Extrusion die with outer resistance and inner anti-shrinkage tail effect
By designing a multi-stage stepped structure inside the feed inlet of the extrusion die, the external resistance is gradually increased, which solves the problem of tail shrinkage in the production of profiles by the extrusion die and achieves high-quality forming of aluminum plates, aluminum bars and aluminum square bars.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XINGFA ALUMINUM CHENGDU
- Filing Date
- 2025-05-23
- Publication Date
- 2026-06-09
AI Technical Summary
Existing extrusion dies are prone to tail shrinkage when producing thicker solid profiles, resulting in black lines on the profile cross-section.
Design an extrusion die with external resistance and internal increase to prevent tail shrinkage. By setting multiple steps on the inside of the feed port, the external resistance is increased step by step, pushing the material to be fully squeezed inward and avoiding tail shrinkage.
It effectively avoids the problems of tail shrinkage and black core in the profile forming process, and improves the quality of the profile, especially the forming effect of aluminum plates, aluminum bars and aluminum square bars.
Smart Images
Figure CN224333118U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of extrusion die technology, specifically relating to an extrusion die with external resistance, internal increase and anti-tail shrinkage effect. Background Technology
[0002] In the extrusion process for producing profiles, raw material bars, such as aluminum bars, are fed into the extrusion die through a stepped inlet under extrusion pressure. The material is then extruded through die orifices of the desired shape to obtain a profile with the desired cross-sectional shape. For solid profiles or solid sections within a profile, the greater the thickness, the more prone the profile is to "tailing" (or "end-cutting" or "black core") after extrusion, resulting in a black line appearing on the profile's cross-section. Figure 4 As shown, a new type of extrusion die is needed to solve the tail-reduction problem. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide an extrusion die with external resistance and internal enhancement to prevent tail shrinkage, thereby solving the tail shrinkage problem that exists when producing thicker solid profiles with existing dies, and realizing the stepwise pushing of the bar material from the outside to the inside, effectively avoiding tail shrinkage and improving the quality of the profile.
[0004] According to the technical solution of this utility model, this utility model provides an extrusion die with external resistance, internal increase and anti-tailing effect, including an upper die and a lower die that are installed together; the lower die has a through die hole, and the discharge side of the die hole has a hollow section, the internal space cross-section of the hollow section is larger than the internal space cross-section of the die hole; the upper die has a through stepped feed port, and in the direction from the feed side to the discharge side, the stepped feed port forms a plurality of sequentially connected cross-sectional dimension changing segments, the internal space cross-section of the cross-sectional dimension changing segments is progressively smaller, and a resistance-increasing step is formed between adjacent cross-sectional dimension changing segments, the internal space cross-section of the output side of the stepped feed port is larger than the internal space cross-section of the die hole.
[0005] In some embodiments, the internal space cross-sectional shape of the die hole is rectangular, and the internal cross-sectional shape of each cross-sectional dimension change segment of the stepped feed port is a shape that protrudes outward at the four corners of the rectangle and is recessed inward at the four sides of the rectangle.
[0006] In some implementations, the number of segments with varying cross-sectional dimensions is four or more.
[0007] In some implementations, the reduction in cross-sectional area is the same for any two adjacent cross-sectional dimension change segments in the direction from the feed side to the discharge side.
[0008] In some implementations, the lengths of multiple cross-sectional dimension change segments are all the same in the direction from the feed side to the discharge side.
[0009] In some embodiments, a recessed welding chamber is provided on the feed side of the lower die, and the die hole is located inside the welding chamber.
[0010] In some implementations, the internal spatial cross-section of the stepped feed port output side is consistent with the internal spatial cross-section of the welding chamber.
[0011] In some embodiments, it is a flow-dividing combination mold, the upper mold has multiple flow-dividing holes, at least one of which is a stepped inlet, the flow-dividing holes are connected by flow-dividing bridges, and a protruding mold core is provided on the discharge side of the upper mold.
[0012] Compared with the prior art, the beneficial technical effects of this utility model are as follows:
[0013] This invention relates to an extrusion die with external resistance and internal increase to prevent tail shrinkage. The die features multiple steps on the inner side of the feed inlet. For simple solid profiles, existing feed sides are typically flat or inclined (conical). This design uses stepped feeding, allowing the material on the periphery to gradually increase resistance as it is fed through each step, thus pushing and compressing the material in the center. This results in more complete feeding in the center and a denser structure. Therefore, profiles produced using this extrusion die will not exhibit tail shrinkage or black core issues. Typically, this design is suitable for extruding aluminum sheets, aluminum bars, and aluminum square rods. These profiles generally have rectangular cross-sections. Existing dies produce profiles with less than ideal angles at the four corners and uneven sides adjacent to the corners. To address this, the preferred embodiment of this invention further adjusts the shape of the stepped feed inlet to a larger shape at the four corners, increasing the material at the corners and ensuring sufficient feeding, thereby achieving a more ideal forming effect. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the extrusion die provided by this utility model, viewed from the feeding direction.
