JP6548629B2 - Method for promoting combustion in engine operation and spark plug for engine - Google Patents

Description

  This application claims the benefit of priority to US Ser. No. 13 / 833,226, which is a continuation-in-part, filed Mar. 15, 2013, and US patent application filed on Nov. 23, 2010. Claim the benefits of co-pending U.S. patent application Ser. No. 13 / 042,599, filed March 8, 2011, claiming the benefit of Provisional Application No. 61 / 416,588. U.S. patent application Ser. No. 13 / 833,226, filed Mar. 15, 2013, is a continuation-in-part application and is U.S. Provisional Patent Application No. 61 / 416,588, filed November 23, 2010. Co-pending U.S. Patent Application No. 13 filed January 10, 2012 which is a partial continuation of U.S. Patent Application No. 13 / 042,599 filed March 8, 2011 claiming the benefit of Claim the benefits of / 347, 448.

  This application claims the benefit of US Provisional Application No. 61 / 416,588, filed Nov. 23, 2010, copending US Patent Application No. 13/042, filed Mar. 8, 2011, US filed on October 3, 2013, which is a continuation-in-part of US patent application Ser. No. 13 / 833,226, filed on Mar. 15, 2013, which is a partial continuation application of US Pat. Claims priority to patent application no. 14 / 045,625. No. 14 / 045,625, filed Oct. 3, 2013, which is a continuation of U.S. patent application Ser. No. 13 / 833,226, filed Mar. 15, 2013, is incorporated herein by reference. It is a continuation-in-part of US Patent Application No. 13 / 042,599 filed March 8, 2011 claiming the benefit of US Provisional Patent Application No. 61 / 416,588, filed on March 23, It is a continuation-in-part and claims benefit of co-pending US patent application Ser. No. 13 / 347,448, filed Jan. 10, 2012.

  This specification relates to a spark plug for an internal combustion engine.

  Engines operated with gaseous fuels, such as natural gas, are generally supplied with a lean mixture. A lean mixture is a fuel mixture that contains excess air that is "chemically correct" or stoichiometric (theoretical). The use of a lean mixture often leads to misfires, incomplete combustion and other combustion defects and reduced fuel consumption, and attempts to improve combustion lead to detonation (abnormal combustion causing knocking) or a decrease in spark plug life. It often results in the use of high spark energy. One of the factors causing such a situation is that the conventional spark plug has a low ability to effectively and reliably (thin) the ignition of the lean mixture in the cylinder of the operating engine. By using a pre-combustion chamber or pre-chamber, lean mixtures can be burned more effectively.

  Pre-chamber spark plugs are typically used to increase the lean burn limit of lean burn engines such as natural gas lean burn engines or automotive lean gasoline engines. In the known pre-chamber spark plugs as disclosed in U.S. Pat. No. 5,554,908, the spark gap corresponds to a relatively small portion of the total displacement (total stroke volume) of the engine cylinder. It is contained in the cavity which has it. A portion of this cavity is dome-shaped and has various tangential inlet / outlet holes. During operation of the engine, as the piston of the engine moves upward in the compression cycle, the fuel mixture is forced into the prechamber through the inlet holes. The orientation (orientation) of this hole determines the movement of the fuel mixture inside the cavity of the prechamber and the reaction jet (jet) leaving the prechamber.

  As the burn rate of the fuel mixture in the prechamber cavity increases, a flame jet (jet) is generated that has a high penetration into the combustion chamber of the engine. Even if the fuel mixture is lean, this flame jet enhances the engine's ability to achieve rapid and reproducible flame propagation within the engine's combustion chamber. Many conventional pre-chamber spark plugs are not repeatable and unpredictable in their performance characteristics, resulting in excesses beyond the desired coefficient of variation (COV) values and misfires on the scale of roughness (roughness). Connect. In addition, many of the conventional pre-chamber spark plugs are susceptible to manufacturing variations and suffer from under-combustion gas removal that results in further increases in COV.

  Fresh air filling in internal combustion engines is usually non-homogeneous and non-reproducible per cycle at many points (e.g. equivalence ratio, turbulence, temperature, residuals), but is challenged by spark plug designs One of the problems is to create a new plug that is reproducible in the combustion process and achieves controllable ignition delay time. It is also desirable to realize a spark plug that is relatively insensitive to variations in manufacturing or parts or their assembly.

  Another challenge to the spark plug design is the premature wear of the spark plug. Typically, premature wear of the spark plug is caused by the high combustion temperature of the theoretical mixture. It is not uncommon for spark plugs applied to engines with high BMEP (Net Average Effective Pressure) to have only 800 to 1000 hours to require replacement. This causes unplanned engine downtime and increases the operating cost for the engine operator.

  In some embodiments, spark plugs have low COV, long life, and can produce high speed flame jets. Thereby, combustion in the main chamber can be performed more quickly, and the trade-off relationship between NOx and fuel efficiency (or fuel efficiency) is improved.

  In embodiments, the pre-chamber (pre-combustion chamber) spark plug includes a metal shell, an end cap attached to the shell, a center electrode, and a ground electrode. The pre-chamber spark plug also includes an insulator disposed within the shell. In some implementations, the center electrode has a first portion surrounded by an insulator and a second portion extending from the insulator into the prechamber. The volume of the prechamber is defined by the shell and the end cap. In some implementations, the ground electrode is attached to the shell. In some implementations, the ground electrode includes an inner ring spaced around the center electrode, an outer ring attached to the shell, and a plurality of spokes connecting the inner ring and the outer ring. In some implementations, the ground electrode is formed in a cylindrical shape, which causes the flow (primary) flowing into the central hole and passing through the gap between the central electrode and the ground electrode in the transverse direction. Do not disturb the flow (secondary) flowing through the holes. Also, with this cylindrical shape, the flow of transverse holes through the back side of the ground electrode at the periphery is directed to merge with the flame kernel as it exits the gap. In addition, the central electrode has an aerodynamic shape that improves the streamlines of the flow from the central bore through the gap.

  In another aspect, combustion in the internal combustion engine is promoted. The fuel mixture is ignited in the prechamber of the prechamber spark plug. In some implementations, igniting the fuel mixture in the pre-chamber provides a first port to flow a first quantity of fuel mixture into the gap between the center electrode and the ground electrode. Here, the flow direction is mainly the reverse direction from the pre-chamber of the pre-chamber (most of the flow is this direction, and in some cases, all the flow is this direction) And igniting the fuel mixture in the gap, this ignition generates a flame kernel. The flame kernel is moved to the back chamber of the prechamber, and the second port is inserted into the front chamber so that a second quantity of fuel mixture flows to the back chamber and is ignited by the flame kernel. Allows (lateral) flow of fuel mixture in an amount of. Also, the second flow acts as a swirl that acts to spread the expanding flame in the back chamber in the azimuth direction so that the uniformity in the azimuth angle is improved and turbulence is generated in the pre-chamber. And the combustion may be further accelerated. By igniting the first and second quantities of fuel mixture, the pressure in the pre-chamber is increased causing the flame jets to flow out of the first and second ports. The size and angle of the port holes can be controlled (eg, optionally improved or optimized, etc.) to maximize flame jet velocity and penetration into the main chamber, and can be controlled within the main chamber. The combustion can be intensified. The size of the holes controls both inflow and outflow. The size of the holes can be controlled to achieve the engine's desired desired ignition delay time, jet velocity, and flame jet penetration and thus burn rate in the main chamber (eg, possibly improved or optimized Etc.).

  In yet another aspect, the pre-chamber spark plug includes a shell and an end cap attached to the shell. In addition, the pre-chamber spark plug includes an insulator disposed within the shell. In some implementations, the center electrode has a first portion surrounded by an insulator and a second portion extending from the insulator into the prechamber. The prechamber is defined by the shell and the end cap. In some implementations, the ground electrode is attached to the shell. In some implementations, the ground electrode includes an inner ring spaced around the center electrode and a plurality of spokes projecting radially outwardly from the inner ring to hold the inner ring in place. . Depending on the implementation, the end of each spoke is attached to the shell.

  In another aspect, a pre-chamber spark plug is manufactured. A ground electrode is attached to the shell. In some implementations, the ground electrode includes a cylindrical electrode. In some implementations, the tubular electrode has an inner ring disposed to surround the center electrode.

  In some implementations, noble metals are attached to the center and ground electrodes that are spark surfaces. The gap between the center electrode and the ground electrode is formed with a gap forming tool during manufacture and assembly so that it is accurately formed during manufacture and assembly, thereby requiring regap formation after manufacture Sex decreases. In some implementations, the gap forming tool is inserted between the center electrode and the ground electrode before the ground electrode is finally attached to the shell. In some instances, if this is the final heating step of such a process, the gap is maintained at its best. In some implementations, the spark gap is formed after the ground electrode is attached by electron beam (EB), water jet, and other suitable material removal methods to form precise, high tolerance gaps. The ideal new spark gap range is 0.15 mm to 0.35 mm.

  Depending on the implementation, an arrangement where the cylindrical ground electrode and the center electrode are coaxial allows flow to pass through the gap and create a condition towards the back of the ground electrode, but such an arrangement is a pre-chamber In a head design which does not require the shell of the spark plug such that the pre-chamber of the cylinder head substitutes for the shell wall of the spark plug. Furthermore, the lean operating limit may be further extended by adding fuel to either the pre-chamber spark plug or the pre-chamber in the cylinder head assembly. Such devices can be referred to as "fueled" devices.

  In another aspect, the pre-chamber spark plug includes a shell, an insulator, a center electrode, and a ground electrode. The shell includes a plurality of vents. An insulator is disposed within the shell. The center electrode is surrounded by an insulator and extends into the pre-chamber defined by the shell. The insulator is coaxially disposed around the center electrode. The ground electrode is attached to the insulator and surrounds the distal end of the center electrode. The ground electrode includes a tubular ring spaced around the center electrode and radially beyond the distal end of the center electrode forming a shape that acts as an aerodynamic ram area Have circumferential extensions offset to each other.

  In another aspect, combustion is promoted in an internal combustion engine. The fuel mixture is ignited in the prechamber of the prechamber spark plug. Ignition of the fuel mixture includes providing a plurality of vents to allow primary flow of the fuel mixture into the spark gap of the prechamber, and igniting the fuel mixture, The ignition generates a flame kernel. Next, the flame kernel is moved to the first stage of the prechamber, and the first stage of the prechamber is a cavity disposed between the center electrode and the ground electrode mounted on the insulator coaxially with the center electrode. And function as a "flame holder" by forming a recirculation zone. After the flame kernel has been moved to the first stage, a secondary fuel mixture across the second stage of the prechamber defined by the cavity located outside the ground electrode attached to the insulator. As the flow is diffused, a secondary flow of fuel mixture is provided to the pre-chamber through the plurality of vents. Finally, the flame kernel travels from the first stage to the second stage to ignite the secondary flow of the fuel mixture, causing the flame to spread throughout the prechamber and Burn part of the fuel. This causes the pressure to rise significantly and the flame jets to be emitted from the vent.

