JP2008139210A - Gas rate sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems wherein it is difficult to uniformize the resistance value, outer shape, and temperature coefficient of a sensing wire and the detection precision of angular velocity decreases since hot wires are provided in a tensioned state at two or four locations and respective sensing wires H1-H4 are formed each in a conventional gas rate sensor. <P>SOLUTION: At the upper portion of an electrode holder 5, a first electrode 11 arranged opposite to a center region in a nozzle hole 4a for guiding a gas flow 3, and second and third electrodes 12, 13 arranged separately mutually with the first electrode 11 as a center on a straight line passing through the first electrode 11 are implanted, and hot wires are implanted linearly at the first to third electrodes 11-13. The first and second sensing wires H1, H2 are formed by dividing the hot wires between the first and second electrodes 11, 12, and between the first and third electrodes 11, 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas rate sensor for detecting an angular velocity applied to a casing. In particular, the first and second sensing wires are formed by dividing a linearly heated heat ray into two from the center. Further, the present invention relates to a novel improvement that can suppress variation in performance of the second sensing wire, improve angular velocity detection accuracy, and reduce production costs.

  Examples of this type of gas rate sensor that have been used in the past include the configurations disclosed in Patent Document 1, Non-Patent Document 1, and the like. FIG. 6 is a block diagram showing a conventional gas rate sensor. In the figure, a gas is sealed and a space 1 a is provided inside a casing 1, and this gas is supplied as a gas flow 3 to the space 1 a by a gas pump 2. A nozzle plate 4 is attached to one end of the space portion 1a, and the nozzle plate 4 is provided with a nozzle hole 4a for guiding the gas flow 3 to the space portion 1a. An electrode holder 5 is disposed inside the space portion 1 a so as to face the nozzle plate 4, and the electrode holder 5 is provided with a detection unit 6 for detecting an angular velocity applied to the casing 1. ing.

  Next, FIG. 7 is a perspective view showing the detection unit 6 of FIG. 6 and shows a uniaxial detection unit structure. FIG. 8 is a circuit diagram showing the connection of the detection unit 6 of FIG. In the figure, the detection unit 6 is stretched between pin-shaped first to fourth electrodes 11 to 14 and the first and second electrodes 11 and 12 which are independently implanted on the electrode holder 5. A first sensing wire H1 integrally connected to the electrodes 11 and 12 by welding or the like, and a second wire stretched between the third and fourth electrodes 13 and 14 and integrally connected to the electrodes 13 and 14 by welding or the like. It comprises a sensing wire H2. Each of the electrodes 11 to 14 is arranged at a predetermined distance from the center of the gas flow 3 (position facing the central area of the nozzle hole 4a). As shown in FIG. 7, the first and second sensing wires H1, H2 are incorporated in a bridge circuit including first and second resistors R1, R2.

  Next, the operation will be described. A gas flow 3 is supplied into the space 1a under a state in which current flows through the sensing wires H1 and H2. At this time, when an angular velocity is applied to the casing 1, the gas flow 3 is deflected, and the deflection of the gas flow 3 causes a temperature difference between the sensing wires H 1 and H 2. This temperature difference state is detected by a bridge circuit in which the sensing wires H1 and H2 are incorporated on two sides, and the angular velocity is detected as a resistance difference.

  Next, FIG. 9 is a perspective view showing a state where the detection unit 6 of FIG. 6 is changed to a biaxial type. Note that the same or equivalent parts as those of the uniaxial detection structure will be described using the same reference numerals. In the figure, fifth to eighth electrodes 15 to 18 are arranged on the electrode holder 5 at positions separated by a predetermined distance from the position facing the central region of the nozzle hole 4a. The third sensing wire H3 is stretched between the fifth and sixth electrodes 15 and 16 so as to be orthogonal to the extending direction of H1 and H2, and the fourth sensing is performed between the seventh and eighth electrodes 17 and 18. A wire H4 is stretched. The third and fourth sensing wires H3 and H4 are incorporated in a bridge circuit (not shown) independent of the bridge circuit of the first and second sensing wires H1 and H2. With this configuration, angular velocity detection is performed on two axes.

JP-A-1-167671 2, 2, 4 (1) gas rate sensors on page 56 of Gyro Application Technology Introduction (Tamagawa Seiki Co., Ltd., published by the 2002 Industrial Research Committee)

  In the conventional gas rate sensor as described above, each of the sensing wires H1 to H4 is formed by separately stretching hot wires at two or four locations and fixing the hot wires to the electrodes 11 to 18 by electric resistance welding. However, since the heat rays are extremely thin, damage is likely to be applied, and it is difficult to make the resistance values, the outer shape, and the temperature coefficient of the sensing wires H1 to H4 uniform, so that the detection accuracy of the angular velocity is lowered.

