A combined die for drawing aluminum alloy thin-walled tubes and a drawing process

Abstract

The present invention discloses a combined die for drawing aluminum alloy thin-walled tubes and a drawing process, which relates to the technical field of aluminum alloy drawing processing. The combined die for drawing aluminum alloy thin-walled tubes is used to draw the thin wall of an aluminum alloy tube with an outer diameter of B mm and a wall thickness of 0.5 ± 0.05 mm into an aluminum alloy with an outer diameter of A mm and a wall thickness of 0.3 ± 0.05 mm. The combined die for drawing aluminum alloy thin-walled tubes and the drawing process optimize and improve the structures of the inner and outer drawing dies, conduct a combined matching design of the inner and outer dies, divide the deformation amount of the secondary drawing, process it in sections, and adopt a combined drawing method to perform a one-time drawing forming process, so as to realize the production mode of one-time forming of thin-walled tube drawing, which can effectively improve the production efficiency and save the production and processing costs and the corresponding consumption losses of resources and energy.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy drawing processing, and specifically relates to a combined die and drawing process for drawing thin-walled aluminum alloy tubes. Background Art

[0002] At present, the cold processing and forming technology of aluminum alloy tubes covers the drawing and forming methods of welded tubes and seamless tubes. Among them, there are production operation modes of one-pass drawing forming and multi-pass drawing forming;

[0003] For the conventional one-time drawing forming of aluminum alloy tubes, the processed wall thickness dimensions are all in the range of 0.7 - 2.0 mm. When the wall thickness is less than 0.7 mm, multi-pass drawing forming is required to meet the final dimensional control requirements of the product; when the wall thickness of the product is 0.7 mm, the wall thickness of the extrusion material should be about 1.0 mm, and 1000T extrusion production is used, and the extrusion ratio λ is all between 100 - 120. When the wall thickness of the product is 0.3 mm, the wall thickness of the extrusion material should be about 0.6 mm, and 1000T extrusion production is used, and the extrusion ratio λ is all between 150 - 200. The extrusion limit size has been reached, and if the wall thickness is thinner, it will cause adverse factors such as extrusion failure, die jamming, and cracking;

[0004] Currently, thin-walled tubes are applied to circular battery cell casings. For products with φ30 - φ40, the wall thickness requirement is controlled within 0.3 ± 0.05 mm, for products > φ40 - φ60, the wall thickness requirement is controlled within 0.4 ± 0.05 mm, and for products > φ60 - φ80, the wall thickness requirement is controlled within 0.5 ± 0.05 mm. Many factories are developing, producing, and supplying, and all adopt the two-pass drawing forming method to ensure product accuracy and prevent the product from having defects such as being pulled and broken.

[0005] Publication No. CN113351664A discloses a special-shaped steel drawing method and drawing device. Although it discloses the design of multi-core head one-time drawing, it cannot be used for drawing thin-walled aluminum alloy tubes. Summary of the Invention

[0006] (I) Technical Problems to be Solved

[0007] In view of the deficiencies of the prior art, the present invention provides a combined die and drawing process for drawing thin-walled aluminum alloy tubes, and solves the following technical problems:

[0008] 1. For the existing 0.3 mm aluminum alloy tube drawing, two-pass drawing forming is required to ensure product accuracy and prevent the product from having defects such as being pulled and broken;

[0009] 2. Although increasing the extrusion ratio can make the wall thickness of the drawn aluminum alloy tube thinner, an excessive extrusion ratio will cause die jamming and cracking during the drawing process.

[0010] 3. When the wall thickness of conventional drawing is in the range of 0.7 - 2.0, the die angle R is designed to be 10° - 12° to achieve drawing forming operation with large deformation. However, when dealing with the drawing of 0.3mm aluminum alloy tube, the relatively large die angle R will result in insufficient deformation length during the drawing process, and the long material is often broken during the drawing process.

[0011] (II) Technical Solution

[0012] To achieve the above objectives, the present invention is realized through the following technical solutions: A combined die for drawing thin-walled aluminum alloy tubes is used to draw the thin wall of an aluminum alloy tube with an outer diameter of Bmm and a wall thickness of 0.5 ± 0.05mm into an aluminum alloy tube with an outer diameter of Amm and a wall thickness of 0.3 ± 0.05mm. It includes an inner die and an outer die. The inner die includes inner die A and inner die B. Inner die A and inner die B are connected end to end. Inner die A is arranged on the left side of inner die B. The outer die includes outer die A and outer die B respectively corresponding to inner die A and inner die B.

