JPS6342093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in engines for vehicles, particularly road vehicles such as two-wheeled vehicles and four-wheeled vehicles, and its object is to provide a lightweight and compact multi-cylinder engine.

One embodiment of the present invention illustrated in the drawings will be described below. 1 is offset by X and Y in the front and back and left and right directions, as shown in FIG. 2, while the center lines of the cylinders 2a and 2b remain parallel. In a 2-cycle, 2-cylinder gasoline engine for a motorcycle, the cylinders 2a and 2b have pistons 3a and 2b, respectively.
The pistons 3a and 3b are fitted to connect rods 4a and 4, respectively, so as to be slidable up and down.
It is connected to each crank 5a, 5b in the crank chambers 6a, 6b via b.

However, among the cylinders 2, the rear cylinder 2b with respect to the front cylinder 2a is set upwardly at a higher position by Z, as shown in FIG.

Further, the crank chamber 6 includes both the cylinders 2a and 2, as shown in FIGS. 3 to 5.
Parallel plane 1 along the front-back direction passing through each center line of b
It is vertically divided into three parts 7, 8, and 9 by 0a and 10b.

Furthermore, as shown in FIG. 2, an air supply system device 13 consisting of a reed valve 11, which is a type of one-way valve, a carburetor 12, etc., is provided behind each of the cylinders 2. In addition, exhaust port 1 is installed in front of both cylinders 2.
4, an exhaust system device 16 consisting of an exhaust passage 15, etc.
The exhaust system device 16b is placed closer to the front cylinder 2a of the rear cylinder 2b, which is one cylinder, and the air supply system is placed closer to the rear cylinder 2b of the front cylinder 2a, which is the other cylinder. A device 14b is arranged.

Furthermore, both the cylinders 2a, 2b and the crank chambers 6a, 6b are connected to the main scavenging passages 17a, 1.
7b and sub-scavenging air passages 18a and 18b, and the intake and exhaust operations are similar to those of a normal crank case scavenging type engine, but other scavenging systems may be used.

Crank gears 19a and 19b are fitted integrally to the right side (front side in FIG. 1) of both cranks 5a and 5b at different levels, and the front crank gear 19a is connected to the primary shaft 2.
The rear crank gear 19b is indirectly meshed and connected to the second gear 22 of the primary shaft 20 via the idle gear 24, and the crank gear 19a, the first gear 21, and the crank The gear 19b and the second gear 22 are each formed to have the same dimensions, so that both cranks 5a, 5b rotate at the same rotational speed in mutually opposite directions.

Further, the clutch drive gear 23 of the primary shaft 20 is meshed with a flywheel gear 25 that also serves as a flywheel.
Transmission 34 has the same center of rotation as
A multi-plate friction clutch 26 is interposed between the flywheel gear 25 and the main shaft 35, and the clutch 26 is connected to a disk 27 integral with the flywheel gear 25 and the main shaft 35. The disk 2 is integrated with a key or spline-coupled center clutch 29.
7 and a large number of disks 27 and plates 28 are connected to a center clutch 29.
A clutch lifter 30 that clamps the clutch in cooperation with the clutch lifter 30, a coil spring 31 that presses the clutch lifter 30 against the center clutch 29, and a lift rod 32 that pushes the center clutch 29 to the left (upward in the drawing) with a clutch cam 33 and disconnects the clutch. If the cam ridge of the clutch cam 33 is not facing leftward (upward in the drawing) as shown in FIG. 3, the spring force of the coil spring 31 sets the clutch 26 in the connected state, When the cam ridge 33 faces leftward, the clutch 26 is set to the disconnected state.

Further, in the transmission 34, the main shaft 35 and the countershaft 40 are shifted to a multi-stage gear ratio by multi-stage axial movement of gear shift forks 37, 39 operated by two gear shift shafts 36, 38. It is becoming more and more common.

Furthermore, a chain drive sprocket 41 is integrally connected to the countershaft 40, and the chain drive sprocket 41 is connected to a chain sprocket of a rear wheel (not shown) via a chain.

However, the right casing 9 (lower in the drawing)
An auxiliary cover 42 is detachably attached to cover the crank gear 19b, the second gear 22 of the primary shaft 20, and the idle gear 24.

Since the illustrated embodiment is configured as described above, when the engine 1 is started with a starter (not shown), if the front crank 5a rotates clockwise, the rear crank 5b rotates in the opposite direction. It rotates at the same speed as the front crank 5a.

In this state, the rotational torque of the front crank 5a is applied to the crank gear 19a, the first gear 21, the primary shaft 20, and the clutch drive gear 2.
3. The transmission is transmitted to the main shaft 35 of the transmission 34 via the flywheel gear 25 and the multi-plate friction clutch 26, and is reduced to an appropriate gear ratio by the transmission 34 and transmitted to the chain sprocket 41, as shown in the figure. The rear wheel is driven through the chain that is not connected to the rear wheel chain and the rear wheel chain sprocket, and the motorcycle is able to run.

Further, the rotational torque of the rear crank 5b is transmitted to the primary shaft 20 via the crank gear 19b, the idle gear 24, and the second gear 22, and thereafter is transmitted to the rear wheel in the same manner as the torque transmission of the front crank 5a. It will be done.

