JP2819085B2 - 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 for manufacturing a disk with a rim having a cylindrical rim connected to the periphery of the disk, and a method for manufacturing a wheel for an automobile using the apparatus.

[0002]

2. Description of the Related Art As a rotary forging device for manufacturing a disk with a rim, there is a rotary forging device already proposed in Japanese Patent Application No. 5-281510. A rim (1) continuously connected to the periphery of the rim comprises a straight cylindrical first rim (11) projecting to one side and a similarly shaped second rim (12) projecting to the opposite side. Can be manufactured.

[0003] As shown in FIG.
The lower surface of the upper mold (301) and the upper surface of the lower mold (302) are opposed to each other, the lower surface of the upper mold (301) is formed in an umbrella shape, and the upper mold (301) is arranged such that one generatrix is substantially horizontal. The axis of (301) is inclined, and a cylindrical auxiliary mold (303) that is coaxial with the lower mold (302) is fitted to the upper mold (301). The outer body of the auxiliary mold (303) is provided with a rim forming surface corresponding to the inner surface of the second rim (12), and the outer body of the lower mold (302) is provided with a first rim. A rim forming surface is provided that matches the inner peripheral surface of the rim (11).

In this type, as shown in FIG.
01) and the upper surface of the lower mold (302) with a thick disk-shaped work (10) interposed between them, and while rotating these molds synchronously, the upper mold (301) and the auxiliary mold (303) ) Is lowered synchronously, the work (10) is pressed down by the rotary forging action of the upper mold (301) and the lower mold (302), and this work (10)
Starts to protrude annularly from the mold boundary. At this time, a cylindrical pressure roller (4), which coincides with the outer peripheral surface from the end of the first rim (11) to a part of the second rim (12), is located on the side of the mold boundary. Further, since the projecting material reaches the surface of the pressure roller (4) since it is located at a predetermined interval on the inclined side of the upper mold (301), as shown in FIG. And grows in each direction. The downwardly directed material is formed on the first rim (11) in conformity with the rim forming surface of the lower mold (302) and the forming cross section of the pressure roller (4). Extruded from the boundary between the lower part of the mold (303) and the pressure roller (4),
It grows along the rim forming surface of the auxiliary mold (303) and finally becomes the second rim (12) (the state of FIG. 3).

In the rotary forging device using the auxiliary die (303), the inner peripheral surface of the material grows in a state in which it coincides with the rim forming surface of the auxiliary die (303) over the entire circumference. (12) It is possible to eliminate the deterioration of the molding accuracy of the open end portion remote from the disk (2). However, in this device,
Since the auxiliary type (303) fits on the lower part of the body of (301),
The periphery of the disk (2) comes off the periphery (rotational forging area) of the upper die (301), and there is a problem that the shape of the periphery of the disk is not accurately formed. In order to solve this problem, the outer diameter of the lower part of the upper die (301) is made to substantially match that of the upper end of the lower die (302), and
Although it is conceivable to make the body part of the body extremely thin, in this case, the strength of the body part is insufficient, and it is not practical. [About the invention of claim 1]

[0006]

[Technical Problem] The present invention has been made in view of the above points, and has been made in consideration of the following problem.
02) and the upper die (3) so that one of the generatrixes on the substantially umbrella-shaped lower surface of the upper die (301) is substantially horizontal.
01), the upper die (301) is attached to the lower die (30
A cylindrical rotatable auxiliary mold (303) coaxial with 2) is externally fitted, and a work (10) is interposed between the lower surface of the upper mold (301) and the upper surface of the lower mold (302), The upper mold (301) and the lower mold (302)
The workpiece (10) is pressed down while the molds are opposed to each other while being rotated synchronously, and the material protruding from the reduced area is placed on the side of the mold boundary and on the inclined side of the upper mold (301). A rotary forging device that forms a rim (1) projecting up and down on the disc (2) by being separated vertically by the pressurized roller (4). disk
It is an object of the present invention to improve the molding accuracy of both peripheral portions of (2).

