PCD (Poly Crystal Diamond) saw blade cutter processing machine tool

Abstract

The invention discloses a PCD (Poly Crystal Diamond) saw blade cutter processing machine tool, which belongs to the technical field of PCD saw blade cutters, and comprises a machine tool body, a multi-coordinate driving table arranged on the machine tool body, a cutter arranged on the multi-coordinate driving table, and a mounting plate arranged on the machine tool body in a sliding manner, and further comprises a polishing assembly arranged on the mounting plate and used for cleaning saw tooth surfaces, the polishing assembly comprises a swing plate rotationally arranged on the mounting plate, two polishing wheels used for polishing the sawteeth are rotationally arranged at the bottom of the swing plate and are in transmission connection, the left-right deflection angle of the sawteeth can be adjusted according to the radian of the sawteeth when the two polishing wheels conduct polishing, and the two ends of the swing plate can be adjusted up and down when the polishing wheels conduct polishing. The machining efficiency of the saw blade is guaranteed, meanwhile, the machining quality of the saw blade is guaranteed, and the situation that carbonized layers are left on the surface of the saw blade, and consequently use of the saw blade is affected is avoided.

Description

Technical Field

[0001] This invention belongs to the field of PCD saw blade technology, and particularly relates to a PCD saw blade processing machine tool. Background Technology

[0002] The tooth profile of polycrystalline diamond saw blades is commonly machined using laser cutting and electrical discharge machining (EDM). However, both methods form a carbonized and modified layer on the saw tooth surface during the high-temperature forming process. Due to the carbonization of diamond and the loss of cobalt binder, the hardness and wear resistance of this layer decrease sharply, and micro-cracks are present. If left directly on the cutting edge, it will cause the saw blade to wear and chip rapidly during actual cutting, severely limiting its intended ultra-long lifespan.

[0003] Existing machine tools cannot directly clean the saw blade surface after processing. They require disassembling the saw blade and using sandblasting and polishing, which is often a rough post-processing method with significant limitations. They cannot accurately distinguish between the saw tooth matrix and the carbonized layer, and are ill-suited to the complex saw tooth curvatures designed for optimized cutting performance, such as the three-dimensional contours of trapezoidal teeth or beak teeth. Conventional equipment can only perform homogenization, which can easily damage key geometric features of the saw teeth or result in uneven cleaning, leaving carbonized layers on complex curved surfaces such as the tooth root and ventral side. It's difficult to balance cleaning effectiveness and precision. Furthermore, disassembly increases the number of saw blade processing steps, leading to lower saw blade production efficiency. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a PCD saw blade processing machine tool, which solves the problem that existing equipment cannot adequately clean the saw blade processing area during saw blade processing, resulting in low saw blade production efficiency and affected saw blade quality.

[0005] This invention is implemented as follows: a PCD saw blade processing machine tool includes a bed, a multi-axis drive table mounted on the bed, a cutter mounted on the multi-axis drive table, and a mounting plate slidably mounted on the bed, and further includes: A grinding assembly for cleaning saw teeth surfaces is mounted on a mounting plate. The grinding assembly includes a swing plate rotatably mounted on the mounting plate. Two grinding wheels for grinding the saw teeth are rotatably mounted at the bottom of the swing plate. The two grinding wheels are connected by a drive, and their left and right deflection angles can be adjusted according to the curvature of the saw teeth when the grinding wheels are grinding. The two ends of the swing plate can be adjusted up and down when the grinding wheels are grinding.

[0006] As a preferred embodiment of the present invention, the grinding assembly further includes a drive motor disposed on the swing plate, and a connector is disposed on the swing plate, wherein the output end of the drive motor is connected to the two grinding wheels via the connector.

[0007] As a preferred embodiment of the present invention, the connecting component includes a slider slidably disposed on the swing plate, and a drive pulley is provided on both the slider and the grinding wheel, and the three drive pulleys are configured for transmission. The output end of the drive motor is fixedly disposed with one of the drive pulleys, and a hydraulic rod for driving the slider to move up and down is provided at the bottom of the swing plate.

[0008] As a preferred embodiment of the present invention, the swing plate is provided with an angle adjustment component for adjusting the left and right deflection of the grinding wheel.

