JP2001259750A - Forming method of metal product and forming die used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method to easily form a metal product, in which a flat section with a sufficient width is arranged to the outer face of an inner flange integrally formed between a cylindrical part and a rising part of the cylindrical part, without deteriorating of strength of the flange and generation of a seam, etc., and a forming die used therefor. SOLUTION: By applying drawing for a bottom part 32 of a preformed body 28 with a bottomed cylindrical shape and a stepped face 34 to the outer peripheral face of a cylindrical wall part 30, a rising part 16 of an objective metal product is formed, further, by pushing-in the cylindrical wall part 30 of the preformed body 28 into an inner flange formed part 94 of a groove shape up to so that the stepped face 34 is brought into contact with a flat bottom part 90 of the inner flange formed part 94, a cylindrical part 12 of the metal product is formed to a thick stock part 38 more to opening side than the stepped face 34 of the cylindrical wall part 30, an inner flange 14 is formed in the inner flange forming part 94 while a thin stock part 36 more to bottom side than the stepped face 34 of the cylindrical wall part 30 is compressed and thickened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a metal product and a molding die used for the method, and more particularly, to an inner flange integrally formed at one end of a cylindrical portion so as to protrude inside the cylindrical portion. And a method of advantageously forming a metal product in which a cylindrical rising portion protruding toward the other end side of the cylindrical portion is integrally provided at a tip end portion of the inner flange. The present invention relates to a molding die suitably used in such a molding method.

[0002]

2. Description of the Related Art In general, various kinds of metal products having various shapes are used for automobile parts and the like, and as one type thereof, a predetermined cylindrical portion is provided, and one end of the cylindrical portion is provided. An inner flange protruding inside the cylindrical portion is formed integrally with the portion, and a cylindrical rising portion protruding toward the other end side of the cylindrical portion is formed at a front end of the inner flange. There is a metal product in which a part is integrally provided.

[0003] As a method for forming such a metal product, the following method is known. That is, first,
Using a flat metal material, drawing processing is performed on the metal material to form the metal material into a bottomed cylindrical shape, and then, with respect to the bottom of the metal material having the bottomed cylindrical shape, By performing reverse redrawing, the metal material is formed into a shape in which two cylindrical wall portions formed on the outside and the inside are connected by a plate-shaped connection portion provided at the bottom, The outer cylindrical wall portion forms the cylindrical portion, the inner cylindrical wall portion forms the cylindrical rising portion, and the plate-shaped connecting portion forms the inner flange. To obtain a metal product.

When such a metal product is used, for example, as a component of an automatic transmission or the like, the surface of the inner flange opposite to the direction in which the rising portion protrudes, that is, the outer surface of the inner flange is limited. It is required to have as large a flat surface as possible within the specified width. However, in the forming method based on the combination of the above-described drawing, it is inevitable that the corners are curved due to the drawing, and it is not possible to sufficiently meet such a demand.

Therefore, conventionally, when such a metal product is obtained, for example, the outer surface of the inner flange of the metal product formed as described above is cut by a predetermined thickness. A portion including a curved outer surface side corner portion at both ends of the inner flange (a corner portion formed between the outer surface of the inner flange and the inner peripheral surface of the cylindrical rising portion and the outer peripheral surface of the cylindrical portion). A method has been adopted in which the width of the flat portion on the outer surface of the inner flange is increased by removing it. However, in such a method, the thickness of the inner flange is inevitably reduced by cutting the inner flange, thereby causing a serious problem that the strength of the inner flange, and consequently the entire metal product is reduced. It was.

As another method, an inner side surface corresponding to the inner peripheral shape of the cylindrical rising portion, an outer side surface corresponding to the outer peripheral shape of the cylindrical portion of the metal product, and a flat bottom surface are formed. A metal product formed as described above using a molding die having a molding groove having the molding groove is formed by forming the inner peripheral surface of the rising portion, the outer peripheral surface of the cylindrical portion of the metal product, and the outer surface of the inner flange into the molding groove. Under the condition that the metal product is housed in the molding groove so as to be brought into contact with both side surfaces and the bottom surface of the metal product, the cylindrical portion or the rising portion of the metal product is moved from the opening side of the cylindrical portion toward the bottom side. Pressing and pressing the curved outer-side corners at both ends of the inner flange against the bottom surface of the molding groove to correspond to the angular inner corners formed by the bottom surface of the molding groove and both side surfaces thereof. Is compression-molded to an approximate shape, and the outer side corners at both ends of the inner flange The radius of curvature (so-called, R) in a curved shape without reducing the even and a method of increasing the width of the flat portion on the outer surface of the flange Te than are employed.

However, in such a method, in a state where the metal product is accommodated in the forming groove, a pressing force is applied to the cylindrical portion or the rising portion of the metal product, and the outer side of the inner flange is formed. When the corner portion is pressed against the bottom surface of the forming groove, first, the inner flange is compressed in the width direction in the forming groove with the movement of the cylindrical portion and the rising portion toward the bottom surface side of the forming groove. Becomes Then, the outer flange of the inner flange is pressed against the bottom surface of the molding groove with a larger pressing force, so that the inner flange is further compressed. The outer side corner is formed into a shape approximating the sharp inner corner of the forming groove, and the radius of curvature in the curved shape of the outer side corner is reduced. It will be reduced.

Therefore, in such a method, in order to make the radius of curvature in the curved shape of the outer surface side corner of the inner flange smaller, or to make the outer surface side corner angular,
When the outer side corner of the inner flange is pressed with a larger pressing force against the bottom surface of the forming groove, the inner flange is excessively compressed, and the inner side corner of the inner flange (the inner flange side) is pressed. In some cases, a wrinkled overlapping portion, a so-called seam, may occur on the inner surface, the outer peripheral surface of the cylindrical rising portion, and the corner formed between the inner peripheral surface of the cylindrical portion.

Therefore, even when the above-described method using a molding die having a molding groove is adopted, a flat portion having a sufficiently large width is formed on the outer surface of the inner flange without forming a seam. It was not easy to do.

[0010]

Here, the present invention has been made in view of the circumstances described above, and the problem to be solved is that one end of a cylindrical portion is provided inside the cylindrical portion. While the protruding inner flange is integrally formed,
At the tip of the inner flange, a cylindrical rising portion protruding and extending toward the other end of the cylindrical portion is integrally provided, and on the outer surface of the inner flange having a limited width, Metal products with flat parts with a sufficiently large width,
A method for forming a metal product that can be easily formed without causing problems such as a decrease in strength of the inner flange and generation of a seam, and a forming die that can be advantageously used in such a forming method. To provide.

