CN223210798U - Elbow assembly quality and workstation - Google Patents

Abstract

The utility model discloses an elbow assembling device which comprises a base, a fixed seat and a movable seat, wherein the fixed seat is fixedly connected to the base, the movable seat is connected to the base in a sliding mode along the X direction, the fixed seat is connected with an elbow clamping mechanism, the movable seat is connected with a straight pipe clamping mechanism, the elbow clamping mechanism comprises a first clamping assembly, a second clamping assembly and a Y-direction clamping driving device, the first clamping assembly comprises a first clamping frame and a first floating clamping jaw, the second clamping assembly comprises a second clamping frame and a second floating clamping jaw, the first clamping frame and the second clamping frame are respectively connected to one side of the fixed seat in a sliding mode along the Y direction, and the straight pipe clamping mechanism comprises a first three-jaw clamping assembly connected to one side of the movable seat.

Description

Elbow assembly quality and workstation

Technical Field

The utility model relates to the technical field of pipeline assembly, in particular to a bent pipe elbow assembly device and a workstation.

Background

In the process of installing and manufacturing a pipeline system, the butt joint assembly of the bent pipe and the straight pipe is a key link. The traditional assembly method mainly depends on manual operation, so that the efficiency is low, the assembly quality is easily affected by human factors, and the assembly precision and consistency are difficult to ensure. Particularly in large-scale assembly line operation, the traditional manual assembly mode can not meet the high-efficiency and accurate production requirements.

Currently, there are some devices on the market for pipe fitting, but most of these devices are designed for pipes of specific specifications and shapes, with poor versatility and flexibility. For elbows of different diameters and contoured surfaces, it is often difficult for conventional devices to achieve a stable and accurate grip, thereby affecting the quality and efficiency of the assembly. In addition, conventional devices may lack sufficient support during clamping, resulting in shifting or deformation of the pipe during assembly, further reducing the accuracy of the assembly.

Disclosure of utility model

The utility model aims to solve the problems in the prior art and provides an elbow assembly device and a workstation. Through adopting clamping component and the floating clamping jaw design that the symmetry set up, can adapt to the return bend on different diameters and profile surfaces, strengthened the commonality and the flexibility of device, realize return bend and straight tube's high-efficient, accurate butt joint, improved the degree of automation and the uniformity of pipeline assembly.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

The bent pipe elbow assembling device comprises a base, a fixed seat and a movable seat, wherein the fixed seat is fixedly connected to the base, the movable seat is connected to the base in a sliding mode along the X direction, the fixed seat is connected with a bent pipe clamping mechanism, the movable seat is connected with a straight pipe clamping mechanism, the bent pipe clamping mechanism comprises a first clamping assembly, a second clamping assembly and a Y-direction clamping driving device, the first clamping assembly comprises a first clamping frame and a first floating clamping jaw connected to the first clamping frame, the second clamping assembly comprises a second clamping frame and a second floating clamping jaw connected to the second clamping frame, the first clamping frame and the second clamping frame are respectively connected to one side of the fixed seat in a sliding mode along the Y direction, the Y-direction clamping driving device is used for driving the first clamping frame and the second clamping frame to be close to and far away from each other so as to clamp a bent pipe, and the straight pipe clamping mechanism comprises a first three-jaw assembly connected to one side of the movable seat and an outer wall used for radially clamping the straight pipe.

The first floating clamping jaw and the second floating clamping jaw comprise a clamp shell, one side of the clamp shell is outwards extended to be provided with a thimble array, the thimble array is composed of a plurality of thimbles which are uniformly distributed at intervals, the clamp shell is provided with an air cavity, the air cavity is connected with an external air source, and the thimbles are connected with the clamp shell through springs and are connected with the air cavity.

The first clamping frame is connected with two first floating clamping jaws, the second clamping frame is connected with two second floating clamping jaws, one pair of the first floating clamping jaws and the second floating clamping jaws are used for clamping the outer wall of the first end of the bent pipe, and the other pair of the first floating clamping jaws and the second floating clamping jaws are used for clamping the outer wall of the second end of the bent pipe, so that the bent pipe is in a side standing posture.

