Stepping type straightening equipment for large-diameter thin-wall seamless steel pipe and straightening application

Abstract

The invention discloses stepping type straightening equipment for a large-diameter thin-wall seamless steel pipe and straightening application, and belongs to the technical field of steel pipe straightening. The device comprises a base, a support A, a support B and a support C, the support A, the support B and the support C are arranged on the base, power shafts A are rotationally arranged on the support A and the support B respectively, sleeves A are arranged on the power shafts A in a sleeving mode, a plurality of inner straightening assemblies distributed in an axial symmetry mode are arranged on the periphery of the sleeves A through inner roller radial telescopic assemblies, and each inner straightening assembly comprises an inner roller frame, an inner roller shaft, an inner straightening roller and a movable plug pin A; a sleeve B is rotationally arranged on the support C, a mounting frame B is arranged on the sleeve B in a sleeving mode, a plurality of outer straightening assemblies distributed in an axial symmetry mode are arranged on the mounting frame B through an outer roller radial telescopic mechanism, and each outer straightening assembly comprises an outer roller frame, an outer roller shaft, an outer straightening roller and a movable plug pin B. The straightening equipment is reasonable in structure, has friction force mode switching and internal and external double straightening modes, and can be used for straightening the large-diameter thin-wall steel pipe.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the technical field of steel pipe straightening, in particular to a step-by-step straightening equipment for large-diameter thin-wall seamless steel pipes and a straightening application. BACKGROUND

[0002] Seamless steel pipes have excellent mechanical properties due to the absence of welds and can be used as important fluid conveying channels. However, after heat treatment, the seamless steel pipes inevitably exhibit significant local bending deformation and significant end "gooseneck" phenomenon, so the steel pipes need to be straightened after production. In the prior art, there are two straightening modes for steel pipes: one is a die straightening mode, which uses upper and lower dies consistent with the outer diameter size of the steel pipe for straightening. This straightening method is simple and practical, but the upper and lower dies need to be replaced frequently to adapt to steel pipes of different diameters. The other is a straightening roller straightening mode, which uses a pair of upper and lower straightening rollers. According to the relationship between the axis of the upper and lower straightening rollers and the axis of the steel pipe, it is divided into oblique roller straightening and normal roller straightening. In normal roller straightening, the axis of the straightening roller is perpendicular to the axis of the steel pipe, and the seamless steel pipe does not move along its own axis direction during straightening. In oblique roller straightening, the axis of the straightening roller is oblique to the axis of the steel pipe, and automatic conveying of the seamless steel pipe can also be achieved during straightening. Although the existing technology realizes external straightening of the seamless steel pipe, it is usually suitable for small-diameter steel pipes or back wall steel pipes, because: 1. The existing die straightening mode cannot be used for die straightening of large-diameter thin-wall steel pipes due to the limitation of die length and inner diameter size; 2. The existing straightening roller straightening mode cannot make ring straightening around the circumference of the steel pipe because the axis of the straightening roller is not coplanar with the axis of the steel pipe, i.e. there is a missed straightening position; 3. The existing straightening roller straightening mode cannot completely eliminate the "gooseneck" effect at the end of the thin-wall steel pipe. Therefore, there is an urgent need to design a straightening equipment suitable for large-diameter thin-wall steel pipes. SUMMARY

[0003] The technical problem to be solved by the present application is that, in view of the technical problems existing in the prior art, the present application provides a straightening equipment with reasonable structure, friction force mode switching and internal and external double straightening mode, which can be used for straightening of large-diameter thin-wall steel pipes.

[0004] In order to solve the above problems, the present application provides a large-diameter thin-walled seamless steel pipe stepping straightening equipment, which comprises a base, a support A fixedly arranged on the right end of the base, a support B elastically and slidably arranged on the left end of the base, a support C slidably arranged on the middle part of the base, coaxial power shafts A rotatably arranged on the supports A and B, sleeves A slidably sleeved on the power shafts A, a plurality of axisymmetric inner straightening assemblies arranged on the periphery of the sleeves A through inner roller radial expansion and contraction assemblies, a plurality of inner straightening assemblies having the same structure, each comprising an inner roller frame arranged on the inner roller radial expansion and contraction assembly, an inner roller shaft rotatably arranged on the inner roller frame, an inner straightening roller fixedly arranged on the inner roller shaft for supporting and straightening the inner wall of the steel pipe, and a movable bolt A slidably arranged on the inner roller frame for prohibiting or allowing the inner straightening roller to rotate.

