JPH07119435A - Muffler for small engine - Google Patents

Abstract

PURPOSE:To provide a muffler for small engine which can be disassembled and which is capable of effectively absorbing sound without increasing the number of part items. CONSTITUTION:A muffler 3 to be mounted on a small engine is formed of bodies 1, 2 molded by aluminium die-casting, and ribs 6, 7 right-angled to walls 4, 5 and a number of fine irregularities 8 are provided near the inside center of the muffler by the walls 4, 5 having a window and both surfaces of the window.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler for a small engine.

[0002]

2. Description of the Related Art A muffler of a conventional general small-sized engine is formed by joining steel plate molded products. The adsorption method is
A partition plate was provided in the muffler to weaken the sound energy by increasing the internal resistance, or a sound absorbing material was provided.
That is, if it is attempted to enhance the sound absorption effect of the conventional muffler, the number of parts will increase and the cost will increase, and since the steel sheet molded products have been joined by methods such as caulking and welding, it is difficult to disassemble and carbon etc. in the muffler. Could not be removed.

[0003]

In the muffler of the conventional small engine, if the sound absorbing effect is to be enhanced as described above, the number of parts is increased and the cost is increased, and the joining method of the parts is caulking and welding. There was a problem that the inside of the muffler could not be cleaned because it was difficult to disassemble. An object of the present invention is to provide a muffler for a small engine that can be disassembled and can effectively absorb sound without increasing the number of parts.

[0004]

Means for Solving the Problems The above object is to provide a muffler for a small-sized engine with walls, ribs, which cause movements having sound absorbing effects such as expansion, resonance, and dispersion in exhaust sound from a cylinder,
This is achieved by using a structure in which a window and two aluminum die-cast moldings having many fine irregularities are screwed together.

[0005]

[Operation] The engine muffler configured as described above is
When exhaust gas enters, it expands in the muffler, decelerates and decompresses, flows into the next room, and when exhaust gas passes, the ribs resonate and are reflected by numerous fine irregularities provided on the inner surface of the body and dispersed. To do. Also, since the muffler is made of aluminum die casting, the muffler body also has a sound absorbing effect.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The muffler 3 is molded by aluminum die casting, etc. 2
It is composed of two bodies 1 and 2. The body 1 is attached to the cylinder 13 with a screw 9, and the body 2 is attached to the body 1 with a screw 10. The bodies 1 and 2 are provided with walls 4 and 5 having windows near the center thereof, and ribs 6 and 7 are provided at both ends of the windows near the centers of the walls 4 and 5 at right angles to the walls 4 and 5. When the bodies 1 and 2 are put together, the end faces of the walls 4 and 5 are aligned and the inside of the muffler 3 is divided, and the windows near the centers of the walls 4 and 5 are aligned to form an intermediate vent. A large number of fine irregularities 8 are provided on the inner surfaces of the bodies 1 and 2.

Since it is constructed as described above, the cylinder 13
The exhaust gas from the exhaust port 14 flows into the muffler 3 through the muffler intake port 12, but the exhaust gas expands because the inside of the muffler 3 is wider than the cylinder exhaust port 14 or the muffler intake port 12. The speed and pressure are reduced, and exhaust gas equivalent to the area of the intermediate vent flows to the next room,
It expands again, reducing speed and pressure. When the exhaust gas passes through the intermediate vent, the ribs 6 and 7 add a resonance effect. Further, the expanded exhaust gas is reflected and dispersed by a large number of fine irregularities 8 provided on the inner surfaces of the bodies 1 and 2. Further, since the muffler 3 is an aluminum die cast product, the material itself has a sound absorbing effect. The exhaust gas absorbed by these is released from the exhaust pipe 11.

In addition to the above-mentioned embodiment, the inside of the muffler 3 may be divided into any number of pieces by walls, and the numerous fine irregularities 8 on the inner surfaces of the bodies 1 and 2 may be formed into other shapes such as needles. The same effect as the embodiment can be obtained.

[0009]

According to the present invention, since the muffler of the small engine is composed of two aluminum die-cast products, it is easy to divide and can be realized without increasing the number of parts. The sound absorbing structure divides the inside of the muffler with a wall to repeatedly expand the inflowing exhaust gas and resonates with a rib provided in an intermediate vent connecting the room divided by the wall,
Dispersion is performed at the same time by a large number of fine irregularities provided inside the muffler, and since the aluminum itself has good sound absorption, the muffler itself is also effective in absorbing sound.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a muffler of the present invention is attached to a cylinder of a small engine.

FIG. 2 is a perspective view showing the internal structure of the muffler.

[Explanation of symbols]

1 and 2 are bodies, 3 are mufflers, 4 and 5 are walls, 6 and 7 are ribs, and 8 is fine irregularities.

Claims (1)

[Claims] 1. A muffler to be mounted on a small engine, wherein a wall having a window is provided in the vicinity of the center of a body made of two aluminum die cast moldings, and ribs are provided at both ends of the window in a direction perpendicular to the wall, When the two bodies are joined together, the end faces of the respective walls are matched to divide the inside of the muffler into a plurality of parts, and the windows near the center of the wall are also matched to form an intermediate vent hole, and the inner surface of the body is further A small engine muffler characterized by a large number of fine irregularities.