A medium and small caliber pipe with long straight section of the inner hole of the elbow polishing device

Abstract

The present application relates to the technical field of pipe processing, in particular to a kind of elbow inner hole polishing and grinding device of small and medium caliber pipe with long straight pipe section.The cover shell, abrasive head power device, axial feed device and eccentric device of abrasive head are included, the cover shell is movably arranged in the elbow, the abrasive head power device includes the abrasive head at the front end of the cover shell, the abrasive head motor at the rear end of the cover shell and the flexible shaft assembly passing through the cover shell and being connected with the eccentric device of abrasive head and the abrasive head motor at both ends respectively, the axial feed device is slidably arranged on the workbench and can drive the cover shell to reciprocate along the axial direction, the abrasive head is connected with the eccentric device of abrasive head and is eccentrically arranged compared with the cover shell, the axial feed device is provided with a guide device, and the guide device is connected with the cover shell and is used to drive the cover shell to bend horizontally.The device can realize the polishing and grinding of elbow inner hole in the range of φ230-φ450 small and medium caliber, with different bending angles and different lengths of straight pipe section, and the wall thickness, size and surface roughness need to be strictly controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe processing, in particular to a kind of inner hole polishing device of elbow pipe with long straight pipe section of medium and small caliber. BACKGROUND

[0002] The elbow pipe with long straight pipe section of medium and small caliber in the field of pipe processing generally refers to the elbow pipe with the aperture of φ230-φ450, and the length of straight pipe section of one end or both ends is 500≤L<2000. The stainless steel elbow pipe of medium and small caliber is formed into various types of elbow pipe with the angle of 0° to 90° by overall cold bending of straight pipe. Two problems are prone to occur due to bending technology defects: in the bending process, the inner wall of the pipe will have scratches, burrs and impurities due to core mold stripping; the side generatrix of R arc segment of inner hole (0° outside generatrix, 180° inside generatrix) will have wrinkles; the bending pipe will form an oxidized surface after solid solution; the R bending inner hole of the elbow pipe cannot be mechanically processed, and after the overall outer shape of the elbow pipe and the inner hole of the straight pipe section are mechanically processed, the bending part and the inner hole of the straight pipe section will have a processing step at the joint position. The wall thickness, size and surface roughness of the elbow pipe are required to be higher. The inner hole of the elbow pipe of φ230-φ450 medium and small caliber is narrow in space, and the length of straight pipe section at the inlet and outlet ends exceeds 500 mm. The conventional method is to use various electric and pneumatic grinding head tools held by operators to polish and grind the surface to be processed. This is in the condition that the finishing process is not limited by space, and the surface quality, uniformity and grinding efficiency are not required in this occasion. In the narrow space and specific conditions, the surface quality and wall thickness size control are strict, and ordinary manual polishing and polishing, as well as existing polishing machines and tools, are difficult to realize the processing of the inner hole surface of the elbow pipe with long straight pipe section of medium and small caliber. SUMMARY

[0003] The purpose of the present application is to overcome the defects of the prior art, and to provide an inner hole polishing device of elbow pipe with long straight pipe section of medium and small caliber, which can polish and grind the inner hole of the elbow pipe with different bending angles and different lengths of straight pipe section in the range of φ230-φ450, and strictly control the wall thickness, size and surface roughness.

[0004] This invention provides a grinding device for the inner bore of a small-to-medium diameter bent pipe with a long straight section, comprising a housing, a grinding head power unit, an axial feed device, and a grinding head eccentric device. The housing is movably disposed inside the bent pipe. The grinding head power unit includes a grinding head located at the front end of the housing, a grinding head motor located at the rear end of the housing, and a flexible shaft assembly passing through the housing and connecting the grinding head eccentric device and the grinding head motor at both ends. The grinding head eccentric device is used to drive the grinding head to rotate circumferentially around the inner wall of the bent pipe. The axial feed device is slidably disposed on a worktable and can drive the housing to reciprocate axially. The grinding head is connected to the grinding head eccentric device and is eccentrically disposed relative to the housing. The axial feed device is provided with a guide device, which is connected to the housing and used to drive the housing to bend horizontally.

[0005] Preferably, the housing includes several housing units connected end to end, adjacent housing units are hinged to each other at the top and bottom, and the rear end of the housing unit is fixedly connected to the axial feed device.

