JPS6327529B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a muffler device for a motorcycle or the like, and particularly to one in which a muffler tail is attached to the rear part of a muffler body.

Conventionally, a muffler tail, which is an extension of the outer circumferential wall of the muffler body connected to the exhaust side of the engine, is provided at the rear end of the muffler body so that its rear end surface is inclined with respect to the axis of the muffler body, giving the muffler an excellent appearance as a whole. There is something I did.

When such a muffler tail is provided, in order to prevent the cavity inside the muffler tail from becoming a resonance chamber,
Exhaust must be carried out along the inside of the outer wall of the muffler tail, and the exhaust passage must have a ring-shaped opening at the rear end.
Therefore, when the rear end of the muffler tail is cut diagonally with respect to the axis of the muffler body as described above, there will inevitably be lengths and shorts in the exhaust passage. Exhaust resistance increases, making it impossible to exhaust evenly.

The present invention has been made to improve this problem, and its purpose is to integrally attach a muffler tail having a rear end portion cut diagonally with respect to the axis of the muffler body to the rear of the muffler body. To provide a muffler device capable of achieving good exhaust balance.

In order to achieve such an object, the present invention has a structure in which the front end of the muffler tail is connected to the expansion chamber by the outer tail plate and the inner tail plate, and the rear end is opened in a ring shape along the circumference of the rear end of the muffler tail. Furthermore, the main feature is to form exhaust passages with partially different flow path lengths, and to provide regulating portions in these exhaust passages to match the flow resistance of the exhaust gas.

An example of the implementation of the present invention will be explained in detail below based on the accompanying drawings.

FIG. 1 is an overall side view of a motorcycle to which a muffler device according to the present invention is applied. Be prepared. An engine 6 is mounted on an intermediate portion extending rearward and downward from the front of the frame 2, a fuel tank 7 is provided above the engine 6, and a seat 8 extends behind the fuel tank 7. . Further, the base of a rear fork 10 that supports the rear wheel 9 is pivotally supported at the rear lower part of the frame 2, and an exhaust pipe 11 is extended rearward and downward from the engine 6, and a muffler 12 is attached to the rear end of the exhaust pipe 11.
is installed. The muffler 12 has a front half facing slightly outward and rising rearward and upward, and a rear half parallel to the axle and substantially horizontal.

FIG. 2 is a side sectional view showing the internal structure of the muffler 12, in which the muffler 12 is bent at the middle part and a separator 15 is attached inside the cylindrical muffler main body 13 cut diagonally at the rear end. The interior of the muffler body 13 is divided from the left in the figure into a first expansion chamber 18 and a second expansion chamber 19, which also serve as exhaust gas inflow chambers.

The separator 15 has an inner pipe 2 that communicates the first expansion chamber 18 and the second expansion chamber 19.
1 and 21, and the inner pipe 22 has many small holes for sound absorption formed in the central opening of the reinforcing ring 16.
A glass wool 22a for sound absorption is wound around the outside of the middle part of the inner pipe 22 via the outer pipe 23 and the caps 24, 24.

At the rear end of the inner pipe 22, a tip opening of a tail plate outer 25 is attached, which has a substantially funnel-like shape and gradually widens from the tip toward the rear. This tail plate outer 25 has its rear end circumference approximately aligned with the obliquely cut rear end circumference 13b of the rear part 13a of the muffler body 13, which also serves as the outer circumferential wall of the muffler tail 26, so that the ridgeline partially Different lengths.

The second expansion chamber 19 is formed by the tail plate outer 25, the separator 15, the reinforcing ring 16, and the muffler main body rear part 13a.

Further, a tail plate inner 27 is disposed within the tail plate outer 25. This tail plate inner 27 is the tail plate outer 2.
A shape that can maintain a constant distance from the inner surface of 5, that is,
It has a shape that is approximately similar to the tail plate outer 25. Thus, an exhaust passage 28 is formed in the muffler tail 26, which is connected to the rear end of the inner pipe 22 at the front, gradually widens toward the rear, and opens in a ring shape at the rear end of the muffler tail 26. .

Since the lengths of the ridge lines of the tail plate outer 25 and the tail plate inner 27 that form the exhaust passage 28 are partially different, the length of the exhaust passage 28 is also not constant. In the case of this embodiment, the rear end of the muffler tail 26 is cut diagonally forward and downward from above so that its end face faces slightly outward, so the exhaust passage 28b that is slightly inward from the upper end is the longest. The exhaust passage 28a located slightly outward from the lower end is the shortest.

As shown in the end view of the muffler tail 26 in FIG. 3 and the cross-sectional view in FIG. Similarly, a long exhaust passage 28 is formed.
A part of the outer tail plate 25 forming the outer tail plate 25 is bulged into the passage 28b to form a regulating portion 29b, and the inner tail plate 27 is welded to these regulating portions 29a, 29b. Note that in FIG. 2, the restricting portion 29b of the long exhaust passage 28b is not shown due to the cross-sectional view of the arrows.

The regulating part 29a has a larger volume than the regulating part 29b, and by doing so, a balance is maintained between the long passage 28b with high flow resistance and the short passage 28a with low flow resistance.
The exhaust gas is discharged from the rear end opening of the exhaust passage 28 in a well-balanced manner.

Next, the order of assembling the muffler 12 will be explained. First, the reinforcing ring 14, separator 15, and reinforcing ring 16 are inserted into the muffler main body 13 in order, and then welded by spot welding, and the rear end of the muffler main body 13, that is, the rear end of the outer periphery of the muffler tail 26 is folded inward. The rear end of the ring-shaped holder 30, which has a tapered tip, is inserted into the bent portion and held. Then, prepare something like this as a separate item.

