JPH0584612A - Machining method for extrusion die - Google Patents

Abstract

PURPOSE:To machine the undercut part of an extrusion die made of aluminum, etc., into a smooth surface. CONSTITUTION:A conical through hole 6 is drilled in a die material 16 by a wire cut electric discharge machine so as to recover the remainder, and the die material is machined to form a bearing part with a specified width. Then, the tip side of the remainder is cut to a specified height, and a step is provided at the tip side to form an electrode. The undercut part of the die material is machined using this electrode 11 by an electrochemical machine to produce an extrusion die.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a die used for aluminum extrusion.

[0002]

2. Description of the Related Art The machining of the undercut part of a die used for conventional aluminum extrusion is electrical discharge machining (EDM).
Therefore, it was not possible to use an electrode made of a steel material of the same material as the mold because the electrode was worn out quickly due to discharge. Therefore, as the material of the electrodes, graphite carbon, copper tungsten alloy electrodes and the like have been manufactured using various processing machines. The manufacturing process will be described as shown in FIG. Numerical control from Graphite Carbon Block 1 to Diamond Cutter 2 (N /
By cutting out the base material 3 of the electrode by C), the base material shown in FIG. 15 is formed.

Next, as shown in FIG. 16, the base material 3 is blended with the blends 3a, 3b and 3c to complete the electrode 11. The blending process is a step provided according to the length of the bearing portions 4a, 4b, 4c of the mold 4 (that is, a portion where an extruded material such as aluminum is formed) as shown in FIG. is there.

As shown in FIG. 17, the electrode 3 is inserted into the undercut portions 5a to 5g, which have been cut out by a wire-cut electric discharge machine in advance, and the undercut portion is electric discharge machined. Mold 4 is completed.

[0005]

However, in the electric discharge machining, the machined surface has a matte surface. This is because in extrusion, sometimes the head of the material in the initial stage of extrusion bends up, down, left, and right, so that the die 4 as shown in FIG.
The head 21a of the material 21 such as aluminum collides with the matte surface of the undercut portion 6 of FIG.

Further, by electric discharge machining, 5a shown in FIG.
A predetermined undercut amount m at the boundary between the undercut portion of 5 g (6 in FIG. 18) and the bearing portions 4a to 4c.
Although the outer corner portion 8 of FIG. 18 is formed, the outer corner portion 8 has a sharp 90 angle without forming R as shown in FIG. 18 by electric discharge machining, and has a slight unevenness. ..

Therefore, the extruded profile is restricted by the shrink width L of the mold in the bearing 7 (FIGS. 19 and 20, and FIG. 20 is an enlarged view of FIG. 19).
As shown at the instant m ₁ passing therethrough ^{_{2/100 ~ 3/100 m}} / m
Expands. At this time, due to the unevenness of the outer corner portion 8, scratches (vertical stripes) are generated on the surfaces 9 and 10 of the profile, and the surface texture is deteriorated. Further, when the extrusion is continuously progressed, scrape-like debris shown by 9a and 10a in FIG. 20 is generated and adheres to the surface of the profile.

Further, in the electric discharge machining, the consumption on the electrode 11 side cannot be made zero in the current machining machine performance, and the surface roughness is as large as the extrusion die allows (the smaller the surface roughness is, the longer the machining time is. Is longer), about 18μ is economically the highest. Therefore, the consumption of the electrode 11 is 3 to 5%, and the electrode size is 0.2 to 0.5 ^m / _m (the mold accuracy is ± 0.2
^m / _m ), and depending on the shape, the process of FIG. 17 needs to be performed up to three times. The present invention has been made in view of the above circumstances.

[0009]

In order to solve the above problems, the present invention has an extrusion hole in which a bearing portion having a predetermined shrink wall thickness and an undercut portion are formed in the axial direction from the front surface to the back surface, The extrusion hole is a method for processing an extrusion die having the following steps in an extrusion die continuously punched according to the cross-sectional shape of an extrusion-molded product.

(1) A step of continuously punching through-holes having a tapered cross-section in a die material with a wire-cut electric discharge machine, and collecting the residual material generated by the punching,

(2) A step of forming a bearing portion by cutting a narrow hole width of the through hole having the tapered cross section into a parallel width and a predetermined width with a wire cut electric discharge machine,

(3) A step of cutting the tip side of the residual material to a predetermined height,

(4) A step of forming an electrode by forming a step on the tip side according to the bearing length,

(5) A step of inserting an electrode up to a predetermined position from the back surface by using an electrolytic processing machine to supply an electric current while flowing an electrolytic solution from the front surface to the back surface of the through hole of the extrusion die.

