JP2816548B2 - Sheet metal having boss portion and method of forming boss portion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal plate having a cylindrical boss for rotating shaft fitting and formed integrally with a metal plate such as a poly V pulley or a crankshaft pulley.
And a method of forming a boss .

[0002]

2. Description of the Related Art Hitherto, a cylindrical boss formed integrally with a sheet metal has been formed by burring.

[0003]

However, in the case of burring, a hole is formed in a flat portion by a punch or the like,
Since the flat part around the hole is raised while pushing and widening the hole, an attempt to obtain a cylindrical boss having a high height also increases the inner diameter of the boss. That is, assuming that the height of the boss portion is h and the radius of the inner diameter of the boss portion is r, only a boss portion of h <r could be made. For this reason, if you try to obtain a high boss with a small diameter hole,
Only the boss portion was manufactured separately, and the only option was to attach the boss portion to a flat portion with a hole by welding or a fastener.

[0004] In view of such circumstances, the present invention has a small diameter.
A metal plate with a boss for fitting a rotating shaft that is high with holes
The purpose is to provide. Another object of the present invention is to provide a method for forming a small-diameter and high-height boss for fitting a rotary shaft , which is a cylindrical boss that is bent from a flat portion and integrally protruded.

[0005]

Sheet metal having a boss portion of the present invention According to an aspect of the rotating protruded integrally bent from the flat portion
The protrusion height of the cylindrical boss portion for shaft fitting is formed to be higher than the radius of the inner diameter of the boss portion. Also, as a method of forming the boss portion, a metal material which is curved into a mountain-shaped convex and a hole is formed in the curved top portion is formed, and a curved portion between the outer peripheral edge of the material and the peripheral portion of the hole is formed. By pressing the portion in the direction opposite to the bulging direction, the portion is narrowed down to a height longer than the radius of the inner diameter of the boss portion for fitting the rotating shaft to be formed in a cylindrical shape, and the protrusion height is reduced. The boss portion and the flat portion are formed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a method of forming a boss portion of a sheet metal pulley (sheet metal member) will be described with reference to the drawings. The boss of this embodiment has a diameter of 90 to 100 m.
As shown in FIG. 8, the inner diameter d1 of the boss portion is set to 12 using a circular plate-shaped metal material having a thickness of about m and a thickness t of about 5 mm.
mm (radius r1 is about 6 mm), outer diameter d2 of pulley
Is about 80 mm, the height h from the lower surface of the flat portion 8 to the tip of the boss 6 is about 35 to 36 mm, and the projection height h1 of the boss 6 is about 30 to 31 mm.

First, in the first bending (aperture) step, FIG.
As shown in the figure, a circular flat metal material 1 is
a and the upper die 3 including the die 3a and the die holder 3b after being set on the lower die 2 including the punch holder 2b and the die 3a and the die holder 3b, as shown in FIG. The metal material 1 is entirely curved toward the projecting side of the boss portion into a convex two-stage convex bulge. The curved shape at this time is lower mold 2
Shape of punch 2a and die holder 3b of upper die 3
Is determined by the shape of the entrance tapered surface 3b1.

In the second bending (drawing) step, as shown in FIG. 2A and FIG. 2B, the punch 2a having a different tip shape and the die holder 3b having a different shape of the inlet tapered surface 3b1 are replaced and used, and the upper die is formed in the same manner as described above. By bringing the lower mold 3 and the lower mold 2 close to each other, the material 1 is drawn into a substantially conical shape.

Next, as shown in FIG. 3, the material 1 curved as described above is held in a dedicated hole holder 4 and a top portion thereof is formed by using a drilling tool 5 for a lathe or a drilling machine. A hole 5A having a diameter of about 7 mm is formed.

Subsequently, the process shifts to a bending (ironing) step for forming a cylindrical boss portion penetrating vertically, and this bending (ironing) step is performed as shown in FIGS. 4A to 7B. Step (FIGS. 4A and 4B), Second Step (FIGS. 5A and 5)
B), the third step (FIGS. 6A and 6B), and the fourth step (FIG. 7).
A, FIG. 7B), and in each of these steps, a mold dedicated to ironing that is different from the mold used in the first and second bending (drawing) steps is used. While sequentially changing the protrusion amount and the curvature of the tip of the punch 12a of the lower die 12 and the curvature of the entrance corner 13b2 of the die holder 13b of the upper die 13,
This is performed by bringing the upper mold 13 and the lower mold 12 close to each other.

In each of the bending steps of FIGS. 4A to 7A, a curved portion 1b between the outer peripheral edge 1e and the hole peripheral portion 1c of the material 1 shown in FIGS.
When b is pressed in the direction opposite to the bulging direction, the boss portion 6 is gradually narrowed down to a height longer than the radius of the inner diameter of the boss portion 6 to be formed, as a result.
As shown in FIGS. 7B and 8, a cylindrical boss 6 which is bent from the flat portion 8 and integrally protrudes vertically is obtained at the center of the flat portion 8, and the protrusion of the boss 6 is obtained. The height h1 is formed at a height longer than the radius (r1) of the inner diameter d1 of the boss portion 6.

FIGS. 4A, 5A, 6A, and 7A show a state in which the upper die 13 is located above the material 1. FIG.
B, FIG. 5B, FIG. 6B, and FIG. 7B show a state in which the upper mold 13 presses while pressing the curved portion 1b of the material 1.

Also, in the multiple bending steps shown in FIGS. 4A to 7B, the outer peripheral edge 1e of the material 1 is
Protrusion 12 formed annularly on the punch holder 12b
Since the radially outward spread is always restricted by being in contact with the inner surface of c, the material of the raw material 1 does not escape at all in the radially outward direction but escapes to the cylindrical boss portion 6 side to be formed. Thus, the thickness of the boss portion 6 and the length (height) of the linear portion can be sufficiently large.

Incidentally, the boss 6 shown in FIG.
Is as small as about 12 mm, and the protrusion height h1 is 30 to
The metal plate 7 is about 31 mm.

Next, another embodiment of the boss portion forming method will be described.

In the bending (drawing) step, as shown in FIG. 9A, a circular flat metal material 1 is set on a lower die 2 comprising a punch 2a and a punch holder 2b, and then the lower die 2 and a die 3a are set. And the upper die 3 including the die holder 3b are brought close to each other by a press machine,
As shown in FIG. 9B, the metal material 1 is squeezed as a whole toward the protruding side of the boss portion, and is curved into a substantially arc-shaped convex bulge. The curved shape at this time is determined by the shape of the tip of the punch 2a of the lower die 2 and the shape of the entrance tapered surface 3b1 of the die holder 3b of the upper die 3 as in the case of the above embodiment.

Next, as shown in FIG. 10, while holding the material 1 curved as described above in a dedicated hole holder 4, a top portion thereof is formed by using a drilling tool 5 of a lathe or a drilling machine. A hole 5A having a diameter of about 4 to 5 mm is drilled.

Subsequently, as shown in FIGS. 11A and 11B, using a mold different from the mold used in the bending (drawing) step, the lower mold 12 is formed in a ring shape on the punch holder 12b. A lower mold 12 having a punch 12a1 for burring in a state where the outer peripheral edge 1e of the material 1 curved in a substantially arc shape is brought into contact with the inner surface of the projecting portion 12c so as to restrict the radial outward spread. By bringing the upper mold 13 and the upper mold 13 closer to each other, the peripheral portion 1c of the hole 5A is bent in the bulging direction of the material 1.

