Abstract: In a spark plug for an internal combustion engine, a discharge gap is formed between a central electrode and a ground electrode in an axial direction of the spark plug. An insulator of a cylindrical shape has an axial hole and an insulator front end part. The axial hole is formed in the insulator, into which the central electrode is arranged and supported. The insulator front end part projects further toward a front side of the insulator in the axial direction of the spark plug than a location of an opening part formed at a front end side of the axial hole. The discharge gasp is formed in an auxiliary combustion chamber. The outer peripheral side of the auxiliary combustion chamber is covered with the insulator front end part.
Abstract: A spark plug including a ground electrode including a base material, a tip having a discharge surface, and a melt portion interposed over an entire area between the tip and the base material and joining the tip to the base material; and a center electrode with a spark gap formed between the center electrode and the discharge surface. The tip has, in an inner area surrounded by an outer peripheral portion of the tip, a thin portion in which a distance between the discharge surface and the melt portion is shorter than a distance between the discharge surface and the melt portion in the outer peripheral portion. The thin portion extends from a part of the outer peripheral portion to a part other than the part of the outer peripheral portion.
Abstract: In a spark plug for an internal combustion engine, an insulator is held inside a housing such that a proximal end thereof projects in an axial direction. A center electrode is held inside the insulator such that a distal end thereof projects. A terminal fitting is connected to the proximal end of the insulator and provided such that electricity is conducted between the center electrode and the terminal fitting. A ground electrode forms a spark discharge gap between the distal end of the center electrode and the ground electrode. A first gap is formed between the proximal end of the insulator and the terminal fitting, a second gap is formed between a proximal end of the housing and the insulator, and at least one of the first gap and the second gap is filled with a filler.
Abstract: A spark plug having a metal shell and an insulator, wherein a stepped portion that includes a rear-end-side facing surface that retains an insulator either directly or via another member is provided at an inner periphery of a metal shell. The stepped portion includes a first convex portion that includes the rear-end-side facing surface, a second convex portion that is disposed on a front end side of the first convex portion and that is adjacent to the first convex portion, and a connection portion that connects the first convex portion and the second convex portion to each other.
Abstract: The spark plug includes an insulator, a metal shell, and a buffering member. The buffering member is filled in a space that is enclosed by an inner peripheral surface of the metal shell and an outer peripheral surface of the insulator. 3 mm2?L×T is satisfied in a case where: a length in a direction of an axial line of a filled portion filled with the buffering member is defined as a filling length L; a thickness, of a screw portion of the metal shell, that is half a difference left after subtraction of the inner diameter of the metal shell from the pitch diameter of the screw portion is defined as an effective thickness; and a minimum value of the effective thickness of a portion, of the screw portion, present rearward of an inner diameter reduction portion of the metal shell is defined as a minimum thickness T.
Abstract: A spark plug includes: an insulator with an axial hole; a center electrode held in a front end side of the axial hole; a cylindrical metal shell disposed around the insulator and having a seal part brought into contact with an outer circumferential surface of the insulator; a ground electrode arranged to form a gap with the center electrode; and a cap connected to a front end part of the metal shell to define therein an auxiliary combustion space in which the gap is formed, the cap having at least one through hole formed to provide communication between the auxiliary combustion space and the outside, wherein the condition (B/A)?0.25 is satisfied where A represents a volume of an imaginary space defined at a position frontward of the seal part; and B represents a volume of parts of the ground and center electrodes located in the imaginary space.
Abstract: A firing tip for a corona igniter is provided. The firing tip includes a base formed of metal, such as nickel, and rivets formed of precious metal, such as iridium. The base includes indentations, and the rivets are disposed in the indentations of the base. The rivet has a melting point and/or wear resistance greater than the base. Typically, the indentations of the base include a concave surface and the rivets have a cylindrical shape matching the shape of the indentations. The rivets can be sharpened to a point. The rivets can include a first piece formed of precious metal and a second piece formed of nickel or nickel alloy, wherein an end of the first piece is welded to an end of the second piece, and the second piece is welded to the base. Alternatively, the rivets can be formed entirely of the precious metal.
