Aluminum alloy rectangular pipe material distributing die structure

Abstract

This utility model discloses a flow-dividing die structure for aluminum alloy rectangular tubes, including an upper die and a lower die adapted to the upper die. The inner ends of the two long-side flow-dividing holes and the two short-side flow-dividing holes all protrude from the circumferential sidewalls of the core head, forming pressure-enhancing bosses. By using this aluminum alloy rectangular tube flow-dividing die structure, and by adding pressure-enhancing bosses to the outer sides of each long-side flow channel and each short-side flow channel, the flow-enhancing effect is achieved, optimizing the metal flow path. This promotes the full concentration of metal at the four corners of the die hole, thereby increasing the metal supply at the corners. This not only avoids the problem of outward protrusion of the rectangular tube at the four large surfaces, reducing the processing difficulty of the die and shortening the processing cycle, but also improves extrusion efficiency without causing scratches or streaks on the surface of the aluminum alloy tube.

Description

Technical Field

[0001] This utility model relates to the field of aluminum alloy profile extrusion die technology, specifically to a flow divider die structure for aluminum alloy rectangular tubes. Background Technology

[0002] Rectangular tubing is one of the most widely used aluminum alloy profiles. For the manifold dies used in extruding rectangular tubing, the layout of the manifold bridges is typically as follows: Figure 1 The cross-shaped arrangement shown or the X-shaped arrangement disclosed in Chinese invention patent application CN108555051A.

[0003] For rectangular tube extrusion dies with cross-shaped flow dividers, all four corners of the rectangular tube are exposed in the flow dividers, resulting in good metal flowability, which is beneficial for improving extrusion efficiency and also increases die strength. However, a problem exists: since the four flow dividers are located on the four major surfaces of the rectangular tube, weld seams (or weld joints) will exist on all four major surfaces. For rectangular tube products that undergo subsequent surface treatments such as anodizing and coloring, there is a risk of significant color differences, affecting the aesthetics of the rectangular tube product.

[0004] For a rectangular tube extrusion die with an "X"-shaped arrangement of flow dividers, the four flow dividers are located at the four corners of the rectangular tube. Therefore, the weld seams of the rectangular tube are located at the four corners, so even if the rectangular tube product requires subsequent surface treatments such as anodizing and coloring, there will be no obvious color difference, ensuring the aesthetic appeal of the rectangular tube product. However, for the extrusion molding of rectangular tubes, the metal flow at the four corners is already poor. The problem of the flow dividers further obstructing the flow results in even worse metal flow, leading to an uneven overall material supply and causing excessive gaps (usually, the four large faces of the rectangular tube bulge outwards). This necessitates repeated mold trials and repairs during die processing, increasing the difficulty and time complexity of the die manufacturing process. To solve these problems, please refer to Chinese invention patent application CN108555051A. A common solution is to add a flow-blocking strip 320 in the welding chamber 312 of the lower die 300 near the lower die hole 310, or to lengthen the working strip length at the large face of the rectangular tube. Whether it's adding flow-blocking strips in the welding chamber or lengthening the working belt, it not only easily causes scratches or stripes on the surface of the aluminum alloy tube, but also significantly reduces the extrusion efficiency. Utility Model Content

[0005] In view of this, the present invention provides a flow divider structure for aluminum alloy rectangular tubes.

[0006] The technical solution is as follows:

[0007] The first aspect of this application relates to a flow-diverting mold structure for aluminum alloy rectangular tubes, including an upper mold and a lower mold adapted to the upper mold. The lower mold has a cavity penetrating both end faces of the cavity, and the cavity wall has a circumferentially extending lower mold working strip. The upper mold has a core head adapted to the cavity, and the outer periphery of the core head inserted into the cavity has a circumferential upper mold working strip corresponding to the lower mold working strip. The gap between the upper mold working strip and the lower mold working strip forms a mold hole, which has two long-side flow channels and two short-side flow channels arranged in a rectangle. The outer end face of the upper mold has two long-side flow-diverting holes and two short-side flow-diverting holes arranged in a cross shape. Any two adjacent long sides... A flow divider bridge is provided between the flow divider holes and the short-side flow divider holes. The four flow divider bridges are arranged in an "X" shape. The two ends of each long-side flow channel and the two ends of each short-side flow channel extend to the inner side of the corresponding flow divider bridge. The inner ends of the two long-side flow divider holes and the two short-side flow divider holes protrude on the circumferential sidewall of the core head to form a pressure boosting boss. Each pressure boosting boss covers the outer side of the corresponding long-side flow channel or short-side flow channel. The outer surface of the pressure boosting boss is provided with a feed ramp, a guide plane and a discharge ramp in sequence towards the working zone of the upper die. The guide plane is a planar structure parallel to the axial direction of the upper die. The feed ramp and the discharge ramp are ramp structures that extend from the corresponding ends of the guide plane to the sidewall of the core head.

