Continuously adjustable pipe-reducing device, and continuous forming method for pipe fitting

Abstract

A continuously adjustable pipe-reducing device, and a continuous forming method for a pipe fitting. The continuously adjustable pipe-reducing device comprises a first roller and a second roller, which are connected to a driving mechanism, wherein the first roller is located directly above the second roller; a first mold cavity is provided on the side wall of the first roller in the circumferential direction of the first roller; a second mold cavity is provided on the side wall of the second roller; the first roller is rotationally arranged on a shaft seat; and the shaft seat is connected to a lifting driving mechanism by means of a displacement control rod. The perimeter of the cross section of a pipe fitting can be changed by means of the vertical movement of the first roller and the relative rotation between the first roller and the second roller, and the pipe fitting having different perimeters at different parts can be produced by means of only one set of rollers; thus, the continuously adjustable pipe-reducing device occupies a small space, and is convenient to control. Connecting portions are fixedly provided on two sides of the first mold cavity, the connecting portions are arranged in the circumferential direction of the first roller, and the connecting portions are inserted in the second mold cavity; and when the position of the first roller is changed, the effective connection between the first mold cavity and the second mold cavity can be ensured without a gap, thereby realizing the continuous forming of the pipe fitting with different diameters / shapes.

Description

A continuously adjustable pipe shrinking device and a continuous pipe forming method Technical Field

[0001] The present invention relates to the technical field of plastic forming, in particular to a continuous adjustable pipe shrinking device and a pipe continuous forming method. Background Art

[0002] The integrally formed parts of variable-section special-shaped pipe fittings have the advantages of low cost, light weight, and excellent mechanical properties. They are widely used in many industries, especially in the manufacturing fields of automobiles, aviation, and mobile equipment. The application of special-shaped pipe fittings largely determines the performance of the overall equipment. Traditional processing methods for variable-section special-shaped pipe fittings are generally divided into two types: one is to form the required pipe fittings in sections and then assemble and weld them together; the other is the radial expansion process.

[0003] Since it is difficult for spliced ​​parts to meet the expected requirements in terms of mechanical strength, external dimensions, performance, and appearance, and the radial expansion process is difficult to control the distribution of tube diameter expansion, the production of pipe fittings is restricted. To address the defects of traditional processing methods, a pipe fitting roll extrusion method has emerged (such as publication number CN114653769B), which uses a forming roller group to continuously form the tube blank without applying internal pressure, thereby reducing production costs.

[0004] However, the overall structure of the device used in the existing pipe roller extrusion method is complex. For example, when continuously forming pipes with large deformation, multiple sets of forming roller groups need to be set up, which not only increases the use cost, but also increases the production space occupied. It is also inconvenient to use. The staff needs to debug the forming roller groups at different positions in advance to ensure that the forming space between the two rollers in the same group meets the size requirements, which greatly increases the labor intensity. Summary of the Invention

[0005] In order to solve the technical problems in the above-mentioned background technology that the existing pipe roller extrusion forming method is inconvenient to use, occupies a large space and has high cost, the present invention provides a continuously adjustable pipe shrinking device and a continuous pipe forming method.

[0006] The technical solutions of the present invention are as follows:

[0007] The present invention provides a continuously adjustable tube shrinking device, comprising a first roller and a second roller connected to a driving mechanism, the first roller being located directly above the second roller, a first cavity being provided on the side wall of the first roller along its circumferential direction, a second cavity being provided on the side wall of the second roller, the first roller being rotatably arranged on an axle seat, the axle seat being connected to a lifting driving mechanism via a displacement control rod, the second roller being rotatably arranged on a base, the first roller being able to move vertically, the first roller and the second roller being assembled and rotated to change the cross-sectional circumference of the tube blank, thereby realizing continuous reduction of the tube blank at different axial positions The cross-sectional circumference is adjusted to obtain prefabricated pipes with unequal diameters at various locations. A set of roller groups can produce pipe blanks with different circumference variations, which takes up little space and is easy to control. There is no need to arrange several roller groups in advance, which facilitates use and reduces production costs. Connecting parts are fixed on both sides of the first cavity, and the connecting parts are arranged along the circumferential direction of the first roller. The connecting parts are inserted into the second cavity. When the first roller moves vertically to change its position, it can ensure effective connection between the first cavity and the second cavity without any gap, and effectively roll-extrude the pipe blank to achieve continuous forming of different pipe diameters / tube shapes.

[0008] Preferably, the first cavity includes a first arc segment, the connecting portion includes a first straight segment and a transition segment, the first straight segment is located on the outside of the connecting portion, the first straight segment is perpendicular to the side wall of the first roller, and the transition segment is located on the inside of the connecting portion and connected to the first arc segment.

