Pre-chamber ignition device with variable volume capability for internal combustion engines

An engine prechamber, comprising:

• a body, comprising:
• a first end and a second end at opposite axial ends of the body;
• an inner side surface;
• and
• an interior defined between the first end, the second end, and the inner side surface;
• a plurality of nozzles formed in the first end of the body;
• a prechamber piston slidably disposed in the interior of the body;
• a spring positioned between the second end of the body and the prechamber piston;
• an ignition chamber in fluid communication with the interior of the body via an ignition chamber opening, wherein the ignition chamber opening is formed along the inner side surface of the body;
• and
• an adjustable volume limiter provided at the second end of the prechamber, wherein when the adjustable volume limiter is set in a first position, the adjustable volume limiter extends a first axial distance from the second end, and when the adjustable volume limiter is set in a second position, the adjustable volume limiter extends a second axial distance from the second end greater than the first distance.

A method, comprising:

• providing an engine comprising:
• a prechamber in fluid communication with a main chamber of an engine cylinder via a plurality of nozzles located along a first end of the prechamber;
• a primary piston slidably positioned in the engine cylinder;
• and
• a prechamber piston slidably positioned in the prechamber, wherein a variable volume is defined in an interior of the prechamber between the prechamber piston and the first end of the prechamber;
• supplying a combustible mixture to the main chamber;
• compressing the combustible mixture within the main chamber during a compression stroke of the primary piston to direct a portion of the combustible mixture through the plurality of nozzles into the prechamber;
• using the portion of the combustible mixture directed into the prechamber to move the prechamber piston in a first axial direction to increase the variable volume in the prechamber;
• igniting the portion of the combustible mixture in the prechamber using an ignition device in fluid communication with the variable volume in the prechamber;
• jetting the ignited portion of the combustible mixture from the prechamber through the plurality of nozzles into the main chamber during an expansion stroke of the primary piston;
• using a spring to move the prechamber piston in a second axial direction, opposite the first axial direction, to decrease the variable volume in the prechamber and to further eject the ignited portion of the combustible mixture out of the prechamber;
• and
• providing an adjustable volume limiter at the second end of the prechamber;
• when the engine is operating in a first engine load range, setting the adjustable volume limiter in a first position, where the adjustable volume limiter extends a first distance from the second end;
• and
• when the engine is operating in a second engine load range, less than the first engine load range, setting the adjustable volume limiter in a second position, where the adjustable volume limiter extends a second distance from the second end greater than the first distance.