JP2719933B2 - Motorcycle muffler - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a muffler for a motorcycle, and more particularly to a muffler for a motorcycle in which a muffler outer cylinder is covered with a cover for decoration or the like.

[Related Art] In a muffler of a motorcycle, for example, in the case of a large-displacement vehicle, the muffler outer cylinder may be discolored by the exhaust heat.

As described above, since the muffler outer cylinder is discolored and its appearance is impaired, for example, as described in Japanese Utility Model Application Laid-Open No. 61-59128, the outer portion of the muffler outer cylinder is covered with a muffler cover to form a double structure. In some cases, the surface temperature of the cover is reduced to prevent discoloration of the outer portion of the muffler outer cylinder.

[Problem to be Solved by the Invention] In addition, the end opening of the muffler outer cylinder is closed by a partition wall forming an expansion chamber. It is preferable to attach an end cover to the end to form a double structure so that the discolored portion is invisible from the outside.

In this way, the muffler can prevent discoloration due to exhaust heat or make it invisible from the outside.However, if the muffler cover and end cover are attached to the muffler outer cylinder by welding in the circumferential direction, the trouble will be reduced. In addition, the heat of welding discolors the connections of these covers. For this reason, even if the vehicle is provided in consideration of the arrangement position of the muffler, the portion discolored by welding cannot be hidden from the outside because it is welded in the circumferential direction.

For this reason, rivet joining is used instead of welding. However, if the muffler outer cylinder is covered with a muffler cover and the end covers are connected to these ends at the same time, three members are stacked. It is necessary to perform rivet bonding, which makes it difficult to position the rivet holes. In addition, the appearance is poor due to a step at the connection between the muffler cover and the end cover.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a muffler for a motorcycle in which a muffler cover and an end cover can be easily attached to a muffler outer cylinder without impairing the appearance.

[Means for Solving the Problems] In order to solve the above problems, the present invention covers the outer periphery with a muffler cover while leaving the end of the muffler outer cylinder, and welds and fixes it in the muffler axial direction. The end cover is abutted against the muffler cover and is flush with the end cover, and the end cover and the end of the muffler outer cylinder are riveted together.

[Operation] In the present invention, since the outer periphery of the muffler cylinder is covered with the muffler cover and the muffler cover is welded and fixed in the muffler axial direction, the muffler is provided on the vehicle body so that the welded portion is not visible from the outside. be able to.

Also, with the end cover and the muffler cover butt,
Since the rivet is joined to the outside of the muffler outer cylinder, it is easy to align the rivet holes without overlapping the muffler cover, and the end cover is flush with the muffler cover,
Steps at these connecting portions can be eliminated.

Embodiment Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view of a motorcycle to which one embodiment of the present invention is applied. In the figure, reference numeral 1 denotes a motorcycle, a front wheel 5 is supported on a head pipe 3 of a frame 2 via a front fork 4, and a fuel tank 7 is mounted on left and right main frames 6 extending rearward from the head pipe 3. At the same time, the internal combustion engine 8 is suspended, and an air cleaner 9 and a carburetor 10 are provided below the fuel tank 7.

A seat frame 12 is attached rearward to a bracket 11 at a rear end of the main frame 6, and a seat 13 is provided on the seat frame 12. A rear wheel 15 is provided at a rear end of the main frame 6 via a rear arm 14. Supported.

A radiator 16 is provided in front of the internal combustion engine 8. The exhaust pipe 18 is covered with a cowling 17 from the front of the head pipe 3 to the side of the internal combustion engine 8, and extends rearward from the front surface of each cylinder of the internal combustion engine 8. A muffler 19 is provided at the end.

The muffler 19 is constructed as shown in FIGS. 2 to 4, wherein FIG. 2 is a sectional view of the muffler, and FIG.
FIG. 4 is an enlarged view of a connecting portion between the muffler outer cylinder and the muffler cover and the end cover.

Inside the muffler outer cylinder 20 of the muffler 19, partition walls 21, 22, 23, 24
Are provided to define a first expansion chamber 25, a second expansion chamber 26, and a third expansion chamber 27.

