A coiled condenser inner core pipe forming device

Abstract

The utility model discloses a serpentine condenser inner core pipe forming device belongs to pipe bending processing technical field, aims at solving the problem that pipe material is easy to appear wrinkle, depression, cross section distortion in the process of ordinary pipe bending, especially suitable for high accuracy, thin wall or small diameter pipe material processing. The device is mainly composed of core rod, winding pipe subassembly and clamping block: the core rod surface spiral distribution half round groove, the outer diameter and target pipe diameter adaptation, provide the radial support for pipe inner wall to maintain cross section circle; winding pipe subassembly contains handle, rotating wheel and other components, and can move along the core rod axial through handle transmission operating force drive pipe bending; clamping block is used for fixed pipe material position. The utility model discloses through "internal support + external drive" synergistic effect balance pipe bending stress, can continuous forming serpentine pipe, simple structure, convenient operation, the processing and assembling difficulty are low, can satisfy the high accuracy requirement of aviation, automobile manufacturing and other fields to pipe bending quality, effectively promotes pipe bending consistency and yield.

Description

Technical Field

[0001] This utility model relates to a serpentine condenser inner core tube forming device, which is used to solve problems such as wrinkles, dents and cross-sectional distortion that easily occur in pipes during ordinary pipe bending. It is especially suitable for bending processing of high-precision, thin-walled or small-diameter pipes, and is widely used in aerospace, automobile manufacturing, petrochemical, medical device and other fields. Background Technology

[0002] The technical background of this utility model mainly stems from the higher requirements of industrial production for the quality of pipe bending and the limitations of traditional pipe bending methods, as detailed below: Expanding Application Scenarios and Increasing Quality Requirements for Pipes: With the development of industries such as aerospace, automotive manufacturing, and petrochemicals, the demand for pipes is constantly increasing, and higher requirements are being placed on the quality of pipe bending. For example, in the aerospace field, aircraft hydraulic conduits and fuel lines require precise bending angles and dimensional accuracy, while ensuring the strength and sealing of the pipes. Traditional pipe bending methods are difficult to meet these high-precision requirements. In automotive manufacturing, mass-produced pipes such as chassis brake lines and engine cooling lines require good bending consistency to ensure assembly quality and system performance.

[0003] Processing Requirements for Thin-Walled Pipes and Pipes Made of Special Materials: In modern industry, the application of thin-walled pipes and high-strength special material pipes such as stainless steel and titanium alloys is becoming increasingly widespread. Due to their thin walls, thin-walled pipes are prone to wrinkles, dents, and cross-sectional distortions during bending, and ordinary bending methods cannot provide sufficient support to ensure bending quality. Meanwhile, high-strength materials such as stainless steel and titanium alloys require greater external force during bending, making them more susceptible to defects. Therefore, more effective bending techniques are needed to ensure processing feasibility and quality.

[0004] Limitations of traditional pipe bending methods: Traditional coreless pipe bending methods, such as roll bending and pressure bending, cause the inner wall of the pipe to wrinkle and dent due to compression force, while the outer wall is prone to thinning or even cracking due to tension force. Furthermore, it is difficult to control the cross-sectional shape of the pipe, which can easily lead to excessive ellipticity and fail to meet the requirements of modern industry for pipe bending quality. Utility Model Content

[0005] This invention aims to solve problems such as wrinkles, dents, and cross-sectional distortion that easily occur in pipes during ordinary pipe bending. By using the synergistic effect of "internal support + external drive", the stress distribution during pipe bending is balanced, ultimately achieving a "high-quality, high-precision, and widely adaptable" pipe bending effect, thus solving the existing technical problems.

[0006] This utility model is achieved through the following technical solution: A serpentine condenser inner core tube forming device mainly consists of three parts: a core rod (3), a tube winding assembly (4), and a clamping block (5).

