JP2018015802A - Forging processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forging processing device capable of molding a forging processing product excellent in accuracy of a projection part height.SOLUTION: The present invention aims at a forging processing device for manufacturing a forging processing product of forming a projection part on a plan view polygonal baseplate, and comprises a die 1 having a cross-sectional polygonal molding hole 11 in response to the baseplate and a punch 3 formed in a cross-sectional polygonal shape in response to the molding hole 11 and driven in the molding hole 11. A projection part molding recessed part 42 is formed on a bottom surface of the molding hole 11 in the die 1, and a baseplate molding part 41 is formed between a tip surface of the punch 3 and the bottom surface of the molding hole 11, and a burr molding part 43 is formed between an outer peripheral surface of the punch 3 and an inner peripheral surface of the molding hole 11. A clearance C1 between a projected corner part 35 in the outer peripheral surface of the punch 3 and a recessed corner part 15 in the inner peripheral surface of the molding hole 11, is set smaller than a clearance C2 between an outside surface of the punch 3 and an inside surface of the molding hole 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a forging device, a forging method, and a forging material for producing a forged product in which a plurality of convex portions such as fins are formed on a base plate.

  When manufacturing a heat sink in which a large number of fins are formed on the front surface or the back surface of the base plate by die forging, for example, a semi-sealed forging device (die) as shown in Patent Document 1 is often used. Yes.

  A forging device for forming a heat sink includes a die (lower die) and a punch (upper die). For example, a large number of fin forming recesses for forming fins are formed on the bottom surface of a die forming hole. ing. Then, when the punch is driven into the forming hole of the die in which the forging material is set, the forging material is pressurized and plastically flows, and the metal material (metal) as the forging material is filled in the fin forming recess and the fin Is formed, and surplus metal is filled in the burr forming portion between the inner peripheral side surface of the die forming hole and the outer peripheral side surface of the punch to form a burr. Further, the base plate is formed by the metal existing in the base plate forming portion between the bottom surface of the die forming hole and the pressing surface of the punch.

Japanese Patent Laid-Open No. 2015-50318

  In the above-described conventional forging process, particularly when the base plate forms a forged product having a square shape in plan view, among the many fin forming recesses of the lower mold, the fin forming recesses corresponding to the four corners of the base plate are made of metal. Is difficult to fill, and the amount of metal filled in the fin-formed concave portion is insufficient, and there is a possibility that a lack of thickness may occur. When such a lack of thickness occurs, the fin height of the heat sink cannot be made uniform, and there arises a problem that a high-quality forged product (heat sink) cannot be manufactured.

  The present invention has been made in view of the above problems, and a forging device and a forging method capable of producing a high-quality forged product excellent in dimensional accuracy of the height of a convex portion such as a fin height. And it aims at providing a forging raw material.

  In order to solve the above problems, the present invention comprises the following means.

[1] A forging device for producing a forged product in which a convex portion is formed on a polygonal base plate in plan view,
A die having a forming hole with a polygonal cross section corresponding to the base plate;
A punch formed into a polygonal cross-section corresponding to the molding hole and driven into the molding hole;
On at least one of the bottom surface of the molding hole and the tip end surface of the punch in the die, a convex molding concave portion is formed,
A base plate molding portion is formed between the front end surface of the punch and the bottom surface of the molding hole,
A burr molding part is formed between the outer peripheral surface of the punch and the inner peripheral surface of the molding hole,
The clearance between the protruding corner portion on the outer peripheral surface of the punch and the entering corner portion on the inner peripheral surface of the forming hole is set to be smaller than the clearance between the outer surface of the punch and the inner surface of the forming hole. A forging device characterized by that.

  [2] The forging device as recited in the aforementioned Item 1, wherein the protruding corner portion of the punch is configured to contact the entering corner portion of the forming hole.

  [3] The forging device according to item 1 or 2, wherein a corner portion of the forming hole is configured by a chamfered portion.

  [4] The forging device according to item 3, wherein the chamfered portion is formed in a C chamfered shape.

  [5] The forging device according to any one of items 1 to 4, wherein the forming hole and the die are formed in a quadrangular cross section.

