JP3780128B2 - Sheet metal member forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, while rotating and pressed sandwiching the blank between the upper and lower molds, relates to molding how the sheet metal member for rolling molding against the forming roll on the outer peripheral portion of the blank.
[0002]
[Prior art]
As a method for forming a sheet metal member, a disc-shaped blank having a center hole or a blank having a boss portion formed in the center is crimped and rotated between an upper die that is rotationally driven and a lower die that is driven and rotated. On the other hand, for example, a single V groove or a poly V groove is cold formed on the outer peripheral portion of the blank to form a V belt pulley by pressing a rolling roll on the outer peripheral portion of the blank. This is known in Japanese Patent Publication No. 8-29375.
[0003]
[Problems to be solved by the invention]
However, in the sheet metal member forming method, the blank is sandwiched between the lower end surface of the upper mold formed in a horizontal plane and the upper end surface of the lower mold formed in the same horizontal plane. However, in such a horizontal pressing and clamping method of the blank, a phenomenon occurs in which the material of the blank flows and moves radially outward when the rolling roll strongly presses the outer peripheral portion of the blank. As a result, there is a problem that deformation occurs in the central hole portion of the blank, or a thinning phenomenon that the blank can be thinned causes a decrease in dimensional accuracy and a decrease in strength.
[0004]
As a solution to such a problem, for example, as disclosed in JP-A-63-140732 and WO 98/05446, while annular ribs are formed concentrically on a disk-shaped blank, A method for forming a sheet metal member is proposed in which an annular concavo-convex portion corresponding to the rib is formed on the upper and lower molds, and a blank is crimped and sandwiched between the upper and lower molds so as to engage the annular rib between the annular concavo-convex portions. Has been.
[0005]
However, in such a solution, when the rolling roll is pressed against the outer peripheral portion of the blank that is pressure-clamped between the upper and lower molds, the material of the inner region portion is formed from the annular rib in the radial direction of the blank. Although it is prevented from flowing and moving radially outward from the annular rib, the material of the outer region portion from the annular rib still flows and moves radially outward. A thinning phenomenon occurs in the outer region than the annular rib, and there is room for further improvement in this respect.
[0006]
The object of the present invention is to solve the above-mentioned problems, and it is possible not only to prevent the deformation of the central hole portion of the blank by devising a method for crimping and clamping the blank between the upper and lower molds. is to provide a molding how the sheet metal member strength by suppressing the thinning phenomenon of the blank throughout its radial can be secured.
[0007]
[Means for Solving the Problems]
The sheet metal member forming method of the present invention is a blank projecting from the outer periphery of the upper and lower molds while being clamped and rotated between the upper end face of the lower mold for rotationally driving the blank and the lower end face of the upper mold for driven rotation. In the method of forming a sheet metal member, which is formed by pressing a rolling roll that rotates following the blank in a radial direction on the outer peripheral portion of the blank, the plate surface portion to be crimped and sandwiched by the upper and lower molds of the blank is previously conical. The outer periphery of the conical portion is formed in a horizontal plane and a central hole is provided in the conical portion, and the lower end surface of the upper die is a convex cone that matches the conical shape of the conical portion of the blank. And a protrusion corresponding to the central hole of the blank is formed at the center of the concave conical surface, and the upper end surface of the lower mold is a concave conical surface that matches the conical shape of the conical portion of the blank. Formed and this A recess for receiving the lower mold protrusion is formed in the center of the mold conical surface, and the center hole is fitted to the lower mold protrusion between the upper mold conical surface and the lower mold conical surface. The conical portion of the blank is crimped and clamped, and in this crimping sandwiched state, the blank has a V-shaped groove on the outer peripheral surface in the horizontal outer periphery of the blank projecting outward from the upper and lower molds. by driven rotation about the axis of said transfer forming roll while pressing strongly the groove of the forming roll in the radial direction following to the blank, and thickened outer peripheral portion of the blank, thickened in the outer peripheral portion Thereafter, the conical portion is characterized in that it is horizontally shaped perpendicular to the axial direction .
