JPH0459980B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a multistage pulley and a method for manufacturing the same.

2. Description of the Related Art As this type of multi-stage pulley, for example, a cast pulley as shown in FIG. 5 has been widely used. The pulley body 1a shown in FIG.
A multi-stage pulley 1 is formed by forming a multi-striped V-groove 2a for a belt and a single V-groove 2b having a smaller diameter than the multi-striped V-groove 2a.

Furthermore, recently, there has been a tendency to use a pulley made of sheet metal as shown in FIG. 6 instead of the above-mentioned cast metal pulley. This sheet metal pulley 3 is made by first forming a sheet metal material with a uniform thickness into a cup shape, and then plastically deforming the cup shape material to form a two-stage V.
Grooves 4a and 4b are formed therein.

Problems to be Solved by the Invention Among the conventional multi-stage pulleys mentioned above, the former cast-fabricated pulley has a poor weight balance as a product due to its manufacturing peculiarity, so it is necessary to reduce uneven rotation as a pulley. In order to do so, it is necessary to perform balance adjustment as a post-processing process, and the weight of the entire pulley increases.

In addition, although the latter pulley made of sheet metal can be lighter than the former cast metal pulley, the length l from the end of the rim 6 to the web 5 is too long. Since it is extremely cantilevered, it tends to cause uneven rotation during use and has poor durability. Moreover, since the thickness of the material does not change from the raw material stage to the finished product, when selecting the thickness of the material, the thickness of the entire material is adjusted to the thickness of the part where the required thickness is greatest. There must be. Therefore, even though a sheet metal material is used, there is a limit to how thin the material can be made, and it is not possible to sufficiently reduce the weight of the pulley product.

The present invention aims to provide a multi-stage pulley that uses sheet metal material, has less uneven rotation, and is further lightweight, and at the same time provides a manufacturing method that requires fewer steps and is compatible with the above-mentioned pulley. be.

Means for Solving the Problems The multi-stage pulley, which is the first invention of the present application, has slotted grooves in the radial direction from the outer peripheral end surface of a disc-shaped web, thereby extending the outer peripheral edge of the web in the thickness direction. A pair of rims that are thicker than half the thickness of the web and have different directions and diameters are formed by dividing the web into two parts, and a single or multiple V-grooves are formed on the outer peripheral surface of this rim. Features.

In addition, in the method for manufacturing a multi-stage pulley, which is the second invention of the present application, a slotted roller that rotates synchronously with the material is pressed against the outer peripheral end surface of the disc-shaped material, so that the peripheral edge of the material is rotated in the radial direction. forming a pair of rims that are thicker than half the thickness of the material and have different orientations and diameters, by compressing and increasing the thickness of the material and dividing it into slots in the thickness direction;
The method includes the step of pressing a forming roller that rotates synchronously with the material against the outer circumferential surface of the rim to form a single or multiple V-groove.

Effect As is clear from the above configuration, in the first invention, both rims are in a cantilevered state, but since there is a web at the center of both rims, it is different from the one shown in FIG. In comparison, uneven rotation is less likely to occur.

In addition, the second invention is based on slotting and plastic flow processing as described above, and the plate thickness changes until the finished product is produced, so the material must be of the minimum necessary thickness. It is enough. Therefore, the thinning of the material and the weight reduction of the pulley are further promoted.

Embodiment FIG. 1 is a sectional view showing a first embodiment of the first invention, and illustrates a multi-stage V-groove type multi-stage pulley. As shown in the figure, a pair of rims 8a are provided at the outer peripheral edge of the web 7, which are each divided from the web 7 in the thickness direction and have different diameters.
8b, and multi-strip V grooves 9a, 9b are formed by rolling on the outer peripheral surfaces of these rims 8a, 8b, respectively. Here, as a specific method for forming the rims 8a and 8b, as described later, the circumferential edge of the web 7 is compressed and thickened in the radial direction, and slotted grooves are formed in the radial direction from the outer peripheral end surface of the web 7. The method is to expand in the thickness direction. As a result, each rim 8a, 8b has a thickness greater than half the thickness of the web 7.

Further, if necessary, an embossed portion E is formed at the center of the web 7, and a hole G into which a shaft or bearing is inserted is further formed in this embossed portion E.

FIG. 2 is a diagram showing the second embodiment, in which the multi-striped V groove 1
A rim 18a with a groove 9a formed thereon and a single V groove 19b
This embodiment differs from the first embodiment in that it is combined with a rim 18b formed with a rim 18b. Of course, the rims 18b, 18b are provided with a single V-groove 19b (not shown).
You can also combine them.

