A linear grinding assembly and method for the inner wall of a seamless steel pipe

Abstract

This invention discloses a linear grinding assembly and method for the inner wall of a seamless steel pipe, relating to the field of steel pipe processing technology. The invention mainly includes structures such as a grinding airflow injection pipe, a grinding airflow return pipe, a positioning injection mechanism, and a positioning return mechanism. By designing the grinding airflow injection pipe and the grinding airflow return pipe to be pre-inserted into the steel pipe cavity from both sides, and then limiting the grinding airflow injection pipe side by the positioning injection mechanism and the grinding airflow return pipe by the positioning return mechanism, the invention injects grinding powder airflow into the grinding airflow injection pipe through the positioning injection mechanism. It also incorporates a discharge slot, a suction slot, and a flow-dividing sphere aligned with the weld seam of the steel pipe, achieving comprehensive and uniform individual friction grinding of the weld seam area by the grinding powder airflow, effectively resolving the conflicting grinding force between the weld seam area and other areas of the inner wall of the steel pipe.

Description

Technical Field

[0001] This invention relates to the field of steel pipe processing technology, and in particular to a linear grinding assembly and method for the inner wall of a seamless steel pipe. Background Technology

[0002] During the welding process of steel pipes, if the penetration depth exceeds the pipe wall thickness, the molten metal flows out from the back of the weld, resulting in a non-smooth weld area on the inner wall of the steel pipe. In order to improve the corrosion resistance of the steel pipe, it is generally necessary to coat both the inner and outer sides of the steel pipe, which requires first treating the non-smooth weld area on the inner wall of the steel pipe.

[0003] Currently, grinding balls are typically injected directly into one end of the steel pipe and then discharged from the other end to polish the entire inner wall of the pipe. However, there is a significant difference between the required polishing intensity for the non-weld areas and the weld areas. Using existing grinding balls for comprehensive polishing cannot evenly balance the polishing level between the smooth areas of the inner wall and the non-smooth areas of the weld. Over-polishing may result in a smooth weld area, but the remaining non-weld areas may also be over-polished. Conversely, insufficient polishing will leave the weld area unpolished.

[0004] The contradiction between the non-smoothness of the weld area on the inner wall of the steel pipe and the need for uniform grinding of the inner wall of the steel pipe using existing grinding methods has become a problem that needs to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a linear grinding component and method for the inner wall of a seamless steel pipe, thereby realizing comprehensive and uniform airflow of grinding powder to perform individual friction grinding on the weld seam, effectively resolving the contradiction between the grinding force between the weld seam area and other areas of the inner wall of the steel pipe.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0007] This invention provides a linear grinding assembly for the inner wall of a seamless steel pipe. The grinding assembly includes a grinding airflow injection pipe and a grinding airflow return pipe pre-inserted into the steel pipe cavity. The assembly also includes a positioning injection mechanism inserted into one side of the steel pipe and injecting airflow containing grinding powder into the grinding airflow injection pipe, and a positioning return mechanism inserted into the other side of the steel pipe and absorbing airflow from the grinding airflow return pipe under negative pressure. The grinding airflow injection pipe includes an injection fitting, an injection long pipe, an discharge fitting, and a flow-dividing ball fixedly connected to the side end of the discharge fitting. The grinding airflow injection pipe has an injection airflow cavity penetrating the injection fitting, the injection long pipe, and the discharge fitting.

[0008] The flow divider sphere is aligned with the weld seam of the steel pipe. Multiple evenly distributed discharge slots are located at the connection point between the discharge fitting and the flow divider sphere, and these discharge slots are connected to the injection airflow chamber. The grinding airflow return pipe includes an intake fitting, a return long pipe, and a return fitting. A return airflow chamber extends through the intake fitting, the return long pipe, and the return fitting.

[0009] The suction fitting part has a contact spherical surface that mates with the flow divider sphere at its side end. Multiple suction slots facing the surface of the flow divider sphere are also provided on the side end of the suction fitting part, and these slots communicate with the return airflow cavity. Rotary support assemblies that roll into contact with the inner wall of the steel pipe cavity are provided around the injection fitting part, discharge fitting part, suction fitting part, and return fitting part.

[0010] The positioning injection mechanism is equipped with an injection-side displacement box and a first insertion tube extending into one end of the steel pipe cavity. The first insertion tube has a built-in injection tube for injecting grinding powder gas flow into the injection gas flow chamber. The injection-side displacement box is equipped with a grinding gas flow injection pump connected to the built-in injection tube. The positioning return mechanism is equipped with a return-side displacement box and a second insertion tube extending into the other end of the steel pipe cavity. The second insertion tube has a built-in return tube for drawing in grinding powder gas flow from the return gas flow chamber. The return-side displacement box is equipped with a grinding gas flow return pump connected to the built-in return tube. Both the first and second insertion tubes have a movable annular rotating part. The injection-side displacement box is equipped with a first servo motor for driving the rotation of the annular rotating part at the first insertion tube side end, and the return-side displacement box is equipped with a second servo motor for driving the rotation of the annular rotating part at the second insertion tube side end. Both the injection fitting part and the return fitting part are equipped with multiple elastic connectors. The side end of the elastic connector facing the annular rotating part is provided with a contact end, which includes a ball head. The side end face of the annular rotating part facing the contact end is provided with multiple continuously distributed concave spherical grooves. The ball head and the concave spherical grooves are mutually limited and fitted together.

[0011] As a preferred embodiment of the grinding assembly of the present invention: an injection end ring plate is provided on the side of the injection mating part, and a return end ring plate is provided on the side of the return mating part. Both the injection end ring plate and the return end ring plate have multiple through-hole structures. The elastic connector includes a movable rod that moves through the through-hole structure, with a contact end located at one end of the movable rod. A rear limiting structure is provided on the other end of the movable rod, and a tension spring that elastically supports the contact end is sleeved on the movable rod.

[0012] As a preferred technical solution of the grinding component of the present invention: the rotating support component includes an inner support ring, an outer support ring rotatably connected to the inner support ring, and a plurality of outer rollers movably embedded on the outer ring side of the outer support ring, wherein the outer rollers are in contact with the inner wall of the steel pipe cavity.

[0013] As a preferred embodiment of the grinding assembly of the present invention: the side end of the injection fitting part is provided with an injection conical port communicating with the injection airflow chamber, and the side end of the return fitting part is provided with a return conical port communicating with the return airflow chamber. Both the side end of the built-in injection tube and the side end of the built-in return tube are provided with conical airflow inserts. The conical airflow insert at the side end of the built-in injection tube is inserted into the injection conical port, and the conical airflow insert at the side end of the built-in return tube is inserted into the return conical port.

[0014] As a preferred technical solution of the grinding component of the present invention: a movable ring is movably installed on the outer ring side of the conical airflow tube.

[0015] As a preferred technical solution of the grinding component of the present invention: an inner bearing ring is provided between the inner circumference of the annular rotating part at the side end of the first insertion tube and the built-in injection tube, and between the inner circumference of the annular rotating part of the second insertion tube and the built-in return tube.

[0016] As a preferred embodiment of the grinding assembly of the present invention: both the output end of the first servo motor and the output end of the second servo motor are connected to drive shafts. The drive shaft connected to the output end of the first servo motor extends into the first insertion tube, and the drive shaft connected to the output end of the second servo motor extends into the second insertion tube. A bevel gear is provided on the side end of the drive shaft, and a conical toothed edge that meshes with the bevel gear is provided on the side of the annular rotating part facing the bevel gear.

[0017] As a preferred technical solution of the grinding component of the present invention: both the injection side displacement box and the return side displacement box are provided with an outer limiting ring that engages with the side end of the steel pipe.

[0018] This invention provides a method for linear grinding of the inner wall of a seamless steel pipe, comprising the following steps:

[0019] S1. Steel pipe to be ground enters the airflow fitting insertion process: The automated equipment injects the grinding airflow into the fitting and inserts it from one side of the steel pipe. The automated equipment then returns the grinding airflow to the fitting and inserts it from the other side of the steel pipe.

[0020] S1.1. When inserting the grinding airflow injection fitting, first insert the discharge fitting with the flow divider ball into the steel pipe cavity.

[0021] S1.2. When inserting the grinding airflow return pipe fitting, first insert the suction fitting into the steel pipe cavity.

[0022] S2. After completing the above-mentioned process steps, the steel pipe with grinding airflow injection into the pipe fitting and grinding airflow return into the pipe fitting enters the next station.

[0023] S2.1. The automated equipment drives the positioning injection mechanism to move toward the steel pipe side of the grinding airflow injection pipe fitting. The first insertion tube of the positioning injection mechanism is inserted into the steel pipe cavity, and the annular rotating part of the first insertion tube is pressed into contact with the elastic connector of the grinding airflow injection pipe fitting.

[0024] S2.2. The automated equipment drives the positioning and return mechanism to move toward the steel pipe side of the grinding airflow return pipe fitting. The second insertion tube of the positioning and return mechanism is inserted into the steel pipe cavity, and the annular rotating part of the second insertion tube is pressed into contact with the elastic connector of the grinding airflow return pipe fitting.

