JPH0222210B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a silencer for an internal combustion engine such as a motorcycle,
Relating to a manufacturing method.

[Conventional technology]

Conventionally, in this type of silencer, it is known that the inner surface of the silencer outer plate is lined with a sound absorbing material such as glass wool with a porous inner plate (for example,
163424, JP-A-55-137307).

[Problem to be solved by the invention]

However, it is troublesome to fix the above-mentioned sound absorbing material and porous inner panel to the outer panel, and conventionally, for example, the inner and outer panels were formed into a desired shape in advance, and then cut to fit the size of the space between the inner and outer panels. A pine-shaped sound absorbing material is set on the inner surface of the outer panel, a porous inner panel is covered from the inside, and the periphery is welded and fixed to the outer panel.
Variations in density due to deformation of the sound absorber and misalignment of the inner plate during welding are likely to occur, which can cause unstable quality.

In addition, especially for those with half-split outer panels,
Since the edge of the inner panel is fixed to the inner circumferential surface inward from the outer panel mating area, the sound absorber cannot be provided on the entire inner circumferential surface of the outer panel. There was a risk of exhaust noise leaking.

The present invention has been proposed in view of the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a silencer that can easily and inexpensively mass-produce silencers with good quality and silencing performance.

[Means to solve the problem]

That is, in the present invention, a mat-like sound absorber 1 made of laminated heat-resistant fibers such as glass wool is formed to have approximately the same size as the inner peripheral surface of the half-shaped silencer outer plate 3 to be loaded, A wire mesh 2 made of expanded metal or the like which is wider than that is pasted on one side of the sound absorber 1.

With the wire mesh 2 inside, the wire mesh 2 and the sound absorber 1
The wire mesh 2 is molded to have approximately the same shape as the inner surface of the half-split outer panel 3, and the peripheral edge of the wire mesh 2 protruding from the edge of the sound absorber 1 is bent along the end surface of the sound absorber 1 so as to extend outward from the end surface. A flange portion 2a protruding from the flange portion 2a is formed.

Then, the above molded product is fitted to the inner surface of the half-split outer panel 3, and the bent flange portion 2a of the wire mesh 2 is overlapped with the mating flange 3a formed at the opening edge of the outer panel 3,
A pair of half-shaped outer panels 3 processed as described above are placed facing each other, and the flange sections 2a, 2a of the wire mesh 2 are overlapped between the flange sections 3a, 3a of the half-shaped outer panels 3, and fixed together by welding or the like. The company manufactures silencers for internal combustion engines.

[Effect]

The sound absorber 1 and the wire mesh 2 are attached to a half-split outer plate 3 to be loaded.
At the same time, the sound absorber 1 is easily formed into a shape that follows the inner surface of the sound absorber 1, and the shape of the sound absorber 1 is maintained by the wire mesh 2, making it easy to load the sound absorber 1 into the inner surface of each half-shaped outer panel.

The sound absorbers 1 loaded on the inner surface of each half-shaped outer plate are butted against each other, and the flange portion 2a of the wire mesh 2 protruding from the edge of the sound absorber 1 is sandwiched between the facing flange portions 3a, 3a of the outer plate 3. They are fixed together by welding, and the sound absorber 1 is loaded onto the entire inner peripheral surface of the outer plate 3 in a slightly compressed state due to the elasticity of the wire mesh 2.

〔Example〕

The embodiment shown in the figure is applied to a half-pillow-shaped silencer.

That is, a flat mat-shaped sound absorber 1 is formed in advance to have approximately the same size as the entire inner circumferential surface of the half-split outer panel 3, and a larger one is placed on one side of the mat-shaped sound absorber 1. Attach a relatively fine-mesh and soft wire mesh 2 such as expanded metal (Figure 3).
As shown in FIG. 4, it is molded into a bowl shape as shown in FIG. 5 using molds 4 and 5. This is the half-split outer panel 3,
The flange portion 2 on the periphery of the wire mesh 2 is fitted onto each inner surface of the wire mesh 2.
a is sandwiched between the flange portions 3a, 3a of the outer plate 3 and fixed by welding or the like (Fig. 2). In the figure, 6 is an exhaust pipe, and 7 is an exhaust pipe.

〔Effect of the invention〕

Since the present invention has the above-mentioned configuration, the sound absorber 1 and the wire mesh 2 can be easily molded at the same time to match the inner surface shape of the outer panel 3 to be loaded, and the sound absorber 1 can be easily molded into the wire mesh 2.
Since it retains its shape, it does not lose its shape and can be easily loaded onto the inner surface of the outer panel. Further, since the flange 2a of the wire mesh 2 is sandwiched and fixed between the opposing flanges 3a of the half-split outer plate 3, the sound absorber 1 can be assembled easily and reliably. Furthermore, the sound absorber 1 is loaded onto the entire inner circumferential surface of the outer panel 3, and is maintained in a slightly compressed state averaged over the whole by the elasticity of the wire mesh 2, so there is no possibility of variation in the density of the sound absorber as in the conventional method. Moreover, it is effective in mass-producing a silencer with good noise reduction performance easily and inexpensively because it does not cause any positional shift.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a half-split pillow-shaped silencer to which the present invention is applied, Fig. 2 is a sectional view thereof, Fig. 3 is a sectional view of a sound absorber with a wire mesh pasted on it, and Fig. 4 is its sectional view. FIG. 5 is a cross-sectional view of the molded state, and FIG. 5 is a perspective view of the molded wire mesh, sound absorber, and outer panel. 1 is a sound absorber, 2 is a wire mesh, 2a is a flange thereof, 3 is an outer plate, and 3a is a flange.

Claims (1)

[Scope of Claims] 1. A pine-like sound absorber made of laminated heat-resistant fibers such as glass wool is formed to have a size approximately the same as the inner circumferential surface of a half-shaped silencer outer plate to be loaded; A wider wire mesh such as expanded metal is pasted on one side of the sound absorber, and the wire mesh and the sound absorber are molded to have approximately the same shape as the inner surface of the half-split outer panel, with the wire mesh inside. The peripheral edge of the wire mesh that protrudes from the edge of the sound absorber is bent along the end surface of the sound absorber to form a flange that protrudes outward from the end surface, and the molded product is fitted onto the inner surface of the half-shaped outer panel. The bent flange part of the sound absorber is overlapped with the mating flange part formed on the opening edge of the outer panel, and the pair of half-shaped outer panels processed as described above are placed facing each other between the flange parts of the half-shaped outer panels. A method of manufacturing a silencer for an internal combustion engine in which the flange portions of wire mesh are overlapped and fixed together by welding or the like.