JPS6228036A - Production for multigrooved v pulley with separative belt - Google Patents

Abstract

PURPOSE:To produce the V pulley having good product strength with rolling by constituting so as to locate the overlapping part generated on the inner peripheral face of a thickened item at about center part in the axial direction of a projecting bar part by varying the tip angle of a bending roller. CONSTITUTION:The projecting apex part with uneven curved face formed on the cylindrical part of a bending item 36 is biased by the prescribed distance to the roller 26 side from its center part in the axial direction by varying the tip angle of bending rollers 26, 28 in the bending stage of a cup-shaped preform. In a thickneing stage, a thickened thicker item 40 is formed by averaging with pressing the uneven curved face by pressing a thicknening roller 38 to the bend cylindrical part of a bending item 36. On this thickened item 40 an overlapping part 45 is generated on the inner peripheral face of the cylindrical wall corresponding to the projecting bar part 44 in the peripheral direction of the cylindrical wall outer peripheral face. In the groove cutting stage a V groove 52 and separative belt part 48 are rolled on the cylindrical wall outer peripheral face of the thickened item 40 by using a grooving roller 46. The V pulley having good product strength can thus be produced with rolling.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for manufacturing a multi-groove V-pulley in which a separation band is formed between multi-stage grooves, and particularly relates to a method for manufacturing a multi-groove V-pulley in which a separation band is formed between multi-stage grooves. When forming separation strips that are divided into a plurality of groups, the strength of the product of the pulley is not reduced, and the multi-groove V pulley with such separation strips can be formed using a rolling process. Moreover, it relates to a technology that can be easily manufactured.

(Prior art and its problems) The multi-groove V pulley with a separation band as described above generally has a plurality of V grooves extending in the circumferential direction on the cylindrical outer peripheral surface of the pulley material, which has a substantially bottomed cylindrical shape. The grooves are provided in multiple stages, and a convex separation band is formed in the circumferential direction at an intermediate position in the axial direction to divide the plurality of V grooves into a plurality of groups, and the grooves are divided by the separation band. In each group with multiple grooves,
V-belts each having a plurality of V protrusions corresponding to the plurality of V-grooves are wrapped around each other, and are used, for example, to transmit the rotational force of the multi-groove V-pulley to two or more drive systems. It is something that will be done.

By the way, in manufacturing such a multi-groove V-pulley, a cutting process has conventionally been adopted. According to this document, first, a pulley material having a substantially cylindrical shape is formed by casting, and then the pulley material is cut using a cutting tool or the like to form a multi-groove V groove having a large number of V grooves and separation strip parts. He had obtained a pulley.

However, in such a cutting method, ■
Since the cylindrical wall of the pulley material that forms the grooves and separation strips is relatively thick, it is cast and then cut, which hinders the flow of a series of processes.
It took time to process, and because the flow of the metal structure was disrupted, it was weak in strength (therefore, productivity and material yield were poor, and in addition, the product was heavy.

On the other hand, in recent years, in order to solve the above-mentioned problems, metal blanks,
For example, an attempt is made to manufacture a desired multi-groove V-boo by carving a plurality of V-grooves and separation strips on the outer surface of the peripheral wall of a cup-shaped molded product obtained by deep drawing a rolled steel plate using a rotational forming method. A forming method using so-called rolling processing has been considered. By using such a rolling process, the material yield, productivity, economic efficiency, and product weight can be effectively improved.

By the way, when manufacturing a multi-groove V pulley by such a rolling process, since multiple V grooves are carved into the relatively thin peripheral wall of a cup-shaped molded product, the thickness of the groove bottom part of the groove is insufficient. Therefore, it is considered advantageous to use a molding method in which the circumferential wall of the cup-shaped molded product is made relatively thick, and then the grooves are carved by plastic flow on the outer circumferential surface of the circumferential wall.

That is, in this forming method, first, a metal blank punched into a circular shape is formed into a cup-shaped molded product having a substantially bottomed cylindrical shape by a predetermined deep drawing process or the like. Thereafter, while rotating this cup-shaped molded product around its center line (axis), a pair of bending rollers are pressed against both ends of the peripheral wall, and the cup-shaped molded product is pressurized from both sides in the axial direction.
A bending process is performed in which both bending rollers are pressed and brought closer to each other. As a result, flange portions are formed at both ends of the peripheral wall of the cup-shaped molded product, and a portion of the peripheral wall between the pair of flange portions is curved outward. Next, while rotating the cup-shaped molded product with the pair of flanges formed thereon, a thickening roller having a concave groove is pressed against the curved peripheral wall portion at the position where the separation band portion is formed. By flattening the wall and increasing the thickness by forming convex stripes in the area where the separation band is to be formed, this peripheral wall portion is temporarily made thicker than the other portions, and is further thickened. A preformed product is obtained in which a protruding strip is formed. In addition, this thickening is due to
This is to enable better formation of the V-groove and separation zone that will be planned later. After that, a grooving roller is pressed against the peripheral wall of the thickened preform to perform a grooving process in which multiple V-grooves and separation strips are carved into the desired pulley product. be.

