JP4380879B2 - Intake silencer for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake silencer for reducing noise in an intake system of an internal combustion engine.
[0002]
[Prior art]
In order to reduce noise in an intake system of an internal combustion engine, for example, pulsation noise and airflow noise, a relatively simple silencer may be conventionally provided in the intake system. As this silencer, in addition to a resonator composed of a simple Helmholtz-type resonance element, one using a sound absorbing material such as urethane foam is known.
[0003]
For example, an intake air having a configuration in which an intake passage is constituted by a porous tube, a casing is provided so as to cover the porous tube, and a sound absorbing material is filled so as to fill a space between the inner peripheral surface of the casing and the porous tube. Silencers have been known for some time. In this intake silencer, a kind of expansion element is constituted by a perforated pipe passing through the inside of the casing, whereby a part of the intake system noise is silenced and a part of the noise is silenced by the sound absorbing material through the opening of the perforated pipe. Is done.
[0004]
[Problems to be solved by the invention]
In the intake silencer of the type using the sound absorbing material as described above, it is desirable in terms of noise reduction 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 tube as described above, the exposed area is very small, and sound is absorbed only by the inner peripheral surface of the sound absorbing material. Compared with noise reduction effect.
[0005]
In general, if a large exposed area of the sound absorbing material is to be secured, the structure for fixing the sound absorbing material in the casing tends to be complicated.
[0006]
Accordingly, an object of the present invention is to provide an intake silencer that has a relatively simple configuration and can ensure a large exposed area of the sound absorbing material.
[0007]
[Means for Solving the Problems]
An intake silencer for an internal combustion engine according to the present invention,
A casing that is generally cylindrical as a whole, has an intake inlet at one end in the longitudinal direction, and has 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;
A partition plate sandwiched between two chambers sandwiched between the joint surfaces of the first and second members of the casing, and having a communication hole in the center;
An inner tube integrally formed with the partition plate and extending from the communication hole toward the intake outlet;
A number of openings formed in the peripheral surface of the inner tube so as to communicate with one chamber;
A flange formed in the center with an annular passage portion continuous with the intake outlet, the tip of the inner tube is fitted to the inner periphery of the opening edge of the passage portion, and is formed at the tip of the inner tube A sound-absorbing material sandwiched and fixed in the axial direction between the portion and the end surface of the casing;
It is characterized by having.
[0008]
An appropriate resonance element or expansion element may be provided in the other chamber, that is, the chamber on the intake inlet side, or a sound absorbing material may be simply provided.
[0009]
In the intake silencer of the present invention, the intake air flowing into the casing from the intake inlet is guided into the inner tube through the communication hole at the center of the partition plate, and flows out from the intake outlet through the inner tube and the passage portion of the sound absorbing material. To do. The inner peripheral surface of the sound absorbing material is exposed to the intake air, and a part of the noise energy is absorbed by this portion. Further, since the inside of the inner tube communicates with one of the chambers through the opening on the peripheral surface, it 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, part of the noise energy is absorbed. Therefore, the intake system noise is effectively reduced.
[0010]
The sound absorbing material is fixedly held between the inner tube and the casing by the inner tube tip by assembling a partition plate integral with the inner tube to the casing. That is, it is assembled in the casing without using a separate support member.
[0011]
Further, the invention of claim 2 dependent on claim 1 is
An inlet-side inner tube extending from the communication hole toward the intake inlet integrally with the partition plate;
One or a plurality of openings provided on the peripheral surface of the inlet-side inner tube so as to communicate with the other chamber;
The passage portion connected to the intake inlet is formed in a ring shape in the center, the tip of the inlet side inner tube is fitted to the inner periphery of the opening edge of the passage portion, and the tip of the inlet side inner tube is An inlet-side sound absorbing material that is sandwiched and fixed in the axial direction between the formed flange portion and the end surface of the casing;
Is further provided.
[0012]
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. In addition, when the said inlet side inner tube is equipped with many opening parts, this inlet side chamber becomes an expansion element. Further, if the inlet side inner tube has a single opening in the cervical shape, the inlet side chamber serves as a resonance element, and noise at a specific frequency can be reduced.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 is a cross-sectional perspective view showing a first embodiment of an intake silencer according to the present invention.
[0015]
The intake silencer is interposed at an appropriate position of the intake system of the internal combustion engine, for example, upstream of the air cleaner, and the casing 1 has a substantially cylindrical shape as a whole, and an intermediate portion in the longitudinal direction. The cover 2 serving as the first member and the body 3 serving as the second member are divided into two parts, and both are integrally joined to each other at the joint flange 4. More specifically, the casing 1 is made of a synthetic resin such as polypropylene or polyamide, and is joined to the joining flange 4 by means such as high-frequency welding. An intake inlet 5 and an intake outlet 6 are arranged in the center of each end face of the casing 1. The intake inlet 5 and the intake outlet 6 have a relatively short cylindrical shape, and an intake pipe (not shown) is connected thereto.
