JPH04158264A - Gas rate sensor - Google Patents

Abstract

PURPOSE:To downsize an entire configuration and also improve sensor characteristics by providing a gas pump in a casing, providing a plurality of sensors in the casing and composing the gas pump of an electromagnetic pump. CONSTITUTION:When a predetermined ac signal is applied to a driving coil 26, a vibrator 4a vibrates based on electrode function with a magnet 22, gas in a pump chamber 12 is compressed, and the gas is sent from a discharge port 23a through a gas passage 30 to sensors 7a,7b. The gas circulates along a direction of an arrow in a sealed casing 1. When angle speed is applied from outside, a gas flow is displaced in the casing 1 to cause nonuniformity between respective heat coils 7a,7b so that a slight difference in voltage occurs between the respective heat coils 7a,7b. By measuring the difference in voltage, the angle speed applied to the casing 1 can be detected. Since an electromagnetic pump 4 can freely change its shape, a shape and size of a gas rate sensor can be freely changed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas rate sensor, and in particular, to a novel gas rate sensor that circulates gas using an electromagnetic pump, miniaturizes the overall structure, and improves characteristics. Regarding improvements.

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. The configuration disclosed in the conventional example of Japanese Patent Application No. 61-224868 can be mentioned.

In the figure, the casing designated by the reference numeral 1 is approximately cylindrical as a whole and has both ends open. Each end of the casing 1 is connected to a pump holder 2.
and the relay terminal plate 3, respectively, and the casing 1
The inside 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 the electrostrictive oscillating pump 4 (gas 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 is constructed as shown in FIG.

That is, the electrode holder 5 has four gas guide holes 5a to
Further, four electrodes 6a to 6d are arranged symmetrically with respect to the central axis. These electrodes 6
Between electrodes 6a and 6b and between electrodes 6C and 6d among 8 to 6d
Hot wires 7a and 7b are connected therebetween by welding.

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 at approximately the middle W 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 guide hole. It is sent to the gas flow path 13 via 5a to 5d.

An IC is located outside the relay terminal plate 3 of the casing 1.
A signal processing circuit section 14 is provided, which 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.

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

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 pin 16, as well as to the shaft inside the casing 1. 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.

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. The flow flows into the flow path 13 through the discharge port 5e of Each electrode 6a is arranged inside the space lb in la.
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 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 deflected within the casing 1. However, an uneven state occurs between each of the hot wires 7a and 7b, and therefore a slight voltage difference occurs between each of the hot wires 7a and 7b.By measuring this voltage difference, it is possible to determine the voltage applied to the casing 1. Angular velocity can be detected.

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

In other words, in the conventional configuration, a piezoelectric bimorph type pump was used as the gas pump to circulate gas, but the shape and dimensions of this bimorph and its natural frequency (which uses resonance) are closely related. Generally, when a device is made smaller, its natural frequency and vibration amplitude become smaller.

Therefore, in order to miniaturize the gas rate sensor, it is necessary to miniaturize the bimorph, but in reality it is almost impossible to make bimorphs with various dimensions, and the dimensions of standard bimorphs that are generally commercially available. The actual situation was to manufacture a gas rate sensor according to the actual situation.

For this reason, there are limits to the use of bimorphs when it comes to improving the characteristics and reducing the size of gas rate sensors.Furthermore, regarding the characteristics of bimorphs, the temperature characteristics of the bimorph's natural vibration frequency and vibration amplitude are limited. This has been the biggest bottleneck in improving the characteristics of gas rate sensors.

The present invention has been made to solve the above-mentioned problems, and in particular, it provides a gas rate sensor that uses an electromagnetic pump to circulate gas, downsizes the overall structure, and improves the characteristics. The purpose is to provide.

81 Means for Solving the Problems A gas rate sensor according to the present invention includes a gas pump provided in a casing and a plurality of sensors provided in the casing. In the gas rate sensor, the gas pump is configured to include an electromagnetic pump.

More specifically, the electromagnetic pump includes a magnet provided in a holding case, a vibrator provided opposite to the magnet, and a magnetic body provided in the vibrator and opposed to the magnet.
This configuration includes a drive coil provided on the magnetic body.

e Function In the gas rate sensor according to the present invention, since an electromagnetic pump is used as the gas pump, the gas can be circulated by the vibration of the vibrator caused by electromagnetic vibration.
The shape of the magnet, coil, and vibrator can be changed arbitrarily, eliminating the need to use the resonance point of the vibrator, and the shape and dimensions of the gas rate sensor can be changed freely, improving characteristics. I can do it.

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

1 to 3 are for showing the gas rate sensor according to the present invention, and FIG. 1 is a cross-sectional view showing the overall configuration;
FIG. 2 is a side view of the electromagnetic pump, and FIG. 3 is a sectional view of the electromagnetic pump.

