Pre-chamber system for an internal combustion engine

#The present invention concerns a pre-chamber system for an internal combustion engine, as well as an internal combustion engine having such a pre-chamber system.

#In operation of an internal combustion engine—in particular a gas engine—with a substantially stoichiometric ratio of fuel and air, very high temperatures can occur. These high temperatures are detrimental to the exhaust gas behavior of such an engine. It is possible to counteract that situation by exhaust gas recycling. That, however, leads to a worsening in terms of the ignition characteristics.

#Using a pre-chamber to be filled with combustion gas for ignition purposes in that case, as is a standard solution adopted in regard to large-volume lean-burn engines, is initially problematic. The mixture which upon compression is urged out of the main combustion chamber into the pre-chamber does not in fact have an air excess, whereby a fuel-air mixture which can be well ignited does not prevail in the pre-chamber.

#Further advantages and details of the invention will be apparent from the Figures and the related specific description. In that respect, FIGS. 1 through 4 show sectional views of various configurations of pre-chamber systems according to the invention.

#FIG. 1 firstly shows the pre-chamber volume (space) 4 of the pre-chamber system 1, the ignition device 6, the flow transfer passage 5 with its flow transfer passage opening 16, and a fuel gas passage 7. The flow transfer region 2 is delimited (separated) from the ignition region 3 by an intermediate wall 9, the two regions 2,3 being connected by a connecting passage 11 with a connecting passage opening 15. The flow transfer passage 5 is here tangential relative to the inside wall 17. An annular passage 13 which is formed in an annular configuration around the longitudinal axis X is connected to the rest of the flow transfer region 2 by an annular gap 14. The air feed passage 8 opens into the annular passage 13, and the air feed passage 8 permits both the feed of charge air and also the feed of compressed air, the feed of compressed air being regulated by an electronic valve 12.

#FIG. 2 shows a pre-chamber system according to the invention in which the connecting passage 11 is also inclined with respect to the longitudinal axis X. In addition, there is a second electronic valve 12 which regulates the feed of charge air.

#FIG. 3 shows an embodiment without a connecting passage 11.