FIG. 3 shows a third embodiment, which differs from the first embodiment in that slotted grooves are also formed from the inner periphery of the web 7 to divide it into two in the thickness direction. auxiliary rims 10a, 10b corresponding to the rims 8a, 8b are formed. A bearing unit or a clutch unit is accommodated on the inner periphery of the auxiliary rims 10a, 10b during use.

FIG. 4 is a diagram showing an embodiment of the second invention, and illustrates the case where the multistage pulley shown in FIG. 1 is molded.

First, in a preliminary step using a press, a disk-shaped material Q is formed by punching out a steel plate as shown in FIG. 4(A). At this time, as described above, embossed portions E or holes G are formed as necessary.

In the slotting process shown in Fig. 4B, the rotary receiving mold 1
A material Q is held between 1a and the rotating mold 11b. Then, while rotating the material Q together with both dies 11a and 11b, a slotted roller 12 having a mountain-shaped cross section is pressed against the outer peripheral end surface of the material Q. As a result, the slotted roller 12 also rotates synchronously, compressing the material Q in a direction to reduce its diameter, and at the same time slotting the outer peripheral edge of the material Q to form the slotted groove 13. At this time, the material Q is increased in thickness in the plate thickness direction by the material material flowing as it is compressed in the radial direction.

In the expanding step shown in FIG. further expand. That is, by further expanding the slotted groove 13, a pair of rims 8a and 8b extending in the thickness direction of the outer peripheral edge of the material Q is formed.

In this case, the material Q is held between the rotary receiving mold 15a and the rotary pressing mold 15b, and these molds 15a, 1
5b and the expansion roller 14 rotate in synchronization, forming progresses, and a pair of so-called stepped rims 8a, 8b having a thickness greater than half the thickness of the material Q and having different diameters are formed. Ru. Therefore, the portion that is not cracked through the above steps becomes the web 7.

In the forming process shown in FIG. 4D, the rims 8a, 8b
A forming roller 16 having a multi-thread shape corresponding to the shape of the final product is pressed against the outer circumferential surface of the V-grooves 9a and 9b to roll-form the multi-thread V grooves 9a and 9b. In this process as well, molding progresses as the material Q held between the rotary receiving mold 17a and the rotary pressing mold 17b rotates in synchronization with the molding roller 16. In addition, the final forming process here may be performed in two steps for each rim 8a, 8b, and between the expanding process (Fig. 4C) and the forming process (Fig. 4D). A preforming step may also be added. Through the above steps, a pulley W having multiple V-grooves and multiple stages as shown in FIG. 1 is formed.

Furthermore, when molding the multi-stage pulley shown in FIGS. 2 and 3, basically the same method as above is used.

Effects of the Invention As described above, according to the multistage pulley of the present invention,
Even though it is made of sheet metal, the web exists in the center of both rims, so it is less likely to cause uneven rotation or runout during use, and is highly durable, as well as being much lighter than conventional rims.

Furthermore, according to the manufacturing method of the present invention, the pair of rims to be slotted and divided is divided while being compressed and thickened in the radial direction, so that the thickness of each rim is increased by changing the thickness of the material based on plastic flow processing. is thicker than if the web thickness was simply halved, and the strength of the rim can be improved, so the number of processes is relatively small, and the material is thinner than the minimum required thickness. This allows the product pulley to be made lighter.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing a first embodiment of the pulley of the present invention, FIG. 2 is a half-sectional view showing the second embodiment, and FIG. 3 is a half-sectional view showing the third embodiment. 4 are process explanatory diagrams showing one embodiment of the manufacturing method of the present invention, and FIGS. 5 and 6 are sectional views showing a conventional multistage pulley. 7... Web, 8a, 8b... Rim, 9a, 9
b...Multi-striped V groove, 12...Slit roller, 1
3... Slit groove, 14... Expansion roller, 16
...Forming roller, 18a, 18b...Rim, 1
9a...Multi-line V groove, 19b...V groove, Q...Material.

Claims (1)

[Scope of Claims] 1. A pair of rims, which are thicker than half the thickness of the web and have different directions and diameters, are created by dividing the outer peripheral edge of a disc-shaped material in the direction of its thickness. A multi-stage pulley characterized in that the rim has a V-groove formed on its outer circumferential surface. 2 A slotted roller that rotates synchronously with the material is pressed against the outer peripheral end surface of the disc-shaped material, and the peripheral edge of the material is compressed and thickened in the radial direction while being slotted in the thickness direction of the material to increase the thickness of the material. A process of forming a pair of rims having a thickness greater than half the thickness of the rim and having different orientations and diameters, and a forming roller that rotates synchronously with the material against the outer circumferential surface of the rim to form an independent mold for each rim. A method for manufacturing a multi-stage pulley, comprising the step of rolling forming a V-groove.