Subsequently, the process proceeds to a bending (ironing) process for forming a cylindrical boss. This bending (ironing) step is performed by bringing the upper die 13 and the lower die 12 close to each other using a punch 12a dedicated to ironing, as shown in FIGS. The curved portion 1b between the hole peripheral portion 1c subjected to the burring process in the previous step is squeezed, and the curved portion 1b is pressed in a direction opposite to the bulging direction, thereby forming a cylindrical shape. The height is narrowed down to a height longer than the radius of the inner diameter of the boss portion 6 to be formed. As a result, a flat portion 8 is formed, and the hole peripheral portion 1c is deformed along the outer peripheral surface of the punch 12a. A substantially completed boss 6 is formed at the center of the flat portion 8. Also in this bending step, the outer peripheral edge 1e of the raw material 1 is in contact with the inner surface of the projection 12c formed in an annular shape on the punch holder 12b of the lower die 12, so that the radial outward expansion is always restricted. Because it remains
The material of the raw material 1 does not escape outward at all in the radial direction, but escapes to the side of the cylindrical boss portion 6 to be formed, so that the formed boss portion 6 can have a sufficiently large thickness.

After the bending step as described above, FIG.
As shown in FIG. 13A and FIG.
By using the 2a2 and the die holder 13b2, the end face 6a of the cylindrical boss 6 is compressed in the axial direction, so that a finishing step is performed so that the cylindrical boss 6 is adjusted to a predetermined protrusion height.

Through the above steps, as shown in FIG. 14, a cylindrical boss portion 6 which is bent from the flat portion 8 and protrudes vertically and is integrally formed at the center of the flat portion 8 is obtained.
The protruding height h1 of the boss 6 is formed at a height longer than the radius (r1) of the inner diameter of the boss 6.

Next, a process of forming a poly-V groove on the outer peripheral wall portion of the sheet metal member 10 will be described.

First, a step of increasing the thickness of the outer peripheral wall for forming the poly-V groove is performed. In this thickening step, as shown in FIG. 15, the lower die 14 and the upper die 1
And 5 are brought close to each other via a press machine,
The flat portion 8 of the sheet metal 10 is pressed from its thickness direction.
Thereby, the material of the flat portion 8 flows to the outer peripheral side, and the outer peripheral portion 10a of the sheet metal 10 is thickened. At this time, the position of the boss portion 6 is almost regulated, and only a part of the material of the flat portion 8 flows, and the height and the wall thickness are hardly changed.

Next, the step of forming the outer peripheral wall portion 10a thickened as described above is performed. As shown in FIG. 16, the slit forming step sandwiches the flat portion 8 and the boss portion 6 except for the thick outer peripheral wall portion 10a of the sheet metal member 10 between the rotary inner die 16 and the rotary upper die 17, and rotates them. Inner die 16
The whole of the sheet metal 10 is rotated by the rotation of the rotary upper die 17. Then, a V-shaped notch protruding portion 18a formed on the outer peripheral surface of the rolling roller 18 is pressed against the central portion of the thick outer peripheral wall portion 10a of the rotating sheet metal member 10 from the outside while being rotated. The thick outer peripheral wall portion 10a is cut into a V shape by being cut into the side.

Subsequently, as shown in FIG. 17, while rotating the whole metal plate 10 by the rotation of the rotary inner die 16 and the rotary upper die 17, the rotating metal plate 10 is cut into a V-shape. The rolling roller 19 for forming a wide outer peripheral wall is pressed against the outer peripheral wall portion 10a from outside thereof while rotating the outer peripheral wall portion 10a.
b is roll formed. The above-described split forming step and wide peripheral wall forming step may be performed simultaneously using a common mold, or may be performed separately using separate molds.
Further, the molding is not limited to the case where the molding is performed once, but may be performed a plurality of times.