  The gas rate sensor according to the present invention includes a casing having a space portion therein, a gas pump provided in the casing for circulating gas as a gas flow, and disposed at one end of the space portion. A nozzle plate provided with a nozzle hole for guiding, a first electrode disposed in the space portion so as to face the nozzle plate, and opposed to a central region of the nozzle hole, and the first electrode. An electrode holder provided with second and third electrodes arranged on a straight line and spaced apart from each other with the first electrode as a center, and a heat wire stretched linearly on the first to third electrodes The first and second electrodes for detecting the angular velocity from the deflection of the gas flow when the angular velocity is applied to the casing, formed by being divided between the first and second electrodes and between the first and third electrodes. And the second sensing device And a ya.

  Further, the electrode holder includes fourth and fourth electrodes arranged perpendicular to a straight line passing through the second and third electrodes and spaced apart from each other around the first electrode on a straight line passing through the first electrode. Five electrodes are further provided, and the first, fourth, and fifth electrodes are linearly stretched between the first and fourth electrodes and between the first and fifth electrodes. And third and fourth sensing wires for detecting the angular velocity in a direction orthogonal to the first and second sensing wires.

  The electrode holder includes a fourth electrode disposed to face the central region of the nozzle hole together with the first electrode, and a fourth electrode orthogonal to a straight line passing through the second and third electrodes. And a fifth electrode and a sixth electrode arranged apart from each other about the fourth electrode on a straight line passing therethrough, and the heat wire stretched linearly on the fourth to sixth electrodes A third and a second for detecting the angular velocity in a direction orthogonal to the first and second sensing wires, formed by being divided between the fourth and fifth electrodes and between the fourth and sixth electrodes. Further comprising 4 sensing wires.

  Further, the first electrode and the fourth electrode are arranged so that their positions are shifted from each other when the electrode holder is viewed from the nozzle plate side.

  In addition, a pin-shaped insulating member disposed on the electrode holder facing the central region of the nozzle hole is further provided, and the first electrode and the fourth electrode are separated from the electrode holder by the insulating member. They are arranged so that their heights are different from each other.

  According to the gas rate sensor of the present invention, the first and second sensing wires have a single continuous heat wire stretched linearly between the first to third electrodes and between the first and second electrodes. Since it is formed by being divided between the first and third electrodes, variation in the performance of the first and second sensing wires can be suppressed, the angular velocity detection accuracy can be improved, and the production cost can be reduced. .

  The third and fourth sensing wires are spaced apart from each other about the first electrode on a straight line passing through the first electrode and perpendicular to the straight line passing through the first electrode and the second and third electrodes. Formed by dividing one continuous heat ray stretched linearly between the fourth and fifth electrodes arranged between the first and fourth electrodes and between the first and fifth electrodes Therefore, the angular velocity can be detected in two axes while suppressing variations in the performance of the sensing wires.

  The third and fourth sensing wires are orthogonal to a straight line passing through the second electrode and the fourth electrode disposed opposite to the central region of the nozzle hole together with the first electrode and the first electrode. On the straight line passing through the four electrodes, a single continuous heat ray stretched in a straight line with the fifth and sixth electrodes arranged apart from each other with the fourth electrode as the center is the fourth and fifth electrodes. Between the first and second sensing wires and the third and fourth sensing wires are electrically connected to each other. The angular velocity detection accuracy can be further improved.

  Further, since the first electrode and the fourth electrode are arranged so as to be shifted from each other when the electrode holder is viewed from the nozzle plate side, each bridge circuit is more securely electrically separated. can do.

  Further, the first electrode and the fourth electrode are arranged so as to be shifted from each other by the insulating member so that the height from the electrode holder is different from each other. The positions of the electrodes can be made the same, and the detection accuracy of the angular velocities can be further improved by making the detection conditions of each sensing wire equal.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
Since the overall configuration of the gas rate sensor of the first embodiment is the same as that of the conventional gas rate sensor, only the characteristic part will be described. FIG. 1 is a perspective view showing a detection unit of a gas rate sensor according to Embodiment 1 of the present invention. The same or equivalent parts as those of the conventional gas rate sensor will be described using the same reference numerals (the same applies to other embodiments). In the figure, on the upper part of the electrode holder 5, the first electrode 11 disposed opposite to the central region of the nozzle hole 4 a and the first electrode 11 on the straight line passing through the first electrode 11. The second and third electrodes 12 and 13 that are spaced apart are implanted, and one continuous heat ray is stretched in a straight line on the first to third electrodes 11 to 13. For example, the electrodes 11 to 13 are electrically connected and fixed by welding or the like. That is, the first and second sensing wires H1 and H2 have an angular velocity applied to the casing 1 such that the heat ray is between the first and second electrodes 11 and 12, and between the first and third electrodes 11 and 13. It is formed by being divided, and is incorporated in the bridge circuit shown in FIG. The central region of the nozzle hole 4 a is a predetermined region including the center of the nozzle hole 4 a and is a region considered as the center of the gas flow 3.