The Y-direction clamping driving device comprises a Y-direction screw rod, a shaft sleeve, a belt pulley assembly and a driving motor, wherein the Y-direction screw rod is rotatably connected to the fixing seat through the shaft sleeve, two sections of threads which are opposite in rotation direction are arranged on the Y-direction screw rod, the first clamping frame and the second clamping frame are respectively provided with threaded holes and are respectively connected with the two sections of threads of the Y-direction screw rod, one end of the Y-direction screw rod is connected with the belt pulley assembly, and the driving motor drives the Y-direction screw rod to rotate through driving the belt pulley assembly so as to achieve approaching and separating of the first clamping frame and the second clamping frame.

The elbow assembling workstation comprises the elbow assembling device, a feeding mechanical arm, and an elbow feeding clamp or a straight pipe feeding clamp connected to the tail end of the feeding mechanical arm, wherein the elbow feeding clamp is used for clamping an elbow and butting the elbow with the elbow clamping mechanism under the driving of the feeding mechanical arm, and the straight pipe feeding clamp is used for clamping a straight pipe and butting the straight pipe with the straight pipe clamping mechanism under the driving of the feeding mechanical arm.

The bent pipe feeding clamp comprises a clamp mounting seat connected to the tail end of the feeding mechanical arm, a three-jaw clamping assembly II and a three-jaw clamping assembly III which are respectively connected to the clamp mounting seat, wherein the three-jaw clamping assembly II is used for radially clamping the outer wall of the first end of the bent pipe, the three-jaw clamping assembly III comprises a first clamping cylinder, a second clamping cylinder and a third clamping cylinder which are respectively connected to the clamp mounting seat, the first clamping cylinder stretches into an inner hole of the second end of the bent pipe and is used for pushing the inner wall of the inner hole of the second end of the bent pipe, and the second clamping cylinder and the third clamping cylinder are symmetrically arranged on two sides of the first clamping cylinder and are respectively used for pushing the outer wall of the second end of the bent pipe.

Compared with the prior art, the utility model has the beneficial effects that:

1. the elbow assembly device and the workstation realize the efficient and accurate butt joint of the elbow and the straight pipe through accurate mechanical design and automatic control, and remarkably improve the assembly precision and consistency;

2. The floating clamping jaw in the device is designed to adapt to bent pipes with different diameters and profile surfaces, so that the device can clamp pipelines with various specifications and shapes, the universality and the flexibility of the device are enhanced, and the assembly requirements under different production scenes are met;

3. the thimble array in the floating clamping jaw is designed to be in close contact with the outer wall of the bent pipe, so that not only is Y-direction clamping force provided, but also Z-direction supporting force is provided, the stability and accuracy of clamping are enhanced, the bent pipe is ensured not to deviate or deform in the assembly process, and the assembly quality is ensured;

4. through introducing material loading arm and dedicated material loading anchor clamps, realized the automatic material loading and the butt joint of return bend and straight tube, reduced manual operation's degree of difficulty and intensity, improved the efficiency and the accuracy of assembly.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an assembly device according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing the overall structure of an assembling device according to an embodiment of the present application;

FIG. 3 is a schematic diagram illustrating a disassembly structure of an assembling device according to an embodiment of the present application;

FIG. 4 is a schematic diagram showing a disassembly structure of the elbow clamping mechanism according to an embodiment of the present application;

FIG. 5 is a schematic diagram of the overall construction of a workstation according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a bent pipe feeding fixture according to an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating a disassembly structure of a feeding clamp for bent pipes according to an embodiment of the application;

In the figure, 1, a base; 2, a fixed seat, 3, a movable seat, 4, a first clamping frame, 5, a first floating clamping jaw, 6, a second clamping frame, 7, a second floating clamping jaw, 8, a first three-jaw clamping assembly, 9, a Y-direction screw rod, 10, a belt pulley assembly, 11, a driving motor, 12, a feeding mechanical arm, 13, a bent pipe feeding clamp, 15, a clamp mounting seat, 16, a second three-jaw clamping assembly, 17, a third three-jaw clamping assembly, 18, a first clamping cylinder, 19, a second clamping cylinder and 20, a third clamping cylinder.

Detailed Description

The following description of the embodiments of the present utility model will be made more apparent and fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on embodiments of the present utility model, are within the scope of the present utility model.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in use of the inventive product, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, or may be directly connected, or may be indirectly connected through an intermediate medium, or may be in communication with the inside of two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In a first aspect of the present application, as shown in fig. 1 to 4, there is provided an elbow fitting device, comprising a base 1, a fixed seat 2 and a movable seat 3, wherein the fixed seat 2 is fixedly connected to the base 1, the movable seat 3 is slidably connected to the base 1 along an X direction, the fixed seat 2 is connected to an elbow clamping mechanism, the movable seat 3 is connected to a straight pipe clamping mechanism, the elbow clamping mechanism comprises a first clamping assembly and a second clamping assembly which are symmetrically arranged, and a Y-direction clamping driving device, the first clamping assembly comprises a first clamping frame 4, a first floating clamping jaw 5 connected to the first clamping frame 4, the second clamping assembly comprises a second clamping frame 6, and a second floating clamping jaw 7 connected to the second clamping frame 6, the first clamping frame 4 and the second clamping frame 6 are slidably connected to one side of the fixed seat 2 along the Y direction respectively, the Y-direction clamping driving device is used for driving the first clamping frame 4 and the second clamping frame 6 to approach and separate from each other to realize elbow clamping, and the clamping mechanism comprises a three-jaw clamping assembly 8 connected to one side of the movable seat for radially clamping an outer wall of a straight pipe.

Specifically, fixing base 2 connects return bend clamping mechanism, and movable seat 3 connects straight tube clamping mechanism, and both clamp return bend and straight tube respectively. The bent pipe clamping mechanism adopts a first clamping assembly and a second clamping assembly which are symmetrically arranged, and drives the first clamping assembly and the second clamping assembly to slide along the Y direction through the Y-direction clamping driving device, so that stable clamping of the bent pipe is realized. The straight pipe clamping mechanism radially clamps the outer wall of the straight pipe through the three-jaw clamping assembly, so that the stability of the straight pipe in the assembly process is ensured. When the movable seat is used, the bent pipe and the straight pipe are respectively placed in the corresponding clamping mechanisms to be clamped, then the axes of the bent pipe and the straight pipe are aligned through the preset positions, and finally the movable seat is controlled to move along the X direction, so that the precise butt joint of the bent pipe and the straight pipe is realized.

The application of the elbow assembly device realizes the efficient and accurate butt joint of the elbow and the straight pipe, remarkably reduces manual operation in the traditional assembly process, improves the assembly automation degree, ensures the assembly consistency of the elbow and greatly improves the assembly line operation efficiency.

The floating clamping jaw in the device is designed to adapt to bent pipes with different diameters and profile surfaces, so that the universality and the flexibility of the device are enhanced, and the clamping stability of the bent pipes is ensured.

In some embodiments, as shown in fig. 3 and 4, the first floating clamping jaw 5 and the second floating clamping jaw 7 each comprise a clamp housing, one side of the clamp housing extends outwards to form a thimble array, the thimble array is composed of a plurality of thimbles which are uniformly distributed at intervals, the clamp housing is provided with an air cavity, the air cavity is connected with an external air source, and the thimbles are connected with the clamp housing through springs and connected with the air cavity.

