JP2700946B2 - Die for light metal extrusion - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light metal extrusion die, particularly to an aluminum or aluminum alloy extrusion die, and more particularly to a molding portion of the extrusion die (hereinafter referred to as a die bearing groove). Dies) having improved structures.

[Prior Art] In extrusion molding of a light metal such as aluminum or an aluminum alloy, a piece of material called a billet is first inserted into a container-like tool called a container, and the billet is pressed by a ram, and is pressed through a hole in a die. By being extruded into a certain shape, it is formed as an extruded material.

That is, for example, as shown in FIG. 5 which is a schematic cross-sectional view of a conventional front extrusion type aluminum or aluminum alloy extruder tip, the tip of an extruder used for aluminum or aluminum alloy is usually A die 2 incorporated in the die holder 8 to determine the outer shape of the extruded material, a flow guide 1 for guiding the billet 9 to the die by a pressing force, and a die backer 11 as a spacing piece with a bolster 10 behind the die 2. The ram 13 or a stem 14 connected thereto is pressurized through a pressure plate 15 from a one-way entrance of a container 12 for accommodating the billet 9 to press the billet 9 into the container 12. Into the flow guide groove 3 through the die bearing groove 16 and extruded as an extruded material having a constant thickness t. Is done. The arrows indicate the billet extrusion direction.

[Problems to be Solved by the Invention] As described above, the flow of metal (hereinafter, referred to as metal flow) in which aluminum or an aluminum alloy flows from a container to a flow guide or die is referred to as a force direction of a stem or a radial direction in heating a billet. In addition, due to uneven temperature in the longitudinal direction and speed difference of metal flow in the billet radial direction, the flow does not always become parallel and constant speed in the die bearing groove, and as a result, the shape of the extruded profile is In many cases, a desired shape or surface shape cannot be obtained due to a wavy deformation, a shape bending phenomenon, or a skin roughening phenomenon due to coarsening of crystal grains.

Conventionally, in order to prevent these drawbacks, the bearing wall surface of the die was hand-processed using tools such as files, welding machines, ruders, etc., and the bearing wall angled, wall height cut, overlay, graded And modifications such as the increase in the bearing groove width.

However, such a correction work is a difficult work requiring a high level of skill and experience, and has a poor processing accuracy.

In addition, the service life of the die is short because the bearing wall of the extruded portion is directly corrected.

Therefore, an object of the present invention is to solve the above-mentioned problems, and in correcting the die shape in the die bearing groove, is released from conventional manual processing requiring advanced skill and experience, and the processing accuracy of the correction work is high, and as a result, An object of the present invention is to provide a novel die in which the obtained molding material has sufficient reproducibility.

[Means and Actions for Solving the Problems] The present inventor has conducted intensive studies to achieve the above object,
The bearing groove of the conventional die has a two-stage structure, and a molding area that can be formed slightly larger by the final shape called a sub-bearing groove in the first stage along the extrusion molding direction is formed, and this is a dedicated area for correction processing. Assuming that the second stage is a molding region which should be referred to as a main bearing groove portion and which does not need to be modified as a molding dedicated region, the machining accuracy can be improved without using the conventional high skill and experience of manual machining. The present inventor has found that an extruded material which can be modified by high mechanical cutting, can extend the service life of the die, and is reproducible, and can be reproducible, has reached the present invention.

That is, the present invention is to insert a billet made of a light metal such as aluminum or aluminum alloy into a container of an extrusion press, and when the billet is processed by forward extrusion or backward extrusion by pressing means, the shape of the extruded material, A die used to determine dimensions,
The die bearing groove, which is a forming part of the die, has a two-stage structure consisting of (a) a first-stage sub-bearing groove and (b) a second-stage main bearing groove along the pressure forming direction. The former (a) is provided as a correction processing area for making a correction to the die forming part according to the properties of the obtained molding material, and the latter (b) is dedicated to extrusion molding without any correction. A die for extruding a light metal such as aluminum or an aluminum alloy, which is provided as a region, is provided.

