JPH0740648Y2 - Muffler for engine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION This invention relates to an engine muffler (silencer). More specifically, it is a small two-cycle widely used as a drive mechanism for hand-held chainsaws and brush cutters. It relates to the improvement of the muffler in the engine.

[0002]

2. Description of the Related Art Conventionally, a two-cycle engine has been widely adopted as a drive mechanism for a hand-held working machine such as a chain saw or a brush cutter because it is lightweight and easy to handle. In this type of small two-cycle engine, since the exhaust gas discharged from the cylinder is at a high temperature immediately after combustion, the soot adhering to the inside of the muffler body may be heated and scattered as sparks to the surroundings. Therefore, as a means for preventing the scattering of such sparks, the muffler is provided with a spark arrester formed of a fine mesh stainless steel wire mesh or the like.

By the way, since it is difficult to attach the wire mesh spark arrester to the muffler as a wire mesh alone, for example, a plate-like mesh body is fixed to the frame plate in advance by spot welding, or a tail pipe is formed into a bag shape. It is manufactured as a spark arrester member by charging a net and fixing it by spot welding, and this member is subsequently attached to a predetermined location of the muffler, but in such a spark arrester member, There are problems that the number of parts increases, the manufacturing cost and weight increase, and that cleaning and replacement work after long-time use is troublesome.

Therefore, for example, in Japanese Utility Model Publication No. 63-12651.
As described in Japanese Patent Laid-Open Publication No. 1-1989, a silencer (muffler) is separably formed by a silencer body and an expansion chamber cover that forms an expansion chamber through the silencer body and a partition plate, There has been proposed a structure in which a spark scattering prevention net made of a wire mesh member is supported between the inside of the expansion chamber cover and the inside. However, in this silencer, since the spark scattering prevention net is only supported along the axis of the expansion chamber cover, it is not possible to completely prevent the scattering of the sparks and the assembly is complicated. There was a point to be solved.

[0005]

[Means for Solving the Problems] Therefore, in this invention,
The muffler body is divided and formed by the cylinder side mounting body having the exhaust gas introduction port and the lid body, and the spark arrester is formed by the cylindrical wire mesh member, and the tubular spark arrester is provided between the lid body and the cylinder side mounting body. A cylindrical spark formed by providing a tail pipe forming portion on either the cylinder side mounting main body or the lid of the engine muffler that is supported by, and in which the mesh direction is inclined at a predetermined angle with respect to the longitudinal axis thereof. By sandwiching the arrester between the tail pipe forming part formed on the cylinder side mounting body or the lid and the lid body or the cylinder side mounting body, and holding them tightly, it is possible to prevent the scattering of sparks as much as possible. It is the one.

[0006]

In the engine muffler according to the present invention, when the muffler body is assembled with the cylinder side mounting body having the exhaust gas introduction port and the lid body, the cylindrical spark arrester is provided on the cylinder side mounting body or the lid body. It is sandwiched between the tail pipe forming part and a predetermined position of the lid or the cylinder side mounting main body, and the mesh direction of this cylindrical spark arrester is inclined at a predetermined angle with respect to the longitudinal axis, so its adhesion is preferable. Will be achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A muffler attached to a two-cycle engine will be illustrated as a preferred embodiment of an engine muffler according to the present invention, and will be described in detail below with reference to the accompanying drawings.

1 to 3, an engine muffler 10 according to the present invention comprises a mounting body 16 having an inlet 14 for exhaust gas discharged from a cylinder of a two-cycle engine 12, and the mounting body 16. The cover body 18 is formed separately, and the attachment body 16 and the cover body 18 are attached to predetermined positions on the outer side of the cylinder via the stoppers 20 to form an expansion chamber 22 therein. It is supposed to be done.

A reinforcing plate 24 having a predetermined thickness is attached to the inner peripheral edge of the introduction port 14 formed in the mounting body 16 by means such as spot welding, and the stopper is provided at a position sandwiching the introduction port 14. The insertion holes 26, 26 of the tool 20 are opened.

Further, insertion holes 28, 28 for the odor 20 and a tail pipe mounting hole 30 are provided at predetermined positions of the lid body 18, and a tail pipe 32 coated with a sealing agent is inserted into the mounting hole 30 for spotting. It is fixed by means such as welding.
In this case, the tail pipe 32 has its end 32a
It is fixed to the inside of the lid 18 so as to protrude by a predetermined dimension.

On the other hand, inside the expansion chamber 22, the inlet 14
An internal space assembly 34 formed by combining a plurality of plate materials is housed so that exhaust gas entering from the inside does not directly hit the side surface of the mounting body 16 or the lid 18 and becomes high temperature. On the other hand, it also functions as a spacer when the lid 18 is fixed by the stopper 20 (see FIG. 2).

