JP3118206B2 - Extrusion dies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion die capable of extruding an aluminum material from an inlet to an outlet through a bearing surface.

[0002]

2. Description of the Related Art In FIG. 8, a die 10 for extruding aluminum or an aluminum alloy (hereinafter abbreviated as "aluminum material") passes an aluminum material pushed from an inlet 11 through a bearing surface 14 to an outlet. 1
6 to be extrudable. Reference numeral 12 denotes a chamber-side standing surface, reference numeral 17 denotes a relief portion, and reference numeral 18 denotes a back escape portion.

Since the surface properties of the extruded product primarily depend on the surface roughness of the bearing surface 14, the extruded product is finished as high as possible (for example, 2-3 μm in maximum height (Ry)). . However, the surface properties (such as dice marks and partial gully) are affected by many factors (such as the type of aluminum material, heating temperature, extrusion pressure, and extrusion speed), and the results are determined exclusively by this. The fact is that it is determined by the eyes of those who adopt.

[0004] Thus, conventionally, various proposals have been made in order to take countermeasures in the case where the result of visual judgment is determined to be defective and to further improve the quality. For example, the bearing surface (1
(4) a method for making the thermal expansion constant (for example, Japanese Patent Application Laid-Open No. 9-1230), a relief portion (17) at an outlet portion
And the cross-section radius of the bearing surface outlet is relatively large (for example, Japanese Patent Application Laid-Open No. 9-24415).

[0005]

However, even in any one of the trials and the trials combining them, it is often impossible to meet the demand for higher quality.

An object of the present invention is to provide an extrusion die capable of stably producing while greatly improving the surface properties.

[0007]

SUMMARY OF THE INVENTION Conventionally, a bearing surface 14 is provided.
It is considered that the precision (surface roughness) of the extruded product affects the surface properties of the extruded product, and the practice is carried out as such.
The upright surface 8 has the relief portion 17 and the bearing surface 14 which have the effective length of the bearing surface 14 and expands in the extrusion direction.
It is provided inevitably for mechanical and physical continuity with the above, and was not considered to affect the surface properties. In other words, no consideration has been given to the effect. Therefore, even in the die forming process, the reality is that the relief portion 17 is processed with an appropriate accuracy (surface roughness) on an extended line.

However, the quality of an extruded product of an aluminum material (for example, an aluminum sash) is delicate. On the other hand, higher quality is required.
Therefore, the surface properties of a good product (for example, 3 to 5 μm in Ry)
In contrast, m) may be determined to be defective even if the surface property is 6 μm in Ry, for example. Then, while keeping other conditions constant, the influence and degree of the difference in the surface roughness of the back escape standing surface on the surface properties of the extruded product were examined.

That is, the surface roughness of the conventional back escape standing surface is generally about 20 to 30 μm. On the other hand, as described above, an attempt has been made to improve the surface roughness of the bearing surface 14 in consideration of the influence of non-quantitative and actually unmeasurable thermal deformation. If so,
The magnitude of the surface roughness of the back escape rising surface is determined by, for example, the bearing surface 14 as a resistance to the pressing force from the extruded material side.
Therefore, it is presumed that the influence cannot be ignored depending on the surface properties of the extruded product required as a non-defective product.

More specifically, as shown in FIGS. 1 and 2 schematically shown, the pushing force of the heated aluminum material is Fx, and the pushing force Fx of the surface uneven portion 14A which determines the surface properties of the extruded product on the bearing surface 14. The pressing force Fy, which is considered as a component force of the pressing force Fx of the surface uneven portion 19A of the back escape standing surface 19 from the heated aluminum material, where the reaction force is fx.
If the resistance to the surface roughness is fy, the back escape rising surface which is extremely large in surface roughness (Ry = 20 to 30 μm) with respect to the minute surface roughness (Ry = 2 to 3 μm) of the surface uneven portion 14A As shown by a two-dot chain line in FIG. 1 (the lower side is not shown) in FIG. 1, the surface irregularities 19A are displaced discontinuously or vibrate continuously to affect the surface properties of the extruded product. Hypothesized.

The present invention is an invention devised based on this hypothesis by reproducing and confirming through a number of tests and studies. As a result, when Ry of the bearing surface was 2 to 3 μm, a die mark was generated even if the rear escape standing surface 19 was improved to 20 μm to 15 μm with Ry, but under the same conditions, Ry was 10 μm or less. Then the dice mark was greatly reduced.