[0008]
[Action]
When the outer diameter of the blank is the same by pressing and clamping the conical part of the blank between the convex convex surface of the upper mold and the concave conical surface of the lower mold, the blank pressing and clamping area is the horizontal of the upper mold Larger than the conventional blank crimping and clamping method described above, which is crimped and sandwiched between the lower end surface and the horizontal upper end surface of the lower die, and therefore rolled to the outer periphery of the blank that is crimped and sandwiched between the upper and lower molds. When the roll is pressed and formed by rolling, the frictional force can be increased accordingly, so that the blank material is prevented from flowing and moving radially outward. As a result, even in the case of a blank having a center hole, the center hole portion can be prevented from being deformed, and the thinning phenomenon of the blank can be suppressed over the entire radial direction, thereby ensuring strength.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a cross-sectional view showing an example of a sheet metal member obtained by the method of the present invention, FIG. 2 is a cross-sectional view of a blank formed in advance before the rolling process, and FIGS. 3 to 6 are sheet metal by the method of the present invention. FIG. However, in FIG. 3 thru | or FIG. 6, since a blank, an upper mold | type, and a lower mold | type are rotationally symmetrical shapes, they are shown in the semi-missing state.
[0010]
The sheet metal member shown in FIG. 1 is obtained by rolling by the following forming method using a thin disk-shaped steel plate blank, and the outer periphery of the circular substrate portion 2 having the center hole 1. The circumferential wall portion 3 is integrally formed.
[0011]
Next, an example of a method for forming the sheet metal member will be described with reference to FIGS.
First, the center hole 1 is provided in the blank 4 made of a thin disk-shaped steel plate as shown in FIG. 2 by press forming, and the outer peripheral plate surface portion of the center hole 1 is formed in a conical shape. The part 6 is formed in a horizontal plane.
[0012]
Next, the blank 4 thus formed in a conical shape is set in a molding die 7 as shown in FIG. The molding die 7 includes an upper die 8 and a lower die 9. An upper end surface 10 of the lower die 9 is formed as a concave conical surface 11 that matches the conical shape of the conical portion 5 of the blank 4, and a projection 12 corresponding to the central hole 1 of the blank 4 at the center of the concave conical surface 11. Is formed. On the other hand, the lower end surface 13 of the upper die 8 is formed on a convex conical surface 14 that matches the conical shape of the conical portion 5 of the blank 4, and the projection 12 of the lower die 9 is formed at the center of the convex conical surface 14. A receiving recess 15 is formed. Thus, as shown in FIG. 3 (A), the blank 4 has the center hole 1 fitted to the protrusion 12 of the lower die 9 and the conical portion 5 is superimposed on the concave conical surface 11 and the outer peripheral portion 6 is lowered. The mold 9 is placed on the upper end surface 10 of the lower mold 9 so as to project outward from the upper end surface 10 of the mold 9.
[0013]
Thereafter, as shown in FIG. 3 (B), the upper die 8 is lowered and the conical portion 5 of the blank 4 is clamped and sandwiched between the convex conical surface 14 and the concave conical surface 11 of the lower die 9. Then, while rotating the blank 4 by rotating the lower mold 9 around the axis O ₁ and rotating the upper mold 8 to follow, the outer peripheral portion 6 of the blank 4 projecting outward from the upper and lower molds 8, 9 The rolling roll 16 follows the blank 4 and is driven around the axis O ₂ while strongly pressing the groove 16a of the rolling roll 16 for thickening molding having a V-shaped groove 16a on the outer peripheral surface in the radial direction. By rotating, the outer peripheral portion 6 of the blank 4 is increased in thickness. This increase in the thickness of the increased outer peripheral portion 17 is caused by the material flow generated in the groove 16 a as the rolling roll 16 is pressed.
[0014]
In this thickening process, if a sufficient thickness cannot be obtained at one time, as shown in FIGS. 4 (A) and 4 (B), the conical portion of the blank 4 having the outer peripheral portion 17 which has been thickened first. 5 while pressing and sandwiching and rotating 5 between the convex conical surface 19 of another upper mold 18 and the concave conical surface 21 of the lower mold 20 formed in the same shape as the upper and lower molds 8 and 9. A groove 22a having a V-shaped cross section of the rolling roll 22 is pressed against the meat outer peripheral portion 17 in the radial direction, and the thickening forming process is repeated once again. Of course, in this case, the rolling roll 22 having a groove 22a having a groove width wider than the groove 16a of the rolling roll 16 shown in FIG. 3 is used.
[0015]
Next, as shown in FIG. 5A, the blank 4 having the outer peripheral portion 17 increased in thickness to the desired thickness is transferred to the next curved thickening forming step, and the increased outer peripheral portion 17 of the blank 4 is curved. Further thickening is performed. In this process, the upper and lower molds 23 and 24 having the same shape as the upper and lower molds 8 and 9 are used, and the rolling roll 25 is formed with a circular arc-shaped groove 25a on the outer peripheral surface so as to meet the processing purpose. Is used. At the time of processing, as shown in FIG. 5B, the conical portion 5 of the blank 4 having the thickened outer peripheral portion 17 is placed between the convex conical surface 26 of the upper die 23 and the concave conical surface 27 of the lower die 24. The lower die 24 is rotationally driven around the axis O ₁ and the upper die 23 is driven to rotate to rotate the blank 4, and the groove 25 a of the rolling roll 25 is radiused on the thickened outer peripheral portion 17. by rotated about the axis O ₂ of said transfer forming roll 25 while pressing strongly in the direction following the blank 4, further be thickened while bending the thickened peripheral portion 17 downward in the axial direction.
[0016]
Next, the blank 4 having the thickened outer peripheral portion 17 which has been thickened by bending is transferred to the next circumferential wall portion forming step, and the thickened outer peripheral portion 17 is transferred to the circumferential wall portion 3 as shown in FIG. Molding. Also in this process, the upper and lower molds 28 and 29 having the same shape as the upper and lower molds 8 and 9 are used, and the rolling roll 30 is formed in a shape having a stepped outer peripheral surface 30a so as to meet the processing purpose. . At the time of the molding, as shown in FIG. 6B, the conical portion 5 of the blank 4 having the thickened outer peripheral portion 17 which is thickened by bending is used as the convex conical surface 31 of the upper die 28 and the concave conical shape of the lower die 29. crimp sandwiched between the surface 32, and rotates the lower mold 29 about the axis O _1, while rotating the blank 4 by the upper die 28 is driven to rotate, the forming roll in the thickened outer peripheral portion 17 by driven rotation of the stepped outer peripheral surface 30a of 30 the said transfer forming roll 30 while pressing strongly in the radial direction about the axis O ₂ following the blank 4, the lower die 29 a thickened outer peripheral portion 17 of the blank 4 The outer peripheral wall portion 29a is pressed and straightened in the axial direction to form the circumferential wall portion 3 by rolling. The sheet metal member thus obtained is shown in FIG.
[0017]
In any of the processes of the above-described first and second stage thickening, curved thickening, and circumferential wall molding, the blank 4 has the conical portion 5 as the convex conical surface of the upper mold 8, 18, 23, 28. 14, 19, 26, 31 and the concave conical surfaces 11, 21, 27, 32 of the lower molds 9, 20, 24, 29 are respectively crimped and clamped so that the crimping clamping area is as large as possible. When the rolling rolls 16, 22, 25, and 30 are pressed against the outer peripheral portion 6 of the blank 4 for rolling, the frictional force can be increased accordingly. Therefore, the material of the blank 4 flows and moves radially outward. Be blocked. Therefore, the central hole 1 portion of the blank 4 can be prevented from being deformed, and the thinning phenomenon of the blank 4 can be suppressed over the entire radial direction.