[0009] As a preferred embodiment of the present invention, the angle adjustment assembly includes a universal ball rod disposed within the swing plate, the grinding wheel being rotatably disposed at the end of the universal ball rod, and a traction member for pulling the grinding wheel to engage with the saw teeth is disposed between the universal ball rod and the swing plate.

[0010] As a preferred embodiment of the present invention, the traction component includes a slide rod and a slide sleeve respectively hinged to the bottom of the universal ball joint and the swing plate, and the slide rod is slidably disposed in the slide sleeve, and a first spring is disposed between the end of the slide rod and one side of the slide sleeve.

[0011] As a preferred embodiment of the present invention, the swing plate is provided with an offset component for driving the end of the swing plate to swing. The offset component includes airbags symmetrically arranged between the mounting plate and the swing plate. The swing plate is provided with a piston part for filling the airbag with gas, and when the grinding wheel grinds, the gas in the piston part enters the airbag.

[0012] In a preferred embodiment of the present invention, the piston part includes a piston rod, a piston tube, and a piston plate disposed on the piston rod. The piston rod is slidably disposed inside the piston tube, and a second spring is sleeved on the piston rod. Two airflow plates are symmetrically disposed on the sliding sleeve, and the airflow plates are disposed on both sides of the grinding wheel. The piston tube is connected to the air bladder and the airflow plates respectively, and a U-shaped tube is disposed on the piston tube. The upper and lower sides of the piston tube are connected to each other through a U-shaped tube. A cam is disposed at the output end of the drive motor, and the cam is in movable contact with the piston rod.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes two grinding wheels mounted on a swing plate to effectively grind the outer and inner diameters of the saw teeth alternately, resulting in higher grinding efficiency and reducing the need for secondary processing after disassembly. The contact between the grinding wheels and the saw teeth ensures more precise grinding, avoiding the inaccuracies that can occur with sandblasting or other methods, which can affect other parts of the saw blade and compromise its quality. During grinding, the position of the swing plate and the left-right adjustment of the grinding wheels allow them to fully conform to the surface of the saw teeth, adjusting to their curvature. This effectively improves the cleaning quality of the equipment and prevents mismatches caused by varying saw tooth curvature during grinding, further enhancing the practicality and ease of use of the equipment. It also improves grinding quality and reduces subsequent saw blade disassembly and cleaning steps, allowing grinding to be completed immediately after cutting, thus reducing subsequent processing steps. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the front view structure of the present invention; Figure 2 This is a schematic diagram of the partial frontal view structure of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the partial frontal view structure of the present invention. Figure 2 ; Figure 4 This is a schematic diagram of the structure from a partial lower view of the present invention; Figure 5 This is a schematic diagram of the structure from a partial upper view of the present invention; Figure 6 This is a schematic diagram of the cross-sectional structure from a partial left-side perspective of the present invention; Figure 7 This is a schematic diagram of the cross-sectional structure from a partial frontal view of the present invention; Figure 8 This is a schematic diagram of the workflow of the present invention.

[0015] In the picture: 1. Bed; 2. Multi-axis drive stage; 3. Cutter; 4. Mounting plate; 5. Grinding assembly; 51. Grinding wheel; 52. Drive motor; 53. Hydraulic rod; 54. Slider; 55. Swing plate; 6. Angle adjustment assembly; 61. Sliding sleeve; 62. Sliding rod; 63. First spring; 64. Universal ball joint; 7. Offset assembly; 71. Airbag; 72. Piston; 73. Second spring; 74. Airflow plate; 75. Cam. Detailed Implementation

[0016] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings.

[0017] The structure of the present invention will now be described in detail with reference to the accompanying drawings.

