JPH0523874A - Manufacture of axle housing - Google Patents

Abstract

PURPOSE:To eliminate the necessity of having an axle end pipe inserted into the body of the axle housing for welding with a substantially long length of engagement by forming the tapered joining end parts of the axle housing body and the axle end pipe for friction welding and thereby increasing the joined strength. CONSTITUTION:The feature of this method is that either the joining end 12a of the axle housing body or the joining end 13a of the axle end pipe 13 is formed to be a protrudent tapered face 12b, the other remaining end to be a recessed tapered face 13b, and both ends 12a, 13a are abutted for friction welding. Also, a spheroidal graphite cast iron is used for the axle housing body to make it light in weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an axle housing, and more particularly, to improve the joint strength by forming the joint end portion of the main body of the axle housing and the axle end pipe into a tapered shape and frictionally welding them. Eliminating the need to insert the axle end pipe into the body of the axle housing with a considerably long mating length and welding, and to significantly reduce the weight of the axle housing by forming the body of the axle housing from spheroidal graphite cast iron. The present invention relates to a method of manufacturing an axle housing that can be manufactured.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG.
In the conventional axle housing 1, when the joining end portion 2a of the axle housing body 2 and the joining end portion 3a of the axle end pipe 3 are joined, the groove cannot be taken from the inside of the axle end pipe 3, Junction end 2
a, 3a, and a small diameter portion 3b is formed on the joint end portion 3a of the axle end pipe 3, and the small diameter portion 3b is fitted to the main body 2 with a considerably long fitting length. It was manufactured by abutting 2a and 3a, melting them to about half of the wall thickness, and welding them with beads 4.

The axle housing body 2 is made of a material such as cast steel or alloy steel other than spheroidal graphite cast iron, which has a large specific gravity of about 7.8, and the weight of the small diameter portion 3b of the axle end pipe is considerable. However, there is a drawback that the weight of the axle housing 1 cannot be reduced due to these factors.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to join the axle housing main body and the axle end pipe by butting. In the method of manufacturing an axle housing, one of the joint end portion of the axle housing body and the joint end portion of the axle end pipe is formed into a convex taper surface, and the other is formed into a concave taper surface having the same taper as the taper surface. These joint ends are abutted against each other and friction-welded to increase the joint area, thereby improving the joint strength, and by doing so, the small diameter portion of the joint end of the axle end pipe is fitted to the main body of the axle housing. Eliminates the need to combine and weld,
The goal is to significantly reduce the weight of the axle housing.

Another object is to reduce the specific gravity of the main body of the axle housing by forming the main body of spheroidal graphite cast iron, and to reduce the weight by about 9% as compared with the conventional axle housing body of cast steel or alloy steel. Is to try.

[0006]

In summary, the method of the present invention (claim 1) is a method of manufacturing an axle housing in which an axle housing body and an axle end pipe are butted and joined to each other, and the joint end portion of the axle housing body and the One of the joining ends of the axle end pipe is formed into a convex tapered surface and the other is formed into a concave tapered surface having the same taper as the tapered surface, and these joining ends are abutted against each other for friction welding. It is what The method of the present invention (claim 2) is a method for manufacturing an axle housing in which an axle housing body and an axle end pipe are butted and joined to each other, wherein the axle housing body is formed of spheroidal graphite cast iron, and the joint end of the axle housing body is formed. Section and one of the joining ends of the axle end pipe are formed in a convex tapered surface and the other is formed in a concave tapered surface having the same taper as the tapered surface, and these joining ends are abutted against each other for friction welding. It is characterized by that.

[0007]

EXAMPLE As shown in FIG. 1, an axle housing 11 comprises a pair of axle end pipes 13 fixed to both sides of a central axle housing body 12 at friction welding joints 11a.

The method of manufacturing the axle housing 11 according to the present invention is the same as the method of manufacturing the axle housing 11 in which the axle housing body 12 and the axle end pipe 13 are butted and joined to each other. One of the joint ends 13a of the pipe 13 is provided with a convex tapered surface 12b.
And the other side is a concave tapered surface 1 having the same taper as the tapered surface.
3b, and these joint ends 12a and 13a are butted against each other and frictionally welded to each other. In friction welding, as shown in FIG. 2, the axle housing main body 12 is fixed, the axle end pipe 13 is butted against this, and is pressed with a strong force as indicated by arrow A, so that the axle end pipe 13 is indicated by arrow B. And rotate both joint ends 12a, 13
This is a welding method in which frictional heat is generated between a and the joining ends are melted and joined.