August 27, 2018
Date of Patent:
July 14, 2020
Kristapher I. Mixell, James D. Lykowski, Yusuf Esmail Neemuchwala
Abstract: A spark plug for an internal combustion engine includes a housing, an insulator, a center electrode, a ground electrode, and a plug cover. The housing has a cylindrical shape. The insulator is held on an inner side of the housing. The insulator has a cylindrical shape. The center electrode is held on an inner side of the insulator. The ground electrode forms a discharge gap with the center electrode. The plug cover, together with the housing, configures an auxiliary combustion chamber in which the discharge gap is arranged. The plug cover includes a spray hole that communicates between the inside and outside of the plug cover. The ground electrode is connected to a plurality of locations on an auxiliary-chamber inner wall surface that includes surfaces of the housing and the plug cover that are exposed to the auxiliary combustion chamber.
Abstract: A spark plug includes a ground electrode that is curved to oppose a tip end surface of a center electrode. A predetermined virtual plane that passes through a center axis of the spark plug along the curved ground electrode faces a flow direction of airflow. The ground electrode includes a main body including: an opposing surface on a first side facing the tip end surface of the center electrode; and a sloped surface on a second side opposite the first side. The main body satisfies 10 [°]?Dg?70 [°], 1.0 [mm]?Th, and 1.5 [mm]?Wd, where Dg is a slope angle of the sloped surface relative to the opposing surface, Th is a thickness of the main body in an insertion direction of the center electrode, and Wd is a width of the ground electrode in a direction perpendicular to the virtual plane.
Abstract: A spark plug electrode assembly and method of manufacturing a spark plug assembly having an inner and outer electrode component, one of which or both being formed using metal injection molding (MIM). Forming at least one of the inner or outer electrode components with MIM allows for the creation of a mechanical lock and a metallurgical bond at an interface between the components such that the components may be joined without a weld.
January 14, 2019
Date of Patent:
May 26, 2020
FEDERAL-MOGUL IGNITION GMBH
Werner Niessner, Rene Trebbels, Andreas Zeh
Abstract: An ignition plug includes a main metal fitting; an earth electrode having one end fixed to the main metal fitting and including, in a part of the other end, an inclined portion inclined toward the center axis line of the main metal fitting; an earth electrode-side chip joined to the inclined portion; and a center electrode having one end exposed from the main metal fitting. The ignition plug includes: a pedestal which has an elliptic cylindrical shape, is disposed so as to have a minor axis directed toward the earth electrode-side chip, and has an end surface forming an inclined surface inclined along the minor axis with respect to the center axis line; and a center electrode-side chip laser-welded to the inclined surface. The earth electrode-side chip and the center electrode-side chip face each other.
Abstract: A spark plug includes a tip extending in a first direction and an electrode base metal having an extending portion extending in the first direction and connected to the tip through a fusion zone. In a section taken along the first direction and containing a center axis of the tip, in a case where two ends of the interface between the extending portion and the fusion zone are located at the same position with respect to the first direction, the linear distance between the ends is denoted by A, or, in a case where one end is located forward of the other end, the distance from the one end to an intersection between a straight line passing the one end and extending perpendicularly to the center axis and the outline of the fusion zone is denoted by A. The interface length B satisfies a relational expression B/A?1.2.
Abstract: The spark plug includes: an insulator having an axial hole formed along an axial line; and a metal terminal provided on a rear side of the axial hole of the insulator. The metal terminal has, at a rear end portion thereof, a bottom surface facing rearward and a projection projecting rearward from an outer edge of the bottom surface, and a mark is provided to at least a part of the bottom surface. The Vickers hardness of the projection is 100 HV or higher. A rear end surface of the projection is positioned on a rear side with respect to a rear end of the mark. An area of the rear end surface is 3 mm2 or greater.
Abstract: In a spark plug, a discharge gap is formed between a ground electrode and a central electrode. The ground electrode has a rod-shaped part and an opposing part. The opposing part faces the central electrode, and has a flat surface part and a slope surface part. The slope surface part is formed on a part of the opposing part in an extending direction of the ground electrode, and formed on the opposing part and gradually separated from the central electrode along a width direction of the opposing part. The spark plug has a ratio V/W within a range of 0.5<V/W<2.0. V indicates a length of the opposing part measured in a gap formation direction in which the central electrode, the discharge gap and the opposing part are arranged in order. W indicates a length of the opposing part in the ground electrode width direction.