[0007]

[Technical Means] The technical means of the present invention taken to solve the above-mentioned problem is that the upper die (301) has a small-diameter trunk (321) above a lower trunk (311) continuous with the lower surface thereof. The auxiliary type (303) is fitted around the small diameter body (321) with a margin,
The bus on the pressing roller (4) side of the rim forming surface of the auxiliary mold (303) was continued on the extension of the bus on the pressing roller (4) side on the outer peripheral surface of the lower trunk (311). " .

[0008]

The above technical means of the present invention operates as follows. In this apparatus, a work (10) is interposed between the lower surface of an upper die (301) and the upper surface of a lower die (302), and the upper die (301) and the lower die (302) are rotated while being synchronously rotated. When the molds are brought close to each other, the work (10) is reduced by these rotary forging actions, and the outer peripheral portion of the work (10) starts to protrude from the mold boundary. After reaching the surface of the pressure roller (4), the projecting material is separated vertically and grows in each direction.

[0009] The upper material is a pressure roller (4) and an upper die (30).
It grows upward from the boundary with the lower part (311) of 1). At this time, the auxiliary die (30) is attached to the small-diameter trunk (321) of the upper die (301).
3) fits on the outside, the lower end of this auxiliary type (303) and the lower part of the torso (311)
Although a gap is formed between them, the auxiliary type (30
3) The generatrix on the pressure roller (4) side of the rim forming surface is
The material is transferred to the rim forming surface over the gap because the material is continuous with the extension of the generatrix on the pressure roller (4) side on the outer peripheral surface of (311). Thereafter, the material grows in a state where the inner peripheral surface of the raw material coincides with the rim forming surface over the entire circumference. Finally, the material that has grown up and down is formed on the rim (1).

In this case, the rim (1) at the time of completion of molding
The upper open end portion is in a state of being aligned with the rim forming surface over the entire circumference. Further, the substantially umbrella-shaped lower surface of the upper mold (301) comes into contact with the periphery of the disk (2).

[0011]

According to the present invention having the above configuration, the following specific effects are obtained. In this case, the upper open end of the rim (1)
Since it is in a state of being coincident with the rim forming surface of the auxiliary mold (303) over the entire circumference, the forming accuracy of the open end is improved.
In addition, since the lower surface of the upper die (301) comes into contact with the peripheral portion of the disk (2), the molding accuracy of the peripheral portion of the disk is improved. [Regarding the invention of claim 2] The invention of claim 2 is directed to the rotary forging device according to the invention of claim 1 described above.
(2) A rim-equipped disk in which the rim portion projecting upwards has a flared shape whose diameter increases toward the open end can be manufactured. Technical means for that purpose are as follows.
"The rim forming surface of the auxiliary mold (303) has a flare shape whose diameter increases upward."

