JP5180756B2 - Method for producing hollow extruded material - Google Patents

Description

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

  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.

  Generally, the extruded material in the extrusion process is cooled by disposing a cooling device on the downstream side of the extrusion die and cooling from the outside by air cooling, water cooling, or mist. In general, heat-treatable aluminum alloy extruded materials such as Al-Cu-Mg-based 2000 series alloys, Al-Mg-Si-based 6000 series alloys, and Al-Zn-Mg-based 7000 series alloys are subjected to solution treatment after extrusion. An aging treatment is performed after quenching, and a method of quenching simultaneously with extrusion by performing die quenching for cooling the product immediately after extrusion is also known (see Patent Documents 1 and 2).

Also, for cooling the hollow extruded material, a male outlet of the port hole die is provided with a refrigerant discharge port on the end surface of the mandrel, and a refrigerant passage that opens to the side surface of the die via the bridge portion communicates with the discharge port. And the method of cooling from the inner side of an extrusion material is also proposed by discharging the refrigerant | coolant introduced into this channel | path for refrigerant | coolants from the said discharge port in a hollow part (refer patent document 3).
JP-A-7-132318 JP 2002-275603 A JP-A-8-206729

  However, cooling from the outside as in Patent Documents 1 and 2 slows down the inside of the extruded material, resulting in uneven cooling in the cross section, and consequently, the internal quality of the extruded material becomes non-uniform.

  The hollow extruded material can be cooled from the inside, and cooling can be promoted by cooling from both the outside and inside of the hollow extruded material. However, the cooling method described in Patent Document 3 has a problem that the cooling efficiency is poor because the temperature rises while the refrigerant passes through the hot die.

  An object of this invention is to provide the manufacturing method of the hollow extrusion material which can cool a hollow extrusion material from the inside efficiently, and its related technique in view of the technical background mentioned above.

  That is, this invention has each structure as described in the following [1]-[13].

  [1] Using an extrusion die having a refrigerant passage having a suction port opened on the downstream end face of the mandrel for forming the hollow portion of the extruded material, while extruding the metal, the refrigerant in the hollow portion of the extruded material is A method for producing a hollow extruded material, comprising sucking from a suction port of a mandrel to draw an external refrigerant from the opening of the extruded material into the hollow portion and circulate through the hollow portion.

  [2] The method for producing a hollow extruded material as recited in the aforementioned Item 1, wherein a new refrigerant drawing opening is formed in the extruded material while extruding the extruded material.

  [3] The plurality of hollow portions of the extruded material according to the above item 1 or 2, wherein a refrigerant passage is provided in a mandrel for forming these hollow portions, and a refrigerant suction amount in each hollow portion is independently controlled. A method for producing a hollow extruded material.

  [4] The method for producing a hollow extruded material according to any one of the above items 1 to 3, wherein a thickness of an outer wall of the extruded material is 0.5% or less of a diameter of a circumscribed circle in a cross section of the extruded material.

  [5] The extrusion material according to any one of the above items 1 to 4, wherein the extruded material has a hollow portion that does not face the outer wall, and the refrigerant passage is provided in a mandrel that forms the hollow portion so that the refrigerant flows through the hollow portion. A method for producing a hollow extruded material.

  [6] The extrusion material according to any one of the preceding items 1 to 5, wherein the extruded material has an inner wall that is thicker than an outer wall, and the refrigerant passage is provided in a mandrel for forming a hollow portion facing the inner wall to allow the refrigerant to flow through the hollow portion. The manufacturing method of the hollow extruded material in any one.

  [7] The method for producing a hollow extruded material as recited in any one of the aforementioned Items 1 to 6, wherein the extruded material has a unit weight of 2 kg / m or more.

  [8] The method for producing a hollow extruded material according to any one of items 1 to 7, wherein a diameter of a circumscribed circle in a cross section of the extruded material is 100 mm or more.

  [9] The method for producing a hollow extruded material according to any one of items 1 to 8, wherein the extruded material has an asymmetric cross-sectional shape.

  [10] The method for producing a hollow extruded material according to any one of items 1 to 9, wherein the extruded material is cooled from the outside.

