JPS582411A - Silencer - Google Patents

Abstract

PURPOSE:To prevent the noise in a silencer from being emitted outward by disposing expansion chambers and resonance chambers thereof inside an external casing. CONSTITUTION:Exhaust gas from an engine is fed from a guide pipe 45 into the first expansion chamber 24 for expansion and comes into a resosnance chamber 30, which is communicated therewith through a hole 39, for resonance so that the gas is silenced by those expansion and resonance effects. The gas is then carried into the second expansion chamber 32 through a pipe 41 having many pores 43 and into a resonance chamber 31, which are communicated with holes 28 on a partition wall 29 and pores 43 on the pipe 41, so that the gas is silenced by those respective expansion and resonance effects. Thereafter, the gas is discharged outside from a pipe 47. In this silencer, the first expansion chamber 24 and the resonance chamber 31 are formed by three partition walls 22, 23, 29 between casings 25, 26, owing to which noise or vibration in each of the chambers 24, 31 is dampened inside the casings and will not be directly emitted outward.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a muffler, for example, a muffler for muffling the exhaust noise of an internal combustion engine.

As a conventional muffler, one shown in FIG. 1, for example, is known. To explain the configuration of this silencer, (1
) is an outer shell with a space inside, and this space is a partition wall (
2) (31 (by 41, the first expansion chamber (5), the cavity (6)
), a resonance chamber (7) and a second expansion chamber (8).The first expansion chamber (5) has an exhaust inlet pipe (
9) is open, and this exhaust inlet pipe (
9) The other end opens to the exhaust manifold of the internal combustion engine (not shown) [
1. The first expansion chamber (5) and the cavity (6) are connected by the first passage (old) of the first communication pipe (10), and the first expansion chamber (5) and the cavity (6) are connected by a Helmholtz tube. It consists of a resonator (12) and mutes sounds in the low frequency range. (
13) is a second passage formed in the second communication pipe (141), and both ends thereof open to the first and second expansion chambers (51(8)). small hole (
15) are formed, and these small holes (15) communicate the second passage (13) and the resonance chamber (7). The second expansion chamber (8) communicates with the outside air via the exhaust pipe (17), and the exhaust pipe (16) has an exhaust pipe (17).
A small hole 08) is formed which communicates the resonance chamber (7) with the resonance chamber (7). The aforementioned small hole (15) and the resonance chamber (the sword as a whole constitute a resonator (19), which muffles sounds in the high frequency range (for example, Publication of Utility Model Publication No. 5'6-23457). Conventional silencers such as the first expansion chamber (
5) was in contact with the outside air through the outer shell (11), so the first
There was a problem in that the exhaust gas from the internal combustion engine introduced into the expansion chamber (5) caused the outer shell to vibrate and generate noise.

This invention was made by focusing on such conventional problems, and includes an inner shell having a first expansion chamber therein, and a cavity and a space defined between the inner shell and the inner shell. a partition wall that divides the space into a resonance chamber and a second expansion chamber, and has a plurality of holes that communicate the resonance chamber and the second expansion chamber to form a resonator together with the resonance chamber; a first passage communicating with the cavity, the first passage forming a resonator together with the cavity; a second passage communicating the first expansion chamber with the second expansion chamber; a second connecting pipe formed with a plurality of holes that communicates the two passages with the resonance chamber;
By providing a silencer equipped with an inlet pipe that opens into each expansion chamber and an exhaust pipe that opens into a second expansion chamber,
The purpose is to solve the above problems.

The present invention will be explained below based on the drawings.

FIG. 2.3 is a diagram showing an embodiment of the present invention, and the configuration will be explained first. (21) is composed of two curved plates t22+ (
It is an inner shell formed by overlapping 23+, and a first expansion chamber (24) is defined inside the inner shell. This inner shell (2
1) is covered with two curved plates (2 (g) t26+, and these curved plates (25) (26+) have an outer shell (
27). The space defined between the curved plates C3) and (26) is divided into two by a partition wall (29) in which a large number of small holes (28) are formed, and as a result, the inner shell C!
There is a cavity (30) and a resonance chamber (3) between υ and the outer shell (271).
υ and a second expansion chamber (3) are defined respectively. The small hole (28) and the resonance chamber (31) constitute a resonator (33) that muffles sound in a predetermined high frequency range. These curved plates (22) (2:31(,!51 t26+ and the partition wall (29+) are seam welded around them, resulting in a first expansion chamber (24), a cavity (30), a resonance chamber (31), Since the second expansion chambers C32) are isolated from each other, the exhaust gas flows through the first and second passages, small holes, and small holes (, '
Noise-dampening effect can be enhanced without mutual inflow and outflow through the channels other than 8). The first expansion chamber (24) and the cavity (30) communicate with each other through the first passage (391) of the first connecting pipe, and the first passage t31 and the cavity (30) as a whole form a Helmholtz resonator. (40) The cross-sectional area (S), longitudinal length (1), and volume (T) of the cavity (30) on the first passage side are selected so that a predetermined low frequency sound can be suppressed.

