CN105537363A - Molding device and method for heat expansion of aluminum alloy hollow part - Google Patents

Abstract

The invention discloses a thermal expansion forming device and method for an aluminum alloy hollow part. The thermal expansion forming device for an aluminum alloy hollow part comprises a pressurizing punch (2), a feeding punch (8), a forming die (5), Heating wire (10), elastic element (3), one end of the booster punch (2) is a booster head (4), and the inside of the molding die (5) is provided with a heating wire (10); the outer diameter of the feed punch (8) The diameter of the blank tube (6) is equal, and the feed punch (8) is blocked at both ends of the tube blank (6) to play the role of sealing the tube blank (6); then use the heating wire in the mold to heat the tube blank (6). Heating to the forming temperature, at this time the low-melting point alloy melts into a liquid, and under the simultaneous action of the composite punch at both ends, the thermal expansion of the aluminum alloy pipe is realized, and finally an aluminum alloy hollow part with complex spatial shape and good performance is obtained.

Description

Device and method for thermal expansion forming of aluminum alloy hollow parts

technical field

The invention belongs to the technical field of advanced manufacturing of metal hollow components, in particular to a forming device and method for thermal expansion of aluminum alloy hollow components.

Background technique

Realizing the lightweight of automobiles is an important research content of the modernization of automobile products. Nowadays, the weight of automobiles is mainly reduced by using light alloy materials, "substituting empty space for solid", variable cross-section and other methods. Light alloy materials such as aluminum alloys are more and more widely used in aviation, aerospace, automobile manufacturing and other fields due to their low density. However, due to the low plasticity and poor formability of aluminum alloys at room temperature, the forming of light alloy parts with complex shapes is greatly restricted, which in turn affects the production and application of aluminum alloys in actual industry. In recent years, the thermal expansion forming of light alloy hollow pipes by warm forming method has become a hot spot in the research field.

Since the existing hydraulic bulging technology cannot meet the heating requirements, the preparation of aluminum alloy hollow parts is mainly carried out directly at room temperature for bulging, that is, the cold forming process, and the traditional method will have the following disadvantages:

(1) Due to the poor plastic formability of aluminum alloy, hydraulic bulging is performed directly at room temperature, and the shape of hollow parts that can be formed is very limited, which leads to a single structure of aluminum alloy bulging hollow parts, which cannot meet the market requirements needs;

(2) During the cold bulging process of aluminum alloy, due to poor formability and unreasonable material flow, the thinning in some areas will be very serious, which will greatly reduce the quality and performance of the formed part, and limit the hollowness of the aluminum alloy. use of the software.

Contents of the invention

The existing aluminum alloy hydraulic bulging technology cannot satisfy the forming of complex aluminum alloy hollow parts because it cannot meet the requirements of pipe heating. Aiming at the drawbacks of the existing preparation methods, the invention proposes a new forming device and method. The aluminum alloy hollow parts with uniform wall thickness and excellent performance are prepared by the method of thermal bulging, which effectively solves the problems of difficult hydraulic bulging and low forming quality of aluminum alloy pipes in practical applications.

A thermal expansion forming device for an aluminum alloy hollow part, comprising a pressurized punch (2), a feed punch (8), a forming die (5), a heating wire (10), an elastic element (3), a pressurized punch One end of the head (2) is a booster head (4), and the booster head (4) is connected to one end of the booster shaft (11), and the booster shaft (11) passes through the through hole in the middle of the feed punch (8) , the other end of the booster shaft (11) is externally connected to the feed punch (8) through bolts and nuts (1) to form a composite punch; the forming die (5) is provided with a heating wire (10); the feed punch (8 ) outer diameter is equal to the diameter of the tube blank (6), and the feed punch (8) is blocked at both ends of the tube blank (6) to play the role of sealing the tube blank (6); the inside of the tube blank (6) is filled with Low-melting point alloy rods (9), pressurized punches (2) are inserted between the low-melting point alloy rods (9), and the heating wire (10) is used to heat the tube blank (6) to the temperature required for thermal expansion. When the low-melting-point alloy bar (9) is all melted into liquid; according to the volume of the low-melting-point alloy, the feed rate of the composite punch is calculated in conjunction with the diameter of the tube blank, and the composite punch is fed, and the feeding punch (8) is replenished. The pressurized punch (2) extrudes the alloy with low melting point to provide bulging pressure to the inside of the tube blank.

In the aluminum alloy hollow part thermal expansion forming device, the middle part of the bolt connecting the booster shaft (11) and the feed punch (8) is covered with an elastic element (3) to transmit the pressure of the feed punch (8) to the Booster Punch(2)

According to the thermal expansion forming device for aluminum alloy hollow parts, the method for thermal expansion forming of aluminum alloy hollow parts is realized through the following steps:

In the first step, the aluminum alloy tube blank is put into the forming mold (5), the tube blank is loaded with a low-melting point alloy rod (9), and the upper and lower molds are closed;

The second step is to seal the left and right ends of the tube blank with a composite punch combined with a booster punch and a feed punch, wherein the outer diameter of the feed punch is the same as that of the tube blank;

The third step is to use the heating wire in the mold to heat the tube blank to the temperature required for thermal expansion, at this time the low melting point alloy is completely melted into liquid;

The fourth step is to use the composite punch to bulge the aluminum alloy tube blank to obtain parts with complex shapes;

The fifth step is to release the pressure, open the mold, and take out the formed parts;

In the sixth step, the obtained parts are soaked in hot water and taken out, and finally a complex hollow part of aluminum alloy is obtained.

In said method, in the first step, the inside of the pipe is filled with low melting point alloy.

According to the method, the temperature required in the expansion process is 100-150°C.

Beneficial effect:

1. The present invention provides a new forming method for thermal expansion of aluminum alloy hollow parts; the maximum thickness reduction rate of the final formed part is less than 12.5%;

2. The invention effectively solves the problem of difficult forming of aluminum alloy hydraulic bulging complex parts, and at the same time has important guiding significance for improving the forming performance of aluminum alloy and improving the forming quality;

3. The method of the present invention is simple and feasible, has high production efficiency, and has important engineering application value and obvious economic benefits in engineering fields such as aviation, aerospace, and automobile manufacturing.

Description of drawings

Figure 1 is a schematic diagram of the principle of thermal expansion of aluminum alloy;

1 nut, 2 pressurized punch, 3 elastic element, 4 pressurized head, 5 forming die, 6 tube blank, 7 wedge section, 8 feed punch, 9 low melting point alloy bar, 10 heating wire, 11 pressurized axis.

detailed description

The forming process of forming complex hollow parts by thermal expansion of 5182 aluminum alloy, 5083 aluminum alloy and 7075 aluminum alloy will be described in detail below through specific implementation examples.

Example 1

Referring to Fig. 1 , the thermal expansion forming device of an aluminum alloy hollow part includes a booster punch 2, a feed punch 8, a forming die 5, a heating wire 10, and an elastic element 3. One end of the booster punch 2 is a booster head 4, The booster head 4 is connected to one end of the booster shaft 11, and the booster shaft 11 passes through the through hole in the middle of the feed punch 8, and the other end of the booster shaft 11 is connected externally with the feed punch 8 by bolts and nuts 1. Composite punch, the middle part of the bolt connecting the booster shaft 11 and the feed punch 8 is covered with an elastic element 3 to transmit the pressure of the feed punch 8 to the booster punch 2; a heating wire 10 is arranged inside the molding die 5; the feed The outer diameter of the punch 8 is equal to the diameter of the tube blank 6, and the feeding punch 8 is blocked at both ends of the tube blank 6 to play the role of sealing the tube blank 6; the inside of the tube blank 6 is filled with a low melting point alloy rod 9, increasing The punch 2 is inserted between the low-melting-point alloy rods 9, and the heating wire 10 is used to heat the tube blank 6 to the temperature required for thermal expansion. At this time, the low-melting-point alloy rods 9 are all melted into liquid; , combined with the diameter of the tube billet to calculate the feed rate of the compound punch, feed the compound punch, and feed the punch (8) to replenish the material, because the volume of the pressurized punch 2 entering the low melting point alloy becomes larger, extruding the low melting point Alloy, providing bulging pressure to the inside of the tube blank. The pressurized punch is similar to the function of a hydraulic piston, which increases the pressure inside the pipe for bulging, and is the booster medium.

Example 2

In the first step, put the 5182 aluminum alloy with a length of 300mm, a diameter of 50mm, and a wall thickness of 2mm into the tee forming mold, put the low melting point alloy rod into the tube blank, and close the upper and lower molds;

The second step is to seal the left and right ends of the pipe with a composite punch composed of a booster punch and a feed punch, wherein the outer diameter of the feed punch is the same as the outer diameter of the tube blank;

The third step is to use the heating wire in the mold to heat the tube blank to 150°C, and the low melting point alloy will be completely melted into liquid;

The fourth step is to use the composite punch to bulge the aluminum alloy tube billet to obtain the parts of the aluminum alloy tee;

The fifth step is to release the pressure, open the mold, and take out the formed parts;

In the sixth step, the obtained parts are soaked in hot water at 100°C and taken out to finally obtain a hollow tee made of aluminum alloy.

