JP5180742B2 - Manufacturing method of wheel disc for automobile - Google Patents

Description

  The present invention relates to a method for manufacturing a wheel disc for an automobile, and more particularly to a method for manufacturing a wheel disc for an automobile from a flat plate material.

  Conventionally, a wheel disc for automobiles such as trucks, buses, etc. (a) As shown in FIG. 10, a circular blank 4a is press-punched from a square flat plate material, and a rising portion 3 is formed by drawing by a press. Later, hub holes, bolt holes, and decorative holes were processed. Alternatively, (b) as shown in FIG. 11, a circular blank 4a is press-punched from a square flat plate material, and after forming an unequal thickness rising portion 3 by iron spinning by cold spinning, a hub hole is removed. Bolt holes are cut and decorative holes are cut (see, for example, Patent Document 1).

However, the conventional method for manufacturing an automobile wheel disk has the following problems.
Prior Art (a) When the rising portion 3 is formed by drawing with a press (FIG. 10)
The plate thickness of the rising portion 3 is approximately the same as the plate thickness of the hub mounting portion 2 or becomes thicker (thickened) than the plate thickness of the hub mounting portion 2 due to increase / decrease in thickness caused by drawing by press. As a result, the plate thickness of the portion unnecessary for the function and strength of the wheel disc for automobiles is increased, and it is difficult to reduce the weight of the wheel disc for automobiles.
Prior art (b) When the rising portion 3 is formed by iron spinning by cold spinning (FIG. 11)
Although it is possible to reduce the weight of the automobile wheel disk by forming the unequal thickness rising portion 3, the blank 4a is locally processed sequentially by the spinning roll 5, so that it takes time to manufacture the automobile wheel disk. Productivity of automotive wheel discs is poor.
JP 2002-86233 A

  The object of the present invention is to reduce the weight as compared with the case where the rising portion is formed by drawing with a press, and to improve the productivity as compared with the case where the rising portion is formed by ironing spinning by cold spinning. An object of the present invention is to provide a method for manufacturing a wheel disc for an automobile.

The present invention for achieving the above object is as follows.
(1) A flat blank is squeezed and drawn using a squeezing punch and a squeezing die whose side surface is uneven to form a cup-shaped first molded product having a unequal-thickness straight cylindrical rising part. And a process of
Forming a second molded product in which the rising portion of the first molded product has a conical shape;
A method for manufacturing a wheel disk for automobiles having
(2) The vehicle wheel disk according to (1), including a step of press-drawing the blank into a plate shape before the step of ironing and drawing the blank to form the cup-shaped first molded product. Manufacturing method.
(3) The side surface of the ironing die is substantially cylindrical, and the concave and convex surface is convex in the axial direction of the side surface of the ironing die and concave in comparison with other parts or in comparison with other parts. The method for manufacturing a wheel disk for an automobile according to (1), which is formed by providing at least one convex portion.
(4) The side surface of the ironing die is substantially cylindrical, and the uneven surface is convex in the circumferential direction of the side surface of the ironing die and concave in comparison with other portions or in comparison with other portions. The method for manufacturing a wheel disk for an automobile according to (1), which is formed by providing at least one convex portion.

According to the method for manufacturing a wheel disc for an automobile according to the above (1), the blank is squeezed and drawn using a squeeze punch and a squeeze die whose side surface is uneven, and a straight cylindrical rising part having an unequal thickness is formed. Since it has the process of forming the cup-shaped 1st molded article which has, the following effects can be acquired.
Compared to the case where the rising portion is formed by drawing with a conventional press (in the case of the prior art (a)), the plate thickness of the rising portion can be partially reduced, and the wheel disk for automobiles can be reduced in weight. be able to.
Moreover, a blank can be processed simultaneously in the circumferential direction. Therefore, compared to the conventional case where the rising portion is formed by iron spinning by cold spinning (in the case of the prior art (b)), the manufacturing time of the wheel disk for automobiles can be shortened and the productivity of the wheel disk for automobiles is improved. Can be made.
According to the method for producing a wheel disk for automobiles of (2) above, the blank is press-drawn into a dish shape before the step of ironing the blank to form the cup-shaped first molded product. Therefore, the first molded product can be stably formed as compared to the case where the blank is directly ironed and drawn to form the first molded product. Moreover, the load applied to the ironing machine can be reduced.
According to the method for manufacturing a wheel disk for automobile of (3) above, the rising portion of the first molded product can be made unequal in the axial direction of the rising portion.
According to the automobile wheel disk manufacturing method of (4) above, the rising portion of the first molded product can be made unequal in the circumferential direction of the rising portion.