Abstract: An internal combustion engine includes a spark plug which protrudes into a combustion chamber. The spark plug has a central electrode and a ground electrode, and is configured such that a spark is generated between the central electrode and the ground electrode by electrical discharge. The spark plug has a vortex generator that separates an air flow near the ground electrode from the ground electrode and generates a vortex at a downstream side. The central electrode and the ground electrode are placed in a manner such that a spark or a flame deformed by an air flow flowing between the central electrode and the ground electrode enters the trailing vortex, or the spark penetrates through the inside of the trailing vortex.
Abstract: A spark plug includes: a cylindrical mounting bracket attachable to an internal combustion engine; a center electrode that is held by the mounting bracket in an insulated manner and has a first end portion exposed and extended from a first end portion of the mounting bracket; a ground electrode that has a first end side joined to the first end portion of the mounting bracket and has a surface of the second end side extended to be opposed to the first end portion of the center electrode; a convex portion that protrudes from a base material of the ground electrode on the surface of the ground electrode toward the center electrode, has a surface protruded outward, and has surfaces without corners; and a precious metal layer formed on the surface of the convex portion.
Abstract: A spark plug including a center electrode with a tip welded to a front end portion with a fused portion therebetween. The front end portion contains Ni, Cr, and at least one element selected from a group B consisting of Mn, Si, Al, Ti, rare earth elements, Hf, and Zr. Ni is present in the largest proportion, and Cr is present in the second largest proportion and in an amount of 12% by mass or more. The at least one element selected from the group B is present in a total amount of 0.1% by mass or more. The front end portion satisfies f/e?0.15 and m/e?0.015, where f is the Fe content, e is the sum of the Cr, Si, and Al contents, and m is the Mo content.
Abstract: A spark plug for an internal combustion engine is provided which has a center electrode and a ground electrode. The ground electrode includes an upright portion extending in a lengthwise direction of the spark plug and an extension bent from the upright portion in a radial direction of the spark plug. The extension has a slant surface which is shaped to be inclined away from the center electrode downstream in a flow of air-fuel mixture within a combustion chamber when the spark plug is mounted in the engine. This results in an increase in in distance by which a starting point on the ground electrode where a spark is created is moved on the slant surface, thereby increasing a length of time the spark is moved downstream and then blown out to increase the probability of successful ignition of the air-fuel mixture.
Abstract: A spark plug comprising: a first electrode including a tip containing 1r as a main material, and a base member to which the tip is joined; and a second electrode opposed to the tip with a spark gap therebetween. The number of crystal grains appearing in a range of 0.25 mm2 on an arbitrary cross-section of the tip in a first direction connecting the tip and the second electrode within the spark gap, is not less than 20. When a length of each of the crystal grains in the first direction is denoted by Y, and a length of each of the crystal grains in a second direction perpendicular to the first direction is denoted by X, 5 ?m?X?100 ?m and Y/X?1.5 are satisfied.
Abstract: Provided is a spark plug capable of ensuring fouling resistance with a simple configuration. An insulator includes a step portion formed on an outer circumferential surface thereof. A center electrode is arranged in an axial hole of the insulator. A cylindrical metal shell having a shelf portion formed on an inner circumferential surface thereof is arranged radially outside the insulator. The insulator further includes a front end portion located frontward of the step portion. An outer circumferential surface of the front end portion has an arithmetic average roughness of 0.5 ?m or smaller in a circumferential direction. A recess is formed with a depth of 3 to 20 ?m in at least part of an end surface and the outer circumferential surface of the front end portion so as to extend from the front toward the rear.
Abstract: A ceramic porous body has an alumina porous body made up by binding aggregate alumina particles to each other, the aggregate alumina particles being bound to each other by a compound including gadolinium silicate, lanthanum silicate or yttrium silicate synthesized from a silicate mineral and at least one rare-earth oxide selected from Gd2O3, La2O3, and Y2O3, and an inorganic porous film formed on the alumina porous body.
