JPS592901A - Junction type disc wheel of light alloy - Google Patents

Abstract

PURPOSE:To reduce the generation of crack on a rim side and consequently improve the durability of the disc wheel by a method wherein a surface treatment by shot peening is applied on the rim side of a weld bead, which is applied to the junction between the rim and a disc of the vehicular disc wheel. CONSTITUTION:Because the existence of a depression caused by the final end part or a part of boundary line of rim 1 side of weld bead 11 together with a corner 5 so as to form a notch 12 develops the possibility of the generation of cracks 13 in the vicinity of the notch 12, ring-shape shot-peening treatment is applied from a nozzle 15 along the peripheral surface onto a surface 14 near the boundary line of the rim side weld zone of the weld bead. Even if a notch 12 or an unhomogeneous part is generated by welding, the tensile stress generated at the rim 1 and the weld bead during the running for a long period of time can be relieved because of the residual compression stress developed at said rim 1 and weld bead 11 by shot-peening action.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc wheel for a vehicle, and more particularly to a joined type light alloy disc wheel in which a rim and a disc are integrated by melt welding.A rim made of a wrought material and a cast or wrought material. Compared to monolithically cast disc wheels, the joining type light alloy disc wheel is made up of a disc that is integrated with the disc by fusion welding, and the manufacturing cost involved in the casting process is reduced compared to a disc wheel that is cast as a single piece.It is also lighter in weight and has increased impact resistance. It has advantages such as: On the other hand, it is difficult to weld so that the welding pitch formed in an annular shape along the rim is uniform at all parts, and stress concentration may occur if the welding pitch P becomes non-uniform, especially on the rim side. However, there was a problem in that the rim was prone to cracking.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to obtain a joined type light alloy disc wheel with excellent durability and strength even on the welded rim side, which has traditionally been an unstable part of the welded part. purpose.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a part of a vehicular joint type light alloy disc wheel to which the present invention is applied.

l indicates the rim, and 2 indicates the disc. A groove 3 for fitting a tire is formed on the outer periphery of the rim l. To form the groove 31, the rim 1 has a flat bottom part 4 and from this a corner part 5, 5'.
a second flat bottom part 8,8' which is further bent approximately parallel to the flat bottom part 4 by a corner part 7.71; 8' and outermost peripheral parts 9, 9' on the outside, and such a cross-sectional shape is formed into a ring shape to form a rim called, for example, a wide deep rim. Although the rims 1 shown in FIG. 1 have different angles of outward inclination of the outer periphery 6.6', this can of course also be symmetrical, as will be readily understood by a person skilled in the art. That's true.

As is well known, a vehicle wheel includes a disk 2 connected to the periphery of a hub that receives an axle, and an annular ring 11B3 outside the disk 2.
and a rim 1 on which the tire is to be fitted. The rim 1 and the disc 2 are often manufactured by integral casting, but the disc wheel according to the present invention processes the rim 1 and the disc 2 as separate bodies, and then joins them together by melt welding to integrate them. It is something that makes you In this embodiment, the disc 2 is fitted along the aforementioned outer circumferential portion 6 of the rim 1, and the aforementioned corner portion 5 forms a bevel along the curve thereof.

As shown in FIGS. 2 and 3, the groove is indicated at 10 and the weld bead formed by welding is indicated at 11. Welding is performed along the joint circumferential surface of rim l and disc 2 (welding is performed on the inner surface in order to prevent welding marks from being visible from the outside when the wheel is installed on the vehicle). ), the thickness of the rim l is generally not large, and therefore a uniformly smooth weld is required, especially on the rim l side. For example, as shown in FIG. 2, when welding the rounded corner 5 of the rim 1 as the groove 10, the weld bead 11 is smoothly joined to the outer wall of the flat bottom part 4 of the rim l, and this is connected to the peripheral surface. It is preferable that it is applied uniformly in a ring-like manner.

If the terminal end or boundary line of the rim 19111 of the weld bead 11 is recessed to form a notch 12 with the rounded corner 5, as shown in FIG.
A crack 13 may occur near 2. This is one of the nine results of our long-term tests, and was discovered as a result of rotational bending load durability tests. For this reason, welding conditions must be strictly controlled when joining the rim 1 and the disk 2.

In the present invention, shot peening is applied to the surface 14 of the weld bead in the vicinity of the rim-side weld boundary line in a ring shape from a nozzle 15 along the circumferential surface. As a result, even if a notch 12 or a non-uniform spot as described above occurs as a result of welding, the working pressure of shot peening will create compressive residual stress in the sill 1 and the weld bead, so that it will not be possible to maintain it while the vehicle is running. It is possible to alleviate the tensile stress that occurs in the same area over a long period of time, increasing durability.

As explained above, according to the present invention, it is possible to reduce the possibility of cracks occurring on the rim side joined by fusion welding, thereby improving the durability life, easing the management of welding conditions, and improving reliability. It would be very effective if a wheel with improved characteristics could be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view of an embodiment of a joint type disc wheel to which the present invention is applied, and FIGS. 2 and 3 are schematic diagrams for explaining details of weld bead formation. ■...Rim, 2...Disk, 3...Annular groove, 4
...Flat bottom part, 5... Corner part, 6... Outer circumference part, 11.
...Weld bead 14...shot peened surface. Patent applicant Toyota Motor Corporation Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Kyo Nakayama Patent attorney Akira Yamaguchi

Claims (1)

[Claims] A joint type in which the rim and the disc are integrated by joining a disc along the outer circumferential surface of the flat bottom groove of the rim with an annular groove formed therein, and melting welding the nine ring-shaped groove formed at the joint. In light alloy disc wheels, the surface near the rim-side weld boundary line of the molten weld bead applied to the joint between the rim and the disc is subjected to surface treatment by shot-heening to increase the durability of the core. A bonded light alloy disc wheel characterized by: