JP5749708B2 - Manufacturing method of wheel rim for vehicle - Google Patents

Description

  The present invention relates to a method for manufacturing a vehicle wheel rim, and more particularly to a method for manufacturing a vehicle wheel rim for manufacturing a vehicle wheel rim having an unequal thickness from a flat plate material.

Conventionally, Patent Documents 1 and 2 disclose an example of an unequal thickness vehicle wheel rim manufactured from a flat material.
(A) In the manufacturing method of the unequal thickness vehicle wheel rim of Patent Document 1, the unequal thickness is obtained from a flat plate material using a rolling device in which a plurality of stages of a pair of rolls including a pressure roll and a rolling roll are arranged. A flat plate member is produced, the flat plate member of unequal thickness is wound in a cylindrical shape, the ends are welded to form a cylindrical member of unequal thickness, and the cylindrical member of unequal thickness is roll-formed. A vehicle wheel rim shape is produced, and an unequal thickness vehicle wheel rim is manufactured.
(B) In the method for manufacturing an unequal thickness vehicle wheel rim disclosed in Patent Document 2, a cylindrical material is produced from a flat material, and the cylindrical material is unequal thickness by flow forming (floating, spinning, etc.). A cylindrical member is formed, and the unequal thickness cylindrical member is roll-molded to obtain a vehicle wheel rim shape, whereby an unequal thickness vehicle wheel rim is manufactured.

However, the conventional method for manufacturing a wheel rim for a vehicle has the following problems.
(A) Patent Document 1
Since a rolling device having a plurality of stages of a pair of rolls composed of a pressure roll and a rolling roll is used, the equipment is large and expensive.
(B) Patent Document 2
Flow forming requires expensive equipment.
In flow forming, the roll that presses the cylindrical material against the mandrel must be moved in two directions, the material axis direction and the material thickness direction, so that the punch feed direction can be one direction. The equipment is several times more expensive than the equipment.

JP-A-10-180387 Japanese translation of PCT publication No. 2004-512963

  An object of the present invention is a vehicle wheel rim of unequal thickness that can be made unequal with a flat plate material at a lower cost than the prior art and without using unequal thickness with a rolling device and flow forming. It is to provide a manufacturing method.

The present invention for achieving the above object is as follows.
(1) Using an ironing device provided with a punch and a die having an uneven surface on the side facing the punch, ironing is performed on a flat plate material to produce an uneven thickness plate member. Having a process,
In the ironing step, the flat material is set on the die, the ironing device is operated to move the punch relative to the die, and the flat material is formed by the uneven surface of the die and the punch. A method for manufacturing a wheel rim for a vehicle, wherein the plate-shaped material is ironed to produce the unequal-thickness plate-like member while changing the plate thickness.
(2) Before the ironing step, a flange portion that bends one end portion of the flat plate material in one direction to form a bent portion and a flange portion of the flat plate material on the tip side from the bent portion in the flat plate material. Having a molding process,
In the ironing process, the flat plate material is hooked on the die at the flange portion of the flat plate material, and then a pressing member assembled to the ironing device is moved relative to the die to form the flat plate material. The flange portion of the flat plate material is clamped by the pressing member and the die, and then at least a part of the flat plate material other than the flange portion of the flat plate material is squeezed by moving the punch relative to the die. Processed to produce a plate-like member of unequal thickness,
When forming the unequal thickness flat plate member into the vehicle wheel rim shape after the ironing step, at least a part of the flange portion of the flat plate material is in the flange portion of one rim of the vehicle wheel rim. The manufacturing method of the wheel rim for vehicles as described in (1) shape | molded.
(3) The concave-convex surface is a protrusion that makes the gap between the die and the punch narrower than the plate thickness of the flat plate material on the side surface of the die facing the punch in the moving direction of the punch with respect to the die. The manufacturing method of the wheel rim for vehicles as described in (1) or (2) formed by providing at least 1 part.
(4) The concave-convex surface is a direction perpendicular to the moving direction of the punch relative to the die, and the distance between the die and the punch is set on the side surface of the die facing the punch. The method for manufacturing a wheel rim for a vehicle according to (1) or (2), wherein the vehicle rim is formed by providing at least one convex portion to be narrower.
(5) In the clamping step of the flange portion forming step and / or the ironing step, the flange portion of the flat plate material is bent at one or more locations in the one-way intermediate portion of the flat plate material. The method for manufacturing a vehicle wheel rim according to (2), wherein one or more intermediate bent portions are formed in the flange portion of the flat plate-like material.
(6) The vehicle wheel rim manufacturing method according to (5), wherein at least one folding direction of the intermediate bent portion and the bent direction of the bent portion are opposite to each other.
(7) The vehicle wheel according to (1) or (2), wherein in the ironing process, the flat plate material is ironed while pressing a front end of the punch in the movement direction with respect to the die with a discharge plate. Manufacturing method of rim.
(8) After the ironing step, a cylindrical member molding machine is provided for producing the unequal thickness cylindrical member by winding the unequal thickness flat plate member into a cylindrical shape, butting both ends of the winding and welding. (1) The manufacturing method of the wheel rim for vehicles of description.
(9) The method for manufacturing a vehicle wheel rim according to (8), further including a roll forming step of roll forming the unequal thickness cylindrical member into a vehicle wheel rim shape after the cylindrical member forming step.

