JPS6284845A - Forming method for multigroove v-pulley - Google Patents

Abstract

PURPOSE:To prevent the generation of a crack in a side wall part, and to improve the durability of a multigroove V-pulley by bringing a plate-shaped blank to press forming roughly in a cup shape, forming a slot on the outside peripheral surface of a bottom wall of a cup body and forming it as a side wall part, and also forming a multi V-groove in the peripheral wall part. CONSTITUTION:One piece of disk-shaped blank having a uniform wall thickness is brought to press forming in a cup body 4, and thereafter, set to a fixed jig 13. Subsequently, with regard to a slot roller 9 provided with one line of projection 20, the slot roller 9 is also rotated and pressed against a peripheral wall part 8 of the cup body 7, as the cup body 7 rotates, the center part of a bottom wall part 15 and a slot side wall part 11 are formed, and also the other side wall part 10 is also formed simultaneously. Next, in the peripheral wall part 8, a multi V-groove 26 is formed by a preforming roller and a regular forming roller 26. Accordingly, after the cup body 7 has been brought to press forming, all stages are executed by a form-rolling roller, therefore, a crack, etc. are not generated in the side wall part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a multi-striped V-pulley having a multi-striped V-groove in a peripheral wall portion and side wall portions on both sides thereof.

[Conventional technology]

In general, a multi-thread V pulley is equipped with multi-thread V grooves with a shallow groove depth on its peripheral wall, and can more effectively prevent the belt from slipping or slipping than ordinary pulleys. .

Conventionally, as this type of multi-thread V pulley, for example, the one shown in FIG. 7 is known (see Japanese Patent Laid-Open No. 57-88929).This multi-thread V pulley P! First, a sheet of plate-shaped material is pressed into a substantially cup shape, side walls 3 and 4 are formed around the entire circumference at the upper and lower ends of the peripheral wall 2 of this cup body, and then the peripheral wall A multi-striped V-groove 5 is formed in the middle portion of the portion 2 by a rolled a-roller provided with multi-striped protrusions.

[Problem that the invention seeks to solve]

However, in such a conventional multi-row V pulley P1, the side wall portion 4 formed at the lower end of the peripheral wall portion 2 is
Because it had a double structure formed by bending and forming the material, work hardening was likely to occur in the bent portion 6, and there was a risk of cracking in the bent portion 6 when rotating under high load. . Furthermore, when applying surface treatment to the multi-thread V pulley P1, the treatment liquid stagnates in the gap on the back side of the bent portion 6, causing rust.

The present invention has been made based on the above-mentioned viewpoint, and its purpose is to provide a method for forming a multi-thread V pulley that does not cause cracks or the like to occur in the side wall portion and also prevents rust from forming. This is what we provide.

[Means for solving problems]

In order to achieve the above object, the present invention press-works a sheet of plate-like material into a substantially cup shape, and creates radial slots on the outer peripheral surface of the bottom wall of the cup body using a slot roller. The slotted portion of the bottom wall is formed on one side wall of the multi-strip V pulley, and in the next step, a multi-strip V groove is formed on the peripheral wall of the cup body.

〔Example〕

Embodiments of the present invention will be described in detail below based on the accompanying drawings.

In the embodiment shown in FIGS. 1 to 5, the method for forming the multi-thread V pulley P2 begins with the cup body 7 as shown in FIG.
Side wall portions to and tt are formed at the upper and lower ends of the peripheral wall portion 8 using slotted rollers 9, and then, as shown in FIG. 5, multi-strip V grooves 26 are formed in the peripheral wall portion 8.

In this embodiment, the cup body 7 is formed by pressing a disc-shaped material of uniform thickness into a substantially cup shape. The cup body 7 formed in this manner is first set in a fixing jig 13, as shown in FIG. 1, and then the bottom wall portion 15 is clamped by a movable jig 14 from the opposite side.

