Multi-legged robot for grinding irregular curved surface of narrow runner of runner

Abstract

The invention belongs to the technical field of surface grinding, and particularly relates to a multi-legged robot for grinding an irregular curved surface of a narrow runner of a runner, which comprises a walking assembly and a grinding assembly, the walking assembly comprises an outer foot layer, an inner foot layer, an X-axis movement assembly and a Y-axis movement assembly; the outer foot layer and the inner foot layer of the robot are controlled to alternately move through movement cooperation of the X-axis movement assembly and the Y-axis movement assembly, so that peristaltic walking is achieved; the grinding assembly comprises an inner shell, a Z-axis movement assembly and a grinding piece. The grinding assembly moves downwards through the Z-axis movement assembly and makes contact with the weld joint, and the weld joint of the water turbine is ground. High-precision grinding and stable movement in the narrow irregular curved surface environment are jointly achieved through an alternate adsorption wriggling walking mechanism, electromagnet dynamic adsorption control and elastic abrasive belt tensioning force self-adaptive adjustment.

Description

Technical Field

[0001] The invention belongs to the technical field of surface grinding, and in particular relates to a multi-legged robot used for grinding irregular curved surfaces of narrow flow channels of a runner. Background Art

[0002] As one of the world's largest low-carbon clean energy sources, hydropower occupies an important position in the global energy structure. The demand for equipment manufacturing in the hydropower industry continues to grow. However, key components in hydropower equipment (such as turbine runners, seat rings, valves, etc.) have complex internal structures due to their fluid mechanics characteristics. Their special shapes and narrow working spaces bring great challenges to manufacturing, installation and maintenance.

[0003] In the grinding operation of rotary welds in narrow spaces, the traditional method mainly relies on workers to use handheld grinders to grind the end faces. Since there is rigid contact between the grinding wheel and the weld, the contact shape is approximately a line, which requires multiple movements to form an approximately enveloping processing trajectory during the grinding process. However, the rigid contact characteristics cause a large deviation between the trajectory of discrete straight line fitting and the actual profile of the weld, making it difficult to meet the requirements of weld surface consistency and accuracy. In addition, the manual grinding method is not only inefficient, but also the grinding quality consistency and accuracy are difficult to meet the design standard requirements. At the same time, the smoke generated during the grinding process poses a serious threat to workers' health.

[0004] At present, existing grinding robots use wheeled / crawler-type walking parts. Due to the complex internal flow channel structure and narrow space of parts such as turbine runners, such walking parts are difficult to enter effectively, difficult to move, and lack flexibility. Alternatively, walking parts with foot structures are used. Such walking parts have a contradiction between load capacity and gait balance, and have poor stability. It is necessary to improve the robot's adsorption and balance capabilities on inclined and non-continuous surfaces. There are also creeping walking parts that rely on continuous power input and are inefficient. It is necessary to improve the load capacity of the mechanism and reduce energy consumption optimization.

[0005] The grinding parts of existing grinding robots use grinding wheel parts or abrasive belt parts. The grinding wheel parts use a rigid contact method, and their contact shape is a line, which leads to a large deviation between the trajectory of discrete straight line fitting and the actual profile of the weld, making it difficult to meet the requirements of weld surface consistency and accuracy. Insufficient tension during the grinding of the abrasive belt parts will cause the abrasive belt to slip or shake, affecting the grinding quality; excessive tension will cause the abrasive grains of the abrasive belt to fall off or even break. Summary of the invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a multi-legged robot for grinding irregular surfaces in narrow flow channels of running wheels, the robot having walking parts that can move in narrow spaces and complex terrains and a grinding device based on flexible abrasive belts; achieving creeping movement in narrow spaces through an alternating adsorption mechanism; and improving grinding accuracy and surface quality through elastic contact.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner, comprising a walking component capable of moving in narrow spaces and complex terrains, and a grinding component with elastic contact and tension control; The walking assembly includes an outer foot layer, an inner foot layer, an X-axis motion assembly and a Y-axis motion assembly; the X-axis motion assembly is connected to the outer foot layer and the Y-axis motion assembly, and the Y-axis motion assembly is connected to the inner foot layer, and the alternating motion of the outer foot layer and the inner foot layer of the robot is controlled by the movement and coordination of the X-axis motion assembly and the Y-axis motion assembly to realize creeping walking; The grinding assembly includes an inner shell, a Z-axis motion assembly and a grinding piece; the inner shell is installed on the walking assembly through two Z-axis motion assemblies; the grinding piece is installed in the inner shell, and the Z-axis motion assembly is used to move the grinding assembly downward and contact the weld to achieve grinding of the turbine weld.

