JP2001263185A - Intake silencer of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake silencer devised to secure an exposed area of an acoustic material 15 large in simple constitution. SOLUTION: A casing 1 is constituted of a cover 2 and a body 3, and a partition plate 9 is fixed on an inner periphery of a joint flange 4 of both of them. The partition plate 9 is integrally furnished with an outlet side inner tube 11 extending toward an intake outlet 6, and an extensional element is constituted with a chamber 8 by a large number of opening parts 12 on a peripheral surface of the inner tube 11. The ring acoustic material 15 is held between a flange part 14 of a head end of the inner tube 11 and an end surface of the casing 1, the head end 11a of the inner tube 11 is fitted in a passage part 16, and positioning in the diametrical direction is carried out. It is possible to secure acoustic work large as both of the inner peripheral surface and the end surface of the acoustic material 15 are exposed to the air intake.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake silencer for reducing noise in an intake system of an internal combustion engine.

[0002]

2. Description of the Related Art In order to reduce noise in an intake system of an internal combustion engine, for example, its pulsation noise and airflow noise, a conventional method has been proposed.
A relatively simple silencer may be interposed in the intake system.
As this silencer, one using a sound absorbing material such as urethane foam in addition to a resonator composed of a simple Helmholtz type resonance element is known.

For example, an intake passage is formed by a perforated pipe, a casing is provided so as to cover the perforated pipe, and a sound absorbing material is filled so as to fill a space between an inner peripheral surface of the casing and the perforated pipe. An intake silencer having a configuration has been conventionally known. In this intake silencer, a kind of expansion element is constituted by a perforated pipe that passes through the casing, and thereby a part of the intake system noise is silenced and a part of the noise is silenced by a sound absorbing material through the opening of the perforated pipe. Is done.

[0004]

In an intake silencer of the type using a sound absorbing material as described above, it is desirable from the standpoint of sound absorbing performance to ensure a larger exposed area of the sound absorbing material.
However, when the sound absorbing material is exposed through the opening of the perforated pipe as described above, the exposed area is very small, and particularly, since the sound is absorbed only by the inner peripheral surface of the sound absorbing material,
The noise reduction effect is smaller than the volume of the sound absorbing material.

[0005] In general, in order to secure a large exposed area of the sound absorbing material, a structure for fixing the sound absorbing material in the casing tends to be complicated.

Accordingly, an object of the present invention is to provide an intake silencer having a relatively simple structure and capable of securing a large exposed area of a sound absorbing material.

[0007]

SUMMARY OF THE INVENTION An intake silencer for an internal combustion engine according to the present invention has a substantially cylindrical shape as a whole, and has an intake inlet at one longitudinal end and an intake outlet at the other end. The first member and the second member
The casing is divided into two parts, and is sandwiched between the joining surfaces of the first and second members of the casing.
Partitioning into two chambers, a partition plate having a communication hole in the center, an inner tube formed integrally with the partition plate and extending from the communication hole toward the intake outlet, and communicating with one chamber. A plurality of openings formed on the peripheral surface of the inner tube and an annular shape in which a passage portion communicating with the intake outlet is formed in the center, and a tip of the inner tube has an inner periphery of an opening edge of the passage portion. Mated with
In addition, a sound absorbing material is axially held and fixed between a flange portion formed at a distal end portion of the inner tube and an end surface of the casing.

The other chamber, that is, the chamber on the side of the intake port,
Appropriate resonating or expanding elements may be provided, or sound absorbers may simply be provided.

In the intake silencer according to the present invention, the intake air flowing into the casing from the intake inlet is guided into the inner tube through the communication hole in the center of the partition plate, and passes through the inner tube and the passage of the sound absorbing material. Spill from exit. The inner peripheral surface of the passage portion of the sound absorbing material is exposed to the intake air,
In this part, a part of the noise energy is absorbed. In addition, since the inside of the inner tube communicates with one of the chambers through the opening in the peripheral surface, the inner tube acts as an expansion element, and a part of noise is reduced here. Further, the end face of the sound absorbing material is exposed in this chamber, and here also a part of the noise energy is absorbed. Therefore, the intake system noise is effectively reduced.

The sound absorbing material is fixedly held between the casing and the casing by a tip of the inner tube by assembling a partition plate integral with the inner tube to the casing. In other words, without using a separate support member,
Assembled in a casing.

