JPS60261917A - Muffler for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve strength, by a method wherein an outer plate and an inner plate, which are both formed with plural split bodies of a forming sound absorbing material, are joined together to form an outer casing, and the joint of the outer plate is prevented from coincidence with the joint of the inner plate. CONSTITUTION:An outer casing 2 of a muffler 1 is formed by bonding together an inner plate 10a and an outer plate 9a which are both formed with plural split bodies of a forming sound absorbing material. A joint 12 of the inner plate and a joint 13 of the outer plate are disposed in a manner that they are prevented from coincidence with each other. This increases a muffling effect, prevents leakage of exhaust gas past the joints, and also enables improvement of strength.

Description

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

(Prior art) Conventionally, in automobiles, motorcycles, etc., a silencer is connected to the rear end of the exhaust pipe led out from the engine, and the exhaust gas discharged from the engine is passed through the exhaust pipe to a steel plate. The exhaust gas is guided into the muffler outer box, where it is rapidly expanded to dissipate the energy held by the exhaust gas, and furthermore to block noise from leaking from the outer box to the outside.

(Problems with the Prior Art) [As described above, the outer case of the conventional muffler is made of steel plate because it needs to have the strength to withstand high temperature and high pressure exhaust gas. For this reason, the weight is large, it takes time and effort to manufacture, and it is also disadvantageous in terms of cost.

Further, although the steel plate has a blocking effect, it does not have a sound absorbing effect, so that it is not satisfactory in terms of sound deadening effect.

Therefore, it is conceivable to construct the outer case from a molded sound absorbing material with excellent sound absorption and sound insulation properties. However, molded sound absorbing materials are inferior in strength to steel plates, and cannot be welded. As a result, the thickness of the outer box becomes extremely large,
This results in an increase in size, and a problem arises in that it is not possible to expect much reduction in weight.

(Objective of the Invention) The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to provide an excellent sound-deadening effect, lightweight and easy to manufacture, sufficient strength, and a material that can reduce exhaust gas emissions. An object of the present invention is to provide a muffler for an internal combustion engine that can also prevent leakage.

(Structure of the Invention) In order to achieve the above object, a silencer according to the present invention has an outer box formed of an outer plate and an inner plate made of a molded sound absorbing material, and each of the outer plate and the inner plate is connected to a divided body. Further, the structure is characterized in that the joints of the divided bodies forming the outer plate and the joint parts of the divided bodies forming the inner plate do not coincide with each other and are shifted in the circumferential direction.

(Example) Examples of the present invention will be explained below based on the accompanying drawings. Figure 1 is a vertical sectional view of a silencer according to the present invention, and Figure 2 is a vertical cross-sectional view of a silencer according to the present invention.
This is a cross-sectional view taken along the line ■-■ in the figure, and the silencer (1) is located in the outer box (2).
, a front end plate (3) that closes the front end opening of the outer box (2), a rear end plate (4) that closes the rear end opening of the outer box (2), and a rear end plate (4) that is installed by penetrating this rear end plate (0). tail pipe (5),
A separator (6) that partitions the inside of the outer box (2), and an inner pipe (7) that is attached to the separator (8) by penetrating it.
), the front end plate (3), the separator (6) and the rear end plate (0 is connected by a seal plate (8).

Further, the outer box (2) is constructed by joining the inner circumferential surface of a cylindrical outer plate (8) and the outer circumferential surface of a cylindrical inner plate (10) via an adhesive (11). Furthermore, these outer panels (9)
And the inner plate (10) is a divided body (θa), (Illa), (10a), (10a) with a semicircular cross section made of molded sound absorbing material.
are butt-joined via adhesive (11). In addition, on the outer periphery of the divided bodies (9a) and (Ja) constituting the outer panel (9), there is a hard layer (tight layer) (13b) with excellent sound insulation properties.
), (llb) are formed, and the inner layer of the outer panel (8) and the entire inner panel (1o) are porous layers with excellent sound absorption properties. Note that the front end plate (3) is connected to the rear end of the exhaust pipe (ta)j.

Here, the method for forming the divided bodies (lla) and (lea) will be described.

First, inorganic fibers such as glass fibers or ceramic fibers, or organic fibers such as polyester are cut into appropriate lengths and mixed, and then subjected to roller pressure and needling to obtain a mat-like fibrous body. A molded sound absorbing material having a predetermined shape is obtained by impregnating a mat-like fibrous body with a molding agent, setting it in a mold, etc., and performing heating processing such as hot pressing. Here, in order to form the hard layer (8b), the amount of impregnated molding agent may be increased compared to other parts, or the hard layer (8b) may be coated with a resin or the like after molding.

