JPH04111918A - Dies for extruding light metal - Google Patents

Abstract

PURPOSE:To make the correcting work with machinery cutting of high accuracy possible by constituting the forming part of dies of two steps structures of the correcting territory to be corrected corresponding to the property of material to be formed and the exclusive forming territory to be not corrected. CONSTITUTION:The dies bearing groove part of the forming part of dies is made of the sub bearing groove part 4 as the first step and the main bearing groove part 5 as the 2nd step along the direction of pressurizing forming. And the sub bearing groove part 4 is set as the correcting work area to be corrected corresponding to the property of the material to be formed, and the main bearing groove part 5 is set as the exclusive territory for extruding. Therefore, the correcting work can be executed with high accuracy by cut-machining the height H1 of the sub bearing.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a die for extruding light metals, particularly a die for extruding aluminum or aluminum alloy, and more specifically to a forming part (hereinafter referred to as a die bearing groove) of the extrusion die. This relates to a die with an improved structure.

[Prior Art] In extrusion molding of light metals such as aluminum or aluminum alloys, a piece of material called a billet is first inserted into a container-shaped tool called a container, and the billet is pressurized by a ram and extruded from a hole in a die. It is molded as an extruded material by being extruded into a certain shape.

That is, for example, as shown in FIG. 5, which is a schematic cross-sectional view of the tip of a conventional forward extrusion type aluminum or aluminum alloy extrusion device, the tip of an extrusion molding machine used for aluminum or aluminum alloy is usually
A die 2 that is incorporated inside the die holder 8 and determines the external shape of the extruded material, a flow guide 1 that guides the billet 9 to the die by applying pressure, and a die backer 11 that is a spacer between the die 2 and the bolster 10 located behind the die 2. The billet 9 is pressed through a pressure plate 15 by a ram 13 or a stem connected to the ram 13 which is hydraulically pressurized from the one-way inlet of the container 12 containing the billet 9. From the container 12 to the flow guide groove 3
The material then passes through the die bearing groove 16 and is extruded as an extruded material having a constant shape and a wall thickness t. Note that the arrow indicates the extrusion direction of the billet.

[Problems to be Solved by the Invention] As described above, the metal flow (hereinafter referred to as metal flow) in which aluminum or aluminum alloy flows from the container to the flow guide and the die is caused by the force direction of the stem,
Due to nonuniform temperatures in the radial and longitudinal directions during billet heating, and differences in metal flow speeds in the radial direction of the billet, the flow does not necessarily flow in parallel and at a constant speed within the die bearing groove, resulting in the metal flow being extruded. It is often not possible to obtain the desired shape or surface quality of shaped materials due to wavy deformation, bending, or roughening due to coarsening of crystal grains. I got angry.

In order to prevent these defects, conventionally the bearing wall surface of the die was manually processed using tools such as files, welding machines, Luder, etc. to angle the bearing wall surface, cut the wall surface height, build up the wall surface, and create slopes. Modifications have been made, such as widening the bearing groove width.

However, such correction work is difficult work that requires a high degree of skill and experience, and the processing accuracy is also poor.

Furthermore, since the bearing wall surface of the extrusion molding section was directly modified, the life of the die was also short.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to free the conventional manual machining that requires a high degree of skill and experience when modifying the die shape in the die bearing groove, and to achieve high machining accuracy in the modification work. The object of the present invention is to provide a new die in which the resulting molded material has sufficient reproducibility.

[Means and effects for solving the problem] The present inventors:
As a result of intensive research to achieve the above objective, the bearing groove of the conventional die has a two-stage structure, and the first stage along the extrusion molding direction is a forming area that is slightly larger than the final shape called the sub-bearing groove. If we form this as a dedicated area for modification processing, and the second stage is a molding area called the main bearing groove, which will not be modified, it will take a lot of skill and experience to do so. We have discovered that even if manual processing is used, correction processing can be performed by highly accurate machine cutting, the life of the die can be extended, and extruded parts with reproducibility can be obtained, and the present invention has been achieved. did.