[0009] Preferably, the contour line of the second cavity includes a second arc segment and a second straight line segment, the second straight line segment is arranged at both ends of the second arc segment, the second straight line segment is tangent to the second arc segment, and the first straight line segment and the second straight line segment are gap-matched to facilitate the connection between the first cavity and the second cavity, and avoid the formation of a gap between the first cavity and the second cavity when the first roller moves vertically.

[0010] Preferably, the length of the first straight segment is not greater than the length of the second straight segment, so as to avoid contact between the connecting portion and the second arc segment and ensure the rolling quality of the curved surface of the tube blank.

[0011] Preferably, an angle is formed between the transition section and the first straight section, so as to facilitate transitional forming of the tube blank between the first arc section and the second arc section.

[0012] Preferably, the lengths of the first arc segment and the second arc segment are both less than half of the circumference of the tube blank, and the lengths of the first arc segment and the second arc segment are both not less than 2 / 5 of the circumference of the tube blank, thereby ensuring the effectiveness of the tube shrinking work and the fit with the tube blank, ensuring the rolling quality of the tube blank during the continuous forming process, and avoiding the occurrence of wrinkling.

[0013] Preferably, the maximum circumference of the space cross section enclosed by the first cavity, the second cavity and the connecting portion is greater than the circumference of the tube blank, and the minimum circumference is less than the circumference of the tube blank, which facilitates the placement of the tube blank and can play a role in shrinking the tube.

[0014] Preferably, the distance between the two first straight segments is not less than the diameter of the tube blank, and not greater than the distance between the two second straight segments, so as to facilitate the placement of the tube blank and the coordination between the first straight segment and the second straight segment.

[0015] The present invention also provides a continuous pipe forming method, which is as follows:

[0016] Adjust the distance between the first roller and the second roller so that the first straight segment contacts the end of the second straight segment, and place the tube blank between the first cavity and the second cavity;

[0017] Start the driving mechanism to roll-extrude the tube into shape;

[0018] When the tube needs to be shrunk, the shaft seat is controlled to move downward by the displacement control rod to reduce the distance between the first cavity and the second cavity. After the tube is shrunk, the shaft seat is controlled to move upward by the displacement control rod.

[0019] It can be seen from the above technical solutions that the advantages of the present invention are:

[0020] 1. The first roller can move vertically. The first roller and the second roller are assembled and rotated to change the cross-sectional circumference of the tube blank, thereby continuously reducing the cross-sectional circumference of the tube blank at different axial positions to obtain prefabricated tubes with different diameters at different locations. A set of roller groups can produce tube blanks with different circumference changes, which occupies a small space and is easy to control. There is no need to arrange several roller groups in advance, which is convenient for use and reduces production costs. The setting of the connecting part can ensure that the first cavity and the second cavity are effectively connected without any gap when the first roller moves vertically to change its position, so that the tube blank is effectively roll-extruded to achieve continuous forming of different tube diameters / tube shapes.

[0021] 2. The length of the first straight segment is not greater than that of the second straight segment, so as to avoid contact between the connecting portion and the second arc segment and ensure the roll extrusion quality of the curved surface of the tube blank.

[0022] 3. The lengths of the first arc segment and the second arc segment are both less than half of the circumference of the tube blank, and the lengths of the first arc segment and the second arc segment are not less than 2 / 5 of the circumference of the tube blank, which ensures the effectiveness of the tube shrinking work and the fit with the tube blank, ensures the rolling quality of the tube blank during the continuous forming process, and avoids the occurrence of wrinkling.

[0023] 4. The maximum perimeter of the space section enclosed by the first cavity, the second cavity and the connecting portion is greater than the perimeter of the tube blank, and the minimum perimeter is less than the perimeter of the tube blank, which facilitates the placement of the tube blank and can play a role in shrinking the tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] FIG1 is a schematic cross-sectional view of a continuously adjustable tube shrinking device according to one or more embodiments of the present invention (the lifting drive mechanism is not shown);

[0026] FIG2 is a schematic cross-sectional view of a roller assembly according to one or more embodiments of the present invention;

[0027] Figure 3 is a schematic diagram of the cross-sectional profile of a round tube blank and the cross-sectional profile of the tube after processing;

[0028] The components represented by the reference numerals in the figure are:

[0029] 1. First roller; 2. Second roller; 3. Driving machine; 4. Shaft seat; 5. Transmission gear set; 6. Displacement control rod; 7. Base; 8. First arc segment; 9. Connecting part; 91. First straight segment; 92. Transition segment; 10. Second arc segment; 11. Second straight segment. DETAILED DESCRIPTION

[0030] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this patent. Example 1

[0031] In a typical embodiment of the present invention, as shown in Figures 1 to 3, a continuously adjustable tube shrinking device is proposed, including: a roller group for continuous roller extrusion tube billet forming, the roller group includes a first roller 1 and a second roller 2 arranged opposite to each other in an upper and lower direction, the first roller 1 is located directly above the second roller 2, and the side walls of the first roller 1 and the second roller 2 are both provided with cavities along their circumferential directions. Specifically, a first cavity is provided on the side wall of the first roller 1 along its circumferential direction, and a second cavity is provided on the side wall of the second roller 2 along its circumferential direction, and the first cavity cooperates with the second cavity.

[0032] The first roller 1 is rotatably arranged on the shaft seat 4 through the rotating shaft, and the second roller 2 is rotatably arranged on the base 7 through the rotating shaft. The first roller 1 and the second roller 2 are both driven by a driving mechanism and rotate around the axis. A displacement control rod 6 is fixedly installed on the shaft seat 4. There is at least one displacement control rod 6, and the displacement control rod 6 is vertically arranged. The shaft seat 4 is connected to the lifting drive mechanism through the displacement control rod 6, and can drive the shaft seat 4 to move vertically through the lifting drive mechanism, thereby changing the distance between the first roller 1 and the second roller 2, so as to be used for roll extrusion of different pipe diameters and shapes.

[0033] In this embodiment, the driving mechanism includes a driving machine 3, the output end of the driving machine 3 is connected to the rotating shaft of the second roller 2 to drive the second roller 2 to rotate through the driving shaft 3, and transmission gears are fixedly installed on the rotating shafts of the first roller 1 and the second roller 2. The two transmission gears are meshed to form a transmission gear set 5, and then the first roller 1 and the second roller 2 are rotated synchronously through the transmission gear set 5.

[0034] It is understandable that in other embodiments, the transmission gear set 5 can also be replaced with a transmission pulley assembly, or two driving machines 3 can be set to drive the first roller 1 and the second roller 2 respectively. It is best to set two driving machines 3 to avoid restricting the movement of the first roller 1. The specific driving method can be selected according to actual needs, and no excessive restrictions are imposed here.

[0035] The main body of the driving machine 3 is an electric motor, preferably a servo motor, which can accurately control the rotation amount and provide a large rotational torque.

[0036] A connecting portion 9 is also fixedly provided on the side wall of the first roller 1. The connecting portion 9 is located on both sides of the first cavity and is also arranged circumferentially along the side wall of the first roller 1. The connecting portion 9 is used to be inserted into the second cavity on the side wall of the second roller 2 to connect the first cavity and the second cavity. When the first roller 1 moves vertically to change its position, it can ensure effective connection between the first cavity and the second cavity without any gap, and can effectively roll-extrude the tube blank to achieve continuous forming of different tube diameters / tube shapes.

[0037] Specifically, as shown in FIG2 , the contour line of the first cavity includes a first arc segment 8, and the connecting portion 9 includes a first straight segment 91 and a transition segment 92. The first straight segment 91 is located outside the connecting portion 9, and the transition segment 92 is located inside the connecting portion 9. There is an angle of 4° between the transition segment 92 and the first straight segment 91. The first straight segment 91 is perpendicular to the side wall of the first roller 1, and the transition segment 92 is connected to the first arc segment 8.

[0038] The contour line of the second cavity includes a second arc segment 10 and a second straight segment 11. The second straight segment 11 is arranged at both ends of the second arc segment 10, and the second straight segment 11 is tangent to the second arc segment 10 so as to be matched with the first straight segment 91 (such as clearance fit), wherein the length of the first straight segment 91 is not greater than the length of the second straight segment 11 to avoid contact between the connecting portion 9 and the second arc segment 10, thereby ensuring the rolling quality of the curved surface of the tube blank.

[0039] In order to ensure the rolling quality of the tube blank during the continuous forming process and avoid the occurrence of wrinkles, the dimensions of the first cavity, the second cavity and the connecting portion 9 are restricted as follows:

[0040]

[0041] Wherein, D is the diameter of the tube, s1 is the length of the first arc segment 8 , s2 is the length of the second arc segment 10 , a1 is the length of the first straight segment 91 , and a2 is the length of the second straight segment 11 .

[0042] In addition, it is also necessary to ensure that D≤b1≤b2, where b1 is the distance between the two first straight line segments 91 and b2 is the distance between the two second straight line segments 11.

[0043] Through the design of the above device, the minimum cross-sectional perimeter of the pipe after rolling is s1+s2+2*(a2-a1).