[0008] By adopting the above-mentioned aluminum alloy rectangular tube diversion die structure, pressure-boosting bosses are added to the outer sides of each long and short side flow channel to increase the effect and optimize the metal flow path. This allows the metal to fully concentrate at the four corners of the die orifice, thereby increasing the metal supply at the corners. This not only avoids the problem of the rectangular tube bulging outwards at the four major surfaces, reducing the processing difficulty of the die and shortening the processing cycle, but also improves the extrusion efficiency without causing scratches or streaks on the surface of the aluminum alloy tube. In particular, by designing a sloping feed ramp on the pressure-boosting boss, the impact of the metal flow on the mandrel can be reduced, allowing the mandrel to remain stable and not displaced (or with small displacement), thereby reducing the frequency of die repair. By designing a sloping discharge ramp on the pressure-boosting boss, the metal flow can be more fully introduced into the four major surfaces of the rectangular tube, avoiding the problem of outward bulging.

[0009] In some embodiments, the angle between the feed ramp and the extension line of the guide plane is 15°-30°, and the angle between the discharge ramp and the extension line of the guide plane is 10°-40°.

[0010] In some embodiments, the area between the discharge ramp and the upper die working zone is a planar neck buffer section, the length of which increases as the angle between the discharge ramp and the extension line of the guide plane increases.

[0011] In some embodiments, the ratio of the angle between the discharge ramp and the extension line of the guide plane to the length of the neck buffer section is between 1:1 and 1.5:1.

[0012] In some embodiments, the width of the two pressure-boosting bosses located in the two long-side flow dividers is less than or equal to the minimum width of the corresponding long-side flow divider near the center of the upper mold, and the width of the two pressure-boosting bosses located in the two short-side flow dividers is less than or equal to the length of the corresponding short-side flow channel.

[0013] In some embodiments, the inner ends of the two short-side diversion holes each have a guide protrusion on the hole wall on the side away from the corresponding pressure boosting protrusion, and the two guide protrusions are respectively facing the corresponding pressure boosting protrusion.

[0014] In some embodiments, the inner end faces of the flow guide bosses are all planar structures flush with the inner end faces of the upper mold, the side surface of the flow guide bosses near the corresponding pressure boosting bosses are all planar structures parallel to the short side flow channel, and the outer end faces of the flow guide bosses and the two side walls along the circumferential direction of the core head are all arc-shaped structures with a reduced diameter from the hole wall of the corresponding short side flow divider hole to the side surface of the flow guide bosses near the corresponding pressure boosting bosses.

[0015] In some embodiments, the lower die working zone has an inlet section and a sizing section connected in sequence in the direction away from the upper die. The sizing section is a cylindrical structure, and the inlet section is a tapered structure that gradually increases in size in the direction away from the sizing section.

[0016] In some embodiments, the angle between the inlet section and the central axis of the lower mold is 2°-3°.

[0017] In some embodiments, the length of the sizing section is 30%-50% of the length of the lower die working belt. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a flow divider mold in the prior art, where the flow divider bridges are arranged in a cross shape.