Finally, a step of forming a poly-V groove in the wide outer peripheral wall 10b formed as described above is performed. In this poly V groove forming step, as shown in FIG. 18, the flat portion 8 and the boss portion 6 of the metal plate 10 except for the wide outer peripheral wall portion 10b are sandwiched between the inner rotating die 20 and the upper rotating die 21, and the rotation is performed. The sheet metal 1 is formed by the rotation of the inner mold 20 and the rotating upper mold 21.
Rotate the whole of 0. And the rotating metal plate 1
By pressing an uneven forming portion 22a formed on the outer peripheral surface of the rolling roller 22 from the outside while rotating against the wide outer peripheral wall portion 10b of 0, and biting into the rotary shaft core side,
Poly-V comprising a plurality of V-groove groups on the wide outer peripheral wall portion 10b
The groove 11 is roll formed. The poly V-groove 11 may be formed by a single rolling, but it is further rolled into a pre-poly V-groove forming step and a poly-V groove of the sheet metal 10 that has undergone this pre-poly V-groove forming step. And a finishing step of finishing the depth and the pitch as required.
It is preferable to carry out roll forming of (coincidence).

Next, a method for forming another sheet metal pulley using the sheet metal member 10 shown in FIG. 14 will be described with reference to the drawings.

First, a flat part pressing step of the sheet metal 10 is performed. In this flat part pressing step, as shown in FIG. 19, the lower part 23 and the upper part 24 sandwiching the sheet metal 10 are brought close to each other via a press machine, so that the flat part 8 of the sheet metal 10 is Pressure is applied from the thickness direction. As a result, the material of the flat portion 8 is caused to flow toward the outer peripheral side, and is expanded so that the outer diameter D of the sheet metal 10 becomes the required diameter. At this time, the position of the cylindrical boss portion 6 is substantially regulated, and only a part of the material of the flat portion 8 flows, and the height and the wall thickness hardly change.

Next, the outer end 8a side of the flat portion 8 pressed as described above is used for a lower mold 25 and an upper mold 26 as shown in FIG. A peripheral wall forming step of forming the peripheral wall portion 10c for forming the poly-V groove by bending to the one side in the pulley rotation axis direction, specifically, the side different from the projecting direction of the boss portion 6 by the close movement by the press machine with the press machine 26 is performed. It is.

Finally, a step of forming a poly V groove on the peripheral wall portion 10c for forming the poly V groove formed as described above is performed. This poly-V groove forming step is substantially the same as the above-described poly-V groove forming method shown in FIG. 18, and as shown in FIG. 21, the flat portion 8 of the sheet metal member 10 excluding the poly-V groove forming peripheral wall portion 10c. And the boss portion 6 is formed by rotating the inner mold 27 and the upper mold 2.
8 and the rotation of the inner rotary mold 27 and the upper rotary mold 28 causes the entire sheet metal 10 to rotate. And
The peripheral wall portion 10c for forming the poly V groove of the rotating metal plate 10
Then, by pressing a concave-convex forming portion 29a formed on the outer peripheral surface of the rolling roller 29 from the outside while rotating, and pressing the forming portion 29a into the rotation shaft core side, the peripheral wall portion 10c is formed of a plurality of V-groove groups. The V groove 11 is roll formed. In addition,
As described above, the forming of the poly V groove 11 may be performed by a single rolling process. However, the pre-poly V groove forming step and the poly V of the sheet metal 10 having undergone the pre-poly V groove forming step are performed. And a finishing step of subjecting the groove to further rolling to finish the depth and pitch as required.
It is, of course, preferable to carry out roll forming of (coincidence).

In the boss forming method described first (FIGS. 1 to 7B), the burring process shown in FIGS. 11A and 11B and the boss finishing process shown in FIGS. 13A and 13B may be performed. Of course it is.

The method of forming the sheet metal pulley is as follows.
The present invention is not limited to the method of forming the poly V pulley, and may be applied to the formation of a V pulley having a single V groove, and may be applied to the formation of a flat pulley having a wide and flat peripheral wall.

[0033]

As described above, the present invention provides a rotary shaft fitting boss having a small inner diameter and having a sufficient protruding height despite being bent and protruded integrally from a flat portion. Yes
And a suitable method for forming such a boss portion . Further, such a boss can be suitably applied to a sheet metal member such as a sheet metal pulley.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a main part for explaining a first bending (drawing) step performed in advance in forming a boss portion on a sheet metal material, and FIG. 1B is a first bending (drawing) step. It is sectional drawing of the principal part for demonstrating the state from which a process differs.