  In another aspect, the pre-chamber spark plug includes a shell, an insulator, a center electrode, and a ground electrode. An insulator is disposed within the shell. The central electrode has a first portion surrounded by the insulator and a second portion defined by the shell extending from the insulator into the pre-chamber. The ground electrode is attached to the insulator and includes an inner ring spaced around the center electrode forming the spark gap.

  In some embodiments, instead of an electrical spark, the laser beam is focused to a position between the gap surfaces, the AFR is heated to the ignition temperature, and the flame nuclei are formed by photons rather than electrons. Depending on the implementation, it includes means for bringing and focusing light rays in the gap area. Electric sparks require high pressure to achieve breakdown and sparking as the pressure increases, but the advantage of ignition by a laser beam is that it is less sensitive to the pressure conditions of the cylinder. Laser ignition may allow ignition at pressures above the breakdown limit of conventional electrical ignition systems.

  In a first aspect, a method of promoting combustion in the operation of an engine comprising: receiving a fuel mixture from a combustion chamber of the engine into an enclosure of a spark plug; fuel received within a spark gap within the enclosure Igniting the mixture; and peaking the peak flow rate through the spark gap to the enclosure such that the ignited fuel mixture leaves the combustion chamber side end of the enclosure at a peak flow rate through the spark gap at most of the peak flow rate. Directing at a flow rate of 10% or more of the flow rate. Most of the ignited fuel mixture is directed away from the combustion chamber end of the enclosure (such as the enclosure or vessel) but in some cases all of the flow is directed in this direction .

  In a second aspect, in the first aspect, the peak flow velocity through the spark gap is 5 m / sec or more, and the residual gas is purged from the spark gap.

  According to a third aspect, in the first aspect or the second aspect, the height H of the spark gap is 2.5 mm or more, the peak flow velocity in the spark gap is V, and the H / V * 360 * RPM is a crank of the engine The angle is less than 3 degrees.

  According to a fourth aspect, in any one of the first aspect to the third aspect, the fuel mixture contained in the swirl flow, an enclosure around the inside of the enclosure and an enclosure opposite to the combustion chamber side end Directing to the end of the fuel cell; and protecting the fuel mixture igniting in the spark gap from swirling.

  A fifth aspect comprises, in the fourth aspect, protecting the ignited fuel mixture exiting the spark gap from swirl flow.

  According to a sixth aspect, in any one of the first to fifth aspects, the size of the spark plug is M14 to M24, and the maximum pressure in the enclosure due to combustion of the fuel mixture A step of delaying the crank angle of the engine by 7 degrees or more from the ignition of the fuel mixture is provided.

  According to a seventh aspect, in any one of the first to sixth aspects, only when substantially all of the fuel mixture present in the half opposite to the combustion chamber side end of the enclosure is ignited Injecting the ignited fuel mixture into the combustion chamber of the engine from within the enclosure. Most of the fuel mixture is ignited, but in some cases all fuel mixtures are ignited.

  In an eighth aspect, a spark plug for an engine includes: a spark gap in an enclosure of the spark plug; and a passage inside the enclosure, receiving flow from the outside of the enclosure during operation of the engine, the flow passing through the spark gap And a passage directing the majority away from the combustion chamber end of the enclosure; the spark plug includes means for creating a peak flow velocity in the spark gap that is at least 10% of the peak flow velocity into the enclosure. Passages inside the enclosure direct flow away from the combustion chamber end of the enclosure. In some cases, most of the flow is directed in this direction, but in some cases, all flow is directed in this direction.

  In a ninth aspect, in the eighth aspect, the spark plug is configured to produce a peak flow velocity of 5 m / sec or more in the spark gap.

  According to a tenth aspect, in the eighth aspect or the ninth aspect, the height of the spark gap is H, the peak flow velocity in the spark gap is V, and the H / V * 360 * RPM of the crank angle of 3 degrees or less of the engine Produce

  In an eleventh aspect according to the tenth aspect, the spark plugs are M14 to M24, and H is 2.5 mm or more.

  According to a twelfth aspect, in any one of the eighth aspect to the eleventh aspect, the spark plug is a spark plug having a size of M14 to M24, and the passage extends beyond the end of the spark gap and the combustion chamber of the enclosure It extends 1.0 mm or more toward the side end.

  According to a thirteenth aspect, in the twelfth aspect, the passage includes a spark gap, and extends 0.1 mm or more away from the combustion chamber side end of the enclosure from the opposite end of the spark gap.

  A fourteenth aspect is according to the twelfth aspect or the thirteenth aspect, wherein the hole in the combustion chamber end of the enclosure is oriented to direct the flow into the passage; the flow is around the outer periphery of the passage And a hole in the combustion chamber end of the enclosure, oriented to direct toward the end of the enclosure opposite the combustion chamber end.

  According to a fifteenth aspect, in any one of the eighth to fourteenth aspects, the spark plug has a size of M14 to M24, and the spark plug has an engine crank angle of 7 degrees or more from ignition at the spark gap. The combustion of the fuel mixture causes the pressure in the enclosure to reach the maximum pressure.

  A sixteenth aspect according to any one of the eighth through fifteenth aspects, the spark gap comprising: a metal shell; an electrical insulator within the shell; a center electrode extending from the insulator; and a center electrode. And one or more ground electrodes defining the passage.

  In a seventeenth aspect, in the sixteenth aspect, more than one ground electrode defines a passage, and the ground electrodes do not intersect.

  According to an eighteenth aspect, in the sixteenth aspect or the seventeenth aspect, the at least one ground electrode comprises a tube, the tube defining a passage and being away from the combustion chamber side end of the enclosure from the tube toward the shell And an extending arm.

  According to a nineteenth aspect, in any one of the sixteenth to eighteenth aspects, the central electrode has a polygonal axial cross section.

  According to a twentieth aspect, in the nineteenth aspect, the one or more ground electrodes define a passage in the same shape as the axial cross section of the center electrode.

  Other aspects, objects and advantages will become more apparent from the following detailed description and the accompanying drawings.

  The patent or patent application document contains at least one color drawing. Copies of this patent or patent application publication with color drawings may be obtained from the Office upon request and payment of the required fee.

  The accompanying drawings illustrate some aspects of the present patent disclosure.

FIG. 7 is a cross-sectional view of a portion of an example pre-chamber spark plug.

FIG. 1 is a perspective view of an exemplary cylindrical electrode.

It is a figure which shows the example of the surface ring of a 1st and 2nd electrode.

It is a top view of the example cylindrical electrode.

FIG. 5 is a cross-sectional view of an exemplary cylindrical electrode having a surface ring of a first electrode on a substrate.

FIG. 1 is a perspective view of an exemplary cylindrical electrode.

FIG. 7 is an end view of an example end cap for a pre-chamber spark plug.

FIG. 8 is a cross-sectional view of the example end cap of FIG. 7;

FIG. 7 is a cross-sectional view of a portion of an example pre-chamber spark plug.

FIG. 6 is a cross-sectional view of an exemplary pre-chambered spark plug assembly with the dimensions noted.

FIG. 7 illustrates an exemplary pre-chamber spark plug having square electrodes. FIG. 7 illustrates an exemplary pre-chamber spark plug having triangular electrodes.

FIG. 7 illustrates an exemplary spark plug assembly having a plurality of ground electrodes.

FIG. 7 illustrates an exemplary spark plug assembly having a velocity control tube centered above the spark gap.

FIG. 2 is a cross-sectional view of an example large bore piston cylinder assembly and an example pre-chamber spark plug.

FIG. 7 is a cross-sectional view of another exemplary pre-chamber spark plug.

FIG. 16 is a cross-sectional view of the example pre-chamber spark plug of FIG. 15 showing fuel flow into the pre-chamber;

FIG. 6 is a cross-sectional view of an exemplary pre-chamber spark plug having a secondary fuel injector in the pre-chamber.

FIG. 5 is a cross-sectional view of an example combination gas entry valve with a spark / spark plug.

FIG. 19 is an enlarged cross-sectional view of the example spark / spark plug of FIG. 18;

It is an expanded sectional view of a clevis of a prechamber.

FIG. 6 is a cross-sectional view of a portion of an exemplary pre-chamber spark plug including a braze ring.

FIG. 22 is an enlarged view of an exemplary brazing ring disposed within the pre-chamber spark plug of FIG. 21.

FIG. 5 is a top view of a pre-chamber spark plug assembly without a velocity control tube. FIG. 10 is a cross-sectional view of a pre-chamber spark plug assembly without a velocity control tube.

FIG. 23C is a cross-sectional view of the pre-chamber spark plug assembly of FIGS. 23A and 23B having a forward velocity control tube.

FIG. 24 is a cross-sectional view of the pre-chamber spark plug assembly of FIGS. 23A and 23B with a rear speed control tube.

FIG. 24 is a cross-sectional view of the pre-chamber spark plug assembly of FIGS. 23A and 23B having both forward and aft velocity control tubes.

FIG. 5 is a diagram showing the velocity of the result of computational fluid dynamics analysis in a pre-chamber spark plug without a velocity control tube. FIG. 7 shows velocity vectors as a result of computational fluid dynamics analysis in a pre-chamber spark plug without a velocity control tube. FIG. 5 shows the distribution of fuel mixture as a result of computational fluid dynamics analysis in a pre-chamber spark plug without a velocity control tube.

In the pre-chamber spark plug configured as in FIG. 10, it is a diagram showing the velocity of the result of the hydrodynamic analysis by calculation under the same conditions as in FIG. 27A to FIG. In the pre-chamber spark plug configured as shown in FIG. 10, it shows the velocity vector of the result of the hydrodynamic analysis under the same conditions as in FIG. 27A to FIG. In the pre-chamber spark plug configured as shown in FIG. 10, it shows the distribution of the fuel mixture as a result of hydrodynamic analysis by calculation under the same conditions as in FIG. 27A to FIG. 27C.

In the pre-chamber spark plug configured as shown in FIG. 10, it shows the results of computational fluid dynamics analysis showing the velocity under conditions different from those of FIGS. 28A and 28B.

  The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, the drawings, and the claims.

  The concept here relates to a prechamber spark plug. In some instances, the plug aspect addresses the issues associated with providing an ignition delay that can be reproduced and controlled during the combustion process. In some embodiments, the spark plug achieves a more efficient combustion process and a longer life. The pre-chamber spark plug can include, for example, tubular speed control tubes to control flame kernel development, ignition delay time, flame jet radiation, and combustion rate of the main combustion chamber, resulting in improved engine performance It may be. In some cases, the ignition delay time refers to a period from spark to sufficient pressure for combustion to increase the pressure in the prechamber and hence in the main combustion chamber.

