JP2797332B2 - Exhaust control device - Google Patents

Description

The present invention relates to an exhaust control device provided in an exhaust pipe of a multi-cylinder engine mounted on a motorcycle or the like.

(Prior Art) Generally, in a multi-cylinder engine, an exhaust device in which a plurality of exhaust pipes led from each cylinder are assembled and connected to an exhaust silencer is used. In this device, by utilizing the pulsation of the exhaust pressure generated in each exhaust pipe, the intake efficiency of the engine,
It is known that the output of the engine can be improved. In general, the output of a motorcycle is improved in a high rotation range, and the natural frequency of the exhaust pipe is set accordingly.

(Problems to be Solved by the Invention) However, when the output is improved in the high rotation speed range, the negative effect due to the pulsation of the exhaust becomes large in the low and medium speed ranges,
There is a disadvantage that a valley portion of the output occurs.

The present invention has been made in view of such circumstances, and provides an exhaust control device capable of improving output over the entire high and low speed range without generating a valley portion in low to medium speed ranges. With the goal.

[Configuration of the invention]

(Means for Solving the Problems) The present invention relates to a multi-cylinder engine in which a plurality of exhaust pipes led from each cylinder are assembled and connected to an exhaust silencer. While providing a communication hole that communicates the exhaust passage with those partition walls,
An exhaust passage crossing type integrally having a partition valve portion that moves along the partition wall portion to open and close the communication hole, and a passage adjustment valve portion that protrudes and retracts in the exhaust passage and expands / contracts the passage cross-sectional area. One valve mechanism is provided, and the valve mechanism rotates around an axis parallel to the communication hole to close the communication hole at the same time as the narrowing of the exhaust passage, and at the same time, expands the exhaust passage. It is set to open the communication hole.

(Operation) In the high engine speed range, the exhaust passages of the respective exhaust pipes are communicated with each other by a valve mechanism, and the cross-sectional area of each exhaust passage is enlarged. By the communication of the exhaust passage, the output can be improved by effectively using the interference of the exhaust gas, and at the same time, the increase in the cross-sectional area of the exhaust gas passage can cope with an increase in the amount of exhaust gas.

Further, in a low-medium rotation range of the engine, a valve mechanism shuts off the exhaust passages of the respective exhaust pipes and reduces the cross-sectional area of the exhaust passages. The cutoff between the exhaust passages can reduce the negative effect due to the exhaust pulsation to improve the output, and at the same time, can cope with the decrease in the exhaust amount by reducing the passage cross-sectional area of the exhaust passage.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 3 shows the appearance of a motorcycle provided with the exhaust control device according to the present invention, FIGS. 1, 2 and 4 show the structure of the exhaust control device, and FIGS. The effect is shown.

As shown in FIGS. 3 and 4, in this embodiment, a plurality of exhaust pipes 3 guided from each cylinder of a four-cylinder engine 2 mounted on the motorcycle 1 are gathered in a gathering chamber 4 and an exhaust silencer 5 is provided. Connected to

In this arrangement, the collecting portion of the exhaust pipe 3 is arranged vertically and horizontally adjacent to each other, and the valve casing 6 constituting a part of the exhaust pipe 3 is connected to that portion. As shown in FIGS. 1 and 2, the valve casing 6 has substantially the same shape as the gathering portion of the exhaust pipe 3, and the upper exhaust passages 3a and 3b adjacent to each other on the left and right and the lower exhaust passage 3 adjacent on the left and right. Exhaust passage 3c, 3d
It has a communication hole 7 that communicates with each other at a partition wall portion. The valve casing 6 is provided with a valve mechanism 8 having a function of opening and closing the communication hole 7 and a function of expanding and reducing the cross-sectional area of the exhaust passages 3a, 3b, 3c, 3d.

That is, the valve mechanism 8 is provided with a rotating operation shaft 9 parallel to the communication hole 7.
And a valve body 10 integrally attached to the shaft 9. The shaft 9 is provided with bearings 11, 12 on the valve casing 6,
It is attached via a seal member 13, a support member 14, a gasket 15, and the like, and is rotated by a pulley 16 at an end. Valve body
Reference numeral 10 denotes a partition valve portion 17 which moves along the communication hole 7 to open and close it, and a road adjustment valve portion 18 which protrudes and retracts in the exhaust passages 3a, 3b, 3c, 3d to expand and contract the cross-sectional area of the passage. doing.

