JP2002022449A - Angular speed sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angular speed sensor which can detect an angular speed with high sensitivity utilizing Coriolis force. SOLUTION: An oscillator 11 having two sets of tuning fork parts 13, 14 is manufactured by cutting a piezoelectric material into H shape. The tuning fork parts 13, 14 are arrange, at the exciting shaft parts 15, 16 thereof, with two exciting electrodes 31-34 and 41-44 and, at the detection shaft parts 17, 18 thereof, with three exciting electrodes 51-56 and 61-66. The exciting shaft parts 15, 16 and the detection shaft parts 17, 18 are subjected to polarization and the tuning fork parts 13, 14 excite the oscillation shaft parts 15, 16 and the detection shaft parts 17, 18 to be opened/closed at a reverse timing. Under excited state, an angular speed Ω having the central axis C of the tuning fork parts 13, 14 as the rotational axis is applied and a piezoelectricity generated in the detection shaft parts 17, 18 being flexed by a Coriolis force in the opposite directions is taken out and the angular speed Ω is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor, and more particularly, to an angular velocity sensor for detecting an applied angular velocity using a Coriolis force.

[0002]

2. Description of the Related Art In recent years, as information has become more sophisticated, sensors capable of obtaining more accurate information have been demanded, and sensors have been developed in various fields. In particular, angular velocity sensors are among the most demanding of these sensors, and among them, the tuning fork vibration type is widely used in a wide field because it can be reduced in size and weight.

As a conventional tuning fork vibration type angular velocity sensor of this type, for example, a sensor as shown in FIG. 11 is known. This angular velocity sensor supports a U-shaped metal vibration plate 103 on a fixed shaft 102 erected on a base 101, and also makes a metal plate 104, 1
05 is supported on each of the upper ends of the metal diaphragm 103. On the U-shaped vertical outer surface of the metal vibration plate 103, an excitation piezoelectric element 106 and a monitoring piezoelectric element 107 are fixed by an adhesive, respectively.
The piezoelectric elements 108 and 109 for Coriolis detection are fixed to the vertical surfaces of the piezoelectric elements 104 and 105 in the same direction by an adhesive, so that the piezoelectric elements 106 and 107 and the piezoelectric element 1 are fixed.
Tuning fork vibrator 110 in which 08 and 109 are orthogonal to each other
It has. The tuning fork vibration type angular velocity sensor detects the angular velocity by being constructed in such a configuration. Each of the piezoelectric elements 106 to 109 is connected to a lead wire 11 respectively.
1, the lead pins 112 are electrically insulated from the base 101 via an insulator 113 such as glass.

[0004] This angular velocity sensor is composed of a piezoelectric element 1 for excitation.
By applying a voltage to the tuning fork vibrator 110, the tuning fork vibrator 110 can be excited in the direction of arrow A. The excitation frequency and amplitude at this time are monitored by the monitoring piezoelectric element 107, so that the tuning fork vibrator 110 is always The piezoelectric element 10 for excitation is excited so as to be excited at a constant frequency and amplitude.
6 is controlled and used. At this time, as shown in FIG.
When the rotational angular velocity Ω in the direction of arrow B is applied to the detection axis C in the direction coaxial with the direction of the arrow 02, the metal plates 104, 10
5 will bend in the directions of arrows D1 and D2, which are directed in opposite directions.

Here, the Coriolis force F applied to the tuning fork vibrator 110 can be expressed by the following equation: Coriolis force F = 2 mVΩ m: mass of the tuning fork vibrator 110 V: excitation speed Ω: applied rotation angular speed This Coriolis force F is applied to the Coriolis detecting piezoelectric elements 108, 10
In this case, the piezoelectric elements 108 and 109 are subjected to the distortion in the opposite direction, that is, one of the piezoelectric elements 9 is expanded while the other is reduced.
And a differential output via the lead pin 112, and an angular velocity can be detected from the differential output.

[0006]

However, in such a conventional angular velocity sensor, when a rotational angular velocity Ω is generated, a Coriolis force F is applied to the tuning fork vibrator 110, and the tuning fork vibrator 110 as a whole as shown in FIG. Arrow D shown
1 and 2, the rotational moment M is applied to the fixed shaft 102. For this reason, the degree of fixation of the fixed shaft 102, the base 101, and the metal diaphragm 103 (the difference in the degree of vibration restraint) causes a variation in the angular velocity detection accuracy of the sensor.

The piezoelectric element for excitation 106, the piezoelectric element for monitoring 107, and the piezoelectric elements for Coriolis detection 108,
09 is the metal diaphragm 103 and the metal plate 1
04, 105, the variation in adhesion and the temperature characteristics of the adhesive cause the variation in the detection accuracy of the angular velocity Ω as a sensor. In addition, this adhesion accuracy, the bending accuracy of the tuning fork vibrator 110, Variations in the assembly processing accuracy such as the fixing accuracy of the fixed shaft 102, the tuning fork vibrator 110, and the base 101 also cause a variation in the detection accuracy of the angular velocity Ω by the sensor.

Furthermore, the lead wire 111 is connected to each piezoelectric element 10
6 to 109, the metal diaphragm 103 and the diaphragm 10
4 and 105, the torsion of the lead wire 111 causes a variation in detection accuracy of the angular velocity Ω of the sensor.

For this reason, the structure of the conventional angular velocity sensor has a problem that it is difficult to improve the detection accuracy of the angular velocity Ω.

Further, since the shapes (thickness and width) of the metal vibration plate 103 and the metal plates 104 and 105 do not match in the excitation direction and the Coriolis detection direction, as shown in FIG. There is a problem that it is difficult to match the resonance frequency at the time of detection, and it becomes a non-resonance type angular velocity sensor, and the sensitivity is reduced as compared with the resonance type.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide an angular velocity sensor capable of improving the angular velocity detection accuracy.

[0012]

In order to solve the above problems, an angular velocity sensor according to the present invention has an excitation shaft portion and a detection shaft portion which are the same by forming an H-shaped piezoelectric material and fixing the center to a base. A vibrator having two sets of tuning forks extending in the directions, and in an excitation state in which the excitation shaft portion is excited in a direction facing the detection shaft portion, an angular velocity having a center axis of the tuning fork as a rotation axis is applied. In some cases, a Coriolis force generated in a direction perpendicular to the excitation direction of the excitation shaft is detected by piezoelectricity generated by bending of the detection shaft in a direction perpendicular to the excitation direction. Here, the angular velocity sensor of the present invention has a configuration in which two sets of the excitation shaft portion and the detection shaft portion of the tuning fork are arranged at diagonal positions centered on the center of the vibrator, respectively, Due to the tuning fork effect interlocked with the excitation of the excitation shaft portion, the detection shaft portion also excites in the excitation direction, and when the excitation shaft portion and the detection shaft portion perform the opening and closing operation as two sets of the tuning forks, the mutual detection is performed. A configuration in which each of the detection shaft portions bends in a direction perpendicular to the excitation direction when Coriolis force is detected by exciting the opening and closing directions of the excitation shaft portion and the detection shaft portion to be opposite to each other. It is preferable that

According to this structure, the center of the vibrator in which the piezoelectric material is formed in an H shape is fixed to the base.
The vibrator can be formed as a unimorph-type integrated structure without using an adhesive as in the case of forming the bimorph type shown in FIG. Since it is an integral structure, it can be cut out from the piezoelectric material and manufactured. In addition, the two sets of tuning forks can be arranged in a symmetrical positional relationship that is diagonal for each of the excitation shaft portion and the detection shaft portion, so that vibration can be reduced and vibration can be reduced. By causing the vibrations to vibrate in opposite directions with the two sets of tuning forks, the moments exerted during the vibrations can be made to cancel each other, and the vibration leakage can be further reduced. Therefore, an angular velocity sensor capable of detecting angular velocity with high sensitivity can be manufactured at low cost.

In the angular velocity sensor according to the present invention, the excitation shaft portion is provided in parallel with the excitation direction so as to extend from a base fixed to the base in an end direction. One excitation electrode is formed on the front and back surfaces, and a surface perpendicular polarization process for reversing the polarization direction is performed between the excitation electrodes facing each other on the front and back surfaces, while the detection shaft portion includes the base portion. The three detection electrodes arranged in parallel with the excitation direction are formed on the front and back surfaces so as to extend from the front end to the end direction. Along with performing in-plane polarization processing between the detection electrodes on both sides adjacent in the plane, performing a plane perpendicular polarization processing to reverse the polarization direction between each of the detection electrodes on both sides facing each other on the front and back surfaces, The excitation electrode and the detection electrode can be connected at the base. To it was poured configuration are preferred.

According to this configuration, by forming two excitation electrodes on each of the front and back sides of the excitation shaft portion, the excitation electrode area can be increased because of in-plane excitation in the direction in which the excitation electrodes are arranged. Excitation efficiency can be improved. In addition, a detection electrode that becomes zero potential due to in-plane polarization is disposed at the center of the detection axis, and a detection electrode that becomes potential in the opposite direction is disposed on both sides by plane-perpendicular polarization, thereby detecting Coriolis force. The output can be taken out by the differential between the detection electrodes on both sides and the zero-potential detection electrode at the center, and noise can be canceled to improve the detection sensitivity. Furthermore, by extending and connecting both the excitation and detection electrodes at the base portion, the signal line connection with the circuit board can be performed at the base portion with less vibration, and the reliability of the connection can be improved. It is possible to prevent the detection accuracy from being lowered.

Further, in the angular velocity sensor according to the present invention, the base portion fixed to the base has a stepped shape projecting outward from an extension surface of the excitation shaft portion and the detection shaft portion. A clamper block for holding and fixing the vibrator by the spring property of a split portion, wherein the clamper block has a V-shaped or semi-circular cross-section to form a corner of the stepped shape of the base portion. A groove portion to be abutted and fixed is provided, and the gap between the inner surface of the groove portion of the clamper block and the corner of the stepped shape of the vibrator is previously covered with the inner surface of the groove portion and reflowed. It is preferable that the structure is filled with a melting point material.

According to this configuration, the stepped corner of the vibrator can be held and fixed in the V-shaped or semicircular groove portion of the clamper block in a very stable state without any variation, and the variation in the fixation increases the detection sensitivity. The influence can be reduced. In addition, the plating of low melting point material such as solder coated on the fixing point between the vibrator and the clamper block, etc., can be reflowed after clamping, thereby filling the minute gap existing between the clamper block due to shape errors etc. In addition to stabilizing the fixation, it is possible to keep the fixation constant and to minimize the influence of the variation on the detection sensitivity.

In the angular velocity sensor according to the present invention, the vibrator is installed in a package which is vacuum-sealed, but the clamper and the vibrator are integrally installed and installed in a vacuum-sealed package. Thereby, Q during vibration can be extremely increased, and the angular velocity detection sensitivity can be improved, which is preferable.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 10 are views showing an embodiment of an angular velocity sensor according to the present invention.

In FIG. 1, the angular velocity sensor is configured such that a vibrator 11 manufactured by cutting a piezoelectric material into an H shape is held and fixed on a clamper block (base) 70 shown in FIGS. The vibrator 11 is held and fixed to a clamper block 70 by being housed and packaged in a unit.
A base portion 12 formed in a stepped shape by projecting the center of the mold to the side, and a tuning fork portion 13 having two sets of tuning forks extending in a direction away from each other with the base portion 12 as a center; 14 and
It has.

In the vibrator 11, the shafts forming the tuning forks 13 and 14 have the excitation shafts 15 and 16 and the detection shaft 1 respectively.
The tuning forks 13 and 14 are configured to function as angular velocity sensors by configuring the tuning forks 13 and 14.
The excitation shaft portions 15 and 16 and the detection shaft portions 17 and 18 are arranged so as to be rotationally symmetric and positioned diagonally about the base 12.

That is, as shown in FIGS. 4 to 6, the vibrator 11 drives the excitation shaft portions 15 and 16 in a direction facing the detection shaft portions 17 and 18 so that the detection shaft portions 17 and 18 are driven. 18 can also be excited and vibrated in conjunction with the tuning fork structure (effect).
When an angular velocity Ω having a central axis C (central axis between the excitation axis section 15 (16) and the detection axis section 17 (18)) of 3 and 14 as a rotation axis is applied, the detection axis sections 17 and 18 are applied. Extracts piezoelectric generated by bending by Coriolis force in a direction perpendicular to the excitation direction, and detects its angular velocity Ω. At this time, the vibrator 11 operates so as to open and close the excitation shaft 15 and the detection shaft 17 of the tuning fork 13 and the excitation shaft 16 and the detection shaft 18 of the tuning fork 14 at timings opposite to each other. By doing so, it is possible to cancel the moment due to the excitation vibration applied to the base portion 12 and to reduce the leakage of the vibration, and to reduce the detection shaft portion 17 when the Coriolis force is applied in the excitation state. By bending the base 18 in the opposite direction, the moments applied to the base 12 are canceled each other, and leakage of vibration can be reduced.

Specifically, the vibrator 11 includes the excitation shaft 1
5 and 16, two excitation electrodes 31 to 3
4, 41 to 44 are arranged in parallel, while the detection shafts 17, 18 are arranged in parallel.
The three detection electrodes 51-56, 6
1 to 66 are arranged in parallel, and the excitation electrodes 31, 3
2, 41 and 42 are connected with wires 36 to 38, and the excitation electrodes 33, 34, 43 and 44 on the back side are similarly connected with wires 46 to 48 to ensure conduction,
The detection electrodes 51 to 56 and 61 to 66 also have electrodes formed on the front and back surfaces of the base portion 12 so that the detection electrodes 51 and 61 and the detection electrodes 5
2, 62, detection electrodes 53, 63, detection electrodes 54, 64,
The detection electrodes 55 and 65 and the detection electrodes 56 and 66 are formed in a circuit configuration in a state where they are electrically conductive. In the drawings, the surface of the electrode is hatched, but this is only for the purpose of making the electrode easier to see, and does not show a cross section.

The excitation shaft portion 15 of the tuning fork portion 13 has a structure shown in FIG.
As shown in FIG. 4, while the surface perpendicular polarization process is performed between the excitation electrodes 31 and 33 opposed on the front and back surfaces and between the adjacent excitation electrodes 32 and 34 so that the polarization directions a and b are opposite to each other, The excitation shaft portion 16 of the tuning fork portion 14 has the same polarization direction c at diagonal positions with respect to the excitation shaft portion 15 of the tuning fork portion 13,
The plane perpendicular polarization process is performed between the excitation electrodes 41 and 43 facing each other on the front and back surfaces and between the excitation electrodes 42 and 44 so as to be d.

Similarly, the direction of polarization e and f of the detection shaft 17 of the tuning fork 13 is set between the detection electrodes 51 and 54 facing each other on the front and back surfaces and between the detection electrodes 53 and 56 on the opposite side. The surface of the tuning fork 1
The detection shaft portion 18 of the fourth fork 13 has a portion between the detection electrodes 61 and 64 facing each other on the front and back surfaces so as to have the same polarization direction g and h at diagonal positions with respect to the detection shaft portion 17 of the tuning fork portion 13. , And between the detection electrodes 63 and 66 are subjected to a plane perpendicular polarization process.
In addition, the detection shaft portion 17 is provided with the detection electrodes 51 and 53 and the detection electrodes 54 on both sides adjacent to each other in the same plane so that the central detection electrodes 52 and 55 facing each other on the front and back surfaces have a zero potential. , 56, an in-plane polarization process in which the polarization directions i1, i2 and the polarization directions j1, j2 are reversed,
Similarly, the same polarization direction k1, k2, l1,
In-plane polarization processing is performed between the detection electrodes 61 and 63 and the detection electrodes 64 and 66 by setting the center detection electrodes 62 and 65 to zero potential so as to be l2.

From the above, after vibrating, the excitation electrodes 32, 33, 41, and 44 and the detection electrodes 51, 56, 63, and 64 have the positive potential after the polarization processing, and the excitation electrodes 31, 34 , 42, 43 and detection electrodes 53, 5
4, 61 and 66 are negative potentials, and the detection electrodes 52, 55 and 62 and 65 are zero electrodes.