Below, with reference to FIGS. 1-9, the manufacturing method of the wheel disk for motor vehicles of the Example of this invention is demonstrated.
First, an automotive wheel disk (hereinafter also simply referred to as a wheel disk) 10 manufactured by the manufacturing method of the embodiment of the present invention will be described.
The wheel disc 10 is a wheel disc for automobiles such as trucks and buses. However, the wheel disc 10 may be a wheel disc for passenger cars, commercial vehicles, industrial vehicles, and the like. As shown in FIG. 1, the wheel disc 10 is a wheel disc made by molding from a plate, and does not include a cast wheel. The wheel disk 10 is welded to an annular rim (not shown) (part for holding a tire) after manufacture.

  The wheel disc 10 includes a hub attachment portion 20 (may be referred to as a flat plate portion) attached to a hub (not shown) and a rising portion (side wall portion, flange portion or disc) that rises from the outer periphery of the hub attachment portion 20 in the wheel axis direction. 30, which may be referred to as an outer peripheral portion). The wheel disc 10 is welded to a rim (not shown) at the rising portion 30.

The hub attachment part 20 is usually flat or substantially flat. When the hub mounting portion 20 has a flat plate shape or a substantially flat plate shape, the hub mounting portion 20 is in a plane orthogonal to or substantially orthogonal to the wheel axial direction (the axis of the wheel disk 10). The hub mounting portion 20 is provided with a hub hole 21 and a plurality of bolt holes 22 into which hub bolts (both not shown) extending from the hub are inserted.
One or more decoration holes 23 are provided from the hub attachment portion 20 or the hub attachment portion 20 to the rising portion 30.

Next, a method for manufacturing the wheel disc 10 will be described.
The manufacturing method of the wheel disk 10 includes (i) a step of press-punching a flat disk material 40 to obtain a flat blank 41, and (ii) an iron punch 51c and an uneven surface as shown in FIG. A blank 41 is squeezed and drawn using a squeezing die 51d (having a side surface designated as a concavo-convex surface 51e), and a cup having a hub mounting portion 20 and a straight cylindrical rising portion 30 of unequal thickness. Forming a first molded product 11 having a shape, and (iii) forming a second molded product 12 in which the rising portion 30 of the first molded product 11 is conical by press molding as shown in FIG. Have. In the step of forming the second molded product 12, the outer peripheral portion of the hub mounting portion 20 of the first molded product 11 may be drawn.

Step (i) In the step (i), as shown in FIG. 1, the rectangular disc material 40 is punched out into a circular shape or a substantially circular shape, or four corners are pressed out into an arc shape and dropped. Thus, a blank 41 is obtained.

Regarding the process (ii), as shown in FIG. 2 (enlarged view of the process A in FIG. 1), the ironing punch 51c and the ironing die 51d whose side surface is an uneven surface 51e are components of the ironing and drawing machine 51. It is. The ironing punch 51c is provided on one of the upper die 51a and the lower die 51b that are components of the ironing and drawing device 51, and the ironing die 51d is provided on the other of the upper and lower die 51a and 51b of the ironing and drawing device 51. It has been.
The gap d between the ironing punch 51c and the ironing die 51d at the position where the plate thickness is reduced at the position corresponding to the rising portion 30 is set to be narrower than the plate thickness (material plate thickness) of the disk material 40. The gap d in the portion where it is not necessary to reduce the plate thickness is set wider than the plate thickness (material plate thickness) of the disk material 40.
The uneven surface 51e on the side surface of the ironing die 51d has a relatively thick plate portion at the rising portion 30 where the thickness and the strength of the wheel disc 10 are required, and the thickness and thickness of the wheel disc 10 are not required. This is provided in order to make the plate thickness of the rising portion 30 relatively thin (in order to make the rising portion 30 unequal).

