JPH057456Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust muffler structure for an internal combustion engine such as an air-cooled two-stroke gasoline engine used in a small working machine such as a brush cutter.

[Conventional technology]

Conventionally, in a two-stroke gasoline engine or the like of a small working machine as described above, exhaust gas is discharged from an exhaust port of a cylinder to an exhaust muffler, and the exhaust gas is muffled and discharged to the outside.

The exhaust muffler is provided for noise reduction and purification of exhaust gas, and so far, sound-absorbing materials such as perforated plates and glass wool have been placed inside the exhaust muffler, various catalysts, etc. A large number of products are available, including those that purify exhaust gas using

[The problem that the idea attempts to solve]

As mentioned above, if sound absorbing materials such as glass wool or various catalysts are used, the exhaust gas may be affected by carbon deposits, tar stains, etc. caused by the combustion of lubricating oil mixed with fuel, which is unique to small two-stroke gasoline engines. This further accelerates the accumulation of carbon and tar in the gas passages, causing problems such as increased weight of the exhaust muffler and increased back pressure due to exhaust gas, which shortens the interval between exhaust muffler maintenance and shortens the useful life of the exhaust muffler. There was a problem that the length was significantly shorter.

This invention was made in view of the above circumstances,
It makes it possible to quickly remove carbon deposits and tar stains inside the exhaust muffler, makes it easy to replace the purifying material, and eliminates the need to replace the exhaust muffler, making it economical and improving the efficiency of exhaust gas purification. It is an object of the present invention to provide an exhaust muffler structure for an internal combustion engine for a small working machine, which achieves the following.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has a structure in which an exhaust muffler piece fixed to the main body of the engine and an outer exhaust muffler piece fitted to the exhaust muffler piece can be vertically divided into two and integrated. A sound-absorbing and purifying material holding portion is formed in the inner facing portions of both the muffler pieces, and a stopper is disposed across the surface of the joint portion of both the exhaust muffler pieces, and the outer side Only the exhaust muffler piece is removable.

[Effect]

In the present invention, exhaust gas generated, for example, by the operation of a two-stroke gasoline engine, is discharged into the exhaust muffler 10 from the exhaust port 7 of the cylinder 1 of the engine a, as in the prior art. Then, the exhaust gas is passed through a sound absorbing and purifying material 13 provided inside the exhaust muffler 10, and after being muffled and purified, it is finally discharged to the outside from the exhaust pipe 15.

After that, if use continues and carbon buildup or tar stains on the sound absorbing and purifying material 13 progresses and malfunction occurs, remove the stopper 16 and remove only the outer exhaust muffler piece 10b. In this case, the sound absorbing and purifying material 13 interposed or sandwiched therein may be removed and cleaned or replaced.
Therefore, it is not necessary to replace the entire exhaust muffler 10, which is economical, and after the cleaning of the sound absorbing and purifying material 13 is completed, the outer exhaust muffler piece 10b is replaced with the main body part a of the engine. The installation of the muffler is completed by simply attaching it with the stopper 16 to the exhaust muffler piece 10a fixed to the exhaust muffler piece 10a, so the work is extremely easy. In addition, a sound absorbing and purifying material holding portion 14a is provided in the internal facing portion.
14b, it is extremely easy to hold the sound absorbing and purifying material 13.

〔Example〕

An embodiment of the present invention will be described in detail below based on the drawings.

FIG. 3 shows a conventional example, in which a is the main body of a two-stroke gasoline engine, b is an exhaust muffler, and c is a fuel tank.

The main body part a includes a cylinder 1, a crank chamber 2,
It is composed of a piston 3, a crankshaft 4, a spark plug 5, etc., and the cylinder 1 is connected to an intake port 6 communicating with a carburetor and an air cleaner (not shown), the exhaust muffler part b, and an exhaust muffler 10. An exhaust port 7 is formed.

The exhaust muffler 10 is formed, for example, by integrating two box-shaped exhaust muffler pieces 10a and 10b whose main body is press-molded from a steel plate by folding or welding, and into which exhaust gas is introduced. A pipe 11 and a discharge pipe 15 are provided.

Reference numeral 8 designates an exhaust muffler cover, which is removably fixed to the cylinder cover 9 side, and is further provided between the main body part a and the fuel tank c of the engine and the exhaust muffler part b, so that the heat of the exhaust muffler part b is transferred to the engine part a. A heat insulating plate 18 is provided to prevent the heat from being transmitted to the fuel tank c side.

The present invention relates to the structure of the exhaust muffler section b, an example of which is shown in detail in FIG.

Reference numeral 10 denotes an exhaust muffler, which is vertically divided into two parts: an exhaust muffler piece 10a fixed to the engine body part a, and an outer exhaust muffler piece 10b fitted to the exhaust muffler piece 10a, and provided at the upper end. It is constructed so that it can be divided into parts and sealed together using a latch type stopper 16 and a hinge 17 provided at the lower end.

