JP2967147B2 - Gas rate sensor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas rate sensor, and more particularly to a novel gas rate sensor for improving a rise drift by providing a conductor having a large thermal resistance between a hot wire and an electrode. Regarding improvement.

b. Conventional technology Various configurations have been adopted as this type of gas rate sensor that has been used in the past, and a typical configuration is described in FIGS. 4 to 6. The structure disclosed in the conventional example of Japanese Patent Application Laid-Open No. 63-81270 can be cited.

In the drawing, a reference numeral 1 denotes a casing having a substantially cylindrical shape as a whole and having both ends opened, and each end of the casing 1 is respectively formed by a pump holder 2 and a relay terminal plate 3. It is closed, and the inside of the casing 1 is shut off from the outside.

The pump holder 2 is provided with a vibrating plate 4a made of an electrostrictive ceramic disk, and its peripheral portion is integrally fixed to the pump holder 2 so that the electrostrictive vibrating pump 4 (gas pump) is formed. ) Is formed.

An electrode holder 5 is disposed inside the casing 1 at a position separated from the diaphragm 4a by a predetermined distance.
The electrode holder 5 is configured as shown in FIG.

That is, the electrode holder 5 has four gas guide holes 5a to 5a.
5d is formed, and four electrodes 6a to 6d are symmetrically arranged with respect to the central axis. Among these electrodes 6a to 6d, hot wires 7a and 7b are connected by welding between the electrodes 6a and 6b and between the electrodes 6c and 6d.

Further, a nozzle plate 10 having a nozzle hole 8 and an auxiliary hole 9 is provided in a position near the relay terminal plate 3 in the casing 1, and between the relay terminal plate 3 and the nozzle plate 10, A dust plate 11 is provided at a substantially intermediate position between the two.

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 supplied to a gas guide hole. The gas is sent to the gas channel 13 via 5a to 5d.

An IC is provided outside the relay terminal plate 3 of the casing 1.
A signal processing circuit unit 14 is provided. The signal processing circuit unit 14 receives power from the outside, and is connected to the relay terminal 15 of the relay terminal plate 3 for taking out output signals of the hot wires 7a and 7b to the outside. It is connected.

Further, lead pins 16 are provided on the relay terminal plate 3, and the lead pins 16 are connected to external terminals 18 provided on an external casing 17.

The external terminal 18 supplies electric power required for operating the electrostrictive vibration pump 4 and electric power required for heating the hot wires 7a and 7b to a signal processing circuit unit 14 and a lead pin 16, and to a shaft in the casing 1. It has the function of appropriately supplying via a plurality of lead wires 19 arranged in the directions.

The external terminal 18 has a function of outputting the output signals of the hot wires 7a and 7b after passing through the signal processing circuit section 14.

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

First, when the electrostrictive vibration pump 4 (gas pump) is energized, the vibration plate 4a vibrates to compress the gas in the pump chamber 12, and the compressed gas is discharged from the discharge port 4b of the vibration plate 4a and the electrode holder 5a. Flows through the discharge port 5e into the flow path 13 and is guided to the space formed between the nozzle plate 10 and the dust plate 11, and passes through the nozzle hole 8 and the auxiliary port 9 to form the hollow cylindrical portion in the casing 1. In the space 1b in 1a, it is jetted toward each of the electrodes 6a to 6d.

The above-described compressed gas uniformly cools the hot wires 7a and 7b welded to the electrodes 6a to 6d, and then cools the gas guide holes 5a to 5d.
The exhaust gas is discharged toward the diaphragm 4a through 5d, and this exhaust gas is again actuated by the electrostrictive vibration pump 4 (gas pump).
It returns to the nozzle plate 10 via the flow path 13 and circulates in the casing 1 in the direction of the arrow.

In the above-mentioned state, when no angular velocity is applied to the casing 1, the hot wires 7a and 7b are uniformly cooled, but when an angular velocity is applied from the outside, the gas flow is deviated in the casing 1. And each hot wire 7a and 7b
A non-uniform state occurs between the hot wires 7a and 7b, so that a small voltage difference is generated between the hot wires 7a and 7b. By measuring the voltage difference, the angular velocity applied to the casing 1 can be detected.

c. Problems to be Solved by the Invention Since the conventional gas rate sensor is configured as described above, the following problems exist.

