JP2001286961A - Forming method of stock for rotation part from plate material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a stock for rotation part having a hub part thickened and a rib part thinned by welding/machining from a plate material in a forming method of the stock for rotation part from the plate material. SOLUTION: Prior to forming a hub from a plate material 10, a projecting section 10-2 opposite to a protruding direction of the hub is formed to a center part of the plate material by shallow drawing, successively, by conducting pierce burring while rolling in the projecting section 10-2, the center part of the plate material is protruded in a cylindrical shape, the plate material section protruded in a cylindrical shape is the hub. By holding a cylindrical protruded part to a die while providing a clearance in the radial direction and by strongly pressing, the cylindrical protruded part is made into the hub thickened in the end. Further, a rib part is thinned by plastic working of side ward slippage by a cone shape roller under a low pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of integrally forming a material having a hub, a rib, and a rim, which are the basis of a rotary part such as a pulley, from a thin plate having a thickness of several millimeters by plastic working.

[0002]

2. Description of the Related Art Integral molding of a rotating member such as a pulley has conventionally been performed by casting or forging. However,
These methods generally have a minimum wall thickness of about 7 millimeters due to the limitations of metal rollability and molten metal fluidity. This is a wall thickness suitable for a rim part to be subjected to groove and gear processing, a key groove and a hub part to be subjected to spline processing. However, in a small machine part such as φ100 mm or a medium-sized machine part such as φ200 mm, the rib receives torque all around its circumference, so that the required strength can be sufficiently obtained even with a wall thickness of 2 to 3 mm. Therefore, when weight reduction is a priority condition, the wall thickness is reduced by the cutting process. Since cutting is required, the number of steps increases, and this is disadvantageous in terms of material resources and economy.

[0003] As a material for a large number of V-groove pulleys as a method not based on casting or forging, a small-diameter hub portion at the center is formed by cutting from a peeled material, and a rib portion and a rim portion are punched, punched and drawn from a flat plate. Are formed by a series of press workings, and these are joined by welding or the like. Since the rib and rim are made of a plate material and are thin, weight reduction can be realized. However, since the hub and the rib are welded, the number of processes increases, which increases the manufacturing cost, and the rim is the same as the rib. Since the rim portion is thin, deep irregularities such as gears cannot be machined on the rim portion, and when formed into a large number of V-groove pulleys, there is a disadvantage that only a groove having a small depth can be formed.

[0004] It is not impossible to reduce the thickness of the ribs by forging with a press. However, in thinning by cold forging, even a small object such as φ100 mm has a large press of 3,200 tf for medium-sized machine parts such as 800 tf and φ200 mm. Work on the machine. Further, according to the hot forging, the forming force can be suppressed, but heating energy and heat management are required, and in any case, the cost is increased. For this reason, conventionally, thinning by forging has not been carried out due to cost problems.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to increase the thickness of a hub portion from a plate material without welding, and to reduce the thickness of a rib by cutting. It is an object of the present invention to be able to carry out plastic working under a low pressure without involving high-energy press work such as forging.

[0006]

According to a first aspect of the present invention, there is provided a method of forming a material for a rotating part having a hub from a plate material, wherein a direction of the projection of the hub is formed at a central portion of the plate material prior to formation of the hub. In the opposite direction, the shallow drawing is used to reduce the thickness of the surrounding material by metal flow, and then the piercing burring process with less wall thinning is performed while involving the drawn meat in the convex portion given by the shallow drawing. A method for forming a material for a rotating component from a plate material is provided, wherein the central portion of the plate material is formed into a cylindrical shape by applying the material, and a portion of the plate material protruding into the cylindrical shape serves as a hub.

The function and effect of the first invention will be described. Prior to molding the hub, a convex shape is provided by a shallow drawing in a direction opposite to a direction in which the hub protrudes. Shallow drawing produces a flow of meat that is drawn toward the center.
Since the portion of the meat drawn toward the center in this way is wrapped around the portion of the material protruding into a cylindrical shape by the piercing burring process serving as the hub, it is possible to suppress the thickness reduction of the hub after the execution of the piercing burring process. As a result, there is an effect that the thickness of the key groove and the hub portion on which the spline processing is performed can be increased.

