JPS59138718A - Exhaust system control device for multi-cylinder type internal-combustion engine - Google Patents

Abstract

PURPOSE:To build a resonance chamber compactly by furnishing the resonance chamber in a comparatively large dead space between two exhaust pipes. CONSTITUTION:The first and the second resonance chamber 101 and 102 formed by partitioning the inside of a box are furnished between the first and second exhaust pipes 71 and 72. One side of the third exhaust pipe 73 is provided with the third resonance chamber 103. When the number of revolutions of a crank shaft 1 cannot be risen to a fixed value of high speed, a centrifugal governor 15 maintains an output member 15a at a retired position, and opens the opening and closing valves 121 122 and 123 to connect the first, the second and the third resonance chambers 101, 102 and 103, through to the first, the second, and the thirs exhaust pipes 71, 72 and 73. The natural frequency of the exhaust pipe 12 is kept low to make use of the pulsating efficiency inside the exhaust pipe to improve the suction efficiency at low and medium speed areas. At high speed, the opening and closing valves 121, 122, and 123 are intercepted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-cylinder internal combustion engine, particularly an internal combustion engine in which at least two exhaust pipes extending in substantially the same direction are connected to the engine main body, in which a resonance valve is provided in the middle of the exhaust pipe. The present invention relates to an exhaust system control device that communicates chambers.

Such an exhaust system control device lowers the natural frequency of the exhaust pipe by opening the on-off valve and activating the resonance chamber, thereby reducing the pulsation effect in the exhaust pipe by reducing the exhaust pipe's elongated state. low of.

By adapting it to the medium-speed operating range, and by closing the on-off valve and making the resonance chamber inactive, the natural frequency of the exhaust pipe is increased, and the pulsation inside the exhaust pipe is reduced as if the exhaust pipe were shortened. The effect is adapted to the high-speed operating range of the engine,
This makes it possible to effectively utilize the pulsation effect within the exhaust pipe over the entire operating range to increase the intake efficiency of the engine and improve output performance.

By the way, when such an exhaust system control device is applied to an internal combustion engine of a motorcycle installed in a limited narrow space, it is difficult to arrange a relatively large volume or a zonation chamber. be.

The present invention focuses on the fact that the multi-cylinder internal combustion engine has a relatively large dead space between two exhaust pipes, and utilizes this space for arranging a resonance chamber. It is an object of the present invention to provide the exhaust system control device that can be compactly incorporated into an internal combustion engine.

Hereinafter, an embodiment in which the present invention is applied to a multi-cylinder internal combustion engine of a motorcycle will be described with reference to the drawings.In a cradle-type body frame F of a motorcycle, an internal combustion engine E has its crankshaft 1 connected to a front wheel, a rear wheel Ff, It is mounted parallel to the Wr's axle.

The internal combustion engine E is a V-type three-cylinder, two-stroke, water-cooled engine. That is, the crankcase C that supports the crankshaft 1 is provided with a first cylinder for each cylinder. 2nd and 3rd cylinder blocks B, , B2.

B3 are bound together, and the first and second cylinder blocks B,...
The third cylinder block B3 is arranged approximately horizontally at a constant interval in the axial direction of the crankshaft 1 so as to face the front of the vehicle. It is arranged substantially vertically so as to form an angle and stand up from a central position between them. Water jackets are formed in these cylinder blocks B, B2, and B3, and a radiator R communicating with them is mounted on the front surface of the vehicle body frame F. Therefore, crank case C
The cylinder blocks B, B2, and B3 constitute the engine body.

1st. Second. 3rd cylinder block B, , B2゜B
3) 2+, 2z, 23 are the 1st. Second
Cylinder blocks B, B, and third cylinder block B
3, facing the V-shaped space 3 defined between the two.

1st. 2nd cylinder block B1, B2 exhaust port)
6. ．． 6° is directed downward, and the exhaust port 63 of the third cylinder block B3 is located at the rear of the vehicle.

These exhaust ports 61 are opened toward each other.

62. 63 has the 1st. Second. Third exhaust pipe 71, 7□.