In this apparatus, since the rim forming surface of the auxiliary mold (303) has a flared shape whose diameter increases upward, the rim forming surface extends upward from the boundary between the pressure roller (4) and the lower body part (311). The material grows along the rim forming surface in such a manner as to expand in diameter. Therefore, it is possible to manufacture a rim-attached disk in which the rim portion projecting above the disk (2) has a flared shape whose diameter increases toward the open end. [Invention of claim 3] The invention of claim 3 relates to a method of manufacturing an automobile wheel using the above-mentioned rotary forging apparatus, wherein "the bottom of the drop center of the rim (1) is provided on the periphery of the disk (2)". A method of manufacturing a vehicle wheel in which a wall portion is continuously provided, and a side wall portion on an inner rim side of the drop center has a flared shape whose diameter increases inward, wherein a substantially umbrella-shaped lower surface of an upper die (301) is provided. And the upper surface of the lower die (302) is opposed to the upper die (301), and the axis of the upper die (301) is inclined so that one of the generatrixes on the lower surface of the upper die (301) is substantially horizontal. The upper surface of the upper die (30) has the same shape as the outer flat surface of the disk (2) and the peripheral surface of the disk (2), the inner peripheral surface of the outer rim, and the side surface of the rim flange following the outer rim.
1) has a configuration in which a small-diameter trunk portion (321) is provided above a lower trunk portion (311) that is continuous with a substantially umbrella-shaped lower surface, and the small-diameter trunk portion (321) has a lower mold (302). A cylindrical rotatable auxiliary mold (303) that is coaxial with the outer mold is provided with a margin, and the outer peripheral body of this auxiliary mold (303) matches the inner peripheral surface of the side wall on the inner rim side of the drop center. In addition to providing a flared rim forming surface, the outer peripheral shape of the lower part (311) matches the inner peripheral surface of the bottom wall of the drop center, and the outer rim of the pressure roller (4) has a rim (1). A first molding portion (41) having a shape matching from the drop center bottom wall portion to the outer rim end portion on the outer peripheral surface of the first member;
. Interposing a workpiece (10) between the upper surface of the lower mold (302) and the lower surface of the upper mold (301); The lower mold (302) and the upper mold (301) are caused to face each other while being rotated synchronously, and the work (10) is pressed down. The upper material is separated into upper and lower parts by the pressing roller (4) and the lower mold (30
2), the upper material is extruded upward from the boundary between the pressure roller (4) and the lower part of the body (311), and the material is pushed along the rim forming surface of the auxiliary mold (303). Forming a flared inner rim-equivalent portion (121) by growing in a manner to increase the diameter of the inner rim. Finishing a predetermined range from the open end of the inner rim equivalent portion (121) into a bead sheet and a rim flange of the inner rim by roll forming ”.

According to this method, since the portions other than the bead seat and the rim flange of the inner rim in the vehicle wheel are formed by rotary forging, the productivity of the vehicle wheel is improved. [Invention of Claim 4] The invention of Claim 4 is the invention of Claim 3 in which the unevenness formed on the outer flat surface of the disk (2) can be accurately formed. There is a technical means for this: `` An annular wall (37) having a height corresponding to the thickness of the rim flange is provided on the outer peripheral side of the rim flange forming portion on the upper surface of the lower mold (302), The rim flange forming part is a concave part, and the pressure roller (4) is
The lower end face is disposed in contact with or close to the upper end of the annular wall (37). "

In this apparatus, the material protruding downward from the mold boundary portion is formed by the lower end surface of the pressure roller (4) and the annular wall (3).
7) The outer rim is finished according to the cross-sectional shape surrounded by. Thereafter, the latter half of the disk (2) and the inner rim is formed while the outer periphery of the outer rim is restrained. Therefore, since the concave and convex portions formed on the outer flat surface of the disk (2) are formed in the outer peripheral constrained state, the concave and convex shape is accurately formed, and an incompletely formed portion does not occur. [Regarding the invention of claim 5] The invention of claim 5 is the invention of claim 3 or 4, wherein the productivity of the vehicle wheel is further improved. The technical means of the present invention is to use an annular bent cross section that is continuous with the upper end of the flare-shaped rim forming surface of the auxiliary mold (303) and that matches the bead seat of the inner rim and the inner peripheral surface of the rim flange.
(35) was established. "

In this apparatus, while the semi-finished product on which the inner rim equivalent portion (121) is formed is mounted on the rotary forging apparatus, a predetermined range from the upper end of the inner rim equivalent portion (121) is:
Since the bead sheet and the rim flange of the inner rim are finished by roll forming such as spinning, the productivity of the wheel is further improved. [Regarding the invention of claim 6] The invention of claim 6 is to improve the productivity of the wheel further in the invention of claim 5 described above, and the technical means therefor is as follows. On the upper side of the first forming portion (41) of the pressure roller (4), a second forming portion (42) whose body shape matches the outer peripheral surface of the bead seat and the rim flange is provided. After the formation of the rim-equivalent portion (121), the pressure roller (4) is moved upward to move a predetermined range from the upper end of the inner rim-equivalent portion (121) to the second molding portion of the pressure roller (4). (42) and auxiliary type (30
The bead sheet and the rim flange are finished by roll forming with the bent cross section (35) of 3). "

