JPH0149576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and a device for thickening the peripheral wall of a poly V pulley made of a sheet metal. In a sheet metal poly V pulley constructed by molding poly V grooves, the present invention relates to a thickening method and a thickening device for thickening the peripheral wall of a cup-shaped material prior to molding the poly V groove array. This is related.

[Conventional technology]

Conventionally, this type of poly V pulley made of sheet metal, that is, a cup-shaped material formed by deep drawing a sheet metal material to form a base part and a peripheral wall part connected to this base part via a step part, has been manufactured. After thickening the peripheral wall, this thickened peripheral wall is coated with
A sheet metal poly-V pulley is known that is constructed by molding a plurality of poly-V grooves arranged at a predetermined pitch.

4 and 5, the sheet metal poly V
An overview of the means for manufacturing a pulley, particularly a means and apparatus for thickening the peripheral wall of a cup-shaped material are shown here.

That is, in the manufacturing process shown in FIG. 4, the cup-shaped material 1a (FIG. 4a), in which a substrate portion 2 and a peripheral wall portion 4 connected to the substrate portion 2 via a step portion 3 are respectively formed, is first manufactured by: As a preforming process for increasing the thickness, the peripheral wall portion 4 is bent outward by an amount corresponding to the increase in thickness and is bulged to form a preformed cup-shaped material 1b (Fig. b ).

Next, as a thickening forming step, the circumferential wall bulging portion 5 of the preformed cup-shaped material 1b is compressed by applying pressure from the outside while maintaining the positions of both ends in the axial direction. The circumferential wall bulging portion 5 is thickened in accordance with the degree of bulge to form a poly V groove molded portion 6, and an ear portion molded portion 8a for a folded ear portion 8 is formed at the end on the substrate portion 2 side. A thickened cup-shaped material 1c (FIG. 3c) is formed with an ear part molding part 9a for a terminal ear part 9 on each open end side.

Furthermore, after that, the thickened cup-shaped material 1c
After going through a poly V groove preforming step (d in the same figure) in which each coarse poly V groove 7a is formed on the thickened poly V groove molded part 6, finally, a poly V groove finishing step is performed. , each pre-stage poly V groove 7a and each ear molded part 8a, 9a are finished molded, and as a result, a plurality of poly V grooves 7 lined up at a predetermined pitch in the poly V groove molded part 6 and this poly V groove Folded ears 8 are formed on the ends of the substrate 2 in the 7 rows of V-grooves, and termination ears 9 are formed on the open ends (see e in the same figure). In this way, the sheet metal product is formed. Poly V
Thus, pulley 10 is obtained.

In the preforming process for increasing the thickness, as shown in the apparatus configuration of FIG. Using upper and lower outer molds 102 and 104 each having mold surfaces 102a and 104a that regulate the bulged cross-sectional shape of the bulged portion 5,
The upper outer mold 102 is pressed by another pressing mold 103,
The preformed cup-shaped material 1b is obtained by applying pressure as shown by the arrow to form the desired peripheral wall bulging portion 5 described above.

In addition, in the thickening forming process, as shown in FIG. 5b, the preformed cup-shaped material 1b
is fitted and supported on the rotating inner mold 111 of the lower support mold 113, and the mold surfaces 112a, 114a, 114b that regulate the cross-sectional shapes of the poly V groove molded part 6 and the ear molded parts 8a, 9a are formed. Using an upper press die 112 and an auxiliary forming roll die 114 each formed with a let me,
The thickened cup-shaped material 1c is obtained by molding the desired poly V-groove molded portion 6 and the ear molded portions 8a, 9a, respectively.