[0011]

According to the present invention, in order to solve the above-described problem, an inner flange that protrudes inside the cylindrical portion is integrally formed at one end of the cylindrical portion,
A method of molding a metal product in which a cylindrical rising portion protruding toward the other end of the cylindrical portion is integrally provided at a distal end portion of the inner flange, the method comprising: Due to the cylindrical shape, the stepped surface provided on the outer peripheral surface of the cylindrical wall portion made the bottom side portion a thin portion, while the opening side portion was made a thick portion giving the cylindrical portion of the metal product. A step of preparing a preform; (b) a first punch having an outer peripheral surface corresponding to the inner peripheral surface shape of the cylindrical rising portion of the metal product; and a first punch forming a pair with the first punch. Forming the cylindrical rising portion by performing drawing on the bottom of the prepared preform using a die of (c), and (c) forming an outer surface of an inner flange of the metal product. A groove having a bottom surface of a corresponding shape, and an inner side surface of the groove has a While being formed in a shape corresponding to the peripheral shape, using a molding die having an inner flange forming portion whose outer side surface has a shape corresponding to the outer peripheral shape of the cylindrical portion of the metal product, The cylindrical wall portion of the preformed body is pressed from the opening side to the bottom side until the stepped surface of the cylindrical wall portion contacts the bottom surface of the inner flange forming portion. By pressing the thinner portion on the bottom side than the stepped surface in the inner flange forming portion,
The inner flange is formed while forming the cylindrical part of the metal product at the thick part on the opening side of the cylindrical wall part and compressing and increasing the thickness of the thin part in the inner flange forming part. And a step of forming a metal product.

In short, in the method of forming a metal product according to the present invention, since the preforming body is only subjected to drawing and compression processing, but not to use cutting processing, the preform is not used. It can be advantageously avoided that such a thin portion caused by the cutting process is partially generated in the formed metal product, and the inner flange of the metal product is formed by the step of the cylindrical wall portion of the preform. Although it is formed at the thinner part on the bottom side than the attached surface, it is formed into the desired shape by increasing the thickness by compression processing, so the thickness of the inner flange is also thin Therefore, the strength of the components of the metal product, such as the inner flange, the rising portion, and the cylindrical portion, and the strength of the entire metal product can be effectively secured.

Further, in the method of the present invention, the stepped surface of the cylindrical wall is pressed against the bottom of the inner flange forming part while pressing the cylindrical wall of the preformed body from the opening side to the bottom side. By pushing into the inner flange forming part until it contacts, the thin part on the bottom side of the stepped surface of the cylindrical wall is compressed and increased in the inner flange forming part, and the inner flange of the target metal product is increased. Is formed, and at the same time as the completion of the step of forming the inner flange by increasing the thickness of the thinner portion, the thicker portion of the cylindrical wall portion closer to the opening than the stepped surface of the cylindrical wall portion is completed. The corner formed by the outer surface of the portion and the stepped surface can provide an outer surface side corner having an angular shape or a curved shape with a small radius of curvature, thereby flattening the outer surface of the inner flange. The part is simply flat In the metal product obtained according to the conventional method of performing drawing and reverse redrawing on the metal material, the outer side corner can be made sufficiently larger than the flat portion of the inner flange having a curved shape. It becomes.

Therefore, according to the method of the present invention, the target metal product can be formed with a flat portion having a sufficiently large width on the outer surface having a limited width of the inner flange. Unlike the conventional method of forming a metal product by the conventional method, after forming the metal product, it is necessary to further process the formed metal product to increase the flat portion on the outer surface of the inner flange. But can be effectively eliminated.

Further, in the method of the present invention, as described above, the cylindrical wall portion of the preformed body is pressed until the stepped surface of the cylindrical wall portion contacts the bottom surface of the inner flange forming portion. By simply pushing the thin part of the part into the inner flange forming part, the thin part is appropriately compressed and the inner flange is formed, and at the same time, the inner part has an angular shape or a curved shape with a small radius of curvature with respect to the inner flange. From the place where the outer side corners can be provided, the pressing force is applied to the cylindrical portion or the rising portion of the metal product formed by the conventional method described above, so that the inner flange has a curved shape. By pressing the outer surface side corners against the bottom surface of a predetermined molding groove, unlike the case where the outer surface side corners are compression-molded to a shape corresponding to or approximate to the angular inner corner of the molding groove,
It is not necessary to particularly increase the pressing force on the preform in order to make the outer side corner of the inner flange into an angular shape or a curved shape with a small radius of curvature, and therefore it is not necessary to increase the pressing force. Due to the excessive compression of the inner flange, it is possible to extremely effectively prevent a seam from being generated at the inner side corner of the inner flange.

Therefore, according to the metal product forming method according to the present invention, the inner flange is formed integrally at one end of the cylindrical portion so as to protrude inside the cylindrical portion and extends. At the tip, a cylindrical rising portion protruding toward the other end of the cylindrical portion is integrally provided, and on the outer surface of the inner flange having a limited width,
A metal product having a flat portion with a sufficiently large width can be easily formed without causing a decrease in the strength of the inner flange or occurrence of a seam, and with a smaller number of steps than when the conventional method is employed. Can be done.

According to one advantageous aspect of the method for forming a metal product according to the present invention, the second punch having an outer peripheral surface corresponding to the inner peripheral surface shape of the cylindrical portion; A second die having a hole into which the second punch is inserted, and an opening-side portion into which the second punch is inserted in an inner peripheral portion of the hole of the second die, the outer peripheral portion of the cylindrical portion. While being configured with an inner peripheral surface corresponding to the surface shape, a portion of the inner peripheral portion that is continuous with the opening side portion is inward over the entire periphery by a step surface provided on the inner peripheral surface of the hole. Using a drawing die that is a stepped portion that is stepped so as to protrude toward the flat metal material that gives the metal product, drawing with the second punch and the second die By processing, the bottom side of the cylinder wall is thinner with a step and a bottomed cylinder And the stepped surface is formed by a stepped surface in the hole of the second die, and further, a thick portion on the opening side of the cylindrical wall portion provides a cylindrical portion of the metal product. The prepared preform is molded and prepared.

In the method of the present invention having such a configuration, the metal material for providing the target metal product is simply subjected to a single drawing process, so that a stepped surface is formed on the outer peripheral surface and the cylinder is formed. From a place where a preformed body having a stepped bottomed cylindrical shape in which the bottom side of the wall portion is a thin portion is formed, for example, a metal material was formed into a bottomed cylindrical shape by drawing. Thereafter, a cutting process is performed on the bottom side of the cylindrical wall portion of such a molded body, and as compared with a case where a preformed body having a thinner bottom portion of the cylindrical wall portion is formed, only a portion not subjected to the cutting process is used. The number of steps for forming the preform can be advantageously reduced, and thus the efficiency of the work in forming and preparing the preform, and thus the efficiency of the work in forming the target metal product Can be effectively enhanced. In addition, since no cutting process is performed in forming the preformed body, there is an advantage that the material for providing the metal material is not wasted.

According to a preferred embodiment of the method for forming a metal product according to the present invention, a thin portion on the bottom side of the cylindrical wall portion of the preformed body is pushed into the inner flange forming portion to form the thin portion. While forming the inner flange while compressing and increasing the thickness, in the inner flange forming portion,
On the surface of the thin wall portion of the cylindrical wall portion opposite to the bottom surface side of the inner flange forming portion, a space where the thickened portion of the cylindrical wall portion can enter can be formed. A method in which a thin portion is pushed into the flange forming portion is advantageously employed.

In the case of employing such a configuration, when a thin portion of the cylindrical wall portion of the preformed body is increased in the inner flange forming portion, an extra portion generated by the thickening operation is formed. Is added to a surface of the thin portion opposite to the bottom surface of the inner flange forming portion, whereby the surface of the inner flange formed portion formed by the thickening of the thin portion on the bottom surface side of the inner flange forming portion is added. That is, it is possible to avoid adding the excess portion to the outer surface of the inner flange as much as possible, so that the outer surface of the inner flange has a shape corresponding to the bottom surface over its entire surface. It can be formed with As a result, a flat portion having a sufficiently large width can be more reliably provided on the outer surface of the inner flange portion.