[0005] A sleeve B is rotatably arranged on the support C, coaxial with the power shaft A and allowing the steel pipe to pass through the inside of the sleeve B, an installation frame B is fixedly sleeved on the sleeve B, and a plurality of axisymmetric outer straightening assemblies are arranged on the installation frame B through outer roller radial expansion and contraction mechanisms; the plurality of outer straightening assemblies have the same structure, each comprising an outer roller frame arranged on the outer roller radial expansion and contraction mechanism, an outer roller shaft rotatably arranged on the outer roller frame, an outer straightening roller fixedly arranged on the outer roller shaft for straightening the outer wall of the steel pipe, and a movable bolt B slidably arranged on the outer roller frame for prohibiting or allowing the outer straightening roller to rotate.

[0006] The present application further comprises a motor A for driving the power shaft A to rotate, a built-in axial power assembly arranged on the power shaft A for driving the sleeve A to slide axially along the power shaft A, an outer roller revolution power assembly arranged on the support C for driving the sleeve B to rotate, and an outer roller radial expansion and contraction power assembly arranged on the installation frame B for providing power for the operation of the outer roller radial expansion and contraction mechanism.

[0007] The inner roller radial expansion and contraction assembly is used for driving the plurality of inner straightening assemblies to move radially and synchronously along the steel pipe, and the outer roller radial expansion and contraction mechanism is used for driving the plurality of outer straightening assemblies to move radially and synchronously along the steel pipe.

[0008] Further, the inner roller radial telescopic assembly comprises: a mounting frame A sleeved on the power shaft A and fixedly connected with the sleeve A, a plurality of bidirectional screws rotatably mounted on the mounting frame A in parallel with the power shaft A and axially symmetrically distributed, a left-handed nut block and a right-handed nut block threadedly sleeved on the bidirectional screws in left-handed and right-handed modes respectively, a connecting rod A having two ends respectively hingedly connected with the inner roller frame and the left-handed nut block, a connecting rod B having two ends respectively hingedly connected with the inner roller frame and the right-handed nut block, a synchronous wheel A fixedly mounted on the end of the bidirectional screw, a ring gear A sleeved on the outside of the power shaft A and internally meshed with the synchronous wheel A, and a motor B mounted on the mounting frame A and used for driving the bidirectional screw to rotate; the number of the bidirectional screws is equal to the number of the inner straightening assembly, and the connecting rod A and the connecting rod B of each pair are in a splayed structure; the left-handed nut block and the right-handed nut block of each pair are axially slidably mounted on the outer wall of the sleeve A.

[0009] Further, the built-in axial power assembly comprises a mounting disc and an electric telescopic rod, the mounting disc is fixedly sleeved on the power shaft A, and the two ends of the electric telescopic rod are respectively connected with the mounting disc and the mounting frame A.

[0010] Further, the outer roller radial telescopic mechanism comprises: a plurality of ball screws rotatably mounted on the mounting frame B in parallel with the steel pipe and axially symmetrically distributed, a guide rod fixedly mounted on the mounting frame B at one end and slidably penetrating the outer roller frame at the other end in the radial direction, a bevel gear A fixedly mounted on the ball screw, a plurality of power shafts B rotatably mounted on the mounting frame B in parallel with the axis of the steel pipe and axially symmetrically distributed, and a bevel gear B fixedly mounted on the power shaft B and externally meshed with the bevel gear A and a synchronous wheel B internally meshed with a ring gear B; the ring gear B is sleeved on the outside of the sleeve B, and the end of the ball screw close to the steel pipe penetrates the outer roller frame in a spiral manner.

[0011] Further, the outer roller radial telescopic power assembly comprises: a power shaft D rotatably mounted on the mounting frame B, a driving wheel fixedly mounted on the power shaft D and internally meshed with the ring gear B, and a motor D mounted on the mounting frame B and having an output shaft connected with the power shaft D.

[0012] Further, the outer roller revolution power assembly comprises: a cylindrical gear A fixedly mounted on the sleeve B, a power shaft C rotatably mounted on the support C, a cylindrical gear B fixedly mounted on the power shaft C and in meshing transmission with the cylindrical gear A, and a motor C mounted on the support C and having an output shaft connected with the power shaft C.

[0013] Further, the application further comprises: a limiting plate fixedly arranged on the base, limiting springs connected with the support B and the limiting plate respectively at two ends, a linear guide rail fixedly arranged on the base and parallel to the axis of the power shaft A, a sliding block A and a sliding block B slidingly arranged on the linear guide rail, and a linear driving mechanism driving the linear motion of the sliding block B; the support B is fixedly connected with the sliding block A, and the support C is fixedly connected with the sliding block B.

[0014] Another aspect of the application is to apply the above straightening device to the straightening operation of steel pipes, and the objects of the straightening operation include but are not limited to seamless steel pipes, seamed steel pipes, thin-walled steel pipes and back-walled steel pipes.