Furthermore, in the poly V groove finishing step,
As shown in FIG. 5c, the thickened cup-shaped material 1c has a smaller diameter than this and has a V-shaped convex mold surface 121a corresponding to the poly V groove 7 on the outer peripheral surface, and the terminal ear portion 9. mold surfaces 122a, 124a, 12 that regulate the cross-sectional shape of the poly V groove 7 and the ears 8, 9, with the inner mold surfaces 121b of the inner mold surfaces 121b of
Using an upper pressing mold 122 and a V-groove forming roll mold 124, each having a diameter of 4b and 124c, while rotating the rotating inner mold 111, the thickened cup-shaped material 1c is supported by the upper pressing mold 122. , the V-groove forming roll die 124 is pressurized as shown by the arrow, and the above-mentioned desired poly V-groove is formed by rolling forming by cooperation between the rotating internal die 111 and the V-groove forming roll die 124. 7 and the respective ears 8 and 9 are finished-molded, respectively, and in this way, a sheet metal poly V pulley 10 is obtained as a product.

[Problem that the invention seeks to solve]

Here, in the manufacturing method of the sheet metal poly V pulley according to the above-mentioned conventional example, generally about five strips of the poly V groove 7 are formed for the thickened poly V groove molded part 6.
However, the following problems occur when molding each of these poly V grooves 7.

That is, first of all, when using the preformed cup-shaped material 1b as a material and thickening the circumferential wall bulging portion 5, that is, in the thickening forming process from FIG. 5 b to c, the circumferential wall swelling The projecting portion 5 is simply pressurized and compressed from the outside using a predetermined mold, and the plastic flow of the material forms the poly V groove molding portion 6 and the respective ear molding portions 8a and 9a. Because of this, the pressure applied to the peripheral wall bulge 5 from the outside,
Due to the influence of the reaction force, many fine wrinkles, burrs, or cracks are likely to be formed on the surfaces of the poly V-groove molded portion 6 and the ear molded portions 8a, 9a. be.

Second, in the poly V-groove preforming and final molding steps, that is, the steps from c to d and e in FIG. Poly V groove 7 in molded part 6
Also, each ear part 8, 9 is attached to each ear part molding part 8a, 9a.
Similarly to the above, when forming a mold, the finishing molding is simply performed by applying pressure using a predetermined mold, which causes the following inconvenience.

In other words, on the one hand, minute wrinkles and burrs overlap and grow, and the cracks in the cracks become deeper and their edges swell.
Even if the wall thickness is made thicker, not only will weak parts be created and the strength will be reduced, but if these unevenness and bulges occur on the molding surface of the poly V groove 7, the poly V groove 7 will be
There is a risk of damaging the contact surface of the V-belt stretched across the groove 7.

On the other hand, the poly V groove 7 of each strip to be molded
Of these, the various disadvantages and constraints that occurred during the molding of the poly V grooves in the middle part, although not so much about the poly V grooves in the middle part, are concentrated in the poly V groove parts at both end parts. In other words, for example, the unevenness of the surface of the poly V-groove molded part 6, the residual stress on the surface, and the excess plastic flow are gradually transferred from the middle part side to the both end parts, and the same both ends each poly V groove 7 of the part and each outer ear part 8,9 thereof
These poly V grooves 7, ears 8,
9 is difficult to mold accurately, and even if it is forcibly molded, it is easily deformed due to residual internal stress.

This invention was made to improve these conventional problems, and its purpose is to make it possible to easily and accurately mold each poly V groove and both side ear parts. An object of the present invention is to provide a new method and device for thickening the peripheral wall of this type of sheet metal poly-V pulley.

[Means for solving problems]

In order to achieve the above object, a method for thickening the peripheral wall of a sheet metal poly V pulley according to the present invention includes:
The bulging portion of the circumferential wall of the preformed cup-shaped material is pressurized in a first stage from the outside, and the material has bending concave portions at both ends in the axial direction, and is slightly bulged into an arched cross-section, resulting in a thickened material. a rough and thickening molding step of forming a coarse poly V groove molded part and, if necessary, forming an ear molded part on the outside of each bending recess;
While the groove molded part is held by each bending recess at both ends in the axial direction, a second stage of pressure is applied from the outside to form a poly V groove molded part thickened to the desired thickness, and at the same time. , a thickening molding step of forming coarse poly V grooves at both end portions corresponding to each of the bent recesses,
It is characterized by including at least sequentially.

Further, the device for thickening the peripheral wall of the sheet metal poly V pulley according to the present invention has a first device that fits the peripheral wall bulge of the preformed cup-shaped material and holds the open end side of the material against it. a lower rotary inner mold, an upper rotary outer mold that is press-fitted from above to the preformed cup-shaped material fitted and held in the first lower rotary inner mold to regulate the position of the material on the substrate side; The circumferential wall bulging portion of the preformed cup-shaped material fitted and held in the lower rotary inner mold of No. 1 is pressurized from the outside in a first stage to form bent recesses at both axial ends of the material and the circumferential wall bulging portion. The part has a first rotary molding roll mold that forms a coarse poly V-groove molded part that is slightly bulged in an arched cross-section and then becomes thicker. A combination of molds for obtaining a thickened cup-shaped material, and a second mold that fits into the coarse poly V-groove molded portion of the coarsely thickened cup-shaped material and holds the open end side of the material in abutment. a lower rotary inner mold, said upper rotary outer mold that is pressurized from above into a coarsely thickened cup-shaped material fitted and held in a second lower rotary inner mold to regulate the position of the material on the substrate side; The first rotary molding roll mold follows the pressure regulation of each bending recess and the coarse poly V-groove molded part of the coarsely thickened cup-shaped material fitted and held in the second lower rotating internal mold, and the pressure regulation The following rough poly V-groove molded part is pressurized in a second stage to form a poly V-groove molded part thickened to the desired thickness, and at the same time, both end portions corresponding to each bending recess are formed. and a second rotary molding roll mold for forming a coarse poly V groove in each of the molds, and a combination of the respective molds for molding a coarse thickened cup-shaped material to obtain a thickened cup-shaped material. It is characterized by

[Effect]

Therefore, in the case of the present invention, in the thickening forming process, the peripheral wall bulge of the preformed cup-shaped material is
In a state where it is regulated and held by a rotary molding roll mold,
By the first stage pressure, in order to form a slightly thickened coarse poly V-groove molded part on the arcuate surface and bent concave parts at both axial ends, the rough polygon is formed within a regulated range. Thickened parts can be well formed with little residual stress and no surface irregularities, and in the thickened forming process, in the case of coarse poly V-groove molded parts,
In the controlled follow-up state with the first rotary molding roll mold for each bending recess, the desired thickened poly V
In addition to molding the groove molding part, we also mold each rough poly V groove corresponding to the position of each bending recess, so that even the thickened V groove molding part can be formed within the regulated range. It can be formed accurately with a predetermined thickness, and
At the same time, each coarse poly V-groove can also be formed, and subsequent high-precision molding of each poly V-groove is extremely easy, and each poly V-groove can be formed on an ideal conductive surface.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the method and device for thickening the peripheral wall of a sheet metal poly V pulley according to the present invention will be described in detail with reference to FIGS. 1 to 3.

Figures 1a to 1c show sheet metal Vs according to this embodiment.
FIGS. 2A and 2B are cross-sectional views of main parts sequentially showing steps for thickening the peripheral wall of a cup-shaped material to which the pulley manufacturing method is applied, and FIGS. 2a and 2b show the same peripheral wall thickening device. Cross-sectional views shown in order of process,
FIG. 3 is a perspective view showing the main molds of the same device.

