JP6190658B2 - Press molding die, press molding method, and press molding apparatus - Google Patents

Description

  The present invention relates to a mold, a method, and an apparatus for press-molding a metal member having a specific shape.

  There are many press-formed products of steel plates in automobile parts and the like. Among them, there are many members having a shape that has a large unevenness difference and cannot be easily formed.

  FIG. 1 shows one such molded member (longitudinal sectional view). The illustrated molded member includes a dome-shaped boss portion 101, a horizontal flange portion 102 protruding from the lower peripheral edge of the boss portion 101, and a cylindrical vertical flange portion 103 protruding upward from the outer peripheral edge of the horizontal flange portion 102. have.

  Usually, in the case of such a molded member, in order to avoid breakage, it is formed by performing drawing processing a plurality of times (multistage drawing processing). Specifically, after the steel plate is formed into a cup shape, the center of the bottom surface is pushed up from the lower side a plurality of times and drawn to form the boss portion 101 gradually. Therefore, the multistage drawing process requires a lot of man-hours, takes time for molding, and the boss portion 101 becomes thin.

  A method of forming such a molded member with a small number of man-hours has also been studied (Patent Documents 1 and 2).

  In FIG. 2, the outline of the processing method of patent document 1 is shown. The mold there is composed of a die 202, a pressing punch 203, a ring punch 204, and the like.

  As shown in (a), the plate-like material 201 is positioned on the guide part 210 of the die 202. The pressing punch 203 and the ring punch 204 are lowered, and the plate material 201 is formed into a cup-shaped member. Subsequently, as shown in (b), the ring punch 204 is further lowered. Then, as shown in (c), the bottom of the cup-shaped member is raised to form a boss.

  In FIG. 3, the outline of the processing method of patent document 2 is shown. The mold there is composed of a die 301, a pressing punch 302, an inner punch 303, an end face punch 304, and the like.

  As shown to (a), the bottomed cylindrical body 310 prepared previously is mounted in the dice | dies 301. FIG. After that, as shown in FIG. 5B, the bottomed cylindrical body 310 is sandwiched between the die 301 and the pressing punch 302, and the end punch 304 presses the end surface of the bottomed cylindrical body 310 while the inner punch 303 holds the bottom. The bottom portion of the bottom cylindrical body 310 is pressurized to form a boss portion 340.

JP-A-9-150223 JP 2004-322104 A

  According to the methods of Patent Documents 1 and 2, it is possible to form with less man-hours than multistage drawing.

  However, since both are multi-axis presses, there is a drawback that the processing time is long. That is, in the method of Patent Document 1, it is necessary to operate the pressing punch 203 and the ring punch 204 while shifting the timing, and in the method of Patent Document 2, the pressing punch 302, the inner punch 303, and the end surface punch 304 are timed. It is necessary to shift the operation.

  For this reason, when combined with a uniaxial press, these methods hinder the reduction of tact time, and there is a problem that a single press or transfer press excellent in capital investment and mass productivity cannot be used.

  Accordingly, an object of the present invention is to provide a press mold or the like that can shorten tact time and can use a single press or a transfer press when forming a member having a specific shape that usually requires drawing.

  The disclosed press molding die has a boss portion from the center portion of the bottom wall portion with respect to a metal bottomed cylindrical body having a cylindrical peripheral wall portion and a bottom wall portion that closes one end of the peripheral wall portion. Used for molding to bulge in the direction.

  The press mold includes a first member in which a molding hole into which the bottomed cylindrical body is inserted, a second member to be inserted into the bottomed cylindrical body that is inserted into the molding hole at the time of molding, Is provided. The first member has an annular recess formed by recessing a peripheral portion of the bottom surface of the forming hole.

  The second member slides along the peripheral surface of the molding hole, and a press-fit portion that contacts the opening end of the peripheral wall portion, and a cylindrical support that is provided integrally with the press-fit portion and contacts the inner surface of the peripheral wall portion A surface portion, an annular convex portion that is in contact with a peripheral portion of the bottom wall portion and is fitted into the annular concave portion, and a molding space that is formed with a recess between the annular convex portions and that can receive the boss portion. doing.

  And at the time of shaping | molding, before the said cyclic | annular convex part contacts the peripheral part of the said bottom wall part, it is comprised so that the said press-fit part may contact | connect the opening end of the said surrounding wall part.