Further, in FIG. 3, reference numeral 36 is a spark arrester which is formed in a cylindrical shape by using a wire mesh member 38. The cylindrical spark athlete 36 has a tail pipe end 32a and an inner surface of the mounting body 16. It is firmly held in a state of being sandwiched between and. Specifically, the tubular spark athlete 36 is formed such that the mesh direction M of the wire mesh member 38 is inclined at a predetermined angle with respect to the longitudinal axis C, for example, about 45 degrees, and the tail pipe end 30 is formed.
Since it is assembled in a compressed state when it is inserted between a and the inner surface of the mounting body 16, the adhesion is improved, and external scattering of sparks through the tail pipe 32 is prevented as much as possible. Is. In addition, although the cylindrical spark athleteer 36 is formed in a cylindrical shape in the present embodiment, it is not limited to this shape, and is formed in, for example, a polygonal cylindrical shape in view of the entire shape of the engine or a relationship with other parts. Needless to say, it is okay.

In the muffler according to the present invention constructed as described above, the exhaust gas entering the expansion chamber 22 through the inlet 14 passes through the internal space assembly 34 and the tail pipe end 32a.
Is discharged from the tail pipe 32 to the outside through a spark arrester 36 which is sandwiched and held between the spark arrester 36 and the tail pipe end 30a and the inner surface of the mounting body 16. Since it retains extremely good properties, it is possible to reliably prevent the sparks from scattering to the outside, and since the tubular spark arrester 36 is entirely formed of the wire mesh member, it is possible to reduce the weight and the resistance of exhaust gas. It is reduced and functions properly as a spark arrester.

In FIG. 4, the tail pipe 32 is integrally formed by pressing on the inside of the lid body 18 by pressing, and the protrusions 40 are provided at predetermined positions inside the mounting body 16, and both ends of the cylindrical spark athlete 36 are provided. It is another embodiment of the muffler according to the present invention, which is configured so as to be attached to and sandwiched between the tail pipe 32 and the ridge portion 40. In the case of this embodiment, the adhesion of the cylindrical spark athlete 36 is improved. It is possible to further improve the manufacturing cost and reduce the manufacturing cost by integrating the tail pipe.

[0015]

As described above, in the engine muffler according to the present invention, since the entire spark arrester is formed only by the wire mesh member, it is possible to reduce the weight and the manufacturing cost. In addition, maintenance such as cleaning and replacement work after a long time of use becomes easy, and furthermore, the cylindrical spark athlete is assembled in a compressed state when it is inserted between the end of the tail pipe and the inner surface of the mounting body. Therefore, the adhesiveness is good, and therefore various advantages such as being able to prevent inconveniences such as the scattering of the sparks from the gap to the outside as much as possible are provided.

Although the preferred embodiment of the engine muffler according to the present invention has been described above, the present invention is not limited to this embodiment, and, for example, the overall shape of the engine or the mutual relationship with other parts. 5, the tail pipe 32 is provided on the mounting body 16 side, and the tubular spark athlete 36 is sandwiched and held between the tail pipe end 32a and the inside of the lid 18. etc,
It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a side view showing a preferred embodiment of an engine muffler according to the present invention.

FIG. 2 is a cross-sectional explanatory view taken along the line AA of FIG.

FIG. 3 is a cross-sectional explanatory view taken along the line BB of FIG.

FIG. 4 is a cross-sectional explanatory view corresponding to FIG. 3 showing another embodiment of the engine muffler according to the present invention.

FIG. 5 is a cross-sectional explanatory view corresponding to FIG. 3 showing still another embodiment of the engine muffler according to the present invention.

[Explanation of symbols]

10 muffler, 12 engine, 14
Inlet, 16 mounting body, 18 lid,
20 stoppers, 22 expansion chambers, 24 reinforcing plates, 26 insertion holes, 28 insertion holes,
30 mounting hole, 32 tail pipe, 34
Internal space assembly, 36 spark arrester, 38 wire mesh member, 40 ridge,

Claims (1)

[Scope of utility model registration request] 1. A muffler body is separately formed by a cylinder side mounting body having an exhaust gas introduction port and a lid body, and a spark arrester is formed by a tubular wire mesh member, and the tubular spark arrester is attached to the lid body and the cylinder side. In an muffler for an engine configured to be supported between a mounting body and a mounting body, a tail pipe forming portion is provided on either the cylinder side mounting body or the lid body, and a tail pipe forming portion is formed on the cylinder side mounting body or the lid body. A cylindrical spark arrester formed so that the mesh direction inclines at a predetermined angle with respect to the longitudinal axis of the cover and the lid or the cylinder-side mounting body, is tightly held by being inserted. Scarf.