According to a second aspect of the present invention, there is provided a method of forming a material for a rotating part having a hub from a plate material, wherein the central portion of the plate material is subjected to piercing burring to project the central portion of the plate material into a cylindrical shape. The cylindrical projection is held by a mold while providing a gap in the radial direction, the back surface is clamped, and the open end surface of the cylindrical projection is strongly pressed to form the cylindrical projection as a hub. Provided is a method for forming a material for a rotating component from a plate material.

The operation and effect of the second invention will be described. Since the cylindrical projection formed by piercing burring from the plate material is strongly pressed from the open end face, the thickness of the cylindrical projection is reduced in the radial direction to fill the gap. , And can be formed into a rotating component material having a thickened hub. Also,
It is also possible to simultaneously perform plastic working of splines and the like.

According to a third aspect of the present invention, there is provided a method for forming a rotary component material having a hub from a plate material, wherein a convex portion is formed in a central portion of the plate material in a direction opposite to a direction in which the hub projects, prior to forming the hub portion. The shape is given by shallow drawing, and then the central part of the plate material is projected into a cylindrical shape by applying piercing burring to the convex part given by the shallow drawing,
The cylindrical protrusion is held by a mold while providing a gap in the radial direction, the back surface is clamped, and the open end surface of the cylindrical protrusion is strongly pressed to increase the thickness of the cylindrical protrusion to form a hub. A method of forming a raw material for a rotating part from a plate material is provided.

[0011] The function and effect of the third invention will be described. A convex shape opposite to the direction in which the hub protrudes is provided by a shallow draw to induce a flow of meat drawn toward the center, and then piercing burring. The thickness of the piercing burring process is minimized by applying piercing burring, and the cylindrical protrusion that is obtained by the piercing burring process is strongly pressed to fill the gap with the mold from the open end side. The thickness of the projection can be increased.

According to a fourth aspect of the present invention, there is provided a method of forming a rotating component material having a thin rib from a plate material, wherein a forming roller is moved in a radial direction with respect to a cone-shaped rotary forming jig. By pressing down, the plate material is turned over along the cone-shaped surface of the rotary molding shaft, thereby reducing the thickness of the portion of the plate material that comes into contact with the cone-shaped surface, and making this thinned portion a rib. The present invention provides a method for forming a material for a rotating component from a plate material to be formed.

The operation and effect of the fourth invention will be described. The plate material is pressed down against the cone-shaped surface of the rotary forming jig by a forming roller, and the plate material is turned over. By being plastically deformed so as to cause a lateral slip, it is possible to form a thinned rib. And, because the thickness is reduced by shearing, the pressure at the time of processing can be made extremely small as compared with the thickness reduction by forging, and large-scale equipment is unnecessary and further non-cutting. There is an effect that the processing cost can be reduced without wasting material.

[0014] In the fourth aspect of the invention, following the thickness reduction of the rib, the portion lying down at the time of the thickness reduction can be flattened or uneven or curved by a stamping or a roller, thereby forming after the thickness reduction. It can be a material for a rotating part having ribs.

According to the fifth aspect of the present invention, a thick hub,
This is a method of forming a material for uneven thickness rotating parts having a thin rib and a thick rim, wherein a convex shape opposite to the direction in which the hub protrudes is applied to the center of the plate material by shallow drawing prior to the formation of the hub. Then, the central portion of the plate material is projected in a cylindrical shape by performing piercing burring on the convex portion provided by the shallow drawing, and this cylindrical projected portion is held in a mold while providing a gap in the radial direction. At the same time, the cylindrical projection is thickened by pressing strongly on the open end face of the cylindrical projection while clamping the back surface to form a hub, and the outer peripheral side of the hub is pressed against a rotary molding jig by a forming roller. By moving the forming roller in the radial direction, it is turned over on the outer peripheral side from the hub to reduce the thickness of the portion of the plate material that comes into contact with the cone-shaped surface. Following meat, forming method of the rotating component material from the plate material, characterized in that flattening or uneven or curved, etc. by stamping or roller sideways by site during thinning is provided.

The function and effect of the fifth invention will be described. The piercing burring process is performed by causing the flow of meat to the central portion by performing shallow drawing in the central portion of the plate in the direction opposite to the direction in which the hub protrudes. By reducing the wall thickness during piercing burring, the hub can be thickened by strong pressure from the open end so as to fill the gap with the mold, and the ribs are formed by rotating rollers with forming rollers By laying down on the tapered surface of the jig, the flow of meat in contact with the tapered surface is obtained, thinning is realized, and then by forming such as flattening, there is a rib thinner than the material thickness. Thus, it is possible to obtain a material for rotating parts.

In the first to fifth inventions, the final shape of the rotating part can be completed by subjecting the obtained material to drawing by pressing or spinning drawing.

In the first to fifth inventions, a pulley, a V pulley, a multi-V-groove pulley, a flat pulley, a gear and the like are formed by subjecting a rim portion of the obtained material to a forming process such as a tearing process or a rotary disk rolling process. Can be completed as a rotating part.

According to the sixth aspect of the present invention, there is provided a base material for rotating parts such as a pulley, a flat belt wheel and a V pulley,
It consists of a hub, a rib, and a rim.The hub, the rib, and the rim are an integrally molded product that is formed only by plastic working under a low pressure from a plate material without welding or cutting. There is provided a material for a rotating component, characterized in that the material has been reduced in thickness.

According to a sixth aspect of the present invention, the base material for rotating parts such as pulleys, flat belt wheels and multiple V-groove pulleys according to the present invention is lower than the plate material without welding or cutting. Hubs, ribs, and rims are formed only by plastic deformation under pressure, so that light weight, resource saving, energy saving, and low cost can be realized.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method of forming a material for a rotating component according to an embodiment of the present invention will be described step by step. In this forming step, as a first step, the plate material is subjected to shallow drawing in a direction opposite to the direction in which the hub protrudes, thereby forming a flow of meat toward the center of the plate material. The reduction in the thickness of the cylindrical projection is suppressed by the entanglement of the meat during the formation of the cylindrical projection by burring. Next, as a third step, the opening end is held while being held by a material die and a punch and the back surface is clamped. Then, the material is turned over by pressing the outer part of the hub, which becomes a rib, against a tapered cone-shaped core metal with a rotating roller as a fourth step. By pressing the material against the tapered surface and causing the material to slide sideways, the material is reduced in thickness. And shaped into immediately or curved shape, and a rotating component material having a thickening hubs and thinning the ribs and the rim.

FIG. 1 shows that the plate 10 is placed on the lower die 12 for the shallow drawing as the first stage, and the plate 10 is pressed by the lower die 12 by the upper die 14. The upper die 14 has a hollow portion 16 for accommodating the narrowed portion at the center of the plate material 10 in the shallow drawing process. The pressing force of the plate material 10 against the lower die 12 by the upper die 14 prevents the retreat of the plate material 10 during the drawing process of the plate material 10, but is set so as to allow the free flow of the material in the drawing process. In order to start the shallow drawing, the punch 18 starts to move upward from the state shown in FIG.

When the punch 18 is completely lifted, the central portion 10-1 of the plate 10 is lifted toward the cavity 16 as shown in FIG. The peripheral part due to the displacement of the central part 10-1 is drawn toward the central part from the outer periphery, and the inclined part 10-2
Becomes Due to the free flow of the material, the wall thickness is hardly reduced in the inclined portion 10-2, and the meat is drawn toward the center from the outer peripheral side by the amount of the inclination. As described above, it is possible to suppress a decrease in wall thickness in the formation of the cylindrical protrusion by piercing burring as the next step after the meat is drawn from the outer periphery to the center.

