Eccentric bending round die of coaxial heat exchanger

Abstract

The utility model discloses an eccentric bending round die for a coaxial heat exchanger, relates to the technical field of coaxial heat exchanger processing, and aims to solve the problem that a bent pipe section and a bending die body are prone to physical interference when a tight spiral structure is manufactured by the traditional copper pipe spiral bending. The eccentric groove extending along the spiral track and the rotation notch used for avoiding a bent pipe section in the rotation process of the die are formed in the circular die body, the rotation notch is formed in the outer circumferential face of the circular die body, the radial depth and size of the rotation notch are matched with the diameter of a to-be-bent pipe, and the rotation notch effectively provides an avoiding space, so that the yield of the to-be-bent pipe is improved. The problem of bending interference is thoroughly solved, so that tight spiral coiling of pipes with smaller screw pitches can be achieved, machining efficiency is improved, complex processes are not needed, and the structure is simple and practical.

Description

An eccentrically bent circular mold for a coaxial heat exchanger Technical Field

[0001] This utility model relates to the field of coaxial heat exchanger processing technology, and in particular to an eccentric bending circular mold for coaxial heat exchangers. Background Technology

[0002] Coaxial heat exchangers are widely used in refrigeration and heating due to their compact structure and high heat exchange efficiency. The core component of a coaxial heat exchanger is the inner and outer coiled heat exchange coil, and the key manufacturing process is to spirally bend the metal tubes.

[0003] Various equipment and dies exist for helical bending of pipes, but traditional bending dies or processes often face technical challenges when manufacturing coaxial heat exchanger coils requiring very tight helical pitches. During the continuous bending and helical winding of the pipe, the already formed pipe segment gradually occupies space. For situations requiring a tight helix, when the die rotates to a certain angle, the bent pipe segment can easily interfere with other non-working surfaces of the die body, especially areas that may be swept by the die during rotation. Existing technologies may require increasing the helix pitch to avoid this interference, sacrificing the compactness and heat exchange efficiency of the coaxial heat exchanger; or employing complex step-by-step bending processes, or even twisting the pipe during bending. These methods increase process complexity, reduce production efficiency, and may still fail to achieve the required extremely small helical pitch. Therefore, designing a bending die that effectively avoids interference with the already bent pipe segment during the bending process, thereby achieving helical bending of pipes with smaller pitches, is a pressing technical problem in this field.

[0004] Therefore, this application provides an eccentric bending circular mold for a coaxial heat exchanger to meet the requirements. Summary of the Invention

[0005] The purpose of this application is to provide an eccentric bending circular mold for coaxial heat exchangers, aiming to solve the problem that during the continuous bending and spiral winding of the tube, the already formed tube segment gradually occupies space. For situations requiring a tight spiral, when the mold rotates to a certain angle, the solid body of the bent tube segment is prone to interference with other non-working outer surfaces of the mold body, especially with areas that may be swept by the mold during rotation. To avoid this interference, existing technologies may have to increase the spiral pitch, sacrificing the compactness and heat exchange efficiency of the coaxial heat exchanger; or adopt complex step-by-step bending processes, or even twist the tube during bending. These methods increase process complexity, reduce production efficiency, and may still be difficult to achieve the extremely small spiral pitch requirement.

[0006] To achieve the above objectives, this application provides the following technical solution: an eccentric bending circular mold for a coaxial heat exchanger, comprising an eccentric circular mold, a heat exchange coil, and a CNC tube bending machine. The CNC tube bending machine is further provided with a fixed mold frame, a fixed guide mold, and a rotation mechanism. The CNC tube bending machine processes the heat exchange coil through the eccentric circular mold. The eccentric circular mold also includes a mold body, on which a rotation notch and an eccentric groove are provided on the outer circumference of the mold body. The rotation notch is provided on the mold body to avoid the bent pipe section during the rotation of the eccentric circular mold, effectively solving the bending interference problem.

[0007] Preferably, the circular mold body is also provided with a fixing pin hole for quick assembly and disassembly. The fixing pin hole is located on the axis of the rotation center of the circular mold body, which facilitates quick mold replacement.

