Double-outlet step die for extruding high-strength aluminum alloy thin-wall profile

Abstract

The utility model belongs to the technical field of hot extrusion die manufacturing, and discloses a double-outlet step die for extruding a high-strength aluminum alloy thin-wall section bar, which comprises an upper die and a lower die which are matched with each other, a feeding side of the upper die is provided with a feeding port, and the feeding port comprises a central shunting hole and an outer side shunting hole. A trapezoid groove is formed in the outer edge of each outer side flow dividing hole, the outer side flow dividing holes are divided through auxiliary flow dividing bridges, the bridge positions of the auxiliary flow dividing bridges are lower than the feeding end face of the upper die, main flow dividing bridges are arranged on the left side and the right side of the center flow dividing hole, the bridge positions of the main flow dividing bridges are lower than the bridge positions of the auxiliary flow dividing bridges, and the discharging ends of the two main flow dividing bridges are connected with die cores. An upper welding part is arranged on the discharging side of the upper die, two welding-on chambers are arranged at the positions, corresponding to the upper welding part, of the feeding side of the lower die, the lower die is provided with two discharging ports, and work heads of the two die cores penetrate through the corresponding upper welding part and the corresponding welding-on chambers respectively and then are inserted into the discharging ports by partial depths. The utility model can reduce the mold blockage, improve the production efficiency, reduce the stress of the mold and prolong the service life of the mold.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of hot extrusion die manufacturing, specifically discloses a double-out stepped die for extruding high-strength aluminum alloy thin-walled section bar. BACKGROUND

[0002] In the production process of aluminum alloy section bar, 7 series aluminum alloy is widely used due to its excellent performance. However, the existing 7 series aluminum alloy extrusion die has many problems in actual production, which seriously affects the production efficiency and product quality. Specifically, the breakthrough pressure of 7 series aluminum alloy is relatively large during extrusion, which not only increases the production energy consumption, but also easily leads to equipment failure. At the same time, the die is prone to die blocking phenomenon during extrusion, which frequently interrupts the production process and greatly reduces the production efficiency. In addition, the problem of poor welding is also common, which affects the overall performance and appearance quality of the extruded product. Moreover, the service life of the existing die is relatively low, which needs to be frequently replaced, increasing the production cost. Taking 7004 aluminum alloy as an example, when extruding thin-walled hollow products, a bridge-type tongue die is usually used. Although this die can reduce the required extrusion force and improve the extrusion speed to a certain extent, it still has obvious defects, such as long extrusion residue, which not only causes material waste, but also increases the difficulty of subsequent processing. More importantly, the ordinary bridge-type tongue die cannot realize continuous extrusion, and the production efficiency is difficult to further improve. In addition, most traditional aluminum extrusion dies adopt single-out mode, and the feeding end is greatly limited in design when the shunt hole is designed, which leads to the fact that the friction force and the pressure in the cavity cannot be effectively controlled, thereby producing a series of inherent defects, such as unshaped extruded products and unstable product quality. In summary, the existing 7 series aluminum alloy extrusion die has many problems in breakthrough pressure, die blocking, poor welding, production efficiency and die service life, which seriously restricts the efficient production and high-quality manufacturing of 7 series aluminum alloy section bar. In view of the above problems, it is necessary to design a new type of double-out stepped die for extruding high-strength aluminum alloy thin-walled section bar to overcome the problems existing in the existing hot extrusion die. CONTENT OF THE UTILITY MODEL

[0003] The utility model discloses a double-out stepped die for extruding high-strength aluminum alloy thin-walled section bar to solve the problems of large breakthrough pressure and easy die blocking when extruding thin-walled hollow section bar in the existing hot extrusion die.

[0004] The utility model provides a kind of double stepped die for extruding high-strength aluminum alloy thin-walled section, including mutually coordinated upper die and lower die, the feeding side of the upper die is equipped with feeding port, the feeding port includes center shunt hole and outer side shunt hole, the center shunt hole is arranged in the middle part of the upper die feeding side, the outer side shunt hole is multiple, the outer side shunt hole is arranged in the radial outer side of the center shunt hole, and multiple the outer side shunt hole is evenly distributed, the outer edge of each the outer side shunt hole is equipped with trapezoidal groove, the outer side shunt hole is divided by vice shunt bridge, the bridge position of the vice shunt bridge is lower than the upper die feeding end face, the left and right sides of the center shunt hole are equipped with main shunt bridge, the bridge position of the main shunt bridge is lower than the bridge position of the vice shunt bridge, the feeding end of two the main shunt bridge is connected with die core, the feeding side of the upper die is equipped with upper welding, the feeding side of the lower die is equipped with two welding chambers with the upper welding corresponding place, the lower die is equipped with two discharge ports, and the foreman of two the die core is inserted into discharge port part depth after passing through corresponding upper welding and welding chamber.