The present invention is a further preferred embodiment thereof, and particularly as an effective dice when the light metal is aluminum or an aluminum alloy, in the shape of the sub-bearing groove and the main bearing groove, the height of the sub-bearing groove in the molding direction. A certain sub-bearing height
H ₁ is extruded material thickness t × 0.75 to 1.0, the sub bearing Mizodai w ₂ is 0.5~1.5mm a level difference between the sub-bearing grooves and main bearing groove, the main is the height of the main bearing groove in the molding direction bearing height H ₂ is extruded material thickness t × 1.5 to 2.0, and main bearing angle θ is the tilt angle of the main bearing wall for forming direction
An object of the present invention is to provide a dice having the above-mentioned structure formed in dimensions or angles of 15 'to ¹⁰ '.

1 to 4 are diagrams for explaining an extrusion die according to the present invention. FIG. 1 is a front view of the flow guide and the die as viewed from the molding direction of the extruded material, FIG. 42 is a top view of FIG. 1, and FIG. 3 is XX of FIG.
A schematic cross-sectional view taken along a line and FIG. 4 are schematic cross-sectional views showing a state where an extruded material is extruded through a flow guide and a die. The configuration of the present invention will be described with reference to these figures.

The extrusion die according to the present invention is characterized in that two stages of bearing grooves are provided in the extrusion molding direction,
Each has a dedicated area for the first-stage correction processing and a dedicated area for the second-stage molding.

The area dedicated to the first-stage correction processing is the sub-bearing groove 4, which is an area where the billet is formed to have a slightly larger outer shape than the final product dimensions. It consists Mizodai w ₂ Prefecture, which is the relevant part for carrying out each time correction processing when happened deformed Toka deflection phenomenon wavy shape of the extruded profiled.

The dedicated area for the second stage molding is the main bearing groove 5
A is, the main bearing groove 5 main bearing wall 51, main bearing width t _1, and consists of a main bearing height H _2, meat extrusion material to be obtained a metal which has flowed from the sub bearing groove 4 This is a portion to be formed to have a thickness t, and is a portion where correction processing is not performed even if a wavy deformation or bending phenomenon occurs in the extruded formed material. Further, as will be described later, the dimensions of each part are taken into consideration so as not to cause skin roughening due to coarsening of crystal grains.

The design of each component relating to the die and the flow guide is performed by setting the outer shape and height 33 of the flow guide 1 and the die 2 in accordance with the shape of the extruded material to be obtained and the maximum circumscribed circle thereof.
After the outer shape and the height H ₄ is determined, the flow guide width 32 as the order, sub bearing height H _1, the sub bearing Mizodai
w _2, the main bearing height H _2, the main bearing width t _1,
It is determined in the order of the back escape width w ₃ and the main bearing angle θ.

Further, in the above configuration requirements, flow guide width 32, main bearing width t _1, the width w ₃ back relief is equivalent to conventional design criteria, however, the sub-bearing height H _1, the sub-bearing Mizodai w _2, main bearing As described above, it has been recognized that a particularly good effect can be obtained when the height H ₂ and the main bearing angle θ have respective unique numerical ranges found by the present inventors as a result of earnest studies.

Hereinafter, constituent requirements given by these unique numerical ranges are listed.

The dimensions of the sub-bearing height H ₁ is extruded material thickness t × 0.75 to 1.0 to be obtained, the sub-bearing Mizodai w ₂ is 0.5
It is preferable to set the range to 1.5 mm. In addition, as shown in FIG. 1, the sub bearing groove allowance w ₂ is provided with uniform dimensions along the entire outer periphery of the main bearing groove 5.

If the sub-bearing height H ₁ is less than t × 0.75, the repairable area is small and repair maintenance cannot be performed.On the other hand, if the sub-bearing height H ₁ exceeds t × 1.0, the resistance due to metal flow is large, H ₁ for rough skin symptoms extrusion material obtained by coarsening of crystal grains occurs t × 0.75 to.
It is preferable to set the range to 0.

