JPH01262201A - Joining method for end part of annular rim - Google Patents

Abstract

PURPOSE:To improve an external appearance and joining strength by forming a fitting projection part on one part of the end face of a rim stock and a fitting recessed part on the other part of the end face and joining the end part by fitting the projection part by press-fitting it to the recessed part in the annular rim for a bicycle, etc. CONSTITUTION:A plane view rectangular fitting projection part 2 is formed by cutting on the end face of the strip sheet part 1a of the end part of one part of the rim stock 1 extruded in U sectional shape having the strip sheet part 1a and rise edge parts 1b, 1b by Al-Zn Mg alloy. Similarly, side face view triangular fitting projection parts 3, 3 are formed on the rise edge parts 1b, 1b. The fitting recessed parts 4, 5, 5 corresponding to these fitting projection parts 2, 3, 3 are formed at the end part of the other part. The rim stock 1 is then bent annularly and the fitting projection parts 2, 3, 3 are fitted by press- fitting to the corresponding recessed parts 4, 5, 5. The joining strength can be improved with good external appearance by this structure.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method for joining ends of annular rim materials used as rims for bicycles and motorcycles.

Conventional technology Conventionally, as a method of joining the ends of this type of annular rim material, the ends were butted and then joined and fixed by flash pad welding, or the opposite end surfaces of the ends were joined. A method of connecting and fixing is adopted by forming a hole and press-fitting a connecting pin into the hole.

Problem to be Solved by the Invention However, when using flash pad welding, so-called burr is formed around the entire circumference of the joint including the inner peripheral surface side that is visible when used as a rim. Puff polishing is required, and the finishing process is troublesome.

On the other hand, when using a method of fixing using a pin, there is a problem in that it tends to wobble during use.

In view of the above-mentioned problems, the present invention provides an end joint for an annular rim material that provides a good appearance and strong joint strength that does not cause wobbling during use. The present invention provides a method.

As a means for solving the problem, the method for joining the ends of an annular rim according to the present invention includes the following steps when joining opposite ends of the annularly curved rim members (1) (lO): Fitting protrusions (2) (3) (20
), and the convex portion (2) is formed on the other opposing end surface.
(3) Fitting recess (4) corresponding to (20)
(5) (40) is formed, and the recess (4) (5)
The convex portions (2), (3), and (20) are press-fitted into (40).

The alloy of the rim material used in this invention is not particularly limited, but for example, AQ-Mg-3i, A
Aluminum alloys such as fl-Zn-Mg series, especially A
Q-Zn-Mg alloys are advantageous in that they can improve strength and reduce weight, so they can be suitably employed.

From the viewpoint of manufacturing cost and quality, the rim material can be suitably manufactured by homogenizing the aluminum alloy ingot and extruding it into the cross-sectional shape of the rim.

Then, the rim material is bent into an annular shape, and both ends of the rim material are joined together. In this invention, when joining, a fitting convex portion (2) is formed on one opposing end surface of the annular rim material. (3) (20) are formed, and fitting recesses (4), (5), and (40) corresponding to the projections (2), (3), and (20) are formed on the other opposing end surface. These fitting protrusions (2), (3) (20) and fitting recesses (4), (5), and (40) are the rim material (1).
(10) may be formed by cutting both ends thereof before bending.

Then, the shape of the rim is bent, and the fitting convex part (2) is inserted into the fitting concave part (4) (5) (40).
(3) (20) shall be press-fitted.

The fitting protrusions (2), (3), and (20) and the fitting recesses (4, 5, and 40) are only connected to each other in the circumferential, radial, and axial directions of the annular rim material. It is preferable to set the shape, position, or number appropriately so as to maintain strong connection strength, but it is also possible to supplement the strength by using conventional connection bottles together.

The alumite treatment as a surface treatment for the rim material may be performed after the connection is fixed, as in the case of flash butt welding, but when using the method of the present invention, there is no occurrence of flashing during joining; Since there is no need to perform puff polishing or the like after that, it is permissible to perform polishing on the long shape material before joining. This makes it possible to reduce the cost compared to the case where alumite treatment is performed after the ends are joined.

Example The present invention will be described in detail below.

