JPH105850A - Die for extrusion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die for extrusion which is excellent in durability including the wear resistance and easy in manufacture. SOLUTION: A die 31 is provided with a plate 33 of flat disk shape which is made of cemented carbide, a flow guide 35 made of hot tool steel, and a case 37. When a billet 61 is pressed from the upstream side of the flow guide 35, the metallic material is successively passed through an opening part 45 in the flow guide 35, a die hole 43 in the plate 33, and a tapered hole 49 in the case 37 and extruded as an extrusion stock (panel). The flow guide 35 adjusts the flow-in ratio of the metallic material to each part of the die hole 43. Even when the bearing length of the die hole 43 is equal, the flow speed of the metallic material in the die hole 43 is unified to obtain excellent extrusion stock. Increase in the working cost and breakage can be avoided even when the cemented carbide is applied to the plate 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an extrusion die for extruding a metal material such as an aluminum alloy.

[0002]

2. Description of the Related Art When a metal material is extruded with an extrusion die, the thickness of the die hole (distance between the wall surfaces of the die hole) and the distance from the die center differ depending on the difference in the thickness of the metal material in the die hole. Difficulty of flowing.
Therefore, unless appropriate measures are taken, the finally extruded metal material is deformed.

Therefore, generally, FIGS. 4 (a) to 4 (c)
In forming the die hole 3 in the bearing member 1, the length of the bearing portion 5 in the extrusion direction (so-called bearing length) is set at a position where the flow velocity in the die hole 3 tends to be high. It is shortened where it tends to be long and slow. For example, in the case of the illustrated die hole 3, the flow velocity at the outermost end 3a is relatively slow because the distance from the die center is large, so the bearing length is shorter than at other locations. Further, since the flow velocity in the central portion 3b is higher than that on both sides, the bearing length is increased.

Further, in order to continuously extrude the extruded material on the upstream side of the bearing member 1 by jointly pushing billets (lumps of metal material), an opening having a shape determined according to the shape of the die hole 3. 7 is provided. 4A is a front view illustrating the configuration of a conventional extrusion die, FIG. 4B is a cross-sectional view taken along line AA, and FIG. 4C is a cross-sectional view taken along line BB. , Respectively.

On the other hand, in recent years, in order to improve the wear resistance of this type of extrusion die, it has been considered that the bearing member 1 and the like are made of a hard material such as a cemented carbide or ceramics. For example, a cemented carbide obtained by sintering WC powder with Co powder is excellent in hot wear resistance, and when used in an extrusion die, the wear life can be greatly extended.

[0006]

However, since this kind of hard material is difficult to process, it takes a long time to form the above-described bearing portion 5 having a complicated shape, and the manufacturing cost increases. . In addition, since this kind of hard material has low toughness, it is easily damaged at stress concentration points (points Q1 to Q7 illustrated in FIGS. 4B and 4C) during bearing processing. Therefore, it was difficult to apply the hard material as it is to a conventional extrusion die.

Therefore, an object of the present invention is to provide an extrusion die having excellent durability such as abrasion resistance and easy to manufacture.

[0008]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a bearing member having a die hole made of a hard material and having an equal bearing length. A flow guide, which is formed of a material having better workability than the member, and is disposed on the upstream side of the bearing member and adjusts an inflow ratio of the metal material to each part of the die hole. The gist is a processing die.

In the present invention thus configured, the flow guide adjusts the inflow ratio of the metal material into each part of the die hole. For this reason, even if the bearing length of the die hole of the bearing member is made equal, the flow velocity of the metal material in the die hole is made uniform, and a good extruded material can be obtained. Therefore, it is not necessary to perform complicated processing that requires adjustment of the bearing length on the bearing member, and even if a hard material having good wear resistance is applied to the bearing member, the processing cost is not so high. Further, as described above, most of such hard materials have low toughness, but the bearing member of the present invention does not have a portion where the bearing length is switched as described above. For this reason, breakage of the bearing member can also be prevented.

