Auxiliary positioning mechanism for precise sheet metal machining

Abstract

The invention relates to the technical field of laser machining, in particular to an auxiliary positioning mechanism for precise sheet metal machining, which comprises a machining table, a clamping assembly is arranged on the top surface of the machining table, a moving frame is slidably connected to the machining table, a welding head is slidably connected to the moving frame, and a first electric push rod is fixed on the side wall of the welding head. A connecting frame is fixed to the movable end of the first electric push rod, two second electric push rods are fixed to the surface of the connecting frame, sliding blocks are fixed to the movable ends of the two second electric push rods, and the first roller is arranged on the front side of the moving path of the welding head to extrude the follow-up welding position, so that the warping position can be smoothened; and the heat influence in the welding process is reduced in a local preheating mode, meanwhile, the local preheating range is small, and the adverse influence caused by solidification of the welding position in the early stage can be reduced.

Description

Technical Field

[0001] The invention relates to the field of laser processing, and in particular to an auxiliary positioning mechanism for precision sheet metal processing. Background Art

[0002] Laser welding uses a high-energy-density laser beam as a heat source. The laser beam irradiates the surface of the material to be welded, causing the material to be rapidly heated to a molten or even vaporized state. Subsequently, during the cooling and solidification process, the molten materials fuse with each other, thereby achieving the connection of the materials. Its energy transfer is based on the thermal effect of light. The focused laser beam concentrates the energy in a very small area, thereby achieving the purpose of rapidly heating the welding area.

[0003] During laser welding, the welding area is instantly heated to a very high temperature, while the temperature of the surrounding area is relatively low, thus forming a large temperature gradient inside the plate, thereby generating thermal stress. If the thermal stress is too large and cannot be effectively released, it will cause the plate to deform or even crack. The existing processing method is to preheat the plate as a whole before or during welding. Although this method can reduce the generation of thermal stress, the overall temperature of the plate will increase, which may have an adverse effect on the solidification of the weld, thereby affecting the welding quality. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an auxiliary positioning mechanism for precision sheet metal processing.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: an auxiliary positioning mechanism for precision sheet metal processing, comprising a processing table, a clamping assembly is arranged on the top surface of the processing table, the clamping assembly is used to clamp and position the sheet metal part, a moving frame is slidably connected to the processing table, a welding head is slidably connected to the moving frame, a first electric push rod is fixed to the side wall of the welding head, a connecting frame is fixed to the movable end of the first electric push rod, two second electric push rods are fixed to the surface of the connecting frame, and sliders are fixed to the movable ends of the two second electric push rods, the sliders are slidably connected to the surface of the connecting frame, and the two sliders rotate together The connecting frame is rotatably connected to the first roller, a connecting pipe is fixed on the connecting frame, the connecting pipe is connected to an external heating device, the first roller is made of heat-conducting material, the interior of the first roller is hollow, the connecting pipe is connected to the interior of the first roller, the connecting pipe is rotatably connected to the side wall of the first roller, an extension plate is fixed on the outer wall of the connecting frame, the surface of the extension plate is rotatably connected to an extension cylinder, a third electric push rod is fixed on the outer wall of the extension cylinder, the movable end of the third electric push rod is fixed to the second roller, the second roller is slidably sleeved on the outside of the extension cylinder, the extension cylinder is connected to the interior of the second roller, and the extension cylinder is rotatably connected to the connecting pipe.

[0006] Preferably, a groove is provided on the outer wall of the extension tube, and a first mesh plate is fixed inside the groove.

[0007] Preferably, a second mesh plate is slidably arranged on the surface of the first mesh plate, the mesh holes on the first mesh plate and the second mesh plate are staggered and closed, an elastic pushing member is arranged between one end of the second mesh plate and the groove, a sliding pin is fixed to the other end of the second mesh plate, a clearance hole is provided on the side wall of the groove, the sliding pin contacts the extension plate after passing through the clearance hole, and a guide groove adapted to the sliding pin is provided on the surface of the extension plate.

