JP2689033B2 - Axle housing manufacturing method - Google Patents

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, it is possible to frictionally weld a carbon steel axle end pipe with sufficient strength while forming the body of the axle housing from spheroidal graphite cast iron. This eliminates the need to insert the axle end pipe into the body of the axle housing with a considerably long mating length and welds it, and adopts spheroidal graphite cast iron in the axle housing body to significantly reduce the weight of the axle housing. 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 3 is large. There is a disadvantage 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, the axle housing main body is made of spheroidal graphite cast iron and the axle end pipe is made of carbon steel, and when the axle housing main body is cast, its joint end is rapidly cooled and chilled to form the axle. By friction-welding with the joint end of the end pipe, friction-welding is performed in a state where the joint end structure of the axle housing is cementite, and the precipitation of graphite is eliminated to prevent the friction-welding from being inhibited by the graphite. Friction welding can be performed with sufficient strength even if the joint ends of are simply cut at right angles and abutted. Is that Unisuru.

Another object is to eliminate the necessity of providing a small diameter portion on the axle housing and fitting the small diameter portion to the axle housing body with a considerably long fitting length, and to reduce the specific gravity to the axle housing body. By adopting cast iron (specific gravity 7.1), its specific gravity is reduced to carbon steel (specific gravity 7.
By reducing it by about 9% compared with the case of 8), it is possible to achieve a significant weight reduction of the axle housing.

[0006]

In summary, the method of the present invention comprises:
In a method for manufacturing an axle housing in which an axle housing body and an axle end pipe are butted against each other, the axle housing body is formed of spheroidal graphite cast iron, the axle end pipe is formed of carbon steel, and the axle housing body is cast. At that time, the joint end is rapidly cooled to be chilled, and then frictionally welded to the joint end of the axle end pipe.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. The axle housing 11 is, as shown in FIG.
A pair of axle end pipes 13 are fixed to both sides of the central axle housing body 12 at the friction welding joints 11a.

The method of manufacturing the axle housing 1 according to the present invention is 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.
2 is made of spheroidal graphite cast iron, and the axle end pipe 13 is made of carbon steel.
This is a method in which the joint end portion 12b is rapidly cooled and chilled at the time of casting 2 and then friction-welded with the joint end portion 13b of the axle end pipe 13.

In the friction welding, as shown in FIG. 2, the axle housing main body 12 is fixed, the axle end pipe 13 is abutted against the main body 12 and pressed with a strong force as shown by the arrow A, so that the axle end pipe 13 is pressed. This is a welding method of rotating as indicated by arrow B to generate frictional heat between the joint surfaces 12b and 13b, and melting and joining the joint surfaces.

In the illustrated embodiment, the joint ends 12a, 13a of the axle housing body 12 and the axle end pipe 13 are cut at right angles to the axial direction to form a joint surface 12b at a right angle to the axial direction. 13b, but
At the time of casting, the axle housing body 12 is rapidly cooled with a chill or the like and is chilled, so that its structure is cementite, and therefore graphite does not precipitate during friction welding and the graphite is welded. Therefore, sufficient welding strength can be obtained even with a joint surface perpendicular to the axial direction.

It should be noted that one of the joint ends 12a, 13a of the axle housing body 12 and the axle end pipe 13 has a convex tapered surface (not shown), and the other has the same taper as the convex tapered surface. Even better results can be obtained by forming a concave tapered surface (not shown) to increase the area of both joint surfaces.

The present invention is configured as described above,
Hereinafter, the operation will be described. The joint end portion 12a of the axle housing body 12 is formed by the axle housing body 1
Since it is rapidly cooled during the casting of No. 2 and has a cementite structure, graphite does not precipitate during friction welding, and thus the graphite does not hinder welding. Further, the cementite is changed by the heat generated during friction welding and the brittleness is eliminated. Further, since there is no precipitation of graphite, sufficient bonding strength can be obtained at the bonding surfaces 12b and 13b, and as a result, the comparatively long and heavy small diameter portion 3b (see FIG. 5) of the axle end pipe 3 (see FIG. 5) as in the conventional example (see FIG. 5
(Refer to FIG. 3) is unnecessary, and the weight of the axle housing 11 can be considerably reduced.

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. As a result, the weight of the axle housing 11 can be significantly reduced.

[0014]

As described above, the present invention provides a method of manufacturing an axle housing in which the axle housing body and the axle end pipe are butted and joined to each other as described above, in which the axle housing body is made of spheroidal graphite cast iron and the axle end pipe is made of carbon steel. When the axle housing body is cast, the joint end portion is rapidly cooled and chilled, and then friction welded to the joint end portion of the axle end pipe, so the structure of the joint end portion of the axle housing is cementite. Friction welding under the above condition to prevent the precipitation of graphite to prevent the friction welding from being obstructed by the graphite, and the friction welding should be performed with sufficient strength even if the joint ends of both members are simply cut at right angles. There is an effect that can be.

Further, it is not necessary to provide a small diameter portion on the axle housing and fit the small diameter portion to the axle housing body with a considerably long fitting length, and by adopting spheroidal graphite cast iron having a small specific gravity to the axle housing body,
By reducing its specific gravity by about 9% as compared with the case of carbon steel, it is possible to achieve the effect of achieving a significant weight reduction of the axle housing.

[Brief description of the 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 has been completed according to a conventional example.

[Explanation of symbols]

 11 Axle Housing 12 Axle Housing Main Body 12a Joint End 13 Axle End Pipe 13a Joint End

Continuation of front page (56) Reference JP 62-83203 (JP, A) JP 62-114783 (JP, A) JP 62-46702 (JP, A) JP 4-231183 (JP , A) JP 62-83202 (JP, A) JP 5-23874 (JP, A) JP 53-125253 (JP, A) JP 53-47602 (JP, A) 4-78003 (JP, U) Actual flat 1-109403 (JP, U) Actual flat 1-178103 (JP, U)

Claims (1)

(57) [Claims] A method for manufacturing an axle housing, in which an axle housing main body and an axle end pipe are butted and joined to each other, wherein the axle housing main body is made of spheroidal graphite cast iron, and the axle end pipe is made of carbon steel. A method for manufacturing an axle housing, characterized in that, at the time of casting the main body, the joint end is rapidly cooled and chilled, and then frictionally welded to the joint end of the axle end pipe.