JPS61259847A - Production of mandrel for steering wheel - Google Patents

Abstract

PURPOSE:To prevent the deviation of an annular material from the annular inside peripheral surface of a ring groove by the torsion of said material by bending the mandrel material in the ring part by roller pressing to form the annular material and forming the horizontal ring groove on the inside peripheral surface of the annular material. CONSTITUTION:A round pipe is sandwiched as a material 6 for the mandrel 1 of the ring part by a pair of supply rollers 11 and 12 and is thereby advanced; at the same time, said pipe is passed betwen an annular guide 13 and plural bending rollers 16, by which the pipe is continuously bent and the annular material P is formed. A pair of press rollers 7, 8 are provided in the mid-way of bending to press said materials 6. The hollow semi-circular press groove 9 is provided to each of the peripheral surfaces of the rollers 7, 8 and an endless projection 10 is horizontally provided to the deepest part of the semi-circular press groove of the roller 8. The ring groove 2 is horizontally inscribed and formed on the inside peripheral side of the material P when the material 6 passes between the rollers 7 and 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a method of manufacturing a steering wheel core metal, and particularly to a method of manufacturing a ring portion core metal of the manufacturing method.

(Prior art) Conventionally, in order to make the steering wheel core metal lighter, the ring core metal was made of a material lighter than steel, for example, an aluminum material, and the spoke core metal was also made of a ring core metal. It was manufactured using the same type of material.

In general, the spoke core metal is made of a material that is different from the ring core metal material in terms of strength, price, or design. For example, if the ring core metal material is an aluminum-based material, the spoke core metal material may be made of steel. It was also considered to manufacture the steering wheel core metal using different materials.

In this way, if a material other than steel is used for the core metals of both the ring core metal and the spoke core metal, and the two are joined only by welding, the connection between the ends of the ring core metal and the spoke core metal will be difficult. Strength may be insufficient. Furthermore, if the ring part core metal and the spoke part core metal are made of different materials, there is a problem that it may not be possible to weld the two together.

Therefore, a ring-shaped groove (hereinafter referred to as the ring groove) is provided on the inner peripheral side of the ring core metal in the circumferential direction, and first, the end of the spoke core metal is inserted into the ring groove.・In addition to fixing and supporting the ring part core metal with the spoke part core metal, in order to prevent the two from moving relative to each other, welding them both directly or through other parts It is conceivable to join the ring part core metal and the spoke part core metal by welding.

This will be explained as follows, taking as an example a case where aluminum is used as the ring part core metal and steel is used as the spoke part core metal.

First, a round aluminum pipe is manufactured by bending a pipe in which a ring groove is formed in the length direction by a drawing method or an extrusion method.

As shown in FIG. 5, a steel plate-shaped spoke core 23 is inserted into a ring groove 22 provided on the inner circumferential side of a hollow ring core 21.
One end portion is fitted and inserted, and a boss portion 24 is welded to the other end portion of the spoke portion core metal 23 to form a steering wheel core metal 25.

Further, a coupling auxiliary member 26 made of the same material as the ring part core 21 is riveted to the one end of the spoke core 23, and the end of the coupling auxiliary member 26 is inserted into the ring groove 2.
2 and welded to the ring core metal 21.

(Problems to be Solved by the Invention) Although the steering wheel core metal 25 manufactured in this manner has achieved the original purpose of reducing weight, it has the following problems.

First, the width and depth of the ring groove 22 of the ring core metal 21 are surprisingly large.

This is because there are variations in the width and depth of the mold formed during handling or extrusion molding.

When one end of the spoke core metal 23 is inserted into the ring groove 22, if there is a large variation in the width of the ring groove 22, there will be a clearance between the ring groove 22 and the end of the spoke core metal 23. This causes the spoke core metal 23 to wobble within the ring groove 22.

Therefore, even if the two are joined by welding, the welding is simply an incidental welding for the relative positioning of the two, so the connection between the two cannot be solely dependent on the welding.Secondly, as mentioned above, The ring core bar 21 is manufactured by bending a hollow material into a ring shape, which has a groove for the ring groove 22 in advance, so the material may become twisted into a ring shape during the bending process. There is sex. Therefore, naturally, the ring groove 22 also twists, and the groove 22 deviates from the inner circumferential surface of the ring-shaped object.

This causes a decrease in the work efficiency of inserting and fixing the spoke part core metal 23 into the ring part core metal 21, and reduces the finishing accuracy of the steering wheel core metal 25.

An object of the present invention is to provide a method for manufacturing a steering wheel core metal in which the above-mentioned problems are solved.

