JPS62197636A - Collective exhaust pipe structure for motorcycles, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a collective exhaust pipe structure for a motorcycle or the like in which a plurality of exhaust pipes connected to each exhaust port of a multi-cylinder engine are assembled.

[Conventional technology]

Some conventional motorcycles equipped with multi-cylinder engines are equipped with a collective exhaust pipe in which the exhaust pipes connected to the exhaust port of the engine are collected into a small number of exhaust pipes.

This collective exhaust pipe increases exhaust efficiency through the synergistic effect of the dynamic effects of each exhaust pipe, creating an exhaust inertia effect, increasing torque and increasing engine speed, and improving power performance by reducing weight. 4-cylinder engine
4-1 (41nto
1) Type (7) I Combine IJj Ki W, 4-2-1
．． Structures such as the 4-2-2.2-1 type are known.

Figure 1 shows a waveform diagram of exhaust pressure fluctuation near the valve of the common exhaust pipe, and Figure 2 also shows a power characteristic diagram of the engine. The first reflecting surface (first end) becomes the vibration source.
The wave is then reflected in the same phase near the valve (closed end) and continues as a negative pressure, and the phase is reversed at the first reflecting surface and returns as a positive pressure wave. Although the exhaust pressure fluctuation is a combination of interference from other cylinders, reflected waves after the collecting section, etc., it basically becomes the waveform S+ shown in FIG. 1.

Therefore, when the overlap hits the 0° 5th order negative pressure wave due to gas exchange, it becomes a torque peak, and when the overlap hits the 1.0 order positive pressure wave, it becomes a torque trough, and the power characteristics are as shown in Figure 2. This results in a curve shown by the broken line S1. - (Problem to be Solved by the Invention) However, in the above-mentioned system, the fluctuation in exhaust pressure becomes large due to the synergistic effect of the dynamic effects of each exhaust pipe at the gathering part, so the waveform S1 is Near the point, although the time area TA at the time of overlap is small, there is no reduction in power and torque as shown at point B in Figure 2, but at point A, the time area and positive pressure wave are large, so There was a problem in that the power and torque decreased as shown at point A in Figure 2.

SUMMARY OF THE INVENTION An object of the present invention is to provide a collective exhaust pipe structure that eliminates power down and has wide power characteristics by providing an apertured reflective surface on the exhaust pipe immediately upstream of the collective part.

[Means for solving problems]

The present invention has been made in view of the above-mentioned object, and includes a collective exhaust pipe of a motorcycle, etc., in which the rear ends of a plurality of exhaust pipes connected to each engine cylinder are collected at a collective part. A suitable number of small holes are bored at a position immediately upstream of the small hole, and a sleeve with both ends closed is placed around the outer periphery of the small hole, and a chamber communicates with the exhaust pipe through the small hole inside the sleeve. It is characterized by the formation of

[For production]

By adopting the above exhaust pipe structure, the small hole becomes the open end of the first reflecting surface, and the phase of the excitation source positive pressure wave during exhaust blowdown is inverted and reflected back inside the pipe in sequence, reducing pressure fluctuations inside the exhaust pipe. It is smaller and provides a wide range of power characteristics.

〔Example〕

Hereinafter, the assembly and exhaust pipe of the present invention will be explained based on the drawings.

3 and 4 show a first embodiment of the present invention, in which the collective exhaust pipe 1 is a 4-1 type in which four exhaust pipes are collected into one,
Respective rear ends 2b, 3b, 4b of four exhaust pipes 2.3, 4.5 whose front ends 2a, 3a, 4a, 5a are connected to respective exhaust ports of a four-cylinder engine.

5b are gathered at a collecting part 6, and one exhaust pipe 7 is continuously provided at the rear of the collecting part 6, and at the rear of the exhaust pipe 7,
A muffler 8 is provided.

Rear end 2 of each exhaust pipe 2.3.4.5 at the position immediately upstream of the gathering part 6
A plurality of small holes 9 are formed in each of b, 3b, 4b, and 5b, and a cylindrical sleeve 10 is provided around the outer periphery of each of the small holes 9.
A chamber 11 is thereby formed in the sleeve 10 which communicates with the respective exhaust pipe 2, 3, 4, 5 through the small hole 9.

This chamber 11 is for the purpose of making the small hole 9 an aperture reflecting surface for the exhaust pulsation, and so that the gas flow from the small hole 9 into the chamber 11 does not adversely affect the flow loss or the exhaust inertia effect. Both ends are closed.

In addition, the small hole 9 becomes the open end of the exhaust pulsation, and the exhaust pulsation that returns while sequentially reflecting the phase-inverted negative pressure wave becomes the waveform S2 shown in Fig. 1. At 8 points, the time area TA is small, so the exhaust pulsation does not have much power. Figure 2: 8
As shown in point A of 2, power and 1-lux can be improved.

As mentioned above, the small hole 9 and the chamber 11 are suitably positioned immediately upstream of the collecting part 6. When these are provided at the upstream part of the exhaust pipe, the small hole 9 is located at the first intermediate end, and the position immediately upstream of the collecting part 6 is suitable. becomes the second end, and the waveform becomes a complicated composite wave, causing an obvious power down. Also, if it is installed at a position directly downstream of the gathering part 6, the phase-inverted negative pressure wave of the small hole 9 will be In this embodiment, the number of exhaust pipes is attenuated to about 1/4 of the four exhaust pipes, and no effect is produced.

FIG. 5 shows a second embodiment of the present invention, in which the collective exhaust pipe 12 is a 4-1 type combined pipe in which four exhaust pipes are collected in one tree as in the above embodiment. The rear ends 2b of 62 adjacent exhaust pipes 2, 3 among the four exhaust pipes 2, 3.4°5 connected to the cylinder.

3b, sleeves 10 each forming a chamber 11;
and a small hole 9 are provided.

As in this example, even if small holes and chambers with open ends are provided only in two adjacent exhaust pipes on one side, the output characteristics can be significantly improved, and at the same time, the cost can be reduced and the size can be reduced. , and production efficiency can be improved.

FIG. 6 shows a third embodiment of the present invention, in which the collective exhaust pipe 13 is a 4-2-1 type in which four exhaust pipes are collected into two and further collected into one at the bottom. IyJ end i4a, 15a for each exhaust port of cylinder engine.

Four exhaust pipes 14, 15.1 connecting 16a and 17a
6.17, the rear ends 14b and 15b of the two exhaust pipes 14°15 on the negative side are connected to the collecting part 18, and the rear ends 16b and 17b of the two exhaust pipes 16.170 on the other side are connected to the collecting part 1. At the same time, the rear ends of the two exhaust pipes 20 and 21 that are continuous to the rear part of the collecting part 18 and 19 are further collected in the collecting part 22, and one exhaust pipe is equipped with a muffler 23 at the rear part. The tubes 24 are provided continuously.

Each exhaust pipe 14°15.1 immediately upstream of the gathering part 18.19
6.17 rear ends 14b, 15b, 16b.

The sleeve 17b is provided with a plurality of small holes and a sleeve 10 forming a chamber 11 around the outer periphery thereof, respectively, similarly to the first and second embodiments.

FIG. 7 shows a fourth embodiment showing a modification of the third embodiment, in which the collective exhaust pipe 25 has an integral sleeve 26 for each of the small holes 9 of the - side exhaust pipes 14 and 15, and the other Exhaust pipe 16.1
By covering each small hole 9 of 7 with a similar sleeve 27,
A common chamber 28 is formed around the outer periphery of the small holes 9 of adjacent exhaust pipes.
．． 29 are formed respectively.

FIG. 8 shows a fifth embodiment of the present invention, in which a collective exhaust pipe 30 includes exhaust pipes 14, 15, .
Among 16.17, two exhaust pipes 14.1 adjacent to each other on the negative side
5 only has a small hole 9 and a chamber 11 similar to the third embodiment.
A sleeve 10Ifi is provided.

FIG. 9 shows a sixth embodiment, in which the collective exhaust pipe 31 has small holes 9 in the exhaust pipes 14 and 15 on one side, as in the fifth embodiment.
are respectively bored, and the small holes 9 are integrally covered with the sleeve 26 used in the fourth embodiment, thereby forming a common chillen bar 28 on the outer periphery of the holes 9 for both vehicles.

FIG. 10 shows a seventh embodiment of the present invention, in which a collective exhaust pipe 32 is constructed by combining four exhaust pipes into two, and communicating these two exhaust pipes with each other through a communicating pipe. -2-2 type,
Among the four exhaust pipes 33, 34, 35.36 connected to each exhaust port of the four-cylinder engine, the - side exhaust pipe 33.3
4 rear end 33a.

34a at the collecting part 37, and the rear ends 35a and 36a of the exhaust pipes 35 and 36 on the other side are collected at the collecting part 38, and the collecting part 37
．． 38 are successively provided with exhaust pipes 41.42 each having a muffler 39°40, and both exhaust pipes 41.4
2 are communicated through a horizontal communication pipe 43.

The above exhaust pipes 33, 34.・At 35.36, assembly section 37
．． 38, each rear end 33a, 34a, 35a,
36a is provided with a plurality of small holes 9 and a sleeve 10 forming a chamber 11 on the outer periphery thereof.

FIG. 11 shows an eighth embodiment of the present invention, in which the collective exhaust pipe 4
4 is a 2-1 type in which two exhaust pipes are combined into one, and two exhaust pipes 4 are connected to each exhaust boat of a two-cylinder engine.
5. Gather the rear ends 45a and 46a of 46 at the gathering part 47,
An exhaust pipe 49 having a muffler at the rear of the gathering part 47
are provided consecutively.

