JP2017192953A - Method for manufacturing metal molded product and press molding apparatus - Google Patents

Abstract

An object of the present invention is to ensure a substantial depth of a concave portion without using a thick work. In a first step, a plurality of recesses are formed in a metal work by press molding, and a bulging portion projecting in a direction opposite to a pressing direction is formed at an edge of an opening of the recess. . In a later step, a mold for receiving the inner surface of the recess 22 is set in the recess 22, and in this state, the bulging portion 223 is crushed by press molding to shape the edge of the opening of the recess 22. I do. [Selection diagram] FIG.

Description

  The present invention relates to a method for manufacturing a metal molded product having a recess, and a press molding apparatus used in the manufacturing method.

  In the case of forming a recess in a metal workpiece, a press molding method is employed. However, in this press molding method, the edge of the opening of the recess is formed into a large arc shape by being pulled into the recess by the pressure of the press. For this reason, the boundary between a recessed part and the part of the outer side becomes obscure, and there exists a possibility that the substantial depth of a recessed part may be insufficient. Therefore, when using a recessed part for the specific objective, there exists a possibility that the function as the recessed part cannot be exhibited effectively. Therefore, in order to secure a concave portion that functions effectively, it is necessary to form a deep concave portion using a thick workpiece. If it does in this way, naturally the weight of a workpiece | work will increase and it is often unpreferable as a metal molded product.

  For this reason, the cutting method or the drilling method using a cutting tool may be employ | adopted so that a deep deep recessed part may be formed by making the edge of the opening part of a recessed part into a sharp edge. However, machining by cutting or drilling takes time to process one recess, and simultaneously processing all recesses is difficult. Therefore, these processing methods have low processing efficiency. Furthermore, since cutting and drilling tools are easily worn by processing, it is difficult to maintain processing accuracy unless the tools are frequently reground or replaced. In addition, there is a problem in that the yield of the material is reduced because wastes that are wasted are generated from the portion processed by the tool.

  Patent Document 1 discloses a method of forming a recess in a workpiece by press molding.

JP 2002-1450 A (paragraphs 0023 and 0036 of the specification, FIGS. 1 to 3 of the drawings, etc.)

  In Patent Document 1, the narrow punch portion of the preliminary processing punch is provided corresponding to the die hole of the preliminary processing die, and a bottomed concave preliminary hole having a bottom portion with respect to the workpiece by the operation of the preliminary processing punch. Is formed. This preliminary hole is formed as preliminary processing before punching the workpiece, and the processing accuracy and shape are hardly considered. In addition, even a thin work is not considered to obtain a substantial depth of the recess. Actually, the base part of the punch for preliminary machining is provided with a stress relaxation part having a rounded shape for relaxing concentrated stress at the time of punching, so that the edge of the opening of the preliminary hole is rounded. As described above, the boundary between the concave portion and the outer portion becomes unclear.

  An object of the present invention is to solve such problems, and it is a metal molded product that can sufficiently secure a substantial depth as a recess even in a thin metal workpiece. It is providing the manufacturing method and the press molding apparatus used for the manufacturing method.

  In order to achieve the above object, the method for producing a metal molded product of the present invention includes forming a recess in a metal workpiece by press molding in the preceding step, and reversing the press direction at the edge of the opening of the recess. In the subsequent step, a shaping mold that receives the inner surface of the recessed portion is installed in the recessed portion, and in the installed state, the expanded portion is crushed by press molding to form the recessed portion. The edge of the opening is shaped.

  Further, the press molding apparatus of the present invention is a press molding apparatus provided with a pre-stage press molding section and a post-stage press molding section for press-molding a metal workpiece, wherein the pre-stage press molding section and the post-stage press molding section are the metal workpiece. Each of the first mold for receiving the metal mold and the second mold for pressing the metal workpiece on the first mold, and the second mold of the pre-press forming section includes A recess forming die for forming a recess in the metal workpiece, and a bulging portion forming die for forming a bulging portion protruding in the opposite direction of the press direction at the edge of the opening of the recess, The second mold of the press-molding part includes a crushing mold for crushing the bulging part, and a shaping mold for shaping the inner side surface of the recess in accordance with the crushing. .