That is, since a hot wire having a diameter of several microns is welded to the electrode and used, the thermal time constant of the electrode and the electrode holder supporting the electrode is much larger than that of the hot wire. Since the heat generated by the hot wire flows to the electrode and the electrode holder, the rising drift is deteriorated.

The present invention has been made in order to solve the above-mentioned problems, and in particular, a gas rate sensor that improves a rising drift by providing a conductor having a large thermal resistance between a hot wire and an electrode. The purpose is to provide.

d. Means for Solving the Problems A gas rate sensor according to the present invention comprises an electrode holder having a plurality of implanted electrodes provided in a casing, and at least a pair of hot wires provided between the electrodes. A gas rate sensor configured to supply a gas to each of the hot wires, the gas rate sensor having a conductor having a large thermal resistance provided on the electrode, wherein the hot wire is connected to the conductor. .

e. Function In the gas rate sensor according to the present invention, since the hot wire is provided on the conductor having a high thermal resistance provided on the electrode, the temperature of the hot wire is increased in a state where the temperature of the hot wire is increased. Can be prevented from flowing to the electrode or the electrode holder, the rising drift of the hot wire can be prevented, and stable detection of the angular velocity input can be performed from the time of rising.

f. Embodiment Hereinafter, a preferred embodiment of the gas rate sensor according to the present invention will be described in detail with reference to the drawings.

The same or equivalent parts as those in the conventional example will be described using the same reference numerals.

1 to 3A show a gas rate sensor according to the present invention. FIG. 1 is a sectional view, and FIG.
3 is a perspective view showing the configuration of FIG. 2, and FIG. 3A is a front view of the main part of FIG.

In the drawing, a reference numeral 1 denotes a casing having a substantially cylindrical shape as a whole and having both ends opened, and each end of the casing 1 is respectively formed by a pump holder 2 and a relay terminal plate 3. It is closed, and the inside of the casing 1 is shut off from the outside.

The pump holder 2 is provided with a vibrating plate 4a made of an electrostrictive ceramic disk, and its peripheral portion is integrally fixed to the pump holder 2 so that the electrostrictive vibrating pump 4 (gas pump) is formed. ) Is formed.

In addition, an electrode holder 5 is disposed inside the casing 1 at a position separated from the diaphragm 4a by a predetermined distance, and the electrode holder 5 is configured as shown in FIG.

That is, the electrode holder 5 has four gas guide holes.
5a to 5d are formed, and four electrodes 6a to 6d are symmetrically arranged with respect to the axis.

A conductor 50 having a higher thermal resistance than each of the electrodes 6a to 6d is provided above each of the electrodes 6a to 6d, and the conductor 50 is formed in a thin plate shape made of, for example, a stainless metal material. ing.

A pair of hot wires 7a and 7b having a diameter of several microns are connected to the conductor 50 between the electrodes 6a and 6b and between the electrodes 6c and 6d by welding among the electrodes 6a to 6d.

Further, a nozzle plate 10 having a nozzle hole 8 and an auxiliary hole 9 is provided in a position near the relay terminal plate 3 in the casing 1, and between the relay terminal plate 3 and the nozzle plate 10, A dust plate 11 is provided at a substantially intermediate position between the two.

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 supplied to a gas guide hole. The gas is sent to the gas channel 13 via 5a to 5d.

An IC is provided outside the relay terminal plate 3 of the casing 1.
A signal processing circuit unit 14 is provided, which receives power from the outside and receives hot wires 7a and 7
It is connected to the relay terminal 15 of the relay terminal plate 3 for extracting the output signal of b to the outside.

Further, lead pins 16 are provided on the relay terminal plate 3, and the lead pins 16 are connected to external terminals 18 provided on an external casing 17.

The external terminal 18 supplies electric power required to operate the electrostrictive vibration pump 4 and electric power required to heat each of the hot wires 7a and 7b to a signal processing circuit unit 14 and a lead pin 16, and to a shaft in the casing 1. This has the function of appropriately supplying the power via a plurality of lead wires 19 arranged in the directions.

