JP6645334B2 - Manufacturing method of metal molded product and press molding device - Google Patents

Description

  The present invention relates to a method for manufacturing a metal molded product having a concave portion and a press forming apparatus used for the method.

  When forming a concave part in a metal work, a press molding method is adopted. However, in this press molding method, the edge of the opening of the concave portion is formed into a large arc shape by the pressure of the press so as to be drawn into the concave portion. For this reason, the boundary between the concave portion and the portion outside the concave portion becomes unclear, and the substantial depth of the concave portion may be insufficient. Therefore, when the concave portion is used for a specific purpose, there is a possibility that the function as the concave portion cannot be effectively exhibited. Therefore, in order to secure a concave portion that functions effectively, it is necessary to form a deep concave portion using a work having a large thickness. By doing so, the weight of the work naturally increases, which is often not preferable as a metal molded product.

  For this reason, a cutting method or a drilling method using a cutting tool may be adopted so that the edge of the opening of the concave portion is made sharp to form a substantially deep concave portion. However, machining by cutting or drilling requires time for machining one recess, and it is difficult to simultaneously machine all recesses. Therefore, these processing methods have low processing efficiency. Further, since tools for cutting and drilling are easily worn by processing, it is difficult to maintain the processing accuracy unless the tools are frequently reground or replaced. In addition, there is a problem that since the chips processed by the tool generate chips that are discarded unnecessarily, the yield of the material is reduced.

  Patent Literature 1 discloses a method of forming a concave portion in a work by press molding.

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

  In Patent Literature 1, a thin punch portion of a pre-processing punch is provided corresponding to a die hole of a pre-processing die, and the operation of the pre-processing punch causes a bottomed concave pre-hole having a bottom with respect to a work. Is formed. The preliminary holes are formed as preliminary processing before punching the workpiece, and little consideration is given to the processing accuracy and shape. Moreover, even when the work is thin, no consideration is given to obtaining a substantial depth of the concave portion. As a matter of fact, at the base of the pre-processing punch, a rounded stress relaxing portion for relaxing the concentrated stress at the time of punching is provided. As a result, the boundary between the concave portion and the portion outside the concave portion becomes unclear as described above.

  An object of the present invention is to solve such a problem, and even for a metal work having a small thickness, a metal molded product capable of sufficiently securing a substantial depth as a concave portion. An object of the present invention is to provide a manufacturing method and a press forming apparatus used in the manufacturing method.

  In order to achieve the above object, a method of manufacturing a metal molded product according to the present invention is characterized in that, in a preceding step, a concave portion is formed in a metal work by press molding, and an edge of an opening of the concave portion is formed in a direction opposite to a pressing direction. In the subsequent step, a shaping die for receiving the inner side surface of the recess is installed, and in the installation state, the swelling portion is crushed by press molding, and the recess is formed. The edge of the opening is shaped.

  Further, the press forming apparatus of the present invention is a press forming apparatus provided with a first-stage press forming section and a second-stage press forming section for press-forming a metal work, wherein the first-stage press forming section and the second-stage press forming section include the metal work. And a second die for pressing a metal work on the first die. The second die of the pre-stage press forming section includes a first die for receiving a metal work on the first die. A concave part forming die for forming a concave part in the metal work; and a bulging part forming die for forming a bulging part protruding in a direction opposite to a pressing direction at an edge of an opening of the concave part; The second mold of the press-formed portion includes a crushing die for crushing the bulging portion, and a shaping die for shaping the inner surface of the concave portion with the crushing. .

  According to the above method and configuration, the edge of the concave portion can be formed in a sharp edge shape. Therefore, the substantial depth of the concave portion can be ensured without using a thick work. In addition, even if there are a plurality of recesses, the plurality of recesses can be press-formed at the same time, and high processing efficiency can be obtained. Further, since there is no need to use a cutting tool, a decrease in accuracy due to tool wear can be avoided, high processing accuracy can be maintained, and no chips are discarded, so that the material yield does not decrease.