  According to such a gas rate sensor, the first and second sensing wires H1 and H2 have a single continuous heat ray stretched linearly on the first to third electrodes 11 to 13, respectively. Since it is formed by being divided between the two electrodes 11 and 12 and between the first and third electrodes 11 and 13, variation in performance of the first and second sensing wires can be suppressed, and the angular velocity can be reduced. The detection accuracy can be improved and the production cost can be reduced.

Embodiment 2. FIG.
FIG. 2 is a perspective view showing a detection unit of a gas rate sensor according to Embodiment 2 of the present invention. In the figure, the electrode holder 5 is arranged on a straight line passing through the first electrode 11 and perpendicular to a straight line passing through the second and third electrodes 12 and 13 and spaced apart from each other around the first electrode 11. The fourth and fifth electrodes 14 and 15 are further implanted, and one continuous heat ray is linearly formed on the first electrode 11, the fourth electrode 14, and the fifth electrode 15. For example, the electrodes 11, 13, and 14 are electrically connected and fixed by welding or the like. In other words, the third and fourth sensing wires H3 and H4 for detecting the angular velocity in the direction orthogonal to the extending direction of the first and second sensing wires H1 and H2 are such that the heat rays are the first and third electrodes 11. , 13 and between the first and fourth electrodes 11, 14.

  Next, FIG. 3 is a circuit diagram showing a bridge circuit in which the sensing wires H1 to H4 of FIG. 2 are incorporated. In the figure, first and second sensing wires H1 and H2 are incorporated in a bridge circuit including first and second resistors R1 and R2, and third and fourth sensing wires H3 and H4 are third and third. It is incorporated in a bridge circuit including four resistors R3 and R4, and each of these bridge circuits is connected to a common power source. This is because each heat wire is connected to the first electrode 11 together.

  In such a gas rate sensor, the third and fourth sensing wires H3 and H4 are one continuous heat wire stretched linearly between the first electrode 11 and the fourth and fifth electrodes 14 and 15. Is formed by being divided between the first and fourth electrodes 11 and 14 and between the first and fifth electrodes 11 and 15, while suppressing variations in the performance of the sensing wires H1 to H4, The detection of angular velocity can be made biaxial.

Embodiment 3 FIG.
FIG. 4 is a perspective view showing a detection unit of the gas rate sensor according to Embodiment 3 of the present invention. In the second embodiment, the sensing wires H1 to H4 are connected to the common electrode 11 and the bridge circuits are connected to each other. However, in the gas rate sensor of this embodiment, each bridge circuit is electrically connected. Separated. That is, the fourth electrode 14 is disposed separately from the first electrode 11 at a position facing the central region of the nozzle hole 4 a of the electrode holder 5. In other words, the positions of the first electrode 11 and the fourth electrode 14 are shifted so that they are electrically independent from each other when the electrode holder 5 is viewed from the nozzle plate 4 side. In addition, the electrode holder 5 is arranged on a straight line passing through the fourth electrode 14 and perpendicular to a straight line passing through the second and third electrodes 12 and 13 and spaced apart from each other around the fourth electrode 14. Fifth and sixth electrodes 15 and 16 are implanted. In the third and fourth sensing wires H3 and H4, one continuous heat wire stretched linearly on the fourth to sixth electrodes 14 to 16 is connected between the fourth and fifth electrodes 14 and 15, and the It is formed by being divided between the fourth and sixth electrodes 14 and 16.

  In such a gas rate sensor, the third and fourth sensing wires H3 and H4 have a single continuous heat wire stretched linearly on the fourth to sixth electrodes 14 to 16, respectively. Since it is formed by being divided between the electrodes 14 and 15 and between the fourth and sixth electrodes 14 and 16, the bridge circuit of the first and second sensing wires H1 and H2, and the third and The bridge circuit of the fourth sensing wires H3 and H4 can be electrically separated, and the angular velocity detection accuracy can be further improved.