That is, in the manufacturing process shown in FIG. 1, in the case of this embodiment method, the preformed cup-shaped material 1b is formed by bending and bulging the peripheral wall bulging portion 5 outward by an amount corresponding to the thickening. (a) in the same figure, first,
As the thickening process, the circumferential wall bulging portion 5 of the preformed cup-shaped material 1b is flattened by applying a first step of pressure from the outside while maintaining the positions of both ends in the axial direction. As a result, while the circumferential wall bulging portion 5 is still in a slightly arched bulging state, the thickened rough poly V-groove molded portion is formed by having bent recesses 11b and 11c on both end sides, respectively. 11, and an edge molding part 8 for the folded edge part 8 is formed at the end on the substrate part 2 side, with the bending recess 11b as a border.
a, and on the open end side, an ear molding part 9a for the terminal ear part 9 is formed on each of the bent recesses 11c, and a coarsely thickened cup-shaped material 1e (FIG. 2b) is formed.
shall be.

Next, in the thickening forming process, the slightly thickened coarse poly V-groove molded part 11 of the coarsely thickened cup-shaped material 1e is formed, and the bent recesses 11b and 11c at both ends thereof are formed. While holding it, insert the second
By pressing and flattening in stages, the coarse poly V-groove molded part 11 is thickened to a desired thickness to form the poly V-groove molded part 12, and at the same time, each of the bent recesses 11b, For 11c, rough poly V-grooves 7b, corresponding to both side ends, are made in advance to hold the same.
7c is formed on each of the thickened cup-shaped materials 1
f (FIG. c) to achieve the desired thickness.

After that, the thickened cup-shaped material 1f
On the other hand, as in the case of the conventional example, after going through the poly V groove preforming process and the poly V groove finishing process, the poly V groove forming part 12 is formed with a rough poly V groove 7.
A required number of poly V grooves 7 are formed including the parts b and 7c, and a folded ear part 8 is formed on the ear part molding part 8a, and a terminal ear part 9 is formed on the ear part molding part 9a, respectively. Finally, a poly V pulley 10 made of sheet metal is obtained as a product.

As the peripheral wall thickening device for carrying out each of the above-mentioned process means, the molds shown in FIGS. 2a and 2b and 3 are used. That is, (A) an abutting mold surface 21a that abuts and restricts the open end surface of the material 1b, a mold surface 21b that restricts the inner surface of the material 1b on the V-groove molding portion side, and a mold surface 21b that restricts the end surface of the material 1b on the stepped portion side. a mold surface 21c that presses against the inner surface of the substrate portion of the material 1b, and an abutment mold surface 21d that abuts and restricts the inner surface of the substrate portion of the material 1b.
The first lower rotary inner mold 2 formed with
1. (B) The abutting mold surface 22a that abuts and restricts the outer surface of the substrate portion of the material 1b, the mold surface 22b that restricts the inner surface of the step side of the material 1b, and the outer end surface of the folded edge forming portion of the material 1b. An upper rotary outer mold 22 each having a regulating mold surface 22c formed thereon. (C) A mold surface 23a which is an arcuate arc surface that regulates the rough outer surface of the V-groove molded part of the material 1b, and a mold surface 23a that mainly regulates the rough V-groove surfaces on both ends of the V-groove molded part of the material 1b. , mold surfaces 23b and 23c that are folded together and regulate the inner end surface of each terminal ear molding part.
First rotary molding roll mold 23. (D) An abutting mold surface 24a that abuts and restricts the outer end surface of the end edge molded portion of the material 1e, a mold surface 24b that restricts the thickened inner surface on the V-groove molded portion side of the material 1e, and a step of the material 1e. The second lower rotary inner mold 24 is formed with a mold surface 24c that restricts the corresponding inner surface of the rough V groove on the part side. (E) A mold surface 25a which is a flat surface regulating the outer surface of the V-groove forming part side of the material 1b, and mainly the material 1
Thickening molding of the V-groove molding part b, which regulates the rough V-groove surface on the step side in the V-groove molding part and also forms a mold surface 25b that regulates the inner end surface of the folded ear molding part. Second rotomolding roll mold for 2
5. each of them.

Therefore, each molding operation with this equipment configuration is
It is done as follows.

