A tapered tube rolling forming follow-up crack prevention and limiting mechanism

Abstract

This utility model discloses a follow-up anti-cracking limiting mechanism for tapered tube rolling forming, including a mandrel with a connecting rod at its tail having a diameter smaller than the mandrel. The mechanism also includes a jacking pipe, which is positioned on the tapered tube forming machine via a bearing seat. The inner diameter of the jacking pipe is larger than the outer diameter of the mandrel, and a restraining sleeve is provided at the front end of the jacking pipe. The restraining sleeve has a backstop surface with an inner diameter less than or equal to the outer diameter of the large end of the formed tapered tube, used to limit the radial displacement of the large end of the tapered tube. The restraining sleeve design prevents radial displacement of the tapered tube and provides axial positioning, limiting the runout of the large end of the tapered tube and avoiding cracking caused by radial misalignment. The jacking pipe rotates synchronously with the tapered tube, and the restraining sleeve follows and limits movement, reducing friction and stress concentration, and maintaining stability during operation. The radial adjustment mechanism can adapt to different tapered tube sizes, improving adjustability. The restraining sleeve can be an integrated or detachable design, offering flexible structure and facilitating maintenance and replacement.

Description

Technical Field

[0001] This utility model relates to the technical field of metal pipe processing equipment, specifically to a follow-up anti-cracking limiting mechanism for tapered pipe rolling forming, which is particularly suitable for limiting devices that prevent large-end cracking during the rolling forming process of slender tapered pipes. Background Technology

[0002] On a tapered tube forming machine, for tapered tubes with a small-end taper hole diameter greater than 30mm, a mandrel inner mold is required for rolling forming. Since tapered tubes are slender rods, the large end of the tapered tube (blank) needs to be axially positioned using a jacking tube during forming. The jacking tube and the tapered tube rotate synchronously, and the forming rollers repeatedly roll along the outer surface of the tapered tube along its length to achieve the final shape. However, during the rolling process, the large end of the tapered tube often cracks due to the following reasons: such as thin tube wall thickness and insufficient strength; excessive runout at the large end of the tapered tube; and the jacking tube lacking effective restraint on the outer diameter of the large end of the tapered tube, leading to misalignment between the jacking tube and the end face of the tapered tube.

[0003] In existing technologies, the jacking pipe only provides axial positioning and cannot effectively constrain the radial displacement of the large end of the tapered pipe, leading to stress concentration during the forming process and making it prone to cracking. Therefore, there is an urgent need for a mechanism that can dynamically limit and prevent cracking at the large end of the tapered pipe. Summary of the Invention

[0004] The purpose of this invention is to solve the above problems by providing a follow-up anti-cracking limiting mechanism for tapered tube rolling forming. By adding a restraining sleeve and an adjustable anti-reverse surface, the radial displacement of the large end of the tapered tube is limited, stress concentration during the forming process is reduced, thereby preventing cracking.

[0005] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: a tapered tube rolling forming follow-up anti-crack limiting mechanism, including a mandrel, the tail of which is connected to a connecting rod with a diameter smaller than that of the mandrel, characterized in that it also includes a top tube, the top tube being positioned on the tapered tube forming machine by a bearing seat; the inner diameter of the top tube is larger than the outer diameter of the mandrel, and a restraining sleeve is provided at the front end of the top tube; the restraining sleeve is provided with a backstop surface, the inner diameter of which is less than or equal to the outer diameter of the large end of the formed tapered tube, for limiting the radial displacement of the large end of the tapered tube.

[0006] The aforementioned tapered tube rolling forming follow-up anti-crack limiting mechanism further includes a mandrel, connecting rod, top tube, and formed tapered tube arranged coaxially, wherein the mandrel is fixed on the tail frame of the tapered tube forming machine by the connecting rod, and the formed tapered tube is located in the forming die roller group.