FIG. 3 shows a state where the material obtained according to FIG. 2 is prepared for piercing and burring. That is, the raw material is placed on the lower mold 20 with the squeezed portion facing upward, and an opening 22 is formed (pierced) in the end face (the central part 10-1 of the raw material). Further, the plate member 10 has a slope 10
The lower die 2 is formed by the restraining member 24 in the flat portion on the outer periphery of -2.
It can be suppressed to zero. The punch 26 is provided on the lower end surface of the upper die 28, and the holding member 24 is located on the upper end side of the upper die 2.
8 is slidably accommodated in the bore 28-1. Hydraulic or pneumatic pressure is introduced into the bore 28-1 to urge the holding member 24 downward, and a spring pressure is applied as necessary. The diameter of the punch 26 is made somewhat larger than the diameter of the opening 22 at the overhanging end face of the material, so that when the punch 26 is processed, a portion around the opening 22 of the material is deformed while being wound.

FIG. 4 illustrates a deformed state of a material during piercing burring. That is, the lower end of the punch 26 is in contact with the peripheral portion of the opening 22, so that the plate material 10
It transforms while rolling in like 10-3. Due to such deformation while being involved, it is possible to suppress a decrease in wall thickness when the tubular portion is formed by piercing burring.

FIG. 5 shows a state in which the upper die 28 is lowered to the lowermost end. A cylindrical projection 10-4 which will later become a hub is formed in the center of the material by the punch 26. In this invention, as shown in FIG. 2, in forming the hub, first, the thickness of the peripheral portion of the plate material is drawn toward the center by squeezing in the direction opposite to the projecting direction of the hub to increase the thickness. Since the meat portion is formed into the cylindrical protrusion 10-4 while being turned upside down by the punch 26 as shown in FIG. 4, the thickness t of the finally obtained cylindrical protrusion 10-4 is obtained as shown in FIG. it is possible to suppress the reduction of _1, 8 for the first of the wall thickness t ₀ of the plate 10
It can be about 5 to 90% (t ₁ = 0.85 to 0.9 t ₀ ). Unlike the present invention, in the formation of a cylindrical projection by simple piercing burring without drawing in the opposite direction, the thickness of the cylindrical projection is said to be 50 to 70% of the thickness of the plate material. It is clear that the wall thickness of the cylindrical protrusion 10-4 after the completion of the piercing burring can be suppressed.

As the next step, a step of increasing the wall thickness of the cylindrical projection by strongly pressing the cylindrical projection 10-4 of FIG. 5 from the open end side is performed. That is, as shown in FIG. 6, the plate member 10 having the cylindrical protrusion 10-4 is held between the upper die 30 and the lower die 32 at its outer periphery. The metal core 34 provided in the upper mold 30 is inserted into the cylindrical protrusion 10-4, and is inserted into the cylindrical space 36 between the center hole 32-1 of the lower mold 32 and the metal core 34. -4 extend, and a gap is provided inside the cylindrical projection 10-4. A punch 40 with a circular cross section at the tip
Is pushed into the cylindrical space 36 between the cored bar 34 and the lower mold 32, so that the flesh of the cylindrical protrusion 10-4 is plastically oriented in the radial direction so as to fill the gap in the cylindrical space 36. The hub 4 is made to flow, and as shown in FIG.
2 is obtained in the center of the circular plate 10. As shown in FIG. 6, in the thickening step, the outer diameter of the cylindrical projection 10-4 is regulated as shown in FIG. Generally, the increase in wall thickness due to cold pushing during outer diameter regulation is about 1.75 to 1.9 of the original wall thickness.
It is said to be twice. On the other hand, the thickness of the cylindrical protrusion 10-4 after pierce burring in the invention described in connection with FIG. 5 is t ₁ = 0.85~0.9t _0, therefore,
If the thickness of the post-thickening by pushing and t ₂ t ₂ = (0.85~0.
9) the _{× (1.75~1.9) t 0 = 1.5~1.7t} 0. in this way,
In the present invention, the hub 42 which is increased in thickness by 50 to 70% with respect to the thickness of the material by drawing in the direction opposite to the direction in which the hub protrudes as the first stage of hub formation and piercing and piercing while continuing to roll in the hub. Can be obtained.