In this apparatus, after forming the inner rim equivalent part (121) by rotary forging, the pressing roller (4) is moved upward to move a predetermined range from the upper end of the inner rim equivalent part (121) to: The second forming part (42) of the pressure roller (4) and the auxiliary mold (30)
Roll forming with the bent cross section (35) of 3) finishes the bead sheet and rim flange of the inner rim. According to this method, the step of forming the inner rim-equivalent portion (121) and the step of roll forming the same can be performed continuously without switching the pressure roller (4), so that productivity is further improved. .

[0017]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] In this embodiment 1, as shown in FIG. 7, a rim (1) continuously provided on the outer periphery of a disk (2) projects to one side and has a flange (11a) at the tip. An embodiment of a rotary forging device for producing a rimmed disc of the type comprising a straight, cylindrical first rim (11) and a similarly shaped second rim (12) projecting on the opposite side. It is.

[Configuration of Each Part of Apparatus] Lower Die (302)
As shown in FIG. 4, is formed in a substantially cylindrical shape, and its rotation axis is upright with respect to the horizontal plane. The upper surface (31) is a horizontal surface, and the body following the upper surface (31) has the same shape as the inner peripheral surface of the first rim (11) and the end surface of the flange (11a) following it. A first rim forming surface (32) having a predetermined shape is provided. The lower mold (302) is connected to a rotating shaft (52) of a driving device (not shown) disposed below the lower mold (302) and is driven to rotate at a fixed position.

The upper die (301) has its lower surface (33) formed as an umbrella-shaped surface having a large apex angle, and its body has a truncated conical shape having a smaller diameter at its upper end than at its lower end as a whole. A small diameter body (32) above a body lower part (311) continuous with the lower surface (33).
1) is connected continuously. And this upper mold
The axis of (301) is set to be inclined about 2 to 5 degrees with respect to the axis of the lower mold (302). In this inclined state,
The lower surface (3) so that one of the generatrix of the lower surface (33) is substantially horizontal.
The shape of 3) is set. Furthermore, the upper die (30) is located on the side of the boundary between the upper die (301) and the lower die (302).
A pressure roller (4) described later is arranged on the inclined side of 1). The upper die (301) has a support shaft protruding from the upper end surface thereof rotatably supported by a support (5). The support (5) is connected to a hydraulic jack ( (Not shown), and is connected to the lower end of an output shaft (51) which is suspended from the lower die (302).

Then, the small-diameter trunk portion (321) of the upper die (301) is formed.
A cylindrical auxiliary mold (303) whose upper end is held in a paired state by a support annular body (6) to be described later is externally fitted with a margin. The rotation axis of the auxiliary mold (303) coincides with that of the lower mold (302), and the outer peripheral surface of the auxiliary mold (303) has the same diameter as the inner diameter of the second rim (12) from the upper end to the lower end. The second rim forming surface (34) is provided. The bus bar on the pressure roller (4) side on the second rim forming surface (34) is the same as the bus bar on the pressure roller (4) side on the outer peripheral surface of the lower body (311) of the upper die (301). The structure is continuous on the line. Further, in order to realize the above-mentioned pairing, an annular convex portion (36) is protruded from the inner peripheral surface of the upper end portion of the auxiliary mold (303), and the other supporting annular member (6) is provided from the central lower surface thereof. A flange (62) is provided on the outer peripheral side of the lower end of the protruded cylindrical portion (63), and the annular convex portion (36) is provided between the cylindrical portion (63) and the flange (62). It is an aspect fitted in. Furthermore, bearings that receive an axial load are interposed between the upper surface of the auxiliary mold (303) and the support ring (6), and between the lower surface of the annular protrusion (36) and the flange (62). And the annular projection (3
A bearing for receiving a load in the circumferential direction is interposed between the inner peripheral surface of 6) and the cylindrical portion (63). In addition, output shafts (61) (61) hanging from a plurality of hydraulic jacks (not shown) similar to the above are connected to the support annular body (6), whereby the auxiliary type (303) is It can be driven up and down in the axial direction of the lower mold (302).

