摘要:
In a spark plug (100), the resistor composition constituting a resistor (15) contains semiconductive ceramic particles, offering a superior load life characteristic. Also, the value of (&agr;2−&agr;1)/&agr;1>=−0.30, where a value of electric resistance between a terminal (13) and a center electrode (3) is &agr;1 at 20° C. and &agr;2 at 150° C., so that deterioration of the radio frequency noise prevention performance at high temperatures can be effectively suppressed. The resistor composition contains semiconductive ceramic particles whose temperature coefficient of electric resistance shows a positive value, or a negative value of relatively small absolute value, (e.g., TiO2 particles having a rutile type crystalline structure, titanate or zirconate of alkali earth metal elements, titanium suboxide, etc.), or titanium metal. Thus, the invention provides a resistor-incorporated spark plug which is enabled to offer a stable load life characteristic even when a high load acts thereon, and which is unlikely to deteriorate in the radio frequency noise prevention performance even under high temperatures.
摘要:
In a spark plug (100), the resistor composition constituting a resistor (15) contains semiconductive ceramic particles, offering a superior load life characteristic. Also, the value of (.alpha.2-.alpha.1)/.alpha.1 >=-0.30, where a value of electric resistance between a terminal (13) and a center electrode (3) is .alpha.1 at 20.degree. C. and .alpha.2 at 150.degree. C., so that deterioration of the radio frequency noise prevention performance at high temperatures can be effectively suppressed. The resistor composition contains semiconductive ceramic particles whose temperature coefficient of electric resistance shows a positive value, or a negative value of relatively small absolute value, (e.g., TiO.sub.2 particles having a rutile type crystalline structure, titanate or zirconate of alkali earth metal elements, titanium suboxide, etc.), or titanium metal. Thus, the invention provides a resistor-incorporated spark plug which is enabled to offer a stable load life characteristic even when a high load acts thereon, and which is unlikely to deteriorate in the radio frequency noise prevention performance even under high temperatures.
摘要:
Disclosed is a spark plug 100 with a built-in resistor comprises an insulator 2 having an axially extending passing-through-hole 6, a terminal metal fitting 13 fixed within the passing-through-hole 6 at an end thereof, a center electrode 3 fixed within the same passing-through-hole at the other end thereof and a resistor 15 provided between the terminal metal fitting 13 and the center electrode 3 within the passing-through-hole 6. A surface layer region including the surface of the center electrode 3 which is exposed to the resistor 15 is a metallic layer 30 formed of a metal based on at least one of Zn, Sn, Pb, Rh, Pd, Pt, Cu, Au, Sb and Ag or a Ni alloy containing at least one of B and P, so that the center electrode 3 is provided in direct contact with the resistor 15 on the surface of the metallic layer 30.
摘要:
In a spark plug, a resistor is placed between a terminal and a center electrode within a through hole of an insulator. The through hole of the insulator has a first portion which allows the center electrode to be inserted therethrough, and a second portion which is formed on a rear side of the first portion so as to be larger in diameter than the first portion and which accommodates the resistor therein, where the second portion is connected to the first portion via a connecting portion including a two- or more-stepped reduced-diameter portion. Then, an electrically conductive glass seal layer is placed at a position corresponding to the connecting portion between the resistor and the center electrode. When the glass seal layer is formed by filling electrically conductive glass powder and its heating and compression, the pressurizing cross-sectional area in the axial direction is reduced to an extent of diameter reduction by the reduced-diameter portion of the connecting portion, so that a sufficient compressing force can be ensured in the event that the pressurizing force is lost, for example, due to friction between the upper filler material (e.g., resistor material powder) and the wall surface of the through hole. By virtue of this arrangement, the sintering of the glass seal layer progresses sufficiently so that the burns of carbon in the glass seal portion and the oxidization of metal components become unlikely to occur. Thus, such trouble as increase in conduction resistance can be avoided over a long term.
摘要:
A resistor spark plug includes an insulator having an axially extending through-hole. A center electrode is disposed within the through-hole of the insulator such that the center electrode projects from a tip end of the insulator. A terminal metal piece is disposed within the through-hole of the insulator such that the terminal metal piece projects from a tail end of the insulator. A conductive coupling layer is disposed within the through-hole and located between the center electrode and the terminal metal piece. The conductive coupling layer comprises a conductive glass seal layer formed on at least an end facing the terminal metal piece. A surface layer region of the terminal metal piece that comes into contact with the conductive glass seal layer is formed mainly of one or more metals selected from the group consisting of Zn, Sn, Pb, Rh, Pd, Pt, Cu, Au, Sb, and Ag.
摘要:
In a spark plug in which a space between a center electrode at the top end side and a terminal electrode at a rear end side which are arranged to be opposite to each other in an axial hole of an insulator, the glass seal is effected at a temperature within the range of 500 to 1000° C. and under a condition where the concentration of oxygen is 4-12 vol %.
摘要:
Resistor compositions for producing a resistor for use in resistor-incorporated spark plugs and comprising a glass, an inorganic aggregate, and carbon black and/or a carbonaceous substance as a regulating agent for resistance value, with or without a stabilizing agent for resistance under load of the resistor, are now modified by addition of a reducing metallic powder such as powder of Al, Mg, Zn, Sn, Ti, Zr, Fe, Ga and Ag or alloys thereof, to improve the service life characteristics under load of the resistor. Such compositions are further modified by additional presence of a ceramic aggregate of a particle size of 100 to 800 .mu.m, to improve the electric wave noise-preventing property.
摘要:
In a spark plug in which a space between a center electrode at the top end side and a terminal electrode at a rear end side which are arranged to be opposite to each other in an axial hole of an insulator, the glass seal is effected at a temperature within the range of 500 to 1000.degree. C. and under a condition where the concentration of oxygen is 12 vol % or less.
摘要:
There is provided a new glow plug that can be easily determined as to whether or not it is a new article.An additional circuit 12 formed by connecting a diode 13, a fuse 14, and an adjusting resistor 15 in series in this order is connected in parallel to a heating element 11 of a glow plug 1. The diode 13 is provided so as to have an anode located on the positive electrode side of the heating element 11 and a cathode located on the fuse 14 side. In the case of a unit inspection, by applying a positive voltage for test to a heating element negative electrode connecting portion 3a, it is possible to determine whether or not the glow plug 1 is normal without blowing the fuse 14 before the glow plug 1 is used in a vehicle.
摘要:
To suppress current fluctuations upon commencement of driving and prolong lifespan by reducing electric stress caused by current fluctuations.A glow plug 1, a glow switch 2, and a stabilizing coil 3 are series-connected, and upon commencement of the driving of the glow plug 1, a repetition frequency of PWM signals that control the opening and closing of the glow switch 2 is made into a higher frequency than a repetition frequency in a normal drive state and the opening and closing of the glow switch 2 is controlled (S104), and when a predetermined drive shift condition has been met (S106), the repetition frequency of the PWM signals is returned to the frequency during normal driving and the opening and closing of the glow switch 2 is controlled (S108), whereby the current upon commencement of driving is smoothed and the occurrence of an instantaneous large current is suppressed.