  According to the press-molding die thus configured, the bottomed cylindrical body made of metal is inserted into the molding hole of the first member, and the second member is inserted into the bottomed cylindrical body, whereby the boss portion Is formed. At that time, since the press-fit portion contacts the opening end of the peripheral wall portion before the annular convex portion contacts the peripheral portion of the bottom wall portion, the peripheral wall portion is first pushed by the press-fit portion, and the peripheral wall portion of the bottomed cylindrical body The lower portion and the peripheral portion of the bottom wall portion enter the annular recess and deform.

  At this time, since the annular convex portion is located above the annular concave portion, the peripheral portion of the bottom wall portion can be easily deformed in the drawing direction, and the formation of the boss portion can be induced. Further, when the peripheral wall portion is pushed in by the press-fitting portion, the central portion of the bottom wall portion rises and swells in the forming space, so that the boss portion can be formed.

  Therefore, according to this press molding die, the boss portion that bulges greatly inward from the central portion of the bottom wall portion of the bottomed cylindrical body only by the uniaxial pressing process in which the second member is abutted against the first member. Therefore, the tact time can be shortened and a single press or transfer press can be used.

  Specifically, it is preferable that cross sections of the annular recess and the annular projection are formed in an arc shape.

  If it does so, shaping | molding of a boss | hub part can be induced | guided | derived smoothly.

  More specifically, it is preferable to form a tapered surface that narrows toward the back on the inner surface of the second member that defines the molding space and that continues from the annular convex portion.

  If it does so, shaping | molding of a boss | hub part can be induced | guided | derived more smoothly by a taper surface.

  More specifically, the first member further includes a slide member for displacing the bottomed cylindrical body, and the second member retracts to a retracted position away from the first member, whereby the first member An open space that allows the bottomed cylindrical body to enter and exit is formed between the member and the second member, and the slide member causes the metal member to move between the transfer position in the open space and the molding hole. It is preferable to be displaced to the molding position.

  If it does so, since a bottomed cylindrical body is always set in the transfer position in the open space which can enter / exit before and after shaping | molding, carrying in and carrying out of a bottomed cylindrical body can be performed easily.

  For example, it is preferable that the molding surface is coated with a protective film, and the protective film includes at least one of Ti-based, Al-based, Cr-based, and V-based ceramic films.

  By doing so, the wear resistance and releasability are remarkably improved, and stable molding over a long period of time becomes possible.

  The press molding method using these press molding dies includes a preparation step for setting the bottomed cylindrical body and a molding step for molding the boss portion. And the said formation process inserts the peripheral part of the said bottom wall part in the said annular recessed part by press-fitting the opening end of the said surrounding wall part in the said press-fit part, and induces the deformation | transformation to the said boss | hub part. The molding space is formed by press-fitting a portion from the peripheral wall portion to the bottom wall portion with the annular convex portion while pressing the opening end of the peripheral wall portion with the first insertion portion. And receiving a central portion of the bottom wall portion to form the boss portion.

  A press forming apparatus disclosed includes a main forming apparatus using the above-described press forming mold, and a pre-forming apparatus that presses a steel plate to form the bottomed cylindrical body, and the main forming apparatus and the pre-forming apparatus. Are operated synchronously.

  This press forming apparatus is excellent in mass productivity because it can be efficiently continuously formed from the steel plate to the boss.

  When a press molding die having the above-described slide member is used in the main molding apparatus, the transfer position of the main molding apparatus is flush with the transfer position of the bottomed cylindrical body in the preforming apparatus. It is preferable to further include a transfer device that is provided to be positioned at the position and transfers the bottomed cylindrical body along the plane.

  If it does so, transfer between apparatuses becomes easy and improvement in productivity can be aimed at.

  According to the present invention, it is possible to realize a press mold having excellent productivity.