  [6] The forging device according to any one of items 1 to 5, wherein the convex molding concave portion is configured by a fin molding concave portion for molding a fin of a heat sink.

[7] A forged material that is finished into a forged product in which convex portions are formed on a polygonal base plate in plan view,
A burr projecting upward along its outer peripheral edge is formed on the upper surface of the base plate,
A forging shape material characterized in that, among the burrs, a burr corresponding to a corner portion is formed lower than a burr corresponding to a side portion.

  [8] The forged material according to item 7, wherein the base plate is formed in a square shape in plan view.

  [9] The forged material according to item 7 or 8, wherein no burr corresponding to the corner portion of the base plate is formed.

  [10] The forged material according to any one of items 7 to 9, wherein the forged product is a heat sink.

[11] A forging method for producing a forged product in which a convex portion is formed on a polygonal base plate in plan view,
A process of setting a forging material in a forming hole having a polygonal cross section corresponding to the base plate;
A step of punching a punch with a polygonal cross section corresponding to the molding hole into the molding hole and pressurizing the forging material,
The clearance between the protruding corner portion on the outer peripheral surface of the punch and the entering corner portion on the inner peripheral surface of the molding hole is set to be smaller than the clearance between the outer surface of the punch and the inner surface of the molding hole. While performing the process of pressurizing the forging material,
Forming a convex portion by a convex molding concave portion formed on at least one of the bottom surface of the molding hole in the die and the tip end surface of the punch;
A base plate is formed by a base plate forming portion formed between the front end surface of the punch and the bottom surface of the forming hole,
A forging method characterized in that a burr is formed by a burr forming portion formed between the outer peripheral surface of the punch and the inner peripheral surface of the forming hole.

  According to the forging apparatus of the invention [1], since the clearance between the protruding corner portion of the punch outer peripheral surface and the inner corner portion of the forming hole inner peripheral surface is set small, in the corner portion of the base plate forming portion By restricting the metal material (metal) flowing out from the base plate forming part to the burr forming part, the metal flow rate at the corner part of the base plate forming part can be sufficiently secured, and the convex forming concave part located at the corner part The metal can be reliably filled. For this reason, it is possible to prevent the occurrence of a lack of thickness in all the convex molding concave portions, to make all the convex heights coincide with each other with high accuracy, and to produce a high quality forged product.

  According to the forging device of the invention [2], the punch protruding corner is joined to the forming hole entering corner, so that the punch can be positioned with respect to the die forming hole. For this reason, for example, it is possible to prevent variations in the amount of burrs discharged, eliminate variations in the amount of flow of metal, allow the fluid to flow in a balanced manner, and further improve the dimensional accuracy.

  According to the forging apparatus of inventions [3] and [4], since the corners of the die forming holes are formed by the chamfered portions, it is effective that the stress due to the punch load is concentrated locally on the corners. Can be avoided. For this reason, early breakage of the corners in the die can be prevented, and the mold life can be extended.

  According to the forging device of the invention [5] and [6], the above effect can be obtained more reliably.

  According to the forged base material of the invention [7] to [10], the specific shape of the forged base material formed by the forging device of the above invention [1] to [6] is specified. The same effect as described above can be obtained.

  According to the forging method of the invention [11], since the forging method using the forging device of the inventions [1] to [6] is specified, the same effects as described above can be obtained.

FIG. 1 is a perspective view schematically showing a forging apparatus according to an embodiment of the present invention. FIG. 2 is a horizontal sectional view schematically showing the forging device according to the embodiment. FIG. 3 is an enlarged horizontal sectional view showing the periphery of the punched corner in the forging device according to the embodiment. FIG. 4A is a front sectional view schematically showing a state before the start of molding in the forging device according to the embodiment. FIG. 4B is a front sectional view schematically showing a state immediately after the start of pressurization in the forging device of the embodiment. FIG. 4C is a front sectional view schematically showing a state immediately after the completion of pressurization in the forging device of the embodiment. FIG. 4D is a front cross-sectional view schematically showing a state immediately after the forging raw material discharge is started in the forging device of the embodiment. FIG. 5 is a perspective view showing a forged material formed by the forging device of the embodiment. FIG. 6 is an enlarged horizontal sectional view showing the periphery of the punched out corner in the forging apparatus according to the first modification of the present invention. FIG. 7 is an enlarged horizontal sectional view showing the vicinity of a punched out corner in a forging device which is a modification of the present invention. FIG. 7 (a) is a horizontal sectional view of the second modification, and FIG. FIG. 3C is a horizontal sectional view of the fourth modified example, FIG. 4D is a horizontal sectional view of the fifth modified example, and FIG. 4E is a horizontal sectional view of the sixth modified example. FIG. 5F is a horizontal sectional view of the seventh modification.

