JP2819084B2 - Rotary forging device and method for manufacturing automobile wheel using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary forging apparatus and a rotary forging method using the same, and more particularly, to a rotary forging apparatus for manufacturing a disk with a rim having a rim formed on the periphery of the disk section. The present invention relates to a method for manufacturing an automobile wheel using the same.

[0002]

2. Description of the Related Art A method or an apparatus for forming a rim portion (11) on the periphery of a disk portion (1) by rotary forging has already been disclosed in Japanese Patent Application Laid-Open No. 61-226132. As shown in FIG. 1, this rotary forging method uses a thick disk-shaped material or a short cylindrical material (hereinafter referred to as a work (10)).
Between the lower surface of the upper die (301) and the upper surface of the lower die (302), which rotate synchronously, to form the disk (1) and the rim (11) into the final shape using the pair of dies. To finish. These processes are usually performed by hot working.

[0003] The upper surface of the lower mold (302) has a disk portion (1).
And a shape adapted to the inner peripheral surface below the rim portion (11). The rotation axis of the other upper mold (301) is slightly (for example, 2 to 5) with respect to the rotation axis of the lower mold (302).
Degree), and the lower surface is a substantially conical surface as a whole. The apex angle of the conical surface is determined so that one oblique side of the longitudinal section of the conical surface is horizontal. The shape of the oblique side of the vertical section corresponds to the shape of the portion corresponding to the upper surface of the section of the disk portion (1).

A rough forming roller (2
1) and the final molding roller (22) can be inserted alternately. According to this prior art, in a first step, the rough molding roller (21) is interposed at the boundary between the upper mold (301) and the lower mold (302). In the second step, the rim portion (11) is formed into a final shape by using the other final forming roller (22) in a second step.

In the first step, the upper mold (301) is lowered toward the lower mold (302) to the final position. As a result, an annular rim-equivalent portion (110) having a rectangular cross section formed by the rough molding roller (21) is formed on the periphery of the disk portion (1) having the final shape. Further, in the second step, the disk portion (1) and the rim-equivalent portion (110) are clamped by the upper die (301) and the lower die (302) (however, not pressed). The final molding roller (22) is pressed against the rim-corresponding portion (110) while rotating the rollers synchronously. As a result, as shown in FIG.
Is finished to the rim portion (11) of the final shape.

[0006] As described above, in this conventional device, the work
Since the process from (10) to the final molding with a rim can be performed while holding the work (10) in the upper die (301) and the lower die (302), productivity is good. However,
In this conventional method, the rim portion (1
A product whose cross-sectional shape of (1) is symmetrical with respect to the disc (1) can be formed by rotary forging, but the cross-sectional shape of the rim (11) as shown in Fig. 3 is asymmetric with respect to the disc (1). Products cannot be molded.

The rim-equivalent portion (1
This is because cracks are formed at the center of the disk part (1) and in the vicinity thereof when molding 10). Although the reason for this is not clearly understood, it is thought to be due to the following reason. Upper die (30
When 1) is pushed down to the lower mold (302) side, the work (10) is pressed down and flattened. Then, the outer peripheral surface of the material of the work (10) is molded by the surface of the rough molding roller (21). Looking at the rolling state of the work (10) at this time, the upper die (3
The area pressed down by the lower surface of (01) has a fan shape as shown in FIG. A rough molding roller (21) is in contact with the center of the arc-shaped peripheral portion of the fan-shaped rolling region (101). At the contact portion of the rough molding roller (21), the material of the work (10) is prevented from flowing outward in the radial direction due to the pressing of the upper mold (301). However, the fan-shaped reduction zone (10
On both sides of the rough forming roller (21) at the peripheral edge of (1), the material of the work (10) flows outward in the radial direction and swells outward in the radial direction as shown in FIG. Therefore, the fan-shaped reduction area
In the cross section of the inner portion of (101), a radial compressive force and a spreading force are repeatedly applied while the outer peripheral portion of the work (10) passes through the rough forming roller (21). As a result, it is considered that a crack is generated in the inner part of the sector-shaped reduction zone (101) and in the vicinity thereof.