It is the schematic which showed one of the conventional press-formed products. (A)-(c) is the figure simplified in order to demonstrate one of the conventional shaping | molding methods. (A), (b) is the figure simplified in order to demonstrate another one of the conventional shaping | molding methods. It is a schematic perspective view which shows the shaping | molding member shape | molded by the press molding die etc. of this embodiment. It is the schematic which shows the press molding apparatus of this embodiment. (A)-(c) is the schematic which shows each process of the shaping | molding process at the time of preforming. It is a schematic perspective view which shows the metal mold | die (press molding metal mold | die) used with this shaping | molding apparatus. (A), (b) is the schematic which shows each process of the preparatory process at the time of this shaping | molding. (A), (b) is the schematic which shows each process of the shaping | molding process at the time of this shaping | molding. (A), (b) is the schematic which shows each process of the shaping | molding process at the time of this shaping | molding. (A), (b) is the schematic which shows each process of the payout process at the time of this shaping | molding.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

<Molded member>
FIG. 4 shows a molding member (boss member 10) molded by the press molding die of this embodiment.

  The boss member 10 is a member used for the cover of the transmission, and is formed by compressing and deforming a steel plate having a thickness of about 3 mm. The material of the steel plate is made of die steel, high speed steel, alloy tool steel, etc., and SKD11 is used in this embodiment.

  The boss member 10 includes a boss portion 12 that bulges in a dome shape, a cylindrical vertical flange portion 13 that is positioned around the boss portion 12, a lower peripheral edge of the boss portion 12, and a lower end of the vertical flange portion 13. The cross section which continues to arc-shaped horizontal flange part 14 has.

  The outer diameter of the boss member 10 is about 150 mm. The ratio (drawing ratio: φ2 / φ1) of the inner diameter φ2 of the boss portion 12 to the inner diameter φ1 of the vertical flange portion 13 is 0.4 to 0.7, more specifically 0.5 to 0.6. Yes. The longitudinal section of the boss member 10 is line-symmetric with respect to the center line at any position.

  The peripheral wall 12a of the boss portion 12 has a shape narrowed toward the tip side, and its cross section is inclined with a steep slope. The top portion 12b of the boss portion 12 spreads while gently descending from the center toward the upper end edge of the peripheral wall 12a, and protrudes upward from the edge of the upper end 13a of the vertical flange portion 13.

<Press molding equipment>
In FIG. 5, the press molding apparatus 1 of this embodiment is shown. The press forming apparatus 1 includes a preliminary forming apparatus 3, a main forming apparatus 5, a transfer apparatus 7, and the like, and can continuously form the boss member 10 from the rolled steel plate 11.

  The preforming device 3 forms the intermediate body 20 from the steel plate 11 by uniaxial pressing. The intermediate body 20 has a cylindrical peripheral wall portion 21 and a flat bottom wall portion 22 that closes one end of the peripheral wall portion 21, and the opposing surface of the bottom wall portion 22 is opened (a bottomed cylindrical body). ). A boundary portion between the peripheral wall portion 21 and the bottom wall portion 22 is formed in a round shape and has a circular arc cross section (R processing).

  The main forming apparatus 5 forms the boss member 10 from the intermediate body 20 by uniaxial pressing. Specifically, the molding apparatus 5 deforms the portion from the bottom wall portion 22 of the intermediate body 20 to the peripheral wall portion 21 and causes the boss portion 12 to bulge inward from the center portion of the bottom wall portion 22.

  The intermediate body 20 and the boss member 10 are transferred by the transfer device 7. Each transfer device 7 includes a plurality of sandwiching arms 7a, a drive control unit 7b that drives and controls the sandwiching arms 7a, and the like.

  The steel plate 11, the intermediate body 20, and the boss member 10 are configured so that they can be transferred along a horizontal plane S having the same height.

  Each clamping arm 7a can be displaced in two vertical and horizontal directions along the horizontal plane S, and its operation is controlled by a drive control unit 7b based on a preprogrammed control program.

  For example, each clamping arm 7 a clamps the bottom portion of the intermediate body 20 from the outer peripheral side, transfers the intermediate body 20 while sliding it from the preforming device 3, and sets the intermediate body 20 in the main molding device 5. Moreover, each clamping arm 7a clamps the bottom part of the boss member 10 from an outer peripheral side, and transfers it while sliding the boss member 10 toward the next process (not shown) from the main forming apparatus 5.

  The preforming device 3 and the main forming device 5 operate in synchronization.

  That is, the length and timing of the time for forming one intermediate 20 and the time for forming one boss member 10 are set to coincide. Further, the length and timing of the transfer time of the intermediate body 20 and the transfer time of the boss member 10 are also set to coincide with each other.

