JPH05208211A - Manufacture of extruded hollow-shaped aluminum shapes - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent scratches on the inner peripheral surface of the obtained hollow aluminum extruded profile. [Structure] Before assembling a male die 1, a female die 2 and a die sling 3 into which these two die 1, 2 are fitted, they are preheated in the atmosphere. After completion of preheating, the bearing surface 1a of the male die 1 is polished to remove the oxide layer. Then, both types 1,
2 and the die sling 3 are combined and mounted in an extrusion processing apparatus, and extrusion molding is performed by this extrusion processing apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hollow aluminum extruded profile by using a combination die including a male die, a female die and a die ring into which both the die are fitted.

In this specification, the term "aluminum" includes aluminum alloy in addition to pure aluminum. Further, the term "hollow type" includes not only a completely hollow extruded shape but also a semi-hollow extruded shape in which a slit extending in the length direction is formed on the peripheral wall over the entire length.

[0003]

2. Description of the Related Art Conventionally, a hollow type aluminum extruded shape material used for a cylinder tube of an air cylinder, for example, has been manufactured as follows. That is, the male type,
After assembling a female die and a die sling into which both of these dies are fitted, they were preheated in the atmosphere, mounted on an extrusion apparatus after completion of preheating, and then extruded by this extrusion apparatus.

[0004]

However, when a hollow type aluminum extruded profile is manufactured by the conventional method,
There is a problem in that the surface of the extruded profile is scratched in the length direction. Moreover, when such a scratch is generated on the inner peripheral surface, it is extremely difficult to remove it. Particularly, in the case of a cylinder tube for an air cylinder, the surface roughness of the inner peripheral surface is required to be 9 μm or less at the maximum height (R _max ). The surface roughness often becomes larger than R _max 9 μm, and there is a problem that it cannot be used as a cylinder tube.

Therefore, as a result of various studies conducted by the present inventors to find out the cause of the above problems, the oxide layer formed on the bearing surface during the preheating of the combination die causes the above scratches. I found that.

An object of the present invention is to provide a method for manufacturing a hollow type aluminum extruded profile which solves the above problems.

[0007]

The first method for manufacturing a hollow aluminum extruded profile according to the present invention uses a combination die including a male die, a female die, and a die sling into which both of these die are fitted. When manufacturing extruded aluminum profiles, pre-heat the male die, female die and die sling in the atmosphere before combining them, and after preheating, polish at least the male bearing surface of both die bearing surfaces. The oxide layer is removed by means of the above method, and then the two molds and the die sling are combined and mounted on an extrusion processing apparatus, and extrusion molding is performed by this extrusion processing apparatus.

A second method for manufacturing a hollow aluminum extruded profile according to the present invention is a hollow type aluminum extruded profile using a male die, a female die, and a combination die including a die ring into which both die are fitted. In manufacturing, after combining male type, female type and die sling,
It is characterized in that these are preheated in an inert gas atmosphere, mounted on an extrusion processing apparatus after the completion of preheating, and extrusion-molded by this extrusion processing apparatus.

In the above, the combination die includes a well-known porthole die, bridge die, spider die and the like.

The inert gas used in the second method may be an inert gas of the periodic table such as argon gas or helium gas, or a nitrogen gas inert to the metal material forming the die. Etc. are also included.

[0011]

According to the first method of the present invention, before the male die, the female die and the die sling are combined, at least the male oxide layer formed on the bearing surfaces of the male die and the female die during preheating is used. Removes the oxide layer on the bearing surface of the mold,
There is no oxide layer on the male bearing surface during extrusion. Moreover, since the preheating is performed before combining the male mold, the female mold and the die sling, the oxide layer can be removed before combining them.

According to the second method of the present invention, since the combined die in which the male die, the female die and the die sling are combined is preheated in an inert gas atmosphere, the male and female bearings are preheated. The formation of an oxide layer on the surface can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The following examples apply the method of the present invention to a method for producing a hollow aluminum extruded profile using a porthole die made of die steel, for example. Throughout the drawings, the same parts and the same parts are designated by the same reference numerals, and the description thereof will be omitted.