Abstract: Disclosed is a spark plug having a ground electrode in which a weld zone is formed a tip and electrode base. The weld zone has: a back region exposed at an opposite surface of the electrode base; a joint region at which the tip is joined; and a connection region connects the joint region and the back region without being exposed at side surfaces of the electrode base. In a cross section of the ground electrode taken through the side surfaces of the electrode base along a plane passing through the centers of the top and bottom surfaces of the tip, a value of a width of the top surface of the tip being divided by a width of the facing surface of the electrode base is greater than 0.3, and a maximum width of the connection region is larger than a width of the back region.
Abstract: Disclosed is a production method of a spark plug in which a ground electrode has an electrode base and a tip welded to a surface of the electrode base via a weld metal. The production method includes an image capture step, an image analysis step and an inspection step. The image capture step is to capture image data about the surface of the electrode base to which the tip has been welded. The image analysis step is to perform analysis of the image data, thereby detecting an edge of the electrode base and an edge of the weld metal, determining a center point of a contour of the weld metal and then detecting an edge of the tip in a specific area of the image data. The inspection step is to inspect a welding position of the tip based on the detected edges of the electrode base and the tip.
Abstract: When one of a center chip and a ground chip of a spark plug is defined as a first chip and another one is defined as a second chip, a discharge starting ridge line, which is a straight ridge line that forms a boundary between two surfaces having different normal line directions, is formed in a portion closest to the second chip in the first chips, and a distance from the discharge starting ridge line to the second chip is configured to be equal at a portion where the first chip and the second chip are opposed to each other.
Abstract: A spark plug having a noble metal tip that is joined to a tip-joining surface of a ground electrode so as to face an end face of a center electrode. When the noble metal tip is projected onto a projection plane parallel to the tip-joining surface, the noble metal tip has an elliptical shape in the projection plane. When the ground electrode is also projected onto the projection plane, an angle of 45° or less is formed between the major axis of the elliptical shape in the projection plane and a straight line extending in the lengthwise direction of the ground electrode and passing through the center of the noble metal tip in the projection plane.
Abstract: A spark plug having a resistor disposed between a metal terminal and a center electrode so as to be electrically connected to the metal terminal and the center electrode, wherein the resistor is in contact with an inner circumferential surface of the insulator. On a cross section taken along the axial line so as to include the axial line, in a case where a plurality of points are plotted at predetermined intervals in a direction of the axial line so as to be present on a partial boundary line, within an arbitrary range in the direction of the axial line, of a boundary line between the insulator and the resistor, and a regression line is drawn by a least-squares method with use of the plurality of points, an average value of distances in a direction perpendicular to the regression line between the regression line and the partial boundary line is 0.1 to 0.3 ?m.
Abstract: Disclosed is a spark plug including: an insulator having an axial hole formed along an axis of the spark plug; a center electrode disposed in a front end side of the axial hole; and a metal shell fixed around an outer circumference of the insulator, with a front end portion of the insulator protruding frontward from a front end of the metal shell. The front end portion of the insulator consists only of a first section and a second section located adjacent to and frontward of the first section and having an inner diameter larger than that of the first section. The second section has a chamfered area formed on an inner circumferential surface thereof so as to continue to a front end of the insulator.
Abstract: A base end portion of a ground electrode of a spark plug includes a skin portion, an intermediate portion, and a core portion 52. A center cross section CP containing the center axis PX of the spark plug and the center axis EX of the base end portion includes a first multilayer portion in which the intermediate portion is disposed inward of the skin portion and the core portion is disposed inward of the intermediate portion, and a second multilayer portion in which the skin portion and the core portion are in direct contact with each other. The center cross section CP includes an intersection point PI at which a first boundary line BLa between the metallic shell and the skin portion and a second boundary line between the metallic shell and the core portion meet with a third boundary line BLc.