Further, the pressure roller (4) is rotatably supported by a vertical shaft and is supported so as to be movable in the radial direction of the lower mold (302). The outer peripheral body is formed in a substantially cylindrical shape, and is made to coincide with the outer peripheral surface in the range from the end of the flange (11a) of the first rim (11) to a part of the second rim (12). I have. [Regarding Practical Forming] When manufacturing the rim-attached disk shown in FIG. 7 using the above apparatus, first, as shown in FIG. 4, the lower surface of the upper die (301) and the upper surface of the lower die (302) The work (10) is interposed between them. At this time, the pressing roller (4) is moved toward these molds so that the body of the pressing roller (4) has the first rim (11) and the straight cylindrical portion (12) of the final shape.
a) Fix at the position corresponding to the outer peripheral surface of. The work (10) used in this embodiment is in the form of a thick disk, and its volume is set to be slightly larger than the volume of the rim-mounted disk in the final molded state.

In this state, the upper mold (301) and the auxiliary mold (303) are lowered synchronously while rotating the lower mold (302).
Then, the upper mold (301) rotates synchronously with the lower mold (302) in the same direction via the work (10), and the work () is performed by the rotary forging action of the lower mold (302) and the upper mold (301). 10) is reduced and flattened. Then, the outer peripheral portion gradually protrudes from the boundary between these molds to the outer peripheral side. After the protruding material reaches the surface of the pressing roller (4), it is vertically moved by the pressing roller (4). The lower material is the pressure roller (4) and the lower mold (302).
The first rim (11) is extended to extend between the rim forming surface (32) and the final rim (11) in conformity with the forming cross section therebetween. Further, the upper material is pushed upward from the boundary between the lower part of the body (311) and the pressure roller (4) (the state of FIG. 5).
At this time, a small gap is formed between the lower end of the auxiliary mold (303) and the lower part of the trunk (311),
Since the generatrix on the pressure roller (4) side on the rim forming surface (34) is continuous with the generatrix on the pressure roller (4) side on the outer peripheral surface of the lower trunk (311), The raw material smoothly moves over the gap to the second rim forming surface (34). At this point, the auxiliary type (30
3) Due to the frictional resistance between the inner peripheral surface of the material and
(303) starts to rotate in the same direction as the material. Then, the material grows upward along the second rim forming surface (34) and
The rim (12) is finished (the state of FIG. 6). [Embodiment 2] In Embodiment 2, as shown in FIG. 10, the second rim (12) has a flared shape in which the diameter increases toward the open end. This is an embodiment of a forging device, and has basically the same configuration as the rotary forging device of the first embodiment. In addition, the second
The end of the rim (12) on the disk (2) side is a straight cylindrical portion (12a) having the same diameter as the first rim (11).

In this apparatus, as shown in FIG.
The second rim forming surface (34) of (303) is formed in a flared shape whose diameter increases upward, and is configured to match the inner peripheral surface of the second rim (12). Also, the generatrix of the outer peripheral surface of the lower part of the body (311) on the side of the pressure roller (4) coincides with the inner peripheral surface of the straight cylindrical portion (12a). And the second rim forming surface
(34), the lower end of the generating line on the side of the pressure roller (4) and the lower part of the trunk (3
11) and the extension of the generatrix on the side of the pressure roller (4) on the outer peripheral surface is continuous. Furthermore, a pressure roller (4)
Has the outer peripheral body portion coincident with the outer peripheral surface in the range from the end of the flange (11a) of the first rim (11) to the straight cylindrical portion (12a) of the second rim (12).