[0025] S2.3. The positioning injection mechanism pushes the grinding airflow injection pipe to move, and the positioning return mechanism pushes the grinding airflow return pipe to move. The contact spherical surface at the side end of the suction fitting and the diversion ball of the discharge fitting are squeezed into contact.

[0026] S2.4. The conical airflow cannula of the first cannula is inserted into the injection mating part, and the conical airflow cannula of the second cannula is inserted into the return mating part.

[0027] S3. The first servo motor of the positioning injection mechanism and the second servo motor of the positioning return mechanism are started. The first servo motor drives the annular rotating part of the first insertion tube to rotate, and the second servo motor drives the annular rotating part of the second insertion tube to rotate. When the annular rotating parts rotate, the contact end of the elastic connector is pressed into the concave spherical groove position on the side end face of the annular rotating part. The annular rotating part of the first insertion tube drives the grinding airflow injection pipe to rotate, and the annular rotating part of the second insertion tube drives the grinding airflow return pipe to rotate. The grinding airflow injection pipe and the grinding airflow return pipe rotate at the same speed and in the same direction.

[0028] S4. The grinding air injection pump of the positioning injection mechanism starts, injecting grinding powder airflow into the built-in injection pipe and injection airflow chamber. At the same time, the grinding air return pump of the positioning return mechanism starts, discharging the grinding powder airflow from the return airflow chamber and built-in return pipe under negative pressure. The grinding powder airflow enters the injection airflow chamber and exits from the discharge slot along the surface of the splitting sphere. The grinding powder airflow comes into frictional contact with the weld seam of the steel pipe, and then enters the return airflow chamber along the surface of the splitting sphere and the suction slot.

[0029] Compared with existing technologies, the beneficial effects of this invention are:

[0030] This invention designs grinding airflow injection pipes and grinding airflow return pipes, pre-inserting them into the steel pipe cavity from both sides. A positioning injection mechanism limits the grinding airflow injection pipe, and a positioning return mechanism limits the grinding airflow return pipe. Grinding powder airflow is injected into the grinding airflow injection pipe through the positioning injection mechanism. The invention also includes a discharge slot, a suction slot, and a flow-dividing ball aligned with the weld seam of the steel pipe. This allows for comprehensive and uniform grinding of the weld seam area using grinding powder airflow (after initial grinding of the weld seam, subsequent grinding from one end of the steel pipe to the other facilitates comprehensive and even grinding by the grinding balls). This effectively resolves the conflicting grinding intensity between the weld seam area and other areas of the inner wall of the steel pipe. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall assembly and installation of the grinding components in this invention.

[0032] Figure 2 This is a schematic diagram of the positioning injection mechanism, positioning return mechanism and steel pipe in this invention.

[0033] Figure 3 This is a schematic diagram of the grinding airflow injection pipe in this invention.

[0034] Figure 4 for Figure 3 A magnified schematic diagram of a portion of point B in the middle.

[0035] Figure 5 This is a schematic diagram of the grinding airflow return pipe in this invention.

[0036] Figure 6 for Figure 2 A magnified schematic diagram of a portion of point A in the middle.

[0037] Figure 7 This is a schematic diagram of the positioning and injection mechanism in this invention.

[0038] Figure 8 for Figure 7 A magnified schematic diagram of a portion of point C in the middle.

[0039] Figure 9 This is a schematic diagram of the positioning and reflux mechanism in this invention.

[0040] Figure 10 This is a schematic diagram of the overall structure of the grinding airflow injection pipe and related components in this invention.

[0041] Figure 11 This is a schematic diagram of the structure of the grinding airflow return pipe and related components in this invention.

[0042] Figure 12 This is a schematic diagram showing the distribution of the concave spherical grooves on the side end of the annular rotating part in this invention.

[0043] Wherein: 1-steel pipe, 101-weld, 102-pipe cavity; 2-grinding airflow injection fitting, 201-injection mating part, 2011-injection end ring plate, 202-injection long pipe, 203-discharge mating part, 2031-discharge slot, 204-diverting sphere, 205-injection airflow cavity, 2051-injection conical opening; 3-grinding airflow return fitting, 301-return mating part, 3011-return end ring plate, 302-return long pipe, 303-suction mating part, 3031-suction slot, 304-contact spherical surface, 305-return airflow cavity, 3051-return conical opening; 4-positioning injection mechanism, 401-injection side displacement box, 402-grinding airflow injection pump, 403-first servo motor 404-First insertion tube; 405-Built-in injection tube; 5-Positioning reflux mechanism; 501-Reflux side displacement box; 502-Grinding airflow reflux pump; 503-Second servo motor; 504-Second insertion tube; 505-Built-in reflux tube; 6-Rotating support assembly; 601-Inner support ring; 602-Outer support ring; 603-Outer roller; 7-Elastic connector; 701-Modible rod; 702-Contact end; 7021-Ball head; 703-Tension spring; 704-Rear limiting structure; 8-Conical airflow insertion tube; 9-Modible ring; 10-Drive shaft; 11-Bevel gear; 12-Annular rotating part; 1201-Conical toothed edge; 1202-Inner concave spherical groove; 13-Inner bearing ring; 14-Outer limiting ring. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] Example 1: This invention designs a linear grinding assembly for the inner wall of a seamless steel pipe, mainly including a grinding airflow injection pipe 2, a grinding airflow return pipe 3, a positioning injection mechanism 4, and a positioning return mechanism 5, etc. The specific structural contents and their mutual cooperation relationships are as follows:

[0046] Please see Figure 1 , Figure 2 The grinding airflow injection fitting 2 and the grinding airflow return fitting 3 are pre-inserted into the cavity 102 of the steel pipe 1. The positioning injection mechanism 4 is inserted into one side of the steel pipe 1 and injects the airflow containing grinding powder into the grinding airflow injection fitting 2. The positioning return mechanism 5 is inserted into the other side of the steel pipe 1 and absorbs the airflow in the grinding airflow return fitting 3 under negative pressure.

[0047] Please see Figure 3 , Figure 10The main components of the grinding airflow injection fitting 2 are: injection mating part 201, injection long pipe 202, discharge mating part 203, and flow divider ball 204. The flow divider ball 204 is fixedly installed on the side end of the discharge mating part 203, combined with... Figure 2 The position of the flow divider sphere 204 is aligned with the position of the weld seam 101 of the steel pipe 1. An injection airflow cavity 205 is opened inside the grinding airflow injection fitting 2. The injection airflow cavity 205 passes through the injection fitting part 201, the injection long pipe 202, and the discharge fitting part 203. Multiple evenly distributed discharge slots 2031 are opened on the side end of the discharge fitting part 203. The discharge slots 2031 are connected to the injection airflow cavity 205. The airflow from the discharge slots 2031 is in direct contact with the surface of the flow divider sphere 204.

[0048] Please see Figure 5 , Figure 11 The main components of the grinding airflow return pipe 3 are: an intake fitting 303, a return long pipe 302, and a return fitting 301. The grinding airflow return pipe 3 has a return airflow chamber 305, which passes through the intake fitting 303, the return long pipe 302, and the return fitting 301. Figure 6 The suction fitting part 303 has a contact spherical surface 304 on its side end, and a plurality of suction slots 3031 facing the surface of the diversion ball 204 are opened on the side end of the suction fitting part 303. The suction slots 3031 are connected to the return airflow cavity 305, and the contact spherical surface 304 and the diversion ball 204 are in a squeezed contact fit.

[0049] Please see Figure 3 , Figure 5 , Figure 10 , Figure 11 Rotary support components 6 are installed around the injection fitting part 201, the discharge fitting part 203, the suction fitting part 303, and the return fitting part 301. The rotary support components 6 are in rolling contact with the inner wall of the cavity 102 of the steel pipe 1.

[0050] Please see Figure 2 , Figure 7 The positioning injection mechanism 4 is equipped with an injection-side displacement box 401, a grinding air injection pump 402, a first insertion tube 404, and an internal injection tube 405. The first insertion tube 404 extends into one end of the cavity 102 of the steel pipe 1, and the internal injection tube 405 is located inside the first insertion tube 404. Figure 3 The built-in injection pipe 405 injects grinding powder airflow into the injection airflow chamber 205. The injection side displacement box 401 is equipped with a grinding airflow injection pump 402, which is connected to the built-in injection pipe 405.

[0051] Please see Figure 2 , Figure 9The positioning and reflux mechanism 5 is equipped with a reflux-side displacement box 501, a grinding airflow reflux pump 502, a second insertion tube 504, and an internal reflux pipe 505. The second insertion tube 504 is fixedly connected to the reflux-side displacement box 501 and extends into one end of the cavity 102 of the steel pipe 1. The internal reflux pipe 505 is located inside the second insertion tube 504. Figure 5 The built-in return pipe 505 draws in the grinding powder airflow from the return airflow chamber 305, and the grinding airflow return pump 502 is connected to the built-in return pipe 505.

[0052] Please see Figure 3 , Figure 4 , Figure 7 The elastic connector 7 is movably installed at the injection fitting part 201 and the return fitting part 301. The elastic connector 7 is provided with a contact end 702, which includes a ball head 7021. The ball head 7021 of the contact end 702 faces the annular rotating part 12 and engages with it. Figure 12 The annular rotating part 12 has multiple continuously distributed concave spherical grooves 1202 on its side end face facing the contact end 702. The ball head 7021 and the concave spherical grooves 1202 are mutually limited and fitted together.