[0015] Compared with the prior art, the application has the following advantages and beneficial effects: the large-diameter thin-walled seamless steel pipe step-type straightening device of the application is provided with inner straightening assemblies and outer straightening assemblies capable of switching the friction state and the working state, when the inner straightening assemblies are in the rolling friction state and the inner straightening state, and the outer straightening assemblies are in the sliding friction state and the outer straightening state, the outer straightening rollers play the role of fixing and supporting the steel pipe, and the inner straightening rollers can straighten the end part and the vicinity of the end part of the steel pipe; when the inner straightening assemblies are in the sliding friction state and the inner straightening state, and the outer straightening assemblies are in the rolling friction state and the outer straightening state, the inner straightening rollers play the role of fixing and supporting the steel pipe, and the outer straightening rollers can straighten the outer wall of the steel pipe; when the outer straightening assemblies are in the outer contraction state, the linear driving mechanism can drive the support C and the outer straightening assemblies to move step by step, so as to straighten the whole length of the steel pipe step by step; the support B is elastically and slidingly installed on the base, so as to provide axial flexibility for the straightening process of the steel pipe from bending to straightening. Therefore, the application is a straightening device with reasonable structure, friction force mode switching and inner-outer double straightening mode, and can be used for straightening large-diameter thin-walled steel pipes. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural principle schematic diagram of the large-diameter thin-walled seamless steel pipe step-type straightening device of the application.

[0017] Figure 2 is Figure 1 is a partial enlarged view of part A in the figure.

[0018] Figure 3 is Figure 1 is a partial enlarged view of part B in the figure.

[0019] Figure 4 is a relative position schematic diagram of the meshing transmission of the synchronous wheel B, the driving wheel and the inner gear ring B of the application.

[0020] In the figure, 10 - steel pipe; 11 - base; 12 - support A; 13 - support B; 14 - support C; 15 - power shaft A; 16 - sleeve A; 17 - sleeve B; 18 - motor A; 19 - mounting frame B; 21 - inner roller frame; 22 - inner roller shaft; 23 - inner straightening roller; 31 - outer roller frame; 32 - outer roller shaft; 33 - outer straightening roller; 41 - mounting frame A; 42 - bidirectional screw; 43 - left-handed nut block; 44 - right-handed nut block; 45 - connecting rod A; 46 - connecting rod B; 47 - synchronous wheel A; 48 - inner ring A; 49 - motor B; 51 - mounting disc; 52 - electric telescopic rod; 61 - inner ring B; 62 - ball screw; 63 - guide rod; 64 - bevel gear A; 65 - bevel gear B; 66 - power shaft B; 67 - synchronous wheel B; 71 - cylindrical gear A; 72 - cylindrical gear B; 73 - power shaft C; 74 - motor C; 75 - power shaft D; 76 - driving wheel; 77 - sliding block A; 78 - sliding block B; 81 - limit spring; 82 - limit plate. DETAILED DESCRIPTION

[0021] The application will be further described in detail below in combination with the drawings and specific examples. For the convenience of description, the large-diameter thin-walled seamless steel pipe to be straightened is denoted as steel pipe 10, the state of the inner straightening assembly when the several inner straightening rollers 23 are not in contact with the inner wall of the steel pipe 10 is denoted as the inner contraction state of the inner straightening assembly, the state of the inner straightening assembly when the several inner straightening rollers 23 are in contact with the inner wall of the steel pipe 10 is denoted as the inner straightening state of the inner straightening assembly, the state of the outer straightening assembly when the several outer straightening rollers 33 are not in contact with the outer wall of the steel pipe 10 is denoted as the outer contraction state of the outer straightening assembly, and the state of the outer straightening assembly when the several outer straightening rollers 33 are in contact with the outer wall of the steel pipe 10 is denoted as the outer straightening state of the outer straightening assembly.

