JP2010099727A - Method for manufacturing hollow extruded material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a hollow extruded material while cooling an extrusion die at low cost. <P>SOLUTION: By using an extrusion die (20) having an opening part (28) in an end face on the downstream side of a mandrel (22) for forming a hollow part (2) of an extruded material (1), and provided with a refrigerant passage (26) communicating with the outside, the material is extruded while a fore end (3) of the extruded material (1) is closed, and the inside of the hollow part (2) is set in a negative pressure state. Thus, a refrigerant (C) is sucked from the opening part (28) of the refrigerant passage (26) into the hollow part (2), and the outside refrigerant (C) is sucked into the refrigerant passage (26). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a metal hollow extruded material.

  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.

  Further, in order to flow the refrigerant into the refrigerant passage in the die, it is necessary to work with a cooling device such as a compressor for compressing a fluid, a cylinder for compressed gas, and a flow rate control device for the refrigerant. Furthermore, when a refrigerant other than air, such as liquid nitrogen or argon gas, is used, it is necessary to ensure safety in handling and storage of the refrigerant. For this reason, there is a problem that it is expensive to implement the conventional cooling method.

  An object of this invention is to provide the method of manufacturing a hollow extrusion material, cooling an extrusion die at low cost in view of the technical background mentioned above.

  That is, this invention has each structure as described in following [1]-[11].

[1] Using an extrusion die having an opening on the downstream end face of the mandrel for forming the hollow portion of the extruded material, and having a refrigerant passage communicating with the outside,
By extruding the extruded material in a closed state and making the inside of the hollow portion have a negative pressure, the refrigerant is sucked into the hollow portion from the opening of the refrigerant passage and the outside refrigerant is sucked into the refrigerant passage. A method for producing a hollow extruded material.

  [2] The method for producing a hollow extruded material as recited in the aforementioned Item 1, wherein the refrigerant passage of the extrusion die is set such that the heat exchange efficiency inside the bearing portion is higher than the heat exchange efficiency in the upstream portion.

  [3] The method for producing a hollow extruded material as recited in the aforementioned Item 2, wherein the coolant passage is provided with a cooling promoting portion with increased heat exchange efficiency inside the bearing portion.

  [4] The method for producing a hollow extruded material as recited in the aforementioned Item 3, wherein the cooling promoting part is formed by expanding the surface area of the refrigerant passage.

  [5] The method for producing a hollow extruded material as recited in the aforementioned Item 4, wherein the cooling promoting part is provided with irregularities in the refrigerant passage to increase the surface area.

  [6] The method for producing a hollow extruded material as described in any one of [3] to [5], wherein the cooling promoting portion is formed by enlarging a cross-sectional area of the refrigerant passage.

  [7] The hollow extrusion according to any one of [3] to [6], 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 to the inner wall surface of the refrigerant passage. A method of manufacturing the material.

  [8] The method for producing a hollow extruded material as described in any one of [2] to [7], wherein in the refrigerant passage, a cooling suppression unit having reduced heat exchange efficiency is provided on the upstream side of the bearing unit.

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

  [10] The method for producing a hollow extruded material as recited in any one of the aforementioned Items 1 to 9, wherein a part of the opening on the downstream end face of the mandrel is closed.

  [11] The method for producing a hollow extruded material as recited in any one of the aforementioned Items 1 to 10, wherein the extruded material is sheared with a shear blade, and the end of the extruded material is simultaneously closed and cut.

  According to the invention described in [1] above, when extrusion is performed in a state in which the end of the extruded material is closed, the sealed hollow portion is in a negative pressure state and is hollow from the opening of the refrigerant passage of the extrusion die. The refrigerant is sucked into the part. With this suction, the external refrigerant is sucked into the refrigerant passage, and a refrigerant flows from the outside through the refrigerant passage of the extrusion die to the hollow portion of the extruded material. The die and the extruded material are cooled from the inside by the flow of the refrigerant. In the extrusion die, the bearing portion is cooled to prevent seizure and wear. In addition, in the extruded material, uniform and efficient cooling can be performed on the hollow material, which is difficult to cool sufficiently only by cooling from the outside. Furthermore, since the internal pressure of the hollow portion approaches the atmospheric pressure due to the suction of the refrigerant, it is possible to suppress the deformation of the extruded material due to the pressure difference between the inside and the outside.