[0018] like Figures 1 to 8 As shown, an embodiment of the present invention provides a PCD saw blade processing machine tool, including a bed 1, a multi-axis drive stage 2 disposed on the bed 1, a cutter 3 disposed on the multi-axis drive stage 2, and a mounting plate 4 slidably disposed on the bed 1, and further including: A grinding assembly 5 is mounted on the mounting plate 4 for cleaning the saw tooth surface. The grinding assembly 5 includes a swing plate 55 rotatably mounted on the mounting plate 4. Two grinding wheels 51 for grinding the saw teeth are rotatably mounted at the bottom of the swing plate 55. The two grinding wheels 51 are connected by a drive, and when the two grinding wheels 51 are grinding, their left and right deflection angles can be adjusted according to the curvature of the saw teeth. When the grinding wheels 51 are grinding, the two ends of the swing plate 55 can be adjusted up and down. refer to Figure 1 and Figure 8 The saw blade to be processed is placed on the bed 1 using the existing clamping device. At the same time, the multi-axis drive table 2 is controlled to move the cutter 3, which then cuts the saw blade to form saw teeth. The cutter 3 can use electrical discharge cutting or laser cutting. Since the cutting method is existing technology, the cutting content will not be described in detail. After the saw blade is cut, whether it is electrical discharge cutting or laser cutting, the cutting position of the saw blade will be heated and carbonized. At this time, the grinding wheel 51 can be controlled to rotate, and then the cutting position can be ground, as follows. Mounting plate 4 is slidably mounted on the bed 1, so it can be lowered by the existing hydraulic rod to a suitable position, that is, to adjust the grinding wheel 51 above the saw blade. After the saw blade is processed, it forms multiple teeth, which generally have a certain curvature. Therefore, grinding includes both the outer and inner diameters of the teeth. Figure 8 The two methods, A and B, involve grinding and cleaning the inner and outer diameters. A. Grinding, also known as outer diameter grinding, involves moving the mounting plate 4 to a suitable position and adjusting the angle of the swing plate 55. This causes the side of the swing plate 55 closest to the outer diameter of the saw teeth to move downwards, meaning the grinding wheel 51, which is close to the outer diameter of the saw teeth, moves closer to the outer diameter surface of the saw teeth. Meanwhile, the end of the swing plate 55 furthest from the outer diameter surface rises. When the grinding wheel 51 contacts the outer diameter of the saw teeth, the surface of the saw teeth can be effectively ground by controlling the rotation of the grinding wheel 51. Since the grinding wheel 51 can be adjusted left and right on the swing plate 55, as the end of the swing plate 55 continues to descend, the grinding wheel 51 will adhere to the outer diameter surface of the saw teeth and move according to the curvature of the saw teeth. This not only grinds the outer diameter of the saw teeth but also allows the grinding wheel 51 to adapt to the curvature of the saw teeth, ensuring the convenience and efficiency of grinding and reducing the drawbacks of grinding. B. Grinding, i.e. inner diameter grinding, can be repeated. Adjust the swing plate 55 to the end closest to the inner diameter and lower it. At the same time, by lowering one end of the swing plate 55, the grinding wheel 51 can be made to fit against the surface of the inner diameter of the saw teeth. At the same time, by rotating the grinding wheel 51, the inner diameter of the saw teeth can be fully ground. This achieves the alternation of the position of the grinding wheel 51, and grinds both the inner and outer diameters of the saw teeth, ensuring the quality of saw teeth processing. This invention utilizes two grinding wheels 51 mounted on a swing plate 55 to effectively grind the outer and inner diameters of the saw teeth alternately, resulting in higher grinding efficiency and reducing the need for secondary processing after disassembly. The contact between the grinding wheels 51 and the saw teeth ensures more precise grinding, avoiding the inaccuracies that can occur with sandblasting or other methods, which can affect other parts of the saw blade and compromise its quality. During grinding, the position of the swing plate 55 and the left-right adjustment of the grinding wheels 51 allow them to fully conform to the surface of the saw teeth, adjusting according to their curvature. This effectively improves the cleaning quality of the equipment and prevents mismatches caused by varying saw tooth curvature during grinding, further enhancing the practicality and ease of use of the equipment. It also improves grinding quality, reduces subsequent saw blade disassembly and cleaning steps, and allows grinding to be completed immediately after cutting, minimizing subsequent processing steps.

