JP2711524B2 - Manufacturing method of disk with rim - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a disk with a rim, and more particularly to a method of manufacturing a disk with a rim such as an automobile wheel by rotary forging from a material having high plastic workability such as an aluminum alloy. .

[0002]

2. Description of the Related Art A rotary forging method for molding an automobile wheel is disclosed in Japanese Patent Application No. 4-307347. As shown in FIGS. 1 to 3, the rotary forging device used for this includes a lower mold (3 a) having a vertical rotation axis and a slightly higher rotation axis above the lower mold (3 a). An upper mold (3c) that is inclined and a first mold located beside the boundary between these molds.
And a forming roller device (4) in which a forming roller (4a) and a second forming roller (4b) are arranged.

The upper end surface of the one lower mold (3a) is a first pressing end surface (311) having a shape conforming to the outer surface of the disk portion (1), and is followed by the lower mold (3a). The outer peripheral surface of the body has a shape that matches the inner peripheral surface and the outer peripheral surface of the outer rim (2a). The lower end surface of the other upper mold (3c) is a conical second pressure end surface (312) having a large apex angle, and the inclination angle of the rotation axis of the upper mold (3c) is:
(180 ° -the apex angle) / 2. One generatrix of the second pressure end surface (312) is substantially parallel to the first pressure end surface (311), and a disc portion (1) is provided between the generatrix and the first pressure end surface (311). Is a molding gap (300) for molding. The shape of the bus bar and the bus bar of the body following the outside of the bus bar is the shape of the disc (1).
And the inner peripheral surface of the inner rim (2b).

At the time of processing, a workpiece (10) having a shape in which an annular rim-equivalent portion (12) is raised around the periphery of a disk-shaped disk-equivalent portion (11) is provided with an upper die (3c) and a lower die. (3a), the rim equivalent part (12)
It is externally fitted to the upper mold (3c) (the state of FIG. 1). Thereafter, when the upper mold (3c) and the lower mold (3a) are opposed to each other in a synchronous rotation state, the molding gap (300) is formed.
As a result, the disk-equivalent portion (11) is locally pressurized. As a result, the disk equivalent portion is pressed down and flattened, and finally, the disk portion (1) is molded (the state of FIG. 3).

On the other hand, in the rolling step,
The first molding roller (4a) is pressed against the rim-equivalent portion (12). As a result, the rim-equivalent portion (12) and the material projecting from the molding gap (300) due to the pressing down are
It is spread between the body of the upper mold (3c) and the lower mold (3a) and molded into the drop center part (D) of the rim part (2) (the state of FIG. 2). Thereafter, as shown in FIG. 3, another rim cross section is finished by the second molding roller (4b). As described above, the step of molding the workpiece (10) into a product is performed by the upper mold (3c) and the lower mold (3).
This is performed while holding the workpiece (10) in a). Therefore, productivity is good.

[0006]

However, this conventional method has a problem that the disk portion (1) is formed in a conical shape. In this conventional method, as shown in FIG. 4, one part of a second pressure end face (312) having a conical shape with respect to a disk equivalent part (11) supported on a substantially flat first pressure end face (311). The part is pressurized. Accordingly, the amount of elongation in the direction of rotation of the mold of the area under pressure (101) pressed by the second pressure end surface (312) differs between the upper layer and the lower layer of the area under pressure (101). The amount of elongation is large.

Therefore, when the thickness of the disk-equivalent portion (11) is large at the initial stage of the rolling, the disk-equivalent portion (11) is maintained in a disk shape entirely by its own rigidity. Progresses and the wall thickness decreases, the difference in the amount of elongation causes the disc equivalent portion (1
The circumferential section of 1) is bent upward. Also, since the pressure-receiving area (101) has a fan shape that extends from the center to the peripheral edge of the disk-equivalent portion (11), the difference in the amount of elongation also increases toward the peripheral edge. As a result, the disk-equivalent portion (11) as a whole is
And a conical shape as shown by a two-dot chain line in FIG. Therefore, with this conventional method, the disk portion (1) cannot be formed into a flat plate shape.

A first aspect of the present invention is a method for manufacturing a rim-mounted disk from a material having high plastic workability, such as an aluminum alloy, by rotary forging, wherein a first pressing end surface (311) having a substantially horizontal upper end surface. And the lower mold (3
a), the lower end surface of which is a substantially conical second pressing end surface (312) facing the first pressing end surface (311), and whose rotation axis is inclined with respect to that of the lower mold (3a). Molding for molding the disk portion (1) formed by a mold (3c) and one bus of the first pressure end surface (311) and the second pressure end surface (312) substantially parallel thereto. A rotary forging device including a gap (300) and a molding roller device (4) disposed outside the molding gap (300) is used, and the first and second pressure end faces (311) ( 31
2) After the workpiece (10) is interposed between them, the upper mold (3c) and the lower mold (3a) are opposed to each other in a synchronously rotating state, so that the workpiece (10) is The disk portion (1) is molded by being pressed down by the molding gap (300), and the material of the workpiece (10) projecting outward from the molding gap (300) is removed from the molding roller device (4). ), A method of manufacturing a disk with a rim which is formed into a rim portion (2) by molding the disk portion (1) into a flat shape.