As shown in FIG. 3, the vibrator 11 has excitation electrodes 31, 32, 41 and 42 formed on the surfaces of the excitation shafts 15 and 16 of the tuning forks 13 and 14, respectively.
The excitation electrodes 33, 34, 43, and 44 formed on the back surface are connected to the other grounded terminal 92, so that positive and negative voltages are alternately applied. The excitation shaft portions 15 and 16 repeatedly extend and retract the left half and the right half in FIG. 3 alternately, and approach the detection shaft portions 17 and 18 at opposite timings.
In contrast to the excitation drive that is separated, the detection shafts 17 and 1
8 can also be excited and vibrated so as to be close to and apart from each other by the tuning fork effect of the excitation shaft portions 15 and 16.
As a result, as shown in FIG. 4, when the excitation shaft 15 vibrates in the direction of the arrow in FIG. 4, the detection shaft 17 also vibrates in the direction of the arrow in FIG. By vibrating in the direction of the arrow in FIG. 4, the detection shaft 18 also vibrates in the direction of the arrow in FIG. 4 due to the tuning fork effect, and at the next moment, each of the detection shaft portions 18 vibrates in the direction opposite to the direction of the arrow in FIG. Are alternately repeated, so that this tuning fork 1
3, 14 open and close at the opposite timing.

On the other hand, when the tuning forks 13 and 14 are excited and a rotational angular velocity Ω having the central axis C as a rotation axis is applied, as shown in FIGS.
5 and 16 and the detection shaft portions 17 and 18 are bent in a direction orthogonal to the excitation direction by Coriolis force in a direction indicated by an arrow in the drawing.
Is a differential output between the detection electrode 54 and the detection electrode 56 with the center detection electrodes 55 and 65 as ground electrodes, and the voltage generated by the alternate expansion and contraction of the upper half and the lower half in FIG. By inputting the differential output between the detection electrode 64 and the detection electrode 66 to the differential amplifier 95, the voltage can be extracted from the output terminals 96 and 97 to the outside with high sensitivity as a voltage value corresponding to the Coriolis force. . The detection electrodes 54, 56, 64, 66 are connected to the detection electrodes 51, 53, 61, 63 on the back side via the connection line 23, respectively. The detection sensitivity can be further improved by canceling the charge.

The vibrator 11 is provided with protruding portions 12a and 12b protruding outward so as to further form the side surface of the base portion 12 into a stepped shape.
On the back side of 2b, connection electrodes 35, 45 which are formed by extending the excitation electrodes 33, 44 on the back side of the excitation shaft parts 15, 16 to the corners.
On the back side (front side) of the connection electrodes 35, 45, independent fixed electrodes 39, 49 are provided, and these electrodes 35, 39, 45, 49 are soldered. Then, the angular velocity sensor unit is manufactured by being held and fixed to the clamper block 70 shown in FIGS. 7 to 10, sealed in a vacuum in the storage case 80, and packaged.

As shown in FIGS. 7 to 9, the clamper block 70 has grooves 71 formed in a V-shaped (or semi-circular) cross section, facing each other.
The corners of the protruding portions 12a and 12b of the
And a center block 73 for supporting the side block 72. The center block 73 is formed with a slit (slit) 74 that opens to the lower surface side. The center block 73 and the side block 72 are formed with the slits 75 facing each other, so that a spring force acting in a direction to approach the groove 71 is developed, and the base 12 of the vibrator 11 is held and fixed by the spring force. It has become. Further, the side block 72 of the clamper block 70 is formed with a slipper 77 formed in a direction orthogonal to the groove 71 and opening outward, and the protrusion 12 a of the base 12 of the vibrator 11, 12b is fixed more reliably and without variation. Further, the clamper block 70 includes the vibrator 11
A claw 78 for opening and closing the groove portion 71 when mounting is mounted on the side block 72.

