초록 ▼

A device which serves to measure the mass of a flowing medium, in particular the mass of the air aspirated by an internal combustion engine. The device includes a substrate on the bottom and top of which there is disposed a respective temperature-dependent resistor electrically connected in parallel

A device which serves to measure the mass of a flowing medium, in particular the mass of the air aspirated by an internal combustion engine. The device includes a substrate on the bottom and top of which there is disposed a respective temperature-dependent resistor electrically connected in parallel and preferably embodied as a film, on both sides of which at peripheral areas low-impedance electrical conductor tracks are provided. The peripheral areas of the substrate are partially encompassed by U-shaped deformations provided on metallic retainers. The retainers simultaneously serve as electrical connections via soldered areas provided between the U-shaped deformations and the conductor tracks. The retainers protrude into the flow of the medium and have good thermal conductivity, so that they are virtually at the temperature of the flowing medium, and hence the temperature of the peripheral areas is also kept at the temperature of the flowing medium. To reinforce this effect, additional thermal conduction surfaces on the retainers or further thermal conduction elements which have good thermal conductivity, can be provided. With the temperatures of the peripheral areas kept to the temperature of the flow of the medium, short startup and response times are provided by the device even when there are sudden major changes in the mass of the flowing medium.

대표청구항 ▼

A method for measuring the mass of a medium having an ambient temperature and flowing through a housing, in particular for measuring an air mass aspirated by an internal combustion engine, comprising the steps of: applying a first film to a portion of a surface of a substantially rectangular substra

A method for measuring the mass of a medium having an ambient temperature and flowing through a housing, in particular for measuring an air mass aspirated by an internal combustion engine, comprising the steps of: applying a first film to a portion of a surface of a substantially rectangular substrate having a longitudinal extent to form at least one temperature- dependent resistor having sides, disposing along said longitudinal extent of the substrate and on opposite sides of the at least one temperature-dependent resistor respective second films to form protective heating resistors having greater length than said at least one temperature-dependent resistor, orienting said film on said surface so that said at least one temperature-dependent resistor is disposed substantially medially of terminal portions of the substrate, disposing at least one of said terminal portions in a metallic, thermally-conductive support means for thermal contact therewith, further disposing said support means so that the at least one temperature-dependent resistor lays transversely to a flow direction of said medium and said terminal portions are exposed thereto, connecting a resistance detection device having a regulating function to said at least one temperature-dependent resistor to form a closed loop for detecting a resistance value of the at least one temperature-dependent resistor, regulating the at least one temperature-dependent resistor to a predetermined resistance temperature by varying a supply of energy thereto, and maintaining said protective heating resistors at a temperature that approximates said predetermined resistance temperature of the at least one temperature-dependent resistor, whereby the at least one terminal portion of the substrate may be maintained at substantially the temperature of the medium.