  FIG. 1 is a cross-sectional view of a portion of an example pre-chamber spark plug 100. The pre-chamber spark plug 100 extends along the longitudinal axis 101 and along the longitudinal axis 101 and further from the insulator 104 into the pre-combustion chamber divided into the rear chamber 106 and the front chamber 108 And a center electrode 102. The cylindrical electrode 110 functioning as a ground electrode is disposed inside the shell 112. In FIG. 1, the cylindrical electrode 110 is shown as a series of (unbroken) cylinders (cylindrical), but this cylindrical electrode 110 may be of other cylindrical shapes (e.g. square, triangular, etc.) In some cases, it may conform to the axial cross section of the center electrode 102. In some implementations, the shell 112 is made of a high strength metal that can withstand high temperature exposure. The shell 112 forms part of the pre-chamber volume of the spark plug. The shell 112 is attached to the insulator 104 and holds the end cap 116. End cap 116 defines one end of the pre-chamber volume of spark plug 100 and the boundary of front chamber 108. End cap 116 may be flat and may be dome-shaped, V-shaped or other shapes. In some cases, the end cap 116 can be integral to the shell 112 rather than as a separate piece attached to the shell 112 as shown. The disk portion 114 of the cylindrical electrode 110 is provided to separate the rear chamber 106 and the front chamber 108. As shown in FIG. 1, in some implementations, the inner surface 118 of the shell 112 is stepped so that the tubular electrode 110 can be seated on the stepped portion 120 in the assembly of the pre-chamber spark plug 100. It may have a portion 120.

  FIG. 2 is a perspective view of an exemplary cylindrical electrode 110. The cylindrical electrode 110 has an inner ring 130 and an outer ring 132 incorporated in the cylindrical ground electrode 110. In the example of FIG. 2, the inner ring 130 and the outer ring 132 are connected by three spokes 134. Extending from the inner ring 130 at the central portion of the cylindrical electrode 110 is a cylindrical inner ring or speed control tube 136. As shown in FIG. 1, the speed control pipe 136 is provided to extend in one direction from the disk portion 114 into the front chamber 108. A central opening 138 is provided extending through the inner ring 130 and the speed control tube 136. In another example, the ground electrode 110 is another design such as a J-shape in which a spark gap is formed by the end or side wall of the center electrode 102, and the center electrode 102 is welded to the front side and / or the rear side Or attached to form a speed control tube.

  With further reference to FIG. 2, the illustrated tubular electrode 110 can be made of a copper alloy, a nickel alloy, or other relatively high conductivity metal. In some implementations, a noble metal is affixed or deposited on the inner surface 140 of the inner ring 130. Noble metals are typically used on spark plug electrodes to extend the spark plug life and improve performance. The noble metals selected in this case have a high melting point, high conductivity and high oxidation resistance. Depending on the implementation, for example, the inner ring 130 by means of the surface ring 142 of the first electrode provided with platinum (platinum) or an alloy thereof, rhodium or an alloy thereof, tungsten or an alloy thereof, nickel or an alloy thereof, iridium or an alloy thereof. The inner surface 140 of the is lined. In some implementations, the inner surface 140 of the inner ring 130 is lined with an iridium-rhodium alloy or a nickel alloy. Referring again to FIG. 1, the surface ring 144 of the second electrode is provided with a material similar to or similar to the surface ring 142 of the first electrode and is affixed or deposited to the outer surface 146 of the center electrode 102. The surface material constitutes the entire structure of the center electrode 102 and / or the tubular electrode 110 or is attached to the structure by welding, brazing or other suitable attachment method. In the case of the ground electrode, alternative spark facings can be made to the shape of the cylinder being press-fit, brazed or welded into the structure of the ground electrode. The tubular electrode 110 may have a ring of different material inserted into the inner diameter of the base structure of the tubular electrode 110. The different material may be, for example, a material having high corrosion resistance or oxidation resistance and different from the material of the base of the cylindrical electrode 110. The purpose of inserting the ring is to enhance the corrosion and oxidation resistance of the electrode by adding expensive corrosion and oxidation resistant materials only to the spark surface.

  Referring again to FIG. 2, the exemplary spokes 134 may be provided with square edges to facilitate manufacturing, or to reduce the resistance of the gas flowing in the space between the spokes 134. It may be provided as a curved surface. The support structure of the tubular electrode 110 may be a solid "wheel" type, with spokes or any other mechanism that supports the tubular electrode 110 concentric with the center electrode 102. Exemplary support mechanisms include tabs or legs or the like attached to the side wall, back wall, or other portions of the shell 112. In some cases, the number of spokes connecting the inner ring 130 and the outer ring 132 may be increased or decreased. In some cases, the tubular electrode 110 is not provided with a surface ring of a noble metal electrode. In one example, the entire cylindrical electrode 110 is provided by a single material such as a nickel alloy.

  The illustrated cylindrical electrode 110 may be cast or machined as a substantially single piece (e.g. single piece or a small number such as 3 or 4), but the surface ring of the first electrode May be provided in a separate ring of some noble metal or similar suitable metal. It is also conceivable to manufacture the cylindrical electrode 110 by sintering or injection molding powder metal. Other manufacturing techniques are conceivable which melt rather than sinter the powder metal. In some implementations, the surface rings 142, 144 of the first and second electrodes are manufactured, for example, from cylindrical or rectangular bars that can be cut to any length to form a ring. Depending on the implementation, the surface rings 142, 144 of the first and second electrodes are manufactured from flat sheet material, and the surface rings 142, 144 of many electrodes are punched out from a single flat sheet material using a punch press. FIG. 3 shows an example of the surface rings 142 144 of the first and second electrodes. Here, the surface rings of the two electrodes are punched out in a single step (one shot), and the surface rings 142, 144 of the first and second electrodes are attached and provided via the three tabs 148. In some implementations, the surface rings 142, 144 of the first and second electrodes are assembled to the tubular electrode 110 by the tabs 148 at a position where the correct spacing between the surface rings 142, 144 of the electrodes is maintained. After the surface ring 142 of the first electrode is attached to the cylindrical electrode 110 and the surface ring 144 of the second electrode is attached to the center electrode 102, the tab 148 is removed. The surface ring 142 of the first electrode may be cut into one or more semicircular portions to accommodate manufacturing, assembly, mounting, and / or thermal expansion.

  FIG. 4 shows another example of the cylindrical electrode. In this example, the inner ring 130, the outer ring 132, the spokes 134, and the speed control tube 136 are provided substantially the same as the cylindrical electrode 110 (without any change affecting operation as described). However, in the cylindrical electrode 111, the surface ring 144 of the second electrode is provided attached to the surface ring 142 of the first electrode by the three tabs 156. Thus, the correct spacing between the surface rings 142, 144 of the first and second electrodes is maintained until assembly is complete. After assembly, the tabs 156 can be removed mechanically, or by an electron beam, or by a water jet, or in a similar manner. However, depending on the implementation, the tab 156 may be made of, for example, a material having a substantially lower melting point than the material used in the cylindrical electrode 111 and the surface ring 144 of the second electrode. In this way, the tab 156 is removed by burning or melting after assembly of the tubular electrode 111 to the prechamber spark plug 100 without damaging the tubular electrode 111 or other components of the prechamber spark plug 100. be able to.

  There are several ways of attaching the surface ring 142 of the first electrode to the illustrated cylindrical electrode 110. In some implementations, the cylindrical electrode 110 is cast around the first electrode surface ring 142. In some implementations, a separate metal ring, with a noble metal layer or similar suitable metal layer affixed to its inner surface, is assembled to the inner ring 130 of the tubular electrode 110.

  For example, physical vapor deposition (PVD) or chemical vapor deposition (CVD) can be used to deposit the material of the surface ring of the electrode onto the powder metal substrate. A powder metal substrate may be provided on the hollow cylinder and the material of the surface ring of the electrode may be deposited on the inner surface of the hollow cylinder. The cylinder can be cut into sections to obtain the surface rings 142 of a number of first electrodes. If the same material is deposited on the outside of a small hollow cylinder, it can be cut into slices to obtain the surface rings 144 of a number of second electrodes. By manufacturing in this way, the surface ring 142 of the first electrode can be inserted into the central opening of the cylindrical electrode 110 and can be welded or brazed in place. FIG. 5 is a cross-sectional view of the cylindrical electrode 110 in which the surface ring 142 of the first electrode is fixed or deposited on a base material 143 made of, for example, a nickel alloy or a highly conductive alloy. In some implementations, welding is done by tack welding at one or more locations, allowing relative movement due to different coefficients of thermal expansion for each material. By using the above method of adding noble metal to the cylindrical electrode 110, the pre-chamber spark plug 100 can be manufactured with less noble metal than the typical amount used in conventional pre-chamber spark plugs, The pre-chamber spark plug 100 can be manufactured less expensively than many conventional pre-chamber spark plugs.

  Depending on the implementation, the tubular electrode 110 may be assembled from separate components. FIG. 5 also shows a cross-sectional view of a tubular electrode 110 having a separate disc portion 114 and a speed control tube 136. In some implementations, the velocity control tube 136 has a notch 152 at one end, which is press fit into the annular receiver 154 of the disk portion 114. Depending on the implementation, the annular receiver 154 may be pressed inwardly into the notch 152 of the velocity control tube 136 which holds it in place. Depending on the implementation, the notch portion 152 includes an annular protrusion, and the recess of the annular receiving portion 154 of the cylindrical electrode 110 is fitted around the outer periphery of the annular protrusion so that the disc portion 114 and the speed control tube 136 Make the installation between the better. In some implementations, the notches 152 may be threaded (machined) to correspond to the inner surface of the annular receiver 154 so that the speed control tube 136 can be threaded onto the disc 114.

  Referring again to FIG. 1, in the illustrated mode of operation of the engine, the fuel mixture is from the main cylinder of the engine (not shown) and the central bore 162 of the end cap 116 (see FIGS. 7 and 8). It is drawn into the front chamber 108 of the pre-chamber spark plug 100 through the plurality of outer edge holes 164 (see FIGS. 7 and 8). The central bore 162 is oriented to direct its flow at the velocity control tube 136 into the velocity control tube 136. Therefore, the fuel mixture drawn in through the central hole 162 flows through the speed control pipe 136 into the spark gap between the central electrode 102 and the cylindrical electrode 110 where the ignition by the electric spark is performed. The velocity control tube 136 collects the flow from the central bore 162 and stagnates the flow inside the tube 136 to produce a pressure higher than the pressure around the outside of the tube 136 and the pressure at the outlet of the cylindrical electrode 110. The velocity of the flow from the central bore 162 and the pressure differential create a high velocity flow which is guided to the velocity control tube 136 and through the spark gap towards the rear chamber 106. Similarly, the velocity of the fuel mixture causes the first flame kernel to be moved to the rear chamber 106.

