Glow plug with pressure sensor

Patent metadata

Field	Value
Publication number	US-9897063-B2
Application number	US-201314356316-A
Country	US
Kind code	B2
Filing date	Apr 18, 2013
Priority date	Apr 20, 2012
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A glow plug ( 100 ) includes: a housing ( 130 ) having a metal shell ( 110 ) and a cap unit ( 120 ); and a heater unit ( 150 ). A coupling member ( 180 ) is joined with the housing ( 130 ) and is also joined with the heater unit ( 150 ) at its edge portion ( 188 ), so as to enable the heater unit ( 150 ) to move along an axis line O and couple the heater unit ( 150 ) with the housing ( 130 ). When the edge portion 188 of the coupling member 180 is irradiated with a laser, at least part of the edge portion ( 188 ) melted by laser welding fills a gap ( 50 ) between the coupling member ( 180 ) and the heater unit ( 150 ) to form a welded part ( 210 ). As a result, even when there is a gap prior to welding, the weld strength between the coupling member ( 180 ) and the heater unit ( 150 ) can be maintained.

First claim

The invention claimed is:

1. 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 enables the heater unit to move along the direction of the axis line and couples the heater unit with the housing; and
the pressure sensor detects a pressure based on a load transmitted via the heater unit, wherein
an edge portion of the coupling member and the heater unit are joined together by laser welding performed from a coupling member side,
a portion of the coupling member other than the edge portion is arranged to face the heater unit with a gap therebetween,
the edge portion of the coupling member is joined with the heater unit via a welded part formed by melting at least part of the edge portion of the coupling member by the laser welding,
the welded part is formed by irradiating the edge portion of the coupling member with a laser emitted in an oblique direction crossing the axis line from a front end side to a rear end side of the heater unit, and
an angle between an extension direction of the welded part and a direction orthogonal to the axis line is between 10 to 40 degrees.

2. The glow plug with the pressure sensor according to claim 1 , wherein
the welded part is formed by irradiating the edge portion of the coupling member with a laser emitted from a direction orthogonal to the axis line.

3. The glow plug with the pressure sensor according to claim 1 , wherein
the welded part includes:
a first welded part that is formed on a side of the axis line in a direction orthogonal to the direction of the axis line; and
a second welded part that is formed at a position more distant from the axis line than the first welded part in the direction orthogonal to the direction of the axis line and has a greater width than a maximum width of the first welded part in the direction of the axis line, wherein

a portion of the second welded part is extended to the heater unit.

4. A method for manufacturing of a glow plug with a pressure sensor as claimed in claim 1 including: 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 enables the heater unit to move along the direction of the axis line and couples the heater unit with the housing; and a pressure sensor that detects a pressure based on a load transmitted via the heater unit, the method comprising a step of:
joining the heater unit with the other end of the coupling member having a shape parallel to the heater unit by laser welding performed from a coupling member side, such that at least part of a melted edge portion of the coupling member melted by the laser welding fills a gap formed between the coupling member and the heater unit.

5. The method for manufacturing of the glow plug with the pressure sensor according to claim 4 , wherein
the step of joining the heater unit with the coupling member irradiates the edge portion of the coupling member with a laser emitted from a direction orthogonal to the axis line.

6. The method for manufacturing of the glow plug with the pressure sensor according to claim 4 , wherein
the step of joining the heater unit with the coupling member irradiates the edge portion of the coupling member with a laser emitted in an oblique direction crossing the axis line from a front end side to a rear end side of the heater unit.

Assignees

• Ngk Spark Plug Co

Inventors

• Maeda Shunsuke
• Nakamura Yoshihiro
• Kawakatsu Masahiro
• Suzuki Hiroyuki

Classifications

• F23Q2007/005

  pressure sensors · CPC title

• B23K26/28

  of curved planar seams · CPC title

• G01L11/00

  Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 · CPC title

• F23Q7/001

  Glowing plugs for internal-combustion engines · CPC title

• F02P19/028 Primary

  the glow plug being combined with or used as a sensor · CPC title