According to the vehicle wheel rim manufacturing method of (1) above, since the flat plate material is formed into an unequal thickness flat plate member by ironing, the conventional non-uniform thickness is reduced by a rolling device and flow forming. Without using it, the flat plate material can be made unequal. In addition, the conventional equipment for the compaction device and flow forming is replaced with the ironing die and punch in the present invention, and the ironing die compared to the equipment cost of the compaction device and flow forming, Since the total cost of the punch and the ironing device is low, the equipment cost can be reduced as compared with the prior art, and the vehicle wheel rim can be manufactured at a lower cost and with an unequal thickness.
Further, since the punch is moved relative to the die and the flat plate material is ironed to produce an unequal thickness flat plate member, a conventional press can be used for one-way stroke movement of the punch die. As a result, the molding time can be shortened and the cost of the molding equipment can be reduced.

According to the method for manufacturing a vehicle wheel rim of (2) above, the flat plate material is dragged by the die by hooking the flange portion of the flat plate material to the die in the ironing process. Movement with respect to the die is suppressed, and high-precision molding becomes possible.
Further, in the ironing process, since the flange portion of the flat plate material is clamped by the pressing member and the die, and at least a part of the flat plate material other than the flange portion of the flat plate material is ironed, the flat plate shape Compared to the case where the flange portion of the material is not clamped between the pressing member and the die, the flat plate material is further restrained from being dragged by the punch and moving relative to the die during molding.

According to the method for manufacturing a vehicle wheel rim of the above (3) or (4), the concavo-convex surface is provided with at least one convex portion on the die that makes the space between the die and the punch narrower than the plate thickness of the flat plate material. Therefore, it is possible to produce a flat plate member whose thickness changes.

  According to the vehicle wheel rim manufacturing method of (5) above, in the clamping step of the flange portion forming step and / or the ironing step, one or more intermediate bent portions are formed in the flange portion of the flat plate material. The deformation resistance of the flange portion of the flat plate material is increased compared to the case where the intermediate bent portion is not formed in the flange portion of the flat plate material, and the flat plate material is further dragged by the punch and moves relative to the die during molding. It is suppressed.

According to the vehicle wheel rim manufacturing method of (6) above, since at least one folding direction of the intermediate folding portion and the folding direction of the folding portion are opposite to each other, all the folding directions and the folding portions of the intermediate folding portion are provided. Unlike the case where the bending direction is the same, the flange portion of the flat plate material on the distal end side is caught by the pressing member from the intermediate bending portion where the bending direction is opposite to the bending direction of the bent portion. Therefore, compared to the case where all the folding directions of the intermediate folding portion and the folding direction of the folding portion are the same, the flat plate material is further restrained from being dragged by the punch and moving relative to the die during molding. Is done.

According to the vehicle wheel rim manufacturing method of (7) above, in the ironing process, the flat plate material is ironed while pressing the front end of the punch with respect to the die with the discharge plate. Sometimes, it is suppressed that the flat plate material is dragged by the punch and moves relative to the die during molding.

  According to the vehicle wheel rim manufacturing method of (8) above, after the ironing process, an unequal thickness flat plate member is wound into a cylindrical shape and both ends of the winding are butted and welded to form an unequal thickness cylindrical shape. Since it has the cylindrical member formation process which produces a member, an unequal thickness cylindrical member can be produced.

According to the method for manufacturing a vehicle wheel rim of (9) above, since there is a roll forming step of roll forming an unequal thickness tubular member into a vehicle wheel rim shape after the cylindrical member forming step, A thick vehicle wheel rim can be produced.

It is process drawing which shows the flat material preparation process, the flange part formation process, and the ironing process of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. However, this figure is also applicable to the second embodiment of the present invention. It is process drawing which shows the cylindrical member formation process of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. However, this figure is also applicable to the second embodiment of the present invention. It is process drawing which shows the flare process and roll forming process of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. However, this figure is also applicable to the second embodiment of the present invention. It is a fragmentary sectional view which shows the ironing apparatus of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. However, this figure can also be applied to Example 2 of the present invention by setting a die having an uneven surface instead of a backup to receive the squeezing force so that the flat plate material can be squeezed on both sides of the punch. It is. It is an expanded partial sectional view which shows only a discharge plate and its vicinity in case the discharge plate is provided of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. However, this figure is also applicable to the second embodiment of the present invention. The expanded fragmentary sectional view which shows only the flange part of a flat material, and its vicinity in the case of the intermediate bending part being formed in the flange part of the flat material of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. It is. However, this figure is also applicable to the second embodiment of the present invention. It is an expanded fragmentary sectional view which shows only a punch and its vicinity of the manufacturing method of the wheel rim for vehicles of Example 1 of this invention. It is an expanded partial sectional view which shows only a punch and its vicinity of the manufacturing method of the wheel rim for vehicles of Example 2 of this invention.

