US4658792A — Fuel injection system for internal combustion eng…

Claim 1

Independent Claim 198 words

In a method of fuel injection for an internal combustion engine having a combustion chamber comprising a main chamber defined by a recess formed in the lower face of a cylinder head opposed to the top surface of a piston and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center positon and a part of the lower face of the cylinder head around the recess, and an intake passage communicating with the combustion chamber by way of an intake port adapted to be opened and closed by an intake valve, the improvement which comprises injecting fuel into the intake passage near the intake port, controlling said fuel injection, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection by the middle of the intake valve opening time at the latest so that a rich mixture of air and fuel is accumulated in the lower portion of the combustion chamber and a lean mixture thereof in the upper portion of the same, and igniting said rich mixture in the path of squish flow.

Claim 2

Dependent Claim 198 words

In a method of fuel injection for an internal combustion engine having a combustion chamber comprising a main chamber defined by a recess formed in the lower face of a cylinder head opposed to the top surface of a piston and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center positon and a part of the lower face of the cylinder head around the recess, and an intake passage communicating with the combustion chamber by way of an intake port adapted to be opened and closed by an intake valve, the improvement which comprises injecting fuel into the intake passage near the intake port, controlling said fuel injection, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection by the middle of the intake valve opening time at the latest so that a rich mixture of air and fuel is accumulated in the lower portion of the combustion chamber and a lean mixture thereof in the upper portion of the same, and igniting said rich mixture in the path of squish flow.

Claim 3

Dependent Claim 232 words

In a fuel injection system for an internal combustion engine having a combustion engine chamber comprising a main chamber defined by a recess formed in the lower face of a cylinder head opposed to the top surface of a piston and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center position and a part of the lower face of the cylinder head around the recess, and an intake passage communicating with the combustion chamber by way of an intake port adapted to be opened and closed by an intake valve, the improvement which comprises a fuel injection valve positioned in the intake passage near the intake port and adapted to inject fuel into the intake passage, a control means which controls said fuel injection valve, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection by the middle of the intake valve opening time at the latest so that a rich mixture of air and fuel is accumulated in the lower portion of the combustion chamber and a lean mixture thereof in the upper portion of the same, and a spark plug disposed in the path of squish flow with said rich mixture so that the spark plug is provided with said rich mixture when ignited.

Claim 4

Dependent Claim 232 words

In a fuel injection system for an internal combustion engine having a combustion engine chamber comprising a main chamber defined by a recess formed in the lower face of a cylinder head opposed to the top surface of a piston and a squish zone which is a narrow space formed between the top surface of the piston in the top dead center position and a part of the lower face of the cylinder head around the recess, and an intake passage communicating with the combustion chamber by way of an intake port adapted to be opened and closed by an intake valve, the improvement which comprises a fuel injection valve positioned in the intake passage near the intake port and adapted to inject fuel into the intake passage, a control means which controls said fuel injection valve, at least when the engine load is low, to inject fuel by an amount required for one power stroke and to terminate fuel injection by the middle of the intake valve opening time at the latest so that a rich mixture of air and fuel is accumulated in the lower portion of the combustion chamber and a lean mixture thereof in the upper portion of the same, and a spark plug disposed in the path of squish flow with said rich mixture so that the spark plug is provided with said rich mixture when ignited.

Claim 5

Dependent Claim 56 words

A fuel injection system as defined in claim 2 in which said intake port opens in said squish zone, said fuel injection valve is disposed in the direction of said intake port, and fuel injection from said injection valve is substantially conducted in the first half of the intake stroke where the intake valve is opened.

Claim 6

Dependent Claim 41 words

A fuel injection system as defined in claim 2 further comprising a swirl producing means which gives intake air a swirling motion in the circumferential direction of the cylinder forming the combustion chamber at least when the engine load is low.

Claim 7

Dependent Claim 33 words

A fuel injection system as defined in claim 4 further comprising a swirl control means which weakens the swirling motion to be given to intake air when the engine operates at high-load high-speed.

Claim 8

Dependent Claim 29 words

A fuel injection system as defined in claim 2 in which said control means controls the fuel injection valve to start fuel injection before the intake valve is opened.

Claim 9

Dependent Claim 29 words

A fuel injection system as defined in claim 6 in which said control means controls the fuel injection valve to terminate fuel injection before the intake valve is opened.

Claim 10

Dependent Claim 162 words

A fuel injection system as defined in claim 2 in which the top surface of the piston is substantially flat, a single intake valve and a single exhaust valve are provided, an intake port opens in said squish zone, an exhaust port opens in the main combustion chamber, and the intake passage communicated with intake port comprises a primary intake passage through which at least a part of the intake air is introduced into the combustion chamber over the whole operating range of the engine and a secondary intake passage provided with a control valve which limits flow of intake air passing through the secondary intake passage at least when the engine load is low, the primary intake passage being position below the secondary intake passage and opening to the intake port so that the intake air is introduced into the combustion chamber substantially in a horizontal direction and the fuel injection valve being disposed in the direction of the intake port.

Claim 11

Dependent Claim 26 words

A fuel injection system as defined in claim 8 in which said fuel injection valve is disposed downstream from the control valve of the secondary passage.

Claim 12

Dependent Claim 28 words

A fuel injection system as defined in claim 2 in which said squish zone is relatively large and circumscribes at least one of the intake and exhaust valves.

Claim 13

Dependent Claim 61 words

A fuel injection system as defined in claim 10 further comprising a swirl control means which gives intake air a swirling motion in the circumferential direction of the cylinder forming the combustion chamber at least when the engine load is low and weakens the swirling motion to be given to intake air at least when the engine operates at high-load high-speed.

Claim 14

Dependent Claim 42 words

A fuel injection system as defined in claim 11 in which an intake port for introducing intake air into the cylinder in the circumferential direction thereof in order to produce the swirling motion of the intake air opens in said squish zone.

Claim 15

Dependent Claim 71 words

A fuel injection system as defined in claim 12 in which a shallow recess is formed in the squish zone at a position near said recess defining the main combustion chamber and downstream of the same as seen in the direction of the swirling motion of the intake air, and said spark plug is disposed in the shallow recess, the shallow recess merging into the recess defining the main combustion chamber.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-04-20	1990-10-20	1991-04-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-04-20	1994-10-20	1995-04-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-04-20	1998-10-20	1999-04-21	$7700.00	Window Closed / Lapsed

Fuel injection system for internal combustion engine

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