[0013] The die angle of inner die A is 3 - 6°, and the die angle of inner die B is 2 - 5°.

[0014] The right end of inner die B is connected with inner die working belt B. The right end of inner die A is connected with inner die working belt A. The right end of inner die working belt B is connected with the left end of inner die A.

[0015] The diameter of inner die working belt A is Amm.

[0016] The diameter of inner die working belt B is A + 1mm.

[0017] The outer die B includes outer die working belt B, and an opening B is arranged on the left side of outer die working belt B.

[0018] The outer die A includes outer die working belt A, and an opening A is arranged on the left side of outer die working belt A.

[0019] The opening A is connected with the right end of outer die working belt B.

[0020] The diameter of outer die working belt B is A + 1.8mm.

[0021] The diameter of outer die working belt A is A + 0.6mm.

[0022] The outer die B is sleeved outside the inner die B, and the outer die working belt B is sleeved on the inner die working belt B.

[0023] The outer die A is sleeved outside the inner die A, and the outer die working belt A is sleeved on the inner die working belt A.

[0024] The outlet end face of the outer die working belt B is flush with the right end of the inner die working belt B.

[0025] Preferably, the widths of the inner die working belt A and the inner die working belt B are both 1.5 mm;

[0026] The width of the inner die A plus the inner die working belt A is 18 mm;

[0027] The width of the inner die B plus the inner die working belt B is 17 mm.

[0028] Preferably, the width of the outer die working belt B is 8 mm;

[0029] The width of the outer die working belt A is 6 mm;

[0030] The exit depth of the outer die working belt B is 1 mm;

[0031] The exit depth of the outer die working belt A is 5 mm.

[0032] Preferably, a compression belt B is connected to the left end of the outer die working belt B, and the size of the compression belt B is R53;

[0033] A compression belt A is connected to the left end of the outer die working belt A, and the size of the compression belt A is R4.

[0034] A drawing process for a combined die for drawing an aluminum alloy thin-walled tube. In the process, the extrusion ratio λ is X, and the aluminum alloy steel tube to be processed is drawn from the left side to the right side of the combined die.

[0035] (III) Beneficial effects

[0036] The present invention provides a combined die for drawing an aluminum alloy thin-walled tube and a drawing process. The following beneficial effects are achieved:

[0037] The combined die for drawing an aluminum alloy thin-walled tube and the drawing process optimize and improve the structures of the inner and outer drawing dies, perform combined matching design of the inner and outer dies, divide the deformation amount of the secondary drawing through segmented processing, and adopt a combined drawing method for one-time drawing and forming processing, realizing a production mode of one-time forming of the thin-walled tube drawing, which can effectively improve production efficiency and save production processing costs and corresponding resource and energy consumption losses. Description of the drawings

[0038] Figure 1 It is a schematic diagram of the combined inner and outer drawing dies of the present invention;

[0039] Figure 2 It is a schematic diagram of the outer die B structure;

[0040] Figure 3 It is a schematic diagram of the outer die A structure;

[0041] Figure 4 It is a schematic diagram of the outer die B dimensions;

[0042] Figure 5 It is a schematic diagram of the dimensions of the outer mold A;

[0043] Figure 6 It is a schematic diagram of the combined structure of the outer mold A and the outer mold A;

[0044] Figure 7 It is Figure 6 the view from direction A in

[0045] Figure 8 It is a schematic diagram of the combined drawing die of the present invention;

[0046] Figure 9 It is a schematic diagram of the dimensions of the inner mold of the present invention. Specific embodiments

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] Embodiment 1:

[0049] A combined drawing die for aluminum alloy thin-walled tubes is used to draw the thin wall of an aluminum alloy tube with an outer diameter of 35.5 mm and a wall thickness of 0.5 mm into an aluminum alloy tube with an outer diameter of 33.4 mm and a wall thickness of 0.3 mm. It includes an inner mold and an outer mold. The inner mold includes inner mold A and inner mold B. Inner mold A and inner mold B are connected end to end. Inner mold A is arranged on the left side of inner mold B. The outer mold includes outer mold A and outer mold B corresponding to inner mold A and inner mold B respectively;