When the work (10) is lowered by using this device in the same manner as in the first embodiment, the protruding material from the die boundary is separated vertically by the pressing roller (4). As shown, the lower material is a pressure roller (4) and a lower mold (302).
And the upper material extends from the boundary between the lower body part (311) and the pressure roller (4).
It is pushed upward. Then, the upper material is transferred to the second rim forming surface (34) over the gap formed between the lower end of the auxiliary mold (303) and the lower part of the trunk (311). The second rim 12 is grown in a state where the diameter is enlarged (FIG. 9). [Embodiment 3] This embodiment 3 is a rotary forging apparatus for manufacturing the automobile wheel shown in FIG.
As shown in FIG. 14, this automobile wheel has a disk (2) having an uneven surface formed on an outer flat surface and a bottom wall portion of a drop center (110) provided at a position eccentric to the outside of a rim (1). The shape is connected to the outer end of the.

In the case of this apparatus, as shown in FIGS. 11 to 13, the upper surface (31) of the lower mold (302) is connected to the outer flat portion of the disk (2) and the outer rim ( 114) and the shape of the side surface of the rim flange (14) following it, and the molded portion of the rim flange (14) is a concave portion with an annular wall (37) formed on the outer periphery. ing. or,
At the upper end of the second rim forming surface (34) of the auxiliary mold (303), an annular bent section (35) is continuously provided. And upper mold (301)
The shape from the lower part of the torso (311) to the bent cross section (35) of the auxiliary type (303) matches the shape of the inner peripheral surface of the inner rim (113) of the rim (1) and the shape of the rim flange (13). ing.

Further, the pressure roller (4) has a lower part of its body,
A first molded part (41) having a shape corresponding to the outer peripheral surface of the outer rim (114) and the inner surface of the rim flange (14) is provided. Rim (1
13) A second molded portion (42) having a cylindrical shape conforming to the outer peripheral surface of the bead sheet. The shape of the second molded portion (42) also matches the outer peripheral surface of the bottom wall of the drop center (110).

When the rim (1) is formed by using this apparatus, as shown in FIG.
The upper end of the annular wall (37) of the (302) is very close to the upper end of the annular wall (37), and its outer trunk is located at the drop center (11).
0) is maintained at a position corresponding to the outer peripheral surface in the range from the bottom wall portion to the outer rim (114). In this state, when the work (10) is lowered in the same manner as in the first embodiment, after the material projects annularly from the mold boundary and reaches the surface of the pressure roller (4), the material is separated vertically. The downwardly directed material corresponds to the outer rim including the rim flange (14) in conformity with the cross-sectional shape surrounded by the first forming portion (41) of the pressure roller (4) and the annular wall (37).
(114) (state of FIG. 12). At this time, since the front end of the material is closed by the annular wall (37) and the lower end surface of the pressure roller (4), the flow of the material downward is blocked at this point, and the material flows only upward. It will be. On the other hand, the material going upward is the lower part of the body (311) and the pressure roller.
The second rim forming surface (34) is pushed upward in the axial direction from the boundary with the upper part of (4), and exceeds the gap formed between the lower end of the auxiliary mold (303) and the lower part of the trunk (311). After switching to
Along with this, it grows in such a manner that the diameter is enlarged, and is formed into an inner rim-equivalent portion (121) indicated by a broken line in FIG.

Thereafter, while the pressing down of the upper mold (301) is stopped, the pressing roller (4) is moved upward (the state shown by the two-dot chain line in the figure), and the second molding portion (42) is formed. ) And auxiliary type (303)
When a predetermined range from the upper end of the inner rim-equivalent portion (121) is roll-formed with the bent cross section (35) of the inner rim (113), this range becomes a rim flange (13) and a bead sheet following it, and the inner rim (113) Is finished. This completes the molding of the entire rim (1).