[0053] Please see Figure 4 , Figure 5 An injection cone-shaped port 2051 is provided on the side end of the injection fitting part 201, and the injection cone-shaped port 2051 is connected to the injection airflow cavity 205. A return cone-shaped port 3051 is provided on the side end of the return fitting part 301, and the return cone-shaped port 3051 is connected to the return airflow cavity 305.

[0054] An injection end ring plate 2011 is provided on the side end of the injection mating part 201, and a return end ring plate 3011 is provided on the side end of the return mating part 301. Both the injection end ring plate 2011 and the return end ring plate 3011 have multiple through hole structures.

[0055] The elastic connector 7 includes a movable rod 701 that moves through the through hole structure, a contact end 702 that is fixed to one side of the movable rod 701, a rear limiting structure 704 that is located on the other side of the movable rod 701, and a tension spring 703 that is sleeved on the movable rod 701 and elastically supports the contact end 702.

[0056] Please see Figure 7 , Figure 9A ring-shaped rotating part 12 is rotatably mounted on the side of the first insertion tube 404, and a ring-shaped rotating part 12 is also rotatably mounted on the side of the second insertion tube 504. A first servo motor 403 is fixedly installed inside the injection-side displacement box 401. The first servo motor 403 can drive the ring-shaped rotating part 12 on the side of the first insertion tube 404 to rotate. A second servo motor 503 is fixedly installed inside the return-side displacement box 501. The second servo motor 503 can drive the ring-shaped rotating part 12 on the side of the second insertion tube 504 to rotate.

[0057] The output of the first servo motor 403 is connected to the drive shaft 10, and the output of the second servo motor 503 is also connected to the drive shaft 10. The drive shaft 10 of the first servo motor 403 extends into the first insertion tube 404, and the drive shaft 10 of the second servo motor 503 extends into the second insertion tube 504. Figure 8 The bevel gear 11 is mounted on the side of the drive shaft 10, and the annular rotating part 12 is provided with a conical tooth 1201 on the side facing the bevel gear 11, and the bevel gear 11 meshes with the conical tooth 1201.

[0058] A tapered airflow inlet tube 8 is provided at the side end of the built-in injection tube 405, and a tapered airflow inlet tube 8 is also provided at the side end of the built-in return tube 505. A movable ring 9 is movably installed on the outer ring side of the tapered airflow inlet tube 8. An inner bearing ring 13 is installed between the annular rotating part 12 at the side end of the first inlet tube 404 and the built-in injection tube 405, and an inner bearing ring 13 is installed between the annular rotating part 12 of the second inlet tube 504 and the built-in return tube 505. Figure 4 The tapered airflow cannula 8 at the side end of the built-in injection tube 405 is inserted into the injection tapered port 2051. Figure 5 The conical airflow inlet 8 at the side end of the built-in return tube 505 is inserted into the return conical inlet 3051. By providing a movable ring 9, when the conical airflow inlet 8 moves towards the inner wall of the injection conical inlet 2051, the movable ring 9 separates the contact connection between the two, thus... Figure 1 When the grinding airflow injection pipe 2 and the grinding airflow return pipe 3 rotate, the conical airflow insertion pipe 8 is not affected by their rotation. Simultaneously, during the transmission of grinding powder airflow, the movable ring 9 also reduces grinding powder airflow leakage to some extent.

[0059] Please see Figure 4 , Figure 10 , Figure 11 The rotating support assembly 6 includes an inner support ring 601 and an outer support ring 602. The inner support ring 601 is directly connected to the pipe structure of the grinding airflow injection pipe 2 and the grinding airflow return pipe 3. The outer support ring 602 is rotatably connected to the inner support ring 601 and can be considered as a bearing structure. Multiple outer rollers 603 are movably embedded on the outer ring side of the outer support ring 602. Figure 2 The outer roller 603 contacts the inner wall of the cavity 102 of the steel pipe 1.

[0060] Please see Figure 1 , Figure 2 , Figure 7 , Figure 9 Both the injection-side displacement box 401 and the return-side displacement box 501 are equipped with an outer limiting ring 14. The outer limiting ring 14 faces the side of the steel pipe 1 and is engaged at the side end of the steel pipe 1. This provides positioning support for the steel pipe 1 from the outside, reduces the support force of the rotating support assembly 6 on the steel pipe 1 from the inside, and reduces unnecessary friction between the rotating support assembly 6 and the inner wall of the steel pipe 1 cavity 102.