[0050] The die angle of inner mold A is 4°, and the die angle of inner mold B is 3°;

[0051] Inner mold working belt B is connected to the right end of inner mold B, inner mold working belt A is connected to the right end of inner mold A, and the right end of inner mold working belt B is connected to the left end of inner mold A;

[0052] The diameter of inner mold working belt A is 33.4 mm;

[0053] The diameter of inner mold working belt B is 34.4 mm;

[0054] The widths of inner mold working belt A and inner mold working belt B are both 1.5 mm;

[0055] The width of inner mold A plus inner mold working belt A is 18 mm;

[0056] The width of inner mold B plus inner mold working belt B is 17 mm;

[0057] The outer mold B includes an outer mold working belt B, and an opening B is provided on the left side of the outer mold working belt B;

[0058] The outer mold A includes an outer mold working belt A, and an opening A is provided on the left side of the outer mold working belt A;

[0059] The left end of the outer mold working belt B is connected to a compression belt B, and the size of the compression belt B is R53;

[0060] The left end of the outer mold working belt A is connected to a compression belt A, and the size of the compression belt A is R40;

[0061] The opening A is connected to the right end of the outer mold working belt B;

[0062] The diameter of the outer mold working belt B is 35.2 mm;

[0063] The diameter of the outer mold working belt A is 34 mm;

[0064] The width of the outer mold working belt B is 8 mm;

[0065] The width of the outer mold working belt A is 6 mm;

[0066] The outlet depth of the outer mold working belt B is 1 mm;

[0067] The outlet depth of the outer mold working belt A is 5 mm;

[0068] The outer mold B is sleeved outside the inner mold B, and the outer mold working belt B is sleeved on the inner mold working belt B;

[0069] The outer mold A is sleeved outside the inner mold A, and the outer mold working belt A is sleeved on the inner mold working belt A;

[0070] The outlet end face of the outer mold working belt B is flush with the right end of the inner mold working belt B

[0071] Where:

[0072] Modular Design: Currently, in the forming area of the drawing outer die, tungsten carbide alloy grinding is used for forming. The traditional single die can only have one working area to ensure the compliance of one outer diameter dimension. In the conventional production mode of secondary drawing forming, two drawing machines are required, each equipped with a set of drawing dies, and the reduction of diameter and wall thickness needs to be carried out step by step in two drawing passes. For every 100 long materials, the single drawing takes 1 hour, and it takes 2.5 hours to complete two passes (0.5 hour is the auxiliary time for die change). In order to effectively save production operation time and improve drawing production efficiency, the drawing outer die is specially improved and designed. The A / B die corresponding combination assembly is adopted, and the processing method of synchronous double reduction of diameter and wall thickness is carried out on one drawing machine to realize the "one drawing, two reductions" technical improvement operation mode. The operation time is basically the same as that of a single drawing, but in the same production time, the efficiency is nearly doubled. The input of production such as personnel, equipment, energy consumption, and auxiliary tools is also correspondingly saved, and the technical problem that the thin-walled tube with a wall thickness of 0.3mm cannot be formed by one drawing is overcome.

[0073] The drawing outer die is made of 45# steel into a circular die sleeve, and tungsten carbide alloy is inlaid in the middle part. The working belt and the transition R-angle deformation area are ground and formed according to the size requirements of the product drawing. Among them, the A die is a two-pass forming die, and the B die is a one-pass transition deformation die.

[0074] Outer Die Manufacturing Dimension Table (unit: mm)

[0075]

[0076] The drawing inner die is made of 45# steel into a tail connecting rod, and a ground tungsten carbide alloy sleeve die is installed. First, install the alloy for the first pass, then install the alloy for the second pass, and lock it with a fixing nut. The working belt and the transition R-angle deformation area are ground and formed according to the size requirements of the product drawing. Among them, the A die is a two-pass forming die, and the B die is a one-pass transition deformation die. Among them, the compression belt R-angle used for drawing thin-walled tubes has very critical design requirements. When the conventional drawing wall thickness is in the range of 0.7 - 2.0, the die angle R is designed at 10° - 12° to realize the drawing forming operation with a large deformation amount.

