JPH0834202A - Wheel - Google Patents

Abstract

PURPOSE:To provide a wheel which has high mechanical strength and excellent corrosion resistance, and can make its thickness thinner. CONSTITUTION:An outer rim part 1 for composing the outside end of the outer periphery of a wheel, a center hub part 2 for composing the central part of the outside of the wheel, and a connection part 3 being a designed face for connecting the outer rim part 1 to the center hub part 2 are unitedly formed of the casting of two-phase stainless steel composed in the mixed structure of ferrite and austenite for composing a wheel outside half body 4. A central rim part 5 for composing the central part of the outer periphery of the wheel and an inner rim part 6 for composing the inside end part of the periphery of the wheel are formed of austenite system stainless steel for composing a wheel inside half body 7. The wheel outside half body 4 and the wheel inside half body 7 are mutually stuck fast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile wheel.

[0002]

2. Description of the Related Art Conventional automobile wheels are made of mild steel (SS400), aluminum alloy, magnesium alloy or the like. Here, the SS400 wheel has, for example, as shown in FIG. 8, a disk portion 20 composed of a center hub portion and a design surface formed by press working, and an outer rim portion constituting an outer peripheral portion 21 of the wheel. The central rim portion and the inner rim portion are formed by a forming roll of a metal hoop material, and the disc portion and the outer peripheral portion are fixed to each other by fixing means such as spot welding, build-up welding or tap connection. This mild steel steel wheel has a problem in that the disk portion of the wheel is a pressed product, so there is a limit in the degree of freedom in design, and the appearance is not good because the mating portion shown in Fig. 8B is visible. Further, the wheel made of SS400 is heavy and difficult to handle, and there are problems such as corrosion.

In addition, wheels made of aluminum alloy are manufactured by clear coating the surface to prevent corrosion, or by forming a layer of alumite, and then performing clear coating on it to prevent corrosion. There is a problem in that it is time-consuming and costly. The wheel made of aluminum alloy has the coating layer on the outer surface as described above, but when the coating layer is scratched, the base material aluminum is exposed and the scratched portion corrodes. In this case, there is a problem in that the color changes due to corrosion and the appearance also deteriorates.

Further, since a magnesium alloy wheel has a clear coating on its surface in order to prevent corrosion, it takes a lot of time and effort to manufacture it, and the coating layer on the outer surface of the wheel is scratched. When the coating is broken, there is a problem that the base material magnesium is exposed and corrosion becomes severe, and further, there is a problem that the color changes due to corrosion and the appearance deteriorates.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the above-mentioned conventional examples, and its object is to have high mechanical strength, excellent corrosion resistance and clear outer surface. It does not require painting, is cheap, and can be made much thinner and lighter than wheels made of mild steel, and it also has the flexibility of designing the parts visible from the outside. There is a wheel to offer.

[0006]

In order to solve the problems of the above-mentioned conventional examples and to achieve the object of the present invention, a vehicle wheel of the present invention has an outer rim that constitutes an outer end portion of an outer peripheral portion of the wheel. The portion 1, the center hub portion 2 that constitutes the central portion of the outer surface of the wheel, and the connecting portion 3 that serves as a design surface that connects the outer rim portion 1 and the center bubble portion 2 are formed of a mixed structure of ferrite and austenite. The outer half body 4 of the wheel is integrally formed of a cast product of duplex stainless steel, and the central rim portion 5 constitutes the central portion of the outer peripheral portion of the wheel and the inner end portion of the outer peripheral portion of the wheel. The inner rim portion 6 is formed of austenitic stainless steel to form a wheel inner half body 7, and the wheel outer half body 4 and the wheel inner half body 7 are fixed to each other. It is.

