Small-extrusion-ratio and large-wall-thickness extrusion die for 6082 aluminum alloy cylinder body

Abstract

The utility model discloses an extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness, the hole wall of one side, far away from a core head, of each shunting hole is of a conical surface structure, the length of an upper die working tape and the length of a lower die working tape are 1.5-2 times of the maximum hole width of a die hole, the depth of a welding chamber is 1.5-1.7 times of the maximum hole width of the die hole, and the thickness of the welding chamber is 1.5-1.7 times of the maximum hole width of the die hole. The upper die working belt is composed of a plurality of cambered surface sections which are sequentially connected in the circumferential direction, sharp corner parts are formed at the connecting positions of the adjacent cambered surface sections, the peripheral face of the core head is sunken to form a circle of neck clearance cutters, the neck clearance cutters are located at the end, close to the upper die, of the upper die working belt, and the depths of the positions, corresponding to the cambered surface sections, of the neck clearance cutters are equal. And the depth, corresponding to the sharp corner part, of the neck clearance tool is 1-2 times of the depth, corresponding to the cambered surface section, of the neck clearance tool, so that the technical problems that the risk probability of poor welding is extremely high when 6082 aluminum alloy is adopted for extrusion forming of the aluminum alloy section for the cylinder body, and only an extremely low extrusion speed can be adopted for production in order to avoid the condition of pull cracks can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of extrusion dies, in particular to an extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness. Background Art

[0002] Aluminum alloy cylinder products have requirements for air tightness and working pressure, so the quality of the weld of the extruded product is high. Figure 1 Compared with ordinary aluminum alloy profiles, the wall thickness of the aluminum alloy profile used for the cylinder body is very thick, with the thinnest thickness being 34mm and the thickest thickness being 66mm. The weight of the aluminum alloy profile used for the cylinder body reaches 72kg per meter.

[0003] When extruding a φ457 ingot on a 120MN extruder, the extrusion ratio (i.e., the degree of deformation) is very small, only about 6. Generally speaking, when the extrusion ratio is small, the non-uniformity of the mechanical properties of the inner and outer layers of the profile is more serious, and the risk of poor welding is very high. The size and height of the welding chamber have a great influence on the quality of the cylinder weld. If the welding chamber is generally very shallow according to the existing extrusion die design ideas, then when the existing extrusion die is used to extrude the aluminum alloy profile for the cylinder body, the metal does not have enough diffusion welding time in the welding chamber. Since sufficient hydrostatic pressure cannot be established in the welding chamber, the welding pressure is low, which will directly lead to problems with the welding quality.

[0004] In addition, 6082 aluminum alloy is used to extrude thick wall products (such as Figure 1 When the cylinder body shown in the figure is made of aluminum alloy profile), if there are sharp corners in the product structure, it is very easy to crack, which can only be avoided by reducing the extrusion speed, resulting in a significant reduction in production efficiency.

[0005] Solving the above problems has become a top priority. Utility Model Content

[0006] In order to solve the technical problems that the risk of poor welding is very high when 6082 aluminum alloy is used to extrude aluminum alloy profiles for cylinder bodies, and that only extremely low extrusion speeds can be used for production to avoid cracking, the utility model provides an extrusion die for 6082 aluminum alloy cylinder bodies with a small extrusion ratio and large wall thickness.

[0007] The technical solution is as follows:

[0008] An extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness, comprising an upper die and a lower die matched with the upper die, wherein the lower die has a cavity penetrating through both end faces thereof, the cavity wall of the cavity being a lower die working belt, the upper die has a core head matched with the cavity, the outer circumference of the core head corresponding to the position of the lower die working belt being the upper die working belt, after the core head is inserted into the cavity, the gap between the two constitutes a die hole, a plurality of circumferentially uniformly distributed diverter holes are provided on the upper die, an end face of the lower die close to the upper die is concave to form a welding chamber surrounding the cavity, and the characteristic is that the hole wall of each diverter hole away from the core head is a conical structure, so that The cross-sectional area of ​​each diversion hole is gradually increased in the direction approaching the lower die, the lengths of the upper die working belt and the lower die working belt are both 1.5-2 times the maximum hole width of the die hole, the depth of the welding chamber is 1.5-1.7 times the maximum hole width of the die hole, the upper die working belt is composed of a plurality of arc surface segments connected in sequence along the circumferential direction, the connection between adjacent arc surface segments constitutes a sharp corner, the outer peripheral surface of the core head is recessed to form a circle of neck hollow knife, the neck hollow knife is located at one end of the upper die working belt close to the upper die, the depth of the neck hollow knife corresponding to each arc surface segment is equal, and the depth of the neck hollow knife corresponding to the sharp corner is 1-2 times the depth of the corresponding arc surface segment.