[0009] Furthermore, the outer foot layer includes an outer shell and an outer adsorption element. The bottom of the outer shell is open, and the side surfaces of the bottom extend outward to form a mounting surface. External adsorption elements are installed at both ends of the mounting surface. Four external adsorption elements enclose a rectangular surface.

[0010] Furthermore, 1 to 2 external adsorption elements are installed in the middle of the installation surface.

[0011] Furthermore, the X-axis motion assembly includes a first support frame, a first guide rail, a first slider and an electric telescopic rod. The support frame is an L-shaped structure. Two first sliders are slidably installed on the first guide rail. The sides of the two first sliders away from the first guide rail are fixedly installed on the first support frame. The first guide rail is installed on the inner side of the outer shell. The electric telescopic rod is installed on the support frame, and its telescopic direction is parallel to the sliding direction of the slider, both along the X-axis direction; the telescopic end of the electric telescopic rod is connected to the outer shell, and the movement of the outer foot layer along the X-axis direction is realized by the telescopic extension of the electric telescopic rod.

[0012] Furthermore, the electric telescopic rod is implemented by an electric actuator having a stepping motor.

[0013] Furthermore, the Y-axis motion assembly includes two groups, which are symmetrically installed at both ends of the inner side of the first support frame along the Z-axis. It includes a second support frame and a first cylinder slide. The second support frame is fixed to the end of the first support frame in the length direction and is arranged along the Y-axis direction. The first cylinder slide is installed on the inner side surface of the second support frame, and its sliding direction is along the Y-axis direction; the first cylinder slide is connected to the inner foot layer, and the inner foot layer is driven to move along the Y-axis direction by controlling the linear motion of the first cylinder slide.

[0014] Furthermore, the inner foot layer includes two groups, which are respectively connected to the Y-axis motion assembly, and it includes a third support frame and an internal adsorption element. The third support frame is an inverted L-shaped structure, and its top surface is connected to the first cylinder slide. A mounting plate is provided in the middle of its outer side surface, and at least two internal adsorption elements are installed on the mounting plate.

[0015] Furthermore, the structure of the external adsorption element is the same as that of the internal adsorption element, and it includes a micro cylinder and an electromagnet. The telescopic end of the micro cylinder is telescoped downward and connected to the electromagnet. By controlling the current of the electromagnet, the adsorption force of the adsorption element can be controlled. The movement of each electromagnet in the Z-axis direction is individually controlled by the stroke of the micro cylinder.

[0016] Furthermore, the Z-axis motion assembly includes a second guide rail, a second slider and a second cylinder slide; the second slider is installed on the inner side surface of the third support frame and slides with the second guide rail, the second guide rail is installed on the outer side surface of the inner shell along the Z-axis, the second cylinder slide is respectively connected to the inner side surface of the third support frame and the outer side surface of the inner shell, and the moving direction of the second cylinder slide moves along the Z-axis direction, and the movement of the inner shell and the upper grinding assembly installed on the inner shell is realized by controlling the movement of the second cylinder slide.

[0017] Further, the grinding member is installed in the inner shell, and it includes a support plate, a drive assembly, a tension assembly, a grinding assembly and a normal motion assembly, the support plate is fixedly installed on the inner shell, and the drive assembly, the tension assembly, the grinding assembly and the normal motion assembly are fixed on the support plate; The driving assembly includes a driving wheel and a servo motor for controlling the rotation of the driving wheel, the servo motor is fixed to a support plate, the tension assembly includes a tension wheel and a support seat for supporting the tension wheel, the support seat is mounted on the support plate through a normal motion assembly; the grinding assembly includes an elastic sand belt, a grinding wheel and a wheel seat, the grinding wheel is fixed to the support plate through the wheel seat, the driving wheel, the tension wheel and the grinding wheel are distributed in a triangle, and the elastic sand belt is wound around the driving wheel, the tension wheel and the grinding wheel in sequence; The normal drive assembly is implemented by a cylinder slide, and the moving direction of the cylinder slide is the same as the force balance direction of the tension wheel; the position of the tension wheel is fine-tuned by controlling the movement of the cylinder slide, thereby adjusting the tension of the elastic sanding belt.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) Through the alternating adsorption creeping walking mechanism, the dynamic adsorption control of the electromagnet and the adaptive adjustment of the tension of the elastic abrasive belt, high-precision grinding and stable movement can be achieved on narrow and irregular surfaces.