[0019] Figure 2 This is a schematic diagram of the structure of the flow divider mold of this utility model;

[0020] Figure 3 for Figure 2 Sectional view at point BB;

[0021] Figure 4 for Figure 3 Enlarged view of point C in the middle;

[0022] Figure 5 This is a structural schematic diagram of the upper mold of this utility model from one perspective;

[0023] Figure 6 This is a structural schematic diagram of the upper mold of this utility model from another perspective. Detailed Implementation

[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0025] like Figures 2-6 As shown, an aluminum alloy rectangular tube diversion mold structure mainly includes an upper mold 2 and a lower mold 1 adapted to the upper mold 2. The lower mold 1 has a cavity 11 extending through its two end faces. The cavity wall of the cavity 11 has a lower mold working band 111 extending circumferentially. The upper mold 2 has a core 21 adapted to the cavity 11. The outer circumferential surface of the part of the core 21 inserted into the cavity 11 has a ring of upper mold working band 211 corresponding to the lower mold working band 111. The gap between the upper mold working band 211 and the lower mold working band 111 forms a mold hole A. Specifically, the cavity wall of the cavity 11 has a ring of lower mold working band 111 extending circumferentially, and the outer circumferential surface of the part of the core 21 inserted into the cavity 11 has a ring of upper mold working band 211 corresponding to the lower mold working band 111. The gap between the upper mold working band 211 and the lower mold working band 111 forms a mold hole A. In this embodiment, both the upper mold 2 and the lower mold 1 are cylindrical structures, and their diameters are equal.

[0026] The die cavity A has two long-side flow channels A1 and two short-side flow channels A2 arranged in a rectangular shape; that is, the two long-side flow channels A1 and the two short-side flow channels A2 form a rectangular structure. It should be noted that adjacent long-side flow channels A1 and short-side flow channels A2 can be directly joined together to make the die cavity A a conventional rectangular structure. Alternatively, adjacent long-side flow channels A1 and short-side flow channels A2 can be combined in some similar manner. Figure 1 On the special small structures shown (which can be grooves, holes, ribs, etc.), it is sufficient to ensure that the overall shape of the mold hole A is approximately rectangular.

[0027] In this embodiment, the outer end face of the upper mold 2 (the end face away from the lower mold 1) is provided with two long-side diversion holes 22 and two short-side diversion holes 23 arranged in a cross shape. That is, the two long-side diversion holes 22 are arranged opposite each other on both sides of the central axis of the upper mold 2, and the two short-side diversion holes 23 are arranged opposite each other on both sides of the central axis of the upper mold 2. A diversion bridge 24 is provided between any two adjacent long-side diversion holes 22 and short-side diversion holes 23, and the four diversion bridges 24 are arranged in an "X" shape.

[0028] In this embodiment, both the long-side diversion hole 22 and the short-side diversion hole 23 are designed to be as large as possible in the direction close to the central axis of the upper mold 2. By increasing the cross-sectional area of ​​the hole, the pressure-bearing area at the inlet is reduced, and the compression dead zone is reduced accordingly.

[0029] Most importantly, the two ends of each long side flow channel A1 and the two ends of each short side flow channel A2 extend to the inner side of the corresponding flow divider bridge 24 (the side closer to the lower mold 1). The inner ends of the two long side flow divider holes 22 and the two short side flow divider holes 23 protrude on the circumferential sidewall of the core head 21 to form a pressure boosting boss 25. Each pressure boosting boss 25 is respectively shielded on the outer side of the corresponding long side flow channel A1 or short side flow channel A2 (the side away from the lower mold 1).

[0030] Therefore, by adding pressure-boosting bosses 25 to the outside of each long-side flow channel A1 and each short-side flow channel A2, the effect is increased, the path of metal flow is optimized, and the metal can be fully concentrated at the four corners of the die hole A, thereby increasing the metal supply at the corners. This not only avoids the problem of rectangular tubes bulging outwards at the four large surfaces, reducing the processing difficulty of the die and shortening the processing cycle of the die, but also improves the extrusion efficiency without causing scratches or stripes on the surface of the aluminum alloy tube.

[0031] Furthermore, the outer surface of the pressure-boosting boss 25 is provided with a feed ramp 251, a guide plane 252, and a discharge ramp 253 in sequence towards the working zone 211 of the upper die. The guide plane 252 is a planar structure parallel to the axis of the upper die 2, and the feed ramp 251 and the discharge ramp 253 are ramp structures extending from the corresponding ends of the guide plane 252 to the side wall of the core head 21. The feed ramp 251, designed with a ramp structure on the pressure-boosting boss 25, reduces the impact of the metal flow on the core head 21, allowing the core head 21 to remain stable and without displacement (or with small displacement), thereby reducing the frequency of die repair. Simultaneously, the discharge ramp 253, designed with a ramp structure on the pressure-boosting boss 25, allows the metal flow to be more fully introduced into the four large faces of the rectangular tube, avoiding outward bulging and poor forming problems. In general, after the metal enters through the diversion hole, it first climbs a slope, then travels along a flat path, and finally descends a slope. This design extends the flow path of the metal in the diversion hole and the welding chamber.

