JPH09264215A - Active control type silencer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breakage and deterioration in performance of a speaker by arranging a speaker for an active control type silencer in an intake/exhaust system for an internal combustion engine separately form an intake/exhaust passage and emitting sound wave in the opposite phase to that of the noise in the position adjacent to an intake/exhaust port. SOLUTION: An expansion chamber 4, in which an air cleaner 5 is stored, is arranged in the middle of an intake pipe 3 for an internal combustion engine, while an enclosure box 6 separated from the intake air is arranged so as to store a speaker 7. Sound wave in the opposite phase to that of noise is emitted from an opening end 9 of a voice tube 8, so that the noise emitted from the opening end 10 of the intake pipe 3 is canceled. When a backfire or suction of dust or water is generated in the intake pipe 3, breakage or damage is not caused as the speaker is separated, so that deterioration in a silencing action and a failure in a function is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active control silencer installed in an intake system or an exhaust system of an internal combustion engine.

[0002]

2. Description of the Related Art An active control type silencer is provided with a speaker in the middle of a pipe which is connected to a noise source and has one end open to the atmosphere so that noise is emitted and emits a sound wave having a phase opposite to the noise. In order to cancel the noise, for example, Japanese Utility Model Application Laid-Open No. 4-11247 and Japanese Patent Application Laid-Open No. 5-106524 disclose those applied to an intake system of an internal combustion engine. There is also an exhaust system of an internal combustion engine in which a muffler for muffling is provided with a speaker. This is intended to prevent the noise of the engine body from being dissipated into the atmosphere.

[0003]

In the conventional active control silencer for an internal combustion engine, at least the cone portion of the speaker is exposed in the intake pipe line or the exhaust pipe line.
In the case of the intake system, there is damage due to backfire, or when the speaker is on the upstream side of the air flow of the air cleaner, there is damage due to dust or water, and in the case of the exhaust system, there is damage due to the heat of the exhaust gas or the acid or water components of the exhaust gas. There were problems such as deterioration of sound deadening performance and deterioration of durability.

[0004]

According to the active control silencer of the present invention, a speaker is housed in an enclosure box to insulate it from intake air or exhaust air, and the generated sound wave is adjacent to the open end of the intake passage or the exhaust passage. It is designed to be emitted from the open end of the sound transmission tube provided so as to interfere with noise.

[0005]

1 shows an embodiment of an intake system of an internal combustion engine. An intake manifold 2 of an internal combustion engine main body 1 is attached with an intake pipe 3 and an extension chamber 4 is formed in the middle thereof to accommodate an air cleaner 5. Further, an enclosure box 6 is formed by partitioning a part of the expansion chamber 4 to shut off the inside from the intake air flow. Enclosure box 6 is expansion room 4
Instead of dividing the inside, a completely separate box may be provided.

The loudspeaker 7 is fixed in the enclosure box, a sound transmission tube 8 is provided in front of the cone of the speaker 7, and the open end 9 of the sound transmission tube 8 is made into an open end 10 of the intake pipe 3 for sucking the outside air. Adjacent to each other. The speaker 1 has a controller 1
1 is connected, noise is detected and analyzed by an input signal from a noise sensor 12 provided in the intake pipe 3, and an antiphase sound wave effective for silencing is generated from the speaker 7. This sound wave acts at the open end 9 so as to cancel the noise emitted from the open end 10 of the intake pipe 3.

FIG. 2 shows an embodiment of an exhaust system of an internal combustion engine. An exhaust pipe 16 is connected to the exhaust manifold 15 of the internal combustion engine 1, and a sub muffler 17 and a main muffler 18 are incorporated as an expansion type muffler in the middle of the exhaust pipe 16.
Enclosure box 19 outside main muffler 18
And the speaker 20 is housed and fixed. A sound transmission tube 21 is provided so as to be connected to the cone side of the speaker 20, and an open end 22 thereof is provided.
Is adjacent to the open end 23 of the exhaust pipe 16. Speaker 2
A controller 24 connected to 0 is provided, and a signal input from a noise sensor 25 provided in the exhaust pipe causes the speaker 20 to generate a sound wave having an opposite phase suitable for canceling noise. This sound wave acts at the open end 22 to cancel the noise emitted from the open end 23 of the exhaust pipe 16.

[0008]

According to the present invention, since the speaker for generating sound waves is isolated from the intake pipe or the exhaust pipe of the internal combustion engine, the backfire of the internal combustion engine, dust and water in the intake air, heat of the exhaust gas and harmful components are exhausted. Since the speaker is not touched and is not damaged or contaminated due to the touch, deterioration of the silencing effect and deterioration of durability are prevented.

[Brief description of drawings]

FIG. 1 is a diagram of an embodiment of an intake system of the present invention.

FIG. 2 is a diagram of an embodiment of the exhaust system of the present invention.

[Explanation of symbols]

 3 Intake pipe (intake passage) 7, 19 Enclosure box 7, 20 Speaker 8, 21 Sound transmission pipe 9, 22 Open end 16 Exhaust pipe (exhaust passage)

Claims (1)

[Claims] 1. A speaker is provided in an enclosure box isolated from an intake passage or an exhaust passage of an internal combustion engine,
An active control silencer in which a sound transmission tube is attached to an enclosure box and the open end of the sound transmission tube is located adjacent to the open end of the intake passage or the exhaust passage.