Structure of the Invention (Means for Solving the Problems) Then, the present invention involves fitting and fixing one end of the spoke part core metal into a ring groove provided on the inner circumferential side of the ring part core metal. In a method of manufacturing a steering wheel core metal by joining the other end of the core metal to a boss part, the material for manufacturing the ring part core metal is bent into a ring shape to form a ring-shaped object, or at the same time, After forming a ring-shaped product, a press roller having concave press grooves in the circumferential direction on the circumferential surface and a roller similarly equipped with press grooves are used to form a ring-shaped object on the circumferential surface of the press groove. A steering wheel core comprising the step of manufacturing the ring portion core metal by sandwiching the material or the ring-shaped object between a press roller having a protrusion having the same cross section in the circumferential direction and performing roller pressing. The present invention attempts to solve the above-mentioned problems by using a method for producing gold.

(Function) When the material for manufacturing the ring core metal is bent into a ring-shaped object, or after the material is bent into a ring-shaped object, a protrusion having the same cross section as the ring groove of the ring core metal is formed. but,
It rotates together with the press roller to press the inner circumferential side of the ring-shaped object, thereby carving and forming a horizontal ring groove on the inner circumferential side.

(Example) Next, an example embodying the method of the present invention will be described based on FIGS. 1 to 3.

As shown in Figure 1, the outer diameter of aluminum alloy is 16mm.
A round pipe with a thickness of 1.5 mm and a thickness of 1.5 mm is selected as the material 6 for the ring core 1, and this is connected to a pair of supply rollers 11.1.
The ring-shaped guide 13
and a plurality of bending rollers 15 to continuously bend the ring-shaped object P.

Further, a pair of press rollers 7.8 are provided in the middle of the process in which the material 6 is being bent, and the material 6 is forcibly sandwiched between these rollers 7.8 and roller pressed.

As shown in FIG. 2, concave press grooves 9 are provided in the circumferential direction of the circumferential surfaces of the two press rollers 7 and 8, and the cross-sectional shape of the press grooves 9 in the press rollers 7 is semicircular. On the other hand, the press groove 9 in the press roller 8 has a semicircular cross-sectional shape, but has an endless protrusion 10 extending horizontally in the outer circumferential direction at its deepest part.

The cross-sectional shape of the protrusion 10 is the same as the cross-sectional shape of the ring groove 2 of the ring portion core metal 1, and also corresponds to the cross-sectional shape of the end portion of the spoke portion core metal 3. Note that the protrusion 1 in this embodiment
The width a of 0 is 4 mm, and the height b is 6 mm.

Also, among the two press rollers 7.8, the protrusion 10
A roller provided with is placed on the inner peripheral side of the ring-shaped object P.

In this way, when the material 6 is forcibly passed between the two press rollers 7.8, the material 6 is roller pressed as shown in FIG. is drawn inward, and a ring groove 2 having a cross section corresponding to the cross-sectional shape of the protrusion 10 is carved and formed horizontally on the inner peripheral side of the ring-shaped object P.

Next, by welding both ends of the ring-shaped object P, which has been manufactured into a ring shape and has the ring @2 formed on the inner circumferential side, the ring portion core metal 1 is completed.

Then, as shown in FIG. 3, one end of the spoke part core metal 3 made of steel, which is a dissimilar metal, is inserted into and fixed to the ring @2 of the ring part core metal 1, and the two are joined. A boss portion 4 is welded to the other end to form a steering wheel core metal 5.

Roughly, an aluminum alloy coupling auxiliary member 14 is riveted to one end of the spoke core 3, and the end of the coupling auxiliary member 14 is inserted into the ring groove 2, and the ring core 1 and The coupling auxiliary member 14 is welded.

Finally, the steering wheel core metal 5 is set in an insert molding mold, and a synthetic resin such as polyurethane or polyvinyl chloride is insert-molded into the mold, and the outer peripheral surface of the steering wheel core metal 5 is covered with the resin. When coated, the concentric metal 5 becomes a steering wheel covered with an exterior material.

In this way, the ring @2 was roller pressed so as to be carved by the protrusion 10 provided on the inner circumferential side of the ring-shaped object P in the circumferential direction and across the press groove 9 of the press roller 8. 2, and even if one end of the spoke part core metal 3 is inserted into the ring groove 2 of the ring part core metal 1, if the end part is accurately finished, the same result will be achieved. The end part will not wobble in the ring groove 2.

Further, in this embodiment, the material 6 for the ring portion core metal 1 is processed into a ring shape and at the same time roller-pressed by the protrusion 10 on the inner peripheral side thereof, so that the ring-shaped material P is not twisted.

Therefore, in the aluminum alloy ring core metal 1 manufactured in this example, the clearance for the steel spoke core metal 3 in the ring groove 2 is reduced, and the ends of the spoke core metal 3 are placed in the groove 2. is inserted and fixed without wobbling.