The next step is a step of reducing the thickness of a portion to be a rib outside the hub 42. In the present invention, the thickness is reduced by spinning. This thinning step will be described with reference to FIG. 8. The plate material 10 having the hub 42 at the center obtained in FIG. 7 is mounted on a tapered cored bar 44.
The lower end of the hub 42 is inserted into the stub shaft 44-2 at the tip of the tapered portion 44-1 of the core bar 44, the center pin 46-1 of the holder 46 is inserted into the upper end of the hub 42, and the plate 10 is
4 and the holder 46. In this state, rotation is applied to the cored bar 44 as shown by the arrow C. And
The forming roller 48 is pressed against a portion of the plate outside the hub 42. That is, the forming roller 48 is advanced toward the plate material, so that the plate material falls down with respect to the tapered surface 44-1. Then, the plate material is tapered by the forming roller 48.
The molding roller 48 is moved along the tapered surface 44-1 while being pressed against -1. At this time, the material undergoes shearing and slides along the tapered surface, and the wall thickness is reduced in the portion where the slide occurs. FIG. 9 shows the plate material 1 on the tapered surface 44-1.
This is a diagram for schematically explaining the wall thinning action due to a side slip caused by pressing 0. That is, the plate member の in the upright state is plastically deformed by being pressed against the tapered surface of the rotating core metal as shown by the arrow C. In the figure, М ′ represents the material after plastic deformation. The square region S in the material М before pressing becomes a diamond-shaped region S ′ in the material М ′ after pressing. That is, at this time, the material only slides sideways under the shearing force, and the width in the lateral direction is L (= t ₀ ), which is the same before and after pressing М ′. At this time, the thickness M of the material M ′ after plastic deformation is L × sin α. Therefore, it can be seen that can allowed to decrease with respect to the thickness t ₀ of the sine times only the original material of the wall thickness taper angle of the disc by pressing to the tapered surface.

FIG. 10 shows a forming roller 48 along a tapered surface.
5 shows a state in which the movement has been completed, and the portion 50 where the wall thickness is reduced is a portion that becomes a rib. As described above, in the spinning drawing in which the material is pressed against the rotating tapered surface, the material undergoes shearing and slides to reduce the thickness, and the thickness is reduced by the sine of the thickness of the material times the taper angle α. Therefore, when α = 45 °, the thickness t ₃ of the thinned portion 50 is the thickness of the raw material 10 before processing = t ₀ × sin 45 = 0.7 × t _0.
Becomes If this thinning amount is not sufficient, the forming roller 4
The thickness can be reduced to t ₃ = 0.3 to 0.5 × t ₀ by additionally providing ironing and rolling with the core 8 and the core bar 44. In FIG.
42-1 shows a strongly reduced thickness portion obtained when such ironing is partially added. The thickness reduction in this embodiment is performed by pressing the forming roller 48 against the cored bar 44 to cause the material to slide sideways by shearing, and the pressure to be applied to the forming roller 48 at the time of processing is compared with the thickness reduction by forging. Therefore, the equipment cost can be significantly reduced.

The outer peripheral portion 52 of the plate that were not pressed against the tapered portion 44-1 of the core 44 in FIG. 10 is a moiety comprising a rim and remains thickness t ₀ of the material.