Further, in this conventional method, as the work (10) is flattened by the upper mold (301) and the lower mold (302), the material of the work (10) protrudes from the disk molding portion to the outer peripheral side. After the protruding material reaches the surface of the rough forming roller (21),
The space surrounded by the (301), the lower mold (302), and the rough molding roller (21) is substantially equally separated and filled in two upper and lower directions. In FIG. 3, after one of the protruding material portions is first filled in the upper mold (301) side, the other of the protruding material portions is grown by the growth of the protruding material portion due to the continuous rolling down.
The rim-equivalent portion (110) is formed by filling the side. However, when filling the lower mold (302) side,
Since the material is further pushed into the (301) side from the state where the material has already been filled, the upper die (3
The pressure at the end on the 01) side is excessively increased, and the material protrudes between the upper mold (301) and the slight gap between the rough molding roller (21). As a result, a large amount of burrs are generated at one end of the rim of the product.

The present invention has been made in view of the above point, and has been made in consideration of "a substantially conical lower surface of the upper die (301) and a lower die (302)".
And the axis of the upper die (301) is inclined so that one of the generatrixes of the substantially conical lower surface of the upper die (301) is substantially horizontal. A work (10) is interposed between the lower surface of the lower die (302) and the upper surface of the lower die (302), and the upper die (301) and the lower die (302) are rotated while rotating the upper die (301) and the lower die (302) synchronously. The workpiece (10) is lowered by bringing the workpiece (302) into close proximity to the workpiece (10), and the material protruding from the reduced area is formed into a rim (11) by a molding roller and the upper mold (301) and the lower mold (302). In the `` forging device '', when forming a disk with a rim in which the cross-sectional shape of the rim part (11) is asymmetric with respect to the disk part (1), make sure that cracks etc. do not occur in the center part of the disk part (1) or in the vicinity thereof It is another object of the present invention to reduce the occurrence of burrs at the end of the rim. [Invention of Claim 1]

[0010]

The technical means of the present invention for solving the above-mentioned problem is as follows: "The cross-sectional shape of the end of the rim portion (11) in the axial direction which is closer to the disk portion (1)". Matching annular groove
(31) is formed on the outer periphery of the disk molding surface on the upper surface of the lower mold (302), and the upper end edge of the outer peripheral wall (32) of the annular groove (31) is brought into contact with or close to the upper end edge to rotate the molding roller (2). Freely supported ”.

[0011]

The above technical means operates as follows. Upper mold (3
01) and the lower mold (302) reduce the work (10).
As the rolling progresses, the work (10) is flattened, and the material protrudes from the disk molding surface to the outer peripheral side. The protruding material portion is formed so as to be bent or extended in the axial direction by a forming roller (2), and the rim portion (1
1) is formed.

In the process of forming the protruding material portion into the rim portion (11), when the protruding material portion grows, it reaches the body of the forming roller (2), and the forming roller (2) and the upper die are formed. Roll forming by the (301) and the body of the lower mold (302) causes the mold to be spread on both sides in the axial direction of the mold. However, on the upper surface of the lower mold (302), an annular groove corresponding to the cross-sectional shape of the end of the rim portion (11) closer to the disk portion (1) among the axial ends of the rim portion (11) is formed on the outer periphery of the disk forming surface. (31) is formed. Further, the forming roller (2) is supported so as to be able to freely contact the upper end edge of the outer peripheral wall (32) of the annular groove (31). Therefore, in the initial stage of molding the rim portion (11), one of the material projecting portions is provided with the annular groove (31) and the molding roller.
The space enclosed by the end face of (2) is filled.

Thereafter, when the upper die (301) and the lower die (302) are further depressed, the amount of the material of the workpiece (10) protruding increases. Wall (32)
Then, it flows to the other end side of the rim portion (11) by roll forming by the forming roller (2) and the body of the upper mold (301) and the lower mold (302). Then, in the final rolling state, both surfaces of the disk portion (1) are molded by the lower surface of the upper die (301) and the upper surface of the lower die (302), and the rim portion (11) is molded.

When the cross-sectional shape of the rim portion (11) is complicatedly bent like an automobile wheel, the shape of the body portion of the upper die (301) and the forming roller (2) are adjusted accordingly. Determine the shape of the torso.