That is, the present invention provides a method for charging a billet made of a light metal such as aluminum or an aluminum alloy into a container of an extrusion press, and processing the billet by forward extrusion or backward extrusion using a pressurizing means.
The die used for determining method 1 has a die bearing groove, which is a forming part of the die, along the pressure forming direction, (a) a sub-bearing groove of the first stage, and (
B) It has a two-stage structure consisting of a second stage main bearing groove, and the former (a) serves as a correction processing area for modifying the die molding part according to the properties of the molded material to be obtained. The present invention provides a die for extruding light metals such as aluminum or aluminum alloy, characterized in that the latter (b) is provided as a dedicated area for extrusion molding without modification.

The present invention is a further preferable aspect thereof, and provides a die that is particularly effective when the material is light metal, aluminum, or aluminum alloy. The sub-bearing height H
l is the thickness of the extruded material tX0.75~10, the sub bearing groove w2 which is the step difference between the sub bearing groove and the main bearing groove is 0.5~], 5 mm is the height of the main bearing groove in the molding direction The main bear link height H2 is formed to a size or angle in which the thickness of the extruded material is t x 15 to 20, and the main hair ring angle θ, which is the inclination angle of the main bearing wall with respect to the molding direction, is 15' to 1 degree. The present invention provides a die having the above structure.

1 to 4 are diagrams for explaining the extrusion die according to the present invention. That is, Fig. 1 is a front view of the flow guide and die seen from the direction of forming the extruded material;
Fig. 2 is a top view of Fig. 1, Fig. 3 is a schematic sectional view taken along the line X-X of Fig. 1, and Fig. 4 is a schematic diagram showing the state in which the extruded material is extruded through the flow guide and die. FIG. 3 is a cross-sectional view, and the present invention will be described in detail with reference to these figures.

The extrusion die according to the present invention is characterized by having two stages of bearing grooves in the extrusion molding direction, with a dedicated area for correction processing in the first stage and a dedicated area for molding in the second stage, respectively. It is to have.

The dedicated area for the first stage correction machining is the sub-bearing groove 4.
This is an area where the billet is formed into an outer shape slightly larger than the final product size, and this sub-bearing groove 4
consists of a sub-bearing wall surface 41 and a sub-bearing groove w2, and is a corresponding part for carrying out correction processing each time the shape of the extruded molded material undergoes waving deformation or bending phenomenon.

The dedicated area for the second stage molding is the main bearing groove 5, which consists of the main bearing wall surface 51, the main bearing width t1, and the main bearing height H2, and which flows from the sub-bearing groove 4. This is the part that is formed to the thickness t of the extruded material from which the extruded material is to be obtained, and is a part that does not undergo correction processing even if the extruded material undergoes waving deformation or bending phenomena. Further, as will be described later, the dimensions of each part are taken into consideration to prevent roughness caused by coarsening of crystal grains.

The design of each component regarding the die and flow guide is based on the shape and maximum circumscribed circle of the extruded material to be obtained, the outer shape and height 33 of the flow guide 1, and the die 2.
After the external shape and height H4 are determined, the flow guide width 32, sub-bearing height Hl, sub-bearing groove w2, main bearing height H2, main bearing width t1, back relief width w3 and main bearing angle θ are determined in this order. are determined in this order.

In addition, among the above structural requirements, the flow guide width 32, main bearing width j+, and back relief width w3 comply with conventional design standards, but, however, the sub-bearing height Hl, the sub-bearing groove W2, the main bearing height H2, As mentioned above, it has been recognized that particularly good effects can be obtained when the main hair ring angle θ has a unique numerical range found by the inventor as a result of intensive research.

Below, the structural requirements given by these specific numerical ranges will be listed.

The sub-bearing height Hl is determined by adjusting the sub-bearing groove w to the extruded material thickness txo, which is 75 to 1.0.
2 is preferably in the range of 0.5 to 1.5 mm.

Note that, as shown in FIG. 1, the sub-bearing groove w2 is provided with uniform dimensions along the entire outer periphery of the main bearing groove 5.

