(19)
(11) EP 0 650 020 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.06.1996 Bulletin 1996/23

(43) Date of publication A2:
26.04.1995 Bulletin 1995/17

(21) Application number: 94307544.0

(22) Date of filing: 14.10.1994
(51) International Patent Classification (IPC)6: F23Q 7/00
(84) Designated Contracting States:
DE FR GB

(30) Priority: 20.10.1993 JP 284203/93
20.10.1993 JP 284204/93

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

(72) Inventors:
  • Kita, Hideki
    Fujisawa-shi, Kanagawa-ken T251 (JP)
  • Kawamura, Hideo
    Kouza-gun, Kanagawa-ken T253-01 (JP)
  • Hirai, Takene
    Yamato-shi, Kanagawa-ken T242 (JP)

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


(56) References cited: : 
   
       


    (54) A ceramic heater and a method of manufacture thereof


    (57) This invention provides a ceramic heater of current self-control type, which has no gap in the boundary between the enclosure 1 and the filler 2, and which has reduced manufacturing cost, a stable strength and an improved heating performance. The invention also provides a method of manufacturing such a ceramic heater. In this ceramics heater, porous ceramic fillers 2, 3 are filled inside the end portions of the enclosure 1 made of a dense ceramics. The metal coil 10 consisting of the heater coil 6 and the current control coil 9 connected in series with each other is installed inside the enclosure 1, with the end surfaces 15 of the enclosure 1 hermetically closed by the sealing films 4. To prevent corrosion of the metal coil 10, the low heat conductivity ceramics 25 made from ceramic whiskers and/or ceramic powder is disposed in the central portion of the enclosure 1 and an N2 gas is sealed therein. The heater coil 6 is arranged in contact with the inner wall surface 7 of that portion of the enclosure 1 where the filler 2 is located, and the current control coil 9 is spaced from the inner wall surface 8 of the enclosure 1 so as to be heat-insulated.






    Search report