By the way, in the multi-groove V-pulley with separation band manufactured by the above-mentioned rolling process, the separation band is for regulating the position on the pulley with respect to the V-belt wound around both sides thereof. Therefore, it is preferable that the separation zone is formed relatively large. And for that,
Since it is necessary to increase the size of the convex portion formed by the thickening roller, it is inevitable that an overlapping portion will occur on the inner circumferential surface of the preform. However, as shown in Fig. 4, if the two belts 2.4 wrapped around the product have the same width, in other words,
When the separation band 10 is formed approximately at the center of the cylindrical portion of the V-pulley 12, since the overlapping portion 14 is located approximately at the center of the separation band 10, the V-pulley The influence of the strength of the overlapping portion 14 on the structure 12 did not pose a significant problem.

However, as shown in FIG.
In other words, it is a V-boo that can be wrapped around two V-belts 6.8 with different numbers of V protrusions! When manufacturing J16, the separation band 18 is formed to be offset from the axial center position of the V pulley 16, while the overlapping portion 20 is
It has become clear that this occurs at the axial center position of the V-boo U16, causing a problem in that the strength at the overlapped portion 20 of the V-boo U16 is reduced.

Therefore, as a result of investigation by the present inventors, the cause of the above problem is that the formation position of the separation zone is determined during the thickening process in the manufacturing process mentioned above, but the position where the slanted part occurs is due to the bending. It turns out that this is determined by the processing. In other words, as mentioned above, bending or thickening in conventional manufacturing processes is done to ensure the thickness of the groove bottom plate in the finished product, and therefore the shape of the bent product formed by bending is This itself is hardly a problem, and the cylindrical part of the bent product is usually machined so that it is approximately vertically symmetrical with respect to the center line in the direction perpendicular to its axis. Since thickening is performed on a bent product having a shape, the overlapping portion is always located at the axial center of the V-pulley, regardless of the position of the protruding strip formed in the thickening. This is caused to occur. Therefore, in pulleys where separation bands are not formed in the center of adjacent bending rollers, in other words, belts of different widths are wound around, overlapping parts occur in the thin parts, and therefore, such This caused a problem in that the strength of the pulley product decreased.

(Solution Means) Here, the present invention has been made to solve the above-mentioned problems, and the gist thereof is to provide a plurality of V grooves extending in the circumferential direction on the cylindrical outer circumferential surface. To manufacture a multi-groove pulley having multiple stages in the axial direction, and a convex separation band part arranged in the circumferential direction at an intermediate position in the axial direction to divide the plurality of V grooves into a plurality of groups with different numbers of grooves. In the method, (a) a plurality of bending rollers are pressed against the cylindrical wall of a bottomed cylindrical preform obtained from a predetermined metal plate material, and the contact portions of the rollers are recessed; (b) a bending step of forming a bent product whose wall is unevenly bent in the radial direction, and (b) pressing a thickening roller having a concave groove at a portion corresponding to the convex portion of the cylindrical wall against the bent product; , a thickening step of obtaining a thickened product in which circumferential protrusions are formed on the outer circumferential surface of the cylinder wall by thickening the cylinder wall; and (c) a thickening product obtained in the thickening step. Forming is carried out by pressing a predetermined grooving roller against the circumferential convex strip to form the separation band portion that divides the V-grooves into the circumferential convex strip, and to form V-grooves with different numbers of grooves on both sides of the separation band portion. a grooving step for forming groups, while the tip angles of the plurality of bending rollers in the bending step are changed, so that the inner circumferential surface portion of the thickened product corresponds to the convex strip formed in the thickening step. This is because the overlapping portion that occurs in the protruding portion is located approximately at the center in the axial direction of the protruding portion.

(Operations and Effects) As is clear from the above explanation, the present invention also provides a multi-groove V-pulley having a separation band that divides a plurality of V-grooves into a plurality of groups with different numbers of grooves by rolling. Its purpose is to manufacture.

According to the present invention, the uneven shape of the bent product is determined by changing the tip angle of the bending roller used in the bending process. Since the position of the overlapping part generated by forming the convex part in the thickening process is determined by the uneven shape of the bent product, the position of the overlapping part can be determined by this. can always be set at approximately the center in the axial direction of the convex strip formed in the thickening process.

