(19)
(11) EP 0 648 978 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
24.07.1996 Bulletin 1996/30

(43) Date of publication A2:
19.04.1995 Bulletin 1995/16

(21) Application number: 94307223.1

(22) Date of filing: 03.10.1994
(51) International Patent Classification (IPC)6F23Q 7/00
(84) Designated Contracting States:
DE FR GB

(30) Priority: 04.10.1993 JP 269431/93
04.10.1993 JP 269432/93

(71) Applicant: ISUZU CERAMICS RESEARCH INSTITUTE CO., LTD.
Fujisawa-shi, Kanagawa-ken (JP)

(72) Inventor:
  • Kawamura, Hideo
    Kouza-gun, Kanagawa-ken, T253-01 (JP)

(74) Representative: Jenkins, Peter David et al
PAGE WHITE & FARRER 54 Doughty Street
London WC1N 2LS
London WC1N 2LS (GB)

   


(54) Ceramic glow plug


(57) This invention provides a ceramic glow plug of current self-control type with a stable strength and a high-temperature strength resistant to thermal shocks. In this ceramic glow plug, the ceramic pipe (2) is secured to the hollow body (1) having the electrode (10) and is formed with the conductive printed layer (8) on its outer surface. One end of the pipe (2) is sealed by the ceramic filler (4) to form the hollow portion (9) inside the pipe In the hollow portion (9) sealed with N2 gas, the tungsten wire (3) is installed, with one end (7) connected to the conductive printed layer (8) and the other end (16) to the electrode (10). The outer circumferential surface (13) of the pipe (2) is formed with the ceramic outer surface coating layer (5). When the tungsten wire (3) and the conductive printed layer (8) are supplied with electricity, the conductive printed layer (8) functions as the heater portion (12) and the tungsten wire (3) as the current control portion (6).







Search report