[0016]
A disc-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 inside of the casing 1 into two chambers 7 and 8. Specifically, in a state where the cover 2 and the body 3 are combined, a concave groove 10 is formed on the inner circumference of the joint flange 4 over the entire circumference. The outer peripheral edge of the partition plate 9 is fitted. In the joint 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 joint flange 4 at the same time. .
[0017]
The partition plate 9 is integrally provided with an outlet-side inner tube 11. 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 the tip is open. The peripheral surface of the outlet side inner tube 11 has a large number of small rectangular openings 12, and the inside of the inner tube 11 communicates with the chamber 8 through the openings 12. The size and number of the openings 12 and the axial length of the inner tube 11 are tuned according to the frequency region of noise to be reduced.
[0018]
The partition plate 9 and the outlet side inner tube 11 are integrally formed of a synthetic resin such as polypropylene or polyamide. Note that a plurality of triangular ribs 13 are formed at the joint between the two in order to increase rigidity. Further, an annular flange portion 14 is formed at the distal end portion of the outlet side inner tube 11. The flange portion 14 is formed so that the tip 11a of the inner tube 11 remains slightly in a cylindrical shape.
[0019]
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 portion of the casing 1 on the intake outlet 6 side 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 pre-shaped in an annular shape having a passage portion 16 connected to the intake outlet 6 in the center. The tip 11a of the inner tube 11 is fitted to the inner periphery of the edge, and the flange portion 14 is in pressure contact with the outer side 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 in the radial direction, the inner peripheral surface of the casing 1 and the inner tube. The sound absorbing material 15 is constrained by the outer periphery of the tip 11a of the eleven.
[0020]
Further, in this embodiment, a sound absorbing material 17 made of a foamed resin material such as foamed urethane is disposed inside the cover 2 of the casing 1, that is, in the chamber 7. The sound-absorbing material 17 has an outer diameter corresponding to the inner diameter of the casing 1 and is previously formed into an annular or cylindrical shape having a passage portion 18 connected to the intake inlet 5, and includes the partition plate 9 and the casing. 1 is sandwiched in the axial direction with the inner wall surface of the end portion on the intake inlet 5 side, and is restrained in the radial direction on the inner peripheral surface of the casing 1.
[0021]
In the intake silencer described above, the sound absorbing material 15 is disposed in the body 3, the partition plate 9 is disposed on the body 3 side so that the outlet side inner tube 11 is inserted into the central passage portion 16, and the cover 3 is covered. After the sound absorbing material 17 is disposed in 2, the body 3 and the cover 2 are combined, and the two are welded together at the joining flange 4. At this time, by forming the sound absorbing materials 15 and 17 slightly larger, the sound absorbing materials 15 and 17 are compressed in the final assembled state, and rattling of each portion is prevented.
[0022]
In the configuration as described above, the intake air flowing into the casing 1 from the intake inlet 5 first passes through the passage portion 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 into the outlet inner tube 11 from the communication hole at the center of the partition plate 9 and flows out from the intake outlet 6 through the outlet inner tube 11 and the passage portion 16 of the sound absorbing material 15. Since the inner peripheral surface of the passage portion 16 of the sound absorbing material 15 is exposed to the intake air, a part of the noise energy is absorbed by this portion. Further, the outlet side inner tube 11 having a large number of openings 12 and the chamber 8 constitute an expansion element, where a part of noise, particularly noise in a desired frequency region is reduced. Furthermore, the end face of the sound absorbing material 15 is exposed in the chamber 8, and part of the noise energy is absorbed here. That is, the sound absorbing material 15 can obtain a sound absorbing action 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.
[0023]
Moreover, in the said Example, as above-mentioned, it can assemble very easily. In particular, since both of the sound absorbing materials 15 and 17 are held in the casing 1 by the partition plate 9 and the outlet-side inner tube 11 integrated with the partition plate 9 and positioned at a predetermined position, the number of parts is small and the configuration is very high. It will be simple.
[0024]
Next, 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 is substantially symmetrical with the outlet-side inner tube 11 with the partition plate 9 as the center. 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 its tip is opened. In addition, a large number of small rectangular openings 22 are provided on the peripheral surface, and the inside of the inlet side inner tube 21 communicates with the chamber 7 through the openings 22. Further, an annular flange portion 24 is formed at the tip portion at a position where the cylindrical tip 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.