Further, since the flow guide is made of a material having relatively good workability and has a simple shape, the flow guide can be easily manufactured even when it is necessary to adjust the inflow ratio of the metal material in a complicated manner. can do. In addition, when the flow velocity adjustment or the like is required after the die is manufactured, only the flow guide needs to be modified and reworked, and the bearing member need not be reworked. Therefore, the adjustment of the flow velocity becomes easy. That is, the extrusion die of the present invention has excellent durability such as abrasion resistance, and is extremely easy to manufacture and adjust. Therefore, by applying the present invention, the manufacturing cost of the extruded material can be favorably reduced.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the flow guide has an opening whose shape is determined in accordance with the shape of the die hole. The inflow ratio of the metal material into each part of the die hole is adjusted by widening and narrowing, and the opening width C _i of the opening corresponding to the location of the thickness w _i of the die hole is determined by the following equation. It is characterized by.

C _i = C ₀ × (w ₀ −a 1) / (w _i −a 1) / Y _i (1) [where w ₀ is a reference thickness of the die hole, and w _i is a predetermined thickness of the die hole. equivalent thickness at the position, C ₀ is the flow guide opening reference opening width, a1 is the minimum thickness of the die hole, Y _i is a delay coefficient due to the distance from the die center. In the present invention, the thickness of the die hole is the distance between the wall surfaces forming the die hole at the place where the die hole becomes flat.

Among them, the reference thickness w ₀ is a value which may be arbitrarily set within a range in which extrusion can be actually performed. Usually, the reference thickness w ₀ is a thickness of a die hole near the center of the die. The average value of the thickness of each part of the die hole may be used. On the other hand, the equivalent thickness w _i is a value calculated on the basis of an actually measured value. At a place where the die hole is a flat plate, as described above, it is the distance between the wall surfaces forming the die hole. In the part, the bent part, the crossing part, and the like, the thickness of each part is converted into a thickness equivalent to a flat plate part according to the ease of flow of the extruded material.

If a specific example is shown, as illustrated in FIG.
The die hole 10 is formed with the flat plate portions 11, 12, 13, 14 and
To the parts 15, 16, 17, the bent part 18, and the intersection 19
To divide. As shown by the dashed line in the figure,
Of the parts 15, 16, 17, the bent part 18, and the intersection 19
It is determined according to the wall thickness. And the equivalent thickness w of each part _i
Is obtained by the following equation.

Equivalent thickness w _i = area of divided area A × 2
/ Length L of contact wall surface (2) For example, in the case of the end portion 15, it is converted to a value corresponding to ／ of the thickness of the flat plate portion 11 as described below.

[0016]

(Equation 1)

The equivalent thickness w _{i of the} end portions 16 and 17, the bent portion 18, and the intersection portion 19 is calculated in the same manner by the above equation (2). Here, also for the flat plate portion 11 to 14, although it is possible to calculate the equivalent thickness w _i by Equation (2), corresponds thickness w _i in the case of a tabular portion becomes so thick itself.

In the present invention, the opening width of the flow guide opening is a distance between the contour of the die hole and the contour of the flow guide opening surrounding the die hole. It is not the distance between the walls. Among them,
The reference opening width C ₀ is an opening width of the flow guide opening corresponding to the position of the reference thickness w ₀ , and is a value which may be arbitrarily set within a range in which the extrusion can be actually performed. Since the reference opening width C ₀ is a reference for increasing and decreasing the opening width C _i at other locations, a relatively small value may be used as long as the location of the reference thickness w _{0 is} a location where the flow velocity is relatively high. It is desirable to set a relatively large value in a place where the speed is slow.

The minimum thickness a1 is a value calculated based on an actually measured value. As the thickness of the die hole decreases, the extrusion speed on the outflow side tends to decrease as the thickness decreases.However, the relationship between the two can be measured in advance, and the minimum thickness that can be theoretically extruded should be determined from this relationship. Can be.

