JPS6339370Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention mainly relates to an improvement in the mounting structure of an exhaust muffler for a general-purpose engine.

(Prior Art) Many general-purpose engines have an exhaust muffler attached directly to the exhaust passage outlet of the engine body.

FIG. 1 is a side view with a portion of an exhaust muffler assembled in a typical general-purpose engine known in the art, and FIG. 2 is a front view of the exhaust gas inlet.

In the figure, 1 is the exhaust muffler body, 2 is its exhaust gas inlet, and 3 is a mounting screw insertion tube provided through the muffler body 1. One end of this screw insertion tube 3 is formed around the exhaust gas inlet 2. flat joint surface 4
It is open to

Note that at least two screw insertion tubes 3 are provided symmetrically about the center of the exhaust gas inlet 2.

To attach the exhaust muffler having the above configuration to the engine body, it is necessary to connect the joint surface 4 of the muffler body 1 and the corresponding joint surface (not shown) provided on the outer surface of the end of the exhaust passage of the engine body. A gasket is inserted into the engine body, a mounting screw is passed through the screw insertion tube 3, and the tip of the screw is screwed into the engine body for installation.

The above mounting structure has the following drawbacks.

(1) Since the screw insertion tube 3 is provided through the inside of the muffler body, the number of parts increases, making assembly of the exhaust muffler complicated and increasing costs.

(2) Requires screw holes to be machined on the engine side joint surface.

(3) Even if the exhaust muffler is crimped to the engine body with the gasket sandwiched between the mounting screws, the gasket often deteriorates and gas leaks occur when the engine is operated for a long time.

(4) When attaching the exhaust muffler to the engine body, it is necessary to tighten multiple screws, making the work complicated.

(Purpose) This invention was developed in view of the above points, and it is designed to improve the connection between the engine body and the exhaust muffler, simplifying the structure, convenient assembly and handling, and preventing malfunctions such as gas leaks. The purpose is to provide an exhaust muffler mounting structure with excellent durability.

(Structure of the invention) Hereinafter, an embodiment of the structure of this invention shown in the drawings will be described.

FIG. 3 is a partially cutaway side view showing the installed state of this invention, and FIG. 4 is a front view of the exhaust muffler.

In this invention, a connecting port pipe 5 having a double pipe structure consisting of an inner pipe 6 and an outer pipe 7 is provided at the exhaust gas inlet 2 of the muffler body 1.

The inner pipe 6 of this connection port pipe 5 is formed integrally with the formation of the exhaust gas inlet 2 when the casing 8 of the muffler body 1 is press-molded, and the outer pipe 7 is made separately by press-molding, and its flange portion 9 is Muffler body 1
Attach to the casing surface by spot welding or other means.

Incidentally, this outer tube 7 is provided with a notch 10 at an appropriate location.
The diameter can be reduced by tightening.

A connection port pipe 12 is provided at the end of the exhaust passage of the engine body 11, and by connecting with the muffler side connection port pipe 5, the engine side connection port pipe 12 is connected to the inner pipe 6 of the muffler side connection port pipe 5 and the outer pipe. When inserted between the tubes 7, the tip of the inner tube 6 abuts against the step 13 provided on the inner circumferential surface of the engine side connection port tube 12, so that both inner surfaces are continuous without a step.

Then, the outer tube 7 is covered over the engine-side connection port tube 12, and a tightening band 14 is hung thereon, and both ends of the band are tightened with bolts 15.

For the above connection, the muffler side connection port 5
An appropriate packing material 16 for preventing gas leakage is inserted into the gap created between the inner tube 6 and the outer tube 7.

(Effect) This device is constructed as described above,
It has the following effects.

(1) The exhaust muffler can be easily installed and removed by tightening and loosening a single bolt.

(2) Since gas leakage is not prevented by crimping the packing material against the joint surface, the packing material does not wear out and gas leakage does not occur over time.

(3) With the configuration in which the screw insertion tube is provided through the muffler body, the exhaust muffler can be easily assembled without the need for drilling holes in the casing or welding to fix the screw insertion tube around the holes. In addition, the number of parts is reduced, and production costs can be reduced.

(4) There is no need to process screws on the engine body to attach the exhaust muffler, reducing production costs.

(5) There is no need to weld the end of the screw insertion tube to the casing when assembling the exhaust muffler.
It is now possible to use plated steel plates for the casing.
External painting can be omitted after assembly, reducing production costs.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional exhaust muffler for a general-purpose engine with a portion removed, Figure 2 is a front view of the exhaust gas inlet of the same exhaust muffler, and Figure 3 is a partial view of the installed state of this invention. FIG. 4 is a front view of the exhaust muffler. 1... Exhaust muffler body, 2... Exhaust gas inlet, 3... Screw insertion tube, 4... Joint surface, 5... Muffler side joint port pipe, 6... Inner pipe, 7... Outer pipe, 8
... Casing, 9 ... Flange section, 10 ... Notch, 11 ... Engine body, 12 ... Engine side connection port pipe, 13 ... Stepped section, 14 ... Tightening band, 15 ... Bolt, 16 ... ...Packing material.

Claims (1)

[Scope of utility model registration request] The exhaust gas inlet of the exhaust muffler is connected to the exhaust passage outlet of the engine body by inserting the engine side connection pipe between the double pipes of the exhaust gas inlet of the exhaust muffler.
This exhaust muffler mounting structure is characterized in that the tip of the inner pipe of the double pipe is fitted into a step provided on the inner surface of the engine side connection pipe, the outer pipe of the double pipe is fitted onto the engine side connection pipe, a fastening band is placed on top and tightened with a bolt, and a packing material to prevent gas leakage is inserted into the space inside the double pipe of the muffler side connection pipe.