JPH0348067B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a steering wheel for an automobile, and simplifies the connection between a main ring and spokes.
This is intended to improve the strength of the joint against the load.

2. Description of the Related Art Conventionally, rings and spokes of an automobile steering wheel have generally been connected by three methods shown in FIGS. 4 to 6.

In the method shown in FIG. 4, the ring is composed of a main ring 1 and a sub-ring 2, and the other ends of two spokes 4, 4, one end of which is welded to a boss plate 3, are bent, and the bent portions 4a, 4a are bent. The tip of the main ring 1 is inserted into the open end of the main ring 1 and welded (Y in the figure), and the other end is welded to the tip of the sub-ring 2 to be connected. In this method, each spoke 4 must be welded to the main ring 1 and the sub-ring 2, respectively, and welding is required at 4 locations in total, and 6 locations including the welded section to the boss plate 3, which is very time-consuming. In addition, since the ring is divided into a main ring and a sub-ring, the number of parts increases, resulting in higher costs. Also, spoke 4
The bent portion 4a must have an R shape that follows the rings 1 and 2, and must also be shaped to fit inside the main ring 1, which poses a problem that requires high precision in the shape of the spoke.

In the method shown in FIG. 5, the tips of the spokes 4' on the ring connection side are flattened, and the flattened portions 4'b are wrapped around the main ring 1 and welded (Y' in the figure). In this method, the flat part 4' to the main ring is
High precision is required for winding the main ring, and the welded part of the main ring becomes thick, which causes problems such as a poor feel when holding the main ring. In addition, in the method of welding the spoke tips and the ring shown in FIG. 5 and FIG. It has the disadvantage that large stress is likely to occur due to the burden.

In the method shown in FIG. 6, the spokes 4'' are integrally molded with the boss plate 3. Since it is not easy to form the bent portions shown in FIG. 4 on the spokes 4'', a T-shaped pipe joint 5 is used. Spokes 4'' are connected to the main ring 1 and the sub-ring 2. That is,
Insert the tip of the spoke 4″ into the opening 5a of the T-shaped pipe joint 5,
The tip of the main ring 1 is inserted into the opening 5b of the joint 5, and the tip of the sub-ring 2 is inserted into the opening 5c of the joint 5, and after the insertion, the fitting parts are welded.
Also in this method, there are three welds for each joint,
There are six locations in total, which is time-consuming and cannot be easily automated. Furthermore, the outer periphery of the T-shaped joint 5 must be aligned with the rings 1 and 2, and the inner diameter must be dimensioned to allow the spokes and rings to fit inside, but the T-shaped joint 5 is usually formed by bulge processing. Therefore, it is difficult to achieve dimensional accuracy of the inner diameter, and since this separate joint is required, the number of parts increases, resulting in high costs. Furthermore, rings 1 and 2
Since the joint 5 is externally fitted on the joint 5, the joint 5 becomes step-like, and when covering with resin after joining, the flow of the resin is poor, and even if the joint is covered with resin, it feels unpleasant to the touch.

Purpose of the Invention This invention aims to solve the above-mentioned conventional problems, and aims to reduce the number of parts and cost by eliminating the need for separate members, and to assemble the spokes and the ring at one welding location each. We simplified the design and improved strength by making the load on the ring borne by the twisting of the entire spoke.
This makes it easy to obtain the desired strength.

Composition of the Invention The present invention has been made to achieve the above-mentioned object, and includes fitting holes for inserting spokes provided at positions on the inner circumferential surface of the main ring, and outer circumferential edges of each of the above-mentioned fitting holes. an overhang that protrudes to a required height from the projection toward the spoke attachment side; a tip end of the overhang is inserted through the fitting hole into the main ring; The present invention provides a steering wheel for an automobile characterized in that the steering wheel is provided with a spoke that is integral with or fixed to a boss plate at the other end thereof.

Embodiments Hereinafter, the present invention will be explained in detail with reference to embodiments shown in FIGS. 1 to 3.

In the figure, 10 is a main ring, 11 and 12 are a pair of spokes, and 13 is a boss plate integrally formed with the spokes 11 and 12.

The main ring 10 is made of one cylindrical pipe, and its both ends are welded to form an annular shape.Both end joints 10a are located at the central position opposite to the driver's side. Fitting holes 10c with cylindrical projections 10b protruding from the spoke mounting side are bored at two locations spaced apart from each other by a required distance (approximately 45 degrees) from the center of the spoke. As shown in the machining process diagram of FIG. 2, the main ring 10 is manufactured by first bending a cylindrical pipe into an annular shape, and then bending the pipe at required intervals from the center P on the driver's side opposite to the both end joints 10a. (approximately 45 degrees), a hole is drilled in advance on the inner circumferential surface side using a known T-drill method, and a fitting hole 10c is formed that protrudes from the outer circumferential edge with the overhanging portion 10b directed toward the center. is being molded. The height H of the projecting portion 10b is greater than that of the main ring 1.
The weld bead width is set to be at least the width of the weld bead (2 mm or more) so as not to adversely affect the high stress part of the weld. In this embodiment, the outer diameter D of the main ring 10 is 15φ, and the wall thickness W
is set to 1.5 mm, the outer diameter d of the overhanging portion 10b is set to 15φ (inner diameter = the diameter of the fitting hole 10c is set to 12φ), and the height H is set to 3 mm.