The delay coefficient Y _i is also a value calculated based on the actually measured value. The flow rate (extrusion speed) of the metal material tends to increase at the die center (center of the die),
This trend, as the ratio of the extrusion rate for the extrusion rate in the die center, in advance can be measured, and the coefficient Y _i delayed the measured extrusion rate ratio. The opening width C
The method of calculating _i is not limited to the above specific example,
In addition, various embodiments can be considered without departing from the gist of the present invention. Further, more specific examples of the calculation method of the opening width C _i should be referred Having described in Japanese Patent Application No. 7-229397.

In the present invention, the opening width C is calculated by the above equation (1).
_i can be calculated and a flow guide can be designed. In the flow guide designed as described above, the inflow ratio of the metal material to each part of the die hole can be adjusted favorably. The reference thickness w ₀ of the die hole, the reference opening width C ₀ of the flow guide opening, the minimum thickness a1 of the die hole, and the delay coefficient Y _i are the material of the metal, the extrusion temperature, and the extrusion speed on the outflow side. Can be determined by performing a simple preliminary experiment after arbitrarily selecting as a processing condition, and thereafter, the equivalent thickness w at a predetermined position of the die hole is calculated by the equation (1).
Depending on _i, it is possible to calculate the opening width C _i of the flow guide openings to be set against the portion of the wall thickness w _i of the die hole.

Therefore, according to the present invention, in addition to the effect of the first aspect of the present invention, the flow guide corresponding to any shape of the die hole can be easily formed by performing a simple preliminary experiment in advance. The effect is that the design can be made in a suitable manner. According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the bearing member is made of a cemented carbide, and the flow guide is made of hot tool steel.

Cemented carbides are extremely excellent in wear resistance and can greatly extend the wear life of dies. Also,
Hot tool steel has sufficient abrasion resistance required as a flow guide and is easy to work. Therefore, in the present invention, in addition to the effects of the invention described in claim 1 or 2,
The effect is obtained that the durability is further improved, such as abrasion resistance, and the manufacturing is easier.

According to a fourth aspect of the present invention, in addition to the structure of any of the first to third aspects, the bearing is made of a material having better workability than the bearing member, and the bearing is formed from a side facing the flow guide. A support member for supporting the member is further provided, and the bearing member is fixed without being shrink-fitted by being sandwiched between the support member and the flow guide.

In the present invention having the above-described structure, the support member supports the bearing member from the side facing the flow guide, and the bearing member is shrink-fit by being sandwiched between the support member and the flow guide. It is fixed without. Generally, when two members are fixed by shrink fitting and used hot, the members to be fixed to each other must have substantially the same coefficient of thermal expansion. On the other hand, in the present invention, since the bearing member is fixed without being shrink-fitted by being sandwiched between the support member and the flow guide, the support member, the flow guide, and the bearing member are made of completely different materials. Can be. Therefore, a material having more excellent wear resistance and the like can be applied to the bearing member, and a material having better workability can be applied to the flow guide and the support member.

Further, it is difficult to replace the member fixed by shrink fitting. However, in the present invention, since the bearing member is not shrink fitted, the replacement is easy. Therefore, in the present invention, in addition to the effects of the invention described in any one of the first to third aspects, there is an effect that the durability such as abrasion resistance is more excellent, and the production and management are easier.

[0027]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing a configuration of an extrusion die (hereinafter, simply referred to as a dice) 31 to which the present invention is applied, and FIG. 2 is a front view showing a configuration of the die 31. As shown in FIG. 1, this die 31 is formed of a flat plate-shaped bearing member made of cemented carbide and a plate 33 as a bearing member, and is formed of hot tool steel, and is disposed upstream of the plate 33. Flow guide 35,
Similarly, a case 37 as a support member for supporting the plate 33 from the side facing the flow guide 35 is provided.

