JPH0717773Y2 - Muffler structure of 2-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a muffler structure of a two-stroke engine.

[Prior Art] Conventionally, an exhaust pipe connected to a vehicle engine and capable of exhausting exhaust gas collected from a plurality of manifolds is formed by a plurality of exhaust gas passages.
See 63-196425.

[Problems to be solved by the invention] However, with such a structure, exhaust gas is continuously fed into the exhaust pipe from a plurality of cylinders, and the exhaust flow causes a substantial valve action. The tuning effect cannot be improved even if such a structure is adopted in a two-cycle engine, and the exhaust pipe cannot be made shorter than the conventional one, so that the muffler is small in size. It also has problems such as difficulty in commercialization.

[Means for Solving the Problems] The present invention is intended to solve such a problem and to improve the tuning effect in the muffler in a two-cycle engine and to make the muffler compact. Inside the muffler, a curved pipe-shaped exhaust pipe that is directly connected to the outside of the outer end port of the exhaust port and that has only a rear end port opened is installed in the muffler. It is configured by forming a plurality of exhaust passages arranged in parallel over the entire length of the exhaust pipe so as to face the outer end opening of the port.

[Operation] Therefore, the exhaust gas discharged from the exhaust port is immediately dispersed in each exhaust passage of the exhaust pipe and flows out into the muffler, and at that time, a flow resistance is exerted in each exhaust passage. As a result, a substantial valve action is performed by the exhaust flow, so that the inside of the cylinder can be made to have a negative pressure and intake can be easily performed, and the tuning effect can be further improved. It is possible to improve the sound deadening effect without emitting raw gas.

Example Next, an example shown in the drawings will be described.

(E) is a portable two-cycle engine such as a brush cutter, which is constructed in the same manner as the conventional structure by connecting an exhaust port (11) in the middle of the cylinder (10).

(20) is a muffler, and both mounting bolts (30) that penetrate the muffler (20) are attached to the outside of the cylinder (10), but exhaust is provided on the lower outside of the muffler (20). Mouth (2
3) is provided, and an opening (24) that can match the outer end opening (11a) of the exhaust port (11) is formed in the upper part of the inner side of the muffler (20), and the opening (24) and the exhaust port (11) are formed. A sealing material (31) is provided on the outer circumference between the outer end opening (11a) of the muffler and a large number of vent holes (36) and openings (32) are provided on the outer circumference of the muffler (20). A muffler cover (33) capable of covering the muffler (20) is connected to the engine cover (34) side with a screw (35) in between.

Further, a tip end of a bent pipe-shaped exhaust pipe (21) is fixed to a flange (25) fixed to the inner and outer circumferences of the opening (24), and the exhaust pipe (21) is fixed to the exhaust pipe (21). Bent pipes that are to be the exhaust passages (22) (22) arranged in parallel over the entire length are formed by adhering, and the front end openings (22a) (22a) of the exhaust passages (22) (22) are the exhaust ports ( The outer end opening (11a) of (11) approaches and faces the outside, and the rear end opening (22) of both exhaust passages (22) (22)
b) Only (22b) is formed so as to open downward in the muffler (20).

Incidentally, FIG. 4 shows another embodiment, in which the inside of the exhaust pipe (21) is divided into four exhaust passages (22) and integrally molded with a heat resistant resin or the like.

Therefore, the exhaust gas discharged from the exhaust port (11) immediately flows out into the muffler (20) by being dispersed in the exhaust passages (22) and (22) of the exhaust pipe (21). In the passages (22) and (22), flow resistance is exerted, and the exhaust flow causes substantial valve action,
Therefore, it is possible to make the inside of the cylinder (10) a negative pressure and to easily perform the intake, so that the tuning effect can be further improved, and the raw gas is discharged into the muffler (20). In addition, the muffling effect can be improved.

[Effects of the Invention] As described above, according to the present invention, the exhaust gas discharged from the exhaust port (11) of the two-cycle engine flows through the exhaust passages (22) and (22) of the exhaust pipe (21) while the muffler ( Since it will flow into the inside of 20), the exhaust flow will cause a substantial valve action, so that the inside of the cylinder (10) can be made a negative pressure and the intake can be easily performed and tuning is performed. The effect can be further improved, and moreover, the muffler (20) can be further improved in the muffler (20) without being discharged with raw gas, and the muffler (20) can be improved by the exhaust pipe ( 21) can be made into a compact structure that only has the interior, and it has the features that it can be suitably implemented as a muffler for a two-cycle engine that is lightweight and compact.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an embodiment of the present invention, FIGS. 2 and 3 are sectional views taken along lines II-II and III-III of FIG. 1, respectively, and FIG. Another embodiment will be described. (10) …… Cylinder, (11) …… Exhaust port (11a) …… Outer end port, (20) …… Muffler (21) …… Exhaust pipe, (22) …… Exhaust passage (22a) …… Tip port , (22b) …… Rear end

Claims (1)

[Scope of utility model registration request] 1. An exhaust port (1) communicating with a cylinder (10).
In a two-cycle engine configured by connecting a muffler (20) to (1), the muffler (20) is directly connected to the outside of the outer end opening (11a) of the exhaust port (11) and is connected to the muffler (20). A curved pipe-shaped exhaust pipe (21) having only a rear end port (22b) opened therein is installed in the inside of the exhaust pipe (20), and each of the front end ports (22a) of the exhaust pipe (21) is connected to the exhaust port (11). A muffler structure comprising a plurality of exhaust passages (22) arranged in parallel over the entire length of an exhaust pipe (21) facing the outer end opening (11a).