[11] An extrusion die including a refrigerant passage having a suction port opened on a downstream end face of a mandrel for forming a hollow portion of the extruded material;
An extrusion apparatus comprising: suction means for sucking the refrigerant from the suction port via the refrigerant passage.

  [12] The extrusion apparatus according to [11], further including a refrigerant supply unit disposed on the downstream side of the extrusion die.

  [13] A refrigerant passage having a suction port opened at a downstream end face of a mandrel for forming a hollow portion of the extruded material, and a connection portion with a suction means is formed at the other end of the refrigerant passage. A featured extrusion die.

  According to the method for producing a hollow extruded material according to the invention described in [1], an external refrigerant can be directly drawn into the hollow portion of the extruded material and can be circulated in the hollow portion. Can be cooled. Since the cooling from the inside of the extruded material is uniform in the cross section, the internal quality of the extruded material is made uniform. Moreover, since quenching is possible because of high cooling efficiency, a quenching effect can also be obtained. Furthermore, the cooling of the dice is also performed by the refrigerant sucked from the suction port of the mandrel flowing through the refrigerant passage.

  According to the invention described in [2] above, high cooling efficiency can be maintained for a long time.

  According to the invention described in [3] above, precise cooling control corresponding to the shape of the extruded material is possible, and further uniform cooling is possible.

  According to the invention described in [4] above, deformation can be prevented in the production of an extruded material having a thin outer wall.

  According to the inventions described in [5], [6], [7], [8], and [9], the extruded material having a shape that is difficult to cool efficiently and uniformly by cooling from the outside is cooled from the inside. To efficiently and uniformly perform cooling.

  According to the invention described in [10] above, the cooling efficiency is improved by the cooling from both the inside and the outside of the extruded material, and the quenching effect can be enhanced. Moreover, the bending rate and the deformation | transformation of an extrusion material by cooling can be suppressed by making the cooling rate difference inside and outside an extrusion material small.

  According to the extrusion apparatus concerning each invention as described in said [11] [12], the manufacturing method of the extrusion material of this invention can be implemented, and an extrusion material can be cooled efficiently from an inner side.

  The extrusion die according to the invention described in [13] can efficiently cool the extruded material from the inside by being incorporated in the extrusion apparatus.

  The extruded material produced by the method of the present invention has at least one hollow part. For example, the extruded material (1) shown in FIG. 1 is a cylindrical tube having the same thickness in the circumferential direction, and has one hollow portion (2). Further, the extruded materials (70), (80), (90), and (100) shown in FIGS. 3 and 5 to 7 have a plurality of hollow portions.

  Hereinafter, the present invention will be described in detail with reference to FIG. 2 exemplifying a port hole die for extruding the hollow material (1) and an extrusion apparatus equipped with the port hole die.

  The port hole die (10) shown in FIG. 2 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). 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 mandrels (22) for forming the hollow portion (2) projecting from the center to the downstream side of the die base (21) and penetrating around the mandrel (22) in the extrusion direction. Has a porthole (23). 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 to the side surface of the die base (21) to form a connection portion (27) to the suction means (60), and reaches the axis of the die through the leg portion (24). Then, it is bent at the axis and passes 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 a suction port (28) for the refrigerant (C). The connecting portion (27) is threaded and attached with a joint (61) for communicating with the suction device (60). In the refrigerant passage (26), the suction port (28) has an enlarged passage diameter and a larger cross-sectional area and surface area than the upstream side portion (26a), thereby facilitating the suction of the refrigerant (C) and the bearing portion. A cooling promoting part (29) for efficiently cooling (25) is formed. The cooling promotion part (29) is located inside the bearing part (25).

  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 flowing into the respective port holes (23) merge in the welding chamber and are extruded as hollow materials (1) from the molding gap.

  The suction device (60) includes a discharge pipe (62) communicating with the connection portion (27) and suction means such as a pump, and the refrigerant (C) sucked through the refrigerant passage (26) is removed from the die. It is supposed to be discharged.

