On an inner wall surface of a plug hole, an internal thread portion and a seat portion are formed. The seat portion has a tapered seat surface. A glow plug with a combustion pressure sensor includes a housing, a glow heater, a load transfer member, and a pressure detector. The housing has an external thread and a seat facing portion. The seat facing portion has a tapered contact surface in surface contact with the tapered seat surface. A recessed portion recessed to be in non-contact with the seat portion is formed annularly about a central axis of the housing.

A pressure-sensor-integrated glow plug which can increase reliability of a bonding portion between a ceramic heater and a metal-made outer sleeve while being manufactured with relatively simple manufacturing steps and, at the same time, can maintain airtightness over a long period, and a method of manufacturing such a pressure-sensor-integrated glow plug.

A pressure sensor includes a tubular housing; a diaphragm which is joined to one end portion of the housing through a fusion zone; and a sensor element which is disposed in the housing and to which pressure received by the diaphragm is transmitted. As viewed in a section which contains the center axis of the housing, a pair of the fusion zones exist, and each of the fusion zones is formed in such an inclined manner that its distance from the center axis increases as it extends from the outer surface of the diaphragm toward the other-end-portion side of the housing.

A glow plug including a substantially cylindrical housing extending in an axial direction; a rod-shaped heater unit having a front end protruding from the front end of the housing and movable in the axial direction; a connecting member connecting the heater unit to the housing within the housing and allowing the heater unit to move in the axial direction; and a pressure sensor that detects pressure received by the heater unit. The heater unit has a large-diameter portion at the rear end thereof and a small-diameter portion frontward of the large-diameter portion and having a diameter smaller than the diameter of the large-diameter portion. The connecting member connects the small-diameter portion of the heater unit to the housing within the housing.

A glow plug wherein a combustion gas prevention wall (67) extends radially outward on the outer circumferential surface of heater (10) such that when the heater (10) is viewed rearward from its forward end (10a) along the axial direction, the combustion gas prevention wall (67) closes an annular gap K1 at a position forward of annular membrane portion (63) of seal member (60). The combustion gas prevention wall (67) has an outer diameter D2 greater than the inner diameter D1 of forward end (136) of the housing.

Described is a pressure measuring glow plug with a housing, a glow pin, which projects out of the housing and can be displaced in its longitudinal direction relative to the housing against a restoring force. A sensor acquires the position of the glow pin or a pressure acting on the glow pin, and a center pole is arranged in the housing and electrically connected to the glow pin via a contact spring. This disclosure provides that the contact spring is a U-shaped, bent metal strip, which in a middle section has a reduced width, and broadens from the middle section toward its two ends.

Described is a glow plug having a casing and a ceramic glow pin protruding out of the casing. The glow pin has a tapered end section inside the casing. A metal protective tube protrudes out of the casing and surrounds the glow pin. The protective tube has a widened end section inside the casing. A center electrode is arranged in the casing and electrically connected to the glow pin. The glow plug includes an annular or sleeve-shaped contact element through which the glow pin projects and to which the tapered end section of the glow pin is soldered. The contact element is at least partly surrounded by the widened end section of the protective tube.

On an inner wall surface of a plug hole, an internal thread portion and a seat portion are formed. The seat portion has a tapered seat surface. A glow plug with a combustion pressure sensor includes a housing, a glow heater, a load transfer member, and a pressure detector. The housing has an external thread and a seat facing portion. The seat facing portion has a tapered contact surface in surface contact with the tapered seat surface. A recessed portion recessed to be in non-contact with the seat portion is formed annularly about a central axis of the housing.

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.

A control apparatus (100) controls a diesel engine (10). A glow plug (32) which can detect cylinder pressure is provided on the engine (10). An ECU (70) computes a parameter related to a change in cylinder pressure obtained from the glow plug (32). The ECU (70) controls fuel injection timing such that the parameter falls within a target range when combustion in the engine (10) is switched from premixed combustion to diffusion combustion.