JPH0576972A - Method for forming edge part in plate metal made poly-v pulley - Google Patents

Abstract

PURPOSE:To sufficiently make large of the projecting quantity from the outer peripheral walls of edge parts for preventing come-out of a belt formed in the outer peripheral walls of a plate metal-made poly-V pulley. CONSTITUTION:After the outer peripheral wall 13 is formed as tapered state, the outer peripheral wall 13 is covered on a rotary inner die 112 under condition of existence of a space S at between the base part of the outer peripheral wall 13 and the rotary inner die 112. The outer peripheral wall 13 is held with the holding faces 114, 115, of the rotary die 112, and while rotating a rotary outer die 213, the base part of the outer peripheral wall 13 is pushed to the rotary inner die 112 and the projecting part 214 for forming the edge part is bitten so as to slit the base part into two from the outside by the rotary outer die.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an ear portion of a sheet metal poly-V pulley, and more specifically, to prevent the poly-V belt from being detached from one end portion of an outer peripheral wall where a poly-V groove is formed. And a method for forming an annular ear portion that protrudes outward in the radial direction.

[0002]

2. Description of the Related Art The applicant of the present application has filed Japanese Patent Application No. 1-507920.
Proposed the following method as a method for forming the ears of a sheet metal poly-V pulley. In this method, a sheet metal material having an outer peripheral wall formed on the bottom wall is put on a rotary inner die for supporting the inner surface thereof, and the base of the outer peripheral wall corresponding to the range of the thickness of the bottom wall of the material is covered. Into the part, while rotating the V-shaped ear part forming projection formed on the roller surface of the outer rotating type so as to split the root part of the outer peripheral wall into two from the outside,
This is a method of forming an annular ear portion projecting outward in the radial direction for preventing the poly V belt from coming off at one end portion of the outer peripheral wall where the poly V groove is formed.

[0003]

However, according to this conventional method, even if the ear-molding projection of the outer rotating type is made to dig into the root portion of the outer peripheral wall, the ear portion facing outward in the radial direction of the outer peripheral wall. It was discovered that the amount of protrusion may be insufficient.

The present invention has been made in view of the above circumstances, and when the rotating outer type ear forming projection is made to bite into the root portion of the outer peripheral wall, a sufficient amount of the ear is formed in the radial direction of the outer peripheral wall. An object of the present invention is to provide a method for forming an ear portion of a sheet metal poly-V pulley that can be surely projected outward.

[0005]

According to the method of forming an ear portion of a sheet metal pulley according to the present invention, a poly V is formed on one end of the outer peripheral wall.
In the method of forming an annular ear portion protruding outward in the radial direction for preventing the belt from coming off, the outer peripheral wall is molded so that the tip side portion is smaller in diameter than the root portion, and then the outer periphery is formed. The outer peripheral wall is covered by the inner rotating mold with a space existing between the root part of the wall and the inner rotating mold, and the outer peripheral wall is sandwiched by a pair of upper and lower clamping surfaces of the inner rotating mold covering the outer peripheral wall. While fixing and rotating the outer rotating die, the root portion of the outer peripheral wall is pressed and deformed by the outer rotating die toward the inner rotating die side, and the V-shaped ear part forming protrusion provided in the outer rotating die is used to That is, the ear forming projection is made to bite so that the root part is divided into two parts from the outside.

[0006]

With this configuration, the outer peripheral wall having the constricted tip sandwiched between the upper and lower holding surfaces of the rotary inner die has a space between its root portion and the rotary inner die. Since the part is pressed and deformed by the outer rotating mold toward the inner rotating mold, the amount of the material flowing radially outward of the root part of the outer peripheral wall is increased. Therefore, the root part is provided in the outer rotating mold. When the V-shaped ear forming projection is formed so as to be divided into two parts from the outer side, a large amount of the material of the root portion flows radially outward, and the ear can be sufficiently protruded radially outward.

[0007]

EXAMPLES Next, a method of manufacturing a sheet metal poly-V pulley adopting an example of the present invention will be described item by item for each step. As the flat material (not shown) as a starting material, the same thickness as that required for the outer peripheral wall 13 provided with the poly V groove 15 in the sheet metal poly V pulley to be manufactured is used. There is.