The electrolytic solution used in the electrolytic processing machine is a sodium nitrate solution.

[0016]

[Operation] Since the machining residual material by wire cut electric discharge machining is used, the machining process is reduced. Further, since the electrolytic processing machine is used for processing the undercut portion of the mold, there is no electrode consumption and the processing time is short. Furthermore, the surface of the undercut portion becomes very smooth, and smooth R is formed at the outer corner portion.

[0017]

The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view of an extrusion die, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a schematic view showing a taper machining procedure by wire cut electric discharge machining and a shape of an extrusion hole. In the figure, reference numeral 12 denotes a shrink groove, which is machined on the die 13 by a wire cut electric discharge machine. 6 is an undercut part, 7
Is the bearing part, L is the shrink wall thickness (slit width),
D is the bearing length, m is the undercut amount, and β is the undercut angle.

First, a wire-cut electric discharge machine is used to continuously machine through-holes having a tapered cross-section in a die material. The wire cut electric discharge machine is numerically controlled to machine through holes. In FIG. 2, where the undercut amount m is large, the undercut angle β is large. Also, bearing length D
The undercut angle β is determined by taking into account the length of the undercut angle. Figure 3
[Fig. 3] is a schematic view showing a program procedure of taper processing by wire cutting.

The dashed line is the required shape. The solid line indicates the residual material 15 cut by the wire cut electric discharge machine. H is the thickness of the mold material 16. First, according to the shrink wall thickness L, the bearing length D and the undercut amount m
Is determined. Next, the inclined surface 6a of the undercut portion 6 is formed at a predetermined taper angle from both ends of the undercut dimension L ₁ .
Pull 6b. As described above, the extrusion groove to be formed in the mold material 16 is drawn by the broken line.

To form a through-hole having a tapered cross-section, the points 14, 14 lowered from the outer corner portion 8 by about 0.1 mm and the lower ends of the inclined surfaces 6a, 6b are joined to form a through-hole having a tapered cross-section. Draw lines 15a and 15b. This 15
A continuous shape of a and 15b is processed by a wire cut electric discharge machine by numerical control. This processed state is shown in FIG.
In the figure, 17 is a wire wire of a wire cut electric discharge machine. Wire-cut residual material 15 as described above
Are taken out downwards as shown in FIG.

Next, as shown in FIG. 6, in the wire cut electric discharge machine, the width of the narrower through hole having a tapered cross section is set to the width L of the shrink groove 12 shown in FIGS.
The bearing portion 7 is formed by cutting in parallel as shown in FIG.

As shown in FIG. 7, the residual material 15 is cut at a position where the tip end side has an undercut dimension L ₁ . That is, the tip side is cut at the position of line 18 in FIG.

After fixing the cut residual material on the mounting pedestal 19 as shown in FIG. 8, steps 20a to 20g (blend) according to the bearing length D (FIG. 3) as shown in FIG.
Add and cut. Thus, the electrode 11 used in the electrolytic processing machine is completed.

The undercut portion 6 is formed by using the electrode.
And the outer corner portion 8 is processed by an electrolytic processing machine (ECM). Next, a processing process by the electrolytic processing machine will be described. FIG. 10 is a plan view of the mold, 12a is a shrink groove, 13a is a mold,
11 is a sectional view taken along line BB of FIG.

In order to manufacture the mold 13a shown in FIGS. 10 and 11, first, a through hole having a tapered cross section is machined by a wire cut electrolytic machine (FIGS. 4 and 5), and then a bearing is formed as shown in FIG. A mold member 16 formed by wire-cutting the parts 7 in parallel is set in an electrolytic processing machine with the back surface facing upward as shown in FIG. 12, and an electrolytic processing liquid (sodium nitrate solution in this case) is applied from the lower surface. An undercut dimension L ₁ including the undercut portion 6 and the outer corner portion 8 is formed by energizing while flowing into the through hole, inserting the electrode 11 from above, and moving it to a predetermined position shown in FIG.

[0026]

According to the present invention described in detail above, the following effects can be obtained.

Since the machining residual material of the wire cut electric discharge machine can be used, the machining man-hours of the die are greatly reduced, and the material cost such as the graphite carbon and the copper tungsten alloy for separately manufacturing the conventional electrode is increased. It becomes unnecessary.

Since the electrode consumption is zero as compared with the conventional electric discharge machining, it is not necessary to modify the electrode and the number of steps can be reduced.

The machining time is shortened as compared with the conventional electric discharge machining.

Since the surface roughness of the approach portion becomes much smoother than that of the electric discharge machining, even if the head of the material hits the surface of the undercut portion at the initial stage of extrusion during extrusion, it can be easily slipped and pushed forward. The profile does not get stuck in the mold.

Since the outer corner has a smooth R, when the extruded profile is regulated by the shrink width of the mold and passes through, there is no flaw (vertical stripe) at the outer corner and the surface is smooth. You can make various products.

[Brief description of drawings]

FIG. 1 is a plan view of an extrusion die of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a schematic diagram showing a procedure of taper machining by wire cut electric discharge machining and a shape of an extrusion hole when machining the mold of the present invention.

FIG. 4 is a cross-sectional view showing a step of processing a tapered through hole when processing the die of the present invention.

FIG. 5 is a cross-sectional view showing a state where a tapered through hole is processed and a residual material can be removed when the die of the present invention is processed.

FIG. 6 is a cross-sectional view showing a step of processing a bearing portion when processing the mold of the present invention.

FIG. 7 is an explanatory diagram showing a residual material of the present invention.

FIG. 8 is a perspective view of an electrode of the present invention before a step is processed.

FIG. 9 is a perspective view of a completed electrode of the present invention.

FIG. 10 is a plan view of the extrusion die of the present invention.

11 is a sectional view taken along line BB of FIG.

FIG. 12 is a cross-sectional view showing the middle of the electrolytic processing step in the method for processing an extrusion die of the present invention.

FIG. 13 is a cross-sectional view showing a final step of electrolytic processing in the method for processing an extrusion die of the present invention.

FIG. 14 is a perspective view showing a state where a base material of a conventional electrode is cut out from a block of material.

FIG. 15 is a perspective view showing a conventional electrode cut out from a material block.

FIG. 16 is a perspective view showing a conventional blended electrode.

FIG. 17 is a cross-sectional view showing a processed state of an undercut portion of an extrusion die using a conventional electrode.

FIG. 18 is a cross-sectional view showing a state in which the head of the material extruded during an extruding operation using a conventional extrusion die hits an undercut portion.

FIG. 19 is a cross-sectional view showing a relationship between a material extruded during an extruding operation using a conventional extrusion die and an outer corner portion.

FIG. 20 is a cross-sectional view showing a state in which a material extruded during an extruding operation using a conventional extrusion die has a flawed surface at an outer corner portion.

[Explanation of symbols]

6 Undercut part 6a, 6b Inclined surface 7 Bearing part 8 Outer corner part 9, 10 Surface 11 Electrode 12, 12a Shrink groove 13, 13a Mold 15 Remaining material 16 Mold material 20a, 20b, 20c, 20d, 20e, 20f, 2
0g Step (blend) m Undercut amount D Bearing length α, β Undercut angle L Shrink wall thickness (slit width) L ₁ Undercut dimension

Claims (2)

[Claims] 1. An extrusion hole having a bearing portion and an undercut portion each having a predetermined shrink thickness in the axial direction from the front surface to the back surface, and the extrusion hole is continuously formed in accordance with the cross-sectional shape of the extrusion-molded product. In the punched extrusion die, a method of processing the extrusion die having the following steps, (1) A wire cut electric discharge machine is used to continuously punch through-holes with a tapered cross-section in the die material, and the residual material generated by the punching (2) a wire cut electric discharge machine to form a bearing part by cutting the narrower width of the through hole having the tapered section in parallel and to a predetermined width, (3) the residual material Cutting the tip side of the to a predetermined height, (4) forming a step on the tip side according to the bearing length to form an electrode, (5) using an electrolytic processing machine, the electrolytic solution is extruded into a die. Through the through hole of the Step, and inserting the electrode from the back surface to a predetermined position. 2. The method for processing an extrusion die according to claim 1, wherein the electrolytic solution is a sodium nitrate solution.