JP2010017747A - Extrusion die and method of manufacturing extrusion material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion die having a structure capable of selectively cooling a bearing part. <P>SOLUTION: The extrusion die (20) has the bearing part (25) for forming the inside surface (2a) of an extrusion material (1) and is provided with a passage (26) for cooling media, which passes through the inside of the bearing part (25) and has an opening part (28) on the end face of the downstream side. In the passage (26a) for the cooling media, heat exchanging efficiency in the inside (29) of the bearing part (25) is set higher than the heat exchanging efficiency in the part (26a) of the upstream side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an extrusion die for forming an inner surface of an extruded material, and a method for producing an extruded material using the extrusion die.

  In the description of the present specification and claims, the direction in which the extruded material and the extruded material travel is referred to as downstream or downstream side, and the reverse direction is referred to as upstream or upstream side.

  In extrusion dies, if heat is generated during extrusion and the temperature of the bearing part rises, the surface quality of the extruded material will deteriorate due to seizure, etc., and the wear of the bearing part will become severe, so the temperature of the die will be lowered. (See Patent Documents 1 and 2).

  The loader wheel described in Patent Document 1 is provided with a flow path for a non-oxidizing fluid inside a male mold, and communicates with the flow path at the tip surface of the mandrel, and the outer edge (downstream surface) of the bearing portion. ), A nozzle having a plurality of ejection holes arranged opposite to each other is provided, and fluid supplied from the outside is ejected from the nozzle and sprayed to the outer edge of the bearing portion.

The holrodice described in Patent Document 2 is provided with a cooling gas conduction hole that opens at the front end face of the mandrel so as to cool the mandrel from the inside.
JP-A-4-66216 (Claim 2, FIG. 1) Japanese Patent No. 3645963 (Claim 2, FIG. 1)

  However, in the method of spraying fluid on the outer edge of the bearing portion (Patent Document 1), since the fluid is sprayed from the downstream side, it is the extruded material that is cooled most, and the bearing portion is not sufficiently cooled. Further, the method of cooling the mandrel from the inside (Patent Document 2) cools the entire conduction hole through which the cooling gas circulates. Therefore, if the bearing part is lowered to the expected temperature, a low-temperature refrigerant or An increase in the flow rate of the refrigerant is required. However, when this is done, the entire die is cooled, and the material is excessively cooled on the upstream side of the bearing portion, making extrusion difficult.

  An object of this invention is to provide the extrusion die which has a structure which can selectively cool a bearing part in view of the technical background mentioned above, and the manufacturing method of the extrusion material using this extrusion die.

  That is, the extrusion die of the present invention has each configuration described in the following [1] to [15], and the manufacturing method of the extruded material has each configuration described in [11] below.

[1] An extrusion die having a bearing portion for molding the inner surface of the extruded material, including a refrigerant passage that passes through the inside of the bearing portion and has an opening at a downstream end surface,
The extrusion die according to claim 1, wherein the refrigerant passage is set such that a heat exchange efficiency inside the bearing portion is higher than a heat exchange efficiency in an upstream portion thereof.

  [2] The extrusion die as recited in the aforementioned Item 1, wherein in the refrigerant passage, a cooling promotion part with increased heat exchange efficiency is provided inside the bearing part.

  [3] The extrusion die as recited in the aforementioned Item 2, wherein the cooling promotion part is formed by increasing the surface area of the refrigerant passage.

  [4] The extrusion die as recited in the aforementioned Item 3, wherein the cooling promoting portion has a surface area enlarged by providing irregularities in the refrigerant passage.

  [5] The extrusion die according to any one of [2] to [4], wherein the cooling promotion part is formed by enlarging a cross-sectional area of the refrigerant passage.

  [6] The extrusion die according to any one of [2] to [5], wherein the cooling promotion portion is formed by attaching a cooling promotion member made of a material having better thermal conductivity than the die material in the refrigerant passage.