Further, as the engine 1 operates, the carburetor 12a, reed valves 11a, 11b, and crank chambers 19a, 19b of the rear air supply system devices 13a, 13b are
and scavenging passages 17a, 17b, 18a, 18b
The air-fuel mixture is taken into the cylinders 2a and 2b through the cylinders 2a and 2b, respectively.
The combustion gas inside is scavenged and the exhaust ports 14a, 14 of the exhaust system devices 16a, 16b located in the front are scavenged.
b and exhaust passages 15a and 15b.

In this way, the air supply system devices 13a, 13b of both cylinders 2a, 2b are located at the rear of the engine 1, and the exhaust system devices 16a, 16b are located at the front of the engine 1, and are arranged parallel to each other. , the air supply system device 13 and the exhaust system device 16 of the engine 1 can be rationally combined and made compact.

Furthermore, in the embodiment, the two cylinders 2a and 2b are arranged in a staggered manner in the front, back, left and right, as shown in FIG. 2, so that the front, back, left and right dimensions of the engine 1 as a whole can be reduced.

Further, as shown in FIG. 1, since the cylinder 2b located at the rear by Z is located above the front cylinder 2a, the longitudinal dimension of the engine 1 as a whole can be further reduced.

Furthermore, the transmission 34 connects the crank gear 19b to the second gear 22 of the primary shaft 20 via the idle gear 24.
Since the main shaft 35 of the engine 1 can be moved forward, the overall dimensions of the engine 1 and transmission 34 can be made compact.

Furthermore, the front crank gear 19a is meshed with the first gear 21 of the primary shaft 20, the rear crank gear 19b is meshed with the second gear 22 of the primary shaft 20 via the idle gear 24, and the auxiliary cover 42 is connected to the outside thereof. Since the auxiliary cover 42 is removed and the idle gear 24 is removed, the crank angle of the front cylinder 2a and the rear cylinder 2b can be changed as appropriate. You can easily change the explosion timing.

In addition, since the crank chamber 6 is vertically divided into three by planes 10a and 10b that pass through the center line of both pistons 2a and 2b and are perpendicular to the crankshaft, the crank 5
It is no longer necessary to position the axes a and 5b, the primary shaft 20, the main shaft 35 of the transmission 34, and the countershaft 40 on the same plane. The engine 1 can be made sufficiently compact, the engine 1 can be easily processed, and the engine 1 is lightweight but has high rigidity.

In the embodiment described above, there are two cylinders, but it is also possible to have two or more cylinders, and in the case of an odd number, bilateral symmetry can be obtained.

Further, in the embodiment described above, the air supply system device is placed at the rear and the exhaust system device is placed at the front, but this arrangement may be reversed.

As described above, the present invention configures a multi-cylinder engine by arranging at least two cylinders offset from front to back and left to right, so that the front and rear and left and right dimensions of the engine are shortened and the engine is made lighter. Can be made compact.

Further, in the present invention, in the multi-cylinder engine, the exhaust system device of the other cylinder is disposed on the side of the one cylinder adjacent to the other cylinder, and the exhaust system device of the other cylinder is disposed on the side of the other cylinder adjacent to the one cylinder. Since the air supply system device is arranged, the exhaust system device can be rationally placed on one side of the engine, and the air supply system device can be rationally placed on the other side of the engine, and these parts can also be made more compact. Can be done.

Although the present invention has been described above in detail with respect to the embodiments shown in the drawings and the embodiments not shown in the drawings, the present invention is not limited to such embodiments and can be modified without departing from the spirit of the invention. The design can be freely modified as necessary.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view illustrating an embodiment of a multi-cylinder engine according to the present invention, and FIGS. 2 to 4 are cross-sectional views taken along lines -, -, and - in FIG. 1, respectively. It is a front view. 1...Engine, 2...Cylinder, 3...Piston, 4...Connecting rod, 5...Crank, 6...Crank chamber, 7, 8, 9...Crankcase block, 10...Dividing surface , 11... reed valve, 12... carburetor, 13... air supply system device, 14... exhaust port, 15... exhaust passage, 1
6...Exhaust system device, 17...Main scavenging path, 18
...Sub scavenging passage, 19...Crank gear, 20...
...Primary shaft, 21...1st gear, 2
2... Second gear, 23... Clutch drive gear, 24... Idle gear, 25... Flywheel gear, 26... Multi-plate friction clutch, 27... Disc, 28... Plate, 29... Center clutch , 30...Clutch lifter, 31...Coil spring, 32...Lifter rod, 33...Clutch cam, 34...Transmission, 35
...Main shaft, 36...Gear shift shaft, 37...Gear shift fork, 38...Gear shift shaft, 39...Gear shift fork,
40... Countershaft, 41... Chain drive sprocket, 42... Auxiliary cover.

Claims (1)

[Claims] 1. In a multi-cylinder engine in which at least two cylinders are arranged offset from front to back and left to right, if the exhaust system device for one cylinder is arranged on the side of one cylinder adjacent to the other cylinder, A multi-cylinder engine characterized in that an air supply system for the one cylinder is disposed on a side adjacent to the one cylinder.