Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from the main chamber central axis at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through the precombustion chamber central axis and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The cross-sectional area of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region is smaller than the cross-sectional area of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber including a small-diameter cylinder chamber communicating with the main combustion chamber via a plurality of nozzle holes and a large-diameter cylinder chamber, an ignition device disposed in the large-diameter cylinder chamber of the precombustion chamber, and a precombustion-chamber-gas supply device for supplying a precombustion-chamber fuel gas to the precombustion chamber not via the main combustion chamber.

Abstract: A knocking detection method includes: a step of obtaining an oscillation waveform generated by combustion in the combustion chamber; a step of setting a first time window preceding a maximum inner pressure time at which an inner pressure of the combustion chamber is at maximum in a single combustion cycle and a second time window immediately after the maximum inner pressure time, and transforming each of a first waveform portion included in the first time window and a second waveform portion included in the second time window into an expression-domain expression, of the oscillation waveform; and a step of extracting a first peak at which amplitude of the frequency domain expression of the first waveform portion is at maximum in the first frequency windows and a second value at which the amplitude of the frequency domain region of the second waveform portion is at maximum in the second frequency window and determining whether knocking has occurred on the basis of the second peak value and the first peak value.

Abstract: A precombustion chamber gas engine including a precombustion chamber communicating with a main combustion chamber includes: a precombustion-chamber-fuel supply line through which a precombustion chamber fuel flows; a precombustion-chamber-fuel supply valve connected to the precombustion-chamber-fuel supply line and controlling supply of the precombustion chamber fuel to the precombustion chamber, the precombustion-chamber-fuel supply valve being configured to open when a precombustion chamber fuel line pressure, which is a pressure of the precombustion-chamber-fuel supply line, is larger than a precombustion chamber pressure, which is a pressure of the precombustion chamber; a precombustion-chamber-fuel-line-pressure adjustment valve disposed on the precombustion-chamber-fuel supply line and capable of adjusting the precombustion chamber fuel line pressure; an exhaust-precombustion-chamber-pressure acquisition unit capable of obtaining an exhaust precombustion chamber pressure which is a pressure related to t

Abstract: A knocking detection method includes: a step of obtaining an oscillation waveform generated by combustion in the combustion chamber; a step of setting a first time window preceding a maximum inner pressure time at which an inner pressure of the combustion chamber is at maximum in a single combustion cycle and a second time window immediately after the maximum inner pressure time, and transforming each of a first waveform portion included in the first time window and a second waveform portion included in the second time window into an expression-domain expression, of the oscillation waveform; and a step of extracting a first peak at which amplitude of the frequency domain expression of the first waveform portion is at maximum in the first frequency windows and a second value at which the amplitude of the frequency domain region of the second waveform portion is at maximum in the second frequency window and determining whether knocking has occurred on the basis of the second peak value and the first peak value.

Abstract: A method of detecting knocking includes: an in-cylinder pressure obtaining step of obtaining an in-cylinder pressure of a cylinder of the internal combustion engine at a plurality of crank angles; a heat generation rate calculation step of calculating a heat generation rate of the cylinder at each of the plurality of crank angles; an in-cylinder pressure maximizing crank angle obtaining step of obtaining an in-cylinder pressure maximizing crank angle at which the in-cylinder pressure of the cylinder of the internal combustion engine is at a maximum value; a knock determination crank angle region decision step of deciding a knock determination crank angle region which is a region between a smaller crank angle smaller than the in-cylinder pressure maximizing crank angle by a first value and a larger crank angle larger than the in-cylinder pressure maximizing crank angle by a second value; a heat generation rate differentiation step of calculating a differential value of the heat generation rate in the knock det

Abstract: An internal combustion engine includes: an engine body (10) having at least one cylinder; and an air-supply manifold (4) including an adjustment pipe (12). The length of the adjustment pipe is set so that a first pressure wave (14A) propagating from the air-supply manifold toward the adjustment pipe and a second pressure wave (14B) propagating from the adjustment pipe toward the air-supply manifold have opposite phases from each other at the cylinder.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine including a precombustion chamber communicating with a main combustion chamber includes: a precombustion-chamber-fuel supply line through which a precombustion chamber fuel flows; a precombustion-chamber-fuel supply valve connected to the precombustion-chamber-fuel supply line and controlling supply of the precombustion chamber fuel to the precombustion chamber, the precombustion-chamber-fuel supply valve being configured to open when a precombustion chamber fuel line pressure, which is a pressure of the precombustion-chamber-fuel supply line, is larger than a precombustion chamber pressure, which is a pressure of the precombustion chamber; a precombustion-chamber-fuel-line-pressure adjustment valve disposed on the precombustion-chamber-fuel supply line and capable of adjusting the precombustion chamber fuel line pressure; an exhaust-precombustion-chamber-pressure acquisition unit capable of obtaining an exhaust precombustion chamber pressure which is a pressure related to t

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber including a small-diameter cylinder chamber communicating with the main combustion chamber via a plurality of nozzle holes and a large-diameter cylinder chamber, an ignition device disposed in the large-diameter cylinder chamber of the precombustion chamber, and a precombustion-chamber-gas supply device for supplying a precombustion-chamber fuel gas to the precombustion chamber not via the main combustion chamber.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from the main chamber central axis at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through the precombustion chamber central axis and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The cross-sectional area of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region is smaller than the cross-sectional area of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region.

Abstract: A precombustion-chamber engine includes a cylinder, a cylinder head disposed on a top of the cylinder, and a piston reciprocably disposed within the cylinder. A main combustion chamber is defined between the piston and the cylinder head. The cylinder head includes a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle. The precombustion chamber includes a cylindrical first passage part extending upwardly from the nozzle, a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area, and a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed. Center O of a cross-section, orthogonal to straight line L, of the second passage part is eccentric with respect to straight line L composed of an axis of the first passage part and an extended line of the axis.

Abstract: An internal combustion engine includes: an engine body (10) having at least one cylinder; and an air-supply manifold (4) including an adjustment pipe (12). The length of the adjustment pipe is set so that a first pressure wave (14A) propagating from the air-supply manifold toward the adjustment pipe and a second pressure wave (14B) propagating from the adjustment pipe toward the air-supply manifold have opposite phases from each other at the cylinder.

Abstract: An object is to provide a precombustion-chamber gas engine in which occurrence of knocking is restricted. The precombustion-chamber gas engine includes: a cylinder; a cylinder head; a piston delimiting a main combustion chamber with the cylinder head; a precombustion-chamber cap delimiting a precombustion chamber inside thereof and including a plurality of nozzle holes through which the precombustion chamber is in communication with the main combustion chamber; an intake valve for opening and closing an intake port that opens on the cylinder head; and an exhaust valve for opening and closing an exhaust port that opens on the cylinder head. In a planar view where the cylinder head is seen from below, there are at least one intake-side nozzle hole and at least one exhaust-side nozzle hole, and a total nozzle-hole area of the at least one intake-side nozzle hole is larger than that of the at least one exhaust-side nozzle hole.

Abstract: A precombustion-chamber engine includes a cylinder, a cylinder head disposed on a top of the cylinder, and a piston reciprocably disposed within the cylinder. A main combustion chamber is defined between the piston and the cylinder head. The cylinder head includes a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle. The precombustion chamber includes a cylindrical first passage part extending upwardly from the nozzle, a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area, and a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed. Center O of a cross-section, orthogonal to straight line L, of the second passage part is eccentric with respect to straight line L composed of an axis of the first passage part and an extended line of the axis.

Abstract: Particular embodiments may provide a piston for a prechamber-type gas engine and a prechamber-type gas engine taking into consideration the shape of the piston top surface portion so that the region where flame propagation due to torch jet is delayed, a piston for a prechamber-type gas engine where torch jet formed by combustion a prechamber fuel in a precombustion chamber is injected to a main combustion chamber through a plurality of injection holes, may include a piston top surface portion comprising a land portion formed in a first region extending between axis line directions of adjacent injection holes, and the first region is positioned at a higher position than a second region extending across the axis line direction. The land portion may be formed on a cavity formed in the piston top surface portion.

Abstract: In a laser ignition device which is mounted in an internal combustion engine and at least includes a laser spark plug equipped with an optical window which protects an optical device from high temperature and high pressure generated in a combustion chamber and a prechamber cap equipped with a cylindrical prechamber, a prechamber throat portion that is a bottomed cylinder with a sectional area smaller than that of the prechamber, and a plurality of prechamber spray holes which communicate with a combustion chamber on a side of a closed end of the prechamber throat portion, the prechamber cap is arranged between the optical window and the combustion chamber. A converging point FP is located inside the prechamber to ignite an air-fuel mixture delivered into the prechamber, thereby jetting combustion flames from the prechamber into the combustion chamber to fire the internal combustion engine.