RU17982U1 - THERMAL ANEMOMETRIC SENSOR OF MASS AIR FLOW - Google Patents

Abstract

Hot-wire air mass flow sensor containing a sensing probe installed in the pipe, consisting of a ring, a thermistor, a V-shaped heated thread, installed under ∠α to the direction of flow through the holder and oriented against the direction of flow, characterized in that the V-shaped heated thread is oriented in the direction of flow, and the holder is made springy.

Description

 THERMOANEMOMESTER SENSOR OF MASS MUD. . . AHEAD,:. - The field knew the model related: to the measuring technique, it can be used to measure the mass flow rate of air. of spirit, for example, consumed by an internal combustion engine, - Those are rheumatic sensors (OE, patent / L 3016923, .1980; yes, patent 1 3109608, 1981) containing a sensing element installed in the pipe in the form of heating (. - - thread installed perpendicular to the direction of flow. The disadvantage of such devices is the limited scope ;. With such an arrangement of the heated pin, it will deform at high costs. This will lead to a malfunction of the device and a change in calibration characteristics Known thermoanemometric mass air flow sensor (D, application and 3631343, 1986), containing a sensing element in the form of a heated thread installed in the pipe and located along the flow direction. The disadvantage of this device is the insufficient resistance of the heated thread when using sensor in automotive technology. In the internal combustion engine, the reverse air exhaust may be present. - - - ./, which is .backflow © (Щвдру а эщ К) - ... - a wave This can lead to a break in the heated ifUfUGi The closest in technical essence to n | Shch1; the best technical solution is the hot-wire anemometer of the mass air flow rate (Z), and 3003671 AI, 1/68, 1981), w Р

containing a sensitive architect installed in the pipe, consisting of a ring, a thermistor, a V-shaped heated thread, installed under the direction of flow through a rigidly mounted holder and oriented against the direction of flow.

The disadvantage of such a sensor is that such an arrangement of the heated filament can lead to sagging: of the heated filament at high and pulsating flow rates, as it often has a test in the inlet tract of the internal combustion engine of a car. As a result, a change in the calibration characteristics may occur. In addition, when using the sensor in automotive technology, reverse exhaust air may be drawn into the internal combustion engine. It is a shock wave propagating in the opposite direction, while aerodynamic forces stretch the thread, which, if the holder is rigidly installed, can lead to the breakage of the thread.

The objective of the useful model is to increase the mechanical resistance of the heated filament to more than 5 air flow rates and reverse exhaust, which affects the metrological stability of the sensor. This is achieved by the fact that in the hot-wire anemometer of the mass air flow rate containing the sensitive zozz installed in the pipe, consisting of a ring, a thermoresistor ,. V-shaped heated thread installed under (to. The direction of flow through the holder and oriented, against the direction of flow, V - shaped heated thread is oriented in the direction of flow, and the holder is spring-loaded.::

The location of the heated filament under - cL is poisoning along. --- .-. V -, -: - # О - - .. - -. - - the flow reduces the possibility of deformation of the heated thread from the side of the aerodynamic forces that occur when air flow is worse due to the extension of the heated thread, which is compensated by the damping effect of the spring holder in direct flows, which does not lead to a deterioration in the metrological characteristics of the sensor. With reverse impulse flows, Pr. retaining properties of the holder stabilize the tension of the thread, preventing, beyond, the fluidity of the material of the thread, which increases its mechanical resistance under the action of reverse exhausts. The essence of the utility model is illustrated by the drawings. Fig. I schematically shows a hot-wire anemometer sensor of class air flow; FIG. 2 is a side view. . The device comprises a sensing probe 2 installed in the pipe I, containing a ring 3, a thermistor 4, a V-shaped heated thread 5., mounted under Z. 28 °, to the direction of flow through the spring holder 6 and oriented in the direction of flow. The sensor. Works as follows. When air is consumed through a sensitive ZOBD 2, which contains a thermo-rotor 4 for measuring the tegra temperature of the air and a heated thread 5, the difference between the telescopes; heated press 6 and flowing air is kept constant, the flow of the measured medium cools the heated thread. 5. The greater the air flow, the greater should be. CURRENT required to maintain the temperature difference of the heated filament 5 and the passing air. The magnitude of the current required to maintain a constant temperature difference between the heated filament 5 and the passing air will be a measure of coli. -. .: 4 -

X -: -.

the amount of air passing through the pipe I,

. - -Heatable, thread 5, installed under (уС to the direction of flow through the spring holder 6 and the orientated bathtub by the flow direction prevents the heating thread from defrring at high air flow rates and reverse exhaust.;

Claims (1)

Hot-wire air mass flow sensor containing a sensing probe installed in the pipe, consisting of a ring, a thermistor, a V-shaped heated thread installed under ∠α to the direction of flow through the holder and oriented against the direction of flow, characterized in that the V-shaped heated thread is oriented in the direction of flow, and the holder is made springy.