Below, the manufacturing method of the wheel rim for vehicles of this invention is demonstrated with reference to drawings.
1 to 7 are applicable to the first embodiment of the present invention, and FIG. 8 is applicable to the second embodiment of the present invention. However, FIGS. 1 to 3, FIG. 5, and FIG. 6 can also be applied to the second embodiment of the present invention. FIG. 4 shows a die having an uneven surface instead of a backup that receives a squeezing force. It is applicable also to Example 2 of this invention by enabling it to iron a flat material on both sides of this.
Portions common to all the embodiments of the present invention are denoted by the same reference numerals throughout the embodiments of the present invention.

First, parts common to all the embodiments of the present invention will be described.
The vehicle wheel rim 10 </ b> C manufacturing method of the present invention is a method for manufacturing a vehicle wheel rim 10 </ b> C of unequal thickness from the flat plate material 2 as shown in FIGS. 1 to 3. The material of the flat material 2 is a metal, and the metal is, for example, steel, non-ferrous metal (including aluminum, magnesium, titanium, and an alloy thereof).
As shown in FIG. 1, the vehicle wheel rim 10 </ b> C is formed as a flat plate member 10 </ b> A having an unequal thickness in which one surface of the front and back surfaces is formed as an uneven surface by ironing the flat plate material 2. As shown in FIG. 3, the unequal thickness flat plate member 10A is wound to form an unequal thickness cylindrical member 10B having a straight wall parallel to the axis, and as shown in FIG. The member 10C is a member 10C having a wall that is further roll-formed to bend in the direction perpendicular to the axis. The unequal thickness tubular member 10B is, for example, a straight cylindrical unequal thickness tubular member, and the unequal thickness vehicle wheel rim 10C is, for example, a wheel rim for passenger cars, trucks / buses, and industrial vehicles. is there.

  The manufacturing method of the vehicle wheel rim 10C of the present invention includes the flat plate material manufacturing step of manufacturing the flat plate material 2 shown in FIG. 1 (a), as shown in FIG. 1 (c) and FIGS. Using the ironing device 20 provided with a punch 26 and a die 22 having a concave-convex surface 24 on the side facing the punch 26, the flat plate material 2 is ironed to obtain a flat plate member 10A having an unequal thickness. An ironing process to be produced.

In the flat plate material production step, as shown in FIG. 1 (a), the flat plate material (rectangular material) 2 is obtained by, for example, drawing a belt-shaped member 2a linearly from a belt-shaped member 2a wound in a coil shape. It is produced sequentially by cutting every dimension length. The flat plate material 2 may be produced by cutting a flat plate material having an area larger than that of the flat plate material 2 into a required size.
Further, the belt-like member 2a is drawn out linearly from the belt-like member 2a having a constant thickness wound in a coil shape, and ironing is performed without cutting, and the plate is cut to the length of one member to obtain an unequal thickness flat plate. The shape member 10A may be used.
The flat plate-like material 2 may be configured only by walls that are entirely on the same plane, or, as shown in FIG. One end of the flat material 2 is bent in the lengthwise direction of the unequal thickness tubular member 10B when it is formed into the unequal thickness tubular member 10B (hereinafter referred to as the α direction). The bent portion 8 and the flange portion 9 of the flat plate material on the tip side from the bent portion 8 may be formed.
The length of the flange portion 9 of the flat plate material is preferably 6.5 to 17 times the thickness of the flat plate material 2. Furthermore, it is desirable to set it as 7 times-13 times. The thickness of the flat plate material 2 is desirably about 2.0 mm to 8.0 mm. Furthermore, it is desirable to set it as 2.3 mm to 6.0 mm. However, the thickness of the flat plate-like material 2 is not limited to the above range and can be arbitrarily set.
There is no particular limitation on the size of the flat plate material 2. The flat plate material 2 is formed into a non-uniform thickness plate member 10A by a squeezing process, and the non-uniform thickness plate member 10A is formed into a non-uniform thickness cylindrical member 10B by a cylindrical member forming step. When manufacturing a vehicle wheel rim 10C having a size (size) often used as a vehicle wheel rim (passenger car wheel rim, truck wheel rim) by using a thick cylindrical member 10B by a roll forming process, The axial length of the cylindrical member 10B is desirably 76 mm to 265 mm. Furthermore, it is desirable to set it as 150 mm-230 mm. The outer diameter of the unequal thickness tubular member 10B is preferably 177 mm to 600 mm. Furthermore, it is desirable to set it as 280 mm-580 mm.
When the flat plate material 2 has a shape that can be hooked on the die 22 corresponding to the flange portion 9 of the flat plate material from the beginning, the flange portion forming step is unnecessary.
Hereinafter, in the embodiment of the present invention, a case where the flat plate material 2 has a bent portion 8 and a flange portion 9 of the flat plate material will be described.