In the coarse-thickening forming process, FIG. 2a,
As can be seen especially in the left half, first, the preformed cup-shaped material 1b is placed in the first lower rotary inner mold 2.
Using the upper rotary outer mold 22 and the first rotary molding roll mold 23, with the axially open end side of the material 1b held against the mold surface 21a, As seen in the right half of the figure,
Apply pressure to each of these as shown by the arrows,
The pressing force in the axial direction by each mold surface 22a, 22c of the upper rotary outer mold 22, the subsequent regulating and holding of the positions of both ends in the axial direction by the mold surfaces 23b, 23c of the first rotary molding roll mold 23, and the mold surface. 23a, this preformed cup-shaped material 1b
The slightly thickened coarse poly V-groove molded part 1 is still slightly arched and slightly bulged in the peripheral wall bulged part 5.
1 is gradually formed, and at the same time, bending recesses 11b, 11 are formed on a predetermined line on both end sides thereof.
c, and the ear portion molding portions 8a, 9a are formed respectively to obtain a coarsely thickened cup-shaped material 1e.

In this thickening process, the peripheral wall bulge 5 of the preformed cup-shaped material 1b is regulated and held by the mold surfaces 23b and 23c of the first rotary molding roll mold 23, that is, in the axial direction of the material 1b. While regulating and holding the positions of both ends, it is gradually compressed by the first stage of pressure applied by the mold surface 23a, and once as an intermediate process, a coarse poly V-groove molded part with a slightly thickened arched surface is formed. 11, a coarsely thickened portion is formed within a regulated accurate range, and no undue stress is applied to the coarsely thickened portion to be formed. Good plastic flow occurs inside the material, and its residual stress is small.
Even on the surface, there is no risk of unevenness such as fine wrinkles, burrs, or cracks occurring in the conventional example.

Then, in the thickening molding step, a second
As seen in FIG. b, here, the coarsely thickened cup-shaped material 1e is fitted and supported on the second lower rotating inner mold 24, and here, similarly, the material 1e is opened in the axial direction. The upper rotary outer mold 22, the first rotary molding roll mold 23, and the second rotary molding roll mold 2 are held with their end positions abutted against the mold surface 24a.
5, each mold surface 22a, 2 of the upper rotating outer mold 22
2c, and follow regulation by each mold surface 23a, 23b, 23c of the first rotary molding roll mold 23,
In particular, depending on each mold surface 23b, 23c, the second
The rotary molding roll mold 25 of
By applying pressure in stages, the coarse poly V groove molded portion 11 of the coarsely thickened cup-shaped material 1e is gradually compressed by the mold surface 25a, and the thickness is thickened as expected to form a poly V groove.
While forming the groove molding portion 12, at the same time, the bent recesses 11b, 11c are molded using the respective mold surfaces 23b, 23c and 25b, and coarse poly V grooves 7b, 7c are formed corresponding to the positions of both ends thereof, respectively. In this way, the thickened cup-shaped material 1f
This is what we get.

In this thickening forming process, a coarse poly V-groove molded portion 11 with a surface having little residual stress and no unevenness is formed in the coarsely thickened cup-shaped material 1e.
and the mold surface 2 of the first rotary molding roll mold 23 corresponding to each bending recess 11b, 11c.
3b and 23c, and following this with the mold surface 23a, while forming the desired thickened poly V-groove molding part 12, each coarse polyester corresponding to the bending concave parts 11b and 11c is molded. V groove 7b,
Since the molding of 7c is carried out,
Here too, the thickened V-groove molded portion 12 can be accurately formed with a predetermined thickness within a regulated range, and at the same time, the coarse poly V-grooves 7b and 7c can be formed, The subsequent high-precision molding of each poly V-groove 7 becomes extremely easy, and the
This makes it possible to form an ideal conductive surface without risk of damaging the belt.

That is, in the manner described above, the sheet metal poly V pulley 10 as the desired product can be manufactured.

