JP2009264863A - Gyro sensor vibrating body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gyro sensor vibrating body having six legs radially and capable of exhibiting excellent performance, by optimizing the shape and structure of the gyro sensor vibrating body. <P>SOLUTION: The gyro sensor vibrating body has the six vibrating legs 2a-2f arranged inside one plane extending radially from one common base part 1 while forming 60 degrees among them respectively. Two legs being in a straight line out of the six legs, are made into detecting legs by providing, on the two legs, detecting electrodes for detecting deflections of the legs in a direction parallel to the one plane, and the other legs are made into driving legs by providing, on the other legs, driving electrodes for generating vibration of the legs in a direction vertical to the one plane. Moreover, rotational angular speed around a rotating shaft in a direction parallel to the detecting legs is detected by the use of the detecting legs, and the gyro sensor vibrating body is supported by the base part 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shape or structure of a gyro sensor vibrating body that applies a steady vibration to the vibrating body and detects an acting Coriolis force using a change in vibration of the vibrating body. More specifically, the present invention relates to a shape or structure of a gyro sensor vibrating body including a six-legged vibrating body having radially arranged vibrating legs.

  The vibration gyro as a sensor for detecting the rotational angular velocity is improved in accuracy gradually by the successive development of the gyro sensor vibrating body used in the gyro sensor, and the shape is already considerably reduced in size. The usage is expanding more and more. Accordingly, the gyro sensor vibrating body has been required to further improve performance, that is, to improve sensitivity, environmental stability, disturbance resistance, productivity, and the like while maintaining small size.

  Conventionally, there have been several types of gyro sensor vibrating bodies that have achieved a certain degree of success, which are basically based on a tuning fork type vibrating body and have a plurality of parallel vibrating legs. That is, they have 2 to 6 vibration legs that bend and vibrate arranged in parallel, and vibrate all or a part of them in parallel with the plane on which the legs are arranged, resulting in a Coriolis force acting in a specific axial direction. The vibration based on this is detected by any leg.

  Some sensor vibrating bodies based on the tuning fork type do not balance the moment due to the Coriolis force acting in the direction perpendicular to the tuning fork plane. There is a problem in that it is not always easy to adjust the frequency of driving vibration and the frequency of Coriolis force detection vibration because the generated ones or the shapes of vibration legs (bending, branching, etc.) are different.

  Therefore, on the other hand, a multi-leg sensor vibrating body provided with non-parallel vibrating legs has also been studied in response to the above-mentioned request. The sensor of the conventional example illustrated below is a quartz crystal (a piezoelectric crystal material having three-fold rotational symmetry, and an X axis that is an electric axis and a machine around a Z axis that is an optical axis). Using the three-fold symmetry of the crystal material such as the Y-axis that is the axis, three at a time of 120 °, each has three or six legs. These conventional examples are listed below.

A vibrator described in FIG. 5 and paragraphs 0036 to 0040 of JP 2001-82963 A (hereinafter referred to as Conventional Example 1). A vibrating body described in FIG. 19 and paragraph 0047 of Japanese Patent Application Laid-Open No. 2004-354358 (hereinafter referred to as Conventional Example 2). Utility Model Registration No. 3104824 (hereinafter referred to as Conventional Example 3).

  The vibrating body of the above conventional example 1 is an acceleration sensor or a gyro sensor having six radial legs extending in the Y-axis direction in the crystal Z plane. In the case of a gyro sensor, (1) out-of-plane vibration for every other leg. Or detect the in-plane deflection of each leg due to the Coriolis force generated in the plane by the rotation axis parallel to the plane, or (2) cause each leg to vibrate in-plane and out-of-plane the Coriolis force due to the in-plane rotation. There is a description that it is detected as vibration (paragraph 0040).

  The vibrating bodies described in Conventional Example 2 and Conventional Example 3 are sensors that detect angular acceleration in rotation, and are not directly related to the gyro sensor, but use the multi-symmetry of the constituent materials. This is just an example because there is a common point.

  Although the above-mentioned conventional example 1 (Patent Document 1) has a certain degree of description about a gyro sensor having radial legs, it is still incomplete and how to use each leg with a specific role and configuration. From the point of view, it is not enough. In addition, the tip of the vibrating leg is inward and the support part to be supported is an outer frame, and it is considered that a large area needs to be given to obtain sufficient rigidity, and there is a concern about the demand for miniaturization . Also, the optimum structure including the support structure for the vibrating body has not been clarified. Moreover, it is not described how the direction of the detection axis is specified.

  The present invention provides a gyro sensor vibrator having excellent performance while improving the vibrator having the radial six legs to provide an optimum shape and structure, thereby providing a principled simplicity and completeness. For the purpose.

The gyro sensor vibrating body of the present invention has the following features.
(1) having six vibrating legs radially arranged in one plane at an angle of 60 degrees from one common base, and one of the six legs The direction is the direction of the detection axis, and one or two legs parallel to the detection axis are provided with detection (drive) electrodes to form detection legs (drive legs), and the other legs are driven (detection). A driving leg (detection leg) is provided, and the driving leg is excited in an out-of-plane direction, and in-plane vibration generated in the detection leg is detected by a Coriolis force accompanying a rotational motion around the detection axis.

The gyro sensor vibrating body of the present invention may further include one or more of the following features.
(2) In addition to the feature of (1), two legs parallel to the detection axis are set as detection legs (drive legs), and the other four legs are set as drive legs (detection legs). The legs should excite the six legs so that adjacent legs vibrate out of plane in opposite phases.
(3) In addition to the feature of (1), two legs parallel to the detection axis are set as detection legs (drive legs), and the other four legs are set as drive legs (detection legs), and the drive All legs must be excited to have out-of-plane vibrations in phase.
(4) In addition to the feature of any one of (1) to (3) above, the distance between the tip portions of any two legs facing each other at the base of the six legs The value of the ratio of the distance between the bases of the two legs contacting the base is between 2 and 20 times.
(5) In addition to the feature of any one of (1) to (3), further, the distance between the distal ends of any two legs facing each other at the base of the six legs. The value of the ratio to the distance between the bases of the two legs contacting the base is between 4 and 10 times.
(6) In addition to the feature of any one of (1) to (5), the base has a shape having six sides or six vertices, and a root portion of each of the six legs is , Located at the side or vertex.
(7) In addition to any of the features of (1) to (6), the base is further provided with a plurality of through holes for connecting the upper surface electrode and the lower surface electrode of the vibrating leg. Being.
(8) In addition to the feature of (7), the through hole has a non-circular shape and has a radial portion between the adjacent through holes.
(9) In addition to any of the features of (1) to (8), one surface of the base portion is coupled to the support member using a surface that does not exceed the planar shape of the base portion.
(10) In addition to any one of the features of (7) to (9), one surface of the base portion is coupled to a support member at an inner portion of the plurality of through holes.
(11) In addition to any of the features of (1) to (10), the base portion is further provided with a hole for attaching a support member.
(12) In addition to any of the features of (1) to (11), the main material of the base and the six vibrating legs is a single crystal material having at least three-fold rotational symmetry, The direction of the normal line of the one plane is substantially parallel to the three-fold rotational symmetry axis of the single crystal material.
(13) In addition to the feature of (12), the main material of the base and the six vibrating legs is quartz, the direction of the normal of the one plane is close to the Z axis, and the six radial shapes are The direction of the leg of the radial leg is close to the Y axis, and the difference between the normal direction of the one plane and the Z axis direction is within 5 degrees, and the major axis direction and the Y axis direction of each of the radial legs The difference is within 5 degrees.
(14) In addition to any of the features of (1) to (11), the main material of the base and the six vibrating legs is a silicon single crystal material, and each leg is formed on the surface thereof. Having a piezoelectric film member.
(15) In addition to any of the features of (1) to (11), the main material of the base and the six vibrating legs is an isotropic material, and each leg is formed on the surface thereof. Having a piezoelectric film member formed.

The following effects are obtained by the gyro sensor vibrating body of the present invention.
(1) The operation principle is extremely straightforward, and both vibration caused by excitation and vibration caused by Coriolis force are in a dynamic balance, and high sensitivity and stable operation are easily obtained.
(2) Since the center of gravity of the entire vibrating body is on the axis of each vibration leg and can support the center of gravity or the very vicinity of the center of gravity, there is little disturbance to the vibration of the leg even when impact acceleration or the like is applied from the outside. Excellent in disturbance resistance.
(3) Since the radial legs are formed so as to match the symmetry of the material, it is easy to align the shape and dynamic characteristics of each leg.
(4) Since the radial legs are formed so as to match the symmetry of the material, the shape error can be reduced in the processing of each leg, and the productivity is high.

  The drive and detection functions are optimally allocated to the six radial legs, and the connecting function of the electrodes and the support function of the vibrating body are assigned to the central base, thereby miniaturizing the high-performance gyro sensor vibrating body with a simple structure. Realized.

  FIG. 1 is a perspective view illustrating a gyro sensor vibrating body according to the first embodiment, and FIG. 2 is a perspective view illustrating a detailed shape of the base 1. In the first embodiment, the most faithful shape is given in principle. The vibrating body has a flat plate shape and is integrally cut from a quartz Z plate (a plate perpendicular to the optical axis) by, for example, an etching method. The vibrating body is composed of a base 1 and legs that form a relatively small hexagon, and the legs have straight and rectangular cross-sections that are radially arranged at an angle of 60 ° with respect to each other. Leg 2a, 2b, 2c, 2d, 2e, 2f.

  The tip of each leg is located outside the vibrating body, and the base of each leg is located inside the vibrating body and at the six vertices of the base 1. The six vertices of the base 1 are fused with the bases of the legs 1a to 1f and are not shown in the figure. The crystal Z plate surface includes an X axis (electrical axis) that forms an angle of 120 ° with each other, and three Y axes (mechanical axes) orthogonal to each of the three X axes. The directions of the legs 1a to 1f are preferably set to face the Y-axis direction or the opposite direction. 1 and 2 show only one of the three X, Y, and Z coordinate axes. The diameter of the outer end circle connecting the tips of the legs is, for example, 6 to 12 mm, the width of each leg is 0.1 to 0.5 mm, and the thickness of the vibrating body is about 0.1 to 1 mm. Size constraints are not fundamental and there are many manufacturing reasons.

  The ratio of the diameter of the outer circle to the diameter of the regular hexagon of the base is preferably between 2 and 20 times. Because, in principle, it is desirable that the ratio of the mass of the vibrating leg to the mass of the entire sensor vibrating body is desirable, but the base is connected to the vibrating leg, the path of the lead wire from the surrounding electrode of the vibrating leg, and the lead This is because a considerable area is required because it has a space for providing an electrode pad for connecting the wire to an external circuit, a function as a base for the vibrating body or a support for the container, and the like. Further, the shape of the base portion does not need to be a circle or a regular polygon in principle. Each leg may not be exactly the same length as long as the natural frequency is correctly adjusted. Therefore, the above ratio is expressed as follows. That is, the ratio of the distance between the tip portions of any two legs facing each other at the base to the distance between the roots of the two legs contacting the base is between 2 times and 20 times. Is good. More preferably, it is between about 4 times and 10 times.

  As shown in FIG. 2, the base 1 is provided with six triangular holes 1 a to 1 f penetrating the plate material slightly inside the base of each leg (that is, near the center of the base 1). The role of this hole is through-holes in which a conductor film is formed inside the hole in order to connect the electrode films provided on the front and back of each leg and the base 1, and secondly, the rigidity distribution in the base is adjusted And to reduce the effects of vibration. In other words, the six radial portions of the wheel that are left between adjacent holes, such as “radiation (or) or spoke”, can easily transmit force between the vibrating legs outside. While mitigating the force from reaching the inner support. In order to make the second role effective, various geometrical and dimensional studies are required. For example, the shape of the hole is often an irregular shape (non-circular) such as a square shape. Further, in order to fix the vibrating body to the support member of the base or the container (not shown) on which the vibrating body is placed, it is performed by using either the front or back (or both surfaces) of the surface (Z surface) of the base 1. Good.

  For the fixing area of the support, the surface of the base 1 (one side) is used. Although it is meaningful in terms of strength to use the surface to the full shape of the base portion, it is generally preferable that the surface is small, and therefore, on one side of the portion closer to the center of the base portion 1 than the holes 1a to 1f, Adhere.

  As the support member, a crystal material or a glass material whose linear expansion coefficient is close to that of crystal is preferable when importance is attached to the characteristics of the gyro sensor, and a metal material is preferable when strength is important. In the case where the adhesive is also rigidly supported, for example, an epoxy resin or a low melting point metal (for example, solder or Au / Sn alloy) is preferably fused, and in the case of soft support, a heat-resistant and flexible material such as silicone rubber is used. . In particular, when soft support is performed, it is easy to extend the adhesion surface with the support material to the hole position or to the outside of the hole or the entire surface of the base. However, even in the case of rigid support, even if the adhesive is applied to the edge of the hole or the inside of the hole, it is expected that some vibration buffering effect remains.

  Next, the operation of the vibrating body as a gyro sensor will be described with reference to FIGS. This effect is common to other embodiments described later.

  In FIG. 3, among the six legs, legs 2a and 2d drawn with thick dotted lines in the vertical direction serve as detection legs for detecting vibration due to Coriolis force. The other legs 2b, 2c, 2e, and 2f drawn with thick solid lines play a role of driving (steady excitation). The vibration directions of the drive legs 2b, 2c, 2e, and 2f are so-called out-of-plane vibrations that are perpendicular to the vibration body plane, and the legs 2b and 2f are in phase and the legs 2c and 2f are in opposite phases. The detection legs 2a and 2d also perform out-of-plane vibration in a direction that cancels out the inertial force of the entire vibrating body by the vibration force transmitted from the base. Eventually, by exciting the drive legs, the legs 2a, 2c and 2e steadily perform out-of-plane vibration with the same phase (Vz +) and the legs 2b, 2d and 2f with the opposite phase (Vz−).

  In this state, consider a case where the vibrating body rotates around the rotation axis in the direction of the legs 2a and 2d. (The direction of the legs 2a and 2d is the direction of the detection axis of the angular velocity.) As shown in FIG. 4, due to the angular velocity ωy of this rotation, each leg has a Coriolis force Fc in the direction of the product of the vibration velocity vector and the angular velocity vector. Act. (For convenience of explanation, it is shown to act on the tip of the leg.) These Coriolis forces cause in-plane deflection in the direction shown in the figure regardless of the detection leg or the driving leg. A voltage having an amplitude proportional to the Coriolis force Fc is piezoelectrically detected by the detection electrodes provided on the detection legs 2a and 2d. The detection voltage is amplified by, for example, a well-known method, subjected to synchronous detection, and rectified to obtain an output proportional to the angular velocity.

Electrical means for performing the above drive and detection will be described with reference to FIG.
In FIG. 5, the electrode film disposed around each leg is shown in a cross-sectional view at a position extended to the outside of each leg. Electrodes 4a, 4b, 4c, and 4d arranged around the cross section of the driving legs 2b, 2c, 2e, and 2f are driving electrodes, and the terminals A are connected to the electrodes 4a and 4c of each leg. A terminal B is formed by connecting the leg electrodes 4b and 4d, and the terminals of the respective driving legs are connected in series as ABABABAB or like A + A + A + A and B + B + B + B. Are connected in parallel to each other and connected to the output of a two-terminal oscillation circuit (not shown), an electric field in the X-axis direction is generated in each drive leg in the quartz plate in the opposite direction, and each vibration leg has a bending force in the out-of-plane direction. In response, the out-of-plane vibration described with reference to FIGS. It is ideal that there is an electrode portion on the side surface of the leg shown in the figure, but it is omitted because of the difficulty in forming the divided portion on the side surface of the leg, and the electrodes are only on the upper and lower (front and back) planes of the leg. The drive electrode may be constituted by a film.