[0020] (2) Through the alternating adsorption and movement of the outer foot layer and the inner foot layer (coordinated control of the X-axis and Y-axis motion components), the robot can achieve peristaltic walking in a narrow flow channel; both the outer adsorption element and the inner adsorption element adopt a "micro cylinder + electromagnet" combination, which controls the adsorption force by adjusting the current, and adjusts the Z-axis displacement separately through the micro cylinder to ensure that it fits the curved surface.

[0021] (3) An elastic abrasive belt is used to wrap around the driving wheel, tension wheel and grinding wheel (triangular distribution). The tension wheel position is adjusted in real time through the normal motion component to optimize the tension of the abrasive belt. The servo motor drives the abrasive belt to move, and the grinding depth is adjusted in combination with the Z-axis motion component to form an elliptical contact area to adapt to irregular surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the polishing robot of the present invention.

[0023] Figure 2 It is a schematic structural diagram of the walking assembly of the present invention.

[0024] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure.

[0025] Figure 4 It is a schematic diagram of the structure of the motion component of the present invention.

[0026] Figure 5 It is a schematic diagram of the structure of the grinding assembly of the present invention.

[0027] Figure 6 It is a schematic diagram of the structure of the grinding piece of the present invention.

[0028] Markings in the figure: 100, walking component; 110, outer foot layer; 111, outer shell; 112, outer adsorption element; 120, inner foot layer; 121, third support frame; 122, inner adsorption element; 130, X-axis motion component; 131, first support frame; 132, first guide rail; 134, electric telescopic rod; 140, Y-axis motion component; 141, second support frame; 142, first cylinder slide; 200, grinding component; 210, inner shell; 211, support plate; 220, Z-axis motion component; 221, second slider; 222, second guide rail; 223, second cylinder slide; 230, grinding piece; 231, drive component; 232, tension component; 233, grinding component; 234, sanding belt; 235, normal motion component; 301, micro cylinder; 302, electromagnet. DETAILED DESCRIPTION

[0029] like Figure 1 As shown, this embodiment provides a multi-legged robot for grinding irregular curved surfaces of narrow channels of a runner, the robot comprising a walking component 100 capable of moving in narrow spaces and complex terrains, and a grinding component 200 with elastic contact and tension control.

[0030] like Figures 2~4 As shown, the walking component 100 includes an outer foot layer 110, an inner foot layer 120, an X-axis motion component 130 and a Y-axis motion component 140; in this embodiment, the X-axis motion component 130 and the Y-axis motion component 140 cooperate to control the alternating motion of the outer foot layer 110 and the inner foot layer 120 of the robot to achieve creeping walking.

[0031] The outer foot layer 110 includes an outer shell 111 and an outer adsorption element 112. The bottom of the outer shell 111 is open, and the side of the bottom extends outward to form a mounting surface. The two ends of the mounting surface are mounted with outer adsorption elements 112. The four outer adsorption elements 112 enclose a rectangular surface. To increase the adsorption force, 1 to 2 outer adsorption elements 112 can be added in the middle of the mounting surface. Because the robot described in this embodiment is a downward grinding robot, an observation port is opened on one side of the outer shell 111, so two outer adsorption elements 112 are installed in the middle of the mounting surface on the other side, and a total of 6 outer adsorption elements 112 are arranged on the outer foot layer 110.

[0032] The X-axis motion assembly 130 includes a first support frame 131, a first guide rail 132, a first slider and an electric telescopic rod 134. The first support frame 131 is an L-shaped structure. Two first sliders are slidably mounted on the first guide rail 132. The sides of the two first sliders away from the first guide rail 132 are fixedly mounted on the first support frame 131. The first guide rail 132 is mounted on the inner side of the outer shell 111. The electric telescopic rod 134 is mounted on the support frame, and its telescopic direction is parallel to the sliding direction of the slider, both along the X-axis direction; the telescopic end of the electric telescopic rod 134 is connected to the outer shell 111, and the movement of the outer foot layer 110 along the X-axis direction is achieved by the telescopic extension of the electric telescopic rod 134. The electric telescopic rod 134 is implemented by an electric actuator with a stepping motor, specifically, LEY25D of SMC; the maximum travel of the electric telescopic rod determines the maximum distance that the robot moves along the X-axis.

[0033] The Y-axis motion assembly 140 includes two groups, which are symmetrically installed at both ends of the inner side of the first support frame 131 along the Z axis. It includes a second support frame 141 and a first cylinder slide 142. The second support frame 141 is fixed to the end of the first support frame 131 in the length direction and is arranged along the Y-axis direction. The first cylinder slide 142 is installed on the inner side surface of the second support frame 141, and its sliding direction is along the Y-axis direction; the first cylinder slide 142 is connected to the inner foot layer 120, and the inner foot layer 120 is driven to move along the Y-axis direction by controlling the linear motion of the first cylinder slide 142.

[0034] The inner foot layer 120 includes two groups, which are respectively connected to the Y-axis motion component 140, and it includes a third support frame 121 and an internal adsorption element 122. The third support frame 121 is an inverted L-shaped structure, and its top surface is connected to the first cylinder slide 142. A mounting plate is provided in the middle of its outer side surface, and at least two internal adsorption elements 122 are installed on the mounting plate. In this embodiment, the mounting plate is installed with three internal adsorption elements 122, and the two inner foot layers 120 include six internal adsorption elements 122.

[0035] The outer adsorption element 112 has the same structure as the inner adsorption element 122, and includes a micro cylinder 301 and an electromagnet 302. The telescopic end of the micro cylinder 301 telescopes downward and is connected to the electromagnet 302. In this embodiment, the adsorption force of the adsorption element is controlled by controlling the current of the electromagnet 302. The movement of each electromagnet 302 in the Z-axis direction is controlled individually through the stroke of the micro cylinder 301 to ensure that the electromagnet 302 better fits the internal curved surface of the flow channel, thereby achieving a better adsorption effect and effectively avoiding the robot from static instability such as sliding tendency, longitudinal overturning, lateral flipping, etc. during movement, which may cause the robot to detach from the curved surface of the flow channel.

[0036] Walking principle: When the robot moves, the micro cylinder 301 first retracts to make the electromagnet 302 of the outer adsorption element 112 move in the Z-axis direction until it is adsorbed on the inner surface of the flow channel, and then the inner foot layer 120 is driven to move along the X-axis direction by driving the electric telescopic rod 134, and then the inner foot layer 120 is driven to move along the Y-axis direction by controlling the first cylinder slide 142. The movement amount in the X-axis direction and the Y-axis direction is related to the movement path. After the movement is in place, the electromagnet 302 of the inner adsorption element 122 moves downward under the drive of the micro cylinder 301 and adsorbs on the inner surface of the flow channel. After the adsorption is stable, the current of the electromagnet 302 of the outer adsorption element 112 is reduced to reduce the adsorption force, and the micro cylinder 301 is controlled to move upward, and then the electric telescopic rod and the first cylinder slide 142 are controlled to move the outer foot layer 110 along the X-axis and Y-axis directions, and then the micro cylinder 301 is controlled to retract to make the electromagnet 302 of the outer adsorption element 112 move and adsorb in the Z-axis direction. Through the alternating movement of the outer foot layer 110 and the inner foot layer 120 and the adsorption of the electromagnet 302, the robot can achieve the needs of climbing and moving on the inner wall curved surface of the narrow flow channel and adjusting the posture.

[0037] like Figure 5 , 6 As shown, the grinding assembly 200 includes an inner shell 210, a Z-axis motion assembly 220 and a grinding piece 230; the inner shell 210 is installed on the inner side surface of the third support frame 121 through two Z-axis motion assemblies 220; the grinding piece 230 is installed in the inner shell 210, and the Z-axis motion assembly 220 is used to move the grinding assembly 200 downward and contact the weld to achieve grinding of the weld of the turbine.