In the first expansion chamber 25, a cylindrical body 29 is supported by a ring-shaped mounting member 28 and a partition wall 22, and a heat insulating material 30 is disposed between the cylindrical body 29 and the muffler outer cylinder 20. Mounting member 28 is a muffler outer cylinder
The partition 21 is fixed to the mounting member 28 by welding. The partition 21 is formed in a conical shape and has an exhaust pipe 28.
Are connected, the axis of which is inclined with respect to the axis of the muffler.First, the attachment member 28 is welded to the muffler outer cylinder 20 and the partition 21 is attached to the attachment member 28 by welding. The welding torch does not interfere with the conical portion of the partition wall 21.

An exhaust conduit 31 is mounted between the partitions 22 and 23, an exhaust conduit 32 is mounted on the partition 23, and an exhaust conduit 33 is mounted between the partitions 23 and 24 via a mounting member 33a. 25 and the second expansion chamber 26, the second expansion chamber 26 and the third expansion chamber 27
27 communicates with the outside air.

The outer portion of the muffler outer cylinder 20 is covered with a muffler cover 34 slightly shorter than the muffler outer cylinder 20. The muffler cover 34 is formed of, for example, an aluminum plate in consideration of decoration, and this attachment is wound around the muffler outer cylinder 20 and an end 34a formed in the muffler axial direction is fixed to the muffler outer cylinder 20 by welding. . In this manner, the muffler 19 has a double structure with the muffler outer cylinder 20 and the muffler cover 34, thereby lowering the surface temperature of the muffler cover 34, eliminating discoloration of the muffler cover 34 due to exhaust heat, and improving decorativeness. .

At both ends of the muffler outer cylinder 20, there are formed portions that are not covered by shortening the muffler cover 34, and this end 20a has a cone-shaped end cover that covers the partition walls 21 and 24 on both sides.
35 and 36 are applied in a state where the muffler cover 34 and the abutment surface are flush with each other. Both ends 20a of the muffler outer cylinder 20 and end covers 35, 36
Are joined by a predetermined number of rivets 37 in the circumferential direction. The end covers 35, 36 and the muffler cover 34 are flush,
Since there is no step between the two and the muffler outer cylinder 20, which may be discolored by the influence of exhaust heat, is entirely covered with the end covers 35, 36 and the muffler cover 34, the appearance of the muffler 19 is improved.

The exhaust pipe 18 is inserted into the hole 35a of the front end cover 35, and the end cover 35 covers the partition 21 connected to the exhaust pipe. Further, an exhaust pipe 38 is inserted into the hole 36a of the rear end cover 36, and the two are welded together.
Covers 24.

In this way, the end covers 35, 36 need only be installed by aligning the rivet holes formed in the end covers 35, 36 and the two end portions 20a of the muffler outer cylinder 20, respectively. Due to the double structure, rivet joining can be easily performed.

[Effects of the Invention] As described above, the present invention covers the outer periphery with a muffler cover except for the end of the muffler outer cylinder, and welds and fixes it in the muffler axial direction, and attaches the end cover to the end of the muffler outer cylinder. Since the end cover and the end of the muffler outer cylinder are riveted to the muffler cover, the muffler can be provided on the vehicle body such that the welded portion of the muffler is not visible from the outside. .

Also, with the end cover and the muffler cover butt,
Since the rivet is joined to the outside of the muffler outer cylinder, positioning of the rivet holes is easy because the muffler cover does not overlap.
Moreover, the end cover can be flush with the muffler cover, so that there is no step at these connecting portions, and the appearance of the muffler is improved.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle to which one embodiment of the present invention is applied, FIG. 2 is a cross-sectional view of a muffler, and FIG. 3 is III in FIG.
FIG. 4 is an enlarged view of a connecting portion between the muffler outer cylinder, the muffler cover and the end cover. In the figure, reference numerals 1 are a motorcycle, 19 is a muffler, 20 is a muffler outer cylinder, 20a is an end, 34 is a muffler cover, 35 and 36 are end covers, and 37 is a rivet.

Claims (1)

(57) [Claims] An outer cover is covered with a muffler cover except for an end of the muffler outer cylinder, and the outer periphery is welded and fixed in a muffler axial direction. A muffler for a motorcycle in which the end cover and the end of the muffler outer cylinder are riveted.