  In some exemplary implementations, the flow through the primary central hole includes a fresh air fuel mixture with low levels of residue. This primary flow penetrates into the spark gap area and pushes the residue generated from the previous combustion event back uniformly out of the spark gap area. This action effectively purges the residue of the spark gap, i.e. "controls" the residue in the pre-chamber. With conventional pre-chamber spark plugs, residual gas can not be "controlled" or not "controlled" well, resulting in an uncontrolled and unknown mixture of fresh air and residues from sparking. This is the main cause of inter-shot combustion variation in conventional pre-chamber spark plugs. Thus, such a design provides control of the residual gas, which purges the residue back (away from the end cap) efficiently, which in some cases achieves very low variation (COV) it can.

  In some embodiments, the peripheral holes 164 are oriented to generate swirl movement (vortex movement) in the fuel mixture drawn through the peripheral holes 164. The fuel mixture performing the swirling motion passes outside the speed control pipe 136 and flows toward the rear chamber 106. In the aft chamber 106, the fuel mixture is ignited by the flame kernel which rides the flow from the central bore. The turbulent flow generated due to the swirling motion of the fuel mixture mainly consumes the fuel in the rear chamber 106 and distributes (distributes) flame nuclei spreading around the rear chamber 106. For example, the flame kernel can consume all but a small amount of fuel in the rear chamber 106. In some cases, the flame kernel consumes all of the fuel in the rear chamber 106. As a result, as the combustion of the fuel mixture proceeds from the rear chamber 106 to the front chamber 108, the fuel burns faster, and the pressure in the prechamber rapidly increases. As a result, the pressure in the pre-chamber increases as the fuel mixture burns more completely. As a result, high-speed flame jets (jets) pass through the center hole 162 and the plurality of outer edge holes 164 and flow into the main combustion chamber (not shown).

  In this manner, ignition can be delayed by the flow of the flame kernel into the rear chamber 106. In some implementations, the combustion process is initiated in the rear chamber 106 and the combustion process passes through the front chamber 108 before the generated flame is emitted into the main combustion chamber. By extending the ignition delay time, the process is more repeatable and less fluctuating, as combustion is more complete, resulting in a lower COV (coefficient of variation) than typical conventional pre-chamber spark plugs. . A further advantage of the ignition delay is that the spark can be initiated early in the combustion cycle when the cylinder pressure is lower than without the ignition delay. By starting the spark when the pressure in the cylinder is low, the life of the pre-chamber spark plug 100 is extended. The pre-chamber spark plug 100 is configured to reach the maximum enclosure pressure (enclosure pressure, vessel pressure) due to combustion of the fuel mixture at an engine crank angle of 7 degrees or more after a spark event in the spark gap.

  Furthermore, in constructing the exemplary pre-chamber spark plug, the volumes of the rear chamber 106 behind the cylindrical electrode 110 and the front chamber 108 in front of the cylindrical electrode 110 are specified (or, in some cases, improved or optimized) By controlling the expansion of the flame kernel, the ignition delay time can be controlled. The ratio of the volume of the front chamber 108 to the volume of the rear chamber 106 controls the size and penetration of the flame jet (jet) exiting the central bore 162.

  FIG. 6 is a perspective view of an exemplary cylindrical electrode 180. The cylindrical electrode 180 functions as a ground electrode, and the cylindrical electrode 180 is the same as the cylindrical electrode 110 except that it has no outer ring. The cylindrical electrode 180 includes an inner ring 130 having a central opening 138. The inner ring 130 extends axially to form a speed control tube 136. In the embodiment shown in FIG. 6, the three spokes 134 extend radially outward from the outer surface of the inner ring 130. In some implementations, the tubular electrodes 180 are assembled to the pre-chamber spark plug 100 by attaching the end 182 of each spoke 134 directly to the shell 112. The attachment can be performed by welding or brazing.

  7 and 8 are end and top views, respectively, of an exemplary end cap 116 of the pre-chamber spark plug 100. FIG. In some implementations, the end cap 116 is cup-shaped and slightly protrudes from the end of the shell 112. The end cap 116 has a central hole 162 centered on the longitudinal axis 101 of the pre-chamber spark plug 100, depending on the implementation. The central bore 162 is configured to control the flow rate (flow rate) of the fuel mixture into the front chamber 108 and the velocity in the spark gap. End cap 116 further includes a plurality of outer edge holes 164. These outer edge holes 164 may be drilled or shaped in the side wall 166 of the end cap 116 or the shell 112 itself. The outer edge holes 164 are configured to generate swirl (swirl / swirl) motion of the fuel mixture within the pre-combustion chamber. In some implementations, the end cap 116 is attached to the shell 112 by welding, brazing or the like. End cap 116 may be flat (perpendicular to the shell) or "V" shaped. The shape of the shell 112 and the end cap 116 may be formed such that the end cap 116 is flat and most of the insertion depth is due to the length of the shell 112. The shape of the shell 112 and the end cap 116 is such that the shape of the end cap 116 is protruding (dome or "V" shaped) and a portion of the insertion depth is due to the length of the shape of the end cap And so on.

  7 and 8 show examples of end caps 116 having seven outer edge holes 164 and seven outer edge hole axes 168 in the side wall 166. Only one outer hole axis 168 is shown in FIG. 7 for ease of explanation. FIG. 7 is a view from an end view of the end cap 116 further including an exemplary swirl angle (pivot angle) for the outer edge hole 164 and the longitudinal axis 101 of the pre-chamber spark plug 100. In this figure, the end cap 116 is located at the position that would be present when assembled to the shell 112. FIG. 8 is a cross-sectional view of the end cap 116 showing an exemplary penetration angle for the outer edge hole 164. The size of the central hole tends to be in the range of 0.1 mm to 2.0 mm in diameter, but may be larger.

  Other implementations of the illustrated end cap 116 may have more than seven outer edge holes 164. The outer edge holes 164 are oriented such that no outer edge hole axis 168 intersects the longitudinal axis 101. As described above, FIG. 7 shows the swirl angle of the outer edge hole 164. As shown in FIG. 7, the swirl angle is defined as the angle between the perimeter hole axis 168 and the radial line 169, the radial line 169 projects from the center of the end cap 116 and is defined by the perimeter hole 164. Passing a point on the intermediate outer hole axis 168 between the two ends of the cylinder.

  In the example shown in FIGS. 7 and 8, the swirl angle is provided at 45 degrees, but in another example, the angle may be provided at an angle other than 45 degrees. FIG. 8 is a view showing the penetration angle of the outer edge hole 164. As shown in FIG. 8, the penetration angle is defined by the angle between the outer bore axis 168 and the longitudinal axis 101 or a line 171 parallel to the longitudinal axis 101. During operation of the engine, when the fuel mixture is introduced into the pre-chamber 108 of the pre-chamber, the angle formed by the outer edge holes 164 creates a swirl (swirl / swirl) effect on the fuel mixture in the pre-chamber. The exact location (i.e., location on sidewall 166) and configuration (e.g., diameter, angle) of outer edge hole 164 is such as to achieve the desired flow field and fuel mixture distribution within the pre-combustion chamber. It will be determined.

  FIG. 9 is a cross-sectional view of an exemplary pre-chamber spark plug 200. The prechamber spark plug 200 has a longitudinal axis 201. The center electrode 102 is provided to extend along the longitudinal axis 201 and further to extend into the pre-chamber divided from the insulator 104 into the back chamber 106 and the front chamber 108. The cylindrical electrode 210 is disposed inside the shell 112 and functions as a ground electrode. The disk portion 214 of the cylindrical electrode 210 is provided to separate the rear chamber 106 from the front chamber 108. End cap 116 defines the end of pre-chamber spark plug 200 and defines the boundary of front chamber 108. In some implementations, the inner surface 118 of the shell 112 may have a stepped portion 120 so that the tubular electrode 210 can be seated on the stepped portion 120 in the assembly of the pre-chamber spark plug 200. Good. The ground electrode may also be configured as a thin ring, which is attached anywhere near the base where the core extends from the shell (112) or anywhere in the shell including near the tip (108) of the shell Or by a leg attached from the end cap itself (116). The tube may also be attached using any attachment method such as welding, brazing, laser welding and the like.

  In operation, the illustrated pre-chamber spark plug 200 operates similar to the operation of the illustrated pre-chamber spark plug 100 described above. However, as can be seen in FIG. 9, a tubular inner ring or speed control tube 236 is provided extending axially towards both the front chamber 108 and the rear chamber 106. The ignition delay time can be further extended by increasing the length of the speed control tube 236, ie, by adding a portion extending into the rear chamber 106. In this case, the ignition delay time is controlled by the length of the extension to the rear of the speed control pipe 236 and the flow velocity in the extension to the rear of the speed control pipe 236. The flow rate in the speed control tube 236 is a function of mass flow through the central port (central bore) 162. The extension of the ignition delay time by extending the speed control pipe 236 enables spark initiation earlier than in the case of the pre-chamber spark plug 100. The earlier spark initiation at lower cylinder pressures prolongs the life of the spark plug. Such a design allows for the manufacture of a pre-chamber spark plug having a center electrode and a ground electrode without any precious metals. This can reduce the material cost and simplify the substantial manufacture and assembly of the spark plug. However, it is also possible to design the noble metal or non-noble metal ring to be able to be inserted into the ground electrode, since the noble metal or non-noble metal ring is in electrical contact with the body of the ground electrode and thus also in contact with the shell. The ring insert may be attached by press fit, interference fit, laser pre-welding, laser welding, brazing. This design keeps the ring insert in place, even if the weld softens or breaks due to differences in thermal expansion between the spoke-constrained portion and the unconstrained portion of the ground electrode tube. Be done.

FIG. 10 is a cross-sectional view of an exemplary pre-chamber spark plug assembly similar to the pre-chamber spark plug assembly of FIG. Certain related dimensions in FIG. 10 are shown as A-K. The dimensions relate to pre-chamber spark plugs of size M14 to M24 (ie spark plugs in which the threaded portion of the shell is a M14 to M24 metric thread). Thus, for example, the outer diameter of the shell is slightly smaller than the root diameter of the screw. Thus, the total volume of the rear chamber 106 and the front chamber 108 is in the range between 1000 mm ³ and 3000 mm ³ .