Next, the outer pipe 23 is placed in the middle part, and the tail plate outer 2 is placed in the rear end part of the inner pipe 22 which holds the glass wool 22a through the cap 24.
At the same time, the tail plate inner 27 is butted against the regulating parts 29a, 29b of the tail plate outer 25 and spot welded. Then, the tip of the inner pipe 22 is lightly press-fitted into the center opening of the reinforcing ring 16 of the muffler main body prepared as a separate unit from the assembly thus integrated, and the rear end of the tail plate outer 25 is inserted. Rear end 13b of muffler body 13
The rear part 1 of the muffler body 13 is pressed against the inner periphery of the muffler body 13.
The muffler body 13, the holder 30, and the tail plate outer 25 are plug welded to form the muffler 12 in the recess 31 formed on the outer periphery of the muffler 3b.

With this configuration, the exhaust gas flowing from the exhaust pipe 11 flows from the first expansion chamber 18 into the second expansion chamber 19 via the inner pipe 21. Here, in the second expansion chamber 19, the holder 30
Since the tail plate outer 25 and the tail plate outer 25 are in pressure contact with each other, exhaust gas will not leak. Then, the exhaust gas in the second expansion chamber 19 flows into the exhaust passage 28 in the muffler tail 26 via the inner pipe 22. As described above, the exhaust gas is distributed in a well-balanced manner and exhausted to the outside through the ring-shaped opening of the exhaust passage 28.

FIG. 5 is a sectional view of the muffler tail part of another embodiment.
FIG. 6 shows the end face of the muffler tail of the other embodiment. In this embodiment, the tail plate outer bulges out to form the regulating part, whereas in this embodiment, the tail plate outer bulges to form the regulating part. The point is that the inner plate is made to bulge out.

That is, the rear end portion 1 of the muffler main body 113 has the rear end portion 113b cut diagonally as in the embodiment described above.
13b is bent inward, and the rear end portion of the cylindrical holder 130, which has a tapered tip, is held at this bent portion, and on the other hand, the inner pipe 1 facing the expansion chamber is
The tip of a funnel-shaped tail plate outer 125 that gradually expands toward the rear is inserted into the rear end of the tail plate 22, and a short exhaust passage 128a is formed inside the tail plate outer 125 between the tail plate outer 125 and the tail plate outer 125. and a tail plate inner 12 forming an exhaust passage 128 including a long exhaust passage 128b.
7, and a part of the tail plate inner 127 is bulged to open the exhaust passages 128a, 12.
He is trying to form regulation parts 129a and 129b facing into 8b.

In the assembly, the tip of the tail plate outer 125 is inserted into the rear end of the inner pipe 122 and welded, and the regulating part 129a,
At 129b, the tail plate outer 125 and the tail plate inner 127 are spot welded to form one assembly, which is attached to the main body 113.
Lightly press fit into the separator etc. inside the main body 11.
3. Welding the tail plate outer 125, the holder 130, and the main body 113 by plug welding in which the weld metal does not protrude outside the wall of the main body 113 and does not require post-processing in the recess 131 formed on the outer periphery, Get an integrated muffler. In this embodiment as well, by optimizing the volume of the restricting portion 129a provided in the short exhaust passage 128a, the balance of the exhaust discharged from the exhaust passage 128 can be made good.

As is clear from the above description, according to the present invention, in a muffler device in which a muffler tail is integrally attached, the rear end of which is cut obliquely with respect to the axis of the muffler body, the front end is located within the muffler tail. A tail plate outer and a tail plate inner form an exhaust passage that receives exhaust from the expansion chamber, has a ring-shaped rear end opening at the rear end of the muffler tail, and has partially different lengths. A regulating portion that matches the flow resistance of the exhaust gas in the exhaust passage is provided by bulging the tail plate outer or the tail plate inner, so that the flow resistance of the exhaust gas in the short exhaust passage and the long exhaust passage can be matched. This has many advantages, such as the ability to efficiently perform the entire exhaust process, and the support structure of the tail plate inner to be simplified and assembly to be easily performed.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention.
The figure is an overall side view of a motorcycle to which the muffler device according to the present invention is applied, FIG. 2 is a side sectional view of the same muffler device, FIG. 3 is an end view of the same muffler device, and FIG. - A sectional view, FIG. 5 is a side sectional view of a main part of another embodiment, and FIG. 6 is an end view of the same embodiment. In addition, in the drawing, 12 is a muffler, 13 and 113 are the muffler main body, 13a and 113a are the rear end of the muffler main body,
25,125 is the tail plate outer, 26,1
26 is a muffler tail, 27, 127 is a tail plate inner, 28, 128 is an exhaust passage, 28a,
128a is a short exhaust passage, 29a, 29b, 1
29a and 129b are regulating portions.

Claims (1)

[Claims] 1. In a muffler device in which a muffler tail whose rear end is cut obliquely with respect to the axis of the muffler body is integrally attached to the muffler body, the front end receives exhaust air from the expansion chamber within the muffler tail, and the rear end The tail plate outer part and the tail plate inner part open in a ring shape along the circumference of the rear end of the muffler tail, and an exhaust passage with partially different flow path lengths is formed by the tail plate outer and the tail plate inner. What is claimed is: 1. A muffler device characterized in that a regulating section is provided, and the regulating section of the long exhaust passage is made smaller than the regulating section of the short exhaust passage to match the flow resistance of exhaust gas in these exhaust passages.