JPH0777025A - Silencer - Google Patents

Abstract

PURPOSE:To provide a silencer which reduces generation of the radiant noise from a shell by exhaust pulsation and reduces air current noise in addition. CONSTITUTION:In a silencer, where the inside of a shell 1 both openings of which are blocked with end plates 3 and 5 is partitioned with a plurality of baffle plates 7 and 8 and a chamber 13 where the end of the inserted exhaust pipe 17 opens is an expansion chamber, the end of the inserted exhaust pipe 17 is made larger in diameter than the exhaust pipe 17, and besides it is covered with a foaming metallic pipe 25 consisting of many continuous pore bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer mounted on a vehicle exhaust system.

[0002]

2. Description of the Related Art In order to reduce exhaust noise when a vehicle is running,
Conventionally, a vehicle exhaust system is equipped with a muffler as shown in Japanese Utility Model Laid-Open No. 2-24024 or FIG. 13, and the muffler has an expansion damping action in an expansion chamber and a resonance damping action in a resonance chamber. The exhaust noise is silenced by.

In FIG. 13, reference numeral 1 denotes a shell whose both end openings are closed by end plates 3 and 5, and the inside of the shell 1 is shown in FIG.
With two baffle plates 7 and 9 as shown in
From the upstream end plate 3 side, the first chamber 11 and the second chamber 1
Three chambers, the third chamber 15 and the third chamber 15, are defined.

An exhaust gas introducing pipe 17 is inserted into the upstream end plate 3 so as to pass through the baffle plate 7, and the end portion on the insertion side is open to the second chamber 13.
Further, an exhaust lead-out pipe 19 is inserted into the downstream end plate 5 so as to penetrate the baffle plates 7 and 9, and the exhaust lead-out pipe 19 has an end portion on the insertion side which is open to the first chamber 11. .

Further, the baffle plate 9 has a second chamber 1
The resonance pipe 21 that connects the third chamber 15 and the third chamber 15 to each other is the exhaust gas introduction pipe 1
7, and a baffle plate 7 is fitted with a single communication pipe 23 that connects the first chamber 11 and the second chamber 13 to each other. And the second
The chamber 13 functions as an expansion chamber, and the third chamber 15 functions as a resonance chamber.

[0006]

However, in the above-described conventional silencer, when the exhaust gas introduced into the silencer through the exhaust introduction pipe 17 flows into the second chamber 13, the exhaust introduction is performed. There is a drawback that a secondary generated sound (air flow sound) is generated from the edge portion of the end of the pipe 17 on the insertion side, and the shell 1 resonates due to exhaust pulsation accompanying the inflow of exhaust gas, and the sound emitted from the shell 1 is emitted. There was also a drawback that it would occur.

In recent years, the shell 1 has been made thinner in order to reduce the weight of the silencer. However, as the shell 1 becomes thinner, the emission noise due to the pulsation of the exhaust gas is remarkably generated. It was left as a problem to be solved in order to reduce the weight of.

The present invention has been devised in view of the above circumstances, and an object thereof is to provide a silencer that reduces the generation of radiation noise from the shell due to exhaust pulsation and also reduces the air flow noise. To do.

[0009]

In order to achieve such an object, the invention according to claim 1 is such that a shell having both end openings closed by end plates is partitioned by a plurality of baffle plates to insert an exhaust gas introducing pipe. In a muffler having a chamber having an open end as an expansion chamber, a foam metal pipe having a large diameter at the insertion side end of the exhaust gas introduction pipe and having a larger diameter than the exhaust gas introduction pipe and comprising a plurality of continuous pores. It is characterized by being covered with.

The invention according to claim 2 is the invention according to claim 1.
In the silencer described above, the foam metal pipe is installed between two baffle plates partitioning and forming an expansion chamber, and both baffle plates are provided with a plurality of notches facing each other on the same circumference. A plurality of projecting pieces that can be engaged with the respective notches are formed at both ends of the foam metal pipe.

According to a third aspect of the present invention, in the muffler according to the first aspect, the metal foam pipe is installed between two baffle plates or baffle plates and an end plate that define an expansion chamber, The both baffle plates or the baffle plate and the end plate are characterized in that projecting portions for supporting both ends of the metal foam pipe are provided so as to project toward the expansion chamber on the same circumference.

[0012] In the invention according to claim 4, the inside of the shell whose both end openings are closed by the end plates is partitioned by a plurality of baffle plates, and the chamber in which the end portion on the insertion side of the exhaust introduction pipe is opened is an expansion chamber. In the container, the end portion of the exhaust introduction pipe on the insertion side is covered with a porous pipe having a diameter larger than that of the exhaust introduction pipe and having a large number of small holes in the peripheral wall and an opening ratio of 100% or more. .

[0013]

According to the invention described in each claim, when the engine is driven, the exhaust gas flows into the muffler through the exhaust introduction pipe, and the exhaust pulsation is propagated in the muffler accordingly.
The exhaust pulsation propagated into the silencer via the exhaust introduction pipe is
It will be attenuated when passing through the continuous pores of the foam metal pipe or the small holes of the perforated pipe covering the insertion side end of the exhaust gas introduction pipe.

On the other hand, the exhaust gas flowing into the silencer via the exhaust introduction pipe is rectified and diffuses into the expansion chamber when passing through the continuous pores of the foam metal pipe or the small holes of the porous pipe.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. The same parts as those of the conventional example shown in FIG. 13 are designated by the same reference numerals, and their structural description will be omitted.

1 to 5 show a first embodiment of a silencer according to claims 1 and 2, and in FIG. 1, reference numeral 25 is an insertion side end portion 17a of an exhaust introduction pipe 17 and a resonance pipe 21. One end 2
A metal foam pipe is provided between the baffle plates 7 and 9 so as to cover 1a, and 27 is also one end 23a of the communication pipe 23.
Is a foam metal pipe that is installed between the baffle plates 7 and 9 and covers both of the foam metal pipes 25 and 27. Each of the foam metal pipes 25 and 27 is a foam (sponge) -shaped inorganic material (for example, It is a pipe member made of a continuous porous body formed by cylindrically forming (porous aluminum material, porous nickel material), and has a larger diameter than the exhaust introduction pipe 17, the resonance pipe 21, and the communication pipe 23.

There are various types of foamed metal depending on the degree of foaming, but generally, what is called foamed metal has a porosity of 8
It is 0 to 90%, and any type within this range can be used in the present invention.

As shown in FIGS. 2 and 3, eight projecting pieces 25a and 27a are integrally formed at equal intervals on both ends of the foam metal pipes 25 and 27, respectively. on the other hand,
The baffle plate 7 that separates the first chamber 11 and the second chamber 13 corresponds to the protrusions 25a and 27a around the exhaust introduction pipe insertion hole 29 and the communication pipe insertion hole 31, respectively, as shown in FIG. Then, the notch 7a is provided on the same circumference.

As shown in FIG. 5, the baffle plate 9 for partitioning the second chamber 13 and the third chamber 15 also has a notch 9a facing the notch 7a formed in the baffle plate 7 and having the same notch 9a. The metal foam pipes 25, 2 provided above
7, the protrusions 25a and 27a of the valve 7 engage with the notches 7a and 9a, respectively, and the insertion side end portion 17a of the exhaust gas introducing pipe 17 and the resonance pipe 21.
A foam metal pipe 25 is installed between the baffle plates 7 and 9 so as to cover one end 21a of the same, and a foam metal pipe 27 is installed between the baffle plates 7 and 9 so as to cover one end 23a of the communication pipe 23. .

Thus, in the muffler according to this embodiment, as described above, the projecting pieces 25a, 27a are engaged with the notches 7a, 9a so that the foam metal pipe 2 is provided between the baffle plates 7, 9.
5, 27, and then the exhaust introduction pipe 17, the exhaust discharge pipe 19, the resonance pipe 21, and the communication pipe 23 are respectively attached to the baffle plates 7, 9, and then these are housed in the shell 1 to open both ends thereof. It is formed by closing the portion with the end plates 3 and 5.

As with the silencer shown in FIG. 13, the second chamber 13 defined by the baffle plates 7 and 9 functions as an expansion chamber, and communicates with the second chamber 13 via the resonance tube 21. The third chamber 15 functions as a resonance chamber, and the exhaust outlet pipe 19 opens to the first chamber 11 that communicates with the second chamber 13 via the communication pipe 23, and the first chamber 11 functions as an expansion chamber. It is like this.

Since the muffler according to the present embodiment is constructed in this way, when the engine is driven, exhaust gas flows into the muffler through the exhaust introduction pipe 17, and exhaust pulsation is accompanied by this. The exhaust pulsation propagated into the silencer, but propagated into the silencer via the exhaust introduction pipe 17, the exhaust introduction pipe 1
It is attenuated when passing through the innumerable continuous pores of the metal foam pipe 25 that covers the insertion-side end 17a of No. 7 and the one end 21a of the resonance tube 21.

The exhaust pulsation thus attenuated has a significantly reduced level as compared with the conventional exhaust pulsation, so that the resonance of the shell 1 due to the exhaust pulsation is reduced, and
Radiation noise from the shell 1 can be prevented, and the adverse effect on the pressure resistance of the silencer can be reduced.

The exhaust gas flowing into the muffler through the exhaust introduction pipe 17 passes through the numerous continuous pores of the foam metal pipe 25, diffuses into the second chamber 13, and then the count of foam metal pipe 27. The exhaust gas is rectified when passing through the infinite number of continuous pores of the foam metal pipes 25 and 27.

Therefore, according to this embodiment, it is possible to solve the conventional drawback that the radiation noise is generated due to the resonance of the shell 1 due to the exhaust pulsation, and it is possible to reduce the adverse effect of the pressure resistance of the silencer and to reduce the exhaust gas. Does not directly contact the shell 1 so that heat transfer to the shell 1 is reduced and thermal deformation of the shell 1 is reduced. Furthermore, the metal foam pipes 25 and 27 installed between the baffle plates 7 and 9 function as a reinforcing material. In combination with increasing the rigidity of the silencer, the thickness of the shell 1 can be reduced, which contributes to weight reduction of the silencer.

Further, as described above, according to this embodiment, the exhaust gas is rectified when passing through the innumerable continuous pores of the foam metal pipes 25 and 27, so that the generation of air flow noise is reduced as compared with the conventional case. Has the effect that can.

In the first embodiment, the invention according to claims 1 and 2 is applied to the muffler in which the resonance pipe 21 is arranged coaxially with the exhaust introduction pipe 17, but FIG. In the muffler in which the resonance pipe 21 is not arranged coaxially with the exhaust introduction pipe 17 as in the second embodiment shown, the baffle plates 7 and 9 are provided with notches 7a and 9a, respectively, on the same circumference so as to face each other. Then, the foam metal pipe 25 is installed between the baffle plates 7 and 9 by engaging the projecting pieces 25a with the respective cutouts 7a and 9a, and the insertion side end portion 17a of the exhaust gas introducing pipe 17 is connected by the foam metal pipe 25. Just cover it.

Thus, also in the second embodiment, as in the first embodiment, the conventional defect that the radiation sound is generated due to the resonance of the shell 1 due to the exhaust pulsation can be solved, and the silencer of the silencer can be eliminated. In addition to being able to reduce the adverse effect of pressure resistance,
Since the exhaust gas does not directly hit the shell 1, heat transfer to the shell 1 is reduced and thermal deformation of the shell 1 is reduced. Furthermore, the foam metal pipe 25 laid between the baffle plates 7 and 9 functions as a reinforcing material. In combination with increasing the rigidity of the silencer, the thickness of the shell 1 can be reduced, which contributes to weight reduction of the silencer.