The next step is a step of straightening the thinned portion 50 which becomes a rib by stamping and bending the peripheral portion 52 which remains the thickness of the plate material which becomes a rim by drawing while forming a concave and convex shape. . That is, FIG.
In FIG. 1, the material is stamped and drawn into a desired shape such as a cup shape by means of an upper mold 56 with a portion 42 serving as a hub being mounted on a lower mold 54 with a portion 50 serving as a tapered rib having a reduced thickness facing upward. Is performed. That is, the upper mold 5
6 is pressed against the lower mold 54, and as a result, FIG.
As shown in (1), the thinned portion 52 serving as a rib is returned to be flat, that is, the outer peripheral portion 52 serving as a rim is subjected to squeezing and bent so as to be orthogonal to the thinned portion 50.
This increases the thickness of the hub 42 and the reduced thickness of the rib 50.
And the rim 52 with the thickness of the material kept as it is, a raw material for a rotating part is obtained.

FIG. 13 shows an example of a multi-V-groove pulley obtained from the rotary component material shown in FIG. In other words, while rotating the material of FIG. 12, a molding roller having a sectional shape complementary to the sectional shape of the pulley groove is pressed against the rim 52 of the rotating component material of FIG. Can be formed.

FIG. 14 shows an example in which a V-shaped pulley is obtained by pressing a forming roller having a V-shaped cross section against the rim 52 in the rotary component material shown in FIG.

FIG. 15 shows an example in which a disk pull is applied to the rim 52 in the rotary component material shown in FIG. 12 to form a flat pulley.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a circular plate material is held between an upper die and a lower die for shallow drawing. Shows the first.

FIG. 2 shows the completion of shallow drawing, in which the circular plate material held between the upper and lower dies is pre-shallow drawn by a punch in the direction opposite to the direction in which the hub protrudes.

FIG. 3 is a cross-sectional view showing a state in which a plate material subjected to shallow drawing is held between upper and lower molds for performing a piercing burring step.

FIG. 4 is a diagram showing a state in which meat around an opening of a plate is rolled in the middle of a piercing burring step.

FIG. 5 shows the completion of the piercing burring step, in which a tubular projection is formed at the center of the plate material.

FIG. 6 shows a state in which a plate material is held between upper and lower molds prior to a step of increasing the thickness of a cylindrical projection obtained by piercing burring.

FIG. 7 shows a step of increasing the wall thickness of the cylindrical projection obtained by piercing burring by strongly pressing the cylindrical projection from its open end side.

FIG. 8 is a diagram showing a state in which the hub has a tapered shape holding a material whose thickness has been increased in order to reduce the thickness of an outer peripheral side portion of the increased thickness hub.

FIG. 9 is a view showing the principle of reducing the thickness by pressing a material against a tapered surface and laterally moving the meat by shearing.

FIG. 10 is a diagram showing a state in which a step of pressing a material against a tapered surface to reduce the thickness is completed.

FIG. 11 shows a state in which the material is held in a lower mold with a tapered surface facing upward in order to flatten and push back a rib portion of the material after thickness reduction by stamping.

FIG. 12 shows a state in which a thinned portion serving as a rib is flattened by stamping, and an outer peripheral portion is bent to complete a cup-shaped rotating component material.

FIG. 13 is a sectional view showing a multiple V-shaped groove pulley obtained from the material of FIG.

FIG. 14 shows a V-pulley obtained by tearing a rim of the material of FIG.

FIG. 15 is a sectional view showing a flat pulley obtained by subjecting the outer peripheral hub portion of the material obtained in FIG. 12 to disk rolling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Plate material 12 ... Lower mold 14 ... Upper mold 16 ... Cavity 18 ... Punch 20 ... Lower mold 24 ... Holding member 26 ... Punch 28 ... Upper mold 30 ... Upper mold 32 ... Lower mold 34 ... Core metal 36 ... Cylindrical space 10-4: cylindrical protrusion 42: hub 44: core metal 46: holder 48: forming roller 44-1: tapered surface 50: rib 52: rim 54: lower die 56: upper die

Claims (9)