That is, according to the first aspect of the present invention, in an extrusion die capable of extruding an aluminum material from an inlet portion to an outlet portion through a bearing surface, at least a portion of the back escape rising surface of the outlet portion which is close to the bearing surface. Is an extrusion die having a maximum surface roughness (Ry) of 10 μm or less.

[0013] In this invention, since the surface roughness of the back escape standing surface is set to 10 μm or less in maximum height (Ry),
Even if there is displacement or vibration due to the pressing force from the heated aluminum material, it does not affect the surface properties of the extruded product.
That is, the surface properties of the extruded product can be made to depend only on the high surface roughness of the bearing surface. Therefore, the surface properties can be greatly improved and stable production can be guaranteed.

[0014] The invention of claim 2 is an extrusion die in which a portion close to the bearing surface is less than 1/3 of the height of the back relief rising surface from the bearing surface.

In this invention, at least one-third of the rear escape standing surface, which is closer to the bearing surface, is Ry10 μm.
m or less. Therefore, in addition to providing the same operation and effect as the case of the first aspect of the present invention, it becomes easier to process the back relief rising surface by, for example, an electric discharge machine.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The extrusion die has the same basic structure as that of the conventional example (FIG. 8). However, as shown in FIG. 3, the surface roughness of a portion of the back escape standing surface 19 close to the bearing surface 14 has a maximum height. The thickness (Ry) is reduced to 10 μm or less.

That is, in FIG.
The surface texture of No. 4 is obtained by measuring the distance in the height direction from the highest peak to the deepest valley using an electric discharge machine, that is, the maximum height (R
In y), finish processing was performed to 2-3 μm. The bearing surface 1
Extrusion molding object No. 4 is a surface part St of the aluminum sash W shown in FIG.

Here, the back escape standing surface 19 of the back escape portion 18
Has a surface property of 7 to 7 in Ry using the same electric discharge machine.
Finish processing was performed with a target of 10 μm.

This technical basis is based on the fact that, as described above, when the surface property of the back escape standing surface 19 is 20 to 15 μm in Ry, a dice mark is generated if other conditions still fluctuate. It depends on the cost situation in actual operation and the difficulty of measurement confirmation.

That is, as shown in FIG. 8, the back escape rising surface 19 is a part of the back escape portion 18 having a narrow range when viewed from the whole of the die 10. In addition, the plane (area) is very small because it is far from the outlet side 16 and approaches the bearing surface 14 that opens.

In other words, although the bearing surface 14 is conventionally finished to a high degree (Ry2 to 3 μm) from the above situation, the back escape standing surface 19 is required due to the technical and cost conditions of the finishing process. It's no exaggeration to say that the finishing process has been forsaken.

In this sense, even in the case of this embodiment, the size of the entire die, the diameter of the relief portion 16, the height H (for example, 1 mm) of the back relief rising surface 19 shown in FIG. Due to the size (diameter) of the wire and the like, the portion h close to the bearing surface 14 has a height H of 1
Finishing was performed with a target of less than / 3 (h = 1 / 3H).
Of course, based on the above-mentioned hypothesis, it is based on the fact that the portion which affects the surface properties of the extruded product is the portion of the back escape rising surface 19 which is close to the bearing surface 14.

It should be noted that if the die is of a split type, and the entire surface of the rear escape rising surface 19 is finished with a target of 10 μm or less in Ry, it can be considered that processing can be facilitated. But,
In this case, not only is the cost increased, but also due to the difficulty in assembling and the like, there is a strong possibility that the improvement of the fine surface properties of the back escape standing surface 19 itself will be obliterated. Thus, the significance of the present invention in that a portion close to the bearing surface 14 is highly finished is understood.

Here, the surface roughness of the rear escape standing surface 19 after the finish processing was measured using a three-dimensional measuring machine [BRT-504 type ... (K
K) manufactured by Mitutoyo Corporation]. In addition,
Use a probe with a diameter of 0.4 mm and set the measurement pitch to 0.0
According to a cross-sectional curve measuring method with a pitch of 5 mm. Therefore, points 1, 2, and 3 are intended to measure the same point, but are not considered to be physically the same point. However, I am convinced that there is no problem with regard to the effect on surface properties.

As a result, the difference between the maximum and the minimum, that is, R
y has a maximum of 12.2 μm in all times (1st to 4th times),
The minimum is 3.7 μm and the average of each round is 9.7,6.
5, 4.0, 4.8 μm, the average of which is 6.25 μm.
m.

