JPS60206927A - Exhauster for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the heat insulation and sound absorbing effects simultaneously, in a system where the exhaust gas from an internal-combustion engine is led through an exhaust pipe to a muffler, by covering at least a portion of an exhauster with a protector made of molded sound absorbing member. CONSTITUTION:An exhauster 10 is comprised of an exhaust pipe 12 to be led out from an engine 11 and a muffler 14 to be coupled to the rear end of said pipe 12 and positioned at the side of rear wheel 13. A protector 15 made of molded sound absorbing member is wound over said pipe 12 then held to the chassis side through a fixing band 16. The protector 15 is formed, for example, by bonding the upper and lower half bodies 17, 18 through heat-resistant adhesive 19 where the inside section is made of porous layer 15a having excellent heat insulation performance and sound absorbing performance while the outside section is made of hard layer 15b having excellent sound shield performance and rigidity. Consequently, the heat insulation and sound absorbing effects of exhauster can be improved through simple and light structure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust system that discharges exhaust gas generated by combustion in an internal combustion engine to the outside.

Generally, in internal combustion engines such as engines, exhaust gas generated by combustion is guided into a muffler through an exhaust pipe, and the exhaust gas is expanded in the muffler to dissipate the energy held by the exhaust gas. jJF is working to reduce the noise associated with air pollution.

The exhaust pipe and muffler through which IA gas flows are heated by the exhaust gas and reach high temperatures.
It is necessary to protect adjacent members from heat and prevent operators from directly touching them. Therefore, conventionally, as shown in Figure 1, a steel plate protector (3) is attached to the stay (2) that protrudes outward from the exhaust pipe (1) to protect the outside of the exhaust pipe (1), which gets hot. I try to cover it. Furthermore, the outside of the silencer is similarly covered with a protector.

With such a structure, it is possible to insulate the exhaust system, which is an exhaust pipe or a muffler, from the outside, but it is not possible to improve the soundproofing effect. In other words, although the exhaust system uses a muffler to exert a soundproofing effect, it is not sufficient, and even if the outside of the exhaust pipe or muffler is covered with a protector like the one described above, the protector itself does not have sound absorption properties. Since there is almost no soundproofing effect, sufficient soundproofing effect cannot be obtained.

The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide an exhaust system for an internal combustion engine that can achieve not only a heat insulation effect but also a sound absorption effect with a simple structure.

In order to achieve this object, the gist of the present invention is to cover at least a portion of an exhaust device such as an exhaust pipe or a muffler with a protector made of a molded sound absorbing material.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 13.

FIG. The exhaust system (10) includes an exhaust pipe (12) led out from the engine (11), and a muffler (14) connected to the rear end of the exhaust pipe (12) and located on the side of the rear wheel (13). A protector (15) made of a sound-absorbing molded material is wound around the outside of the pointed exhaust pipe (12), and is held on the vehicle body side via a handle and J band (16).

As shown in Figure 3, the protector (!5) is made up of upper and lower halves (17) and (18) joined together via a heat-resistant adhesive (18), and the inner part has heat insulation and sound absorption properties. It has an excellent porous layer (15a), and the outer part is a hard layer (tight layer) (15b) with excellent sound insulation and rigidity.

Here, each half-off (17), (1
An example of the molding method of 8) will be described below.

First, inorganic fibers or organic fibers such as long glass fibers or ceramic fibers are cut into appropriate lengths and mixed, and this is subjected to roller pressure and needling to form matte fibers Mt. After being impregnated with a binder such as ice cream, the matte m#n is placed in a mold having a molding surface capable of forming a predetermined shape, that is, a half-pattern (17), (18), and fired. As a result, half-layers (17) and (18) are obtained in which the portion in contact with the hot molding surface is a hard layer (15b) and the other portion is a porous layer (15a). Therefore, the inner surfaces of the obtained half-holes (17) and (18) were fitted so as to be in close contact with the outer circumferential surface of the exhaust pipe (12), and each half-hole (17) and (18) were glued with heat-resistant adhesive as described above. (
18), the structure shown in FIG. 3 is obtained.

The hard layer (15b) can also be formed by simply firing matte fibers impregnated with water glass as a binder, but the hard layer (+5b) may be formed using phenol resin, epoxy If a thermosetting resin such as resin is used as a binder, a hard layer (15b) with excellent hardness can be formed by firing. Further, since the porous layer (15a) has excellent heat insulation properties, heat is not easily transmitted to the outer surface. Therefore, after firing each of the half-cups (17) and (18), a thermoplastic resin may be applied to the surface thereof.

