Thermal air flow rate measuring apparatus and its flowmeter and internal combustion engine and thermal air flow rate measuring method using it

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said heating resistor in a flow direction of the fluid;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values to produce quantized signals;
• and means for operating said flow rate and a direction of said fluid based on said quantized signals, wherein said temperature detecting resistors are arranged in multistage along a longitudinal direction of said heating resistor individually at said upstream part and said downstream part and wherein a plurality of said quantized signals is adjusted by a plurality of parameters expressed by a function of at least a first order equation, and said adjusted signals are individually multiplied as output.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• means for operating said flow rate based on said quantized signals using at least two parameters, wherein at least one of said quantized signals is adjusted by a plurality of parameters expressed by a function of the first or higher order equation, and said plurality of adjusted signals are individually multiplied to be output.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• and means for operating said flow rate based on said quantized signals using at least two parameters, wherein at least one of the quantized signals by said quantizing means is adjusted by said plurality of parameters each expressed by a function of the first or higher order equation, and magnitude of said plurality of adjusted signals is judged to output said signal having the larger magnitude.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• and means for operating said flow rate based on said quantized signals using at least two parameters, wherein at least one of said parameters is a function relating to temperature, at least one of the at least two parameters is processed arithmetically by applying a function of at least a first order equation and wherein the air flow signal is obtained arithmetically as the function relating to the temperature.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• and operating means for operating said flow rate based on said quantized signals using at least two parameters, wherein said quantizing means is composed of a plurality of quantizing devices which are set independently of a reference voltage to be used as a reference of quantization.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• and operating means for operating said flow rate based on said quantized signals using at least two parameters, wherein at least one of said signals is pre-added with a temperature characteristic by a temperature compensation resistor.

A thermal air flow rate measuring apparatus comprising at least one heating resistor disposed in a gas fluid;

• temperature detecting resistors formed at an upstream part and a downstream part of said fluid with respect to said heating resistor;
• means for outputting at least two signals relating to a flow rate of said fluid from said heating resistor and from said temperature detecting resistors;
• means for quantizing said output values as quantized signals;
• and operating means for operating said flow rate based on said quantized signals using at least two parameters, wherein said quantized signals are operated using said parameters and then converted to air flow rates, and said converted air flow rate values are selectably output by an external signal, and selected output is any one of an analog value obtained by analog-converting a quantized digital value corresponding to an air flow rate, a frequency obtained by pulse-converting said digital value, or a duty obtained by PWM pulse-converting said digital value.