  According to the above method and configuration, the edge of the recess can be formed in a sharp edge shape. For this reason, even if it does not use a thick thing as a workpiece | work, the substantial depth of a recessed part is securable. Moreover, even if there are a plurality of recesses, the plurality of recesses can be press-molded simultaneously, and high processing efficiency can be obtained. Further, since it is not necessary to use a cutting tool, it is possible to avoid a decrease in accuracy due to tool wear and maintain a high processing accuracy, and since no waste chips are generated, the yield of the material does not decrease.

  According to the present invention, there is an effect that a substantially deep recess can be formed in a metal molded product.

The perspective view of the metal workpiece before a process. Sectional drawing of a metal workpiece. The perspective view of a metal molded product. The front view which shows a metal molded product and a back | latter stage press molding part. The front view which shows the metal workpiece and the front stage press molding part in the state which the front stage press molding completed. Sectional drawing of the metal workpiece of the state which the press molding of the front | former stage was complete | finished. The bottom view of the upper mold | type of a front stage press molding part. The side view which shows the front | former stage press molding state of a 1st recessed part. The side view which shows the front | former stage press molding state of a 2nd recessed part. The side view which shows the back | latter stage press molding state of a 1st recessed part. The side view which shows the back | latter stage press molding state of a 2nd recessed part. The front view of the metal molded product which showed the example of a change and abbreviate | omitted the 2nd recessed part. The bottom view which shows the metal mold | die used for the press molding of the example of a change of FIG. The front view of the metal molded product which showed the example of a change and formed the recessed part alternately. The cut perspective view of the metal molded product which showed the example of a change and formed the recessed part in the metal plate.

DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.
First, the configuration of a metal molded product (hereinafter simply referred to as a molded product) 21 will be described.
As shown in FIGS. 3 and 4, the molded product 21 is made of stainless steel and has a rectangular cross section and is formed in a long shape. A plurality of (in the embodiment, 10) first recesses 22 that are recessed in the thickness direction of the molded product 21 are formed on one side surface of the molded product 21 at equal intervals in the length direction of the molded product 21. In the middle position between the pair of adjacent first recesses 22, one second recess 23 that is recessed in the thickness direction is formed in the same manner as the first recess 22. The second recess 23 is formed deeper than the first recess 22. The molded product 21 is formed with first flat portions 25 located between both end portions of the molded product 21 and the first concave portion 22, and a pair of second flat portions 26 are formed on both sides of the second concave portion 23. Has been. The second flat part 26 is arranged at a position higher than the first flat part 25.

Next, a method for manufacturing the molded product 21 and a press molding apparatus will be described.
As shown in FIGS. 1 and 2, a metal workpiece (hereinafter simply referred to as a workpiece) 40 before becoming a molded product 21 is cut out from a plate material (not shown) or drawn from a thick material with a die. Thus, it is formed in a quadrangular cross section and has a rod shape as a whole.

  Then, the first press forming portion 42 shown in FIGS. 8 and 9 of the press forming apparatus 41 and the second press forming portion 61 shown in FIGS. 10 and 11 are formed so that the first concave portion 22 and the second concave portion 23 are formed. Thus, the workpiece 40 is press-molded twice before and after. Accordingly, the former process is executed by the former press molding unit 42 and the latter process is executed by the latter press forming part 61.

  5 and 6 show the workpiece 40 at a stage where the press forming by the pre-stage press forming unit 42 has been completed. 3 and 4 show the molded product 21 after the press molding by the subsequent press molding unit 61 is completed.

  FIG. 5 shows a front press molding section 42 of a press molding apparatus 41. The front press molding section 42 includes a lower mold 43 as a first mold and an upper mold 44 as a second mold. Have. The lower die 43 is in a fixed position, and the upper die 44 is raised and lowered. The lower mold 43 is formed with a plurality of recessed portions 431 (10 in the embodiment) at equal intervals and a recessed portion 432 positioned at one position between the pair of recessed portions 431.

  As shown in FIGS. 5, 7, 8, and 9, the upper mold 44 includes a plurality of (10 in the embodiment, but short at both ends) first planar molds 45 and a pair of second planar molds 46. Is provided. In addition, the upper mold 44 is provided with a plurality of (10 in the embodiment) first projecting molds 47 and one second projecting mold 48 constituting a recess molding mold. In the present embodiment, the upper and lower sides in FIGS. 8 to 11 are the upper and lower sides of the apparatus. Here, as indicated by a two-dot chain line in FIGS. 8 and 9, when the upper mold 44 is in the raised position, the lower surfaces of the flat molds 45 and 46 and the lower surfaces of the protruding molds 47 and 48 are substantially the same height. There is. 8 and 9, when the upper mold 44 is lowered, the projecting molds 47 and 48 are moved downward even after the lowering of the flat molds 45 and 46 is stopped. It projects below 46.

The depressions 431 and 432 of the lower mold 43 are formed at positions corresponding to the first and second protruding molds 47 and 48, respectively.
4, FIG. 10 and FIG. 11 show a rear press forming portion 61 of the press forming apparatus 41. FIG. The post-stage press forming unit 61 includes a lower mold 62 as a first mold and an upper mold 63 as a second mold. The lower die 62 is in a fixed position, and the upper die 63 is raised and lowered. The lower mold 62 is formed with a plurality of (in the embodiment, ten) recesses 621 and a recess 622 located at one location between the pair of recesses 621. The upper mold 63 is provided with a plurality of first planar molds 64 (10 in the embodiment, but short at both ends) and a pair of second planar molds 65 constituting a crush mold.

  Further, the upper mold 63 is provided with a plurality of (9 in the embodiment) first projecting molds 66 and a pair of second projecting molds 67 constituting the mold. The lower surface of the upper mold 63 appears in the same manner as the upper mold 44 shown in FIG. 10 and 11, when the upper mold 63 is in the raised position, the lower surfaces of the planar molds 64 and 65 and the lower surfaces of the protruding molds 66 and 67 are substantially at the same height. However, when the upper mold 63 is lowered, the projecting molds 66 and 67 are moved downward and are projected below the planar molds 64 and 65 even after the lowering of the planar molds 64 and 65 is stopped.

The depressions 621 and 622 of the lower mold 62 are formed at positions corresponding to the first and second protruding molds 66 and 67, respectively.
In the press molding apparatus 41 configured as described above, as shown in FIGS. 8 and 9, the workpiece 40 is set on the lower die 43 of the front press molding portion 42 for the front press molding.

  When the upper die 44 is lowered, the work 40 placed on the lower die 43 is punched by the first and second flat dies 45 and 46 and the first and second projecting dies 47 and 48. For this reason, a portion between the first and second recesses 22 and 23 is press-molded by the first and second projecting dies 47 and 48, and at the same time, the first and second flat dies 45 and 46 are used to Second flat portions 25 and 26 are formed.

  Here, at the positions corresponding to the first and second projecting dies 47 and 48, the lower mold 43 is formed with the depressions 431 and 432, so that the convex portions are formed on the bottom side of the concave portions 22 and 23 of the workpiece 40 by punching. 50 and 51 are formed.

  Arc-shaped curved surface portions 471 and 481 are formed on both side portions of the distal end portions of the first and second projecting dies 47 and 48, so that curved portions are formed on the inner corner portions on both sides of the bottom portions of the concave portions 22 and 23. Curved surface portions 221 and 231 having the same curvature as 471 and 481 are formed. Further, both side surfaces 472 and 482 of the first and second projecting molds 47 and 48 are inclined surfaces that slightly extend upward, and therefore the inner surfaces 222 and 232 of the recesses 22 and 23 are also inclined slightly upward. Formed into a taper shape.

  An inclined surface 451 raised to the first projecting mold 47 side is formed at the edge of the lower surface of the first planar mold 45 on the first projecting mold 47 side. Therefore, as the upper die 44 is punched, the slope 451 and the side surface of the first protruding die 47 cause both ends of the first flat portion 25, that is, the edge of the first concave portion 22 adjacent to the first flat portion 25. A bulging portion 223 is formed in the outer corner portion, which is a portion, upward, that is, in the direction opposite to the pressing direction. Therefore, the first flat mold 45 having the inclined surface 451 and the first projecting mold 47 constitute a bulging portion mold.

  Moreover, since the 2nd recessed part 23 is formed in the narrow space | interval between the adjacent 1st recessed parts 22, in the 2nd flat part 26 between the 1st recessed part 22 and the 2nd recessed part 23, the whole Stress is applied in the direction of rising. Therefore, the molding surface of the second flat mold 46 is formed at a position higher than the molding surface of the first flat mold 45, and the upper surface of the second flat portion 26 between the second recesses 23 is higher than the upper surface of the first flat portion 25. Highly formed. However, the inclined surface is not formed in the second planar mold 46, and the bulging portion 223 is not formed at the edge of the opening of the second recess 23 and the edge of the first recess 22 on the second recess 23 side. .

The workpiece 40 press-formed as described above is set in the subsequent press-forming portion 61 shown in FIGS. 10 and 11 and further press-formed.
When punching is performed on the workpiece 40 placed on the lower die 62 by lowering the upper die 63, the first and second recesses 22 and 23 of the workpiece 40 are caused by the first and second projecting dies 66 and 67. Is shaped, and the first and second flat portions 25 and 26 are shaped by the first and second planar dies 64 and 65.

  That is, the lower surface of the first planar mold 64 is flat. For this reason, the bulging part 223 of the flat part 25 becomes flat by crushing by punching of the first flat mold 64, and the meat part constituting the bulging part 223 is moved to the first recess 22 side. As described above, the bulging portion 223 is crushed and moved to the first concave portion 22 side, and is drawn toward the inner side of the first concave portion 22 by the punching of the first protruding die 66. The position of the side surface 662 is restricted. For this reason, the edge of the opening of the first recess 22 is formed to be sharp. In other words, the outer corner portion constituting the edge of the opening of the first recess 22 is shaped into a sharp edge with a very large curvature, and thus the height of the inner surface 222 of the first recess 22 is increased. Can do.

  On the other hand, as described above, since the second recess 23 is formed within a narrow interval between the adjacent first recesses 22, the second flat portion 26 between the first recess 22 and the second recess 23 has The stress in the direction that rises high acts. For this reason, the molding surface of the second flat die 65 of the upper die 63 is formed at a high position, as in the previous press molding. Therefore, the second flat part 26 is shaped at a position higher than the first flat part 25. Therefore, both inner side surfaces 232 of the second recess 23 and the inner side surfaces 222 on the second flat portion 26 side of the pair of first recesses 22 on both sides of the second recess 23 are more than the inner side surfaces 222 of the other first recesses 22. Formed high and shaped in that state.

  In addition, arc-shaped curved surface portions 661, 671 having a larger curvature than the curved surface portions 471, 481, in other words, having a shorter radius of curvature, are formed on both side portions of the tip portions of the first and second projecting dies 66, 67. Therefore, the curved surface portions 221 and 231 of the inner corner portions on both sides of the bottom portions of the concave portions 22 and 23 are formed to have a substantially right-angled large curvature. Furthermore, both side surfaces 662 and 672 of the first and second projecting molds 66 and 67 are upright, and the inner side surface 222 of the first recess 22 is shaped in a direction in which the taper expansion angle is small, so It stands upright so that it lies on a parallel plane.

Further, the first and second flat molds 64 and 65 are shaped so that the upper surfaces of the first and second flat portions 25 and 26 are smooth planes.
In the case where burrs are generated by punching after shaping by the subsequent press molding, the burrs are removed by a cutter or a grindstone to form a molded product 21.