  In the process of extruding metal using the port hole die (10), the tip of the extruded material (1) is opened, and external air as the refrigerant (C) is freely allowed to enter the hollow part (2) from the tip opening. It is supposed to flow in. When the suction device (60) is operated in this state and the fluid in the refrigerant passage (26) is discharged from the connecting portion (27), the refrigerant (C) in the hollow portion (2) is sucked into the end surface of the mandrel (22). The refrigerant is sucked from the opening (28) into the refrigerant passage (26), and the external refrigerant (C) is drawn into the hollow portion (2) from the front end opening of the extruded material (1). The drawn refrigerant (C) passes through the hollow portion (2) and is sucked into the suction port (28), and the tip opening of the extruded material (1), the hollow portion (2), and the suction port of the male mold (20) ( 28), the refrigerant passage (26), the connecting portion (27), and the discharge pipe (62) are sequentially passed through the refrigerant (C) in the direction opposite to the traveling direction of the extruded material (1). And while a refrigerant | coolant (C) distribute | circulates the inside of a hollow part (2), an extrusion material (1) is cooled from an inner side.

  In the illustrated example, the end of the extruded material (1) is opened, and the external refrigerant (C) is drawn from the opening. However, when the front end of the extruded material (1) is closed for chucking or the like. If an opening for drawing the refrigerant is provided near the tip, the refrigerant (C) can be drawn into the hollow part (2) from this opening.

  The cooling structure of the present invention, that is, the cooling structure in which the refrigerant (C) is drawn from the opening of the extruded material (1) and flows through the hollow portion (2) in the direction opposite to the progress of the extruded material (1), The cooling efficiency is superior to the conventional cooling structure (Patent Document 3) in which the water is discharged from the tip of the mandrel and flows in the same direction as the progress of the extruded material. This is because, in the conventional cooling structure, the refrigerant whose temperature is increased by heat exchange with the die is discharged into the hollow portion, whereas in the cooling structure of the present invention, the external refrigerant (C) is directly drawn into the hollow portion (2). This is because the lower temperature refrigerant (C) can be brought into contact with the extruded material (1). In addition, since the refrigerant (C) is used for cooling the extruded material (1) at the same temperature, it is possible to perform highly accurate cooling control by drawing the temperature-controlled refrigerant (C). In the conventional cooling structure, if the temperature of the refrigerant discharged into the hollow portion (2) is to be controlled, the temperature of the refrigerant supplied to the die is controlled in anticipation of the rise in the die. Highly accurate cooling control is difficult because it is affected by the inside die temperature and die structure. Thus, by adopting the cooling structure of the present invention and efficiently cooling the extruded material (1), uniform cooling is performed in the cross section, so that the internal quality of the extruded material (1) is made uniform.

  In the cooling structure of the present invention, the cooling efficiency is good and the extruded material (1) can be rapidly cooled, so that a quenching effect can be achieved. Moreover, quenching can be controlled by controlling the temperature and flow rate of the refrigerant (C) drawn into the hollow portion (2).

  The refrigerant (C) drawn into the hollow portion (2) may be either a gas or a liquid, 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 gaseous 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.

  If these refrigerants are actively supplied by providing a supply means on the front end side of the extruded material (1), the cooling effect can be enhanced. Specifically, the refrigerant supply nozzle is disposed toward the hollow portion (2), and the refrigerant discharged into the hollow portion (2) is sucked from the suction port (28). If the nozzle is moved with the progress of the hollow material (1), the refrigerant can be supplied while being pushed out.

  In addition, when room temperature air is used as the refrigerant, the refrigerant (air) can be drawn in without any special supply means if external air is drawn into the hollow part (2) by suction from the die side. Since the refrigerant storage tank is not required, the extrusion apparatus can be simplified.