[0008] Preferably, the mesh size on the first mesh plate is larger than the mesh size on the second mesh plate, there is a gap between one side of the second mesh plate and the inner wall of the groove, a counterweight bar is fixed to the other side of the second mesh plate, a damping plate is fixed near the bottom end inside the guide groove, the elastic pushing member includes a sliding bar, the sliding bar is slidably connected to the side wall of the groove, and an elastic telescopic rod is fixed between the sliding bar and the second mesh plate.

[0009] Preferably, a friction ring is fixed to the end of the sliding pin, a ball is rotatably connected to the inner ring surface of the friction ring, and there are two damping plates, and a clearance channel is formed between the two damping plates.

[0010] Preferably, a partition is fixed on the inner wall of the extension tube, and the partition divides the interior of the extension tube into an air intake chamber and an exhaust chamber. A plurality of mounting holes are opened on the outer wall of the partition, and a pressure valve is fixed in the mounting hole.

[0011] Preferably, the pressure valve comprises a cylinder, a bracket is fixed inside the cylinder, a sliding rod is slidably connected to the bracket, a sealing plug is fixed at the end of the sliding rod, the sealing plug is inserted inside the cylinder, and a spring is fixed between the sealing plug and the bracket.

[0012] Preferably, the mesh holes on the second mesh plate increase in size in a direction from the second roller to the first roller.

[0013] Preferably, a connecting groove is provided on the inner wall of the second roller, and the position of the connecting groove is adapted to the groove.

[0014] Preferably, a sealing gasket is fixed to the end of the extension tube, a hole is opened at one end of the connecting groove, and a control valve is arranged inside the hole.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting a first roller in front of the moving path of the welding head, the subsequent welding position is squeezed. On the one hand, some welding positions are slightly warped due to local heating. The warped positions can be flattened by squeezing the first roller. On the other hand, by integrating warm air into the first roller, the first roller is heated. Since the first roller is made of heat-conducting material, the first roller becomes a heating cylinder to roll preheat the subsequent welding positions. The heat effect during the welding process is reduced by local preheating. At the same time, the small range of local preheating can also reduce the adverse effects on the solidification of the previous welding positions.

[0016] 2. When the thickness of the sheet metal is large, the heat conduction and dissipation is relatively slow, and the temperature gradient in the thickness direction during welding is large, which can easily cause problems such as welding stress concentration. In order to allow the entire welding area and the surrounding area to be heated more evenly and reduce the impact of thermal stress, it is necessary to increase the preheating range. This implementation method heats the preheating range by setting a second roller and passing warm air into the second roller.

[0017] 3. Some sheet metal parts have convex patterns or other decorations or components. When the second roller encounters these blocking components, the third electric push rod can be started to pull the second roller to the side close to the first roller, and the third electric push rod can be completely installed on the outside of the extension tube to make way for the blocking components, thereby avoiding collision damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the connecting frame, the first roller and the second roller of the present invention.

[0020] Figure 3 The structure of the extension tube of the present invention is schematically shown in FIG. Figure 1 .

[0021] Figure 4 It is a schematic diagram of the local structure of the extension plate of the present invention.

[0022] Figure 5 The structure of the extension tube of the present invention is schematically shown in FIG. Figure 2 .

[0023] Figure 6 It is a schematic diagram of the sliding pin structure of the present invention.

[0024] Figure 7 It is a schematic diagram of the cross-sectional structure of the extension tube and the second roller of the present invention.

[0025] Figure 8 It is a schematic diagram of the cross-sectional structure of the pressure valve of the present invention.

[0026] Fig. 9 It is a schematic diagram of the structure of the damping plate and friction ring of the present invention.