[0015]

[Effect] In the initial stage of rotary forging, the outer periphery of the end of the rim portion (11) on the side approaching the disk portion (1) is restrained by the outer peripheral wall (32) of (31). The subsequent rotary forging process is performed in the constrained state. Therefore, after the outer peripheral constrained state, there is an inconvenience as in the prior art, that is, the radial compressive force and the radially extending force repeatedly act on the cross section of the inner portion of the fan-shaped reduction zone (101). Since such inconvenience does not occur, cracks do not occur in or near the inner portion of the fan-shaped reduction zone (101). Also, the rim (1
In (1), the end on the side approaching the disk portion (1) where the molding pressure is the highest is in the above-mentioned outer peripheral constrained state, so that the material does not protrude at this end and the occurrence of burrs is suppressed. [Other invention] The invention according to claim 2 is the invention according to claim 1, wherein the forming roller (2) is configured to have a truncated conical portion whose body diameter decreases upward. Part is located on the outer periphery of the boundary between the upper mold (301) and the lower mold (302). ”
The distance between the lower surface of (301) and the upper surface of lower mold (302) is reduced. That is, the thickness of the material projecting portion decreases with the progress of the reduction. The frusto-conical portion of the molding roller (2) faces this material protrusion. The diameter of the body of the frustoconical portion decreases upward. Therefore, in the initial stage of the rolling, the gap between the outer peripheral edge of the lower surface of the upper mold (301) and the body of the molding roller (2) is large, but the gap gradually decreases as the rolling progresses. As a result, the upper die
The thickness of the annular body formed by being extended upward by (301) and the forming roller (2) gradually becomes thinner from the upper end toward (1). In this manner, the thickness of the annular body extending long with respect to the disk portion (1) on the distal end side can be set to be thick with respect to the base end portion.

According to a third aspect of the present invention, in the second aspect of the present invention, the disk portion of the axial end of the rim portion (11) is provided.
The end nearer to (1) is the rim flange (121) of the outer rim (12) of the vehicle wheel, and the shape from the upper surface of the lower mold (302) to the trunk is the disk portion (1) of the vehicle wheel. ) To the shape of the inner peripheral surface of the outer rim (12) and the shape of the side surface of the rim flange (121) following the outer rim (12). The shape of the cross section of the annular groove (31) from the inner flat surface of (1) to the shape of the inner peripheral surface of the inner rim (13) near the disk portion (1) is adjusted to the rim flange of the outer rim (12). (121), and the lower part of the body of the forming roller (2) is formed with an outer rim that fits the outer peripheral surface of the outer rim (12) and the inner peripheral surface of the rim flange (121) that follows. Part (25)]. This allows
At the end of rotary forging, the disc part of the car wheel
Both the front and back surfaces of (1) are formed, and at least the entire outer rim (12) and the disc portion of the inner rim (13) of the rim cross section
The process up to the portion near (1) can be performed in one step.

A fourth aspect of the present invention is the invention according to the third aspect, wherein the lower die (30) is maintained while the forming roller (2) is maintained in an upright posture.
2) can be moved in the radial direction and in the direction parallel to the rotation axis. ''), By adjusting the position of the forming roller (2) with respect to the upper mold (301) and the lower mold (302) up, down, left and right. The thickness of the rim can be adjusted. The invention according to claim 5 is a method for manufacturing an automobile wheel using the rotary forging device, wherein the method for manufacturing an automobile wheel in which the disk portion (1) is biased toward the outer rim (12) side, Upper mold
The upper surface of the lower die (302) is opposed to the substantially conical lower surface of the lower die (302) so that one of the generatrix of the lower conical lower surface of the upper die (301) is substantially horizontal. The axis of the mold (301) is inclined, and the upper surface of the lower mold (302) is moved from the outer flat part of the disc (1) and the periphery of the disc (1) to the inner periphery of the outer rim (12). Surface and subsequent rim flange
An annular outer peripheral wall (32) is formed around the outer periphery of the rim flange (121) so as to substantially match the axial thickness of the rim flange (121). The molding roller (2) is rotatably supported by contacting or approaching, and the lower part of the body of the molding roller (2) fits the outer peripheral surface of the outer rim (12) and the inner peripheral surface of the rim flange (121) that follows. Using a rotary forging device with an outer rim forming part (25) with an outer peripheral surface shape Interposing a workpiece (10) between the lower surface of the upper die (301) and the upper surface of the lower die (302); The upper die (301) and the lower die (302) are rotated and forged by rotating the workpiece (10) downward by rotating them synchronously while rotating the work (10). 302)
The outer rim (12) of the rim (11) is molded by
(2) forming a cylindrical inner rim-equivalent portion (130) for molding the inner rim (13) by the lower portion of the upper die (301); And forming a portion corresponding to the inner rim into a cross-section of the inner rim by roll molding. "