Thus, the surface properties of the surface portion St of the aluminum sash W extruded by using the die 10 shown in FIG.
K) manufactured by Mitutoyo Corporation], and the stylus (tip radius of the stylus) was 5 μm.

The measurement results are shown in FIGS. 6A and 7A. FIG. 6 shows analog recording, and FIG. 7 shows values obtained by converting the data into data. It is well known that R
a is the average of the absolute value of the deviation from the average line to the measurement curve,
Rz is the difference between the average of the altitudes of the top five peaks from the highest and the average of the altitude of the fifth valley bottom from the deepest, that is, a ten-point average value.

As a countermeasure against this, the back escape standing surface 1
No. 9 using a conventional die (FIG. 8) having a surface roughness of 20 to 30 μm in Ry, FIGS. 6B and 7 show the measurement results of the same shape aluminum sash W shown in FIG. 4 extruded at the same temperature, extrusion pressure, extrusion speed, and the like.
(B) shows.

Comparing the two measurement results, the surface properties of the conventional extruded product were Ra = 2.02 and R = 2.02 on average shown in FIG.
While y = 15.30 and Rz = 10.80, the surface properties of the extruded product according to the present invention were as follows: Ra =
0.46, Ry = 4.30, Rz = 3.50, all win.

In terms of the quality of the product, it can be visually and tactilely determined that the conventional product (FIGS. 6 (B) and 7 (B)) which has been determined to be defective is good.

Here, the surface roughness of a portion near the bearing surface 14 is not the Ra or Rz but the maximum height (Ry) of 1
The reason why the thickness is set to 0 μm or less is that, as the maximum height is larger, the number of needle-like pieces forming inside the surface uneven portion 19A shown in FIGS. 1 and 2 is also horizontal (vertical) shown in FIG. Left and right)
That there should be a large number of needle-like pieces having a natural frequency that is likely to be isolated and prone to cause vibration during extrusion, that is, the number of such needle-like pieces is 1 to It is based on empirical rules through tests and research that if there is even a few, die marks will be generated on the surface properties of the extruded product.

In FIG. 3, the bearing surface 14 and the back escape standing surface 19 are perpendicular to each other, but the present invention is applicable even if the boundary is an arc surface or the like.

[0033]

According to the first aspect of the present invention, the surface roughness of at least the portion of the back escape rising surface of the outlet portion which is close to the bearing surface is 10 μm or less in maximum height (Ry).
The surface properties of extruded products can be greatly improved and stable production can be guaranteed.

Further, according to the second aspect of the present invention, the portion close to the bearing surface is set to be less than one third of the height of the back escape rising surface from the bearing surface. In addition to the advantageous effects described above, furthermore, for example, the machining of the rear escape standing surface by the electric discharge machine becomes easy.

[Brief description of the drawings]

FIG. 1 is an enlarged side view for explaining the technical basis of the present invention.

FIG. 2 is an enlarged plan view for explaining the technical basis of the present invention.

FIG. 3 is an enlarged side view showing an embodiment of the present invention.

FIG. 4 is a view for explaining an example of an extruded product.

FIG. 5 is a view for explaining the measurement results of the surface roughness of the back escape standing surface.

FIG. 6 is a diagram for explaining a measurement result (1) of the surface property of an extruded product according to the present invention in comparison with a conventional example.

FIG. 7 is a diagram for explaining a measurement result (2) of the surface property of an extruded product according to the present invention in comparison with a conventional example.

FIG. 8 is a diagram for explaining a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extrusion die 11 Inlet part 14 Bearing surface 14A Surface unevenness 16 Exit part 17 Relief part 18 Back escape part 19 Back escape standing surface 19A Surface unevenness

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kouma Iida 2-2-20 Higashishinagawa, Shinagawa-ku, Tokyo Nippon Light Metal Co., Ltd. (72) Inventor Yoshifumi Tonami 2100 Abe, Ochiai-cho, Takahashi-shi, Okayama Japan (58) Field surveyed (Int.Cl. ⁷ , DB name) B21C 25/02

Claims (2)

(57) [Claims] 1. An extrusion die capable of extruding an aluminum material from an inlet to an outlet through a bearing surface, wherein at least a surface roughness of at least a part of the back escape standing surface of the outlet close to the bearing surface has a maximum height. An extrusion die having a thickness (Ry) of 10 μm or less. 2. The extrusion die according to claim 1, wherein a portion close to the bearing surface is less than 1/3 of the height of the back relief rising surface from the bearing surface.