FIG. 2A is a cross-sectional view of a main part for explaining a second bending (aperture) step, and FIG. 2B is a cross-sectional view of a main part for explaining different states of the second bending (aperture) step. It is.

FIG. 3 is a cross-sectional view of a main part for describing a drilling step.

FIG. 4A is a cross-sectional view of a main part for describing a first bending (ironing) step, and FIG. 4B is a first bending (ironing) step.
It is sectional drawing of the principal part for demonstrating the state from which a process differs.

FIG. 5A is a sectional view of a main part for explaining a second bending (ironing) step, and FIG. 5B is a second bending (ironing) step.
It is sectional drawing of the principal part for demonstrating the state from which a process differs.

FIG. 6A is a sectional view of a main part for describing a third bending (ironing) step, and FIG. 6B is a third bending (ironing) step.
It is sectional drawing of the principal part for demonstrating the state from which a process differs.

FIG. 7A is a sectional view of a main part for explaining a fourth bending (ironing) step, and FIG. 7B is a fourth bending (ironing) step.
It is sectional drawing of the principal part for demonstrating the state from which a process differs.

FIG. 8 is a sectional view of the sheet metal after a boss is formed.

FIG. 9A is a cross-sectional view of a main part for describing a bending (drawing) step in another boss portion forming method, and FIG. 9B.
FIG. 4 is a cross-sectional view of a main part for describing different states of the bending (aperture) process.

FIG. 10 is a cross-sectional view of a main portion for describing a hole making step of the above.

11A is a cross-sectional view of a main part for describing a burring step of the above, and FIG. 11B is a cross-sectional view of a main part for explaining different states of the burring step.

12A is a cross-sectional view of a main part for describing a bending (ironing) step of the above, and FIG. 12B is a cross-sectional view of a main part for explaining different states of the bending (ironing) step. is there.

FIG. 13A is a cross-sectional view of a main part for describing a boss part finishing step of the above, and FIG. 13B is a cross-sectional view of a main part for explaining different states of the boss part finishing step.

FIG. 14 is a cross-sectional view of the sheet metal after the boss portion is formed.

FIG. 15 is a half sectional view of a main part for describing a thickening step performed in advance in forming a sheet metal pulley.

FIG. 16 is a half sectional view of a main part for describing a first rotational molding step of the above.

FIG. 17 is a half sectional view of a main part for explaining a second rotational molding step of the above.

FIG. 18 is a half sectional view of a main part for describing a third rotational molding (poly V groove molding) step of the above.

FIG. 19 is a half sectional view of a main part for describing a flat part pressing step in another method of forming a sheet metal pulley.

FIG. 20 is a half sectional view of a main part for describing a peripheral wall forming step of the above.

FIG. 21 is a half sectional view of a main part for describing a poly V groove forming step of the above.

[Explanation of symbols]

 Reference Signs List 1 metal material 1b curved portion 1c hole peripheral portion 1e outer peripheral edge portion 5A hole 6 boss portion 7 sheet metal member 8 flat portion 10 sheet metal member 11 poly V groove (V groove) h1 protrusion height of boss portion r1 radius of inner diameter of boss portion

Claims (2)

(57) [Claims] 1. A flat part is bent and integrally protruded.
A metal plate having a boss portion, wherein a protrusion height of a cylindrical boss portion for fitting a rotating shaft is formed to be longer than a radius of an inner diameter of the boss portion. 2. A metal material which is curved into a chevron shape and has a hole formed in the curved top is formed, and a curved portion between an outer peripheral portion of the material and a peripheral portion of the hole is defined as a bulging direction. 2. The cylindrical boss portion according to claim 1, wherein by pressing in the opposite direction, the cylindrical boss portion is narrowed down to a height longer than the radius of the inner diameter of the boss portion for rotating shaft fitting to be formed in a cylindrical shape. And a boss portion forming a flat portion.