JPH0537738Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a core metal used in an automobile steering wheel.

PRIOR ART The rim of this type of core metal is generally made by bending a hollow pipe into a ring shape, abutting both ends of the hollow pipe, and joining them by arc welding.

By the way, when arc welding is performed in this manner, a bead bulges on the outer periphery of the joint at both ends of the rim and protrudes outward from the outer diameter of the rim.

However, it is extremely inconvenient if the bead protrudes outward beyond the outer diameter of the rim. In other words, steering wheels are generally constructed by coating the core metal with resin by injection molding, but during this injection molding, the beads obstruct the flow of the resin solution, so the product The quality deteriorates.

Therefore, conventionally, this raised bead has generally been removed by a grinding process. However, such a grinding process increases the manufacturing cost of the steering wheel.

Technical problem of the present invention Therefore, the technical problem to be solved by the present invention is that in the core metal of this type of steering wheel, the bead formed on the outer periphery of both ends of the rim during welding does not protrude beyond the outer diameter of the rim. The purpose is to do so.

Summary of the present invention (Structure, operation, effect) In order to solve the above technical problem, the core metal of the steering wheel according to the present invention is constructed as follows.

That is, by inserting a core rod having an outer diameter sufficiently smaller than the inner diameter of the hollow rim between both ends of the hollow rim, and squeezing the both ends together with the ends abutted against each other, the above-mentioned It is characterized in that both ends are crushed and deformed together with the core rod to substantially close the hollow part of the rim, and the entire periphery or a part of the rim is welded along the abutted ends of the two ends.

According to the above configuration, since both ends of the rim are narrowed, the outer diameter of the rim is sufficiently smaller than the outer diameter of the rim. Therefore, even if welding is performed on the outer periphery of both ends of the butt, the bead generated by the welding can be contained within the outer diameter of the rim. Therefore, even in the resin coating process by injection molding of steering wheels,
The flow of molten resin is not obstructed.

Furthermore, according to the above configuration, both ends of the rim are compressed and deformed together with the inserted core rod, and as a result, the hollow part of the rim is almost closed, so that spatter that occurs during welding can be avoided. Droplets are effectively prevented from entering the rim hollow.
When these spatters and droplets enter the hollow rim and cool down, they become spherical or lumpy and roll within the rim of the steering wheel core metal, resulting in problems such as abnormal noises.

Furthermore, the above configuration is very convenient during welding. That is, since both ends of the rim are connected by squeezing, that is, caulked, through the core rod, the abutting state of the two ends is maintained by the core rod. Therefore, the abutment position of the two ends during welding is very stable, making the welding work easier. When this welding is performed by a welding robot, the holding mechanism for the core metal during welding by the robot becomes simple. Further, since both ends of the rim are caulked with a core rod interposed therebetween, the durability of the welded portion is good.

Embodiment An embodiment of the present invention shown in FIGS. 1 to 6 will be described in detail below.

First, a first embodiment shown in FIGS. 1 to 4 will be described.

Figure 1 shows the entire core metal. In the figure, 1 is a hollow rim, 2 is a spoke connected to the rim,
3 is a boss plate connected to the spoke, and 4 is a boss attached to the boss plate 3. These general configurations are no different from conventionally known core metal structures.

Next, the structure of the connecting portions at both ends of the rim 1 of the metal core will be explained with reference to FIGS. 3 and 4 showing the manufacturing process thereof.

First, as shown in FIGS. 3 and 4, a core rod 1 having a square cross section is placed between both ends 10a and 10b of the rim.
Insert 1. This core rod 11 has an appropriate outer diameter that is sufficiently smaller than the inner diameter of the hollow rim 1.

Next, as shown in FIGS. 3 and 4, the ends 10a and 10b are integrally drawn (crimped) with the ends 10a and 10b abutted against each other, and the ends 10a and 10b are attached to the core rod 11. At the same time, the rim 1 is crushed and deformed to substantially close the hollow part of the rim 1. In this example, FIGS. 3, 4 and 2
As shown in the figure, each of the end portions 10a and 10b has a square cross section, and is drawn so that four flat surfaces 13 are formed on the outer periphery thereof. In other words, the outer diameters of the drawn end portions 10a and 10b are approximately equal to or slightly smaller than the rim outer diameter at four locations, but the portions of the flat surfaces 13 are located inside the rim outer diameter. . The core rod 11 is also deformed and integrated with both end portions 10a and 10b.

Next, as shown in FIGS. 3 and 4, arc welding is performed on the outer periphery of the abutting ends of both ends 10a and 10b. In this case, as shown in the figure, the welding points are mainly applied to the portions of each plane 13. Therefore, the bead 12 generated during welding
are formed on the outer periphery of both end portions 10a, 10b in such a manner as to fill these flat surfaces 13. In other words,
These beads 12 can be prevented from protruding beyond the outer diameter of the rim. This welding operation can be performed under very stable conditions. because,
As shown in FIGS. 3 and 4, both ends 10a and 10b are drawn with the core rod 11 interposed in the center, so both ends 10a and 10b are integrated with the core rod 11, As a result, both ends 10a, 1
This is because the butt state of 0b is maintained well. Further, since the core rod 11 substantially closes both ends 10a and 10b, spatter and droplets generated during welding are effectively prevented from entering the rim hollow. Furthermore, due to the presence of the core rod 11, the durability of the welded portions of the rim both ends 10a, 10b is excellent.

A second embodiment is shown in Figures 5a and 5b. In this embodiment, the core rod 11 has a round cross section. Therefore, both end portions 10a and 10b of the rim are also caulked to have a round cross section and then welded.

Figures 6a and 6b show a third embodiment. In this embodiment, the core rod 11 has rim both ends 10a,
Although it is a round bar having an outer diameter approximately equal to the inner diameter of the bar 10b, it has a circumferential groove 11a in its intermediate portion. Then, both ends 10a and 10b of the rim are caulked so as to fit into the circumferential groove 11a of the core rod 11, and then welding is performed thereon.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of a steering wheel core according to the first embodiment, and FIG. 2 shows both joint ends of the rim of the core shown in FIG. FIG. 3 is a cross-sectional process diagram showing the process of joining both ends of the rim in FIGS. 1 and 2, and FIG. 4 is a process diagram similar to FIG. 3. Fig. 5a is a sectional view of the main part of the core bar of the steering wheel according to the second embodiment, Fig. 5b is a sectional view of Fig. 5a, and Fig. 6a is a sectional view of the third embodiment. FIG. 6b is a cross-sectional view of a main part of the core metal of the steering wheel according to the example, and FIG. 6b is a cross-sectional view of FIG. 6a. 1... Hollow rim, 2... Spoke, 3... Boss plate, 4... Boss, 10a, 10b... End, 11... Core rod, 12... Bead, 13... Plane.

Claims (1)

[Scope of utility model registration request] A core rod 11 having an outer diameter sufficiently smaller than the inner diameter of the hollow rim 1 is inserted between both ends 10a, 10b of the hollow rim 1, and the above-mentioned ends 10a, 10
With the two ends 10a and 1 abutted against each other,
By integrally narrowing 0b, both ends 10
a, 10b are crushed and deformed together with the core rod 11 to substantially close the hollow part of the rim 1, and the above-mentioned both ends 10
A core metal for a steering wheel, characterized in that the entire circumference or a part of the circumference is welded along the abutted ends of a and 10b.