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

FIG. 3 is a perspective view of a metal work before processing. Sectional drawing of a metal work. The perspective view of a metal molding. FIG. 2 is a front view showing a metal molded product and a second-stage press molding unit. FIG. 4 is a front view showing a metal work and a pre-stage press forming section in a state where pre-stage press forming has been completed. Sectional drawing of the metal workpiece in the state where press molding of the former stage was completed. FIG. 4 is a bottom view of the upper die of the former press forming section. FIG. 6 is a side view showing a first-stage press forming state of the first recess. FIG. 6 is a side view showing a pre-press forming state of a second recess. FIG. 6 is a side view showing a state of a second-stage press forming of the first recess. FIG. 9 is a side view showing a second-stage press forming state of the second recess. The front view of the metal molded product which showed the modification and omitted the 2nd recessed part. FIG. 14 is a bottom view showing a mold used for press forming in the modification of FIG. 13. The front view of the metal molded product which showed the modification and formed the recessed part alternately. The cut perspective view of the metal molded product which showed the modification and formed the concave part in the metal plate.

An embodiment of 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, has a rectangular cross section, and is formed in an elongated shape. On one side surface of the molded product 21, a plurality (10 in the embodiment) of first concave portions 22 that are depressed in the thickness direction of the molded product 21 are formed at equal intervals in the length direction of the molded product 21. One second concave portion 23 which is depressed in the thickness direction like the first concave portion 22 is formed at an intermediate position between a pair of adjacent first concave portions 22. The second recess 23 is formed deeper than the first recess 22. The molded article 21 has a first flat part 25 located between both ends of the molded article 21 and the first concave part 22, and a pair of second flat parts 26 formed on both sides of the second concave part 23. Have been. The second flat part 26 is arranged at a position higher than the first flat part 25.

Next, a method of manufacturing the molded article 21 and a press molding apparatus will be described.
As shown in FIGS. 1 and 2, a metal work (hereinafter simply referred to as a work) 40 before being formed into a molded product 21 is cut out from a plate material (not shown) or drawn from a thick material by a die. It has a rectangular cross section and has a rod shape as a whole.

  8 and 9 of the press forming apparatus 41 and a rear press forming section 61 shown in FIGS. 10 and 11 so that the first concave portion 22 and the second concave portion 23 are formed. Thus, the work 40 is press-formed twice before and after. Accordingly, the first-stage press forming section 42 executes the first-stage step, and the second-stage press forming section 61 executes the second-stage step.

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

  FIG. 5 shows a pre-press forming section 42 of a press forming apparatus 41. The pre-press forming 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 at a fixed position, and the upper die 44 is raised and lowered. The lower mold 43 is formed with a plurality of (e.g., ten in the embodiment) recesses 431 at equal intervals and a recess 432 located at one location between the pair of recesses 431.

  As shown in FIGS. 5, 7, 8 and 9, the upper mold 44 has a plurality of (10 in the embodiment, but ones at both ends are shorter) first planar molds 45 and a pair of second planar molds 46. Is provided. Further, the upper mold 44 is provided with a plurality of (ten in the embodiment) first protruding dies 47 and one second protruding die 48 constituting a concave forming die. In this embodiment, the upper and lower parts in FIGS. 8 to 11 are the upper and lower parts of the apparatus. Here, as shown by the two-dot chain line in FIGS. 8 and 9, when the upper die 44 is at the raised position, the lower surfaces of the flat dies 45 and 46 and the lower surfaces of the protruding dies 47 and 48 have substantially the same height. There is. Then, as shown by the solid line in FIGS. 8 and 9, when the upper mold 44 is lowered, the protruding dies 47, 48 perform the lowering operation even after the lowering of the flat dies 45, 46 is stopped. It protrudes below 46.

The recesses 431 and 432 of the lower die 43 are formed at positions corresponding to the first and second protruding dies 47 and 48, respectively.
4, 10 and 11 show a second-stage press forming section 61 of the press forming apparatus 41. The subsequent press forming section 61 has a lower mold 62 as a first mold and an upper mold 63 as a second mold. The lower mold 62 is at a fixed position, and the upper mold 63 is raised and lowered. The lower mold 62 is formed with a plurality of (10 in the embodiment) 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 (10 in the embodiment, but shorter at both ends) of a first flat mold 64 and a pair of second flat molds 65 constituting a crush mold.

  The upper die 63 is provided with a plurality of (9 in the embodiment) first protruding dies 66 and a pair of second protruding dies 67 forming a forming die. The lower surface of the upper die 63 appears similarly to the upper die 44 shown in FIG. As shown by a two-dot chain line in FIGS. 10 and 11, when the upper die 63 is at the raised position, the lower surfaces of the flat dies 64 and 65 and the lower surfaces of the protruding dies 66 and 67 are at substantially the same height. However, when the upper dies 63 are lowered, even after the lowering of the flat dies 64 and 65 is stopped, the projecting dies 66 and 67 perform the lowering operation and are protruded below the flat dies 64 and 65.

The recesses 621 and 622 of the lower mold 62 are formed at positions corresponding to the first and second projecting dies 66 and 67, respectively.
In the press forming apparatus 41 configured as described above, as shown in FIGS. 8 and 9, the work 40 is set on the lower die 43 of the former press forming part 42 for the former press forming.

  Then, as the upper mold 44 descends, the work 40 fixed on the lower mold 43 is punched by the first and second flat molds 45 and 46 and the first and second projecting dies 47 and 48. For this reason, the portion between the first and second concave portions 22 and 23 is press-formed by the first and second projecting dies 47 and 48, and at the same time, the first and second concave portions 22 and 23 are formed by the first and second planar dies 45 and 46. Second flat portions 25 and 26 are formed.

  Here, at the positions corresponding to the first and second protruding dies 47 and 48, the depressions 431 and 432 are formed in the lower die 43. 50 and 51 are formed.

  Since arcuate curved portions 471, 481 are formed on both side portions of the distal end portions of the first and second projecting dies 47, 48, curved surface portions are formed at inner corner portions on both sides of the bottom of the concave portions 22, 23. Curved portions 221 and 231 having the same curvature as 471 and 481 are formed. In addition, both side surfaces 472 and 482 of the first and second protruding dies 47 and 48 are inclined surfaces slightly expanding upward, and accordingly, the inner surfaces 222 and 232 of the concave portions 22 and 23 are also slightly inclined upward. It is formed in a shape and becomes a tapered shape.

  A slope 451 that is raised toward the first protruding die 47 is formed at an edge of the lower surface of the first flat die 45 on the first protruding die 47 side. For this reason, with the punching of the upper die 44, both ends of the first flat portion 25, that is, the edges of the first concave portion 22 adjacent to the first flat portion 25 are formed by the slope 451 and the side surface of the first protruding die 47. A bulged portion 223 is formed in an outer corner portion, which is a portion, upward, that is, in a direction opposite to the pressing direction. Therefore, the first flat mold 45 having the inclined surface 451 and the first protruding mold 47 constitute a bulging portion forming mold.

  In addition, since the second concave portion 23 is formed in a narrow space between the adjacent first concave portions 22, the second flat portion 26 between the first concave portion 22 and the second concave portion 23 has the entirety thereof. The stress acts in the direction of rising. For this reason, 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 concave portions 23 is higher than the upper surface of the first flat portion 25. Highly formed. However, no slope is formed on the second flat mold 46, and the bulging portion 223 is not formed on the edge of the opening of the second recess 23 and the edge of the first recess 22 on the side of the second recess 23. .

The work 40 press-formed as described above is set in the second-stage press forming section 61 shown in FIGS. 10 and 11, and further press-formed.
Then, when the work 40 fixed on the lower mold 62 is punched by the lowering of the upper mold 63, the first and second protrusions 66, 67 cause the first and second concave portions 22, 23 of the work 40. Is shaped, and the first and second flat portions 25 and 26 are shaped by the first and second flat molds 64 and 65.