  Therefore, in this press forming apparatus 1, the steel plate 11 can be continuously and efficiently formed from the steel plate 11 to the boss member 10 by supplying the steel plate 11 to the pre-forming device 3 at a predetermined time and timing. Since the pre-forming device 3 and the main forming device 5 are configured with one axis instead of a complicated multi-axis, and operate synchronously, the tact time can be easily reduced.

(Preliminary molding equipment)
FIG. 6 shows a molding process in the preforming device 3. The preforming device 3 is assembled with a preforming mold 30 that operates on one axis. In addition to the preforming mold 30, the preforming device 3 is equipped with a press mechanism capable of uniaxial control, a control device, and the like.

  The preforming mold 30 includes a female mold 31 and a male mold 32. The female die 31 is formed with a bottomed cylindrical preforming hole 33 having a center line A <b> 1 extending in the vertical direction that is the operating direction of the male die 32. A cylindrical elevating member 34 that moves up and down is provided at the bottom of the preforming hole 33 in the female die 31.

  The inner method of the preforming hole 33 is formed according to the outer method of the intermediate body 20 except for the depth, and the outer method of the male mold 32 is formed according to the inner method of the intermediate body 20. The female die 31 is fixed to the preforming device 3 with its flat upper surface aligned with a horizontal surface S having a predetermined height.

  At the time of forming, first, as shown in FIG. 6A, the disk-shaped steel plate 11 cut to a predetermined size is set at a predetermined position (a position where the centers match) on the upper surface of the female die 31. Then, the male die 32 is lowered and fitted into the preforming hole 33 while the steel plate 11 is press-fitted into the preforming hole 33.

  In addition, by attaching a cylindrical cut mold around the male mold 32 and supplying the strip-shaped steel sheet 11 to the upper surface of the female mold 31, the steel sheet 11 is cut into a predetermined shape immediately before being press-fitted into the preforming hole 33. May be.

  Thereby, as shown in FIG. 6B, the steel plate 11 is sandwiched and deformed between the male mold 32 and the female mold 31, and the intermediate body 20 is formed. Subsequently, the male mold 32 is pulled out from the preforming hole 33 and the elevating member 34 is raised. As shown in FIG. 6 (c), the intermediate body 20 is pushed out so that the lower surface of the bottom wall portion 22 becomes the horizontal plane S. It is positioned at a matching position (transfer position).

  Thereafter, the intermediate body 20 is immediately sandwiched between the sandwiching arms 7a, and is transported toward the main forming apparatus 5 by sliding sideways on the horizontal plane S.

(Configuration of this molding device)
FIG. 7 shows a main molding die 50 (press molding die) assembled in the main molding apparatus 5. In addition to the main molding die 50, the main molding apparatus 5 is also equipped with a press mechanism, a control device, and the like capable of uniaxial control.

  The main molding die 50 includes a first member 51 fixed to the main molding apparatus 5 and a second member 52 that slides in the vertical axial direction.

  The first member 51 is made of a columnar steel material having a flat upper surface, and a bottomed cylindrical forming hole 53 into which the intermediate body 20 is fitted is formed on the upper surface. The first member 51 is installed in the main molding apparatus 5 so that the upper surface of the first member 51 coincides with the horizontal plane S. The center line A2 of the forming hole 53 extends in the vertical direction.

  The molding hole 53 has a cylindrical inner peripheral surface 53a having an inner diameter slightly larger than the outer diameter of the intermediate body 20, and a bottom surface 53b connected to the inner corner of the inner peripheral surface 53a. An annular recess 53c having an arcuate cross section that is smoothly connected to the inner peripheral surface 53a is formed on the entire periphery of the peripheral portion of the bottom surface 53b.

  A mounting portion 53d that protrudes relatively in a trapezoidal shape is formed at the center of the bottom surface 53b. Specifically, the placement portion 53d has a truncated cone shape having an inclined surface that smoothly continues from the annular recess 53c and narrows upward, and a flat upper surface that continues to the upper edge of the inclined surface.

