Direct injection two-stroke engine
1 Assignment
0 Petitions
Accused Products
Abstract
A two-stroke engine having a combustion chamber (12), a cylinder (6) having an exhaust port (9) on which is centered a first diametral plane of the cylinder, a piston (4), a cylinder head (10) fitted with a sparkplug (11) on the same side as the exhaust port relative to a second diametral plane (P2-P2) perpendicular to the first, and an injector (20) adapted to spray a jet of fuel into the combustion chamber, which is on the other side of the second diametral plane, the jet injection axis (P) being at an angle α from 30° to 70° to a transverse plane (T-T) of the cylinder and an angle β from +45° to −45° to the first diametral plane. The diffuser angle γ of the jet is from 15° to 75°, injection of fuel begins when the crankshaft (3) is from 45° to 20° ahead of closure of the exhaust port (9), and the injection pressure and the orientation of the jet injection axis are determined as a function of the flow of the gases to obtain a stoichiometric air/fuel mixture in the region of the sparkplug at the moment of ignition.
-
Citations
11 Claims
-
1-8. -8. (canceled)
-
9. A direct-injection two-stroke engine having a cubic capacity of 125 cc at most and a combustion chamber delimited by:
-
a cylinder having a longitudinal axis, at least one inlet port and at least one exhaust port a piston having a substantially flat crown and moved along the longitudinal axis by a connecting rod connected to a crankshaft; and a cylinder head provided with a sparkplug and an injector adapted to spray a jet of liquid fuel under pressure into said combustion chamber along a jet injection axis and with a jet diffuser angle γ
from 15°
to 75°
,wherein said combustion chamber has a first diametral plane containing said longitudinal axis of the cylinder and centered on said exhaust port and a second diametral plane perpendicular to said first diametral plane, said sparkplug is in a first portion of said cylinder head extending from the second diametral plane towards said inlet port, said injector is disposed in a bore in said cylinder head oriented along a determined axis and in said first diametral plane in a second portion of the cylinder head complementary to said first portion, and said jet injection axis is at a first angle α
from 30°
to 70°
to a transverse plane of said cylinder and a second angle β
from +45°
to −
45°
to said first diametral plane,wherein said jet injection axis is at an non-zero angle δ
to said cylinder head bore determined axis,wherein a control system is adapted to command the commencement of injection of fuel when said crankshaft is at an angular position from 45°
to 20°
ahead of the angular position of closure of said exhaust port, andwherein the fuel injection pressure and the orientation of said jet injection axis are determined as a function of the flow of the gases in said combustion chamber to obtain a substantially stoichiometric air/fuel mixture in the region of said sparkplug at the moment of ignition. - View Dependent Claims (10, 11)
-
Specification