  In the example, the dimension A is a length that the ground electrode 210 extends beyond the sparking surface of the center electrode 102 and forms part of the passage. In some cases, the minimum length of dimension A is 1.0 mm. The extending ground electrode forms a velocity control tube 236. Thus, dimension A can characterize the velocity control tube 236 dimensions. The velocity control tube 236 forms a stagnant pressure zone whereby the flow of fuel mixture sweeps the flame kernel into the back chamber 106. In some cases, the gap between the end of center electrode 102 and end cap 116 can vary between 1 mm and 12 mm. Dimension B is the dimension of the extension of the ground electrode 210 in the direction away from the combustion chamber side end of the spark plug enclosure. The extension and the spark gap form part of the passage. In some cases, the length of dimension B is at least 0.1 mm.

  In the illustrated embodiment, dimensions C and D define the cross-sectional area of the inlet tube notch of velocity control tube 236. In some cases, the dimension C, ie the depth of the notch, is in the range between 0.10 and 0.70 mm. In some cases, the dimension D, ie the length of the notch, is in the range between 0.1 and 4.0 mm. The inlet tube notch minimizes flame nucleation effects during low speed operation and cold start. The dimension E defines the depth of the flame retention notch of the center electrode 102. In some cases, the range of dimension E is 0.10 to 0.70 mm. The flame retention notch allows for better recirculation and can reduce the loss effect as the flame kernel travels to the post pre-chamber 106.

  The illustrated center electrode 102 can have a rounded front defined by dimensions F and G. In the example, dimension F is the radius of curvature of the rounded tip of center electrode 102. The rounded tip directs more symmetrical flow into the spark gap and also reduces flow resistance. A flat tip with no curvature is easy to manufacture and although it can also be used in the implementation described here, more turbulence is generated and the flow velocity is also reduced. Thus, in some cases, a rounded tip may be used. The radius of the center electrode 102 is defined by the dimension G. In some cases, the length of dimension G is 3 mm. In some cases, the dimension F can be selected to satisfy G / F ≦ 1.

  In the example, the length of the spark gap surface is defined by the dimension H. In some cases, the range of dimension H is between 2.50 and 6.00 mm. In the example, the spark gap is the distance between the center electrode 102 and the ground electrode 236, which is designated as dimension J. In some cases, the spark gap distance is not a single value along the spark gap surface. The ground electrode 236 can have a conical shape defined by a taper angle K. In some cases, the range of taper angles K can be between 0.10 degrees and 2.5 degrees. In the example, the spark gap distance is minimum at the front of the ground electrode 236 and maximum at the rear of the ground electrode 236.

  In some instances, during a cold start, sparking occurs in the area near the minimum gap at the front of the spark surface. In some cases, when cold, the dimension J can be the smallest dimension in the range between 0.10 and 0.20 mm. When the spark plug is nominally warmed up, the front of the spark gap surface is warmer than the rear of the spark gap surface. As the thermal expansion at the front of the spark gap surface increases, the spark gap distance becomes more uniform and parallel along the length of the spark surface. The dimension J of the spark gap during nominal warm-up operation can be 0.42 mm in length. A spark gap in which both surfaces are parallel can create a spark over its entire length, which can increase the generation of flame nuclei.

  The ground and center electrodes may be cylindrical (cylindrical), polygonal, irregular or other shapes, respectively. For example, FIG. 10 shows a cross section of a cylindrical center electrode 102 and a cylindrical ground electrode 236. The center electrode and the ground electrode may be polygons such as the example square and triangle shown in FIGS. 11A and 11B. The velocity control tube at the front of both electrodes can be similar in shape to both electrodes (i.e. triangular in the case of FIG. 11B) or a shape different from the shape of both electrodes. Both electrodes may be irregular, or some of the electrodes may have different shapes. For example, the shape of the inner periphery of the electrode may be different from the shape of the outer periphery of the electrode. The electrodes can also be shaped to vary along the axial direction. The electrodes may be tapered, stepped or other dimensional change. The center electrode and the ground electrode do not have to have the same shape. For example, the spark surface of the center electrode and the corresponding surface of the ground electrode may coincide, and the portion in front of the center electrode (i.e. the velocity control tube) may be shaped differently.

  Both electrodes may be of different shapes, or may include different or multiple portions, arrangements, locations or sparking surfaces. For example, FIG. 12 shows an exemplary spark plug assembly having a plurality of ground electrodes 704 a, 704 b surrounding a single center electrode 702. The illustrated ground electrodes 704a, 704b are adjacent but do not intersect. The plurality of ground electrodes 704a, 704b define a flow path that passes through the spark gap. The ground electrodes 704a, 704b may have a forwardly extending wall with which the speed control tube is formed beyond the spark gap. Also, both electrodes 704a, 704b may have an extension that extends rearward. In other instances, speed control tubes can be attached to the forward or backward facing surfaces of both ground electrodes 704a, 704b.

  FIG. 13 shows a front cross section of an exemplary spark plug assembly. In this example, the velocity control tube 806 is a cylinder centered on the spark gap between the center electrode 802 and the J-shaped ground electrode 804. The illustrated velocity control tube 806 can be attached to the ground electrode 804 or the center electrode 802. In some cases, the tube 806 can have a portion that extends downwardly above the sides of the gap. The velocity control tube can be cylindrical, polygonal or other shape. There is no need to center the speed control tube on the center electrode.

  FIG. 14 is a cross-sectional view of an exemplary pre-chamber spark plug assembly 300. Pre-chamber spark assembly 300 includes a pre-chamber 304 within the head of a large bore piston cylinder chamber 302. There is a spark plug 306 in the pre-chamber 304, and the spark plug 306 is configured to have the pre-chamber 304 in the head of the large bore piston cylinder 302.

  15 is an enlarged cross-sectional view of the pre-chamber 304 of the example pre-chamber spark plug assembly 300 of FIG. The prechamber 304 is connected to the engine combustion chamber 302 through a series of vents 324 and is bounded by a shell 334. The vents 324 allow fuel mixture to enter the pre-chamber 304 and allow flames to exit the pre-chamber 304 and enter the cylinder assembly 302. Although FIG. 15 illustrates that there are three air vents, it may be more or less. Additionally, the vents 324 (or any of the holes described herein) may be formed as slots or other shaped tangible holes.

  The illustrated pre-chamber 304 has a longitudinal axis 301 and a central electrode 310 extending axially along the longitudinal axis 301 and entering the pre-combustion chamber (pre-chamber) 304. Around the center electrode at the distal end of the center electrode 310 is a ground electrode 308. The ground electrode 308 is attached to the insulator 312, which insulates the center electrode 310 from the ground electrode 308. In some cases, center electrode 310 is connected to a voltage source (not shown) through the interior of insulator 312 to an electrically grounded shell 334.

  The ground electrode 308 forms a circular area around the distal end of the center electrode 310 and forms a spark gap 314 around the distal end of the center electrode 310. In addition, the spark gap 314 is located between the outer peripheral surface of the center electrode 310 and the cylindrical inner ring of the ground electrode 308 disposed at an interval so as to surround the center electrode 310. An insulator 312 extends axially around the center electrode 310 from above the spark gap 314 to the top of the pre-chamber 304. The insulator 312 functions as a speed control pipe. Further, above the spark gap 314 there are two transverse slots or holes 318 drilled in the insulator 312. The transverse holes 318 serve to ventilate the flame kernel after an ignition event.

  In some instances, the area inside center insulator 310 around center electrode 310 is referred to as first stage 320 of pre-chamber 304. The first stage 320 limits the fuel to a small space so that the flame kernel generated at the ignition event is protected and controlled so as not to cause excessive damage to the ground electrode 308 and the center electrode 310. Can. The insulator 312 has two transverse holes 318, but may be more or less.

  In some instances, the area bounded by shell 334 outside insulator 312 is referred to as second stage 322 of pre-chamber 304. In the illustrated example, the second stage 322 is where the flame kernel begins to expand prior to exiting through the vent 324 and into the engine combustion chamber 302 (i.e., the cylinder).

  Furthermore, the illustrated ground electrode 308 extends further back into the pre-chamber 304 than the center electrode 310. As shown in FIG. 15, the exemplary ground electrode 308 has a radially offset circumferential extension axially beyond the distal end of the center electrode 310 forming an aerodynamic nose cone. . The shape of the aerodynamic nose cone is configured to facilitate the flow of the fuel mixture passing through the space between the ground electrode 308 and the center electrode 310. The nose cone is said to be aerodynamic in that it is designed to smoothly guide the flow around the leading edge of the ground electrode 308 (to minimize flow separation). In other examples, the nose of the ground electrode 308 could be rounded. The extension forms an aerodynamic ram area 316 (i.e. a speed control tube). The aerodynamic ram area 316 functions to capture the gas phase (air-fuel mixture) flowing from the main cylinder chamber 302 into the pre-chamber 304. The trapped gas phase is a fuel mixture that is ignited at the spark gap 314. The gas phase passing through the spark gap 314 flows parallel to the spark gap 314, and the flow velocity range is 5 m / sec or more, and may be 50 m / sec in some cases. The spark gap has a relationship of height H, flow velocity V through the gap, and thus H / V * 360 * RPM ((H / V) × 360 × RPM) (RPM is the number of revolutions per minute) The crank can be made 3 degrees or less.

  As an aside, changing the width of the spark gap 314 affects the useful life of the spark plug in some instances. For example, increasing the axial length of the spark gap increases the surface area where sparks are generated. Thus, it takes longer for the materials comprising the center electrode 310 and the ground electrode 310 to corrode until the plug itself needs to be repaired or replaced. However, the disadvantage of increasing the width is that the initial ignition of the fuel becomes more difficult since it reduces the first stage.

  An example of how combustion occurs in the illustrated pre-chamber 304 and how it is managed is illustrated in FIG. First, a mixture of fuel and air flows from the cylinder assembly 302 through the vent 324 into the pre-chamber. During the compression stroke of the associated engine system (not shown), flow is generated by the differential pressure generated between the combustion chamber 302 and the pre-chamber 304 of the engine. The flows are comprised of primary and secondary flows 328 and 330, respectively. When the primary and secondary streams 328, 300 flow into the prechamber 304, the primary and secondary streams 328, 300 are fresh air uniformly dispersed in fuel, sparking residual fuel from the previous ignition step. Purge from the gap 314 and the second stage. The secondary flow is evenly distributed around the second stage 322 of the prechamber 304. The primary flow 328 is captured 316 in the aerodynamic ram area. The aerodynamic ram area 316 collects primary flow around the spark gap 314. The velocity of primary flow 328 into spark gap 314 is between 1 meter and 100 meters per second. A portion of the fuel in primary flow 328 collects around spark gap 314, creating a differential pressure between a location within aerodynamic ram area 316 and first stage 320. Thus, the fuel flows into the first stage 320 of the prechamber 304. The flow entering the spark gap 314 purges the residue of the spark gap 314 and most of the residue is replaced by fresh air. For example, the residue can be replaced by a mixture that is predominantly fresh air. In some cases, the mixture comprises fresh air and residues, but in some cases, all of the mixture is fresh air. In certain embodiments, the distal end of center electrode 310 is flat to facilitate primary flow 328 into spark gap 314.