Specifically, the feeding mechanical arm firstly places the bent pipe between the two clamping assemblies, then the Y-direction clamping driving device drives the first clamping frame 4 and the second clamping frame 6 to be close to each other, after the thimble array contacts the outer wall of the bent pipe, the thimble retracts into the clamp shell along the contacted surface profile of the thimble array, so that the tight contact between the thimble array and the outer wall of the bent pipe is realized, then an external air source inflates the air cavity, and the thimble arrays at two sides of the bent pipe respectively generate pushing force to realize clamping. Because the thimble array is closely contacted along the outline of the outer wall of the bent pipe, the bent pipe has Y-direction clamping force and Z-direction supporting force, and the stability and the accuracy of clamping are enhanced. Due to the flexibility and adaptability of the thimble array, the device can clamp bent pipes with different diameters and shapes, and the universality of the device is improved. The clamping and releasing of the ejector pins are controlled by air pressure, so that the bent pipe is clamped rapidly and efficiently.

Preferably, the first floating clamping jaw 5 and the second floating clamping jaw 7 are pneumatic series pneumatic A type clamps of Suzhou Chassis open industry Intelligent Co.

In some embodiments, as shown in fig. 4, the first clamping frame 4 is connected to two first floating clamping jaws 5, the second clamping frame 6 is connected to two second floating clamping jaws 7, wherein one pair of the first floating clamping jaw 5 and the second floating clamping jaw 7 are used for clamping the outer wall of the first end of the bent pipe, and the other pair of the first floating clamping jaw 5 and the second floating clamping jaw 7 are used for clamping the outer wall of the second end of the bent pipe, so that the bent pipe is in a side standing posture.

Specifically, through adopting two pairs of floating clamping jaws to centre gripping return bend's both ends simultaneously, ensure that the return bend is the side attitude in the assembly process, more be convenient for dock with the straight tube, improved the efficiency and the success rate of assembly.

In some embodiments, as shown in fig. 4, two Y-direction slide rails are disposed on a side wall of one side of the fixing base 2, the first clamping frame 4 and the second clamping frame 6 are respectively connected to the Y-direction slide rails in a sliding manner, the Y-direction clamping driving device comprises a Y-direction screw rod 9, a shaft sleeve, a belt pulley assembly 10 and a driving motor 11, the Y-direction screw rod 9 is rotationally connected to the fixing base 2 through the shaft sleeve, two sections of threads with opposite rotation directions are disposed on the Y-direction screw rod 9, the first clamping frame 4 and the second clamping frame 6 are respectively provided with threaded holes and are respectively connected with two sections of threads of the Y-direction screw rod 9, one end of the Y-direction screw rod 9 is connected with the belt pulley assembly 10, and the driving motor 11 drives the Y-direction screw rod 9 to rotate through the driving belt pulley assembly 10, so that approaching and separating of the first clamping frame and the second clamping frame are achieved.

Specifically, when the driving motor is started, the driving motor drives the Y-direction screw rod to rotate through the belt pulley assembly, and because the Y-direction screw rod is provided with two sections of threads with opposite rotation directions, when the screw rod rotates, the first clamping frame 4 and the second clamping frame 6 can slide along the Y-direction sliding rail simultaneously but in opposite directions, so that the clamping or releasing of the bent pipe is completed. Through the guide of Y to the slide rail, ensured stability and the accuracy of first holder and second holder in the slip in-process. By utilizing the design of two sections of threads with opposite rotation directions of the Y-direction screw rod, the two clamping frames can move simultaneously but in opposite directions, and the bent pipe is ensured to be subjected to uniform and symmetrical clamping force in the clamping process.

In a second aspect of the present application, as shown in fig. 5 to 7, an elbow assembly workstation is provided, which comprises the elbow assembly device, and further comprises a feeding mechanical arm 12, and an elbow feeding clamp 13 or a straight pipe feeding clamp connected to the end of the feeding mechanical arm 12, wherein the elbow feeding clamp 13 is used for clamping an elbow and butting the elbow with an elbow clamping mechanism under the driving of the feeding mechanical arm 12, and the straight pipe feeding clamp is used for clamping a straight pipe and butting the straight pipe with the straight pipe clamping mechanism under the driving of the feeding mechanical arm 12.