  In either case, according to the desired cooling temperature of the extruded material, the amount of refrigerant sucked is adjusted to appropriately adjust the flow rate in the hollow portion. In a male mold having a plurality of mandrels for forming a plurality of hollow portions, if a separate refrigerant passage is provided for each mandrel, the suction amount can be individually adjusted, and the flow rate of the refrigerant is controlled for each hollow portion. Therefore, independent cooling control is possible for each hollow portion, and precise cooling control corresponding to the shape of the extruded material is possible. Also in the refrigerant supply means, the cooling temperature can be adjusted by adjusting the temperature and flow rate of the refrigerant, so that both the suction side and the supply side can be adjusted in combination. In addition, even when the refrigerant passages of a plurality of mandrels are collectively sucked on the discharge side, independent cooling control can be performed for each hollow part by changing the type and temperature of the refrigerant to be drawn for each hollow part. Is possible.

  As shown in FIGS. 3 and 5 to 7, in the production of the extruded material 70, 80, 90, and 100 having a plurality of hollow portions, at least one hollow portion is formed from the inside by the cooling structure described above. If it is cooled, it is included in the present invention, and the number of hollow portions that employ the cooling structure of the present invention can be arbitrarily set.

  The present invention regulates cooling from the inside of the extruded material, but does not exclude cooling from the outside. In order to increase the cooling efficiency, it is preferable to cool from the outside of the extruded material. The quenching effect can be enhanced by increasing the cooling rate. In addition, the cooling rate difference between the inside and outside is reduced by cooling from both the inside and outside of the extruded material, and bending and deformation of the extruded material due to cooling can be suppressed. Furthermore, more complex and precise cooling control can be performed by combining the inner and outer cooling conditions. The cooling method from the outside is not limited at all, and may be appropriately performed by a known method such as air cooling, water cooling, or mist cooling.

  Further, when the extruded material becomes longer, the suction efficiency from the die is reduced due to the pressure loss in the hollow portion, and the cooling efficiency may be reduced near the die due to the temperature rise of the refrigerant. In such a case, an opening for drawing the refrigerant is newly formed in the extruded material while extruding, and if the refrigerant is drawn from the opening, the suction efficiency is recovered and the low-temperature refrigerant is supplied to the vicinity of the die. be able to. By forming a new opening while extruding, high cooling efficiency can be maintained for a long time. The new opening can be formed by cutting and extruding the extruded material or by drilling a hole in the extruded material. For example, FIGS. 14A and 14B show a method of making a slit hole (111) in the upper part of the extruded material (1) with a rotating saw blade (110). A slit-like hole (111) having a desired length can be formed by lowering or further sliding the saw blade (110). 15A and 15B show a method of making a spot-like hole (113) by inserting a needle or drill (112) into the extruded material (1). In addition, when the refrigerant supply nozzle is used, the refrigerant supply nozzle may be moved to a new opening. If a cutting (cutting) position or a drilling position is set in accordance with the original cutting planned position of the extruded material, no waste end material is generated.

  As described above, since the present invention cools the extruded material from the inside, when applied to an extruded material having a shape in which the internal cooling is insufficient or the internal cooling is likely to be uneven when cooling from the outside. A remarkable effect can be obtained. For example, a remarkable effect can be obtained by applying to a large-sized extruded material, an extruded material having an inner wall or a thick wall defining the inside, or an extruded material having an asymmetric cross-sectional shape. Below, the extrusion material of various cross-sectional shapes and cooling of these extrusion materials are demonstrated. In addition, what attached | subjected the code | symbol same as FIG. 2 in the extrusion apparatus of FIG.

  In the extruded material (70) of FIG. 3, four hollow portions (73) are formed by a cross-shaped inner wall (72) that is thicker than the outer wall (71). FIG. 4 shows an extrusion apparatus provided with a port hole die (75) for extruding the extruded material (70). The male mold (76) has four mandrels (77) for forming the hollow portions (73). (Only two are shown), and the refrigerant passage (26) having the connecting portion (27) on the side surface of the die base (21) branches to each mandrel (77) and opens to the front end surface of each die. (28). When the suction device (60) is operated and the refrigerant (C) is sucked from the suction port (28), the refrigerant (C) is drawn into the four hollow portions (73) from the front end opening of the extruded material (70). Then, it is discharged from the discharge pipe (62) through the four hollow portions (73) and the refrigerant passage (26).