  That is, the lower surface of the first flat mold 64 is flat. For this reason, the bulging portion 223 of the flat portion 25 becomes flat by crushing by punching of the first flat mold 64, and the meat portion forming the bulging portion 223 is moved to the first concave portion 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 punching of the first protruding die 66. The position is regulated by the side surface 662 of the light emitting element. Therefore, the edge of the opening of the first concave portion 22 is formed to be sharp. In other words, the outer corner portion forming the edge of the opening of the first concave portion 22 is shaped into a sharp sharp edge having an extremely large curvature, so that the height of the inner side surface 222 of the first concave portion 22 is increased. Can be.

  On the other hand, as described above, since the second concave portion 23 is formed within a narrow space between the adjacent first concave portions 22, the second flat portion 26 between the first concave portion 22 and the second concave portion 23 has , A stress in the direction of rising high acts. For this reason, the molding surface of the second flat mold 65 of the upper mold 63 is formed at a higher position, as in the former press molding. Therefore, the second flat portion 26 is shaped at a position higher than the first flat portion 25. For this reason, both inner side surfaces 232 of the second concave portion 23 and inner side surfaces 222 of the pair of first concave portions 22 on both sides of the second concave portion 23 on the side of the second flat portion 26 are higher than the inner surface 222 of the other first concave portion 22. It is formed high and shaped in that state.

  Also, arcuate curved surfaces 661, 671 having a larger curvature than the curved surfaces 471, 481, in other words, a shorter radius of curvature, are formed on both side portions of the distal end portions of the first and second projecting dies 66, 67. Therefore, the curved surfaces 221 and 231 of the inner corners on both sides of the bottoms of the recesses 22 and 23 are formed with a substantially right-angled large curvature. Further, both side surfaces 662 and 672 of the first and second protruding dies 66 and 67 are upright, and the inner side surface 222 of the first concave portion 22 is shaped in a direction in which the taper spread angle is small, so that the tapered shape causes the inner surfaces 222 to be mutually separated. It is erected to lie on a plane that is parallel.

Further, the upper surfaces of the first and second flat portions 25 and 26 are shaped by the first and second flat molds 64 and 65 so as to be a smooth plane.
If burrs are generated by punching after the shaping by the subsequent press molding is completed, the burrs are removed by a cutter or a grindstone to form the 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, a part of the fin is engaged in the first concave portion 22, and the output portion of the actuator is in the second concave portion 23. Is involved. Then, when the molded product 21 is moved by driving the actuator, the opening angles of all the movable fins are simultaneously adjusted.

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

  (2) Since the second concave portion 23 is formed in a narrow space between the adjacent first concave portions 22, the second flat portion 26 between the second concave portion 23 and the first concave portion 22 has a high height in the rising direction. Stress acts. Therefore, both inner side surfaces 232 of the second concave portion 23 and the inner side surface 222 of the first concave portion 22 on both sides thereof on the side of the second flat portion 26 are formed high. As a result, a deep second concave portion 23 can be formed.

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

  (4) The first and second concave portions 22 and 23 are formed by dividing the work 40 into two front and rear portions, and the bulging portion 223 is formed, and the bulging portion 223 is crushed to form a sharp edge. As a result, the pressing pressure can be significantly reduced, and damage to the apparatus can be reduced.

  (5) The bulging portion 223 is formed at the same time as the formation of the first concave portion 22, and then the first concave portion 22 is formed in two stages before and after so as to crush the bulging portion 223 when shaping the first concave portion 22. Therefore, even if the work 40 is a hard and difficult-to-process material, it is possible to avoid the possibility that the work 40 is broken or the press forming 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 section is increased in the second press forming step. Can be increased without difficulty, and the substantial height of the inner side surfaces 222 and 232 of the first and second concave portions 22 and 23 can be increased.

  (7) The inner side surfaces 222 and 232 of the first and second concave portions 22 and 23 are formed in a tapered shape extending outward in the axial direction of the workpiece 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 set upright, and the first and second concave portions 22 and 23 can be made substantially deeper.

