Extrusion die suitable for single-cavity hollow profile with great wall thickness difference

Abstract

The utility model discloses an extrusion die suitable for a single-cavity hollow profile with great wall thickness difference, which comprises an upper die and a lower die matched with the upper die, and a die hole consists of a thin-wall section and a thick-wall section which jointly form an annular structure. A thick-wall shunting hole for supplying materials to the thick-wall section and at least one thin-wall shunting hole for supplying materials to the thin-wall section are formed in the end face, far away from the lower die, of the upper die, a protective supporting block is formed on the side wall of the core head in a protruding mode, and the protective supporting block at least partially shields the thick-wall section. By the adoption of the extrusion die suitable for the single-cavity hollow profile with the great wall thickness difference, the thick-wall section is shielded by additionally arranging the protection supporting block, the flow speed of metal flowing to the thick-wall section is effectively hindered, and the forming quality of a product is guaranteed; and moreover, the single-cavity hollow profile formed by extrusion has no welding seam at the thick wall, so that the problem of poor welding can be avoided, the problem of chromatic aberration around the welding seam can also be avoided, and the attractive appearance of the product is ensured.

Description

Technical Field

[0001] This utility model relates to the field of aluminum alloy profile extrusion die technology, specifically to an extrusion die suitable for single-cavity hollow profiles with significant differences in wall thickness. Background Technology

[0002] For single-cavity hollow profiles with large differences in wall thickness, uneven flow rate is very likely to occur during extrusion, which affects the molding quality of the product.

[0003] Please see Figure 6 In existing technologies, a flow divider bridge 26 is typically added at the thick-walled section of the upper mold 2 corresponding to the mold hole to block the flow and balance the flow rate. However, this introduces a problem: there will be a weld seam at the thick-walled section (formed by the convergence and welding of two metal streams under the bridge). If the welding is not good, it will lead to the scrapping of a batch of products. Even if the welding is good, if the product is anodized and colored, the presence of the weld seam at the thick-walled section will cause color differences around the weld seam after the profile is colored, affecting the appearance of the product.

[0004] Solving these problems is now a top priority. Utility Model Content

[0005] In view of this, the present invention provides an extrusion die suitable for single-cavity hollow profiles with significant differences in wall thickness.

[0006] The technical solution is as follows:

[0007] The first aspect of this application relates to an extrusion die suitable for single-cavity hollow profiles with significant wall thickness variations, comprising an upper die and a lower die adapted to the upper die. The lower die has a cavity extending through its two end faces, and the cavity wall has a circumferentially extending lower die working band. The upper die has a core head adapted to the cavity, and the outer periphery of the core head inserted into the cavity has a circumferential upper die working band corresponding to the lower die working band. The gap between the upper die working band and the lower die working band forms a die hole, which is composed of thin-walled sections that together form an annular structure. It consists of a thick-walled section and a thin-walled section, wherein the minimum width of the thick-walled section is greater than the maximum width of the thin-walled section. The upper die has a thick-walled diversion hole for feeding material to the thick-walled section and at least one thin-walled diversion hole for feeding material to the thin-walled section on the end face away from the lower die. The thick-walled diversion holes and thin-walled diversion holes are distributed circumferentially along the die hole. A protective support block is formed protruding on the side wall of the core head. The protective support block is located at the feeding end of the upper die working zone, and the projection of the protective support block at the feeding end of the thick-walled diversion hole at least partially blocks the projection of the thick-walled section at the feeding end of the thick-walled diversion hole.

[0008] The above-mentioned extrusion die, suitable for single-cavity hollow profiles with significant differences in wall thickness, feeds material from the thick-walled distribution hole to the thick-walled section of the die cavity. At the same time, a protective support block is added in the thick-walled distribution hole to shield the thick-walled section, effectively hindering the flow rate of metal to the thick-walled section, thereby balancing the flow rates of the thin-walled and thick-walled sections and ensuring the molding quality of the product. Furthermore, since there is no distribution bridge in the thick-walled distribution hole, the extruded single-cavity hollow profile has no weld seam in the thick-walled section, which can avoid the problems of poor welding and color difference around the weld seam, ensuring the aesthetics of the product.