  The suction of the refrigerant is performed by using the negative pressure of the hollow portion generated by the extrusion, so that no device for feeding the refrigerant is required. Furthermore, the flow rate control corresponding to the temperature of the bearing portion is naturally performed. That is, as the extrusion speed increases, the processing heat generation amount increases and the temperature of the bearing portion increases, but the negative pressure in the hollow portion also increases and the amount of refrigerant sucked increases, thereby increasing the cooling capacity. Conversely, the slower the extrusion speed, the smaller the heat generated by the process and the lower the negative pressure in the hollow part.Therefore, the amount of refrigerant sucked is reduced and the cooling capacity is reduced, but the temperature rise of the bearing part is also small. The cooling capacity is small. In this way, since the cooling capacity that naturally requires the flow rate control of the refrigerant is supported, efficient cooling corresponding to the temperature of the bearing portion can be performed without performing artificial flow rate control. Therefore, the extrusion die and the hollow extruded material can be cooled at a low cost.

  According to the invention described in [2] 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. 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 [3] above, it is possible to cause a difference in heat exchange efficiency with the upstream portion by the structure in which the cooling promoting portion is provided inside the bearing portion.

  According to each invention described in the above [4], [5], [6], and [7], the heat exchange efficiency in the cooling promotion portion can be efficiently increased.

  According to the invention described in [8] above, a heat exchange efficiency difference 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 [9] above, the heat exchange efficiency in the cooling suppression unit can be efficiently reduced.

  According to the invention described in [10] above, the heat exchange efficiency inside the bearing portion can be increased.

  According to the invention described in [11] above, since the clogging and cutting of the tip of the extruded material can be performed simultaneously in one step, the extruded material can be produced efficiently.

  The method for producing a hollow extruded material of the present invention will be described in detail with reference to the porthole die (10) in FIG. 1 and an extrusion apparatus equipped with the porthole die (10).

  The extruded material (1) is a cylindrical tube and has one hollow portion (2).

  The port hole die (10) is a combination of a female die (11) for molding the outer peripheral surface of the extruded material (1) and a male die (20) for molding the inner peripheral surface (2a). 20) corresponds to the extrusion die in the present invention. The port hole die (10) is loaded and held in a die ring (15). Air is used as the refrigerant (C).

  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 extruded 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 in the side surface of the die base (21) to form a communication port (27) to the refrigerant passage (16) of the die ring (15), and the leg portion (24) is formed. Passes through the center of the die, bends at the center of the die, passes through the center of the mandrel (22), and the other end opens at the front end surface of the mandrel (22) to serve as a suction port (28) for the refrigerant (C). ing. On the suction port (28) 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 refrigerant passage unit length are larger than those of the upstream portion (26a). Thus, the cooling promotion part (29) in the present invention is formed.

  When the female mold (11) 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 (11). An annular forming gap (not indicated) is formed between them, and a part of the recess (13) for the welding chamber of the female die (11) 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 that have flowed into the respective port holes (23) merge in the welding chamber and are extruded from the forming gap as the extruded material (1).

  The die ring (15) has a refrigerant passage (16) penetrating the peripheral wall, and the inner peripheral side opening is communicated with the communication port (27) of the refrigerant passage (26) of the male mold (20), A refrigerant inlet pipe (17) with an open end is attached to the outer peripheral opening. With these configurations, the external atmosphere passes through the refrigerant inlet pipe (17), the refrigerant passage (16) of the die ring (15), and the refrigerant passage (26) of the male mold (20). To the hollow part (2).

  The process for producing the extruded material (1) using the porthole die (10) using external air (C) as the refrigerant is as follows.

  That is, when extrusion is performed with the end (3) of the extruded material (1) closed, the inside of the sealed hollow portion (2) becomes a negative pressure state with respect to the atmosphere, and the inside of the refrigerant passage (26) Air (C) is drawn into the hollow portion (2) from the suction port (28). With the suction of the air (C), the surrounding air (C) is sucked into the refrigerant suction pipe (17) from the tip of the refrigerant suction pipe (17), and the refrigerant passage (16) of the die ring (15), male It flows through the coolant passage (26) of the mold (20) and flows into the hollow portion (2) of the extruded material (1). In this flow of air (C), the air (C) drawn into the male mold (20) from the outside proceeds in the refrigerant passage (26) while cooling the die, and the mandrel (22) is cooled by the cooling promotion section (29). ) Is cooled, and after being sucked into the hollow portion (2) of the extruded material (1) from the suction port (28), the extruded material (1) is cooled from the inside. Even if the extrusion is stopped, the air (C) in the hollow portion (2) contracts due to cooling from the outer peripheral portion of the extruded material (1), so the air (C) in the refrigerant passage (26) continues. Suction is stopped when the hollow member (2) is sucked, the extruded material (1) is cut and opened, and the internal pressure of the hollow member (2) becomes atmospheric pressure. Then, if necessary, the new tip (3) of the extruded material (1) is closed and the above-described extrusion is repeated.