  Also, in some instances, fuel flows through the transverse holes 318. This flow is mostly backwards away from the end cap. Thus, the majority of the flow is in this direction, and in some cases all the flow is in this direction. The transverse holes 318 are angularly offset so as not to be perpendicular to the central axis 301. This can prevent the fuel mixture from the secondary stream 330 from filling the first stage 320. Thus, the differential pressure generated by the aerodynamic ram area 316 is not impeded by the transverse holes 318. As the flow passes through the transverse holes 318, the velocity at its inlet is maintained. This maintains a pressure lower than the stagnant pressure of fluid in the aerodynamic ram area 316. Thus, a differential pressure is generated across the spark gap.

  Once a spark is generated in the illustrated spark gap 314, the fuel in the spark gap 314 is ignited and a flame kernel 332 is generated. The differential pressure causes the flame kernel 332 to move to the first stage 320 of the prechamber 304, but because the first stage 320 is configured to be relatively small, the flame kernel 332 is protected from the outside environment. The first stage 320 functions as a flame holder. The flame kernel travels up and enters a notch 332 located in the center electrode 310. Notches 332 now introduce the flame kernel into the counterstepped structure 334 of the ground electrode 308. As the primary flow enters the first stage 320, the counter-directed stepped structure forms a recirculation zone. Then, while protecting the flame kernel from being lost by the primary flow flowing into the spark gap 314, some of the fuel existing there is captured to grow the flame kernel slightly. Thus, the notches 332 and the counterstepped stepped structure 334 form a flame holder that protects the flame kernel from the faster primary stream 328.

  Also, the flame kernel 332 remains small because only minimal fuel can enter the first stage 320 from the transverse holes 318. This keeps the temperature in the first stage 320 low and also minimizes damage to the spark gap 314, the ground electrode 308, and the center electrode 310.

In the illustrated embodiment, the flame kernel 332 travels to the second stage 322 of the prechamber 304 through the transverse holes 318 while consuming fuel in the first stage. The flame kernels 332 are carried by the secondary flow 330 and surround the ground electrode 308 . Here, the flame kernel 332 starts to spread, and the fuel in the second stage 322 is consumed. Then, the flame expands and the pressure in the prechamber 304 significantly increases. Then, a flame is injected from the air vent 324 to the engine combustion chamber 302 to ignite the fuel in the engine combustion chamber 302.

  By controlling the flow of flame kernels 332 around the center electrode 310, the useful life of the pre-chamber spark plug assembly 300 can be extended. This is because only the small flame kernel 332 can burn around there since the first stage surrounds the center electrode 310. This is in contrast to conventional systems where the spark gap was exposed without any protection.

  An exemplary secondary fuel injector (fuel injector) 326 in the pre-chamber 304 is shown in FIG. The illustrated secondary fuel injector 326 injects fuel into the pre-chamber 304. Another primary fuel injector (not shown) injects fuel into the main cylinder chamber 302, which moves through the vent 324 into the pre-chamber 304. The secondary fuel injectors 326 allow the mixture in the prechamber to be richer (enriched) than the normal primary injection.

  Typically, the air-fuel ratio of the illustrated cylinder chamber 302 is the stoichiometric air-fuel ratio (stoichiometric ratio). That is, before combustion, the same amount of fuel and air are present in the cylinder 302. Therefore, the air-fuel ratio in the prechamber 304 is less than the stoichiometric air-fuel ratio (lean) as compared to the flow through the vent 324. In the pre-chamber 304 with the secondary fuel injectors 326, the secondary fuel injectors 326 increase the ratio of fuel to air in order to provide a properly fuel-enriched environment. Generally, this increase causes the lean (air excess) mixture entering from the main combustion chamber to be made to the stoichiometric air fuel ratio, in other words, since air is present in the prechamber 304 before combustion, Enrichment (enrichment) of the chamber fuel to more than twice the air-fuel ratio of the main chamber is not special. By enriching the pre-chamber 304, the ignition process becomes hotter. However, if the ignition process is heated to a higher temperature, the service life of the center and ground electrodes 310, 308 is impaired. In this example, since the fuel supply (fuel enrichment) pre-chamber is only minimally enriched or not enriched at all, the air-fuel ratio in the pre-chamber is an air near the lean mixture in the main chamber. It becomes a fuel ratio, and it is as far as possible from the enrichment of the theoretical air fuel ratio. By reducing the enrichment in the pre-chamber, the combustion temperature at and around the spark surface is reduced, extending the life of the spark plug.

  FIG. 18 shows the gas inlet valve 402 integrally formed with the shell 416 of the prechamber 404 and combined with the spark plug 400. In the particular embodiment shown in FIG. 18, there are three different gas inlet valves 402a, 402b, 402c. The gas inlet valves 402 a, 402 b, 402 c supply the fuel of the storage chamber 430 to the pre-chamber 404. As described with respect to FIG. 17, the gas inlet valve 402 allows the user to adjust the concentration of the air-fuel ratio in the pre-chamber 404. Furthermore, in certain embodiments, spark plug 400 including insulator 414, center electrode 406, and ground electrode 408 can be removed from portions of gas entry valve 402 so that spark plug 400 can be quickly replaced. Is promoted.

  FIG. 19 is an enlarged view of the pre-chamber 404 of FIG. The pre-chamber 404 is connected to the cylinder of an engine (not shown) system by an end cap 440 having a vent 412. Similar to the previously discussed implementation, the prechamber 404 includes a center electrode 406, a ground electrode 408, a vent 412, an insulator 414, and a shell 416. There is also an aerodynamic ram 428 in this embodiment. Additionally, the insulator includes transverse holes or slots 418. Similar to the transverse holes 318 (FIG. 15), the provision of the slots 418 allows the first electrode defined by the cavity formed between the ground electrode 408 connected to the insulator 414 and the center electrode 406. Access from the second stage 422 defined by the cavity formed between the stage 420 and the shell 416 and the ground electrode 408 attached to the insulator 414.

  In some instances, the first differential pressure occurs on the compression stroke of the engine system, and the compression stroke causes the fuel mixture to flow through the vent 412 into the prechamber 404 at a speed between 1 and 100 meters per second. Push in the opposite direction and away from the end cap. As the air-fuel mixture flows into the prechamber 404, the air-fuel mixture gathers around the spark gap 424 formed between the center electrode 406 and the ground electrode 408. Because the width of the spark gap 424 is relatively small, a second differential pressure between the first stage 420 and the second stage of the pre-chamber 404 is obtained. Therefore, when a spark is generated in the spark gap 424, the flame kernel generated by spark ignition of the fuel mixture is drawn into the first stage 420 by the second differential pressure. Because the first stage has an enlarged area, the flow is decelerated to form a recirculation zone. The enlarged area is formed by notching the notch at the exit of the spark surface area of the center electrode. The recirculation zone can hold the reactive particles in the recirculation loop and operate efficiently as a flame holder, thereby preventing the flame kernels being flushed out of the spark gas region from becoming extinguished. The flame kernel continues to burn the first stage fuel until it exits the slot 418 to the second stage 422. In the second stage, the flame kernel consumes the fuel in the pre-chamber 404 and grows into a flame. As a result, the pressure in the prechamber 404 is greatly increased, and the flame is ejected from the vent 412.

  The temperature of the spark surface can be lowered by taking out the flame kernel from the spark gap region and injecting it into the flame holder. By reducing the temperature of the spark surface, it is possible to reduce the high temperature oxidation of the spark surface in a high temperature oxidation environment, which is a main cause of the end of life of the spark plug. Therefore, by taking out the high temperature flame kernel from the spark gap after the spark generation, the life of the spark surface and hence the spark plug can be extended, and the possibility of the flame kernel disappearance can be reduced (or prevented).

  In some instances, another role of the central bore flow, i.e., the primary bore flow, is to cool the cylindrical ground electrode and spark area during introduction prior to sparking. This is because fresh air introduced is cooler than residual gas in the pre-chamber. In addition to further extending the life of the surface of the spark plug, this also lowers the surface temperature of the pre-chamber and maintains the temperature below the autoignition temperature of fresh air.

  Similar to the previous example, controlling the flow of flame kernels around the center electrode 406 can significantly extend the useful life of the illustrated spark plug 400. Because, unlike some prior systems where the spark gap was unprotected and exposed, the first stage surrounded the center electrode 406 so that small flame kernels could only burn around it It is because

  In another example, as shown in FIG. 20, a clevis is formed between the outer surface of the ceramic insulator 912 and the inner surface of the shell 934 at a position close to the base or base of the shell 934 and the insulator 912. A (gap) 936 is formed. Clevis 936 is designed to enhance heat transfer from the hot residual fuel / gas to the cooler shell region. The shell region is cooled from the rear surface by being locked by a screw of a cylinder (not shown) (water or oil cooling is assumed). The surface area to volume ratio of Clevis 936 is high, which promotes cooling of the residual gas and thus "quenchs" the reactivity of the residual gas.

  In one embodiment, the volume of the clevis 936 is designed to be about 1/5 to 1/10 of the volume of the pre-chamber 904, so that when the pre-chamber 904 is filled with residual gas, the compression ratio of the engine The residual gas is compressed into Clevis 936 which occupies only a space less than that allowed by (ie, in the case of a CR engine with a compression ratio of 10: 1, the gas volume of the prechamber will be 1/10 by compression).

  In a further embodiment, to further improve the heat removal ability of clevis 936 to cool residual gas, the surface area of the clevis area is increased by the same means as "screwing" shell 934 onto clevis 936. Can be included.

  Regarding the manufacturing method, good heat transfer will be obtained if melting is done in a brazing oven using a brazing ring above or below the ground electrode. Similarly, the ground electrode can be welded to the shell with a laser welder, friction welder or the like.

