Pipe bending mandrel for stainless steel pipe

Abstract

This utility model discloses a bending mandrel for bending stainless steel pipes, including a mandrel head, a bending bead, and a mandrel body. The circumferential sides of the mandrel head, bending bead, and mandrel body are all provided with textured grooves. A connecting steel cable is inserted and installed at the central axis of the mandrel head, bending bead, and mandrel body, with fixed terminals fixed at both ends of the connecting steel cable. A threaded hole is provided at the end of the mandrel head opposite the bending bead, and a hollow adjusting bolt is threaded onto the surface of the fixed terminal at one end of the connecting steel cable. This utility model, by designing the bending bead as a disc with convex conical curved surfaces on both sides, reduces the distance between adjacent bending beads. This results in a smaller distance between support points on the inner wall of the stainless steel pipe on the inner side of the arc, increasing the number of support points per unit length of the stainless steel pipe and reducing the bending radius, thus fully supporting the inner wall of the stainless steel pipe and preventing wrinkles.

Description

Technical Field

[0001] This utility model relates to the field of stainless steel pipe bending technology, specifically a bending mandrel for stainless steel pipe bending. Background Technology

[0002] The bending mandrel plays a crucial role in the bending process of stainless steel pipes. During the bending process, the bending mandrel supports the inner wall of the stainless steel pipe, preventing the bend from collapsing due to uneven stress. At the same time, the material supporting the outer arc of the stainless steel pipe helps control the ellipticity of the bend, keeping it within a reasonable range. The proper use of the bending mandrel can prevent wrinkles from forming on the inner arc of the stainless steel pipe, ensuring the smoothness of the bend and the quality of the bend.

[0003] Most existing bending beads in bending mandrels are spherical or hemispherical. During the bending process of stainless steel tubes, the positions of multiple bending beads arranged on the same straight line gradually change and move to the arc. Due to the limitation of the diameter or width of the bending beads, the distance between the contact points of adjacent bending beads on the inner side of the arc and the inner wall of the stainless steel tube is relatively large. This results in fewer support points or a smaller support surface per unit length for the inner wall of the stainless steel tube. Therefore, when bending stainless steel tubes with a small arc radius, wrinkles are easily generated due to insufficient support, which brings inconvenience to the bending process of small radius stainless steel tubes. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a bending mandrel for bending stainless steel pipes, which solves the problem that existing bending mandrels, with their spherical or hemispherical bending beads, are prone to wrinkling due to insufficient support on the inner side of the arc when bending small-radius stainless steel pipes, as the bead diameter or width is limited.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A bending mandrel for bending stainless steel pipes includes a mandrel head, a bending bead, and a mandrel body. The circumferential sides of the mandrel head, the bending bead, and the mandrel body are all provided with textured grooves. A connecting steel cable is inserted and installed at the central axis position of the mandrel head, the bending bead, and the mandrel body. Both ends of the connecting steel cable are fixed with fixed terminals.

[0007] The end of the mandrel head opposite the bend bead is provided with a threaded hole and a hollow adjusting bolt is threadedly installed on the surface of the fixed terminal at one end of the connecting steel cable. The end of the mandrel head corresponding to the bend bead has a convex conical curved surface structure.

[0008] The bent tube bead is a disc with convex conical curved surface structure on both sides, and the circumferential side of the bent tube bead is a smooth curved surface that convex outwards. The bent tube bead has a ball that is movably sleeved on the surface of the connecting steel cable.

[0009] The core rod body has a convex conical curved surface structure at one end corresponding to the bend bead. The core rod body is provided with a threaded hole two for installing the through rod at the end away from the bend bead. The threaded hole two is provided with an installation hole. A strong spring and a washer are installed inside the installation hole and are sleeved on the surface of the connecting steel cable. The washer is located between the strong spring and the fixed terminal at the end of the connecting steel cable.

[0010] Preferably, the groove is a "well" shaped groove and the angle between the groove and the axis of the mandrel head and the main body of the mandrel is 45°.

[0011] Preferably, the protruding conical surface structure at one end of the mandrel head corresponding to the bend bead, the protruding conical surface structures on both sides of the bend bead, and the protruding conical surface structure at one end of the mandrel body corresponding to the bend bead have the same surface inclination.

[0012] Preferably, the head of the core rod and the opposite ends of the core rod body are provided with ball grooves, and ball bearings that are movably sleeved on the surface of the connecting steel cable are installed in the ball grooves.

[0013] Preferably, the curved tube bead has a two-part spliced ​​structure, and an embedded groove is provided at the center of the two opposing surfaces of the curved tube bead, and the ball is installed in the embedded groove.

[0014] Preferably, the two halves of the bent tube bead are connected and fixed by countersunk bolts, and a wide-mouth relief groove for connecting steel cables is provided at the position of the inner groove corresponding to the opposite side of the two halves of the bent tube bead.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) By setting the bending bead into a disc shape with convex conical curved surface structure on both sides, the distance between two adjacent bending beads can be reduced. The distance between the support points on the inner wall of the stainless steel tube on the inner side of the arc is small, which not only increases the number of support points per unit length of the stainless steel tube, but also reduces the bending radius. It fully supports the inner wall of the stainless steel tube and avoids wrinkles. It solves the problem that the existing spherical or hemispherical bending beads of the bending mandrel are prone to wrinkles due to insufficient support on the inner side of the arc when bending small radius stainless steel tubes.

[0017] (2) By setting the textured grooves on the head of the mandrel, the bend bead and the circumferential side of the mandrel body, this utility model improves the adhesion effect of the applied lubricating oil. In the process of bending stainless steel pipes in large quantities, it not only reduces the frequency of lubricating oil application, but also reduces the amount of lubricating oil used, thus reducing production costs.

[0018] (3) This utility model connects the core rod head, the bend bead and the core rod body by connecting steel cable, and at the same time increases the tension of the connecting steel cable by using a strong spring. This not only prevents the bend bead from being loose before bending, but also allows multiple bend beads to be subjected to force evenly during bending, thereby evenly supporting the stainless steel pipe and effectively improving the bending quality. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the overall structure of the present invention after bending;

[0021] Figure 3 This is a cross-sectional view of the head of the mandrel of this utility model;

[0022] Figure 4 This is a cross-sectional view of the bend bead of this utility model;

[0023] Figure 5 This is a cross-sectional view of the main body of the mandrel of this utility model.

[0024] In the diagram: 1. Core rod head; 2. Bent bead; 3. Core rod body; 4. Corrugated groove; 5. Connecting steel cable; 6. Fixed terminal; 7. Threaded hole one; 8. Adjusting bolt; 9. Ball one; 10. Threaded hole two; 11. Mounting hole; 12. Strong spring; 13. Washer; 14. Ball groove; 15. Ball two; 16. Embedded groove; 17. Countersunk bolt; 18. Relief groove. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figure 1-5 As shown, this utility model provides a technical solution: a bending mandrel for bending stainless steel pipes, including a mandrel head 1, a bending bead 2, and a mandrel body 3. The circumferential sides of the mandrel head 1, the bending bead 2, and the mandrel body 3 are all provided with a textured groove 4. The textured groove 4 is a "well" shaped groove and the angle between the groove and the axis of the mandrel head 1 and the mandrel body 3 is 45°, which helps the applied lubricating oil to adhere to the wall and avoids the inconvenience caused by frequent brushing.

[0027] Both the head 1 and the body 3 of the mandrel are provided with ball grooves 14, and ball bearings 15 are installed in the ball grooves 14 and are movably sleeved on the surface of the connecting steel cable 5 to avoid friction and wear between the connecting steel cable 5 and the ends of the head 1 and the body 3 of the mandrel.

[0028] A connecting steel cable 5 is inserted and installed at the central axis position of the mandrel head 1, the bending bead 2 and the mandrel body 3. Both ends of the connecting steel cable 5 are fixed with fixed terminals 6. The end of the mandrel head 1 away from the bending bead 2 is provided with a threaded hole 7 and a hollow adjusting bolt 8 is threaded and fitted onto the surface of the fixed terminal 6 at one end of the connecting steel cable 5. This is used to adjust the tension of the connecting steel cable 5, thereby adjusting the degree of freedom of movement of the bending bead 2 during the bending of the stainless steel pipe.

[0029] The circumferential side of the bend bead 2 is a smooth curved surface that bulges outward. Inside the bend bead 2, a ball bearing 9 is movably embedded and fitted onto the surface of the connecting steel cable 5. The bend bead 2 has a two-part splicing structure. The two parts of the bend bead 2 are connected and fixed by countersunk bolts 17. An embedded groove 16 is provided at the center of the opposite surface of the two parts of the bend bead 2. The ball bearing 9 is installed in the embedded groove 16. The opposite surfaces of the two parts of the bend bead 2 are provided with a wide relief groove 18 corresponding to the position of the embedded groove 16, which facilitates processing and manufacturing, reduces installation difficulty, and allows for partial replacement when local wear is severe during use, thus reducing usage costs.

[0030] The mandrel head 1 has a convex conical curved surface structure at one end corresponding to the bend bead 2. The bend bead 2 is a disc with convex conical curved surface structures on both sides. The mandrel body 3 has a convex conical curved surface structure at one end corresponding to the bend bead 2. The convex conical curved surface structures at one end of the mandrel head 1 corresponding to the bend bead 2, the convex conical curved surface structures on both sides of the bend bead 2, and the convex conical curved surface structures at one end of the mandrel body 3 corresponding to the bend bead 2 have the same curvature. After bending, the distance between the contact points between the adjacent bend bead 2 and the stainless steel pipe on the inner side of the arc is small, which provides good support for the stainless steel pipe and enables the processing and manufacturing of bends with small bending radii.