[0019] As a preferred embodiment of the present invention, the grinding assembly 5 further includes a drive motor 52 disposed on the swing plate 55, and a connector is disposed on the swing plate 55, wherein the output end of the drive motor 52 is connected to the two grinding wheels 51 through the connector. refer to Figure 4 When the equipment needs to be polished, the drive motor 52 can be turned on, so that the output end of the drive motor 52 drives the connector to work. At the same time, the two polishing wheels 51 are driven to rotate through the connector. When the polishing wheels 51 rotate, they are in contact with the surface of the saw teeth, so as to effectively polish the saw teeth and thoroughly clean the surface of the saw teeth, avoiding the situation where carbonized material sticks to the surface of the saw teeth and affects the quality of the saw teeth.

[0020] As a preferred embodiment of the present invention, the connecting member includes a slider 54 slidably disposed on the swing plate 55, and a drive pulley is provided on both the slider 54 and the grinding wheel 51, and the three drive pulleys are configured for transmission. The output end of the drive motor 52 is fixedly disposed with one of the drive pulleys, and a hydraulic rod 53 for driving the slider 54 to move up and down is provided at the bottom of the swing plate 55. refer to Figure 4 and Figure 6Since the grinding wheel 51 can swing left and right, the connecting piece can effectively serve as a transmission component, ensuring the transmission connection between the two grinding wheels 51. The specific adjustment method of the connecting piece is as follows: Since both the slider 54 and the grinding wheel 51 are equipped with drive pulleys, the drive pulleys can be driven by gears, and the three gears form a triangle-like shape. At this time, the drive motor 52 can drive one of the gears to control the rotation of the other two gears, thereby driving the two grinding wheels 51 to rotate simultaneously. When the angle of the grinding wheel 51 changes, the hydraulic rod 53 can drive the slider 54 to move up and down to adapt to the angle of the grinding wheel 51. The specific adjustment method needs to be adjusted according to the deflection angle of the grinding wheel 51. For example, when the grinding wheel 51 deflects to the left, the hydraulic rod 53 needs to control the slider 54 to descend, and vice versa. This ensures that the two grinding wheels 51 are always in a transmission state, further reducing the manufacturing cost of the equipment, and achieving the goal that the drive motor 52 can still drive the grinding wheel 51 to rotate regardless of whether the grinding wheel 51 deflects to the left or right.

[0021] As a preferred embodiment of the present invention, the swing plate 55 is provided with an angle adjustment component 6 for adjusting the left and right deflection of the grinding wheel 51; By adjusting the angle of the component 6, the left and right swing of the grinding wheel 51 can be effectively controlled. The left and right swing of the grinding wheel 51 can not only adapt to the curvature of the saw teeth, but also adapt to the grinding of the outer and inner diameters of the saw teeth, thereby effectively improving the grinding efficiency and convenience of the saw blade.

[0022] As a preferred embodiment of the present invention, the angle adjustment component 6 includes a universal ball rod 64 disposed in the swing plate 55, a grinding wheel 51 rotatably disposed at the end of the universal ball rod 64, and a traction member for pulling the grinding wheel 51 to engage with the saw teeth is disposed between the universal ball rod 64 and the swing plate 55. refer to Figure 4 and Figure 5 The omnidirectional ball joint 64 comprises two parts: an omnidirectional ball and a fixed rod. The omnidirectional ball is rolled within the swing plate 55, while the grinding wheel 51 is rotatably mounted at the end of the fixed rod. When the end of the swing plate 55 descends, the grinding wheel 51 contacts the outer or inner diameter surface of the saw teeth. As the end of the swing plate 55 continues to descend, the grinding wheel 51 adheres to the surface of the saw teeth and moves. During this movement, because the saw teeth have a certain curvature, the omnidirectional ball rolls within the swing plate 55. Simultaneously, the fixed rod pushes the grinding wheel 51 to adhere to the surface of the saw teeth and move. Through the movement of the grinding wheel 51, the grinding wheel 51 can grind the surface of the saw teeth. Furthermore, in conjunction with its movement, it can effectively adapt to saw teeth with different curvatures, ensuring the grinding effect of the equipment, reducing the drawbacks of the equipment during grinding, and further improving the usage effect of the equipment.