  1 is a perspective view schematically showing a forging device according to an embodiment of the present invention, FIGS. 2 and 3 are horizontal sectional views schematically showing the forging device according to the embodiment, and FIGS. 4A to 4D are embodiments. It is front sectional drawing which shows the forge processing apparatus of no.

  In the present embodiment, a forging material is formed by performing a semi-sealing die forging process on the forging material W using the forging apparatus shown in these drawings.

  As shown in FIG. 5, the forged raw material 9 is used as a heat sink, and is formed of a rectangular (rectangular) base plate 91 and a large number of integrally formed on one surface (lower surface) of the base plate 91. Fins (pin fins) 92 and burrs 93 that are integrally formed on the outer peripheral edge of the other surface (upper surface) of the base plate 91 and are arranged to protrude upward. The burr 93 is formed corresponding to the four surrounding sides excluding the four corners, and the burr 93 formed on each side is formed such that the middle part thereof is high and both end parts thereof are low.

  In this embodiment, the forging base material 9 is subjected to finishing processing such as trim processing, and the burr 93 and the like are removed to obtain a heat sink as a forged product.

  In the present invention, burrs at the corners of the forged element 9 may be formed, and at least the burrs at the corners only need to be formed lower than the burrs 93 on the four sides. In this embodiment, when referring to “sides (sides)” such as surrounding four sides, the end points (corner parts) of the sides are not included.

  As shown in FIGS. 1 to 4A, the forging device according to the present embodiment includes a die (lower die) 1, an anvil 2, and a punch (upper die) 3.

  The anvil 2 is formed with a hollow hole that opens upward and downward, and the die 1 is supported through the anvil 2.

  The die 1 is provided with a molding hole 11 that is recessed downward on the upper surface side. The forming hole 11 is formed in a rectangular shape corresponding to the planar shape of the base plate 91 of the forged raw material 9 in the horizontal cross-sectional shape (cross-sectional shape orthogonal to the axial direction).

  A number of through-holes 12 penetrating in the vertical direction are formed in the bottom wall of the molding hole 11 in the die 1. A knockout pin 13 is disposed in each through hole 12 so as to be slidable in the vertical direction.

  As shown in FIGS. 1 to 3, the forming hole 11 of the die 1 is formed with a chamfered portion 16 having a C-shaped chamfered portion 15 which is four corner portions on the inner peripheral surface. In FIG. 1 and FIG. 2, etc., the chamfered portion 16 is exaggerated so as to be larger than the actual size in order to facilitate understanding of the invention.

  As shown in FIG. 4A and the like, a plate 21 that is driven up and down by an ejector (not shown) is provided in the hollow hole of the anvil 2, and the lower end of each knockout pin 13 is supported on the plate 21. Therefore, when the plate 21 is driven up and down, each knockout pin 13 is moved up and down in conjunction with the plate 21.

  In the present embodiment, the fin forming recess 42 is constituted by the through hole 12 and the knockout pin 13, specifically, the inner peripheral surface of the through hole 12 and the upper end surface of the knockout pin 13.

  In the present embodiment, the through hole 12 is formed in the die 1 in order to form the fin molding recess 42. However, the present invention is not limited to this. In the present invention, a bottomed hole is formed in the die 1. The fin-formed recess 42 may be formed by the bottomed hole. Further, a part of the fin forming recess 42 may be constituted by the through hole 12. For example, half of the fin-formed concave portion 42 may be constituted by the through hole 12 and the other half may be constituted by the bottomed hole.