According to still another preferred embodiment of the method for forming a metal product according to the present invention, the forming die includes the first punch and the first die together with the inner flange forming portion. The step of forming the rising portion and the step of forming the cylindrical portion and the inner flange are both performed using such a molding die. If such a configuration is adopted, the target metal product can be formed at once with a single molding die, whereby the operation for forming the metal product is performed.
It can proceed even more efficiently.

According to the present invention, there is also provided a molding die used in the above-described metal product molding method, wherein the first die and the first die are disposed so as to be relatively close to / separable from each other. A first die having the first punch and the inner flange forming portion, while the second die has the first die, the first die, and the second die. A moving member that is moved relatively closer to the bottom surface of the inner flange forming portion from the opening side of the cylindrical portion of the metal product toward the bottom with the approach of the second mold. Composed of
With the preform positioned between the first die and the second die, the first die and the second die are moved closer to each other, so that the first punch and With the first die, drawing is performed on the bottom of the preform,
The moving member and the inner flange are formed by the approach movement of the moving member and the bottom surface of the inner flange forming portion accompanying the approach movement of the first mold and the second mold while forming the cylindrical rising portion. Between the bottom surface of the forming portion, the cylindrical wall portion of the preformed body is pressed from the opening side to the bottom side,
Until the stepped surface of the cylindrical wall portion contacts the bottom surface of the inner flange forming portion, by pushing the thinner portion on the bottom side than the stepped surface of the cylindrical wall portion into the inner flange forming portion, While forming the cylindrical part of the metal product at the thick part on the opening side of the cylindrical wall part, the inner flange is formed while compressing and increasing the thickness of the thin part in the inner flange forming part. The gist of the invention is also a molding die for a metal product, which is configured to obtain the same.

In such a metal product forming die according to the present invention, the preformed body is subjected to two processes of drawing and compression to form a rising portion, a cylindrical portion, and an inner flange of the metal product. Is formed, whereby the target metal product can be formed from the preform at once.

Therefore, by using the metal product forming die according to the present invention, the efficiency of the target metal product forming operation can be improved more effectively.

According to one of the advantageous aspects of the metal product forming die according to the present invention as described above, a thin portion on the bottom side of the cylindrical wall portion of the preform pressed into the inner flange forming portion. It is configured such that a space can be formed between the first mold and the second mold.

[0026] In the metal product forming die having the above configuration, the approaching movement of the first die and the second die causes
Between the moving member and the bottom surface of the inner flange forming portion, the cylindrical wall portion of the preformed body is pressed from the opening side to the bottom side, and the thin wall on the bottom side than the stepped surface in the cylindrical wall portion By pressing the part into the inner flange forming part, while increasing the thickness by compressing the thin part in the inner flange forming part, when forming the inner flange, with respect to the thin part pushed into the inner flange forming part , Can be configured so that the second mold does not come into contact and exert a direct pressing force,
Thereby, it is advantageous that the second mold exerts a pressing force on the first mold forming the inner flange forming section through the thin wall section pushed into the inner flange forming section. It can be avoided. As a result, it is possible to effectively prevent the second mold from being damaged or damaged by the pressing of the second mold against the first mold.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to clarify the present invention more specifically, a method of forming a metal product according to the present invention and a specific configuration of a forming die used therein will be described with reference to the drawings. , Will be described in detail.

First, FIG. 1 schematically shows, as an embodiment of a metal product formed according to the metal product forming method according to the present invention, a metal part constituting an automatic transmission of an automobile in a longitudinal sectional form thereof. It is shown. As is clear from FIG. 1, the metal component 10 has a generally cylindrical shape with a low height as a whole, and has a cylindrical portion 12 extending vertically and a cylindrical rising portion on the same central axis. Each of the lower ends of the portions 16 has a structure in which the lower ends of the portions 16 are integrally connected by an inner flange 14 having an annular plate shape extending in the horizontal direction.

That is, in the metal part 10, the inner flange 14 is formed at the lower end of the cylindrical portion 12.
It extends inward in the horizontal direction by a predetermined length, and extends continuously in the circumferential direction of the cylindrical portion 12 so as to be integrally formed.
It is provided integrally with the tip of the inner flange 14 so as to protrude vertically upward at a height lower than the cylindrical portion 12 and extend continuously in the circumferential direction of the cylindrical portion 12. It is.

In the metal part 10, in particular, corners located at both radial ends of the lower surface of the inner flange 14, that is, two corners 18 on the outer surface side of the inner flange 14,
Of the inner flange 14, the outer corner 18 of the inner flange 14 on the side where the cylindrical portion 12 is formed has an angular shape, and the inner corner 20 on the side where the rising portion 16 is formed has a curved shape with a small radius of curvature. It has been. Thereby, the outer surface 22 provided on the lower surface of the inner flange 14 is
Is formed with a flat portion having a sufficiently large width, which is close to the distance between the outer peripheral surface 24 and the inner peripheral surface 26 of the cylindrical rising portion 16.

Incidentally, such a metal part 10 is formed, for example, as follows.

First, a metal preform 28 having a shape as shown in FIG. 2 is prepared. More specifically, in the preform 28, a cylindrical tubular wall portion 30 integrally extends upward at a predetermined height from a peripheral portion of a disk-shaped bottom portion 32, As a whole, it has a cylindrical shape with a bottom that opens upward. In addition, the bottom portion 3 which is lower than a half height portion of the outer peripheral surface of the cylindrical wall portion 30 of the preform 28 is formed.
A tapered cylindrical stepped surface 34 whose diameter becomes gradually smaller toward the lower side is formed in the portion on the second side. As a result, the bottom side of the preformed body 28 below the stepped surface 34 of the cylindrical wall portion 30 has a predetermined thickness compared to the opening side above the stepped surface 34 of the cylindrical wall portion 30. It is a thinned thin portion 36, and, on the contrary,
The opening side of the cylindrical wall portion 30 is a thick portion 38. The preformed body 28 is configured such that the thick part 38 on the opening side of the cylindrical wall part 30 has the same shape and size as the cylindrical part 12 of the target metal product 10. -ing

Here, such a preformed body 2
8 is formed and prepared by drawing a metal material made of a circular flat plate. In forming the preform 28, a drawing die 40 having a structure as shown in FIG. 3 is suitably used. The drawing die 40 includes a die holder 42 having a fixed position, and a punch holder 44 which is disposed opposite to the die holder 42 at a predetermined distance from the die holder 42 and is vertically moved by a known hydraulic mechanism or the like (not shown). Made up of In addition, on the lower surface of the punch holder 44, an outer peripheral surface corresponding to the inner peripheral surface shape of the cylindrical wall portion 30 of the preformed body 28 to be formed is provided. A molded body forming punch 46 is fixedly provided, arranged together with the punch holder 44 so as to be able to move integrally in the vertical direction, and has a thick ring shape, and a wrinkle holding pad 48 having a flat lower surface. In a state in which the punch 46 is externally inserted into the preform forming punch 46 and is connected to the punch holder 44 by a compression coil spring disposed between the punch 46 and the preform forming punch 46, They are arranged so that they can be moved up and down independently.