[Claims] 1. A method of forming a material for a rotating part having a hub from a plate material, wherein prior to forming the hub, a convex shape opposite to a direction in which the hub protrudes is formed in a central portion of the plate material by shallow drawing. Pulling, and then applying a piercing burring process to the convex portion provided by the shallow drawing, so that the central portion of the plate material projects cylindrically, and the portion of the projecting plate material becomes a hub A method for forming a material for a rotating part from a plate material. 2. A method of molding a material for a rotating part having a hub from a plate material, wherein a central portion of the plate material is subjected to piercing burring to project a central portion of the plate material into a cylindrical shape. A plate material characterized in that the portion is held by a mold while providing a gap in the radial direction, the back surface is clamped, and the open end surface of the cylindrical projecting portion is strongly pressed to increase the thickness of the cylindrical projecting portion to form a hub. Method of forming materials for rotating parts from Japan. 3. A method of molding a material for a rotating part having a hub from a plate material, wherein prior to the formation of the hub, a flesh is formed in a central portion of the plate material in a direction opposite to the direction in which the hub protrudes by shallow drawing. It is formed by drawing, and then the central portion of the plate material is projected in a cylindrical shape by performing piercing burring on the convex portion provided by the shallow drawing, and this cylindrical projecting portion is formed with a gap in the radial direction. A material for a rotating component from a plate material, wherein the material is held by a mold while being provided, the back surface is clamped, and the open end surface of the cylindrical protrusion is strongly pressed to increase the thickness of the cylindrical protrusion to form a hub. Molding method. 4. A method of forming a material for a rotating part having a thin rib from a plate material, wherein the plate material is rotated by pressing a forming roller against a cone-shaped rotary forming jig while moving in a radial direction. Rotating parts from a plate material characterized in that the portion of the plate material contacting the cone-shaped surface is reduced by making it sideways along the cone-shaped surface of the forming shaft, and the thinned portion is formed as a rib portion. Method of molding materials. 5. The method according to claim 4, wherein, following the thickness reduction of the ribs, the portion turned down at the time of the thickness reduction is flattened or uneven or curved by a press or a roller. A method for molding materials for rotating parts. 6. A method of forming a material for a rotating part having a thick hub, a thin rib and a thick rim from a plate material, wherein a direction opposite to a direction in which the hub protrudes from a center portion of the plate material prior to formation of the hub. The central portion of the plate is projected in a cylindrical shape by applying a piercing burring process to the portion of the convex shape provided by the shallow drawing. The cylindrical projection is thickened by pressing the open end surface of the cylindrical projection while holding the mold with holding a gap while providing a gap, thereby forming a hub, and further forming an outer peripheral side from the hub. By moving the forming roller in the radial direction while pressing it against the rotary forming jig by the roller, it is turned over on the outer peripheral side from the hub to reduce the thickness of the part of the plate material that contacts the cone-shaped surface. A method for forming a material for a rotating part from a plate material, characterized in that, after the thickness of the rib is reduced, the portion lying down at the time of the thickness reduction is flattened or uneven or curved by a press or a roller. . 7. The method according to claim 1, wherein
A method for forming a material for a rotating component from a plate material, wherein the material is formed by pressing, spinning, drawing, or eyeing or punching to make the material have an outer shape conforming to the outer shape of the rotating component. 8. A pulley, a V-pulley, a multi-V-groove pulley, a flat belt wheel, or the like is formed by subjecting a rim portion of the material according to any one of claims 1 to 7 to a forming process such as a tearing process or a rotating disk rolling process. A method for manufacturing a rotating part, which is completed as a rotating part. 9. A base material for rotating parts such as a pulley, a flat belt wheel, and a large number of V-groove pulleys, which comprises a hub, a rib, and a rim, and the hub, the rib, and the rim are welded or cut. A rotating part characterized by being an integrally molded product of only plastic working under a low pressure from a plate material without accompanying, the hub is increased in thickness, and the rib is subjected to uneven thickness processing such as thickness reduction. Material.