Device for determining mass flow and direction of flow

Claim 2

In a device for determining the mass flow and direction of flow of a fluid of substantially unidirectional flow with known mass flow, the device having a mass-flow measuring unit provided with a thermoelectric mass-flow sensor and a temperature sensor, the improvement wherein the device comprises two temperature-measuring elements arranged adjacent the mass-flow sensor; one of said temperature-measuring elements being located, depending on the direction of flow, in a feed stream; and the other of said temperature-measuring elements being located in the discharge stream of the mass-flow sensor; and fuel-metering means operatively coupled to said temperature-measuring elements for controlling fuel injection, in an engine, as a function of the mass flow of the air drawn in; and wherein fuel is fed by said controlling means as a function of the signals given off by the temperature-measuring elements.

Claim 3

The device according to claim 1, further comprising an amplifier, a Schmitt trigger, and a control unit; and wherein said temperature-measuring elements are connected to an input of said amplifier, an output of said amplifier being connected via said Schmitt trigger to a first input of said control unit which is connected by a second input furthermore to said mass-flow measuring unit, an output of said control unit being connected to said fuel-metering means.

Claim 4

The device according to claim 2, further comprising an integrator connected between the output of said control unit and an input of said fuel-metering means.

Claim 5

The device according to claim 3, further comprising a phase shifter connected between an output of the Schmitt trigger and said first input of said control unit.

Claim 6

The device according to claim 3, further comprising a mono-stable flip-flop connected between an output of the Schmitt trigger and said first input of said control unit.

Claim 7

The device according to claim 3, further comprising a phase shifter and a mono-stable flip-flop connected between an output of the Schmitt trigger and said first input of said control unit.

Claim 8

The device according to claim 2, wherein said control unit suppresses a measurement signal provided by said mass-flow measuring unit for as long as the correction signal is present on the second input of said control unit.

Claim 9

The device according to claim 2, wherein said control unit subtracts the value of a measurement signal provided by said mass-flow measuring unit during the duration of a correction signal present on the first input from that value of the measurement signal which is found during a time of absence of the correction signal.

Claim 10

The device according to claim 2, wherein said control unit reduces the value of a measurement signal found during the time that a correction signal is present on the first input to a predetermined fraction of the measurement signal.

Claim 11

In a device for determining the mass flow and direction of flow of a fluid of substantially unidirectional flow with known mass flow, the device having a mass-flow measuring unit provided with a thermoelectric mass-flow sensor and a temperature sensor, the improvement wherein the device comprises two temperature-measuring elements arranged adjacent the mass-flow sensor; one of said temperature-measuring elements being located, depending on the direction of flow, in a feed stream; and the other of said temperature-measuring elements being located in the discharge stream of the mass-flow sensor; a common mount for said mass-flow sensor, said temperature sensor and said two temperature-measuring elements; and fuel-metering means operatively coupled to said temperature-measuring elements for controlling fuel injection, in an engine, as a function of the mass flow of the air drawn in; and wherein fuel is fed by said controlling means as a function of the signals given off by the temperature-measuring elements, said device including further electronic components located on a said common mount, said further electronic components being combined as a single measuring and control unit arranged on a microchip.

Claim 12

In a device for determining the mass flow and direction of flow of a fluid of substantially unidirectional flow with known mass flow, the device having a mass-flow measuring unit provided with a thermoelectric mass-flow sensor and a temperature sensor, the improvement wherein the device comprises two temperature-measuring elements arranged adjacent the mass-flow sensor; one of said temperature-measuring elements being located, depending on the direction of flow, in a feed stream; and the other of said temperature-measuring elements being located in the discharge stream of the mass-flow sensor; a common mount for said mass-flow sensor, said temperature sensor and said two temperature-measuring elements; and fuel-metering means operatively coupled to said temperature-measuring elements for controlling fuel injection, in an engine, as a function of the mass flow of the air drawn in; and wherein fuel is fed by said controlling means as a function of the signals given off by the temperature-measuring elements, said device including further electronic components located on a said common mount, said further electronic components being combined as a single measuring and control unit arranged on a microchip.