At present, during the processing of metal products, the surface of metal products needs to be polished. Polishing is a surface treatment technology that removes uneven parts of the material surface by using mechanical, chemical or electrochemical methods to achieve a smooth and bright effect. It is an indispensable step in the manufacturing process of metal products.
[0003] However, many polishing devices are currently designed for specific metal products or application scenarios, with a poor scope of applicability and difficulty in adapting to metal products of different shapes and sizes. Different workpieces have different shapes and sizes, and different polishing heights and angles are required to ensure that the polishing device can correctly and effectively contact the product surface for appropriate polishing. Utility Model Content
[0004] The purpose of the utility model is to provide a product surface polishing device to solve the problems raised in the above background technology.
[0005] To achieve the above-mentioned purpose, the utility model aims to provide a product surface polishing device, including a support seat, an adjustment mechanism and a clamping mechanism, the adjustment mechanism includes an adjustment frame A and an adjustment frame B, the inner wall of the adjustment frame A is rotatably connected to a connecting rod A, the outer wall of the connecting rod A is fixedly connected to a gear A, the inner wall of the adjustment frame B is rotatably connected to a connecting rod B, the lower surface of the connecting rod B is fixedly connected to a grinding disk, the top of the connecting rod B is fixedly connected to a gear B, a gear C is meshed between the outer edges of the gear B and the gear A, the inner wall of the gear C is fixedly connected to a connecting column, and the adjustment frame A and the adjustment frame B rotate through the connecting column.
[0006] As a further improvement of the present technical solution, the outer wall of the adjusting frame A is symmetrically fixedly connected to two limit slides, the two sides of the adjusting frame B are symmetrically fixedly connected to arc rods, and the outer sides of the arc rods are slidably connected to the inner sides of the two limit slides, the inner wall of the arc rod is fixedly connected to the limit rod, one side of the limit rod is fixedly connected to a screw, one end of the screw is fixedly connected to a clamping block, and the outer wall of the screw is threadedly connected to the side close to the clamping block.
[0007] As a further improvement of the present technical solution, the clamping mechanism includes a support plate and a clamping seat, the lower surface of the support plate is symmetrically fixedly connected with two sliding seats, a sliding sleeve is fixedly connected between the two sliding seats on the outer wall of the support plate, and the upper surface of the support plate is symmetrically fixedly connected with two fixed seats, the inner wall of one of the fixed seats is rotatably connected with a knob, the end of the knob is fixedly connected with a double-segment screw rod, and the outer wall of the double-segment screw rod is symmetrically fixedly connected with two hinged seats, the ends of the two hinged seats are hinged with adjustment plates, and the ends of the two adjustment plates are hinged to the inner wall of the clamping seat, and the inner wall of the clamping seat is symmetrically provided with two limiting grooves, the inner sides of the two limiting grooves are fixedly connected with support springs, the ends of the support springs are fixedly connected with the clamping plate, and the outer wall of the clamping plate is slidably connected to the inner wall of the limiting groove.
[0008] As a further improvement of the present technical solution, two pairs of telescopic rods are symmetrically fixedly connected between the support plate and the outer wall of the clamping seat, and two limiting slide rails are symmetrically fixedly connected to the upper surface of the support seat. The outer walls of the two limiting slide rails are respectively slidably connected to the inner walls of the two slide seats, and a first motor is fixedly installed on the upper surface of the support plate between the two limiting slide rails. The output shaft of the first motor is fixedly connected to a screw rod A, and the outer wall of the screw rod A is slidably connected to the inner wall of the sleeve, and the end of the screw rod A is rotatably connected to a fixed block, and the outer wall of the fixed block is fixedly connected to the upper surface of the support plate.
[0009] As a further improvement of the present technical solution, the upper surface of the support seat is fixedly connected to a support frame, a slideway is provided on the inner wall of the support frame, a screw rod B is rotatably connected to the inner side of the slideway, the outer wall of the screw rod B is threadedly connected to a mounting seat, and the outer wall of the mounting seat is slidably connected to the inner wall of the slideway, and a connecting rod is symmetrically fixedly connected to the lower surface of the mounting seat, and the bottom ends of the outer walls of the two connecting rods are fixedly connected to the outer wall of the adjusting frame A, a second motor is fixedly installed on the inner side of the mounting seat, and the output shaft of the second motor is fixedly connected to the end of the connecting rod A.
[0010] As a further improvement of the present technical solution, a socket is fixedly connected to the outer wall of the support frame, a third motor is fixedly installed on the inner side of the socket, and the output shaft of the third motor passes through the interior of the slideway and is fixedly connected to the end of the screw rod B.
[0011] Compared with the prior art, the utility model has the following beneficial effects:
[0012] 1. In the product surface polishing device, the angle between the adjusting frame A and the adjusting frame B is changed by the connecting column, and the connecting column is limited so that when the angle between the adjusting frame A and the adjusting frame B is changed, the outer edges of the gears B and A can still mesh with the outer edges of the gears C, and then, the connecting rod A rotates to drive the gear A to rotate, and when the gear A rotates, the outer edge meshes with the outer edge of the gear C, so that the gear C drives the gear B to rotate synchronously, and when the gear B rotates, it drives the grinding disc to rotate synchronously through the connecting rod B, so as to perform the grinding work, and by changing the angle between the adjusting frame A and the adjusting frame B, the grinding angle of the grinding disc will change synchronously, so that the polishing device can accurately contact and polish different parts of the metal product, thereby improving the application range of the device.
[0013] 2. In this product surface polishing device, the double-section lead screw is rotated synchronously by turning the knob. When the double-section lead screw rotates, it cooperates with the thread between the two hinged seats, and then the two hinged seats are moved synchronously in relative directions. During the movement, the hinged seat will be hinged with the adjustment plate, so that the two adjustment plates synchronously push the clamping seat to rise and fall, thereby changing the distance between the metal product and the grinding disc, so that the device can be suitable for products of different volumes, and by changing the distance between the metal product and the grinding disc, the contact pressure between the grinding wheel and the surface of the metal product can also be adjusted, thereby improving the product polishing effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0015] Figure 2 It is a schematic diagram of the adjustment structure of the utility model;
[0016] Figure 3 It is a schematic diagram of the adjustment structure of the utility model;
[0017] Figure 4 It is a schematic diagram of the fixing structure of the utility model;
[0018] Figure 5 It is a schematic diagram of the displacement structure of the utility model;
[0019] Figure 6 This is a schematic diagram of the lifting structure of the utility model;
[0020] Figure 7 This is a schematic diagram of the clamping structure of the utility model;
[0021] Figure 8 It is a schematic diagram of the partially enlarged structure of point A in the figure of the present utility model.
[0022] The meaning of each number in the figure is:
[0023] 1. Support seat; 2. Adjustment mechanism; 201. Adjustment frame A; 202. Adjustment frame B; 203. Connecting rod A; 204. Gear A; 205. Connecting rod B; 206. Grinding disc; 207. Gear B; 208. Gear C; 209. Connecting column; 3. Clamping mechanism; 301. Support plate; 302. Clamping seat; 303. Sliding seat; 304. Sliding sleeve; 305. Fixed seat; 306. Knob; 307. Double-section screw rod; 308. Articulated seat; 309. Adjustment mechanism Section plate; 310, limit groove; 311, support spring; 312, clamping plate; 4, limit slide; 401, arc rod; 402, limit rod; 403, screw; 404, clamping block; 405, extrusion block; 5, telescopic rod; 6, limit slide rail; 7, first motor; 8, screw A; 9, fixing block; 10, support frame; 11, slideway; 12, screw B; 13, mounting seat; 14, connecting rod; 15, second motor; 16, clamping seat; 17, third motor. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] See also Figure 1 , Figure 2 and Figure 3 As shown, the purpose of this embodiment is to provide a product surface polishing device, including a support seat 1, an adjustment mechanism 2 and a clamping mechanism 3, characterized in that: the adjustment mechanism 2 includes an adjustment frame A201 and an adjustment frame B202, the inner wall of the adjustment frame A201 is rotatably connected to a connecting rod A203, the outer wall of the connecting rod A203 is fixedly connected to a gear A204, the inner wall of the adjustment frame B202 is rotatably connected to a connecting rod B205, the lower surface of the connecting rod B205 is fixedly connected to a grinding disc 206, the top of the connecting rod B205 is fixedly connected to a gear B207, a gear C208 is meshed between the outer edge of the gear B207 and the gear A204, the inner wall of the gear C208 is fixedly connected to a connecting column 209, and the adjustment frame A201 and the adjustment frame B202 rotate through the connecting column 209.