[0022] As Figures 1 to 4As shown, the step type straightening equipment for large-diameter thin-wall seamless steel pipe of the present application comprises a base 11, a support A 12 fixedly arranged on the right end of the base 11, a support B 13 elastically and slidably arranged on the left end of the base 11, a support C 14 slidably arranged on the middle part of the base 11, coaxial power shafts A 15 rotatably arranged on the supports A 12 and B 13, sleeve A 16 slidably arranged on the power shafts A 15, a plurality of axisymmetric inner straightening assemblies arranged around the sleeve A 16 through inner roller radial expansion and contraction assemblies, a plurality of inner straightening assemblies having the same structure, each comprising an inner roller frame 21 arranged on the inner roller radial expansion and contraction assembly, an inner roller shaft 22 rotatably arranged on the inner roller frame 21, an inner straightening roller 23 fixedly arranged on the inner roller shaft 22 for supporting and straightening the inner wall of the steel pipe 10, and a movable bolt A (not shown in the figure) slidably arranged on the inner roller frame 21 for prohibiting or allowing the inner straightening roller 23 to rotate, a sleeve B 17 rotatably arranged on the support C 14 and allowing the steel pipe 10 to pass through, a mounting bracket B 19 fixedly arranged on the sleeve B 17, a plurality of axisymmetric outer straightening assemblies arranged on the mounting bracket B 19 through outer roller radial expansion and contraction mechanisms, a plurality of outer straightening assemblies having the same structure, each comprising an outer roller frame 31 arranged on the outer roller radial expansion and contraction mechanism, an outer roller shaft 32 rotatably arranged on the outer roller frame 31, an outer straightening roller 33 fixedly arranged on the outer roller shaft 32 for straightening the outer wall of the steel pipe 10, and a movable bolt B (not shown in the figure) slidably arranged on the outer roller frame 31 for prohibiting or allowing the outer straightening roller 33 to rotate. As a preferred embodiment, a limiting plate 82 is further fixedly arranged on the base 11, the limiting plate 82 and the support B 13 are connected with the two ends of a limiting spring 81 respectively, the limiting spring 81 provides rigidity for the support B 13 along the axis direction of the steel pipe 10, so that the inner straightening assembly in the inner contraction state can move along the axial direction of the power shaft A 15 inside the steel pipe 10; a straight line guide rail (not shown in the figure) parallel to the axis of the power shaft A 15 is fixedly arranged on the base 11, a sliding block A 77 and a sliding block B 78 are slidably arranged on the straight line guide rail (not shown in the figure), the support B 13 is fixedly connected with the sliding block A 77, the support C 14 is fixedly connected with the sliding block B 78, and a straight line driving mechanism (not shown in the figure) is arranged on the base 11 for driving the sliding block B 78 and the support C 14 to move linearly. The combination of the sliding block A 77 and the limiting spring 81 can provide flexibility for the support B 13 along the axis direction of the steel pipe 10, so that the steel pipe 10 in the outer straightening state can slightly move horizontally at the left end when it is straightened from being bent.In specific implementation, the number of power shafts A15 is two, the number of sleeves A16 is two, and the number of inner roller radial telescopic assemblies is two; the two sleeves A16 are respectively sleeved on the two power shafts A15, and the two inner roller radial telescopic assemblies are respectively arranged on the two sleeves A16; as an embodiment one, one set of inner straightening assemblies is composed of three sets of inner straightening assemblies which are axially symmetrically distributed; as an embodiment two, one set of inner straightening assemblies is composed of four sets of inner straightening assemblies which are axially symmetrically distributed. In specific use, the two sets of inner straightening assemblies are respectively arranged in the steel pipe 10 from both ends of the steel pipe 10; the inner straightening roller 23 is provided with a plurality of pin holes A corresponding to the movable pin A (not shown in the figure), when the end of the movable pin A (not shown in the figure) is inserted into the pin hole A, the inner straightening roller 23 is in the "inhibit rotation" state, so that the friction between the inner straightening assembly in the inner straightening state and the inner wall of the steel pipe 10 is sliding friction; when the end of the movable pin A (not shown in the figure) is away from the pin hole A, the inner straightening roller 23 is in the "allow rotation" state, so that the friction between the inner straightening assembly in the inner straightening state and the inner wall of the steel pipe 10 is rolling friction. The outer straightening roller 33 is provided with a plurality of pin holes B corresponding to the movable pin B (not shown in the figure), when the end of the movable pin B (not shown in the figure) is inserted into the pin hole B, the outer straightening roller 33 is in the "inhibit rotation" state, so that the friction between the outer straightening assembly in the outer straightening state and the outer wall of the steel pipe 10 is sliding friction; when the end of the movable pin B (not shown in the figure) is away from the pin hole B, the outer straightening roller 33 is in the "allow rotation" state, so that the friction between the outer straightening assembly in the outer straightening state and the outer wall of the steel pipe 10 is sliding friction.

