Anti-deformation elastic lining device for bending copper pipe

Abstract

The utility model belongs to the technical field of metal pipe machining, and particularly relates to an anti-deformation elastic lining device for bending a copper pipe. The device comprises a spiral spring used for being inserted into a to-be-bent area in a copper pipe and traction structures arranged at the two ends of the spiral spring. The pitch of the spiral spring is 0; or, the pitches of the spiral spring from the middle to the set number of turns at the two ends are 0, the pitches within the set number of turns at the two ends are gradually changed from 0 to 1 mm from the set number of turns at the two ends to the two ends, and the set number of turns is 3-5; the difference value between the outer diameter of the spiral spring and the inner diameter of the copper pipe to be bent ranges from 1 mm to 3 mm. The elastic modulus of the spiral spring is greater than the yield strength of the copper pipe to be bent; the traction structure is used for being connected with an external traction tool. According to the copper pipe bending device, the ovality and the wall thickness reduction rate of a bent copper pipe can be reduced, the single-time bending operation time is shortened, and the copper pipe bending device can be repeatedly used.

Description

Technical Field

[0001] This utility model relates to a copper pipe bending deformation prevention device, specifically a copper pipe bending deformation prevention elastic liner device. Background Technology

[0002] In the manufacturing of solid-insulated tubular busbars, T2 copper tubes are prone to problems such as tube wall indentation and excessive ellipticity due to uneven radial stress during bending. Traditional methods use sand filling, low-melting-point alloys, or built-in rigid support rods, but these methods have the following drawbacks:

[0003] 1. After filling with sand, high-temperature sintering and cleaning are required, which is inefficient and pollutes the environment;

[0004] 2. Low-melting-point alloys require repeated melting and recycling, which is costly;

[0005] 3. Rigid support rods cannot bend synchronously with the copper tubes, which can easily lead to damage to the tube walls. Utility Model Content

[0006] The purpose of this invention is to solve the technical problem that the existing technology cannot simultaneously meet the needs of dynamic support, convenient disassembly and assembly, and reusability during the bending process, and to provide a copper tube bending anti-deformation elastic liner device.

[0007] The inventive concept of this utility model is as follows: by using a pre-installed high-strength spring to match the inner diameter of the copper tube, uniform radial support is provided during the bending process, and quick assembly and disassembly are achieved through a hook-shaped structure.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] A copper tube bending-resistant elastic liner device, characterized in that it includes a helical spring; the helical spring has the following features:

[0010] Tight coil spring design: Use steel coil springs with zero pitch; or use end-gradient pitch: The pitch of the coil spring is 0 from the middle to both ends of the set number of turns position, and the pitch within the set number of turns at both ends gradually changes from 0 to 1mm from the set number of turns position at both ends, reducing stress concentration at the bending start point; the set number of turns is 3 to 5 turns.

[0011] The outer diameter of the helical spring is 1mm to 3mm smaller than the inner diameter of the copper tube to ensure that the helical spring fits snugly against the wall of the copper tube and can be freely inserted.

[0012] Dynamic mechanical matching: The elastic modulus of the helical spring is greater than the yield strength of the copper tube. When bending, the deformation of the helical spring absorbs external stress and prevents the copper tube from undergoing plastic deformation.

[0013] Traction structure: The spring is equipped with traction structures at both ends, specifically semi-circular hook-shaped structures, which can be quickly removed by pulling tools and support reuse;

[0014] Surface treatment optimization: The outer surface of the helical spring is coated with a low-friction coefficient lubricating coating (such as PTFE, lubricating oil or silicone grease) to reduce sliding resistance with the inner wall of the copper tube.

[0015] The beneficial effects of this utility model are:

[0016] 1. The ellipticity of the copper tube after bending is ≤2%, and the wall thickness reduction rate is <5%.

[0017] 2. The time for a single bending operation is reduced by 40% (compared to traditional sand core technology).

[0018] 3. The coil spring is reusable, reducing the overall cost by 60%. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the cross-section of the helical spring in the extension direction in an embodiment of this utility model.

[0021] In the picture:

[0022] 01-Copper pipe, 02-Pull tool, 031-Clamping block mold, 032-Pushing module, 033-Bending mold;

[0023] 1-Helical spring, 2-Tension structure. Detailed Implementation

[0024] To make the objectives, advantages, and features of this utility model clearer, the following detailed description of the copper tube bending anti-deformation elastic liner device proposed by this utility model is provided in conjunction with the accompanying drawings and specific embodiments. The advantages and features of this utility model will become clearer according to the following specific embodiments.

[0025] See Figure 1 This embodiment provides a copper tube bending anti-deformation elastic liner device, specifically including a helical spring 1 and a tension structure 2 disposed at both ends of the helical spring 1.

[0026] Example 1 (Basic Structure)

[0027] Parameters of helical spring 1: Material is 65Mn spring steel, outer diameter Φ48mm (matching Φ50mm copper tube 01), the cross-section of the spring wire is rectangular (see...). Figure 2The coil spring 1, measuring 3mm x 2mm, is galvanized for rust prevention. Its elastic modulus is greater than the yield strength of the copper tube 01, thus absorbing external stress through spring deformation and preventing plastic deformation of the copper tube 01 when it is bent using a bending machine. The coil spring 1 has a zero pitch and an outer diameter 1-3mm smaller than the inner diameter of the copper tube 01, ensuring that the coil spring 1 fits snugly against the wall of the copper tube 01 and can be freely inserted.

[0028] This embodiment uses a spring wire with a rectangular cross-section, which has the following advantages compared to a spring wire with a circular cross-section:

[0029] 1. Support effect and contact area

[0030] ① Rectangular cross-section spring wire:

[0031] With a larger contact area with the inner wall of copper tube 01, the pressure during bending can be evenly distributed, reducing local stress concentration. This uniform support can effectively prevent the collapse of the outer tensile area of ​​copper tube 01 and the wrinkling of the inner compression area.

[0032] ② Circular cross-section spring wire:

[0033] Contact can be point-like or line-like, with higher pressure, which may cause indentations or localized deformation on the inner wall of copper tube 01, especially when the material is softer (such as T2 copper).

[0034] 2. Resistance to deformation

[0035] ① Rectangular cross-section spring wire:

[0036] With a larger moment of inertia and higher bending stiffness, it is not easily flattened during bending and can stably maintain the circular cross-section of copper tube 01.

[0037] ② Circular cross-section spring wire:

[0038] With low bending stiffness, it may experience elastic instability or self-deformation under high pressure, resulting in a decrease in support effect.

[0039] Pulling structure 2: Both ends of the helical spring 1 are welded with semi-circular hook-shaped structures to facilitate connection with the external pulling tool 02 for easy pulling out. The welded joints are polished.

[0040] Operating procedures:

[0041] 1. Insert the helical spring 1 into the area to be bent on the copper tube 01;

[0042] 2. A hydraulic bending machine is used in conjunction with a mold to complete the bending of the copper tube; this module specifically includes a clamping block mold 031, a boosting module 032, and a bending mold 033.

[0043] 3. Use the pulling tool 02 to pull the hook-shaped structure to pull the helical spring 1 out of the copper tube 01, clean it, and reuse it.

[0044] Preferably, the bending machine can also be equipped with an automatic spring pushing / retrieving mechanism to automatically insert the helical spring 1 into the copper tube 01 or automatically remove the helical spring 1 from the copper tube 01, thereby achieving full automation when performing the aforementioned operation process.

[0045] Example 2 (Optimized Scheme)

[0046] The difference between this embodiment and Embodiment 1 is that:

[0047] The helical spring has a gradually changing pitch at the end: the pitch from the middle to the end of the first three turns is 0 mm, and the pitch within the last three turns gradually changes from 0 mm to 1 mm from the end of the first three turns to both ends, reducing stress concentration at the starting point of bending.

[0048] Surface coating: A 0.08mm thick PTFE (polytetrafluoroethylene) coating is sprayed onto the surface of the helical spring 1 to reduce the coefficient of friction of the helical spring 1 surface to 0.05-0.1. In other embodiments of this utility model, a lubricating oil coating or a silicone grease coating may be used instead of the aforementioned PTFE coating.

[0049] The other structures in this embodiment are the same as in Embodiment 1.

Claims

1. A copper tube bending anti-deformation elastic liner device, characterized in that: It includes a helical spring (1) for insertion into the bending area of ​​the copper tube (01), and a tension structure (2) provided at both ends of the helical spring (1); The pitch of the helical spring (1) is 0; or, the pitch of the helical spring (1) is 0 from the middle to both ends of the set number of turns position, and the pitch within the set number of turns at both ends gradually changes from 0 to 1mm from the set number of turns position at both ends to both ends, and the set number of turns is 3 to 5 turns; The difference between the outer diameter of the helical spring (1) and the inner diameter of the copper tube (01) to be bent is 1 mm to 3 mm; The elastic modulus of the helical spring (1) is greater than the yield strength of the copper tube (01) to be bent, so that it can absorb external stress through elastic deformation during bending and prevent the copper tube (01) from undergoing plastic deformation. The traction structure (2) is used to connect to an external traction tool (02) to enable the insertion and removal of the helical spring (1).

2. The copper tube bending anti-deformation elastic liner device according to claim 1, characterized in that: The outer surface of the helical spring (1) is coated with a lubricating coating.

3. The copper tube bending anti-deformation elastic liner device according to claim 2, characterized in that: The lubricating coating is a PTFE coating, a lubricating oil coating, or a silicone grease coating, and its thickness is 0.08 mm.

4. The copper tube bending anti-deformation elastic liner device according to any one of claims 1-3, characterized in that: The helical spring (1) is made of spring steel and galvanized. The cross-section of the spring wire in the helical spring (1) is rectangular.

5. The copper tube bending anti-deformation elastic liner device according to claim 4, characterized in that: The spring steel is 65Mn spring steel.

6. The copper tube bending anti-deformation elastic liner device according to claim 1, characterized in that: The tension structure (2) is a semi-circular hook-shaped structure.

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