Embodiment 4 FIG.
FIG. 5 is a perspective view showing the main part of the detection part of the gas rate sensor according to Embodiment 4 of the present invention. In the third embodiment, each bridge circuit is electrically separated by shifting the positions of the first electrode 11 and the fourth electrode 14 when the electrode holder 5 is viewed from the nozzle plate 4 side. However, the bridge circuits can be electrically separated by shifting only the height of the electrodes 11 and 14 with respect to the electrode holder 5. In the figure, a pin-like insulating member 20 is implanted at a position on the electrode holder 5 facing the central region of the nozzle hole 4a. A notch 20 a is provided in the middle of the insulating member 20, the first electrode 11 is provided in the notch 20 a, and the fourth electrode 14 is provided on the top 20 b of the insulating member 20.

  In such a gas rate sensor, the first electrode 11 and the fourth electrode 14 are arranged so that the height from the electrode holder 5 is shifted by the insulating member 20 so that the gas flow 3 The positions of the first and fourth electrodes 11 and 14 with respect to the center of the sensor can be made the same, and the detection accuracy of the angular velocity can be further improved by making the detection conditions of the sensing wires H1 to H4 equal.

It is a perspective view which shows the detection part of the gas rate sensor by Embodiment 1 of this invention. It is a perspective view which shows the detection part of the gas rate sensor by Embodiment 2 of this invention. It is a circuit diagram which shows the bridge circuit in which each sensing wire of FIG. 2 is incorporated. It is a perspective view which shows the detection part of the gas rate sensor by Embodiment 3 of this invention. It is a perspective view which shows the principal part of the detection part of the gas rate sensor by Embodiment 4 of this invention. It is a block diagram which shows the conventional gas rate sensor. It is a perspective view which shows the detection part of FIG. It is a circuit diagram which shows the connection of the detection part of FIG. It is a perspective view which shows the state which changed the detection part of FIG. 6 into the biaxial type.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Casing, 1a Space part, 2 Gas pump, 3 Gas flow, 4 Nozzle plate, 4a Nozzle hole, 5 Electrode holder, 6 Detection part, 11-16 The 1st-6th electrode, 20 Insulating member, H1-H4 1st -4th sensing wire.

Claims (5)

A casing (1) having a space (1a) therein;
A gas pump (2) provided in the casing (1) for circulating gas as a gas flow (3);
A nozzle plate (4) provided at one end of the space (1a) and provided with a nozzle hole (4a) for guiding the gas flow (3) to the space (1a);
The first electrode (11) and the first electrode (11) disposed in the space (1a) so as to face the nozzle plate (4) and to face the central region of the nozzle hole (4a). Electrode holder (5) provided with second and third electrodes (12, 13) spaced apart from each other around the first electrode (11) on a straight line passing through
A heat ray stretched linearly on the first to third electrodes (11 to 13) is formed between the first and second electrodes (11, 12) and between the first and third electrodes (11, 13). First and second sensing wires (H1, H2) formed by being divided and for detecting the angular velocity from the deflection of the gas flow (3) when the angular velocity is applied to the casing (1); A gas rate sensor comprising: The electrode holder (5) is centered on the first electrode (11) on a straight line passing through the first electrode (11) and perpendicular to a straight line passing through the second and third electrodes (12, 13). Are further provided as fourth and fifth electrodes (14, 15) spaced apart from each other,
The heat wires stretched linearly on the first electrode (11), the fourth electrode (14), and the fifth electrode (15) are connected between the first and fourth electrodes (11, 14) and the first electrode. And third and fourth for detecting the angular velocity in a direction perpendicular to the first and second sensing wires (H1, H2). The gas rate sensor according to claim 1, further comprising sensing wires (H3, H4). The electrode holder (5) includes a first electrode (11), a fourth electrode (14) disposed opposite to a central region of the nozzle hole (4a), and the second and third electrodes (12). , 13) perpendicular to the straight line passing through the fourth electrode (14) and spaced apart from each other around the fourth electrode (14) on the straight line passing through the fourth electrode (14) (15, 16). ) And is further provided,
Heat rays linearly stretched between the fourth to sixth electrodes (14 to 16) are formed between the fourth and fifth electrodes (14, 15) and between the fourth and sixth electrodes (14, 16). A third and fourth sensing wires (H3, H4) that are formed by being divided and that detect the angular velocity in a direction orthogonal to the first and second sensing wires (H1, H2) are further provided. The gas rate sensor according to claim 1.   The first electrode (11) and the fourth electrode (14) are disposed so as to be displaced from each other when the electrode holder (5) is viewed from the nozzle plate (4) side. The gas rate sensor according to claim 3 or 4. A pin-shaped insulating member (20) disposed on the electrode holder (5) so as to face the central region of the nozzle hole (4a);
The first electrode (11) and the fourth electrode (14) are arranged so as to be shifted by the insulating member (20) so that the height from the electrode holder (5) is different from each other. The gas rate sensor according to claim 3.

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