[0009] In some embodiments, the projected area of ​​the protective support block at the feed end of the thick-walled diversion hole is greater than or equal to the projected area of ​​the thick-walled section at the feed end of the thick-walled diversion hole, and the projection of the protective support block at the feed end of the thick-walled diversion hole at least 80% obscures the projection of the thick-walled section at the feed end of the thick-walled diversion hole.

[0010] In some embodiments, the outer surface of the protective support block is provided with a feeding ramp, a guide plane and a discharge ramp in sequence toward the working zone of the upper mold. The guide plane is a planar structure parallel to the axial direction of the upper mold, and the feeding ramp and the discharge ramp are ramp structures extending from the corresponding ends of the guide plane to the side wall of the core head.

[0011] In some embodiments, the angle between the discharge ramp and the extension line of the guide plane increases as the width of the thick-walled section increases.

[0012] 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 25°-45°.

[0013] In some embodiments, the area between the discharge ramp and the upper die working zone is a planar neck section, the length of which increases with the increase of the width of the thick-walled section.

[0014] In some embodiments, the end face of the lower mold near the upper mold is recessed to form a lower mold welding chamber surrounding the cavity, and the length of the neck plane segment is greater than or equal to 0.5 times the depth of the lower mold welding chamber and less than or equal to 1 times the depth of the lower mold welding chamber.

[0015] In some embodiments, the lower mold welding chamber is recessed at the position corresponding to the thick-walled section to form a secondary welding chamber.

[0016] In some embodiments, the end face of the lower mold near the upper mold protrudes to form a baffle next to the thick-walled section. The side wall of the baffle near the thick-walled section constitutes part of the working zone of the lower mold, and the working zone of the upper mold is widened at the position corresponding to the baffle to form a widened section of the working zone. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the extrusion die of this utility model;

[0018] Figure 2 This is a cross-sectional view of the extrusion die of this utility model;

[0019] Figure 3 This is a schematic diagram showing the flow of metal in the extrusion die of this invention, where it is fed from the thick-walled diversion orifice to the thick-walled section of the die orifice.

[0020] Figure 4 This is a schematic diagram of the upper mold of this utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the mold hole of this utility model.

[0022] Figure 6 This is a schematic diagram of the structure of an extrusion die used in the prior art for extruding single-cavity hollow profiles with significant differences in wall thickness. Detailed Implementation

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

[0024] like Figures 1-5 As shown, an extrusion die suitable for single-cavity hollow profiles with significant wall thickness variations mainly includes an upper die 2 and a lower die 1 adapted to the upper die 2. The lower die 1 has a cavity 11 extending through its two end faces. The upper die 2 has a core 21 adapted to the cavity 11. After the core 21 extends into the cavity 11, the gap between the two forms a die hole A. Specifically, the cavity wall of the cavity 11 has a lower die working band 111 extending circumferentially. The outer periphery of the part of the core 21 inserted into the cavity 11 has an upper die working band 211 corresponding to the lower die working band 111. The gap between the upper die working band 211 and the lower die working band 111 forms a die hole A. In this embodiment, both the upper die 2 and the lower die 1 are cylindrical structures, and their diameters are equal.

[0025] Please see Figure 1 and Figure 5 The die hole A is composed of a thin-walled section A1 and a thick-walled section A2 that together form an annular structure. The minimum width of the thick-walled section A2 is greater than the maximum width of the thin-walled section A1. Therefore, the width of the thick-walled section A2 is significantly greater than the width of the thin-walled section A1. As a result, the thick-walled section A2 forms the thick-walled part of the profile, and the thin-walled section A1 forms the thin-walled part of the profile. The difference in wall thickness between the thick-walled and thin-walled parts of the profile is quite large.

[0026] In this embodiment, a thick-walled diversion hole 22 for feeding material to the thick-walled section A2 and at least one thin-walled diversion hole 23 for feeding material to the thin-walled section A1 are provided on the end face of the upper mold 2 away from the lower mold 1. The thick-walled diversion holes 22 and thin-walled diversion holes 23 are distributed circumferentially along the mold hole A. There are no diversion bridges in the thick-walled diversion holes 22, so that the extruded single-cavity hollow profile has no weld seam in the thick-walled section. This can avoid the problem of poor welding and the problem of color difference around the weld seam, thus ensuring the aesthetics of the product. Therefore, in order to balance the flow rate of the metal, a protective support block 24 is formed protruding on the side wall of the core head 21. The protective support block 24 is located at the feeding end of the upper die working belt 211, and the projection of the protective support block 24 at the feeding end of the thick-walled diversion hole 22 at least partially blocks the projection of the thick-walled section A2 at the feeding end of the thick-walled diversion hole 22. The thick-walled section A2 of the die hole A is fed by the thick-walled diversion hole 22. At the same time, the protective support block 24 is added in the thick-walled diversion hole 22 to block the thick-walled section A2, which effectively hinders the flow rate of the metal flowing to the thick-walled section A2, thereby balancing the flow rates of the thin-walled section A1 and the thick-walled section A2 and ensuring the molding quality of the product.

[0027] Please see Figure 2 The projected area of ​​the protective support block 24 at the feed end of the thick-walled diversion hole 22 is greater than or equal to the projected area of ​​the thick-walled section A2 at the feed end of the thick-walled diversion hole 22, and the projection of the protective support block 24 at the feed end of the thick-walled diversion hole 22 at least blocks 80% of the projection of the thick-walled section A2 at the feed end of the thick-walled diversion hole 22, ensuring an effective obstruction of metal flow. In this embodiment, the projection of the protective support block 24 at the feed end of the thick-walled diversion hole 22 preferably completely blocks the projection of the thick-walled section A2 at the feed end of the thick-walled diversion hole 22, thereby achieving a better obstruction of metal flow.

[0028] Please see Figures 2-4 The outer surface of the protective support block 24 is provided with a feed ramp 241, a guide plane 242, and a discharge ramp 243 in sequence towards the working zone 211 of the upper mold. The guide plane 242 is a planar structure parallel to the axis of the upper mold 2. The feed ramp 241 and the discharge ramp 243 are ramp structures extending from the corresponding ends of the guide plane 242 to the side wall of the core head 21. The feed ramp 241 with its ramp structure can reduce 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 mold repair. The discharge ramp 243 with its ramp structure can more fully introduce the metal flow into the thick-walled section A2, avoiding defects such as surface depressions.

[0029] In this embodiment, the angle between the discharge ramp 243 and the extension line of the guide plane 242 increases with the increase of the width of the thick-walled section A2. This design can reduce the feeding impact on the core head 21. In this embodiment, the angle between the feed ramp 241 and the extension line of the guide plane 242 is preferably 15°-30°, and the angle between the discharge ramp 243 and the extension line of the guide plane 242 is preferably 25°-45°. An excessively large angle may result in insufficient metal supply to the welding chamber area.

[0030] The lower die 1 has a recessed end face near the upper die 2, forming a lower die welding chamber 12 surrounding the cavity 11. Between the ejection ramp 243 and the upper die working zone 211 is a planar neck section 25. The length of this neck section 25 increases with the width of the thick-walled section A2 to ensure sufficient metal supply to the neck of the core head 21, preventing over-punching that could affect the wall thickness and surface defects at the thick-walled section. In this embodiment, the length of the neck section 25 is preferably greater than or equal to 0.5 times the depth of the lower die welding chamber 12 and less than or equal to 1 times the depth of the lower die welding chamber 12.

[0031] Further, please see Figure 1 The lower mold welding chamber 12 is recessed at the position corresponding to the thick-walled section A2 to form a secondary welding chamber 14, thereby fully guiding the metal to gather in the thick-walled section A2, increasing the metal fluidity at that point, and improving the molding quality of the product.

