A single-extrusion die for controlling coarse grains of solid bars

Abstract

This application discloses a single-output multi-solid bar extrusion die for controlling coarse grains. The die includes a die body with at least two feed inlets and one discharge outlet, each corresponding to a specific material. A stepped multi-step feeding structure with 3-9 steps, each step being 7-15 mm high, is provided at the feed inlet. The initial step and the last step form a die angle of 85°-95°. A working zone is provided between the feed inlet and the discharge outlet, with a working zone angle of 5°-10° between the working zone and the last step. Multiple outputs are achieved through the multiple discharge outlets. This structural innovation achieves synergistic optimization of coarse grain control, defect prevention, efficiency improvement, and material adaptation, meeting the application requirements of high-end aluminum alloy bars in key areas such as vehicle bodies, chassis, and electric drive systems.

Description

Technical Field

[0001] This utility model relates to the field of extrusion bar die technology, and in particular to a single-output multi-solid bar extrusion die for controlling coarse grains. Background Technology

[0002] Aluminum alloy extruded bars are widely used in key areas such as vehicle bodies, chassis, and electric drive systems due to their high strength, high dimensional accuracy, and flexible shapes. These applications place extremely high demands on the surface quality of the bars, especially the control of coarse grains. In existing technologies, traditional flat die extrusion, due to its high extrusion pressure, is prone to abnormal grain growth and coarse grains. Although conical dies can reduce some pressure, impurities and oxide scale on the ingot surface can easily enter the product surface with the metal flow, still failing to meet quality requirements. In terms of production efficiency, single-cavity dies have limited capacity, and the existing "one-out-of-many" design often suffers from pressure imbalance (excessive extrusion ratio) due to a lack of precise control, which exacerbates poor appearance and coarse grain problems, hindering efficiency improvements. In addition, for the extrusion of low-plasticity alloys, existing dies have not effectively solved the problem of stress concentration, which easily leads to surface cracks. Non-contact deformation when the metal flows into the working zone and the collapse and stress cracking of the die edges at high temperatures further affect product quality stability and die life.

[0003] In summary, existing molds have significant shortcomings in terms of coarse grain control, surface defect blocking, efficiency improvement, and material adaptability, and new structural designs are urgently needed to address these pain points from the source. Summary of the Invention

[0004] This utility model aims to solve one of the technical problems existing in the prior art.

[0005] This application provides a single-output multi-solid bar extrusion die for controlling coarse grains, comprising a die body. The die body is characterized by having at least two feed inlets and discharge outlets, each feed inlet and discharge outlet corresponding to each other. A stepped multi-step feeding structure is provided at each feed inlet, having 3-9 steps, each step having a height of 7mm-15mm. An angle of 85°-95° ​​is formed between the initial step and the last step. A working belt is provided between the feed inlet and discharge outlet, and a working belt angle of 5°-10° is provided between the working belt and the last step. Multiple outputs are achieved through the multiple discharge outlets.

[0006] Preferably, the number of steps in the stepped multi-step feeding structure is set to 5 to 7.

[0007] Preferably, the height of the step is set to 10mm~12mm.

[0008] Preferably, the working belt angle is 7°~8° and the die angle is 90°.

[0009] Preferably, the number of the inlet and outlet is set to 3.

[0010] Preferably, the distance between the centers of the three feed inlets is set to be equal.

[0011] Preferably, a feed inlet baffle is provided at the inlet of the feed port. The feed inlet baffle is annular and its inner diameter is smaller than that of the initial step. The inner diameter of the feed inlet baffle is set to be larger than the inner diameter of the next step after the initial step.

[0012] Preferably, the steps of the stepped multi-step feeding structure are evenly distributed.

[0013] Preferably, the connection between the working belt and the last step is provided with an inlet rounded corner, which is set to a rounded corner of 2mm to 7mm.

[0014] Preferably, the discharge port is divided into two sections: one section is a die hole connected to the working belt, and the other section is a trumpet discharge section connected to the die hole. The inner diameter of the trumpet discharge section gradually increases from the inside to the outside, and the inner diameter of the die hole is set to be equal from the inside to the outside.

[0015] The above-mentioned single-output multi-solid bar extrusion die for controlling coarse grains has the following effects:

[0016] 1. Through a stepped, multi-step feeding structure with 3-9 steps and physical separations of 7mm-15mm in height, the frictional resistance between the metal and the die is reduced, lowering the specific pressure during extrusion and suppressing abnormal grain growth caused by high pressure from the source. Simultaneously, the working zone angle of 5°-10° forces deformation on the metal, promoting thorough grain breakage and recrystallization to form a fine-grained structure. In practical applications, the coarse-grained layer depth is reduced from 10%-25% to below 5%, significantly improving the mechanical properties and oxidation uniformity of the bar stock.