Therefore, according to the method of the present invention, various problems caused by cutting such as processing time, material yield, economy, productivity, and product weight can be solved. A multi-groove V-boot having a separation band section dividing the groove into a plurality of groups having different numbers of grooves can also be manufactured efficiently by rolling with excellent strength. In addition, since the position at which the molded portion occurs can be controlled by setting the tip angle of the bending roller, variations in the position at which it occurs can be effectively suppressed, thereby improving product reliability. As a result, manufacturing control can be further improved.

Furthermore, since the reduction in strength due to the occurrence of overlapping portions is eliminated, the thickness of the convex strips formed in the thickness increasing step can be easily increased.

Therefore, even if a relatively large separation band is to be formed in the grooving process, since the portion that should become the separation band has already been formed as a large convex strip,
The amount of excess metal movement needed to raise the separation band is small, and therefore, there is no unsightly missing thickness at the top of the separation band. A pulley product with a relatively large separation zone, which is well regulated against movement, can be easily produced.

(Example) Hereinafter, in order to clarify the present invention more specifically, a specific example of the manufacturing method according to the present invention will be described in detail based on the drawings.

Fig. 1 shows a product with a multi-groove boot with a separation band manufactured according to the method of the present invention, and the series of manufacturing steps thereof are shown in Figs. 2(a) to (e). .

First, as shown in FIG. 2(a), a metal material 22 punched into a circular shape is subjected to a predetermined deep drawing process, etc., to form the metal material 22 as shown in FIG. 2(b). A cup-shaped preform 24 having a substantially bottomed cylindrical shape is formed. Thereafter, as shown in FIG. 2(C), this preform 24 is set in a predetermined rolling processing device, and while being rotated around its center line, both ends of the cylindrical wall are formed. By pressing the bending rollers 26 and 28, the abutting portions thereof are recessed. At the same time, the preform 24 is pressurized from both sides in the axial direction by the upper jig 30 and the lower jig 32, so that both bending rollers 26 and 28 are pressed and brought closer to each other. Through such a bending process,
Flange portions 3 are provided at both ends of the cylindrical wall of the cup-shaped preform 24.
4.degree. 34 is formed, and the cylindrical wall portion between the flange portions 34.degree. 34 is bent in a concave and convex manner in the radial direction to form a bent product 36.

In this embodiment, the tips of the pair of bending rollers 26 and 28 are set so that the convex apex of the uneven curved surface of the bending product is located at a position where a convex strip is formed in the thickness increasing process to be described later. Angle is set. That is, as shown in FIG. 3, the tip angle α of the upper bending roller 26 is made smaller than the tip angle β of the lower bending roller 28, so that the cylindrical portion of the bending crystal 36 is formed. The convex apex of the concavo-convex curved surface is formed to be offset by β from the axial center toward the upper bending roller 26 side.

Next, while rotating the bent product 36, the thickening roller 38 is moved as shown in FIG. By pressing against the bent cylindrical portion of the bent product 36 to even out the uneven curved surface, the cylindrical wall portion is temporarily thickened to form the thickened product 40. Note that the bending roller 38
has a concave groove 39 continuous in the circumferential direction at a portion corresponding to a separation band formed in a groove cutting process to be described later, and the thickened product 40 has a concave groove 39 continuous in the circumferential direction.
Since the product is formed by pressurizing the pad 42 and the pad 42, the thickened product 40 formed by the thickening process described above.
A circumferential protrusion 44 is formed on the outer circumferential surface of the cylinder wall. Further, in accordance with this, an overlapping portion 45 is generated on the inner circumferential surface of the cylindrical wall of the thickened product 40 at a substantially central portion in the axial direction of the convex strip portion 44 .

Thereafter, as shown in FIG. 2(e), the groove cutting rollers 46 are pressed against the thickened product 40 formed in the thickening process and transferred to each other, thereby forming a plurality of grooves on the outer circumferential surface of the cylinder wall. V-groove 52 and separation band portion 4 that separates the V-groove 52
By carving 8, the desired multi-groove with separation band V
The result is a pulley. The grooving roller 46 used in this grooving process is as shown in FIG.
Seven V-shaped protrusions 54 are formed to form multi-stage V-grooves 52 (seven grooves in this embodiment) of the target pulley product 50, and three grooves and three grooves are formed between these V-grooves 52 in the axially intermediate portion. 4
The outer peripheral surface of the cylinder is provided with an annular recess 56 for forming an annular convex separation band 48 that divides the groove into two groups.