  Next, the detection operation will be described with reference to FIG. As shown in the sectional view, detection electrode films 3a, 3b, 3c, and 3d are formed around the detection legs 2a and 2d. In each leg, the electrode 3a and the electrode 3d on the opposite surface are combined to form one detection terminal C, and the electrode 3b and the electrode 3c on the opposite surface are combined to form the other detection terminal D. Terminals C and D are connected as shown in FIG. 5, and become detection output Dt via three differential amplifiers 5a. The drive and detection electrodes are the upper surface of the base 1 (the surface not used for support), the through holes, the side surfaces of the base between the bases of the legs, the lower surface of the base 1 (the side that is coupled to the support member) (Not shown), for example, two for driving and two for detection, for a total of four (two sets of two terminals) electrode pads, are combined in the upper surface of the base.

The effects of the first embodiment will be discussed below.
First, the gyro sensor vibrating body is very simple in principle, and the direction of the detection axis is also clear. The balance of inertia force of out-of-plane vibration in driving and the balance of inertia force of in-plane vibration due to Coriolis force are automatically achieved. In the case of an electrode arrangement as shown in FIG. 5 using a quartz material, the piezoelectric action is relatively weak in driving and strong in detection, but in this embodiment, four legs are assigned to drive and two legs are assigned to detection. Therefore, the balance of piezoelectric action in driving and detection is good.

  The leg extending in each direction operates as a simple straight cantilever, and it is difficult to perform undesirable bending vibrations. Quartz material has little error with respect to the three equivalent machine axis directions, has the same elastic characteristics, and is etched under the same anisotropic conditions, so it has a high shape with very little error, including the shape of the etching residue. Accuracy is obtained, and the natural frequency error before frequency adjustment is small. Also, the sensitivity to the other axes (ωx, ωz) was only about 1 ppm and 10 ppm, respectively, according to the numerical simulation results, and was sufficiently small.

  Further, the size of the base is small, and the proportion of the entire vibrating body in the mass is small. In addition, it is possible to substantially support a portion close to a point where extensions to the bases of the legs are gathered at one point. Since the support point of the vibrating body coincides with the center of gravity of the entire vibrating body, when disturbance acceleration acts on the support point, the disturbance received by the vibrating body is minimized. It is also advantageous from the viewpoint of assembling work that the support point and the external connection portion are close to each other. Further, the rigidity distribution in the base can be adjusted by the holes around the support.

  In addition, the adjustment of the so-called detuning, which gives a predetermined difference in the natural frequency between the drive vibration mode and the detection vibration mode, results in a difference between the width of each leg and the thickness of the material plate. However, a small error can be given in advance, and the final adjustment can be done with a small amount. A means for providing a difference in leg length between the detection leg and the drive leg can also be employed. The drive electrode film or the detection electrode film of each leg is limited to about 60 to 70% of the leg length from the base of the leg, and a film as a mass for adjusting the frequency is provided at the distal end portion thereof. Fine frequency adjustment of the legs can be easily performed by trimming the F tone film. In other words, the vibrating body of the present invention has both a principle advantage and a manufacturing advantage.

  FIG. 6 is a perspective view showing the vicinity of the base 1 according to the second embodiment which is characterized in that the shapes and positions of the holes 1a to 1f of the base 1 are changed from those of the first embodiment. Each hole has a sector shape in which two arcs are two opposite sides and a straight line in the same direction as the leg is the other two opposite sides. Each hole clearly divides the base 1 into a region belonging to the base of the leg and a region fixed to the support member inside each hole so that transmission of force between the vibrating legs is not hindered as much as possible, and The force from the vibrating leg is prevented from reaching the support portion as much as possible. Radial portions, such as vehicle radiation, that delimit each hole are present on the extension of each leg to the base side. Since the second embodiment is merely a change in the shape of the base 1 with respect to the first embodiment, the fundamental, operational, and manufacturing / assembly features of the first embodiment are maintained as they are.

  FIG. 7 is a perspective view showing the vicinity of the base portion 1 of the third embodiment, which is characterized in that the shapes and positions of the holes 1a to 1f of the base portion 1 are changed from those of the first embodiment, as in the second embodiment. . The shape of each hole is two arcs with two sides facing each other, and a straight line in the same direction as the legs is two other sides facing each other. Each hole clearly divides the base 1 into a region belonging to the base of the leg and a region fixed to the support member inside each hole so that transmission of force between the vibrating legs is not hindered as much as possible, and The force from the vibrating leg is prevented from reaching the support portion as much as possible. Radial portions corresponding to vehicle radii that define the boundaries of the holes are provided at angles toward the middle of the legs. The third embodiment also substantially maintains the effects of the first embodiment. Whether the shape of the base part of Example 2 or Example 3 is superior is in the stage of investigation.