[0026] In this embodiment, the angle between the adjusting frame A201 and the adjusting frame B202 is changed by the connecting column 209, and the connecting column 209 is limited so that when the angle between the adjusting frame A201 and the adjusting frame B202 is changed, the outer edges of the gears B207 and A204 can still mesh with the outer edges of the gears C208, and then, the connecting rod A203 rotates to drive the gear A204 to rotate, and when the gear A204 rotates, the outer edge meshes with the outer edge of the gear C208, so that the gear C208 drives the gear B207 to rotate synchronously, and when the gear B207 rotates, it will drive the grinding disc 206 to rotate synchronously through the connecting rod B205, so as to perform the grinding work, and the angle between the adjusting frame A201 and the adjusting frame B202 is changed, so that the grinding angle of the grinding disc 206 will be changed synchronously, so that the polishing device can accurately contact and polish different parts of the metal product, thereby improving the application range of the device.
[0027] like Figure 4 and Figure 8 As shown, the outer wall of the adjustment frame A201 is symmetrically fixedly connected to two limit slides 4, the two sides of the adjustment frame B202 are symmetrically fixedly connected to arc rods 401, and the outer sides of the arc rods 401 are slidably connected to the inner sides of the two limit slides 4, the inner wall of the arc rod 401 is fixedly connected to the limit rod 402, one side of the limit rod 402 is fixedly connected to a screw rod 403, one end of the screw rod 403 is fixedly connected to a clamping block 404, and the outer wall of the screw rod 403 is threadedly connected to the side close to the clamping block 404.
[0028] In this embodiment, when the adjustment frame A201 and the adjustment frame B202 are hinged, the arc rod 401 will slide on the inner side of the limiting slide 4 through the limiting rod 402. When the arc rod 401 slides to a suitable position, the extrusion block 405 is rotated. When the extrusion block 405 rotates, the end of the extrusion block 405 is squeezed toward the outside of the limiting slide 4 through the threaded cooperation with the screw 403, so that the angle between the adjustment frame A201 and the adjustment frame B202 after hinged connection is fixed.
[0029] like Figure 6 and Figure 7As shown, the clamping mechanism 3 includes a support plate 301 and a clamping seat 302. The lower surface of the support plate 301 is symmetrically fixedly connected to two slide seats 303. A sliding sleeve 304 is fixedly connected between the two slide seats 303 on the outer wall of the support plate 301. The upper surface of the support plate 301 is symmetrically fixedly connected to two fixed seats 305. The inner wall of one of the fixed seats 305 is rotatably connected to a knob 306. The end of the knob 306 is fixedly connected to a double-segment screw rod 307. The outer wall of the double-segment screw rod 307 is fixedly connected to the outer wall of the double-segment screw rod 307. There are two hinged seats 308 symmetrically fixedly connected. The ends of the two hinged seats 308 are hinged with adjustment plates 309, and the ends of the two adjustment plates 309 are hinged to the inner wall of the clamping seat 302. The inner wall of the clamping seat 302 is symmetrically provided with two limit grooves 310, and the inner sides of the two limit grooves 310 are fixedly connected with support springs 311, and the ends of the support springs 311 are fixedly connected with clamping plates 312, and the outer wall of the clamping plate 312 is slidably connected to the inner wall of the limit groove 310.
