A pulse tube hot insert die-casting mold and a die-casting method

Abstract

The application discloses a pulse tube hot insert die-casting die, which is characterized by comprising a fixed die and a movable die, the fixed die is provided with movable inserts for forming radiator fins, the fixed die is provided with a positioning core, so that a pulse tube assembly is limited on the positioning core through the positioning holes of the edges, the position of the pulse tube assembly is located at the root of the radiator fins, the middle part of the fixed die is provided with supporting columns, the fixed die is provided with a sprue, the movable die is provided with a pre-positioning device corresponding to the two ends of the pulse tube assembly. The application has the beneficial effects of well fixing the pulse tube, small pressure on the pulse tube, ensuring the die-casting stability of the pulse tube, reducing the deformation of the pulse tube and improving the die-casting quality.

Description

Technical Field

[0001] This invention relates to the field of die casting technology, specifically to a pulse tube hot-embedded die casting mold and a die casting method. Background Technology

[0002] With the widespread adoption of 5G communication technology, the heat dissipation requirements for communication base stations are becoming increasingly stringent, leading to ever-higher heat dissipation fins. Traditional fin-based heat dissipation is no longer sufficient, prompting the introduction of technologies such as press-fitted copper tubes and folded fins to aid in heat dissipation. However, these technologies fall far short of the heat dissipation performance of pulse tubes. Traditional pulse tubes are connected to the base via welding or press-fitting, resulting in unstable welding processes and high costs. Furthermore, the thin walls of pulse tubes, only 1mm thick, lack sufficient strength, and press-fitting can cause wall breakage. These issues have long been a pain point in the industry.

[0003] Furthermore, traditional die casting relies primarily on high aluminum melt temperatures, high injection pressures, and rapid filling speeds. This results in die castings with insufficient internal density, leading to low thermal conductivity. Additionally, the high temperature, high pressure, and high speed of traditional liquid die casting subject heat-embedded products to tremendous impact forces within the mold cavity, causing deformation and potentially damage. Pulse tubes, due to the need for bending and limitations imposed by product wall thickness, can only be made thin and tough, making them unable to withstand the high temperature and high pressure of traditional die casting. Summary of the Invention

[0004] To address the shortcomings of the prior art, this invention provides a pulse tube hot-embedding die-casting mold, which is suitable for hot-embedding die-casting of pulse tubes on radiators, resulting in high die-casting quality and good die-casting stability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A pulse tube hot-fitting die-casting mold, characterized in that: it includes a fixed mold and a moving mold, the fixed mold has a movable insert for forming heat sink fins, the fixed mold is provided with a positioning core, such that the pulse tube assembly is limited on the positioning core through positioning holes on the edge, the pulse tube assembly is located at the root of the heat sink fins, a support column is provided in the middle of the fixed mold, the fixed mold has a sprue, and the moving mold is provided with a pre-positioning device, the pre-positioning device corresponding to both ends of the pulse tube assembly.

[0007] Furthermore, the pulse assembly includes a pulse tube and a fixing plate. The pulse tube is coiled in an S-shape, and the fixing plate clamps the pulse tube from both sides and welds it into a single unit.

[0008] Furthermore, fixing plates are laterally arranged at both ends of the pulse tube along the length direction of the fixed model cavity, and the fixing plates have grooves for accommodating the pulse tube.

[0009] Furthermore, the pre-positioning device includes a pre-positioning block, a pull rod, and a spring. One end of the pull rod is fixed to the moving mold, and the other end of the pull rod has a disc head. The pre-positioning block has a limiting groove that cooperates with the disc head. The spring limits the pre-positioning block to one end near the moving mold. The moving mold has a cavity for accommodating the pre-positioning block.

[0010] Furthermore, the prepositioning block has a contoured groove on one end face away from the moving mold.

[0011] It also aims to provide a pulse tube hot-embedded die-casting method, characterized by including the following steps:

[0012] S1. Fix the fixing plate and the pulse tube to obtain the pulse tube assembly;

[0013] S2. After the die-casting machine opens the mold, the pulse tube assembly is suspended on the fixed mold through the positioning hole, and the middle part of the pulse tube assembly is supported by the fixed mold core support column.

[0014] S3. Start the die-casting machine. On the moving mold side, the spring and the pull rod will push out the prepositioning device. The prepositioning device will press the pulse tube assembly before the moving mold.

[0015] S4. The pre-positioning device retracts into the moving mold core as the mold closing process proceeds until the mold closing is completed;

[0016] S5. After the mold is closed, the molten aluminum is pushed out by the punch and slowly fills the cavity through the sprue.

[0017] The beneficial effects of this invention include: it effectively fixes the pulse tube, reduces the pressure on the pulse tube, ensures the die-casting stability of the pulse tube, reduces pulse tube deformation, and improves die-casting quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the mold structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the core surface structure of the fixed model of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the moving model core surface of the present invention.

[0021] Figure 4 This is a schematic diagram of the pulse tube assembly structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the prepositioning device of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0024] One such Figure 1-5 The pulse tube hot-fit die-casting mold shown includes a fixed mold A and a moving mold D. The moving mold D has a movable insert 4 for forming heat sink fins, used to form spaced heat sink fins on the moving mold side. A positioning core B is provided on the fixed mold A, allowing the pulse tube assembly F to be positioned on the positioning core B through positioning holes 3 on its edge. The pulse tube assembly F is positioned at the root of the heat sink fins, thus enabling hot-fit die-casting. To prevent the pulse tube assembly F from deforming under the pressure of the molten metal during die-casting, this embodiment provides a support column G in the middle of the fixed mold A.

[0025] The fixed mold A has a sprue E, which is an integral sprue without branches, and its inner gate thickness is 8-10mm.

[0026] A pre-positioning device C is provided on the moving mold D, corresponding to both ends of the pulse tube assembly F. The pre-positioning device C includes a pre-positioning block C1, a pull rod L1, and a spring T1. One end of the pull rod L1 is fixed to the moving mold D, and the other end of the pull rod L1 has a disc head. The pre-positioning block C1 has a limiting groove that mates with the disc head. The spring T1 limits the pre-positioning block C1 at the end near the moving mold D. The moving mold D has a cavity to accommodate the pre-positioning block C1, so that the rear part of the pre-positioning block C1 can be hidden inside the moving mold when the mold is closed. The end face of the pre-positioning block C1 away from the moving mold D has a contoured groove, which is used to limit the end of the pulse tube and prevent the pulse tube assembly from shifting due to the mold closing pressure.

[0027] To increase the strength of the pulse tube, the pulse tube assembly F in this embodiment includes a pulse tube 2 and a fixing plate 1. The pulse tube 2 is coiled in an S-shape, and the fixing plate 1 clamps the pulse tube 2 from both sides and welds it into a whole. The fixing plate 1 is arranged laterally at both ends of the pulse tube 2 along the length direction of the A-type cavity of the fixed mold, that is, to fix the bending part of the pulse tube 2. The fixing plate 1 has a groove to accommodate the pulse tube 2.

[0028] The die-casting process of this invention includes the following steps:

[0029] S1. Fix the fixing plate 1 and the pulse tube 2 together to obtain the pulse tube assembly F. The pulse tube is an aluminum tube with a diameter of 1mm and a wall thickness of 1mm. The fixing plate is a steel plate with a single-sided thickness of 2.5mm and a total thickness of 5mm. The pulse tube is made of pure aluminum to avoid contamination of the material composition due to the hot-insertion of metals such as copper. The fixing plate is made of steel plate because the product requires airtightness and PM requirements (model testing). Therefore, the fixing plate must be made of steel plate to ensure seamless integration with the product after hot-insertion and meet the airtightness requirements.

[0030] S2. After the die-casting machine opens the mold, the pulse tube assembly F is suspended from the positioning core B of the fixed mold A through the positioning hole 3. Because a new pulse tube needs to be installed for each die-casting, and considering manufacturing tolerances, the positioning hole on the pulse tube fixing plate is made into one round and one flat hole for subsequent pulse tube mounting. The positioning core B on the mold consists of two cylinders. To prevent the positioning pillars from wearing out and deforming after continuous and stable production, the positioning pillars on the mold are made into forming cores for easy replacement. At the same time, the middle part of the pulse tube assembly F is supported by the fixed mold core support pillar G, and its supporting force can offset the pressure on the pulse tube during molten metal filling.

