JPH01207618A - Gas rate sensor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to gas rate sensors, and more particularly to novel improvements for optically detecting changes in gas flow to detect angular velocity.

b. Conventional technology Various configurations have been adopted as this type of gas rate sensor that has been used in the past, but representative configurations are shown in Figs. 4 to 6. This is as shown in Japanese Patent Application No. 224868 of 1988 (written by the present applicant).

In the figure, the gauging indicated by the reference numeral 1 has a generally cylindrical shape with both ends open, and each end of the gauging 1 is connected to a pump holder 2 and a relay terminal plate 3. Each is closed, and the inside of the casing 1 is 31 times the outside! It is cut off.

The pump holder 2 is provided with a diaphragm 4a made of an electrically shaped ceramic disk, and the peripheral edge of the diaphragm 4a is integrally fixed to the pump holder 2, thereby forming an electrostrictive oscillation pump 4 (gas pump). has been done.

Further, an electrode holder 5 is arranged inside the casing 1 at a position spaced apart from the diaphragm 4a by a predetermined distance.
This electrode holder 5t is constructed as shown in FIG.

That is, the electrode holder 5 has four gas guide holes 5a to
5d is formed, and furthermore, four electric tri 6 a to 6
d are arranged symmetrically with respect to the central axis. Among these electric % 4 a to 6 d, electric Ff! Between 6a and 6b and between 6c and 6c, there are wires 7a and 7b.
are connected by welding.

Furthermore, the relay terminal board 3 in the casing 1
A nozzle plate 10 having a nozzle hole 8 and an auxiliary port 9 is provided near (55LL), and a dust plate 11 is provided between the relay terminal plate 3 and the nozzle plate 10 at an approximately intermediate position therebetween. It is being

A pump chamber 12 is formed between the diaphragm 4a of the electrostrictive vibration pump 4 (gas pump) and the pump holder 2, and the gas sent out by the electrostrictive vibration pump 4 is passed through the gas discharge port 5e. , from the gas guide path 13 to the nozzle hole 8, and from the gas flow path 1a to each gas guide hole 5a to 5b.
sent to.

At the outer position of the relay terminal plate 3 of the gauging 1, there is an IC.
A signal processing circuit section 14 is provided, and this signal processing circuit section 14 is connected to a third relay terminal 15 of a relay terminal board for receiving power from the outside and for taking out the output signals of the hot wires 7a and 7b to the outside. ing.

Further, the relay terminal board 3 is provided with a lead bin 16, and this lead bin 16 is connected to an external terminal 18 provided on the external casing 17.

The conventional gas rate sensor is configured as described above, and its operation will be explained below.

First, when the electrostrictive vibration pump 4 (gas pump) is energized, the diaphragm 4a vibrates, compressing the gas in the pump chamber 12, and this compressed gas flows through the discharge port 4b of the diaphragm 4a and the electrode holder. 5 through the discharge port 5e of the gas guide path 13
The flow passes through the nozzle hole 8 and the auxiliary port 9 to the hollow cylindrical part 1b.
The gas is ejected from the inside of the gas flow path 1a toward each of the electrodes 60 to 6d.

The compressed gas flowing through the gas flow path 1a described above is %6 of each type.
A pair of hot wires 7a and 7b welded to a-6d
After uniformly cooling the gas, it is discharged toward the diaphragm 4 & through each gas guide hole 5a to 5d, and this exhaust gas is again operated by the electric vibrating pump 4 (gas pump) to pass through the gas guide path 13 to the nozzle plate. 10, it circulates within the casing 1 in the direction of the arrow.

In the above-mentioned stratification, each pot wire 7a and 7b is uniformly cooled when no angular velocity is applied to the casing 1, but when an angular velocity is applied from the outside, the gas flow becomes uneven within the casing. Therefore, a slight voltage difference is generated between each hot wire 7a and 7b, and by measuring this voltage difference, the casing is The angular velocity applied to 1 can be detected.

C1 Problems to be Solved by the Invention Since the Song Dynasty gas rate sensor was constructed as described above, it had various problems as described below.

(1) As shown in FIG. 6, each hot wire 7a and 7b is constituted by a bridge circuit, and the ff
The i current flows and heats up.

