JP2525394B2 - V-type 2-cycle engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to an intake device for a V-type two-cycle engine equipped with a reed valve device.

(Prior Art) Since the V-type engine can wrap the cylinder in the axial direction, there is an advantage that the pitch width of the cylinder axis center can be made shorter than that of the parallel engine to reduce the overall width of the engine.
The same applies to the two-cycle engine, and in this case, the engine width can be set according to the pitch width required for each independent crank chamber.

However, in a V-type engine having a two-cycle engine with an intake passage opened to the crank chamber and a reed valve device interposed, the reed valve device is likely to interfere with a cylinder or the like. The narrower the pitch width of the cylinder as described above, the narrower the space on the side of the cylinder becomes, and in general, the mission chamber is connected behind the crank chamber. The degree of freedom in arranging the reed valve device is reduced, resulting in different positional relationships with the cylinders. Generally, the intake characteristic changes depending on the position, direction, etc. of the intake passage opening to the crank chamber with respect to the cylinder. Therefore, the V-shaped intake passages have different positional relationships with respect to the cylinder as described above. Then, there is a problem that the output characteristics of both are unbalanced, the smoothness of rotation is lacked, and the output is lowered as a whole.

(Problems to be Solved by the Invention) As described above, in the V-type two-cycle engine equipped with the reed valve device, the cylinder of the intake passage is installed to avoid interference between the reed valve device and the cylinder or the mission case. There is a problem in that the positional relationship is not uniform, the output is reduced, and the advantage of reducing the cylinder pitch width cannot be fully utilized.

The present invention has been made in view of the above circumstances, and has an object to reduce the cylinder pitch width and to arrange the respective intake passages in the cylinder under the same conditions to improve the output performance. An object of the present invention is to provide an intake device for a two-cycle engine.

[Structure of Invention]

(Means for Solving the Problems) In order to achieve the above object, in the intake system for a V-type two-cycle engine according to the present invention, a substantially horizontal front cylinder is continuously provided in one of adjacent crank chambers, and the other is provided in the other crank chamber. In a V-type two-cycle engine in which a vertical rear cylinder is continuously provided and a transmission chamber is provided rearward from the crank chamber, an intake port opened to the crank chamber of the front cylinder and an intake port opened to the crank chamber of the rear cylinder A reed valve device equipped with a reed valve that opens and closes so as to direct intake air only to the crank chamber side is installed at the mouth and the reed valve on the front cylinder side with respect to the vertical plane orthogonal to the crankshaft core. The reed valve on the rear cylinder side is placed vertically so that it opens and closes in the same direction. It is placed horizontally for opening and closing in a direction orthogonal to the crankshaft direction with respect to a flat plane.

(Operation) With this structure, first, since the horizontal width is reduced by vertically installing the reed valve device, one intake passage is provided in the space on the side of the cylinder which is narrowed by reducing the pitch width. Can be set.

Next, by laying the reed valve device laterally, the other intake passage can be set closer to the upper surface of the mission chamber while maintaining a flat shape. Therefore, for a substantially horizontal front cylinder, the reed valve device is provided on the side of the rear cylinder and arranged behind the front cylinder, while for a substantially upright rear cylinder, the reed valve device is arranged behind the rear cylinder. It is possible to improve the output balance in each cylinder and to reduce the cylinder pitch width to make the engine compact by making it possible to make the relationship position and intake condition of both the cylinder and the intake passage the same. You can

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a motorcycle V-type two-cycle engine,
FIG. 2 is a plan view showing the outline of the configuration. A V-type engine is constructed by connecting a front cylinder 2a, which faces forward substantially horizontally, and a rear cylinder 2b, which is substantially upright, to adjacent crank chambers 1a and 1b. Pistons 3a and 3b of both cylinders 2a and 2b are connected to a common crank pin 5 by connecting rods 4a and 4b, respectively. A transmission chamber 7 is connected to the rear of the crank chambers 1a and 1b via a clutch chamber 6.

In the crank chamber 1a of the front cylinder 2a, an intake port 8a is opened in front of the upper portion thereof. 9a indicates a scavenging passage. The intake port 8a is connected to the rear upper carburetor 11a via an immediately upper reed valve device 10a to form an intake passage 12a.

The reed valve device 10a is formed by arranging a plurality of reed valves 14a in parallel on both sides of a valve body 13a which is formed in a V-shape on the downstream side. The passage cross section is set flat, and the longitudinal direction of the flat shape is the front. The cylinder 2a is installed vertically so as to face the cylinder axis direction. That is, the reed valve device 10a is arranged vertically such that its longitudinal axis (the connecting direction of each reed valve) is orthogonal to the crank axis O of the crankshaft. Reed valve 14a of reed valve device 10a
Is opened and closed in the crankshaft direction with respect to a vertical plane orthogonal to the crankshaft axis O. The reed valve device 10a is arranged laterally of the rear cylinder 2b.

The crank chamber 1b of the rear cylinder 2b is provided with an intake passage 12b which opens an intake port 8b and extends rearward at an upper portion thereof, and a carburetor 11b is connected via a reed valve device 10b.

The reed valve device 10b is provided with a valve body 13b and a reed valve 14b similar to the reed valve device 10a, and is installed horizontally in a flat shape whose longitudinal direction is orthogonal to the cylinder axis. The reed valve device 10b is arranged horizontally so that its longitudinal axis extends along the crankshaft direction of the crankshaft. Reed valve 1 of reed valve device 10b
4a is opened / closed in a direction orthogonal to the crankshaft direction with respect to a substantially horizontal plane passing through the longitudinal axis of the reed valve device 10b parallel to the crankshaft axis O.

That is, as shown in FIG. 2, the front cylinder reed valve device 10a is placed vertically and made smaller in the horizontal direction (engine width direction), so that it can be housed laterally of the rear cylinder 2b without interference, and Can be placed behind 2a.
On the other hand, the rear cylinder reed valve device 10b is
It can be placed horizontally behind b and can be brought closer to the upper surface of the mission chamber 7.

In this way, the pitch width of the cylinder can be reduced, and the positional relationship between the front cylinder 2a and the intake passage 12a and the positional relationship between the rear cylinder 2b and the intake passage 12b can be set to be the same.
The outputs of a and the rear cylinder 2b can be balanced.

〔The invention's effect〕

As described above, the reed valve that opens and closes so as to guide the intake air only to the crank chamber side to the intake port that opens to the crank chamber and the intake port that opens to the crank chamber of the rear cylinder according to the present invention. In addition to disposing a reed valve device equipped with, the reed valve on the front cylinder side is arranged vertically such that it opens and closes in the crank axis direction with respect to a vertical plane orthogonal to the crank shaft core, and the reed valve on the rear cylinder side is The front cylinder reed valve device is placed sideways on the side of the rear cylinder because it is placed horizontally to open and close in a direction orthogonal to the crankshaft direction with respect to a substantially horizontal plane that passes through the longitudinal axis of the reed valve device parallel to the crankshaft axis. The same position and intake conditions for the intake passage for the front cylinder and the intake passage for the rear cylinder, and the Characteristics can be balanced, and also compact engine horizontal width by reducing the cylinder pitch, there is an effect that it is possible to improve the engine output performance.

[Brief description of drawings]

FIG. 1 is a side view in which a V-type two-cycle engine for a motorcycle according to an embodiment of the present invention is partially longitudinally cut, and FIG. 2 is a plan view showing the outline of the same configuration. 1a, 1b …… Crank chamber, 2a …… Front cylinder. 2b: Rear cylinder, 7: Mission chamber, 8a, 8b: Intake port, 10a, 1
0b …… Reed valve device, 11a, 11b …… Carburettor, 12
a, 12b …… Intake passage.

Claims (1)

(57) [Claims] 1. A V type in which a substantially horizontal front cylinder is continuously connected to one of adjacent crank chambers, a substantially vertical rear cylinder is continuously connected to the other crank chamber, and a mission chamber is continuously connected rearward from the crank chamber. Front cylinder in a two-cycle engine
Reed valves 14a and 14b that open and close so as to direct intake air only to the crank chambers 1a and 1b, respectively, to the intake port 8a that opens to the crank chamber 1a of 2a and the intake port 8b that opens to the crank chamber 1b of the rear cylinder 2b. The reed valve devices 10a and 10b provided are arranged, and the reed valve 14a on the front cylinder side is arranged vertically so that it opens and closes in the crankshaft direction with respect to a vertical plane orthogonal to the crankshaft core. The valve 14b is arranged horizontally for opening and closing in a direction orthogonal to the crankshaft direction with respect to a substantially horizontal plane passing through the longitudinal axis of the reed valve device 10b parallel to the crankshaft core. Engine intake device.