Reference numeral 11 denotes an exhaust gas introduction pipe, which is connected to the exhaust port 7 and has a large number of small holes 12 provided in the peripheral wall for communication between the inside and outside. Reference numeral 13 denotes a sound absorbing and purifying material reinforced with punching metal, wire mesh, etc., and is configured to be detachably cylindrical and have an inner diameter that fits the entire outer circumference of the exhaust gas introduction pipe 11.

As the sound absorbing and purifying material 13, it is preferable to use, for example, a ceramic cloth in which a catalyst layer is formed on the surface of silica fiber or alumina fiber and is woven into a cloth shape.

Further, one end of the sound absorbing and purifying material 13 is fitted and supported by a holding part 14a formed on the outer periphery of the mounting base of the introduction pipe 11 inside the exhaust muffler piece 10a on the side of the engine main body part a, and the other end The free end of the introduction pipe 11 is fitted into and supported by a cylindrical holding part 14b provided inside the exhaust muffler piece 10b at a position facing the holding part 14a.

In the figure, 15 is a pipe for finally discharging the exhaust gas to the outside.

In the present invention having the above configuration, while the engine a is in operation, exhaust gas is continuously discharged from the exhaust port 7 of the cylinder 1 to the exhaust gas introduction pipe 11, and the small hole provided in the peripheral wall of the exhaust gas introduction pipe 11 is continuously discharged from the exhaust port 7 of the cylinder 1. After passing through the sound absorbing and purifying material 13, the discharge pipe 15
It is something that is discharged to the outside.

At this time, the exhaust gas is passed through the sound absorbing and purifying material 13 to be muffled and purified. Thereafter, if use continues and carbon deposits, tar stains, etc. develop inside the sound absorbing and purifying material 13 or the exhaust muffler 10, remove the latch type stopper 16 on the upper end side of the exhaust muffler 10, and remove the latch type stopper 16 from the hinge 17. The upper side of the outer exhaust muffler piece 10b is connected to the main body part a of the engine.
It is sufficient to rotate it so as to separate it from the exhaust muffler piece 10a on the side, and then replace the sound absorbing and purifying material 13 or clean the inside. In addition,
The ceramic cloth of the sound absorbing and purifying material 13 includes:
Contains oxidation catalysts supported on platinum, palladium, etc. According to this embodiment, the exhaust muffler 1
It is economical because there is no need to replace the entire sound absorbing and purifying material 13, and only the internal sound absorbing and purifying material 13 needs to be removed and replaced. Further, when replacing the sound absorbing and purifying material 13 or cleaning the inside of the muffler 10, the inside of the muffler 10 can be opened and closed only by attaching and detaching the upper part of the outer exhaust muffler piece 10b. This has the advantage that these operations can be easily performed without much effort.

Next, another embodiment of the present invention shown in FIG. 2 will be described.

In FIG. 2, the same parts as in the embodiment shown in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

This embodiment has almost the same structure as the embodiment shown in FIG. 1, but differs in the structure of the holding parts 14a and 14b for the sound absorbing and purifying material 13. In other words, sound absorption reinforced with punched metal, wire mesh, etc.
The purifying material 13 is configured in a flat plate shape, and groove-shaped holding parts 14a and 14b for receiving the flat sound absorbing and purifying material 13 are provided at opposing positions inside the two divided exhaust muffler pieces 10a and 10b, respectively. It is something that

Furthermore, latch-type stops 16 are used on both the upper and lower sides of the muffler 10, so that the exhaust muffler piece 10b can be completely removed.

[Effect of idea]

According to the present invention, if carbon deposits, tar stains, etc. adhere to the sound absorbing and purifying materials inside the exhaust muffler after long-term use, and its performance deteriorates, there is no need to replace the entire exhaust muffler. It is economical, and also provides effects such as extremely easy work such as sound absorption and replacement of the purifying material.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal sectional view of the main part, Fig. 2 is a longitudinal sectional view of the main part showing another embodiment, and Fig. 3 is a longitudinal sectional view of the main part of the engine body and exhaust muffler section. FIG. 3 is a vertical cross-sectional view of a conventional example. 10...Exhaust muffler, 10a, 10b...Exhaust muffler piece, 13...Sound absorption, purification material, 14a,
14b...Holding section.

Claims (1)

[Scope of utility model registration request] The exhaust muffler piece 10a is fixed to the main body part a of the engine, and the outer exhaust muffler piece 10b is fitted to the exhaust muffler piece 10a. Sound absorbing and purifying material 1 on the internal facing part of 10b
3 holding parts 14a, 14b are constructed, and a stopper 16 is disposed across the surface of the mating part of both exhaust muffler pieces 10a, 10b, so that only the outer exhaust muffler piece 10b can be attached or detached. An exhaust muffler structure for an internal combustion engine for a small working machine, which is characterized by being freely muffled.