[0015] Figure 2 This is a cross-sectional structural diagram of the extrusion die provided by this utility model.
[0016] Figure 3 yes Figure 1 A schematic diagram of the cross-sectional shape of the profile produced by the extrusion die shown.
[0017] Figure 4 This is a schematic diagram of the cross-section and tail reduction of a profile produced using existing technology.
[0018] Explanation of reference numerals in the attached figures:
[0019] 1. Upper mold; 2. Lower mold; 3. Mold hole; 4. Empty section; 5. Stepped inlet; 6. Section with changing cross-sectional dimensions; 7. Resistance-increasing step; 8. Welding chamber. Detailed Implementation
[0020] This invention provides an extrusion die with external resistance and internal enhancement to prevent tail shrinkage, which solves the tail shrinkage problem that exists when producing thicker solid profiles with existing dies. It realizes the stepwise pushing of the bar material from the outside to the inside, effectively avoiding tail shrinkage and improving the quality of the profile.
[0021] Please see Figure 1 , Figure 2 This utility model discloses an extrusion die with external resistance, internal enhancement, and anti-tailing effect, comprising an upper die 1 and a lower die 2 that are fitted together. The lower die 2 has a through die hole 3, the internal spatial cross-sectional shape of which is consistent with the outer contour of the cross-sectional shape of the profile being produced. The discharge side of the die hole 3 has a hollow section 4, for example, a multi-stage hollow section with gradually increasing dimensions. The internal spatial cross-section of the hollow section 4 is larger than that of the die hole 3 to avoid surface damage caused by friction with the lower die 2 during discharge.
[0022] The upper die 1 has a through stepped feed port 5. From the feed side to the discharge side, the stepped feed port 5 forms multiple sequentially connected cross-sectional dimension changing segments 6. The internal cross-sectional area of each cross-sectional dimension changing segment 6 gradually decreases in size. Adjacent cross-sectional dimension changing segments 6 form resistance-increasing steps 7. The internal cross-sectional area of the output side of the stepped feed port 5 is larger than the internal cross-sectional area of the die hole 3. During operation, the raw material bar (such as an aluminum bar) abuts against the feed side of the upper die 1. The raw material (such as aluminum) enters the stepped feed port 5 under the extrusion action of the extruder. During the feeding process, the material on the periphery passes through the resistance-increasing steps 7 step by step, gradually increasing the resistance on the periphery. This causes the material on the periphery to squeeze and push the material in the middle, avoiding defects caused by a loose structure in the middle.
[0023] like Figure 1 , Figure 3 In the specific embodiment shown, the internal cross-sectional shape of the die hole 3 is rectangular, and the corresponding profile is an aluminum plate, aluminum strip, or aluminum square bar. The internal cross-sectional shape of each cross-sectional dimension change segment 6 of the stepped feed port 5 is a shape that protrudes outward at the four corners of the rectangle and is recessed inward at the four sides of the rectangle. In this solution, compared with the rectangular cross-sectional shape of the profile, the stepped feed port 5 is enlarged at the four corners, thereby optimizing the feeding situation at the four corners, ensuring sufficient feeding, and finally producing a profile with ideal corner shape and no deformation.
[0024] Preferably, the number of cross-sectional dimension changing segments 6 is four or more, and in the preferred embodiment shown in the figure, it is five. The number of resistance-increasing steps 7 is one less than the number of cross-sectional dimension changing segments 6. More preferably, in the direction from the feed side to the discharge side, the reduction in cross-sectional area of any two adjacent cross-sectional dimension changing segments 6 is the same, that is, Figure 1 The spacing between the outlines of adjacent cross-sectional dimension changes in segment 6 is the same. And, as... Figure 2 As shown, the lengths of the multiple cross-sectional dimension change segments 6 are all the same in the direction from the feed side to the discharge side. In a preferred embodiment, the cross-sectional dimension change segments 6 are set to be uniformly distributed, and the reduction amount of each stage is also uniform and consistent, so that the effect of gradually increasing resistance and pushing the feed is also more uniform.