Further, the annular recess 56 in the grooving roller 46 corresponds to the groove 39 of the thickening roller 38 used in the thickening process.
Since the overlapping part 45 on the inner circumferential surface of the pulley product 50 is provided at a position corresponding to the separation band part 4
8 at approximately the center in the axial direction.

The pulley product 50 manufactured by the method described above is
It is shown in FIG. As is clear from the figure, this pulley product 50 has a relatively large separation band portion 48 that divides the seven grooves 52 into two groups, so that the pulley product 50 has two The position of the V-belts 58 and 60 on the pulley product 50 can be well regulated, and the overlapping portion 45 generated on the inner circumferential surface of the V-belts 58 and 60 can be positioned in the axial center of the thick separation band portion 48. Because of its position, it does not have any negative impact on the strength of the pulley product 50.

In addition, since the manufacturing process is based on rolling process, compared to conventional pulley products that involve cutting of cast products,
The pulley product 50 with improved economical efficiency and productivity as well as excellent strength could be easily produced.

Although the specific method of the present invention has been described in detail based on one embodiment, the present invention is not to be construed as being limited only to such illustrative specific method;
Although not listed in detail, it goes without saying that the present invention can be implemented in embodiments with various changes, modifications, etc. based on the knowledge of those skilled in the art, and such embodiments include:
It goes without saying that any of these methods are included within the scope of the present invention as long as they do not depart from the spirit of the present invention.

That is, when manufacturing a multi-groove V pulley with a separation band through a bending process, a thickening process, and a grooving process, the method of the present invention reduces the tip inclination of the mutually opposing surfaces of a plurality of bending rollers used in the bending process. By changing the angle, the convex apex of the uneven surface formed between the respective bending rollers in the cylindrical portion of the bent product is positioned approximately at the axial center of the convex strip formed in the thickening process. As a result, the overlapping portion that occurs on the inner circumferential surface of the thickened product in the thickening process is positioned at the axial center of the convex strip. The separation band portion formed in the grooving step is formed on the protruding portion. Therefore, the pulley products to which the method of the present invention can be applied are not limited to those in which one separation band is formed offset from the axial center of the boom as in the above embodiment, but also those in which a plurality of separation bands are formed. Even if the pulley has a band, it is always possible to position the overlapping part that occurs on the inner circumferential surface in the center of the separation band, and therefore the shape and size of such a pulley product may vary. It is not limited by the size. Further, the rolling processing device may be any device as long as it can practically carry out the present invention, and various devices may be appropriately adopted in consideration of its functions.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing a specific example of a multi-groove pulley manufactured by the method of the present invention, and FIG. 2 is an explanatory diagram showing over time the processing steps as an example of a multi-groove pulley according to the method of the present invention. FIG. 3 is an explanatory view showing a bent product formed by rolling using a pair of bending rollers according to the present invention. 4 and 5 are partial cross-sectional views showing multi-groove boots with separation bands formed by rolling according to the conventional method. 24 Nib form 26. 28: Bent roller 36: Bent product 38: Thickening roller 39: Concave groove 40: Thickening product 44: Convex strip portion 45: Overlapping portion 46: Grooving reroller 48: Separation band portion
50: Pulley product 52; ■ Groove Figure 1 Figure 3 Figure 5 Figure 4

Claims (1)

[Claims] A cylindrical outer circumferential surface has a plurality of V grooves extending in the circumferential direction in multiple stages in the axial direction, and the plurality of V grooves are divided into a plurality of groups having different numbers of grooves at intermediate positions in the axial direction. A method for manufacturing a multi-groove V-pulley in which convex separation strips are arranged in the circumferential direction, in which multiple bends are applied to the cylindrical wall of a bottomed cylindrical preform obtained from a predetermined metal plate material. A bending step of forming a bent product in which the cylinder wall is unevenly bent in the radial direction by pressing rollers and recessing the abutting portions of the rollers; A thickening roller having a concave groove is pressed against a portion corresponding to the cylindrical wall to increase the thickness of the cylindrical wall, thereby obtaining a thickened product in which circumferential protrusions are formed on the outer circumferential surface of the cylindrical wall. a step of forming the thickened product obtained in the thickening step by pressing a predetermined grooving roller against the thickened product, forming the separation band portion that divides the V-groove into the circumferential convex strip portion; a grooving step of forming V-groove groups with different numbers of grooves on both sides of the separation band portion, and the tip angles of the plurality of bending rollers in the bending step are changed to form V-groove groups in the thickening step. A multi-groove V with a separation band characterized in that an overlapping portion generated on the inner circumferential surface portion of the thickened product corresponding to the convex strip is located approximately in the center in the axial direction of the convex strip.
How to manufacture pulleys.