On the other hand, the upper surface of the die holder 42 has a thick cylindrical shape as a whole, and a die hole 52 is formed in the cylindrical inner hole. Are provided in a fixed position on the same axis as the punch 46 for forming a preform. Also,
In this die 54 for forming a preform, the die hole 52
In an intermediate portion in the height direction of the inner peripheral portion, an inversely tapered cylindrical step surface 5 corresponding to the stepped surface 34 provided on the outer peripheral surface of the preform 28 and gradually increasing in diameter downward.
6 are formed continuously in the circumferential direction, so that a portion of the inner peripheral portion of the die hole 52 below the stepped surface 56 projects inward over the entire circumference. The step 58 is provided. In the preform molding die 54, the inner peripheral surface of the step portion 58 in the die hole 52 has a shape corresponding to the outer peripheral shape of the thin portion 36 of the preform 28. The opening portion 60 above the step surface 54 in the inner peripheral portion of the die hole 52 is formed by the thick portion 3 of the preform 28.
8, in other words, the target metal part 10
The inner peripheral surface corresponding to the outer peripheral shape of the cylindrical portion 12 is formed. Here, the die hole 5
The corners at both ends of the step surface 56 provided on the inner peripheral portion of the second member 2 are all angular. Also, in FIG.
This is a cushion pad for holding the metal material between the punch 46 for forming a preform.

Then, the drawing die 4 having such a structure is formed.
In order to mold the preformed body 28 using the mold shown in FIG.
As shown in the left half of FIG.
Is placed between the die 54 for forming a preform and the punch 46 for forming a preform, and the metal material 64 is set in the drawing die 40. That is, the metal material 64
Is placed concentrically on the preform molding die 54, and the outer peripheral portion of the metal material 64 is sandwiched between the preform molding die 54 and the wrinkle holding pad 48. At the same time, the inner peripheral portion is sandwiched between the punch 46 for forming a preform and the cushion pad 62.

Next, as shown in the right half of FIG. 3, the preformed body forming punch 46 is moved downward together with the punch holder 44 and gradually enters the die hole 52 of the preformed body forming die 54. The metal material 6
For 4, drawing is performed by the preformed body forming die 54 and the preformed body forming punch 46. Thereby, the metal material 64 is formed into a bottomed cylindrical shape that opens upward and has the bottom portion 32 formed at the inner periphery thereof and the cylindrical wall portion 30 formed at the outer periphery thereof. The preform 28 is obtained.

In such a drawing process for the metal material 64, the cylindrical wall portion 30 formed by the outer peripheral portion of the metal material 64 is formed.
Is formed in a shape corresponding to the shape of the outer peripheral surface of the punch 46 for forming a preformed body.
Is formed in a shape corresponding to the shape of the inner peripheral surface of the die hole 52 in the die 54 for forming a preform. And, on the outer peripheral surface of such a cylindrical wall portion 30,
The stepped surface 34 is formed by the stepped surface 56 of the die hole 52, and the opening side portion of the die hole 52 in the preformed body forming punch 46 and the preformed body forming die 54 in the cylindrical wall portion 30. 60 is the thick portion 38, while the portion sandwiched between the preformed body forming punch 46 and the step 58 of the die hole 52 is the thin portion. This is the part 36.

Accordingly, here, as the drawing of the metal material 64 progresses, the outer peripheral portion of the metal material 64 that provides the cylindrical wall portion 30 is formed by the preformed body forming punch 46 and the preformed body forming die 54. When moved between the inner peripheral portion of the die hole 52 and the inner peripheral portion of the die material 52, the outer peripheral portion of the metal material 64 is sandwiched between the punch 46 for forming a preform and the opening side portion 60 of the die hole 52. The height (length) of the part
When the dimensions are the same as those of the cylindrical portion 12 of the target metal part 10, the drawing of the metal material 64 is finished.

Then, using the preformed body 28 formed and prepared as described above, the target metal part 1 is formed.
In this case, a molding die 66 shown in FIG. 4 is advantageously used. This molding die 66
Is configured to have a lower die 68 as a first die and an upper die 70 as a second die which are opposed to each other in a vertically approachable / separable state. . The lower die 68 includes a fixed platen 72 having a fixed position and the fixed platen 7.
The guide bush 74 includes a large-diameter guide bush 74 fixedly mounted on the upper surface 2 and a cushion pad 76 which is inserted into an inner hole of the guide bush 74 and is vertically movable. A thick cylindrical rising portion forming punch 78 as a first punch is fixed on the cushion pad 76 so as to slide on the inner peripheral surface of the guide bush 74. While being guided by the inner peripheral surface of the inner hole of the guide bush 74, the guide bush 74 and the cushion pad 76 are positioned so as to be integrally movable in the vertical direction. Further, a cylindrical holding pad 80 is inserted into the inner hole of such a rising portion forming punch 78 and inserted upward by a compression coil spring disposed between the holding pad 80 and the cushion pad 76. In an energized state, it is arranged to be vertically movable independently of the rising portion forming punch 78. In the pressing pad 80, the engaging projection 82 provided on the lower end portion is locked by the locking portion 84 provided on the inner peripheral portion of the rising portion forming punch 78, so that Movement to is regulated.

Further, in the lower die 68 having such a structure, the projection 86 having an outer peripheral surface extending in the vertical direction is provided at the center of the upper surface of the rising portion forming punch 78. The outer peripheral surface of the projection 86 is
A rising portion forming surface 88 having a shape corresponding to the inner peripheral surface shape of the cylindrical rising portion 16 of the target metal part 10.
On the other hand, the outer peripheral portion of the upper surface of the rising portion forming punch 78 surrounding the projecting portion 86 has an inner flange forming surface formed of a horizontal plane corresponding to the outer surface of the annular plate-shaped inner flange 14 of the metal component 10. 90. Furthermore,
The inner peripheral surface of the guide bush 74 in which the rising portion forming punch 78 is slidably inserted is constituted by a cylindrical surface extending in the vertical direction with an inner diameter corresponding to the outer diameter of the cylindrical portion 12 of the metal product 10. Accordingly, the inner peripheral surface of the upper opening of the guide bush 74 is a cylindrical part forming surface 92 corresponding to the outer peripheral surface shape of the cylindrical part 12. Here, as described above, the rising portion forming punch 78 is used.
Are arranged slidably with respect to the inner peripheral surface in the inner hole of the guide bush 74, so that the bottom surface is provided by the inner flange forming surface 90 in the inner hole of the guide bush 74. At the same time, an inner flange forming portion 94 having an annular groove shape in which the inner side surface and the outer side surface are provided by the rising portion forming surface 88 and the cylindrical portion forming surface 92, respectively, is formed.

On the other hand, the upper die 70 is disposed above the fixed plate 72 of the lower die 68 so as to face upward with a predetermined distance therebetween, and moves up and down in a vertical direction by a known hydraulic mechanism or the like (not shown). It has a movable platen 96 to be pressed. A die holder 98 made of a thick flat plate and the preform 2
8, a cylindrical first shape having an outer peripheral surface corresponding to the inner peripheral shape of the thick portion 38 of the cylindrical wall portion 30 of the cylindrical part 12 of the target metal component 10. A rising portion forming die 100 as a die is arranged. Then, in a state where the rising portion forming die 100 is opposed to the rising portion forming punch 78 of the lower die 68 and is positioned on the same axis as the punch 78, the lower surface of the movable platen 96 is mounted via the die holder 98. It is fixed. As a result, the rising portion forming die 100 is moved up and down with the movement of the movable platen 96.