1 and 2, the valve body 10 rotates by a predetermined angle in a low-medium engine speed region, and the passage adjusting valve unit 18 is placed in the exhaust passages 3a, 3b, 3c, 3d. The communication hole 7 is closed by the gate valve portion 17 while the passage cross-sectional area is reduced by protruding.

Therefore, in the low and middle rotation range of the engine, the valve mechanism 8 shuts off the exhaust passages 3a, 3b, 3c, 3d and reduces the cross-sectional area of the exhaust passages 3a, 3b, 3c, 3d. By shutting off the exhaust passages 3a, 3b, 3c, 3d, a negative effect due to exhaust pulsation is reduced to improve output, and at the same time, by reducing the passage cross-sectional area of the exhaust passages 3a, 3b, 3c, 3d, It can cope with a decrease in the displacement.

In the high engine speed region, the valve element 10 rotates to a state parallel to the axis of the exhaust passage as shown in FIGS. 5 and 6, and the passage adjusting valve portion 18 retreats from the exhaust passages 3a, 3b, 3c, 3d. As a result, the cross-sectional area of the passage increases, and the gate valve portion 17 moves so as to open the communication hole 7, so that the upper exhaust passages 3a and 3b and the lower exhaust passages 3c and 3d communicate with each other.

Accordingly, in the high engine speed range, the exhaust passages 3a, 3b, 3c, 3d are communicated with each other by the valve mechanism 8, and the cross-sectional area of each of the exhaust passages 3a, 3b, 3c, 3d is enlarged. The communication between the exhaust passages 3a, 3b, 3c, and 3d makes it possible to effectively utilize the interference of the exhaust to improve the output, and at the same time, to improve the exhaust passages 3a, 3
The increase in the cross-sectional area of the passages b, 3c, and 3d can cope with an increase in the displacement.

According to the configuration of such an embodiment, as shown by a white point A in FIG. 7, a composite characteristic of the output characteristic a of the low rotation type and the output characteristic b of the high rotation type is obtained, and the valley of the output is obtained. Part c can be removed. That is, in the high engine speed region, the exhaust passages 3a, 3b, 3c, 3d of the exhaust pipe 3 are communicated by the valve mechanism 8 and the passage cross-sectional area of each of the exhaust passages 3a, 3b, 3c, 3d is enlarged. The output can be improved by effectively utilizing the interference, and an increase in the displacement can be dealt with. In addition, in the low-medium rotation range of the engine, the exhaust passages 3a, 3b, 3c, 3d of the exhaust pipe 3 are made independent by the valve mechanism 8 and the cross-sectional area of each exhaust passage 3a, 3b, 3c, 3d is reduced. Thus, the negative effect due to the exhaust pulsation is reduced to improve the output.

〔The invention's effect〕

As described above, according to the exhaust control apparatus of the present invention, there is an effect that the output can be improved over the entire high and low speed range without generating a trough portion in the low and medium speed range of the engine. You.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an exhaust control apparatus according to the present invention, FIG. 2 is a transverse sectional view showing the embodiment, and FIG. 3 is an automatic control system equipped with the exhaust control apparatus according to the embodiment. 4 is an enlarged perspective view showing an exhaust pipe portion of the motorcycle, FIGS. 5 and 6 are cross-sectional views showing the operation of the embodiment, and FIG. 7 is a view of the embodiment. It is a characteristic diagram which shows an effect | action. 2 ... engine, 3 ... exhaust pipe, 3a, 3b, 3c, 3d ... exhaust passage, 5 ... exhaust silencer, 7 ... communication hole, 8 ... valve mechanism.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 7/10 F02B 27/06

Claims (1)

(57) [Claims] 1. A multi-cylinder engine in which a plurality of exhaust pipes guided from respective cylinders are assembled and connected to an exhaust silencer. While providing a communication hole that communicates with
An exhaust passage crossing type integrally having a partition valve portion that moves along the partition wall portion to open and close the communication hole and a passage adjustment valve portion that protrudes and retracts in the exhaust passage and expands / contracts the passage cross-sectional area. One valve mechanism is provided, and the valve mechanism rotates around an axis parallel to the communication hole to close the communication hole at the same time as the narrowing of the exhaust passage, and at the same time, expands the exhaust passage. An exhaust control device, wherein the communication hole is set to be open.