[0008] Preferably, the cross-sectional shape of the eccentric groove is adapted to the tube shape of the unprocessed heat exchange coil, and the trajectory of the eccentric groove has a spiral trajectory with an upward or downward slope along the rotation axis of the circular mold body to ensure accurate spiral bending forming.

[0009] Preferably, the rotary notch extends within a predetermined angle range along the circumference of the circular mold body, providing sufficient clearance.

[0010] Preferably, the rotary notch is a rectangular notch that intersects with the outer circumferential surface of the circular mold body, which has a simple structure and is easy to manufacture.

[0011] Preferably, the slewing notch has a radial depth, which is greater than or equal to the diameter of the pipe to be bent.

[0012] In summary, the technical effects and advantages of this utility model are as follows:

[0013] In this invention, a rotation notch is provided on the circular mold body. This notch effectively avoids bent pipe sections during the rotation of the eccentric circular mold, solving the technical problem of physical interference between bent pipe sections and the mold body in the prior art, and enabling spiral bending of pipes with a smaller pitch. This makes it possible to manufacture more compact coaxial heat exchangers with a larger heat exchange area per unit volume, thereby improving heat exchange efficiency.

[0014] In this invention, the interference problem is solved by optimizing the mold structure itself, eliminating the need for complex step-by-step bending processes or additional operations such as pipe twisting, thus simplifying the spiral bending process and improving production efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 is a schematic diagram of the structure of this utility model;

[0017] Figure 2 is a top view of the eccentric circular mold of this utility model;

[0018] Figure 3 is a front view of the eccentric circular mold of this utility model;

[0019] Figure 4 is a side view of the eccentric circular mold of this utility model;

[0020] Figure 5 is a top view of the heat exchange coil of this utility model;

[0021] Figure 6 is a front view of the heat exchange coil of this utility model;

[0022] Figure 7 is a schematic diagram of the working state of this utility model.

[0023] In the diagram: 1. Eccentric circular mold; 2. Heat exchange coil; 3. Fixed mold frame; 4. Fixed guide mold; 5. Rotation mechanism; 6. Circular mold body; 7. Fixed pin hole; 8. Rotation notch; 9. Eccentric groove. Detailed Implementation

[0024] 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 scope of protection of the present utility model. Embodiments

[0025] Referring to Figures 1-7, a coaxial heat exchanger eccentric bending die includes an eccentric die 1 and a coaxial heat exchanger. The eccentric die 1 is used in conjunction with a CNC tube bending machine. The CNC tube bending machine is usually equipped with components such as a fixed frame die 3, a fixed guide die 4, and a rotating mechanism 5. The eccentric die 1 is driven to rotate by the rotating mechanism 5. One end of the heat exchange coil 2 to be bent is clamped and positioned by the cooperation of the fixed frame die 3 and the fixed guide die 4, while the other part is in contact with the eccentric die 1.

[0026] As one embodiment of this invention, the eccentric circular mold 1 includes a circular mold body 6. The circular mold body 6 is the main structure of the eccentric circular mold 1, and a rotation notch 8 and an eccentric groove 9 are provided on the circular mold body 6.

[0027] In one embodiment of this invention, an eccentric groove 9 is formed on the outer circumferential surface of the circular mold body 6, extending spirally along the circumferential direction of the circular mold body 6. The cross-sectional shape of the eccentric groove 9 is adapted to the shape of the unprocessed heat exchange coil 2, and is semi-circular. The eccentric groove 9 is designed to be eccentrically positioned relative to the rotation center of the circular mold body 6. This eccentricity determines the bending radius of the final bent heat exchange coil 2. Furthermore, the trajectory of the eccentric groove 9 has an upward or downward slope along the rotation axis of the circular mold body 6. It is through this spiral upward or downward trajectory design, combined with the axial feed mechanism of the CNC tube bending machine, that the unprocessed heat exchange coil 2 is spirally bent, ultimately forming a heat exchange coil 2 with a specific pitch.

[0028] As one embodiment of this invention, the rotation notch 8 is provided on the outer circumferential surface of the circular mold body 6. The rotation notch 8 can be formed by partially cutting off the outer circumferential surface of the circular mold body 6. The rotation notch 8 extends along the circumferential direction of the circular mold body 6 within a predetermined angle range. The rotation notch 8 is a rectangular notch that intersects with the outer circumferential surface of the circular mold body 6. The size of the rotation notch 8 is adapted to the diameter of the heat exchange coil 2 to be bent, so as to ensure that sufficient clearance space is provided during the rotation of the mold.