In this case, since the latter half of the disk (2) is formed with the outer periphery of the outer rim constrained, the irregularities on the outer flat surface of the disk (2) are accurately formed.
Further, since the step of forming the inner rim-corresponding portion (121) and the step of rolling the upper end thereof can be performed continuously without switching the pressure roller (4), productivity is improved.

[Regarding Modification] In the first and second embodiments, the cross-section of the flare-shaped second rim forming surface (34) of the auxiliary mold (303) is formed in an arc shape that is convex toward the inner peripheral side. Needless to say, it is good. . The roll processing in the third embodiment may be performed using a spinning roller different from the pressure roller (4).

[0031] In any of the above embodiments, the upper die (301) is not directly driven to rotate, but is directly driven by a drive motor or the like to rotate the upper die (301) and the lower die (302). The configuration may be such that the rotation is synchronized with the rotation. or,
The auxiliary type (303) may also be rotated synchronously. . In any of the above embodiments, the auxiliary mold (303) is replaced with the upper mold (301).
It is a method of lowering in synchronization with
01) as long as it can move smoothly from the outer peripheral surface of the lower part (311) to the rim forming surface of the auxiliary die (303).
(303) may be held at a fixed position and only the upper mold (301) may be lowered.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an initial stage of a process when a conventional rotary forging apparatus is used.

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

FIG. 3 is an explanatory view at the end of the process.

FIG. 4 is an explanatory view of the initial stage of the process when the rotary forging device of Example 1 is used.

FIG. 5 is an explanatory diagram of the middle stage of the process.

FIG. 6 is an explanatory view at the end of the process.

FIG. 7 is a sectional view of a disk with a rim manufactured thereby.

FIG. 8 is an explanatory diagram of a middle stage of a process when the rotary forging device of Example 2 is used.

FIG. 9 is an explanatory view at the end of the process.

FIG. 10 is a cross-sectional view of a rimmed disc having a flared rim produced thereby.

FIG. 11 is a cross-sectional view of an initial stage of a process when the rotary forging device of the third embodiment is used.

FIG. 12 is an explanatory diagram of a middle stage of the process.

FIG. 13 is an explanatory diagram at the end of the process.

FIG. 14 is a sectional view of an automobile wheel manufactured by the method.

[Explanation of symbols]

 (301) ・ ・ ・ Upper mold (302) ・ ・ ・ Lower mold (303) ・ ・ ・ Auxiliary mold (10) ・ ・ ・ Work (4) ・ ・ ・ Pressure roller (2) ・ ・ ・ Disk (1)・ ・ ・ Rim (311) ・ ・ ・ Body lower part (321) ・ ・ ・ Small diameter body part (121) ・ ・ ・ Inner rim equivalent part (37) ・ ・ ・ Circular wall (35) ・ ・ ・ Bent cross section (41 ) ・ ・ ・ First molded part (42) ・ ・ ・ Second molded part

Claims (6)