73 is connected. 1st. Second exhaust pipe7. ．． 72 protrudes from the lower surface of the cylinder blocks B, B, passes in front of and below the crankcase C, and is piped to extend rearward along both sides of the vehicle body frame F (Q). The rear body frame F protrudes from the rear surface of the cylinder block B3 and passes above the crankcase C;
The exhaust pipes are bent to one side and lined up above the second exhaust pipe 72, and the downstream side of each exhaust pipe 77, 7□+73 is constituted by an exhaust muffler α1.7α2+7a3.

Now, the exhaust system control device of the present invention incorporated in this engine E will be explained with reference to FIGS. 3 to 5. First.
Second exhaust pipe 71. 72, a first box is formed by partitioning the inside of one box. Second resonance damper 101.
102 is provided, and a third exhaust pipe 73 is provided on one side of the third exhaust pipe 73.
A resonance chamber 103 is provided. These resonance chambers 10. , 10□, 103 are the first. Second.
The branch paths 111, 112, and 113 are connected via the 3rd i12 and ii3, respectively. Second. Third on-off valves 12+, 12t, and 12g are provided, respectively.

The on-off valves 121, 122, 123 in the illustrated example are of a butterfly type, with valve shafts 13+, 132 . The output member 15 (Z@' connection 15a of the centrifugal governor 15 provided here is connected to the shaft 1
It is designed to be slid in the direction of arrow a in FIG. 5 along the arrow a. The interlocking mechanism 14 includes a drive lever 16 that connects the tip end to the output member 15 (Z), and a drive lever 16 that connects the tip end to the output member 15 (Z).
A rotating shaft 17 that fixes and supports the 0 base end, and this rotating shaft 1
1 fixed to the outer end of the first. Second intermediate lever 18. ．． 1
82, the first intermediate lever 18□, and the valve shaft 13 of the first on-off valve 121. a first driven lever 19. fixed to the first driven lever 19. A first interlocking link 20. and the first driven lever 19. and the second driven lever 19□ fixed to the valve shaft 13□ of the second on-off valve 12.0, the second interlocking link 202, the second intermediate lever 182, and the third on-off valve 123.
and a third interlocking link 203 that connects the third driven lever 193 fixed to the valve shaft 133 of the third driven lever 193. Second is the rotation axis. The third interlocking link 202, 203 includes a turnbuckle type tuning device 22 for matching the phases of the three on-off valves 12□, 122, 123.

In addition, if a flexible joint such as a ball joint is used to connect each link and lever in this interlocking mechanism 14, the valve shaft 1
3. ．． 132. 13. This is advantageous in terms of layout because it is not necessary to arrange the rotation axis 11 in parallel.

Next, to explain the operation of this embodiment, the centrifugal governor 15 holds the output member 15α in the retracted position unless the crankshaft 10 rotation speed reaches a specified high speed value, and thereby all the on-off valves 121, 122° 123 and the first
．． Second. Third resonance chamber 10. ．． 102.10
3 in the operating state, i.e. the first. Second. Third exhaust pipe r? 72
I am in communication with +13. As a result, each ]′
11 Trachea 121.

122, 123 are kept relatively low, and each exhaust pipe 121 . 122. The pulsation effect within 123 can be effectively used to improve the suction efficiency in the low and medium speed operating range of the engine E.

When the crankshaft 10 rotation speed increases above the high speed value,
Since the centrifugal governor 15 operates the output member in the direction of the arrow a in FIG. 5, the drive lever 16 is accordingly rotated in the direction indicated by the arrow in FIG. Second intermediate lever 181 .

The rotation of the first intermediate lever 181 in the direction of the arrow is transmitted to the first driven lever 19.182 via the first interlocking link 201. In addition, the first. Second interlocking link 20. ．．
20. is also transmitted to the second driven lever 192 via the first driven lever 192. Second on-off valve 121 .