[0027] In the figure: 1, processing table; 2, moving frame; 3, welding head; 4, first electric push rod; 5, connecting frame; 6, second electric push rod; 7, sliding block; 8, first roller; 9, connecting pipe; 10, extension plate; 11, extension cylinder; 12, third electric push rod; 13, second roller; 14, groove; 15, first mesh plate; 16, second mesh plate; 17, sliding pin; 18, clearance hole; 19, guide groove; 20, gap; 21, counterweight bar; 22, damping plate; 23, sliding bar; 24, elastic telescopic rod; 25, friction ring; 26, ball bearing; 27, partition; 28, air inlet chamber; 29, exhaust chamber; 30, mounting hole; 31, pressure valve; 32, cylinder; 33, bracket; 34, sliding rod; 35, sealing plug; 36, spring; 37, connecting groove; 38, sealing pad; 39, hole; 40, control valve. DETAILED DESCRIPTION

[0028] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0029] like Figures 1 to 9 The auxiliary positioning mechanism for precision sheet metal processing shown in the figure comprises a processing table 1, a clamping assembly is arranged on the top surface of the processing table 1, the clamping assembly is used to clamp and position the sheet metal part, a moving frame 2 is slidably connected to the processing table 1, a welding head 3 is slidably connected to the moving frame 2, a first electric push rod 4 is fixed to the side wall of the welding head 3, a connecting frame 5 is fixed to the movable end of the first electric push rod 4, two second electric push rods 6 are fixed to the surface of the connecting frame 5, the movable ends of the two second electric push rods 6 are fixed to a slider 7, the slider 7 is slidably connected to the surface of the connecting frame 5, a first roller 8 is connected to the two sliders 7 for common rotation, and a first roller 8 is connected to the connecting frame 5. A connecting pipe 9 is fixed, and the connecting pipe 9 is connected to an external heating device. The first roller 8 is made of heat-conducting material, and the interior of the first roller 8 is a hollow structure. The connecting pipe 9 is connected to the interior of the first roller 8, and the connecting pipe 9 is rotatably connected to the side wall of the first roller 8. An extension plate 10 is fixed on the outer wall of the connecting frame 5, and an extension cylinder 11 is rotatably connected to the surface of the extension plate 10. A third electric push rod 12 is fixed on the outer wall of the extension cylinder 11, and a second roller 13 is fixed to the movable end of the third electric push rod 12. The second roller 13 is slidably sleeved on the outside of the extension cylinder 11, and the extension cylinder 11 is connected to the interior of the second roller 13, and the extension cylinder 11 is rotatably connected to the connecting pipe 9.

[0030] Specifically, two sheet metal panels are placed on the processing table 1, the panels are clamped by starting the clamping assembly, and then the welding head 3 is started for welding. During the welding process, the welding head 3 is moved by the moving frame 2. The moving method of the moving frame 2 is the existing technology and will not be described in detail. In order to reduce the adverse effects of the heat of laser welding on subsequent welding positions, it is necessary to preheat the subsequent welding positions. A first roller 8 is set on the front side of the moving path of the welding head 3 to squeeze the subsequent welding positions. On the one hand, some welding positions produce slight warping deformation due to local heating. The warping positions can be flattened by squeezing the first roller 8. On the other hand, the first roller 8 is heated by integrating warm air into the first roller 8. Since the first roller 8 is made of heat-conducting material, the first roller 8 becomes a heating cylinder, and the subsequent welding positions are rolled and preheated. The heat impact during welding is reduced by local preheating. At the same time, the small range of local preheating can also reduce the adverse effects on the solidification of the previous welding positions. Furthermore, when the thickness of the sheet metal is large, the heat conduction and dissipation is relatively slow. During welding, the temperature gradient in the thickness direction is large, which can easily cause problems such as welding stress concentration. In order to allow the entire welding area and the surrounding area to be heated more evenly and reduce the influence of thermal stress, it is necessary to increase the preheating range. This embodiment heats the preheating range by setting a second roller 13 and passing warm air into the second roller 13. However, some sheet metal parts have convex patterns and other decorations or components. When the second roller 13 encounters these blocking components, the third electric push rod 12 can be started, and the third electric push rod 12 pulls the second roller 13 to move to the side close to the first roller 8, and is completely set on the outside of the extension tube 11 to make way for the blocking components, thereby avoiding collision damage. Some sheet metal parts are relatively long, and electric welding is often used. Electric welding is first performed at the welding position to pre-position the sheet metal parts, resulting in possible obstruction on the moving path of the first roller 8. The first roller 8 can be pulled up by starting the second electric push rod 6 to make way for the blocking position.