  As shown in FIGS. 1 to 3, the punch 3 is formed in a rectangular shape whose horizontal sectional shape substantially corresponds to the forming hole 11 of the die 1. As for punch 3, the corner part 35 which is four corner parts of the perimeter is not chamfered, etc., but has a sharp edge shape. In a state where the punch 3 is driven into the forming hole 11 of the die 1 (see FIGS. 2 and 3), all four protruding corner portions 35 of the punch 3 are inserted into all four of the die forming holes 11. The chamfered portion 16 as the corner portion 15 is adjusted so as to come into contact with each other. That is, at the time of punch driving, the punch 1 enters the forming hole 11 of the die 1 while each protruding corner portion 35 of the punch 3 is in contact with the entering corner portion 15 of the forming hole 11.

  In the present embodiment, the clearance between the protruding corner portion 35 of the punch 3 and the entering corner portion 15 of the forming hole 11 is set to “0”. However, in the present invention, this clearance is not necessarily set to “0”. It is not necessary to set. For example, in the present invention, as shown in FIG. 6, the clearance C <b> 1 between the punch protruding corner 35 and the forming hole entering corner 15 is set between the outer surface of the punch 3 and the inner surface of the forming hole 11 of the die 1. What is necessary is just to form so that it may become smaller than the clearance C2.

  In the present embodiment, it is preferable to set all four clearances C1 between the punch protruding corner 35 and the forming hole entering corner 15 to be substantially equal. Similarly, all four outer surfaces (four sides in a sectional view) of the punch 3 and all four inner surfaces (four sides in a sectional view) of the forming hole 11 are all four. It is preferable to set the clearance C2 substantially equal.

  Here, in the present invention, it is preferable to set the clearance C <b> 1 between the punch protruding corner 35 and the forming hole entering corner 15 to 10% or less with respect to the diameter of the fin 92. That is, when this clearance C1 is set to a higher specific value, as will be described later, the metal material (metal) can be sufficiently supplied into all the fin forming recesses 42 during the forming process, and the fin height due to the lack of thickness Can be prevented.

  Further, in the present embodiment, in consideration of formability such as a forming load at the time of forging and the form stability of the forged raw material 9, the clearance C2 between the outer surface of the punch 3 and the inner surface of the forming hole 11 is considered. Needs to be set larger than the clearance C1, and preferably 10% to 100% with respect to the diameter of the fin 92.

  In this embodiment, when the punch 3 is driven into the die 1, a space surrounded by the front end surface of the punch 3 and the forming hole 11 of the die 1 is formed as the base plate forming portion 41, and the base A space between the outer peripheral surface of the punch 3 and the inner peripheral surface of the forming hole 11 above the outer peripheral portion of the plate forming portion 41 is formed as a burr forming portion 43. Needless to say, the lower end of the burr forming portion 43 is connected to the base plate forming portion 41 in communication.

  When forging is performed using the forging device of the present embodiment configured as described above, the forging material W1 is introduced into the forming hole 11 of the die 1 as shown in FIG. 4A.

  Although it does not specifically limit as the forge raw material W, The product made from aluminum alloy, the product made from copper alloy, and iron is used suitably. In this embodiment, a plate material made of an aluminum alloy is used as the forging material W. For example, this plate material may be cut from a rolled material by trimming or machining, or may be manufactured by cutting a flat bar-shaped extruded shape or cutting a rectangular continuous cast bar. May be. The forging material W is formed in a size and shape that can be accommodated in the forming hole 11 of the die 1, but preferably has a shape that approximates the bottom (material setting portion) of the forming hole 11 in order to perform positioning with high accuracy. Good to do.

  The forging material W to be charged is lubricated as necessary and heated to about 400 ° C. to 600 ° C., and dies such as the die 1 and the punch 2 are also lubricated and heated as necessary. Needless to say, in the case of cold forging, the forging material W and the mold are not heated.

  Further, the knockout pin 13 disposed in the through hole 12 of the die 1 is disposed at a position lowered to a predetermined position so that the fin forming recess 42 having a predetermined length is formed by the pin 13 and the through hole 12. ing.