  The molded product 21 molded as described above is used, for example, in a louver device having a plurality of movable fins, and a part of the fin is engaged in the first recess 22 and the output portion of the actuator in the second recess 23. Will be taken in. When the molded product 21 is moved by driving the actuator, the opening angles of all the movable fins are adjusted simultaneously.

The present embodiment has the following effects.
(1) In the preceding press molding step, the first recess 22 is formed, and the bulging portion 223 is formed at the edge of the opening of the first recess 22 in the direction opposite to the press direction. Then, in the subsequent press forming step, the bulging portion 223 is crushed, and the inner surface of the first recess 22 is received by the second projecting die 67 so that the edge of the first recess 22 has a sharp edge shape. It is shaped. Therefore, even if the action of being drawn toward the inside of the first recess 22 by press molding works, since the bulging portion 223 is formed, the inner surface of the first recess 22 can be formed high. For this reason, even if the molded product 21 is thin, the deep 1st recessed part 22 can be formed. Accordingly, the weight of the molded product 21 can be reduced, and the function of the first recess 22 can be effectively exhibited.

  (2) Since the second concave portion 23 is formed within a narrow interval between the adjacent first concave portions 22, the second flat portion 26 between the second concave portion 23 and the first concave portion 22 is high in the rising direction. Stress acts. For this reason, both the inner surface 232 of the 2nd recessed part 23 and the inner surface 222 by the side of the 2nd flat part 26 of the 1st recessed part 22 of the both sides are formed high. As a result, the deep second recess 23 can be formed.

  (3) Since the first and second concave portions 22 and 23 are simultaneously press-formed by punching, unlike the case where the first and second concave portions 22 and 23 are formed by a cutting tool, high processing efficiency can be obtained. In addition, since there is no problem of premature wear as in a cutting tool, high-precision machining is possible even if machining is continued many times over a long period of time. In addition, since no waste chips are generated, the yield of the work material can be improved.

  (4) Forming the first and second recesses 22 and 23 by dividing the work 40 twice in front and rear, forming the bulging portion 223, and crushing the bulging portion 223 to form a sharp edge. As a result, the press pressure can be remarkably lowered, and damage to the apparatus can be reduced.

  (5) The bulging portion 223 is formed simultaneously with the formation of the first concave portion 22, and then the first concave portion 22 is formed in two stages, front and rear, so that the bulging portion 223 is crushed when the first concave portion 22 is shaped. Therefore, even if the workpiece 40 is hard and difficult to process, it is possible to avoid the possibility that the workpiece 40 is broken or the press molding apparatus 41 is damaged.

  (6) The inner corner portions of the first and second recesses 22 and 23 are formed in a curved shape in the first press forming step, and the curvature of the inner corner portion is increased in the second press forming step to increase the curvature of the inner corner portion. Can be increased without difficulty, and the substantial height of the inner side surfaces 222, 232 of the first and second recesses 22, 23 can be increased.

  (7) The inner side surfaces 222 and 232 of the first and second recesses 22 and 23 are formed in a taper shape extending outward in the workpiece axial direction in the first press forming step, and the inner side surfaces 222 and 232 are formed in the second press forming step. In order to reduce the taper expansion angle, the inner side surfaces 222 and 232 can be made upright to make the first and second recesses 22 and 23 substantially deeper.

In addition, this invention is not limited to the said embodiment, It can be actualized with the following aspects.
-In the said embodiment, it divided into two times before and after, and it was press-molded, However, At least one of a pre-process and a post-process should be divided into several steps, and it should be divided into three or more times as a whole, and may be pressed. In this case, the bulging portion 223 is formed in a plurality of times or is crushed in a plurality of times. Accordingly, it is possible to reduce the burden on the press forming apparatus 41 per punching.