[0031] The core rod body 3 is provided with a threaded hole 10 for installing the through rod at one end away from the bend bead 2. The threaded hole 10 is provided with an installation hole 11. A strong spring 12 and a washer 13 are installed inside the installation hole 11 and are sleeved on the surface of the connecting steel cable 5. The washer 13 is located between the strong spring 12 and the fixed terminal 6 at the end of the connecting steel cable 5.

[0032] Working principle:

[0033] Select a bending mandrel of appropriate diameter according to the inner diameter of the stainless steel pipe to be bent, and connect and fix it to the mandrel rod of the bending equipment through the threaded hole 10 of the mandrel body 3. Apply lubricating oil to the surface of the mandrel head 1, bending bead 2 and mandrel body 3. The textured groove 4 on the surface can improve the effect of lubricating oil adhering to the wall, avoid frequent brushing, and bring convenience to the processing. Stainless steel pipe is fitted onto the surface of the mandrel head 1, bending bead 2 and mandrel body 3. Under the action of the bending machine and its mold, the stainless steel pipe can be bent. Due to the small thickness of the bending bead 2, the distance between the contact points between adjacent bending beads 2 and the inner wall of the stainless steel pipe is small, which increases the number of support points per unit length of stainless steel pipe and can also reduce the bending radius, fully support the inner wall of stainless steel pipe and avoid wrinkles.

Claims

1. A bending mandrel for bending stainless steel pipes, comprising a mandrel head (1), a bending bead (2), and a mandrel body (3), characterized in that: The circumferential sides of the mandrel head (1), the bent bead (2) and the mandrel body (3) are all provided with a textured groove (4). A connecting steel cable (5) is inserted and installed at the central axis position of the mandrel head (1), the bent bead (2) and the mandrel body (3). Both ends of the connecting steel cable (5) are fixed with fixed terminals (6). The head of the mandrel (1) is provided with a threaded hole (7) at the end away from the bend (2) and a hollow adjusting bolt (8) is threaded and fitted onto the surface of the fixed terminal (6) at one end of the connecting steel cable (5). The head of the mandrel (1) is provided with a protruding conical curved surface structure at the end corresponding to the bend (2). The bent tube bead (2) is a disc with a convex conical curved surface structure on both sides, and the circumferential side of the bent tube bead (2) is a smooth curved surface that convex outwards. The bent tube bead (2) is movably embedded with a ball bearing (9) that is movably sleeved on the surface of the connecting steel cable (5). The core rod body (3) has a convex conical curved surface structure at one end corresponding to the bend bead (2). The core rod body (3) is provided with a threaded hole (10) for installing the through rod at the end away from the bend bead (2). The threaded hole (10) is provided with an installation hole (11). A strong spring (12) and a washer (13) are installed inside the installation hole (11) and are sleeved on the surface of the connecting steel cable (5). The washer (13) is located between the strong spring (12) and the fixed terminal (6) at the end of the connecting steel cable (5).

2. The bending mandrel for bending stainless steel pipes according to claim 1, characterized in that: The groove (4) is a "well" shaped groove and the angle between the groove and the axis of the mandrel head (1) and the mandrel body (3) is 45°.

3. The bending mandrel for bending stainless steel pipes according to claim 1, characterized in that: The protruding conical surface structure at one end of the mandrel head (1), the protruding conical surface structures on both sides of the bend (2), and the surface inclination of the protruding conical surface structure at one end of the mandrel body (3) corresponding to the bend (2) are the same.

4. The bending mandrel for bending stainless steel pipes according to claim 1, characterized in that: Both the head (1) of the core rod and the opposite ends of the core rod body (3) are provided with ball grooves (14), and ball two (15) that are movably sleeved on the surface of the connecting steel cable (5) are installed in the ball grooves (14).

5. A bending mandrel for bending stainless steel pipes according to claim 1, characterized in that: The curved tube bead (2) has a two-part splicing structure. The two opposing surfaces of the curved tube bead (2) are provided with an embedded groove (16), and the first ball (9) is installed in the embedded groove (16).

6. A bending mandrel for bending stainless steel pipes according to claim 5, characterized in that: The two halves of the bent tube bead (2) are connected and fixed by countersunk bolts (17), and the opposite sides of the two halves of the bent tube bead (2) are provided with a wide-mouth relief groove (18) corresponding to the connection of the steel cable (5) at the position of the inner groove (16).

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