[0009] Compared with the prior art, the utility model has the following beneficial effects:

[0010] 1. The outer wall of each diversion hole is designed as a conical structure, which reduces the extrusion pressure and effectively increases the area of ​​the welding chamber, thereby effectively improving the welding quality;

[0011] 2. The deep welding chamber is combined with the extra-long working belt. The interaction between the two can build up sufficient hydrostatic pressure in the welding cavity formed by the upper die covering the welding chamber of the lower die, thereby ensuring sufficient welding pressure and improving welding quality;

[0012] 3. For the neck empty cutter, all the arc surface segments are designed with equal width, and combined with the widened sharp corners, it can not only effectively avoid the problem of cracking at the sharp corners of the aluminum alloy profile for the cylinder body caused by the increase of extrusion speed or temperature, thereby increasing the extrusion speed and improving production efficiency, but also ensure sufficient material supply in the concave part of the mold core during the extrusion process, which is further conducive to the increase of extrusion speed and creates conditions for increasing the range of extrusion process parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the aluminum alloy profile for the cylinder body;

[0014] Figure 2 It is a structural schematic diagram of the utility model;

[0015] Figure 3 It is a structural schematic diagram of the upper die;

[0016] Figure 4 is a cross-sectional view of the upper die;

[0017] Figure 5 for Figure 3 Sectional view at the middle BB;

[0018] Figure 6 It is a structural schematic diagram of the lower mold;

[0019] Figure 7 This is a cross-sectional view of the lower die. DETAILED DESCRIPTION

[0020] The utility model is further described below in conjunction with embodiments and drawings.

[0021] like Figure 2-Figure 7 As shown, an extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness mainly comprises an upper die 2 and a lower die 1 matched with the upper die 2, the lower die 1 having a cavity 11 penetrating through the end faces at both ends thereof, the upper die 2 having a core head 21 matched with the cavity 11, and after the core head 21 extends into the cavity 11, the gap between the two constitutes a die hole A. In this embodiment, the upper die 2 and the lower die 1 are both cylindrical structures, and the diameters of the two are equal.

[0022] See also Figure 2-Figure 4 The upper die 2 is provided with a plurality of diverter holes 22 evenly distributed along the circumferential direction, and the end surface of the lower die 1 close to the upper die 2 is recessed to form a welding chamber 12 surrounding the cavity 11. The hole wall of each diverter hole 22 on one side away from the core head 21 is a conical structure, so that the cross-sectional area of ​​each diverter hole 22 gradually increases toward the direction close to the lower die 1. Therefore, in this embodiment, the outer hole wall of each diverter hole 22 is designed as a conical structure, which effectively increases the area of ​​the welding chamber while reducing the extrusion force, thereby effectively improving the welding quality.

[0023] In this embodiment, the cone angle of the hole wall of each diversion hole 22 away from the core head 21 is 4-8°, which can improve the welding quality while ensuring the structural strength of the upper mold 2, making the upper mold 2 durable and reducing the maintenance frequency.

[0024] See also Figure 2 , Figure 4 and Figure 7, the cavity wall of the cavity 11 is the lower die working belt 111, that is, the circumferential side wall of the cavity 11 is the lower die working belt 111. The position of the outer circumference of the core head 21 corresponding to the lower die working belt 111 is the upper die working belt 211. In this embodiment, the upper die working belt 211 is located at the outer end of the core head 21. The lengths of the upper die working belt 211 and the lower die working belt 111 are both 1.5-2 times the maximum hole width of the die hole A, and the depth of the welding chamber 12 is 1.5-1.7 times the maximum hole width of the die hole A. Therefore, the use of a large-depth welding chamber 12 with an extra-long working belt, the interaction between the two can enable the upper die 2 to cover the welding chamber 12 of the lower die 1 to form a sufficient hydrostatic pressure in the welding cavity, thereby ensuring sufficient welding pressure and improving welding quality.