[0025] Preferably, a recessed welding chamber 8 is provided on the material feeding side of the lower mold 2, and the mold hole 3 is located inside the welding chamber 8. Figure 1 , Figure 2 In the illustrated embodiment, the internal cross-section of the stepped feed inlet 5 on the output side is consistent with the internal cross-section of the welding chamber 8. Furthermore, the bottom corners of the welding chamber 8 are chamfered. The material is welded after entering the welding chamber 8, and then extruded into the die 3 for molding.
[0026] The stepped feed inlet 5 of this invention can be used in the upper die of various extrusion dies, such as flow-dividing combination dies. For example... Figure 4 The profile shown is generally rectangular with a thick solid section, where tail-shrinkage is prone to occur. It also has a cavity, requiring a corresponding die core in the extrusion mold. Therefore, the extrusion mold can be a flow-dividing combination mold. The upper mold 1 has multiple flow-dividing holes, at least one of which is a stepped inlet 5. Flow-dividing bridges connect the flow-dividing holes. A protruding die core is provided on the discharge side of the upper mold 1, corresponding to the cavity of the profile. By employing the stepped inlet 5 structure of this invention at the inlet or flow-dividing hole corresponding to the solid section, the tail-shrinkage problem is solved.
[0027] In summary, the extrusion die of this invention, which features external resistance and internal increase to prevent tail shrinkage, has multiple steps on the inner side of the feed inlet. For solid profiles with simple shapes, existing feed sides are generally flat or inclined (conical). This design uses stepped feeding, which allows the material on the periphery to gradually increase resistance as it is fed through each step, thus squeezing and pushing the material in the center. This results in more sufficient feeding in the center and a denser structure. Therefore, profiles produced using this extrusion die will not have tail shrinkage or black core issues. Typically, this design is suitable for extruding aluminum plates, aluminum bars, and aluminum square bars. These profiles generally have rectangular cross-sections. Existing dies produce profiles with unsatisfactory angles at the four corners and uneven sides adjacent to the corners. To address this, the preferred embodiment of this invention further adjusts the shape of the stepped feed inlet to a special shape with larger angles at the four corners, increasing the material at the corners and ensuring sufficient feeding, thereby achieving a more ideal forming effect.
Claims
1. An extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect, characterized in that, It includes an upper mold (1) and a lower mold (2) that are installed together; the lower mold (2) has a through mold hole (3), and the discharge side of the mold hole (3) has a hollow section (4), the internal space cross section of the hollow section (4) is larger than the internal space cross section of the mold hole (3); the upper mold (1) has a through stepped inlet (5), and in the direction from the inlet side to the outlet side, the stepped inlet (5) forms a number of cross-sectional size change segments (6) connected in sequence, the internal space cross section of the cross-sectional size change segment (6) is gradually reduced, and a resistance step (7) is formed between adjacent cross-sectional size change segments (6), and the internal space cross section of the output side of the stepped inlet (5) is larger than the internal space cross section of the mold hole (3).
2. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to claim 1, characterized in that, The internal space cross-sectional shape of the die hole (3) is rectangular. The internal cross-sectional shape of each cross-sectional dimension change segment (6) of the stepped feed port (5) is a shape that protrudes outward at the four corners of the rectangle and is recessed inward at the four sides of the rectangle.
3. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to claim 1, characterized in that, The number of cross-sectional dimension change segments (6) is more than four.
4. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to claim 1, characterized in that, In the direction from the feed side to the discharge side, the reduction in cross-sectional size of any two adjacent cross-sectional size change segments (6) is the same.
5. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to any one of claims 1-4, characterized in that, In the direction from the feed side to the discharge side, the lengths of multiple cross-sectional dimension change segments (6) are all the same.
6. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to any one of claims 1-4, characterized in that, A recessed welding chamber (8) is provided on the material feeding side of the lower mold (2), and the mold hole (3) is located inside the welding chamber (8).
7. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to claim 6, characterized in that, The internal space cross section of the stepped feed port (5) on the output side is consistent with the internal space cross section of the welding chamber (8).
8. The extrusion die with external resistance, internal increase, and anti-tail-shrinkage effect according to any one of claims 1-4, characterized in that, It is a flow-dividing combination mold. The upper mold (1) has multiple flow-dividing holes, of which at least one flow-dividing hole is a stepped inlet (5). The flow-dividing holes are connected by a flow-dividing bridge. A protruding mold core is provided on the discharge side of the upper mold (1).