[0007] The function of the mandrel (3) is to provide radial support for the inner wall, counteract compressive stress, prevent wrinkles in the inner wall, and limit the shrinkage or expansion of the pipe section, maintain the circularity of the section, and avoid cross-sectional distortion. Its outer diameter matches the middle diameter of the target bend pipe, and its surface has a spirally distributed semi-circular groove. The groove pitch is consistent with the pitch of the target bend pipe, and the groove radius is consistent with the radius of the pipe to be bent.

[0008] The pipe winding assembly (4) is a power device for driving bending. It transmits operating force through the handle (14) and achieves bending drive of the pipe by means of the synergistic effect of each component.

[0009] Clamping block (5) is used to fix the position of the pipe during the forming process to ensure the stability and safety of the pipe during the bending process.

[0010] The beneficial effects of this utility model are: 1. It can be continuously formed. After completing multiple rounds of forming, the clamping block (5) can be removed. By rotating the mandrel (3), the winding tube assembly (4) can be moved to the top of the mandrel (3), the clamping block (5) can be installed, and the bending tube operation can be repeated to form a continuous "snake tube". 2. The structure is relatively simple, the processing and assembly are less difficult, which facilitates production and manufacturing, and also facilitates later maintenance and parts replacement; 3. The operation is relatively convenient. It can be operated directly through the handle (14), and the bending process can be controlled intuitively. No complicated operation training is required, and workers can easily get started. Attached Figure Description

[0011] Figure 1 A 3D structural diagram of a serpentine condenser; Figure 2 This is a three-dimensional structural diagram of the device of this utility model; Figure 3 This is an exploded view of the tube winding assembly; Figure 4 This is an assembly diagram of the tube winding assembly; In the diagram: 1-Inner core tube; 2-Outer tube; 3-Mandrel; 4-Wound tube assembly; 5-Clamping block; 6-Rotating wheel; 7-Deep groove ball bearing; 8-Bearing cap; 9-Pin; 10-Thrust bearing; 11-Spring; 12-Cotter pin; 13-Sleeve; 14-Handle; Detailed Implementation

[0012] The following will refer to the accompanying drawings of the embodiments of this utility model ( Figures 1-4This document provides a clear and complete description of the technical solutions in the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0013] 1. Device component preparation and parameter setting (1) Preparation of mandrel (3) High-quality structural steel (grade 45) is selected as raw material and processed into a cylindrical structure by CNC lathe to ensure that the error between the outer diameter of the mandrel (3) and the middle diameter of the target bent pipe is ≤ ±0.02mm (for example, when the middle diameter of the target bent pipe is 30mm, the outer diameter of the mandrel is processed to be 30±0.02mm). A spirally distributed semi-circular groove is machined on the surface of the mandrel (3) using a five-axis milling machine. The groove pitch is consistent with the pitch of the target bent pipe (for example, when the pitch of the bent pipe is 25mm, the groove pitch is set to 25mm). The groove radius is the same as the radius of the pipe to be bent (for example, when the outer diameter of the pipe is 10mm, the groove radius is set to 5mm). Finally, the surface of the mandrel (3) is treated by precision grinding process to make the surface roughness Ra≤0.8μm, thereby reducing the frictional resistance with the inner wall of the pipe.

[0014] (2) Preparation of the winding tube assembly (4) Rotating wheel (6): 45 steel is selected and machined by turning and milling. An arc-shaped groove is machined on the outer periphery (the radius is consistent with the radius of the pipe to be bent). The surface roughness of the groove Ra≤1.6μm; a bearing mounting hole is reserved in the center of the wheel body, and the hole diameter is adapted to the outer diameter of the deep groove ball bearing (7).

[0015] Deep groove ball bearing (7): Select standard bearing of model ZB6000 to ensure that its inner diameter is precisely matched with the outer diameter of the pin (9) and the bearing mounting hole of the rotating wheel (6), and the radial clearance is controlled at 0.01-0.03mm.

[0016] Pin (9): Made of 45 steel, the surface is heat treated (hardness HRC28-32) and chrome plated (plating thickness 0.02-0.03mm), and a pin hole is machined at one end for installing cotter pin (12).