[0061] Example 2: This invention designs a linear grinding method for the inner wall of a seamless steel pipe, the specific method of which is as follows:

[0062] First, the steel pipe 1 to be ground enters the airflow pipe insertion process: the automated equipment inserts the grinding airflow injection pipe 2 from one side of the steel pipe 1, and the automated equipment inserts the grinding airflow return pipe 3 from the other side of the steel pipe 1. When the grinding airflow injection pipe 2 is inserted, the discharge fitting 203 with the flow divider ball 204 is first inserted into the cavity 102 of the steel pipe 1. When the grinding airflow return pipe 3 is inserted, the suction fitting 303 is first inserted into the cavity 102 of the steel pipe 1.

[0063] Then, after completing the above-mentioned process steps, the steel pipe 1 with the grinding airflow injection fitting 2 and the grinding airflow return fitting 3 inside the cavity 102 enters the next station and begins the air intake and rotation limit, as follows:

[0064] In the first step, the automated equipment drives the positioning injection mechanism 4 to move toward the steel pipe 1 side of the grinding airflow injection pipe 2. The first insertion tube 404 of the positioning injection mechanism 4 is inserted into the cavity 102 of the steel pipe 1, and the annular rotating part 12 of the first insertion tube 404 is pressed into contact with the elastic connector 7 of the grinding airflow injection pipe 2.

[0065] In the second step, the automated equipment drives the positioning and return mechanism 5 to move toward the steel pipe 1 side of the grinding airflow return pipe 3. The second insertion tube 504 of the positioning and return mechanism 5 is inserted into the cavity 102 of the steel pipe 1. The annular rotating part 12 of the second insertion tube 504 is pressed into contact with the elastic connector 7 of the grinding airflow return pipe 3.

[0066] In the third step, the positioning injection mechanism 4 pushes the grinding airflow injection pipe 2 to move, and the positioning return mechanism 5 pushes the grinding airflow return pipe 3 to move. The contact spherical surface 304 at the side end of the suction fitting 303 and the diversion ball 204 of the discharge fitting 203 are pressed into contact.

[0067] In the fourth step, the conical airflow cannula 8 of the first cannula 404 is inserted into the injection mating part 201, and the conical airflow cannula 8 of the second cannula 504 is inserted into the return mating part 301.

[0068] Then, the first servo motor 403 of the positioning injection mechanism 4 and the second servo motor 503 of the positioning return mechanism 5 are started. The first servo motor 403 drives the annular rotating part 12 of the first insertion tube 404 to rotate, and the second servo motor 503 drives the annular rotating part 12 of the second insertion tube 504 to rotate. When the annular rotating part 12 rotates, the contact end 702 of the elastic connector 7 is pressed and pushed into the concave spherical groove 1202 position on the side end face of the annular rotating part 12. The annular rotating part 12 of the first insertion tube 404 drives the grinding airflow injection tube 2 to rotate, and the annular rotating part 12 of the second insertion tube 504 drives the grinding airflow return tube 3 to rotate. The grinding airflow injection tube 2 and the grinding airflow return tube 3 rotate at the same speed and in the same direction.

[0069] In this invention, the grinding air injection pump 402 is connected upstream to the air supply and material supply equipment. When the grinding air injection pump 402 of the positioning injection mechanism 4 is started, the grinding powder airflow is injected into the built-in injection pipe 405 and the injection airflow chamber 205. At the same time, the grinding airflow return pump 502 of the positioning return mechanism 5 is started, and the grinding powder airflow in the return airflow chamber 305 and the built-in return pipe 505 is discharged under negative pressure. The grinding airflow return pump 502 leads the grinding powder airflow downstream through the filtration and screening equipment, so that the grinding powder can be recycled and reused.