[0006] Preferably, the bottom of the housing is provided with first rolling bearings on both sides, the central axis of the first rolling bearings is parallel to the cross section of the housing, and the support height of the first rolling bearings is equal to the gap between the inner wall of the bend and the outer wall of the housing.

[0007] Preferably, the eccentric grinding head device includes a second rolling bearing, a large gear, a third rolling bearing, a small gear, a drive shaft, and an eccentric motor. The large gear has an eccentric hole at its center, and the second rolling bearing is nested within the eccentric hole. A first connecting sleeve is nested within the second rolling bearing. One end of the first connecting sleeve is fixedly connected to the center of the grinding head, and the other end extends into and is fixedly connected to the second rolling bearing. The large gear is nested within the third rolling bearing, which is nested within the housing. The small gear meshes with the large gear along its outer circumference. The small gear is coaxially connected to the output rotor of the eccentric motor via the drive shaft. The centers of the first connecting sleeve, the second rolling bearing, and the eccentric hole are all located on the same centerline O. The centers of the large gear, the third rolling bearing, the cross-sectional center of the housing, and the cross-sectional center of the bent tube are all located on the same centerline O′. The centerlines O and O′ are parallel but do not coincide.

[0008] Preferably, the transmission ratio between the pinion and the gear is 1:4, and the center line O is located 10 mm above the center line O′.

[0009] Preferably, the axial feed device includes a feed motor, a sprocket drive assembly, a roller frame, rollers, pulleys, a pulley seat, a first traction wire rope, and a guide rail carriage. The guide rail carriage is slidably mounted on the worktable via an axially arranged guide rail. The pulley seat and roller frame are respectively fixed at the beginning and end of the worktable. The rollers are horizontally mounted on the roller frame. The rollers are driven to the output end of the feed motor via the sprocket drive assembly. The pulleys are mounted on the pulley seat. The first traction wire rope passes around the pulley and is fixed to the rollers through its two free ends. The first traction wire rope is fixedly connected to the guide rail carriage at the bottom.

[0010] Preferably, the guiding device includes two second traction steel wire ropes, a ratchet mechanism, and a crank. A set of ratchet mechanisms is fixed on each of the two front sides of the guide rail vehicle. Each ratchet mechanism is connected to a crank for driving its rotation. One end of each of the two second traction steel wire ropes is connected to a set of ratchet mechanisms, and the other end passes through the inner cavity of the cover and is fixed to the left and right side walls of the front end of the inner cavity of the cover. The connection point between the second traction steel wire rope and the cover is at the same height as the center line of the cover.

[0011] Preferably, the flexible shaft assembly includes a first connecting sleeve, a universal joint, a flexible shaft, and a second connecting sleeve. One end of the first connecting sleeve is coaxially fixed to the grinding head, and the other end is fixed to one end of the universal joint. The other end of the universal joint is fixed to one end of the flexible shaft, and the other end of the flexible shaft is connected to one end of the second connecting sleeve. The other end of the second connecting sleeve is connected to the output shaft of the grinding head motor. The grinding head motor is fixed on the axial feed device and can follow the axial feed device to perform axial reciprocating motion along the worktable.

[0012] Preferably, the housing units are provided with a bending gap on one side for the housing to bend along the bend of the tube.

[0013] Preferably, the inner cavity of the cover shell is provided with a plurality of supporting ribs along the length direction. The supporting ribs are circular structures parallel to the cross section of the cover shell. The center of the supporting ribs is provided with a flexible shaft through hole for the flexible shaft to pass through and to support the flexible shaft.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. This device can be applied to the polishing of inner bores of bent pipes with varying diameters (φ230-φ450), bending angles, and straight pipe lengths, requiring strict control of wall thickness, dimensions, and surface roughness. The polishing device reciprocates along the axis of the section to be ground in the bent pipe; its shape changes with the bending angle of the pipe, achieving overall polishing of the inner bore surface; the eccentric grinding head supports and fixes the grinding head relative to the housing (i.e., a protrusion) in a uniform circular rotation on the inner wall of the pipe, rapidly and evenly removing local wrinkles, steps, scratches, burrs, impurities, and oxide surfaces from the inner bore surface. This polishing method replaces manual grinding, resulting in high-quality finished surfaces, overcoming the limitations of existing grinding machinery and tools, and offering stable structure and high efficiency.