  FIG. 21 is a cross-sectional view of a portion of an exemplary pre-chamber spark plug having a braze ring. FIG. 22 is an enlarged view of a braze ring disposed within the pre-chamber spark plug of FIG. 21; The outer ring 1032 of the ground electrode 1010 has an angled notch 1006 and the brazed ring 1002 rests on the annular gap 1004 created by the notch 1006 prior to laser welding. In the example shown in FIG. 21, at the time of assembly, the ground electrode 1010 is pressed into the shell 112, whereby the ground electrode 1010 is mounted on the step 120. After the ground electrode 1010 is mounted on the step 120, the braze ring 1002 is placed in the annular gap 1004. After the brazing ring 1002 is placed in the annular gap 1004, the laser welding machine is used to melt the brazing ring 1002 and pour it into the annular gap 1004, and the ground electrode 1010 is bonded to the shell 112 by brazing. be able to. As a result, the ground electrode 1010 and the shell 112 are firmly coupled, so that thermal deformation does not occur between the ground electrode 1010 and the shell 112 after the coupling. Also, only the brazing ring 1002 melts, and the ground electrode 1010 and the shell 112 do not deform after brazing. Furthermore, the angled notch 1006 may not be angled, and the notch of the ground electrode 1010 may be of any suitable shape for retaining the braze ring 1002 It may be. For example, the notch may be conical or rectangular. Additionally, the step of flowing the molten braze ring 1002 into the annular gap 1004 may be assisted with a flux. Flux may be applied to the angled notch 1006 or shell 112 to be drawn towards the angled notch 1006 and the shell 112 as the braze ring 1002 melts to fill the annular gap 1004. . Typical fluxes used for brazing are borax, borates, fluoroborates, fluorides, chlorides and the like. As an aside, it is not necessary to use the process of brazing welding for this process. The ground electrode 1010 can be attached to the shell 112 by a brazing process. Regardless of the brazing process and the brazing welding process, the brazing ring is made of an alloy such as aluminum silicon alloy, copper alloy, copper-zinc alloy, gold-silver alloy, nickel alloy, silver alloy and the like.

  Furthermore, the center electrode may be made of a solid metal alloy, or one cylinder is called a substrate and the other is a weld between two cylinders called noble metal material. May be After proper alignment (alignment, centering) is obtained in the manufacturing process, the noble metal and the base material can be joined by various methods such as resistance welding, inertia welding, and laser welding.

  Similarly, a hollow cylinder made of precious metal can be made and placed over the center electrode of reduced diameter to obtain a structure in which the cylinder is outside the "pin". The noble metal hollow cylinder is held in place by a holding cap which is fixed by welding or mechanical means (such as screws).

  The concepts herein are applicable to other structures of the pre-chamber spark plug, but can be configured to include speed control tubes in existing structures. For example, FIGS. 23A and 23B show a spark plug 500 with an end cap 512 but without a speed control tube. FIG. 23A is a top view of the end cap of the spark plug 500. FIG. 23B is a cross-sectional view of the spark plug 500. FIG. A cylindrical ground electrode 505 is supported from the shell 503 by the arms 506a, 506b. The arms 506 a, 506 b are not attached to the side wall of the shell 503 but extend in the opposite direction and attached to the rear surface of the shell 503. The ground electrode 506 surrounds the center electrode 502 but is spaced apart from the center electrode 502 by a spark gap 504. End cap 512 encloses electrodes 502 and 506. End cap 512 has a plurality of central holes 510a-510f and a plurality of transverse holes 508a, 508b at its top.

  FIG. 24 shows an example of how to apply spark plug 500 in accordance with the concepts herein to produce spark plug 520. The illustrated spark plug 520 is generally similar to the spark plug 500 shown in FIG. 23 (without any changes to affect the described operation), but includes a forward velocity control tube 514. The velocity control tube 514 can be attached to the front of the ground electrode 506, to the arms 506a, 506b, and any other support member such as a ring.

  FIG. 25 shows an example of how to apply spark plug 500 in accordance with the concepts herein to produce spark plug 530. As shown in FIG. The illustrated spark plug 530 is generally the same as the spark plug 500 shown in FIG. 23 (without changes that affect the described operation), but includes a rearward velocity control tube 515. The velocity control tube 515 can be attached to the rear of the ground electrode 506 to the arms 506a, 506b and any other support member such as a ring.

  FIG. 26 shows an example of how to apply spark plug 500 in accordance with the concepts herein to produce spark plug 540. The illustrated spark plug 540 is generally the same as the spark plug 500 shown in FIG. 23 (without changes to affect the described operation), but includes both forward and aft speed control tubes 514 and 515. The speed control tubes 514, 515 can be attached to the ground electrode 506, to the arms 506a, 506b and any other support member such as a ring.

  Computational Fluid Dynamics (CFD) analysis was performed using a pre-chamber spark plug configured as shown in FIG. 10 and a pre-chamber spark plug identical in size and structure but not including a velocity control tube. FIG. 27A is a plot of the velocity of a spark plug without a velocity control tube. FIG. 28A is a plot of the speed of a spark plug configured as shown in FIG. In both figures, the end of the spark plug projects into the engine combustion chamber. An arrow is superimposed over the plot to indicate the direction of flow. FIG. 27B is a plot of the velocity vector of a spark plug without a velocity control tube. FIG. 28B is a plot of the velocity vector of the spark plug configured as shown in FIG. FIG. 27C is a plot of the fuel mixture distribution of a spark plug without a velocity control tube. FIG. 28C is a plot of the fuel mixture distribution of the spark plug configured as shown in FIG.

  Both configurations have a 3.0 mm diameter sparking surface (i.e. an adjacent surface forming a spark gap) and a maximum spark gap of 0.42 mm, and the shell 112 and end cap are identical in structure to the M18 plug It is. The situation outside shell 112 was modeled to show the condition at a 20 mm crank angle before top dead center for an engine with a bore diameter of 155 mm and a 180 mm stroke rotating at 750 rpm. 27A-27C show a typical ring-shaped ground electrode 505 that does not have a velocity control tube and does not extend beyond the sparking surface or the end of the center electrode 502 or rearward from the sparking surface. Have. The axial length of the ground electrode 505 is 1.25 mm, and forms a sparking surface having a length of 1.25 mm. 28A-28C have a ground electrode with a speed control tube 236 extending beyond the end of the center electrode 102 towards the end of the plug on the combustion chamber side. A tube 236 extends rearward from the sparking surface around the center electrode 102. The extent to which the velocity control tube 236 extends beyond the end of the center electrode 102 was selected using conventional fluid analysis to obtain the velocity described below. The extent to which the velocity control tube 236 extends aft of the sparking surface was selected using conventional fluid analysis to isolate the flow exiting the spark gap from pre-chamber turbulence. The sparking surface of FIGS. 28A-28C starts at the base of the rounded tip of the center electrode 102 and extends rearward to a step of diameter, the length of which is 3.5 mm.

  27A and 28A show that the peak velocity of the fresh air fuel mixture flowing from the combustion chamber through the central hole 162 is 64 m / s in FIG. 27A and 54 m / m in FIG. 28A, as can be seen from the velocity plot. It was almost the same in any case of seconds. However, in FIGS. 27A, 27 B, the inflowing flow impinges on the end of the center electrode 502 and most of the flow is directed laterally outward, gradually rotating around the ground electrode 505 to the pre-chamber. It will come to the rear. Thus, most of the flow is in this direction, and in some cases all flows are in this direction. The stagnant zone at the end of the center electrode 502 generates high pressure which directs the incoming flow further laterally outward. Conversely, the high velocity ahead of the ground electrode 505 creates a low pressure zone that draws the flow from the back of the prechamber through the spark gap. The peak velocity at the midpoint of the spark surface is 8 m / s, but this flow is from the rear to the front. During engine operation, residual gas (burned fuel mixture) tends to accumulate at the rear of the prechamber. Thus, with this cycle, residual gas is provided to the spark gap in a backward to forward flow. Referring to FIG. 27C, it can be seen that the highest lambda value (ie, the leanest fuel mixture) is seen aft in the pre-chamber and in and behind the spark gap.

  In contrast, in FIGS. 28A, 28 B, the incoming flow impinges on the end of the center electrode 102 and is initially oriented transversely, but the flow is trapped in the wall of the velocity control tube 236 , Directed backward into the spark gap. A stagnant zone at the end of the center electrode 102 generates high pressure which directs the flow further into the velocity control tube and aft. The length of the velocity control tube 236 is selected to achieve this flow pattern. The peak velocity at the midpoint of the spark surface is 44 m / s. Further, this flow is a fresh air fuel mixture directly received from the combustion chamber via the central bore 162. Referring to FIG. 28C, it can be confirmed that the lowest lambda value (i.e., the richest air-fuel ratio) is observed from the central hole 162 through the inside of the speed control pipe 236 into the spark gap. Thus, this cycle provides fresh air fuel mixture to the spark gap in a forward to aft flow. The fresh air fuel mixture supplies fuel to the back region of the prechamber while sweeping away any residue present in the spark gap (due to the previous combustion cycle) all over the spark surface and back of the prechamber. Maintain sufficient speed to do. When the spark plug is ignited, the flame kernel generated by the electric spark passes quickly through the spark gap to the back of the prechamber, reducing the possibility of the nucleus being lost at the spark surface. In some cases, the speed at which this flame kernel passes through the spark gap makes it possible to obtain a large spark surface without losing the kernel, which is obtained when the speed through the gap is zero or low. Larger than face. In general, the larger the spark surface, the greater the surface area that generates an electrical spark, and the less wear on the material that generates the spark, the longer the life of the spark plug.

  In the example of FIGS. 28A-28C, the peak velocity at the midpoint of the sparking surface is 81% of the peak velocity at the central hole 162 of the incoming flow, but the concept here is only between 10% and 100%. Function. FIG. 29 shows another example in which the pre-chamber plug of FIG. 28A to FIG. 28C is operated at the same rotation speed as 1500 rpm under the same conditions as FIG. 28A to FIG. 28C. In this example, the peak velocity of the fresh air fuel mixture entering the combustion chamber through the central bore 162 is 55 m / s. The peak velocity at the midpoint of the spark surface is 27 m / s. Thus, the peak velocity at the midpoint of the spark surface is 49% of the peak velocity at the central hole 162 of the incoming flow. In particular, as mentioned above, the spark gap is supplied with a stream of fresh air mixture from the front to the back for combustion, but this speed is maintained up to the entire spark surface and to the back of the prechamber. . Similar flow patterns and performance are obtained with all implementations described herein (except for FIG. 23).

  Although the specification contains many details, it should be understood that they are not intended to limit the scope of what may be claimed, but rather to a description of the particular features in a particular example. Certain features described herein may also be combined in the context of separate implementations. Conversely, various features that are described in the context of a single implementation can also implement multiple implementations separately or optionally in appropriate subcombinations (subcombinations).