  When the extruded material (70) is cooled only from the outside, the inner wall (72) is cooled only by heat removal from the outer wall (71), and the cooling is slow because it is thick. However, the cooling structure of the present invention is adopted for the hollow part (73), and the inner wall (by cooling the refrigerant (C) through the hollow part (73) facing the thick inner wall (72) from the inner side ( 72) can be cooled efficiently.

  Note that the refrigerant passage (26) in FIG. 4 is branched into four mandrels (77) and suctioned from one connecting portion (27), and the refrigerant (C However, if each mandrel (77) has a separate refrigerant passage and is provided with a separate connection (opening on the discharge side) for suction, the refrigerant flow in each hollow portion (73) can be made independent. Can be controlled. Independent cooling control can also be performed by changing the refrigerant conditions to be drawn into the hollow portions (73).

  5 has four polygonal hollow portions (82) (82) (82) (82) facing the outer wall (81) and these polygonal hollow portions (82) (82) (82). ) (82) has one circular hollow portion (83) that does not face the outer wall (81). The circular hollow portion (83) is surrounded by the circular inner wall (84), and the partition wall (85) between the adjacent polygon hollow portions (82), (82) is thicker than the outer wall (81). When the extruded material (80) having such a shape is cooled only from the outside, the partition wall (85) is cooled only by heat removal through the outer wall (81), and the circular inner wall (84) has the outer wall (81) and the partition wall (85). These coolings are slow because they are cooled only by heat removal through the. In particular, since the circular inner wall (83) is cooled via the outer wall (81) and the partition wall (85), the cooling rate is slow, and the cooling rate is uneven in the cross section. If the circular inner wall (84) is directly cooled from the inside by adopting the cooling structure of the present invention in the circular hollow portion (83), the cooling rate of the circular inner wall (84) is increased and the cooling rate in the cross section becomes uniform. . Further, since the four polygonal hollow parts (82) facing the outer wall (81) also face the circular inner wall (84) and the partition wall (85), the cooling of the present invention is also applied to these polygonal hollow parts (82). If the structure is adopted to cool from the inside, cooling of the circular inner wall (84), the partition wall (85) and the outer wall (81) can be promoted.

  The extruded material (90) in FIG. 6 is an irregular cross-sectional material having an asymmetric cross-sectional shape. The thickness of 97) (98) (99) is also different. It is difficult to uniformly cool the extruded material (90) having such a cross-sectional shape by cooling from the outside. Cooling is promoted by employing the cooling structure of the present invention in at least one of the hollow portions (91), (92), (93), and (94). Further, the cooling structure of the present invention is adopted in each hollow part (91) (92) (93) (94), and the cooling rate of each hollow part (91) (92) (93) (94) is independently adjusted. As a result, the cooling rate can be further increased and the cooling rate in the cross section can be made uniform. In particular, since the extruded material (90) having an asymmetric cross-sectional shape is difficult to cool uniformly from the outside, the hollow structure (91) (92) (93) (94) employs the cooling structure of the present invention, or Furthermore, the significance of performing the cooling control independently is great.

  In addition, the following extruded materials have great significance in applying the cooling structure of the present invention.

  First, since a large amount of extruded material and a large-sized extruded material are slow to cool, the cooling promotion effect by cooling from the inside is large.

  The single amount is preferably applied to an extruded material of 2 kg / m or more, and particularly preferably applied to an extruded material of 5 kg / m or more.

  As dimensions, it is preferable to apply to a large extruded material having a circumscribed circle in a cross section of 100 mm or more, and particularly to an extruded material having a circumscribed circle of 300 mm or more.

  On the other hand, the significance of application of the present invention is also great for an extruded material (100) having a thin outer wall (101) as shown in FIG. The thin outer wall (101) may be deformed when the temperature difference between the outer peripheral surface and the inner peripheral surface increases due to cooling from the outside. In such a case, the deformation can be prevented by cooling from the inside of the extruded material (100) to reduce the temperature difference between the outer peripheral surface and the inner peripheral surface. Specifically, in the thin extruded material (100) in which the wall thickness (t) of the outer wall (101) is 0.5% or less, particularly 0.2% or less of the diameter (D) of the circumscribed circle of the cross section. The application significance of the present invention is great.

  Moreover, the material of the hollow extrusion material manufactured by this invention is not limited at all as long as it is a metal, Aluminum, copper, iron, and these alloys can be illustrated.

  By the way, as shown in FIG. 2, the refrigerant (C) still has the cooling ability when it reaches the suction port (28) at the tip of the mandrel (22), and the refrigerant passage (26) There is an effect of cooling the dice by exchanging heat with the male mold (20) during distribution.

  Since the temperature of the refrigerant (C) flowing through the refrigerant passage (26) is increased by heat exchange, the refrigerant temperature is lowest at the suction port (28) close to the bearing portion (25), and at the connection portion (27). The highest. As the refrigerant (C) is closer to the suction port (28), the temperature difference from the die is larger and the heat exchange efficiency is higher, and as the refrigerant is closer to the connection part (27), the temperature difference from the die is smaller and the heat exchange efficiency is lowered. I will do it. Such a decrease in the heat exchange efficiency of the refrigerant (C) favors the cooling of the male mold (20).

  That is, in order to suppress seizure and wear in the bearing part (25) of the mandrel (22), it is desirable to lower the die temperature that has been raised by the processing heat, but in the die base (21) and leg part (24), it is desirable to reduce the die temperature. If the temperature is too low, the material temperature will drop and cause extrusion failure. For this reason, it is preferable that the die base (21) and the leg (24) are not excessively cooled while the bearing (25) is cooled. When the refrigerant (C) is circulated from the suction port (28) of the mandrel (22) to the connection portion (27) of the die base (21), the bearing portion (25) close to the suction port (28) is well cooled. On the other hand, the root of the mandrel (22), the die base (21), and the leg (24) are not cooled as much as the bearing (25).

  Further, since the refrigerant (C) flows from the hollow portion (2) of the extruded material (1) into the suction port (28) having a smaller cross-sectional area than the hollow portion (2), the flow velocity is increased. ) Cooling is promoted. As the cross-sectional area advances from the cooling promoting portion (29) to the upstream portion (26a), the cross-sectional area further decreases and the refrigerant (C) is accelerated, but the surface area decreases and the refrigerant (C) temperature increases. As a result, the base of the mandrel (22) and the die base (21) are not cooled as much as the bearing part (25), and the die base (21) is excessively cooled, resulting in poor extrusion. Can be avoided.

  Further, since the temperature difference between the refrigerant (C) and the die is the smallest before the connecting portion (27), the leg portion (24) provided with the refrigerant passage (26) and the leg portion not provided ( The temperature difference from 24) is also small. In the conventional die, the temperature of the refrigerant is the lowest at the leg close to the inlet and the temperature difference from the die is the largest, so the temperature difference of the leg due to the presence or absence of the refrigerant passage is larger than in the present invention. The temperature difference between the plurality of legs causes uneven thickness due to imbalance in die strength (high temperature deformation resistance value) affected by temperature and material temperature imbalance. Accordingly, since the die used in the present invention has a small temperature difference between the plurality of legs (24), the die strength and the material temperature imbalance are also reduced.

  In view of the above, the cooling structure of the present invention is useful not only for cooling the extruded material (1) but also for cooling the extrusion die.

  Furthermore, the cooling promotion part (29) in the mandrel (22) described above has a higher heat exchange efficiency because its cross-sectional area and surface area are larger than those of the upstream part (26a). When the refrigerant (C) is introduced into the refrigerant passage (26) having such a structure, the bearing portion (25) is efficiently cooled, while cooling the root of the mandrel (22) and the die base (21) are suppressed.

  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. In the following drawings, the same reference numerals as those in FIG.

  The cooling promotion part (30) shown in FIG. 8A and FIG. 8B expands the diameter of the refrigerant passage (26) more than the upstream part (26a), and increases the number 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. Is 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. 9A and 9B also have an enlarged surface area of the refrigerant passage (26). The cooling promotion part (32) in FIG. 9A 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. 9B 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 portion (36) in FIG. 10 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. 11 expands the diameter of the refrigerant passage (26) in the same manner as in FIG. 2, 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).

