JPS63308568A - Gas rate sensor - Google Patents

Abstract

PURPOSE:To achieve a higher reliability, by forming a fine-dia. section at a part of an electrode along the length thereof to eliminate mechanical deformation during the energization of a hot wire. CONSTITUTION:Fine dia. sections 20 and 20 are formed at parts of electrodes 6a and 6b along the length thereof in a gas rate sensor. When a hot wire 7a is energized, possible mechanical deformation can be prevented as an extension portion caused by thermal expansion of the wire 7a can be absorbed by bending to the electrodes 6a and 6b owing to pliability thereof. Then, a stable rate output signal can be obtained starting from the energization.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a gas rate sensor, and more particularly to a novel improvement for preventing mechanical deformation or distortion from occurring when a hot wire is energized.

b. Conventional technology Various configurations have been adopted as this type of gas rate sensor that has been used in the past.To describe a typical configuration, here we will list the names of documents disclosing its contents. Although not listed here, the configurations shown in FIGS. 6 to 8 and manufactured in-house by the present applicant can be mentioned.

In FIGS. 6 to 8, the casing designated by the reference numeral 1 is generally cylindrical in shape, with both ends open, and each end of the casing 1 is
The pump holder 2 and the relay terminal plate 3 are respectively closed, and the inside of the casing 1 is cut off from the outside.

This pump holder 2 is provided with a diaphragm 4a made of an electrostrictive ceramic disk, and the peripheral edge of the diaphragm 4a is integrally fixed to the pump holder 2, so that an electrostrictive oscillating pump 4 (gas pump) can be operated. It is formed.

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

These electric i! Among i 6 a to 6d, hot wires 7a and 7b are connected by welding between electrodes 6a and 6b and between electrodes 60 and 6d.

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

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 flows through the gas discharge hole. It is sent to the gas flow path 13 via 5e.

At the outer position of the relay terminal plate 3 of the casing]-, there is an I
The signal processing circuit section 14 is provided with a relay terminal 15 of the relay terminal board 3 for receiving power from the outside and for taking out the output signals of the hot wires 7a and 7b to the outside. It is connected to the.

The external terminal 18 transmits the electric power required to operate the electrostrictive vibration pump 4 and the electric power required to heat the hot wires 7a and 7b to the shaft inside the casing 1 through the signal processing circuit section 14 and the lead bin 16. It has the function of appropriately supplying the liquid through the plurality of lead wires 19 arranged in the direction.

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

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

=3- First, when the electrostrictive vibration pump 4 (gas pump) is energized, the diaphragm 4a vibrates, compressing the gas in the pump chamber 12, and the compressed gas flows through the discharge port 4b of the diaphragm 4a. and flows into the flow path 13 via the discharge hole 5e of the electrode holder 5,
Each of the electrodes 6a to 6 is guided into the space formed between the nozzle plate 10 and the dust plate 11, passes through the nozzle hole 8 and the auxiliary port 9, and passes through the space lb in the hollow cylindrical part 1a in the casing 1. It is ejected towards 6d.

After the aforementioned compressed gas uniformly cools each hot wire 7a and 7b welded to each electrode 6a to 6d, it is discharged toward the diaphragm 4a through gas guide holes 58 to 5d, and this exhaust gas By the action of the electrostrictive vibration pump 4 (gas pump), the gas returns to the nozzle plate 10 via the flow path 13 and circulates within the casing 1 in the direction of the arrow.

In the above-mentioned state, when no angular velocity is applied to the gauging 1, each hot wire 7a and 7b is cooled uniformly, but when an external angular velocity is applied, the gas flow is deflected within the casing. , non-uniform cooling occurs between the hot wires 7a and 7b, which causes a slight voltage difference between the hot wires 7a and 7b, and by measuring this voltage difference, the angular velocity applied to the casing can be calculated. can be detected.

C1 Problems to be Solved by the Invention Since the conventional gas rate sensor was constructed as described above, it had the following problems.

(1) When the gas rate sensor is energized, the hot wire generates heat to several hundred degrees, and thermal expansion caused by this heat generation causes buckling and elongation, which is combined with internal stress and changes in spatial position due to mechanical deformation. occurs.

For this reason, the output signal line of the gas rate sensor suffers from unstable output due to voltage changes corresponding to the mechanical deformation of this hot wire, until the position of this hot wire is determined. .

(2) Also, for the mechanical deformation of the pot wire mentioned above,
Each of the electrodes has high rigidity and cannot absorb mechanical deformation of the pot wire, which is the biggest drawback of this type of gas rate sensor.

The present invention has been made to solve the above problems, and in particular, it is an object of the present invention to provide a gas rate sensor that does not cause mechanical deformation or distortion when a hot wire is energized.

Means for Solving Problem d1 The gas rate sensor according to the present invention includes a gas pump provided within a casing, an electrode holder provided adjacent to the gas pump, and an electrode holder provided opposite to the electrode boulder. a nozzle plate having a nozzle, a plurality of electrodes provided on the electrode holder, and a hole I provided between each of the electrodes;
This configuration includes a wire and a narrow diameter portion formed in a portion of the electrode in the longitudinal direction.

82 Effect In the gas rate sensor according to the present invention, since a small diameter portion is formed in a part of the electrode, when the hot wire is heated and deformed and extended during energization, the electrode will expand according to the deformation of the hot wire. Since it has the flexibility to bend in the same direction as the longitudinal direction of the bot wire, the stress generated in the hot wire is absorbed by the deformation of the electrode, suppressing changes in the spatial position of the hot wire and making it possible to bend the hot wire in the same direction as the power is turned on. A stable rate output signal can be obtained.