For this reason, when turning on the power, etc., each hole 1 to wire 7
When the heating conditions of a and 7b change, the resistance of each hot wire 7a and 71) constituting the bridge circuit changes even in the field 6 where there is no deflection of the gas flow, causing a detection error of the gas rate sensor.

(2) Each of these hot wires 7a and 7b is
Expansion and deflection occur due to heating, which causes vibrations due to vibrations of the gas flow or vibrations applied to the case of the gas rate sensor, and this vibration causes noise etc. in the gas rate sensor.

The present invention has been made in order to solve the above-mentioned problems, and in particular, it is an object of the present invention to provide a gas rate sensor that detects angular velocity by optically detecting changes in gas flow. do.

d9 Means for Solving Problems The gas rate sensor according to the present invention comprises a gas pump provided in a casing, a nozzle plate having a force nozzle for guiding the gas sent by the gas pump, and a gas rate sensor in which the gas is This configuration includes two pairs of a light emitter and a light receiver for passing light into a flowing gas flow path, and detects angular velocity using the output deviation of each of the light receivers.

e, f? The gas rate sensor according to the present invention has a configuration in which a light receiving body receives light from a light emitting body disposed in a gas flow path as a means for detecting angular velocity, so a conventional heated hot wire can be used. Unlike the configuration used, there is no error or noise, and extremely stable detection operation can be obtained.

Preferred embodiments of the gas rate sensor according to the present invention will be described in detail below with reference to the drawings.
Or equivalent parts will be described with the same reference numerals.

The first (2I to third circuit) is for illustrating the gas rate sensor according to the invention.

At the mouth, the casing designated by reference numeral 1 has a substantially cylindrical shape with both ends open, and each end of the casing 1 is connected to a pump holder 2.
and relay terminal plate 3, respectively, and gauging 1
The inside is cut off from the outside.

The pump holder 2 is provided with a diaphragm 4a made of a distorted ceramic disc, and the peripheral edge of the diaphragm 4a is integrally fixed to the pump holder 2. pump) is formed.

Further, an electrode holder 5 is arranged inside the casing 1 at a position spaced apart from the diaphragm 4a by a predetermined distance.
This electrode holder 5 has a plurality of gas guide holes 5a and 5c formed therein.

Furthermore, the relay terminal board 3 in the casing 1
A nozzle plate 10 having a nozzle hole 8 and an auxiliary port 9 is provided near the relay terminal plate 3.
A dust plate 11 is provided approximately in the middle between them.

Said':r1. A pump chamber 12 is provided between the vibration plate 4a of the mechanical vibration pump 4 (gas pump) and the pump holder 2.
is formed, and the gas sent out by this electrostrictive positive pump 4 passes through the gas discharge port 5e and enters the gas guide path 1.
3, through the nozzle hole 8, and from the gas flow path 1a to each gas guide hole 5a, 5c.

Inner wall 11 of hollow cylindrical portion 1b that supports the nozzle plate 10
) A first light emitter 7a and a first light receiver 7b, and a second light emitter 7C and a second light receiver 7d are located near the gas guide holes 5a and 5c in Two pairs of optical sensors 20 are provided, and each of the light emitting bodies 7
The light beams a and 7C are configured to enter the respective photoreceptors 7b and 7d.

In addition, the gas flow described above is mixed with pigment particles that affect the ability of light to pass through each of the photoreceptors 7b and 7d depending on the gas concentration, and the light from each of the light emitters 7a and 7c is opposite to each other. It is configured to emit light from any direction.

Furthermore, the configuration shown in FIG. 3 shows an embodiment of the optical sensor 20, in which a pair of photoreceptors 7f and 7g are stratified perpendicularly to each other in response to light from one light emitter 7c. The gas flow contains particles that affect the scattering of light to each photoreceptor 7'' and 7g, and the scattering from the emitter 7e by each photoreceptor 7'' and 7g. It is configured to receive 3 lights.

An IC is located outside the relay terminal plate 3 of the casing 1.
A signal processing circuit unit 14 is provided, and this signal processing circuit unit 14 receives power from the outside.

Each of the light emitting bodies 7a is connected to each terminal 15 and the lead wire 19.
, 7c and 7e as well as the output signals (
voltage value) is supplied to the signal processing circuit section 4 via a lead wire 19 and a terminal 15.