[0031] As a further embodiment of the present invention, a groove 14 is formed on the outer wall of the extension tube 11 , and a first mesh plate 15 is fixed inside the groove 14 .

[0032] Specifically, since the outer diameter of the extension tube 11 is smaller than the outer diameter of the second roller 13, it is difficult for the extension tube 11 to contact the sheet metal. In order to ensure that the sheet metal under the extension tube 11 can be fully preheated, a first mesh plate 15 is provided on the extension tube 11 so that the gas inside the extension tube 11 can flow out from the mesh holes of the first mesh plate 15 to preheat the sheet metal under the extension tube 11, which is beneficial to ensure that the sheet metal under the extension tube 11 can be fully preheated.

[0033] As a further implementation scheme of the present invention, a second mesh plate 16 is slidably arranged on the surface of the first mesh plate 15, the mesh holes on the first mesh plate 15 and the second mesh plate 16 are staggered and closed, an elastic pushing member is arranged between one end of the second mesh plate 16 and the groove 14, a sliding pin 17 is fixed to the other end of the second mesh plate 16, a clearance hole 18 is provided on the side wall of the groove 14, the sliding pin 17 contacts the extension plate 10 after passing through the clearance hole 18, and a guide groove 19 adapted to the sliding pin 17 is provided on the surface of the extension plate 10.

[0034] Specifically, during the rolling process of the second roller 13 on the sheet metal, the extension tube 11 can be driven to rotate synchronously, and the sliding pin 17 moves with the extension tube 11 and slides on the surface of the extension plate 10. Under the pushing action of the elastic pusher, the second mesh plate 16 and the sliding pin 17 always have a tendency to move toward the side close to the extension plate 10. When the sliding pin 17 moves to the position of the guide groove 19, under the pushing action of the elastic pusher, the second mesh plate 16 moves toward the side close to the extension plate 10, and the sliding pin 17 is inserted into the guide groove 19. The mesh holes on the first mesh plate 15 and the second mesh plate 16 are connected to each other, so that the gas inside the extension tube 11 can flow out from the connected mesh hole position. By designing the position of the guide groove 19, it is set on the side away from the welding position, so that the gas on the extension tube 11 can be sprayed to the side away from the welding position. On the one hand, the unwelded position can be preheated, and on the other hand, the blown gas will not disturb the auxiliary gas in the welding process, and can also avoid adverse effects on the solidification of the welding completion position.

[0035] As a further implementation scheme of the present invention, the mesh size on the first mesh plate 15 is larger than the mesh size on the second mesh plate 16, and there is a gap 20 between one side of the second mesh plate 16 and the inner wall of the groove 14, and a counterweight bar 21 is fixed to the other side of the second mesh plate 16, and a damping plate 22 is fixed near the bottom end of the guide groove 19, and the elastic pushing member includes a sliding bar 23, which is slidably connected to the side wall of the groove 14, and an elastic telescopic rod 24 is fixed between the sliding bar 23 and the second mesh plate 16.

[0036] Specifically, when the second mesh plate 16 rotates to the side of the extension tube 11 surface away from the welding position, the counterweight bar 21 can pull the second mesh plate 16 downward, so that a gap 20 is generated between the top of the second mesh plate 16 and the inner wall of the groove 14. When the sliding pin 17 moves to the end of the guide groove 19, if the sliding pin 17 directly moves out of the guide groove 19, the mesh holes will be staggered and closed. In this embodiment, a damping plate 22 is provided at the end of the guide groove 19. Under the blocking effect of the damping plate 22, the second mesh plate 16 can be restricted from moving with the extension tube 11, so that relative sliding occurs between the second mesh plate 16 and the extension tube 11. Since the mesh size on the first mesh plate 15 is larger than the mesh size on the second mesh plate 16, the second mesh plate 16 is in the process of sliding. The mesh holes on the mesh plate 15 and the second mesh plate 16 are always in a connected state, which is conducive to extending the connection time, extending the air outlet and preheating time, and ensuring that the sheet metal can be fully preheated. As the extension tube 11 moves, the gap 20 between the second mesh plate 16 and the groove 14 gradually decreases until the top of the second mesh plate 16 contacts the inner wall of the groove 14. Under the rigid push of the inner wall of the groove 14, the second mesh plate 16 can be pushed to continue to move, so that the sliding pin 17 gradually moves away from the damping plate 22, until the sliding pin 17 completely leaves the damping plate 22 and contacts the inclined surface at the end of the guide groove 19. Under the guidance of the inclined surface, the sliding pin 17 contacts the surface of the extension plate 10 again, so that the mesh holes on the first mesh plate 15 and the second mesh plate 16 are re-interlaced and closed to prevent gas outflow.