[0044] In this embodiment, the first roller 1 and the second roller 2 of the continuously adjustable tube shrinking device both have a special profile structure, and the first roller 1 can move vertically. The assembly and rotation between the first roller 1 and the second roller 2 can change the cross-sectional circumference of the tube blank, thereby continuously reducing the cross-sectional circumference of the tube blank at different axial positions to obtain prefabricated tubes with unequal diameters at various locations. A set of roller groups can produce tube blanks with different circumference changes, occupying a small space and being easy to control. There is no need to arrange several roller groups in advance, which is convenient for use and reduces production costs. In addition, the preforming process can be combined with a variety of tube forming processes to reduce the difficulty of part forming and broaden the forming capacity of existing processes. Example 2

[0045] In another typical implementation of this embodiment, a method for continuously forming pipes using a continuously adjustable pipe shrinking device is proposed, as follows:

[0046] First, adjust the distance between the first roller 1 and the second roller 2, connect the first cavity and the second cavity, so that the first straight segment 91 contacts the end of the second straight segment 11. At this time, the straight segment formed by the first straight segment 91 and the second straight segment 11 is the longest. Then place the tube blank between the first cavity and the second cavity.

[0047] Start the driving mechanism, and the first roller 1 and the second roller 2 rotate to roll-extrude the tube into shape;

[0048] When tube shrinkage is required, the lifting drive mechanism is started, and the displacement control rod 6 is used to control the shaft seat 4 to move downward a set distance, thereby reducing the distance between the first roller 1 and the second roller 2, and then reducing the distance between the first cavity and the second cavity. After the tube shrinkage is completed, the displacement control rod 6 is used to control the shaft seat 4 to rise, thereby realizing continuously adjustable tube shrinkage forming.

[0049] It should be noted that, during the rising process of the shaft seat 4 , the first straight segment 91 and the second straight segment 11 should be ensured to be connected in a coordinated manner to avoid separation of the first straight segment 91 and the second straight segment 11 .

[0050] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A continuously adjustable tube shrinking device comprising: A first roller (1) and a second roller (2) connected to a driving mechanism (3), wherein the first roller (1) is located directly above the second roller (2), and is characterized in that a first cavity is provided on the side wall of the first roller (1) along its circumferential direction, and a second cavity is provided on the side wall of the second roller (2), the first roller (1) is rotatably provided on a shaft seat (4), the shaft seat (4) is connected to the lifting driving mechanism (3) through a displacement control rod (6), the second roller (2) is rotatably provided on a base (7), and connecting parts (9) are fixedly provided on both sides of the first cavity, the connecting parts (9) are provided along the circumferential direction of the first roller (1), and the connecting parts (9) are inserted into the second cavity.

2. A continuously adjustable tube shrinking device according to claim 1, characterized in that: The first cavity includes a first arc segment (8), and the connecting portion (9) includes a first straight segment (91) and a transition segment (92). The first straight segment (91) is located outside the connecting portion (9), and the first straight segment (91) is perpendicular to the side wall of the first roller (1). The transition segment (92) is located inside the connecting portion (9) and connected to the first arc segment (8).

3. A continuously adjustable tube shrinking device according to claim 2, characterized in that: The contour line of the second cavity includes a second arc segment (10) and a second straight segment (11), the second straight segment (11) is arranged at both ends of the second arc segment (10), the second straight segment (11) is tangent to the second arc segment (10), and the first straight segment (91) and the second straight segment (11) are clearance-matched.

4. A continuously adjustable tube shrinking device according to claim 3, characterized in that: The length of the first straight line segment (91) is not greater than the length of the second straight line segment (11).

5. The continuously adjustable tube shrinking device according to claim 2, characterized in that: An included angle is formed between the transition section (92) and the first straight section (91).

6. The continuously adjustable tube shrinking device according to claim 3, characterized in that: The lengths of the first arc segment (8) and the second arc segment (10) are both less than half of the circumference of the tube blank, and the lengths of the first arc segment (8) and the second arc segment (10) are both not less than 2 / 5 of the circumference of the tube blank.

7. The continuously adjustable tube shrinking device according to claim 3, characterized in that: The maximum perimeter of the spatial cross section enclosed by the first cavity, the second cavity and the connecting portion (9) is greater than the perimeter of the tube blank, and the minimum perimeter is less than the perimeter of the tube blank.

8. The continuously adjustable tube shrinking device according to claim 3, characterized in that: The distance between the two first straight line segments (91) is not less than the diameter of the tube blank, and is not greater than the distance between the two second straight line segments (11).

9. A continuous pipe forming method, using a continuous adjustable pipe shrinking device according to any one of claims 1 to 8, characterized in that: The details are as follows: Adjust the distance between the first roller (1) and the second roller (2) so that the first straight segment (91) contacts the end of the second straight segment (11), and place the tube blank between the first cavity and the second cavity; Start the driving mechanism (3) to roll-extrude the tube into shape; When the tube needs to be shrunk, the shaft seat (4) is controlled to move downward by the displacement control rod (6) to reduce the distance between the first cavity and the second cavity. After the tube is shrunk, the shaft seat (4) is controlled to rise by the displacement control rod (6).

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