[0030] In this embodiment, the metal product to be processed is placed on the surface of the clamping seat 302, and the clamping plate 312 slides on the inner wall of the limiting groove 310. While sliding, the clamping plate 312 causes the support spring 311 to be contracted. Then, the tension generated by the contraction of the support spring 311 causes the clamping plate 312 to clamp and fix the metal product. Then, by turning the knob 306, the double-segment screw rod 307 rotates synchronously. When the double-segment screw rod 307 rotates, it is connected to the threaded connection between the two hinge seats 308. The two hinged seats 308 are then moved synchronously in relative directions, and the hinged seats 308 are hinged with the adjustment plates 309 during the movement, so that the two adjustment plates 309 synchronously push the clamping seats 302 to rise and fall, thereby changing the distance between the metal product and the grinding disc 206, so that the device can be suitable for products of different volumes, and by changing the distance between the metal product and the grinding disc 206, the contact pressure between the grinding wheel and the surface of the metal product can also be adjusted, thereby improving the polishing effect of the product.
[0031] like Figure 6 As shown, two pairs of telescopic rods 5 are symmetrically fixedly connected between the outer walls of the support plate 301 and the clamping seat 302, and two limit slide rails 6 are symmetrically fixedly connected to the upper surface of the support seat 1. The outer walls of the two limit slide rails 6 are respectively slidably connected to the inner walls of the two slide seats 303, and a first motor 7 is fixedly installed on the upper surface of the support plate 301 between the two limit slide rails 6. The output shaft of the first motor 7 is fixedly connected to a screw rod A8, and the outer wall of the screw rod A8 is slidably connected to the inner wall of the sleeve 304, and the end of the screw rod A8 is rotatably connected to a fixed block 9, and the outer wall of the fixed block 9 is fixedly connected to the upper surface of the support plate 301.
[0032] In this embodiment, the first motor 7 is started to drive the screw rod A8 to rotate synchronously. When the screw rod A8 rotates, it can drive the support plate 301 to move through the threaded cooperation with the sleeve 304, so that the metal product to be processed can be pushed toward the grinding disc 206, thereby playing a feeding role. In the process of moving, the support plate 301 limits the slide seat 303 through the limiting slide rail 6, thereby ensuring the stability of the support plate 301 during movement.
[0033] like Figure 5 As shown, the upper surface of the support seat 1 is fixedly connected to the support frame 10, the inner wall of the support frame 10 is provided with a slideway 11, the inner side of the slideway 11 is rotatably connected to the screw rod B12, the outer wall of the screw rod B12 is threadedly connected to the mounting seat 13, and the outer wall of the mounting seat 13 is slidingly connected to the inner wall of the slideway 11, the lower surface of the mounting seat 13 is symmetrically fixedly connected to the connecting rod 14, the outer wall bottom ends of the two connecting rods 14 are fixedly connected to the outer wall of the adjusting frame A201, the inner side of the mounting seat 13 is fixedly installed with a second motor 15, and the output shaft of the second motor 15 is fixedly connected to the end of the connecting rod A203.
[0034] In this embodiment, the adjusting frame 201 is fixed by the connecting rod 14 to ensure that when the second motor 15 drives the connecting rod A203 to rotate, the adjusting frame A will not rotate along with the rotation of the connecting rod A203, and then the threaded cooperation between the screw rod B12 and the mounting seat 13 is used to drive the mounting seat 13 to slide on the inner wall of the slide 11, so that the position of the grinding disc 206 can be adjusted.
[0035] like Figure 5 As shown, a holder 16 is fixedly connected to the outer wall of the support frame 10, a third motor 17 is fixedly installed on the inner side of the holder 16, and an output shaft of the third motor 17 passes through the interior of the slideway 11 and is fixedly connected to the end of the screw rod B12.
