JPS62214211A - Exhaust silencer - Google Patents

Abstract

PURPOSE:To reduce the dimension of the captioned silencer and facilitate the cleaning the inside of the silencer by constituting the exhaust silencer by joining a cover plate which forms an exhaust flow passage and a part of an expansion chamber and a muffler body which forms almost all the part of the expansion chamber. CONSTITUTION:A silencer 1 is constituted by joining a cover plate 2 and a muffler body 3. The inner surface of the cover plate 2 is formed into recessed form in the connection of an exhaust inflow passage 4, cover 5 for closing the opened port of the muffler body 3, and an exhaust discharge passage 6, and further cooling fins 7 are projectingly installed onto the outer surface. The muffler body 3 is constituted of a plate 9 which forms the joint part with the cover plate 2 together with the supplementary part of the exhaust inflow passage 4 formed in recessed form onto the cover plate 2, casing 10 welded onto the plate 9, and a separator 11 accommodated into the casing 10. Therefore, the silencer can be made small-sized, and the assembly and disassembly of the silencer are simplified, and the cleaning inside is facilitated.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an exhaust muffler for reducing exhaust discharge noise, and particularly to an exhaust muffler that is disassembleable and has a relatively large volume expansion chamber arranged compactly. This invention relates to an improved silencer that can be installed.

<Prior Art> In order to reduce exhaust discharge noise from internal combustion engines, etc., a muffler that combines an expansion chamber and a maze-like passage is used. These mufflers generally reduce the exhaust noise by dividing the interior with a separator to form a complex exhaust passage and expansion chamber, and by reflecting and reciprocating the exhaust flow. In terms of noise reduction effect, it is advantageous to make the passage more complex and at the same time make the expansion chamber larger in volume.

<Problems to be Solved by the Invention> However, the trailing passage makes it easy for carbon in the exhaust to accumulate inside the muffler, which may cause a reduction in engine output. Further, sound absorbing materials are generally used inside the muffler, but if moisture or carbon in the exhaust gas adheres to the sound absorbing materials, the sound absorbing effect will be significantly reduced, and at the same time, the output of the engine will also be reduced.

Therefore, it is desirable to be able to clean the inside of the muffler as needed, and there is a technology in which the muffler can be disassembled by inserting a perforated small-diameter tube equipped with a baffle into the outer cylinder. This is disclosed in Japanese Patent Publication No. 52-37142, but it tends to be long and is not necessarily suitable for general-purpose engines.

On the other hand, a large-volume expansion chamber increases the external dimensions of the entire device, which can be a factor that hinders compactness, especially when the engine is housed in an integrated housing in combination with a generator, a pump, etc.

In view of these problems in the prior art, the main object of the present invention is to provide an exhaust muffler that allows for easy internal cleaning and allows for a more compact overall device configuration. There is a particular thing.

<Means for Solving the Problems> According to the present invention, the object is to provide an exhaust muffler having an inflow passage, an expansion chamber, and a discharge passage, wherein most of the inflow passage and the expansion chamber The first part formed integrally with a part of
and a second part formed by integrally forming a complementary part of the inflow path and most of the expansion chamber, and the first part and the second part are separable. In addition,
The second part is integrally assembled by detachable engagement means, and the second part has a plane facing the first part and is formed to protrude from the plane in a direction away from the first part. This is achieved by providing an exhaust muffler characterized by the following.

In particular, the second portion includes a bottomed casing that is formed separately so as to be separable from each other, and a separator that has a cylindrical portion that partitions the inside of the casing into a central chamber and an annular chamber. and the inflow path communicates with the central chamber,
The central chamber and the annular chamber communicate with each other through a through hole formed in the separator, and the annular chamber and the discharge passage communicate with each other through a pipe member provided inside the separator. , it is preferable to assemble the first part and the second part integrally using bolts or the like.

