JPS60261915A - Muffer for internal-combustion engine - Google Patents

Abstract

PURPOSE:To increase coupling strength, by a method wherein the inner layer of the outer casing of a 2-layer structure and a separator, which axially partitions the interior of the outer casing, are formed by a sound absorbing material, and the separator is held to the outer casing by means of rod members having the one end extended through the inner layer into an outer layer. CONSTITUTION:A separator 22 having inner plates 23 and 24 is located within an outer casing 2, formed with an inner layer 3 and an outer layer 4, of a muffer 1 to axially partition the interior of the outer casing. The inner layer 3 of the outer casing and the separator 22 are formed by a sound absorbing material, and the separator 22 is held to the outer casing by means of rodform coupling members 25 and 26 having the one end extended through the inner layer 3 into the outer layer 4. This increases a mufferling effect, and enables the separator to be held with sufficient strength.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a muffler for reducing harmful gas noise from an engine or the like.

(Prior Art) Conventionally, in automobiles, motorcycles, etc., a muffler is connected to the rear end of an engineered oxygen pipe led out from the engine in order to reduce noise caused by exhaust gas. The muffling mechanism is one that rapidly expands the exhaust gas in the muffler to dissipate the energy held by the exhaust gas. Therefore, in order to enhance the sound deadening effect, a silencer is already known which has a structure in which the inside of the outer box, which is the main body of the silencer, is divided into a plurality of expansion chambers by separators.

On the other hand, since high-temperature, high-pressure exhaust gas is introduced into the expansion chamber, strength to withstand this is required.

For this reason, in conventional silencers, both the outer box and the separator are obtained by press-forming steel plates or the like.

(Problems with the Prior Art) As shown in the above, in the conventional silencer, both the outer box and the separator are made of steel plates, and as a result, they are heavy, complicated to manufacture, and disadvantageous in terms of cost.

Furthermore, although steel plates have a sound insulation effect, they do not exhibit a sound absorption effect.

Therefore, the conventional muffler is not satisfactory in terms of muffling effect.

Therefore, it is conceivable to form the outer box and separator with a molded sound-absorbing material that has excellent sound absorption and heat insulation properties, but welding cannot be applied to molded sound-absorbing materials, so any method can be used to form the outer box and separator. The problem is how to integrate the separator and the separator.

(Objective of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an excellent sound-deadening effect, lightweight and easy to manufacture, sufficient strength, and good appearance. An object of the present invention is to provide an excellent silencer for internal combustion engines.

(Structure of the Invention) In order to achieve the above object, the structure of the present invention is such that the outer box of the silencer has two layers, an inner layer and an outer layer, the inner layer and the separator are formed of a molded sound absorbing material, and the separator is made of a molded sound absorbing material. is attached to the outer box by a rod-shaped coupling member that penetrates the inner layer and has one end protruding into the outer layer.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a silencer according to the present invention, and FIG.
It is a sectional view taken along the line AA in the figure.

The outer box (2) of the silencer (+) consists of an inner layer (3) made of molded sound absorbing material and an outer layer (4) formed on the outside of this inner layer (3). An inversely tapered opening (5) that tapers toward the rear is formed, and an inversely tapered opening (6) that tapers toward the rear is formed at the rear end.

The rear end of the exhaust pipe (7) is inserted into the opening (5), and a heat insulating material (8) having a tapered outer peripheral surface is filled between the exhaust pipe (7) and the opening (5). This heat insulating material (8) is brought into close contact with the inner circumferential surface of the opening (5) using sealing and fibrillation agent (9), and the rear end of this heat insulating material (8) is bonded to the flange portion of the exhaust pipe (7). (lO), and furthermore, the front end of the outer box (2) is bonded to the flange (11) welded to the exhaust pipe (7) via a sealing adhesive (8). Thus, the outer box (2) is firmly held against the exhaust pipe (7). Further, a tail pipe (12) is inserted into the first opening (6), and a heat insulating material (13) having a tapered outer peripheral surface is inserted between the tail pipe (12) and the opening (6).
is filled with a sealing adhesive (9), the front end of this heat insulating material (13) is held down by a flange (14) welded to the tail pipe (12), and the front end of the heat insulating material (13) is held down by a flange (14) welded to the tail pipe (12). The welded flange (15) is adhered to the rear end of the outer box (2) via a sealing adhesive (9). Thus, the tail pipe (12) is firmly held against the outer box. In this manner, the exhaust pipe (7) and tail pipe (12) are attached to the outer case via the sealing adhesive (9), so that leakage of exhaust gas is effectively prevented. In addition, the exhaust pipe (7) and tail pipe (12)
A large number of small holes (7a) and (12a) for sound absorption are formed in the portions corresponding to the heat insulating materials (8) and (13).