According to this method, a portion other than the inner rim (13) of an automobile wheel in which the disc portion (1) is biased toward the outer rim (12) side with respect to the rim portion (11) is formed by rotary forging. Because of this, the productivity of automobile wheels is improved.
Also, even if there is an uneven portion on the upper surface of the lower mold (302) that coincides with the outer flat surface of the disk portion (1), the rim flange (121) was formed at the initial stage of rotary forging. When
Since its outer peripheral side is restrained by the outer peripheral wall (32),
The material of the work (10) is reliably filled in the concave and convex pattern portion by the subsequent reduction. Therefore, the concavo-convex pattern formed on the surface of the disk portion (1) exactly follows the concavo-convex portion of the lower mold (302). That is, the molding accuracy of the uneven pattern portion is improved.

[0019]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. Embodiment 1 shown in FIGS. 5 to 7 is a rotary forging for manufacturing a product in which a cylindrical rim portion (11) is continuously connected to the outer periphery of a disk-shaped disc portion (1) as shown in FIG. It is an Example of an apparatus.

The rim part (11) of this product has a disk part (1)
A flange portion (14) provided at a position slightly deviated from
A rim main body (111) extending in the axial direction from the inner peripheral end of the flange portion (14). The axis of rotation of the lower mold (302) is upright with respect to the horizontal plane, and the upper surface thereof has a flat portion corresponding to the lower surface of the disc portion (1), and an annular groove formed upwardly following the outer peripheral side thereof. (31). The inner peripheral surface, the outer peripheral surface, and the bottom surface of the annular groove (31) are each provided with a flange portion (14).
Are set to dimensions corresponding to the inner peripheral surface, the outer peripheral surface, and the lower surface.

The upper mold (301) has a lower surface set to a conical surface having a large apex angle, and a trunk portion formed at the upper end portion into a truncated conical shape having a smaller diameter than the lower end portion. The axis of the upper mold (301) is set so as to be inclined at about 2 to 5 degrees with respect to the axis of the lower mold (302), and is supported to be able to move up and down in this inclined state. Then, in this inclined state, the lower surface of the upper die (301) and the torso are arranged such that one generatrix of the lower surface of the upper die (301) is substantially horizontal and one generatrix of the trunk is substantially vertical. Is set. It is needless to say that the apex of the conical surface on the lower surface of the upper mold (301) coincides with the rotation axis of the lower mold (302).

Outside the boundary where the lower surface of the upper die (301) and the upper surface of the lower die (302) come closest to each other, a cylindrical molding roller (2) is rotatably supported, and the lower die (302) is rotatably supported. (302) so as to be movable in the radial direction. And
This support position is such that the lower end face of the molding roller (2) is an annular groove.
It is set at a position having a very small gap (for example, 02. mm to 1 mm) from the upper end of the outer peripheral wall (32) outside the (31).

The upper die (301) and the lower die (302) are a transmission device.
It is driven by the driving device (4) via (41). The upper die (301) and the lower die (302) are rotated in the same direction and synchronously rotated by the transmission (41). Also, lower mold
(302) is driven to rotate at a fixed position, and the upper die (301) is driven to move up and down at a predetermined timing by a lifting and lowering drive device (5).
The upper die (301) is rotatably supported by a shaft support (51) of an output unit of the elevation drive device (5), and the shaft support (51) moves the upper die (301) as described above. It is configured to be supported in a tilted posture and free to rotate. Further, a vertically extending guide shaft (52) penetrates through the shaft support portion (51), whereby the shaft support portion (51) moves up and down in a fixed posture in accordance with the advance / retreat of the output shaft of the lift drive device (5). I do.

The transmission (41) includes a drive (4)
A first gear transmission mechanism (42) for transmitting the output shaft of the upper die (301) to the rotating shaft of the upper die (301); a second gear transmission mechanism (43) for driving the lower die (302) to rotate; A transmission mechanism (44) including a pulley transmission or a chain transmission for transmitting the input shaft of the mechanism (43) and the output shaft of the driving device (4).
The upper die (301) is set by setting the transmission ratio and the transmission direction of the first gear transmission mechanism (42), the second gear transmission mechanism (43), and the transmission mechanism (44) to predetermined values or directions. And lower mold (30
2) is synchronously rotated in the same direction.

