Direct fuel injection

Claim 2

A spark ignited internal combustion engine fuel injection system wherein a metered quantity of fuel entrained in a gas is delivered directly to a combustion chamber of the engine through a selectively openable nozzle, said nozzle comprising a nozzle body having an internal cavity wherein the metered quantity of fuel is entrained in the gas, a port in the nozzle body communicating the cavity with an external face of said body which in use is located within the engine combustion chamber, an internal annular seal face located in said port between the cavity and said external face of said body, a valve member having an external annular seal face adapted to normally sealably engage said internal seal face to close said port, means operable to selectively move said valve member relative to the port to a port open position, an annular internal terminal surface in the port extending from said internal seal face to said external face of the body, an annular external terminal surface on the valve member extending from said external seal face and defining with said internal terminal surface in the port when the valve member is in the open position an annular passage having in radial section an included angle between the internal and external terminal surfaces of 0° to 40° and with the internal terminal surface in the radial section inclined to the passage axis at an angle not greater than about 15°, the passage being of maximum width at the external surface of the body.

Claim 3

A fuel injection system as claimed in claim 1 wherein the external annular terminal surface on the valve member is substantially cylindrical.

Claim 4

A fuel injection system as claimed in claim 1 or 2 wherein the internal annular terminal surface in the port is of conical form divergent in the direction of flow through the passage with an included angle of not more than about 20°.

Claim 5

A fuel injection system as claimed in claim 1 wherein the external annular terminal surface on the valve member is of conical form convergent in the direction of flow through the passage with an included angle of not more than 10°.

Claim 6

An internal combustion engine operating on the two stroke cycle having a fuel injection system as claimed in any one of claims 1 or 2.

Claim 7

A fuel injection system as claimed in claim 4 wherein when the valve member is in the port open position, the valve member does not project beyond said external face of the nozzle body.

Claim 8

A spark ignited internal combustion engine operating on the two stroke cycle and having a piston reciprocating in an engine cylinder defining a variable volume combustion chamber, and a cavity in said piston forming part of said combustion chamber, said engine having a fuel injection system wherein a metered quantity of fuel entrained in a gas is delivered directly to a combustion chamber of the engine through a selectively openable nozzle, said nozzle comprising a nozzle body having an internal cavity wherein the metered quantity of fuel is entrained in the gas, a port in the nozzle body communicating the cavity with an external face of said body which in use is located within the engine combustion chamber, an internal annular seal face located in said port between the cavity in said external face of said body, a valve member having an external annular seal face adapted to normally sealable engage said internal seal face to close said port, means operable to selectively move said valve member relative to the port to a port open position, an annular internal terminal surface in the port extending from said internal seal face to said external face of the body, an annular external terminal surface on the valve member extending from said external seal face and defining with said internal terminal surface in the port when the valve member is in the open position in an annular passage having in radial section an included angle between the internal and external terminal surface of 0° to 40° and with the internal terminal surface in the radial section inclined to the passage axis at an angle not greater than about 15°, the passage being of maximum width at the external surface of the body, the nozzle located so that at least part of the fuel issuing from the annular passage into the combustion chamber is directed to enter said cavity in the piston.

Claim 9

A spark ignited internal combustion engine operating on the two stroke cycle and having a piston reciprocating in an engine cylinder defining a variable volume combustion chamber, and a cavity in said piston forming part of said combustion chamber, said engine having a fuel injection system wherein a metered quantity of fuel entrained in a gas is delivered directly to a combustion chamber of the engine through a selectively openable nozzle, said nozzle comprising a nozzle body having an internal cavity wherein the metered quantity of fuel is entrained in the gas, a port in the nozzle body communicating the cavity with an external face of said body which in use is located within the engine combustion chamber, an internal annular seal face located in said port between the cavity in said external face of said body, a valve member having an external annular seal face adapted to normally sealable engage said internal seal face to close said port, means operable to selectively move said valve member relative to the port to a port open position, an annular internal terminal surface in the port extending from said internal seal face to said external face of the body, an annular external terminal surface on the valve member extending from said external seal face and defining with said internal terminal surface in the port when the valve member is in the open position in an annular passage having in radial section an included angle between the internal and external terminal surface of 0° to 40° and with the internal terminal surface in the radial section inclined to the passage axis at an angle not greater than about 15°, the passage being of maximum width at the external surface of the body, the nozzle located so that at least part of the fuel issuing from the annular passage into the combustion chamber is directed to enter said cavity in the piston.

Claim 10

An internal combustion engine as claimed in claim 7, wherein the nozzle is located so that the internal and external annular terminal surfaces are co-axial with the cavity in the piston.

Claim 11

An internal combustion engine as claimed in claim 7 or 8, wherein the cavity in the piston is of cylindrical form.

Claim 12

An internal combustion engine as claimed in claim 7 or 8, wherein there is provided means to control the timing of the fuel delivery through said nozzle into the combustion chamber in relation to the cylinder cycle, said means being adapted to vary said timing of said fuel delivery in relation to engine load over at least part of the engine load range so that within that engine load range the timing of the fuel delivery is later for low loads than for high loads in said load range, whereby at said low loads a greater proportion of fluid is delivered into said cavity in the piston than at said high loads in said load range each cycle of the engine.

Claim 13

An internal combustion engine as claimed in claim 10 wherein the means to control the timing of the fuel delivery is arranged so that the major part of the fuel is delivered into the combustion chamber during said low loads is delivered into said cavity in the piston.

Claim 14

An internal combustion engine as claimed in claim 10, wherein the cavity in the piston is of cylindrical form.

Claim 15

An internal combustion engine as claimed in claim 7 or 8, wherein the external annular terminal surface on the valve member is of conical form convergent in the direction of flow through the passage with an included angle of not more than 10°.

Claim 16

An internal combustion engine having a fuel injection system as claimed in claim 4.

Claim 17

The combination claimed in claim 7, wherein the engine is an outboard marine engine operating on the two stroke cycle.

Claim 18

The combination claimed in claim 7, wherein the engine is an automobile engine operating on the two stroke cycle.