FIG. 7 is an enlarged sectional view of the essential parts of a first embodiment of a silencer according to claims 1 and 3, and FIG. 8 is a view of FIG.
7 shows a cross-sectional view taken along the line VIII-VIII, and in FIG. 7, reference numeral 33 denotes a foam metal pipe which is installed between the baffle plates 7 and 9 so as to cover the insertion side end portion 17a of the exhaust introduction pipe 17 and the one end portion 21a of the resonance pipe 21. The foam metal pipe 33 is made of the same material as that of the foam metal pipe 25.
The exhaust introduction pipe 1 is formed to have the same size as the space between
7 and the resonance tube 21 are formed to have a larger diameter.

Further, 35 and 37 are bead-shaped projecting portions projectingly provided on the baffle plate 7 so as to project toward the second chamber 13, and both projecting portions 35 and 37 are foamed as shown in FIG. Around the exhaust introduction pipe insertion hole 29 with a space corresponding to the thickness of the metal pipe 33, the metal pipe 33 is projected on the same circumference, and one end of the foam metal pipe 33 is provided between the protruding portions 35 and 37. Can be supported.

On the other hand, the baffle plate 9 is also provided with projections 39 and 41 having the same shape as the above projections 35 and 37 so as to project toward the second chamber 13 in correspondence with the projections 35 and 37. By supporting one end of the metal foam pipe 33 between the protrusions 35 and 37 and supporting the other end of the metal foam pipe 33 between the protrusions 39 and 41 as described above, the baffle plates 7 and 9 are A foam metal pipe 33 is installed between them.

Thus, the muffler according to this embodiment also has the foam metal pipe 3 between the baffle plates 7 and 9 as described above.
3, the exhaust introduction pipe 17, the exhaust discharge pipe 19, the resonance pipe 21, and the communication pipe 23 are inserted and attached to the baffle plates 7 and 9, and these are housed in the shell 1 and the openings at both ends thereof are end plates. It is formed by closing at 3,5.

The muffler according to this embodiment is constructed in this way, and when the engine is driven, exhaust gas flows into the muffler through the exhaust introduction pipe 17, and the exhaust pulsation is muffled accordingly. Although it is propagated inside the container, this embodiment also
The exhaust pulsation propagated into the muffler through the exhaust introduction pipe 17 passes through the numerous continuous pores of the foam metal pipe 33 that covers the insertion-side end 17a of the exhaust introduction pipe 17 and the one end 21a of the resonance pipe 21. It will be attenuated.

The exhaust pulsation thus attenuated has a significantly reduced level as compared with the conventional exhaust pulsation, so that the resonance of the shell 1 due to the exhaust pulsation is reduced, and
Radiation noise from the shell 1 can be prevented, and the adverse effect on the pressure resistance of the silencer can be reduced.

Further, the exhaust gas flowing into the muffler through the exhaust introduction pipe 17 passes through the numerous continuous pores of the foam metal pipe 33, diffuses into the second chamber 13, and then flows into the communication pipe 23. However, the exhaust gas is rectified as it passes through the numerous continuous pores of the foam metal pipe 33.

Therefore, according to this embodiment, as in the embodiment shown in FIG. 1, it is possible to eliminate the conventional drawback that the radiation sound is generated due to the resonance of the shell 1 due to the exhaust pulsation, and
It is possible to reduce the influence of deterioration of the pressure resistance performance of the silencer, and since exhaust gas does not directly hit the shell 1, heat transfer to the shell 1 is reduced and thermal deformation of the shell 1 is reduced, and furthermore, the baffle plates 7 and 9 are also reduced. Foamed metal pipe 33 installed between
Also functions as a reinforcing material to increase the rigidity of the muffler, and the thickness of the shell 1 can be reduced to contribute to the weight reduction of the muffler.

Further, as described above, since the exhaust gas is rectified as it flows through the numerous continuous pores of the foam metal pipe 33, there is an advantage that the generation of air flow noise can be reduced as compared with the conventional case.

