JPS6117210Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a muffler for an internal combustion engine that has low exhaust resistance, reduces the drop in engine output, and improves the muffling effect.

The muffler of an internal combustion engine emits exhaust gas through a narrow diaphragm into a wide muffling chamber, expands it, and repeats this process repeatedly to muffle the sound. In this case, tightening the throttle will improve noise reduction, but the back pressure of the exhaust gas will increase accordingly, reducing engine output. On the other hand, if the throttle is weakened, the back pressure will be lowered, but the noise will not be sufficiently muffled.In this way, muffling the noise and reducing the engine output are contradictory, and improving one will come at the expense of the other.

In view of this, this idea was developed to improve heat dissipation while minimizing the drop in output.
Embodiments of the present invention shown in the drawings will be described below.

The muffler tube 1 has a long cylindrical shape, and has a plurality of silencing chambers 3 partitioned by partition walls 2 at the rear thereof. The buff-full pipe 4 is inserted into the muffler tube 1 from the rear end, and is connected by a swash plate 5 at a location in the middle of the muffler chamber 3, with the connecting end surface of the buff-full pipe 4 being open. Further, a large number of small holes 6 are bored in the full pipe 4, and a collar piece 7 is fixed thereto. A sound absorbing material 8 is wrapped between the flange pieces 7. The sound absorbing material 8 may be glass wool or the like. When the full pipe 4 is inserted into the muffler tube 1, the hole 9 of the partition wall 2 and the collar piece 7 fit together to isolate the silencing chambers 3.

The effect will be explained.

Engine exhaust gas flows inside the muffler tube 1 from top to bottom in the figure. The exhaust gas flowing inside the buttful pipe 4 is passed through the small hole 6 at the top of the buttful pipe 4.
It enters the upper muffling chamber 3 through the swash plate 5, and then passes through the baffle pipe 4 from the end of the buffful pipe 4 cut out by the swash plate 5 and enters the lower muffling chamber 3. When the exhaust gas enters the muffling chamber 3 from the full pipe 4, it expands and is muffled. Since the sound absorbing material 8 is provided in the sound deadening chamber 3, sound deadening is good. When passing through the full pipe 8, the sound is absorbed by the sound absorbing material 8 through the small holes 6 in the portion where the sound absorbing material 8 is wound, so that the sound silencing effect is great. Further, since the buttful pipe 4 is cut in the middle and connected by the swash plate 5, the large end face is open, allowing the exhaust gas to pass through easily, and the back pressure is low, so that a decrease in engine output can be suppressed.

As explained above, this invention is designed to divide the inside of the muffler cylinder with a partition wall to create multiple sound deadening chambers, and to insert a buttful pipe into a hole in the partition wall from the rear end. Connect the corresponding parts with a swash plate, fix the collar piece to the buttful pipe, and wrap sound absorbing material around the buttful pipe.
Since the flange pieces fit into the holes in the partition wall, the sound-absorbing material is inserted into the sound-absorbing chamber, and the sound-absorbing material can enhance the sound-damping effect. In addition, the full pipe is connected by a swash plate in the middle of the silencing chamber, and the end face is wide open, so exhaust gas can pass through easily, there is little back pressure, and there is little drop in engine output. In this way, the noise reduction effect can be enhanced while suppressing a decrease in engine output. Furthermore, since the sound absorbing material is wrapped around the buttful pipe and inserted into the sound deadening chamber, if the sound absorbing material becomes clogged by removing the buttful pipe, it can be easily replaced.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing an embodiment of the present invention. 1... Muffler tube, 2... Partition wall, 3... Sound deadening chamber, 4... Bumpy pipe, 5... Swash plate, 7...
Flange piece, 8...sound absorbing material, 9...hole.

Claims (1)

[Scope of utility model registration request] In the case where the inside of the muffler cylinder is divided by a partition wall to form a plurality of silencing chambers, and the buttful pipe is inserted from the rear end into the hole provided in the partition wall, the middle portion of the silencing chamber of the buttful pipe is connected with a swash plate, A muffler for an internal combustion engine, characterized in that a collar piece is fixed to a full pipe, a sound absorbing material is wrapped around the full pipe, and the collar piece fits into a hole in a partition wall.