[0029] As one embodiment of this invention, the circular mold body 6 is also provided with a fixing pin hole 7 for installation and positioning. The fixing pin hole 7 is located on the rotation center axis of the circular mold body 6 and is used to reliably install the circular mold body 6 onto the rotating mechanism 5 of the CNC pipe bending machine.

[0030] As one embodiment of this invention, the overall shape of the circular mold body 6 can be approximated as a cylinder with about one-third cut off along a plane parallel to the axis, and a rotary notch 8 and an eccentric groove 9 are opened on the remaining outer circumference. The material of the circular mold body 6 is preferably a high-strength, wear-resistant metal material, such as mold steel.

[0031] The working principle of this practical tool is as follows: The heat exchange coil 2 to be bent is placed on a CNC tube bending machine, with one end fixed between the fixed mold 3 and the fixed guide mold 4, and the other part passing through the fixed guide mold 4 and contacting the eccentric groove 9 of the eccentric circular mold 1. The CNC tube bending machine and the rotating mechanism 5 are started, driving the eccentric circular mold 1 to rotate around its rotation center axis. Due to the eccentric design of the eccentric groove 9, when the eccentric circular mold 1 rotates, the unprocessed heat exchange coil 2 is bent into an arc matching the radius of the groove under the guidance and compression of the eccentric groove 9. At the same time, the CNC tube bending machine will perform axial feed according to the set pitch, cooperating with the eccentric groove 9. The spiral trajectory causes the pipe to coil upwards along the axial direction. To avoid interference with the circular mold body 6 when the heat exchange coil 2 is bent to nearly 180 degrees during the bending process, the rotation notch 8 is set precisely on the outer circumference of the already bent pipe section. The radial depth and circumferential range of the rotation notch 8 are sufficient to accommodate the cross-section of the already bent pipe section, avoiding a physical collision between the pipe section and the mold. This allows the CNC pipe bending machine to continue driving the mold to rotate and perform axial feeding until the bending of the entire heat exchange coil is completed, minimizing the spacing between the spiral coils and achieving a tight coiled structure.

[0032] The electromechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments; they are common knowledge.

[0033] Components not described in detail in this article are existing technologies.

[0034] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An eccentric bending die for a coaxial heat exchanger, comprising an eccentric die (1), a heat exchange coil (2), and a CNC bending machine, wherein the CNC bending machine is further provided with a fixed frame die (3), a fixed guide die (4), and a rotating mechanism (5), and the CNC bending machine processes the heat exchange coil (2) through the eccentric die (1), characterized in that: The eccentric circular mold (1) also includes a circular mold body (6), on which a rotation notch (8) and an eccentric groove (9) are provided. The notch (8) is provided on the outer circumferential surface of the circular mold body (6) and is used to avoid the bent pipe section during the rotation of the eccentric circular mold (1).

2. The eccentric bending circular mold for a coaxial heat exchanger according to claim 1, characterized in that: The circular mold body (6) is also provided with a fixing pin hole (7) for quick assembly and disassembly. The fixing pin hole (7) is located on the axis of the rotation center of the circular mold body (6).

3. The coaxial heat exchanger eccentric bending circular mold according to claim 2, characterized in that: The cross-sectional shape of the eccentric groove (9) is adapted to the tube shape of the unprocessed heat exchange coil (2), and the trajectory of the eccentric groove (9) has a spiral trajectory with an upward or downward slope along the rotation axis of the circular mold body (6).

4. The eccentric bending circular mold for a coaxial heat exchanger according to claim 3, characterized in that: The rotary notch (8) extends within a predetermined angle range along the circumferential direction of the circular mold body (6).

5. The eccentric bending circular mold for a coaxial heat exchanger according to claim 4, characterized in that: The rotary notch (8) is a rectangular notch that intersects with the outer circumferential surface of the circular mold body (6).

6. The coaxial heat exchanger eccentric bending circular mold according to claim 5, characterized in that: The slewing notch (8) has a radial depth greater than or equal to the diameter of the pipe to be bent.

Images