A sparkplug assembly having a prechamber volume is operatively associated with the combustion chamber of an internal combustion engine such that the prechamber volume is in fluid communication with the combustion chamber. To purge exhaust gasses from the prechamber volume prior to ignition, the sparkplug assembly is operatively associated with a high-pressure air/fuel source that directs a pressurized air/fuel purge charge to the prechamber volume. The pressurized air/fuel purge charge may be at stoichiometric conditions. The high-pressure air/fuel source is configured to direct the pressurized air/fuel purge charge during at least a portion of the compression stroke to maintain a largely stoichiometric mixture of air and fuel in the prechamber volume.

A combustion driven fastener hand tool is disclosed having an extruded front body component including two to three parallel bores. A first bore forms a cylinder for the piston which drives the fastener. A second bore forms a primary combustion chamber in which a fuel and air mixture is ignited and directed into the adjacent piston cylinder. A third bore (or alternately an attached component) forms a pathway for the fuel and air mixture to be directed into the primary combustion chamber. The combustion driven fastener hand tool includes numerous other features affording improvements over the prior art.

An internal combustion engine including at least one combustion chamber having a main chamber and a prechamber, wherein the prechamber is in fluid connection with the main chamber via at least one bore. The at least one combustion chamber is connected to a charging path for the supply of a combustion air-fuel mixture into the combustion chamber via the charging path. A fuel intermixing region is arranged in a section of the charging path separately assigned to the combustion chamber, which fuel intermixing region is in fluid connection with the charging path on one side and with a fuel line on the other side for the supply of fuel into the fuel intermixing region via a controllable fuel valve. The internal combustion engine wherein the prechamber and the fuel intermixing region are in fluid connection with one another via a check valve.

In an internal combustion engine, gaseous fuel is injected in a first injection through a pre-combustion chamber into the combustion chamber to mix with air in the combustion chamber. The pre-combustion chamber has a jet aperture in fluid communication between the pre-combustion chamber and the combustion chamber. Mixed gaseous fuel and air is then ingested into the pre-combustion chamber from the combustion chamber and ignited. In a second injection, injecting gaseous fuel into the pre-combustion chamber and expelling, with the second injection, ignited gaseous fuel and air from the pre-combustion chamber through the jet aperture and into the combustion chamber as a flaming jet with a core of gaseous fuel.

A sparkplug assembly having a prechamber volume is operatively associated with the combustion chamber of an internal combustion engine such that the prechamber volume is in fluid communication with the combustion chamber. To purge exhaust gasses from the prechamber volume prior to ignition, the sparkplug assembly is operatively associated with a high-pressure air/fuel source that directs a pressurized air/fuel purge charge to the prechamber volume. The pressurized air/fuel purge charge may be at stoichiometric conditions. The high-pressure air/fuel source is configured to direct the pressurized air/fuel purge charge during at least a portion of the compression stroke to maintain a largely stoichiometric mixture of air and fuel in the prechamber volume.

A combustion driven fastener hand tool is disclosed having a piston driven by combustion within a chamber, the piston affixed to a driver for forcing a fastener. The piston forms a retention chamber having a lower internal pressure (vacuum) than that of the surrounding combustion chamber when the piston is disposed in the starting position for operation of the device. The lower internal pressure of the retention chamber (generated from a previous combustion cycle) momentarily holds the piston in place such that combustion behind the piston must first increase sufficiently to overcome holding force of the retention chamber before the piston moves. Requiring build up of combustion chamber pressure before piston motion greatly improves efficiency and power of the device. Use of the vacuum retention chamber is readily tunable with proper sizing of the chamber.

In an internal combustion engine, gaseous fuel is injected in a first injection through a pre-combustion chamber into the combustion chamber to mix with air in the combustion chamber. The pre-combustion chamber has a jet aperture in fluid communication between the pre-combustion chamber and the combustion chamber. Mixed gaseous fuel and air is then ingested into the pre-combustion chamber from the combustion chamber and ignited. In a second injection, injecting gaseous fuel into the pre-combustion chamber and expelling, with the second injection, ignited gaseous fuel and air from the pre-combustion chamber through the jet aperture and into the combustion chamber as a flaming jet with a core of gaseous fuel.

A controller for a gas engine includes a cycle detection unit 67 configured to detect a crank angle period of a single combustion cycle of an engine including a plurality of cylinders based on a crank angle detection value inputted from a crank angle detector 75, a misfire detection unit 69 configured to detect a misfire in a combustion chamber 37 based on an in-cylinder pressure detection value inputted from the in-cylinder pressure detector 59, and a simultaneous misfire determination unit 73 configured to determine a simultaneous misfire of more than one cylinder when a total number of cylinders where the misfire is detected in the single combustion cycle by the misfire detection unit 69 is not less than a preset threshold value of a cylinder number. The fuel gas to all of the cylinders is shut off when the simultaneous misfire of more than one cylinder in the single combustion cycle is determined by the simultaneous misfire determination unit 73.

A system, comprising, a combustion chamber, and a free-radical injector configured to inject free radicals into the combustion chamber at an ignition timing to trigger combustion of a fuel-air mixture.

An internal combustion engine having a main combustion chamber, a prechamber, a first ignition plug and a second ignition plug. The main combustion chamber in fluid communication with the prechamber. The first ignition plug disposed in the prechamber for igniting a charge to form a flame jet directed into the main combustion chamber. The second ignition plug disposed in the main combustion chamber for igniting the charge in the main combustion chamber in the path of the flame jet from the prechamber. The second ignition plug configured to ignite the charge in the main combustion chamber prior to the ignition of the charge by the first ignition plug in the prechamber.