JP3758780B2 - Uneven thickness disc - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk for an automobile wheel.
[0002]
[Prior art]
As shown in FIG. 7, the automobile wheel is manufactured by joining a dish-shaped disk 1 and an annular rim 2. In particular, for buses and trucks, as shown in FIG. 9, conventionally, as shown in FIG. 9, a flat blank 3 is punched out by a press or a circular blank 4 is prepared by gas cutting. The disk shape was made, hub holes, bolt holes and decorative holes were punched with a press machine, and the nut seat was dished with multiple drills. As shown in FIG. 7, a disk formed by drawing from a flat plate by a press machine is formed so that the thickness of the cross section of the disk is substantially equal. Also, as shown in Fig. 8, there is a case where the thickness is gradually reduced by cold spin processing, but based on the thickness of the hub mounting part as a reference, the end part is reduced to about 1/2 of the original thickness. Have been used for a long time.
[0003]
[Problems to be solved by the invention]
However, these equal-thickness discs, and those with a gradual decrease in wall thickness toward the end, are not necessarily the shapes determined as a result of scientific analysis, so they have improved durability and reduced weight. I couldn't respond to the demand to measure.
In order to meet these demands, the applicant first analyzed the stress distribution acting on the wheel using the finite element method and developed an automobile wheel shown in JP-A-7-257101. However, this automobile wheel is effective when the general part of the rim and disk (the part where the wall is present) is the weakest part, but depending on the wheel, fatigue cracks often occur from the decorative hole. When the hole is the weakest part, the purpose could not be achieved.
An object of the present invention is to provide a disc capable of improving the generated stress distribution more comprehensively including not only the general portion but also the peripheral portion of the hole, improving the durability fatigue strength of the disc wheel, and reducing the weight. .
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the uneven thickness disc of the present invention is as follows.
(1) a hub mounting portion extending in a direction perpendicular to the wheel axis;
And extending buildings bend the continuous with hub mounting portion, from which curved from the hub mounting portion toward the axially inner and radially outwardly,
A design surface portion that extends from the curved portion, while being curved at a radius of curvature larger than the radius of curvature of the curved portion, radially outward and axially inward.
A terminal portion extending to the inner side in the axial direction;
A plurality of decorative holes provided in the design surface portion;
In the wheel disc having
A straight line inclined 45 degrees from a straight line passing through the center of the decorative hole and connecting the center of the decorative hole and the center of the wheel, when the thickness distribution of the design surface portion is viewed in the axial direction of the decorative hole. A non-uniform plate thickness disc characterized in that a portion intersecting the periphery of the hole and the vicinity thereof are made thicker than the other periphery of the decorative hole to increase the thickness of the decorative hole.
(2) The uneven thickness disc according to (1), wherein the decorative hole thickening portion is formed by thickening the back side of the design surface portion.
(3) The thickness distribution of the disk is made thinner in the order of the hub mounting portion, the decorative hole thickening portion, the curved portion, the design surface portion having the same diameter as the central portion of the decorative hole, and the terminal portion (1), (2) The uneven thickness disc as described above.
(4) Assuming that the thickness of the disk is 1 for the hub mounting part, the decorative hole thickening part is 0.62 to 0.70, the curved part is 0.50 to 0.58, the decorative hole center part is The uneven thickness disc according to (1) or (2), wherein the design surface portion on the same diameter is 0.42 to 0.50 and the terminal portion is 0.35 to 0.42.
[0005]
In the disk of (1) above, in the conventional disk, stress tends to concentrate on the periphery of the decorative hole of the disk, and in particular, it is inclined 45 degrees to the left and right from the straight line passing through the center of the decorative hole and connecting the center of the decorative hole and the wheel center from portions or near the straight line intersects the periphery of the hole ornament, a crack occurs, Atsushi increasing the plate thickness of the portion of its as increase vent thick section was strengthened that part.
In the disc (2), the decorative hole thickening portion is provided on the back surface of the disc, so that the stress balance is improved and the durability is further improved.
In the disks (3) and (4) above, the plate thickness distribution is reduced in the order of the hub mounting portion, the thickened portion of the decorative hole, the curved portion, the design surface portion having the same diameter as the central portion of the decorative hole, and the terminal portion. As a result, the stress balance is good and the durability fatigue strength is improved without increasing the weight. In addition, the weight of the disc can be reduced, which can contribute to an improvement in fuel consumption by reducing the vehicle weight. Formation of the plate thickness distribution can be easily realized by cold spinning or the like.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
1 to 6 show a disk according to an embodiment of the present invention. The same parts as those in the conventional configuration are denoted by the same reference numerals as those in FIGS.