  [7] The extrusion die according to any one of [1] to [6], wherein in the refrigerant passage, a cooling suppression unit that reduces heat exchange efficiency is provided on the upstream side of the bearing unit.

  [8] The extrusion die as recited in the aforementioned Item 7, wherein the cooling suppression portion is formed by attaching a cooling suppression member made of a material having a lower thermal conductivity than the die material to the inner wall surface of the refrigerant passage.

[9] An extrusion die having a coolant passage having a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having an opening at the downstream end surface,
An extrusion die characterized in that the refrigerant passage has a surface area on the inner side of the bearing portion that is larger than a surface area in an upstream portion thereof.

[10] An extrusion die having a bearing portion for molding the inner surface of the extruded material, including a refrigerant passage that passes through the inside of the bearing portion and has an opening portion on the downstream end surface,
The refrigerant passage has an extrusion die characterized in that a cross-sectional area inside the bearing portion is larger than a cross-sectional area in an upstream portion thereof.

[11] An extrusion die having a bearing portion for molding the inner surface of the extruded material, including a refrigerant passage that passes through the inside of the bearing portion and has an opening at the downstream end surface,
An extrusion die, wherein a cooling promoting member made of a material having a thermal conductivity better than that of a die material is attached to a wall surface inside the bearing portion of the refrigerant passage.

[12] An extrusion die having a bearing portion for molding the inner surface of the extruded material, including a refrigerant passage that passes through the inside of the bearing portion and has an opening portion on the downstream end surface,
An extrusion die, wherein a cooling suppression member made of a material having a lower thermal conductivity than the die material is attached to an inner wall surface on the upstream side of the bearing portion of the refrigerant passage.

  [13] The extrusion die according to any one of items 1 to 12, wherein a part of the opening of the downstream end surface is closed.

  [14] The extrusion die according to any one of [1] to [13], wherein the bearing portion forms an inner peripheral surface of a hollow portion or a contour surface of a bay-shaped recess.

  [15] By using the extrusion die according to any one of items 1 to 14 above, a bearing portion is formed by circulating a refrigerant introduced from the outside through the refrigerant passage and discharging the metal from the opening on the downstream end face. A method for producing an extruded material, characterized in that the inner surface of the extruded material is molded while cooling at a higher heat exchange efficiency than the upstream portion.

  According to the invention described in [1] above, the bearing portion can exchange heat more quickly than the upstream portion due to the difference in heat exchange efficiency, and the bearing portion can be cooled to a temperature lower than that of the upstream portion. Then, by cooling the bearing portion, seizure and die wear can be prevented. And since a bearing part is cooled efficiently, the fall of the die intensity | strength and excessive cooling by providing the channel | path for refrigerant | coolants can be avoided.

  According to the invention described in [2] above, a heat exchange efficiency difference can be generated between the upstream portion and the upstream portion due to the structure in which the cooling promoting portion is provided inside the bearing portion.

  According to the inventions described in [3], [4], [5], and [6], the heat exchange efficiency in the cooling promotion portion can be efficiently increased.

  According to the invention described in [7] above, a difference in heat exchange efficiency can be generated between the upstream portion and the upstream portion by the structure in which the cooling suppression portion is provided on the upstream side of the bearing portion.

  According to the invention described in [8] above, the heat exchange efficiency in the cooling suppression unit can be efficiently reduced.

  According to each invention described in the above [9], [10], [11] and [12], the bearing portion is cooled more quickly than the upstream portion, and the bearing portion can be cooled to a temperature lower than that of the upstream portion. Then, by cooling the bearing portion, seizure and die wear can be prevented. In addition, since the bearing portion is efficiently cooled, the refrigerant passage only needs to have a small-diameter hole, and a reduction in die strength and excessive cooling due to the provision of the refrigerant passage can be avoided.

  According to the invention described in [13] above, the heat exchange efficiency inside the bearing portion can be increased.