[0037] As a further embodiment of the present invention, a friction ring 25 is fixed to the end of the sliding pin 17 , a ball 26 is rotatably connected to the inner ring surface of the friction ring 25 , and there are two damping plates 22 , and a clearance channel is formed between the two damping plates 22 .

[0038] Specifically, when the sliding pin 17 slides inside the guide groove 19, the ball 26 rolls in contact with the inner wall of the guide groove 19, which is conducive to reducing friction and reducing the movement resistance of the sliding pin 17. When it moves to the position of the damping plate 22, the ball 26 can move in the make way channel formed between the two damping plates 22. The friction ring 25 and the damping plate 22 are both made of flexible rubber. The damping plate 22 is trapezoidal and has inclined surfaces on both sides. When the ball 26 passes between the two damping plates 22, the friction ring 25 first contacts the inclined surface of the damping plate 22 and gradually moves along the inclined surface to the top of the damping plate 22 to form an extrusion state. After being extruded, the damping plate 22 and the friction ring 25 are pressed against each other to produce a damping effect, thereby limiting the continued movement of the sliding pin 17.

[0039] As a further implementation scheme of the present invention, a partition 27 is fixed on the inner wall of the extension tube 11, and the partition 27 divides the interior of the extension tube 11 into an air intake chamber 28 and an exhaust chamber 29. A plurality of mounting holes 30 are opened on the outer wall of the partition 27, and a pressure valve 31 is fixed in the mounting hole 30.

[0040] Specifically, when the mesh holes on the second mesh plate 16 are connected to the mesh holes on the first mesh plate 15, if the gas is discharged directly from the mesh holes, it may cause the air pressure in the extension tube 11 and the second roller 13 to drop rapidly, affecting the heating of the second roller 13, and further affecting the preheating effect of the second roller 13. This embodiment can solve the above problems. The specific operation method is as follows: by dividing the extension tube 11 into an air inlet chamber 28 and an air exhaust chamber 29, after the gas enters the air inlet chamber 28, it enters the second roller 13 along the air inlet chamber 28. As the pressure in the second roller 13 and the air inlet chamber 28 increases, the pressure valve 31 can be pushed open under the action of air pressure, so that the gas enters the exhaust chamber 29 and is discharged from the open mesh position, thereby maintaining the pressure in the second roller 13, ensuring that the gas can always heat the second roller 13, and ensuring the preheating effect of the second roller 13.

[0041] As a further embodiment of the present invention, the pressure valve 31 includes a cylinder 32, a bracket 33 is fixed inside the cylinder 32, a slide rod 34 is slidably connected to the bracket 33, a sealing plug 35 is fixed at the end of the slide rod 34, the sealing plug 35 is inserted into the cylinder 32, and a spring 36 is fixed between the sealing plug 35 and the bracket 33.

[0042] Specifically, in the initial state, the sealing plug 35 is inside the cylinder 32, and its side wall can seal the cylinder 32. Under the push of air pressure, the sealing plug 35 will move to the outside of the cylinder 32, thereby opening the cylinder 32. When the air pressure decreases, under the pulling action of the spring 36, the sealing plug 35 will reset and enter the cylinder 32 to re-seal the cylinder 32.