If the sub bearing groove allowance w ₂ is less than 0.5 mm, it is difficult to obtain the processing accuracy during die production, and as a result, the processed dies also have processing unevenness, and when directly modifying the bearing molding part as in the past Similarly, a high degree of skill and experience is required, and even if a correction is made, it is not possible to prevent wavy deformation or bending of the shape.

On the other hand, if the sub bearing groove allowance w ₂ exceeds 1.5 mm,
Increased resistance due to the metal flow, also be a sub-bearing height H ₁ decreases by the correction processing by cutting, phenomena there be skin caused by grain coarsening occurs in the extrusion material in which the correcting effect can be obtained without.

Main bearing height H ₂ is the extruded material wall thickness of t × 1.5 to 2.0 to be obtained, the main bearing angle θ is
It is preferred to be in the range of 15 'to 1 °.

If the main bearing height H ₂ is less than t × 1.5, bending stress acts on the step surface 6 and the main bearing wall surface 51, resulting in uneven distortion of the main bearing wall surface 51,
In addition, the main bearing angle θ expands to 0 ° or less, and the resulting extruded material undergoes wavy deformation and bending.

On the other hand, if the main bearing height H ₂ exceeds t × 2.0, the resistance to the main bearing wall surface 51 due to the metal flow is large, and the resulting extruded material has a rough surface due to coarsening of crystal grains.

The reason for setting the main bearing angle θ to 15 'to 1 ° is that
The main bearing height H ₂ and the back clearance width w ₃ are in a “cantilever” relationship, and when a load is applied to the step surface 6 and the main bearing wall surface 51, the protrusion of the back clearance width w ₃ of the main bearing groove portion 5. Only the bending stress acts and the main bearing wall 51 is tilted by the load during pressing, so that the main bearing angle θ is set in the range of 15 ′ to 1 ° in advance, and the main bearing angle θ is parallel at the time of pressing (that is, θ = 0 °). Alternatively, by maintaining the value to be slightly positive, the metal flow acts uniformly on the main bearing wall surface 51, and as a result, the obtained extruded material has a uniform crystal grain without skin roughness.

When the main bearing angle θ is less than 15 ′, θ becomes negative when pressed, the metal flow on the main bearing wall 51 becomes uneven, and the obtained extruded material has partially irregular crystal grains, resulting in a shaped material having a rough skin phenomenon. Occurs.

On the other hand, if θ exceeds 1 °, the main bearing wall 51
The resistance of the metal flow is increased, and the resulting extruded material has a coarsened crystal grain with a roughening phenomenon.

Next, a correction method, a correction item, and a correction range in the sub-bearing groove 4 will be described.

Method of correction, the sub bearing height H _1, the molding direction of FIG. 4 extruded material indicated by the arrows, the resulting wavy deformation of the extruded material, extruded etc. deflection phenomenon was profiled shape Machine cutting is performed in the range of 0.2 to 0.5 mm according to. Note that modifying the cutting width w ₁ is flow guide width 3 from above 5mm
Up to 2.

The reason why the cutting width w ₁ and 5mm or more, in less than the cutting width w ₁ is 5mm, it can not be sufficient metal flow control even when the sub-bearing height H ₁ and 0.2~0.5mm machine cutting.

Die maintenance on a maximum machining height during modification that can be used to be up to the sub-bearing height H _1, if you more mechanical cutting, will be machining the main bearing wall 51, in this case Will abandon the dice.

 Hereinafter, the present invention will be further described with reference to examples.

[Example] An extruder having a container diameter of 210 mm, which has an extruded material shown in FIG. 6, that is, a wall thickness of 1.2 mm, a width of 175 mm and a height of 65 mm.
In the form of 50 mm, the extruded material of the cross-sectional area 361 mm ^2, in billets 6063 alloy 204mm specified in JISH4100 heated to 450 ° C., by forward extrusion method, and extrusion molding.

The dies used at that time were: sub bearing height H ₁ = 2 mm, sub bearing groove allowance w ₂ = 0.7 mm, main bearing height H ₂ = 2 mm, and main bearing angle θ = 2
Except that it was 0 ', it was in accordance with the conventional die design standard.