Note that the clearance can be reduced relatively inexpensively by pressing the ends of the spoke part core metal 3 at the same time as forming the concentric metal 3, and by using a material that increases the accuracy of the plate thickness of the insertion part. I can do it.

Further, the ring groove 2 of the ring portion core metal 1 functions to prevent rotation of the exterior material covering the core metal 1.

The method of the present invention is not limited to the above embodiments, but includes, for example,
It can be implemented by the following aspect.

(1) As shown in FIG. 4, the material 6 is processed into a ring-shaped object P, and then the ring-shaped object P is transferred to two press rollers 7.
8, and the ring groove 2 may be formed on the inner peripheral side of the ring-shaped object P.

In this case, the ring-shaped object P may be spiral-shaped, or it may be a complete ring as shown in FIG.

In the case of a ring, the distance between the axes of the two press rollers 7.8 is separated so that the ring-shaped object P can be inserted between the two press rollers 7.8, and the ring-shaped object P is moved between the rollers. Once pressed, allow the two day-ra 7.8 to be pulled apart again.

(2) When roller pressing is performed simultaneously with the bending of the material 6, the press rollers 7.8 may be placed at any position during the bending process as long as the effects of the present invention are not impaired.

(3) The material 6 itself may be solid, but
For the purpose of further reducing the weight of the ring core metal 1, it is better to have a hollow shape. When using a hollow material, it is possible to gradually process it into a round pipe shape using a strip instead of using a round pipe from the beginning.

(4) The cross-sectional shape of the ring core metal 1 does not have to be arcuate except in the vicinity of the ring groove 2.

(5) The material of the ring part core metal 1 and the material of the spoke part core metal 3 may be the same. In this case, preferably, the ends of the spoke part core metal 3 are inserted and fixed into the ring groove 2 of the ring part core metal 1, and then both are brought into contact with each other.

(6) As the material for the two core metals, light metals, particularly aluminum or aluminum alloy, can be preferably used from the viewpoint of reducing the weight of the steering wheel core metal 5, but in some cases, steel can be used, In general, the ring part core metal 1 can be made of steel, and the spoke part core metal 3 can be made of a light metal.

(7) Any means for bending may be used as long as the material 6 can be formed into a ring-shaped object P.

Effects of the Invention In the method of the present invention, the inner circumferential side of the ring-shaped object is roller-pressed so as to carve a ring groove using the protrusions provided in the press groove of the press roller, thereby eliminating variations in the width and depth of the groove. This results in improved machining accuracy.

Therefore, the clearance between the ring groove and the end of the spoke part core metal is reduced, and variations are also reduced, so that the spoke part core metal can be firmly fitted and fixed to the ring part core metal.

In addition, since the material for the ring core metal is processed into a ring shape at the same time or after being formed into a ring shape, the inner circumferential side of the material is roller pressed. Compared to the method of bending
The core metal of the ring part and, by extension, the ring groove will not be twisted.

[Brief Description of the Drawings] Figure 1 is an explanatory diagram showing a process of manufacturing a ring-shaped object using the method of the present invention, Figure 2 is a front view of a press roller, and Figure 3 is a partial view of a steering wheel core metal. FIG. 4 is an explanatory view showing another process of manufacturing a ring-shaped object, and FIG. 5 is a partial cross-sectional view showing an example of a conventional steering wheel core metal. Ring part core metal 1, ring groove 2'', spoke part core metal 3, boss part 4, steering wheel core metal 5, material 6, press roller 7.8, press groove 9, protrusion 101 ring-shaped object P0

Claims (1)

[Claims] 1. Ring groove (2
), one end of the spoke part core metal (3) is inserted and fixed, and the other end of the spoke part core metal (3) is joined to the boss part (4) to form a steering wheel core metal (5). In the manufacturing method, the material (6) for manufacturing the ring portion core metal (1) is bent into a ring shape to form a ring-shaped object (P), or at the same time, after forming the ring-shaped object (P), the periphery is Concave press grooves on the surface (
9) in the circumferential direction, and a roller similarly equipped with a press groove (9), and a protrusion (10) on the circumferential surface of the press groove (9). The method includes a step of manufacturing the ring portion core metal (1) by sandwiching the material (6) or the ring-shaped object (P) between a press roller (8) provided in a direction and performing roller pressing. A method for manufacturing a steering wheel core metal characterized by: 2. The method for manufacturing a steering wheel core metal according to claim 1, wherein the material (6) for manufacturing the ring portion core metal (1) is a light metal pipe. 3. The method for manufacturing a steering wheel core metal according to claim 1, wherein the ring portion core metal (1) is made of a light metal, and the spoke portion core metal (3) is made of steel. 4. The method for manufacturing a steering wheel core metal according to claim 2 or 3, wherein the light metal is aluminum or an alloy thereof.