Specifically, during operation, the loading arm 12 is configured to carry bent pipes and straight pipes from a loading area to an assembly area. When the bent pipe needs to be assembled, the bent pipe feeding clamp can clamp the bent pipe and accurately butt-joint the bent pipe into the bent pipe clamping mechanism under the driving of the feeding mechanical arm. Similarly, when the straight pipe needs to be assembled, the straight pipe feeding clamp can clamp the straight pipe, and the straight pipe is accurately butted into the straight pipe clamping mechanism under the guidance of the feeding mechanical arm, so that preparation is made for subsequent assembly and butt joint work.

By introducing the feeding mechanical arm 12 and the special feeding clamp, automatic feeding and butt joint of the bent pipe and the straight pipe are realized, the assembly efficiency and accuracy are improved, and the manual operation difficulty and strength are reduced. The feeding mechanical arm is used for feeding the steel pipe, so that the accuracy and the consistency of the bent pipe and the straight pipe in the butt joint process are ensured, and the quality and the stability of assembly are improved.

In some embodiments, as shown in fig. 6 and 7, the bent pipe feeding clamp 13 comprises a clamp mounting seat 15 connected to the tail end of the feeding mechanical arm 12, and a three-jaw clamping assembly two 16 and a three-jaw clamping assembly three 17 respectively connected to the clamp mounting seat 15, wherein the three-jaw clamping assembly two 16 is used for radially clamping the outer wall of the first end of the bent pipe, the three-jaw clamping assembly three 17 comprises a first clamping cylinder 18, a second clamping cylinder 19 and a third clamping cylinder 20 respectively connected to the clamp mounting seat 15, the first clamping cylinder 18 extends into the inner hole of the second end of the bent pipe and is used for pushing the inner wall of the inner hole of the second end of the bent pipe, and the second clamping cylinder 19 and the third clamping cylinder 20 are symmetrically arranged on two sides of the first clamping cylinder 18 and are respectively used for pushing the outer wall of the second end of the bent pipe.

Specifically, through the cooperation of the three-jaw clamping assembly II 16 and the three-jaw clamping assembly III 17, the omnibearing clamping of the bent pipe is realized, and the stability and the accuracy of the bent pipe in the feeding and abutting processes are ensured.

When the clamping operation starts, the three clamping cylinders are started simultaneously, the first clamping cylinder 18 applies force outwards, namely the piston rod of the first clamping cylinder stretches out to push the inner wall of the inner hole at the second end of the bent pipe to form a first stress point, meanwhile, the piston rods of the second clamping cylinder 19 and the third clamping cylinder 20 also stretch out to push the outer wall of the second end of the bent pipe respectively, and as the two cylinders are symmetrically arranged at two sides of the first clamping cylinder 18, the jacking force generated by the two cylinders is uniformly distributed at two sides of the first stress point, so that three-point clamping of the bent pipe is formed together, and the side wall of the second end of the bent pipe is firmly clamped under the combined action of the three stress points, so that the butting stability is maintained.

It should be noted that, the three-jaw clamping assembly one 8 and the three-jaw clamping assembly three 17 are in the prior art, and have wide application in the industrial automation field, and are generally composed of three movable clamping jaws, which are uniformly distributed on the circumference, and when a workpiece needs to be clamped, the three clamping jaws are simultaneously moved inwards by a driving mechanism (such as air pressure, hydraulic pressure or a motor) to realize clamping.

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

Claims (6)

1. The bent pipe elbow assembling device is characterized by comprising a base (1), a fixed seat (2) and a movable seat (3), wherein the fixed seat (2) is fixedly connected to the base (1), and the movable seat (3) is slidably connected to the base (1) along the X direction;

The bent pipe clamping mechanism comprises a first clamping assembly, a second clamping assembly and a Y-direction clamping driving device which are symmetrically arranged;

the first clamping assembly comprises a first clamping frame (4) and a first floating clamping jaw (5) connected with the first clamping frame (4), the second clamping assembly comprises a second clamping frame (6) and a second floating clamping jaw (7) connected with the second clamping frame (6), the first clamping frame (4) and the second clamping frame (6) are respectively connected to one side of the fixed seat (2) in a sliding manner along a Y direction, and the Y-direction clamping driving device is used for driving the first clamping frame (4) and the second clamping frame (6) to be close to and far away from each other so as to realize bent pipe clamping;

The straight pipe clamping mechanism comprises a first three-jaw clamping assembly (8) connected to one side of the movable seat and used for radially clamping the outer wall of the straight pipe.