[0007]

According to the present invention, however, by forming the wheel of the automobile from stainless steel, the weight is reduced, the handling becomes easier, and the surface is not required to be corrosion-prevented. When the wheel is made of stainless steel, the outer rim portion 1 forming the outer end portion of the outer peripheral portion of the wheel, the center hub portion 2 forming the center portion of the outer surface of the wheel, the outer rim portion 1 and the center bubbling portion. The wheel outer half body 4 is formed by integrally forming the connecting portion 3 serving as a design surface that connects 2 with a cast product of a duplex stainless steel composed of a mixed structure of ferrite and austenite. Even if the cross-section is complicated, the wheel outer half 4 made of duplex stainless steel can be easily and accurately formed by a casting such as the lost wax method. The wheel outer half 4 has the center hub portion 2. It is the part where the strength is required most, but since it is made of duplex stainless steel, it is composed of a mixed structure of ferrite and austenite. The 2
Since it is made of duplex stainless steel, it has a high mechanical strength and can be made thinner than a wheel made of SS400, and the wheel outer half 4 is a part that can be seen from the outside. Duplex stainless steel composed of a mixed structure with austenite has extremely high corrosion resistance, is not easily affected by snow melting agents and salt damage, and can maintain a beautiful state on the outer surface for a long period of time. Further, a wheel inner half body 7 is formed by forming a central rim portion 5 that constitutes the central portion of the outer peripheral portion of the wheel and an inner rim portion 6 that constitutes the inner end portion of the outer peripheral portion of the wheel from austenitic stainless steel. by doing,
A cheap wheel can be provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.
1 to 3 show an embodiment of the wheel of the present invention. In the present invention, the wheel is made of two pieces, and the wheel outer half body 4 and the wheel inner half body 7 are fixed to each other. That is, the wheel outer half body 4 includes the outer rim portion 1 forming the outer end portion of the outer peripheral portion of the wheel,
A center hub portion 2 that constitutes the central portion of the outer surface of the wheel,
The outer rim portion 1 and the center bubble portion 2 are integrally formed with a connecting portion 3 that serves as a design surface, and is formed of a mixed structure of ferrite and austenite.
It is a cast product of duplex stainless steel and is formed by the lost wax method. Here, a connecting portion 9 is provided at an inner end portion of the outer rim portion 1 of the wheel outer half body 4. As described above, the outer rim portion 1 that constitutes the outer end portion of the outer peripheral portion of the wheel, the center hub portion 2, and the connecting portion 3 that serves as a design surface that connects the outer rim portion 1 and the center bubble portion 2 are 2 Since it is a cast product made of duplex stainless steel by the lost wax method, it has a degree of freedom in design and improves the designability of the wheel outer half 4 which is a part that can be seen from the outside like a wheel made of aluminum alloy. Is.

The inner wheel half 7 is formed by integrating a central rim portion 5 which constitutes a central portion of the outer peripheral portion of the wheel and an inner rim portion 6 which constitutes an inner end portion of the outer peripheral portion of the wheel. , Austenitic stainless steel. As the wheel inner half body 7, for example, one formed by bending an austenitic stainless steel plate into a cylindrical shape and fixing both ends to each other by welding or the like and bending an inner rim portion 6 is used. Alternatively, an austenitic stainless steel casting is used, and a connecting portion 10 is provided at the outer end of the central rim portion 5 of the wheel inner half body 7. When a stainless steel plate is used, it is easy to manage the thickness, and it is possible to easily cope with it by appropriately selecting one having a different thickness according to the required strength.

The wheel outer half body 4 and the wheel inner half body 7 having the above-described structure are overlapped with both connecting portions 9 and 10 and welded to each other so that the wheel as shown in FIGS. It is what constitutes. In FIG. 1, reference numeral 8 indicates a welded portion. FIGS. 4 to 6 show another embodiment of the present invention, in which both connection portions 9 and 10 of the wheel outer half body 4 and the wheel inner half body 7 are connected to the bolt 1.
1, an example in which they are fixed by a nut 12 is shown. Of course, in the present invention, the shape of the wheel is not limited to that shown in FIGS. 1 to 3 or 4 to 6.