1 to 3 show an embodiment of the present invention, in which an AQ-Zn-Mg alloy ingot is homogenized as the rim material (1), and a strip plate portion is formed as shown in FIG. (1a) was extrusion-molded to have a substantially U-shaped cross section and a pair of rising edges (lb) parallel to both side edges. Then, by cutting one end of the band plate part (l
A fitting convex portion (2) having a rectangular shape in plan view extending from the middle part in the width direction of the end face of a), and a side surface extending from the middle part in the height direction of the end face of (lb) A fitting convex portion (3) (3) having a triangular shape in view is formed respectively, and a fitting concave portion (4) corresponding to each of the above-mentioned fitting convex portions (2) (3) (3) is formed at the other end. (5) (5) was formed. This rim material (1) was then subjected to alumite treatment and then bent into the shape of an annular rim. Then, as shown in FIG. 2, the corresponding fitting convex portion (2) is press-fitted into the fitting concave portion (4) of the strip plate portion (1a), and the rising edge (lb) The corresponding fitting convex portions (3) (3) were fitted into the fitting concave portions (5) (5) of (lb). The latter fitting acts to reinforce the strength of the rim in the radial direction compared to the former press-fitting connection. If a connecting pin is not used as in this embodiment, good dynamic balance characteristics can be maintained as an annular rim member.

4 to 6 show another embodiment of the present invention, in which an extruded material similar to that of the above embodiment is used as the rim material (10), and one end of the extruded material is cut. A fitting convex part (20) having a rectangular shape in plan view extending in the middle part in the width direction of the end of the band plate part (LOA), a rising edge part (JOB)
A connecting pin fitting hole (108) (10c) having a circular cross section is formed at the lower end of the (fob), and a fitting recess (108) (10c) corresponding to the fitting protrusion (20) is formed at the other end.
40) and the connecting bottle fitting hole (l Oc) (l
Connecting bottle fitting hole (l Oc) corresponding to (I
Oc) were formed respectively.

After anodizing, it is bent into an annular shape, and each end of the connecting pin (30) (30) is inserted into the corresponding connecting bottle fitting hole (10c) (10c) (10c) (10c).
) are press-fitted into the respective fitting convex portions (2).
o) was press-fitted into the fitting recess (40). In the case of this embodiment, the former fitting mainly acts to reinforce the strength of the annular rim in the radial direction compared to the latter fitting connection.

It was confirmed that the rims obtained by any of the above methods not only had a good appearance but also had a sufficiently strong joint strength.

Effects of the Invention The method for joining the ends of an annular rim material according to the present invention is as follows.
When joining opposite ends of two circularly curved rim materials, a fitting convex portion is formed on one opposing end surface of the rim material, and the convex portion is formed on the other opposing end surface. A fitting recess corresponding to the rim is formed, and the protrusion is press-fitted into the recess. Therefore, when used as a rim, such as when the opposite end surfaces are joined together by flash pad welding, There is no possibility that so-called cracks will be formed at the joint including the inner circumferential surface side that is visible, and the appearance will not be deteriorated. This not only eliminates the need for finishing work such as puff polishing to remove the above-mentioned particles, but also allows bending after alumite treatment, which is different from the case where the same treatment is performed after annular bending. It is possible to reduce costs by comparison.

Further, unlike the method of fixing using only pins, there is no wobbling over time, and the durability of the rim can be improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view of the vicinity of the joint showing the process of joining, FIG. 2 is a partially cutaway perspective view of the vicinity of the joint showing the joining state, and FIG. 3 is a perspective view of the vicinity of the joint showing the joining state. Figure 2■
4 to 6 show other embodiments, and FIG. 4 is a perspective view of the vicinity of the joint corresponding to FIG. 1, and FIG. 5 corresponds to FIG. 2. FIG. 6 is a partially cutaway perspective view of the vicinity of the joint, and FIG. 6 is a sectional view taken along the line Vl--Vl in FIG. (1) (10)...Rim material, (2) (3) (
20)...Fitting convex portion, (4) (5) (40)
...Mating recess. that's all

Claims (1)

[Claims] When joining the opposing ends of the annularly curved rim materials (1) and (10), a fitting convex portion (2) and (3) is attached to one of the opposing end surfaces of the rim materials (1) and (10). (20), and the convex portions (2), (3), and (20) are formed on the other opposing end surface.
Fitting recesses (4) (5) (40) are formed corresponding to the recesses (4) (5) (40), and the projections (2) (3) (2) are formed in the recesses (4) (5) (40).
0) A method for joining ends of an annular rim material, characterized by press-fitting.