Example 3

In the first step, put a 5083 aluminum alloy tube blank with a length of 350mm, a diameter of 60mm, and a wall thickness of 3mm into a box-shaped mold, fill the tube with a low-melting point alloy rod, and close the upper and lower molds;

The second step is to seal the left and right ends of the pipe with a composite punch composed of a booster punch and a feed punch, wherein the outer diameter of the feed punch is the same as the outer diameter of the tube blank;

The third step is to use the heating wire in the mold to heat the tube blank to 120°C, at this time the low melting point alloy is completely melted into liquid;

The fourth step is to use the composite punch to bulge the aluminum alloy tube blank to obtain the formed part;

The fifth step is to release the pressure, open the mold, and take out the formed parts;

In the sixth step, the obtained parts are soaked in hot water at 100°C and taken out to finally obtain the hollow parts of aluminum alloy box-shaped parts.

Example 4

The first step is to put the aluminum alloy tube blank with a length of 400mm, a diameter of 40mm and a wall thickness of 2mm into the stepped pipe fitting mold, fill the pipe with low melting point alloy rods, and close the upper and lower molds;

The second step is to seal the left and right ends of the pipe with a composite punch composed of a booster punch and a feed punch, wherein the outer diameter of the feed punch is the same as the outer diameter of the tube blank;

The third step is to use the heating wire in the mold to heat the tube blank to 100 ℃, at this time the low melting point alloy is completely melted into liquid;

The fourth step is to use the composite punch to bulge the aluminum alloy tube blank to obtain stepped parts;

The fifth step is to release the pressure, open the mold, and take out the formed parts;

In the sixth step, the obtained parts are soaked in hot water at 100°C and taken out to finally obtain a stepped hollow part of aluminum alloy.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

Claims (5)

1. a kind of aluminum alloy hollow member thermal expansion forming device is characterized in that, comprises pressurization punch (2), feeding punch (8), molding die (5), heating wire (10), elastic element ( 3), one end of the booster punch (2) is a booster head (4), the booster head (4) is connected to one end of the booster shaft (11), and the booster shaft (11) passes through the feed punch ( 8) The through hole in the middle, the other end of the booster shaft (11) is externally connected with the feed punch (8) through bolts and nuts (1) to form a composite punch; the forming mold (5) is internally provided with a heating wire (10); The outer diameter of the feed punch (8) is equal to the diameter of the tube blank (6), and the feed punch (8) is blocked at both ends of the tube blank (6) to seal the tube blank (6); (6) The interior is filled with low-melting-point alloy rods (9), the pressurized punch (2) is inserted between the low-melting-point alloy rods (9), and the tube blank (6) is heated and expanded by the heating wire (10). The required temperature, at this time, the low-melting point alloy bar (9) is completely melted into liquid; according to the volume of the low-melting point alloy, combined with the diameter of the tube blank, the feed rate of the composite punch is calculated, and the composite punch is fed, and the feed punch (8) Feeding and pressurizing the punch (2) Extruding the low-melting point alloy to provide bulging pressure to the inside of the tube blank. 2. The aluminum alloy hollow member thermal expansion forming device according to claim 1, characterized in that the middle part of the bolt connecting the booster shaft (11) and the feed punch (8) is covered with an elastic element (3) to transmit The pressure of the feed punch (8) is applied to the booster punch (2). 3. According to claim 1 or 2, the method for thermal expansion forming of aluminum alloy hollow parts by the thermal expansion forming device of aluminum alloy hollow parts is characterized in that, it is realized through the following steps: In the first step, the aluminum alloy tube blank is put into the forming mold (5), the tube blank is loaded with a low-melting point alloy rod (9), and the upper and lower molds are closed; The second step is to seal the left and right ends of the tube blank with a composite punch combined with a booster punch and a feed punch, wherein the outer diameter of the feed punch is the same as that of the tube blank; The third step is to use the heating wire in the mold to heat the tube blank to the temperature required for thermal expansion, at this time the low melting point alloy is completely melted into liquid; The fourth step is to use the composite punch to bulge the aluminum alloy tube blank to obtain parts with complex shapes; The fifth step is to release the pressure, open the mold, and take out the formed parts; In the sixth step, the obtained parts are soaked in hot water and taken out, and finally a complex hollow part of aluminum alloy is obtained. 4. The method according to claim 3, characterized in that in the first step, the interior of the pipe is filled with low-melting point alloy. 5. The method according to claim 3, characterized in that: the required temperature in the process of thermal expansion is 100-150°C.