Here, the wheel outer half 4 is formed of the two-phase stainless steel composed of the mixed structure of ferrite and austenite as described above.
As the duplex stainless steel, for example, "2-phase stainless DSD1H" manufactured by Daido Steel Co., Ltd. can be used. The chemical composition of C is ≤0.04, Mn is 0.8, and P is ≤0.
040, S is ≤0.030, Cu is ≤0.3, Ni is 5.5, Cr is 24.0, Mo is 1.5, and Nb is a small amount. As shown in the above chemical composition, the main component is SUS3
Chromium is higher than 04 steel, nickel is lowered, molybdenum and several special elements are added, and in the standard state, it is composed of a mixed structure of about 70% ferrite and about 30% austenite. In FIG. 7, 2 used in the present invention
Fig. 7 shows a Schaeffler plot of phase stainless steel.
Medium a is the product of the present invention.

In the present invention, the wheel outer half 4 is composed of a mixed structure of the above ferrite and austenite by a casting method such as the lost wax method.
It is made of phase stainless steel, and the heat treatment conditions are heating temperature of 1050 to 1100 ° C and heating time of 30 minutes / 2.
It is 5 mm and then water cooled. The two-phase stainless steel composed of a mixed structure of ferrite and austenite has high mechanical strength (proof strength), for example, SUS30.
It is about twice as much as No. 4, the fatigue strength is about twice as much as SUS304, and the abrasion resistance is excellent. In addition, general corrosion resistance shows a corrosion resistance of SUS316 or more, and stress corrosion cracking resistance, which is a weak point of austenitic stainless steel,
The pitting corrosion resistance and intergranular corrosion resistance are improved, especially the stress corrosion cracking resistance and the pitting corrosion resistance are excellent, and the thermal expansion is small and the thermal conductivity is good, and thermal strain does not occur. It has various characteristics.

Therefore, since the mechanical strength is high as described above, sufficient strength can be exhibited even if the wall thickness of the conventional wheel made of SS400 is thin. Since the wheel outer half 4 which is the main body of the wheel is integrally formed by a cast product such as the lost wax method by the duplex stainless steel having the above characteristics, it is about the same as the wheel made of mild steel. When it is attempted to express the strength of, the thickness can be made thinner than the wheel made of mild steel and the weight can be reduced. Moreover, as with the aluminum alloy wheel, the degree of freedom in the design of the part visible from the outside can be obtained. In particular, the wheel outer half 4 forms not only the connecting portion 3 which is the design surface but also the outer rim portion 1 and the center hub portion 2 which are exposed to the outside and can be seen from the outside. Since the wheel outer half 4 which is a visible portion is formed of a material having excellent corrosion resistance as described above, it is hardly affected by a snow melting agent or salt damage, and can maintain a beautiful appearance for a long time. In addition, since the duplex stainless steel itself has excellent corrosion resistance, even if it is damaged, the base material will be damaged due to scratches like aluminum alloy wheels and magnesium alloy wheels that have a skin layer. There is no danger of being exposed and rusting from there,
Since the material itself has corrosion resistance, it is not necessary to separately treat the surface for corrosion, unlike aluminum alloy wheels and magnesium alloy wheels.

Further, since the inner wheel half 7 is formed of austenitic stainless steel, since this portion is not the portion exposed to the outside, the corrosion resistance of the outer wheel half 4 exposed to the outside is not required. Therefore, it is composed of a mixed structure of ferrite and austenite.
It is made of austenitic stainless steel, which is cheaper than the phase stainless steel, but the austenitic stainless steel can be thinner than the steel wheel, and the weight can be reduced in this respect as well.

[0015]

According to the present invention, as described above, the outer rim portion forming the outer end portion of the outer peripheral portion of the wheel,
A cast product of duplex stainless steel in which a center hub portion that constitutes the central portion of the outer surface of the wheel and a connecting portion that serves as a design surface that connects the outer rim portion and the center bab portion are made of a mixed structure of ferrite and austenite. Are integrally formed with each other to form a wheel outer half body, and a central rim portion that constitutes a central portion of the outer peripheral portion of the wheel and an inner rim portion that constitutes an inner end portion of the outer peripheral portion of the wheel are austenitic stainless steel. The inner half of the wheel is formed by and the outer half of the wheel and the inner half of the wheel are fixed to each other, so that the entire body is made of stainless steel, and the wall thickness is made thinner than that of the mild steel steel wheel. It is lightweight and easy to handle, and because it is made entirely of stainless steel, it is made of aluminum alloy wheels and magnesium alloy. Not necessary to Corrosion on the surface as in manufacturing of the wheel, the cost is also cheap. Moreover, when the wheel is made of stainless steel, the outer rim portion that forms the outer end portion of the outer peripheral portion of the wheel, the center hub portion that forms the center portion of the outer surface of the wheel, and the outer rim portion and the center bubbling portion are connected. The outer half of the wheel, which is the exposed portion to the outside and which constitutes the main body of the wheel, is composed of a mixed structure of ferrite and austenite.
Since it is made of cast stainless steel, the degree of freedom in design of the outer half of the wheel, which is the part that can be seen from the outside, is improved by casting, and the design is improved like the wheel made of aluminum alloy. Yes, again
Since the outer half of the wheel is made of duplex stainless steel, it has high mechanical strength, extremely high corrosion resistance, is not easily affected by snow-melting agents and salt damage, and has an outer surface such as aluminum alloy wheels and magnesium alloy wheels. When the coating layer on the outer surface is broken and the outer surface is corroded, there is no risk of discoloration of this portion, and the surface seen from the outside can be kept beautiful for a long period of time. In particular, at present, there are wheels of mild steel steel and wheels of aluminum alloy whose design surface has been subjected to expensive chrome plating, but the outer half of the wheel is made of duplex stainless steel as in the present invention. Therefore, it is possible to secure the design only by processing the mirror surface processing of the part visible from the outside, and when using it, it is possible to regenerate an excellent mirror surface at any time just by re-polishing for small scratches etc. This is an effect peculiar to the present invention, which is impossible with a treated wheel. Further, in forming a wheel made entirely of stainless steel, a central rim portion that constitutes the central portion of the outer peripheral portion of the wheel and an inner rim portion that constitutes the inner end portion of the outer peripheral portion of the wheel are made of austenitic stainless steel. An inexpensive wheel can be provided by configuring the wheel inner half formed by the above.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a wheel of the present invention.

FIG. 2 is a partially cutaway front view showing the outer surface side of the above.

FIG. 3 is a partially cutaway rear view showing the inner surface side of the above.

FIG. 4 is a cross-sectional view showing another example of the wheel of the present invention.

FIG. 5 is a partially cutaway front view showing the outer surface side of the above.

FIG. 6 is a partially cutaway rear view showing the inner surface side of the above.

FIG. 7 is a state diagram of Schaeffler of duplex stainless steel used in the present invention.

FIG. 8 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Outer rim part 2 Center hub part 3 Connecting part 4 Wheel outer half body 5 Center rim part 6 Inner rim part 7 Wheel inner half part

Claims (1)

[Claims] 1. An outer rim portion forming an outer end portion of an outer peripheral portion of a wheel, a center hub portion forming a center portion of an outer surface of the wheel, and a connection serving as a design surface connecting the outer rim portion and the center bubbling portion. And a central rim portion that forms a wheel outer half body by integrally forming a part with a cast product of a duplex stainless steel composed of a mixed structure of ferrite and austenite, and forms a central portion of the outer peripheral portion of the wheel, The inner rim portion that constitutes the inner end portion of the outer peripheral portion of the wheel is formed of austenitic stainless steel to form the wheel inner half body, and the wheel outer half body and the wheel inner half body are fixed to each other. The characteristic wheel.