Further, the clamper block 70 has a
As shown in FIG. 0, a low melting point plating 76 such as solder is applied so as to cover the inner surface of the groove 71, and the base 11 is heated by clamping the vibrator 11 and then reflowing the low melting point plating 76. 12 projections 12a, 12
b, the connection electrodes 35, 45 and the fixed electrode 39,
The solder 76a is also fixed to 49.
As a result, the inner surface of the groove 71 and the protrusion 12
A small gap generated according to the processing accuracy (contact accuracy) between the a and 12b corners can be filled and fixed by the solder 76a, and the variation in the degree of fixing can be reduced.
The fixing of the vibrator 11 is stabilized, and the variation in the degree of fixing does not affect the detection sensitivity. In the clamper block 70, the side block 72 and the center block 73 are made of a metal material (conductive material), and the excitation electrodes 33, 44 formed on the back surfaces of the excitation shaft portions 15, 16 are mounted on a base. Part 12
The connection electrodes 35 and 45 extended to
An excitation electrode 34 that is conducted by wires 46 to 48;
43 and grounded.

On the other hand, the storage case 80 is provided with a stem 81 to which the clamper block 70 is fixed by an adhesive or the like, and a vibration space 8 for the excitation shaft portions 15 and 16 and the detection shaft portions 17 and 18.
The vibrator 11 is vacuum-sealed by joining a cap 82 to cover the vibrator 11 so as to secure the vibrator 3. Therefore, the vibrator 11 can be installed in a package to be vacuum-sealed as an integral structure with the clamper block 70, and the Q during vibration can be extremely increased to detect the angular velocity Ω with high sensitivity.

More specifically, the vibrator 11 is attached to the stem 81.
Excitation electrodes 32 (31, 41, 42) and detection electrodes 51
(61) and the detection electrode 53 (63) are connected by a bonding wire 87 to a lead pin 85 hermetically fixed at three of the four corners by a sealing glass 84, and the detection electrode 52 (62) is A lead pin 86 that is hermetically joined by brazing or the like is connected by a bonding wire 87. Thereafter, full-circle ring projection welding or cold pressure welding for joining the cap 82 to the peripheral edge in a state of vacuum suction is performed. By doing so, the space 83 accommodating the vibrator 11 is evacuated to produce an angular velocity sensor unit.

Therefore, when detecting and measuring the angular velocity Ω of the vehicle, the lead pin is set so that the upper direction in FIG. 7 of the central axis C of the vibrator 11 shown in FIG. When the vehicle is mounted on the vehicle with the conductors 85 and 86 electrically fixed, the yaw rotation of the vehicle works with the center axis C of the tuning fork portions 13 and 14 as the rotation axis, and the angular velocity Ω can be detected with high sensitivity.

As described above, the present embodiment has a structure in which the vibrator 11 obtained by cutting out the piezoelectric material into H-shape is held and fixed by the clamper block 70 so as to be integrated, and is vacuum-sealed in the storage case 80. The vibrator 1
1 without using an adhesive, and two sets of tuning forks 1
The unimorph type vibrator 11 including the components 3 and 14 can be manufactured at low cost, and the excitation shaft portions 15 and 16 and the detection shaft portions 17 and 18 of the tuning fork portions 13 and 14 can be vibrated with little leakage. , The angular velocity applied with high sensitivity can be detected.

[0036]

As described above, the present invention has a structure in which the center of a vibrator formed of a piezoelectric material in an H-shape is fixed to a base, thereby eliminating the need for using an adhesive. Can be integrally cut out of the piezoelectric material to form an electrode, and the two sets of tuning fork excitation and detection shafts can be fixed to a structure that vibrates with less leakage. Therefore, an inexpensive angular velocity sensor having excellent detection sensitivity can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of an embodiment of an angular velocity sensor according to the present invention, where (a) is a front view and a front side,
(B) is a side view, and (c) is a front view back surface.

FIG. 2 is a top view and a bottom view showing the polarization direction.

FIG. 3 is a connection diagram showing a use circuit thereof.

FIG. 4 is a front view showing the operation.

FIG. 5 is a side view showing the operation.

FIG. 6 is a perspective view showing the operation.

FIG. 7 is a perspective plan view illustrating the packaging.

FIG. 8 is a front perspective view illustrating the packaging.