[0023] Referring to Figure 1 and Figure 4, The application also comprises a motor A18 for driving the rotation of the power shaft A15, an internal axial power assembly arranged on the power shaft A15 for driving the sleeve A16 to slide along the power shaft A15 in the axial direction, an outer roller revolution power assembly arranged on the support C14 for driving the sleeve B17 to rotate, and an outer roller radial expansion power assembly arranged on the mounting frame B19 for providing power for the operation of the outer roller radial expansion mechanism. As a preferred embodiment, the internal axial power assembly comprises a mounting disc 51 fixedly sleeved on the power shaft A15 and an electric telescopic rod 52, the two ends of which are connected with the mounting disc 51 and the mounting frame A41 respectively. The outer roller radial expansion power assembly comprises a power shaft D75 rotatably arranged on the mounting frame B19, a driving wheel 76 fixedly arranged on the power shaft D75 and internally meshed with the internal gear ring B61, and a motor D (not shown in the figure) arranged on the mounting frame B19, the output shaft of which is connected with the power shaft D75. The outer roller revolution power assembly comprises a cylindrical gear A71 fixedly arranged on the sleeve B17, a power shaft C73 rotatably arranged on the support C14, a cylindrical gear B72 fixedly arranged on the power shaft C73 and meshed with the cylindrical gear A71 for transmission, and a motor C74 fixedly arranged on the support C14, the output shaft of which is connected with the power shaft C73. In a specific implementation, the number of the motor A18 is two, the two motors A18 are arranged on the support B13 and the support A12 respectively, and the output shafts of the two motors A18 are respectively connected with the two power shafts A15 for transmission. The number of the internal axial power assembly is two, the two internal axial power assemblies are arranged on the two power shafts A15 respectively, and the movable ends of the two electric telescopic rods 52 are respectively connected with the two mounting frames A41. In a specific use, the internal straightening assembly is first brought into an internal contraction state, i.e. the internal straightening roller 23 is separated from the inner wall of the steel pipe 10, and then the internal axial power assembly is started. After the internal axial power assembly is started, the movable end of the electric telescopic rod 52 in the internal axial power assembly extends outward, pushes the mounting frame A41 to move along the axial direction of the power shaft A15 towards the direction of approaching the central part of the steel pipe 10, the movable end of the electric telescopic rod 52 in the internal axial power assembly retracts inward, pulls the mounting frame A41 to move along the axial direction of the power shaft A15 towards the direction of moving away from the central part of the steel pipe 10, and the support B13 is rigidly constrained by the limiting spring 81 in the process of extension and retraction of the movable end of the electric telescopic rod 52, i.e. the support B13 is static relative to the base 11 under the action of the limiting spring 81. The outer straightening assembly is first brought into an outer straightening state, i.e. the outer straightening roller 33 abuts against the outer wall of the steel pipe 10, and then the outer roller revolution power assembly is started. The motor C74 in the outer roller revolution power assembly drives the power shaft C73 to rotate, the cylindrical gear B72 drives the cylindrical gear A71 to rotate, the sleeve B17 fixedly connected with the cylindrical gear A71 rotates around the axis of the steel pipe 10, and the plurality of outer straightening assemblies straighten the steel pipe 10 from the outside of the steel pipe 10.The motor D (not shown in the figure) in the outer roller radial telescopic power assembly drives the power shaft D75 to rotate forward, and the driving wheel 76 drives the inner ring gear B61 in the outer roller radial telescopic mechanism to rotate forward. The motor D (not shown in the figure) in the outer roller radial telescopic power assembly drives the power shaft D75 to rotate reversely, and the driving wheel 76 drives the inner ring gear B61 in the outer roller radial telescopic mechanism to rotate reversely.

[0024] Referring to Figure 1 and Figure 3, the inner roller radial telescopic assembly is used to drive several inner straightening assemblies to move synchronously in the radial direction of the steel pipe 10; as preferred, the inner roller radial telescopic assembly comprises a mounting frame A41 sleeved on the power shaft A15 and fixedly connected with the sleeve A16, several bidirectional screws 42 rotatably mounted on the mounting frame A41 in parallel with the power shaft A15 and symmetrically distributed in the axial direction, a left-handed nut block 43 and a right-handed nut block 44 respectively threadedly sleeved on the bidirectional screws 42 in the left-handed and right-handed modes, a connecting rod A45 having two ends respectively hingedly connected to the inner roller frame 21 and the left-handed nut block 43, a connecting rod B46 having two ends respectively hingedly connected to the inner roller frame 21 and the right-handed nut block 44, a synchronous wheel A47 fixedly mounted on the end of the bidirectional screw 42, an internal gear ring A48 sleeved on the outside of the power shaft A15 and internally meshed with the synchronous wheel A47, and a motor B49 mounted on the mounting frame A41 and used to drive the bidirectional screw 42 to rotate; the number of the bidirectional screws 42 is equal to the number of the inner straightening assemblies, and the connecting rod A45 and the connecting rod B46 are in the shape of an eight-character; the left-handed nut block 43 and the right-handed nut block 44 are axially slidably mounted on the outer wall of the sleeve A16. In the specific implementation, each bidirectional screw 42 is provided with a nut pair composed of the left-handed nut block 43 and the right-handed nut block 44, each inner roller frame 21 is provided with a connecting rod pair composed of the connecting rod A45 and the connecting rod B46, the large end of the connecting rod pair faces the power shaft A15, and the number of the connecting rod pair is equal to the number of the nut pair; each bidirectional screw 42 is provided with a synchronous wheel A47 at the end thereof, and the output shaft of the motor B49 is drivingly connected with one of the bidirectional screws 42. In the specific use, the motor B49 in the inner roller radial telescopic assembly drives one of the bidirectional screws 42 to rotate in the forward direction, the synchronous wheel A47 fixedly mounted on the bidirectional screw 42 drives the internal gear ring A48 meshed with the synchronous wheel A47 to rotate in the forward direction, and the internal gear ring A48 drives the remaining synchronous wheels A47 in the inner roller radial telescopic assembly to rotate in the forward direction, so that all the bidirectional screws 42 in the inner roller radial telescopic assembly synchronously rotate in the forward direction. Since the left-handed nut block 43 and the right-handed nut block 44 can only slide in the axial direction of the sleeve A16, the left-handed nut block 43 and the right-handed nut block 44 move close to each other, the corresponding connecting rod pairs drive the corresponding inner straightening assemblies to move in the radial direction of the steel pipe 10 and away from the inner wall of the steel pipe 10 in the centrifugal direction until the inner straightening rollers 23 abut against the inner wall of the steel pipe 10, at which time the inner straightening assemblies change from the inner contraction state to the inner straightening state. According to the similar working principle, the motor B49 in the inner roller radial telescopic assembly drives one of the bidirectional screws 42 to rotate in the reverse direction, all the bidirectional screws 42 in the inner roller radial telescopic assembly synchronously rotate in the reverse direction, the left-handed nut block 43 and the right-handed nut block 44 move away from each other, and the inner straightening assemblies move in the radial direction of the steel pipe 10 and toward the inner wall of the steel pipe 10 in the centripetal direction until the inner straightening rollers 23 are separated from the inner wall of the steel pipe 10, at which time the inner straightening assemblies change from the inner straightening state to the inner contraction state.