Abstract: A spark plug includes an insulator body and a central electrode having a spark-end and a terminal-end. The central electrode is disposed within the insulator body, with the spark-end and the terminal-end protruding from the insulator body at opposite ends thereof. A metal electrode surrounds the insulator body and extends to form a gap with the central electrode at the spark-end. A capacitor with metalized inner and outer surfaces is provided, with the metalized inner surface being connected to the central electrode and the metalized outer surface being connected to the metal electrode. A first resistive component is embedded within the central electrode between the capacitor and the terminal-end, and a second resistive component embedded within the central electrode between the capacitor and the spark-end.
Abstract: A spark plug includes an insulator; a center electrode; a metal shell; and a ground electrode whose base end is fixed to the metal shell. A distal end of the ground electrode includes a first surface facing the center electrode, a second surface facing a side opposite to the first surface, and an inclined surface that is inclined with respect to the second surface. A noble metal tip is partially buried in the inclined surface. A width of the inclined surface is larger than that of the noble metal tip. In this spark plug, A B is satisfied, where A is a distance from a distal end of the ground electrode to a proximal-end-side end portion of the inclined surface and B is a distance from the distal end of the ground electrode to a proximal-end-side end portion of the noble metal tip.
Abstract: A corona igniter including a hermetic combustion seal between an insulator and center electrode is provided. The combustion seal includes a metallic coating, such as a nickel-based layer applied to a layer of molybdenum-manganese, and the metallic coating is disposed on the insulator inner surface. Optionally, a shot of copper-based powder can be disposed on a head of the center electrode. The center electrode and/or the copper-based powder is then brazed to the metallic coating on the inner surface of the insulator. The process can include applying the metallic coating to the inner surface while applying a metal coating to an outer surface of the insulator. The method further includes brazing the center electrode and/or the copper-based powder to the metallic coating on the inner surface while brazing the metal coating on the outer surface to a metal shell.
Abstract: A system for testing an insulative material for a spark plug comprises a test spark plug having at least a center electrode and an insulator comprised of an insulative material surrounding at least a portion of the center electrode, wherein the insulator has an end that is closed, whereby the closed end of the insulator encloses an end of the center electrode. The system may further include a test engine that simulates engine conditions, wherein a conventional spark plug is installed in a first ignition port of the test engine and the test spark plug is installed in a second ignition portion of the test engine and a control system for controlling ignition signals to the test spark plug and the conventional spark plug.
June 16, 2017
Date of Patent:
January 22, 2019
Farm Group IP LLC
Jing Zheng, Corey Eiden, Matthew B. Below
Abstract: An electrode tip for a spark plug, wherein Pt is contained as a main component, 7% by mass or more of Rh is contained, and a total content of Pt and Rh is greater than or equal to 95% by mass. The electrode tip includes: a narrow portion having the same cross-sectional shape in a direction of an axis; and a wide portion which is adjacent to the narrow portion and has a cross-sectional area, in a radial direction, which is greater than the narrow portion.
Abstract: A spark plug wherein when a discharge tip is viewed from a direction of an axial line, a melted portion is formed in at least a region on a second-end side of an electrode base material from a center of a discharge layer, and wherein in a section that includes a center line along a longitudinal direction of a ground electrode and that is parallel to an axial line, a proportion of a length of the melted portion along the longitudinal direction to a length of the discharge tip along the longitudinal direction of the electrode base material is greater than or equal to 76.2%, with the length of the melted portion along the longitudinal direction being within a range in which the discharge tip exists along the longitudinal direction.
Abstract: An ignition plug includes a center electrode; a cylindrical insulator that surrounds at least the circumference of a front end portion of the center electrode and that includes a bottom portion at the front side; and a cylindrical metal shell that holds the insulator from the outer circumference side. The center electrode includes a shaft portion that extends along an axial line and a head portion disposed at a front end of the shaft portion. The head portion has a width greater than that of the shaft portion in the radial direction. The insulator includes a first and second insulator. The first insulator has an axial hole and a diameter smaller than the maximum diameter of the head portion. The second insulator is joined to the first insulator. The shaft portion is disposed in the axial hole of the first insulator. The second insulator encloses the head portion.