  FIG. 8 is a plan view of the gyro sensor vibrating body according to the fourth embodiment. An additional mass having the same shape is integrally formed at the tip of each leg 1a to 1f of the vibrating body according to the first embodiment. Is reduced to the desired value. In addition, about the base 1, although the base shape of Example 2 is employ | adopted, it is not limited to it. In the fourth embodiment, the basic functions and effects are the same as those in the first embodiment.

Although the four embodiments of the present invention have been described above, various modifications will be described below.
(1) Drive / detection mode:
As in the first embodiment, when a driving signal is given to each adjacent leg so as to cause out-of-plane vibration in the opposite phase, the number of detection legs is not limited to two. For example, even if there is one detection leg, it is possible to detect Coriolis force with the direction of the leg as the detection axis. It is also conceivable to use three detection legs. When three adjacent legs are used as detection legs, the same property as in the first embodiment can be detected. When every other three detection legs are used as detection legs, it is considered that the direction of the detection axis is not fixed. However, the present invention can be implemented in applications where that is acceptable. In addition, there are four detection legs (the function of the legs is replaced in the first embodiment, that is, two detection legs are arranged on the left and right of the detection axis), or five (the direction of the center leg is the detection axis direction). ) Is not impossible. Note that the shape of the legs may be bent instead of straight as long as undesirable vibration modes are not induced.

  As another modification, four drive legs and two detection legs (straight line arrangement) are used as in the first embodiment, but all the drive legs are vibrated out of plane with the same phase. The detection leg causes out-of-plane vibration due to the reaction, the detection leg direction is the detection axis direction of the angular velocity, and the Coriolis force generates an in-plane vibration mode in which the two detection legs are deformed into an arcuate shape. Is detected. The effect can be expected to be almost the same as in the first embodiment. In this case, further modification is possible with two drive legs and four detection legs (the detection axis is the symmetry axis of the four detection legs).

(2) About the shape of the base of the leg and the connection of the base:
It is preferable that the width of the planar shape of the base portion gradually increases from the strength requirement of the vibrating body to avoid stress concentration such as impact force acting on the base portion of the leg. In each of Examples 1 to 4, the legs extend in a direction that bisects the angle between the apex of the regular hexagon and the adjacent side, so the above condition is satisfied to some extent. However, it is also possible to more actively attach an R to the root portion, or to make the hexagonal shape a star shape (a shape like the contour of a so-called David star) to further reduce the apex angle. If an appropriate R is provided, the root portion can be arranged on the side. Further, the root portions of adjacent legs may be connected by a large R or a polygon having a large number of sides.

(3) About the mode of support at the base:
In Example 1, one side of the base is bonded and fixed to the support member, but other support structures are also conceivable. For example, a small hole may be provided at the center of the base and a metal support member having a thin columnar portion may be inserted and bonded, which can provide a strong support structure with a small area. The small holes can be provided separately from the through holes, or one or more of the through holes can be used as supporting holes. For example, the position of one hole is shifted toward the center, or the support member is a multi-pin and is inserted into a plurality of holes and bonded. The number of through holes is not limited to six. The number of through holes may be increased or decreased as long as the connection needs are satisfied and the vibration mitigating action is not particularly hindered. Accordingly, the number of radial portions that form the vehicle radiation is not limited to six. For example, the number of holes may be 3 or 12.

  Moreover, in Example 1, the electrode pad for connection of an excitation or a detection electrode and an external circuit was provided in the surface facing the support surface of a base. In this case, external connection by wire bonding is good. However, by mounting face-down bonding of the electrode pad directly to the mating substrate, it is possible to provide a mounting structure for a vibrating body that serves as both support and connection.