[0016] 2. The grinding head power unit adopts a flexible shaft and universal joint design to realize the transmission of torque between the grinding head and the motor on different axes and in different directions. It drives the front grinding head grinding wheel and flap wheel to change with the bending angle of the bend tube and rotate at high speed to perform the main grinding motion.

[0017] 3. The axial feed device, driven by the feed motor, pulleys, rollers, and wire rope, drives the polishing device fixed on the guide rail carriage to achieve uniform axial feed of the inner surface of the bent pipe, thus achieving grinding of the entire bent pipe section. The guiding device uses a ratchet mechanism to pull the wire rope, driving the housing unit and its grinding head to adjust the angle within the inner hole of the bent pipe, overcoming folds and steps on the inner wall of the bent pipe, thereby achieving a fit between the housing and the bent pipe.

[0018] 4. The eccentric grinding head device incorporates a 10mm eccentric support hole in the center of the large gear, allowing for the eccentric arrangement of the grinding head for support and fixation. The motor drives the large gear to rotate at a uniform speed within the housing, which in turn drives the eccentric rotation of the grinding head. The protruding grinding head then grinds the circumferential surface of the inner hole of the bent pipe. This solves the problem of grinding the inner hole of small- and medium-diameter bent pipes with long straight sections. The structure is stable, achieving uniform grinding of the inner hole surface of the bent pipe with high efficiency, consistent surface texture, and a surface roughness of Ra1.6. When used with a thickness gauge, the wall thickness accuracy can be controlled to within 0.04mm. Attached Figure Description

[0019] Figure 1 This is the front view of the present invention;

[0020] Figure 2 This is a top view of the present invention;

[0021] Figure 3 This is a front view of the housing structure of the present invention;

[0022] Figure 4 This is a top view of the housing structure of the present invention;

[0023] Figure 5This is a horizontal sectional view of the housing structure of the present invention;

[0024] Figure 6 for Figure 3 PP section view;

[0025] Figure 7 This is a schematic diagram of the structure of the grinding head power device of the present invention;

[0026] Figure 8 This is a front view of the axial feed device of the present invention;

[0027] Figure 9 This is a top view of the axial feed device of the present invention;

[0028] Figure 10 This is a front view of the guiding device of the present invention;

[0029] Figure 11 This is a top view of the guiding device of the present invention;

[0030] Figure 12 This is an axial sectional view of the eccentric grinding head device of the present invention;

[0031] Figure 13 for Figure 12 Sectional view along axis AA;

[0032] Figure 14 This is a schematic diagram showing the distribution of parts on the center line O of the eccentric device of the grinding head in this invention;

[0033] Figure 15 This is a schematic diagram of the component distribution on the center line O′ of the eccentric device of the grinding head of the present invention. Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0038] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0039] Example 1

[0040] Figures 1-15 This illustration shows a structural schematic diagram of a small-to-medium diameter pipe inner hole polishing device with a long straight pipe section according to a preferred embodiment of this application. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0041] like Figure 1 and 2As shown, a small-to-medium diameter pipe bending inner hole polishing device with a long straight pipe section includes a housing 1, a grinding head power unit 2, an axial feed device 3, and a grinding head eccentric device 5. The housing 1 is movably disposed inside the bending pipe 7. The grinding head power unit 2 includes a grinding head 2-2 located at the front end of the housing 1, a grinding head motor 2-7 located at the rear end of the housing 1, and a flexible shaft assembly passing through the housing 1 and connecting the grinding head eccentric device 5 and the grinding head motor 2-7 at both ends respectively. The grinding head eccentric device 5 is used to drive the grinding head 2-2 to rotate circumferentially around the inner wall of the bending pipe 7. The axial feed device 3 is slidably disposed on the worktable 6 and can drive the housing 1 to reciprocate axially. The grinding head 2-2 is connected to the grinding head eccentric device 5 and is eccentrically disposed relative to the housing 1. The axial feed device 3 is provided with a guide device 4, which is connected to the housing 1 and used to drive the housing 1 to bend horizontally.

[0042] like Figures 3-6 As shown, the housing 1 includes several housing units 1-1 connected end to end. Adjacent housing units 1-1 are hinged to each other at the top and bottom. The rear end of the housing unit 1-1 is fixedly connected to the axial feed device 3.

[0043] In one embodiment, the bottom two sides of the housing 1 are provided with first rolling bearings 1-7, the central axis of the first rolling bearings 1-7 is parallel to the cross section of the housing 1, and the support height of the first rolling bearings 1-7 is equal to the gap between the inner wall of the bend 7 and the outer wall of the housing 1.