[0031] S3. Start the die-casting machine. On the moving mold side, spring C1 and pull rod L1 push out the prepositioning device C. The prepositioning device C presses the pulse tube assembly F before the moving mold; to prevent the pulse tube from being knocked off by the pressure when the mold is closed.

[0032] S4. The pre-positioning device C retracts into the moving mold core as the mold closing process proceeds until the mold closing is completed.

[0033] S5. After the mold is closed, the molten aluminum is pushed out by the punch and slowly fills the cavity through the sprue E. The sprue E is an integral sprue without branches, and its ingate thickness is 8-10mm to reduce the impact force of the molten aluminum, reduce the pressure on the pulse tube 2, and prevent the pulse tube 2 from shifting.

[0034] In this embodiment, the casting pressure is selected as 200-300 MPa. The reduction in casting pressure is more conducive to the integrity of the pulse tube. The ingate speed is selected as 15-25 m / s, which is much lower than the ingate speed of traditional high-pressure die casting. The reduction in speed reduces the impact force of molten aluminum on the pulse tube.

[0035] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A pulse tube hot-embedding die-casting mold, characterized in that: The device includes a fixed mold (A) and a moving mold (D). The moving mold (D) has a movable insert (4) that forms radiator fins. The fixed mold (A) is provided with a positioning core (B) so that the pulse tube assembly (F) is limited on the positioning core (B) through the positioning hole (3) on the edge. The pulse tube assembly (F) is located at the root of the radiator fins. The fixed mold (A) is provided with a support column (G) in the middle to support the middle part of the pulse tube assembly (F). The pulse tube assembly (F) includes a pulse tube (2) and a fixing plate (1). The pulse tube (2) is S-shaped and coiled. The fixing plate (1) clamps the pulse tube (2) from both sides and welds it to a whole. The fixed mold (A) has a sprue (E), and the moving mold (D) is provided with a pre-positioning device (C). The pre-positioning device (C) corresponds to both ends of the pulse tube assembly (F). The pre-positioning device (C) includes a pre-positioning block (C1), a pull rod (L1), and a spring (T1). One end of the pull rod (L1) is fixed on the moving mold (D), and the other end of the pull rod (L1) has a disc head. The pre-positioning block (C1) has a limiting groove that cooperates with the disc head. The spring (T1) is limited to one end of the pre-positioning block (C1) near the moving mold (D). The moving mold (D) has a cavity that accommodates the pre-positioning block (C1).

2. The pulse tube hot-embedding die-casting mold according to claim 1, characterized in that: The pulse tube (2) is horizontally fixed at both ends along the length of the cavity of the fixed mold (A), and the fixed plate (1) has a groove to accommodate the pulse tube (2).

3. The pulse tube hot-embedding die-casting mold according to claim 1, characterized in that: The prepositioning block (C1) has a contoured groove on one end face away from the moving mold (D), which is used to limit the end of the pulse tube.

4. A pulse tube hot-embedded die-casting method, which is based on the pulse tube hot-embedded die-casting mold according to any one of claims 1-3, characterized in that: Includes the following steps, S1. Fix the fixed plate (1) and the pulse tube (2) to obtain the pulse tube assembly (F); S2. After the die-casting machine opens the mold, the pulse tube assembly (F) is suspended on the fixed mold (A) through the positioning hole (3), and the middle part of the pulse tube assembly (F) is supported by the fixed mold core support column (G). S3. Start the die-casting machine. On the moving mold side, the spring (T1) and the pull rod (L1) push out the prepositioning device (C). The prepositioning device (C) presses the pulse tube assembly (F) before the moving mold. S4. The pre-positioning device (C) retracts into the moving mold core as the mold closing process proceeds until the mold closing is completed. S5. After the mold is closed, the molten aluminum is pushed out by the punch and slowly fills the cavity through the sprue (E).

Images