Glow plug with pressure sensor
First Claim
1. A glow plug with a pressure sensor comprising:
- a cylindrical housing having an axial hole extending in an axial line direction;
a ceramic heater that is inserted into the axial hole so that at least a front end part of the ceramic heater protrudes from a front end of the housing, said ceramic heater being relatively displaceable with respect to the housing along the axial line direction, and having at least an outer surface made of ceramic;
a pressure sensor fixed directly or indirectly to the housing and configured to output a signal based on a relative displacement of the ceramic heater;
a fixed member fixed to the ceramic heater at a first joint portion while the ceramic heater is arranged to an inner circumference of the fixed member; and
a welded member welded to an outer circumference of the fixed member at a second joint portion, whereinan inner circumferential surface of the second joint portion is spaced apart from the outer surface of the ceramic heater, andthe second joint portion is positioned rearward in the axial line direction with respect to the first joint portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A glow plug includes a housing having an axial hole extending in an axial line direction; a ceramic heater that is relatively displaceable with respect to the housing along the axial line direction and has at least outer surface made of ceramic; and a pressure sensor fixed to the housing and configured to output a signal based on the relative displacement of the ceramic heater. A fixed member fixed to the ceramic heater while the ceramic heater is arranged to an inner circumference of the fixed member. A welded member is welded to an outer circumference of the fixed member. An inner circumferential surface of a portion of the fixed member to which at least the welded member is welded is spaced apart from the outer surface of the ceramic heater.
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Citations
15 Claims
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1. A glow plug with a pressure sensor comprising:
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a cylindrical housing having an axial hole extending in an axial line direction; a ceramic heater that is inserted into the axial hole so that at least a front end part of the ceramic heater protrudes from a front end of the housing, said ceramic heater being relatively displaceable with respect to the housing along the axial line direction, and having at least an outer surface made of ceramic; a pressure sensor fixed directly or indirectly to the housing and configured to output a signal based on a relative displacement of the ceramic heater; a fixed member fixed to the ceramic heater at a first joint portion while the ceramic heater is arranged to an inner circumference of the fixed member; and a welded member welded to an outer circumference of the fixed member at a second joint portion, wherein an inner circumferential surface of the second joint portion is spaced apart from the outer surface of the ceramic heater, and the second joint portion is positioned rearward in the axial line direction with respect to the first joint portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15)
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12. A glow plug with a pressure sensor comprising:
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a cylindrical housing having an axial hole extending in an axial line direction; a ceramic heater that is inserted into the axial hole so that at least a front end part of the ceramic heater protrudes from a front end of the housing, said ceramic heater being relatively displaceable with respect to the housing along the axial line direction, and having at least an outer surface made of ceramic; a pressure sensor fixed directly or indirectly to the housing and configured to output a signal based on a relative displacement of the ceramic heater; a fixed member fixed to the ceramic heater while the ceramic heater is arranged to an inner circumference of the fixed member; and a welded member welded to an outer circumference of the fixed member, wherein an inner circumferential surface of a portion of the fixed member, to which at least the welded member is welded, is spaced apart from the outer surface of the ceramic heater, the ceramic heater has a base member made of insulating ceramic and a heating element provided inside the base member, an outer surface of the base member contacting an inner surface of the fixed member, and the heating element has an electrode extraction part exposed in an outer surface of the base member.
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Specification