4 to 10 are cross-sectional views showing other embodiments of the protector (15), and in the embodiment shown in FIG.
A hard layer (15c) is also formed on the inner circumferential surface of the protector in contact with the outer circumferential surface of the exhaust pipe (12), and in the embodiment shown in FIG. 5, the protector (15) surrounding the exhaust pipe (12) is A gap (s) is formed between the inner surface of the porous layer (15a) of the protector (15) and the outer peripheral surface of the exhaust pipe (12). Diameter protector (1
A hard layer (+5c) is formed inside the porous layer (15a) of 5), and this hard layer (15c) and the exhaust 1 pipe (1
2), and in the embodiment shown in FIG. 7, a holding stay (20) is fixed to the exhaust pipe (12), and this holding stay (20) The space (S) is maintained constant between the pipe (12) and the hard layer (15c), and in the embodiment shown in FIG. (21) are formed at opposing positions, and the space (S) is kept constant by the hard layer (1'5c) formed on the surface of the protrusion (21), and the embodiment shown in FIG. In this case, no hard layer is formed inside the porous layer (15a), and 3
Protrusions (21) are provided at several locations, and a certain space is maintained by abutting these protrusions (21) against the outer periphery of the exhaust pipe (12). Furthermore, in the embodiment shown in FIG.
When firing the protector (15), a cylinder (22) made of resin or steel plate is set separately in the mold in advance, and by firing the cylinder (22) becomes a porous layer (15).
a) Protrusions (21) are provided in the porous layer (15a) inside the cylinder (22) in the same way as described above, and these protrusions (21) connect the porous layer (15a) and the exhaust. A space (S) between the pipe (12) and the pipe (12) is maintained at a constant interval. In this way, the hard layer (15c) is formed on the inner circumferential surface of the protector (15), and the
) by forming a space (S) between the inner peripheral surface of the exhaust pipe (12) and the outer peripheral surface of the exhaust pipe (12), or by interposing a cylindrical body (22) as a separate body within the porous layer (5a), Further heat insulation and sound insulation effects can be expected, and rigidity is also improved. In addition, in Figures 7 to 10, the protector (
15) is shown as integrally molded, but it may also be molded as a half-piece and then joined.

1] Figure 1 is a sectional view showing the internal structure of the silencer (14) connected to the exhaust pipe (12).
Similar to the protector (15), the outer box (23) of 4) is made of mat-like glass fiber or ceramic fiber,
It is made of a molded sound absorbing material impregnated with a binder and fired in a mold, and has a porous layer (23a) on the inner side, a hard layer (23b) on the outer side, and an outer box (23b).
3) The inner space is divided into the first +w tension chamber (
25) and the second rtj/diastolic chamber (28),
As shown in the enlarged perspective view of FIG. 12, the molded sound absorbing material constituting the first expansion chamber (25) has a heat-resistant layer (23c) made of a molding agent with excellent heat resistance on the inside of the porous layer (23a). It has a three-layer structure including a hard layer (23b). Further, on the surface of the separator (24) on the second w tension chamber (26) side, a hard layer (23d) is formed using a molding agent that has heat resistance and relatively excellent molding force.

Furthermore, when installing the exhaust pipe (12) and the outer box (23), the hard layer (23d) is attached to the front end surface of the outer box (23).
Cylindrical vibe presser molded using the same molding agent as (2)
7) through adhesive, and this pipe holder (27)
Insert and join the exhaust pipe (12) inside. In addition, a communication pipe (28) is inserted and fixed into the separator (24), and a tail pipe (29) is inserted into the rear end wall of the outer box (23).
is inserted and fixed.

FIG. 13 shows another embodiment of the molded sound absorbing material forming the outer box (23), and in this molded sound absorbing material, the porous layer (23a)
Hard layers (23b-1), (23b-2), (23b-2), (23b-1), (23b-2), (
23b-3), (23b-4), and a silencer (14
) to meet the heat resistance and hardness required in each part of the outer box (23). Further, a heat-resistant layer (23c) similar to that shown in FIG. 12 may be formed inside the porous layer (23a) of the embodiment shown in FIG. 13.

In this way, if a molded sound absorbing material is molded using two or more types of monomers, such as a thermosetting resin, as a binder, the sound absorbing material can be
Since the muffler can have different damping properties for each part, it is possible to absorb a wide range of exhaust noise from low frequencies to high frequencies, and it is also possible to improve the heat resistance of the parts that become high temperature.

It should be noted that the following only shows one example of the embodiment of the present invention.
In the illustrated example, the outside of the exhaust pipe (12) is covered with a protector (15) made of molded sound absorbing material.
The outside of the muffler (14) may be covered with a protector (15).

As explained below, according to the present invention, the outside of the exhaust pipe, muffler, and other members that constitute the exhaust system of an internal combustion engine are covered with a protector made of molded sound-absorbing material. At the same time, it has many advantages such as being able to exhibit a sound absorbing effect, and also having a simple structure and being lightweight.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional protector, FIG. 2 is a side view of an exhaust system according to the present invention, and FIG. 3 is a line taken along line A-A in FIG.
4 to 10 are sectional views similar to FIG. 3 showing another embodiment of the protector, FIG. 11 is a sectional view showing the internal structure of the silencer, and FIG. FIG. 13 is a partially enlarged perspective view of the box, showing another embodiment of the outer box. In the drawing, (lO) is an exhaust system, (11) is an engine,
(12) is an exhaust pipe, (14) is a silencer,
-(15) is a protector, (+5a) is a porous layer, (
15b), (15c) are hard layers, (21) is a protrusion, (2
2) is a cylinder. Patent applicant Kida Giken Kogyo Co., Ltd. Nakagawa Sangyo Co., Ltd.

Claims (1)

[Claims] An exhaust device configured to guide exhaust gas from an internal combustion engine to an extinguisher via an exhaust pipe, characterized in that at least a portion of the exhaust device is covered with a protector made of a molded sound-absorbing material. Exhaust system for internal combustion engines.