The output shaft of the drive unit (4) is composed of two shafts connected in series, and is connected by a spline fitting part (45) so as to be extendable and contractible. Therefore, the upper die (301) is
It can move up and down while maintaining the transmission state with (4). In order to manufacture the product shown in FIG. 8 according to this embodiment, as shown in FIG. 5, a thick disk or columnar shape is formed between the lower surface of the upper die (301) and the upper surface of the lower die (302). Work (10) is interposed.

Then, the molding roller (2) is moved inward, and its body is fixed at a position corresponding to the outer peripheral surface of the rim main body (111). In this state, the driving device (4) is driven to rotate the upper die (301) and the lower die (302) synchronously, and the lifting drive (5) is driven downward. As a result, the upper die (301) moves to the lower die (302) side, and the lower surface of the upper die (301) and the lower die (302) move.
The work (10) is reduced with the upper surface of the work. Then work
As (10) is flattened, its outer peripheral edge gradually protrudes outward from the boundary between both types. Then, the protruding material is formed by a forming roller (2) into an annular body extending up and down of the body.

As the rolling progresses, the lower annular body enters the annular groove (31) as shown in FIG. The lower annular body eventually fills the space defined by the molding roller (2) and the annular groove (31), and the flange portion (14) is molded. The upper annular body protrudes upward as it is.
As the rolling further proceeds, plastic deformation proceeds such that only the axial length of the upper annular body extends while the flange portion (14) remains molded. At this time, the flange
Since the outer periphery of (14) is constrained by the outer peripheral wall (32), the compression generated in the material reduction zone (101) between the lower surface of the upper die (301) and the upper surface of the lower die (302). The difference between force and spreading force is extremely small. Therefore, no crack is generated in the rolling-down area (101) in the rotary forging step.

Then, when the final pressing state is reached, the upper mold (30
The material between the lower surface of (1) and the upper surface of the lower mold (302) becomes the disk part (1) of the set thickness, and the cylindrical part extending upward on the outer periphery becomes the rim main body (111). . Thus, the product of FIG. 8 is manufactured. [Embodiment 2] The embodiment shown in FIGS. 9 and 10 uses the same upper mold (301) and lower mold (302) as in the above-mentioned Embodiment 1 and mainly uses a rim.
This is a rotary forging apparatus capable of molding the cross-sectional shape of (111) into a substantially triangular shape having a thick tip and a thin base.

For this purpose, the forming roller (2) is formed in a truncated cone shape. The lower end face of the molding roller (2) faces the upper end of the outer peripheral wall (32) of the annular groove (31) with a very small gap. In the initial state where the work (10) is interposed between the lower surface of the upper die (301) and the upper surface of the lower die (302), the lower surface of the upper die (301) is located at the middle of the body of the molding roller (2). There is a relationship that is located above.

When a work (10) is formed using this rotary forging apparatus, the upper die (30) immediately after the material projecting from both dies comes into contact with the body of the forming roller (2) in the initial stage of rotary forging.
The distance (α) between the lower surface of (1) and the body of the molding roller (2) matches the thickness of the tip of the rim main body (111). (Refer to FIG. 9) Then, as the work (10) is further reduced,
As in the first embodiment, a part of the material projecting portion is formed in an annular groove (3
The space formed by 1) and the forming roller (2) is filled to form a flange portion (14). The other part moves toward the annular portion opposite to the flange portion (14), and the annular body grows in the axial direction. At this time, since the position of the lower surface of the upper mold (301) is lowered, the distance between the lower surface and the body of the molding roller (2) gradually decreases. Accordingly, the thickness of the annular portion on the base end side gradually decreases. Then, as shown in FIG. 11, when the upper mold (301) is driven down to the final lowering position, the distance between the lower surface of the upper mold (301) and the body of the molding roller (2) is minimized. Becomes the thickness of the base end of the rim main body (111). Therefore, the rim subject (1
The cross section of 11) is substantially triangular.