  According to the invention described in [14] above, the above-described effect can be achieved in the extrusion of a hollow material having a hollow portion or a semi-hollow material having a bay-shaped recess.

  According to the invention described in [15] above, since the bearing portion is selectively cooled and seizure is prevented, a high quality extruded material can be manufactured.

  The present invention can be applied to an extrusion die for forming the inner surface of an extruded material, for example, a die for extruding a hollow material (1) shown in FIG. 1 or a semi-hollow material (3) shown in FIG. The inner surface of the extruded material in the present invention is a surface that is not exposed to the outside in the extruded material, and in the hollow material (1), the hollow material (1) that forms a closed hollow portion (2) The semi-hollow material (3) is the contour surface (4a) of the bay-shaped recess (4) in which a part of the hollow portion is opened. The extrusion die includes a refrigerant passage that passes through the inside of the bearing portion for forming the inner peripheral surface (2a) and the contour surface (4a) and has an opening on the downstream end surface, and allows the refrigerant to flow through the refrigerant passage. Thus, the die can be cooled from the inside.

  Hereinafter, the extrusion die of the present invention will be described in detail with reference to FIGS. 3 to 9B by exemplifying a port hole die for extruding the hollow material (1).

  The port hole die (10) shown in FIG. 3 is a combination of a female die (11) for molding the outer peripheral surface of the hollow material (1) and a male die (20) for molding the inner peripheral surface (2a). The male mold (20) corresponds to the extrusion die of the present invention.

  The female mold (11) has a bearing hole (12) in the center, a recess (13) for a welding chamber is formed on the upstream side of the bearing hole (12), and a relief hole (14) is formed on the downstream side. Is formed.

  The male mold (20) has a plurality of port holes (23) penetrating in the extrusion direction around the mandrel (22), with a mandrel (22) protruding downstream from the center of the die base (21). ing. A leg portion (24) for supporting the mandrel (22) at the base end portion is formed between the adjacent port holes (23) and (23). A bearing portion (25) for forming the inner peripheral surface (2a) of the hollow material (1) is projected from the peripheral surface on the front end side of the mandrel (22).

  The male mold (20) has a refrigerant passage (26) inside. One end of the refrigerant passage (26) opens to the side surface of the die base (21) to serve as an inlet (27) for the refrigerant (C), passes through the leg (24) and reaches the axis of the die. And bent through the center of the mandrel (22), and the other end is opened at the front end surface of the mandrel (22) to serve as an outlet (28) for the refrigerant (C). On the outlet side, the diameter of the refrigerant passage (26) is enlarged inside the bearing portion (25), and the cross-sectional area and the surface area per unit length of the refrigerant passage are enlarged from the upstream portion (26a). The cooling promotion part (29) is formed. The inlet (27) is threaded to attach a joint for refrigerant piping.

  When the female mold (10) and the male mold (20) are combined, the bearing portion (25) of the mandrel (22) of the male mold (20) is fitted into the bearing hole (12) of the female mold (10). An annular molding gap (not indicated) is formed between them, and a part of the recess (13) for the welding chamber of the female die (10) is blocked by the end face of the die base (21) of the male die (20). Thus, a welding chamber communicating with the port hole (23) is formed. Then, the extruded materials flowing into the respective port holes (23) merge in the welding chamber and are extruded as hollow materials (1) from the molding gap.

  In the step of extruding the metal using the port hole die (10), the refrigerant (C) introduced from the outside through the inlet (27) on the side surface of the die base (21) is cooled with the refrigerant passage ( 26), and passes through the cooling promotion part (29) and is discharged from the outlet (28) at the end face of the mandrel (22) into the hollow part (2) of the extruded material (1). The cooling promoting portion (29) has a heat exchange efficiency that is increased because its cross-sectional area and surface area are larger than those of the upstream portion (26a). Moreover, when the refrigerant (C) flows into the cooling promotion part (29) having a large cross-sectional area, turbulent flow is generated, and the refrigerant (C) is agitated to further increase the heat exchange efficiency. For this reason, the bearing portion (25) is heat-exchanged more quickly than the base side portion of the upstream mandrel (22) and the die base (21) and cooled to a lower temperature, and seizure and wear are prevented. Moreover, since the bearing portion (25) is efficiently cooled by the cooling promotion portion (29), the refrigerant passage (26) is sufficient with a small-diameter hole, and the die strength due to the provision of the refrigerant passage (26) is sufficient. Degradation and excessive cooling can be avoided. The refrigerant (C) discharged from the outlet (28) cools the extruded material (1).

  Further, since the bearing portion (25) is selectively cooled and seizure is prevented, a high quality extruded material (1) can be manufactured.

  The cooling promoting part with improved heat exchange efficiency can be realized by other structures. Below, the structure of another cooling promotion part is demonstrated. Note that the same reference numerals as those in FIG.

  The cooling promotion part (30) shown in FIGS. 4A and 4B expands the diameter of the refrigerant passage (26) more than the upstream part (26a), and increases the number of refrigerants from the wall surface toward the axis of the mandrel (22). (31) is a projecting fin. The refrigerant (C) that has entered the cooling promotion part (30) enters between the adjacent fins (31) to exchange heat, and the surface area has been greatly expanded by the large number of fins (31), resulting in high heat exchange efficiency. Achieved. In the illustrated example, the fin (31) is provided in the refrigerant passage (26) whose diameter has been expanded, but the fin can be provided without being expanded in diameter. Even when the fins are provided without increasing the diameter, the heat exchange efficiency can be increased more than the upstream portion if the improvement in the heat exchange efficiency due to the surface area increase exceeds the decrease in the heat exchange efficiency due to the reduction in the cross-sectional area.

  The cooling promotion portions (32) and (34) shown in FIGS. 5A and 5B are also enlargements of the surface area of the refrigerant passage (26). The cooling promotion part (32) in FIG. 5A is provided with a convex part (33) having a triangular cross section instead of the fin (31). Since the expansion ratio of the surface area is smaller than that of the cooling promotion part (30), the improvement rate of the heat exchange efficiency is also small, but the processing is easier than the thin plate-like fins (31). In this way, the surface area can be increased by providing irregularities in the refrigerant passage. The cooling promotion part (34) in FIG. 5B is obtained by providing a lattice (35) in the refrigerant passage to enlarge the surface area.

  The above-described fins (31), protrusions (33), and lattices (35) can be formed by, for example, sculpting electric discharge machining. Further, the fin (31) and the like may be formed integrally with the mandrel (22), or may be manufactured as a separate member and attached in the refrigerant passage (26). In the case of attaching as a separate member, only the fin or the like may be manufactured and attached as a separate member, or the one in which the fin or the like is integrally formed inside the ring is used as a separate member, and this is used as the refrigerant passage (26). It can also be fitted inside.

  The cooling promoting part (36) in FIG. 6 is obtained by enlarging the cross-sectional area and the surface area by enlarging the diameter of the refrigerant passage (26) in a tapered shape.

  Although the cooling promotion part is formed by changing the cross-sectional shape of the refrigerant passage as described above, the cooling promotion part can also be formed using a material having better thermal conductivity than the die material.

  The cooling promotion part (38) shown in FIG. 7 expands the diameter of the refrigerant passage (26) in the same manner as in FIG. 1, and has a cylindrical cooling promotion made of a material having better thermal conductivity than the die material in the expanded space. The member (39) is fitted in a close contact state. Even if the cross-sectional shapes of the passages are the same, the heat exchange efficiency can be increased more than the upstream portion (26a) made of the die material by attaching the cooling promotion member (39).

  Since the object of the present invention is to lower the temperature of the bearing portion than that of the upstream portion, the object can be achieved by providing a difference in heat exchange efficiency between the inside and the upstream portion of the bearing portion. 8A and 8B show that in the refrigerant passage (26), a cylindrical cooling suppression member (40) made of a material having a lower thermal conductivity than the die material is attached to the inner wall surface on the upstream side of the bearing portion (25). In this way, the heat exchange efficiency of the upstream part (26a) is lowered to form a cooling suppression part, thereby showing a structure in which the heat exchange efficiency inside the bearing part (25) is relatively higher than that of the upstream part (26a). ing. The cooling suppression member (40) may be attached so as to protrude from the wall surface of the refrigerant passage (26) as shown in FIG. 8A, or the passage diameter of the attachment portion is enlarged as shown in FIG. 8B for cooling. The suppressing member (40) and the wall surface may have the same height.

  As a raw material for the extrusion die, die steel such as SKD61, SKT4, SKD4, SKD5, SKD7, SKD8, SKD11, SKD12, or the like is used. Among these die steels, the thermal conductivity at 20 ° C. is 30.6 W / (m · K) for SKD61, 36 W / (m · K) for SKT4, and 29 W / (m · K) for SKD11. Other die steels have the same thermal conductivity. As described above, when materials with different thermal conductivities are used to make a difference in heat exchange efficiency, copper and aluminum can be exemplified as materials having better thermal conductivity than die steel, and thermal conductivity is worse than die steel. Examples of the material include ceramic materials and stainless steel materials. The thermal conductivity at 20 ° C. of these materials is 401 W / (m · K) for copper, 236 W / (m · K) for aluminum, 2 W / (m · K) for zirconia-based ceramics, and 16 W / (m for SUS304.・ K).

  Further, as a means for further increasing the heat exchange efficiency of the cooling promoting portion, there is a method of closing a part of the outlet of the refrigerant passage. 9A and 9B show a pin (50) driven from the outlet side into the center of the finned cooling promotion portion (30) of FIGS. 4A and 4B. The leg (51) of the pin (50) is inserted into the cylindrical space formed at the tip of each fin (31) to close the cylindrical space, and the large-diameter head (52) is the outlet (28). A part of is blocked. Further, the tip of the leg (51) has a tapered shape. And the refrigerant | coolant (C) which flowed into the cooling acceleration | stimulation part (30) from the upstream spreads radially at the leg part (51), reaches the root of each fin (31), and heat exchange is performed. And since the front-end | tip part of a leg part (51) is a taper shape, a refrigerant | coolant (C) can be spread efficiently and equally. In this way, the flow of the refrigerant (C) is forcibly changed by closing a part of the outlet (28) of the cooling promotion part (30), and the refrigerant (C) passes through the cylindrical space (see FIG. 4A). ) Can be used to utilize heat exchange by the fins (31).

  Various structures for providing a difference in the heat exchange efficiency described above can be combined. For example, if a fin or the like is separately manufactured with a material having better thermal conductivity than a die material, or a member with a fin or the like protruding from the inside of a ring is manufactured and attached to a refrigerant passage with an expanded diameter, The heat exchange efficiency can be increased by obtaining both the surface area expansion effect by the fins and the effect by the difference in the thermal conductivity of the material. Moreover, while providing a cooling promotion part inside a bearing part, a cooling suppression part can be provided in an upstream part, and the height difference of heat exchange efficiency can also be expanded. The difference in heat exchange efficiency between the inside and the upstream portion of the bearing portion is set as appropriate according to the expected cooling temperature of the bearing portion and the temperature difference with the upstream portion.

  The refrigerant introduced into the refrigerant passage may be either gas or liquid, but a non-oxidizing refrigerant can be recommended. The non-oxidizing refrigerant is used because the refrigerant released from the die comes into contact with the extruded material, so that the surface of the extruded material is not oxidized. Examples of the gas refrigerant include air, nitrogen gas, and argon gas, and examples of the liquid refrigerant include water and liquid nitrogen. The liquid refrigerant is vaporized in the refrigerant passage, and a cooling effect is also obtained by the heat of vaporization. The supply amount, pressure, temperature, and the like of the refrigerant are appropriately set according to the expected cooling temperature of the bearing portion. Further, the refrigerant only needs to be supplied during the extrusion, and may be stopped at the time of pushing.