The first expansion chamber (24) and the second expansion chamber (3) are connected by the second connecting pipe (411) and the second expansion chamber (4).
The connecting pipe (41) has a second passage (42) and a resonance chamber C31).
A large number of small holes (43) are formed to communicate with the
4) is a first exhaust pipe, and one end of the first exhaust passage (4) formed in this first exhaust pipe (44) communicates with the exhaust manifold of the internal combustion engine. (4
The other end of 4) freely passes through the first passage (39), and the other end of the first exhaust passage (451) communicates with the first expansion chamber (24J). The second exhaust passage (4η) communicates the second expansion chamber (32) with the outside air.

Next, the effect will be explained. Exhaust gas discharged from the internal combustion engine flows from the exhaust manifold into the first expansion chamber (24) via the first exhaust passage (451).At this time, the curved plate (221CI!31) vibrates and generates noise. , a curved plate (221 (a cavity (30) between 231 and the outside air,
Noise is not transmitted to the outside because there is a resonance chamber (31) and a second expansion chamber (33).

In addition, since the entire circumference of the curved plate (221 (231 (25) t26) is overlapped and welded, the inner and outer shells (2υ
(27) has high rigidity and contributes to prevention of vibration. A certain frequency component of this exhaust gas pulsation is generated in the first expansion chamber (2
4) Helmholtz resonator (40) with reduction within
This mutes sounds in a predetermined low frequency range. Especially the first
Since the exhaust pipe (44) loosely passes through the first passage (39), the resistance in this portion is increased, and a sufficient noise reduction effect can be obtained. Next, the exhaust gas flows into the six second expansion chambers through the second passage (42), and high frequency sounds in the exhaust gas are muffled by the resonator (33). In this way, the exhaust gas whose sounds in the low and high frequency ranges have been muffled is sent to the second exhaust passage (4
It passes through η and is discharged to the outside.

Note that two second exhaust pipes may be provided in parallel with each other, and two first exhaust pipes may also be provided depending on the type of internal combustion engine to which they are connected.
A book may be provided.

As described above, according to the present invention, a silencer includes an inner shell having a first expansion chamber therein, an outer shell enclosing the inner shell and defining a cavity and a space between the inner shell and the inner shell. A plurality of holes that divide this space into a resonance chamber and a second expansion chamber and communicate the resonance chamber and the second expansion chamber communicate the partition wall that forms a resonator together with the resonance chamber and the first expansion chamber and the cavity. a first connecting pipe having a first passageway, the first passageway forming a resonator together with the cavity; and a second passageway communicating the first expansion chamber and the second expansion chamber, and connecting the second passageway and the resonance chamber. a second connecting pipe in which a plurality of holes are formed to communicate with each other; an introduction pipe having one end connected to a noise generation source and the other end passing through the first passage loosely and opening into the first expansion chamber; and an introduction pipe opening into the second expansion chamber. Since the exhaust pipe is cleanable, noise caused by vibration of the inner shell can be prevented from being transmitted to the outside.

[Brief explanation of the drawing]

FIG. 1 is a model diagram of a conventional silencer, FIG. 2 is a sectional view showing an embodiment of the silencer according to the present invention, and FIG. 3 is a view taken along arrows ll'I-III in FIG. , (211... Inner shell, (241... First expansion chamber (271... Outer shell, (Audience... Hole (29)... Partition wall, (30)... Cavity (
31)... Resonance chamber, (32)... Second expansion chamber (33)... Resonator, μs)... First connecting pipe (turbidity... First passage, (40)...・Resonator (41)...Second connecting pipe, (42)...Second passage (4 holes/holes, (44)・Introduction pipe (46)・
·Exhaust pipe.

Claims (1)

[Claims] an inner shell having a first expansion chamber therein; an outer shell enclosing the inner shell and defining a cavity and space between the inner shell; and dividing this space into a resonance chamber and a second expansion chamber; A plurality of holes that communicate with the resonance chamber and the second expansion chamber form a resonator together with the resonance chamber, and a first passage that communicates with the first expansion chamber and the cavity, and the first passage resonates with the cavity. a first connecting pipe forming a container; a second connecting pipe having a second passage communicating with the first expansion chamber and the second expansion chamber; and a second connecting pipe having a plurality of holes communicating with the second passage and the resonance chamber; and an introduction pipe having one end connected to the noise generation source and the other end passing through the first passage and opening into the first expansion chamber, and an exhaust pipe opening into the second expansion chamber. vessel.