As shown in FIG. 12, the body of the molding roller (2) has a cylindrical shape (2) below the frustoconical shape (23).
4) may be a continuous shape. In this case, the upper mold
When the lower surface of (301) coincides with the column or disk,
The thickness of the rim main body (111) formed by the upper mold (301) and the forming roller (2) becomes constant. Accordingly, the rim main body (111) is formed such that the thickness is constant in a certain range from the disk portion (1) of the product and the thickness gradually increases on the tip side.

[Embodiment 3] In this embodiment, as shown in FIG. 16, a disc wheel (1) for manufacturing an automobile wheel in which the disc portion (1) is biased toward the outer rim (12) of the rim portion (11) is manufactured. Device. The cross-sectional shape of the rim (11) is
The side wall of the outer rim (12) on the side of (5) is bent at a substantially right angle, and the disk portion (1) is continuously provided near the side wall. The side wall on the inner rim (13) side of the drop center portion (15) has a tapered surface (1
51), and a tire seal portion (132) is formed outside thereof.

In the apparatus of this embodiment, an intermediate product before being formed into the shape shown in FIG. The upper die (301), lower die (302), and forming roller (2) of this rotary forging device are shown in FIG.
This is the configuration shown in FIG. On the upper surface of the lower mold (302),
A press-molded surface corresponding to the outer flat portion of (1) is formed.
The pressure-molded surface is provided with a concavo-convex pattern forming portion (16) that matches the concavo-convex pattern portion formed on the outer flat surface portion of the disk portion (1). The shape of the outer peripheral portion of the rim matches the shape of the inner peripheral surface of the outer rim (12) and the side surface of the rim flange (121) following the peripheral edge of the disk portion (1), and further, the rim is formed on the outer periphery thereof. An annular outer peripheral wall (32) substantially corresponding to the axial thickness of the flange (121) is formed.

The shape of the lower surface of the upper mold (301) is
The shape is matched to the shape of the inner flat part of (1). The shape of the body is substantially conical as a whole, with the diameter of the upper part being smaller, and the shape from the lower surface to the lower part of the body is an inner rim.
The shape up to the tapered surface (151) of (13) is matched. The diameter of the upper part of the body is set smaller than the tapered portion (33) corresponding to the tapered surface (151).

The forming roller (2) has a cylindrical portion in the upper half, and a lower portion thereof has an outer rim forming portion (25) conforming to the shape from the outer peripheral surface of the outer rim (12) to the inner surface of the rim flange (121). )
There is. In order to manufacture an automobile wheel using the above-described apparatus, the lower end surface of the forming roller (2) is positioned at a height position having a very small gap with the upper end portion of the outer peripheral wall (32). Fix the body of (2) at the position corresponding to the outer peripheral surface of the rim (11) of the product, and place the disc-shaped work (10) between the upper mold (301) and the lower mold (302). And forged by rotation.

Then, in the initial stage of the rotary forging, the outer rim (12) from the disk portion (1) to the rim flange (121) is formed into a final shape by the outer rim forming portion (25) and the lower mold (302). It is molded. In the subsequent steps, the upper mold (301) and lower mold (30
The material protruding from the boundary of (2) flows upward and flows to the inner rim (1).
An inner rim equivalent portion (130) corresponding to 3) is molded (FIG. 14).
reference).

When this inner rim equivalent part (130) is molded,
The material protruding from the boundary between the upper mold (301) and the lower mold (302) is formed into a cylindrical shape by the surface of the cylindrical portion of the molding roller (2) and the outer periphery of the lower end of the body of the upper mold (301). And work (10)
The cylinder extends in the axial direction as the rolling of the cylinder progresses. However, the tapered surface (1
51), the cylindrical portion is flared and formed into a tapered cylindrical portion as it grows in the axial direction.

In the state where the upper die (301) is lowered to the position of the bottom dead center (the state where the work (10) is most pressed down), as shown in FIG. The rim (12) is molded into the final shape. In the inner rim-equivalent portion (130) formed inside the disk portion (1), the drop center portion (15) and the tapered surface (151) are molded into a final shape, and the end following this is not formed. It is formed as it is in the tapered portion in the processing state.

In this embodiment, a disk portion is provided on the inner peripheral area of the upper rim (12) corresponding to the outer rim (12).
An uneven pattern forming part (16) corresponding to the uneven pattern part formed on the outer flat part of (1) is provided. And, in the molding completed state, the uneven pattern portion is also finished to the final shape, but when the uneven pattern portion is molded, the outer peripheral portion of the subsequent rim portion is restrained by the outer peripheral wall (32). The uneven pattern portion is accurately molded, and an incompletely molded portion does not occur.

