US 4,203,393 AGranted

Plasma jet ignition engine and method

AssigneeFord Motor Company

InventorDante S. Giardini

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Abstract

A method and apparatus for carrying out combustion in an internal combustion engine of the stratified charge type is disclosed. The piston and cylinder are shaped in a manner to define a variable volume space and a main combustion chamber residing as a cavity in the top face of the piston, the cavity being in communication with the variable volume space. The cylinder has an intake port oriented to induce a swirl motion to air inducted into the variable volume space. A shock wave chamber is defined with walls projecting from the cylinder head into the main combustion chamber when the piston in its top dead center position. The shock wave chamber (or intermediate chamber) has openings to permit circulatory transfer motion of the air to enter and exit from the central bottom thereof. The intermediate chamber is adapted to receive a plasma sonic jet directed axially downwardly therethrough to penetrate the exit opening of said intermediate chamber. Fuel injection is timed to introduce a spray of fuel to said intermediate chamber to be ignited by said plasma sonic torch passing therethrough to promote a flaming jet which extends into said main combustion chamber for completion of combustion.

Claims14

Dependent claims

An apparatus for carrying out combustion in an internal combustion engine, said engine having a piston and cylinder effective to define a variable volume space and a main combustion chamber residing as a cavity in the top of the piston and communicating with the variable volume space, said cylinder having an intake port oriented to induce a swirl motion to air inducted into said variable volume space, and said space being varied in volume by said piston during compression to induce a high radially inwardly squish motion to said air to form a circulatory path having an air column entering and extending into the central region of said main combustion chamber and exiting therefrom along the sides, said swirl motion and squish motion cooperating to impart a circulatory transfer motion to charge elements in said main chamber, the improvement comprising:

(a) means defining a shock wave chamber integral with said cylinder and having walls extending into said piston cavity when said piston is in a substantially top dead center condition, said shock wave chamber having an exit and an entrance respectively aligned with the path of the circulatory transfer motion of said charge elements,
(b) means defining a plasma cavity in communication with said shock wave chamber, said plasma cavity having an orifice communicating with said shock wave chamber at a side opposite from said exit, said orifice being aligned with the exit of said shock wave chamber,
(c) means for injecting fuel into said shock wave chamber during compression so that the charge elements are forced to enter said plasma cavity momentarily prior to ignition,
(d) means for applying a high energy discharge about 200 millijoules, through said plasma cavity causing the charge elements forced thereinto to be shock heated to an ionized condition and increased in pressure so that the ionized gas is ejected as a directed body of combusted ionized gases through said orifice, said ionized plasma jet igniting the mixture within said shock wave chamber and extending outwardly from the exit thereof preceded by said shock wave to additionally ignite the gaseous mixture in the main combustion chamber, said plasma jet extending through said shock wave cavity into the air column extending through said main combustion chamber.

1 more element

A method of carrying out combustion in an internal combustion engine, said engine having a piston and cylinder effective to define a variable volume space and a main combustion chamber residing as a cavity in the top face of the piston in communication with the variable volume space, the steps comrising:

(a) interposing walls to define an intermediate chamber and to segregate a portion of the variable volume space, said chamber projecting into said main combustion chamber when the piston is substantially at top dead center, said intermediate chamber having an entrance and an exit aligned with the predetermined circulatory path of gases in said space,
(b) inducting air into said variable volume space with a swirling motion about the axis of said cylinder,
(c) compressing the air within said variable volume space and imparting a high radially inwardly squish motion to the air therein as said piston progressively approaches top dead center, said swirling motion and squish motion combining to define a circulatory path having a transfer motion from said variable volume space into said main combustion chamber defining a central air column which exits from said main combustion chamber along the sides thereof,
(d) generating a sonic plasma jet having an energy level of at least 200 millijoules, and directing said jet through said intermediate chamber so as to penetrate the exit thereof and extend into said main combustion chamber, said plasma jet having a turbulating action and igniting action to promote combustion throughout said intermediate chamber and main combustion chamber, said jet also serving to aspirate air from said variable volume space through said entrance openings into said intermediate chamber and outwardly through said exit opening along with said jet, and
(e) introducing a spray of fuel into said intermediate chamber in a predetermined time duration relative to the entrance of said plasma jet thereinto.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/000,957Filed 4 Jan 1979
Granted: 20 May 1980
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H01T 13/50
Sparking plugs: having means for ionisation of gap
F02B 17/005
Engines characterised by means for effecting stratification of charge in cylinders: having direct injection in the combustion chamber
F02B 19/108
With only one pre-combustion chamber: with fuel injection at least into pre-combustion chamber, i.e. injector mounted directly in the…
F02B 23/101
With separate admission of air and fuel into cylinder: the injector being placed on or close to the cylinder centre axis, e.g. with mixture…