[0023] As a preferred embodiment of the present invention, the traction component includes a slide rod 62 and a slide sleeve 61 respectively hinged to the bottom of the universal ball rod 64 and the swing plate 55, and the slide rod 62 is slidably disposed in the slide sleeve 61, and a first spring 63 is disposed between the end of the slide rod 62 and one side of the slide sleeve 61. refer to Figure 5 When the grinding wheel 51 is in contact with the surface of the saw teeth, the friction between the universal ball rod 64 and the swing plate 55 is relatively small, which may cause the grinding wheel 51 to separate during grinding, thus affecting the grinding effect. At this time, the slide rod 62 slides in the sliding sleeve 61. At the same time, as the grinding wheel 51 shifts, the slide rod 62 will keep the grinding wheel 51 in contact with the surface of the saw teeth under the traction of the first spring 63, thereby avoiding separation during grinding. At the same time, the tension of the first spring 63 ensures that the surface of the saw teeth can be thoroughly cleaned during grinding, ensuring the cleaning effect and quality.

[0024] As a preferred embodiment of the present invention, the swing plate 55 is provided with an offset component 7 for driving the end of the swing plate 55 to swing. The offset component 7 includes an airbag 71 symmetrically arranged between the mounting plate 4 and the swing plate 55. The swing plate 55 is provided with a piston part 72 for filling the airbag 71 with gas. When the grinding wheel 51 grinds, the gas in the piston part 72 enters the airbag 71. refer to Figure 4 , Figure 7 and Figure 8 Gas is generated by the piston 72 and enters the air bladder 71. When one air bladder 71 is filled with gas, the gas in the other air bladder 71 is discharged. When the air bladder 71 is filled with gas, it can fully expand. Through the expansion of the air bladder 71, the end of the swing plate 55 at its lower part can be effectively pushed down, thereby pushing the grinding wheel 51 closer to the saw tooth surface. The air bladder 71 is equipped with an exhaust valve (not shown in the figure). After grinding is completed, the gas in the air bladder 71 can be discharged through the exhaust valve, which pushes the swing plate 55 to reset, and then the grinding wheel 51 moves away from the saw tooth. Through the repeated expansion and exhaust of the air bladder 71, the grinding wheel 51 can be effectively pushed to move on the saw tooth surface, thereby achieving the effect of cleaning the saw tooth surface and further improving the convenience of cleaning the equipment.

[0025] As a preferred embodiment of the present invention, the piston part 72 includes a piston rod, a piston tube, and a piston plate disposed on the piston rod. The piston rod is slidably disposed inside the piston tube, and a second spring 73 is sleeved on the piston rod. Two airflow plates 74 are symmetrically disposed on the sliding sleeve 61, and the airflow plates 74 are disposed on both sides of the grinding wheel 51. The piston tube is connected to the airbag 71 and the airflow plates 74 respectively, and a U-shaped tube is disposed on the piston tube. The piston tubes are connected to each other through a U-shaped tube. A cam 75 is disposed at the output end of the drive motor 52, and the cam 75 is in movable contact with the piston rod. refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 A solenoid valve is installed at the flexible tube that connects to the piston tube. The piston tube is interconnected with both the air bladder 71 and the airflow plate 74. A solenoid valve is also installed inside the U-shaped tube on the piston tube. When the drive motor 52 operates, it simultaneously drives the cam 75 to rotate. To control the rotational speed of the cam 75 driven by the drive motor 52, a reduction gearbox (not shown in the figure) is installed at its output position. This allows the drive motor 52 to drive the grinding wheel 51 to rotate and push the piston rod to move, ensuring high rotational speed of the grinding wheel 51 while controlling the movement speed of the piston rod. When the cam 75 protrudes and presses the piston rod, the piston rod moves upward, closing the U-shaped tube. The airflow generated by the upward movement of the piston rod can enter the flexible tube that connects to the air bladder 71. In other words, the solenoid valve at the air bladder 71, which needs to be inflated, opens. When the piston rod moves downward, the solenoid valve at the U-shaped tube opens, allowing gas to pass through the U-shaped tube. The tube enters the piston tube. When the piston rod moves upward again, it can inject gas back into the air bladder 71. This reciprocating motion continues until the air bladder 71 is inflated to the appropriate length. At this point, the hose connected to the air bladder 71 can be completely closed. Meanwhile, the drive motor 52 drives the grinding wheel 51 to rotate continuously. The drive motor 52 can still control the piston rod to move up and down via the cam 75. The negative pressure generated by the up and down movement of the piston rod and the ejected gas can be discharged through the airflow plate 74, thus acting on the surface of the saw teeth. Through the flow of air, the waste generated by the grinding wheel 51 can be cleaned, preventing the waste from sticking. At the same time, the airflow acting on the grinding position can also cool the grinding position, preventing the saw teeth from getting too hot when grinding the inner and outer diameters one by one, which could lead to internal cracks. This further improves the grinding effect of the equipment and ensures the grinding quality of the equipment.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A PCD saw blade processing machine tool, comprising a bed (1), a multi-axis drive stage (2) disposed on the bed (1), a cutter (3) disposed on the multi-axis drive stage (2), and a mounting plate (4) slidably disposed on the bed (1), characterized in that: Also includes: A grinding assembly (5) for cleaning the saw teeth surface is set on the mounting plate (4). The grinding assembly (5) includes a swing plate (55) rotatably set on the mounting plate (4). Two grinding wheels (51) for grinding the saw teeth are rotatably set at the bottom of the swing plate (55). The two grinding wheels (51) are connected by a drive. When the two grinding wheels (51) grind, their left and right deflection angles can be adjusted according to the curvature of the saw teeth. When the grinding wheels (51) grind, the two ends of the swing plate (55) can be adjusted up and down.