[0009]

Means for Solving the Problems [Invention of claim 1] The invention of claim 1 is based on "an upper mold (3c) and a lower mold (3c).
A pressing means (30) for pressing the outer peripheral portion of the workpiece (10) protruding from the boundary of (a) downward is provided, and in the step of lowering the workpiece (10), the die rotating direction is reduced. The outer peripheral portion of the portion of the material to be processed (10) other than the region under the pressure is the second pressing end surface (3) of the molding gap (300).
12) The reduction proceeds while being pressed by the pressurizing means (30) at a position substantially coincident with the height of the generatrix.

First and second pressure end faces (311) (312)
The workpiece (10) interposed between the upper mold (3c)
When the lower mold (3a) is opposed to and approached in a synchronous rotation state, the lower mold (3a) is pressed down by the molding gap (300) to be flattened. When the reduction proceeds and the material (10) becomes thinner, the material (10) tends to curve upward.

However, the reduction proceeds while the outer peripheral portion of the workpiece (10) protruding from the boundary of the mold is pressed downward by the pressing means (30). The pressing position is an outer peripheral portion of a portion other than the region under the pressure of the workpiece (10) in the mold rotation direction, and the second pressing end surface (312) of the molding gap (300). At the position substantially coincident with the height of the bus bar of the workpiece (1).
The upward bending of 0) is prevented.

[Invention of Claim 2] The invention of Claim 2 is the invention of Claim 1 described above.
"The pressurizing means (30) is a cylindrical mold (3) which is fitted onto the upper mold (3c) and whose axis of rotation coincides with that of the lower mold (3a).
b), and the lower end of the cylindrical mold (3b) constitutes the molding gap (300).
Are supported in a relationship substantially corresponding to the height of the bus. "

[0013] A cylindrical mold (3) externally fitted to the upper mold (3c).
b) is supported so as to substantially coincide with the height of the generatrix of the second pressing end face (312) constituting the molding gap (300). The outer peripheral portion of the workpiece (10) projecting from the boundary between the mold (3c) and the lower mold (3a) is pressed downward over the entire circumference by the cylindrical mold (3b). The portion of the rim portion (2) above the disk portion (1) is the cylindrical mold (3b).
And the molding roller device (4).

[0014]

As described above, according to the first aspect of the present invention, the upward bending when the material to be processed (10) is pressed down to a small thickness is prevented. (1) is molded into a flat plate shape. According to the second aspect of the present invention, since the outer peripheral portion of the workpiece (10) is constantly pressed over the entire circumference by the cylindrical mold (3b), the upper part of the workpiece (10) is pressed. Is more reliably prevented. Therefore, the disk portion (1) is more accurately formed into a flat plate shape.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIGS. 5 to 7, the present invention is applied to the manufacture of an automobile wheel.

* Each part of the apparatus * Each part of the rotary forging apparatus used for the production will be described below. The lower die (3a) is a first pressing end surface (311) having a shape whose upper end surface matches the disk outer surface (1a) of the disk portion (1) of the vehicle wheel. The outer peripheral surface of the body portion continuing to (311) is a first rim molding surface (32) having a shape corresponding to the inner peripheral surface of the outer rim (2a) and the outer surface following it. This lower mold (3
In a), the rotation axis is substantially vertical, and is driven to rotate at a fixed position by a driving device (not shown) disposed below the rotation axis.

Above the lower mold (3a), there is disposed an upper mold (3c) having a shape of a truncated cone as a whole. The upper mold (3c) has a substantially conical second pressure end face (31) whose lower end face faces the first pressure end face (311).
2). The rotation axis of the upper mold (3c) is inclined by a certain angle θ with respect to that of the lower mold (3a). The inclination angle of the generatrix of the second pressing end surface (312) (the angle with respect to the plane perpendicular to the rotation axis of the upper mold (3c)) matches the inclination angle θ of the rotation axis. Thereby, one generatrix of the second pressure end surface (312) (the left line in the figure)
Is substantially parallel to the rotation surface of the first pressure end surface (311). The space between the one bus and the first pressure end surface (311) is the molding gap (300) according to claim 1 described above.

In the upper mold (3c), a support shaft protruding from an upper end surface thereof is held by a support (5) so as to be rotatable, and the upper mold (3c) is rotatable. (5)
It is rotationally driven by a driving device (51) attached to the. The driving device (51) has a configuration in which the upper mold (3c) can be synchronously rotated in the same direction as the lower mold (3a).
The support (5) is connected to the lower end of an output shaft (52) of a hydraulic jack (not shown) mounted on the main body frame, and is capable of moving back and forth in the axial direction of the lower mold (3a).