[0038] The Z-axis motion assembly 220 includes a second guide rail 222, a second slider 221 and a second cylinder slide 223; the second slider 221 is installed on the inner side surface of the third support frame 121 and slides with the second guide rail 222, the second guide rail 222 is installed on the outer side surface of the inner shell 210 along the Z-axis, the second cylinder slide 223 is respectively connected to the inner side surface of the third support frame 121 and the outer side surface of the inner shell 210, and the moving direction of the second cylinder slide 223 moves along the Z-axis direction, and the movement of the inner shell 210 and the upper grinding assembly 200 installed on the inner shell 210 is realized by controlling the movement of the second cylinder slide 223.

[0039] The grinding component 230 is installed in the inner shell 210, and it includes a support plate 211, a drive component 231, a tension component 232, a grinding component 233 and a normal motion component 235. The support plate 211 is fixedly installed on the inner shell 210, and the drive component 231, the tension component 232, the grinding component 233 and the normal motion component 235 are fixed on the support plate 211. The grinding component 200 is independently modularized through the support plate 211, which is convenient for replacement and maintenance.

[0040] The driving assembly 231 includes a driving wheel and a servo motor for controlling the rotation of the driving wheel, the servo motor is fixed on the support plate 211, the tension assembly 232 includes a tension wheel and a support seat for supporting the tension wheel, and the support seat is installed on the support plate 211 through a normal motion assembly 235; the grinding assembly 233 includes an elastic sanding belt 234, a grinding wheel and a wheel seat, the grinding wheel is fixed on the support plate 211 through the wheel seat, the driving wheel, the tension wheel and the grinding wheel are distributed in a triangle, and the elastic sanding belt 234 is wrapped around the driving wheel, the tension wheel and the grinding wheel in sequence.

[0041] In the entire robot, the grinding assembly 233 is located at the bottom, the tension assembly 232 is located above the grinding assembly 200, and the driving assembly 231 is located on one side of the grinding assembly 200 and the tension assembly.

[0042] The normal drive assembly 231 is implemented by a cylinder slide, and the moving direction of the cylinder slide is the same as the force balance direction of the tension wheel; the position of the tension wheel is fine-tuned by controlling the movement of the cylinder slide, thereby adjusting the tension of the elastic sand belt 234, thereby improving the grinding efficiency and extending the life of the sand belt 234. By reasonably designing the tension, it is ensured that the elastic sand belt 234 will neither slip nor be damaged due to excessive tension during operation.

[0043] Grinding principle: After the moving parts are moved into place, the Z-axis motion assembly 220 moves downward, so that the grinding piece 230 contacts the weld, and the servo motor drives the driving wheel to rotate, thereby driving the sanding belt 234 to move; the grinding wheel contacts the weld, and the sanding belt 234 forms an elliptical contact area with the weld surface to achieve efficient grinding. The Z-axis motion assembly 220 and the tensioning wheel adjust the distance and angle between the grinding wheel and the weld in real time according to the position and shape of the weld to ensure the uniformity and consistency of the grinding. The elastic characteristics of the sanding belt 234 and the contact wheel enable better fit to the weld surface during the grinding process, reduce the number of movements, and thus improve the grinding efficiency and surface quality.

[0044] The above description is only a preferred implementation manner of the present invention, but the protection scope of the present invention is not limited thereto, and any modification and replacement based on the technical solution and inventive concept provided by the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-legged robot for grinding irregular curved surfaces in narrow flow channels of a runner, characterized in that: It includes walking components that can move in narrow spaces and complex terrains, and grinding components with elastic contact and tension control; The walking assembly includes an outer foot layer, an inner foot layer, an X-axis motion assembly and a Y-axis motion assembly; the X-axis motion assembly is connected to the outer foot layer and the Y-axis motion assembly, and the Y-axis motion assembly is connected to the inner foot layer, and the alternating motion of the outer foot layer and the inner foot layer of the robot is controlled by the movement and coordination of the X-axis motion assembly and the Y-axis motion assembly to realize creeping walking; The grinding assembly includes an inner shell, a Z-axis motion assembly and a grinding piece; the inner shell is installed on the walking assembly through two Z-axis motion assemblies; the grinding piece is installed in the inner shell, and the Z-axis motion assembly is used to move the grinding assembly downward and contact the weld to achieve grinding of the turbine weld.

2. A multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 1, characterized in that: The outer foot layer includes an outer shell and an outer adsorption element. The bottom of the outer shell is open, and the side of the bottom extends outward to form a mounting surface. The two ends of the mounting surface are both installed with outer adsorption elements. The four outer adsorption elements enclose a rectangular surface.

3. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 2, characterized in that: Install 1~2 external adsorption elements in the middle of the installation surface.

4. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 2, characterized in that: The X-axis motion assembly includes a first support frame, a first guide rail, a first slider and an electric telescopic rod. The support frame is in an L-shaped structure. Two first sliders are slidably installed on the first guide rail. The sides of the two first sliders away from the first guide rail are fixedly installed on the first support frame. The first guide rail is installed on the inner side of the outer shell. The electric telescopic rod is installed on the support frame, and its telescopic direction is parallel to the sliding direction of the slider, both along the X-axis direction; the telescopic end of the electric telescopic rod is connected to the outer shell, and the movement of the outer foot layer along the X-axis direction is realized by telescoping the electric telescopic rod.

5. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 4, characterized in that: The electric telescopic rod is realized by an electric actuator with a stepping motor.

6. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 4, characterized in that: The Y-axis motion assembly includes two groups, which are symmetrically installed at the two ends of the inner side of the first support frame along the Z axis. It includes a second support frame and a first cylinder slide. The second support frame is fixed to the end of the first support frame in the length direction and is arranged along the Y-axis direction. The first cylinder slide is installed on the inner side surface of the second support frame, and its sliding direction is along the Y-axis direction; the first cylinder slide is connected to the inner foot layer, and the inner foot layer is driven to move along the Y-axis direction by controlling the linear motion of the first cylinder slide.

7. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 6, characterized in that: The inner foot layer includes two groups, which are respectively connected to the Y-axis motion component. It includes a third support frame and an internal adsorption element. The third support frame is an inverted L-shaped structure, whose top surface is connected to the first cylinder slide, and a mounting plate is provided in the middle of its outer side surface, and at least two internal adsorption elements are installed on the mounting plate.

8. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 7, characterized in that: The structure of the external adsorption element is the same as that of the internal adsorption element, and it includes a micro cylinder and an electromagnet. The telescopic end of the micro cylinder is telescoped downward and connected to the electromagnet. The adsorption force of the adsorption element is controlled by controlling the current of the electromagnet. The movement of each electromagnet in the Z-axis direction is individually controlled by the stroke of the micro cylinder.

9. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 1, characterized in that: The Z-axis motion assembly includes a second guide rail, a second slider and a second cylinder slide; the second slider is installed on the inner side surface of the third support frame and slides with the second guide rail, the second guide rail is installed on the outer side surface of the inner shell along the Z-axis, the second cylinder slide is respectively connected to the inner side surface of the third support frame and the outer side surface of the inner shell, and the moving direction of the second cylinder slide moves along the Z-axis direction, and the movement of the inner shell and the upper grinding assembly installed on the inner shell is realized by controlling the movement of the second cylinder slide.

10. The multi-legged robot for grinding irregular curved surfaces of narrow flow channels of a runner according to claim 1, characterized in that: The grinding component is installed in the inner shell, and it includes a support plate, a drive assembly, a tension assembly, a grinding assembly and a normal motion assembly. The support plate is fixedly installed on the inner shell, and the drive assembly, the tension assembly, the grinding assembly and the normal motion assembly are fixed on the support plate; The driving assembly includes a driving wheel and a servo motor for controlling the rotation of the driving wheel, the servo motor is fixed to a support plate, the tension assembly includes a tension wheel and a support seat for supporting the tension wheel, the support seat is mounted on the support plate through a normal motion assembly; the grinding assembly includes an elastic sand belt, a grinding wheel and a wheel seat, the grinding wheel is fixed to the support plate through the wheel seat, the driving wheel, the tension wheel and the grinding wheel are distributed in a triangle, and the elastic sand belt is wound around the driving wheel, the tension wheel and the grinding wheel in sequence; The normal drive assembly is implemented by a cylinder slide, and the moving direction of the cylinder slide is the same as the force balance direction of the tension wheel; the position of the tension wheel is fine-tuned by controlling the movement of the cylinder slide, thereby adjusting the tension of the elastic sanding belt.

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