The invention according to claim 2 which depends on claim 1 is such that an inlet side inner tube extending from the communication hole toward the intake inlet integrally with the partition plate and communicate with the other chamber. One or a number of openings provided on the peripheral surface of the inlet-side inner tube and an annular shape in which a passage connected to the intake inlet is formed at the center thereof,
The distal end of the inlet-side inner tube fits into the inner periphery of the opening edge of the passage portion, and is axially held and fixed between the flange formed at the distal end of the inlet-side inner tube and the end face of the casing. And an inlet-side sound absorbing material.

That is, similarly to the intake outlet side, an inner tube is also provided on the intake inlet side, and the inlet side sound absorbing material is fixedly held by the inlet side inner tube. When the inlet-side inner tube has a large number of openings, the inlet-side chamber is an expansion element.
In addition, if the inlet-side inner tube has a single opening in the form of a neck tube, the inlet-side chamber becomes a resonance element, and noise at a specific frequency can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of an intake silencer according to the present invention.
It is a sectional perspective view showing an example.

The intake silencer is provided at an appropriate position in the intake system of the internal combustion engine, for example, at the upstream side of the air cleaner. The casing 1 has a substantially cylindrical shape as a whole and has a middle portion in the longitudinal direction. A cover 2 serving as a first member
And a body 3 serving as a second member.
Both are integrally joined to each other at the joining flange 4. The casing 1 is made of, for example, a synthetic resin such as polypropylene or polyamide, and is joined to the joining flange 4 by means such as high-frequency welding. At the center of each end face of the casing 1, an intake inlet 5 and an intake outlet 6 are arranged, respectively. The intake inlet 5 and the intake outlet 6 have a relatively short cylindrical shape, and are connected to an intake pipe (not shown).

A disk-shaped partition plate 9 is sandwiched and fixed between the cover 2 and the body 3 of the casing 1 so as to partition the interior of the casing 1 into two chambers 7 and 8. Specifically, with the cover 2 and the body 3 combined,
A concave groove 10 is formed on the entire inner periphery of the joining flange 4, and the outer peripheral edge of the partition plate 9 is fitted into the concave groove 10. In the joining flange 4, the cover 2 and the body 3 are joined to each other and are not welded to the partition plate 9. However, the partition plate 9 may be joined to the joining flange 4 at the same time. .

The partition plate 9 is provided on the outlet side inner tube 1.
1 are integrally provided. The inner tube 11 extends from a communication hole (not shown) provided in the center of the partition plate 9 toward the intake outlet 6 along the axis of the casing 1, and has an open end. The peripheral surface of the outlet side inner tube 11 has a large number of small rectangular openings 12.
The inside of the inner tube 11 communicates with the chamber 8 through the opening 12. The size and number of the openings 12 and the axial length of the inner tube 11 are tuned according to the frequency range of the noise to be reduced.

The partition plate 9 and the outlet side inner tube 11 are integrally formed of a synthetic resin such as polypropylene or polyamide. In order to increase rigidity, a plurality of triangular ribs 13
Are formed. The outlet side inner tube 1
An annular flange portion 14 is formed at the distal end of the first member 1. The flange portion 14 is formed so as to slightly leave the distal end 11a of the inner tube 11 in a tubular shape.

A sound absorbing material 15 made of a foamed resin material such as urethane foam is interposed between the inner wall surface of the end of the casing 1 on the side of the intake outlet 6 and the inner tube 11. The sound absorbing material 15 has an outer diameter corresponding to the inner diameter of the casing 1 and is preliminarily formed in an annular shape having a passage portion 16 connected to the intake outlet 6 at the center. The distal end 11a of the inner tube 11 is fitted to the inner periphery of the edge, and the flange portion 14 is pressed against the outside of the opening edge of the passage portion 16 in the axial direction.
That is, the sound absorbing material 15 is sandwiched in the axial direction between the flange portion 14 and the inner wall surface at the end of the casing 1 on the intake outlet 6 side, and the inner circumferential surface of the casing 1 and the inner tube are radially arranged. The sound absorbing material 15 is constrained by the outer periphery of the tip 11a of the eleventh portion.