A. First Drawing Step This step is a step of forming a bottom wall-corresponding portion 1 and a peripheral wall-corresponding portion 2 by squeezing a plate-shaped raw material, which is a starting material, with an inner die 100 and an outer die 200 as shown in FIG. Then, in the peripheral wall equivalent part 2, an inner peripheral wall equivalent part 3 which becomes an inner peripheral wall 10 for bearing press-fitting of a manufactured sheet metal poly-V pulley, and a tip end of the inner peripheral wall equivalent part 3 is projected outward. An outer peripheral wall-corresponding portion 4 serving as an outer peripheral wall 13 provided with the groove 15 is provided. Through the first drawing step, the bottom wall corresponding portion 1 and the inner peripheral wall corresponding portion 3 are thinned. Specifically, the wall thickness is 2.8 mm
When using the flat plate material, the bottom wall equivalent part 1 has a wall thickness of 2.6.
mm, and the inner peripheral wall equivalent part 3 is thinned to about 1.8 to 2.1 mm. In many cases, the wall thickness of the outer peripheral wall equivalent portion 4 does not change. The aperture depth is set to 15.1 mm.

B. Drilling Step In this step, as shown in FIG. 2, the inner die 101 and the punch 201 are used to open a hole 5 in the center of the bottom wall corresponding portion 1. The hole 5 formed in this process is to be machined into the shaft hole 16 in the subsequent process, and the inner diameter of the shaft hole 16 is 3 mm.
When 1.0 mm is required, the inner diameter of the hole portion 5 may be set to 15.7 mm, which is about half the inner diameter. 6 is a scrap generated by drilling, and this scrap 6 is punched from the thinned bottom wall equivalent portion 1, and by punching out the hole portion 5 which is about half the size of the shaft hole 16. Since it has occurred, the amount is extremely small.

C. Second drawing step In this step, the bottom wall equivalent part 1 and the inner peripheral wall equivalent part 3 of the material (hereinafter referred to as a hat-shaped material W) that has undergone the perforation step described in FIG. And the outer mold 202 are used to further squeeze, and thereby the hole 5 of the bottom wall equivalent portion 1
Is a step of expanding the diameter. In the hat-shaped material W that has undergone the second drawing process, the bottom wall equivalent portion 1 and the inner peripheral wall equivalent portion 3 are continuous via the radiused portion 7 having a relatively large radius of curvature, and the radiused portion 7 is meat. The thickness is reduced to about 1.6 to 1.7 mm. Further, the inner peripheral wall equivalent portion 3 is 1.6 to
The thickness is reduced to about 1.7 mm.

D. Handling Step This step is a step of further narrowing down the inner peripheral wall equivalent portion 3 narrowed down in the second narrowing step to adjust its shape. Therefore, this handling step can be said to be the third drawing step performed after the second drawing step, and the first handling step shown in FIG. 4 and the second handling step shown in FIG. 5 are performed. Contains.
By passing through this step, the corner portion 8 of the hat-shaped material W is formed at the boundary portion between the bottom wall-corresponding portion 1 and the inner peripheral wall-corresponding portion 3 at a right angle or near a right angle. That is, in the first handling step of FIG. 4, the radius of curvature of the rounded portion 7 shown in FIG. 3 is slightly reduced by the inner die 103 and the outer die 203, and then,
By performing the second handling step of FIG. 5, the rounded portion 7 of the inner mold 104 and the outer mold 204 is shaped as a corner portion 8 which is closer to a right angle, and at the same time, the bottom wall equivalent portion 1 is formed on the bottom wall 9. The inner peripheral wall equivalent portion 3 is formed on the inner peripheral wall 10.