[0032] In this embodiment, the angle between the feed ramp 251 and the extension line of the guide plane 252 is preferably 15°-30°, and the angle between the discharge ramp 253 and the extension line of the guide plane 252 is preferably 10°-40°, so as to ensure sufficient metal supply while supplying the metal box to the corners as much as possible.

[0033] Furthermore, there is a planar neck buffer section 26 between the discharge slope 253 and the upper die working zone 211. The length of the neck buffer section 26 increases as the angle between the discharge slope 253 and the extension line of the guide plane 252 increases, which further ensures sufficient material supply to the welding chamber and improves the molding quality.

[0034] In this embodiment, the ratio of the angle between the discharge slope 253 and the extension line of the guide plane 252 to the length of the neck buffer section 26 is preferably between 1:1 and 1.5:1, resulting in good overall material supply balance.

[0035] Furthermore, the width of the two pressure-boosting bosses 25 located on the two long-side diversion holes 22 is less than or equal to the minimum width of the side of the corresponding long-side diversion hole 22 closest to the center of the upper mold 2, and the width of the two pressure-boosting bosses 25 located on the two short-side diversion holes 23 is less than or equal to the length of the corresponding short-side flow channel A2, ensuring sufficient material supply to the four large surfaces of the rectangular tube and avoiding problems of poor molding.

[0036] Furthermore, the inner ends of the two short-side diversion holes 23 each have a guide boss 27 protruding from the hole wall on the side away from the corresponding pressure boosting boss 25. The two guide bosses 27 are respectively directly opposite the corresponding pressure boosting bosses 25. After the metal enters the short-side diversion hole 23, it first sinks a certain thickness along the outer wall of the short-side diversion hole 23. Then, the guide bosses 27 cause the flow channel at the large surface of the formed rectangular tube to narrow rapidly, thereby making the flow channels at the four corners of the formed rectangular tube relatively wider. This causes the metal to change its flow path, that is, to make the metal fully gather at the four corners, increasing the metal supply at the corners and balancing the overall flow rate.

[0037] In this embodiment, the inner end faces of the flow guide bosses 27 are all planar structures flush with the inner end face of the upper mold 2 (the end face closer to the lower mold 1). The side surface of the flow guide bosses 27 near the corresponding pressure boosting bosses 25 is a planar structure parallel to the short side flow channel A2. The outer end face of the flow guide bosses 27 and the two side walls along the circumference of the core head 21 are arc-shaped structures with a reduced diameter from the hole wall of the corresponding short side flow divider hole 23 to the side surface of the flow guide bosses 27 near the corresponding pressure boosting bosses 25. The flow guide bosses 27 can effectively guide the metal through the three arc-shaped structures while changing the flow channel width. Furthermore, the end of the flow guide bosses 27 extends to the inner end face of the upper mold 2, making the structure of the flow guide bosses 27 highly reliable and reducing the frequency of mold repair.

[0038] Furthermore, the lower die working zone 111 has an inlet section 111a and a sizing section 111b connected sequentially in the direction away from the upper die 2. The sizing section 111b is a cylindrical structure, and the inlet section 111a is a tapered structure that gradually increases in size in the direction away from the sizing section 111b. The design of the inlet section 111a can achieve good pressure boosting and balance the flow velocity at various positions in the die hole A.

[0039] In this embodiment, the angle between the inlet section 111a and the central axis of the lower die 1 is preferably 2°-3°. The small angle design of the inlet section 111a is beneficial to ensuring the surface quality of the extruded profile during high-speed extrusion.

[0040] Furthermore, the length of the sizing section 111b is 30%-50% of the length of the lower die working zone 111, thereby making the inlet section 111a as long as possible and achieving a better effect in balancing the metal flow rate.

[0041] Finally, it should be noted that the above description is merely a preferred embodiment of the present utility model. Those skilled in the art, under the guidance of the present utility model, can make various similar representations without departing from the spirit and claims of the present utility model, and such modifications all fall within the protection scope of the present utility model.