(57) [Claims] An umbrella-shaped lower surface of an upper mold (301) and a lower mold (30) are provided.
2) and the upper die (3) so that one of the generatrix of the substantially umbrella-shaped lower surface of the upper die (301) is substantially horizontal.
01), the upper die (301) is attached to the lower die (30
A cylindrical rotatable auxiliary mold (303) coaxial with 2) is externally fitted, and a work (10) is interposed between the lower surface of the upper mold (301) and the upper surface of the lower mold (302), The upper mold (301) and the lower mold (302)
The workpiece (10) is pressed down while the molds are opposed to each other while being rotated synchronously, and the material protruding from the reduced area is placed on the side of the mold boundary and on the inclined side of the upper mold (301). The upper die (301) is connected to the lower surface of a rotary forging device that separates the rim (1) from the upper and lower parts of the disk (2) by separating the rim (1) from the upper and lower parts by the pressurizing roller (4). A small-diameter trunk (321) is provided above the lower torso (311), and the auxiliary die (303) is fitted over the small-diameter trunk (321) with a margin, and the rim forming surface of the auxiliary die (303) is formed. A rotary forging device in which the generating line on the side of the pressure roller (4) is continuous with an extension of the generating line on the side of the pressing roller (4) on the outer peripheral surface of the lower part of the trunk (311). 2. The rotary forging device according to claim 1, wherein the rim forming surface of the auxiliary mold (303) has a flared shape whose diameter increases upward. 3. A bottom wall portion of a drop center of the rim (1) is continuously provided on a peripheral edge of the disk (2), and a side wall portion on an inner rim side of the drop center has a flare shape whose diameter increases inward. In the method for manufacturing a vehicle wheel of the type, the substantially umbrella-shaped lower surface of the upper die (301) and the upper surface of the lower die (302) are opposed to each other, and one of the buses on the lower surface of the upper die (301) is substantially Incline the axis of this upper mold (301) so that it is horizontal,
The upper surface of the lower mold (302) conforms to the outer flat surface of the disc (2) and the shape of the inner peripheral surface of the outer rim from the peripheral edge of the disc (2) and the side surfaces of the rim flange following the outer rim. (3
01) has a configuration in which a small-diameter trunk portion (321) is provided on the upper side of a trunk lower portion (311) continuous with a substantially umbrella-shaped lower surface, and the small-diameter trunk portion (321) has a lower mold (302). A cylindrical rotatable auxiliary mold (303) that is coaxial with the outer mold is provided with a margin, and the outer peripheral body of this auxiliary mold (303) matches the inner peripheral surface of the side wall on the inner rim side of the drop center. In addition to providing a flared rim forming surface, the outer peripheral shape of the lower part (311) matches the inner peripheral surface of the bottom wall of the drop center, and the outer rim of the pressure roller (4) has a rim (1). A first molding portion (41) having a shape matching from the drop center bottom wall portion to the outer rim end portion on the outer peripheral surface of the first member;
. Interposing a workpiece (10) between the upper surface of the lower mold (302) and the lower surface of the upper mold (301); The lower mold (302) and the upper mold (301) are caused to face each other while being rotated synchronously, and the work (10) is pressed down. The upper material is separated into upper and lower parts by the pressing roller (4) and the lower mold (30
2), the upper material is extruded upward from the boundary between the pressure roller (4) and the lower part of the body (311), and the material is pushed along the rim forming surface of the auxiliary mold (303). Forming a flared inner rim-equivalent portion (121) by growing in a manner to increase the diameter of the inner rim. Finishing a predetermined range from the open end of the inner rim-equivalent portion (121) into a bead seat and a rim flange of the inner rim by roll forming. 4. An annular wall (37) having a height corresponding to the thickness of the rim flange is provided on the outer peripheral side of the rim flange forming portion on the upper surface of the lower mold (302), and the rim flange forming portion is recessed. 4. The method for manufacturing an automobile wheel according to claim 3, wherein the pressure roller is disposed as a part, and a lower end surface thereof is disposed in contact with or close to an upper end of the annular wall. 5. An annular bending section (35), which is continuous with the upper end of the flare-shaped rim forming surface of the auxiliary mold (303), and which coincides with the bead seat of the inner rim and the inner peripheral surface of the rim flange. The method for manufacturing a vehicle wheel according to claim 3 or 4. 6. A second forming part (42) having a body part conforming to the outer peripheral surfaces of the bead seat and the rim flange is provided above the first forming part (41) of the pressure roller (4). After forming the inner rim-equivalent portion (121) by rotary forging, the pressure roller (4) is moved upward to move a predetermined range from the upper end of the inner rim-equivalent portion (121) to the pressure roller (4). 6. The bead seat and the rim flange are formed by roll forming with the second forming part (42) of the second mold and the bent cross section (35) of the auxiliary mold (303).
3. The method for manufacturing an automobile wheel according to claim 1.