摘要:
A spark plug for use in an internal combustion engine includes a tubular insulator (140, 340) having an axial hole extending therethrough; a center electrode (120) fitted into the axial hole and having a distal end portion (120b) protruding from a distal end of the insulator (140, 340); and a ground electrode (110, 310) arranged such that at least a portion of spark discharge generated between the ground electrode (110, 310) and the distal end portion (120b) of the center electrode includes creeping discharge along the surface of the distal end portion of the insulator (140, 340). The distal end portion (120b) of the center electrode (120) contains Ni as a primary component in an amount of 80 wt% or more and Fe and Cr as secondary components in a total amount of 2.5 wt% to 10.0 wt% and further contains Al as a secondary component in an amount of 0.2 wt% to 0.8 wt%.
摘要:
In a dual polarity type ignition system for a spark plug group, a cylindrical metal shell is provided in which an insulator is provided. The insulator has an axial bore in which a center electrode is provided whose front end has a first noble metal tip. A ground electrode extends from a front end of the metal shell and having a second noble metal tip to form a spark discharge gap between the first noble metal tip and the second noble metal tip. The group of the spark plugs is divided into two groups, one is a positive polarity spark plug group in which a positive high voltage is applied to the center electrode, and the other group is a negative polarity spark plug group in which a negative high voltage is applied to the center electrode. The first noble metal tip of the center electrode of the positive polarity spark plug group is dimensionally smaller than the first noble metal tip of the center electrode of the negative polarity spark plug group. The second noble metal tip of the ground electrode of the negative polarity spark plug group is dimensionally smaller than the second noble metal tip of the ground electrode of the positive polarity spark plug group.
摘要:
In a misfire detector device for use in internal combustion engine, an electrical interrupter circuit on-off actuates a primary current flowing through a primary circuit of an ignition coil to induce a sparkplug voltage. A check diode is provided in a secondary circuit of the ignition coil to prevent a current flowing back to the ignition coil. The spark plug has a center electrode, a front end of which is projected from an insulator, and an outer surface area of the projected front end being 25 mm² or more. A sparkplug voltage detector circuit detects an attenuation time length of a sparkplug voltage waveform presented subsequent to a time period predetermined after an end of a spark action of the spark plug. On the basis of the attenuation time length, a distinction circuit determines whether a misfire occurs in a cylinder of an internal combustion engine.
摘要:
In a misfire detector device for use in internal combustion engine, a secondary circuit is provided to apply voltage to a spark plug of an internal combustion engine. A secondary voltage waveform detector is provided to detect a secondary voltage waveform. An integral circuit is provided to integrate the secondary voltage waveform detected by the secondary voltage waveform detector during a predetermined period including a part of sparking time period of the spark plug. A comparator is provided to compare the secondary voltage waveform with an integral value of the integral circuit. A misfire is determined by a relationship between the integral value of the integral circuit and the secondary voltage waveform based on an electrical resistance of a spark gap changing depending upon whether air-fuel mixture is normally ignited or not when the spark plug is energized.
摘要:
A spark plug for use in an internal combustion engine includes a tubular insulator (140, 340) having an axial hole extending therethrough; a center electrode (120) fitted into the axial hole and having a distal end portion (120b) protruding from a distal end of the insulator (140, 340); and a ground electrode (110, 310) arranged such that at least a portion of spark discharge generated between the ground electrode (110, 310) and the distal end portion (120b) of the center electrode includes creeping discharge along the surface of the distal end portion of the insulator (140, 340). The distal end portion (120b) of the center electrode (120) contains Ni as a primary component in an amount of 80 wt% or more and Fe and Cr as secondary components in a total amount of 2.5 wt% to 10.0 wt% and further contains Al as a secondary component in an amount of 0.2 wt% to 0.8 wt%.