  In the refrigerant passage (26) of the male mold (20), the cooling promoting portion (29) has a cross-sectional area and surface area per refrigerant passage unit length that is larger than that of the upstream portion (26a). Heat exchange efficiency is enhanced. 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. Further, since the bearing portion (25) is selectively cooled and seizure is prevented, the extruded material (1) having a good surface quality can be manufactured.

  The extruded material (1) is cooled from the inside by the refrigerant (C) sucked into the hollow portion (2). Since the cooling is performed from the inside, it is possible to perform uniform and efficient cooling on the hollow material, which is difficult to cool sufficiently only by cooling from the outside. Especially for large extruded materials with insufficient internal cooling, thick extruded materials, extruded materials with inner walls, and extruded materials with asymmetric cross-sections that are prone to non-uniform internal cooling. Can do. For extruded materials having a plurality of hollow portions, by providing a suction port for the refrigerant passage in each mandrel or any mandrel, the inside of the hollow portion formed by the bearing portion and the bearing portion of the mandrel is cooled. be able to.

  In extrusion, as the extrusion speed increases, the processing heat generation amount increases and the temperature of the bearing portion (25) rises. Therefore, it is necessary to increase the cooling capacity by the refrigerant (C). According to the method of the present invention, as the extrusion speed increases, the negative pressure in the hollow portion (2) increases and the difference from the atmospheric pressure increases, so the suction amount of the refrigerant (C) increases and the cooling capacity increases. Go up. Conversely, the slower the extrusion speed, the smaller the heat generated by the process and the lower the negative pressure in the hollow part (2), so the suction amount of the refrigerant (C) decreases and the cooling capacity decreases, but the bearing part ( Since the temperature rise in 25) is small, the required cooling capacity is also small. In this way, since it corresponds to the cooling capacity that requires the flow rate control of the refrigerant (C) naturally performed, the efficiency corresponding to the temperature of the bearing portion (25) can be achieved without performing artificial flow rate control. Good cooling is done.

  Further, when the refrigerant (C) is sucked into the hollow portion (2), the internal pressure rises and approaches atmospheric pressure, so that the deformation of the extruded material (1) due to the pressure difference between the inside and outside is suppressed. In particular, since a thin extruded material is easily deformed by a pressure difference, it is preferable to apply the method of the present invention.

  The suction of the refrigerant (C) is performed using the negative pressure of the hollow portion (2) generated by extrusion. For this reason, a fluid compression apparatus such as a compressor for feeding the refrigerant into the male refrigerant passage is not required. Further, as described above, since the flow rate is controlled by the extrusion speed, no special flow rate control is required. For this reason, the male mold (20) and the extruded material (1) can be cooled at low cost. However, the present invention does not exclude a device or refrigerant control for performing more precise cooling control.

  The refrigerant (C) drawn into the hollow portion (2) is not limited to the air described above. Either a gas or a liquid may be used, but a non-oxidizing refrigerant can be recommended. The non-oxidizing refrigerant is used in order not to oxidize the inner peripheral surface (2a) of the extruded material (1). 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 hollow portion (2), and a cooling effect is also obtained by the heat of vaporization. The refrigerant may be a mixture of the liquid refrigerant and the gas refrigerant mentioned above. In the case of a mixture of the liquid refrigerant and the gas refrigerant, the adjustment of the cooling effect is easy. Further, among the mixture of the liquid refrigerant and the gas refrigerant, a mixture in which the particles of the liquid refrigerant are levitated in the gas refrigerant, that is, a so-called mist may be used. When the mist is used as the refrigerant, an effect of stabilizing the adjusted cooling effect can be obtained. These refrigerants (C) can be sucked during extrusion if the refrigerant container and the refrigerant passage (26) of the male mold (20) are in communication. In the example of FIG. 1, the die ring (15) is provided with a refrigerant passage (16) communicating with the outside and the refrigerant passage (26) of the male mold (20), and a refrigerant intake pipe is provided in the refrigerant passage (16). Since (17) is attached, the refrigerant inlet pipe (17) may be communicated with the refrigerant container.

  When air at room temperature is used as the refrigerant (C), the die and the extruded material can be cooled without any special supply means, and even the refrigerant container is not required, so that the extrusion apparatus can be simplified. In addition, external air can be drawn directly from the opening of the refrigerant passage (16) of the die ring (15), but since the ambient temperature is high in the vicinity of the die ring (15), As described above, the refrigerant intake pipe (17) may be attached to draw in cooler air from a remote location. However, it is necessary to appropriately set the length and the inner diameter of the refrigerant drawing pipe (17) so that the pressure loss caused by the refrigerant drawing pipe (17) can be minimized and the refrigerant can be sucked efficiently. Further, by blowing the liquid refrigerant into the refrigerant drawing pipe (17) in the form of a mist, it is possible to form a mist refrigerant and draw the mist refrigerant.

  In the extrusion die, the cooling promoting part with improved heat exchange efficiency can be realized by another structure. 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 FIG. 2A and FIG. 2B has a larger diameter of the refrigerant passage (26) than the upstream part (26a), and a large number of them 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. 3A and 3B also have an enlarged surface area of the refrigerant passage (26). The cooling promotion part (32) of FIG. 3A 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. 3B 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. 4 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. 5 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).

  Furthermore, since the temperature of the bearing portion only needs to be lower than that of the upstream portion, the above object can be achieved by providing a difference in the heat exchange efficiency between the inside and the upstream portion of the bearing portion. 6A and 6B 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. 6A, or the passage diameter of the attachment portion is enlarged as shown in FIG. 6B 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. 7A and 7B show a pin (50) driven from the outlet side into the center of the finned cooling promotion part (30) of FIGS. 2A and 2B. 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 section (30), and the refrigerant (C) passes through the cylindrical space (see FIG. 2A). ) 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.

  If the refrigerant passage of the extrusion die communicates with the downstream end face of the mandrel and the outside, the refrigerant suction can be performed using the negative pressure in the hollow portion of the extruded material. A case where there is no difference in heat exchange efficiency between the side portions is also included in the present invention. In the above embodiment, the die ring (15) is exemplified as a member for holding the port hole die (10). However, as long as the die coolant passage communicates with the outside, the die holding member is not limited. Not.

  As shown in FIG. 1, 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 bends in an L shape to form both openings. Communicates. Such a passage does not need to be cut into an L-shape, and the first passage toward the center of the mandrel (2) from the communication port (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 extruding direction and communicates with the suction port (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 a method for closing the tip of the extruded material, shearing with a shear blade can be recommended. As shown in FIG. 8A and FIG. 8B, when the extruded material (1) is sheared with the shear blade (60), the extruded material (1) is cut in a crushed state, so that the extruded material (1) is blocked. The shearing by the shear blade (60) can be performed either during the start of pressing or during extrusion. Since the extruded material (1) is crushed and cut, when shearing with a shear blade (60) when pushing a long extruded material, cutting and closing of the new tip (3) can be performed simultaneously. it can. According to this method, since the end (3) of the extruded material (1) can be simultaneously closed and cut in one step, the extruded material (1) can be produced efficiently.

  In the present invention, the method for closing the extruded material is not limited at all. Examples of other closing methods include the methods shown in FIGS. FIG. 9 shows a method of compressing with a press, in which the extruded material (1) is cut with a shear blade or a saw blade, and then the tip (3) is crushed with a press die (61) and closed. FIG. 10 shows a method of attaching the plug (62) to the opening of the tip (3) of the extruded material (1). When cut with a saw blade or the like, the cut is opened, but can be closed by attaching, for example, a tapered plug (62). FIG. 11 shows a method of bending the tip (3) of the extruded material (1). If it is bent with a press die (61) as in the illustrated example, the tip (3) is bent and closed in a crushed state.

  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.

  The present invention sucks the refrigerant into the die by using the negative pressure state of the hollow portion generated by extrusion, and can be applied to the production of various hollow extruded materials.

It is sectional drawing which shows the extrusion apparatus which enforces the manufacturing method of the hollow extrusion material of this invention. It is sectional drawing which shows the principal part of other embodiment of the extrusion die used for the manufacturing method of the hollow extrusion material of this invention. It is the side view which looked at the extrusion die of Drawing 2A from the downstream. It is a side view which shows the modification of the extrusion die of FIG. 2A. It is a side view which shows the other modification of the extrusion die of FIG. 2A. It is sectional drawing which shows the principal part of other embodiment of the extrusion die used for the manufacturing method of the hollow extrusion material of this invention. It is sectional drawing which shows the principal part of other embodiment used for the manufacturing method of the hollow extrusion material of this invention. It is sectional drawing which shows the principal part of other embodiment used for the manufacturing method of the hollow extrusion material of this invention. It is sectional drawing which shows the modification of the extrusion die of FIG. 6A. It is sectional drawing which shows other embodiment of the extrusion die used for the manufacturing method of the hollow extrusion material of this invention. It is the side view which looked at the extrusion die of Drawing 7A from the lower stream side. It is a perspective view which shows the state which crushed the extrusion material in the shearing of the extrusion material by a shear blade. It is a perspective view which shows the state which cut | disconnected the extrusion material in the shearing of the extrusion material by a shear blade. It is a perspective view which shows the obstruction | occlusion method of the extrusion material by a press. It is a perspective view which shows the closing method of the extrusion material by mounting | wearing with a stopper. It is a perspective view which shows the obstruction | occlusion method by bending of an extrusion material.

Explanation of symbols

1 ... Extruded material (hollow extruded material)
2 ... Hollow part
2a… Inner peripheral surface (inner surface)
10 ... Porthole Dice
15 ... Die ring
20 ... Male mold (extrusion die)
21 ... Dice base
25… Bearing part
26 ... Refrigerant passage
26a… Upstream part
27 ... Communication entrance
28… Suction port (opening)
29,30,32,34,36,38… Cooling promotion part
39… Cooling promotion member
40 ... Cooling suppression member (cooling suppression part)
60 ... Shear blade C ... Air (refrigerant)

Claims (11)

Using an extrusion die having an opening on the downstream end face of the mandrel for forming the hollow portion of the extruded material, and having a refrigerant passage leading to the outside,
By extruding the extruded material in a closed state and making the inside of the hollow portion have a negative pressure, the refrigerant is sucked into the hollow portion from the opening of the refrigerant passage and the outside refrigerant is sucked into the refrigerant passage. A method for producing a hollow extruded material.   2. The method for producing a hollow extruded material according to claim 1, wherein the refrigerant passage of the extrusion die is set such that a heat exchange efficiency inside the bearing portion is higher than a heat exchange efficiency in an upstream portion thereof.   The manufacturing method of the hollow extrusion material of Claim 2 with which the cooling promotion part which improved the heat exchange efficiency was provided inside the bearing part in the said channel | path for refrigerant | coolants.   The said cooling promotion part is a manufacturing method of the hollow extrusion material of Claim 3 formed by expanding the surface area of the channel | path for refrigerant | coolants.   The method for producing a hollow extruded material according to claim 4, wherein the cooling promotion part has a surface area enlarged by providing irregularities in the refrigerant passage.   The said cooling promotion part is a manufacturing method of the hollow extrusion material in any one of Claims 3-5 formed by expanding the cross-sectional area of the channel | path for refrigerant | coolants.   The hollow extrusion material according to any one of claims 3 to 6, 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 to the inner wall surface of the refrigerant passage. Production method.   The manufacturing method of the hollow extrusion material in any one of Claims 2-7 in which the cooling suppression part which reduced the heat exchange efficiency was provided in the upstream for a bearing part in the said channel | path for refrigerant | coolants.   The said cooling suppression part is a manufacturing method of the hollow extrusion material of Claim 8 currently formed by attaching the cooling suppression member which consists of material with a heat conductivity worse than a die raw material to the channel | path inner wall surface for refrigerant | coolants.   The manufacturing method of the hollow extrusion material in any one of Claims 1-9 by which a part of opening part of the downstream end surface of the said mandrel is obstruct | occluded.   The method for producing a hollow extruded material according to any one of claims 1 to 10, wherein the extruded material is sheared by a shear blade, and the end of the extruded material is closed and cut simultaneously.

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