If the sub-bearing height Hl is less than txo, 75, the area that can be corrected is small and correction maintenance is not possible.On the other hand, if the sub-bearing height Hl exceeds tx10, the resistance due to metal flow is large and it cannot be obtained. Hl is tX because a roughening phenomenon occurs in the extruded material due to coarsening of crystal grains.
o, preferably in the range of 75 to 1.0.

If the sub-bearing groove w2 is less than 0.5 mm, it will be difficult to obtain machining accuracy during die manufacturing, and as a result, machining unevenness will occur in the machined die, making it difficult to directly correct the bearing molding part as in the conventional method. Similarly, a high degree of skill and experience is required, and even if corrections are made, waving and bending of the shape cannot be prevented.

On the other hand, if the sub-bearing groove w2 exceeds 1.5 mm, the resistance due to metal flow will be large, and even if the sub-bearing height Ho is reduced by cutting, the correction effect will not be obtained and the extrusion molding A roughening phenomenon occurs in the material due to coarsening of crystal grains.

It is preferable that the main bearing height H2 be set to a dimension corresponding to the desired extruded material thickness tX of 1.5 to 2.0, and the main bearing angle θ to be in the range of 15' to 1°.

When the main bearing height H2 is less than tXl, 5, bending stress acts on the stepped surface 6 and the main bearing wall surface 51, resulting in uneven distortion on the main bearing wall surface 51, and the main bearing angle θ is 0°. As a result, the resulting extruded material exhibits waving deformation and bending phenomena.

On the other hand, when the main bearing height H2 exceeds tX2.0, the resistance against the main bearing wall surface 51 due to the metal flow is large, and a roughening phenomenon occurs in the resulting extruded material due to coarsening of crystal grains.

The reason why the main bearing angle θ is set to 15' to I0 is that the main bearing height H2 and back relief width w3 have a "cantilever" relationship, and the step surface 6 and main bearing wall surface 5
When a load is applied to the main bearing groove 5, a bending stress is applied to the protruding part of the main bearing groove 5 having a back clearance width w3, and the main bearing wall surface 51 is inclined due to the load during pressing, so the main bearing angle θ is set in advance to 15' to 1°. range, and the main bearing angle θ is parallel (i.e. θ = 0) during suppression.
°) or slightly positive, the metal flow acts uniformly on the main bearing wall surface 51, and as a result, the obtained extruded material has a shape with uniform crystal grains without roughness. .

In addition, if the main bearing angle θ is less than 15', θ becomes negative during pressing, and the metal flow on the main bearing wall surface 51 becomes uneven, and the crystal grains of the obtained extruded material become partially irregular, resulting in a profile with a rough surface phenomenon. arise.

On the other hand, when θ exceeds 1°, the main bearing wall surface 51
The resistance to the metal flow increases, and the resulting extruded material has rough grains with coarse grains.

Next, the correction method, correction items, and correction range within the sub-bearing groove 4 will be described.

The correction method is to adjust the sub-bearing height Hl in the direction of molding of the extruded material shown by the arrow in Fig. 4, depending on the shape of the extruded material, such as waving deformation or bending of the obtained extruded material. Accordingly, it is machine cut in the range of 0.2 to 0.5 mm. Note that the corrected cutting width w1 is from 5 mm or more to the flow guide width 32.

The reason why the cutting width w1 is set to 5 mm or more is that the cutting width w1 is 5 mm or more.
If it is less than mm, the sub-bearing height Hl should be set to 0.2 to 0.
This is because even with 5 mm mechanical cutting, sufficient metal flow control cannot be achieved.

For die maintenance and management, the maximum mechanical cutting height that can be used for correction is up to the sub-bearing height Hl, and if machine cutting is performed beyond that, the main bearing wall surface 51 will be machine-cut. The dice will be discarded.

The present invention will be further explained below with reference to Examples.

[Example Q: Using an extruder with a container diameter of 210 mm, the extruded material shown in FIG.
m, height 65mm and mouth shape of 50mm, cross-sectional area 361m
JIS H4 where m2 of extruded material was heated to 450°C
A billet of 6063 alloy specified in No. 100 (2+" 204 mm) was extruded using a forward extrusion method.