In the figure, the casing designated by reference numeral 1 is approximately cylindrical as a whole, with both ends open.One end 1a of the casing 1 functions as a terminal plate having a terminal 18. A holding case 2 is provided, and a lid body 20 having a U-shaped cross section and a ring-shaped holding body 21 are provided at the other end 1b.

A magnet 22 is provided on the inner surface 2a of the pump holder 2, and a vibrator holder 23 having a plate-shaped vibrator 4a is opposed and fixed in the casing 1 spaced apart from the holding case 2. It is provided.

The vibrator 4a is made of a flexible metal plate, and is provided via an annular support 25 so as to form a pump chamber 24 with a gap between the vibrator 4a and the vibrator holder 23. A discharge hole 23a is formed in the vibrator holder 23.

The vibrator 4a includes a magnetic body 2 having a drive coil 26.
7 is provided, and this magnetic body 27 is disposed opposite to the magnet 22 with a space therebetween.

Therefore, the aforementioned holding case 2, magnet 22, magnetic body 27,
The drive coil 26, the vibrator 4a, the vibrator holder 23, and the discharge hole 23a constitute an electromagnetic pump 4 as a gas pump.

A collar portion 5a of an electrode holder 5 is fixed in the casing 1 adjacent to the vibrator holder 23, and a pair of rod-shaped rods are provided on the inner side 5b of the electrode holder 5, as in the conventional structure. Sensors 7a, 7b are provided, each consisting of a pair of hot wires stretched between electrodes 6a, 6c and 6b, 6d.

A holding hole 21a formed at the center of the annular holding body 21 has one end 1 of a nozzle body 10 in the shape of a longitudinal cap.
0a is fitted and held, and the other end 1 of this nozzle body 10
0b is connected to the electrode holder 5.

Therefore, the gas discharged from the discharge hole 23a is transmitted through the first through hole 5C1 of the electrode holder 5, the gas passage 30 formed between the cylindrical shape 10c of the nozzle body 10, and the casing 1;
Via the second through hole 21b formed in the annular holder 21 and the nozzle hole 8 formed in the nozzle body 10, it is supplied to each sensor 7a, 7b as shown by the arrow, and each holder 7
a.

The gas that has passed through 7b is configured to return into the pump chamber 12 through the discharge hole 23a.

That is, the discharge hole 23a is a well-known technique, but as shown in FIG. 1A, the continuous vibration of the vibrator 4a discharges gas along the arrow A, and at the same time discharges gas from the surrounding area along the arrow B. Configured to inhale gas.

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

First, when a predetermined AC signal is applied to the drive coil 26,
The vibrator 4a vibrates based on the electromagnetic interaction with the magnet 22,
The gas in the pump chamber 12 is compressed, and this compressed gas is sent from the discharge port 23a through the gas flow path 30 to each sensor 7a, 7b.

The compressed gas described above uniformly cools each sensor 7a, 7b and circulates within the sealed 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. , an uneven state occurs between each hot wire 7a and 7b, and therefore a slight voltage difference occurs between each hot wire 7a and 7b,
By measuring this voltage difference, the angular velocity applied to the casing 1 can be detected.

Note that the sensors 7a and 7b are not limited to hot wires, and strain gauges or the like may also be used.

g0 Effects of the Invention Since the gas rate sensor according to the invention is configured as described above, it can have the following effects.

In other words, since an electromagnetic pump is used as the gas pump, its shape can be changed freely without being limited to the shape and dimensions of conventional bimorph pumps, and the shape and dimensions of the gas rate sensor can be changed. can be changed freely and characteristics can be improved.

[Brief explanation of drawings]

Figures 1 to 3 are for showing the gas rate sensor according to the present invention, and Figure 1 is a sectional view showing the overall configuration;
Figure 1A is an enlarged cross-sectional view of the main part of Figure 1, Figure 2 is a side view of the electromagnetic pump, Figure 3 is a cross-sectional view of the electromagnetic pump, and Figures 4 to 6 show a conventional gas rate sensor. It shows,
FIG. 4 is a sectional view, FIG. 5 is a side view of essential parts, and FIG. 6 is a block diagram. 1 is gauging, 2 is a holding case, 4 is a gas pump (electromagnetic pump), 4a is a vibrator, 7a and 7b are sensors, 22
is a magnet, 26 is a drive coil, and 27 is a magnetic body. Figure 1 (1) shows the casing (Figure 2, Figure 3, Figure 4, Figure 5). .

Claims (2)

[Claims] (1) Gas pump (4) installed in the casing (1)
and a plurality of sensors (7a, 7b) provided in the casing (4), each sensor (7a
, 7b), wherein the gas pump is an electromagnetic pump. (2) The electromagnetic pump (4) includes a magnet (22) provided in the holding case (2), a vibrator (4a) provided opposite to the magnet (22), and the vibrator (4a). ) and facing the magnet (22);
The gas rate sensor according to claim 1, further comprising a drive coil (26) provided on the magnetic body (27).