[0077] When drawing thin-walled tubes, a variable mode of slow reduction of diameter and wall thickness is required. We specially design the inner die compression die R to be 3° - 4° to extend the deformation length position, realize slow compression deformation in advance, avoid the abnormal breakage of long materials during the drawing deformation process, and at the same time adopt a forming processing mode of continuous deformation in two passes. When drawing, 1000T is used, and the extrusion ratio λ is 100 - 150.

[0078] Inner Die Manufacturing Dimension Table (unit: mm)

[0079]

[0080] Comparative Example 1:

[0081] The difference from Example 1 is that the die angle of the inner die A is 12° and the die angle of the inner die B is 10°.

[0082] In Comparative Example 1, the deformation length was insufficient during drawing, and the long material was often broken during drawing.

[0083] It should be noted that in the description of the invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is the description of the structure of the present invention based on the drawings shown, and is only for the convenience of describing the present invention simply, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0084] For the "first" and "second" in this technical solution, they are only the appellation distinctions for the same or similar structures, or the corresponding structures with similar functions, rather than the arrangement of the importance of these structures, nor are there sorting, or comparing sizes, or other meanings.

[0085] In addition, unless otherwise clearly defined and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two structures. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the general idea of the present invention and in connection with the specific situation of this solution.

Claims

1. A combined die for drawing aluminum alloy thin-walled tubes, which is used to draw the thin wall of an aluminum alloy tube with an outer diameter of B mm and a wall thickness of 0.5 ± 0.05 mm into an aluminum alloy tube with an outer diameter of A mm and a wall thickness of 0.3 ± 0.05 mm. It includes an inner die and an outer die, and is characterized in that: The inner die includes inner die A and inner die B. Inner die A and inner die B are connected end to end. Inner die A is arranged on the left side of inner die B. The outer die includes outer die A and outer die B corresponding to inner die A and inner die B respectively. The die angle of inner die A is 3 - 6°, and the die angle of inner die B is 2 - 5°. Inner die A and inner die B can extend the deformation length position during the drawing of the aluminum alloy tube, realizing the slow pre-compression deformation of the aluminum alloy tube and avoiding the abnormal breakage of the aluminum alloy tube during the drawing deformation process. The right end of inner die B is connected with inner die working belt B, the right end of inner die A is connected with inner die working belt A, and the right end of inner die working belt B is connected with the left end of inner die A. The diameter of inner die working belt A is Amm. The diameter of inner die working belt B is A + 1mm. The outer die B includes outer die working belt B, and an opening B is arranged on the left side of outer die working belt B. The outer die A includes outer die working belt A, and an opening A is arranged on the left side of outer die working belt A. The opening A is connected with the right end of outer die working belt B. The diameter of outer die working belt B is A + 1.8mm. The diameter of outer die working belt A is A + 0.6mm. The outer die B is sleeved outside the inner die B, and the outer die working belt B is sleeved on the inner die working belt B. The outer die A is sleeved outside the inner die A, and the outer die working belt A is sleeved on the inner die working belt A. The outlet end face of the outer die working belt B is flush with the right end of the inner die working belt B.

2. The combined die for drawing of an aluminum alloy thin-walled tube according to claim 1, wherein: The widths of both the inner die working belt A and the inner die working belt B are 1.5mm. The width of inner die A plus the inner die working belt A is 18mm. The width of inner die B plus the inner die working belt B is 17mm.

3. The combined die for drawing of an aluminum alloy thin-walled tube according to claim 1, characterized in that: The width of the outer die working belt B is 8mm. The width of the outer die working belt A is 6mm. The outlet depth of the outer die working belt B is 1mm. The outlet depth of the outer die working belt A is 5mm.

4. A combined die for drawing an aluminum alloy thin-walled tube according to claim 1, characterized in that: The left end of the outer die working belt B is connected with a compression belt B, and the size of the compression belt B is R53. The left end of the outer die working belt A is connected with a compression belt A, and the size of the compression belt B is R40.

5. The drawing process of a combined drawing die for an aluminum alloy thin-walled tube according to any one of claims 1 to 4, characterized in that: The extrusion ratio λ in the process is X, and the aluminum alloy steel pipe to be processed is drawn from the left side to the right side of the combined die.

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