The bent portion 8 and the flange portion 9 of the flat plate material are formed in the flange portion forming step before the ironing step.
The bent portion 8 is a bent portion (curved portion) in which the flat plate material 2 is bent (curved) at an angle of 90 degrees or less or 90 degrees or more. The flange portion 9 of the flat plate material is positioned by hooking the flat plate material 2 to the die 22 by the flange portion 9 of the flat plate material in the ironing process, and the flat plate material 2 is displaced with respect to the die 22 during the ironing process. Helps not to be. The bent portion 8 and the flange portion 9 of the flat plate material are formed, for example, by sandwiching and deforming the flat plate material 2 with a pair of molds 52a and 52b.

As shown in FIG. 6, one or more intermediate bent portions 9a may be formed in the flange portion 9 of the flat plate material. FIG. 6 shows a case where only one intermediate bent portion 9a is formed on the flange portion 9 of the flat plate material. The intermediate bent portion 9a is formed by bending (curving) an intermediate portion in the α direction of the flange portion 9 made of a flat plate material at an angle of 1 to 90 degrees. The intermediate bent portion 9a is formed in the clamping step of the flange portion forming step and / or the ironing step. The intermediate bent portion 9a may be formed only in the flange portion forming step, may be formed only in the pressing step of the ironing step, or formed in both the flange portion forming step and the pressing step of the ironing step. May be. When the intermediate bent portion 9a is formed in the pressing step of the ironing process, the intermediate bent portion 9a is a flange portion of the flat plate material by a force for pressing the flange portion 9 of the flat plate material by the pressing member 23 and the die 22. 9 is deformed.
In the illustrated example, at least one bending direction of the intermediate bending portion 9a and the bending direction of the bending portion 8 are opposite to each other, but they may be bent in the same direction. When the bending angle of the bent portion 8 is large or when the force required for ironing is small, the intermediate bent portion 9a may be omitted.
The bending angle of the bent portion 8 and the intermediate bent portion 9a may be 90 degrees or more, but the processing becomes difficult in the step of returning the flange portion of the unequal thickness flat plate member 10A after the ironing step. Or the amount of processing increases. Even if the bending angle at the intermediate bent portion 9a and the bent portion 8 is relatively small (less than 90 degrees) by forming the intermediate bent portion 9a, the flat plate material 2 is dragged by the punch 26 in the ironing process. It becomes easy to carry out cylindrical member shaping | molding in a cylindrical member shaping | molding process.

In the ironing process, the flat plate material 2 (the flat plate material 2 having the bent portion 8 and the flange portion 9 of the flat plate material) is hung on the die 22 by the flange portion 9 of the flat plate material and set on the die 22.
Thereafter, the ironing device 20 is operated to move the punch 26 relative to the die 22.
When the pressing member 23 and the punch 26 are moved relative to the die 22 in the α direction of the flat plate material 2 (approached), the flat plate material 2 of the flat plate material 2 set on the die 22 is formed. The pressing member 23 and the die 22 are pressed against the flange portion 9 to press the flange portion 9 of the flat plate material (the pressing member 23 presses the flat plate material flange portion 9 against the die 22), and the pressing member 23 stops. The punch 26 is further moved (approached) relative to the die 22 only in the α direction of the flat plate material 2, and the portions other than the flange portion 9 of the flat plate material 2 of the flat plate material 2 are formed on the uneven surface 24 of the die 22 and the punch. The flat plate material 2 is ironed while changing the plate thickness of the flat plate material 2 according to No. 26 to produce a flat plate member 10A having an unequal thickness.
By ironing, the hardness is increased by work hardening and the accompanying resistance and fatigue strength are improved. When the material of the flat plate-like material 2 is steel, the ironing rate {(plate thickness before processing−plate thickness after processing) / plate thickness before processing × 100} is preferably 60% or less. This is because if it is larger than 60%, galling and cracking are likely to occur in the unequal thickness flat plate member 10A. However, you may process the ironing rate 60% or more.
In addition, when the force required for ironing is small, the pressing member 23 may not be provided.
It is desirable to perform a lubrication process (bonding process, lubricating oil) or the like on the flat plate material 2 before or during the ironing process. This is because seizure of the unequal thickness plate member 10A and generation of wrinkles can be suppressed. However, ironing may be performed without performing the lubrication process.

For example, the ironing device 20 includes a press machine 30 as shown in FIG.
The press machine 30 includes a gantry 32, a ram driving unit 34 attached to the gantry 32, a ram 36 that is moved up and down by the ram driving unit 34, a bolster 38, and a discharge plate driving unit 42 that moves the discharge plate 40 up and down.
The press machine 30 is assembled with the die 22, the punch 26, the pressing member 23, and the discharge plate 40. The die 22 is fixed to the bolster 38 or a member fixed to the bolster 38. The punch 26 is fixed to the ram 36 or a member fixed to the ram 36. The pressing member 23 is attached to the ram 36 or a member fixed to the ram 36 so as to be movable up and down. The discharge plate 40 is fixed to the bolster 38 or a member fixed to the bolster 38, and is attached to the discharge plate driving means 42 so as to be vertically driven. At the upper end of the side surface of the die 22, an inclined portion or stepped portion 22 d is formed to catch the flange portion 9 of the flat plate material 2 of the flat plate material 2. The flat plate material 2 is set on the die 22 by bringing the flange portion 9 of the flat plate material into contact with the inclined portion or the stepped portion 22d and hooking it.