Further, a lead bin 16 is provided on the relay terminal board 3, and the terminal 15 is connected to an external terminal 18 provided on an external Y-ring 17 by this lead bin 16.

The gas rate sensor according to the present invention is configured as described above, and the deflection ftE will be explained below.

First, when the electrical vibration pump 4 (gas pump) is energized, the diaphragm 4a vibrates and the gas in the pump chamber 12 is compressed.
It flows into the gas guide path 13 through the discharge port 5e of the Ii holder 5, passes through the nozzle hole 8 and the auxiliary port 9, and passes through the optical sensor 20 within the gas flow path 1m in the hollow cylindrical portion lb. The gas is returned through each gas guide hole 5n, 5c.

If no angular velocity is applied to the casing 1 due to the above-mentioned condition, no change occurs in the gas flow, so each photoreceptor 7b
, 7c, uniform New Year's Day light enters each photoreceptor 7b, 7c.
Equal output voltages are obtained from both, and the absence of applied angular velocity is detected.

Further, when an angular velocity as shown by the arrow is applied around the axis perpendicular to the axis of the gauging 1, the gas flow changes to the first
The light emitter 7a and the first light receiver 7b side, or the second light emitter 7c
and 1a toward either the second photoreceptor 7d side.

Either the light receiving element 7b or 7 on the side where this gas flow is deflected
Since the output voltage of the light receiving element d decreases and the output voltage of the other light receiving element increases, the deviation of each output voltage in this state is extracted to detect the angular velocity.

In addition, the above explanation of the operation was based on the case where the concentration difference in the gas flow shown in Fig. 2 is used, but when detecting the angular velocity using the scattered light shown in Fig. 3, the angular velocity is
, the gas flow becomes biased, and the state of scattering of light from the emitter 7e against particles in the gas flow changes, causing a difference in the amount of light received by each of the photoreceptors 7r and 7g, and the scattering rate increases. It can be detected as a difference in output voltage due to changes in .

g1 Effects of the Invention Since the gas rate sensor according to the invention is configured as described above, it is possible to obtain the following effects.

(1) Since changes in gas flow are detected by an optical sensor, as long as there are no changes in gas flow and as long as the power supply is stable, there will be no change in the output voltage, resulting in stable operation without malfunction. angular velocity detection can be achieved.

(2) Unlike conventional systems, there is no heating means built into the gas flow path, so there is no noise caused by deflection due to thermal expansion, vibration of the gas flow, or vibration due to external impact on the gauging. Malfunctions due to false detection can be prevented.

(3) Since the detection means is based on an optical sensor, there is no need for preheating in a cage to improve the rise characteristics, unlike the hot wire type of IK, and stable detection can be performed from the moment the power is turned on. At the same time, it is possible to significantly reduce power consumption.

[Brief explanation of the drawing]

The third circuit from FIG. 1 is for showing the gas rate sensor according to the present invention; FIG. 1 is a side sectional view, and FIG.
Fig. 3 is an enlarged sectional view showing the main part of the figure, Fig. 3 is an enlarged sectional view showing another embodiment of Fig. 2, Figs. 4 to 6 show the conventional configuration, and Fig. 4 is a side sectional view. , FIG. 5 is an enlarged front view of the main part of FIG. 4, and FIG. 6 is a circuit diagram. 1 is a casing, 1a is a gas flow path, 4 is a gas pump, 7
g, 7c, 7e are light emitters, 7b, 7d, 7 (7g is a photoreceptor, 8 is a nozzle, 1o is a nozzle plate) 'TT, - Figure 1 ( 1) is the casing (la), and the gas pump (4) is the gas pump (7a, 7c, 7e). ! “1fS (7b, 7d,
7f, 7g) L approval (8) is nozzle (10) nozzle plate Fig. 2 Fig. 3 Fig. 4

Claims (2)

[Claims] (1), gas pump (
4) and a nozzle plate (10) having a nozzle (8) for guiding the gas sent by the gas pump (4).
and a light emitter (7a, 7c, 7e) and a light receiver (7) for passing light into the gas flow path (1a) through which the gas flows.
b, 7d, 7f, 7g), and each of the photoreceptors (7b
, 7d) to detect angular velocity using the output deviation. (2) The gas rate according to claim 1, wherein the gas contains pigment particles for changing the gas concentration or particles for changing the scattering of light. sensor.