Many examples have been described. Nevertheless, it goes without saying that various modifications can be made. Accordingly, other implementations are within the scope of the following claims.
1. The method of the first aspect is
A method of promoting combustion in the operation of an engine:
Receiving a fuel mixture from a combustion chamber of the engine into a spark plug enclosure;
Igniting the received fuel mixture within a spark gap within the enclosure;
The peak flow rate through the spark gap is set at 10% of the peak flow rate into the enclosure such that the ignited fuel mixture leaves the combustion chamber side end of the enclosure at the peak flow rate mostly through the spark gap. Directing at a flow rate of% or more.
2. In the method of the second aspect, in the first aspect, the peak flow velocity through the spark gap is 5 m / sec or more, and the residual gas is purged from the spark gap.
3. In the method according to the third aspect, in the first aspect or the second aspect, the height H of the spark gap is 2.5 mm or more, and the peak flow velocity in the spark gap is V, H / V * 360 * RPM is less than 3 degrees crank angle of the engine.
4. In the method of the fourth aspect, in any of the first to third aspects,
Directing the fuel mixture contained in the swirl flow to the periphery of the interior of the enclosure and to the end of the enclosure opposite the combustion chamber end;
Protecting the fuel mixture ignited in the spark gap from the swirl flow.
5. The method of the fifth aspect comprises, in the fourth aspect, protecting the ignited fuel mixture exiting the spark gap from the swirl flow.
6. In the method according to the sixth aspect, in any of the first to fifth aspects, the size of the spark plug is M14 to M24, and the maximum pressure in the enclosure due to the combustion of the fuel mixture is And a step of delaying the crank angle of the engine by 7 degrees or more from the ignition of the fuel mixture at the spark gap.
7. In the method according to the seventh aspect, in any one of the first aspect to the sixth aspect, substantially all of the fuel mixture present in the half opposite to the combustion chamber side end of the enclosure is ignited Only if this is the case is the step of injecting the ignited fuel mixture from within the enclosure into the combustion chamber of the engine.
8. A spark plug for an engine of the eighth aspect;
With a spark gap in a spark plug enclosure;
A passage inside the enclosure that receives flow from the outside of the enclosure during engine operation, and the flow is directed through the spark gap such that the majority of the flow is away from the combustion chamber end of the enclosure Equipped with an aisle;
The spark plug includes means for creating a peak flow rate in the spark gap that is at least 10% of the peak flow rate into the enclosure.
9. In the spark plug of the ninth aspect, in the eighth aspect, the spark plug is configured to generate the peak flow velocity of 5 m / sec or more in the spark gap.
10. In a spark plug according to a tenth aspect, in the eighth aspect or the ninth aspect, the height of the spark gap is H, the peak flow velocity in the spark gap is V, and the crank angle of the engine is 3 degrees or less Produces H / V * 360 * RPM.
11. In a spark plug according to an eleventh aspect, in the tenth aspect, the spark plugs are M14 to M24, and H is 2.5 mm or more.
12. In a spark plug according to a twelfth aspect, in any of the eighth aspect to the eleventh aspect, the spark plug is a spark plug having a size of M14 to M24, and the passage exceeds an end of the spark gap. It extends 1.0 mm or more toward the end on the combustion chamber side of the enclosure.
13. In the spark plug of the thirteenth aspect, in the twelfth aspect, the passage includes the spark gap, and is separated from the combustion chamber side end of the enclosure from the opposite end of the spark gap. .1 mm or more.
14. The spark plug of the fourteenth aspect is the hole according to the twelfth aspect or the thirteenth aspect, wherein the hole in the combustion chamber side end of the enclosure is oriented to direct the flow into the passage;
A hole in the combustion chamber end of the enclosure, oriented to direct flow towards the outer periphery of the passage and to the end of the enclosure opposite the combustion chamber end. Prepare.
15. In the spark plug of the fifteenth aspect, in any of the eighth aspect to the fourteenth aspect, the size of the spark plug is M14 to M24, and the spark plug is configured to ignite the engine from the ignition at the spark gap. At a crank angle of 7 degrees or more, the pressure in the enclosure reaches the maximum pressure by the combustion of the fuel mixture.
16. The spark plug of the sixteenth aspect is any one of the eighth to fifteenth aspects described above,
With metal shells;
An electrical insulator in said shell;
A center electrode extending from the insulator;
The center electrode may include at least one ground electrode defining the spark gap and at least one ground electrode defining the passage.
17. In the spark plug of the seventeenth aspect, in the sixteenth aspect, more than one ground electrode defines the passage, and the ground electrodes do not intersect.
18. The spark plug of the eighteenth aspect is the spark plug according to the sixteenth aspect or the seventeenth aspect, wherein the one or more ground electrodes comprise a tube, the tube defining the passage and directing from the tube to the shell. And an arm extending away from the combustion chamber end of the enclosure.
19. In the spark plug of the nineteenth aspect, in any of the sixteenth to eighteenth aspects, the central electrode has a polygonal axial cross section.
20. In the spark plug of the twentieth aspect, in the nineteenth aspect, the one or more ground electrodes define the passage in the same shape as an axial cross section of the center electrode.

100, 200 pre-chamber spark plug 102, 406, 502, 702, 802 center electrode 104, 414, 912 insulator 106 back chamber 108 front chamber 110, 111, 210, 180 cylindrical electrode 112, 334, 416, 503, 934 Shell 114, 214 Disc portion 116, 440, 512 End cap 118 Surface 120 Stepped portion 130 Inner ring 132, 1032 Outer ring 134 Spokes 136, 236, 514, 515, 806 Speed control tube 138 Central opening 140 Inner surface 142 First The surface ring 144 of the electrode The surface ring 146 of the second electrode Outer surface 148, 156 Tab 152 Notch 154 Annular receiver 162 Center hole 164 Outer hole 168 Peripheral hole 168 Outer hole axis 169 Radial 171 parallel to the longitudinal axis Line 182 End 201, 301 Longitudinal axis 300 Prechamber spark assembly 302 Piston cylinder 304, 404, 904 Prechamber 314, 424, 504 Spark gap 316 Aerodynamic ram area 318, 508a, 508b Transverse bore 320, 420 First stage 322, 422 Second stage 324, 412 Vent 330 Secondary flow 332 Flame core 400, 500, 520, 530, 540 Spark plug 402a, 402b, 402c Gas entry valve 408, 505, 704a, 704b 804, 1010 Grounding electrode 418 Slot 428 Aerodynamic ram 430 Storage chamber 506a, 506b Arm 510a-f Central hole 936 Clevis 1002 Brazing ring 1004 Annular gap 1006 Cutting Missing

Claims (20)

A method of promoting combustion in the operation of an engine:
Receiving a fuel mixture from a combustion chamber of the engine into a spark plug enclosure;
Igniting the received fuel mixture within a spark gap within the enclosure;
The ignited fuel-air mixture, and through the spark gap, more than 10% of the peak flow rate of the peak flow rate entering the enclosure, and the step applying rectangular direction away from the end of the combustion chamber side of the enclosure ;
Moving the ignited and directed fuel mixture to a first stage forming a recirculation zone ;
Method. The peak flow velocity through the spark gap is 5 m / s or more, and purges residual gas from the spark gap.
The method of claim 1. The height H of the spark gap is 2.5 mm or more, the peak flow velocity in the spark gap is V, and ( H / V ) × 360 × RPM is 3 crank angles or less of the engine.
A method according to claim 1 or claim 2. Directing the fuel mixture contained in the swirl flow to the periphery of the interior of the enclosure and to the end of the enclosure opposite the end on the combustion chamber side;
Protecting the fuel mixture ignited in the spark gap from the swirl flow in the first stage ;
A method according to any one of the preceding claims. The fuel mixture in said said ignited first stage exiting from the spark gap, an internal step is moved Ru is consumed fuel in the swirl flow in the periphery of the enclosure,
5. The method of claim 4. The sizes of the spark plugs are M14 to M24,
Delaying the maximum pressure in the enclosure due to the combustion of the fuel mixture from the ignition of the fuel mixture at the spark gap by a crank angle of at least 7 degrees of the engine;
A method according to any one of the preceding claims. Only when the fuel mixture existing in the half opposite to the end on the combustion chamber side of the enclosure is almost completely ignited, the ignited fuel mixture is transmitted from the inside of the enclosure to the combustion chamber of the engine With the step of injecting
A method according to any one of the preceding claims. A spark plug for an engine,
A spark gap in the spark plug enclosure;
An inner passage of the enclosure to receive the flow from the outside of the enclosure during operation of the engine, the flow, and through the spark gap, the direction away from the end of the combustion chamber side of the enclosure Equipped with an aisle;
The spark plug extends beyond the end of the center electrode toward the end on the combustion chamber side of the spark plug, creating a peak flow velocity in the spark gap that is 10% or more of the peak flow velocity to the enclosure one or more ground electrodes having a speed control tube seen including,
Downstream of the spark gap, there is provided a first stage into which the flow ignited in the spark gap enters and which forms a recirculation zone.
Spark plug. The spark plug is configured to produce the peak flow velocity of 5 m / s or more in the spark gap,
The spark plug according to claim 8. The height of the spark gap is H and the peak flow velocity in the spark gap is V, producing ( H / V ) x 360 x RPM with a crank angle of 3 degrees or less of the engine,
The spark plug according to claim 8 or 9. The spark plugs are M14 to M24, and H is 2.5 mm or more.
A spark plug according to claim 10. The spark plug is a spark plug having a size of M14 to M24, and the passage extends beyond the end of the spark gap toward the end on the combustion chamber side of the enclosure by 1.0 mm or more.
A spark plug according to any one of claims 8 to 11. Said passage, said extending above 0.1mm from opposite ends of the spark gap away from the end of the combustion chamber side of the enclosure together comprising the spark gap,
A spark plug according to claim 12. A first hole in the combustion chamber end of the enclosure, oriented to direct flow into the passageway;
Flow, and an outer periphery of said passage, said the end of the combustion chamber side is oriented to direct the an end portion of the enclosure on the opposite side, the inside end portion of the combustion chamber side of the enclosure With 2 holes;
The spark plug according to claim 12 or claim 13. The sizes of the spark plugs are M14 to M24,
The spark plug is configured such that the pressure in the enclosure reaches a maximum pressure by combustion of a fuel mixture at a crank angle of 7 degrees or more of the engine from ignition at the spark gap.
The spark plug according to any one of claims 8 to 14. With metal shells;
An electrical insulator in said shell;
It said center electrode extending from the insulator;
And a least one ground electrode defining the one or more ground electrodes and said passage defining said spark gap by said central electrode;
The spark plug according to any one of claims 8 to 15. More than one ground electrode defines the passage, the ground electrodes do not intersect;
The spark plug according to claim 16. The one or more ground electrodes comprise a tube, the tube defining the passage and comprising an arm extending from the tube towards the shell and away from the combustion chamber end of the enclosure.
A spark plug according to claim 16 or 17. The central electrode is polygonal in axial cross section,
A spark plug according to any one of claims 16 to 18. The one or more ground electrodes define the passage in the same shape as the axial cross section of the center electrode,
The spark plug according to claim 19.