[0017] Spring (11): Made of carbon spring steel (model 65Mn), with an elastic modulus of 8N / mm, a free length of 50mm, and a compression of 5-8mm to provide stable buffering force.

[0018] Handle (14) and sleeve (13): The handle (14) is 300mm long for easy gripping, and one end is machined with a through hole diameter that matches the pin (9); the sleeve (13) is made of seamless steel pipe (material 20# steel), and one end is welded to the handle (14).

[0019] (3) Clamping block (5) Preparation The U-shaped block structure is made of Q235 carbon steel. A 2.5mm thick nitrile rubber pad is glued to the inside. The surface of the rubber pad is treated with anti-slip texture to ensure that the surface is not scratched when fixing the pipe, while providing sufficient friction to prevent the pipe from sliding.

[0020] 2. Equipment Assembly Process Referring to Figure 3 (exploded view of the tube winding assembly) and Figure 4 (assembled view of the tube winding assembly), complete the overall assembly of the device according to the following steps: (1) Insert the deep groove ball bearing (7) into the bearing mounting hole of the rotating wheel (6) and cover it with the bearing cap (8).

[0021] (2) Pass one end of the pin (9) through the thrust bearing (10) and the spring (11) in sequence, and then insert it into the mounting hole of the handle (14). Insert the cotter pin (12) into the other end of the pin (9) to achieve axial positioning of the pin (9) and the sleeve (13).

[0022] (3) Place the assembled tube winding assembly (4) on the outside of the mandrel (3) so that the arc groove of the rotating wheel (6) corresponds to the semi-circular groove of the mandrel (3); finally, fix the clamping block (5) in the designated position of the mandrel (3) with bolts to ensure that the distance between the inner rubber pad of the clamping block (5) and the surface of the mandrel (3) is equal to the radius of the tube to be bent, and complete the assembly of the entire device (refer to Figure 2, three-dimensional structure diagram of the device).

[0023] 3. Steps for forming the inner core tube of the serpentine condenser Taking the processing of a nickel (N5) inner core tube (1) with an outer diameter of 6mm and a wall thickness of 1mm as an example, the target bending pitch is 12mm and the bending radius is 17mm. The operation process is as follows: (1) Pipe pretreatment: Anneal the nickel pipe to be bent to eliminate internal stress; blow the inner wall of the pipe with compressed air (pressure 0.6MPa) to remove impurities and oil stains.

[0024] (2) Pipe clamping: Place one end of the pre-treated pipe between the semi-circular groove on the surface of the mandrel (3) and the arc-shaped groove of the rotating wheel (6), adjust the position of the pipe so that the starting end of the bending is aligned with the starting point of the first groove of the mandrel (3); close the clamping block (5) so that the rubber pad layer is tightly attached to the outer wall of the pipe, ensuring that the pipe is fixed and has no obvious deformation.

[0025] (3) Tube bending and forming: The operator holds the handle (14) and slowly rotates it counterclockwise (the speed is controlled at 10-15 r / min). The torque is transmitted through the handle (14) to drive the rotating wheel (6) to rotate. The arc groove of the rotating wheel (6) drives the tube to bend along the semi-circular groove of the mandrel (3). During the bending process, the mandrel (3) provides radial support for the inner wall of the tube to avoid wrinkles on the inner wall. The spring (11) provides stable pressure to the rotating wheel (6) through the thrust bearing (10) to ensure that the outer wall of the tube fits tightly with the arc groove and maintains the circular cross-section.

[0026] (4) Continuous forming operation: After completing 30 turns of tube bending, loosen the adjusting screw of the clamping block (5), rotate the mandrel (3) to drive the winding assembly (4) to move along the axial direction of the mandrel (3), so that the rotating wheel (6) aligns with the first groove section of the mandrel (3); close the clamping block (5) again to fix the tube, and repeat the bending operation of step 3 until the forming of the entire serpentine inner core tube (1) is completed (see reference). Figure 1 (3D structural diagram of a serpentine condenser)

[0027] (5) Finished product removal and inspection: After molding, completely loosen the clamping block (5), rotate the mandrel (3), and slowly unscrew the serpentine inner core tube (1); use vernier calipers to measure the ellipticity of the bent pipe section (required ≤5%) and the pitch error (required ≤±0.5mm), and use a surface roughness tester to inspect the surface quality of the inner and outer walls of the pipe (required Ra≤3.2μm) to ensure that the finished product meets the quality standards.