[0025] Referring toFigure 1 and Figure 2 The outer roller radial telescoping mechanism is used to drive the several outer straightening assemblies to move synchronously along the radial direction of the steel pipe 10. As preferred, the outer roller radial telescoping mechanism comprises: several ball screws 62 which are arranged on the mounting frame B19 in an axis-symmetrical manner and rotate along the radial direction of the steel pipe 10, a guide rod 63 which is fixedly arranged on the mounting frame B19 at one end and slides through the outer roller frame 31 at the other end along the radial direction, a bevel gear A 64 which is fixedly arranged on the ball screw 62, several power shafts B 66 which are arranged on the mounting frame B19 in an axis-symmetrical manner and rotate parallel to the axis of the steel pipe 10, and a bevel gear B 65 which is fixedly arranged on the power shaft B 66 and externally engages with the bevel gear A 64, and a synchronous wheel B 67 which internally engages with the inner ring B 61; the inner ring B 61 is sleeved on the outside of the sleeve B 17, and the ball screw 62 spirally passes through the outer roller frame 31 at the end close to the steel pipe 10. In the specific implementation, the number of the ball screws 62 is equal to the number of the outer straightening assemblies. In the specific use, the outer roller radial telescoping power assembly drives the inner ring B 61 in the outer roller radial telescoping mechanism to rotate forward, the inner ring B 61 drives the several synchronous wheels B 67 to rotate forward synchronously, the bevel gear B 65 drives the bevel gear A 64 to rotate, the ball screw 62 rotates forward, the outer roller frame 31 moves along the radial direction of the steel pipe 10 under the action of the guide rod 63 and moves centripetally towards the outer wall of the steel pipe 10, until the outer straightening roller 33 in the outer straightening assembly abuts against the outer wall of the steel pipe 10, that is, the outer straightening assembly changes from the outer telescoping state to the outer straightening state; the outer roller radial telescoping power assembly drives the inner ring B 61 in the outer roller radial telescoping mechanism to rotate reversely, the inner ring B 61 drives the several synchronous wheels B 67 to rotate reversely synchronously, the bevel gear B 65 drives the bevel gear A 64 to rotate, the ball screw 62 rotates reversely, the outer roller frame 31 moves along the radial direction of the steel pipe 10 under the action of the guide rod 63 and moves centrifugally away from the outer wall of the steel pipe 10, until the outer straightening roller 33 in the outer straightening assembly is separated from the outer wall of the steel pipe 10 and returns to the initial position, that is, the outer straightening assembly changes from the outer straightening state to the outer telescoping state.

[0026] The above straightening equipment is applied to the straightening operation of the steel pipe, and the objects of the straightening operation are, for example, seamless steel pipes, jointed steel pipes, thin-walled steel pipes and rear wall steel pipes.

[0027] The working process and working principle of the present application are as follows: First step, preparation: by pulling the support B13 away from the support A12, the steel pipe 10 is placed between the support B13 and the support A12 by means of the tool commonly used in the prior art, the support B13 is loosened until it returns to the initial state, and the inner straightening assembly is entirely located inside the steel pipe 10, and the outer straightening assembly is entirely located outside the steel pipe assembly; the support C14 is driven to move to the right end of the steel pipe 10 by the linear drive mechanism (not shown in the figure), the inner straightening assembly is switched to the inner straightening state by the inner roller radial telescopic assembly, and the outer straightening assembly is switched to the outer straightening state by the outer roller radial telescopic mechanism. The inner straightening roller 23 is switched to the "allowed to rotate" state by using the movable bolt A (not shown in the figure), and the outer straightening roller 33 is switched to the "inhibited to rotate" state by using the movable bolt B (not shown in the figure).

