JPH0521620Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to an exhaust muffler used for muffling the exhaust noise of an internal combustion engine, and more specifically, to an exhaust muffler that aims to reduce vibrations transmitted from the internal combustion engine. .

(Prior Art) As is well known, an exhaust muffler guides exhaust gas from an exhaust manifold of an internal combustion engine into a box body, and suppresses exhaust noise by the action of a muffling chamber such as an expansion chamber or a resonance chamber defined inside the box body. Mute the sound. Conventionally, such exhaust mufflers are known, such as those described in, for example, Japanese Utility Model Application Publication No. 100520/1982 and Japanese Patent Application Laid-open No. 252822/1983.

The former exhaust silencer consists of a first muffler made of a steel plate and a second muffler made of a light alloy. The tip of the second muffler is inserted into the outside of the gasket cylinder, and the tip is brought into contact with the cushion ring and tightened with a tightening band, bolts, and nuts.

In addition, the latter exhaust silencing device inserts one pipe into another pipe through a cushion material, and interposes an elastic ring between the stopper ring provided on the one pipe and the other pipe to prevent exhaust leakage. This is intended to prevent vibrations as well as provide vibration isolation.

(Problem to be solved by the invention) However, in the former structure, vibration countermeasures are only taken at the tip side of the second muffler 6.
Since the second muffler 6 is made of metal, it is not possible to muffle sound or insulate the body of the second muffler 6. Also, the latter requires cushioning material, elastic rings, etc. in addition to the pipe, so the structure is complicated,
There was also a problem with poor assembly.

(Means for Solving the Problems) This invention provides an exhaust silencer that guides exhaust gas from an exhaust introduction pipe to a silencing chamber to muffle exhaust noise. It includes a box with a defined chamber and a substantially cylindrical support part formed integrally with the box, and the box and the exhaust introduction pipe are connected to each other via a substantially cylindrical coupling member. The coupling member includes at least a cap located on an inner surface side of the support portion and fixed to the exhaust introduction pipe, and a heat-resistant elastic material located between the support portion and the cap. It is characterized by

According to the exhaust silencer according to this invention, a cylindrical support part through which the exhaust pipe can be inserted is formed integrally with the box body, and a heat insulating elastic material is formed between the inner peripheral surface of the support part and the exhaust introduction pipe. Since the box body and the exhaust inlet pipe are elastically supported by interposing a connecting member consisting of
Further, since the assembly can be performed by fixing the coupling member to one of the box body or the exhaust introduction pipe and fixing them to the other, the assembly work is also easy. Further, this exhaust muffler does not need to be provided with an external coupling portion for coupling with the exhaust introduction pipe, and can be made smaller.

(Example) An example of this invention will be described below based on the drawings.

Figures 1 to 3 show an exhaust muffler according to an embodiment of this invention; Figure 1 is an overall sectional view;
The figure is a sectional view taken along the - arrow in FIG. 1, and FIGS. 3 a to 3 c are sectional views illustrating the manufacturing process.

In FIG. 1, reference numeral 11 denotes a hollow box with an internal sound deadening chamber 12 defined, and the box 11 is constructed by joining two halves 11a and 11b with a caulking tool 13 (a second (see figure). These halves 11
a and 11b have the same shape, and each includes a hard and highly rigid outer skin layer 14 formed by impregnating an inorganic heat-resistant fiber such as glass wool or rock wool with a thermosetting resin such as unsaturated polyethylene, and the above-mentioned inorganic heat-resistant fiber. A silencing chamber 12 is defined in the box body 11 by using the inner layer 15 as a wall. At the left end of the box body 11 in the figure, a mounting hole 15a is formed in the inner layer 15, and a cylindrical portion (supporting portion) 14a is integrally provided coaxially with the mounting hole 15a in the outer skin layer 14. At the left end in the figure of 11, cylindrical portions 15b and 14b are formed coaxially on the inner layer 15 and the outer skin layer 14, respectively, and a connecting portion 16 is configured. This connection part 16 has
The silencing chamber 1 is constructed using the inner surface of the cylindrical portion 15b of the inner layer 15 as a peripheral wall.
An exhaust outlet passage 17 opening to the exhaust outlet 2 is formed, and an exhaust pipe (not shown) communicating with the exhaust outlet passage 17 is connected to the connecting portion 16 .