The inner mold 104 used in the second handling step is
A molding surface 105 having a uniform outer diameter is provided, and the molding surface 105 of the inner mold 104 is covered with the inner peripheral wall corresponding portion 3 of the hat-shaped material W. In addition, the outer mold 204 corresponding to the inner mold 104
Means that the inner diameter of the pressing surface 205 with respect to the inner peripheral wall equivalent portion 3 of the hat-shaped material W covered by the inner mold 104 is the boundary portion of the inner peripheral wall equivalent portion 3 with the bottom wall equivalent portion 1, that is, the inner peripheral wall equivalent portion 3. The diameter increases as it moves away from the portion that presses the base end portion (corresponding to the corner portion 8) in the axial direction. When the inner peripheral wall 10 is formed by handling the inner peripheral wall equivalent part 3 of the hat-shaped material W covered with the inner mold 104 by using the outer mold 204, the formed inner peripheral wall 10 has a corner which is the base end thereof. The thicker it gets from the part 8, the thicker it becomes. That is, in the hat-shaped material W that has undergone the second handling step, the corner portion 8 and the inner peripheral wall 10 in the immediate vicinity thereof have a wall thickness of about 1.7 mm, and the portion immediately near the tip of the inner peripheral wall 10 has a wall thickness of about 2.1 mm. Become. Then, in this way, it was confirmed that even if the hat-shaped material W was released from the mold, the inner diameter of the inner peripheral wall 10 was finished uniformly. Therefore, when the bearing is press-fitted into the inner peripheral wall 10, a misalignment between the bearing and the pulley does not occur, and the bearing can be surely inserted into a predetermined position. In FIG. 5, the difference in the wall thickness of each axial portion of the inner peripheral wall 10 is exaggerated.

E. Finishing process of the portion corresponding to the outer peripheral wall In this process, as shown in FIG.
7 is a step of cutting and removing the outer peripheral edge of the outer peripheral wall corresponding portion 4. 11 is scrap.

F. Reverse drawing step In this step, as shown in FIG. 7, the outer peripheral wall equivalent portion 4 of the hat-shaped material W put on the inner dies 108 and 109 and sandwiched between the outer dies 209.
The outer peripheral wall 1 is concentric with the inclined annular portion 12 and the inner peripheral wall 10 by being folded back at.
3 is a step of forming.

G. Bulge step In this step, as shown in FIG. 8, the inner die 110 is covered with the hat-shaped material W which has undergone the reverse drawing step described in FIG. 7, and the tip of the outer peripheral wall 13 is attached to the supporting surface 111 provided in the inner die 110. This is a step of supporting the surface and pressing the annular portion 12 from the state by the outer die 210 to expand the boundary portion between the outer peripheral wall 13 and the annular portion 12, that is, the root portion of the outer peripheral wall outward. The outer peripheral wall 13 of the hat-shaped material W that has undergone this step is formed such that the tip side portion is smaller in diameter than the root portion, and in some cases it is simultaneously thickened.

H. Ear portion forming step This step is a step of forming a single-layer annular ear portion 14 at the intersection of the outer peripheral wall 13 and the annular portion 12. This step is performed as follows. That is, as shown in FIG. 9, the rotating inner molds 112, 113 are covered with the hat-shaped material W that has undergone the bulge process and sandwiched, and at the same time, the rotating inner molds 112, 11
The upper and lower clamping surfaces 114 and 115 of the outer peripheral wall 13
Cling to. Rotate the hat-shaped material W in this way
Covering 12, 113, the outer peripheral wall 13 and the rotating inner mold 112
A space S is formed between and.

While rotating the outer rotating mold 213 in this state, as shown in FIG. 10, the root portion of the outer peripheral wall 13 is pressed against the inner rotating mold 112 side to deform so that the space S disappears. The ear forming protrusion 214 provided on the outer rotating mold 213 from the outside so as to divide the root portion into two.
And bite into. By doing so, the root portion of the outer peripheral wall 13 having the constricted tip end held between the holding surfaces 114, 115 of the inner rotary dies 112, 113 is radially outward due to the deformation when the space S is eliminated. The amount of material flowing increases, and the amount of protrusion of the ear portion 14 from the outer peripheral wall 13 becomes sufficiently large. The outer peripheral wall 13 that has undergone this process is thickened to a thickness of about 2.9 mm.

I. Poly V Groove Forming Step This step is a step of forming the poly V groove 15 on the outer peripheral wall 13. In this step, as shown in FIG. 11, FIG. 12 or FIG. 13, the hat-shaped material W is sandwiched between the inner rotating dies 112 and 113, and the outer wall 13 has a poly V groove 1 made up of a plurality of V groove groups.
5 is formed by rolling and forming the poly V groove 15, but the poly V groove 15 is formed by the preliminary poly V groove forming step and the preliminary poly V groove forming step more than the case of forming by one rolling. It is preferable that the poly V groove of the outer peripheral wall 13 that has been subjected to the rolling is further subjected to rolling, and a finishing step of finishing the depth and pitch thereof as required is performed by plural times of rolling forming.

