Glow plug with pressure sensor
AssigneeNgk Spark Plug Co., Ltd.
InventorsHiroyuki Suzuki, Akimitsu Sassa
Life of this patent
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Abstract
A coupling member (180) of a glow plug (100) includes a first bend (183) and a second bend (184) folded in an axis direction OD and a joint section (185) in a tapered shape configured to connect the first bend with the second bend and reduce the diameter toward a rear end side of a body portion. Accordingly, in a limited space formed between a housing (130) and a heater unit (150), this configuration increases the length of the coupling member (180), compared with a configuration without any bend folded in the axis direction OD. This results in decreasing the spring constant k of the coupling member 180 and suppressing extension of the coupling member 180 in the axis direction due to thermal expansion.
Claims7
A glow plug with a pressure sensor comprising:
- a housing in a cylindrical shape that is extended in a direction of an axis line;
- a heater unit in a rod shape that has a rear end part placed in the housing and a front end part protruded from a front end of the housing and is movable along the direction of the axis line;
- a coupling member in a thin film shape that is connected at one end with the housing and at the other end with the heater unit and is configured to enable the heater unit to move along the direction of the axis line and couple the heater unit with the housing;
- and
- a pressure sensor that detects a pressure based on a load transmitted via the heater unit, wherein
- the coupling member includes:
- a first bend and a second bend folded in the direction of the axis line;
- and
- a joint section in a tapered shape configured to connect the first bend with the second bend and reduce diameter toward a rear end side of the housing, wherein
- the first bend is located closer in a direction orthogonal to the axis line to the housing than the second bend and is located closer in the direction of the axis line to a front end side of the housing than the second bend, and
- the first bend has a greater bend radius than a bend radius of the second bend.
Dependencies are inferred from the claim text.