[0044] In one embodiment, a bending gap 1-3 is provided on one side between the housing units 1-1 for the housing 1 to bend along the bend 7.

[0045] In one embodiment, the inner cavity of the housing 1 is provided with a plurality of supporting ribs 1-6 along the length direction. The supporting ribs 1-6 are circular structures parallel to the cross section of the housing 1. The center of the supporting ribs 1-6 is provided with a through hole for the flexible shaft 2-5 to pass through and to support the flexible shaft 2-5.

[0046] In this embodiment, the length of the housing 1 is equal to the arc length of the bend, comprising nine housing segments 1-1. Each segment 1-1 is equally divided and of equal length. A connecting block 1-5 is welded to the top and bottom of each housing segment 1-1, and they are sequentially hinged together using 16 pins 1-2. A bending gap 1-3 is provided on one side between the housing segments 1-1 to allow the housing 1 to bend along the bend 7, enabling the housing segments 1-1 to rotate a maximum angle of 11.25° around the fixed pins, thus allowing the housing 1 to change shape from a straight state to a maximum bending angle of 90°. Eight first rolling bearings 1-7 (which can be ф30 stainless steel rolling bearings) are evenly distributed to the left and right below the center horizontal line of the housing segments 1-1. The support height of the bearing assembly is equal to (inner diameter D of the bend 7 - outer diameter d of the housing segment) / 2, which is the gap between the bend 6 and the housing segment. A horizontal push rod 1-4 is fixedly connected to the rear end of the housing 1. The end of the push rod 1-4 is welded and fixed to the front end of the guide rail 3-9 of the axial feed device 3. When the guide rail 3-9 moves with the axial feed device 3, it can drive the push rod 1-4 to push the first rolling bearing 1-7 below the housing 1-4 to move along the inner wall of the bend 7. The housing 1 changes its shape and posture according to the bending radius and bending angle of the pipe, and can bend and move freely in the inner hole of various types of bends from 0 degrees to 90 degrees.

[0047] like Figure 7 As shown, the grinding head power unit 2 includes a shank 2-1 located at the front end of the housing 1, a grinding head 2-2, a grinding head motor 2-7 located at the rear end of the housing 1, and a flexible shaft assembly that passes through the housing 1 and connects the grinding head eccentric device 5 and the grinding head motor 2-7 at both ends. The flexible shaft assembly includes a first connecting sleeve 2-3, a universal joint 2-4, a flexible shaft 2-5, and a second connecting sleeve 2-6. One end of the first connecting sleeve 2-3 is coaxially fixed to the grinding head 2-2, and the other end is fixed to one end of the universal joint 2-4. The other end of the universal joint 2-4 is fixed to one end of the flexible shaft 2-5. The other end of the flexible shaft 2-5 is connected to one end of the second connecting sleeve 2-6. The other end of the second connecting sleeve 2-6 is connected to the output shaft of the grinding head motor 2-7. The grinding head motor 2-7 is fixed on the axial feed device 3 and can follow the axial feed device 3 to perform axial reciprocating motion along the worktable 6. During assembly, all parts should be aligned on the same centerline. The flexible shaft can be a 16×3500G type power flexible shaft. The grinding head 2-2 can be a grinding wheel or a flap wheel. The grinding head and the high-power motor are connected by a flexible shaft and a connecting sleeve to achieve torque transmission between the grinding head and the motor along different axes and in different directions, driving the front grinding head grinding wheel and flap wheel to rotate at high speed for the main grinding motion.

[0048] like Figures 8-9As shown, in one embodiment, the axial feed device drives the housing and the grinding head power device fixed therein to realize the axial feed and return of the grinding head. The axial feed device 3 includes a feed motor 3-1, a sprocket transmission assembly, a roller frame 3-6, a roller 3-7, a pulley 3-11, a pulley seat 3-12, a first traction steel wire rope 3-10, and a guide rail 3-9. The guide rail 3-9 is slidably mounted on the worktable 6 via an axially arranged guide rail. The pulley seat 3-12 and the roller frame 3-6 are respectively fixed at the beginning and end of the worktable 6. The roller 3-7 is horizontally mounted on the roller frame 3-6. The roller 3-7 is transmitted to the output end of the feed motor 3-1 through the sprocket transmission assembly. The pulley 3-11 is mounted on the pulley seat 3-12. The first traction steel wire rope 3-10 passes around the pulley 3-11 and is wound and fixed to the roller 3-7 through its two free ends. The first traction steel wire rope 3-10 is fixedly connected to the guide rail 3-9 at the bottom.