〔Effect of the invention〕

As described in detail above, according to the present invention, the circumferential wall bulging portion of the preformed cup-shaped material whose axially both end positions are regulated is subjected to first-stage pressure from the outside by the first rotary molding roll die. It has bending recesses at both ends in the axial direction, and forms a thickened coarse poly V-groove molded part when it slightly bulges in an arched cross-section, and each bending recess is formed as necessary. Since the ear molded portions are formed on the outside, it is possible to form the coarsely thickened portions and the ear molded portions within a precise regulated range, and to prevent undue stress from being applied to the coarsely thickened portions. As a result, effective plastic flow occurs inside the material, reducing residual stress, and at the same time, it does not cause undesirable unevenness such as minute wrinkles, burrs, or cracks on the surface. Subsequently, the rough poly V-groove molded portion of the coarsely thickened cup-shaped material obtained in this way is rolled with the first rotary molding roll at each bending recess at both ends in the axial direction. With the pressure regulated by the mold, a second rotational molding roll mold applies a second stage of pressure from the outside, thereby thickening the coarse poly V-groove molded part to the desired thickness and forming the poly V-groove. At the same time, coarse poly V-grooves were formed at both end portions corresponding to each bent recess, so the desired thickened poly V-groove molded portion could be formed in the same manner here. In addition, it can be formed accurately and easily with a predetermined thickness within a regulated range, and furthermore, since rough poly V grooves corresponding to both ends are formed in advance, unreasonable stress and deformation are likely to be concentrated. The poly V-grooves at both ends can be roughly formed and positioned, making subsequent high-precision molding of each poly V-groove extremely easy. It has excellent features such as being able to be formed on an ideal conductive surface without any turbulence.

[Brief explanation of drawings]

FIGS. 1a to 1c are sectional views of essential parts showing step-by-step means for thickening the circumferential wall of a cup-shaped material to which an embodiment of the method for manufacturing a sheet metal poly-V pulley according to the present invention is applied, and FIG. 2a , b are cross-sectional views showing the general configuration of the peripheral wall thickening device for each process,
FIG. 3 is a perspective view showing the arrangement of the main molds of the same device, and FIGS. 4 a to 4 e show important parts of a conventional method for manufacturing a sheet metal poly-V pulley in order of process. The sectional views and FIGS. 5A to 5C are sectional views showing the main stages of the same manufacturing apparatus for each process. 1a...Cup-shaped material, 1b...Preformed cup-shaped material, 1e...Roughly thickened cup-shaped material, 1f
... Thickened cup-shaped material, 10 ... Sheet metal poly V pulley as a product. 2... Substrate part, 3... Step part, 4... Peripheral wall part, 5... Peripheral wall bulging part, 7a...
Rough poly V groove, 7b... Rough poly V groove at both ends, 7
... Poly V groove, 8a, 9a ... Ear molding part, 8,
9... Ear part, 11... Rough poly V-groove molded part, 11
b, 11c...Bending concave portion, 12...Poly V groove molding portion. 21...First lower rotating inner mold, 21a to 2
1d...Same type surface. 22... Upper rotating outer mold, 22
a to 22c...Same type surface. 23...first rotary molding roll mold, 23a to 23c...the same mold surface. 24...Second lower rotating inner mold, 24a to 2
4c...Same type surface. 25...Second rotary molding roll mold, 25a and 25b...Same mold surface.