As shown in FIG. 15, the front end side of the portion (130) corresponding to the inner rim of the semi-finished wheel formed as described above is subjected to spinning to seal the tire seal portion (13) of the inner rim (13).
When molded into 2), the inner rim (13) is molded into the final shape and the automobile wheel is completed. In this embodiment, when the work (10) is pressed down to the final thickness, the protrusion length and the thickness of the inner rim-equivalent portion (130) are different from the cross-section of the final shape of the inner rim (13). It goes without saying that the value is set to a value corresponding to the length. In this embodiment, the thickness of the inner rim equivalent portion (130) is set to be larger than the thickness of the inner rim (13), and the inner rim (13) is used during the spinning for the finish molding. May be molded so as to correspond to the thickness of the metal. [Others] Aluminum or an alloy thereof, a magnesium alloy, or the like is used as a material of the work (10), and the above-described rotary forging steps are performed by hot working.

In the above embodiment, the apparatus for molding the rim portion while maintaining the molding roller (2) in an upright posture and fixing it at a fixed position has been described. However, as shown in FIG. 2) is provided with a driving device (6) for moving the lower die (302) in a radial direction and a direction parallel to the rotation axis while maintaining the upright posture. The thickness of the rim can be arbitrarily changed by the control. In the case of this embodiment, if the outer peripheral surface of the forming roll (2) is set to a shape having a trapezoidal portion as shown in FIG.

In the above embodiment, the disk-shaped work (10)
A rim-equipped disk is formed from the disk (10), which is formed by forming a disk portion having an uneven shape as shown in FIG. 18 and an outer rim portion subsequent to the disk portion by ordinary forging or the like. It may be. In this case, the work (10) is set on the lower mold (302) in a state where the edge corresponding to the outer rim is fitted into the annular groove (31) with a little margin. When the upper mold (301) and the lower mold (302) are operated, the outer rim (1) shown in FIG.
2) and the inner rim equivalent portion (130) are formed. In this case, since the roughly formed work (10) is formed, the formability in the rotary forging process is improved, and immediately after the start of forming. As a result, the outer periphery is constrained, thereby improving the effect of preventing the disk from cracking.

Further, in the above embodiment, the case where the annular groove (31) is located below the lower surface of the disk portion (1) has been described as an example. However, depending on the product shape, the bottom of the annular groove (31) may be used. May be configured to match the lower surface of the disk unit (1), or may be configured to be located above the lower surface of the disk unit (1).

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first step of a conventional example.

FIG. 2 is an explanatory view of a second step of the conventional example.

FIG. 3 is an explanatory view of molding a shape in which a disk portion (1) is biased with respect to a rim portion (11) by a conventional device.

FIG. 4 is an explanatory view of a relationship between a pressing region (101) and a forming roller (2) in this case.

FIG. 5 is an explanatory view of an apparatus according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of an intermediate step in the case of molding using the apparatus of the first embodiment.

FIG. 7 is an explanatory view of a completed molding state.

FIG. 8 is a sectional view of a disk with a rim molded according to the first embodiment.

FIG. 9 is a sectional view of a main part of an apparatus according to a second embodiment.

FIG. 10 is an explanatory view of an intermediate step of molding according to this embodiment.

FIG. 11 is an explanatory view of a completed molding state.

FIG. 12 is an explanatory view of a modification of the second embodiment.

FIG. 13 is an explanatory view of an apparatus according to a third embodiment.

FIG. 14 is an explanatory view of an intermediate step of molding according to this embodiment.

FIG. 15 is an explanatory view of a spinning process.

FIG. 16 is an explanatory view of a vehicle wheel manufactured according to this embodiment.

FIG. 17 is an explanatory diagram for controlling the position of the forming roll (2) in the vertical and horizontal directions.

FIG. 18 shows that a work (10) roughly formed by normal forging is put into a lower mold (30).
Explanatory drawing of the state set to 2)

FIG. 19 is an explanatory view of a state in which the molding is completed.