Further, below the movable platen 96, a pressing pad 102 as a moving member, which has a thick ring shape and has a horizontal flat surface on the lower surface, is mounted on the rising portion forming die 1.
00, and is slidably disposed on the outer peripheral surface of the die holder 9.
8 is connected via a compression coil spring disposed therebetween. As a result, the pressing pad 102 is positioned on the inner peripheral portion of the lower surface thereof so as to face the inner flange forming surface 90 of the inner flange forming portion 94 formed in the inner hole of the guide bush 74 of the lower die 68. And, as the movable platen 96 moves downward,
While being moved toward the inner flange forming surface 90 of the inner flange forming portion 94, the inner flange forming portion 94 can be moved up and down independently of the rising portion forming die 100.

In the upper die 70 having such a structure, the inner die formed in the inner hole of the guide bush 74 of the lower die 68 at the outer peripheral portion of the lower surface of the rising portion forming die 100. Inner flange forming surface 9 of flange forming portion 94
A stepped projection 104, which is stepped in two steps and protrudes downward, is formed so as to extend continuously in the circumferential direction at a portion opposed to zero. In the stepped projection 104, the inner stepped portion 106a formed of the inner peripheral portion has a front end surface formed of a horizontal flat surface, and is substantially the same as the thickness of the bottom portion 32 of the preform 28. With the height dimension,
It is formed to be stepped higher than the inner peripheral portion of the lower surface of the rising portion forming die 100 by one step. Further, an outer step portion 106b formed of an outer peripheral portion of the stepped protrusion 104
Has a distal end surface having a curved surface shape that is convex downward,
In addition, the metal component 10 is formed to have a height sufficiently lower than the height of the rising portion 16 from the inner flange 14 at the rising portion 16 and to be further raised one step higher than the inner step portion 106a.

Accordingly, here, as described later,
With the preformed body 28 positioned on the rising portion forming punch 78 of the lower die 68, the rising portion forming die 10
0 is moved downward so that the rising portion forming punch 7
8 and the die 100 for forming a rising portion.
When the state is such that the pinch is sandwiched, the inner stepped portion 106a of the stepped projection 104 of the rising portion forming die 100 is formed.
Is located at the same distance from the inner flange forming surface 90 of the inner flange forming portion 94 as the height dimension of the rising portion 16 of the metal part 10, and Although the outer step portion 106b is made to protrude into the inner flange forming portion 94, the outer step portion 106b is located at a sufficient distance from the inner flange forming surface 90.

Further, the rising portion forming die 100
The pressing pad 80 of the lower die 68
A wrinkle pressing protrusion 108 is integrally formed at a portion opposed to the upper portion, and a rising portion forming die 1 is formed at the center thereof.
Pilot pin 11 extending downward along the central axis of 00
0 is fixed with its tip protruding downward by a predetermined length. When the rising portion forming die 100 is moved downward toward the rising portion forming punch 78, the distal end portion of the pilot pin 110 penetrates the center portion of the holding pad 80 and the cushion pad 76.
Is inserted through a guide hole 112 extending to the upper part of the die, so that the downward movement of the rising portion forming die 100 can be guided. Further, in FIG.
Reference numeral denotes an ejector pin for projecting an intermediate molded body 122 described later, which is molded by the molding die 66, and detaching it from the molding die 66.

In order to form the target metal part 10 using the molding die 66 having such a structure, first, as shown in the left half of FIG. The completed preform 28 is disposed between the lower mold 68 and the upper mold 70 and set in the molding die 66.
That is, in a state where the upper mold 70 is sufficiently separated from the lower mold 68, the preformed body 28 is
After being placed concentrically on the rising portion forming punch 78 of the lower die 68 in a direction in which the upper die 70
By moving the movable platen 96 downward by a predetermined distance, the entire upper die 70 is brought closer to the lower die 68, and the movable die 96 is inserted into the through hole 116 provided at the center of the bottom 32 of the preform 28.
The distal end portion of the pilot pin 110 of the upper die 70 is inserted, while the inner peripheral portion of the lower surface of the pressing pad 102 is brought into contact with the upper end surface of the cylindrical wall portion 30. As a result, the preform 28 is placed between the lower mold 68 and the upper mold 70 so as to be immovable in the horizontal direction and the vertical direction (vertical direction), and set in the molding die 66. It becomes. At this time, the bottom 32 of the preform 28 is
At the center of the outer surface of the press pad 80 of the lower mold 68,
The pilot pin 11 is brought into contact with the upper surface thereof and inserted through the through hole 116 of the bottom 32.
The leading end of the “0” is pushed into the guide hole 112 provided through the center of the holding pad 80.

Next, the die 1 for forming the rising portion of the upper mold 70
00 is moved downward together with the movable platen 96. During the downward movement of the rising portion forming die 100, the pressing pad 10 abutting on the upper end surface of the cylindrical wall portion 30 of the preform 28.
2 and a die holder 98 located above the compression pad, the compression of a compression coil spring causes the pressing pads 1
Until the 02 and the die holder 98 are brought into contact with each other, the rising portion forming die 100 is relatively moved with respect to the pressing pad 102 and protrudes into the inner hole of the cylindrical wall portion 30 of the preform 28. Then, the pressing pad 102
After being brought into contact with the die holder 98, it is pressed by the die holder 98, and the rising portion forming die 100 is pressed.
Together with the pressing pad 1
The preformed body 28 abutting on the base member 02 is lowered, and the bottom 32 side portion is made to enter the inner hole of the guide bush 74. Thereby, as shown in FIG.
The thick portion 38 of the cylindrical wall portion 30 of the preformed body 28 is formed so that the outer peripheral surface of the rising portion forming die 100 and the guide correspond to the inner peripheral surface shape and the outer peripheral surface shape of the cylindrical portion 12 of the target metal part 10. It will be pinched between the inner peripheral surface of the bush 74.

Incidentally, the penetration of the preform 28 into the inner hole of the guide bush 74 due to the lowering of the pressing pad 102 is caused by the rising portion forming punch 78 and the holding pad 80 on which the preform 28 is placed. Are restricted by the contact of the cushion pad 76 with the fixed plate 72 (see FIG. 4). In this case, the outer side surface of the inner flange forming portion 94 formed in the inner hole of the guide bush 74 is provided when positioned at the lower moving end of the rising portion forming punch 78 and the holding pad 80. The height of the cylindrical portion forming surface 92 is set to be the same as the height of the thick portion 38 of the preformed body 28, in other words, the same height as the cylindrical portion 12 of the target metal part 10. is there.

Subsequently, the die 1 for forming a rising portion is formed.
00 is further moved downward so that the inner peripheral portion of the lower surface of the pressing pad 102 is moved closer to the inner flange forming surface 90 which provides the bottom surface of the inner flange forming portion 94, so that the pressing pad At 102, the preform 2
8 is pressed from the opening side toward the bottom 32 side. Thus, as shown in FIG. 6, the lower end portion of the cylindrical wall portion 30 of the preformed body 28 including the entire thin portion 36 and the outer peripheral portion of the bottom 32 of the preformed body 28 are placed in the inner flange forming portion 94. By pushing, the inner peripheral portion of the bottom portion 32 is moved upward relative to the outer peripheral portion of the bottom portion 32 by the projecting portion 86 provided at the center of the rising portion forming punch 78. Then, drawing is performed on the bottom 32, and the bottom 32 is gradually formed into a bottomed cylindrical shape that opens downward. In the drawing of the bottom 32 of the preform 28, the center of the bottom 32 is held between the wrinkle pressing projection 108 of the rising portion forming die 100 and the pressing pad 80 of the lower die 68. (See FIG. 4).

Thereafter, as the die 100 for forming the rising portion is further lowered, the cylindrical wall portion 30 of the preformed body 28 is pressed by the pressing pad 102, and the lower end of the cylindrical wall portion 30 of the preformed body 28 is pressed into the inner flange. As shown in FIG. 7, by further pushing into the molded portion 94, the thin portion 3 of the cylindrical wall portion 30 is formed.
6 is compressed in the width direction of the inner flange forming portion 94 to increase the thickness, and the lower surface of the thickened portion is replaced with the inner flange forming surface 9.
A horizontal flat surface corresponding to 0 is formed. At the same time, the drawing of the bottom 32 of the preform 28 is further advanced.

At this time, the inner peripheral part and the outer peripheral part of the bottom part 32 of the preformed body 28, which provide the bottom part and the cylindrical wall part of the bottomed cylindrical body formed by the drawing process, respectively, are used for forming the rising part. Due to the inner corners of the inner step portion 106a of the stepped projection 104 of the die 100, the die is gradually separated as the rising portion forming die 100 is lowered, and the outer peripheral portion of the bottom portion 32 of the preform 28 is The tip of the inner step 106a is pressed downward. Accordingly, the outer peripheral portion of the bottom portion 32 and the thin portion 3
The radius of curvature in the curved shape of the corner formed by the thickened portion made of 6 is gradually reduced. Here, since the cylindrical wall portion 30 of the preformed body 28 pressed by the pressing pad 102 is sandwiched between the rising portion forming die 100 and the guide bush 74, the cylindrical wall portion 30 falls down. Without being bent or bent,
That is, it can be pressed straight in the vertical direction from the opening side toward the bottom 32 side.

Then, as shown in FIG. 8, until the stepped surface 34 of the cylindrical wall portion 30 of the preform 28 contacts the inner flange forming surface 90 of the inner flange forming portion 94, the cylindrical wall portion 30 is formed. Is further pushed into the inner flange forming portion 94. As a result, the outer surfaces of the thick part 38 and the thin part 36 of the cylindrical wall part 30 of the preformed body 28 and the outer peripheral part of the bottom part 32 become the cylindrical part forming surface 92 of the inner flange forming part 94,
The shape corresponds to the inner flange forming surface 90 and the rising portion forming surface 88, respectively. Also, the thick portion 38 of the cylindrical wall portion 30
Although the cylindrical shape is maintained, the thin portion 36 is inwardly increased from the lower end portion of the thick portion 38 in a state in which the thin portion 36 is increased in thickness until the thickness becomes approximately the same as the appropriate thickness. The outer wall of the bottom portion 32 is formed in the shape of an annular plate that protrudes and extends continuously in the circumferential direction, and the outer peripheral portion of the bottom portion 32 extends vertically upward from the distal end of the thin portion 36 of the cylindrical wall portion 30. Part 3
Thus, it is formed into a cylindrical shape which protrudes with a height lower than 8 and extends in the circumferential direction and has a height lower than the thick portion 38. In particular, both side corners located at both radial ends of the lower surface of the thin portion 36 formed in the shape of a circular plate, that is, of the two outer side corners of the thin portion 36 formed in the shape of a circular plate. The outer corner portion on the side of the thick portion 38 is formed to have an angular shape corresponding to the corner portion of the stepped surface 34 of the cylindrical wall portion 30 and the thick portion 38, while being formed into the cylindrical shape of the bottom portion 32. The inner corner portion on the side of the formed portion has a curved shape with a small radius of curvature.

Here, as described above, when the bottom portion 32 of the preformed body 28 is sandwiched between the rising portion forming die 100 and the rising portion forming punch 78,
The tip surface of the inner stepped portion 106a of the stepped protrusion 104 of the rising portion forming die 100 is
The inner flange forming surface 90 of FIG. 4 is opposed to the inner flange forming surface 90 at the same distance as the height of the rising portion 16 of the metal component 10, while the distal end surface of the outer step portion 106 b is It is designed to be located at a sufficient distance from the flange forming surface 90.

Therefore, at the bottom 32 of the preformed body 28, the height of the cylindrically formed part is the same as the height of the rising part 16 of the target metal part 10. Further, a gap 118 is formed between the upper surface of the thin portion 36 of the cylindrical wall portion 30 formed into an annular plate shape and the distal end surface of the outer step portion 106b, whereby the thin portion 3 is formed.
In the process of forming the ring 6 into an annular plate shape, the outer peripheral edge of the rising portion forming die 100 is
To be abutted directly or via the pre-formed body 28, and the thin-walled portion 36 increased in the inner flange-formed portion 94 can be prevented. The excess portion can be made to enter the gap 118.

Thus, as shown on the right side of FIG.
A cylindrical portion 12 formed of a thick portion 38 in a cylindrical wall portion 30 of the preformed body 28; an inner flange 14 formed by increasing a thin portion 36 of the cylindrical wall portion 30;
A rising portion 16 composed of an outer peripheral portion of a bottom portion 32 of the
The intermediate molded body 122 having the disk portion 120 composed of the inner peripheral portion 2 is molded.

Then, after the intermediate molded body 122 is detached from the molding die 66, the disk portion 120 is cut off by a known method, thereby forming the target metal part having a shape as shown in FIG. You get 10.

As described above, in the present embodiment, first, a preform 28 is formed by drawing a metal material made of a circular flat plate, and then the preform 28 is formed. The target metal part 10 is formed by performing drawing or compression processing, and no cutting is performed until the target metal part 10 is obtained from a metal material. However, in the metal part 10 to be formed, it is possible to advantageously eliminate the occurrence of a thin portion formed by the cutting process.
Can be effectively secured. However, although a part of the cylindrical wall portion 30 of the preform 28 is formed as a thin portion 36, the thin portion 36 is increased in thickness by compression processing.
Since it is formed as an inner flange, the strength of the target metal component 10 does not partially decrease due to the thin portion 36 at all.

In the present embodiment, the lower end portion of the preformed body 28 including the thin wall portion 36 of the cylindrical wall portion 30 is attached to the cylindrical wall portion 30.
Is pressed into the inner flange forming portion 94 until the stepped surface 34 formed on the inner flange forming portion 94 contacts the inner flange forming surface 90 of the inner flange forming portion 94. Is increased to form the inner flange 14, and at the same time, of the outer surface side corners 18, 20 at both ends of the inner flange 14, the outer corner 18 at the cylindrical portion 12 side is The inner wall portion 20 on the rising portion 16 side is formed to have a curved shape having a small radius of curvature, while the inner wall portion 20 on the rising portion 16 side is formed to have a curved shape. However, a sufficiently large flat portion with respect to the outer surface 22 can be formed with good work efficiency without performing any post-processing on the formed inner flange 14 to increase the flat portion of the outer surface 22. , It become a fact which can be very advantageously applied.