[0049] The sprocket drive assembly includes a coupling 3-2, a connecting rod 3-3, a sprocket 3-5, and a chain 3-4. The sprocket 3-5 includes a top sprocket and a bottom sprocket. The output shaft of the feed motor 3-1 is connected to the bottom sprocket via the coupling 3-2 and the connecting rod 3-3. The bottom sprocket drives the top sprocket to rotate via the chain 3-4, thereby driving the roller 3-7 on the roller frame 3-6 to rotate. The forward or reverse rotation of the feed motor 3-1 can realize the forward or reverse rotation of the roller. Since the first traction wire rope 3-10 passes around the pulley 3-11 and is fixed to the roller 3-7 through two free ends, this winding and fixing method can be achieved by setting two fixed points on the roller, fixing one free end of the first traction wire rope 3-10 to this fixed point, and winding and tightening the first traction wire rope 3-10 on the roller until the other free end is reached, and then fixing the other free end to the other fixed point. When the roller rotates forward or backward, the pulley 3-11 can be used to retract or extend the first traction wire rope 3-10. A fixed point is provided at the bottom of the guide rail carriage 3-9. One side of the wire rope corresponding to one free end of the first traction wire rope 3-10 can be fixed to this fixed point first, and then connected to the fixed point of the roller. Thus, during the retraction or extension of the first traction wire rope, as the roller rotates, it drives the guide rail carriage 3-9 to reciprocate along the axially arranged guide rail on the worktable 6. The push rod 1-4 pushes the first rolling bearing 1-7 below the housing to move along the inner wall of the bend pipe 7.

[0050] like Figures 10-11As shown, the guiding device 4 includes two second traction steel wire ropes 4-3, a ratchet mechanism 4-2, and a crank handle 4-1. A set of ratchet mechanisms 4-2 is fixed to each side of the front end of the guide rail carriage 3-9. Each ratchet mechanism 4-2 is connected to a crank handle 4-1 for driving its rotation. One end of each of the two second traction steel wire ropes 4-3 is connected to a set of ratchet mechanisms 4-2, and the other end passes through the inner cavity of the cover housing 1 and is fixed to the left and right side walls of the front end of the inner cavity of the cover housing 1. The connection point between the second traction steel wire ropes 4-3 and the cover housing 1 is at the same height as the centerline of the cover housing 1. Rotation of the crank handle generates unidirectional intermittent motion, driving the second traction steel wire ropes 4-3 to flexibly adjust the angle of the grinding head, traversing inner wall folds and steps to grind and eliminate defects. Simultaneously, it can also keep the bending state of the cover housing consistent with the bent pipe.

[0051] like Figures 12-15 As shown, the eccentric grinding head device 5 includes a second rolling bearing 5-2, a large gear 5-3, a third rolling bearing 5-4, a small gear 5-6, a drive shaft 5-5, and an eccentric motor 5-9. The large gear 5-3 has an eccentric hole 5-1 at its center, within which the second rolling bearing 5-2 is nested. The second rolling bearing 5-2 has a first connecting sleeve 2-3 nested inside it. One end of the first connecting sleeve 2-3 is fixedly connected to the center of the grinding head 2-2, and the other end extends into and is fixedly connected to the second rolling bearing 5-2. The large gear 5-3 is nested within the third rolling bearing 5-4, which is nested within the housing 1. The small gear 5-6 meshes with the large gear 5-3 along their outer circumference. A support frame 5-7 is welded and fixed to the inner cavity of the housing 1. A bearing hole for support is located at the welded position, into which a fourth rolling bearing 5-8 is installed, and through which the drive shaft 5-5 passes. The support frame 5-7 is connected to the tail end seat of the eccentric motor 5-9, thus fixing the eccentric motor 5-9. The pinion 5-6 is coaxially connected to the output rotor of the eccentric motor 5-9 via the transmission shaft 5-5. The centers of the first connecting sleeve 2-3, the second rolling bearing 5-2, and the eccentric hole 5-1 are all located on the same center line O. The centers of the large gear 5-3, the third rolling bearing 5-4, the cross-sectional center of the housing 1, and the cross-sectional center of the bent pipe 7 are all located on the same center line O′. Center lines O and O′ are parallel but do not coincide. The transmission ratio between the pinion 5-6 and the large gear 5-3 is 1:4, and center line O is located 10 mm above center line O′. When the eccentric motor starts, the pinion drives the large gear to rotate at a constant speed relative to the housing device. The eccentric hole in the middle of the large gear supports and fixes the grinding head part to rotate circumferentially by 10 mm, realizing the circumferential rotation of the grinding head relative to the housing with a 10 mm protrusion, thus completing the directional grinding in the circumferential direction of the bent pipe.