In the above-described embodiment, as shown in FIGS. 7 and 8, the baffle plates 7 and 9 are provided with a gap corresponding to the thickness of the foam metal pipe 33, and the protrusions 35, 37 and 3 are respectively formed.
9, 41 are provided on the same circumference, but instead of such a structure, as in the embodiment shown in FIG. 9, for example, the foam metal pipe 33 is supported by abutting the outer peripheral end of the foam metal pipe 33. The protrusions 37, 41 may be provided on the baffle plates 7, 9 or, as in the embodiment shown in FIG. 10, the foam metal pipe 33 is brought into contact with the inner peripheral end portion of the foam metal pipe 33. Protrusions 35 and 39 for supporting may be provided on the baffle plates 7 and 9, and the protrusions 35, 37, 39 and 41 may be provided on the foam metal pipe 3 as in the embodiment shown in FIG.
The foam metal pipe 33 may be alternately provided on the inner and outer peripheries of 3 to support the foam metal pipe 33, and the foam metal pipe 33 can be installed between the baffle plates 7 and 9 in each of these embodiments. Exhaust gas introduction pipe 17 with pipe 33
By covering the insertion side end portion 17a of the above, it is possible to achieve the intended purpose as in the above embodiments.

Further, in the embodiment shown in FIGS. 7 and 8, the protrusions 35, 37, 39, 41 are provided on the baffle plates 7, 9, but the expansion chamber where the exhaust introduction pipe 17 is opened is the baffle plate and the end. In the muffler partitioned by the plate, the protrusions 35, 37, 39 and 41 may be formed on the baffle plate and the end plate, respectively.

FIG. 12 is an enlarged sectional view of an essential part of an embodiment of a silencer according to claim 4, in which 43 is an exhaust introduction pipe 17.
Of the perforated pipe inserted into the perforated pipe insertion hole 45 of the baffle plate 7 so as to cover the insertion-side end portion 17a and the one end portion 21a of the resonance pipe 21 arranged coaxially with the exhaust introduction pipe 17. One end is welded to the baffle plate 9.

The perforated pipe 43 is a pipe member having a large number of small holes 47 in the peripheral wall and an opening ratio of 130%, and has a larger diameter than the exhaust introduction pipe 17, the resonance pipe 21, and the communication pipe 23. It is molded.

In this embodiment, the aperture ratio is 100%.
Since a pipe member of less than 100% is not preferable because the back pressure becomes high, various pipe members having an appropriate opening ratio of 100% or more are selected as the porous pipe 43.

The muffler according to this embodiment is constructed in this way, and like the above embodiments, when the engine is driven, the exhaust gas flows into the muffler through the exhaust introduction pipe 17, and Along with this, the exhaust pulsation is propagated into the muffler, but most of the exhaust pulsation propagated into the muffler via the exhaust introduction pipe 17 is due to the insertion side end 17 a of the exhaust introduction pipe 17 and the resonance pipe 21. After passing through a large number of small holes 47 of the perforated pipe 43 covering the one end 21a, it is attenuated.

Since the exhaust pulsation thus attenuated has a significantly reduced level as compared with the conventional exhaust pulsation, the resonance of the shell 1 due to the exhaust pulsation is reduced, and
Radiation noise from the shell 1 can be prevented, and the adverse effect on the pressure resistance of the silencer can be reduced.

Most of the exhaust gas flowing into the muffler through the exhaust introduction pipe 17 passes through the many small holes 47 of the perforated pipe 43 and diffuses into the second chamber 13, but many exhaust gas is emitted. It is rectified when passing through the small holes 47 of the.

Therefore, according to the present embodiment, as in the above-described embodiments, the conventional drawback that the radiation sound is generated due to the resonance of the shell 1 due to the exhaust pulsation can be solved, and the deterioration of the withstand voltage performance of the silencer is affected. At the same time, the exhaust gas does not directly hit the shell 1 so that the heat transfer to the shell 1 is reduced and the thermal deformation of the shell 1 is reduced, and furthermore, the porous pipe 43 installed between the baffle plates 7 and 9 is reinforced. Along with the fact that it functions as a material and increases the rigidity of the silencer, the shell 1 can be made thinner, which contributes to weight reduction of the silencer.

Of course, as described above, also in this embodiment, most of the exhaust gas flowing into the silencer is the porous pipe 4.
Since it is rectified when passing through the small holes 47 of No. 3, it has an effect of reducing the generation of airflow noise as compared with the conventional case.

