CN114798786A

CN114798786A - Cold backward extrusion process for rectangular box-shaped aluminum alloy thin-wall shell

Info

Publication number: CN114798786A
Application number: CN202110055488.8A
Authority: CN
Inventors: 蒋鹏; 张建波; 陈浩; 陈威; 陈利广; 陈妙静; 刘威; 陈东辉; 田北宁
Original assignee: Hai'an Beijing Institute Of Mechanical And Electrical Forging Industry R & D Center; Nanjing East Mold Machinery Manufacturing Co ltd; Nantong Changyuan Heavy Industry Machinery Co ltd; Zhengzhou Guangyuan Battery Material Co ltd; Beijing Research Institute of Mechanical and Electrical Technology
Current assignee: China National Machinery Institute Group Beijing Electromechanical Research Institute Co ltd; Zhengzhou Guangyuan Battery Material Co ltd
Priority date: 2021-01-20
Filing date: 2021-01-20
Publication date: 2022-07-29

Abstract

The invention belongs to the technical field of plastic forming, and particularly relates to a cold backward extrusion process for an aluminum alloy rectangular box-shaped thin-wall shell, which comprises the following steps: a1, processing a blank with a specific shape and carrying out annealing treatment; a2, installing the die on a hydraulic press and taking down a stripper plate; a3, placing the blank at the bottom of a cavity of a female die, and assembling a stripper plate with the female die; a4, driving the male die to move downwards to extrude the blank by a hydraulic press until the lower surface of the male die pressing plate is contacted with the upper surface of the discharging plate; a5, driving the male die to move upwards by the hydraulic press, and ejecting and discharging the workpiece stuck on the male die when the workpiece contacts a discharging plate; a6, removing the stripper plate and taking out the workpiece. By changing the multi-pass deep drawing forming process into the single cold extrusion forming process, the production efficiency of the workpiece is improved, the number of dies is reduced, and the performance of the formed workpiece is enhanced. The die with the simple structure is designed, the die guiding and workpiece discharging functions are concentrated on the same part discharging plate, the precision of the thin-wall shell can be guaranteed, and the workpiece can be conveniently discharged.

Description

Cold backward extrusion process for rectangular box-shaped thin-wall aluminum alloy shell

Technical Field

The invention belongs to the field of metal plastic forming, and relates to a cold backward extrusion process of an aluminum alloy rectangular box-shaped thin-wall shell.

Background

Aluminum alloy rectangular box-shaped thin-walled cases are often used for battery case applications, are thinner and lighter than steel battery cases, and in addition, once the battery explodes, the aluminum alloy battery case also has weaker bursting force than the steel case, and is relatively less harmful. In the processing of the rectangular box-shaped thin-wall aluminum alloy shell, a multi-pass drawing process is generally adopted, and a plate is continuously sent into a plurality of different drawing dies to be drawn until the plate is formed into a required workpiece.

However, in the processing process of the shell, the shell needs to be drawn by dies with different shapes for many times, so that the requirement on the number of the dies is high, and the cost of the dies is high. Because each time needs to be drawn for many times, the time is long, and the production efficiency of the shell is low. The workpiece produced by the drawing process often has the problems of tension cracking and wrinkling, and the basic performance is poor.

Therefore, how to improve the production efficiency of the housing, reduce the number of dies, and enhance the performance of the workpiece is a technical problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide a cold backward extrusion process for an aluminum alloy rectangular box-shaped thin-wall shell, which aims to improve the production efficiency of workpieces, reduce the number of dies and enhance the performance of the workpieces.

The purpose of the invention is realized by the following technical scheme:

a1, processing the blank with a specific shape and annealing;

a2, mounting the backward extrusion die on a hydraulic press and taking down the stripper plate 5;

a3, placing the blank at the bottom of the cavity of the female die 6 of the backward extrusion die, and accurately assembling the stripper plate 5 and the female die 6;

a4, the male die 10 of the backward extrusion die is driven by the hydraulic press to contact and extrude the blank until the lower surface of the male die pressing plate 4 contacts with the upper surface of the discharging plate 5, and the hydraulic press stops driving the male die 10 to move downwards;

a5, the punch 10 of the backward extrusion die is driven by the hydraulic press to move upwards, the workpiece stuck on the punch 10 moves upwards along with the punch 10 and is jacked and unloaded when contacting the middle part in the stripper plate 5;

a6, removing the stripper plate 5 and taking out the workpiece.

The blank in the step A1 is a cuboid with a downward concave top and round corners.

And B, the clearance between the outer wall of the blank in the step A3 and the inner wall of the cavity of the female die 6 is 0.05-0.1 mm.

Step a3 also includes applying a lubricant to the billet and the counter extrusion die.

The extrusion speed of the step A4 hydraulic press is 10-20 mm/s.

The die comprises an upper male die assembly and a lower female die assembly, wherein the upper male die assembly and the lower female die assembly are provided with a downward movement die assembly and an upward movement die opening, the upper male die assembly comprises a driving male die 10 for completing backward extrusion, a male die pressing plate 4 and an inner hexagon screw 11 for fixing the male die 10, an upper base plate 2 and a T-shaped groove bolt 1 which are connected with the upper table top of a press machine; the lower female die assembly comprises a female die 6, a female die insert 8 for ejecting a workpiece, a stripper plate 5 for guiding the male die 10 and unloading the workpiece, a lower backing plate 7 and a T-shaped groove bolt 1 which are connected with the lower table surface of the press machine, and a hexagon socket head cap screw 9 for connecting the stripper plate 5, the female die 6 and the lower backing plate 7.

The invention has the following beneficial effects: 1. only one set of die is used, so that the number of the die is reduced, and the cost for maintaining and replacing the die is reduced; 2. the workpiece can be formed by extruding once, so that the processing time is shortened, and the production efficiency of the shell is improved; 3. the improvement of the microstructure and the mechanical property of the obtained workpiece is promoted; 4. the mold has simple structure, the forming process is easy to operate, and the automation is convenient to realize.

Drawings

FIG. 1 is a schematic view of the structure of the mold of the present invention.

Fig. 2 is a schematic structural diagram of an aluminum alloy rectangular box-shaped thin-walled shell processed by the invention.

Fig. 3 is a schematic view of the structure of the machined blank of the present invention.

Wherein: 1. t-shaped groove bolt, 2, upper backing plate, 3, nut, 4, male die pressing plate, 5, stripper plate, 6, female die, 7, lower backing plate, 8, female die insert, 9, screw M16X 160, 10, male die, 11 and screw M16X 55.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and embodiments.

In a specific embodiment, a cold backward extrusion process for an aluminum alloy rectangular box-shaped thin-walled shell according to an embodiment of the present invention includes the steps of:

a1, processing a blank with a specific shape, wherein the material is 3003 aluminum alloy, and carrying out 480-500 ℃ heat preservation for 8-10h annealing treatment;

a2, fixing the die on a 500-ton hydraulic press by using a pressure plate and a T-shaped groove bolt 1, moving the male die 10 upwards and taking down the stripper plate 5;

a3, mixing industrial alcohol and zinc stearate powder according to a certain proportion to form sticky paste, coating a zinc stearate lubricant on the working surfaces of a male die 10 and a female die 6, coating the annealed blank with the zinc stearate lubricant, placing the zinc stearate lubricant at the bottom of a cavity of the female die 6 of the backward extrusion die, placing a gap between the outer wall of the blank and the inner wall of the cavity of the female die 6 to be less than 0.1mm, placing a discharging plate 5 on the female die 6, accurately assembling according to the gap between the outer wall of the blank and the cavity of the female die, and fixing by using a screw 9;

a4, the male die 10 enters the upper half part of the discharging plate 5 under the drive of the hydraulic press and is guided, and the blank is extruded at the speed of 10-20mm/s until the lower surface of the male die pressing plate 4 contacts with the upper surface of the discharging plate 5, and the hydraulic press stops driving the male die 10 to move downwards;

a5, the male die 10 moves upwards under the drive of the hydraulic press, the workpiece stuck on the male die 10 moves upwards along with the male die 10 and is ejected by being propped against when contacting the middle part in the stripper plate 5;

a6, removing the screw 9 and the stripper plate 5 and taking the workpiece out of the die 6.

The die comprises an upper male die assembly and a lower female die assembly, wherein the upper male die assembly and the lower female die assembly are provided with a downward movement die assembly and an upward movement die opening, the upper male die assembly comprises an active male die 10 for completing backward extrusion (a working belt with the height of 3-5mm is arranged at the bottom of the male die 10), a male die pressing plate 4 for fixing the male die 10, an inner hexagonal screw 11 (the male die pressing plate 4 and the male die 10 are in transition fit), an upper base plate 2 connected with the upper table surface of a press machine and a T-shaped groove bolt 1; the lower female die assembly comprises a female die 6, a female die insert 8 for ejecting a workpiece (the female die insert 8 and the female die 6 are in clearance fit), a stripper plate 5 for guiding the male die 10 and unloading the workpiece (the stripper plate 5, the male die 10 and the female die 6 are in clearance fit), a lower cushion plate 7 and a T-shaped groove bolt 1 which are connected with the lower table surface of the press machine, and an inner hexagon screw 9 for connecting the stripper plate 5, the female die 6 and the lower cushion plate 7.

Although the present invention has been described in detail with reference to the above specific embodiments, it will be apparent to one skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

1. A cold backward extrusion process of an aluminum alloy rectangular box-shaped thin-wall shell is characterized by comprising the following steps:

a1, processing a blank with a specific shape and carrying out annealing treatment;

a5, the punch 10 of the backward extrusion die is driven by the hydraulic press to move upwards, and the workpiece stuck on the punch 10 moves upwards along with the punch 10 and is jacked to be unloaded when contacting the middle part inside the unloading plate 5;

a6, removing the stripper plate 5 and taking out the workpiece.

2. The cold backward extrusion process of an aluminum alloy rectangular box-shaped thin-walled shell according to claim 1, wherein the step a1 comprises the shape of the blank is a cuboid with a downward concave top and round corners.

3. The cold backward extrusion process of the rectangular box-shaped thin-walled aluminum alloy shell as claimed in claim 1, wherein the step a2 includes a gap between the outer wall of the blank and the inner wall of the cavity of the female die 6 being 0.05-0.1 mm.

4. The cold backward extrusion process of an aluminum alloy rectangular box-shaped thin-walled shell according to claim 1, wherein said step a2 further comprises applying a lubricant to said blank and said backward extrusion die.

5. The cold backward extrusion process of an aluminum alloy rectangular box-shaped thin-walled shell according to claim 1, wherein the step a4 includes the extrusion speed of the hydraulic press being 10-20 mm/s.

6. The cold backward extrusion die for the rectangular box-shaped thin-walled aluminum alloy shell according to claim 1, wherein the die insert 8 for ejecting the workpiece is arranged at the bottom of the die 6, the working band with the height of 3-5mm is arranged at the bottom of the punch 10, the upper part of the inner hole of the stripper plate 5 is in clearance fit with the punch 10 to provide guidance for the punch 10, the middle part is used for discharging, and the lower part is used as an extension of the cavity of the die 6.