The shape of the die used at that time was: sub-bearing height H, -2 mm, sub-bearing groove w2 = 0.7 mm
, conventional die design standards were followed except that the main bearing height H2 = 2 mm and the main bearing angle θ = 20'.

Although the above extrusion was carried out at an extrusion pressure of 40 kg/mm2, no waving deformation, bending of shape, or roughness was observed in the obtained long grooved material.

However, during repeated extrusion molding, some roughness was observed in the molded material, but this could be overcome by mechanically cutting the sub-bearing height Ho in the sub-bearing groove.

[Effects of the Invention] As explained above, since the correction work on the die of the present invention involves mechanical cutting of the sub-bearing height Hl, it is not necessary to perform manual correction using tools such as a pickpocket, a welding machine, a Luder, etc. as in the past. Unlike conventional machining, it does not require a high level of skill and experience, and can be performed with high machining accuracy of 1 mm for t, ooo.

In addition, unlike conventional methods, there is no need to directly modify the bearing wall surface of the extrusion molded part, such as directly angulating, cutting the wall height, overlaying, grading, or widening the bearing width, so the die can have a long lifespan. This has the effect of increasing time.

[Brief explanation of drawings]

1 to 4 are views for explaining the extrusion die according to the present invention, and FIG. 1 is a front view of the flow guide and the die as seen from the direction of forming the extruded material. FIG. 2 is a top view of FIG. 1. FIG. 3 is a schematic cross-sectional view taken along the line XX in FIG. 1. FIG. 4 is a schematic sectional view showing a state in which the extruded material is extruded through a flow guide and a die. FIG. 5 is a schematic sectional view of the tip of a conventional extrusion molding apparatus using a forward extrusion method. FIG. 6 is a sectional view of an extruded material used in an example of the present invention. Explanation of symbols 1...Flow guide 2...Dice 3...Flow guide groove 4...Sub bearing groove 5...Main bearing groove 6...Sub bearing groove Step surface 7 between the main bearing groove and the back relief groove 8 Die holder 9 Billet IO Bolster 11 Die backer 12... Container 13... Ram 14... Stem 15... Pressure plate 16... Die bearing groove 31... ... Flow guide wall surface 32 ... Flow guide width 33 ... Flow guide height 41 ... Sub-bearing wall surface 51 ... Main bearing wall surface t ... ...
Extruded material thickness tl...Main bearing width Ho...Sub bearing height H2...Main bearing height H3...Back relief height H4...Die height θ... ... Main bearing angle W1 ... Corrected cutting width during correction machining w2 ... Sub-bearing groove shape W3 ... Back relief width

Claims (3)

[Claims] (1) A die used to determine the shape and dimensions of the extruded material when a billet of light metal is charged into the container of an extrusion press and processed by forward extrusion or backward extrusion using a pressurizing means. The die bearing groove, which is the molding part of the die, extends along the pressure molding direction into (a) the first stage sub-bearing groove and (b) the second stage sub-bearing groove.
It has a two-stage structure consisting of a main bearing groove in the third stage, the former (A) is provided as a modification processing area for modifying the die molding part according to the properties of the molded material to be obtained, and the latter (B) is a light metal extrusion die characterized by being provided as a dedicated area for extrusion molding without any modification. (2) The extrusion die according to claim 1, wherein the light metal is aluminum or an aluminum alloy. (3) In the shape of the sub-bearing groove and the main bearing groove, the sub-bearing height H_1, which is the height of the sub-bearing groove in the molding direction, is the thickness of the extruded material t x 0.75 to 1.0, and the sub-bearing groove The sub-bearing groove width w_2, which is the step difference between the main bearing groove and the main bearing groove, is 0.5 to 1.5 mm, and the main bearing height H_, which is the height of the main bearing groove in the molding direction.
3. The die according to claim 2, wherein 2 is the wall thickness of the extruded material t x 1.5 to 2.0, and the main bearing angle θ, which is the inclination angle of the main bearing wall with respect to the forming direction, is 15' to 1°.