JPS61169611A - Structure of exhaust gas silencer - Google Patents

Abstract

PURPOSE:To enhance rigidity of an after-end plate by installing a connection pipe which is fixed to a partition plate in a cylindrical main body, so that one end of the pipe is situated near the after-end plate, and providing a projected part to the after-end plate in such a manner that clearance is ensured between the after-end plate and an opening of the connection pipe. CONSTITUTION:A plurality of partition plates 2 and 5 are installed in a cylindrical main body 1a of an exhaust silencer 1, thereby forming more than one resonance rooms 4 and 8 and an expansion room 6. An inlet pipe 9 and an outlet pipe 11 are installed to the fore and after-end plates 7 and 3, respectively, of the cylindrical main body 1a. In this situation, a connection pipe 13 is fixed to the partition plate 2. At this time, one end of the connection pipe 13 is open to the expansion room 6, while the other end is positioned at the vicinity of the after-end plate 3, opening to the resonance room 4. The after-end plate 3 is provided with a nearly conically projected part 14, which faces toward the inside of the cylindrical main body 1a, in such a manner that the plate 3 becomes parallel with the end surface of an opening part 13a of the connection pipe 13 and that a predetermined clearance 15 is ensured.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an exhaust silencer structure, and more particularly, to a silencer in which a protrusion is formed on a rear end plate supporting an outlet pipe toward an opening of a communicating pipe. Regarding. This is used in the field of silencers to muffle explosion sounds in engine exhaust gas.

C. Prior Art] In order to reduce or prevent explosion sounds caused by combustion from being emitted along with the exhaust gas, there are
A silencer is installed.

In order to enhance the noise reduction effect, a silencer in which a cylindrical body is divided into a plurality of chambers by a partition plate, and a plurality of communication pipes are passed through the partition plate to communicate the resonance chamber and the expansion chamber, is used. It is described in Publication No. 56-49215. In such a silencer, one end of the cylindrical body is closed with a front end plate that supports an inlet pipe, and the other end is closed with a rear end plate that supports an outlet pipe, so that exhaust gas from the engine is passed through the inlet pipe. Once introduced, the muffled exhaust gas is led out through the outlet pipe.

The communication pipes provided inside such a silencer tend to be longer in number or one by one because the longer the path of exhaust gas passing through the siren, the higher the silencing effect. As a result, when a car is rear-ended by another car, the outlet pipe fixed to the rear end plate is often pushed forward, causing the silencer to burst. In particular, modern silencers use thin plates to reduce weight, so the rear end plate may easily deform. If the deformation becomes significant, the opening of the communication pipe extending toward the front surface of the rear end plate will pierce through the rear end plate, and high-temperature exhaust gas will leak out from the silencer, which is undesirable. In addition, the rear end plate that forms the resonance chamber is thinner, and the explosion sound propagating in the communication pipe is introduced into the resonance chamber in a pulsating manner in the exhaust gas. There is a problem in that it tends to resonate with the explosion sound, reducing the silencing effect.

[Purpose of the invention]

The present invention was made in view of the above-mentioned problems, and its purpose is to reduce damage to the rear end plate due to the communication pipe installed inside the silencer when a car is rear-ended, and to To provide an exhaust silencer structure capable of improving the rigidity of a rear end plate, avoiding resonance with explosion noise, and fully exhibiting a silencing effect.

[Structure of the invention]

A feature of the exhaust silencer structure of the present invention is that the communication pipe fixed to the partition plate extends close to the rear end plate, and is parallel to the opening of the communication pipe and maintains a predetermined gap from the rear end plate. In other words, a convex portion extending toward the inside of the cylindrical body is provided.

〔Example〕

Hereinafter, the present invention will be explained in detail based on examples thereof.

FIG. 1 is a sectional view of an exhaust silencer l to which the present invention is applied, in which a cylindrical body 1a is divided into a plurality of chambers by a partition plate 2, and a space between the cylindrical body 1a and a rear end plate 3 that closes one end of the cylindrical body 1a. A resonance chamber 4 is formed therein. In this example, another partition plate 5 is provided in the silencer 1, and an expansion chamber 6 is provided between the two partition plates.
Another resonance chamber 8 is provided between the front end plate 7 which closes the other end of the cylindrical body 1a.

An inleft pipe 9 for introducing exhaust gas from the engine through an exhaust pipe (not shown) is attached to the silencer 1, and is airtightly fixed to the front end plate 7 by welding or the like.

The rear end side is inserted into a support hole 10 provided in the partition plate 5 and supported so that it can be expanded by thermal expansion. The rear end of such an inleft pipe 9 is an expansion chamber 6.
At the same time, a plurality of holes (not shown) are opened in a portion of the resonance chamber 8 to extract a part of the explosion sound in the exhaust gas. On the other hand, the outlet pipe 11 that leads out exhaust gas from the silencer 1 is hermetically fixed at the rear end plate 3, and its front end is connected to the partition plate 2.
It is supported in the support hole 12 of.