2. The elbow assembly device according to claim 1, wherein the first floating clamping jaw (5) and the second floating clamping jaw (7) each comprise a clamp housing, one side of the clamp housing is outwards extended to be provided with a thimble array, the thimble array is composed of a plurality of thimbles which are uniformly distributed at intervals, the clamp housing is provided with an air cavity, the air cavity is connected with an external air source, and the thimbles are connected with the clamp housing through springs and are connected with the air cavity.

3. The elbow fitting device according to claim 2, wherein the first clamping frame (4) is connected to two first floating clamping jaws (5), the second clamping frame (6) is connected to two second floating clamping jaws (7), one pair of the first floating clamping jaws (5) and the second floating clamping jaws (7) are used for clamping a first end outer wall of an elbow, and the other pair of the first floating clamping jaws (5) and the second floating clamping jaws (7) are used for clamping a second end outer wall of the elbow, so that the elbow is in a side standing posture.

4. The elbow assembly device according to claim 1, wherein two Y-direction sliding rails are arranged on a side wall of the fixed seat (2), and the first clamping frame (4) and the second clamping frame (6) are respectively and slidably connected to the Y-direction sliding rails;

The Y-direction clamping driving device comprises a Y-direction screw rod (9), a shaft sleeve, a belt pulley assembly (10) and a driving motor (11), wherein the Y-direction screw rod (9) is connected to the fixing seat (2) through shaft sleeve rotation, two sections of threads which are opposite in rotation direction are arranged on the Y-direction screw rod (9), threaded holes are respectively formed in the first clamping frame (4) and the second clamping frame (6) and are respectively connected with the two sections of threads of the Y-direction screw rod (9), one end of the Y-direction screw rod (9) is connected with the belt pulley assembly (10), and the driving motor (11) drives the belt pulley assembly (10) to drive the Y-direction screw rod (9) to rotate so as to achieve approaching and separating of the first clamping frame and the second clamping frame.

5. The elbow assembling work station is characterized by comprising the elbow assembling device according to any one of claims 1 to 4, a feeding mechanical arm (12), and an elbow feeding clamp (13) or a straight pipe feeding clamp connected to the tail end of the feeding mechanical arm (12), wherein the elbow feeding clamp (13) is used for clamping an elbow and butting the elbow with the elbow clamping mechanism under the driving of the feeding mechanical arm (12), and the straight pipe feeding clamp is used for clamping a straight pipe and butting the straight pipe with the straight pipe clamping mechanism under the driving of the feeding mechanical arm (12).

6. The elbow assembly workstation according to claim 5, wherein the elbow feeding clamp (13) comprises a clamp mounting seat (15) connected to the tail end of the feeding mechanical arm (12), and a three-jaw clamping assembly two (16) and a three-jaw clamping assembly three (17) respectively connected to the clamp mounting seat (15);

The second three-jaw clamping assembly (16) is used for radially clamping the outer wall of the first end of the bent pipe;

The three-jaw clamping assembly (17) comprises a first clamping cylinder (18), a second clamping cylinder (19) and a third clamping cylinder (20) which are respectively connected to the clamp mounting seat (15), wherein the first clamping cylinder (18) stretches into an inner hole at the second end of the bent pipe and is used for pushing the inner wall of the inner hole at the second end of the bent pipe, and the second clamping cylinder (19) and the third clamping cylinder (20) are symmetrically arranged on two sides of the first clamping cylinder (18) and are respectively used for pushing the outer wall at the second end of the bent pipe.