The exhaust pipes 45, 46 are provided with a plurality of small holes 9 and a sleeve 10 forming a chamber 11 around the outer periphery of the small holes 9 at rear ends 45a, 46a of the exhaust pipes 45, 46, located immediately upstream of the collecting portion 47, respectively.

Note that the 4-2-2 nested exhaust pipes shown in the seventh embodiment may be such that the small holes and chambers forming the openings are provided only in the two exhaust pipes on the − side. Also, with respect to the 2-1 exhaust pipe of the eighth embodiment, only one exhaust pipe may be provided.

Therefore, according to each of the embodiments described above, exhaust pressure fluctuations are smoothed and the power band can be widened.

(Effects of the Invention) As explained above, the collective exhaust pipe of the present invention collects a plurality of exhaust pipes connected to each exhaust port of a multi-cylinder engine at a collecting part, and exhausts the exhaust pipes immediately upstream of the collecting part. A plurality of small holes are bored at the rear end of the tube, and a sleeve with both ends closed is placed around the outer periphery of the small holes to form a chamber in the sleeve that communicates with the exhaust pipe through the small holes. As a result, fluctuations in exhaust pressure in the exhaust pipe can be smoothed out, making it possible to widen the power band and increase engine speed, thereby improving power performance.

[Brief explanation of drawings]

Figure 1 is a waveform diagram of exhaust pressure fluctuations due to the conventional and present collective exhaust pipes, Figure 2 is a power characteristic diagram of the engine,
3 to 11 show each embodiment of the present invention, FIGS. 3 and 4 are the first embodiment, FIG. 3 is a front view of the collective exhaust pipe, and FIG. 4 is the same as in FIG. An enlarged cross-sectional view of the main parts, FIG. 5 is a front view of the collective exhaust pipe of the second embodiment, FIG. 6 is a front view of the collective exhaust pipe of the third embodiment, and FIG. 7 is a front view of the collective exhaust pipe of the fourth embodiment. 8 is a front view of the collective exhaust pipe of the fifth embodiment, and FIG. 9 is a front view of the collective exhaust pipe of the fifth embodiment.
The figure is a front view of the collective exhaust pipe of the sixth embodiment, and FIG.
FIG. 11 is a front view of the collective exhaust pipe of the eighth embodiment. 1.12, 13, 25, 30, 31.32.44...
Collective exhaust pipe 2, 3.4, 5, 7, 14゜15.1
6.1.7.20, 21.24.33, 34.35.3
6,41,42.49...exhaust pipe 2b, 3b, 4b,
5b, 14b, 15b, 16b, 17b, 33a, 34
a, 35a, 36a--rear end 6, 18.19.2
2.37, 38.47...Collection part 9...Small hole
'I0.26.27...Sleeve 11.28
．． 29...Chisemba Patent Filer Honda Motor Co., Ltd. Agent Patent Attorney Den Kido-Den Kito-
Production volume Ogawa
Makoto - 1st cause slow 2nd garden Ne (technique〉shi〉echo autumn) Go 6 evil pot 7 cause

Claims (1)

[Scope of Claims] 1. In a collective exhaust pipe of a motorcycle or the like in which the rear ends of a plurality of exhaust pipes connected to each exhaust port of a multi-cylinder engine are collected at a collecting part, the exhaust pipes are directly connected to the collecting part of the exhaust pipes. An appropriate number of small holes are bored in the upstream position, and a sleeve with both ends closed is placed around the outer periphery of the small holes to form a chamber that communicates with the exhaust pipe through the small holes within the sleeve. A collective exhaust pipe structure for motorcycles, etc., characterized by the following. 2. Claim 1, wherein the collective exhaust pipe is a 4-1 type in which four exhaust pipes are collected into one.
Collective exhaust pipe structure for motorcycles, etc. as described in Section 2. 3. The collective exhaust of a motorcycle or the like as set forth in claim 2, wherein at least two adjacent exhaust pipes among the four exhaust pipes are provided with the small hole and the chamber. tube structure. 4. The collective exhaust pipe is a 4-2-1 type in which four exhaust pipes are collected into two and then collected into one at the rear thereof. Collective exhaust pipe structure for motorcycles, etc. as described in item 1. 5. The above-mentioned collective exhaust pipe is a 4-2-2 method in which four exhaust pipes are collected into two, and then these two exhaust pipes are communicated with each other.
A collective exhaust pipe structure for a motorcycle or the like according to claim 1, which is a type. 6. Claim 4, characterized in that the small hole and the chamber are provided in any one set of at least two exhaust pipes among the four exhaust pipes. Or a collective exhaust pipe structure for motorcycles, etc. as described in item 5. 7. Claim 1, wherein the collective exhaust pipe is a 2-1 type in which two exhaust pipes are collected into one.
Collective exhaust pipe structure for motorcycles, etc. as described in Section 2. 8. The collective exhaust pipe structure for a motorcycle or the like according to claim 7, wherein at least one of the two exhaust pipes is provided with the small hole and the chamber.