JPS5833257Y2 - Air cleaner suction noise reduction device for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an intake noise reduction device for an air cleaner for an internal combustion engine, which is capable of reducing noise in a low frequency range.

Internal combustion engines use clean air by installing an air cleaner in the intake pipe.

Intake of the internal combustion engine is performed rapidly and intermittently, resulting in fluctuations in intake and intake noise due to air flow.

In particular, it is difficult to prevent noise in the low frequency range.By reducing the cross-sectional area of the air cleaner's suction pipe, noise in the low frequency range can be reduced, but there is a limit as the intake resistance increases and the engine output decreases. .

Additionally, increasing the length of the outlet pipe connecting the air cleaner and the carburetor can also help reduce noise in the low frequency range.
This too has space limitations.

This invention has been improved in view of these points, and an embodiment of the invention shown in the drawings will be described below.

The cleaner case 1 has a cleaner element 2 installed therein, a suction pipe 3 erected on one side, and an outlet pipe 4 erected on the other side.

Accordingly, in the present invention, a resonance chamber 5 is provided around the suction pipe 30, and a spiral passage 6 is provided on one side of the resonance chamber 5.

The inner end of the swirl passage 6 communicates with the suction pipe 3 through a hole 7, and the outer end of the swirl passage 6 opens into the resonance chamber 5.

A side hole 9 communicating with the resonance chamber 5 is provided in the side plate 8 of the spiral passage 6 as appropriate.

The effect will be explained.

The swirl passage 6 is similar to a long pipe installed upright in the suction pipe 3, and reduces low-frequency sounds.

Further, the side hole 9 of the spiral passage 6 is similar to a short pipe erected in the suction pipe 3, and it is possible to reduce sound at a specific frequency.

In combination with the resonance chamber 5, suction noise can be reduced.

As explained above, this invention provides a resonance chamber around the suction pipe installed upright in the cleaner case, provides a spiral passage within the resonance chamber, and communicates the inner end of the spiral passage with the suction pipe. In addition to opening the outer end into the resonant chamber, we also provided appropriate side holes in the side plates of the spiral passages that lead to the common chamber.The spiral passages can reduce low-frequency sounds, and depending on the position of the side holes, specific frequency sounds can be reduced. Can be done.

In addition, in combination with a resonance chamber, intake noise can be reduced.

Further, the suction pipe does not need to be made any thinner than necessary, and there is no adverse effect on the engine output.

Furthermore, the spiral passage can be made compact and small.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, with Figure 1 being a longitudinal sectional view and Figure 2 being a longitudinal sectional view.
The figure is a cross-sectional view taken along the line A-A in FIG. 1... Cleaner case, 3... Suction pipe, 5... Resonance chamber, 6... Spiral passage, 8
-... Side plate, 9... Side hole.

Claims (1)

[Scope of utility model registration request] A resonance chamber is provided around the suction pipe installed vertically in the cleaner case, a spiral passage is provided in the resonance chamber, the inner end of the spiral passage is communicated with the suction pipe, and the outer end of the spiral passage is opened into the resonance chamber. A suction noise reduction device for an air cleaner for an internal combustion engine, characterized in that a side hole communicating with a resonance chamber is appropriately provided in a side plate of a passage.