Internal combustion engine

Patent metadata

Field	Value
Publication number	US-10161296-B2
Application number	US-201615132317-A
Country	US
Kind code	B2
Filing date	Apr 19, 2016
Priority date	Nov 27, 2012
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

An internal combustion engine includes a pre-chamber. In another aspect, pressure within a pre-chamber is equal to or greater than pressure within a main combustion chamber at least prior to ignition in the main combustion chamber. In yet another aspect, internal combustion engine control software automatically controls pressure within a turbulent jet ignition pre-chamber, controls a valve-actuator to admit a fuel-air charge into the pre-chamber, and causes an igniter to initiate combustion in the pressurized pre-chamber. This also permits the rate of combustion to be controlled in the primary chamber regardless of the air-fuel ratio or the diluent fraction in the main chamber. Another aspect employs a pre-chamber purge pump with separate air and fuel injection.

First claim

The invention claimed is:

1. An internal combustion engine comprising:
a pre-chamber including multiple apertures which are always open between the pre-chamber and main combustion chamber;
a main combustion chamber connected to the pre-chamber via the apertures;
an igniter operably releasing energy in the pre-chamber;
at least one injector having an outlet connected to the pre-chamber, the at least one injector supplying fuel separately from air, in an unmixed state, into the pre-chamber;
the air being injected into the pre-chamber prior to injection of the fuel to purge the pre-chamber of any prior combustion particles;
a first mixture of the air and the fuel combusting in the pre-chamber which thereafter ignites a second fuel air mixture in the main combustion chamber through the apertures; and
the pre-chamber having an internal pressure equal to or greater than that of the main combustion chamber at least prior to ignition in the main combustion chamber;
a first cam causing an air valve to move for an air purge pump; and
a second cam causing a supplemental piston to move fresh air from the purge pump into the pre-chamber.

2. The engine of claim 1 , wherein:
the igniter is at least partially located in the pre-chamber; and
an internal hollow volume of the purge pump is at least twice an internal hollow volume of the pre-chamber.

3. The engine of claim 2 , further comprising:
a main driving piston linearly moveable within the main combustion chamber and being connected to a crank shaft;
timing of at least the air valve associated with air flow from the purge pump being controlled by movement of the crank shaft.

4. The engine of claim 1 , further comprising springs being coaxially aligned with an elongated centerline axis of the purge pump.

5. The engine of claim 1 , wherein the purge pump and the pre-chamber are linearly located between the cams and the main combustion chamber.

6. The engine of claim 1 , wherein the pre-chamber has a constant volume.

7. The engine of claim 1 , further comprising pressure sensors associated with the pre-chamber and main combustion chamber operably sending signals to an electronic controller which uses the signals to automatically control the pressure and combustion timing of a subsequent cycle in the pre-chamber, and to automatically control timing of injection of the air separately from injection of the fuel into the pre-chamber.

8. The engine of claim 1 , further comprising oil acting on a valve to control valve opening of the purge pump, and a spring biasing a portion of the purge pump.

9. A method of operating an internal combustion engine in an automotive vehicle, the method comprising:
(a) pressurizing a constant volume pre-chamber, with a source external to a main piston chamber, to at least that of the main piston chamber connected therewith by multiple apertures which are always open;
(b) supplying a fuel into the pre-chamber through a fuel port;
(c) moving a valve of a purge pump due to rotation of a cam;
(d) supplying air to the purge pump and supplying air from the purge pump into the pre-chamber through an air port separate from the fuel port and at least partially prior to step (b);
(e) creating ignition energy in the pre-chamber to ignite the fuel and air in the pre-chamber;
(f) supplying fuel and air into the main piston chamber;
(g) moving combusted material from the pre-chamber through at least one of the apertures;
(h) moving a supplemental piston in the purge pump due to rotation of another cam;
(i) igniting the fuel and air in the main piston chamber with reacting mixture flowing through the apertures of the pre-chamber; and
(j) linearly moving an entire main driving piston away from the pre-chamber, within the main piston chamber.

10. The method of claim 9 , further comprising oil acting on the valve to control valve opening of the purge pump, and a spring biasing a portion of the purge pump.

11. The method of claim 9 , further comprising essentially completely combusting the fuel and air which is a 1.0 (a) or leaner fuel-air mixture in the main piston chamber.

12. The method of claim 9 , further comprising:
sensing pressure in the main piston chamber; and
automatically changing at least one of: a fuel-air ratio in the pre-chamber, a quantity of the fuel and air in the pre-chamber, ignition timing in the pre-chamber, injection timing of the air versus the fuel in the pre-chamber, or pressure in the pre-chamber.

13. The method of claim 9 , further comprising:
sensing ionization in the main piston chamber; and
automatically changing at least one of: a fuel-air ratio in the pre-chamber, a quantity of the fuel and air in the pre-chamber, ignition timing in the pre-chamber, injection timing of the air versus the fuel in the pre-chamber, or pressure in the pre-chamber.

Assignees

• Univ Michigan State

Inventors

• Schock Harold
• Zhu Guoming
• Toulson Elisa
• Stuecken Thomas Richard

Classifications

• F02F1/4285

  of both intake and exhaust channel · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• F02B35/00

  Engines characterised by provision of pumps for sucking combustion residues from cylinders · CPC title

• F02B19/1023

  pre-combustion chamber and cylinder being fed with fuel-air mixture(s) · CPC title

• F02B19/1042

  auxiliary intake, valve drive · CPC title