JPH04220516A - Gas rate sensor - Google Patents

Abstract

PURPOSE:To constitute a pair of sensor parts by welding a wire sensor body to at least three electrodes so as to reduce fluctuations in respective sensor parts. CONSTITUTION:A sensor body is connected to three electrodes provided on an electrode board by means of welding to constitute a pair of sensor parts, whereby fluctuations in characteristics in respective sensor parts can be reduced as much as possible and a highly reliable gas rate sensor can be obtained.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a gas rate sensor, and in particular, connects one sensor body to three electrodes to form a pair of sensor parts, eliminates variations in each sensor part, Concerning new improvements to improve assembly accuracy.

0002

BACKGROUND OF THE INVENTION There are various types of gas rate sensors that have been used in the past, but a typical configuration is described in Japanese Patent Application Laid-open No. 1-1-1 shown in FIGS. 4 to 6.
The configuration disclosed in the conventional example of Publication No. 67671 can be mentioned. In the figure, the casing designated by reference numeral 1 is approximately cylindrical as a whole, with both ends open. Each end of the casing 1 is connected to a pump holder 2 and a relay terminal plate 3. blocked,
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 disc, 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) can be operated. It is formed.

[0003] Also, inside the casing 1, an electrode holder 5 is located at a predetermined distance from the diaphragm 4a.
is arranged, and this electrode holder 5 is constructed as shown in FIG. That is, four gas guide holes 5a to 5d are formed in the electrode holder 5, and four electrodes 6a to 6d are arranged symmetrically with respect to the central axis. Among these electrodes 6a to 6d, hot wires 7a and 7b are connected by welding between electrodes 6a and 6b and between electrodes 6d. Further, a nozzle plate 10 having a noise hole 8 and an auxiliary hole 9 is provided in the vicinity of 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. 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.

[0004] A signal processing circuit section 14 consisting of an IC is provided at a position outside the relay terminal plate 3 of the casing 1;
This signal processing circuit section 14 receives power from the outside, and
It is connected 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. 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 constructed 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 It flows into the flow path 13 through the discharge port 5e, 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 then flows into the hollow cylindrical portion 1a in the casing 1. Each electrode 6a
It is ejected towards ~6d.

After uniformly cooling the hot wires 7a and 7b welded to the electrodes 6a to 6d, the compressed gas is discharged toward the diaphragm 4a through the gas guide holes 5a to 5d. The gas passes through the flow path 13 and reaches the nozzle plate 10 again by the action of the electrostrictive vibration pump 4 (gas pump).
It returns to , 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, a uniform state occurs between each hot wire 7a, 7b, and therefore a slight voltage difference occurs between each hot wire 7a, 7b,
By measuring this voltage difference (output difference), the angular velocity applied to the casing 1 can be detected.

[0007]

[Problems to be Solved by the Invention] Since the conventional gas rate sensor is constructed as described above, it has had the following problems. In other words, since two independently configured hot wires are connected and stretched between each pair of electrodes, there is a large variation in the characteristics of the pair of temperature-sensitive resistors (sensor parts), and two pairs of the same characteristics It was extremely difficult to obtain the configuration. Also, in order to obtain a pair of sensor parts,
Connections had to be made at four locations (for example, by welding, etc.), and variations in contact resistance at the time of connection also led to variations in characteristics. In addition, there are two short and extremely thin (approximately 1
It is extremely difficult to connect to the electrode of the sensor section (diameter: 5 μm), resulting in an increase in assembly man-hours, resulting in an increase in cost and a decrease in assembly accuracy.

The present invention has been made to solve the above-mentioned problems.In particular, one sensor body is connected to three electrodes to form a pair of sensor parts, and each sensor part is connected to three electrodes. It is an object of the present invention to provide a gas rate sensor that eliminates variations in gas rate and improves assembly accuracy.

[0009]

[Means for Solving the Problems] A gas rate sensor according to the present invention supplies a gas flow sent from a gas pump to at least one pair of sensor parts provided between each electrode of an electrode plate, and In a gas rate sensor configured to detect angular velocity (ω) based on an output difference, the pair of sensor parts is formed by connecting one sensor body through three of the electrodes. It is.

More specifically, the sensor body is arranged in a straight line.

More specifically, the sensor body is formed in a dogleg shape with a central electrode located at the center of each of the electrodes.