The present invention is not limited to the above embodiment, but can be embodied in the following modes.
In the above-described embodiment, the press forming is performed in two steps before and after, but at least one of the pre-process and the post-process is divided into a plurality of stages, and the press process is performed in three or more times as a whole. In this case, the bulging portion 223 is formed in a plurality of times or crushed in a plurality of times. Therefore, the load on the press forming apparatus 41 per punching can be reduced.

A shallow concave portion 70 is formed on the upper surface of the flat portions 25 and 26 as shown by a two-dot chain line in FIGS. 10 and 11.
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 first press forming section 42 and the second press forming section 61 are omitted. For example, as shown by a two-dot chain line in FIG. 12, the molded product 21 in which the second concave portion 23 and the second flat portion 26 are not formed is formed by symmetrically forming a pair of molded products 21 so that the first concave portion 22 faces. , The space between the opposing first concave portions 22 can be used as a fluid passage.

-The first concave portions 22 are formed at irregular intervals.
Use of a work other than a rod shape, for example, a ring-shaped or plate-shaped work 40. In the case of the ring-shaped work 40, the end face in the axial direction of the work 40 is processed. In addition, the ring-shaped workpiece 40 can be obtained by cutting a pipe material.

  As shown in FIG. 14, the recesses 23 are formed on both the front and back surfaces of the work 40. 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 concave portion 22 is formed in the plate-shaped work 40.
・ The work 40 is chamfered in advance.

  -Depressed parts 431 and 432 of the former press forming part 42 are omitted.

  Reference numeral 21 denotes a metal molded product, 22 denotes a first concave portion, 23 denotes a second concave portion, 40 denotes a metal work, 41 denotes a press forming device, 42 denotes a front press forming portion, 61 denotes a rear press forming portion, and 223 denotes a bulging portion.

Claims (8)

In front of the step, by press molding a metal workpiece so as to form a flat portion and a concave portion, the edge of the opening of the recess, are continuously bulged portion protruding in the direction opposite to the pressing direction in the flat portion Forming
In a subsequent step, a shaping die for receiving the inner surface of the recess is installed in the recess, and in the installed state, the metal that shapes the edge of the opening of the recess by crushing the bulging portion by press molding. Manufacturing method of molded article.   The method for manufacturing a metal molded product according to claim 1, wherein a plurality of the concave portions are formed, and the concave portions are simultaneously press-formed.   The method for manufacturing a metal molded product according to claim 1, wherein a surface of the metal work opposite to the concave portion is received by a concave portion of a mold.   The metal according to any one of claims 1 to 3, wherein the inner corner portion of the concave portion is formed in a curved shape in the first step, and the curvature of the curved surface of the inner corner portion is increased in the second step. Manufacturing method of molded article.   The inner surface of the concave portion is formed in a tapered shape expanding toward the opening side of the concave portion in the first step, and the taper expansion angle of the inner surface is reduced in the second step. A method for producing a metal molded product according to claim 1.   The manufacturing of the metal molded product according to any one of claims 1 to 5, wherein, in the former step, the concave portions are formed at equal intervals, and another concave portion is press-formed between a pair of adjacent concave portions. Method. In a press forming apparatus having a first-stage press forming unit and a second-stage press forming unit for press-forming a metal work,
The first-stage press forming unit and the second-stage press forming unit each include a first mold for receiving the metal work, and a second mold for pressing the metal work on the first mold. ,
The second die of the first-stage press forming section includes a flat mold for forming a flat portion on the metal work, a concave forming die for forming a concave portion, and the flat mold and the concave forming mold. A bulging portion molding die for continuously forming a bulging portion projecting in the opposite direction to the pressing direction at the edge of the opening of the concave portion to the flat portion ,
The second mold of the second-stage press forming section includes a press forming apparatus including a crushing mold for crushing the bulging portion and a shaping mold for shaping the inner surface of the concave portion with the crushing. .   The press-forming apparatus according to claim 7, wherein at least a first mold of the second-stage press-forming section has a recess for receiving the concave portion of the metal work.

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