Claims

1. A flow-dividing mold structure for aluminum alloy rectangular tubes, comprising an upper mold and a lower mold adapted to the upper mold, wherein the lower mold has a cavity penetrating its two end faces, the cavity wall of which has a circumferentially extending lower mold working strip, the upper mold has a core head adapted to the cavity, the outer periphery of the core head inserted into the cavity has a circumferentially extending upper mold working strip corresponding to the lower mold working strip, the gap between the upper mold working strip and the lower mold working strip forms a mold hole, the mold hole having two long-side flow channels and two short-side flow channels arranged in a rectangle, two long-side flow-dividing holes and two short-side flow-dividing holes arranged in a cross shape are provided on the outer end face of the upper mold, a flow-dividing bridge is provided between any two adjacent long-side flow-dividing holes and short-side flow-dividing holes, the four flow-dividing bridges are arranged in an "X" shape, and the two ends of each long-side flow channel and the two ends of each short-side flow channel extend to the inner side of the corresponding flow-dividing bridge, characterized in that: The inner ends of the two long-side flow holes and the two short-side flow holes protrude on the circumferential sidewall of the core head to form pressure-increasing bosses. Each pressure-increasing boss covers the outer side of the corresponding long-side flow channel or short-side flow channel. The outer surface of the pressure-increasing boss is provided with a feed ramp, a guide plane and a discharge ramp in sequence towards the working zone of the upper die. The guide plane is a planar structure parallel to the axial direction of the upper die. The feed ramp and the discharge ramp are ramp structures that extend from the corresponding end of the guide plane to the sidewall of the core head.

2. The aluminum alloy rectangular tube diversion mold structure according to claim 1, characterized in that: The angle between the feed ramp and the extension line of the guide plane is 15°-30°, and the angle between the discharge ramp and the extension line of the guide plane is 10°-40°.

3. The aluminum alloy rectangular tube diversion mold structure according to claim 1 or 2, characterized in that: The area between the discharge ramp and the upper die working zone is a planar neck buffer section, the length of which increases as the angle between the discharge ramp and the extension line of the guide plane increases.

4. The aluminum alloy rectangular tube diversion mold structure according to claim 3, characterized in that: The ratio of the angle between the discharge ramp and the extension line of the guide plane to the length of the neck buffer section is between 1:1 and 1.5:

1.

5. The aluminum alloy rectangular tube diversion mold structure according to claim 1, characterized in that: The width of the two pressure-boosting bosses located in the two long-side flow dividers is less than or equal to the minimum width of the corresponding long-side flow divider near the center of the upper mold. The width of the two pressure-boosting bosses located in the two short-side flow dividers is less than or equal to the length of the corresponding short-side flow channel.

6. The aluminum alloy rectangular tube diversion mold structure according to claim 1, characterized in that: The inner ends of the two short-side diversion holes each have a guide protrusion on the hole wall on the side away from the corresponding pressure boosting protrusion, and the two guide protrusions are respectively facing the corresponding pressure boosting protrusion.

7. The aluminum alloy rectangular tube diversion mold structure according to claim 6, characterized in that: The inner end faces of the flow guide bosses are all planar structures flush with the inner end faces of the upper mold. The side surface of the flow guide bosses near the corresponding pressure boosting bosses are all planar structures parallel to the short side flow channel. The outer end face of the flow guide bosses and the two side walls along the circumference of the core head are all arc-shaped structures with a reduced diameter from the hole wall of the corresponding short side flow divider hole to the side surface of the flow guide bosses near the corresponding pressure boosting bosses.

8. The aluminum alloy rectangular tube diversion mold structure according to claim 1, characterized in that: The lower die working zone has an inlet section and a sizing section connected in sequence in the direction away from the upper die. The sizing section is a cylindrical structure, and the inlet section is a conical structure that gradually increases in size in the direction away from the sizing section.

9. The aluminum alloy rectangular tube diversion mold structure according to claim 8, characterized in that: The angle between the inlet section and the central axis of the lower mold is 2°-3°.

10. The aluminum alloy rectangular tube diversion mold structure according to claim 8, characterized in that: The length of the sizing section is 30%-50% of the length of the lower die working belt.

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