[0005] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the bridge position of the vice shunt bridge is lower than the upper die feeding end face by 10% of the upper die axial length, the feeding end of the vice shunt bridge is an arc structure that protrudes outward in the middle, the thickness of the discharge end of the vice shunt bridge gradually decreases, and the vice shunt bridge divides the outer side shunt hole into six.

[0006] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the trapezoidal groove is provided with a step that expands radially outward, the axial length of the radially outward step is 80% of the upper die axial length, and the step connection of the trapezoidal groove is provided with a round corner transition.

[0007] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the bridge position of the main shunt bridge is lower than the upper die feeding end face by 20% of the upper die axial length, and the feeding end of the main shunt bridge is an arc structure that protrudes outward in the middle.

[0008] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the feeding end of the main shunt bridge is an arc structure that protrudes outward in the middle.

[0009] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the thickness of the main shunt bridge and the span ratio of the two main shunt bridges are 1:1.2-1:1.3.

[0010] According to some embodiments of the application, a double stepped die for extruding high-strength aluminum alloy thin-walled section, the two discharge ports of the lower die are centrally symmetrically arranged.

[0011] According to some embodiments of the present application, a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles is provided, wherein the two welding chambers of the lower die have the same shape and a butterfly-shaped cross section, and the cross section of the inlet corresponds to the cross sections of the two welding chambers.

[0012] According to some embodiments of the present application, a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles is provided, wherein the outer contour of the welding chamber is transitioned by a fillet with a radius of 3-5 mm.

[0013] According to some embodiments of the present application, a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles is provided, wherein the axial length of the upper welding chamber is 2.8-3.2 times the axial length of the welding chamber.

[0014] The double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles provided by the present application sets a double-die-hole discharge, which can effectively disperse the pressure during metal flow, significantly reduce the extrusion pressure inside the die, and effectively solve the pressure build-up problem that is prone to occur during the extrusion process of traditional dies, thereby avoiding profile defects and die damage caused by excessive pressure, greatly improving the stability and reliability of the production process. At the same time, the design of double-hole discharge increases the channel for metal flow, making the metal flow in the die more smooth, reducing the accumulation and retention of metal inside the die, and greatly reducing the probability of die clogging. Not only does it reduce production interruptions caused by die clogging, but it also improves the surface quality and dimensional accuracy of the profile, ensuring the quality stability of the product. In addition, double-hole discharge can also achieve simultaneous production of two profiles, further improving production efficiency and reducing product production costs, bringing significant economic benefits. By optimizing the structure of the die inlet end and adopting a stepped feeding design, the force borne by the die and the breakthrough pressure during extrusion can be reduced, the possibility of die bridge cracking during extrusion can be reduced, and the service life of the die can be improved. Reducing the height of the lower die welding chamber effectively reduces the hydrostatic pressure of the lower die welding chamber, and also reduces the breakthrough pressure during extrusion. Increasing the size of the upper welding chamber can improve the welding quality of the profile product while increasing the welding space, making up for the deficiency of the small height of the lower die welding chamber. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a front view of a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles according to an embodiment of the present application;

[0016] Figure 2 FIG. 2 is a cross-sectional view of a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles according to an embodiment of the present application;

[0017] Figure 3 FIG. 3 is a schematic view of the inlet end structure of an upper die according to an embodiment of the present application.

[0018] Figure 4 It is the upper die discharge end structure schematic view of the embodiment of the utility model;

[0019] Figure 5 It is the lower die feeding end structure schematic view of the embodiment of the utility model;

[0020] Figure 6 It is the profile structure schematic view of the embodiment of the utility model.

[0021] In the figure, 1, upper die, 1-1, center shunt hole, 1-2, outer shunt hole, 1-3, trapezoidal groove, 1-4, auxiliary shunt bridge, 1-5, main shunt bridge, 1-6, die core, 1-61, foreman, 1-7, upper welding, 2, lower die, 2-1, welding chamber, 2-2, discharge port. DETAILED DESCRIPTION

[0022] The embodiment of the utility model is further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the utility model, but cannot be used to limit the scope of the utility model.