Abstract: A spark plug having a tip provided on at least one of a center electrode and a ground electrode. The tip includes a body portion, a coating layer, and a high specific resistance layer. The body portion contains mostly Ir. The high specific resistance layer is provided on a side peripheral surface of the body portion, has a Ni content greater than the Ni content of the body portion and less than 50 mass %, and has a thickness of 2 ?m or greater and 45 ?m or less. The coating layer is provided on a side peripheral surface of the high specific resistance layer, contains 50 mass % or more of Ni, and has a thickness of 3 ?m or greater and 20 ?m or less. The tip has a specific resistance of 20×10?8 ?m or less at room temperature.
Abstract: An ignition plug includes an insulator having an outer-diameter reduction surface and a metal shell. The metal shell includes a rear end portion, a curved deformation portion, and a stepped portion. In a section including an axial line, the average hardness of a surface layer portion, which extends along a specific surface, of a rear end surface of the stepped portion is higher than the average hardness of the rear end portion and the average hardness of the deformation portion.
Abstract: A method for manufacturing a spark plug includes pressing a tip in a first direction from a first surface thereof toward a second surface thereof via a jig when the tip is in contact with an electrode base material; and welding the electrode base material to the tip being pressed by the jig. The jig has a recessed portion which is brought into contact with an edge of the tip, and the recessed portion has a diameter-decreasing portion having an inner dimension that gradually decreases toward a second direction opposite to the first direction. The inner dimension of a first end portion in the first direction of the diameter-decreasing portion is larger than the outer dimension of the edge, and the inner dimension of a second end portion in the second direction of the diameter-decreasing portion is equal to the outer dimension of the edge.
Abstract: A method of inspecting a spark plug insulator that includes a collar portion, a rear body portion located in rear of the collar portion and a leg portion located in front of the collar portion. The inspection method includes: performing measurement of a distance in a radial direction of the insulator between an outer circumferential surface of the leg portion at a first measurement point and an outer circumferential surface of the any portion of the insulator other than the leg portion at a second measurement point, wherein the measurement is performed at a plurality of positions in a circumferential direction of the insulator with no contact to the measurement target; determining, as a circular runout, a difference between maximum and minimum values among measurement results of the distance; and making pass/fail judgment of the insulator based on the determined circular runout.
Abstract: A spark plug includes an insulator having an axial hole formed therethrough in the direction of an axis of the spark plug, a center electrode disposed in a front side of the axial hole and a metal shell disposed around an outer circumference of the insulator and having a collar-shaped tool engagement portion and a crimp portion located on a rear side of the tool engagement portion and reduced in diameter toward the rear, wherein the crimp portion of the metal shell is made of a carbon steel material having a grain size number equal to or greater than No. 11 as measured according to JIS G 0551.
Abstract: A spark plug includes a central electrode and a noble metal tip, which are joined together with a fusion portion interposed therebetween. A tip-adjoining boundary of the fusion portion has a shape that curves convexly toward the fusion portion. A central-electrode-adjoining boundary of the fusion portion has a shape that curves convexly toward the central electrode. The outline of a portion of the fusion portion exposed to the outer surface has a shape that curves concavely into the inner side of the fusion portion.
Abstract: A reversed-assembled corona igniter including an insulator, central electrode, and metal shell, wherein an outer diameter of the insulator increases adjacent a lower end of the metal shell to achieve an electrical advantage is provided. In addition, the insulator maintains strength because is not placed under tension during or after assembly, or once disposed in an engine. To achieve the increase in insulator outer diameter, the insulator includes a lower shoulder adjacent the shell firing end. An intermediate part, such as braze and/or a metal ring, is disposed between the insulator outer surface and the shell adjacent the shell firing end. To prevent tension in the insulator, the insulator can be supported at only one location between the insulator upper end and the insulator lower end, for example along the intermediate part.
August 18, 2016
Date of Patent:
August 21, 2018
John Antony Burrows, John E. Miller, Kristapher I. Mixell, James D. Lykowski
Abstract: Disclosed herein is a spark plug capable of suppressing electrode consumption caused by a spark discharge and a method of manufacturing the same. A section except a welded section formed by welding a tip surface of a center electrode is defined as an unwelded section in side surfaces of a center chip, and a length of the unwelded section along a center axis of the center chip is defined as an unwelded section length. Under this definition, the welded section is formed in order for an unwelded section length in a side surface opposite to an inclination direction side of the center chip in the center chip to become longer than an unwelded section length in a side surface of the inclination direction side of the center chip in the center chip.