<Function> In this way, the exhaust gas inflow path and the expansion chamber can be formed so that they can be disassembled, and the interior can be cleaned easily. In addition, it is possible to make the majority of the rtB compartment protrude only in one direction with respect to the exhaust flow line of the exhaust inflow path that connects the engine and the expansion chamber, so that the engine body and the engine are The silencer can be disposed by effectively utilizing the dead space created between the silencer and the casing in which it is housed.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show a first embodiment of a muffler according to the invention, which muffler 1 generally comprises a cover plate 2 as a first part and a muffler as a second part. The image parts 2 and 3 are made to be able to be joined to each other on the same plane.

The cover plate 2 is made of, for example, cast light alloy, and has an exhaust inlet passage 4 and a cover 5 that closes the opening of the muffler body 3 on its inner surface.
, and an exhaust discharge passage 6 are continuously recessed, and cooling fins 7 are provided protruding from the outer surface thereof. In addition, near the upstream end of the exhaust inflow path 4 and around the cover 5,
A plurality of bolt holes 8.8a are drilled into which bolts to be described later are loosely fitted.

The muffler main body 3 has a plate 9 that forms a joint with the lid plate 2 together with a complementary part of the exhaust inflow passage 4 recessed in the lid plate 2, and the plates 1 to 9 are opposite to the joint surface of the lid plate 2. It consists of a casing 10 welded to the side surface and a separator 11 housed inside the casing 10.

The casing 10 is made by drawing a metal plate into a cup shape, has a flange formed outward at the opening, and is welded to the plate 9 as described above.
For example, a sound absorbing material 12 made of glass wool is attached.

The separator 11 is formed in a substantially similar shape to the casing 10 with external dimensions that can form an annular chamber 13 of an appropriate volume between its outer surface and the inner surface of the sound absorbing material 12,
An outwardly facing flange 14 is formed in the opening. In addition, a plurality of through holes 15 are bored in a position relatively close to the opening of the peripheral wall, and a pipe member 16 is provided in the center of the inside of the separator 11, protruding from the bottom wall of the separator 11 toward the opening. It is set up. The pipe member 16 has its axis curved at a substantially right angle within the separator 11, and its free end is formed in a semicircular cross section (Fig. 3).
, the flat part of the semicircular opening end 17 is the separator 1
It is fixed to the upper surface of the flange 14 of No. 1.

The plate 9 is formed to have a substantially similar shape to the cover plate 2, and has an exhaust inlet 18 at one end and a receiving hole 19 through which the separator 11 is inserted in the center of the attachment part of the casing 10. . A recess 9a corresponding to the flange 14 of the separator 11 is formed around the receiving hole 19, so that the surfaces of the flange 14 and the plate 9 are flush with each other and face the cover plate 2 when assembled. Furthermore, tap holes 21 are provided around the plate 9 at positions that align with the bolt holes 8 around the cover 5 of the lid plate 2.
is cut out.

When assembling the silencer 1 configured in this way,
After loosely fitting the separator 11 into the receiving hole 19 of the plate 9 and then joining the cover plate 2 to the surfaces of the plates 1 to 9 via the gasket 21, insert the port 22 from the port 1 to the hole 8 and tap it. Screw into hole 21.

At this time, the flange 14 of the separator 11 is held between the lid plate 2 and the recess 9a of the plate 9, and the casing 10
The separator 11 is held and fixed inside. Further, an exhaust inlet passage 4 and a central chamber 23 are defined by the recess on the inner surface of the cover plate 2 and the surface of the plate 9, and an exhaust discharge passage 6 serving as a tail pipe communicating with the open end of the pipe member 16 is formed. is formed. The exhaust inlet 18 is aligned with the exhaust port of the engine E, and a bolt hole 8a drilled near the inlet through the cover plate 2 and the plate 9 serves as a mounting hole for the engine E. That is, the exhaust inlet passage 4 portions of both the cover plate 2 and the plate 9 are configured to be able to serve as a stay for attaching the muffler body 3 to the engine.