[0023] In the description of the utility model, it needs to be explained that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In the description of the utility model, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. In addition, in the description of the utility model, unless otherwise specified, the meaning of "multiple" is two or more.

[0024] The embodiment provides a double-out stepped die for extruding high-strength aluminum alloy thin-walled profiles, which comprises Figures 1-5As shown, the upper die 1 and the lower die 2 are matched, the feeding side of the upper die 1 is provided with a feeding port, the feeding port comprises a central distribution hole 1-1 and a plurality of outer distribution holes 1-2, the central distribution hole 1-1 is arranged in the middle of the feeding side of the upper die 1, the outer distribution holes 1-2 are arranged outside the central distribution hole 1-1 in the radial direction, and the outer distribution holes 1-2 are uniformly distributed, each outer distribution hole 1-2 is provided with a trapezoidal groove 1-3 at the outer edge, the outer distribution holes 1-2 are divided by a sub-distribution bridge 1-4, the bridge position of the sub-distribution bridge 1-4 is lower than the feeding end surface of the upper die 1, the left and right sides of the central distribution hole 1-1 are provided with a main distribution bridge 1-5, the bridge position of the main distribution bridge 1-5 is lower than the bridge position of the sub-distribution bridge 1-4, the feeding ends of the two main distribution bridges 1-5 are connected with a mold core 1-6, the feeding side of the upper die 1 is provided with an upper welding 1-7, the feeding side of the lower die 2 is provided with two welding chambers 2-1 corresponding to the upper welding 1-7, the lower die 2 is provided with two discharge ports 2-2, the working head 1-61 of the two mold cores 1-6 is inserted into the discharge port 2-2 to a certain depth after passing through the corresponding upper welding 1-7 and welding chamber 2-1. The profile extruded by using the embodiment is shown in Figure 6 .

[0025] As a preferred embodiment of the present embodiment, specifically, as shown in Figure 3 , the feeding port adopts a longitudinal stepped step mode, the bridge position of the sub-distribution bridge 1-4 is lower than the feeding end surface of the upper die 1 by 10% of the axial length of the upper die 1, the feeding end of the sub-distribution bridge 1-4 is an arc structure protruding outward from the middle, specifically a circular arch structure, which can effectively increase the amount of molten aluminum and the guiding property, the bridge position of the main distribution bridge 1-5 is lower than the feeding end surface of the upper die 1 by 20% of the axial length of the upper die 1, the feeding end of the main distribution bridge 1-5 is also an arc structure protruding outward from the middle, specifically a circular arch structure, which can effectively increase the amount of molten aluminum and the guiding property. In addition, the structure at the feeding port is that the bridge position of the central main distribution bridge 1-5 is stepped down from the bridge position of the surrounding sub-distribution bridge 1-4, and the feeding end of the main distribution bridge 1-5 and the sub-distribution bridge 1-4 is a circular arch, which can pre-cut the aluminum bar and make the aluminum bar form multiple fluid streams into the corresponding distribution hole in advance. Compared with the ordinary flat combined die, the stepped structure can effectively reduce the pressure area of the distribution bridge, disperse stress, improve the carrying capacity of the distribution bridge, and at the same time reduce the pressure bearing by the die, so as to achieve the effect of reducing the extrusion pressure and also reduce the breakthrough pressure of the extruded product. At the same time, the bridge position of the middle main distribution bridge 1-5 is lower than the bridge position of the surrounding sub-distribution bridge 1-4, so that the main distribution bridge 1-5 can relatively late bear the extrusion pressure and the friction force with the bar, which can effectively reduce the force borne by the bridge position of the middle main distribution bridge 1-5. In the case of extruding 7-series aluminum alloy, the middle bridge position is easily extruded and cracked. Such stepped structure can well reduce the possibility of failure of the middle main distribution bridge 1-5 bridge position and improve the service life of the die.

[0026] As a preferred embodiment of the present embodiment, specifically, as shown inFigure 4 As shown in the drawings, the thickness of the sub-flow bridge 1-4 outlet end gradually decreases, and the sub-flow bridge 1-4 divides the outer side flow hole 1-2 into six parts. The thickness of the main flow bridge 1-5 and the span ratio of the two main flow bridges 1-5 are 1:1.2-1:1.3, which optimizes the bridge thickness and bridge span ratio, improves the mold deformation resistance, and increases the support area of the pier root of the two main flow bridges 1-5 to resist the high back pressure during the extrusion of the 7-series aluminum alloy.

[0027] As a preferred embodiment of the present embodiment, specifically, the conventional outer side flow hole 1-2 generally adopts a slope of 20°-25°, as shown in Figure 4 As shown in the drawings, the outer edge of the outer side flow hole 1-2 in the utility model is different from the slope of the outer edge of the conventional outer side flow hole 1-2. The outer edge of the outer side flow hole 1-2 in the utility model adopts the form of trapezoidal groove 1-3. Specifically, the trapezoidal groove 1-3 is provided with a radially outwardly expanded step, and the axial length of the radially outwardly expanded step is 80% of the axial length of the upper die 1. In this way, the aluminum holding capacity can be effectively increased, the cavity pressure can be reduced, and the mold damage can be prevented. At the same time, the stepped connection of the trapezoidal groove 1-3 is provided with a round corner transition. Specifically, the radius of the round corner can be 3mm-5mm, which reduces the flow dead zone and turbulence caused by the high deformation resistance of the 7-series aluminum alloy.

[0028] As a preferred embodiment of the present embodiment, specifically, as shown in Figure 5 As shown in the drawings, the two discharge ports 2-2 of the lower die 2 are centrally symmetrically arranged. The two welding chambers 2-1 of the lower die 2 are the same shape and the cross sections of the two welding chambers 2-1 are both butterfly-shaped structures. The cross section of the inlet port corresponds to the cross sections of the two welding chambers 2-1, and is also a butterfly-shaped structure. The center flow hole 1-1 and the outer side flow hole 1-2 of the inlet port are uniformly distributed around the center line of the mold, which ensures the flow balance of the metal flowing into the two welding chambers 2-1, so that the quality of the extruded product is higher, and the quality of the products extruded by the two discharge ports 2-2 is the same.

[0029] As the preferred embodiment of the present application, specifically, the outer contour of the welding chamber 2-1 is transitioned with a fillet with a radius of 3mm to 5mm, which can reduce the flow dead zone and turbulence of the metal when flowing, and avoid the flow dead zone increasing to cause the welding chamber 2-1 to be blocked. In the present application, the axial length of the upper welding 1-7 is 2.8 to 3.2 times the axial length of the welding chamber 2-1, in the present embodiment, the selected matched extruder is 2750T, and the conventional welding chamber depth is 15-20cm from the profile structure and design experience. Since the present scheme extrudes 7 series aluminum alloy, in order to ensure the stability and strength of the head, the axial length of the welding chamber 2-1 is designed to be 0.6 times the axial length of the conventional welding chamber, and the axial length of the conventional welding chamber is 20% of the axial length of the lower die. However, the axial length of the welding chamber 2-1 of the present application is set to 12% of the axial length of the lower die, and the shortened part is added to the axial length of the upper welding 1-7, which can effectively reduce the air knife length, and effectively improve the overall strength and fusion effect of the upper die 1.

[0030] The present application also simulates and analyzes the overall structure, and simulates according to the set extrusion process. The overall stress simulation result of the upper die 1 after simulation shows that the main and auxiliary flow bridges 1-5 and 1-4 are regarded as a whole as the entire flow bridge, the flow bridge is the main stress position, and the maximum internal stress value of the flow bridge is 1291MP. Generally, when extruding 7 series aluminum alloy thin-walled profiles, the maximum internal stress value of the conventional flow bridge position is about 1800MP, while the present application is only 1217MP, which fully shows that the stepped arc arch flow bridge plays a positive role in dispersing the internal stress of the flow bridge position and improving the bearing capacity. More specifically, the stress of the main flow bridge 1-5 in the middle position is much smaller than that of the surrounding auxiliary flow bridge 1-4, and the stress value of the main flow bridge 1-5 is 564MP, which verifies that the stepped flow bridge plays a good protective role on the middle main flow bridge 1-5 position. The overall stress simulation result of the lower die shows that the breakthrough pressure value of the lower die is 138MP, which is much smaller than the 320MP of the conventional flat combined die, which shows that the stepped arc arch flow bridge is a decisive factor in reducing the breakthrough pressure, and also verifies the correctness of the method of reducing the axial length of the lower die welding chamber 2-1 to reduce the hydrostatic pressure of the welding chamber 2-1, thereby reducing the breakthrough pressure value during extrusion. The simulation result shows that the overall deformation value of the double stepped body for extruding high-strength aluminum alloy thin-walled profiles of the present application is ≤0.7mm, which is much smaller than the deformation value of the conventional device.