  Further, in the extrusion of the hollow material, when the temperature rise of the bearing portion due to processing heat generation is small, air is sucked into the refrigerant passage by the negative pressure in the hollow portion. In such a case, the bearing is cooled without actively supplying the refrigerant. Further, since the internal negative pressure is canceled by the intake of air, the deformation of the hollow material is avoided. In addition, since the air suck | inhaled by a negative pressure acts as a refrigerant | coolant, the case where a refrigerant | coolant is not supplied actively is also contained in the manufacturing method of the extrusion material of this invention.

  As shown in FIG. 3, the refrigerant passage (26a) has openings on the side surface of the die base (21) and the downstream end face of the mandrel (22), and is bent in an L shape to form both openings. Communicates. Such a passage does not need to be cut into an L-shape. The first passage toward the center of the mandrel (2) from the inlet (27) on the side of the die base (21) through the leg (24) and the mandrel ( A second passage that penetrates the center of 22) in the extrusion direction and leads to the outlet (28) is formed, and an L-shaped passage is formed by closing the upstream opening of the second passage. The closing method may be suitably performed by bolting, welding or shrink fitting of a rod-like closing member. Further, the second passage leading to the inlet (27) is not necessarily limited to being provided through the leg (24), but the upstream end face of the die base (21) and a plate (not shown) arranged on the upstream side of the die. ) And a position facing the mating surface.

  As explained at the beginning of this section, the extrusion die of the present invention can also be applied to a die for extruding a semi-hollow material (3) having a bay-shaped recess (4) in which a part of the hollow portion is opened. For the extrusion of the semi-hollow material, either a female die and a male die or a flat die are used. In the case of a combination die, the inner surface (4a) that forms the contour of the bay-shaped recess (4) is formed by a male mold, so that the male mold has the same structure as the male mold (20) of the porthole die (10) described above. And the heat exchange efficiency inside the bearing portion may be higher than that of the upstream portion. In the case of a flat die, a structure may be employed in which a refrigerant passage is provided inside the required bearing portion so that the heat exchange efficiency is higher than that of the upstream portion. Further, for a die for extruding an extruded material having both a hollow portion and a bay-shaped recess, or a die for extruding a plurality of hollow portions or a plurality of bay-shaped recesses, the upstream portion of the bearing portion for molding at least one inner surface If there is a difference in the heat exchange efficiency with the above, it corresponds to the extrusion die of the present invention.

  Moreover, as long as the material shape | molded using the extrusion die of this invention is a metal, it will not be limited at all, and aluminum, copper, iron, and these alloys can be illustrated.

  According to the present invention, since the bearing portion can be selectively cooled, it can be applied to an extrusion die for forming the inner surface of a hollow material or a semi-hollow material.

It is sectional drawing of the hollow material shape | molded by the extrusion die of this invention. It is sectional drawing of the semi-hollow material shape | molded by the extrusion die of this invention. It is sectional drawing which shows one Embodiment of the extrusion die of this invention. It is sectional drawing which shows the principal part of other embodiment of the extrusion die of this invention. It is the side view which looked at the extrusion die of Drawing 4A from the lower stream side. It is a side view which shows the modification of the extrusion die of FIG. 4A. It is a side view which shows the other modification of the extrusion die of FIG. 4A. It is sectional drawing which shows the principal part of other embodiment of the extrusion die of this invention. It is sectional drawing which shows the principal part of other embodiment of the extrusion die of this invention. It is sectional drawing which shows the principal part of other embodiment of the extrusion die of this invention. It is sectional drawing which shows the modification of the extrusion die of FIG. 8A. It is sectional drawing which shows other embodiment of the extrusion die of this invention. It is the side view which looked at the extrusion die of Drawing 9A from the downstream.

Explanation of symbols

1 ... Hollow material (extruded material)
2 ... Hollow part
2a… Inner peripheral surface (inner surface)
3 ... Semi-hollow material (extruded material)
4 ... Bay-shaped recess
4a… Contour surface (inner surface)
10 ... Porthole Dice
20 ... Male mold (extrusion die)
21 ... Dice base
25… Bearing part
26 ... Refrigerant passage
26a… Upstream part
28 ... Exit (opening)
29,30,32,34,36,38… Cooling promotion part
39… Cooling promotion member
40 ... Cooling suppression member (cooling suppression part)
C: Refrigerant

Claims (15)

An extrusion die comprising a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having a refrigerant passage having an opening at the downstream end surface,
The extrusion die according to claim 1, wherein the refrigerant passage is set such that a heat exchange efficiency inside the bearing portion is higher than a heat exchange efficiency in an upstream portion thereof.   2. The extrusion die according to claim 1, wherein in the refrigerant passage, a cooling accelerating portion with increased heat exchange efficiency is provided inside the bearing portion.   The extrusion die according to claim 2, wherein the cooling promotion portion is formed by increasing a surface area of the refrigerant passage. The extrusion die according to claim 3, wherein the cooling promotion part has a surface area enlarged by providing irregularities in the refrigerant passage.   The extrusion die according to any one of claims 2 to 4, wherein the cooling promotion part is formed by enlarging a cross-sectional area of the refrigerant passage.   The extrusion die according to any one of claims 2 to 5, wherein the cooling promotion portion is formed by attaching a cooling promotion member made of a material having better thermal conductivity than the die material in the refrigerant passage.   The extrusion die according to any one of claims 1 to 6, wherein a cooling suppression portion having reduced heat exchange efficiency is provided upstream of the bearing portion in the refrigerant passage.   The extrusion die according to claim 7, wherein the cooling suppression portion is formed by attaching a cooling suppression member made of a material having a lower thermal conductivity than the die material to the inner wall surface of the refrigerant passage. An extrusion die comprising a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having a refrigerant passage having an opening at the downstream end surface,
An extrusion die characterized in that the refrigerant passage has a surface area on the inner side of the bearing portion that is larger than a surface area in an upstream portion thereof. An extrusion die comprising a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having a refrigerant passage having an opening at the downstream end surface,
The refrigerant passage has an extrusion die characterized in that a cross-sectional area inside the bearing portion is larger than a cross-sectional area in an upstream portion thereof. An extrusion die comprising a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having a refrigerant passage having an opening at the downstream end surface,
An extrusion die, wherein a cooling promoting member made of a material having a thermal conductivity better than that of a die material is attached to a wall surface inside the bearing portion of the refrigerant passage. An extrusion die comprising a bearing portion for molding the inner surface of the extruded material, passing through the inside of the bearing portion, and having a refrigerant passage having an opening at the downstream end surface,
An extrusion die, wherein a cooling suppression member made of a material having a lower thermal conductivity than the die material is attached to an inner wall surface on the upstream side of the bearing portion of the refrigerant passage.   The extrusion die according to any one of claims 1 to 12, wherein a part of the opening of the downstream end face is closed.   The extrusion die according to any one of claims 1 to 13, wherein the bearing portion forms an inner peripheral surface of a hollow portion or a contour surface of a bay-shaped recess.   Using the extrusion die according to any one of claims 1 to 14, the refrigerant is introduced from the outside through the refrigerant passage and discharged from the opening on the downstream end face, thereby extruding the metal, thereby causing the bearing portion to move upstream. A method for producing an extruded material, comprising molding the inner surface of the extruded material while cooling at a higher heat exchange efficiency than the side portion.

Images