Internal-combustion engines – Combustion chamber means having fuel injection only – Injection of fuel onto igniter – deflector – heater – or atomizer
Reexamination Certificate
2000-03-27
2001-09-18
Argenbright, Tony M. (Department: 3747)
Internal-combustion engines
Combustion chamber means having fuel injection only
Injection of fuel onto igniter, deflector, heater, or atomizer
C123S305000
Reexamination Certificate
active
06289870
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a direct fuel injection-type spark-ignition internal combustion engine.
2. Description of the Related Art
There has heretofore been known a stratified charge combustion produced by directly injecting fuel into a cylinder to form a mixture (hereinafter referred to as combustible mixture) that can be favorably ignited only in the vicinity of a spark plug, at the ignition timing, to burn a lean mixture in the cylinder as a whole. To carry out the stratified charge combustion, in general, the fuel injection valve injects fuel in the latter half of the compression stroke. It is intended that the thus injected fuel proceeds into a concave combustion chamber formed in the top surface of the piston, is vaporized by robbing heat from the wall surfaces of the combustion chamber, is deflected by the shape of the combustion chamber toward the spark plug, and forms a combustible mixture near the spark plug.
In the direct fuel injection-type spark-ignition internal combustion engine for performing the stratified charge combustion, in general, the spark plug is arranged nearly at the center in the upper part of the cylinder, the fuel injection valve is arranged in the periphery in the upper part of the cylinder, and the combustion chamber extends from nearly the central portion of the top surface of the piston toward the periphery of the top surface of the piston on the side of the fuel injection valve, and includes the bottom wall, the spark plug side wall, and the fuel injection valve side wall. Fuel injected into the combustion chamber collides with the bottom wall of the combustion chamber, thereafter proceeds toward the spark plug side wall along the bottom wall, and thereafter is deflected toward the spark plug by the spark plug side wall.
In order to favorably vaporize the fuel utilizing heat of the wall surface of the combustion chamber, the distance for moving fuel along the wall surface of the combustion chamber must be lengthened so that the injected fuel stays in contact with the wall surface of the combustion chamber for an extended period. In order to realize this without changing the shape of the combustion chamber, it has been proposed to inject fuel at a relatively large acute angle with respect to the horizontal plane. This makes it possible to move the position where fuel collides with the bottom wall away from the spark plug side wall of the combustion chamber, while maintaining the same position of injection hole of the fuel injection valve, as compared with when the fuel is injected at a relatively small acute angle with respect to the horizontal plane, and, hence, to extend the distance the fuel moves on the bottom wall of the combustion chamber.
When the fuel is injected at a relatively large acute angle with respect to the horizontal plane, however, fuel collided with the bottom surface is diverted and all of fuel does not proceed toward the spark plug side wall along the bottom surface; i.e., fuel only partly proceeds toward the fuel injection valve side wall along the bottom surface.
Accordingly, an amount of the combustible mixture formed near the spark plug via the spark plug side wall of the combustion chamber is decreased, and the engine output is not produced as intended. Besides, the mixture formed by fuel proceeding toward the fuel injection valve side wall of the combustion chamber cannot be favorably burned, and unburned fuel may be emitted in increased amounts.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a direct fuel injection-type spark-ignition internal combustion engine in which, when stratified charge combustion is carried out, fuel is injected toward the bottom wall of a cavity formed in the top surface of a piston so as to proceed mainly toward the spark plug side wall along the bottom wall of the cavity, is deflected by the spark plug side wall and is led to near the spark plug, and in which even when the fuel that has collided with the wall surface of the cavity is diverted toward the spark plug side wall of the cavity and toward the fuel injection valve side wall, all of fuel injected into the cavity is burned as the combustible mixture to produce the engine output as intended.
According to the present invention, there is provided a direct fuel injection-type spark-ignition internal combustion engine comprising a spark plug, a fuel injection valve and a cavity formed in the top surface of the piston, said cavity having a bottom wall, a spark plug side wall and a fuel injection valve side wall, the fuel injection valve injecting fuel toward the bottom wall of the cavity in stratified charge combustion, the fuel mainly proceeding toward the spark plug side wall of the cavity along the bottom wall, being deflected by the spark plug side wall and being led to the vicinity of the spark plug, wherein the spark plug side wall of the cavity is provided with a deflecting portion inclined toward the inside of the cavity, a first part of the deflecting portion provided on both sides of the spark plug side wall functions to lead the fuel to the vicinity of the spark plug, and a second part of the deflecting portion provided on the central portion of the spark plug side wall functions to lead the fuel to a region neighboring the side of the fuel injection valve from the vicinity of the spark plug.
According to the present invention, there is provided another direct fuel injection-type spark-ignition internal combustion engine comprising a spark plug, a fuel injection valve and a cavity formed in the top surface of the piston, the cavity having a bottom wall, a spark plug side wall and a fuel injection valve side wall, the fuel injection valve injecting fuel toward the bottom wall of the cavity in the stratified charge combustion, the fuel mainly proceeding toward the spark plug side wall of the cavity along the bottom wall, being deflected by the spark plug side wall and being to the vicinity of the spark plug, wherein, at least at a position where the fuel comes into collision, the bottom wall of the cavity is so inclined as to be deeper on the side of the fuel injection valve side wall than on the side of the spark plug side wall, and an extended plane of the central portion of the fuel injection valve side wall intersects the upper wall of the cylinder at an obtuse angle on the side of the spark plug.
The present invention will be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.
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patent: 5720253 (1998-02-01), Matoba et al.
patent: 5775288 (1998-07-01), Suzuki et al.
patent: 6035823 (2000-03-01), Koike et al.
patent: 0 519 275 A1 (1992-12-01), None
patent: A-9-158736 (1997-06-01), None
Hattori Fumiaki
Kanda Mutsumi
Kashiwagura Toshimi
Shimizu Rio
Argenbright Tony M.
Oliff & Berridg,e PLC
Toyota Jidosha & Kabushiki Kaisha
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