Example 1 This example is shown in FIGS. 1 and 2. 1 and 2, first, the male porthole die (1),
The female mold (2) and the die sling (3) into which both molds (1) and (2) are fitted are placed in the preheating furnace (4) before they are assembled. Then, these are preheated for a predetermined time by heating them to a temperature of about 450 ° C. in the atmosphere. After preheating, take out male type (1), female type (2) and die sling (3) from preheating furnace (4),
The bearing surface (1a) of the male die (1) is polished with a # 2 abrasive paper to remove the oxide layer formed on the bearing surface (1a) during preheating. Then, the molds (1) and (2) and the die sling (3) are combined, and the combined die (5) is mounted on an extrusion processing device (not shown). Then, extrusion molding is performed by a known method using an aluminum billet by an extrusion processing device. In this way, a hollow aluminum extruded profile having no scratch on the inner peripheral surface is manufactured.

In this embodiment, the female mold is
The bearing surface of (2) may also be polished with polishing paper to remove the oxide layer formed on the bearing surface.

Example 2 This example is shown in FIG. In FIG. 3, first, the port hole die male type (1), the female type (2) and the die ring (3) into which both types (1) and (2) are fitted are combined to form a combination die (5). Then, the combination die (5) is put into the preheating furnace (4), and the inert gas (6) is supplied into the preheating furnace (4) by an inert gas supply device (not shown). Then, the combination die (5) is preheated for a predetermined time by heating it to a temperature of, for example, about 450 ° C. in an inert gas atmosphere. After preheating, combine dies (5)
Is taken out of the preheating furnace (4) and mounted in an extrusion device (not shown). Then, extrusion molding is performed by a known method using an aluminum billet by an extrusion processing device. In this way, a hollow aluminum extruded profile having no flaws on the inner and outer peripheral surfaces is manufactured.

[0017]

According to the first method of the present invention, as described above, since the oxide layer does not exist on the male bearing surface during extrusion, the obtained hollow aluminum extrusion mold is obtained. It prevents scratches on the inner surface of the material. Moreover, since the oxide layer can be removed before combining them, the removing operation is simplified.

According to the second method of the present invention, as described above, it is possible to prevent the formation of the oxide layer on the male and female bearing surfaces during the preheating, and thus it was obtained. It is possible to prevent the inner and outer peripheral surfaces of the hollow aluminum extruded profile from being scratched.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of the method of the present invention at the stage of preheat treatment.

FIG. 2 is a partially cutaway side view showing a state in which a male die, a female die and a die sling are combined after the oxide layer on the male bearing surface is removed.

FIG. 3 is a vertical cross-sectional view of the stage of the preheat treatment showing Example 2 of the method of the present invention.

[Explanation of symbols]

 1 port hole die male type 1a bearing surface 2 port hole die female type 3 die ring 5 combination die 6 inert gas

Claims (2)

[Claims] 1. A male die, a female die and a die die ring are combined to produce a hollow type aluminum extruded profile using a combination die comprising a male die, a female die and a die ring into which both die are fitted. Prior to preheating these in the atmosphere, after preheating, at least the male bearing surface of both molds is ground to remove the oxide layer, and then both molds and die slings are combined to form an extrusion machine. A method for manufacturing a hollow aluminum extruded shape material, which comprises mounting and extruding using this extrusion processing device. 2. A male die, a female die and a die die ring are combined to produce a hollow type aluminum extruded profile using a combination die comprising a male die, a female die and a die ring into which both of these die are fitted. After that, these are preheated in an inert gas atmosphere, and after preheating, they are mounted in an extrusion processing apparatus and extrusion-molded by this extrusion processing apparatus, which is a method for producing a hollow aluminum extrusion profile.