The above extrusion was performed at an extrusion pressure of 40 kg / mm ² , but no wavy deformation, shape bending phenomenon, or skin roughness phenomenon was observed in the obtained long channel material. However, although rough skin symptoms were observed in a part of the molding material in which repeated extrusion could be overcome by 0.3mm machining the sub bearing height H ₁ in the sub-bearing groove.

As has been described [Effect of the Invention Since correction operation in the die of the present invention by mechanical cutting the sub bearing height H _1, as in the prior art rasp, welder, hand processed using a tool such as Ryuda Unlike making corrections, it can be performed with a high machining accuracy of a thousandth of a millimeter without requiring a high level of skill and experience.

Also, on the bearing wall of the extruded part to be obtained,
Since there is no need to perform a modification such as direct angling, wall height cutting, overlaying, grading, and bearing width enlargement as in the related art, the service life of the die is increased.

[Brief description of the drawings]

1 to 4 are diagrams for explaining an extrusion die according to the present invention, and FIG. 1 is a front view of a flow guide and a die as viewed from a molding direction of an extruded material. FIG. 2 is a top view of FIG. FIG. 3 is a schematic cross-sectional view taken along line XX of FIG. FIG. 4 is a schematic sectional view showing a state where the extruded material is extruded via a flow guide and a die. FIG. 5 is a schematic cross-sectional view of a distal end portion of a conventional extrusion molding apparatus using a front extrusion method. FIG. 6 is a sectional view of the extruded material used in the embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Flow guide 2 ... Die 3 ... Flow guide groove 4 ... Sub bearing groove 5 ... Main bearing groove 6 ... Step surface between sub bearing groove and main bearing groove 7 ... Back escape groove 8 ... Die holder 9 ... Billet 10 ... Bolster 11 ... Die backer 12 ... Container 13 ... Ram 14 ... Stem 15 ... Pressure plate 16 ... Die bearing groove 31 ... Flow guide wall 32 ... Flow guide width 33 …… Flow guide height 41 …… Sub bearing wall surface 51 …… Main bearing wall surface t …… Extrusion material wall thickness t ₁ …… Main bearing width H ₁ …… Sub bearing height H ₂ …… Main bearing Height H ₃ …… Back clearance height H ₄ …… Die height θ …… Main bearing angle w ₁ …… Correct cutting width at the time of correction machining w ₂ …… Sub bearing groove allowance w ₃ …… Back clearance width

Continuation of the front page (56) References JP-A-1-241319 (JP, A) JP-A-57-152319 (JP, U) JP-A-57-136510 (JP, U)

Claims (3)

(57) [Claims] When a billet of a light metal is charged into a container of an extrusion press and the billet is processed by forward or backward extrusion by a pressurizing means, the shape of an extruded material after a metal flow passes through a flow guide. A die used to determine the dimensions, and a die bearing groove, which is a forming part of the die, is formed along the pressing direction (a).
A right-angled staircase-like unit consisting of a first-stage sub-bearing groove with vertical walls and no radius at the entrance, and (b) a second-stage main bearing groove with an inclined wall but a right angle just before the entrance. It has a two-stage structure, and the former (a) is provided as a correction processing area for performing correction on the die forming part according to the properties of the obtained molding material,
The latter (b) is a light metal extrusion die, which is provided as a dedicated area for extrusion molding without modification. 2. The extrusion die according to claim 1, wherein the light metal is aluminum or an aluminum alloy. 3. The shape of the sub-bearing grooves and main bearing groove, the sub-bearing height H ₁ is extruded material thickness t × 0.75 to 1.0 is the height of the sub-bearing groove in the molding direction, the sub-bearing groove portion The sub bearing groove allowance w ₂ which is a step with the main bearing groove is
0.5 to 1.5 mm, main bearing height H ₂ is the height of the main bearing groove in the molding direction are extruded material thickness t
The die according to claim 2, wherein the main bearing angle?, Which is an angle of inclination of the main bearing wall with respect to the molding direction, is 15 'to ¹⁰ x 1.5 to 2.0.