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

Note that the same parts as in the conventional example will be described with the same reference numerals.

1 to 5 show a gas rate sensor according to the present invention, and the one indicated by the reference numeral 1 in the figures is a casing having a generally cylindrical shape with both ends open. Each end of the casing 1 is closed by a pump holder 2 and a relay terminal plate 3, so that the inside of the casing 1 is isolated from the outside.

This pump holder 2 is provided with a diaphragm 4a made of an electrostrictive ceramic disk, and the peripheral edge of the diaphragm 4a is integrally fixed to the pump holder 2, so that the electrostrictive oscillating pump 4 (gas pump) It is formed.

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

Among these electrodes 68 to 6d, the electrodes M 6 a and 6b
Hot wires 7a and 7 are connected between 60 and 6d.
b are connected by welding.

As shown in FIG. 2, each of the electrodes 6a to 6d is formed with a concave narrow diameter portion 20 having a constricted shape in the longitudinal direction, and each of the electrodes 6a to 6d is connected to the hot wire. In the longitudinal direction of 7a and 7b, as shown by the arrow, it is configured to have flexibility so that it can be bent and deformed.

Therefore, when the hot wires 7a and 7b are extended and deformed when energized, the electrodes 6a and 6d and 6c and 6d are bent in opposite directions.

Further, each of the electrodes 6a to 6d is not limited to the above-mentioned configuration, but may have a narrow diameter portion 20 continuously formed upward from the base portion 21 to the upper end, as shown in FIGS. 4 and 5, for example. Even in this case, similar effects can be obtained.

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

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 flows through the gas discharge hole. It is sent to the gas flow path 13 via 5e.

An IC is located outside the relay terminal plate 3 of the casing 1.
This signal processing circuit section 14 receives power from the outside and connects to the relay terminal 15 of the relay terminal board 3 for taking out the output signals of the hot wires 7a and 7b to the outside. It is connected.

The external terminal 18 transmits the electric power required to operate the electrostrictive vibration pump 4 and the electric power required to heat the hot wires 7a and 7b through the signal processing circuit section 14 and the lead pins 16, as well as to the inside of the casing 1. It has the function of supplying it as appropriate via a plurality of lead wires 19 arranged in the axial direction.

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

The gas rate sensor of the present invention 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 and the gas in the pump chamber 12 is compressed. 5 into the flow path 13 through the discharge hole 5e,
Each electrode 68 to 6d and the hot wires 7a and 7b.

In this case, even if the hot wires 7a and 7b undergo mechanical deformation and elongation due to thermal expansion at the same time as electricity is applied, each electrode 6a to 6d has flexibility, so the hot wires 7a and 7b Since the hot wires 7a and 7b are bent in the longitudinal direction, the hot wires 7a and 7b do not bend and are kept stretched in a straight line from the moment the power is turned on.
- output signal can be obtained.

After the aforementioned compressed gas uniformly cools each hot wire 7a and 7b welded to each electrode 6a to 6d, it is discharged toward the diaphragm 4a through the gas guide holes 5a to 5d, and this discharged gas is again Due to the action of the electrostrictive vibration pump 4 (gas pump), the gas returns to the nozzle plate 10 through the flow path 13 and circulates within the casing 1 in the direction of the arrow.

In the above-mentioned state, when no angular velocity is applied to the casing 1, each hot wire 7a and 7b is cooled uniformly, but when an angular velocity is applied from the outside, the gas flow is deviated within the casing. , non-uniform cooling occurs between the hot wires 7a and 7b, which causes a slight voltage difference between the hot wires 7a and 7b, and by measuring this voltage difference, the angular velocity applied to the casing can be calculated. can be detected.

g1 Effects of the Invention Since the gas rate sensor according to the present invention is constructed as described above, when electricity is applied to the gas rate sensor, the elongation due to thermal expansion of the hot wire that occurs is reduced by bending due to the flexibility of each electrode. Therefore, a stable rate output signal can be obtained from the time of energization, and zero voltage shift of the signal can be eliminated.

Thereby, the reliability of the gas rate sensor can be significantly improved, and an extremely large amount of stability can be provided to the directional control of various devices.

[Brief explanation of drawings]

1 to 5 are for showing the gas rate sensor according to the present invention, and FIG. 1 is a sectional view showing the overall configuration;
Fig. 2 is an enlarged side view of the main part of Fig. 1, Fig. 3 is a plan view of Fig. 2, Fig. 4 is a side view showing another embodiment of the configuration of Fig. Figure 4 is an enlarged side view, and Figure 8 is a plan view of Figure 7. 1 is a casing, 4 is a gas pump, 5 is an electrode holder, 6
a to 6d are electrodes, 7a and 7b are hot wires, 8 is a nozzle, 10 is a nozzle plate, 20 is a narrow diameter portion, and 21 is a base.

Claims (3)

[Claims] (1), a gas pump (
4), an electrode holder (5) provided adjacent to the gas pump (4), a nozzle plate (10) provided opposite to the electrode holder (5) and having a nozzle (8); A plurality of electrodes (6a to 6d) provided on the electrode holder (5)
), a hot wire (7a, 7b) provided between each of the electrodes (6a to 6d), and a narrow diameter portion (20) formed in a part of the electrode (6a to 6d) in the longitudinal direction. The electrodes (6a to 6d) are connected to the hot wire (7).
A gas rate sensor characterized by having flexibility in the longitudinal direction of (a) and (7b). (2) The gas rate sensor according to claim 1, wherein the narrow diameter portion (20) has a concave shape. (3) The gas rate sensor according to claim 1, wherein the narrow diameter portion (20) is formed on the entire upper portion except for the base portion (21).