[Explanation of symbols]

 (301) ・ ・ Upper die (302) ・ ・ Lower die (10) ・ ・ ・ Work (11) ・ ・ ・ Rim (31) ・ ・ ・ Ring groove (2) ・ ・ ・ Forming roller (1) ・ ・・ Disk part

Claims (6)

(57) [Claims] 1. A substantially conical lower surface of an upper mold (301) and a lower mold (3).
02), and the axis of the upper mold (301) is inclined such that one of the generatrix lines of the substantially conical lower surface of the upper mold (301) is substantially horizontal. Work (10) is interposed between the lower surface of (301) and the upper surface of lower mold (302),
The upper die (301) and the lower die (302) are opposed to each other while rotating the upper die (301) and the lower die (302) synchronously, and the work (10)
In a rotary forging device in which a material protruding from the reduced area is finished to a rim portion (11) by a molding roller and the upper die (301) and the lower die (302), the axis of the rim portion (11) The annular groove (31) having a cross-sectional shape that matches the cross-sectional shape of the end closer to the disk portion (1) of the ends in the direction
Formed on the outer periphery of the disk molding surface on the upper surface of the annular groove (3
A rotary forging device in which the forming roller (2) is rotatably supported by contacting or approaching the upper end edge of the outer peripheral wall (32) of (1). 2. The molding roller (2) is provided with a truncated conical portion having a body diameter decreasing upward, and the truncated conical portion is defined as a boundary between an upper die (301) and a lower die (302). The rotary forging device according to claim 1, wherein the rotary forging device is located at an outer peripheral portion of the rotary forging device. 3. An end of the rim portion (11) in the axial direction, which is closer to the disk portion (1), is used as a rim flange (121) of an outer rim (12) of an automobile wheel. The shape from the upper surface of (302) to the torso is
From the outer flat part of (1) to the inner peripheral surface of the outer rim (12) and the shape of the side surface of the rim flange (121) following it,
01) to the lower part of the body
The shape of the cross section of the annular groove (31) from the inner flat surface of (1) to the shape of the inner peripheral surface of the inner rim (13) near the disk portion (1) is adjusted to the rim flange of the outer rim (12). (121), and the lower part of the body of the forming roller (2) has an outer rim forming part (outer rim shape () that fits the outer peripheral surface of the outer rim (12) and the inner surface of the rim flange (121) following it. 25. The rotary forging device according to claim 1, wherein the rotary forging device comprises: 4. The rotary forging apparatus according to claim 3, wherein the forming roller is movable in a radial direction of the lower mold and in a direction parallel to the rotation axis while maintaining the upright posture. 5. A method for manufacturing an automobile wheel in which a disk portion (1) is biased toward an outer rim (12) side, the method comprising:
1) and the upper surface of the lower die (302) is opposed to the upper die (302), and the upper die (301) is arranged such that one of the generatrix of the lower conical lower surface is substantially horizontal. (301), the upper surface of the lower mold (302) is moved from the outer flat surface of the disc portion (1) of the automobile wheel and the peripheral edge of the disc portion (1) to the inner peripheral surface of the outer rim (12). And the following rim flange (1
21), and an annular outer peripheral wall (32) substantially corresponding to the axial thickness of the rim flange (121) is formed on the outer periphery thereof, and the outer peripheral wall is in contact with the upper end edge of the outer peripheral wall. Alternatively, the molding roller (2) is rotatably supported by approaching, and the lower part of the body of the molding roller (2) fits the outer peripheral surface of the outer rim (12) and the inner peripheral surface of the rim flange (121) following the outer rim (12). Using a rotary forging device with an outer rim molding part (25) with an outer peripheral surface shape, Interposing a workpiece (10) between the lower surface of the upper die (301) and the upper surface of the lower die (302); The upper die (301) and the lower die (302) are rotated and forged by rotating the workpiece (10) downward by rotating them synchronously while rotating the work (10). 302)
The outer rim (12) of the rim (11) is molded by
(2) forming a cylindrical inner rim-equivalent portion (130) for molding the inner rim (13) by the lower portion of the upper die (301); Forming the inner rim equivalent portion (131) into a cross section of the inner rim by roll forming. 6. The method for manufacturing an automobile wheel according to claim 5, wherein a concave / convex pattern forming portion corresponding to the concave / convex pattern portion of the disk portion (1) is formed in a predetermined range from the center of the upper surface of the lower mold (302).