When the ram drive unit 34 is operated (the press machine 30 is operated) and the ram 36 is lowered, the pressing member 23 and the punch 26 are moved relative to the die 22 (down, approach). When the pressing member 23 and the punch 26 move relative to the die 22, the pressing member 23 hits the flange portion 9 of the flat plate material 2 set on the die 22, and the step portion 22 d between the pressing member 23 and the die 22. And the flange portion 9 of the flat plate material is clamped (the flange portion 9 of the flat plate material is pressed against the stepped portion 22d of the die 22 by the pressing member 23), and the pressing member 23 stops. The punch 26 further moves relative to the die 22, and changes the plate thickness of the flat plate material 2 due to the uneven surface 24 of the die 22 and the punch 26 except for the flange portion 9 of the flat plate material 2 of the flat plate material 2. Accompanied by the ironing process.
When the flat plate material 2 is ironed, the length of the flat plate material 2 in the α direction gradually increases (extends) in the direction in which the punch 26 moves relative to the die 22.

In order to prevent the flat plate material 2 from being displaced with respect to the die 22 in the ironing process of the flat plate material 2, the discharge plate 40 moves the flat plate material 2 in the direction opposite to the moving direction of the punch 26 with respect to the die 22. You may push (support). In this case, the flat plate-shaped material 2 is ironed while the front end (lower end) of the punch 26 in the moving direction with respect to the die 22 is pressed by the discharge plate 40. When the flat plate material 2 is ironed, the length of the flat plate material 2 in the α direction gradually increases (extends) in the direction in which the punch 26 moves relative to the die 22, but the discharge plate The position 40 is controlled by the discharge plate driving means 42, and the discharge plate 40 is retracted with the change in the length of the flat plate material 2, and the discharge plate 40 is a flat plate material 2 with a constant load or a substantially constant load. It is possible to continue pressing during ironing. The movement of the discharge plate 40 may control the load acting on the discharge plate 40 or may control the amount of displacement in the α direction. Further, by holding the discharge plate 40 firmly at a predetermined position, the change in the length of the flat plate material 2 in the α direction can be restrained, and the length in the α direction can be kept constant.

As shown in FIG. 5, the side surface of the die 22 on the side facing the protruding portion 28 of the punch 26 is an uneven surface 24.
The concavo-convex surface 24 is a surface in which the distance between the protrusions 28 of the punch 26 (the distance in the thickness direction of the flat plate-like material 2) is not uniform and has different portions. The concave / convex surface 24 of the die 22 is formed as shown in FIG. 5 in order to make the distance between the side surface facing the protrusion 28 of the punch 26 and the protrusion 28 of the punch 26 smaller than the plate thickness of the flat plate material 2. It is formed by providing at least one convex portion 24a that is convex on the side of the projecting portion 28 of the punch as compared to a portion (concave portion 24b) adjacent in the direction parallel to or orthogonal to the moving direction of the punch 26 with respect to the die 22. Yes. The protruding amount of the convex portion 24a is determined by the target plate thickness of each part of the unequal thickness flat plate member 10A, and may be constant or different in one convex portion 24a. When a plurality of convex portions 24a are provided, the protruding amount of each protruding portion 24a is determined by the target plate thickness of each portion of the unequal thickness flat plate member 10A, and the protruding amount of each protruding portion 24a is the same. Or may be different. The convex portion 24 a only needs to be formed on at least a part of the side surface of the die 22 on the side facing the punch 26.
The punch 26 has a protrusion 28 that protrudes toward the die 22 in the vicinity of the tip when moved toward the die 22, and the flat material 2 is squeezed by the protrusion 28.

  The thick portion (the portion where the plate thickness is not thinned) of the unequal thickness flat plate member 10A is a portion where a large load (load, force) is generated (bending portion, rim flange) when used as the vehicle wheel rim 10C. The thin-walled portion (the portion where the plate thickness is reduced) in the unequal thickness flat plate member 10A is a portion where a small load (load, force) is generated when used as the vehicle wheel rim 10C. (Parts other than the bent part and the flange part of the rim). As a result, while maintaining the required strength and rigidity in the final product state, weight reduction, material saving, and cost reduction are achieved.