The upper mold (3c) has a cylindrical mold (3b) whose axis of rotation coincides with that of the lower mold (3a).
Fits outside. This cylindrical mold (3b) is provided with the upper mold (3).
c) is circumscribed at the lower end of the body on the molding gap (300) side, and is supported at a height position where the lower end of the body and the lower end of the cylindrical mold (3b) substantially coincide with each other. I have. The outer peripheral surface of the cylindrical mold (3b) is a second rim molding surface (34) having a shape adapted to the inner peripheral surface of the inner rim (2b) and the outer surface following the inner peripheral surface.

The upper end of the cylindrical mold (3b) is supported by a supporting annular body (6) in a paired state.
The annular support (6) has a configuration in which a flange (62) protrudes from the lower end of a cylindrical portion (63) hanging down from the inner peripheral portion to the outer peripheral side. An annular projection (36) projecting inward from the upper end of the mold (3b) is held. A bearing for receiving loads in the radial direction and the axial direction is interposed between the support annular member (6) and the annular convex portion (36). With such a configuration, the above-mentioned surrounding pair state is realized. In addition, output shafts (61) and (61) of a plurality of hydraulic jacks (not shown) similar to the above are connected to the support annular body (6), and the output shafts (61) and (61) are moved forward and backward. The cylindrical mold (3
b) is driven up and down in synchronization with the upper mold (3c).

Further, a first molding roller (4a) and a second molding roller (4) are provided outside the molding gap (300).
A forming roller device (4) consisting of b) is arranged. The body of one first forming roller (4a) conforms to the shape of the outer peripheral surface from the drop center part (D) to the end of the outer rim (2a) in the rim part (2), and the other part of the second forming roller The body of the roller (4b) conforms to the shape of the annular riser (22) and the tire bead (23) of the inner rim (2b).

* Regarding Practical Forming * Next, a description will be given below of the practical use of the above-described rotary forging apparatus to manufacture a vehicle wheel. The material to be processed (10) used in this production has a shape in which a cylindrical rim-equivalent part (12) or a cylindrical rim-equivalent part (12) is raised on the outer periphery of a disk-shaped disk equivalent part (11).

The material to be processed (10) is a lower mold (3)
a) Set on top. Next, when the upper mold (3c) and the cylindrical mold (3b) are driven downward, the rim-equivalent portion (12) is externally fitted to the cylindrical mold (3b) and the disk-equivalent portion ( 11) is the first and second pressure end surfaces (311)
(312) It will be in the state pinched between. Further, the first forming roller (4a) is moved to the rim-equivalent portion (12) side, and the maximum diameter portion (41) is brought into a state in which the maximum diameter portion (41) coincides with the rim-equivalent portion (12) (the state of FIG. 5).

Thereafter, the upper mold (3c) and the cylindrical mold (3c)
The lower mold (3a) and the upper mold (3c) are driven to rotate synchronously while b) is further pressed downward from the above-described sandwiched state. As a result, the disk equivalent part (11) is pressed down by the molding gap part (300) and flattened. Further, by the pressurization, the material of the disk equivalent part (11) is reduced
The outer surface (1a) of the disc is molded by filling the irregular surface of the first pressure end surface (311) of (a). That is, the disk part (1) is molded (the state of FIG. 7).

In the rolling step, when the disk-equivalent part (11) becomes thin, the disk-equivalent part (1) becomes thinner.
1) tends to curve upward. However, the cylindrical mold (3b) has a disk equivalent part (1) formed by the upper mold (3c).
Since the pressure is moved downward in synchronism with the downward movement accompanying the rolling down of 1), the vicinity of the inner peripheral side of the rim-equivalent portion (12) is constantly downward over the entire circumference by the cylindrical mold (3b). Pressurized. Therefore, the upward bending is prevented.

In the cylindrical mold (3b) and the upper mold (3c), the one generatrix of the second pressing end face (312) is always higher than the lower end of the cylindrical mold (3b). The relationship of being located slightly below is maintained, so that the flow of the material to the outside due to the reduction of the upper mold (3c) is not hindered by the cylindrical mold (3b), and the cylindrical mold (3b) No excessive force acts on the lower end of the. The height of the lower end of the cylindrical mold (3b) may be the same as that of the bus bar.