Next, the flow of exhaust gas will be explained with reference to Figure 2.
Exhaust gas discharged from the exhaust port of the engine E flows into the central chamber 23 inside the separator 11 via the exhaust inflow path 4 . The exhaust discharge passage 6 is connected to the open end 17 of the pipe member 16.
is fitted, so exhaust gas does not directly escape into the atmosphere. In addition, in this embodiment, a guide rib 24 is provided on the inner surface of the cover 5 and has a curved surface that is continuous with one inner surface of the exhaust inlet passage 4 (see FIG. 1), which swirls the exhaust flow. By doing so, the sound is diffusely reflected inside the separator 11, and the sound deadening effect is further improved (the guide ribs 24 are omitted from illustration in FIG. 2). The exhaust gas expanded in the central chamber 23 flows into the annular element 13 between the separator 11 and the casing 10 through the through hole 15, and after further expansion, the separator 1
1 Exhaust discharge passage 6 passes through a pipe member 16 fixed to the bottom.
released into the atmosphere.

FIG. 4 shows a second embodiment based on the present invention, and parts corresponding to the first embodiment are given the same reference numerals and detailed explanation thereof will be omitted. In this embodiment, the relationship between the cover plate 2, the casing 10, and the separator 11 is generally the same as in the first embodiment, but the pipe member 16 is made into a straight pipe and the bottom of the separator 11 is It is removably fitted to the wall, and a stud bolt 31 extending inward from the bottom wall of the casing 10 passes through its center. The stud port 31 also passes through the cover 5 part of the cover plate 2, and by screwing a nut 32 onto the tip that protrudes outside of the cover plate 2, the first part of the cover plate 2 and the first part are connected to each other. The muffler body 3, which is the part 2, is integrated with the muffler body 3.

A partition part vU33 is fixed to the upper part of the pipe member 16. The partition member 33 has a flat portion 34 having a contour equal to the outer circumferential contour of the seven flange 14 of the separator 11, and a recess 3 having an inner portion corresponding to the inner surface of the separator 11.
5 are integrally formed by press working, and the pipe member 16 described above is inserted into the hole bored in the bottom wall of the recess 35.
is inserted and fixed. This partition member 33 is connected to the lid plate 2
The outer peripheral portion of the flat portion 34 is held between the separator 11 and the flange 14 of the separator 11 between the separator 11 and the plate 9 .

A portion of the flat portion 34 of the partition member 33 adjacent to the guide rib 24 is notched to correspond to the curved surface of the guide rib 24, and is bent at a substantially right angle along a fold line in a direction intersecting the kite rib 24. The peripheral edge of the protruding piece 36 formed by this bending abuts the edge of the guide rib 24 and the inner surface of the cover 5 with relatively little gap. As a result, an inlet 37 from the exhaust gas inflow path 4 to the central chamber 23 is formed, and a discharge chamber 38 is defined between the inner surface of the cover 5 and the separator 11.

In the case of this embodiment, the exhaust flow flows into the central chamber 23 while creating a more effective swirl due to the action of the guide ribs 24 and the protruding pieces 36. The gas then reaches the discharge chamber 38 through the through hole 15, the annular member 13, and the pipe member 16, and is discharged to the outside through the exhaust discharge path 6.

The volume of the discharge chamber 38 shown in this embodiment can be arbitrarily adjusted by adjusting the depth of the recessed portion 35 of the partition member 33, and in some cases, the discharge chamber 38 may have a simple flat plate shape.
Furthermore, this partition member 33 can also be applied to the first embodiment.

Incidentally, the attachment part to the engine is no different from the first embodiment.

5 and 6 partially show a small-sized generator incorporating an engine having a silencer 1 according to the above embodiment, and the engine body 41 has its cylinders oriented horizontally and the crankshaft The recoil starter 42 is arranged to face vertically, and the recoil starter 42 is located at the upper end of the crankshaft.
A rotor 43 of an alternating current generator is fixed to each lower end. A fan 43a is installed on the top of the rotor 43.
The outer periphery of the fan cover 1 is covered with a fan cover 43b.

The muffler 1 is disposed diagonally below the cylinder head 44 with the axis of the muffler body 3 facing in the horizontal direction and in a direction orthogonal to the cylinder axis. These are entirely covered by a casing 45, and an exhaust outlet 46 opens at the lower left of the side surface of the casing 45 when viewed from the cylinder head 44 side.

By configuring the silencer in this way, the exhaust flow line from the exhaust inflow path connected to the exhaust boat of the cylinder head to the exhaust discharge path is provided on the same plane approximately parallel to the cylinder axis, and is relatively smooth. It is possible to fit the muffler body having a large volume expansion chamber within the dimension of the engine body 41 in the [1] direction.

Note that the cover plate 2 is not limited to the casting shown in the above embodiment, but may be formed by press molding of sheet metal.

<Effects of the Invention> As described above, according to the present invention, it is possible to easily disassemble and assemble a plurality of inflated air pipes and a thin thread-bent exhaust passage after forming them. This makes it possible to maintain and manage exhaust noise silencing performance at a high level, and is extremely effective in preventing a drop in engine output.

Furthermore, as shown in the above embodiments, the body can be made thinner, which has a great effect of improving marketability.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of a first embodiment of an exhaust muffler according to the present invention. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. FIG. 3 is a sectional view taken along the line ■-■ in FIG. 1. FIG. 4 is a partially cutaway perspective view of the second embodiment. FIG. 5 is a partial plan view of the small generator equipped with the exhaust muffler shown in FIG. FIG. 6 is a partial elevational view of the small generator shown in FIG. 1... Silencer 2... Cover plate 3... Muffler body 4... Exhaust inflow path 5... Cover
6...Exhaust discharge passage 7...Cooling fin 8.8
a...Bolt hole 9...Play 1~9a...
Recess 10...Casing 11...Separator 1
2...Sound absorbing material 13...Annular chamber 14...Flange 15...Through hole 16...Pipe member
17... Opening end 18... Exhaust inlet 19...
Reception hole 20...Tap hole 21...Gasket 22...Bolt 23...Central chamber 24-...
Guide rib 31...Stud pole 1-32...
Nut 33...Partition member 34...Plane part
35... Depression 36... Protrusion 37.
...Inflow port 38...Discharge chamber 41...Engine body 42...Starter 43...Rotor 43
a...Fan 43b...Fan shroud 4
4...Cylinder head 45...Casing 46...Exhaust discharge port Patent Applicant: Representative of Honda Motor Co., Ltd. Patent attorney: Yo Oshima - Figure 3, Figure 4, Figure 5

Claims (6)

[Claims] (1) An exhaust muffler having an inflow passage, an expansion chamber, and a discharge passage, the first part being formed by integrally forming most of the inflow passage and a part of the expansion chamber; It has a second part formed by integrally forming a complementary part of the inflow path and most of the expansion chamber, and the first part and the second part are separable and detachable. An exhaust muffler characterized in that it is integrally assembled with possible engagement means. (2) Claim 1, wherein the engaging means is a bolt screwed around a joint between the first part and the second part. exhaust silencer. (3) The engaging means is a stud bolt that protrudes from the second portion so as to penetrate the first portion. Exhaust silencer. (4) An exhaust muffler having an inflow passage, an expansion chamber, and a discharge passage, the first part being formed by integrally forming most of the inflow passage and a part of the expansion chamber; a second portion formed by integrally forming a complementary portion of the inflow path and most of the expansion chamber, the second portion having a plane facing the first portion; An exhaust muffler characterized in that the exhaust muffler is formed to protrude from the plane in a direction away from the first portion. (5) The second portion includes a bottomed casing that is formed separately so as to be separable from each other, and a separator that has a cylindrical portion that partitions the inside of the casing into a central chamber and an annular chamber. The inflow passage communicates with the central chamber, the central chamber and the annular chamber communicate through a through hole formed in the separator, and the annular chamber and the discharge passage communicate with the inside of the separator. The exhaust muffler according to claim 1 or 4, characterized in that the exhaust muffler communicates with the provided pipe member. (6) A patent claim characterized in that the separator has a flange formed outward at the opening, and the flange is sandwiched between the joint surfaces of the first part and the second part. The exhaust silencer according to item 5.