[0036] In this embodiment, the third motor 17 is started to drive the screw rod B12 to rotate. When the screw rod B12 rotates, the screw rod B12 cooperates with the mounting seat 13 through the thread, so that the mounting seat 13 can drive the grinding disc 206 to adjust the position.
[0037] In summary, the working principle of the utility model is as follows:
[0038] During use, when metal products of different volumes need to be processed, the metal products to be processed are placed on the surface of the clamping seat 302, and at the same time, the clamping plate 312 will slide on the inner wall of the limiting groove 310, and the clamping plate 312 will force the support spring 311 to contract while sliding, and then the tension generated by the contraction of the support spring 311 causes the clamping plate 312 to clamp and fix the metal product, and then the double-section lead screw 307 is rotated synchronously by turning the knob 306, and when the double-section lead screw 307 rotates, it cooperates with the thread between the two articulated seats 308, and then the two articulated seats 308 move synchronously in relative directions, and During the movement, the articulated seat 308 will be hinged with the adjusting plate 309, so that the two adjusting plates 309 synchronously push the clamping seat 302 to rise and fall, thereby changing the distance between the metal product and the grinding disc 206, so that the device can be suitable for products of different volumes, and by changing the distance between the metal product and the grinding disc 206, the contact pressure between the grinding wheel and the surface of the metal product can be adjusted, thereby improving the polishing effect of the product. When the grinding angle of the device needs to be adjusted, the angle of the adjusting frame A201 and the adjusting frame B202 is changed by connecting the connecting column 209, and the connecting column 209 is limited to allow the adjusting frame A201 and the adjusting frame B202 to be aligned with each other. When the angle between the frame B202 changes, the outer edges of the gears B207 and A204 can still mesh with the outer edges of the gears C208. When the angle is adjusted to a suitable position, the extrusion block 405 is rotated. When the extrusion block 405 rotates, the end of the extrusion block 405 is squeezed toward the outside of the limiting slide 4 through the threaded fit between the screw 403, so that the angle between the adjustment frame A201 and the adjustment frame B202 after the hinge is fixed. Subsequently, the connecting rod A203 is driven to rotate by the second motor 15, and the connecting rod 14 fixes the adjustment frame 201 to ensure that when the second motor 15 drives the connecting rod A203 to rotate, the adjustment frame A It will not rotate along with the rotation of the connecting rod A203. When the connecting rod A203 rotates, it drives the gear A204 to rotate. When the gear A204 rotates, it meshes with the outer edge of the gear C208 through the outer edge, and then the gear C208 drives the gear B207 to rotate synchronously. When the gear B207 rotates, it drives the grinding disc 206 to rotate synchronously through the connecting rod B205, so as to perform the grinding work. By changing the angle between the adjusting frame A201 and the adjusting frame B202, the grinding angle of the grinding disc 206 will be changed synchronously, so that the polishing device can accurately contact and polish different parts of the metal product, thereby improving the application range of the device.
[0039] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.
Claims
1. A product surface polishing device, comprising a support seat (1), an adjustment mechanism (2) and a clamping mechanism (3), characterized in that: The adjusting mechanism (2) comprises an adjusting frame A (201) and an adjusting frame B (202); the inner wall of the adjusting frame A (201) is rotatably connected to a connecting rod A (203); the outer wall of the connecting rod A (203) is fixedly connected to a gear A (204); the inner wall of the adjusting frame B (202) is rotatably connected to a connecting rod B (205); the lower surface of the connecting rod B (205) is fixedly connected to a grinding disc (206); the top of the connecting rod B (205) is fixedly connected to a gear B (207); a gear C (208) is meshed between the gear B (207) and the outer edge of the gear A (204); the inner wall of the gear C (208) is fixedly connected to a connecting column (209); the adjusting frame A (201) and the adjusting frame B (202) are rotated via the connecting column (209).
2. A product surface polishing device according to claim 1, characterized in that: The outer wall of the adjustment frame A (201) is symmetrically fixedly connected to two limit slides (4), and the two sides of the adjustment frame B (202) are symmetrically fixedly connected to arc rods (401), and the outer sides of the arc rods (401) are slidably connected to the inner sides of the two limit slides (4), and the inner wall of the arc rod (401) is fixedly connected to the limit rod (402), one side of the limit rod (402) is fixedly connected to a screw rod (403), one end of the screw rod (403) is fixedly connected to a clamping block (404), and a squeeze block (405) is threadedly connected to the outer wall of the screw rod (403) on the side close to the clamping block (404).
3. A product surface polishing device according to claim 1, characterized in that: The clamping mechanism (3) comprises a support plate (301) and a clamping seat (302); two slide seats (303) are symmetrically fixedly connected to the lower surface of the support plate (301); a sliding sleeve (304) is fixedly connected to the outer wall of the support plate (301) between the two slide seats (303); two fixed seats (305) are symmetrically fixedly connected to the upper surface of the support plate (301); a knob (306) is rotatably connected to the inner wall of one of the fixed seats (305); a double-segment screw rod (307) is fixedly connected to the end of the knob (306); and the double-segment screw rod (307) is fixedly connected to the inner wall of the two fixed seats (305). The outer wall is symmetrically fixedly connected with two hinged seats (308), the ends of the two hinged seats (308) are hinged with adjustment plates (309), and the ends of the two adjustment plates (309) are hinged with the inner wall of the clamping seat (302), the inner wall of the clamping seat (302) is symmetrically provided with two limit grooves (310), the inner sides of the two limit grooves (310) are fixedly connected with support springs (311), the ends of the support springs (311) are fixedly connected with clamping plates (312), and the outer wall of the clamping plate (312) is slidably connected with the inner wall of the limit groove (310).
4. A product surface polishing device according to claim 3, characterized in that: Two pairs of telescopic rods (5) are symmetrically fixedly connected between the outer walls of the support plate (301) and the clamping seat (302); two limiting slide rails (6) are symmetrically fixedly connected to the upper surface of the support seat (1); the outer walls of the two limiting slide rails (6) are respectively slidably connected to the inner walls of the two slide seats (303); a first motor (7) is fixedly installed on the upper surface of the support plate (301) between the two limiting slide rails (6); a screw rod A (8) is fixedly connected to the output shaft of the first motor (7); the outer wall of the screw rod A (8) is slidably connected to the inner wall of the sliding sleeve (304); the end of the screw rod A (8) is rotatably connected to a fixed block (9); and the outer wall of the fixed block (9) is fixedly connected to the upper surface of the support plate (301).
5. A product surface polishing device according to claim 1, characterized in that: The upper surface of the support seat (1) is fixedly connected to a support frame (10), the inner wall of the support frame (10) is provided with a slideway (11), the inner side of the slideway (11) is rotatably connected to a screw rod B (12), the outer wall of the screw rod B (12) is threadedly connected to a mounting seat (13), and the outer wall of the mounting seat (13) is slidably connected to the inner wall of the slideway (11), the lower surface of the mounting seat (13) is symmetrically fixedly connected to connecting rods (14), the outer wall bottom ends of the two connecting rods (14) are fixedly connected to the outer wall of the adjustment frame A (201), the inner side of the mounting seat (13) is fixedly installed with a second motor (15), and the output shaft of the second motor (15) is fixedly connected to the end of the connecting rod A (203).
6. A product surface polishing device according to claim 5, characterized in that: The outer wall of the support frame (10) is fixedly connected with a holder (16), the inner side of the holder (16) is fixedly mounted with a third motor (17), and the output shaft of the third motor (17) passes through the interior of the slideway (11) and is fixedly connected with the end of the screw rod B (12).