122 is closed as shown. Also, the second intermediate lever 1
The rotation in the direction of the arrow 82 is transmitted to the third driven lever 193 via the third interlocking link 203, and the third on-off valve 123
Similarly close. Thus, the first. Second. Third resonance chamber 10. ．． 102°103 is the first. Second. Third exhaust pipe 11. It is cut off from γ2 and γ13, respectively, and becomes inactive. As a result, each exhaust pipe 7. The natural frequency of lγ2.13 increases, and the pulsation effect within each exhaust pipe B +12.13 can be effectively used to improve the intake efficiency of the engine E.

Figure 6 shows a modification of the butterfly type on-off valve.
This is typically applied to the first on-off valve 121.

This on-off valve 12. is the valve stem 13. The half portion 12a on the exhaust pipe γ1 side when the on-off valve 121 is open is substantially perpendicular to the axis of the branch passage 11 when the on-off valve 121 is closed. In this way, the valve stem 1
31 can be placed sufficiently close to the exhaust pipe γ1 side, so that when the on-off valve 121 is closed, the branch passage 111
The useless space S left in communication with the exhaust pipe T1 can be significantly reduced.

FIG. 7 shows another embodiment of the present invention applied to the first and second exhaust pipes γ1 and T2, in which a first resonance chamber 1101 is provided outside the first exhaust pipe γ1, and 1. A second resonance chamber 1102 is disposed between the second exhaust pipes γ1.120, and each branch path 1
1.1. ．． 1st to open and close 111□. Second opening/closing intermediary 112
1,112□ is configured in a poppet type. These on-off valves 112. .

1122 valves are connected to each resonance chamber iio.

Bearing 30 provided on the end wall of 1102. ．． 302 in a slidable manner, and the opening/closing valve 11 is attached to the outer end thereof by rotation.
2. ．． 1122 to open and close (slide). Second
Driven lever 19. ．． 192 are connected. These driven levers 19. ．． 19□ is pivotally supported by one stay 31 which is bridged and fixed to both exhaust pipes 11 and γ2. The rest of the structure is the same as that of the previous embodiment, and in FIG. 7, the same reference numerals are given to the parts corresponding to those of the previous embodiment. In this way, the on-off valve 11
If a poppet valve is adopted as 28,112□, the branch path 11. , 11. This makes it possible to significantly shorten the length.

In the present invention, a solenoid valve operated by an electric signal may be used as the opening/closing valve, and in this case, a mechanical interlocking mechanism is not required, and the structure can be simplified. In addition to the engine speed, parameters such as engine intake negative pressure and throttle valve opening may be added to the control signal for the opening/closing valve.

As described above, according to the present invention, a resonance chamber is provided between at least two exhaust pipes extending in substantially the same direction and communicated with at least one of the exhaust pipes via an on-off valve. The space between the exhaust system controllers can be used as an effective space for installing a relatively large-volume zonal chamber without being a dead space, and as a result, the exhaust system control device can be compactly incorporated into the internal combustion engine.

[Brief explanation of drawings]

1 to 5 show a first embodiment of the present invention, in which FIG. 1 is a side view of a motorcycle equipped with an internal combustion engine equipped with a device of the present invention, FIG. 2 is a plan view thereof, and FIG. 4 is an enlarged side view of the internal combustion engine, FIG. 4 is a plan view with the main parts cut away, FIG. 5 is a control system diagram of the device of the present invention, and FIG. 6 is a plan view showing a modification of the on-off valve in the device of the present invention. 7 are partially longitudinal sectional plan views showing a second embodiment of the present invention. B,, B2, B3... Cylinder block which is a part of the engine body, E... Internal combustion engine, 72 +13... Two exhaust pipes extending in substantially the same direction, 101, 102... 1102 . . . a zonation chamber disposed between both exhaust pipes, 12. ．． 12□, 1
12゜...Those on-off valve patent applicant Honda Motor Co., Ltd.

Claims (1)

[Claims] In a multi-cylinder internal combustion engine in which at least two exhaust pipes extending in substantially the same direction are connected to the engine body, a resonance chamber is provided between the two exhaust pipes and communicating with at least one of the exhaust pipes via an on-off valve. An exhaust system control device for a multi-cylinder internal combustion engine.