As shown in FIG. 1, the wheel 4 is manufactured by fitting a disc-like disc 1 on the inner peripheral side of an annular rim 2 formed in the shape of a rim and welding the end 1e of the disc 1 by welding. Is done. The disc 1 has a hub mounting portion 1a, a curved portion 1b, a design surface portion 1d, and a terminal portion 1e. The design surface portion 1d has both end portions that are curved in the opposite direction to the curvature of the design surface portion 1d in order to smoothly connect to the curved portion 1b and the terminal portion 1e. The hub mounting portion 1a extends in a direction perpendicular to the disc axis (coincident with the wheel axis). Curved portion 1b is continuous with integrally with the hub attachment portion 1a, and connect from there curved from the hub mounting portion 1a extending the Activity toward the axial direction of the wheel inwardly and radially outwardly, the end portion of the design surface portion 1d Yes. The design surface portion 1d is continuous with the curved portion 1b and extends radially outward and axially inward while being curved with a radius of curvature larger than that of the curved portion 1b. The terminal portion 1e is connected to the design surface portion 1d, and extends in parallel or substantially in parallel with the disk axis toward the inner side in the wheel axis direction. The rim 2 and the disk 1 are welded and joined at the tip of the disk terminal portion 1e. 4b shows the welded part. As shown in FIGS. 2 and 4, the design surface portion 1 d of the disk 1 has a plurality of substantially circular decorative holes 3 on substantially the same circumference for the purpose of improving design properties, improving heat dissipation, and reducing weight. The number is formed (six in FIG. 4).
[0007]
As shown in FIG. 1, the disk 1 has a change in the thickness of each part. The plate thickness of the hub mounting portion is equal or nearly equal. The plate thickness of the curved portion 1b is in the range of 0.50 to 0.58 when the plate thickness of the hub mounting portion 1a is 1. The design surface portion 1d has a decorative line that passes through the center of the decorative hole 3 and is inclined 45 from a straight line connecting the center 3a of the decorative hole 3 and the center 4a of the wheel 4 in the axial direction of the decorative hole (FIG. 2). The hole 3 has a portion 3b intersecting with the peripheral edge 3c (four in one decorative hole) and other portions, and the crossing portion 3b and the vicinity thereof are thicker than other peripheral portions by increasing the plate thickness. As part 1c. The decorative hole thickening portion 1c is in the range of 0.62 to 0.70 when the hub mounting portion 1a is 1, and the plate thickness of this portion is formed thicker than the hub mounting portion 1a. In addition, the thickening of the decorative hole thickening portion 1c provides a stress balance between the front and back sides as compared with the conventional shape (C) even if it is formed on the front side of the design surface portion 1d as shown in FIG. Although it can be improved, as shown in FIG. 5A, it is more desirable to form on the back surface side of the design surface portion 1d. The plate thickness of the other design surface portion 1d is in the range of 0.42 to 0.50 when the hub mounting portion 1a is 1. The plate thickness of the terminal portion 1e is formed in the range of 0.35 to 0.42 when the plate thickness of the hub mounting portion 1 is 1.
From the above configuration, the plate thickness distribution is thinner in the order of the hub mounting portion 1a, the decorative hole thickening portion 1c, the curved portion 1b, the design surface portion 1d, and the terminal portion 1e.
[0008]
As shown in FIG. 4, a hub hole 5 is formed in the center of the hub mounting portion 1a, and a plurality of decorative holes 3 are formed in the design surface portion 1d at intervals in the circumferential direction. The disc 1 is mounted on a hub of a vehicle and fixed by a hub bolt (not shown), a bolt hole 6 and a nut seat 6a.
[0009]
The uneven thickness disc can be produced by cold spinning as shown in FIG. In FIG. 3, a circular material 21 is formed from the uniform plate thickness material 20 by press punching or the like, and then a spinning process is performed using a cold spinning machine 22 so as to satisfy the above-described thickness relationship. Next, the hub hole 5, the bolt hole 6, and the decorative hole 3 are punched out by a press machine, and further, the nut seat 6a of the bolt hole 6 is processed by a multiple drill. In the conventional spinning process, the hub mounting portion 1a is formed so as to be gradually thinner between the terminal portions 1e, or the curved portion 1b is formed so as to be thinner than the terminal portion 1e. 1d, where the straight line inclined 45 degrees from the straight line connecting the center of the decorative hole 3 and the center of the wheel 4 where stress is most likely to concentrate intersects the periphery of the decorative hole 3 and its vicinity. The thickness of the plate was increased from that of the other portions to form a decorative hole thickened portion 1c.
It may be manufactured by a method other than cold spinning as long as the above plate thickness relationship can be achieved. For example, a recently developed swing forging method or other forming methods may be used.