Further, in the present embodiment, as described above, one of the two outer side corners 18 and 20 of the inner flange 14 is connected to the cylindrical wall 3 of the preform 28.
0, the cylindrical wall portion 30 is sufficiently pushed into the inner flange forming portion 94 from the portion formed at the corner of the stepped surface 34 so as to increase the thickness of the outer wall of the inner flange 14. By extruding the portion providing the corner portion 18 outward, compared to a case where a conventional method in which the radius of curvature of the outer corner portion 18 having a curved shape is reduced is adopted.
The amount of pushing of the cylindrical wall portion 30 into the inner flange forming portion 94 can be advantageously reduced, so that the amount of pushing of the cylindrical wall portion 30 into the inner flange forming portion 94 increases. An excessive compression of the flange 14 can extremely effectively prevent a seam from being generated at the inner corner of the inner flange 14.

Further, in the present embodiment, the cylindrical wall 3
0 is composed of a thick portion 38 and a thin portion 36, and the preform 28, which is configured so as to have partially different thicknesses, is obtained by simply performing a single drawing process on a metal material formed of a circular flat plate. From the place where it is supposed to be formed only by applying, for example, after forming a metal material into a bottomed cylindrical shape by drawing, a cutting process is performed on the bottom side of the cylindrical wall portion of such a formed body By making the bottom side of the cylindrical wall thinner, the number of steps can be reduced, the work efficiency can be improved, and the material can be preformed without waste as compared with the case where the preformed body 28 is formed. The body 28 and thus the intended metal part 10 can be formed very advantageously.

In the present embodiment, when the thickness of the thin portion 36 of the cylindrical wall portion 30 of the preformed body 28 is increased in the inner flange forming portion 94 to form the inner flange 14,
Thinned portion 36 to be increased in thickness and die 1 for forming a rising portion
A gap 118 is provided between the outer step 106b of the stepped projection 104 formed at the outer peripheral edge of the thin section 00 and the extra portion of the thinned portion 36 to be increased in thickness is made to enter the gap 118. As a result, it is possible to advantageously avoid the addition of a surplus portion to the outer surface 22 of the inner flange 14 formed by increasing the thickness of the thin portion 36, which corresponds to the inner flange forming surface 90. Thereby, the entire surface of the outer surface 22 of the inner flange 14 can be more reliably formed into a shape corresponding to the inner flange forming surface 90 having a flat surface shape.
Thus, a flat portion having a large width can be more reliably applied to the outer surface 22 of the first embodiment.

Further, as described above, in the present embodiment, in the inner flange forming portion 94, the thin portion 36 to be increased in thickness and the rising portion forming die 100, with respect to the rising portion forming punch 78, are the most. Since the gap 118 is provided between the stepped projection 104 and the outer step 106b of the stepped projection 104 having an extremely small area at the front end surface, the rising section forming die 10
It is possible to avoid that the outer step portion 106b of the zero stepped projection 104 is brought into contact with the rising portion forming punch 78 directly or via the preform 28. However, when the inner flange 94 is formed, the preform 28
The rising force forming die 100 is caused to act on the outer step 10
6b and the like can be effectively prevented from being partially broken or damaged.

Further, in the present embodiment, the molding die 66 includes a rising portion forming punch 78 and a rising portion forming die 100 for forming the rising portion 16 of the target metal part 10, An inner flange forming portion 94 for forming the inner flange 14 of the metal component 10 is provided, and the rising portion 16 and the inner flange 14 can be formed at one time by such a single molding die 66. Therefore, the target metal part can be quickly and easily formed with excellent workability and efficiency.

Although the specific configuration of the present invention has been described in detail above, this is merely an example, and the present invention is not limited by the above description.

For example, in the above-described embodiment, the bottomed cylindrical body formed by performing the drawing process on the disk-shaped metal material 64 using the predetermined drawing die 40 is used as the target metal part. 10 has been used as the preformed body 28, the preformed body 28 has a bottomed cylindrical shape, and the bottom side portion is formed by the stepped surface 34 provided on the outer peripheral surface of the cylindrical wall portion 30. If the opening portion is a thick portion 38 that provides the cylindrical portion 12 of the target metal part 10 on the other hand, if the thin portion 36 is used, the method may be a ready-made one or a method other than drawing as described above. Of course, those molded with can be used.

In the above embodiment, the punch 78 for forming the rising portion and the die 100 for forming the rising portion for forming the rising portion 16 of the target metal component 10 and the inner flange 14 of the metal component 10 are formed. A molding die 66 having both an inner flange forming portion 94 for forming the inner flange 1 and the rising portion 16 and the inner flange 1 is formed by the single molding die.
4 can be formed all at once, but a molding die for forming the rising portion 16 having only the rising portion forming punch 78 and the rising portion forming die 100,
A molding die for forming the inner flange 14 having only the inner flange molding portion 94 is used, and the rising portion 16 and the inner flange 14 are formed on the preform 28 by the two types of molding dies. Even if they are formed separately, there is no problem.

Even when the forming die 66 having the rising portion forming punch 78 and the rising portion forming die 100 and the inner flange forming portion 94 is used, for example, the rising portion forming punch 78 and the rising portion may be used. The detailed structure such as the arrangement structure and arrangement position of the molding die 100 or the shape and arrangement position of the inner flange forming portion 94 is not particularly limited to that shown in the above embodiment.

Further, in the above-described embodiment, the target metal component 10 is formed such that the lower end of each of the cylindrical portion 12 and the cylindrical rising portion 16 extending in the vertical direction has an annular plate-shaped inner flange extending in the horizontal direction. 14, the metal parts 10 are integrally connected.
Is formed integrally at one end of the tubular portion with an inner flange protruding inside the tubular portion and extending toward the other end of the tubular portion. What is necessary is just to have the structure in which the cylindrical rising part which protrudes and extends is provided integrally. Therefore, the target metal part 10
However, a structure in which the cylindrical portion or the rising portion has a rectangular cylindrical shape, a structure in which both or one of the cylindrical portion and the rising portion extends obliquely with respect to the vertical direction, or the inner flange has a horizontal direction. Structure that spreads in a direction inclined to
Even if the inner flange has a structure formed integrally with the upper end of each of the cylindrical portion and the rising portion, there is no problem at all.

In addition, in the above embodiment, a specific example of applying the present invention to a method of forming a metal part constituting an automatic transmission of an automobile and a forming die used therein has been described. , Other,
At one end of the tubular portion, an inner flange that protrudes inside the tubular portion is integrally formed, and at the tip of the inner flange, projects toward the other end of the tubular portion. The present invention can be advantageously applied to a method of forming a metal product used for various applications, which is provided with a cylindrical rising portion integrally extending, and a forming die used for the method. That is, of course.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be performed in embodiments, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0071]

As is apparent from the above description, according to the method for forming a metal product according to the present invention, an inner flange protruding inside the cylindrical portion is integrally formed at one end of the cylindrical portion. And at the tip of the inner flange,
A cylindrical rising portion protruding toward the other end of the cylindrical portion is integrally provided, and has a flat portion having a sufficiently large width on the outer surface of the inner flange having a limited width. The metal product can be easily formed with a relatively small number of steps without causing a decrease in the strength of the inner flange, generation of a seam, and the like.

Further, by using the metal product forming die according to the present invention, the efficiency of the target metal product forming operation can be improved.
It can be achieved more effectively.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an example of a metal product formed according to the method of the present invention.

FIG. 2 is an explanatory longitudinal sectional view showing an example of a preform used for molding the metal product shown in FIG. 1 according to the method of the present invention.