0012

[Operation] In the gas rate sensor according to the present invention, one sensor body is connected and stretched through three electrodes, so the central electrode located at the center of each electrode becomes a common electrode, and one sensor body is connected and stretched through three electrodes. The sensor body is electrically configured into a pair of sensor parts. Therefore, a pair of independent three-electrode type sensor sections can be obtained by the center electrode and each of the other electrodes, and an input of angular velocity based on the deviation of the gas flow can be detected.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the gas rate sensor according to the present invention will be described in detail below with reference to the drawings. Note that the same or equivalent parts as in the conventional example will be described with the same reference numerals. 1 to 3 are for illustrating a gas rate sensor according to the present invention, in which FIG. 1 is a schematic sectional view, FIG. 2 is an enlarged perspective view of the main part, and FIG. 3 is another embodiment of FIG. 2. FIG. In the figure, the reference numeral 1 indicates a casing having a cylindrical overall shape, and an electrode plate 5 having three electrodes 6a, 6b, and 6c is provided inside the casing 1. The electrode plate 5 is provided with a hollow cylindrical portion 1a having a nozzle hole 8 at the axial center position, and the electrode plate 5 is formed with a gas discharge hole 5e and a gas guide hole 5a.

[0014] An end plug 2 is provided at one end 1a of the casing 1.
, a pump chamber 12 is formed between the end plug 2 and the electrode plate 5.
A gas pump 4 made of a piezoelectric plate is provided inside the gas pump 2 . Further, a circuit section 14 such as a signal processing circuit is provided at the other end 1b of the casing 1, and a terminal 18 is provided to protrude from this circuit section 14.

The electrodes 6a, 6b, 6c are arranged in a straight line on the electrode plate 5, as shown in FIG. A sensor body 50 made of hot wire or the like is stretched across a welded portion 51. Therefore, the electrode 6b is used as a common electrode, the sensor body 50 between the electrodes 6a and 6b constitutes the first sensor section 7a, and the sensor body 50 between the electrodes 6b and 6c constitutes the second sensor section 7b. In another embodiment shown in FIG. 3, the electrodes 6a, 6b, 6c are arranged in a non-linear dogleg shape, and one sensor body 5
0 is stretched in a dogleg shape through each welded portion 51, as in FIG. In the above-described configuration, by connecting each sensor section 7a, 7b to a bridge circuit similar to the conventional one shown in FIG. , 7b can detect the magnitude of the input angular velocity. Although a hot wire is used as the sensor body 50, a strain sensor or the like may also be used.

[0016]

[Effects of the Invention] Since the gas rate sensor according to the present invention is constructed as described above, the following effects can be obtained. That is, since each sensor section is constituted by one continuous sensor body, variations in each sensor section can be significantly reduced compared to the conventional configuration. Furthermore, the number of electrodes can be reduced compared to the conventional configuration, and the number of welding points is reduced, resulting in reductions in assembly man-hours and costs. Furthermore, since one sensor body is configured in a straight line or dogleg shape, it is possible to improve assembly accuracy and reliability, and it is possible to improve the parallelism of each sensor part as in the past. This eliminates the need for assembly, resulting in a significant reduction in assembly costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a gas rate sensor according to the invention.

FIG. 2 is an enlarged perspective view of the main part of FIG. 1;

FIG. 3 is a perspective view showing another embodiment of FIG. 2;

FIG. 4 is a sectional view showing a conventional gas rate sensor.

FIG. 5 is a plan view showing the main parts of FIG. 4;

FIG. 6 is a block diagram.

[Explanation of symbols]

4 Gas pump 4A Gas flow 5 Electrode plate 6a　　　Electrode 6b 6c 7a　　　Sensor part 7b Sensor part 50 Sensor body

Claims (3)

[Claims] Claim 1: A gas flow (4A) sent from a gas pump (4) is applied to each electrode (6a, 6b, 6c) of an electrode plate (5).
) at least one pair of sensor parts (7a, 7
b), and detects the angular velocity (ω) based on the output difference of each sensor part (7a, 7b). A gas rate sensor characterized in that the pair of sensor parts (7a, 7b) is configured by connecting a book sensor body (50). 2. The gas rate sensor according to claim 1, wherein the sensor body (50) is arranged in a straight line. 3. The sensor body (50) includes an electrode (6a, 6b, 6c) located at the center of the electrodes (6a, 6b, 6c).
2. The gas rate sensor according to claim 1, wherein the gas rate sensor is formed in a dogleg shape through the gas rate sensor b).