  A cylindrical slide hole 54 extending in the vertical direction is formed in the deepest portion of the annular recess 53c, and a cylindrical slide member 55 is slidably assembled therein. The slide member 55 is controlled so as to be displaced between a lowered position where the slide member 55 enters the slide hole 54 and an elevated position where the upper portion protrudes into the molding hole 53.

  The second member 52 is formed of a substantially columnar member that is inserted into the intermediate body 20 that is inserted into the molding hole 53 at the time of molding, and includes a substantially columnar main body portion 57 and a cylindrical press-fit portion 58. ing. The second member 52 is retracted to a retracted position away from the first member 51 during standby, and moves up and down once during molding.

  The press-fit portion 58 has an outer diameter that matches the inner diameter of the molding hole 53, and is fixed in close contact with the outer peripheral surface of the main body portion 57. The press-fit portion 58 may be formed integrally with the main body portion 57, but in the present embodiment, the press-fit portion 58 is configured by a separate member so that the fixed position can be finely adjusted with respect to a molding error. The thickness of the press-fit portion 58 is equal to or less than the thickness of the steel plate 11.

  The press-fit portion 58 is fixed to the upper portion of the main body portion 57, and the lower end of the press-fit portion 58 is a ring-shaped flat surface facing in the vertical direction. A support surface portion 59, an annular convex portion 60, a molding space 61, and the like are formed below the main body portion 57 exposed from the press-fit portion 58.

  The support surface portion 59 is a cylindrical portion that continues to the lower end of the press-fit portion 58 of the main body portion 57. The outer diameter of the support surface portion 59 is formed in accordance with the inner diameter of the intermediate body 20. The annular protrusion 60 is connected to the lower side of the support surface portion 59 and protrudes in an annular shape. The protruding end of the annular convex portion 60 is formed in a cross-sectional arc shape smaller than the annular concave portion 53c by the thickness of the steel plate 11.

  The space between the annular convex portions 60 is recessed upward to form a space in which the boss portion 12 can be received (molding space 61). Of the inner surface of the main body 57 that defines the molding space 61, a tapered surface 61 a that narrows toward the back of the molding space 61 is formed on the opening side portion of the molding space 61 that continues from the annular convex portion 60. Yes.

  As shown in an enlarged view in FIG. 7, the molding surfaces used for molding the first member 51 and the second member 52 (portions where the intermediate body 20 can come into contact, such as the molding hole 53 and the lower surface of the main body portion 57) are as follows. It is coated with a mirror-finished protective film 63 having a thickness of about 1 to 10 μm.

  The protective film 63 of this embodiment is a composite film having a three-layer structure, and is composed of a Ti-based ceramic film, that is, a compound containing a Ti element. Specifically, the protective film 63 is composed of a titanium nitride layer 63a, a titanium nitride carbide layer 63b, and a titanium carbide layer 63c, which are sequentially stacked from the surface side of the base material, and physical vapor deposition (PVD: Physical Vapor Deposition). ) Method.

  By coating with the protective film 63, wear resistance and releasability are remarkably improved, so that the boss member 10 can be stably molded over a long period of time.

  Unlike the illustration, the boundaries between the layers are not clear, and the ratio of C and N in the titanium nitride carbide layer 63b may be gradually changed so that the composition gradually changes along the thickness direction. . If it does so, the adhesiveness of the protective film 63 can be improved. The protective film 63 is not limited to Ti, but may be an aluminum (Al), chromium (Cr), or vanadium (V) ceramic film, or a composite film of each of these.

(Operation of this molding device)
The molding operation in the present molding device 5 will be specifically described with reference to FIGS.

  FIG. 8 shows a preparation step for setting the intermediate body 20 in the main molding apparatus 5. As shown to (a) of FIG. 8, in the initial state of a preparation process, the slide member 55 exists in a raise position, and the front-end | tip is positioned on the horizontal surface S. As shown in FIG.

  Further, the second member 52 is in a standby state, and is retracted to a retracted position. Thereby, between the 2nd member 52 and the 1st member 51, the open space of the magnitude | size which the intermediate body 20 can enter / exit without trouble from the side is formed.

  The intermediate body 20 sandwiched by the sandwiching arm 7a enters the open space while sliding, and the bottom wall 22 is supported by the tip of the slide member 55, and the center of the intermediate body 20 coincides with the center line A2 (transfer). Position).