FIG. 9 is a side perspective view illustrating the packaging.

FIG. 10 is a partially enlarged sectional view showing a main part of the packaging.

FIG. 11 is a perspective view showing the prior art.

FIG. 12 is a perspective view showing the operation.

FIG. 13 is a graph showing the characteristics.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Vibrator 12 Base part 12a Projection part 13,14 Tuning fork part 15,16 Excitation shaft part 17,18 Detection shaft part 23 Connection line 31-34,41-44 Excitation electrode 35,45 Connection electrode 36-38,46- 48 Wire 39, 49 Fixed electrode 51-56, 61-66 Detection electrode 70 Clamper block 71 Groove 72 Side block 73 Center block 75, 77 Swari 76 Low melting plating 76a Solder 80 Storage case 81 Stem 82 Cap 83 Vibration space 84 Sealing Glass 85, 86 Lead pin 87 Bonding wire 90 Power supply 95 Differential amplifier

Continuation of the front page (72) Inventor Haruhiko Sekino 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. No. 1 Matsushita Communication Industrial Co., Ltd. F-term (reference) 2F105 BB02 BB03 BB15 CC01 CD02 CD06 CD13

Claims (7)

[Claims] 1. A vibrator having two sets of tuning forks in which an excitation shaft portion and a detection shaft portion extend in the same direction by forming a piezoelectric material into an H-shape and fixing the center to a base. Coriolis force generated in a direction perpendicular to the excitation direction of the excitation shaft when an angular velocity is applied with the central axis of the tuning fork as a rotation axis in an excitation state in which the unit is excited in a direction facing the detection shaft. Is detected by piezoelectricity generated by bending of the detection shaft portion in a direction perpendicular to the excitation direction. 2. The tuning shaft according to claim 1, wherein the excitation shaft portion and the detection shaft portion of the two sets of the tuning forks are respectively arranged at diagonal positions about the center of the vibrator. Angular velocity sensor. 3. The detection shaft portion is also excited in the excitation direction by a tuning fork effect interlocked with the excitation of the excitation shaft portion, and the excitation shaft portion and the detection shaft portion open and close as two sets of the tuning forks. When the Coriolis force is detected, each of the detection shafts is in a direction opposite to the excitation direction by exciting the excitation shaft and the detection shaft so that the opening and closing directions of the excitation shaft and the detection shaft are opposite to each other. The angular velocity sensor according to claim 1, wherein the angular velocity sensor bends in a right angle direction. 4. The excitation shaft portion has two excitation electrodes arranged on the front and back surfaces thereof in parallel with the excitation direction so as to extend in an end direction from a base fixed to the base. Forming
While performing a surface perpendicular polarization process of reversing the polarization direction between the respective excitation electrodes facing each other on the front and back surfaces, the detection shaft portion is configured to extend from the base portion toward the end portion. Three detection electrodes arranged side by side with respect to the excitation direction are formed on the front and back surfaces, and the detection electrodes on both sides adjacent in the same plane so that the center detection electrode facing the front and back surfaces has zero potential. In-plane polarization treatment is performed between the two electrodes, and surface perpendicular polarization treatment for reversing the polarization direction is performed between each of the detection electrodes on both sides facing each other on the front and back surfaces, and the excitation electrode and the detection electrode are mounted on the base. The angular velocity sensor according to any one of claims 1 to 3, wherein the angular velocity sensor is extended so as to be connectable at a portion. 5. A base portion fixed to the base is formed in a stepped shape protruding outward from an extension surface of the excitation shaft portion and the detection shaft portion. A groove formed in the clamper block, the cross-section of which is formed in a V-shape or a semicircular shape, and which is fixed by abutting the corner of the stepped shape of the base portion. The angular velocity sensor according to any one of claims 1 to 4, further comprising: 6. A gap between the inner surface of the groove of the clamper block and the corner of the stepped shape of the vibrator is filled with a low-melting material previously coated on the inner surface of the groove and reflowed. The angular velocity sensor according to claim 5, wherein 7. The angular velocity sensor according to claim 1, wherein the vibrator is installed in a package to be vacuum-sealed.