[0043] As a further embodiment of the present invention, the mesh openings on the second mesh plate 16 are gradually increased in size along the direction from the second roller 13 to the first roller 8 .

[0044] Specifically, when the pressure valve 31 is opened, the gas will be discharged from the nearest mesh, resulting in uneven gas discharge from each mesh. In order to ensure uniform gas discharge, the mesh size can be designed so that the mesh closer to the pressure valve 31 is smaller, reducing the gas discharge amount at this position, so that the gas can flow to other mesh positions for discharge, thereby ensuring uniformity of the discharged gas and uniformity of gas preheating. As a further embodiment of the present invention, a connecting groove 37 is formed on the inner wall of the second roller 13 , and the position of the connecting groove 37 is adapted to the groove 14 .

[0045] Specifically, when the second roller 13 shrinks and gives way, since it is sleeved on the outside of the extension tube 11, the extension tube 11 blocks the heating effect of the gas on the second roller 13. In view of this, this embodiment opens a connecting groove 37 on the inner wall of the second roller 13. When the second roller 13 shrinks, the connecting groove 37 can be connected with the groove 14, so that the mesh holes on the second mesh plate 16 are connected with the connecting groove 37. When the mesh holes are exhausted, the gas can be discharged into the connecting groove 37 to directly heat the second roller 13, thereby ensuring the heating effect of the second roller 13 after shrinkage. In addition, by opening the connecting groove 37, the thickness of the outer wall of the second roller 13 is also reduced, further enhancing the heating effect.

[0046] As a further embodiment of the present invention, a sealing gasket 38 is fixed to the end of the extension tube 11 , a hole 39 is opened at one end of the communication groove 37 , and a control valve 40 is arranged inside the hole 39 .

[0047] Specifically, when the second roller 13 contracts, the original preheating position is difficult to be heated. In this embodiment, when the second roller 13 contracts, the connecting groove 37 is connected to the inside of the groove 14, and the inner wall of the second roller 13 pushes the slide rod 34 of the pressure valve 31, and the sealing plug 35 is pushed by the slide rod 34, so that the pressure valve 31 is opened, so that the pressure valve 31 is always in an open state when the second roller 13 is contracted, reducing the resistance of airflow, and thus facilitating the airflow to smoothly pass through the pressure valve 31 and the mesh, enter the inside of the connecting groove 37, and be discharged from the position of the control valve 40, so as to blow and heat the side of the second roller 13, and ensure that after the contraction, the original preheating position The preheating effect of the position is achieved to avoid the situation where the welding effect is affected by insufficient preheating, wherein, when the second roller 13 is in the expanded state, the control valve 40 is in the closed state, and when the second roller 13 is in the contracted state, the control valve 40 is in the open state. It can be seen from the above embodiment that under the adjustment of the second mesh plate 16, the mesh holes on the second mesh plate 16 will only be opened when the specified position is reached, so that even if the control valve 40 is fully opened, gas will only be ejected from the control valve 40 on the side away from the welding position. By making the ejected preheating airflow away from the welding position, it is helpful to reduce the adverse effects of the preheating airflow on welding.

[0048] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. An auxiliary positioning mechanism for precision sheet metal processing, comprising a processing table (1), a clamping assembly is arranged on the top surface of the processing table (1), the clamping assembly is used to clamp and position the sheet metal part, a moving frame (2) is slidably connected to the processing table (1), and a welding head (3) is slidably connected to the moving frame (2), wherein: A first electric push rod (4) is fixed on the side wall of the welding head (3); a connecting frame (5) is fixed to the movable end of the first electric push rod (4); two second electric push rods (6) are fixed to the surface of the connecting frame (5); a slider (7) is fixed to the movable end of the two second electric push rods (6); the slider (7) is slidably connected to the surface of the connecting frame (5); and a first roller (8) is rotatably connected between the two sliders (7); A connecting pipe (9) is fixed on the connecting frame (5), and the connecting pipe (9) is connected to an external heating device. The first roller (8) is made of a heat-conducting material, and the interior of the first roller (8) is a hollow structure. The connecting pipe (9) is connected to the interior of the first roller (8), and the connecting pipe (9) is rotatably connected to the side wall of the first roller (8); An extension plate (10) is fixed on the outer wall of the connecting frame (5); an extension tube (11) is rotatably connected to the surface of the extension plate (10); a third electric push rod (12) is fixed on the outer wall of the extension tube (11); a second roller (13) is fixed to the movable end of the third electric push rod (12); the second roller (13) is slidably sleeved on the outer side of the extension tube (11); the extension tube (11) is connected to the inside of the second roller (13); and the extension tube (11) is rotatably connected to the connecting pipe (9).