The side surface of the ironing die 51d is substantially cylindrical. The concavo-convex surface 51e is formed by providing (a) at least one concave portion that is concave in comparison with other portions or convex portions that are convex in comparison with other portions in the axial direction of the side surface of the ironing die 51d. (B) In the circumferential direction of the side surface of the ironing die 51d, it is formed by providing at least one concave portion that is concave compared to other portions or a convex portion that is convex compared to other portions. (C) As shown in FIGS. 7 and 8, it may be formed of a composite of (a) and (b).
The depth of the concave portion or the protruding amount of the convex portion may be constant or different in one concave portion or convex portion. In the case of (c) above, the shape of the concave portion or the convex portion may be a polygonal shape (including a substantially polygonal shape) equal to or greater than a triangle in front view, may be an elliptical shape, and may be a circular shape. It may be other shapes.

  As shown in FIG. 2, the rising portion 30 of the first molded product 11 has a right cylindrical shape extending in a direction parallel to the axis of the first molded product 11.

Step (iii) In the step (iii), as shown in FIG. 3 (enlarged view of the step B in FIG. 1), a press machine 52 having an upper die 52a and a lower die 52b is used. The rising part 30 of one molded product 11 is formed into a conical shape, and the second molded product 12 is formed in which the rising part 30 has a final disk shape. In the above step (iii), instead of pressing by the press machine 52, as shown in FIG. 9, spreading spinning forming by cold spinning (unlike ironing spinning forming, the plate thickness is hardly changed. May increase the diameter of the rising portion 30 of the first molded product 11 to form the second molded product 12. Spreading spinning molding by cold spinning is performed using a spreading spinning molding die 60 and at least one spinning roll 61.

As shown in FIG. 4, in addition to the steps (i) to (iii), the manufacturing method of the wheel disc 10 is further after the step (i) and before the step (ii) ( ii ′) The blank 41 may be press-drawn into a dish shape (step C in FIG. 4).
In the step (ii ′), the plate-like blank 41 obtained in the step (i) is directly converted into a cup-shaped first portion having a straight cylindrical rising portion 30 of unequal thickness in the step (ii). Instead of forming one molded article 11, as shown in FIG. 5 (enlarged view of the step C in FIG. 4), the flat blank 41 obtained in the step (i) is used in the step (ii). This is a step for pre-preparing in the shape of a dish.
In the step (ii ′), the blank 41 is press-drawn into a dish shape by the second press machine 50 including the upper die 50a and the lower die 50b.

  After the step (iii), the wheel disk 10 is manufactured by punching the hub hole 21, the bolt hole 22, and the decorative hole 23 as shown in FIGS.

Next, the operation of the embodiment of the present invention will be described.
In the embodiment of the present invention, the blank 41 is squeezed and drawn using a squeezing punch 51c and a squeezing die 51d whose side surface is an uneven surface 51e, and a cup-shaped first part 30 having an unequal thickness straight cylindrical rising part 30 is drawn. Since it has the process of forming 1 molded article 11, the following effects can be acquired.
1. Compared to the case where the rising portion is formed by drawing with a conventional press (in the case of the prior art (a)), the thickness of the rising portion 30 is partially reduced without causing problems in function and strength of the wheel disk 10. The wheel disk 10 can be reduced in weight, and the wheel disk 10 can be reduced in weight.
2. The blank 41 can be simultaneously processed in the circumferential direction. Therefore, the manufacturing time of the wheel disk 10 can be shortened and the productivity of the wheel disk 10 can be improved as compared with the case where the rising portion is formed by iron spinning by conventional cold spinning (in the case of the prior art (b)). Can do.
3. An appropriate plate thickness arrangement of the rising portion 30 can be obtained by ironing and drawing.

  Prior to the step of squeezing and drawing the blank 41 to form the cup-shaped first molded product 11 (step (ii) above), the step of press drawing the blank 41 into a plate shape (above (ii) ′) Therefore, the first molded product 11 can be stably formed as compared with the case where the flat blank 41 is directly ironed and drawn. Moreover, the load concerning the ironing machine 51 can be reduced.