Next, an example of the manufacturing procedure of the silencer (1) having the above structure will be explained based on FIG. 3.

To manufacture the silencer (1), first prepare the divided bodies (9a), (9a), (10a), and (10a) made of molded sound absorbing material, and then first prepare the front end plate (3) and the separator. (6) and the rear end plate (4) are integrated by a seal plate (8). Welding or adhesion can be considered as a means of integration. Also, at this time, the inner pipe (7) is attached to the separator (8), and the tail pipe (
5) are fixed in place.

From this state, as shown by the arrow (a) in Fig. 3, the divided body (
10a) and (10a), the front end plate (3), the separator (6), and the rear end plate (divided body (lea) surrounding 0.

(10a) and apply adhesive (11) to this butt part.
) to join. Thus, the inner plate (10) is formed.

In this case, the joint portion (12) of the divided body (lea) (10a) is made to abut against the seal plate (8).

Next, as shown by the arrow (b), one divided body (10a) is formed.

The divided bodies (9a) and (9a) are butted against each other so as to surround the inner plate (10) formed by joining the parts (10a). In this case, the outer peripheral surface of the inner plate (lO), the divided bodies (9a), (9
Adhesive (11) is applied to the inner circumferential surface of a) and the abutting end surfaces of the divided bodies (9a) and (9a).In this way, the divided bodies (9a), so as to surround the inner plate (1G), (9a) are butted together and the divided bodies (9a) and (9a) are joined together to form the outer plate (8), and the outer plate (8) and the inner plate (10
) are joined to form the outer box (2).

In addition, when joining the divided bodies (θa) and (la), the joint part (13) is the divided body (lea), (1
0a) c7) Do not coincide with the joint (12).

5 is a longitudinal sectional view showing the internal structure of a silencer (1) according to another embodiment, and FIG. 6 is a sectional view taken along the line ■-Vl in FIG. In this embodiment, the seal plate (8) also serves as a part of the inner pipe (17). That is, the inner pipe (17) is also shown in FIG. As shown, it does not have a perfect pipe shape, but a slit-shaped opening (17a) is formed in the hole, and this opening (1?a) is closed with a seal play (8). With such a configuration, weight reduction can be achieved compared to the case where a conventional inner pipe is used.

Further, Fig. 7 is a sectional view similar to Fig. 6 showing an example in which a part of the seal plate (18) is used as an inner pipe. A wide part is provided in a part of the pipe (18), and this wide part is wound to form a one-inner pipe (27). With this configuration, the conventional inner pipe is no longer necessary, and this installation Work can also be omitted, which is advantageous in terms of productivity and cost reduction.

(Effects of the Invention) As is clear from the above description, according to the present invention, since the outer box of the muffler is made of a molded sound absorbing material, it is possible to obtain a muffler with excellent sound absorption, sound insulation, and heat insulation properties. In addition, the outer box is divided into an outer panel and an inner panel, and these outer panels and inner panels are constructed by joining the divided bodies, and the joints of each divided body are made so that they do not coincide between the outer panel and the inner panel. This makes it possible to effectively prevent exhaust gas leakage from the joints and to provide a silencer with excellent strength.In particular, if the seal plate and the joints of the divided bodies constituting the inner plate are made to coincide with each other, It has many effects such as improved sealing performance.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a silencer according to the present invention, and FIG.
Fig. 3 is a diagram showing one manufacturing procedure of the silencer, Fig. 4 is an enlarged sectional view of the main part of the silencer, Fig. 5
The figure is a longitudinal cross-sectional view of a silencer according to another embodiment, FIG. 6 is a cross-sectional view taken along the line VI-Vl in FIG. 5, and FIG. 7 is a cross-sectional view similar to FIG. 6 showing yet another embodiment. . In the drawing, (1) is a silencer, (2) is an outer box, (6) is a separator, (7) and (17) are inner pipes, (
8). (18) is a seal plate, (8) is an outer plate, (lO) is an inner plate, (9a), (10a) are divided bodies, (12), (1
3) is the joint. Patent Applicant Honda Motor Co., Ltd. Agent Patent Attorney Part III Yu-Buma Patent Attorney Kuni Ohashi Production Volume Patent Attorney Yu Koyama

Claims (1)

[Claims] In a silencer connected to the rear end of an exhaust pipe, the outer box of this silencer is made by bonding the outer surface of a cylindrical inner plate made of molded sound-absorbing material to the inner surface of the cylindrical outer plate made of molded sound-absorbing material. Each of these outer panels and inner panels is constructed by joining a plurality of divided bodies, and the joints of the divided bodies that constitute the outer panel and the joints of the divided bodies that constitute the inner panel are the same. A silencer for an internal combustion engine, which is characterized by a silencer for an internal combustion engine.