  Then, as indicated by an arrow in FIG. 8B, after the holding arm 7a is separated from the intermediate body 20, the slide member 55 is lowered to the lowered position. Since the lower corner of the intermediate body 20 is rounded, the intermediate body 20 is stably fitted into the molding hole 53 even if the center is slightly shifted. As a result, the intermediate body 20 is fitted into the molding hole 53 and displaced to the molding position shown in FIG.

  The intermediate body 20 at the molding position has the center portion of the bottom wall portion 22 placed on the upper surface of the placement portion 53d, and almost the inner surface of the molding hole 53 except for the peripheral portion of the bottom wall portion 22 in contact with the annular recess 53c. Is in contact with

  9 and 10 show a molding process for molding the boss portion 12 on the bottom wall portion 22. In the molding process, the peripheral portion of the bottom wall portion 22 is inserted into the annular recess 53c to be deformed, and the first portion for inducing deformation to the boss portion 12 is received, and the central portion of the bottom wall portion 22 is received in the molding space 61 The two-stage molding of the second stage for forming the boss portion 12 is continuously performed in the process of inserting the second member 52 into the molding hole 53.

  As shown in FIG. 9A, when the second member 52 is lowered, first, the annular convex portion 60 enters the inside of the peripheral wall portion 21. At this time, since the protruding end of the annular convex portion 60 is a curved surface, the annular convex portion 60 stably enters the inside of the peripheral wall portion 21 even if it is slightly deviated.

  Then, in a state where the support surface portion 59 is in contact with the inner surface of the peripheral wall portion 21, the annular convex portion 60 further enters the back, and the lower end of the press-fit portion 58 abuts against the opening end 21 a of the peripheral wall portion 21. When the second member 52 is further lowered, a downward load is applied to the peripheral wall portion 21, so that the intermediate body 20 is press-fitted into the molding hole 53. Accordingly, as shown in FIG. 9B, the lower portion of the peripheral wall portion 21 and the peripheral portion of the bottom wall portion 22 enter the annular recess 53c and deform.

  At this time, the annular recess 53c is a curved surface having an arcuate cross section, and the annular protrusion 60 is located above the annular recess 53c. Therefore, the peripheral portion of the bottom wall portion 22 can be easily deformed in the drawing direction. Can do.

  Further, when the second member 52 is lowered, the peripheral wall portion 21 is further pushed by the press-fit portion 58, and accordingly, the central portion of the bottom wall portion 22 is guided by the annular recess 53 c and swells to the molding space 61. To do. Subsequently, as shown in FIG. 10A, the bulged portion (bulged portion) contacts the annular convex portion 60. Since the taper surface 61 a is formed on the inner surface of the main body 57 that defines the molding space 61, the bulging portion can be smoothly guided to be deformed into the boss portion 12.

  Further, as shown in FIG. 10B, when the second member 52 is lowered to the lowest point, the boss member 10 is formed. In other words, the vertical flange portion 13 is formed when the press-fit portion 58 pushes the upper portion of the peripheral wall portion 21 to a predetermined position. The annular convex portion 60 is fitted into the annular concave portion 53c, and a part of the peripheral wall portion 21 sandwiched between the annular convex portion 60 and the annular concave portion 53c is deformed into a circular arc shape, and the lateral flange portion 14 is formed.

  And the peripheral wall 12a of the boss | hub part 12 is formed by the bulging to the side of a bulging part being blocked | prevented by the taper surface 61a. The upper surface of the bulging portion is located in the space of the molding space 61, and is naturally curved to form the top portion 12b of the boss portion 12.

  FIG. 11 shows a payout process for paying out the molded boss member 10 from the main mold 50. When the boss member 10 is molded, the second member 52 rises to the standby position as shown in FIG. The slide member 55 is also raised, and the boss member 10 is pushed out from the molding hole 53 to the transfer position by the slide member 55.

  The boss member 10 pushed out to the transfer position is clamped by the clamp arm 7a, and is slid horizontally from the transfer position along the horizontal plane S as shown in FIG. Simultaneously with the transfer of the boss member 10, as shown in FIG. 8A, the intermediate body 20 to be molded next is newly transferred to the transfer position, and the next molding starts.

  Thereafter, a series of these operations are repeated, and the boss member 10 is continuously formed.