FIG. 3 is an explanatory view showing an example of a step of forming the preform shown in FIG. 2; a left half shows a state in which a metal material giving the preform is set in a drawing die; Shows a state in which a metal material is subjected to drawing processing to form a preform.

FIG. 4 is an explanatory view showing an example of a step of molding the metal product shown in FIG. 1 according to the method of the present invention, wherein a left half shows a state where a preform is set in a molding die, and a right half Shows a state in which the preform has been subjected to drawing and compression processing to form an intermediate formed body which gives a target metal product.

FIG. 5 is an explanatory view showing another example of the step of forming the metal product shown in FIG. 1 according to the method of the present invention, wherein the upper die is moved closer to the lower die to form a rising portion of the upper die. It shows a state in which a cylindrical wall portion of a preformed body is sandwiched between a forming die and a guide bush of a lower die.

6 is an explanatory view showing still another example of the step of forming the metal product shown in FIG. 1 according to the method of the present invention, wherein the upper mold is moved closer to the lower mold to move the upper mold. By pressing the cylindrical wall portion of the pre-formed body from the opening side to the bottom side with the pressing pad, the thin wall portion of the cylindrical wall portion is pressed into the lower flange inner flange forming portion. I have.

FIG. 7 is an explanatory view showing another example of the step of forming the metal product shown in FIG. 1 in accordance with the method of the present invention, wherein a thin portion of a cylindrical wall portion of a preform is formed in an inner flange forming portion of a lower die. 2 shows a state in which the thin part is compressed and deformed in the inner flange forming part.

8 is an explanatory view showing still another example of the step of forming the metal product shown in FIG. 1 according to the method of the present invention, wherein the stepped surface of the cylindrical wall portion of the preformed body is formed of the inner flange formed portion. The state is shown in which the cylindrical wall portion, the inner flange, and the rising portion of the target metal product are formed by pushing the cylindrical wall portion into the inner flange forming portion until it comes into contact with the inner flange forming surface.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Metal part 12 Cylindrical part 14 Inner flange 16 Rise part 18 Outer corner part 20 Inner corner part 22 Outer surface 28 Preformed body 30 Cylindrical wall part 32 Bottom part 34 Stepped surface 36 Thin part 38 Thick part 40 Drawing type 46 Preformed body Forming punch 54 Preforming body forming die 56 Stepped surface 58 Stepped portion 66 Molding die 78 Rising portion forming punch 88 Rising portion forming surface 90 Inner flange forming surface 92 Cylindrical portion forming surface 94 Inner flange forming portion 100 Rising portion forming Die 102 press pad 118 gap

Claims (6)

[Claims] An inner flange protruding inward from the cylindrical portion is integrally formed at one end of the cylindrical portion.
A method of forming a metal product in which a cylindrical rising portion protruding toward the other end side of the cylindrical portion is integrally provided at a distal end portion of the inner flange, the bottomed cylindrical shape Preforming is performed by the stepped surface provided on the outer peripheral surface of the cylindrical wall portion so that the bottom side portion is a thin portion while the opening side portion is a thick portion providing a cylindrical portion of the metal product. A step of preparing a body, using a first punch having an outer peripheral surface corresponding to the inner peripheral surface shape of the cylindrical rising portion of the metal product, and a first die paired with the first punch. Forming the cylindrical rising portion by performing drawing on the bottom of the prepared preform, and a groove having a bottom surface having a shape corresponding to the outer surface of the inner flange of the metal product. Wherein the inner side surface of the groove corresponds to the inner peripheral surface shape of the rising portion. While using a molding die having an inner flange forming portion whose outer side surface has a shape corresponding to the outer peripheral surface shape of the cylindrical portion of the metal product, the cylinder of the preformed body is used. The wall portion is pressed from the opening side to the bottom side, and the stepped surface of the cylindrical wall portion is pressed from the stepped surface of the cylindrical wall portion until the stepped surface contacts the bottom surface of the inner flange forming portion. Also, by pushing the thin part on the bottom side into the inner flange forming part, a cylindrical part of the metal product is formed at the thick part on the opening side of the cylindrical wall part, and inside the inner flange forming part. Forming the inner flange while compressing and increasing the thickness of the thin portion. A second punch having an outer peripheral surface corresponding to an inner peripheral surface shape of the cylindrical portion, and a second die having a hole into which the second punch is inserted, The opening side portion of the inner hole of the die hole into which the second punch is inserted has an inner peripheral surface corresponding to the outer peripheral shape of the cylindrical portion. A portion continuous with the portion is formed by a stepped surface which is stepped so as to protrude inward over the entire circumference by a stepped surface provided on the inner peripheral surface of the hole, using an aperture die having a stepped portion, A stepped bottomed cylinder in which the bottom side of the cylinder wall is thinned by performing drawing with the second punch and the second die on a flat metal material that gives a metal product. A shape, and wherein the stepped surface is formed by a stepped surface in the hole of the second die; 2. The metal product according to claim 1, wherein the preformed body is prepared by forming a thick portion on the opening side of the cylindrical wall portion as a portion for providing a cylindrical portion of the metal product. Molding method. 3. When forming the inner flange while pushing a thin portion on the bottom side of the cylindrical wall portion of the preformed body into the inner flange forming portion to compress and increase the thickness of the thin portion, In the inner flange forming portion, a space is formed on a surface of the thin wall portion of the cylindrical wall portion opposite to the bottom surface side of the inner flange forming portion so that a thickened portion of the cylindrical wall portion can enter. 3. The method for forming a metal product according to claim 1, wherein the thin portion of the cylindrical wall portion is pushed into the flange forming portion. 4. The molding die is configured to also have the first punch and the first die together with the inner flange molding portion, and the rising portion is formed by using the molding die. The method of forming a metal product according to any one of claims 1 to 3, wherein both the step of forming the cylindrical part and the step of forming the cylindrical portion and the inner flange are performed. 5. A molding die used in the method of molding a metal product according to claim 4, wherein the first die and the second die which are disposed so as to be relatively close to / separable from each other are formed. The first die has the first punch and the inner flange forming portion, while the second die has the first die, the first die and the second die. With the approach, from the opening side of the cylindrical portion of the metal product to the bottom side, the moving member is configured to move relatively approaching to the bottom surface of the inner flange forming portion, With the preform positioned between the first die and the second die, the first punch and the second die are moved closer to each other to move the first punch and the second die together. At the first die,
The drawing process is performed on the bottom of the preform to form the cylindrical rising portion, and the moving member and the inner flange forming in accordance with the approach movement of the first mold and the second mold. By approaching the bottom surface of the portion, the cylindrical wall portion of the preformed body is pressed from the opening side to the bottom side between the moving member and the bottom surface of the inner flange forming portion, and Until the stepped surface of the wall portion comes into contact with the bottom surface of the inner flange forming portion, the thin portion of the cylindrical wall portion on the bottom side with respect to the stepped surface is pushed into the inner flange forming portion. A tubular portion of the metal product is formed at a thick portion on the opening side of a wall portion, and the inner flange can be formed while compressing and increasing the thickness of the thin portion in the inner flange forming portion. A metal product molding die, characterized in that it is configured as follows. 6. A space can be formed between the thin portion on the bottom side of the cylindrical wall portion of the preformed body pressed into the inner flange forming portion and the second mold. A molding die for a metal product according to item 1.