Title:
CLEANING METHOD AND APPARATUS OF HEAT GENERATING RESISTANCE OF HEAT GENERATING RESISTANCE TYPE AIR FLOW SENSOR AND ENGINE CONTROL DEVICE
Document Type and Number:
Japanese Patent JPH0579877
Kind Code:
A
Abstract:
PURPOSE:To burn off the dust adhered to a heat generating resistance body of a heat generating resistance type air flow sensor well, thereby to enhance the detecting accuracy of the sucking amount of air and to elongate the life of the heat generating resistance body. CONSTITUTION:The dust adhered to a heat generating resistance body is mainly composed of oil in summer or sand in winter because of the dry air. The oil can be burnt off by heating the same to a boiling point. The sand is necessary to be red-hot to 1000 deg.C. The amount of the dust adhered to the heat generating resistance body is dependent on the running distance since the dust was burnt off last time. The particle size of the dust is detected from the pressure of an air filter in the succeeding stage. Therefore, a plurality of combinations of the conductive pattern to a hot wire and the changing pattern of the air flow directed to the heat generating resistance body at the heating time are prepared beforehand. One of the combinations is selected in accordance with each detecting value of the temperature of the cooling water of the engine, the running distance, the pressure of the air filter in the succeeding stage. The heat generating resistance body is heated according to the selected pattern to burn off the dust. The air flow is applied to blow the dust off.
Inventors:
UCHIYAMA KAORU
Application Number:
JP23989691A
Publication Date:
March 30, 1993
Filing Date:
September 19, 1991
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F02D41/18; F02D45/00; G01F1/68; G01F1/688; G01F1/698; G01F15/12; (IPC1-7): F02D41/18; F02D45/00; G01F1/68
Attorney, Agent or Firm:
Masami Akimoto
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