The concave / convex surface 51e of the ironing die 51d is provided with at least one concave portion that is concave compared to other portions or a convex portion that is convex compared to other portions in the axial direction of the substantially cylindrical side surface of the ironing die 51d. When formed, the rising portion 30 of the first molded product 11 can be made unequal in thickness in the axial direction of the rising portion 30.
Further, the uneven surface 51e of the ironing die 51d has at least one concave portion that is concave compared to other portions or a convex portion that is convex compared to other portions in the circumferential direction of the substantially cylindrical side surface of the ironing die 51d. When formed by being provided at a location, the rising portion 30 of the first molded product 11 can be made unequal in the circumferential direction of the rising portion 30.

The process of producing a cup-shaped first molded article having a straight cylindrical rising portion of unequal thickness after obtaining a flat blank in the method for manufacturing a wheel disk for an automobile according to an embodiment of the present invention. FIG. In A and B in the figure, the left half shows before molding and the right half shows after molding. It is process drawing which shows the state before and behind a process of only the ironing drawing process of FIG. In the figure, the left half shows before molding and the right half shows after molding. It is process drawing which shows the state before and behind a process of only the press molding process of FIG. In the figure, the left half shows before molding and the right half shows after molding. After the flat blank is press-drawn into a dish shape in the method for manufacturing a wheel disk for an automobile according to an embodiment of the present invention, a cup-shaped first molded product having a unequal-thickness straight cylindrical rising portion is formed. FIG. In C, D, and E in the figure, the left half shows before molding and the right half shows after molding. It is process drawing which shows the state before and behind a process only of the process of press-drawing the flat blank of FIG. 4 into a plate shape. In the figure, the left half shows before molding and the right half shows after molding. It is process drawing which shows the state before and behind a process of only the ironing drawing process of FIG. In the figure, the left half shows before molding and the right half shows after molding. An uneven surface is formed by providing at least one recess or protrusion in the axial direction and the circumferential direction of the side surface of the ironing die used in the ironing drawing step of the manufacturing method of the wheel disk for automobile according to the embodiment of the present invention. It is a partial front view which shows only a recessed part or a convex part and its vicinity in the case of being carried out. It is FF sectional drawing of FIG. FIG. 7 is a process diagram showing a state before and after the process when forming a second molded product by expanding the diameter of the rising portion of the first molded product by cold spinning, instead of the press molding process of FIG. 1. In the figure, the left half shows before molding and the right half shows after molding. It is process drawing in the case of forming a rising portion by drawing with a press in a conventional method for manufacturing a wheel disk for automobiles. It is a process figure in the case of forming an unequal thickness rising portion by iron spinning by cold spinning in a conventional method for manufacturing a wheel for an automobile.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Automotive wheel disk 11 1st molded article 12 2nd molded article 20 Hub attachment part 21 Hub hole 22 Bolt hole 23 Decoration hole 30 Rising part 40 Disc material 41 Blank 50 Second press machine 50a Upper mold 50b Lower mold 51 Ironing Drawing machine 51a Upper mold 51b Lower mold 51c Ironing punch 51d Ironing die 51e Concavity and convexity surface 52 Press machine 52a Upper mold 52b Lower mold

Claims (4)

A step of squeezing and drawing a flat blank using a squeezing punch and a squeezing die whose side surface is uneven, and forming a cup-shaped first molded product having a unequal-thickness, straight cylindrical rising part; and ,
Forming a second molded product in which the rising portion of the first molded product has a conical shape;
A method for manufacturing a wheel disk for automobiles having   The manufacturing method of the wheel disk for motor vehicles of Claim 1 which has the process of press-drawing the said blank in a plate shape before the process of ironing and drawing the said blank and forming the said cup-shaped 1st molded product. .   The side surface of the ironing die is substantially cylindrical, and the concave-convex surface has a concave portion that is concave compared to other portions or a convex portion that is convex compared to other portions in the axial direction of the side surface of the ironing die. The manufacturing method of the wheel disc for motor vehicles of Claim 1 currently formed by providing at least one place.   The side surface of the ironing die is substantially cylindrical, and the concave-convex surface has a concave portion that is concave compared to other portions or a convex portion that is convex compared to other portions in the circumferential direction of the side surface of the ironing die. The manufacturing method of the wheel disc for motor vehicles of Claim 1 currently formed by providing at least one place.

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