[0025]
A sound absorbing material 25 made of a foamed resin material such as urethane foam is interposed as an inlet side sound absorbing material between the inner wall surface at the end of the casing 1 on the intake inlet 5 side and the inlet side inner tube 21. The sound absorbing material 25 has an outer diameter corresponding to the inner diameter of the casing 1 in the same manner as the sound absorbing material 15 on the outlet side, and is formed in advance in an annular shape having a passage portion 26 connected to the intake inlet 5 in the center. Thus, 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 flange portion 24 is in pressure contact with the outer side of the opening edge of the passage portion 26 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, and in the radial direction, the inner peripheral surface of the casing 1 and the inlet side. The sound absorbing material 25 is restrained by the inner tube 21.
[0026]
Here, the size and number of the openings 22 in the inlet-side inner tube 21 and the axial length of the inner tube 21 are tuned according to the frequency region of noise to be reduced. By tuning to a frequency region different from that of the inner tube 11, noise can be reduced in a wider region as a whole.
[0027]
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 fitted and positioned at the centers of the sound absorbing materials 15 and 25, respectively. Therefore, as in the first embodiment, the entire assembly is very easy, and the intake silencer including two expansion elements can be configured with a very small number of parts.
[0028]
Next, FIG. 3 shows a third embodiment of the present invention. In the third embodiment, similarly to the second embodiment, the partition plate 9 is further provided with an inlet-side inner tube 21, and has the same configuration as the flange portion 24 and the like in the second embodiment. A sound absorbing material 25 is sandwiched between the inlet inner tube 21 and the inner wall surface of the end portion of the casing 1 on the intake inlet 5 side. And in this 3rd Example, the inlet side inner tube 21 is provided with the cervical canal 31 in the surrounding surface, and this cervical canal 31 is opening to the chamber 7 as a single opening part.
[0029]
Therefore, in this third embodiment, the resonance element is constituted by the inlet side inner tube 21 and the chamber 7, and by tuning the characteristic to a desired frequency, noise of a specific frequency in question can be obtained. Mainly can be reduced.
[0030]
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 fitted and positioned at the centers of the sound absorbing materials 15 and 25, respectively. Therefore, as in the first and second embodiments, the entire assembly is very easy, and the intake silencer including the expansion element and the resonance element can be configured with a very small number of parts.
[0031]
【The invention's effect】
As apparent from the above description, according to the intake silencer of the internal combustion engine according to the present invention, both the end surface and the inner peripheral surface of the sound absorbing material disposed at the casing end are exposed to the intake air. The exposed area can be ensured larger than the volume of the material, and the sound absorption performance is improved. Therefore, in combination with the silencing element composed of the inner tube having the opening and the chamber, the noise of the intake system can be effectively reduced.
[0032]
In addition, since the sound absorbing material is securely fixed and held in the casing by the distal end portion of the inner tube integrated with the partition plate, the total number of parts can be reduced and assembly is facilitated.
[0033]
Further, according to the invention of claim 2, since 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. Effective noise reduction is possible. In particular, noise in a desired frequency region can be reduced by tuning the expansion element or the resonance element.
[Brief description of the drawings]
FIG. 1 is a cross-sectional perspective view showing a first embodiment of an intake silencer according to the present invention.
FIG. 2 is a cross-sectional perspective view showing a second embodiment.
FIG. 3 is a cross-sectional perspective view showing a third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Cover 3 ... Body 4 ... Joint flange 5 ... Intake inlet 6 ... Intake outlet 7, 8 ... Chamber 9 ... Partition plate 11 ... Outlet side inner tube 14 ... Flange part 15, 17 ... Sound absorption material

Claims (2)

A casing that is generally cylindrical as a whole, has an intake inlet at one end in the longitudinal direction, and has 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;
A partition plate sandwiched between two chambers sandwiched between the joint surfaces of the first and second members of the casing, and having a communication hole in the center;
An inner tube integrally formed with the partition plate and extending from the communication hole toward the intake outlet;
A number of openings formed in the peripheral surface of the inner tube so as to communicate with one chamber;
A flange formed in the center with an annular passage portion continuous with the intake outlet, the tip of the inner tube is fitted to the inner periphery of the opening edge of the passage portion, and is formed at the tip of the inner tube A sound-absorbing material sandwiched and fixed in the axial direction between the portion and the end surface of the casing;
An intake silencer for an internal combustion engine, comprising: An inlet-side inner tube extending from the communication hole toward the intake inlet integrally with the partition plate;
One or a plurality of openings provided on the peripheral surface of the inlet-side inner tube so as to communicate with the other chamber;
The passage portion connected to the intake inlet is formed in a ring shape in the center, the tip of the inlet side inner tube is fitted to the inner periphery of the opening edge of the passage portion, and the tip of the inlet side inner tube is An inlet-side sound absorbing material that is sandwiched and fixed in the axial direction between the formed flange portion and the end surface of the casing;
The intake silencer for an internal combustion engine according to claim 1, further comprising:

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