[0031] The utility model discloses a step -type main shunt bridge 1 -5 and vice shunt bridge 1 -4 structure, main shunt bridge 1 -5 and vice shunt bridge 1 -4 inlet section are set as arc structure and can very good solution thin -walled hollow section extrusion when the problem of easily appearing breakthrough pressure bigger, extrusion product not shaping, welding is bad, production efficiency is not high and mould service life low etc.

[0032] Embodiments of the present application are presented for the purpose of example and description, and are not exhaustive or limiting of the present application to the precise form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments are chosen and described in order to best explain the principles of the present application and its practical application, and to enable others skilled in the art to understand the present application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A double-exit stepped die for extruding high-strength aluminum alloy thin-walled profiles, characterized in that, The device includes an upper mold (1) and a lower mold (2) that cooperate with each other. The upper mold (1) has an inlet on its inlet side, which includes a central diversion hole (1-1) and outer diversion holes (1-2). The central diversion hole (1-1) is located in the middle of the inlet side of the upper mold (1). There are multiple outer diversion holes (1-2), which are located radially outside the central diversion hole and are evenly distributed. Each outer diversion hole (1-2) has a trapezoidal groove (1-3) on its outer edge. The outer diversion holes (1-2) are divided by a secondary diversion bridge (1-4), and the bridge position of the secondary diversion bridge (1-4) is lower than that of the upper mold. (1) On the feed end face, the left and right sides of the central diversion hole (1-1) are provided with main diversion bridges (1-5). The bridge position of the main diversion bridge (1-5) is lower than that of the secondary diversion bridge (1-4). The discharge ends of the two main diversion bridges (1-5) are connected to the mold cores (1-6). The upper mold (1) has an upper weld (1-7) on the discharge side. The lower mold (2) has two welding chambers (2-1) on the feed side corresponding to the upper weld (1-7). The lower mold (2) has two discharge ports (2-2). The forks (1-61) of the two mold cores (1-6) pass through the corresponding upper weld (1-7) and welding chamber (2-1) and are inserted into the discharge port (2-2) to a certain depth.

2. The double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The bridge position of the sub-diversion bridge (1-4) is 10% lower than the material inlet end face of the upper mold (1) by the axial length of the upper mold (1). The material inlet end of the sub-diversion bridge (1-4) is an arc-shaped structure that bulges outward from the center. The thickness of the material outlet end of the sub-diversion bridge (1-4) gradually decreases. The sub-diversion bridge (1-4) divides the outer diversion hole (1-2) into six.

3. The double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The trapezoidal groove (1-3) is provided with a radially outward step, the axial length of which is 80% of the axial length of the upper mold, and the step connection of the trapezoidal groove (1-3) is provided with a rounded corner transition.

4. The double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The bridge position of the main diversion bridge (1-5) is 20% lower than the material inlet end face of the upper mold (1) by the axial length of the upper mold (1). The material inlet end of the main diversion bridge (1-5) is an arc-shaped structure with the middle part protruding outward.

5. A double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The feed end of the main diversion bridge (1-5) is an arc-shaped structure with the middle part protruding outward.

6. A double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The ratio of the thickness of the main diversion bridge (1-5) to the span of the two main diversion bridges (1-5) is 1:1.2 to 1:1.

3.

7. A double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The two discharge ports (2-2) of the lower mold (2) are centrally symmetrically arranged.

8. A double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The two welding chambers (2-1) of the lower mold (2) have the same shape and the cross-section of the two welding chambers (2-1) is a butterfly structure, and the cross-section of the inlet corresponds to the cross-section of the two welding chambers (2-1).

9. A double-step die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The outer contour of the welding chamber (2-1) is transitioned by a rounded corner with a radius of 3mm to 5mm.

10. A double-outlet stepped die for extruding high-strength aluminum alloy thin-walled profiles according to claim 1, characterized in that, The axial length of the upper weld (1-7) is 2.8 to 3.2 times the axial length of the weld chamber.

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