  After the forging material W is set in the forming hole 11, the punch 3 is lowered and the forging material W is pressurized. In the state immediately after the press on the forging material W is started by the punch 3, as shown in FIG. 4B, the metal material (metal) constituting the forging material W is a metal that flows toward the center (inner diameter direction) and the outer side. It is divided into metal that flows toward (outer diameter direction). Among these, the metal which goes to the center flows into the through-hole 12 (fin molding recessed part 42) of the center part. Further, the metal that flows outward flows into the through hole 12 (fin forming recess 42) in the outer peripheral portion and also flows into the burr forming portion 43 between the punch 3 and the inner peripheral surface of the forming hole 11. Here, since the amount of metal flowing through the central portion of the base plate forming portion 41 is sufficiently ensured, the fin forming concave portion 42 in the central portion is sufficiently filled with metal. On the other hand, among the metals that flow around the outer periphery of the base plate forming portion 41, the amount of metal that flows near the corner portion is smaller than the amount of metal that flows near the inner side surface (side portion). The fin forming recess 42 positioned is sufficiently filled with metal, whereas the fin forming recess 42 positioned at the corner portion is not sufficiently filled with metal, and the metal amount tends to be insufficient.

  Therefore, in the present embodiment, as described above, since the punching corner 35 and the molding hole entering corner 15 are joined at the corner of the molding hole 11, burr molding is performed from the corner of the base plate molding 41. The outflow of metal to the portion 43 is restricted. Therefore, a sufficient amount of metal in the corner portion of the base plate forming portion 41 can be ensured, and the metal is sufficiently filled in the through hole 12 (fin forming concave portion 42) located in the corner portion.

  In this way, the base plate forming portion 41 and the fin forming recess 42 are filled with metal, and excess metal flows out to the burr forming portion 43, whereby the forged base material 9 is formed.

  In this embodiment, back pressure forging can also be performed. That is, the knockout pin 13 disposed on the die 1 is disposed at a position higher than a predetermined position at the time of completion of molding in a state before molding. And it is comprised so that the knockout pin 13 may fall to a predetermined position, providing a back pressure with respect to the metal material (metal) press-fit in the through-hole 12 during shaping | molding. Thereby, back pressure forging can also be implemented using the forging apparatus of this embodiment.

  When pressurization by the punch 3 is completed and the forged material 9 is formed, as shown in FIG. 4D, after the punch 3 is raised and returned to the initial position, the plate 21 of the anvil 2 is raised by driving the ejector. At the same time, the knockout pin 13 rises. The forging material 9 is pushed upward from the forming hole 11 by the rising knockout pin 13 and discharged.

  In the forged raw material 9 formed in this way, burrs 93 are integrally formed on four sides of the outer peripheral edge of the upper surface of the base plate 91 as shown in FIG. Due to this limitation, the burr 93 is not formed.

  In the present embodiment, as described above, the forged shape member 9 is finished to remove the burrs 93 and the like, thereby forming a heat sink as a forged product.

  As described above, according to the forging device of this embodiment, the punched corner portion 35 and the forming hole-inserted corner portion 15 are joined, so that the base plate forming portion is formed at the corner portion of the base plate forming portion 41. By restricting the metal flowing out from the burr forming part 43 to the burr forming part 43, the metal flow rate of the corner part of the base plate forming part 41 can be sufficiently secured, and the fin forming recessed part that is located at the corner part and is likely to cause metal shortage. Sufficient metal can be supplied to 42. For this reason, the fin molding concave portion 42 of the corner portion can be sufficiently filled with metal similarly to the other fin molding concave portions 42 such as the center portion and the side surface portion, and it is possible to effectively prevent the occurrence of the thinning.

  Accordingly, the fin heights of all the heat sinks as the forged product can be made to coincide with each other with high accuracy, and a high quality forged product can be manufactured.

  For reference, when the clearance between the punched-out corner and the forming hole entrance corner is set to be approximately equal to the clearance between the punch outer surface and the forming hole inner surface as in the conventional forging die. In the corner part of the base plate molding part, a large amount of metal flows out to the burr molding part, so the metal amount in the corner part of the base plate molding part is insufficient, and the metal is sufficiently in the fin molding recess located in the corner part. There is a possibility that the fins may not be filled, and it may be difficult to match all the fin heights.

 On the other hand, in the present embodiment, the punch 3 is driven into the forming hole 11 while all the four punch protruding corners 35 are joined to the four forming hole entering corners 15, so that the four directions of front, rear, left and right Thus, the punch 3 can be positioned with respect to the die forming hole 11. For this reason, the clearance C2 (see FIG. 6) between the outer surface of the punch and the inner surface of the forming hole can be set evenly on all four sides, and variation in the burr discharge amount at each position of the four sides can be prevented. It is possible to equalize the burr discharge amount at all positions on the four sides. As a result, there is no variation in the amount of metal flow in the entire area of the molding hole 11, and the metal can be flowed in a well-balanced manner. Therefore, also in this respect, variation in the fin height of the heat sink can be prevented, the fin height can be matched with high accuracy, and a forged product with higher quality can be manufactured.

  Further, in this embodiment, since the chamfered portion 16 is formed at the corner 15 of the rectangular forming hole 11 of the die 1, it is effective that the stress due to the punch load is concentrated on the corner 15 at the extreme. Can be avoided. For this reason, the early breakage of the corners in the die 1 can be prevented, and the durability of the die 1 and the life of the mold can be extended sufficiently.

  In the above-described embodiment, the chamfered chamfered portion 16 is formed at the corner 15 of the die forming hole 11 and the punched corner 35 is brought into contact with the chamfered portion 16. However, in the present invention, the clearance C1 (see FIG. 6) between the punch protruding corner 35 and the forming hole entering corner 15 is set smaller than the clearance C2 between the punch outer surface and the forming hole inner surface. Any configuration can be adopted as long as it can be configured.

  For example, as shown in FIG. 7A, the entrance corner 15 of the die forming hole 11 is formed in the chamfered chamfered portion 16 in the same manner as described above, and the punched out corner 35 is also a chamfered chamfered portion. Alternatively, the chamfered portion 36 of the punched out corner portion 35 may be brought into contact with the chamfered portion 16 of the forming hole-inserted corner portion 15. Further, as shown in FIG. 5B, the corner 15 of the die forming hole 11 is R-chamfered to form a chamfered portion 16 having an R-chamfered shape, and the die exit corner 35 is A chamfered portion 36 having an R chamfered shape that is substantially equal to the radius of curvature may be formed, and the chamfered portion 36 of the punch-out corner portion 35 may be brought into contact with the chamfered portion 16 of the forming hole-inserted corner portion 15. Further, as shown in FIG. 3C, a convex portion 17 projecting in the inner diameter direction is formed at the entrance corner portion 15 of the die forming hole 11, and the punch protruding corner portion is formed at the chevron edge portion at the tip of the convex portion 17. 35 may be contacted. Further, as shown in FIG. 4 (d), an L-shaped guide groove 181 is formed in the convex portion 18 formed in the corner 15 of the die forming hole 11, and the punch protruding corner portion 35 is formed in the guide groove 181. You may make it contact. Further, as shown in FIG. 5 (e), a convex portion 37 projecting in the outer diameter direction is formed at the punched out corner portion 35, and the chevron edge portion at the tip of the convex portion 37 is brought close to the forming hole entering corner portion 15. It may be arranged in the opposite state as described above, or may be arranged in contact with the forming hole entering corner 15. Further, as shown in FIG. 5 (f), the forming hole entering corner 15 is formed in the chamfered portion 16 having an R chamfered shape, while the convex portion 38 is formed in the punch out corner portion 35 and provided at the tip of the convex portion. The formed arc portion may be brought into contact with the chamfered portion 16 of the forming hole entering corner portion 15.

  Moreover, in the said embodiment, although the case where a base plate manufactures a square forge processing product was used as an example, using a thing with a square cross section as the forming hole 11 and the punch 3 of the die 1, it is not limited thereto, The present invention is also carried out in the same manner as in the above-described embodiment even when a die-formed hole and punch are used with a polygon having a cross-sectional triangle or a pentagon or more and a base plate for producing a polygonal forged product other than a quadrangle. can do.

  Here, in the above embodiment, since the chamfered chamfered portion 16 is formed at the four corners 15 of the molding hole 11, if the chamfered portion 16 is regarded as one side of the polygon, strictly speaking, molding is performed. Although the hole 11 is not necessarily an octagon, in the present invention, a small chamfered portion or the like is not a side portion but a corner portion, and the molding hole 11 of the embodiment is regarded as a square in cross section. I have to.

