Methods of introducing fuel into an internal combustion engine and devices therefor

Claim 2

In the combustion of fuel in an internal combustion engine which comprises at least one cylinder provided with an air inlet and an exhaust and wherein compressed air ignites the fuel, the gas expands doing work and exhaust gases are removed during the cycle of suction stroke, compression stroke, power stroke and exhaust stroke, a method of introducing fuel into the combustion zone at or near the end of each compression stroke in said cylinder, comprising the steps of introducing fuel into a fuel chamber located in the proximity of the combustion zone in said cylinder, in an amount adequate for one power stroke, when the communication between said combustion zone and said fuel chamber is closed, opening the communication between said fuel chamber and the combustion zone at the end of each compression stroke in said cylinder to admit compressed air from the said cylinder into said fuel chamber, mixing said compressed air with the fuel, ejecting the mixture into the combustion zone, letting the mixture ignite and keeping said communication continuously open up to and during at least the initial portion of the following suction stroke to secure optimal pressure drop prior to introduction of another portion of fuel, while securing evacuation of gases from said fuel chamber and while establishing a current of fresh cooling air in the proximity of the communication between said fuel chamber and said combustion zone.

Claim 3

A combustion engine which comprises at least one cylinder, air inlet means and exhaust means, a fuel chamber in the proximity of the combustion chamber in said cylinder, a passageway between said fuel chamber and said combustion chamber, valve means operable to open and close said passageway, a fuel source with means for introducing a fuel portion into said fuel chamber for each power stroke in the cylinder, said valve means being adapted to open and close said passageway only once for each cycle of the engine such that said passageway is opened at the end of each compression stroke and closed before the beginning of each subsequent compression stroke, said fuel introducing means being adapted to introduce fuel into said fuel chamber when the passageway between said fuel chamber and said combustion chamber is closed, said valve means when open being adapted to introduce hot compressed air from the combustion chamber into the fuel chamber and to deliver the fuel/air mixture to the combustion chamber under such pressure and temperature conditions that the mixture self-ignites, said valve means being adapted to be kept continuously open up to and during at least the initial portion of the suction stroke whereby evacuating fuel chamber before each introduction of a new fuel portion.

Claim 4

A combustion engine which comprises at least one cylinder, air inlet means and exhaust means, a fuel chamber in the proximity of the combustion chamber in said cylinder, a passageway between said fuel chamber and said combustion chamber, valve means operable to open and close said passageway, a fuel source with means for introducing a fuel portion into said fuel chamber for each power stroke in the cylinder, said valve means being adapted to open and close said passageway only once for each cycle of the engine such that said passageway is opened at the end of each compression stroke and closed before the beginning of each subsequent compression stroke, said fuel introducing means being adapted to introduce fuel into said fuel chamber when the passageway between said fuel chamber and said combustion chamber is closed, said valve means when open being adapted to introduce hot compressed air from the combustion chamber into the fuel chamber and to deliver the fuel/air mixture to the combustion chamber under such pressure and temperature conditions that the mixture self-ignites, said valve means being adapted to be kept continuously open up to and during at least the initial portion of the suction stroke whereby evacuating fuel chamber before each introduction of a new fuel portion.

Claim 5

A combustion engine as claimed in claim 2 wherein said valve means comprise a sluice valve.

Claim 6

A combustion engine which operates according to the cycle of suction stroke, compression stroke, power stroke and exhaust stroke, comprising at least one cylinder, air inlet means and exhaust means, a fuel chamber arranged in the proximity of the combustion chamber in said cylinder, a fuel source, means for introducing one fuel portion into said fuel chamber for each power stroke in the cylinder, operable to open and close a passageway between said fuel chamber and said combustion chamber, said valve means including a valve controlled by the engine and adapted to operate said valve to open and close said passageway only once for each cycle of the engine such that said passageway is opened at the end of each compression stroke and closed well in time before the beginning of each next compression stroke, said fuel introducing means being adapted to introduce fuel into said fuel chamber when the passageway between said fuel and combustion chambers is closed, whereby the fuel chamber, each time said passageway is opened, receives relatively hot compressed air from the combustion chamber and delivers the fuel portion to the air for producing a fuel/air mixture under such pressure and temperature conditions that the mixture is self-ignited, said valve means being adapted to evacuate said fuel chamber prior to introduction of another fuel portion therein and means for cooling said valve means during at least the beginning of the suction stroke, before said valve means are closed again.

Claim 7

A combustion engine which operates according to the cycle of suction stroke, compression stroke, power stroke and exhaust stroke, comprising at least one cylinder, air inlet means and exhaust means, a fuel chamber arranged in the proximity of the combustion chamber in said cylinder, a fuel source, means for introducing one fuel portion into said fuel chamber for each power stroke in the cylinder, operable to open and close a passageway between said fuel chamber and said combustion chamber, said valve means including a valve controlled by the engine and adapted to operate said valve to open and close said passageway only once for each cycle of the engine such that said passageway is opened at the end of each compression stroke and closed well in time before the beginning of each next compression stroke, said fuel introducing means being adapted to introduce fuel into said fuel chamber when the passageway between said fuel and combustion chambers is closed, whereby the fuel chamber, each time said passageway is opened, receives relatively hot compressed air from the combustion chamber and delivers the fuel portion to the air for producing a fuel/air mixture under such pressure and temperature conditions that the mixture is self-ignited, said valve means being adapted to evacuate said fuel chamber prior to introduction of another fuel portion therein and means for cooling said valve means during at least the beginning of the suction stroke, before said valve means are closed again.

Claim 8

The engine according to claim 4 wherein said valve means comprise a sluice valve which is adapted to be closed at a point of time immediately after the lowest pressure has been attained in said combustion chamber and in said fuel chamber.

Claim 9

A method as claimed in claim 1 wherein a valve is located in said communication and the intake air for said cylinder is brought into contact with the valve during at least part of the suction stroke in the corresponding cylinder.

Claim 10

A combustion engine as claimed in claim 2, wherein the fuel chamber is connected with the fuel source by means of a fuel conduit via a non-return valve adapted to transmit fuel to the fuel chamber and to prevent backward flow of fuel and gas from the fuel chamber towards the fuel source.

Claim 11

A combustion engine as claimed in claim 2, wherein the means for reducing the pressure in the fuel chamber each time the chamber has been caused to deliver a fuel portion to the corresponding combustion chamber, includes a means, e.g. a camshaft and a cam, which is driven by the crankshaft of the engine and adapted to bring the fuel chamber into communication with a point for relatively low pressure in the air intake system by keeping a closable communication passage between this system and the fuel chambers open during at least the first part of the suction stroke.

Claim 12

A combustion engine as claimed in claim 3, wherein the fuel chamber and the sluice valve arranged for opening and closing the communication between the fuel chamber and the corresponding combustion chamber are adjusted to low-octane fuel, with respect to dimensions and opening time.

Claim 13

A combustion engine as claimed in claim 3, wherein the sluice valve is adapted to be closed at a point of time immediately after the lowest pressure has been attained in the corresponding combustion chamber and, consequently, in the fuel chamber.