At this time, the peripheral wall 8 of the cup body 7 is disposed within the substantially trapezoidal groove 16 formed between the fixed jig 13 and the movable jig 14, and the peripheral wall 8 and the bottom of the groove 16 A sufficient gap 21 is formed between 17. In addition, the concave groove 16
The bottom surface 17 and shoulder side surfaces 18 and 19 of the cup body 7 serve as surfaces for receiving rollers during molding.6 Next, as shown in FIG.
A slotted roller 9 with 0 is pressed. The protrusion 20 of this slotted roller 9 is set at a predetermined position,
For example, when the cup body 7 is rotated, the slotted roller 9 is also rotated and pressed, which is preferably provided so as to be located near the approximate center of the thickness of the bottom wall part 15 when pressed. A protrusion 20 is provided on the outer peripheral surface of the portion 15.
enters and cracks the center portion of the bottom wall portion 15 in the radial direction.

Then, as shown in FIG. 2, the cup body 7 is slit in a V-shape with a slit roller 9 until the peripheral wall portion 8 of the cup body 7 comes into contact with the bottom surface 17 of the groove 16. At this time, the slotted corner of the bottom wall portion 15 is formed along the shoulder side surface 19 of the groove 16 on one side wall portion ll of the multi-thread V pulley P2. Incidentally, since a gap 21 is formed between the bottom surface 17 of the groove 16 and the peripheral wall portion 8 as shown in FIG. 1, the slot becomes larger accordingly. The peripheral wall portion 8 of the cup body 7 is also roller-formed by the slotted roller 9, and the side wall portion lO on the other side of the multi-thread V pulley P2 is formed along the shoulder side surface 18 of the concave jl l6.
are also formed at the same time.

Next, as shown in FIG. 3, a preforming roller 23 having a multi-striped protrusion 22 is pressed against the peripheral wall 8 of the cup body 7 to form a preliminary multi-striped V-groove 24. At this time, the relationship between the peaks and valleys of the multi-thread V$11124 to be formed is as follows:
This corresponds to that of the multi-line V-groove in the final product. After the preliminary forming is completed, as shown in FIG. 4, the main forming roller 25 is pressed against the peripheral wall part 8 to finish form the multi-striped V groove 26, and the side wall parts 10 and 11 are also finally finished, and the multi-striped pulley P
Complete 2.

FIG. 5 shows a multi-striped V-pulley P2 formed by the above-mentioned forming method, and has a multi-striped groove 26 on its peripheral wall portion 8, and molds the two sides of this multi-striped V-groove 26 by slotting. One side wall portion 11 that has been molded and the other side wall portion 10 that is molded at the same time are formed.

In this method of forming the multi-thread V pulley P2, after the cup body 7 is formed by press working, everything including the slotting is done by rolling rollers, so efficiency can be improved through an integrated process. In addition, multi-line V groove 26
The variation in wall thickness was also extremely small. Also,
According to this forming method, a multi-stage multi-strip V as shown in FIG.
By sequentially performing the above-described forming method step by step for the pulley P3, the multi-strip V grooves 27, 28 and side wall portions 29, 30 of each step can be easily formed.

〔effect〕

As explained above, according to the method for forming a multi-thread V pulley according to the present invention, since the side wall portion is formed by slot molding, there is no concern that cracks will occur in this side wall portion, and accordingly, the multi-thread V pulley is We were able to ensure durability. In addition, since there are no bent parts like in the past, there is less chance of rusting, and it is also possible to reduce costs.

[Brief explanation of drawings]

Figure 1 is a half-cut sectional view showing the state when the cup body is clamped, Figure 2 is a half-cut sectional view during slot molding, Figure 3 is a half-cut sectional view during preforming, and Figure 4 is during main molding. FIG. 5 is a half-cut sectional view of a multi-thread V pulley formed by the forming means according to the present invention, FIG. 6 is a half-cut sectional view showing another example of a multi-thread V pulley, and FIG. It is a half-cut sectional view showing an example of a multi-thread V pulley. 7...Cup body 8...Surrounding wall part 9...Slit rollers to, ti...Side wall part 15...Bottom wall part 26...Multiple V IP# Fig. 6 Fig. 7

Claims (1)

[Claims] A piece of plate-shaped material is pressed into a roughly cup shape,
A slot in the radial direction is formed on the outer peripheral surface of the bottom wall of this cup body using a slotted roller, and the slot in the bottom wall is formed on one side wall of the multi-thread V pulley, and the next step is performed. A method for forming a multi-strip V pulley, characterized in that multi-strip V grooves are formed on the peripheral wall of the cup body.