In addition, inside the cylindrical portion 14a of the outer skin layer 14 and the inner layer 1
A cylindrical cap 18 whose right end in the drawing opens into the muffling chamber 12 is inserted into the mounting hole 15a of No. and welded to the base 18. The cap 18 has a flange portion 18a formed at the left end in the figure, and a plurality of protrusions 18b formed at the axial center portion of the outer circumferential portion, and a center portion including the right end surface of the flange portion 18a and the protrusions 18b in the figure. A bushing 20 is fixed to the outer peripheral surface of. The bush 20 is made of silicone rubber reinforced with a heat-resistant elastic material, for example, inorganic fibers such as glass wool, and its outer circumferential surface is the inner circumferential surface of the cylindrical portion 14a of the cylindrical portion 14a of the outer skin layer 14, and the right end surface in the figure is It is fixed to the outer peripheral surface of the mounting hole 15a of the inner layer 15 at the left end in the figure. In addition, the above-mentioned cap 18 and button 20
corresponds to the coupling member.

In such an exhaust muffler, exhaust gas flows from the internal combustion engine through the exhaust manifold 19 and into the muffling chamber 12 as shown by the arrow, and the muffling chamber 12 muffles the exhaust noise and discharges it from the exhaust outlet path 17. and,
In this exhaust muffler, an elastic bushing 20 is interposed between the box body 11 and the exhaust manifold 19, and the elasticity of the bushing 20 reduces vibrations transmitted from the internal combustion engine. Therefore, vibration of the box 11 can be suppressed, and problems such as peeling of the inner layer 15 can be prevented. In addition, this exhaust silencer has a bushing of 20
Also, since the box body 11 and the exhaust manifold 19 can be connected only with the base 18, the number of parts can be reduced and a simple configuration can be achieved.

On the other hand, such an exhaust muffler is constructed by mounting silicone rubber 21 containing uncured fibers on the outer periphery of the base 18 as shown in FIG. 3a, and molding it as shown in FIG. 3b. do. Then, as shown in FIG. 3c, the halves 11a and 11b of the box body 11 are formed by the outer skin layer 14 and the inner layer 15, and the halves 11a and
11b are joined to form the box body 11. After this,
A thermosetting resin such as polyester is applied to the wall surface of the inner layer 15 of this box body 11, a base 18 having a molded silicone rubber 20 is attached to this box body 11, and these are pressurized and heated to complete the product. can be obtained. Therefore, this exhaust muffler can be easily assembled.

In the above-mentioned exhaust silencer, the bushing 20 is integrally molded on the outer periphery of the base 18 (FIG. 3b), but this bushing 20 is molded as a single piece, and the bushing 20 is screwed into the single molded bushing 20. Needless to say, the cap 18 can also be fixed with the screws.

(Effects of the invention) As explained above, according to the invention, the exhaust inlet pipe is connected to the supporting part (box body) side through a connecting member having elasticity and heat insulation properties, so it has excellent sound deadening and heat insulation properties. , Also, the vibration absorption at the joint part is sufficient.
It can have a simple structure. Furthermore, since the box is made of a molded sound absorbing material, the box can achieve sound deadening and heat insulation.

[Brief explanation of the drawing]

1 to 3 show an exhaust silencer according to an embodiment of this invention, in which FIG. 1 is an overall sectional view, and FIG.
The figure is a sectional view taken along the - arrow in Fig. 1, Fig. 3 a, b,
3c is a cross-sectional view of each component in the manufacturing process. DESCRIPTION OF SYMBOLS 11... Box body, 11a... Half body, 11b... Half body, 12... Sound deadening chamber, 14... Outer skin layer, 14a...
... Cylinder part (supporting part), 14b ... Cylinder part, 15 ... Inner layer, 15a ... Mounting hole, 15b ... Cylinder part, 16...
. . . Connection portion, 18 . . . Base, 18a .

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In an exhaust muffler that muffles exhaust noise by guiding exhaust gas from an exhaust introduction pipe to a muffling chamber, the exhaust muffler is at least made of a molded sound-absorbing material and has a muffling chamber defined therein. a substantially cylindrical support portion integrally formed with the box, the box and the exhaust introduction pipe are coupled via a substantially cylindrical coupling member; The coupling member is characterized in that it includes at least a cap located on the inner surface side of the support portion and fixed to the exhaust gas introduction pipe, and a heat-resistant elastic material located between the support portion and the cap. Exhaust silencer. (2) The exhaust muffler according to claim 1, wherein the connecting member includes a connecting member formed by molding an inner layer of resin of the box body.