  The purpose of providing a difference in the heat exchange efficiency is to lower the temperature of the bearing part than the upstream part, so the purpose is to provide a difference in the heat exchange efficiency between the inside and the upstream part of the bearing part. Achieved. 12A and 12B, 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. 12A, or the passage diameter of the attachment portion is enlarged as shown in FIG. 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 part, there is a method of closing a part of the inlet of the refrigerant passage. 13A and 13B show a pin (50) driven from the suction port (28) side into the center of the finned cooling promotion portion (30) of FIGS. 8A and 8B. The leg (51) of the pin (50) is inserted into a cylindrical space formed at the tip of each fin (31) to close the cylindrical space, and the large-diameter head (52) is a suction port (28 ) Is partly blocked. If the difference between the hollow area (2) of the extruded material (1) and the opening area of the suction port (28) is increased by blocking a part of the suction port (28), the flow rate of the refrigerant (C) increases and cooling is accelerated. The heat exchange efficiency in the part can be increased. And since the heat exchange efficiency improvement effect by expansion of the cross-sectional area and surface area of a cooling promotion part (30) is not impaired, both heat exchange efficiency improvement effects can be enjoyed. Further, when the refrigerant (C) is introduced from the periphery by closing the central portion of the suction port (28), the refrigerant (C) is evenly distributed to the roots of the fins (31), so that heat exchange is performed efficiently. In this manner, the flow of the refrigerant (C) is forcibly changed by closing a part of the suction port (28) of the cooling promotion part (30), and the refrigerant (C) passes through the cylindrical space (FIG. 8A). The heat exchange by the fins (31) can be utilized by hindering (see).

  Various structures for providing a difference in the heat exchange efficiency described above can be combined. For example, if fins etc. are manufactured separately with a material having better thermal conductivity than the die material, or a member with fins protruding from the inside of the ring is manufactured, and these are attached to the expanded refrigerant passage, The heat exchange efficiency can be enhanced by obtaining both the surface area expansion effect by the fins and the effect by the difference in 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.

  Furthermore, the present invention includes a case where the cross-sectional shape of the coolant passage of the die is the same on the inner side of the bearing portion and the upstream portion thereof. This is because the temperature of the refrigerant flowing through the refrigerant passage increases as it goes upstream, and the temperature difference between the refrigerant and the die becomes smaller, so that the upstream portion is naturally less likely to be cooled than the inside of the bearing portion.

  As shown in FIGS. 2 and 4, the refrigerant passage (26) has openings in the side surface of the die base (21) and the downstream end surface of the mandrel (22), and is bent in an L-shape. It leads to the opening. Such a passage does not need to be cut into an L-shape, and is the first from the opening (connecting portion) (27) on the side surface of the die base (21) to the center of the mandrel (2) through the leg portion (24). If a passage and a second passage that penetrates the center of the mandrel (22) in the extruding direction and communicates with the suction port (28) are formed and the upstream opening of the second passage is closed, an L-shaped passage is formed. The closing method may be appropriately performed by bolting, welding of a rod-like closing member, shrink fitting, or the like. Further, the second passage leading to the connecting portion (27) is not necessarily limited to being provided through the leg portion (24), but a plate (not shown) disposed on the upstream end face of the die base (21) and the upstream side of the die. ) And a position facing the mating surface, and can be opened on the side surface of the die base.

  By applying the cooling structure of the present invention to the production of a hollow extruded material and cooling the extruded material efficiently and uniformly, a high quality hollow extruded material can be produced.