Here, FIGS. 3 to 5 show the exhaust pipe (
7) and the outer box (2), and in the example shown in FIG.
As a member replacing 11), a retaining ring (IEI), (1
7) to the exhaust pipe (7), and in the example shown in Fig. 4, the rear end of the exhaust pipe (7) is integrally bent outward to form the flange part (18). death,
A bulging part (18) is formed in the middle part of the exhaust pipe (7), and the front end of the outer box (2) is held between the flange part (18) and the bulging part (19). In the example shown in the figure, a small diameter part (20) is formed in a part of the exhaust pipe (7), and the outer box (2) is placed inside this small diameter part (20).
The front end of the holder is fitted into the front end of the holder. In either structure, the outer box (2) is connected to the exhaust pipe (7).
11 is firmly held without exhaust gas leakage.

In addition, a band-shaped seal plate (21) is welded between the flange parts (10) and (14), and the exhaust pipe (7) and tail pipe (12) are integrated through this seal plate (21). A silencer (1)
It has a structure that improves its own strength.

On the other hand, inside the outer box (2) is a separator (
22) and an upstream expansion chamber (Sθ
and a downstream expansion chamber (Sl) are formed. These expansion chambers (Sl) and (Sl) are connected to the inner pipe (23
), communicated in (24). Here, the separator (
22) to the outer box (2) is a rod-shaped connecting member (
25), according to (2B). That is, the rod-shaped coupling member (25)
.

(2B) is a metal rod, etc., and among these, the connecting member (
25) penetrates the inner layer (3) of the outer box (2), one end thereof protrudes and is held within the outer layer (0), and the other end pierces into the separator (22). (2
B) is the separator (22) and the inner layer (3) of the outer box (2).
), and both ends of the connecting members (25), (2El), which have penetrated or stuck into the separator (22), are held so as to protrude into the outer layer (0). 3) and reaches the outer layer (0),
It will be held across two layers, and the separator (
22) is firmly held against the outer box (2).

In addition, a hard layer (
Tight layers) (3a) and (22a) are formed.

This iron, the upstream expansion chamber (S) is the downstream expansion chamber (S,
), the introduced exhaust gas is at a higher temperature and pressure, so if the expansion chamber (S+) is formed of the inner layer (3) and separator (22) made of molded sound absorbing material, the molded sound absorbing material may scatter or Although a problem arises in terms of durability, by forming the hard layers (3a) and (22a) as described above, it is possible to prevent the molded sound absorbing material from scattering, and the durability against heat is also improved. In addition, by forming the hard layers (3a) and (22a), the porous layer (3b) existing inside the hard layers (3a) and (22a)
, (22b) is reduced, and the effective thickness as a heat insulating layer is increased. In addition, a hard layer (3a) is formed on the inner layer (3) and the separator (22).

(22a) may be formed partially. In this way, you can improve not only heat resistance and durability, but also sound absorption! Wear.

Next, an example of a method for molding the inner layer (3) or separator (22) made of molded sound absorbing material will be described based on FIGS. 6 and 7.

First, inorganic fibers such as glass fibers or ceramic fibers, or organic fibers such as polyester fibers are cut into appropriate lengths and mixed, and then subjected to roller processing and needling to form a pine tree as shown in Figure 6(A). A mat-like fibrous body (27) is formed, and a molding agent (28) is applied to the surface of the mat-like fibrous body (27) as shown in FIG. Suction from the side or leave it for a specified period of time. Then, as shown in FIG. 7, the molding agent (28) travels through the fibers (27a) and enters the inside of the mat-like fiber body (27), and the surface is impregnated with a large amount of molding agent (2B), and the inner part A mat-like fibrous body (28) is impregnated with a medium amount of molding agent (28), and the inside is impregnated with a small amount of molding agent (28) of 4F.
27) is obtained.