[0032] Please see Figures 1-4 The lower die 1 has a protruding end face near the upper die 2, forming a baffle 13 located next to the thick-walled section A2. The side wall of the baffle 13 near the thick-walled section A2 forms part of the lower die working zone 111. The upper die working zone 211 is widened at the position corresponding to the baffle 13, forming a widened working zone section 211a. Therefore, the height of the baffle 13 is the increased length of the lower die working zone 111 and the upper die working zone 211. The purpose of adding the baffle 13 is to increase the frictional resistance between the metal flow and the lower die 1, preventing the metal from flowing too fast.

[0033] In summary, the reduced number of flow channels in the extrusion die, suitable for single-cavity hollow profiles with significant wall thickness variations, not only makes die processing faster but also increases the area of ​​each channel, improving metal flowability and creating conditions for rapid extrusion. Furthermore, due to these structural improvements, the final extruded single-cavity hollow profile has no weld seams in the thick-walled sections, avoiding defects such as poor welding and oxidation color differences.

[0034] 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. An extrusion die suitable for single-cavity hollow profiles with significant wall thickness variations, comprising an upper die and a lower die adapted to the upper die, the lower die having a cavity penetrating its two end faces, the cavity wall having a circumferentially extending lower die working band, the upper die having a core head adapted to the cavity, the outer periphery of the core head inserted into the cavity having a circumferentially extending upper die working band corresponding to the lower die working band, the gap between the upper die working band and the lower die working band forming a die hole, the die hole being composed of a thin-walled section and a thick-walled section forming a ring structure, the minimum width of the thick-walled section being greater than the maximum width of the thin-walled section, the upper die having a thick-walled diversion hole for feeding material to the thick-walled section and at least one thin-walled diversion hole for feeding material to the thin-walled section on the end face of the upper die away from the lower die, the thick-walled diversion holes and thin-walled diversion holes being distributed circumferentially along the die hole, characterized in that: A protective support block is formed protruding on the side wall of the core head. The protective support block is located at the feed end of the upper die working belt, and the projection of the protective support block on the feed end of the thick-walled diversion hole at least partially blocks the projection of the thick-walled section on the feed end of the thick-walled diversion hole.

2. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 1, characterized in that: The projected area of ​​the protective support block at the feed end of the thick-walled diversion hole is greater than or equal to the projected area of ​​the thick-walled section at the feed end of the thick-walled diversion hole, and the projection of the protective support block at the feed end of the thick-walled diversion hole at least 80% blocks the projection of the thick-walled section at the feed end of the thick-walled diversion hole.

3. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 1, characterized in that: The outer surface of the protective support block is provided with a feeding slope, a guiding plane and a discharge slope in sequence towards the working zone of the upper mold. The guiding plane is a planar structure parallel to the axial direction of the upper mold, and the feeding slope and the discharge slope are sloped structures extending from the corresponding ends of the guiding plane to the side wall of the core head.

4. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 3, characterized in that: The angle between the discharge ramp and the extension line of the guide plane increases as the width of the thick-walled section increases.

5. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 3 or 4, 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 25°-45°.

6. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 3, characterized in that: The area between the discharge ramp and the upper die working zone is a neck plane segment with a planar structure. The length of this neck plane segment increases with the increase of the width of the thick-walled section.

7. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 6, characterized in that: The lower mold has a recessed end face near the upper mold to form a lower mold welding chamber surrounding the cavity. The length of the neck plane segment is greater than or equal to 0.5 times the depth of the lower mold welding chamber and less than or equal to 1 times the depth of the lower mold welding chamber.

8. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 7, characterized in that: The lower mold welding chamber is recessed at the position corresponding to the thick-walled section to form a secondary welding chamber.

9. The extrusion die for single-cavity hollow profiles with significant wall thickness variations according to claim 1, characterized in that: The lower mold has a protruding end face near the upper mold to form a baffle next to the thick-walled section. The side wall of the baffle near the thick-walled section constitutes part of the working zone of the lower mold. The working zone of the upper mold is widened at the position corresponding to the baffle to form a widened section of the working zone.

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