Hot line type air flow sensor

Abstract

The invention relates to a hot line type air flow sensor which comprises an upper cover and a base. One end of the upper cover and the base are clamped and form a circuit board installation cavity. Acircuit board is installed in the circuit board installation cavity. A plugging device for being communicated with the interior of the circuit board installation cavity and leading out electric signals is connected with one end of the outer side of the circuit board installation cavity. A stand column perpendicularly erected on the upper cover is arranged at the other end, opposite to a connectingbase, of the upper cover. The two sides of the stand column are provided with a half-opened air inlet channel and a half-opened air outlet channel. The end, away from an opening, of the air inlet channel is communicated with the air outlet channel. A hot line resistor erected oppositely penetrates through the opening of the air inlet channel. The hot line resistor is electrically connected with the circuit board. An L-shaped protection plate with one end perpendicular to the air outlet channel and the other end perpendicular to the upper cover is arranged outside the air outlet channel. A connecting column is arranged between the upper cover and the L-shaped protection plate. A temperature detecting resistor is spot-welded to the connecting column.

Description

technical field [0001] The invention relates to the field of air flow sensors, in particular to a hot wire air flow sensor. Background technique [0002] Automobile air flow sensor is one of the important sensors of EFI engine. It converts the inhaled air flow into an electrical signal and sends it to the electronic control unit (ECU). As one of the basic signals for determining fuel injection, it is a sensor for measuring the air flow inhaled into the engine. In order to obtain the best concentration of mixed gas under all circumstances, it is necessary to correctly measure the amount of air inhaled into the engine at each moment, and use this as the main basis for ECU to calculate (control) the fuel injection amount. If the air flow sensor or the circuit breaks down, the ECU cannot get the correct signal of the intake air volume, and it cannot normally control the fuel injection volume, which will cause the mixture to be too rich or too lean, and the engine will not run n...

AI Technical Summary

Problems solved by technology

If the air flow sensor or circuit breaks down, the ECU cannot get the correct signal of the intake air volume, and it cannot normally control the fuel injection volume, which will cause the mixture to be too rich or too lean, and the engine will not run normally.

There are many types of air flow sensors for electronically controlled gasoline injection systems. Common air flow sensors can be divided into vane (flap) type, measuring core type, hot wire type, hot film type, and Karman scroll type according to their structural types. However, due to the unreasonable circuit design of the traditional hot-film air flow sensor, it often leads to inaccurate air flow measurement, which affects the work of electronically controlled gasoline injection engines.

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