In the above embodiment, the perforated pipe 43 is attached to the baffle plate 7 side, but the baffle plate 9
Of course, the perforated pipe 43 may be attached to the side.

[0049]

As described above, according to the silencer described in each claim, radiation noise is not generated due to resonance of the shell due to exhaust pulsation, and the pressure resistance of the silencer is deteriorated. In addition to being able to reduce the effect, the exhaust gas does not directly hit the shell, so heat transfer to the shell is reduced and thermal deformation of the shell is reduced.Thus, the shell can be made thinner, contributing to the weight reduction of the silencer. Is possible.

In the silencer according to the second and third aspects, since the foam metal pipe installed between the baffle plates increases the rigidity of the silencer as a reinforcing material, the thickness of the shell can be reduced more reliably. Further, the weight of the silencer can be further reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of a silencer according to claims 1 and 2.

FIG. 2 is a side view of a foam metal pipe.

FIG. 3 is a view on arrow A in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is an enlarged sectional view of an essential part of a second embodiment of the silencer according to claims 1 and 2.

FIG. 7 is an enlarged sectional view of an essential part of a muffler according to a first embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is a cross-sectional view of essential parts of a second embodiment of a silencer according to claims 1 and 3.

FIG. 10 is a cross-sectional view of essential parts of a third embodiment of a silencer according to claims 1 and 3.

FIG. 11 is a cross-sectional view of the essential parts of a fourth embodiment of a silencer according to Claims 1 and 3.

FIG. 12 is an enlarged sectional view of an essential part of an embodiment of a silencer according to claim 4;

FIG. 13 is a sectional view of a conventional silencer.

FIG. 14 is a perspective view of the internal structure of a conventional silencer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shell 3,5 End plate 7,9 Baffle plate 7a, 9a Notch 11 1st chamber 13 2nd chamber 15 3rd chamber 17 Exhaust gas inlet pipe 19 Exhaust gas outlet pipe 21 Resonance pipe 23 Communication pipe 25, 27, 33 Foam metal Pipe 25a, 27a Projection piece 35, 37, 39, 41 Projection part 43 Perforated pipe 47 Small hole

Claims (4)

[Claims] 1. An end portion (17a) on the insertion side of an exhaust gas introduction pipe (17), wherein a shell (1) whose both openings are closed by end plates (3, 5) is partitioned by a plurality of baffle plates (7, 9). ) Has a chamber (13) opened as an expansion chamber, the silencer has an insertion side end (17) of the exhaust introduction pipe (17).
a) is a metal foam pipe (25, 3) having a diameter larger than that of the exhaust introduction pipe (17) and including a large number of continuous pores.
A silencer characterized by being covered in 3). 2. A metal foam pipe (25) is installed between two baffle plates (7, 9) that define an expansion chamber, and both baffle plates (7, 9) have a plurality of notches (7a). , 9a) are provided so as to face each other on the same circumference, and a plurality of projecting pieces (25a) engageable with the notches (7a, 9a) are provided at both ends of the foam metal pipe (25).
The silencer according to claim 1, wherein the silencer is formed. 3. A foam metal pipe (33) is installed between two baffle plates (7, 9) or baffle plates (7, 9) and an end plate (3, 5) that define an expansion chamber. The baffle plate (7, 9) or the baffle plate (7, 9) and the end plate (3, 5) have protrusions (35, 37, 41, 43) for supporting both ends of the metal foam pipe (33). The muffler according to claim 1, wherein the muffler is provided so as to project toward the expansion chamber on the same circumference. 4. An end portion (17a) on the insertion side of an exhaust gas introduction pipe (17) is formed by partitioning the inside of a shell (1) whose both openings are closed by end plates (3, 5) with a plurality of baffle plates (7, 9). ) Has a chamber (13) opened as an expansion chamber, the silencer has an insertion side end (17) of the exhaust introduction pipe (17).
A silencer characterized in that a) is covered with a perforated pipe (43) having a diameter larger than that of the exhaust introduction pipe (17) and having a large number of small holes in the peripheral wall and an opening ratio of 100% or more.