A communication pipe 13 is fixed to the partition plate 2 of the silencer 1 by welding, one end of which opens into the expansion chamber 6, the other end extends close to the rear end plate 3, and opens into the resonance chamber 4. are doing. By the way, the longer the path of the explosion sound that pulsates and propagates through the exhaust gas, the greater the silencing effect, and especially the better the attenuation of low-frequency sounds. Therefore, the above-mentioned communication pipe 13
Although not shown in the drawings, a large number of them may be arranged, or their dimensions may be long. In this example, the above-mentioned inleft vibe 9 is arranged in front of this communication pipe 13 so as to face it in a straight line, and the inlet The explosion sound propagating inside the pipe 9 is easily introduced into the resonance chamber 4 via the communication pipe 13.

The rear end plate 3 is provided with a substantially conical convex portion 14 extending inward of the cylindrical body 1a, parallel to the end surface of the opening 13a of the communication pipe 13. Note that a predetermined gap 15 is maintained between the two, which is suitable for allowing thermal expansion of the communicating pipe and for introducing the propagating explosion sound into the resonance chamber 4. The convex portion 14 may be integrally formed by pressing the rear end plate 3, or a convex member may be separately manufactured and integrated with the rear end plate 3.

In any case, it is only necessary to improve the strength of the portion where the communication pipe 13 contacts the rear end plate 3, as well as increase the rigidity and increase the natural frequency of the rear end plate 3. As shown in FIG. 2, if the convex portion 14 is formed with, for example, a diagonal recess i1t14a, the opening 13a of the communication pipe 13 may be damaged in the event of a rear-end collision.
Even if the top surface of the convex portion 14 comes into contact with the
The explosion sound propagating inside can be introduced into the resonance chamber 4.

According to the silencer I configured as described above, it is possible to prevent the silencer from being damaged in the event of a rear-end collision and to reduce the vibration noise of the rear end plate 3. Exhaust gas is introduced into the silencer 1 from an exhaust pipe (not shown) via an inlet pipe 9, and after being silenced is released into the atmosphere from an outlet pipe 11. In this way, while the exhaust gas passes through the silencer=1, the communication pipe 13 expands due to the heat possessed by the exhaust gas, and becomes longer than when it does not receive heat. The communication pipe 13 is connected to the partition plate 2
Since it is only fixed at , it expands both in the expansion chamber 6 and in the resonance chamber 4. In the resonance chamber 4, the convex portion 1
However, since there is a gap 15 between the communicating pipe 13 and the convex portion 14, which is set in anticipation of the amount of expansion of the communicating pipe, expansion of the communicating pipe 13 is allowed, and the gap The sound energy of the explosion that has propagated through the communication pipe 13 from 15 is introduced into the resonance chamber 4. The resonance chamber 4 has a sealed structure so that the exhaust gas is kept in a stagnant state, and the rear end plate 3 of a thin plate with improved rigidity due to the convex portion 14 does not resonate with the explosion sound, effectively muffling the explosion sound. be done.

On the other hand, when a car is rear-ended, the outlet vibe 11
is pushed in the direction of arrow 16. The rear end plate 3, which is integrated by welding, also moves or deforms at the same time, but even if the rear end plate 3 comes into contact with the communication pipe 13, the rear end plate 3 is protected by the convex portion 14 and will not be damaged. is reduced. Since the impact force is distributed and transmitted to other members of the silencer via the communication pipe 13, severe damage to the silencer is avoided and leakage of high temperature exhaust gas to the outside is avoided as much as possible.

Although FIG. 3 is a diagram showing the arrangement of the convex portion 14 and the communicating pipe 13 facing each other, as shown in FIG. 4, the opening 13a of the communicating pipe 13 is inclined and has a top surface parallel to this. It may also be a convex portion 14. In this case, the communication pipe 13
When the convex portion 14 and the rear end plate 3 come into contact with each other, the impact force that deforms the rear end plate 3 is alleviated, and there is an advantage that the degree of damage to the silencer can be further reduced.

- [Effects of the Invention] As can be seen from the description of the embodiments above, the present invention is such that the communication pipe fixed to the partition plate is extended close to the rear end plate, and the opening of the communication pipe is formed in the rear end plate. Since the convex portion is provided with a predetermined gap therebetween, the rigidity of the rear end plate is improved, and generation of vibration noise of the rear end plate in the resonance chamber can be suppressed. Furthermore, even if the rear end plate is deformed by an external force acting on the silencer, the communication pipe comes into contact with the convex portion, so damage to the rear end plate is reduced, and leakage of exhaust gas due to damage to the silencer is suppressed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of an exhaust silencer to which the present invention is applied, FIG. 2 is a view taken along line nn in FIG. FIG. 4 is a diagram showing a facing arrangement of a convex portion of a different shape and a communicating pipe. 1-silencer, 1a--cylindrical body, 2--partition plate, 3-rear end plate, 7-front end plate, 9-in left pipe, 11-outlet vibe, 13 continuous vibe, 13a--opening part, 14-convex part, 15-gap.

Claims (1)

[Claims] (1) The cylindrical body is divided into a plurality of chambers by a partition plate, a plurality of communication pipes pass through the partition plate, one end of the cylindrical body is closed with a front end plate supporting an inlet pipe, and the other end is closed with a front end plate that supports an inlet pipe. In the exhaust silencer for an engine, the exhaust silencer is closed by a rear end plate that supports an outlet pipe, and a communication pipe fixed to a partition plate adjacent to the rear end plate extends close to the rear end plate, and An exhaust silencer structure characterized in that a rear end plate is provided with a convex portion that is parallel to the opening of the communication pipe and extends toward the inside of the cylindrical body while maintaining a predetermined gap.