[0007] In the aforementioned tapered tube rolling forming follow-up anti-crack limiting mechanism, the jacking tube is further positioned on the tapered tube forming machine by two bearing seats, and the jacking tube is supported by bearings and can rotate freely.

[0008] Furthermore, in the aforementioned tapered tube rolling forming follow-up anti-crack limiting mechanism, the restraining sleeve and the jacking tube body are an integral structure.

[0009] Furthermore, in the aforementioned tapered tube rolling forming follow-up anti-crack limiting mechanism, the restraining sleeve and the top tube body are detachable structures.

[0010] In the aforementioned tapered tube rolling forming follow-up anti-crack limiting mechanism, the constraint sleeve is further connected to the jacking tube body via threads; the constraint sleeve may also be connected to the jacking tube body via a column head screw.

[0011] Furthermore, in the aforementioned tapered tube rolling forming follow-up anti-cracking limiting mechanism, the diameter of the hole forming the anti-reverse surface inside the constraint sleeve is adjustable by a radial adjustment mechanism.

[0012] The aforementioned tapered tube rolling forming follow-up crack prevention and limiting mechanism further includes a radial adjustment mechanism comprising a nut seat fixed on the outer diameter of the constraint sleeve, a guide hole on the constraint sleeve, a constraint block in the guide hole, and the constraint block being positioned on the nut seat by an adjusting screw, which pushes the constraint block to move radially. Three constraint blocks are provided, evenly distributed around the circumference of the constraint sleeve; each constraint block has an arc surface that mates with the outer diameter of the connecting rod.

[0013] This technical solution integrates the design of the mandrel, connecting rod, and jacking tube. The jacking tube mates with and rotates synchronously with the large end of the formed tapered tube to ensure that the tapered tube meets the uniform rolling requirements of the forming roller group of the tapered tube forming machine. The outer diameter of the mandrel is smaller than the inner diameter of the jacking tube, allowing the mandrel to pass smoothly through the jacking tube and mate with the forming roller group, and to be easily demolded after the tapered tube is formed. A restraining sleeve is installed at the mating part between the jacking tube and the large end of the tapered tube. Its inner diameter is also larger than the outer diameter of the mandrel, allowing the mandrel to pass smoothly. At the same time, the inner diameter of the restraining sleeve's anti-reverse surface is smaller than or equal to the outer diameter of the large end of the formed tapered tube. That is, the anti-reverse surface formed by the stepped hole in the inner hole provides axial restraint to the end face of the large end of the tapered tube, and the radial displacement of the large end of the tapered tube is limited by the inner hole of the restraining sleeve itself.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: the design of the constraint sleeve prevents radial displacement of the tapered tube and performs axial positioning, restricts the runout of the large end of the tapered tube, and avoids cracking caused by radial misalignment; the top tube and the tapered tube rotate synchronously, and the constraint sleeve follows and limits the movement, reducing friction and stress concentration, and maintaining the stability of the operation process; the radial adjustment mechanism can adapt to different tapered tube sizes, improving adjustability; the constraint sleeve can adopt an integrated or detachable design, which is flexible in structure and easy to maintain and replace. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the working state structure of this utility model.

[0016] Figure 2This is a schematic diagram of the internal structure of the jacking pipe and its mating components of this utility model.

[0017] Figure 3 This is a schematic diagram of a pipe jacking embodiment of the present invention.

[0018] Figure 4 This utility model presents an embodiment of an integrated structure for the jacking pipe and the restraining sleeve.

[0019] Figure 5 This is a schematic diagram of a constraint sleeve structure with a radial adjustment mechanism according to this utility model.

[0020] Figure 6 yes Figure 5 The right view.