  In each of the above embodiments, the case where the fin forming recess 42 is formed on the die 1 side has been described as an example. However, the present invention is not limited thereto, and in the present invention, the fin forming recess may be formed on the punch side. It is also possible to manufacture a heat sink (forged product) in which fins are formed on both the die and the punch to form fins on both sides of the base plate.

  In the above embodiment, the heat sink having pin fins formed on the base plate has been described as an example. However, the present invention is not limited to this, and in the present invention, plate fins are formed on one or both surfaces of the heat sink. The present invention can also be applied when forming a heat sink.

  Moreover, in the said embodiment, although the case where the heat sink was formed according to the present invention was described as an example, the present invention is not limited to the heat sink alone, and the forged product in which a plurality of convex portions are formed on at least one side of the base plate. In the case of manufacturing, the present invention can be adopted in the same manner as described above.

  The forging device of the present invention can be suitably used when manufacturing a forged product such as a heat sink in which a large number of fins are formed on a base plate.

1: Die 11: Molding hole 15: Corner corner 16: Chamfered portion 3: Punch 35: Out corner portion 41: Base plate molding portion 42: Fin molding concave portion 43: Burr molding portion 9: Forging base material 91: Base plate 92: Fin 93: Burr C1, C2: Clearance W: Forging material

Claims (11)

A forging device for producing a forged product in which convex portions are formed on a polygonal base plate in plan view,
A die having a forming hole with a polygonal cross section corresponding to the base plate;
A punch formed into a polygonal cross-section corresponding to the molding hole and driven into the molding hole;
On at least one of the bottom surface of the molding hole and the tip end surface of the punch in the die, a convex molding concave portion is formed,
A base plate molding portion is formed between the front end surface of the punch and the bottom surface of the molding hole,
A burr molding part is formed between the outer peripheral surface of the punch and the inner peripheral surface of the molding hole,
The clearance between the protruding corner portion on the outer peripheral surface of the punch and the entering corner portion on the inner peripheral surface of the forming hole is set to be smaller than the clearance between the outer surface of the punch and the inner surface of the forming hole. A forging device characterized by that.   The forging device according to claim 1, wherein a protruding corner portion of the punch is configured to contact an entering corner portion of the forming hole.   The forging device according to claim 1 or 2, wherein a corner portion of the forming hole is constituted by a chamfered portion.   The forging device according to claim 3, wherein the chamfered portion is formed in a C chamfered shape.   The forging apparatus according to any one of claims 1 to 4, wherein the forming hole and the die are formed to have a square cross section.   The forging apparatus according to any one of claims 1 to 5, wherein the convex molding concave portion is configured by a fin molding concave portion for molding a fin of a heat sink. A forging material that is finished into a forged product in which convex portions are formed on a polygonal base plate in plan view,
A burr projecting upward along its outer peripheral edge is formed on the upper surface of the base plate,
A forging shape material characterized in that, among the burrs, a burr corresponding to a corner portion is formed lower than a burr corresponding to a side portion.   The forged material according to claim 7, wherein the base plate is formed in a square shape in plan view.   9. The forged material according to claim 7, wherein no burr corresponding to a corner portion of the base plate is formed.   The forged material according to any one of claims 7 to 9, wherein the forged product is a heat sink. A forging method for producing a forged product in which convex portions are formed on a polygonal base plate in plan view,
A process of setting a forging material in a forming hole having a polygonal cross section corresponding to the base plate;
A step of punching a punch with a polygonal cross section corresponding to the molding hole into the molding hole and pressurizing the forging material,
The clearance between the protruding corner portion on the outer peripheral surface of the punch and the entering corner portion on the inner peripheral surface of the molding hole is set to be smaller than the clearance between the outer surface of the punch and the inner surface of the molding hole. While performing the process of pressurizing the forging material,
Forming a convex portion by a convex molding concave portion formed on at least one of the bottom surface of the molding hole in the die and the tip end surface of the punch;
A base plate is formed by a base plate forming portion formed between the front end surface of the punch and the bottom surface of the forming hole,
A forging method characterized in that a burr is formed by a burr forming portion formed between the outer peripheral surface of the punch and the inner peripheral surface of the forming hole.

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