In the illustrated embodiment, the axle housing 1
2 is formed into a convex tapered surface 12b and the axle end pipe 13 is formed into a concave tapered surface 13b.
Obviously, this may have the irregularities reversed from those shown. The taper surfaces 12a and 13a have the same taper, and each taper surface is formed at an angle of 45 ° with respect to the axial direction of both members. Therefore, the effective area that contributes to the friction welding is √2 times, that is, 1.4 times, as compared with the case of simply cutting at right angles to the axial direction.

The axle housing body 12 is made of spheroidal graphite cast iron (specific gravity 7.1) which has a specific gravity 9% lighter than that of cast steel (specific gravity 7.8), and the axle end pipe 13 is made of carbon steel similar to the conventional one (for example, It is more effective to use S43C material). According to such a combination, in the case of a joint end cut at a right angle, since graphite is contained in the spheroidal graphite cast iron, the weldability is poor and friction welding cannot be performed with sufficient strength. Since the joining end portion has a tapered surface, the effective area contributing to the friction welding is wide, and it is possible to perform the friction welding with sufficient strength even with a combination of such materials.

Further, in order to further improve the strength of friction welding, when the axle housing body 12 is cast, the joint end portion 12a is rapidly cooled with a chiller or the like to be chilled to form a cementite structure without producing precipitated graphite. When the joint ends 12a and 13a are friction-welded in this way, the metal welding is not hindered by graphite, and the cementite structure is heated by the heat during friction-welding to eliminate brittleness and has no defects. The joint surface can be obtained.

The present invention is configured as described above,
The operation will be described below. Axle housing body 12 and joint end 12 of axle end pipe 13
Since a and 13a are formed on the taper surfaces 12b and 13b having the same taper and frictionally welded to each other, sufficient joining strength can be obtained. As a result, the axle end pipe 3 as in the conventional example is obtained.
(See Fig. 5) Small diameter part 3b which is considerably long and heavy
(See FIG. 5) is unnecessary, and the weight of the axle housing 11 can be reduced considerably.

Further, since the axle housing body 12 can be made of spheroidal graphite cast iron, the specific gravity of the axle housing body can be reduced by 9% as compared with the conventional example, so that the small diameter portion 3b is omitted. A very significant weight reduction can be achieved.

Further, when the material of the axle housing body 12 is spheroidal graphite cast iron, the joining end portion 1 is formed at the time of casting.
By rapidly cooling 2a to chill to form a cementite structure and then friction welding the graphite, the precipitation of graphite is not suppressed and the graphite does not hinder the welding. Therefore, more sufficient bonding strength can be obtained.

[0015]

As described above, the present invention provides a method for manufacturing an axle housing in which an axle housing body and an axle end pipe are butted and joined to each other, as described above, in which one of the joint end portion of the axle housing body and the joint end portion of the axle end pipe is used. One is formed as a convex tapered surface and the other is formed as a concave tapered surface having the same taper as the tapered surface, and these joining ends are abutted against each other for friction welding, so that the joining area is increased and the joining strength is improved. As a result, there is no need to fit and weld the small diameter part of the joint end of the axle end pipe to the body of the axle housing, and the weight of the axle housing can be significantly reduced. There is an effect that can be done.

Further, since the main body of the axle housing is made of spheroidal graphite cast iron, the specific gravity of the main body is reduced, and the main body of the axle housing made of conventional cast steel or alloy steel is approximately 9
There is an effect that the weight can be reduced by%.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention, and FIG. 1 is an overall perspective view of an axle housing.

FIG. 2 is a partially enlarged perspective view showing a shape of both joint ends of an axle housing and an axle end pipe and a state of friction welding.

FIG. 3 is a longitudinal cross-sectional view of a main part of both joint ends showing a state immediately before friction welding.

FIG. 4 is a vertical cross-sectional view of a main part of the axle housing in which friction welding has been completed.

FIG. 5 is a vertical cross-sectional view of a main portion of an axle housing in which friction welding according to a conventional example is completed.

[Explanation of symbols]

11 Axle housing 12 Axle housing body 12a junction end 12b Convex taper surface 13 Axle end pipe 13a junction end 13b concave taper surface

Claims (2)

[Claims] 1. A method for manufacturing an axle housing in which an axle housing body and an axle end pipe are butted and joined to each other, wherein either one of a joint end portion of the axle housing body and a joint end portion of the axle end pipe is convex. A method for manufacturing an axle housing, characterized in that the other is formed as a concave tapered surface having the same taper as the tapered surface, and the joint ends thereof are butted against each other and frictionally welded to each other. 2. A method of manufacturing an axle housing in which an axle housing body and an axle end pipe are butted and joined to each other, wherein the axle housing body is formed of spheroidal graphite cast iron, and the joint end portion of the axle housing body and the axle end pipe. One of the joining ends is formed into a convex tapered surface and the other is formed into a concave tapered surface having the same taper as the tapered surface, and these joining ends are abutted against each other for friction welding. Housing manufacturing method.