Mould for micro-channel flat tube

Abstract

The utility model relates to the field of dies, in particular to a die for a micro-channel flat tube. The die of the micro-channel flat pipe comprises an upper die, a feeding hole is formed in the upper die, a core head neck position is fixedly installed in the feeding hole, the bottom end of the core head neck position extends out of the feeding hole and is provided with a core head, the core head comprises an upper die sizing belt and an upper die hollow cutter, the width of the core head neck position is X, the width of the upper die sizing belt is Y, and the width of the upper die hollow cutter is Y; x is larger than Y. The upper die hollow cutter is arranged at the bottom of the upper die sizing belt, and a material discharging space is reserved between every two adjacent core heads. The die further comprises a lower die which is arranged below the upper die. The die for the micro-channel flat tube has the advantage that the core print is high in strength.

Description

Technical Field

[0001] The utility model relates to the field of molds, in particular to a mold for a microchannel flat tube. Background Art

[0002] Due to their tiny pores and densely packed pores, aluminum alloy microchannel flat tubes are currently manufactured using extrusion, a process that presents significant challenges. This requires an extremely high extrusion ratio, typically between 100 and 800. Furthermore, they demand ultra-high dimensional accuracy, with wall thickness deviations within 0.05mm. The extrusion die operates in high-temperature, high-pressure environments for extended periods, placing increasing demands on die strength and stability. With technological advancements, the structural form, dimensions, and product requirements of flat tubes are constantly being updated to improve heat transfer efficiency. The latest design of microchannel flat tubes features internal ribs that have been upgraded from conventional vertical ribs to slightly angled diagonal ribs, and a symmetrical to an asymmetrical cross-section.

[0003] For example, the patent document with publication number CN114535334A discloses an extrusion die for a double microchannel flat tube, which includes an upper die and a lower die stacked together in the upper and lower directions, the upper die includes an upper die body, an upper die channel is provided at the inner edge of the upper die body, a die bridge is provided in the upper die channel, a diversion bridge is provided on both sides of the die bridge, two die core holes are provided on the die bridge, and a die core is installed in each die core hole; the lower die includes a lower die body, a lower die cavity is provided in the lower die body, the lower die cavity includes a welding chamber, a mold cavity and a molding chamber that are interconnected from top to bottom, the mold cavity includes two lower die holes connected by connecting rib holes, and each mold core passes downward through a lower die hole; the upper die channel is connected to the lower die cavity.

[0004] For another example, the patent document with publication number CN114289537B discloses a profile forming device and method for a heat dissipation element with a microchannel offset layout, which relates to the field of profile extrusion forming, including a mold, wherein the mold is provided with a diverter hole, a mold core and a forming cavity, and diverter holes are respectively provided on both sides of the mold core, and the cross-sectional areas of the diverter holes on both sides are different. The core needle at one end of the mold core extends into the working belt, and the space between the core needle and the working belt serves as a forming cavity, and the distance between the core needle and the thick-walled side working belt is greater than the distance between the core needle and the thin-walled side working belt.

[0005] However, during the extrusion process of the above technology, due to the inclination of the internal ribs, the hydrostatic pressure is unbalanced during the molding process. At the same time, the support strength at the sharp corner of the mold core head is insufficient, causing the core head to deform and resulting in wall thickness deviation. Utility Model Content

[0006] In order to solve the above technical problems, the purpose of the present utility model is to provide a mold for a microchannel flat tube, which has the advantage of high core head strength.

[0007] The technical solution adopted by the utility model to solve the problem is: a mold for a microchannel flat tube, comprising: an upper mold, a feed hole is opened on the upper mold, a core head neck is fixedly installed in the feed hole, the bottom end of the core head neck extends to the outside of the feed hole, a core head is provided on the core head neck, and the core head includes an upper mold sizing belt and an upper mold blank knife, the width of the core head neck is X, the width of the upper mold sizing belt is Y, X is greater than Y, and the upper mold blank knife is arranged at the bottom of the upper mold sizing belt.

[0008] As a further improvement of the above technical solution, the difference between X and Y is 1-2 mm.

[0009] As a further improvement of the above technical solution, it also includes a lower mold, the lower mold includes a primary welding chamber and a secondary welding chamber, the X is greater than the width of the secondary welding chamber, when the upper mold and the lower mold are closed, the core head neck is inserted into the primary welding chamber and a first gap is left between the core head and the primary welding chamber, the upper mold sizing belt is inserted into the secondary welding chamber and a second gap is left between the core head and the secondary welding chamber, the first gap and the second gap are connected to form a transfer channel, and a material space is left between adjacent core heads.