  In addition, the press molding apparatus etc. concerning this invention are not limited to embodiment mentioned above, The other various structure is included.

  For example, the preforming apparatus and the main forming apparatus may be incorporated into one apparatus or may be systematized by connecting individual apparatuses. The preforming and the main forming may be performed by one single-screw press by exchanging the mold.

DESCRIPTION OF SYMBOLS 1 Press molding apparatus 3 Preliminary molding apparatus 5 Main molding apparatus 7 Transfer apparatus 10 Molding member (boss member)
11 Steel plate 12 Boss portion 20 Intermediate body (bottom cylindrical body)
21 peripheral wall portion 21a open end 22 bottom wall portion 50 main molding die (press molding die)
51 1st member 52 2nd member 53 Forming hole 53c Annular recessed part 55 Slide member 57 Main body part 58 Press-fit part 59 Support surface part 60 Annular convex part 61 Forming space 61a Tapered surface 63

Claims (8)

A press mold,
Used for forming a metal bottomed cylindrical body having a cylindrical peripheral wall portion and a bottom wall portion that closes one end of the peripheral wall portion, so that the boss portion bulges inward from the center portion of the bottom wall portion. And
A first member formed with a molding hole into which the bottomed cylindrical body is inserted;
A second member fitted into the bottomed cylindrical body fitted into the molding hole during molding;
With
The first member has an annular recess formed by recessing a peripheral portion of the bottom surface of the molding hole,
The second member is
A press-fit portion that slides along the peripheral surface of the molding hole and is in contact with the open end of the peripheral wall portion;
A cylindrical support surface provided integrally with the press-fit portion and in contact with the inner surface of the peripheral wall;
An annular convex portion that contacts the peripheral portion of the bottom wall portion and fits into the annular concave portion,
A space formed between the annular convex portions is recessed, and a molding space capable of receiving the boss portion;
Have
A press-molding die configured so that the press-fitting portion is in contact with the opening end of the peripheral wall portion before the annular convex portion is in contact with the peripheral portion of the bottom wall portion during molding. In the press-molding die according to claim 1,
A press molding die in which a cross section of the annular recess and the annular projection is formed in an arc shape. In the press-molding die according to claim 1 or 2,
A press-molding die in which a tapered surface that is constricted toward the back is formed on the inner surface of the second member that is continuous from the annular convex portion and defines the molding space. In the press-molding die according to any one of claims 1 to 3,
The first member further includes a slide member that displaces the bottomed cylindrical body,
The second member retracts to a retracted position away from the first member, thereby forming an open space that allows the bottomed cylindrical body to enter and exit between the first member and the second member. And
A press molding die in which the metal member is displaced by the slide member between a transfer position in the open space and a molding position in the molding hole. In the press-molding die according to any one of claims 1 to 4,
The molding surface is coated with a protective film,
A press mold in which the protective film includes at least one of a Ti-based, Al-based, Cr-based, and V-based ceramic film. A press molding method,
Using the press-molding die according to any one of claims 1 to 5,
A preparation step for setting the bottomed cylindrical body;
A molding step of molding the boss part;
Including
The molding step is
A first stage in which a peripheral edge portion of the bottom wall portion is inserted into the annular recess and deformed by press-fitting an opening end of the peripheral wall portion with the press-fitting portion, and the deformation to the boss portion is induced;
While pressing the opening end of the peripheral wall portion with the press-fit portion, the bottom wall portion is inserted into the molding space by press-fitting a portion from the peripheral wall portion to the bottom wall portion with the annular convex portion. A second step of receiving the central portion of the boss and forming the boss portion;
A press molding method including: A press molding apparatus,
A main molding apparatus using the press molding die according to any one of claims 1 to 5,
A preforming device for pressing the steel plate to form the bottomed cylindrical body;
With
A press forming apparatus in which the main forming apparatus and the pre-forming apparatus operate synchronously. The press molding apparatus according to claim 7,
The press molding die according to claim 4 is used in the main molding apparatus,
The transfer position of the main forming apparatus is provided so as to be located on the same plane as the transfer position of the bottomed cylindrical body in the preforming apparatus,
A press molding apparatus further comprising a transfer device for transferring the bottomed cylindrical body along the plane.

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