[0052] This invention solves the problem of mechanical polishing of the inner hole of small and medium diameter pipes with long straight sections. The shape of this device can change with the bending of the pipe, and it can effectively transmit the torque of the grinding head under changing angle conditions. The device runs smoothly during high-speed grinding, the grinding surface is uniform, the polished surface is smooth and flat, and the surface roughness can reach Ra1.6. When used with a thickness gauge, the wall thickness accuracy can be controlled within the range of 0.04 mm.

[0053] The method of using this device is as follows:

[0054] 1) Place the bent pipe 7 horizontally at the front end of the workbench, with the center of one end of the straight pipe aligned with the center of the workbench frame, and the other end of the bent pipe facing the operating area and supported by a wooden sleeper.

[0055] 2) Placement of housing 1: Place the upper and lower hinge pins connecting housing 1 in a direction perpendicular to the worktable; the gap of 11.25 degrees between housing units 1-1 faces the operating area.

[0056] 3) This device is horizontally fixed on the axial guide rail of the workbench. The center of the bend 7 and the center of this device are on the same center line, and the cover 1 is pushed in from the inner hole of the straight end of the bend 7.

[0057] 4) Start the feed motor 3-1. The first traction wire rope 3-10 drives the fixed cover 1 and the grinding head power unit 2 on the guide rail 3-9 to reciprocate within the pipe of the bend 7. Start the eccentric motor to make the grinding head rotate eccentrically by 10 mm. Start the grinding head motor 2-7 to make the grinding head rotate to achieve grinding.

[0058] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A device for polishing the inner hole of a bent pipe with a long straight section and a small to medium diameter, characterized in that: The device includes a housing (1), a grinding head power unit (2), an axial feed device (3), and a grinding head eccentric device (5). The housing (1) is movably disposed inside the bent tube (7). The grinding head power unit (2) includes a grinding head (2-2) located at the front end of the housing (1), a grinding head motor (2-7) located at the rear end of the housing (1), and a flexible shaft assembly that passes through the housing (1) and connects the grinding head eccentric device (5) and the grinding head motor (2-7) at both ends. The grinding head eccentric device (5) The grinding head (2-2) is used to drive the grinding head (2-2) to rotate around the inner wall of the bent tube (7). The axial feed device (3) is slidably set on the worktable (6) and can drive the cover (1) to reciprocate along the axial direction. The grinding head (2-2) is connected to the grinding head eccentric device (5) and is eccentrically set relative to the cover (1). The axial feed device (3) is provided with a guide device (4). The guide device (4) is connected to the cover (1) and is used to drive the cover (1) to bend horizontally. The bottom two sides of the cover (1) are provided with first rolling bearings (1-7). The central axis of the first rolling bearing (1-7) is parallel to the cross section of the cover (1). The support height of the first rolling bearing (1-7) is equal to the gap between the inner wall of the bend (7) and the outer wall of the cover (1). The eccentric device (5) of the grinding head includes a second rolling bearing (5-2), a large gear (5-3), a third rolling bearing (5-4), a small gear (5-6), a transmission shaft (5-5), and an eccentric motor (5-9). The large gear (5-3) has an eccentric hole (5-1) in its center. The second rolling bearing (5-2) is nested inside the eccentric hole (5-1). The second rolling bearing (5-2) has a first connecting sleeve (2-3) nested inside it. One end of the first connecting sleeve (2-3) is fixedly connected to the center of the grinding head (2-2), and the other end extends into the second rolling bearing (5-2) and is fixedly connected to it. The large gear (5-3) is nested in the third rolling bearing (5-4). -4) Inside, the third rolling bearing (5-4) is nested inside the housing (1). The pinion (5-6) and the large gear (5-3) mesh with each other along the outer circumference. The pinion (5-6) is coaxially connected to the output rotor of the eccentric motor (5-9) through the transmission shaft (5-5). The center of the first connecting sleeve (2-3), the center of the second rolling bearing (5-2), and the center of the eccentric hole (5-1) are all located on the same center line O. The center of the large gear (5-3), the center of the third rolling bearing (5-4), the center of the cross section of the housing (1), and the center of the cross section of the bent pipe (7) are all located on the same center line O′. The center line O and the center line O′ are parallel to each other but do not coincide. The housing (1) includes several housing units (1-1) connected end to end. Adjacent housing units (1-1) are hinged to each other at the top and at the bottom. The rear end of the housing unit (1-1) is fixedly connected to the axial feed device (3).