Claims (1)

[Claims] 1. In order to manufacture a sheet metal poly-V pulley, a preformed cup-shaped material is used, in which the peripheral wall of the cup-shaped material is bent outward by an amount equivalent to the thickness increase to form a peripheral wall bulge, The circumferential wall bulging portion of the preformed cup-shaped material is thickened in accordance with the degree of bulge by applying pressure from the outside while maintaining both axial end positions of the peripheral wall bulging portion. , the first stage of pressure is applied from the outside to form a coarse poly V-groove molded part which has bending concave portions at both ends in the axial direction and is slightly bulged in an arched cross-section. In the thickening molding process, the rough poly V-groove molded part was held by each bending recess at both ends in the axial direction, and a second stage of pressure was applied from the outside to thicken it to the desired thickness. A polyester plate made of sheet metal characterized in that it includes at least sequentially a thickening molding step of forming a polyurethane V-groove molded portion and at the same time forming coarse polyurethane V-grooves at both end portions corresponding to each of the bending recesses. A method for thickening the peripheral wall of a V-pulley. 2. In order to manufacture a poly V pulley made of sheet metal, a pre-formed cup-shaped material is used in which the peripheral wall of the cup-shaped material is bent outward by an amount equivalent to the thickness increase to form a peripheral wall bulge, and the peripheral wall bulge is , a method in which the bulging portion of the circumferential wall of the preformed cup-shaped material is thickened in accordance with the degree of bulging by applying pressure from the outside while holding both end positions in the axial direction, and the bulging portion of the circumferential wall of the preformed cup-shaped material is Pressure is applied, and each end has a bent recess at each end in the axial direction,
and a rough-thickening molding step in which a thickened coarse poly V-groove molded portion is formed once the cross-section is slightly bulged into an arched shape, and an ear molded portion is formed on the outside of each of the bent concave portions. Then, while the rough poly V-groove molded part is held by each bending recess at both ends in the axial direction, a second stage of pressure is applied from the outside to thicken the poly V-groove mold to the desired thickness. A peripheral wall of a poly V pulley made of sheet metal, characterized in that the peripheral wall of the poly V pulley made of sheet metal includes at least one sequential step of forming a coarse poly V groove at both end portions corresponding to each of the bending recesses. How to thicken the part. 3. In order to manufacture a poly V pulley made of sheet metal, a pre-formed cup-shaped material is used in which the peripheral wall of the cup-shaped material is bent outward by an amount corresponding to the increased thickness to form a peripheral wall bulge, and the peripheral wall bulge is is a device that applies pressure from the outside while holding both end positions in the axial direction to thicken the material in accordance with the degree of bulge, which fits the bulging portion of the circumferential wall of the preformed cup-shaped material and expands the material. The first part holds the open end side of the
a lower rotary inner mold, an upper rotary outer mold that is press-fitted from above to the preformed cup-shaped material fitted and held in the first lower rotary inner mold to regulate the position of the material on the substrate side; The circumferential wall bulging portion of the preformed cup-shaped material fitted and held in the lower rotary inner mold of No. 1 is pressurized from the outside in a first stage to form bent recesses at both axial ends of the material and the circumferential wall bulging portion. The part has a first rotary molding roll mold that forms a coarse poly V-groove molded part that is slightly bulged in an arched cross-section and then becomes thicker. A combination of molds for obtaining a thickened cup-shaped material, and a second mold that fits into the coarse poly V-groove molded portion of the coarsely thickened cup-shaped material and holds the open end side of the material in abutment. a lower rotary inner mold, said upper rotary outer mold that is pressurized from above into a coarsely thickened cup-shaped material fitted and held in a second lower rotary inner mold to regulate the position of the material on the substrate side; The above-mentioned first part is configured to press and control each bending recess and the coarse poly V-groove molded part of the coarsely thickened cup-shaped material that is fitted and held in the second lower rotating inner mold.
The rotary molding roll mold and the coarse poly V-groove molding part that is followed by pressure regulation are pressurized in a second stage,
A second rotary molding roll mold is provided to form a thickened poly V-groove molded portion to a desired thickness, and at the same time form coarse poly V-grooves at both end portions corresponding to each bending recess. , a combination of molds for forming a coarsely thickened cup-shaped material to obtain a thickened cup-shaped material, and a sheet metal poly V comprising:
A device for thickening the peripheral wall of a pulley.