[0017] 2. The 90° mold angle is set between the initial step and the last step, which can physically intercept oxide scale, impurities and other defects on the surface of the ingot, preventing them from entering the surface of the product with the flow of metal; together with the circular baffle of the feed port, the inner diameter is smaller than the inner diameter of the initial step and larger than the inner diameter of the next step, which initially blocks large impurities. Under the dual action, the surface defect introduction rate is reduced by more than 70%, which significantly improves the purity of the product appearance.

[0018] 3. The 2mm~7mm inlet radius is designed at the connection between the working zone and the last step. This reduces stress concentration when metal flows into the working zone and effectively prevents surface cracks from forming during the extrusion of low-plasticity alloys. At the same time, the rounded corner structure reduces the risk of die corner collapse and stress cracking during high-temperature extrusion and improves the die's adaptability to different materials.

[0019] 4. Employing a multi-outlet design with at least two inlets and three outlets (ideally three), the material is fed independently through multiple parallel inlets, precisely controlling the specific pressure within the optimal range of 15-25. This solves the problems of insufficient capacity of traditional single-cavity molds and excessive extrusion ratios during large-scale production. The flexible design of the mold hole count adapts to different tonnage machines, increasing the single-mold production capacity by three times compared to traditional molds, significantly improving production efficiency.

[0020] 5. The uniform distribution of steps in the stepped multi-step feeding structure, the stress dispersion effect of the inlet rounded corners, and the smooth transition design of the constant inner diameter of the die hole and the gradual change of the inner diameter of the horn discharge section reduce local stress concentration in the die, reduce the risk of die wear under high temperature extrusion, and extend the service life of the die.

[0021] In summary, this mold achieves synergistic optimization of coarse grain control, defect prevention, efficiency improvement, and material compatibility through structural innovation, meeting the application requirements of high-end aluminum alloy bars in key areas such as vehicle body, chassis, and electric drive systems. The beneficial effects of this invention will be detailed in the embodiments, making these effects even more apparent. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of an embodiment of this application.

[0023] Figure 2 This is a cross-sectional structural diagram of one of the inlet and outlet ports in an embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the main structure of an embodiment of this application.

[0025] 1~ Mold body, 2~ Feed inlet, 3~ Feed inlet retainer, 4~ Mold corner, 5~ Inlet rounded corner, 6~ Working zone, 8~ Mold hole, 9~ Horn-shaped discharge section. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0028] The embodiments of this application will be described in detail below with reference to the accompanying drawings and specific examples and application scenarios.

[0029] Example 1:

[0030] like Figures 1-3 As shown, a single-output multi-solid bar extrusion die for controlling coarse grains includes a die body 1, on which three feed ports 2 and three corresponding discharge ports are opened. The center-to-center distance between the three feed ports 2 is equal, realizing one-output three-production.

[0031] Each feed inlet 2 is equipped with a circular feed inlet baffle 3. The inner diameter of the baffle 3 is 48 mm, which is smaller than the inner diameter of the initial step (53 mm) and larger than the inner diameter of the next step (45 mm). This baffle can initially block impurities and oxide scale from the edge of the ingot. The feed inlet 2 is equipped with a stepped multi-step feeding structure with 6 steps evenly distributed circumferentially. Each step is 11 mm high. An 85-95° die angle 4 is formed between the initial step and the last step. The physical separation of the steps reduces metal friction, and the die angle 4 further intercepts surface defects of the ingot from flowing into the product.

[0032] The connection between the working zone 6 and the last step is machined with an entry fillet 5, with a radius of 5mm (within the range of 2mm to 7mm), which can reduce stress concentration during the extrusion of low-plasticity alloys. The working zone angle between the working zone 6 and the last step is set to 7°, which forces metal deformation through a small angle, thereby fully breaking down and refining the surface grains.

[0033] The discharge port is divided into two sections: a die hole 8 connected to the working belt 6 (with an inner diameter of 20mm and a length of 10mm, and the inner diameter remains equal along the discharge direction); and a horn-shaped discharge section 9 connected to the die hole 8. The length of the horn-shaped discharge section 9 is 16mm, and the inner diameter gradually increases from 20mm to 23mm from the inside out, reducing the risk of surface scratches during discharge.

[0034] Example 2:

[0035] The difference from Example 1 is as follows: the mold body 1 has two feed ports 2 and two discharge ports (one-outlet-two-outlet design); the stepped multi-step feeding structure has five steps, each step being 10mm high; the working zone angle is 8°, forming a 90° die angle 4 between the initial step and the last step; the inlet fillet 5 has a radius of 4mm; the inner diameter of the feed port stop 3 is 52mm, the inner diameter of the initial step is 57mm, and the inner diameter of the next step is 49mm; the inner diameter of the die hole 8 is 28mm, and the inner diameter of the horn-shaped discharge section 9 is increased from 28mm to 31mm. This design is suitable for medium-sized bar extrusion, with the specific pressure controlled at 22.

[0036] Example 3:

[0037] This design, suitable for small-diameter bars, features a three-stage feeding structure with seven steps, each 12mm high. The three feed inlets 2 are equidistant from each other. The working zone angle is 7°. The inlet fillet radius 5 is 6mm. The feed inlet retainer 3 has an inner diameter of 40mm, the initial step inner diameter is 45mm, and the next step inner diameter is 38mm. The die hole 8 has an inner diameter of 18mm, and the horn-shaped discharge section 9 has an inner diameter increased from 18mm to 20mm, with the specific pressure stabilized at 19.

[0038] During extrusion, the heated aluminum alloy ingot is pushed by the extrusion shaft. First, large impurities are blocked by the feed inlet baffle 3. After entering the stepped multi-step feeding structure, the evenly distributed steps reduce friction and lower pressure. The 90° die angle 4 intercepts defects such as surface oxide scale. The metal flows smoothly into the working zone 6 through the inlet fillet 5, where the grains are broken and refined under the forced action of the working zone angle. Finally, it is sized through the die hole 8 and smoothly discharged through the trumpet-shaped discharge section 9. In practical applications, the coarse grain layer depth is reduced from 10%~25% to below 5%, the single die output is increased by 3 times, and the specific pressure is controlled within the optimal range of 15~25.

[0039] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0040] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A control of a one-out-of-many solid bar extrusion die of a coarse crystal, comprising a die body (1), characterized in that, The mold body (1) is provided with at least two feed ports (2) and discharge ports. Each feed port (2) and each discharge port are corresponding. A stepped multi-step feeding structure is provided at the feed port (2). The stepped multi-step feeding structure has 3 to 9 steps. The height of each step is 7 mm to 15 mm. The initial step and the last step form a mold angle (4). The mold angle is 85° to 95°. A working belt (6) is provided between the feed port (2) and the discharge port. A working belt angle is provided between the working belt (6) and the last step. The working belt angle is set to 5° to 10°. Multiple discharge ports are used to achieve one-to-many production.

2. A control rough grain one-out-multiple solid bar extrusion die according to claim 1, characterized in that, The number of steps in the stepped multi-step feeding structure is set to 5 to 7.

3. A control rough grain of one out of multiple solid bar extrusion die according to claim 1, characterized in that, The height of the step is set to 10mm~12mm.

4. A control rough grain one-out-multiple solid bar extrusion die according to claim 1, characterized in that, The working belt angle is 7°~8°, and the die angle is 90°.

5. A control rough grain of one out of multiple solid bar extrusion die according to claim 1, characterized in that, The number of inlet and outlet ports is set to 3.

6. A control rough grain of one out of multiple solid bar extrusion die according to claim 5, characterized in that, The distance between the centers of the three feed inlets is set to be equal.

7. The single-outlet multi-solid bar extrusion die for controlling coarse grains according to claim 1, characterized in that, The feed inlet (2) is provided with a feed inlet baffle (3). The feed inlet baffle (3) is circular and its inner diameter is smaller than that of the initial step. The inner diameter of the feed inlet baffle (3) is set to be larger than the inner diameter of the next step of the initial step.

8. A control rough grain of one out of multiple solid bar extrusion die according to claim 1, characterized in that, The steps of the stepped multi-step feeding structure are evenly distributed.

9. A control rough grain of one of a plurality of solid bar extrusion die according to claim 1, characterized in that, The connection between the working belt (6) and the last step is provided with an entrance fillet (5), which is set to a fillet of 2mm to 7mm.

10. A single-outlet multi-solid bar extrusion die for controlling coarse grains according to claim 1, characterized in that, The discharge port is divided into two sections: one is a die hole (8) connected to the working belt (6), and the other is a horn discharge section (9) connected to the die hole (8). The inner diameter of the horn discharge section (9) gradually increases from the inside to the outside, and the inner diameter of the die hole (8) is set to be equal from the inside to the outside.

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