GLOW PLUG WITH COMBUSTION PRESSURE SENSOR
First Claim
1. A glow plug with a combustion pressure sensor comprising a rodlike ceramic heater having a forward heat-generating element provided at a forward end portion and adapted to generate heat through application of electricity, a tubular housing having the ceramic heater disposed therein with a forward end of the ceramic heater protruding forward from a forward end thereof, and a sensor capable of sensing combustion pressure by detecting pressure or displacement generated as a result of the ceramic heater being pressed rearward at the forward end by the combustion pressure,an inner circumferential surface of a forward end portion of the housing and an outer circumferential surface of the ceramic heater defining an annular space communicating with an opening in a forward end of the housing, and the space accommodating a displacement member joined along a circumferential direction to the housing and to the ceramic heater and being deformable so as to allow displacement of the ceramic heater along an axis,the glow plug being characterized in that the ceramic heater has a rear heat-generating element adapted to generate heat through application of electricity, for heating at least a portion of the outer circumferential surface of the ceramic heater in an axial region between a rear end portion of a protruding portion of the ceramic heater protruding forward from the forward end of the housing and a rear end of the displacement member located rearward of the rear end portion of the protruding portion of the ceramic heater.
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Accused Products
Abstract
A glow plug including a heater (200) having a rear heat-generating element (260) formed of a resistance heat-generating element, and provided in an axial region thereof between a forward end (136) of a housing and a rear end (315) of a displacement member (300) located rearward of the forward end (136). The heat-generating element (260) is arranged separately from a forward heat-generating element (205) provided at a forward end portion of the heater.
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Citations
18 Claims
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1. A glow plug with a combustion pressure sensor comprising a rodlike ceramic heater having a forward heat-generating element provided at a forward end portion and adapted to generate heat through application of electricity, a tubular housing having the ceramic heater disposed therein with a forward end of the ceramic heater protruding forward from a forward end thereof, and a sensor capable of sensing combustion pressure by detecting pressure or displacement generated as a result of the ceramic heater being pressed rearward at the forward end by the combustion pressure,
an inner circumferential surface of a forward end portion of the housing and an outer circumferential surface of the ceramic heater defining an annular space communicating with an opening in a forward end of the housing, and the space accommodating a displacement member joined along a circumferential direction to the housing and to the ceramic heater and being deformable so as to allow displacement of the ceramic heater along an axis, the glow plug being characterized in that the ceramic heater has a rear heat-generating element adapted to generate heat through application of electricity, for heating at least a portion of the outer circumferential surface of the ceramic heater in an axial region between a rear end portion of a protruding portion of the ceramic heater protruding forward from the forward end of the housing and a rear end of the displacement member located rearward of the rear end portion of the protruding portion of the ceramic heater.
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2. A glow plug with a combustion pressure sensor comprising a rodlike ceramic heater having a forward heat-generating element provided at a forward end portion and adapted to generate heat through application of electricity, a tubular housing having the ceramic heater disposed therein with a forward end of the ceramic heater protruding forward from a forward end thereof, and a sensor capable of sensing combustion pressure by detecting pressure or displacement generated as a result of the ceramic heater being pressed rearward at the forward end by the combustion pressure,
an inner circumferential surface of a forward end portion of the housing and an outer circumferential surface of the ceramic heater defining an annular space communicating with an opening in a forward end of the housing, and the space accommodating a displacement member joined along a circumferential direction to the housing and to the ceramic heater and being deformable so as to allow displacement of the ceramic heater along an axis, the glow plug being characterized in that the ceramic heater has a rear heat-generating element formed of a resistance heat-generating element, adapted to generate heat through application of electricity, and provided in an axial region between a rear end portion of a protruding portion of the ceramic heater protruding forward from the forward end of the housing and a rear end of the displacement member located rearward of the rear end portion of the protruding portion of the ceramic heater.
Specification