As shown by a two-dot chain line in FIGS. 10 and 11, a shallow recess 70 is formed on the upper surfaces of the flat portions 25 and 26.
As shown in FIG. 12, only the first concave portion 22 and the first flat portion 25 are formed in the molded product 21 without forming the second concave portion 23 and the second flat portion 26. In this case, as shown in FIG. 13, the second protruding mold 67 and the second flat mold 65 of the front press forming section 42 and the rear press forming section 61 are omitted. The molded product 21 in which the second concave portion 23 and the second flat portion 26 are not formed is symmetrical so that the first concave portion 22 faces the pair of molded products 21 as shown by a two-dot chain line in FIG. 12, for example. By overlapping each other, a fluid passage can be formed between the first concave portions 22 facing each other.

-The first recesses 22 should be formed at unequal intervals.
-Use a shape other than a rod shape, for example, a ring-shaped or plate-shaped workpiece 40. In the case of the ring-shaped workpiece 40, the end surface in the axial direction of the workpiece 40 is processed. The ring-shaped workpiece 40 can be obtained by cutting a pipe material.

  -As shown in FIG. 14, the recessed part 23 should be formed in the front and back both surfaces of the workpiece | work 40. As shown in FIG. In this case, the recesses 23 on the front and back sides may be arranged regularly, for example, alternately or irregularly.

-As shown in FIG. 15, the hole-shaped recessed part 22 should be formed in the plate-shaped workpiece 40. FIG.
・ Chamfer the workpiece 40 in advance.

  -Omit the recessed parts 431 and 432 of the pre-stage press forming part 42.

  DESCRIPTION OF SYMBOLS 21 ... Metal molded product, 22 ... 1st recessed part, 23 ... 2nd recessed part, 40 ... Metal workpiece, 41 ... Press molding apparatus, 42 ... Pre-stage press molding part, 61 ... Back | latter stage press molding part, 223 ... Swelling part.

Claims (8)

In the preceding step, a concave portion is formed in the metal workpiece by press molding, and a bulging portion protruding in the reverse direction of the pressing direction is formed at the edge of the opening of the concave portion,
In a subsequent step, a shaping mold that receives the inner surface of the recess is installed in the recess, and in the installed state, the bulging portion is crushed by press molding to shape the edge of the opening of the recess Manufacturing method of molded products.   The method for producing a metal molded product according to claim 1, wherein there are a plurality of the recesses, and the recesses are simultaneously press-formed.   The manufacturing method of the metal molded product of Claim 1 or 2 which receives the surface on the opposite side of the said recessed part of the said metal workpiece | work by the hollow part of a metal mold | die.   The metal according to any one of claims 1 to 3, wherein an inner corner portion of the recess is formed in a curved shape in the preceding step, and a curvature of the curved surface of the inner corner portion is increased in the subsequent step. Manufacturing method of molded products.   5. The method according to claim 1, wherein the inner side surface of the concave portion is formed in a taper shape that widens toward the opening side of the concave portion in the preceding step, and the taper opening angle of the inner side surface is reduced in the subsequent step. A method for producing a metal molded product according to one item.   In the preceding step, the recesses are formed at equal intervals, and another recess is press-formed between a pair of adjacent recesses, The metal molded article according to any one of claims 1 to 5 is manufactured. Method. In a press molding apparatus provided with a former press molding part and a latter press molding part for press molding a metal workpiece,
The first-stage press molding section and the second-stage press molding section each include a first mold for receiving the metal workpiece and a second mold for pressing the metal workpiece on the first mold. ,
The second mold of the former press forming part is formed with a recessed part forming die for forming a recessed part in the metal work and a bulging part protruding in the opposite direction of the pressing direction at the edge of the opening part of the recessed part. And a bulging part mold for
The second mold of the latter press forming part includes a crushing mold for crushing the bulging part and a shaping mold for shaping the inner surface of the concave part in accordance with the crushing. .   The press molding apparatus according to claim 7, wherein at least the first die of the latter stage press molding unit has a recess for receiving the concave portion of the metal workpiece.

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