Note that the hole having the protruding portion may be formed by a well-known flare method instead of the T-drill method.

On the other hand, the spokes 11 and 12 are integrally molded with one end connected to the boss plate 13, and the protruding ends 11a and 12a on the ring attachment side have a simple cylindrical rod shape that fits inside the protrusion 10b. There is.

When joining the spokes 11, 12 and the main ring 10, first, the ends 11a, 12a of the spokes 11, 12 are connected to the overhanging part 10 of the main ring 10.
b, 10b, and insert the tip into the main ring 10 through the fitting hole 10c. After the fitting, the overhanging portion 10b is caulked, and then the overhanging portions 10b, 1
The tip of the 0b and the spokes 11 and 12 are welded together by CO ₂ arc welding 14. Furthermore, spoke 11,1
When there is no gap in the fitting portion between the protruding portion 10b and the protruding portion 10b, and a substantially tight fitting state is achieved, the above-mentioned crimping step is not necessary.

When connecting the spokes 11, 12 and the main ring 10 as described above, since the fitting holes are provided in advance at the attachment positions of the main ring 10, the attachment positions of the spokes can be easily and accurately determined. , 12 into the overhanging portion 10b and welding them, the joining can be extremely simple and automation can be easily performed.

The load resistance of the above-described bonded structure was compared with the conventional example shown in FIGS. 5 and 6. Compared to the conventional example, the load resistance against breakage is improved several times or even tens of times. This is because, in this embodiment, the applied load is converted into torsion of the entire spoke and is borne by the entire spoke volume, so the maximum stress is kept small.

Note that the present invention is not limited to the above-mentioned embodiment, and instead of integrally molding the spokes 11 and 12 with the boss plate 13, they are made separately, and one end is welded to the boss plate while the other end is attached to the main ring 10 by the above method. May be combined. Further, the number of spokes may be two or more, and in that case, it is necessary to provide fitting holes in the main ring side in advance, each having a number of overhangs corresponding to the number of spokes.

Effects of the Invention As is clear from the above explanation, the automobile steering wheel according to the present invention has the following effects.

The ring connection side of the spoke can be easily formed into a simple rod shape, and the fitting hole with the overhang formed on the main ring side can be easily formed using the T-drill method, etc., and the spoke can be easily formed into a simple rod shape. Since the dimensions of the inner diameter can be obtained with high accuracy using the above-mentioned processing method, the molding process of the parts becomes extremely simple, and costs can be reduced.

The spokes and the main ring are connected by simply inserting the tip of the spoke through the overhang and then fixing the tip of the overhang and the spoke by a method such as welding. Since there is only one location per spoke, it is extremely simple and can be automated.

Separate T-shaped pipe joints and the like that were conventionally required are no longer required, and since only the main ring is used without the need for a sub-ring, the number of parts can be reduced and costs can be reduced.

When covering with resin after joining the spokes and the main ring, there are no steps on the main ring, so the fluidity of the resin becomes uniform, and the outer periphery of the main ring is evenly covered with resin, so when you hold the handle. Feels better to the touch.

When a load is applied to the main ring, the spokes bear the load through twisting, which improves load resistance and increases the strength of the connection between the spokes and the main ring, making it easier to obtain the desired strength. I can do it.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view of the main part showing an embodiment of the present invention, Fig. 2 is a drawing showing the machining process of the main ring, Fig. 3 is a perspective view of the main part of the main ring, and Fig. 4
5 and 6 are plan views showing conventional examples, respectively. 10...Main ring, 10a...Joint part, 10b
... Overhanging portion, 10c... Fitting hole, 11, 12... Spoke, 11a, 12a... End portion, 13... Boss plate, 14... Welding.

Claims (1)

[Scope of Claims] 1 Fitting holes for inserting spokes provided on the inner circumferential surface side of the main ring, and a ring protruding from the outer circumferential edge of each of the fitting holes to a required height toward the spoke attachment side. The protrusion part and the tip part are inserted from the protrusion part through the fitting hole into the main ring, the insertion part is fixed to the end part of the protrusion part, and the other end is integrated or fixed to the boss plate. A steering wheel for an automobile, characterized by comprising spokes. 2. The steering wheel for an automobile according to claim 1, wherein the height of the projecting portion formed on the main ring is about 2 mm or more.