In this embodiment, a sound-absorbing material 17 similarly made of a foamed resin material such as urethane foam is provided inside the cover 2 of the casing 1, that is, in the chamber 7. The sound absorbing member 17 also has an outer diameter corresponding to the inner diameter of the casing 1 and is formed in advance into an annular or cylindrical shape having a passage 18 connected to the intake port 5. 1 is held in the axial direction between the inner wall surface at the end on the side of the intake inlet 5 and is constrained in the radial direction by the inner peripheral surface of the casing 1.

In the above-mentioned intake silencer, the sound absorbing material 15 is arranged in the body 3 and the partition plate 9 is arranged on the body 3 side so that the outlet side inner tube 11 is inserted into the central passage 16. After the sound absorbing material 17 is arranged in the cover 2, the body 3 and the cover 2 are combined, and the two are welded to each other at the joining flange 4. At this time, by making each of the sound absorbing members 15 and 17 slightly larger, the sound absorbing members 15 and 17 are in a compressed state in the final assembled state, and rattling of each part is prevented.

In the above configuration, the intake port 5
First, the intake air flowing into the casing 1 passes through the passage 18 in the sound absorbing material 17 in the chamber 7, where a part of the noise energy is absorbed. Then, the air is guided from the communication hole at the center of the partition plate 9 into the inner tube 11 on the outlet side, and flows out from the inlet 6 through the inner tube 11 on the outlet side and the passage 16 of the sound absorbing material 15. The sound absorbing material 15
Since the inner peripheral surface of the passage portion 16 is exposed to the intake air, a part of the noise energy is absorbed in this portion. In addition, an expansion element is constituted by the outlet side inner tube 11 provided with a large number of openings 12 and the chamber 8, where a part of noise, particularly noise in a desired frequency range is reduced. In addition, this room 8
The end face of the sound absorbing material 15 is exposed, and a part of the noise energy is also absorbed here. That is, the sound absorbing material 15
A sound absorbing effect is obtained on both the inner peripheral surface and the end surface of the passage portion 16. Therefore, the intake system noise is effectively reduced as a whole.

In the above embodiment, as described above,
Very easy to assemble. In particular, sound absorbing material 1
Each of the parts 5 and 17 is held in the casing 1 by the partition plate 9 and the outlet side inner tube 11 integral with the partition plate 9 and is positioned at a predetermined position, so that the number of parts is small and the configuration is very simple. Become.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the partition plate 9 is further provided with an inlet-side inner tube 21. The inlet side inner tube 21 has basically the same configuration as the outlet side inner tube 11 described above. In other words, the inlet side inner tube 21 has a substantially symmetric shape with the outlet side inner tube 11 about the partition plate 9. That is, the inlet side inner tube 21
Extends from a communication hole (not shown) provided in the center of the partition plate 9 toward the intake inlet 5 along the axis of the casing 1, and has an open end, and It has a large number of small rectangular openings 22,
2, the inside of the inlet side inner tube 21 communicates with the chamber 7. An annular flange portion 24 is formed at the distal end portion at a position where the cylindrical distal end 21a is slightly left. It should be noted that a rib similar to the rib 13 may be provided at the joint between the inlet side inner tube 21 and the partition plate 9 to increase the rigidity of the joint.

A sound-absorbing material 25 made of a foamed resin material such as urethane foam is interposed between the inlet-side inner tube 21 and the inner wall of the inlet-side inner tube 21 of the casing 1 on the side of the inlet 5. ing. This sound absorbing material 25
Has an outer diameter corresponding to the inner diameter of the casing 1 like the sound absorbing material 15 on the outlet side, and is preliminarily formed into an annular shape having a passage portion 26 connected to the intake inlet 5 at the center. The distal end 21a of the inlet-side inner tube 21 is fitted to the inner periphery of the opening edge of the passage portion 26, and the passage portion 2
The flange portion 24 is pressed against the outside of the opening edge of No. 6 in the axial direction. That is, the sound absorbing material 25 is sandwiched in the axial direction between the flange portion 24 and the inner wall surface at the end of the casing 1 on the intake inlet 5 side. Sound absorbing material 2 with inner tube 21
5 are restrained.

Here, the size and number of the openings 22 in the inlet side inner tube 21 and the inner tube 21
Is also tuned according to the frequency range of the noise to be reduced, but by tuning to a frequency range different from that of the outlet side inner tube 11, the noise in a wider range as a whole is improved. Reduction can be achieved.

In the configuration of the second embodiment, the distal ends 11a and 21a of the outlet side inner tube 11 and the inlet side inner tube 21 integrated with the partition plate 9 are respectively provided.
Is fitted and positioned at the center of the sound absorbing members 15 and 25, so that the entire assembly is very easy as in the first embodiment, and the number of intake mufflers having two expansion elements is extremely small. It can be constituted by the number of parts.

FIG. 3 shows a third embodiment of the present invention. In the third embodiment, as in the second embodiment, the partition plate 9 is further provided with an inlet-side inner tube 21, and the same flange portion 2 as in the second embodiment is provided.
With the configuration such as 4, the sound absorbing material 25 is sandwiched between the inlet side inner tube 21 and the end inner wall surface of the casing 1 on the side of the inlet 5. In the third embodiment, the inlet side inner tube 21 has a cervical tube 31 on the peripheral surface.
The cervical canal 31 opens into the chamber 7 as a single opening.

Therefore, in the third embodiment, a resonance element is constituted by the inlet side inner tube 21 and the chamber 7, and by tuning its characteristic to a desired frequency, a specific frequency which is problematic can be obtained. Noise can be mainly reduced.

In the configuration of the third embodiment, the distal ends 11a and 21a of the outlet side inner tube 11 and the inlet side inner tube 21 integrated with the partition plate 9 are respectively provided.
Is fitted and positioned at the center of the sound absorbing members 15 and 25, so that the whole assembly is very easy as in the first and second embodiments, and the intake silencer provided with the expansion element and the resonance element. The container can be configured with a very small number of parts.

[0031]

As is apparent from the above description, according to the intake silencer for an internal combustion engine according to the present invention, both the end face and the inner peripheral face of the sound absorbing material provided at the end of the casing are opposed to the intake air. Since it is exposed, the exposed area can be secured larger than the volume of the sound absorbing material, and the sound absorbing performance is improved. Therefore, the noise of the intake system can be effectively reduced in combination with the silencing element including the inner tube having the opening and the chamber.

Further, since the sound absorbing material is securely fixed and held in the casing by the distal end of the inner tube integrated with the partition plate, the number of components can be reduced and the assembly becomes easy.

Further, according to the second aspect of the present invention, the expansion element or the resonance element can be constituted by the inlet side inner tube and the inlet side chamber, and at the same time, the inlet side sound absorbing material is provided. As a whole, more effective noise reduction is possible. In particular, the tuning of the expansion element or the resonance element enables noise reduction in a desired frequency range.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view showing a first embodiment of an intake silencer according to the present invention.

FIG. 2 is a sectional perspective view showing a second embodiment.

FIG. 3 is a sectional perspective view showing a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Cover 3 ... Body 4 ... Joining flange 5 ... Intake inlet 6 ... Intake outlet 7, 8 ... Room 9 ... Partition plate 11 ... Outer side inner tube 14 ... Flange part 15, 17 ... Sound absorbing material

Claims (2)

[Claims] 1. A substantially cylindrical shape as a whole, having an intake inlet at one longitudinal end and an intake outlet at the other end, and is divided into a first member and a second member at an intermediate portion in the longitudinal direction. And a casing, which is sandwiched between joining surfaces of the first and second members of the casing,
A partition plate which partitions the inside of the casing into two chambers and has a communication hole in the center, an inner tube formed integrally with the partition plate and extending from the communication hole toward the intake outlet; A plurality of openings formed in the peripheral surface of the inner tube so as to communicate with the inner tube, and a passage formed in the center thereof through which a passage communicating with the intake outlet is formed. A sound absorbing material fitted axially between a flange formed at the distal end of the inner tube and an end face of the casing. An intake silencer for an internal combustion engine. 2. An inlet-side inner tube extending from the communication hole toward the intake port integrally with the partition plate, and a first surface provided on a peripheral surface of the inlet-side inner tube so as to communicate with the other chamber. One or a number of openings, and a passage formed in the center thereof, through which a passage communicating with the intake port is formed, and an end of the inlet-side inner tube is fitted into an inner periphery of an opening edge of the passage, and The inlet-side sound-absorbing material, which is axially held and fixed between a flange portion formed at a distal end portion of the inlet-side inner tube and an end face of the casing, further comprising: An intake silencer for an internal combustion engine.