It is sectional drawing which shows an example of the extrusion material manufactured with the manufacturing method of the extrusion material of this invention. It is sectional drawing which implements the manufacturing method of the extrusion material of this invention, the extrusion apparatus which manufactures the extrusion material of FIG. 1, and a manufacturing method. It is sectional drawing which shows the other example of the extrusion material manufactured with the manufacturing method of the extrusion material of this invention. It is sectional drawing which implements the manufacturing method of the extrusion material of this invention, the extrusion apparatus which manufactures the extrusion material of FIG. 3, and a manufacturing method. It is sectional drawing of the extrusion material suitable for the manufacturing method of the extrusion material of this invention. It is sectional drawing of the other extrusion material suitable for the manufacturing method of the extrusion material of this invention. It is sectional drawing of the other extruded material suitable for the manufacturing method of the extruded material of this invention. It is sectional drawing which shows the principal part of other embodiment of the extrusion die in an extrusion apparatus. It is the side view which looked at the extrusion die of Drawing 8A from the downstream. It is a side view which shows the modification of the extrusion die of FIG. 8A. It is a side view which shows the other modification of the extrusion die of FIG. 8A. It is sectional drawing which shows the principal part of further another embodiment of an extrusion die. It is sectional drawing which shows the principal part of further another embodiment of an extrusion die. It is sectional drawing which shows the principal part of further another embodiment of an extrusion die. It is sectional drawing which shows the modification of the extrusion die of FIG. 12A. It is sectional drawing which shows other embodiment of an extrusion die. It is the side view which looked at the extrusion die of Drawing 13A from the lower stream side. It is a perspective view which shows the method of making a slit-shaped hole in an extrusion material. It is sectional drawing which shows the method of making a slit-shaped hole in an extrusion material. It is a perspective view which shows the method of making a spot-shaped hole in an extrusion material. It is sectional drawing which shows the method of making a spot-like hole in an extrusion material.

Explanation of symbols

1, 70, 80, 90, 100 ... extruded material
2, 73, 82, 83, 91, 92, 93, 94 ... hollow part
10, 75 ... porthole dice
20, 76… Male (extrusion die)
21 ... Dice base
22,77… Mandrel
25… Bearing part
26 ... Refrigerant passage
26a… Upstream part
27… Connection
28… Suction port
29,30,32,34,36,38… Cooling promotion part
39… Cooling promotion member
40 ... Cooling suppression member (cooling suppression part)
60… Suction device (suction means)
71, 81, 95, 101 ... outer wall
72, 97, 98, 99 ... inner wall
85 ... Bulkhead (inner wall)
84… Round inner wall (inner wall)
C: Refrigerant

Claims (10)

Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing a while extruding the extruded material, the empty extruded material in that to form an opening for attracting new refrigerant to the extrusion material. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
A plurality of hollow portions of the extruded material, provided with a coolant passage on the mandrel for molding these hollow portion, the manufacturing method of the air-extruded material within you independently control the refrigerant suction amount in each of the hollow portion. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing air-extruded material in the thickness of the outer wall of the extruded material is Ru der than 0.5% of the diameter of the circumscribed circle of the cross section of the pressing design. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
The extruded material has a hollow portion not facing the outer wall, the production method of the air-extruded material in which Ru was circulated refrigerant in the hollow portion is provided the coolant passage in the mandrel shaping the hollow portion. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
The extruded material has a thick inner wall of the thicker than the outer wall, the production method of the air-extruded material in which Ru was circulated refrigerant hollow portion is provided the coolant passage in the mandrel for molding the hollow portion facing the inner wall . Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing a single heavy empty extruded material in Ru der least 2 kg / m of the said extruded material. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing the extruded material empty extruded material in the diameter of the circumscribed circle of the cross section Ru der least 100 mm. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing air-extruded material in the extrusion material that have a asymmetrical cross-sectional shape. Using an extrusion die provided with a refrigerant passage having a suction opening at the downstream end face of the mandrel for forming the hollow portion of the extruded material, the refrigerant in the extruded hollow portion of the extruded material is sucked into the hollow portion of the extruded material while the metal is extruded. A method for producing a hollow extruded material, in which an external refrigerant is drawn into the hollow portion from the opening of the extruded material and circulated in the hollow portion by sucking from the mouth,
Method for producing air-extruded material within you cool the extruded material from the outside. An extrusion die provided with a refrigerant passage having a suction opening at a downstream end face of a mandrel for forming a hollow portion of the extruded material;
Suction means for sucking refrigerant from the suction port via the refrigerant passage;
Push out device Ru and a coolant supply means which is disposed downstream of the extrusion die.

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