[0028] Second step, removing "goose head bend" at both ends: the two motors A18 drive the two power shafts A15 to rotate in opposite directions, thereby driving the left and right end of the plurality of axisymmetrically distributed inner straightening assemblies to rotate in opposite directions around the axis of the power shaft A15, and the end straightening is performed from the inside of the steel pipe 10 to remove the "goose head bend" at the end.

[0029] Third step, removing "goose head bend" near both ends: the inner straightening assembly is switched to the inner contraction state, the two built-in axial power assemblies drive the two mounting frames A41 to slide a certain distance, which is slightly less than the axial length of the inner straightening roller 23, the inner straightening assemblies at both ends are close to each other, and then the inner straightening assembly is switched to the inner straightening state; repeat the second step to remove the "goose head bend" near the end of the steel pipe 10.

[0030] Fourth step, friction mode switching: the inner straightening roller 23 is switched to the "inhibited to rotate" state by using the movable bolt A (not shown in the figure), and the friction between the inner straightening assembly and the inner wall of the steel pipe 10 is sliding friction; the outer straightening roller 33 is switched to the "allowed to rotate" state by using the movable bolt B (not shown in the figure), and the friction between the outer straightening assembly and the outer wall of the steel pipe 10 is rolling friction.

[0031] Fifth step, external partial straightening: the outer roller revolves power assembly drives a plurality of outer straightening rollers 33 to revolve around the axis of the steel pipe 10, and the steel pipe 10 is partially straightened from the outside.

[0032] Sixth step, step-by-step movement: the outer straightening assembly is switched to the outer contraction state, the support C14 is driven to move a certain distance to the left by the linear drive mechanism (not shown in the figure), which is slightly less than the length of the outer straightening roller 33, and then the outer straightening assembly is switched to the outer straightening state.

[0033] Seventh step, step-by-step straightening: repeat the fifth step to perform position-changing partial straightening from the outside of the steel pipe 10.

[0034] The sixth and seventh steps are repeated until the outer wall of the steel pipe 10 is straightened. During the straightening process, the support B13 is elastically slidably arranged on the base 11, so that the steel pipe 10 can be easily straightened from the bend. During the process of removing the "goose head bend", the friction between the inner straightening assembly and the inner wall of the steel pipe 10 is rolling friction, and the friction between the outer straightening assembly and the outer wall of the steel pipe 10 is sliding friction. Since the sliding friction is much greater than the rolling friction, and the rotating directions of the two power shafts A15 at both ends of the steel pipe 10 are opposite, the steel pipe 10 will not rotate. During the outer straightening process, the friction between the inner straightening assembly and the inner wall of the steel pipe 10 is sliding friction, and the friction between the outer straightening assembly and the outer wall of the steel pipe 10 is rolling friction, so the steel pipe 10 will not rotate.

[0035] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any changes or substitutions without creative labor should belong to the protection scope of the present application.

Claims

1. A step-type straightening device for large-diameter thin-walled seamless steel pipes, comprising a base (11) and a bracket A (12) fixedly mounted on the right end of the base (11); characterized in that: The base (11) is elastically slidably equipped with a bracket B (13) at its left end and a bracket C (14) at its middle. Both the bracket A (12) and the bracket B (13) are rotatably equipped with a coaxial power shaft A (15). A sleeve A (16) is slidably sleeved on the power shaft A (15). Several axisymmetrically distributed inner straightening components are installed around the sleeve A (16) through the inner roller radial telescopic assembly. The several inner straightening components have the same structure and include: an inner roller frame (21) installed on the inner roller radial telescopic assembly, an inner roller shaft (22) rotatably installed on the inner roller frame (21), an inner straightening roller (23) fixedly installed on the inner roller shaft (22) for supporting and straightening the inner wall of the steel pipe (10), and a movable pin A slidably installed on the inner roller frame (21) for prohibiting or allowing the inner straightening roller (23) to rotate. The bracket C (14) is rotatably mounted with a sleeve B (17) that is coaxial with the power shaft A (15) and allows the steel pipe (10) to pass through. The sleeve B (17) is fixedly mounted with a mounting frame B (19). The mounting frame B (19) is mounted with a plurality of axially symmetrically distributed external straightening components through an external roller radial telescopic mechanism. The plurality of external straightening components have the same structure and each includes: an external roller frame (31) mounted on the external roller radial telescopic mechanism, an external roller shaft (32) rotatably mounted on the external roller frame (31), an external straightening roller (33) fixedly mounted on the external roller shaft (32) for straightening the outer wall of the steel pipe (10), and a movable pin B slidably mounted on the external roller frame (31) for prohibiting or allowing the external straightening roller (33) to rotate. It also includes: a motor A (18) for driving the power shaft A (15) to rotate, a built-in axial power assembly mounted on the power shaft A (15) for driving the sleeve A (16) to slide along the axial direction of the power shaft A (15), an outer roller revolution power assembly mounted on the bracket C (14) for driving the sleeve B (17) to rotate, and an outer roller radial extension power assembly mounted on the mounting frame B (19) to provide power for the operation of the outer roller radial extension mechanism; The inner roller radial telescopic assembly is used to drive several inner straightening assemblies to move synchronously along the radial direction of the steel pipe (10), and the outer roller radial telescopic mechanism is used to drive several outer straightening assemblies to move synchronously along the radial direction of the steel pipe (10).

2. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 1, characterized in that, The inner roller radial telescopic assembly includes: a mounting frame A (41) sleeved on the power shaft A (15) and fixedly connected to the sleeve A (16); a plurality of bidirectional lead screws (42) rotatably mounted on the mounting frame A (41) and distributed parallel to the power shaft A (15) and in an axisymmetric manner; left-handed nut blocks (43) and right-handed nut blocks (44) respectively threaded onto the bidirectional lead screws (42); connecting rods A (45) hinged at both ends to the inner roller frame (21) and the left-handed nut blocks (43); and connecting rods A (45) hinged at both ends to the inner roller frame (21) and the right-handed nut blocks (44). The connecting rod B (46), the synchronous wheel A (47) fixedly mounted on the end of the double-acting screw (42), the internal gear ring A (48) sleeved on the outside of the power shaft A (15) and meshing with the synchronous wheel A (47), and the motor B (49) mounted on the mounting bracket A (41) for driving the double-acting screw (42) to rotate; the number of double-acting screws (42) is equal to the number of the internal straightening components, and the paired connecting rods A (45) and connecting rods B (46) form an eight-shaped structure; the paired left-hand nut block (43) and right-hand nut block (44) are axially slidably mounted on the outer wall of the sleeve A (16).

3. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 2, characterized in that, The built-in axial power assembly includes a mounting plate (51) and an electric telescopic rod (52). The mounting plate (51) is fixedly sleeved on the power shaft A (15), and the two ends of the electric telescopic rod (52) are respectively connected to the mounting plate (51) and the mounting bracket A (41).

4. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 1, characterized in that, The outer roller radial telescopic mechanism includes: a plurality of ball screws (62) rotatably mounted on the mounting frame B (19) along the radial direction of the steel pipe (10) and symmetrically distributed; a guide rod (63) with one end fixedly mounted on the mounting frame B (19) and the other end sliding radially through the outer roller frame (31); a bevel gear A (64) fixedly mounted on the ball screws (62); a plurality of power shafts B (66) rotatably mounted on the mounting frame B (19) parallel to the axis of the steel pipe (10) and symmetrically distributed; a bevel gear B (65) fixedly mounted on the power shaft B (66) and meshing externally with the bevel gear A (64); and a synchronous wheel B (67) meshing internally with the internal gear ring B (61); the internal gear ring B (61) is sleeved on the outside of the sleeve B (17); and the end of the ball screw (62) near the steel pipe (10) spirally passes through the outer roller frame (31).

5. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 4, characterized in that, The outer roller radial telescopic power assembly includes: a power shaft D (75) rotatably mounted on the mounting frame B (19), a drive wheel (76) fixedly mounted on the power shaft D (75) and meshing with the internal gear ring B (61), and a motor D mounted on the mounting frame B (19) whose output shaft is connected to the power shaft D (75).

6. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 4, characterized in that, The outer roller revolution power assembly includes: a cylindrical gear A (71) fixedly mounted on the sleeve B (17), a power shaft C (73) rotatably mounted on the bracket C (14), a cylindrical gear B (72) fixedly mounted on the power shaft C (73) and meshing with the cylindrical gear A (71), and a motor C (74) fixedly mounted on the bracket C (14) with its output shaft connected to the power shaft C (73).

7. The step-type straightening device for large-diameter thin-walled seamless steel pipes according to claim 1, characterized in that, Also includes: A limiting plate (82) is fixedly mounted on the base (11), a limiting spring (81) whose two ends are respectively connected to the bracket B (13) and the limiting plate (82), a linear guide rail is fixedly mounted on the base (11) and parallel to the axis of the power shaft A (15), a slider A (77) and a slider B (78) are slidably mounted on the linear guide rail, and a linear drive mechanism for driving the slider B (78) to move linearly; the bracket B (13) is fixedly connected to the slider A (77), and the bracket C (14) is fixedly connected to the slider B (78).

8. A straightening application, characterized in that: The step-type straightening device for large-diameter thin-walled seamless steel pipes as described in any one of claims 1-7 is applied to the straightening operation of seamless steel pipes.

Images