[0021] In the diagram: 1-connecting rod, 2-bearing seat, 201-bearing, 3-jacket tube, 301-restraint sleeve, 3011-anti-reverse surface, 302-nut seat, 303-adjusting screw, 304-stub head screw, 305-restraint block, 4-forming mold roller group, 5-core rod, 6-conical tube. Detailed Implementation

[0022] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0023] This embodiment describes a follow-up anti-crack limiting mechanism for tapered tube rolling and forming, applied to a tapered tube forming machine. The forming area of ​​the tapered tube 6 is located at the forming roller group 4. While the forming roller group 4 moves linearly along the length of the tapered tube 6, the rollers inside the forming roller group 4 continuously roll the surface of the tapered tube 6. During the rolling process, the tapered tube 6 rotates under the action of the rollers. The mandrel 5, as an inner mold, is inserted into the tapered tube 6 and works together with the rollers to form the tapered tube 6. Since the tapered tube 6 is relatively long, a 30mm diameter tapered tube is often more than 1 meter long. Therefore, a connecting rod 1 is connected to the tail end of the mandrel 5. The tail end of the connecting rod is fixed to the tailstock of the tapered tube forming machine. The mandrel 5 is pushed and pulled by the tailstock to complete the entry and exit of the mold. Because the tapered tube 6 needs to be positioned axially during forming, this task is performed by the top tube 3, which requires the top tube 3 and the tapered tube 6 to rotate synchronously.

[0024] like Figure 1 , Figure 2 As shown, since the mandrel 5 needs to pass through the jacking tube 3, the diameter of the connecting rod 1 must be smaller than that of the mandrel 5. The mandrel 5, connecting rod 1, jacking tube 3, and the formed tapered tube 6 are all arranged coaxially.

[0025] The jacking tube 3 is positioned on the tapered tube forming machine by two bearing seats 2. The jacking tube 3 is supported by bearings 201 located in the bearing seats 2 and can rotate freely. The inner diameter of the jacking tube 3 is larger than the outer diameter of the mandrel 5, and the front end of the jacking tube 3 is provided with a restraining sleeve 301.

[0026] like Figure 3 As shown, a retaining surface 3011 is formed inside the restricting sleeve 3 through a stepped hole. The inner diameter of the retaining surface 3011 is less than or equal to the outer diameter of the large end of the formed tapered tube 6, which is used to restrict the radial displacement of the large end of the tapered tube. Of course, this is to ensure that the mandrel 5 can pass through smoothly.

[0027] Example 1: The processing of the tapered tube 6 for a single specification product generally adopts a structure in which the retaining sleeve 301 and the jacking tube 3 body are integrated into one piece, such as... Figure 4 As shown.

[0028] Example 2: The restraining sleeve 301 and the jacking pipe 3 body are detachable. This detachable structure allows the restraining sleeve 301 to be connected to the jacking pipe 3 body via threads, or via head screws 304, as shown below. Figure 5 As shown.

[0029] Example 3: This example can be added under the conditions of the above two examples, that is, the diameter of the hole forming the anti-reverse surface 3011 in the restrictive sleeve 301 is adjustable by a radial adjustment mechanism.

[0030] The specific structure is as follows: Figure 5 , Figure 6 As shown, the radial adjustment mechanism includes a nut seat 302 fixed on the outer diameter of the constraint sleeve 301. The constraint sleeve 301 has a guide hole in its wall thickness, and a constraint block 305 is provided in the guide hole. The constraint block 305 is positioned on the nut seat 302 by an adjusting screw 303. The adjusting screw 303 pushes the constraint block 305 to move radially, thereby changing the diameter of the anti-reverse surface 3011.

[0031] Furthermore, there are three constraint blocks 305, which are evenly arranged around the constraint sleeve 301. Each constraint block 305 has an arc surface that matches the outer diameter of the connecting rod 1.

[0032] Working principle and application:

[0033] During the forming of the tapered tube 6, it rotates under the pressure of the rollers in the forming mold roller group 4. The restraining sleeve 301 at the end of the top tube 3 not only holds the large end of the tapered tube 6, but also has a section (let's call it L) of the large end of the tapered tube 6 located within the restraining sleeve 301. The size of this section length L depends on the tapered tube 6 product. If the tapered tube 6 product is a straight tube + tapered tube structure, that is, the tapered tube is part of the whole tube and the rest is straight tube, then the value of L can be large according to the specific length of the tapered tube 6 product, such as 50-100mm. If the product is a purely tapered tube, then the value of L is relatively small, generally 5-10mm is sufficient. Since the length L is located within the restraining sleeve 301, both the axial and radial directions are constrained by the restraining sleeve 301, and the runout range is controllable, the deformation during the synchronous rotation forming process of the top tube 3 and the tapered tube 6 is completely controlled, thereby avoiding cracking and damage at the large end of the tapered tube 6.

[0034] When the tapered tube 6 product has a straight tube + tapered tube structure, it is finished product after molding and removal. When the tapered tube 6 product has a purely tapered tube structure, after the tapered tube 6 is molded, it is removed and the straight tube length L section is cut off.

[0035] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any equivalent changes or modifications made in accordance with the technical concept proposed by the present invention without departing from the principles of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. A tapered tube rolling forming follow-up anti-crack limiting mechanism, comprising a mandrel (5), wherein the tail of the mandrel is connected to a connecting rod (1) with a diameter smaller than that of the mandrel, characterized in that... It also includes a jacking pipe (3), which is positioned on the tapered tube forming machine by a bearing seat (2); the inner diameter of the jacking pipe is greater than the outer diameter of the mandrel, and a restraining sleeve (301) is provided at the front end of the jacking pipe; the restraining sleeve is provided with a backstop surface (3011), the inner diameter of the backstop surface is less than or equal to the outer diameter of the large end of the formed tapered tube (6), which is used to limit the radial displacement of the large end of the tapered tube.

2. The tapered tube rolling forming follow-up anti-crack limiting mechanism according to claim 1, characterized in that, The mandrel (5), connecting rod (1), top tube (3), and formed conical tube (6) are arranged coaxially, wherein the mandrel is fixed on the tail frame of the conical tube forming machine by the connecting rod, and the formed conical tube is located in the forming mold roller group (4).

3. The tapered tube rolling forming follow-up anti-crack limiting mechanism according to claim 1, characterized in that, The jacking pipe (3) is positioned on the tapered pipe forming machine by two bearing seats (2), and the jacking pipe is supported by bearings (201) and can rotate freely.

4. The tapered tube rolling forming follow-up anti-crack limiting mechanism according to claim 1, characterized in that, The constraint sleeve (301) and the jacking pipe (3) are an integral structure.

5. The tapered tube rolling forming follow-up anti-crack limiting mechanism according to claim 1, characterized in that, The constraint sleeve (301) and the jacking pipe (3) body are detachable structures.

6. The tapered tube rolling forming follow-up anti-cracking limiting mechanism according to claim 5, characterized in that, The constraint sleeve (301) is connected to the jacking pipe (3) body by threads; the constraint sleeve is also connected to the jacking pipe body by a head screw (304).

7. The tapered tube rolling forming follow-up anti-cracking limiting mechanism according to claim 4, 5, or 6, characterized in that, The diameter of the hole forming the anti-reverse surface (3011) inside the constraint sleeve (301) is adjustable by a radial adjustment mechanism.

8. The tapered tube rolling forming follow-up anti-cracking limiting mechanism according to claim 7, characterized in that, The radial adjustment mechanism includes a nut seat (302) fixed on the outer diameter of the constraint sleeve. The constraint sleeve is provided with a guide hole, and a constraint block (305) is provided in the guide hole. The constraint block is positioned on the nut seat by an adjusting screw (303), and the adjusting screw pushes the constraint block to move radially. There are 3 constraint blocks (305), and the 3 constraint blocks are evenly distributed around the constraint sleeve (301). The constraint block has an arc surface that matches the outer diameter of the connecting rod (1).

Images