[0010] As a further improvement of the above technical solution, the core head includes a sharp corner, and the material-free space avoids the sharp corner of the core head.

[0011] As a further improvement of the above technical solution, a diverter bridge is provided in the feed hole, the diverter bridge is cross-shaped, the diverter bridge adopts a three-cut circle bridge surface, and the core head is arranged at the bottom end of the diverter bridge.

[0012] As a further improvement of the above technical solution, the lower die includes a first-level empty knife and a second-level empty knife, the first-level empty knife has an inclination, a step is formed between the second-level empty knife and the first-level empty knife, a lower die sizing belt is provided between the second-level empty knife and the second-level welding chamber, and the second-level welding chamber has an inclination.

[0013] As a further improvement of the above technical solution, a matching stop is provided at the bottom of the upper die, and a groove is provided at the top of the lower die, and the groove is adapted to the matching stop.

[0014] The beneficial effects of the utility model are as follows: by arranging the core head at the core head neck position and the core head does not protrude from the core head neck position, the core head support strength can be improved and the core head life can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further explained below with reference to the accompanying drawings and specific implementation methods.

[0016] Figure 1 This is a schematic structural diagram of a preferred embodiment of the present utility model;

[0017] Figure 2 for Figure 1 Exploded view shown;

[0018] Figure 3 for Figure 2 An enlarged structural diagram of part A is shown;

[0019] Figure 4 It is a front cross-sectional view of the utility model;

[0020] Figure 5 for Figure 4 A schematic diagram of the enlarged structure of part B is shown;

[0021] Figure 6 It is a side sectional view of the present invention.

[0022] In the figure: 1. Upper die; 11. Feed hole; 12. Diverter bridge; 13. Core head and neck position; 14. Upper die sizing belt; 15. Sharp corner position; 16. Upper die blanking knife; 17. Material clearance space; 18. Matching stop; 2. Lower die; 21. First-level blanking knife; 22. Second-level blanking knife; 23. First-level welding chamber; 24. Second-level welding chamber; 25. Lower die sizing belt; 26. Groove. DETAILED DESCRIPTION

[0023] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0024] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0025] In the description of this utility model, the meaning of "several" is one or more, the meaning of "many" is more than two, and the meanings of "greater than", "less than", "exceed", etc. are not inclusive of the number itself, while the meanings of "above", "below", "within", etc. are inclusive of the number itself. If there is a description of "first" or "second", it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features. In the description of this utility model, unless otherwise clearly defined, the terms "set", "install", "connect", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in this utility model in combination with the specific content of the technical solution.

[0026] Reference Figures 1 to 6 A mold for a microchannel flat tube includes an upper mold 1 having a feed hole 11 formed therein. A core neck 13 is fixedly installed in the feed hole 11. The bottom end of the core neck 13 extends outside the feed hole 11. A core head is provided on the core neck 13. The core head includes an upper mold sizing band 14 and an upper mold hollow blade 16. The width of the core neck 13 is X, and the width of the upper mold sizing band 14 is Y, where X is greater than Y. The upper mold hollow blade 16 is provided at the bottom of the upper mold sizing band 14. This ensures that the upper mold sizing band 14 does not protrude from the core neck 13, thereby improving the service life of the upper mold sizing band 14, reducing the hydrostatic pressure of the inner and outer wall thicknesses of the product, lowering the flow rate of the metal on the outer wall of the product, and significantly improving the supporting strength of the mold core head.

[0027] As a preferred embodiment, the difference between X and Y is 1-2 mm. Within this range, the aluminum alloy can flow smoothly.

[0028] As a preferred embodiment, the lower die 2 includes a primary welding chamber 23 and a secondary welding chamber 24. The secondary welding chamber 24 has an inclination, and X is greater than the width of the secondary welding chamber 24. When the upper die 1 and the lower die 2 are closed, the core head neck 13 is inserted into the primary welding chamber 23 with a first gap between the first welding chamber 23 and the upper die sizing belt 14 is inserted into the secondary welding chamber 24 with a second gap between the second welding chamber 24. The first gap and the second gap are connected to form a transfer channel, and a material space 17 is left between adjacent core heads. The core head neck 13 uses the material space 17 to feed the oblique ribs, forming a feed from the inside to the outside, generating an outward-directed hydrostatic pressure on the core head, balancing the hydrostatic pressure from the outside of the core head to the inside, and achieving dynamic torque balance during the extrusion process. The aluminum alloy product needs to turn its flow angle to flow into the upper die sizing belt 14 for forming, which can increase the hydrostatic pressure in the welding chamber by 10-15%, increase the hydrostatic pressure in the vacant space 17, provide greater power for feeding the inner oblique ribs, and ensure sufficient feeding of the product ribs.

[0029] As a preferred embodiment, the core head includes a sharp corner 15, and the material clearance 17 avoids the sharp corner 15. Because the material clearance 17 is located between adjacent core heads, the sharp corner 15 is supported by the core head neck 13; compared with the cantilevered sharp corners of the core heads in the prior art, this technology can improve the mold strength and ensure force and torque balance.

[0030] As a preferred embodiment, a cross-shaped diverter bridge 12 is provided within the feed hole 11. The diverter bridge 12 has a three-sectioned circular bridge surface, and a core head is positioned at the bottom end of the diverter bridge 12. This reduces the reaction force experienced during extrusion of the profile. The cross-bridge structure enhances the structural strength of the upper die 1, minimizing deformation after extrusion, and further enhancing the core head strength.

[0031] As a preferred embodiment, the lower die 2 includes a first-level empty knife 21 and a second-level empty knife 22. The first-level empty knife 21 has an inclination, and a step is formed between the second-level empty knife 22 and the first-level empty knife 21. A lower die sizing belt 25 is provided between the second-level empty knife 22 and the second-level welding chamber 24 to adapt to the core head.

[0032] As a preferred embodiment, the bottom of the upper mold 1 is provided with a matching stop 18, and the top of the lower mold 2 is provided with a groove 26, which is adapted to the matching stop 18. This ensures that the upper mold 1 and the lower mold 2 are connected stably.

[0033] The above are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the utility model concept, or directly or indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A mold for a microchannel flat tube, comprising an upper mold (1), characterized in that: A feed hole (11) is provided on the upper die (1), a core head neck position (13) is fixedly installed in the feed hole (11), the bottom end of the core head neck position (13) extends to the outside of the feed hole (11), a core head is provided on the core head neck position (13), and the core head includes an upper die sizing belt (14) and an upper die blank knife (16), the width of the core head neck position (13) is X, the width of the upper die sizing belt (14) is Y, X is greater than Y, and the upper die blank knife (16) is arranged at the bottom of the upper die sizing belt (14).

2. The mold for a microchannel flat tube according to claim 1, characterized in that: The difference between the X and the Y is 1-2 mm.

3. The mold for a microchannel flat tube according to claim 2, wherein: The invention also includes a lower die (2), wherein the lower die (2) includes a primary welding chamber (23) and a secondary welding chamber (24), wherein X is greater than the width of the secondary welding chamber (24), and when the upper die (1) and the lower die (2) are closed, the core head neck portion (13) is inserted into the primary welding chamber (23) and a first gap is left between the core head neck portion (13) and the primary welding chamber (23), and the upper die sizing belt (14) is inserted into the secondary welding chamber (24) and a second gap is left between the core head neck portion (13) and the secondary welding chamber (24), wherein the first gap and the second gap are connected to form a transfer channel, and a material space (17) is left between adjacent core heads.

4. The mold for a microchannel flat tube according to claim 3, wherein: The core head includes a sharp corner (15), and the material-free space (17) is staggered with the sharp corner (15) of the core head.

5. The mold for a microchannel flat tube according to claim 4, characterized in that: A diverter bridge (12) is provided in the feed hole (11), the diverter bridge (12) is in a cross shape, the diverter bridge (12) adopts a three-section circular bridge surface, and the core head is provided at the bottom end of the diverter bridge (12).

6. The mold for a microchannel flat tube according to claim 5, characterized in that: The lower die (2) comprises a primary empty knife (21) and a secondary empty knife (22); the primary empty knife (21) has an inclination; a step is formed between the secondary empty knife (22) and the primary empty knife (21); a lower die sizing belt (25) is provided between the secondary empty knife (22) and the secondary welding chamber (24); and the secondary welding chamber (24) has an inclination.

7. The mold for a microchannel flat tube according to claim 3, wherein: The bottom of the upper die (1) is provided with a matching stop (18), and the top of the lower die (2) is provided with a groove (26), and the groove (26) is adapted to the matching stop (18).

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