Further, simultaneously with the step of forming the disk portion (1), the first forming roller (4a) is pushed into the rim-equivalent portion (12). Specifically, the first molding roller (4a) moves so that the largest diameter portion (41) moves on the dotted line in FIG. As a result, as shown in FIG.
2) is torn apart and the lower material is removed by the first forming roller (4).
a) and the first rim forming surface (32), the upper material is spread between the first forming roller (4a) and the second rim forming surface (34), and from the drop center portion (D). Outer rim (2
The range up to the tip of a) is finished. Thereafter, as shown in FIG. 7, the cross section on the inner rim (2b) side from the drop center portion (D) is finished by the second molding roller (4b). As described above, the automobile wheel is formed.

* Regarding Other Embodiments *. In the above embodiment, the processing of the rim portion (2) and the processing of the disk portion (1) are performed at the same time. However, the rim portion (2) may be molded after the disk portion (1) is molded. . In the above embodiment, the workpiece (10) in which the rim-equivalent portion (12) protrudes around the outer periphery of the disk-equivalent portion (11)
However, as shown in FIGS. 8 and 9, the first
A thick disk-shaped or columnar workpiece (10) set to have a smaller diameter than the second pressing end surfaces (311) and (312) may be used. In this case, as in the above-described embodiment, the material to be processed (10) is pressed down and flattened, and when the material protrudes from the molding gap (300), the outer peripheral portion thereof is formed into a cylindrical mold (3b). ). Therefore,
Even with the workpiece (10) having such a shape, the same bending prevention action as described above can be obtained. In any case, it goes without saying that the overall volume of the workpiece (10) is set slightly larger than the overall volume of the wheel in the final finished shape.

[0029] In the above embodiment, the rim portion (2)
Is molded by the first and second molding rollers (4a) and (4b), but the entire rim portion (2) may be molded only by the first molding roller (4a). In this case, as the first molding roller (4a), a roller in which the shape of the generatrix of the body matches the entire generatrix of the outer peripheral surface of the rim (2) is used. . In the above embodiment, the inner rim (2b) is molded by the cylindrical mold (3b) and the outer rim (2a) is molded by the lower mold (3a), but these arrangements may be reversed. . The support mechanism and the like of each mold can be replaced with a known one other than the above. . In the above embodiment, the present invention is applied to the manufacture of an automobile wheel. However, it goes without saying that the present invention can be applied to other rim-attached disk products.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a rotary forging device for a vehicle wheel according to a conventional technique.

FIG. 2 is an explanatory diagram of the middle stage of the molding process.

FIG. 3 is an explanatory view at the time of completion of molding.

FIG. 4 is a cross-sectional view showing a state in which a disk equivalent part (11) is rolled down.

FIG. 5 is an explanatory view of a rotary forging device according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of the middle stage of the molding process.

FIG. 7 is an explanatory view at the time of completion of molding.

FIG. 8 is an explanatory diagram of another embodiment.

FIG. 9

[Explanation of symbols]

 (311) ··· First pressing end surface (3a) ··· Lower mold (312) ··· Second pressing end surface (3c) ··· Upper die (300) ··· Molding gap (4) ... forming roller device (10) ... material to be processed (1) ... disk part (2) ... rim part (30) ... pressing means

Claims (2)

(57) [Claims] 1. A method for manufacturing a disk with a rim by rotary forging from a material rich in plastic workability, such as an aluminum alloy, wherein a top end surface is a substantially horizontal first pressing end surface (311) and a rotation axis is substantially A lower mold (3a) which is vertical, and
An upper mold (3c) having a substantially conical second pressure end face (312) facing the pressure end face (311) and having a rotation axis inclined with respect to that of the lower mold (3a); The pressure end face (311) and the second pressure end face (31
2) A molding gap (300) formed by one of the bus bars for molding the disc (1), and a molding roller device (4) disposed outside the molding gap (300).
After the workpiece (10) is interposed between the first and second pressing end surfaces (311) and (312), the upper die (3c) and the lower die are used. The workpiece (10) is pressed down by the molding gap (300) by the mold (3a) being opposed and approached in a synchronously rotating state, whereby the disk part (1) is molded, and the molding gap ( A method of manufacturing a disk with a rim in which a material of a workpiece (10) protruding outward from (300) is spread by the molding roller device (4) and molded into a rim portion (2). (3c) and a pressurizing means (30) for pressurizing the outer peripheral portion of the workpiece (10) protruding from the boundary between the lower mold (3a) and the workpiece (10) are provided. In the rolling-down process, the workpiece (10 Is pressed by the pressing means (30) at a position substantially corresponding to the height of the generatrix of the second pressing end surface (312) of the molding gap (300). A method for manufacturing a disk with a rim in which the reduction proceeds. 2. The pressurizing means (30) is a cylindrical mold (3b) which is fitted onto the upper mold (3c) and whose rotation axis coincides with that of the lower mold (3a). The rim according to claim 1, wherein the mold (3b) is supported such that a lower end thereof substantially coincides with a height of a generatrix of a second pressing end surface (312) constituting a molding gap (300). Disc manufacturing method.