This step is carried out by rotating the inner mold 11 as shown in FIG.
The molding surface 116 of No. 2 and the molding surface 216 of the outer rotary mold 215 both have valleys and peaks alternately and are formed in a shape that can be meshed with each other, or FIG.
1 and FIG. 12, the molding surface 116 of the inner rotating mold 112 is a flat surface in the vertical direction and the molding surface 216 of the outer rotating mold 215.
What is formed may be used, what is formed in the uneven | corrugated surface which has a valley part and a peak part alternately. When the method of FIG. 13 is adopted, a sheet metal poly V pulley having a poly V groove 15 on the outer surface side and an outer peripheral wall 13 having an uneven inner surface is manufactured. When the method of FIGS. 11 and 12 is adopted, a sheet metal poly V pulley having a poly V groove 15 on the outer surface side and an outer peripheral wall 13 whose inner surface is straight in the vertical direction is manufactured.

J. Centering Step This step is a step of centering the inner peripheral wall 10 and the outer peripheral wall 13 by using the inner mold 117 and the outer mold 217 as shown in FIG.

K. Axial hole finishing step This step is performed in the inner die 118 and punch 218 as shown in FIG.
This is a step of cutting and removing the peripheral edge portion of the hole portion 5 whose diameter has been expanded by using and to finish the shaft hole 16. 17 is scrap.

In the embodiment described above, the shaft hole 16 formed by expanding the diameter of the hole portion 5 may have the same inner diameter as the inner diameter of the inner peripheral wall 10. That is, it is possible to manufacture a sheet metal pulley in which the opening portion of the inner peripheral wall 10 serves as a shaft hole without the bottom wall 9.

[0023]

According to the present invention, in the sheet metal poly V pulley, the outer peripheral wall is made thicker to improve the strength against a radial load, and at the same time, the protrusion amount of the ear portion is sufficiently increased. When manufacturing the sheet metal poly-V pulley, there is an effect that the incidence of defective products can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first drawing process.

FIG. 2 is an explanatory diagram of a drilling process.

FIG. 3 is an explanatory diagram of a second drawing process.

FIG. 4 is an explanatory diagram of a first handling step.

FIG. 5 is an explanatory diagram of a second handling step.

FIG. 6 is an explanatory diagram of a finishing process of a portion corresponding to the outer peripheral wall.

FIG. 7 is an explanatory diagram of a reverse drawing process.

FIG. 8 is an explanatory diagram of a bulge process.

FIG. 9 is an explanatory diagram of an ear portion forming process.

FIG. 10 is an explanatory diagram of an ear portion forming process.

FIG. 11 is an explanatory diagram of a poly V groove forming step.

FIG. 12 is an explanatory diagram of a poly V groove forming step.

FIG. 13 is an explanatory diagram of a poly V groove forming step.

FIG. 14 is an explanatory diagram of an alignment process.

FIG. 15 is an explanatory diagram of a shaft hole finishing process.

[Explanation of symbols]

 13 outer peripheral wall 14 ears 112,113 inner rotating mold 114,115 holding surface 213 outer rotating mold 214 ear forming protrusion S space

Claims (1)

[Claims] 1. A method of forming an annular ear portion protruding outward in a radial direction for preventing the poly V belt from coming off at one end portion of the outer peripheral wall, wherein the outer peripheral wall has a root portion thereof. After molding so that the tip side portion has a smaller diameter than that, while covering the outer peripheral wall with the inner peripheral wall while leaving a space between the root part of the outer peripheral wall and the inner rotary mold, While rotating the rotating outer mold by sandwiching its outer peripheral wall with a pair of upper and lower holding surfaces of the covered rotating inner mold, pressing and deforming the root portion of the outer peripheral wall to the rotating inner mold side with the outer rotating mold, The V-shaped ear part forming protrusion provided on the outer rotating mold is used to bite into the ear part forming protrusion so that the root part is divided into two parts from the outside. Pulley ear formation method