2. The PCD saw blade processing machine tool as described in claim 1, characterized in that: The grinding assembly (5) also includes a drive motor (52) mounted on a swing plate (55), and a connector is mounted on the swing plate (55). The output end of the drive motor (52) is connected to the two grinding wheels (51) via the connector.

3. The PCD saw blade processing machine tool as described in claim 2, characterized in that: The connecting component includes a slider (54) that is slidably mounted on the swing plate (55). A drive pulley is provided on both the slider (54) and the grinding wheel (51), and the three drive pulleys are connected in a transmission configuration. The output end of the drive motor (52) is fixedly mounted to one of the drive pulleys. A hydraulic rod (53) for driving the slider (54) to move up and down is provided at the bottom of the swing plate (55).

4. The PCD saw blade processing machine tool as described in claim 3, characterized in that: The swing plate (55) is provided with an angle adjustment component (6) for adjusting the left and right deflection of the grinding wheel (51).

5. The PCD saw blade processing machine tool as described in claim 4, characterized in that: The angle adjustment assembly (6) includes a universal ball rod (64) disposed in the swing plate (55), the grinding wheel (51) is rotatably disposed at the end of the universal ball rod (64), and a traction member is disposed between the universal ball rod (64) and the swing plate (55) for pulling the grinding wheel (51) to engage with the saw teeth.

6. The PCD saw blade processing machine tool as described in claim 5, characterized in that: The traction component includes a slide rod (62) and a slide sleeve (61) respectively hinged to the bottom of the universal ball joint (64) and the swing plate (55), and the slide rod (62) is slidably disposed in the slide sleeve (61), and a first spring (63) is provided between the end of the slide rod (62) and one side of the slide sleeve (61).

7. The PCD saw blade processing machine tool as described in claim 6, characterized in that: The swing plate (55) is provided with an offset component (7) for driving the end of the swing plate (55) to swing. The offset component (7) includes an airbag (71) symmetrically arranged between the mounting plate (4) and the swing plate (55). The swing plate (55) is provided with a piston part (72) for filling the airbag (71) with gas. When the grinding wheel (51) grinds, the gas in the piston part (72) enters the airbag (71).

8. The PCD saw blade processing machine tool as described in claim 7, characterized in that: The piston part (72) includes a piston rod, a piston tube and a piston plate disposed on the piston rod. The piston rod is slidably disposed inside the piston tube and a second spring (73) is sleeved on the piston rod. Two airflow plates (74) are symmetrically disposed on the sliding sleeve (61) and the airflow plates (74) are disposed on both sides of the grinding wheel (51). The piston tube is connected to the air bag (71) and the airflow plates (74) respectively. A U-shaped tube is disposed on the piston tube and the upper and lower sides of the piston tube are connected to each other through a U-shaped tube. A cam (75) is disposed at the output end of the drive motor (52) and the cam (75) is in contact with the piston rod.

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