The external terminal 18 has a function of outputting the output signal of each of the hot wires 7a and 7b after passing through the signal processing circuit unit 14.

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

First, when the electrostrictive vibration pump 4 (gas pump) is energized, the vibration plate 4a vibrates to compress the gas in the pump chamber 12, and the compressed gas is discharged from the discharge port 4b of the vibration plate 4a and the electrode holder 5. It flows into the flow path 13 through the discharge port 5e, is guided to the space formed between the nozzle plate 10 and the dust plate 11, and passes through the nozzle hole 8 and the auxiliary port 9 to form the hollow cylindrical portion 1a in the casing 1. In the inside of the space 1b, it is ejected toward each of the electrodes 6a to 6d.

The above-mentioned compressed gas is uniformly welded to each conductor 50 of each of the electrodes 6a to 6d and cools the heated hot wires 7a and 7b, and then toward the diaphragm 4a via the gas guide holes 5a to 5d. The discharged gas is returned to the nozzle plate 10 via the flow path 13 by the action of the electrostrictive vibration pump 4 (gas pump) again, and circulates in the casing 1 in the direction of the arrow.

In the above-described state, when the angular velocity is not applied to the casing 1, the hot wires 7a and 7b are uniformly cooled. However, when the angular velocity is applied from the outside, the gas flow is deviated in the casing 1. As a result, a non-uniform state occurs between the hot wires 7a, 7b, so that the hot wires 7a, 7b
A slight voltage difference occurs between the two, and by measuring this voltage difference, the angular velocity applied to the casing 1 can be detected.

Therefore, when the above-described hot wires 7a, 7b are heated by applying a current thereto, the heat resistance of each conductor 50 is large, so that the heat of each hot wire 7a, 7b hardly flows to the electrodes 6a to 6d and the like. In addition, the rising drift at the time of the rising after the power is turned on can be made extremely favorable.

Note that, in the present embodiment, the case where gas is used as the gas and the gas is circulated by the gas pump has been described.For example, without using the gas pump, the casing is removed to expose the nozzle plate to the outside, and the high-speed The airflow generated at the time of being attached to the flying object is assigned to each hot wire 7a, 7b
The same operation and effect can be obtained even when the power supply is performed.

g. Effects of the Invention Since the gas rate sensor according to the present invention is configured as described above, the following effects can be obtained.

That is, since the hot wire is provided on the conductor having a high thermal resistance provided on the electrode, it is possible to prevent the temperature of the hot wire from flowing to the electrode or the electrode holder when the temperature of the hot wire is increased. Therefore, it is possible to prevent a rising drift at the time of rising and to detect a stable angular velocity input.

[Brief description of the drawings]

1 to 3A show a gas rate sensor according to the present invention. FIG. 1 is a sectional view, FIG. 2 is a plan view showing a main part of FIG. 1, and FIG. FIG. 3A is a perspective view showing the configuration of FIG. 2, FIG. 3A is a front view of a main part of FIG. 3, FIG. 4 to FIG. 6 show a conventional configuration, FIG. FIG. 6 is a plan view of a main part, and FIG. 6 is a circuit diagram. 1 is a casing, 4 is a gas pump, 5 is an electrode holder, 6a
6d are electrodes, 7a and 7b are hot wires, and 50 is a conductor.

Claims (3)

(57) [Claims] An electrode holder (5) provided in a casing (1) and having a plurality of implanted electrodes (6a to 6d), and at least one pair of hot electrodes provided between the electrodes (6a to 6d). A wire (7a, 7b).
7b) a gas rate sensor configured to supply gas to the electrodes (6a to 6d), comprising a conductor (50) having a large thermal resistance provided on the electrodes (6a to 6d), and the conductor (50) being connected to the hot wire. The gas rate sensor to which (7a, 7b) is connected. 2. The gas rate sensor according to claim 1, wherein said gas is formed by a gas pump (4) provided in said casing (1). 3. The gas rate sensor according to claim 1, wherein the conductor has a plate shape.