JPH0111934Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an exhaust pipe structure for an engine, such as an exhaust system for a motorcycle, in which a sound absorbing pipe made of a sound absorbing and insulating material such as glass wool is disposed inside an exhaust expansion pipe connected to an engine exhaust hole. Regarding.

In this type of exhaust pipe structure, the sound absorbing pipe is
Since the ends are simply cut off, the ends deteriorate significantly due to the exhaust gas flow and become more likely to disturb the gas flow.In addition, in order to prevent the ends from deteriorating and raising, a net or the like is applied to absorb noise. Since the entire inner periphery of the cylinder is pressed down, there are disadvantages such as a reduction in the sound absorption effect.

The purpose of the present invention is to improve such inconveniences, and the present invention is aimed at improving the above-mentioned disadvantages. In the exhaust pipe structure, a tapered part 2a whose thickness gradually increases in the axial direction from the edge is compressed and formed on both sides of the sound absorbing cylinder 2, and an annular presser presses only both sides of the sound absorbing cylinder 2 including the tapered part 2a. The present invention is characterized in that the sound absorbing cylinder 2 is attached inside the exhaust expansion pipe 1 via a plate 3.

To explain this with respect to the illustrated embodiment, a sound absorbing tube 2 made of a sound absorbing and insulating material such as glass wool disposed inside the exhaust expansion pipe 1 is gradually thickened in the axial direction from the edge on both sides substantially perpendicular to the exhaust flow direction. A tapered portion 2a that increases the thickness is compression molded, and the sound absorbing tube 2 is attached to the exhaust expansion pipe 1 via an annular presser plate 3 that presses only both sides of the sound absorbing tube 2 including the tapered portion 2a.

In this way, according to the present invention, the sound absorbing tube 2 made of a sound absorbing and insulating material such as glass wool has tapered portions 2a on both sides of which the wall thickness gradually increases in the axial direction from the edge.
Since the sound absorbing tube 2 is compression molded, its ends will not deteriorate or become fluffy even when subjected to pulsating waves of exhaust gas. Since it is mounted inside the exhaust expansion pipe 1, it can be supported stably, easily and lightweight, and the middle part of the sound-absorbing cylinder 2 is exposed inside the expansion pipe 1, so that a large sound-absorbing effect can be obtained, and it can be used for a long time. It has the effect of maintaining stable performance.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 1...Exhaust expansion pipe, 2...Sound absorbing cylinder, 2a...Tapered portion, 3...Press plate.

Claims (1)

[Scope of utility model registration request] In an engine exhaust pipe structure in which a sound absorbing tube 2 made of a sound absorbing and insulating material such as glass wool is arranged inside an exhaust expansion pipe 1 connected to an exhaust hole of the engine, a sound absorbing tube 2 made of a sound absorbing and insulating material such as glass wool is arranged on both sides of the sound absorbing tube 2 from the end edge in the axial direction. A tapered portion 2a whose wall thickness gradually increases is compressed and formed, and the sound absorbing tube 2 is attached to the exhaust expansion pipe 1 via an annular holding plate 3 that presses only both sides of the sound absorbing tube 2 including the tapered portion 2a. An engine exhaust pipe structure characterized by: