JPH0612188Y2 - Silencer for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a silencer for an internal combustion engine of an automobile or the like.

[Conventional technology]

For this type of silencer, the material to be used is generally selected in consideration of internal corrosion due to condensed water of exhaust from the engine and external corrosion due to salt damage, etc., and recently, the silencer body is made of stainless steel plate. A multi-layer structure including an inner plate and an outer plate made of an aluminum-plated steel plate is often used. In addition, when it is attached to the lower surface of a car, the outer surface of the outer panel is often painted black in order to match the surrounding hue in terms of design.

[Problems to be solved by the invention]

However, in the muffler as described above, it is general that the exhaust pipe communicating with the muffler body is penetrated through the inner plate and the outer plate of the body and welded to the inner and outer plates or the outer plate. In the case where the outer plate is subjected to a surface treatment such as plating or painting as described above, the weldability is not good, and especially MI
In G welding, not only the weld bead portion but the surrounding area becomes very dirty. In addition, the cut surface (cut end) of the exhaust pipe insertion hole formed in the silencer body and the surface treatment of the above-mentioned welded portion are deteriorated or peeled off to impair the external appearance and cause corrosion. Therefore, it is necessary to perform surface treatment such as plating and painting again. In that case, since the above-mentioned surface treatment must be performed after all the welding steps and the like are completed,
Since the weight, size, and shape are bulky, it is troublesome to handle, and there is a problem that the work is troublesome.

The present invention aims to solve the above problems.

[Means for solving problems]

According to the present invention, the muffler body is composed of multiple layers of an inner plate made of a stainless steel plate and an outer plate made of a surface-treated steel plate, and an exhaust pipe communicating with the muffler body is formed in the inner and outer plates. In a silencer for an internal combustion engine that is provided so as to penetrate through an exhaust pipe insertion hole, a short tubular portion that protrudes outward from an exhaust pipe insertion hole of an outer plate is formed at an edge portion of the exhaust pipe insertion hole of the inner plate. The exhaust pipe is fitted and welded to the short tubular portion.

[Action]

With the above structure, the exhaust pipe is fixed to the inner plate made of the stainless steel plate only by welding without being welded to the outer plate made of the surface-treated steel plate, and the surface treatment of the outer plate is deteriorated by the welding as described above. It is prevented from peeling.

〔Example〕

The illustrated example shows an example in which the muffler body 1 is applied to a muffler including a cylindrical body 1a and end plates 1b closing both ends thereof.

The tubular body 1a and the end plate 1b are double formed by an inner plate 11 made of a stainless steel plate and an outer plate 12 made of an aluminum-plated steel plate, respectively.
The peripheral edges of the inner and outer plates 11 and 12 of the end plate 1b are caulked and fixed to the ends of 12.

The exhaust pipe 2 communicating with the inside of the main body 1 is provided so as to penetrate through the insertion holes 3 and 4 formed in the inner and outer plates 11 and 12 of the end plate 1b.

A short cylinder portion 31 is formed at the edge of the exhaust pipe insertion hole 3 of the inner plate 11 by burring or the like, and the short cylinder portion 31 is removed from the exhaust pipe insertion hole 4 formed in the outer plate 12 by punching or the like. It projects to the side.

The exhaust pipe 2 is fitted into the short tubular portion 31 and welded and fixed W. In the case of the figure, the silencer body 1 is attached to the short tubular portion 31.
The exhaust pipe 2 is fitted through a communication pipe 6 disposed inside,
An example in which both the pipes 2 and 6 and the short tubular portion 31 are MIG welded is shown. The pipes 2 and 6 are made of stainless steel plate, and the filler rod for MIG welding is also made of stainless steel.

FIG. 2 shows the edge portion 41 of the exhaust pipe insertion hole 4 formed in the outer plate 22.
Is an example of an air insulating layer formed by folding back the inner plate 21 side to prevent the cut end from being exposed to the outside and forming a space S between the inner plate 21 and the outer plate 22 of the end plate 1b. ,
Other configurations are the same as in the case of the above-mentioned FIG.

The air insulating layer may also be provided between the inner and outer plates 11 and 12 of the tubular body 1a.

Further, the present invention is directed to the inner and outer plates 11.1 of the cylinder 1a and the end plate 1b.
It can also be applied to a structure having three or more layers with a heat insulating material and a sound absorbing material interposed between the two, and is not limited to a cylindrical silencer but also a silencer body divided into two parts. Applicable.

[Effect of device]

As described above, according to the present invention, the short tube portion that protrudes outward from the exhaust tube insertion hole of the outer plate is formed at the edge of the exhaust tube insertion hole of the inner plate made of a stainless steel plate. Since the exhaust pipe is welded and fixed to the portion, the appearance of the surface treatment is not deteriorated or peeled off as in the case where the exhaust pipe is welded to the outer plate made of the surface-treated steel sheet as in the conventional case, and the appearance is good.
Moreover, it can be securely welded and fixed. Further, it is not necessary to perform the surface treatment again on the welded portion, and the productivity can be improved. Further, since the outer plate is not welded as described above, it is possible to use a thin plate as much as possible, and it is possible to reduce the weight.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a silencer for an internal combustion engine showing an embodiment of the present invention, and FIG. 2 is a view showing the same as a modification. 1 is a silencer main body, 1a is a cylinder, 1b is an end plate, 11 is an inner plate, 12 is an outer plate, 2 is an exhaust pipe, and 3 and 4 are exhaust pipe insertion holes.

Claims (1)

[Scope of utility model registration request] 1. A muffler body comprising a multi-layered inner plate made of a stainless steel plate and an outer plate made of a surface-treated steel plate, and an exhaust pipe communicating with the muffler body is formed in the inner and outer plates. In a muffler for an internal combustion engine that is provided by penetrating through the exhaust pipe insertion hole, a short tubular portion protruding outward from the exhaust pipe insertion hole of the outer plate is formed at the edge of the exhaust pipe insertion hole of the inner plate. A silencer for an internal combustion engine, characterized in that the short pipe portion is fitted with the exhaust pipe and fixed by welding.