[0010]
Next, the operation will be described with reference to FIGS. 5 (A) and 5 (B) show the plate thickness distribution in the vicinity of the decorative hole according to the present invention and the increasing direction of the thickened portion of the plate thickness, and FIG. 5 (C) is a comparison of the conventional plate thickness distribution. It is shown for this purpose. FIG. 6 shows the state of stress generation in comparison with the case where the stress value on the straight front side of the conventional example is 1. FIG. 5A shows the thickness of a portion where a straight line that passes through the center of the decorative hole where cracks are most likely to occur and which is inclined 45 degrees from the straight line connecting the center of the decorative hole and the center of the wheel intersects the periphery of the decorative hole and the vicinity thereof. Is increased in the direction of the back side of the design surface portion, as shown in FIG. 6, it is possible to suppress the generation of stress and improve the balance between the back and the front. FIG. 5 (B) shows an increase in thickness on the front side, but the stress is improved as compared with the conventional example (C).
As a result, the product of the present invention can achieve a significant weight reduction as compared with the conventional discs of FIGS. 7 and 8, and can also greatly improve and improve the durability. Even when compared with the disk disclosed in Japanese Patent Laid-Open No. 7-257201, the weight can be reduced by the same or more, and the durability can be further improved.
[0011]
【The invention's effect】
According to claim 1, a portion where the straight line that passes through the center of the decoration hole and is inclined 45 degrees from the straight line connecting the center of the decoration hole and the center of the wheel intersects the periphery of the decoration hole and the vicinity thereof are used as the decoration hole thickening portion. Because it is thicker than the other decorative hole periphery, it can reduce the generated stress, prevent the crack from generating from the decorative hole, improve the durability fatigue strength of the wheel, and reduce the weight it can.
According to the second aspect, since the thickened portion of the decorative hole is thickened on the back side of the design surface portion, the stress balance can be improved and the durability can be further improved.
According to claim 3, the same effects as those of claims 1 and 2 can be obtained.
According to the fourth aspect, optimal durability improvement and weight reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a wheel having a non-uniform thickness disk according to an embodiment of the present invention.
FIG. 2 is a plan view of a decorative hole and its vicinity as viewed from the direction of the arrow z in FIG.
FIG. 3 is a manufacturing process diagram of an uneven thickness disc according to an embodiment of the present invention.
4 is a front view of the wheel of FIG. 1. FIG.
FIG. 5 is a cross-sectional view of a decorative hole thickening portion of the uneven thickness disc of the embodiment of the present invention.
FIG. 6 is a table showing a comparison of stresses in the decorative hole thickened portion of the uneven thickness disc of the embodiment of the present invention.
FIG. 7 is a partial cross-sectional view of a wheel having a conventional uniform thickness disc.
FIG. 8 is a partial sectional view of a wheel having a conventional uneven thickness disc.
FIG. 9 is a process diagram showing a conventional uniform plate thickness disc manufacturing procedure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Disc 1a Hub mounting part 1b Curved part 1c Decoration hole thickening part 1d Design surface part 1e Terminal part 2 Rim 3 Decoration hole 3a Decoration hole center 3b Decoration hole thickening position 4 Wheel 4a Wheel center part

Claims (4)

A hub mounting portion extending in a direction perpendicular to the wheel axis;
And extending buildings bend the continuous with hub mounting portion, from which curved from the hub mounting portion toward the axially inner and radially outwardly,
A design surface portion that extends from the curved portion, while being curved at a radius of curvature larger than the radius of curvature of the curved portion, radially outward and axially inward.
A terminal portion extending to the inner side in the axial direction;
A plurality of decorative holes provided in the design surface portion;
In the wheel disc having
A straight line inclined 45 degrees from a straight line passing through the center of the decorative hole and connecting the center of the decorative hole and the center of the wheel, when the thickness distribution of the design surface portion is viewed in the axial direction of the decorative hole. A non-uniform plate thickness disc characterized in that a portion intersecting the periphery of the hole and the vicinity thereof are made thicker than the other periphery of the decorative hole to increase the thickness of the decorative hole.   The uneven thickness disc according to claim 1, wherein the decorative hole thickening portion is formed by thickening the back side of the design surface portion. The thickness distribution of the disk is made thinner in the order of a hub mounting portion, a decorative hole thickening portion, a curved portion, a design surface portion having the same diameter as the central portion of the decorative hole, and a terminal portion. The uneven thickness disc described. When the thickness distribution of the disk is 1 for the hub mounting part, the decorative hole thickened part is 0.62 to 0.70, the curved part is 0.50 to 0.58, and the diameter is the same as the central part of the decorative hole. The uneven thickness disc according to claim 1 or 2 , wherein the design surface portion is 0.42 to 0.50 and the terminal portion is 0.35 to 0.42.

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