| 摘要 |
To decrease the preheat time and power requirements in preheater-type glow plugs for Diesel engines, a closed ceramic tube (20), for example of aluminum oxide and of about 5 mm diameter has, on the bottom (21) thereof applied a layer or film-like heater element (24, 24'), for example in an undulating or zig-zag configuration (FIG. 2) or in form of a constriction or pinch (FIG. 4: 24') to provide a concentrated point or strip source of heat. The heater layer itself is protected by a protective coating (25) and, to provide for the required heat distribution, the underlying bottom (21, 21') of the tube (20, 20') supports an insulating intermediate layer and possibly a heat conductive layer is intermediate. Preheat times in the order of 1-2 seconds, with lower current consumption than prior wound-wire plugs can be obtained.
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