[0025] by Figure 1 Taking the cylinder body made of aluminum alloy profile as an example, the thinnest thickness is 34 mm and the thickest thickness is 66 mm. In this embodiment, the lengths of the upper die working belt 211 and the lower die working belt 111 are both 100 mm, and the depth of the welding chamber 12 is also 100 mm.

[0026] In this embodiment, the lower die working belt 111 includes an entrance section 111b and a sizing section 111a which are connected in sequence in a direction away from the upper die 2. The sizing section 111a is a cylindrical structure. The outer peripheral surface of the entrance section 111b is a conical structure whose diameter gradually increases in a direction away from the sizing section 111a. The axial length of the sizing section 111a is one tenth of the length of the lower die working belt 111. Through the extra-long entrance section 111b and the conical structure of the entrance section 111b, the metal can be made more uniform in the die hole A, thereby improving the forming surface quality of the aluminum alloy profile for the cylinder body. At the same time, the ultra-short sizing section 111a can eliminate the resistance during sizing to the maximum extent, improve the dimensional accuracy of the profile, and be more conducive to ensuring the surface quality and dimensional controllability of the profile during high-speed extrusion.

[0027] In this embodiment, the cone angle of the inlet section 111b is preferably 4°. The small cone angle design is beneficial to ensuring the surface quality of the extruded profile during high-speed extrusion.

[0028] See also Figure 3 and Figure 6 , there are diverter bridges 23 between adjacent diverter holes 22, each diverter bridge 23 is connected to the corresponding upper die bridge pier 24, and lower die bridge piers 13 corresponding to the upper die bridge piers 24 are formed on the circumferential side wall of the welding chamber 12 inwardly protruding, so that the welding chamber 12 is designed in a petal shape, increasing the area of ​​the lower die bridge pier 13, which is beneficial to the support rigidity of the upper die 2 when it is pressed, and is also beneficial to the strength and safety of the upper die 2. At the same time, the petal-shaped layout of the lower die bridge pier 13 reduces the extrusion dead zone, which is beneficial to reducing the cutting of the extruded product.

[0029] Furthermore, each corner of the circumferential side wall of the welding chamber 12 adopts arc transition, which can better reduce the extrusion dead zone.

[0030] See also Figure 3 and Figure 5 The diverter bridge 23 includes a main body section 231 of equal width and a welding section 232 formed at the bottom of the main body section 231. Both side surfaces of the welding section 232 are inclined structures with the same inclination angle, so that the width of the welding section 232 gradually decreases in the direction away from the main body section 231, so that the cross-section of the diverter bridge 23 is similar to a water drop shape, ensuring that the metal can be fully welded under the bridge.

[0031] In this embodiment, the inclination angles of the two side surfaces of the welding section 232 are both 15°, and the width of the bottom surface of the welding section 232 is approximately one fifth of the width of the main section 231, which can ensure that the metal is fully welded under the bridge.

[0032] In this embodiment, the width of the main body section 231 is preferably 40 mm, and the width of the bottom surface of the welding section 232 is preferably 8 mm.

[0033] For further information, see Figure 7 There is a fillet with a radius of 10-30 mm between the circumferential side wall and the bottom surface of the welding chamber 12, so as to reduce the flow dead zone at the root of the welding chamber 12, reduce the length of the head and tail welding of the ingot, that is, reduce the length of the head and tail of the final aluminum alloy profile for the cylinder body.

[0034] by Figure 1 For example, the inner hole of the cylinder aluminum alloy profile is composed of multiple arc surfaces C1, and there is a sharp corner C2 between adjacent arc surfaces C1. When the cylinder aluminum alloy profile is extruded by 6082 aluminum alloy, it is very easy to crack at the sharp corner C2. Therefore, in this embodiment, please refer to Figure 3 The upper mold working belt 211 is composed of multiple arc surface segments 211a connected in sequence along the circumferential direction, and the connection between adjacent arc surface segments 211a constitutes a sharp corner portion 211b. The outer peripheral surface of the core head 21 is recessed to form a circle of neck hollow knife 212. The neck hollow knife 212 is located at one end of the upper mold working belt 211 close to the upper mold 2. The depth of the neck hollow knife 212 corresponding to each arc surface segment 211a is equal, and the depth of the neck hollow knife 212 corresponding to the sharp corner portion 211b is 1-2 times the depth of the corresponding arc surface segment 211a. With such a design, for the neck hollow knife 212, all the arc surface sections 211a are designed with equal width, and combined with the widened sharp corner portion 211a, it can not only effectively avoid the problem of cracking at the sharp corners of the aluminum alloy profile for the cylinder body caused by the increase in extrusion speed or temperature, thereby increasing the extrusion speed and improving production efficiency, but also ensure that the concave part of the mold core is adequately supplied with material during the extrusion process, which is further beneficial to the increase in the extrusion speed and creates conditions for increasing the range of extrusion process parameters.

[0035] In this embodiment, the depth of the neck hollow knife 212 corresponding to each arc surface segment 211a is preferably 4 mm, and the depth of the neck hollow knife 212 corresponding to the sharp corner portion 211b is preferably 8 mm.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make a variety of similar expressions without violating the purpose and claims of the present invention, and such changes fall within the scope of protection of the present invention.

Claims

1. An extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness, comprising an upper die (2) and a lower die (1) matched with the upper die (2), wherein the lower die (1) has a cavity (11) penetrating through both end faces thereof, the cavity wall of the cavity (11) being a lower die working zone (111), the upper die (2) having a core head (21) matched with the cavity (11), the outer circumference of the core head (21) corresponding to the position of the lower die working zone (111) being the upper die working zone (211), after the core head (21) is inserted into the cavity (11), the gap between the two constitutes a die hole (A), the upper die (2) is provided with a plurality of diverter holes (22) uniformly distributed along the circumferential direction, the end face of one end of the lower die (1) close to the upper die (2) is recessed to form a welding chamber (12) surrounding the cavity (11), characterized in that: The hole wall of each diverter hole (22) on one side away from the core head (21) is a conical structure, so that the cross-sectional area of ​​each diverter hole (22) gradually increases in the direction close to the lower die (1), the length of the upper die working belt (211) and the lower die working belt (111) are both 1.5-2 times the maximum hole width of the die hole (A), the depth of the welding chamber (12) is 1.5-1.7 times the maximum hole width of the die hole (A), and the upper die working belt (211) is composed of a plurality of arc surface segments (211) connected in sequence along the circumferential direction. a), the connection between adjacent arc surface segments (211a) forms a sharp corner portion (211b), the outer peripheral surface of the core head (21) is recessed to form a circle of neck hollow cutters (212), the neck hollow cutters (212) are located at one end of the upper die working zone (211) close to the upper die (2), the depth of the neck hollow cutters (212) corresponding to each arc surface segment (211a) is equal, and the depth of the neck hollow cutters (212) corresponding to the sharp corner portion (211b) is 1-2 times the depth of the neck hollow cutters (212) corresponding to the arc surface segment (211a).

2. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and large wall thickness according to claim 1, characterized in that: A diversion bridge (23) is provided between adjacent diversion holes (22), and each diversion bridge (23) is connected to a corresponding upper mold bridge pier (24). Lower mold bridge piers (13) corresponding to each upper mold bridge pier (24) are formed inwardly protruding on the circumferential side wall of the welding chamber (12).

3. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and large wall thickness according to claim 2, characterized in that: The diverter bridge (23) comprises a main body section (231) of equal width and a welding section (232) formed at the bottom of the main body section (231), and both side surfaces of the welding section (232) are inclined surface structures with the same inclination angle, so that the width of the welding section (232) gradually decreases in a direction away from the main body section (231).

4. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and large wall thickness according to claim 3, characterized in that: The inclination angles of the surfaces on both sides of the welding section (232) are both 15°, and the width of the bottom surface of the welding section (232) is one fifth of the width of the main body section (231).

5. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness according to claim 1, characterized in that: The cone angle of the hole wall of each diversion hole (22) away from the core head (21) is 4-8 degrees.

6. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness according to claim 1, characterized in that: A fillet with a radius of 10-30 mm is provided between the circumferential side wall and the bottom surface of the welding chamber (12).

7. The extrusion die for a 6082 aluminum alloy cylinder body with a small extrusion ratio and a large wall thickness according to claim 1, characterized in that: The lower die working belt (111) comprises an entrance section (111b) and a sizing section (111a) which are connected in sequence in a direction away from the upper die (2); the sizing section (111a) is a cylindrical structure; the outer peripheral surface of the entrance section (111b) is a conical structure whose diameter gradually increases in a direction away from the sizing section (111a); and the axial length of the sizing section (111a) is one tenth of the length of the lower die working belt (111).

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