August 31, 2017
Date of Patent:
August 14, 2018
Ryohei Akiyoshi, Ken Hanashi, Tomoyuki Watanabe
Abstract: An electrode material that may be used in spark plugs and other ignition devices including industrial plugs, aviation igniters, glow plugs, or any other device that is used to ignite an air/fuel mixture in an engine. In one embodiment, the electrode material is a ruthenium-based material that includes ruthenium (Ru) as the single largest constituent on a wt % basis, and at least one of rhenium (Re) or tungsten (W). The electrode material may further include one or more precious metals and/or rare earth metals. The electrode material may be used to form the center electrode, the ground electrode, firing tips, or other firing tip components.
Abstract: A spark plug having a tip formed of an alloy containing Pt. The tip contains not less than 6 mass % of Rh, at least one element selected from an R group consisting of Rh, Re, Ir, Ru, W, Mo, and Nb, not less than 5 mass % of Ni, and at least one element selected from an N group consisting of Ni, Co, Fe, and Cu. The tip contains Rh most among the elements of the R group, and contains Ni most among the elements of the N group. The total of contents of Pt, Rh, and Ni is not less than 91 mass %, and the total of contents of Pt, the R group, and the N group is not less than 95 mass %. A value obtained by dividing the content of the R group by the content of the N group is not less than 0.7 and not greater than 8.
Abstract: A spark plug having a center conductor, an insulator surrounding the center conductor, at least two electrodes forming a spark gap, and a spark plug body surrounding the insulator and having an external thread arranged at the front end of the spark plug for screwing in to an internal combustion engine. A component that is attached to the front end of the spark plug and comes into contact with fuel during operation is formed as a sintered powder injection molded part, referred to as a MIM component.
Abstract: A spark plug, including a housing, an insulator situated in the housing, a center electrode situated in the insulator and a ground electrode situated on the housing, the ground electrode and the center electrode being situated relative to one another in such a way that the ground electrode and the center electrode form a spark gap, and the ground electrode including a core and a sheath surrounding the core, the core being made of a material which has a higher thermal conductivity than the material of the sheath, and a cross sectional area of the ground electrode being not greater than 2.76 mm2, the sheath having a wall thickness c of not greater than 0.4 mm in a first region of the ground electrode.
Abstract: A spark plug having a center electrode, a ground electrode, and a noble metal tip that is joined to a part of the ground electrode near one end of the ground electrode via a fused portion. The fused portion extends outward beyond an outer shape of the noble metal tip so that a part of the fused portion is present at each of positions that are located inward from and separated from both side edges of the ground electrode in a width direction of the ground electrode. The fused portion includes a fused protrusion that is located near at least one of two side edges of the noble metal tip in the width direction of the ground electrode and that protrudes in a direction away from the one end of the ground electrode.
Abstract: A spark plug includes an insulator, a metal shell surrounding the insulator, a center electrode disposed in the insulator, with a front end thereof exposed outside from the insulator, a ground electrode having a fixed end portion fixed to the metal shell and a free end portion located at a predetermined gap apart from the center electrode, and a coating part formed of noble metal or noble metal alloy so as to cover at least a region of an inner surface of the ground electrode from a first intersection to a second intersection, where the first intersection is an intersection at which an imaginary line extending from an outer circumference of the center electrode intersects the ground electrode; and the second intersection is an intersection at which an imaginary plane extending through a midpoint of the predetermined gap in parallel with the front end intersects the ground electrode.
Abstract: A method of converting a diesel engine to a natural gas engine comprising inserting a spark plug into a diesel fuel injector opening in a cylinder head; installing a throttle body on the diesel engine; installing a throttle body adaptor between a throttle body and an intake manifold of said diesel engine; and modifying a piston, whereby the compression ratio of said piston is decreased during operation of said piston. The method also includes installation of a waste gate and waste gate adaptor and a timing mask.