[0070] Combination Figure 6 The grinding powder airflow enters the injection airflow chamber 205 and is discharged from the discharge slot 2031 along the surface of the diverting ball 204. The grinding powder airflow comes into frictional contact with the weld 101 of the steel pipe 1, and then enters the return airflow chamber 305 along the surface of the diverting ball 204 and the suction slot 3031. At this time, the grinding airflow injection pipe 2 and the grinding airflow return pipe 3 are rotating. The grinding powder airflow discharged from multiple discharge slots 2031 is more linear and uniform in its frictional grinding of the weld 101 of the steel pipe 1 along the diverting ball 204.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A linear grinding assembly for the inner wall of a seamless steel pipe, characterized in that: The grinding assembly includes a grinding airflow injection pipe (2) pre-inserted into the cavity of the steel pipe and a grinding airflow return pipe (3). The grinding assembly also includes a positioning injection mechanism (4) inserted into one side of the steel pipe and injecting airflow with grinding powder into the grinding airflow injection pipe (2), and a positioning return mechanism (5) inserted into the other side of the steel pipe and absorbing the airflow in the grinding airflow return pipe (3) under negative pressure. The grinding airflow injection pipe (2) includes an injection fitting (201), an injection long pipe (202), an discharge fitting (203), and a diverter ball (204) fixedly connected to the side end of the discharge fitting (203). The grinding airflow injection pipe (2) has an injection airflow cavity (205) that penetrates the injection fitting (201), the injection long pipe (202), and the discharge fitting (203). The position of the diversion ball (204) is aligned with the position of the weld seam of the steel pipe. Multiple evenly distributed discharge slots (2031) are provided at the connection position between the side end of the discharge fitting part (203) and the diversion ball (204). The discharge slots (2031) are connected to the injection airflow cavity (205). The grinding airflow return pipe (3) includes an intake fitting (303), a return long pipe (302), and a return fitting (301). The grinding airflow return pipe (3) has a return airflow chamber (305) that passes through the intake fitting (303), the return long pipe (302), and the return fitting (301). The suction fitting part (303) has a contact spherical surface (304) that cooperates with the diverting sphere (204) at its side end. The suction fitting part (303) has a plurality of suction slots (3031) facing the surface of the diverting sphere (204) at its side end. The suction slots (3031) are connected to the return airflow cavity (305). Among them, the injection fitting part (201), the discharge fitting part (203), the suction fitting part (303) and the return fitting part (301) are all surrounded by a rotating support assembly (6) that rolls and contacts the inner wall of the steel pipe cavity; The positioning injection mechanism (4) is equipped with an injection side displacement box (401) and a first insertion tube (404) extending into one end of the steel pipe cavity. The first insertion tube (404) is equipped with a built-in injection tube (405) for injecting grinding powder airflow into the injection airflow cavity (205). The injection side displacement box (401) is equipped with a grinding airflow injection pump (402) connected to the built-in injection tube (405). The positioning and reflux mechanism (5) is equipped with a reflux side displacement box (501) and a second insertion tube (504) extending into the other end of the steel pipe cavity. The second insertion tube (504) is equipped with a built-in reflux pipe (505) that draws in the grinding powder airflow in the reflux airflow chamber (305). The reflux side displacement box (501) is equipped with a grinding airflow reflux pump (502) connected to the built-in reflux pipe (505). Both the first insertion tube (404) and the second insertion tube (504) have an annular rotating part (12) movably arranged on their side ends. The injection side displacement box (401) is equipped with a first servo motor (403) for driving the annular rotating part (12) on the side end of the first insertion tube (404) to rotate. The return side displacement box (501) is equipped with a second servo motor (503) for driving the annular rotating part (12) on the side end of the second insertion tube (504) to rotate. Both the injection fitting part (201) and the return fitting part (301) are equipped with multiple elastic connectors (7). The elastic connectors (7) have contact ends (702) on the side facing the annular rotating part (12). The contact ends (702) include ball heads (7021). The annular rotating part (12) has multiple continuously distributed concave spherical grooves (1202) on the side facing the contact ends (702). The ball heads (7021) and the concave spherical grooves (1202) are mutually limited and fitted together.

2. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: The injection fitting part (201) is provided with an injection end ring plate (2011) on its side end, and the return fitting part (301) is provided with a return end ring plate (3011) on its side end. Both the injection end ring plate (2011) and the return end ring plate (3011) are provided with multiple through hole structures. The elastic connector (7) includes a movable rod (701) that moves through the through hole structure, the contact end (702) is located at one end of the movable rod (701), the other end of the movable rod (701) is provided with a rear limiting structure (704), and the movable rod (701) is sleeved with a tension spring (703) that elastically supports the contact end (702).

3. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: The rotating support assembly (6) includes an inner support ring (601), an outer support ring (602) rotatably connected to the inner support ring (601), and a plurality of outer rollers (603) movably embedded on the outer ring side of the outer support ring (602), wherein the outer rollers (603) are in contact with the inner wall of the steel pipe cavity.

4. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: The side end of the injection fitting part (201) is provided with an injection cone-shaped port (2051) that communicates with the injection airflow chamber (205), and the side end of the return fitting part (301) is provided with a return cone-shaped port (3051) that communicates with the return airflow chamber (305). Both the side end of the built-in injection tube (405) and the side end of the built-in return tube (505) are provided with a conical airflow tube (8). The conical airflow tube (8) at the side end of the built-in injection tube (405) is inserted into the injection conical port (2051), and the conical airflow tube (8) at the side end of the built-in return tube (505) is inserted into the return conical port (3051).

5. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 4, characterized in that: The tapered airflow tube (8) has a movable ring (9) installed on its outer ring side.

6. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: An inner bearing ring (13) is provided between the inner circumference of the annular rotating part (12) at the side end of the first insertion tube (404) and the built-in injection tube (405), and between the inner circumference of the annular rotating part (12) of the second insertion tube (504) and the built-in return tube (505).

7. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: The output ends of the first servo motor (403) and the second servo motor (503) are both connected to drive shafts (10). The drive shaft (10) connected to the output end of the first servo motor (403) extends into the first insertion tube (404), and the drive shaft (10) connected to the output end of the second servo motor (503) extends into the second insertion tube (504). The drive shaft (10) is provided with a bevel gear (11) on its side end, and the annular rotating part (12) is provided with a conical tooth (1201) that meshes with the bevel gear (11) on the side facing the bevel gear (11).

8. The linear grinding assembly for the inner wall of a seamless steel pipe according to claim 1, characterized in that: Both the injection-side displacement box (401) and the return-side displacement box (501) are provided with an outer limiting ring (14) that engages with the side end of the steel pipe on the side facing the steel pipe.

9. A method for linear grinding of the inner wall of a seamless steel pipe, characterized in that, The linear grinding assembly for the inner wall of a seamless steel pipe according to any one of claims 1 to 8 includes the following steps: S1. Steel pipe to be ground enters airflow fitting insertion process: The automated equipment injects grinding airflow into the fitting (2) and inserts it from one side of the steel pipe. The automated equipment returns the grinding airflow to the fitting (3) and inserts it from the other side of the steel pipe. S1.

1. When the grinding air injection fitting (2) is inserted, first insert the discharge fitting (203) with the flow divider ball (204) into the steel pipe cavity; S1.

2. When inserting the grinding airflow return pipe fitting (3), first insert the suction fitting part (303) into the steel pipe cavity; S2. After completing the above process steps, the steel pipe with grinding airflow injection fitting (2) and grinding airflow return fitting (3) in the pipe cavity enters the next station; S2.

1. The automated equipment drives the positioning injection mechanism (4) to move toward the steel pipe side of the grinding airflow injection pipe (2). The first insertion tube (404) of the positioning injection mechanism (4) is inserted into the steel pipe cavity. The annular rotating part (12) of the first insertion tube (404) is pressed into contact with the elastic connector (7) of the grinding airflow injection pipe (2). S2.

2. The automated equipment drives the positioning and return mechanism (5) to move toward the steel pipe side of the grinding airflow return pipe fitting (3). The second insertion tube (504) of the positioning and return mechanism (5) is inserted into the steel pipe cavity. The annular rotating part (12) of the second insertion tube (504) is pressed into contact with the elastic connector (7) of the grinding airflow return pipe fitting (3). S2.

3. The positioning injection mechanism (4) pushes the grinding airflow injection pipe (2) to move, and the positioning return mechanism (5) pushes the grinding airflow return pipe (3) to move. The contact spherical surface (304) at the side end of the suction fitting (303) and the diversion ball (204) of the discharge fitting (203) are pressed into contact. S2.

4. The conical airflow cannula (8) of the first cannula (404) is inserted into the injection fitting part (201), and the conical airflow cannula (8) of the second cannula (504) is inserted into the return fitting part (301); S3. The first servo motor (403) of the positioning injection mechanism (4) and the second servo motor (503) of the positioning return mechanism (5) are started. The first servo motor (403) drives the annular rotating part (12) of the first insertion tube (404) to rotate. The second servo motor (503) drives the annular rotating part (12) of the second insertion tube (504) to rotate. When the annular rotating part (12) rotates, the contact end (702) of the elastic connector (7) is squeezed and pushed into the concave spherical groove (1202) on the side end face of the annular rotating part (12). The annular rotating part (12) of the first insertion tube (404) drives the grinding airflow injection pipe (2) to rotate. The annular rotating part (12) of the second insertion tube (504) drives the grinding airflow return pipe (3) to rotate. Among them, the grinding airflow injection pipe (2) and the grinding airflow return pipe (3) have the same rotation speed and direction; S4. The grinding air injection pump (402) of the positioning injection mechanism (4) is started, and the grinding powder airflow is injected into the built-in injection pipe (405) and the injection airflow chamber (205). At the same time, the grinding airflow return pump (502) of the positioning return mechanism (5) is started, and the grinding powder airflow in the return airflow chamber (305) and the built-in return pipe (505) is discharged under negative pressure. The grinding powder airflow enters the injection airflow chamber (205) and is discharged from the discharge slot along the surface of the diversion ball (204). The grinding powder airflow comes into frictional contact with the weld of the steel pipe and then enters the return airflow chamber (305) along the surface of the diversion ball (204) and the suction slot (3031).

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