(19)
(11) EP 2 631 542 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
20.12.2017 Bulletin 2017/51

(43) Date of publication A2:
28.08.2013 Bulletin 2013/35

(21) Application number: 13156421.3

(22) Date of filing: 22.02.2013
(51) International Patent Classification (IPC): 
F23Q 7/00(2006.01)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME

(30) Priority: 22.02.2012 JP 2012035757

(71) Applicant: NGK Spark Plug Co., Ltd.
Nagoya-shi, Aichi 467-8525 (JP)

(72) Inventor:
  • Harada, Sadamitsu
    Nagoya-shi, Aichi 467-8525 (JP)

(74) Representative: Grünecker Patent- und Rechtsanwälte PartG mbB 
Leopoldstraße 4
80802 München
80802 München (DE)

   


(54) Glow plug


(57) [Objective] To more reliably prevent a deterioration of a seal member due to heat.
[Means for Solution] A glow plug 1 includes a cylindrical housing 2, having an axial hole 7 extending in a direction of an axis CL1, which includes an external thread portion 8 for coming into threaded engagement with an internal thread portion FS provided on a mounting hole HO of an internal combustion engine EN; a ceramic heater 4 inserted in the axial hole 7 in a condition in which at least a leading end portion of the ceramic heater 4 protrudes from the leading end of the housing 2; and a center pole 3, having a bar shape extending in the direction of the axis CL1 and inserted into the axial hole 7, which forms an energizing path to the ceramic heater 4. An annular seal member 31 formed from an insulating material is disposed between the inner periphery of the housing 2 and the outer periphery of the center pole 3 within a range of formation of the external thread portion 8 along the axis CL1.







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Search report