2. The auxiliary positioning mechanism for precision sheet metal processing according to claim 1, characterized in that: A groove (14) is provided on the outer wall of the extension tube (11), and a first mesh plate (15) is fixed inside the groove (14).

3. The auxiliary positioning mechanism for precision sheet metal processing according to claim 2, characterized in that: A second mesh plate (16) is slidably arranged on the surface of the first mesh plate (15); mesh holes on the first mesh plate (15) and the second mesh plate (16) are staggered and closed; an elastic pusher is arranged between one end of the second mesh plate (16) and the groove (14); a sliding pin (17) is fixed to the other end of the second mesh plate (16); a clearance hole (18) is provided on the side wall of the groove (14); the sliding pin (17) contacts the extension plate (10) after passing through the clearance hole (18); and a guide groove (19) adapted to the sliding pin (17) is provided on the surface of the extension plate (10).

4. The auxiliary positioning mechanism for precision sheet metal processing according to claim 3, characterized in that: The mesh size of the first mesh plate (15) is larger than the mesh size of the second mesh plate (16); a gap (20) is provided between one side of the second mesh plate (16) and the inner wall of the groove (14); a counterweight bar (21) is fixed to the other side of the second mesh plate (16); a damping plate (22) is fixed to a position near the bottom end of the guide groove (19); the elastic pusher comprises a sliding bar (23); the sliding bar (23) is slidably connected to the side wall of the groove (14); and an elastic telescopic rod (24) is fixed between the sliding bar (23) and the second mesh plate (16).

5. The auxiliary positioning mechanism for precision sheet metal processing according to claim 4, characterized in that: A friction ring (25) is fixed to the end of the sliding pin (17), a ball (26) is rotatably connected to the inner ring surface of the friction ring (25), and there are two damping plates (22), with a clearance channel formed between the two damping plates (22).

6. The auxiliary positioning mechanism for precision sheet metal processing according to claim 3, characterized in that: A partition plate (27) is fixed on the inner wall of the extension tube (11), and the partition plate (27) divides the interior of the extension tube (11) into an air intake chamber (28) and an air exhaust chamber (29). A plurality of mounting holes (30) are formed on the outer wall of the partition plate (27), and a pressure valve (31) is fixed in each mounting hole (30).

7. The auxiliary positioning mechanism for precision sheet metal processing according to claim 6, characterized in that: The pressure valve (31) comprises a cylinder (32), a bracket (33) is fixed inside the cylinder (32), a slide rod (34) is slidably connected to the bracket (33), a sealing plug (35) is fixed at the end of the slide rod (34), the sealing plug (35) is inserted into the cylinder (32), and a spring (36) is fixed between the sealing plug (35) and the bracket (33).

8. The auxiliary positioning mechanism for precision sheet metal processing according to claim 7, characterized in that: The mesh holes on the second mesh plate (16) increase in size in a direction from the second roller (13) to the first roller (8).

9. The auxiliary positioning mechanism for precision sheet metal processing according to claim 8, characterized in that: A communication groove (37) is provided on the inner wall of the second roller (13), and the position of the communication groove (37) is adapted to the groove (14).

10. The auxiliary positioning mechanism for precision sheet metal processing according to claim 9, characterized in that: A sealing gasket (38) is fixed to the end of the extension tube (11), a hole (39) is opened at one end of the communication groove (37), and a control valve (40) is arranged inside the hole (39).

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