Also, as shown in FIG. 1, a die hole 43 having the same bearing length is formed in the plate 33, and an opening for guiding the metal material sent from the upstream side to the die hole 43 is formed in the flow guide 35. 45 are formed. Further, the case 37 has a concave portion 47 capable of accommodating the entire plate 33 without shrink fitting, and a tapered hole 4 communicating with the die hole 43 of the plate 33 accommodated in the concave portion 47.
9 are formed. The diameter of the tapered hole 49 is gradually increased toward the downstream side, and allows the extruded material extruded from the die hole 43 to pass therethrough.

As shown in FIG. 2, the die hole 43 is formed in a shape corresponding to the cross-sectional shape of the extruded material, and the opening 45 is formed in a shape surrounding the die hole 43. The opening width of each part of the opening 45 is determined by the above-described equation (1). For this reason, the flow guide 35 can satisfactorily adjust the inflow ratio of the metal material into each part so that the flow velocity of the metal material in each part in the die hole 43 becomes uniform. As can be seen from the shape of the die hole 43 in FIG. 2, the die 31 has thin portions at both ends, and the thin portion of the extruded material formed by the thin portions is fitted and fixed to another member. This is a die for extruding a panel material.

After the plate 31 is accommodated in the concave portion 47 of the die 31 thus configured, the flow guide 35 and the case 37 are opposed to each other with the plate 33 interposed therebetween, and both of them are provided with a knock pin 51 (a screw or the like). (See FIG. 1). When the billet 61 is pressed from the upstream side of the flow guide 35 via a stem or the like (not shown), the metal material forming the billet 61 sequentially passes through the opening 45, the die hole 43, and the tapered hole 49, and the extruded material is formed. Extruded as (panel material).

Next, the effect of the die 31 will be described. In the die 31, the flow guide 35 is provided with a die hole 43.
Adjust the inflow ratio of the metal material to each part. For this reason, even if the bearing length of the die hole 43 is equal as described above,
The flow rate of the metal material in the die hole 43 is made uniform, and a good extruded material with small deformation can be obtained. Therefore, it is not necessary to perform complicated processing such as adjustment of the bearing length on the plate 33, and the manufacturing cost does not increase so much even if a hard metal having good wear resistance is applied as described above. In addition, since there is no portion where the bearing length is switched in the die hole 43, even if a cemented carbide having relatively low toughness is applied, there is no breakage. For this reason, die 31
Is extremely excellent in durability such as abrasion resistance and is very easy to manufacture.

Further, the flow guide 35 and the case 37
Is made of hot work tool steel having relatively good workability, and the hot work tool steel has sufficient wear resistance required for the flow guide 35 and the case 37. Therefore, the die 31 is easier to manufacture and rework. Therefore, if the die 31 is used, the manufacturing cost of the extruded material can be reduced extremely favorably.

In the die 31, the opening width of the opening 45 is calculated by the above-mentioned equation (1). Therefore, the flow guide 35 corresponding to any shape of the die hole 43 can be easily designed simply by performing a simple preliminary experiment in advance. Furthermore, in the die 31,
The plate 33 is fixed without being shrink-fitted by sandwiching the plate 33 between the flow guide 35 and the case 37. For this reason, even if each part is made of a material having a different coefficient of thermal expansion, such as the above-mentioned cemented carbide and hot tool steel, the strength can be ensured without causing distortion in the material. Also, knock pin 5
The plate 33 can be easily replaced by removing the flow guide 35 and separating the case 37 from the case. Therefore,
The management of the dice 31 is also easy.

[0034]

EXAMPLE Next, a die 31 was actually manufactured (Example), and a die manufactured by a conventional method (conventional example) was compared with its cost. The conventional example is a well-known one in which the entire die is manufactured from hot tool steel and the bearing length is changed according to the shape of the die hole. Table 1 shows the comparison results. In Table 1, various expenses are 1996
Based on the prices as of April, 2004, the material cost of the conventional example (almost entirely hot tool steel) was set to 1 and expressed as a relative value. In this comparative experiment, an aluminum alloy A6063 was used as the metal material, the extrusion temperature was 480 ° C., and the extrusion speed was 25.
Under the condition of m / min, an extruded material having a thickness of 3 ± 0.3 mm was produced.

[0035]

[Table 1]

As shown in Table 1, in the embodiment, since a relatively expensive cemented carbide is used, the material cost is high. However, in the conventional example, since the complicated processing for changing the bearing length is required, the processing cost of the die is twice that of the embodiment. Further, in the conventional example, correction rework (four times) for adjusting the roughness of the bearing surface, the choke angle, and the bearing length with respect to wear occurring during use, and nitriding for improving the wear resistance of the bearing surface. Surface hardening treatment (3
Times) was required. On the other hand, in the example, the repair rework, the surface hardening treatment, and the like became unnecessary, and the maintenance cost of the die became zero. As a result, the cost required for manufacturing and managing the die (die cost) is one in the conventional example and the example.
3.86: 57. The die life was 1: 12.5 in the conventional example and the example.

As a result, the cost of manufacturing an extruded material by using each die was 3: 1, and it was found that the manufacturing cost of the extruded material can be reduced extremely favorably in the embodiment. It should be noted that the present invention is not limited to the above embodiment at all, and can be implemented in various forms without departing from the gist of the present invention. For example, the die hole 43
Can be designed in various shapes other than the shape shown in FIG. Further, the flow guide 35 is provided with the die hole 4.
Any method may be used as long as the flow rate of the metal material in each part in the section 3 is made uniform, and it can be designed by various methods other than the method according to the equation (1). Further, as the hard material, various materials such as a ceramic material can be used in addition to a cemented carbide.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of an extrusion die to which the present invention is applied.

FIG. 2 is a front view showing the configuration of the extrusion die.

FIG. 3 is an explanatory view illustrating a method of dividing a die hole.

FIG. 4 is a front view and a cross-sectional view illustrating a configuration of a conventional extrusion die.

[Explanation of symbols]

31: die for extrusion processing 33: plate 3
5 Flow guide 37 Case 43 Die hole 4
5 Opening 47 Depression 49 Tapered hole 5
1 ... knock pin

Continued on the front page (72) Inventor Hidenori Ito 5-11-3 Shimbashi, Minato-ku, Tokyo Sumitomo Light Metal Industries Co., Ltd. (72) Inventor Takaji Shinozawa 5-11-3 Shimbashi, Minato-ku, Tokyo Sumitomo Light Metal Industry Co., Ltd.

Claims (4)

[Claims] 1. A bearing member made of a hard material and having a die hole having an equal bearing length, and a material having better workability than the bearing member,
An extrusion die, comprising: a flow guide disposed upstream of the bearing member to adjust an inflow ratio of a metal material into each of the die holes. 2. The flow guide has an opening whose shape is determined according to the shape of the die hole, and adjusts the inflow ratio of the metal material into each part of the die hole by changing the opening width of the opening. be one which, extrusion die of claim 1, wherein the opening width C _i of the openings corresponding to the locations of the wall thickness w _i of the die hole, characterized in that it is determined by the following equation. _{C i = C 0 × (w} 0 -a1) / (w i -a1) / Y i [ However, w ₀ is the reference thickness of the die hole, w _i is considerably thicker at the predetermined position of the die hole, C ₀ flow guide opening reference opening width, a1 is the minimum thickness of the die hole, Y _i is a delay coefficient due to the distance from the die center. ] 3. The extrusion die according to claim 1, wherein the bearing member is formed of a cemented carbide, and the flow guide is formed of hot tool steel. 4. A support member, which is made of a material having better workability than the bearing member and supports the bearing member from a side facing the flow guide, wherein the bearing member is configured to be in contact with the support member and the flow member. The extrusion die according to any one of claims 1 to 3, wherein the die is fixed without being shrunk by being sandwiched between the guide and the guide.