This is shown in FIG. 6 CG').

After this, as shown in FIG. 6(b), a molding agent (28) is also applied to the opposite side of the mat-like #ili fiber body (27), and this mat-like fiber body (27) is subjected to press loading or hot By performing press working etc., a predetermined shape is formed as shown in No. 615i11(E), and a hard layer (29a) is formed on the surface.
There is a porous layer (28b) inside and a semi-hard layer (28b) between them.
9c) is obtained. A molded sound absorbing material (29) is obtained.

By the way, the inner layer (3) or separator (22) of the above-mentioned outer box (2) is processed through the process shown in Figure 6 (C), and the sub-step shown in Figure 6 (D) is omitted and subjected to hot pressing, etc. In this case said hard layer (3a) obtained by.

(22a) is formed on the surface coated with the molding agent (28).

In addition, if the outer layer (0) of the outer box (2) is also molded at the same time as the inner layer (3), apply the molding agent (28) to both sides as shown in Figure 6 (D) and then press &i hot press. Here, a molding agent (2
8) Do not apply. In addition, a partially hard layer (3'a),
' When forming (22a), a molding agent (28) is applied to the corresponding part. Note that the outer layer (4) of the outer box (2) does not necessarily need to be made of molded sound-absorbing material, and may be coated with heat-resistant resin, rubber, or the like.

I-The described molding method is superior to conventional methods in the following respects.

That is, in order to make the surface layer of a mat-like fibrous body a hard layer and form a semi-hard layer or a porous layer inside, conventionally, first, a molding agent with excellent fluidity is used to form a mat. A molding agent is impregnated into the inside of the mat-like fiber body, and then a molding agent with high viscosity, that is, with little fluidity, is applied to the surface of the mat-like fiber body, and then hot pressing is performed to form a hard or semi-hard layer. However, since two types of molding agents are used, quality cannot be stabilized by such means. However, according to the method shown in FIG. 6, since only one type of molding agent is used, it is possible to improve the quality of the molded sound absorber.

The above is an example of the implementation of the present invention, and the present invention is not limited to the above. For example, in the illustrated example, a long rod-shaped connecting member and a short rod-shaped connecting member are used. However, all of the connecting members may be long or all of the connecting members may be short, and the connecting members are not limited to linear ones.

(Effects of the Invention) As explained above, the silencer according to the present invention has an outer box composed of an inner layer and an outer layer, the inside of this outer box is divided into a plurality of expansion chambers by a separator, and the inner layer and the outer box are divided into a plurality of expansion chambers. Since the separator is made of molded sound absorbing material, the sound deadening effect is greatly improved compared to conventional mufflers, and weight and cost reductions can be achieved. Further, a rod-shaped connecting member is used as a member for fixing the separator to the outer box, and this rod-shaped connecting member is made to penetrate through the inner layer and one end thereof protrudes into the outer layer. It is held across two layers: the outer layer and the outer layer, and can be expected to have sufficient strength. Further, since the ends of the rod-shaped coupling members do not protrude outward from the outer layer, many effects such as good appearance are exhibited.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a silencer according to the present invention, and FIG.
The cross-sectional view taken along the line A-A in the figure, Figures 3 to 5 are cross-sectional views showing the structure of the connecting part between the exhaust pipe and the outer case, and Figures 6 (^) to (E) are the molded sound absorbing material. FIG. 7 is a partially enlarged view of FIG. 6(C). In the drawings, (1) is the muffler, (2) is the outer box, (3) is the inner layer, (0 is the outer layer, (7) is the exhaust pipe f,
(12)j"? -7L/'<"7", (22)4
"+7e L/ -p," (25) and (2B) are rod-shaped coupling members, (28) is a molded sound absorber, and (S+) and (S2) are expansion chambers. Fig. 1 Fig. 2 Fig. 3 Figure 4”/a Figure 5

Claims (1)

[Claims] In a silencer in which the inside of an outer box is divided in the axial direction by a separator having several inner pipes, the outer box is composed of two layers, an inner layer and an outer layer, and the inner layer and the separator are made of a molded sound absorbing material, The muffler for an internal combustion engine is further characterized in that the separator is held in the outer box by a rod-shaped connecting member that penetrates the inner layer and has at least one end protruding into the outer layer.