[0018]
The sheet metal member of FIG. 7 obtained in this way is formed, for example, by forming the substrate portion 2 by horizontally shaping the conical portion 5 as shown in FIG. By rolling and shaping one or more V-grooves on the outer periphery, it can be used as a pulley for a V-belt, and a piston ring mounting groove is provided on the outer periphery of the circumferential wall 3 so that it can be used as a piston ring. It can also be formed. In addition, it can also be used for an internal gear or an external gear by machining gear teeth on the inner periphery or outer periphery of the circumferential wall portion 3.
[0019]
【The invention's effect】
According to the present invention, the blank is formed in a conical shape in advance, and this conical portion is crimped and sandwiched between the upper convex cone surface and the lower concave cone surface. When rolling forming by pressing a rolling roll on the outer periphery, it is possible to prevent deformation of the center hole even in the case of a blank having a center hole, improving accuracy and reducing the thickness of the blank. There is an advantage that the strength can be secured by suppressing the entire radial direction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a sheet metal member.
FIG. 2 is a cross-sectional view of a blank formed in advance before the rolling process.
FIG. 3A is a half-notch cross-sectional view showing the first-stage thickening process of the sheet metal member in a state before processing, and FIG. 3B is a half-notch cross-sectional view showing the state after processing. .
FIG. 4A is a half-notch cross-sectional view showing a second-stage thickening forming step of a sheet metal member in a state before processing, and FIG. 4B is a half-notch cross-sectional view showing a state after processing. .
FIG. 5A is a half-notch cross-sectional view showing a curved thickening forming step of a sheet metal member in a state before processing, and FIG. 5B is a half-notch cross-sectional view showing a state after processing.
6A is a half-notch cross-sectional view showing the circumferential wall portion forming step of the sheet metal member in a state before processing, and FIG. 6B is a half-notch cross-sectional view showing the state after processing.
FIG. 7 is a cross-sectional view of a sheet metal member immediately after forming a circumferential wall portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Center hole 2 Substrate part 3 Circumferential wall part 4 Blank 5 Conical part 6 Outer part 7 Molding die 8, 18, 23, 28 Upper die 9, 20, 24, 29 Lower die 11, 21, 27, 32 Recessed cone Surface 12 Protrusion 15 Recess 14, 19, 26, 31 Convex-shaped conical surface 16, 22, 25, 30 Rolling roll 17 Increased outer periphery

Claims (1)

While pressing and rotating between the upper end surface of the lower mold that rotates the blank and the lower end surface of the upper mold that is driven to rotate, follow the blank on the outer periphery of the blank that protrudes from the outer periphery of the upper and lower molds. In the method of forming a sheet metal member that is formed by pressing a rolling roll that rotates in a radial direction by rolling,
The plate surface portion to be crimped and sandwiched by the upper and lower molds of the blank is formed in a conical shape in advance , the outer peripheral portion of the conical portion is formed in a horizontal plane and a center hole is provided in the conical portion, and the lower end surface of the upper mold is A convex conical surface that matches the conical shape of the conical portion of the blank is formed, a projection corresponding to the central hole of the blank is formed at the center of the concave conical surface, and the upper end surface of the lower mold is A concave conical surface that matches the conical shape of the conical portion of the blank is formed, and a concave portion that accepts the projection of the lower die is formed at the center of the convex conical surface. Between the concave conical surface of the mold, the conical portion of the blank with the center hole fitted to the protrusion of the lower mold is crimped and sandwiched ,
Under this crimping state, the groove of the rolling roll for thickening molding having a groove with a V-shaped cross section on the outer peripheral surface is strongly strengthened in the radial direction on the horizontal outer periphery of the blank projecting outward from the upper and lower molds. The outer peripheral part of the blank is increased in thickness by following and rotating the rolling roll following the blank while pressing.
After the outer peripheral portion is thickened, the conical portion is shaped horizontally so as to be orthogonal to the axial direction .

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