When the flat plate member 10A having unequal thickness has a cylindrical member forming step, which will be described later, if it is difficult to round it into a cylindrical shape, the cylindrical member forming step is easily performed as shown in FIG. Therefore, there is a step of making the unequal thickness flat plate member 10A into a flat plate shape without the bent portion 8 and the flat plate material flange portion 9 between the ironing step and the cylindrical member forming step. May be. In this step, for example, a pair of molds 53a and 53b sandwich and deform an unequal thickness flat plate member 10A having a bent portion 8 and a flange portion 9 made of a flat plate material, thereby forming an unequal thickness flat plate shape. The member 10A is formed into a flat plate shape without the bent portion 8 and the flange portion 9 of the flat plate material. When the intermediate bent portion 9a is formed, the bending angle of the bent portion 8 and the intermediate bent portion 9a can be made smaller than when the intermediate bent portion 9a is not formed, so that the flat plate not having the bent portion 8 and the flange portion 9 of the flat plate material. Easy to shape.

  In the manufacturing method of the vehicle wheel rim 10C of the present invention, after the ironing process, the flat plate member 10A having an unequal thickness is wound into a cylindrical shape and both ends of the winding (both ends in the direction orthogonal to the α direction) are butted. And a cylindrical member forming step for manufacturing the unequal thickness cylindrical member 10B. In the cylindrical member forming process, the flat plate member 10A having an unequal thickness is wound into a cylindrical shape, and both ends of the winding are brought into contact with each other and welded by flash butt welding, butt welding, arc welding, or the like. Trimming is performed to produce an unequal thickness tubular member 10B. The unequal-thickness cylindrical member 10B is configured by only a linear wall in which one of the inner peripheral surface and the outer peripheral surface is an uneven surface and the other surface extends in parallel with the axis.

In the method for manufacturing the vehicle wheel rim 10C of the present invention, as shown in FIG. 3, after the cylindrical member forming step, roll forming is performed by roll forming the unequal thickness cylindrical member 10B into the vehicle wheel rim shape. You may have a process.
The roll forming process is performed after the axially opposite ends of the unequal thickness tubular member 10B are flared and expanded using the flare processing machine 44. In the roll forming process, the lower roll 46 and the upper roll 47 The lower roll 46 and the upper roll 47 are brought close to each other while the roll is rotated with the wall of the unequal thickness tubular member 10B interposed therebetween, and the unequal thickness tubular member 10B is formed into a vehicle wheel rim shape. Thereafter, the expander and / or the shrinker 48 are used to perform sizing processing (processing to approach a perfect circle and shaping of the vehicle wheel rim cross-sectional shape) to obtain a final vehicle wheel rim shape.
Part or all of the flange portion 9 made of a flat plate material is the flange portion 10a (or 10g) of the rim of the vehicle wheel rim 10C.

  The wheel rim 10C having an unequal thickness after the roll forming process has a flange portion 10a, a bead seat portion 10b, a side wall portion 10c, a drop portion 10d, and a side wall portion in order from one end to the other end in the axial direction. 10e, bead seat portion 10f, and rim flange portion 10g. A vehicle wheel disk (not shown) is fitted into the vehicle wheel rim 10C and welded to form a welding type vehicle wheel. Between each part of vehicle wheel rim 10C, there is a bent part. It is desirable that the bent portions and the flange portions 10a and 10g of the rim have a large load (load, force) generated during normal use and are thicker than the other portions.

Here, the operation of the portion common to all the embodiments of the present invention will be described.
In the embodiment of the present invention, since the flat plate material 2 is formed into an unequal thickness flat plate member 10A by ironing, the flat plate material is formed without using the conventional non-uniform thickness by a rolling device and flow forming. Unequal thickness can be achieved. Further, in the present invention, the conventional equipment for the compaction device and the flow forming is replaced with the ironing die 22, the punch 26, and the press machine 30, and the ironing cost is compared with the equipment cost of the compaction device and the flow forming. Since the total cost of the die 22, the punch 26 and the press machine 30 is low, the equipment cost can be reduced compared to the conventional case, and the unequal thickness vehicle wheel 10C can be manufactured at a lower cost than the conventional case.
Further, compared with the conventional case where the thickness of the material is unequal by flow forming, the time for unequal thickness of the flat plate material can be shortened to about 1/3, and the productivity can be improved.
In addition, since the flow forming is replaced by ironing by punching, unlike the case where the material is made unequal by conventional flow forming, the forming mark of the flow forming forming roll does not remain on the unequal thickness tubular member 10B. Appearance quality is maintained.

Since the punch 26 is moved relative to the die 22 and the flat plate material 2 is ironed to produce the unequal thickness flat plate member 10A, the press machine 30 is used for one-way stroke movement of the punch 26 with respect to the die 22. it can. As a result, the molding time can be shortened and the cost of the molding equipment can be reduced.