[0028] 4. Implementation effect verification Compared with the traditional coreless tube bending method, the key performance indicators of processing the above-mentioned nickel inner core tube using the apparatus of this embodiment are improved as follows: (1) Molding quality: The cross-sectional ellipticity is reduced from 12%-15% in the traditional method to 3%-4%, with no wrinkles or depressions; the surface roughness of the inner wall of the pipe is reduced from Ra5.6-6.3μm to Ra2.8-3.2μm.

[0029] (2) Processing efficiency: The processing time for a single 3m long serpentine inner core tube is reduced from the traditional 40-50 minutes to 15-20 minutes, and no subsequent shaping process is required.

[0030] (3) Material compatibility: It can successfully process thin-walled pipes with a wall thickness of 0.5-2mm and high-strength pipes such as titanium alloy (TC4), while the yield of such pipes is less than 50% when processed by traditional methods. The yield of this device can reach more than 95%.

[0031] In summary, this utility model device effectively solves the quality defects of traditional pipe bending through the synergistic design of "internal support + external drive". It is easy to operate and adaptable to a variety of pipe materials, and has significant practical value and promotion significance in the field of high-precision pipe processing such as aerospace and automobile manufacturing.

Claims

1. A serpentine condenser inner core tube forming device, characterized in that: It mainly consists of a mandrel (3), a winding assembly (4), and a clamping block (5); the mandrel (3) is used to provide radial support for the inner wall of the pipe to be bent, and its outer diameter matches the middle diameter of the target pipe. The surface of the mandrel (3) is spirally distributed with semi-circular grooves, the pitch of the semi-circular grooves is consistent with the pitch of the target pipe, and the radius of the semi-circular grooves is consistent with the radius of the pipe to be bent; the winding assembly (4) is used to drive the pipe to bend along the semi-circular grooves of the mandrel (3), and can move along the axial direction of the mandrel (3); the clamping block (5) is used to fix the position of the pipe to be bent during the forming process.

2. The serpentine condenser inner core tube forming device according to claim 1, characterized in that: The winding assembly (4) includes a rotating wheel (6), a deep groove ball bearing (7), a bearing cap (8), a pin (9), a thrust bearing (10), a spring (11), a cotter pin (12), a sleeve (13), and a handle (14); the handle (14) is fixedly connected to the sleeve (13), the sleeve (13) is sleeved on the outside of the mandrel (3), one end of the pin (9) is sequentially fitted with the thrust bearing (10) and the spring (11), and the other end is limited by the cotter pin (12); the rotating wheel (6) is connected to the pin (9) through the deep groove ball bearing (7), and the bearing cap (8) covers the outside of the deep groove ball bearing (7).

3. The serpentine condenser inner core tube forming device according to claim 1, characterized in that: The mandrel (3) is made of high-quality structural steel with a surface roughness Ra≤0.8μm to reduce friction with the inner wall of the pipe to be bent.

4. The serpentine condenser inner core tube forming device according to claim 1, characterized in that: The clamping block (5) has a rubber pad layer on its inner side. The thickness of the rubber pad layer is 2-3mm, which is used to avoid scratching the surface of the pipe when fixing the pipe.

5. The serpentine condenser inner core tube forming apparatus according to any one of claims 1-4, characterized in that: The outer circumference of the rotating wheel (6) of the pipe winding assembly (4) is provided with an arc-shaped groove. The radius of the arc-shaped groove is consistent with the radius of the pipe to be bent, and it is used to fit the outer wall of the pipe and drive the pipe to bend.

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