Internal-combustion engines – Multiple cylinder
Reexamination Certificate
1999-10-01
2001-02-13
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Multiple cylinder
Reexamination Certificate
active
06186099
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-cylinder engine, in which a plurality of cylinder ore rows, each including a plurality of cylinder bores disposed in parallel to each other, are disposed in such a manner as to be perpendicular to a crank shaft disposed substantially in the horizontal direction. Furthermore, a plurality of cylinder heads, each forming combustion chambers between pistons slidably fitted in the cylinder bores and the cylinder heads, are connected to cylinder blocks corresponding to the cylinder bore rows. A plurality of intake passages and a plurality of exhaust passages provided in the cylinder heads are respectively in communication with the combustion chambers.
2. Background Art
A multi-cylinder engine of this type has been known, for example, from Japanese Patent Laid-open No. Sho 61-291760. In the above multi-cylinder engine, since cylinder bores in each cylinder bore row are offset in the axial line direction of a crank shaft, a plurality of intake passages and a plurality of exhaust passages provided for each cylinder head are generally offset in the axial line direction of the crank shaft. This causes a problem since the structure of an intake system to be connected to the intake passages and the structure of an exhaust system to be connected to the exhaust passages becomes complicated.
SUMMARY OF THE INVENTION
In view of the foregoing, the present invention has been made, and an object of the present invention is to provide a multi-cylinder engine having a plurality of cylinder bore rows, which is capable of simplifying the structures of an intake system and an exhaust system.
To achieve the above object, according to a first aspect of the present invention, there is provided a multi-cylinder engine in which a plurality of cylinder bore rows, each cylinder bore row including a plurality of cylinder bores disposed in parallel, are disposed in such a manner as to be perpendicular to a crank shaft disposed substantially in the horizontal direction. A plurality of cylinder heads, each cylinder head forming a combustion chamber between pistons slidably fitted in the cylinder bores and the cylinder head, are connected to cylinder blocks corresponding to the cylinder bore rows. A plurality of intake passages and a plurality of exhaust passages respectively in communication with the combustion chambers are provided in the cylinder heads. Finally, the multi-cylinder engine includes intake passages and the exhaust passages provided in the cylinder heads corresponding to the cylinder bore rows in such a manner that a relative positional relationship between the intake passages and the exhaust passages for one cylinder head in the axial direction of the crank shaft is nearly equal to that between the intake passages and the exhaust passages for the other cylinder head in the axial direction of the crank shaft.
With this configuration, it is possible to simplify the structures of an intake system and exhaust system of the engine.
According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, a cam shaft for opening/closing a plurality of intake valves and a plurality of exhaust valves provided in each of the cylinder heads is provided in the cylinder head. A transmission mechanism for reducing rotational power to half and transmitting the reduced rotational power to the cam shaft is provided between the cam shaft and one end portion of the crank shaft. Furthermore, the outer end openings of the exhaust passages are offset toward the transmission mechanism side from the axial lines of the cylinder bores.
With this configuration, it is possible to dispose an exhaust system connected to the exhaust passages by making effective use of a space between the transmission mechanisms. Therefore, the engine containing the exhaust system is made as compact as possible.
According to a third aspect of the present invention, in addition to the configuration of the second aspect of the present invention, the engine is mounted on the motorcycle in such a manner that a plurality of the cylinder bores are disposed in parallel with the axial lines thereof extending substantially in the horizontal direction, a pair of the cylinder bore rows are oppositely disposed on both of the sides of the crank shaft, and the crank shaft extends in the longitudinal direction of the motorcycle with one end side provided with the transmission mechanism disposed on the front side of the motorcycle. With this configuration, it is possible to sufficiently ensure a space allowing the driver's feet to rest behind the cylinder heads.
According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the present invention, steps for the driver are disposed behind the pair of cylinder heads, respectively. With this configuration, it is possible to easily dispose the steps.
According to a fifth aspect of the present invention, in addition to the fourth aspect of the present invention, the inner end portions of the steps are disposed inwardly from the outer end openings of the exhaust passages in the width direction of the motorcycle, respectively. With this configuration, it is possible to make the projecting amounts of the steps to the left and right sides of the motorcycle as small as possible, and hence to decrease the restriction of the bank angle given by the steps.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 4541370 (1985-09-01), Sakai
patent: 4589382 (1986-05-01), Tsuboi
patent: 4699232 (1987-10-01), Nebu et al.
patent: 5423295 (1995-06-01), Murata et al.
patent: 5740773 (1998-04-01), Ohshige
patent: 5743219 (1998-04-01), Iio et al.
patent: 2 184 164 (1987-06-01), None
patent: 61-291760 (1986-12-01), None
Akagi Takashi
Tosaka Tetsuya
Ali Hyder
Birch & Stewart Kolasch & Birch, LLP
Honda Giken Kogyo Kabushiki Kaisha
Wolfe Willis R.
LandOfFree
Multi-cylinder engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multi-cylinder engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-cylinder engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2588715