Since the flange portion 9 of the flat plate material is hooked on the die 22 in the ironing process, the flat plate material 2 is restrained from being dragged by the punch 26 and moving relative to the die 22 during molding. High precision molding becomes possible.
Further, in the ironing process, the flange portion 9 of the flat plate material is clamped by the pressing member 23 and the die 22, and then at least a part of the flat material 2 other than the flange portion 9 of the flat plate material 2 is ironed. Therefore, as compared with the case where the flange portion 9 of the flat plate material is not clamped by the pressing member 23 and the die 22, the flat plate material 2 is further dragged by the punch 26 and moves relative to the die 22 during molding. Is suppressed.
Since the flange portion 9 of the flat plate material is not ironed except in the vicinity of the bent portion 8, it is not thinned by ironing. Since the flange portion 9 of the flat plate material becomes the rim flange portion 10a (or 10g) and its vicinity by the roll forming process, it can be made relatively thick when molded into the vehicle wheel rim 10C. The durability of the vehicle wheel rim is improved.

In the clamping step of the flange portion forming step and / or the ironing step, one or more intermediate bent portions 9a are formed in the flange portion 9 of the flat plate material, so that the intermediate bent portion 9a is formed in the flange portion 9 of the flat plate material. The deformation resistance of the flat plate-shaped flange portion 9 is increased as compared with the case where the flat plate-shaped material 2 is not formed, and the plate-shaped material 2 is further dragged by the punch 26 and is prevented from moving with respect to the die 22 during molding. Moreover, since the bending angle of the bending part 8 and the intermediate bending part 9a can be made small by forming the intermediate | middle bending part 9a, shaping | molding in a cylindrical member shaping | molding process becomes easy.

Since at least one folding direction of the intermediate bent portion 9a and the bent direction of the bent portion 8 are opposite to each other, unlike all the folding directions of the intermediate bent portion 9a and the bent direction of the bent portion 8 are the same, The flange 9 portion of the flat plate material on the front end side from the intermediate bent portion 9 a whose bending direction is opposite to the bent direction of the bent portion 8 is caught by the holding member 23. Therefore, as compared with the case where all the folding directions of the intermediate bent portion 9a and the bent direction of the bent portion 8 are the same, the flat plate-like material 2 is further dragged by the punch 26 to the die 22 during molding. The movement is suppressed.

In the case where the intermediate bent portion 9a is formed only in the flange portion forming step, the pressing member 23 and the die 22 are pressed against the flange portion 9 of the flat plate material as compared with the case where the intermediate bent portion 9a is formed in the clamping step of the ironing step. It is possible to suppress the displacement of the flat plate-like material 2 with respect to the die 22 when sandwiched between the two.
When the intermediate bent portion 9a is formed only in the clamping step of the ironing process, it is not necessary to form the intermediate bent portion 9a in the flange portion forming step, and the bent portion 8 and the flange portion of the flat plate material in the flange portion forming step. 9 can be easily formed (the flange portion forming step can be simplified).

Since the flat plate material 2 is ironed while the front end of the punch 26 in the moving direction with respect to the die 22 is pressed by the discharge plate 40, the flat plate material 2 is dragged by the punch 26 during the ironing process. The movement with respect to the die 22 is suppressed. Moreover, it becomes easy to control the amount of elongation of the flat plate-like material 2 by ironing.

The convex / concave surface 24 is a protrusion that makes the gap between the die 22 and the punch 26 smaller than the thickness of the flat plate-like material 2 in the moving direction of the punch 26 with respect to the die 22 or in the direction orthogonal to the moving direction of the punch 26 with respect to the die 22. Since at least one portion 24a is provided on the die 22, an unequal thickness flat plate member 10A having a varying thickness can be produced.

  After the ironing process, there is a cylindrical member forming step in which the unequal thickness flat plate member 10A is wound into a cylindrical shape and both ends of the winding are butted and welded to produce the unequal thickness cylindrical member 10B. An equal-thickness cylindrical member 10B can be produced.

After the cylindrical member forming step, the rolling member further includes a roll forming step of roll-forming the unequal thickness cylindrical member 10B into a vehicle wheel rim shape. By forming at least a part of 10g) from the flange portion 9 made of a flat plate material, an unequal-thick lightweight vehicle wheel rim 10C with improved durability can be produced.
Moreover, the wheel disk for vehicles can also be created by pressing the flat member 10A of unequal thickness after the ironing process.

Next, a configuration peculiar to each embodiment of the present invention will be described.
[Example 1]
In the method for manufacturing the vehicle wheel rim 10C according to the first embodiment of the present invention, as shown in FIGS. 4 and 7, the backup 50 is provided on the opposite side of the punch 26 from the die 22.
The backup 50 is fixed to the bolster 38 or a member fixed to the bolster 38 of the press machine 30. When the punch 26 enters between the die 22 and the backup 50 at the upper end of the side of the backup 50 facing the punch 26 and / or the lower end of the side of the punch 26 facing the backup 50 An inclined portion 56 that suppresses the hook 26 from being caught by the backup 50 is formed. The inclined portion 56 of the backup 50 is inclined upward and away from the die 22.

In the method for manufacturing the vehicle wheel rim 10C according to the first embodiment of the present invention, since the backup 50 is provided on the opposite side of the punch 26 from the die 22, the punch 26 is formed on the uneven surface of the die 22 during the ironing process. Accordingly, it is possible to manufacture the unequal thickness flat plate member 10A that has been reliably changed to the required thickness, and to move the unequal thickness flat plate member 10A in the cylindrical member forming step. The cylindrical member 10B having an unequal thickness can be manufactured by trimming the bulge and burrs of the welded portion 6 by welding with flash butt welding, butt welding, arc welding, etc. The vehicle wheel rim 10C can be manufactured by roll-forming the unequal thickness tubular member 10B.

[Example 2]
In the method for manufacturing the vehicle wheel rim 10C according to the second embodiment of the present invention, as shown in FIG. 8, the two dies 22 are provided on both sides of the punch 26 with the uneven surface 24 facing the punch 26. Two protrusions 28 of the punch 26 are provided so as to face the uneven surface 24 of the die 22.

In the method for manufacturing the vehicle wheel rim 10C according to the second embodiment of the present invention, since the dies 22 are provided on both sides of the punch 26, the flat plate material 2 is set on each of the dies 22 provided on both sides of the punch 26. Thus, the two flat materials 2 can be made unequal in thickness at the same time.

2 Flat plate material 6 Welded portion 8 Folded portion 9 Flat plate flange portion 9a Axial intermediate bent portion 10A Unequal thickness flat plate member 10B Unequal thickness cylindrical member 10C Vehicle wheel rim 10a Rim flange portion 10g Rim flange portion 20 Ironing device 22 Die 23 Holding member 24 Concavity and convexity surface 24a Convex portion 24b Concavity 26 Punch 28 Protruding portion 30 Pressing machine 32 Base 34 Ram drive means 36 Ram 38 Bolster 40 Discharge plate 42 Discharge plate drive means 44 Flare processing machine 46 Lower roll 47 Upper roll 48 Expander and / or Shrinker 50 Backup

Claims (9)

Using an ironing device equipped with a punch and a die having a concavo-convex surface on the side facing the punch, an ironing process for producing an uneven thickness plate member by ironing a plate material is provided. And
In the ironing step, the flat material is set on the die, the ironing device is operated to move the punch relative to the die, and the flat material is formed by the uneven surface of the die and the punch. A method for manufacturing a wheel rim for a vehicle, wherein the plate-shaped material is ironed to produce the unequal-thickness plate-like member while changing the plate thickness. Before the ironing step, a flange portion forming step is performed in which one end portion in one direction of the flat plate material is bent to form a bent portion in the flat plate material and a flange portion of the flat plate material on the tip side from the bent portion. Have
In the ironing process, the flat plate material is hooked on the die at the flange portion of the flat plate material, and then a pressing member assembled to the ironing device is moved relative to the die to form the flat plate material. The flange portion of the flat plate material is clamped by the pressing member and the die, and then at least a part of the flat plate material other than the flange portion of the flat plate material is squeezed by moving the punch relative to the die. Processed to produce a plate-like member of unequal thickness,
When forming the unequal thickness flat plate member into the vehicle wheel rim shape after the ironing step, at least a part of the flange portion of the flat plate material is in the flange portion of one rim of the vehicle wheel rim. The manufacturing method of the wheel rim for vehicles of Claim 1 shape | molded. The concavo-convex surface has at least a convex portion that makes a gap between the die and the punch narrower than a plate thickness of the flat plate material on a side surface of the die facing the punch in a moving direction of the punch with respect to the die. The manufacturing method of the wheel rim for vehicles of Claim 1 or Claim 2 formed by providing one. The uneven surface is in a direction perpendicular to the direction of movement of the punch relative to the die, and the distance between the die and the punch is made smaller than the plate thickness of the flat plate material on the side surface of the die facing the punch. The manufacturing method of the wheel rim for vehicles of Claim 1 or Claim 2 formed by providing at least 1 convex part.   In the clamping step of the flange portion forming step and / or the ironing step, the flat portion material is formed by bending the one-way intermediate portion of the flat plate portion of the flange portion of the flat plate material at one or more places. The manufacturing method of the wheel rim for vehicles of Claim 2 which forms one or more intermediate | middle bending parts in the flange part.   The method for manufacturing a wheel rim for a vehicle according to claim 5, wherein at least one bending direction of the intermediate bending portion and a bending direction of the bending portion are opposite to each other.   3. The vehicle wheel rim manufacturing method according to claim 1, wherein, in the ironing process, the flat plate material is ironed while pressing a front end of the punch in the movement direction with respect to the die with a discharge plate. Method.   After the ironing step, a cylindrical member molding machine is provided for producing the unequal thickness tubular member by winding the unequal thickness flat plate member into a tubular shape, butting and welding both ends of the winding. A method for producing a vehicle wheel rim according to claim 1.   The manufacturing method of the wheel rim for vehicles of Claim 8 which has the roll shaping | molding process of carrying out the roll shaping | molding of the said unequal thickness cylindrical member in the shape of a wheel rim for vehicles after the said cylindrical member shaping | molding process.

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