2. The device for polishing the inner hole of a bent pipe with a long straight section in small and medium diameter as described in claim 1, characterized in that: The transmission ratio between the pinion (5-6) and the gear (5-3) is 1:4, and the center line O is located 10 mm above the center line O′.

3. The device for polishing the inner hole of a bent pipe with a long straight section in small and medium diameter as described in claim 1, characterized in that: The axial feed device (3) includes a feed motor (3-1), a sprocket drive assembly, a roller frame (3-6), rollers (3-7), pulleys (3-11), pulley seats (3-12), a first traction steel wire rope (3-10), and a guide rail carriage (3-9). The guide rail carriage (3-9) is slidably mounted on the worktable (6) via an axially arranged guide rail. The pulley seats (3-12) and roller frame (3-6) are respectively fixed at the beginning and end of the worktable (6). -7) The roller (3-7) is horizontally set on the roller frame (3-6). The roller (3-7) is connected to the output end of the feed motor (3-1) through the sprocket transmission assembly. The pulley (3-11) is set on the pulley seat (3-12). The first traction wire rope (3-10) passes around the pulley (3-11) and is wound and fixed to the roller (3-7) through its two free ends. The first traction wire rope (3-10) is fixedly connected to the guide rail car (3-9) at the bottom.

4. The device for polishing the inner hole of a bent pipe with a long straight section in small and medium diameter as described in claim 3, characterized in that: The guiding device (4) includes two second traction steel wire ropes (4-3), a ratchet mechanism (4-2), and a crank (4-1). A set of ratchet mechanisms (4-2) is fixed on both sides of the front end of the guide rail car (3-9). Each ratchet mechanism (4-2) is connected to a crank (4-1) for driving its rotation. One end of each of the two second traction steel wire ropes (4-3) is connected to a set of ratchet mechanisms (4-2), and the other end passes through the inner cavity of the cover (1) and is fixed to the left and right side walls of the front end of the inner cavity of the cover (1). The connection point of the second traction steel wire rope (4-3) with the cover (1) is at the same height as the center line of the cover (1).

5. The device for polishing the inner hole of a bent pipe with a long straight section in small and medium diameter as described in claim 1, characterized in that: The flexible shaft assembly includes a first connecting sleeve (2-3), a universal joint (2-4), a flexible shaft (2-5), and a second connecting sleeve (2-6). One end of the first connecting sleeve (2-3) is coaxially fixed to the grinding head (2-2), and the other end is fixed to one end of the universal joint (2-4). The other end of the universal joint (2-4) is fixed to one end of the flexible shaft (2-5). The other end of the flexible shaft (2-5) is connected to one end of the second connecting sleeve (2-6). The other end of the second connecting sleeve (2-6) is connected to the output shaft of the grinding head motor (2-7). The grinding head motor (2-7) is fixed on the axial feed device (3) and can follow the axial feed device (3) to perform axial reciprocating motion along the worktable (6).

6. The device for polishing the inner hole of a bent pipe with a long straight section in small and medium diameter as described in claim 1, characterized in that: A bending gap (1-3) is provided on one side between the housing units (1-1) for the housing (1) to bend along the bend (7).

7. The device for polishing the inner bore of a bent pipe with a long straight section in small and medium diameter as described in claim 5, characterized in that: The inner cavity of the cover (1) is provided with a number of supporting ribs (1-6) along the length direction. The supporting ribs (1-6) are circular structures parallel to the cross section of the cover (1). The center of the supporting ribs (1-6) is provided with a through hole for the flexible shaft (2-5) to pass through and to support the flexible shaft (2-5).

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