(4) Material of vibrating body:
In the embodiment, a quartz crystal Z plate was used as the main material of the vibrating body, and its three-fold rotational symmetry was utilized. Therefore, other piezoelectric single crystals having the same rotational symmetry can be used as long as they can be processed. In addition, the vibrator can be processed with high shape accuracy using a silicon single crystal material known as a material that can be easily etched. Since the silicon single crystal has no piezoelectricity, a piezoelectric film, an insulating film, and a conductive film are laminated on the surface of the silicon as necessary to drive, detect, and wire. Further, an isotropic material can be used. For example, a green sheet of piezoelectric ceramic is punched into the shape of the vibrator of the present invention, and then a polarization operation is performed in a necessary direction to form an electrode film to complete the gyro sensor vibrator.

  Since the gyro sensor vibrating body of the present invention is excellent in operating characteristics and productivity, the industrial applicability is high.

3 is a perspective view illustrating a gyro sensor vibrating body according to Embodiment 1. FIG. FIG. 3 is a perspective view showing a detailed shape of a base portion of Example 1. It is the typical top view which showed the role of each leg of Example 1, and the direction and phase of a drive. It is the typical top view which showed the Coriolis force which acts on each leg of Example 1, and the bending shape resulting from it. It is a top view with a sectional view of each leg showing typically electrode arrangement and a detection circuit of a drive leg and a detection leg. It is a perspective view which shows the detailed shape of the base of Example 2. FIG. FIG. 10 is a perspective view showing a detailed shape of a base part in Example 3. 6 is a plan view showing a gyro sensor vibrating body of Example 4. FIG.

Explanation of symbols

1 Base 1a, 1b, 1c, 1d, 1e, 1f Hole 2a, 2b, 2c, 2d, 2e, 2f Leg 3a, 3b, 3c, 3d Detection electrode 4a, 4b, 4c, 4d Drive electrode 5a Differential amplifier 6a, 6b, 6c, 6d, 6e, 6f Additional mass Vz Out-of-plane vibration direction ωy Y-axis rotational angular velocity Fc Coriolis force Dt detection output terminal

Claims (15)

  It has six vibrating legs arranged radially in one plane at an angle of 60 degrees from one common base and detects the direction of one of the six legs. A detection (drive) electrode is provided on one or two legs in a direction parallel to the detection axis to form a detection leg (drive leg), and a drive (detection) electrode is provided on the other leg. A driving leg (detection leg) is provided to excite the driving leg in an out-of-plane direction, and to detect in-plane vibration generated in the detection leg by Coriolis force accompanying a rotational motion around the detection axis. Gyro sensor vibrating body.   Two legs parallel to the detection axis are set as detection legs (drive legs), the other four legs are set as drive legs (detection legs), the drive legs are the six legs, and adjacent legs are The gyro sensor vibrating body according to claim 1, wherein the vibrator is excited so as to vibrate out of plane with opposite phases.   Two legs parallel to the detection axis are set as detection legs (drive legs), and the other four legs are set as drive legs (detection legs), and all the drive legs are excited so as to generate out-of-plane vibrations in the same phase. The gyro sensor vibrating body according to claim 1, wherein:   Of the six legs, the value of the ratio of the distance between the distal ends of any two legs facing each other at the base to the distance between the roots of the two legs contacting the base is: The gyro sensor vibrating body according to any one of claims 1 to 3, wherein the vibrating body is between 2 times and 20 times.   Of the six legs, the value of the ratio of the distance between the distal ends of any two legs facing each other at the base to the distance between the roots of the two legs contacting the base is: The gyro sensor vibrating body according to any one of claims 1 to 3, wherein the vibrating body is between 4 times and 10 times.   6. The base according to claim 1, wherein the base has a shape having six sides or six vertices, and a root portion of each of the six legs is located at the side or the vertices. The gyro sensor vibrating body according to 1.   The gyro sensor vibrator according to claim 1, wherein a plurality of through holes for connecting the upper surface electrode and the lower surface electrode of the vibration leg are provided in the base portion. .   The gyro sensor vibrator according to claim 7, wherein the shape of the through hole is non-circular and has a radial portion between the adjacent through holes.   9. The gyro sensor vibrating body according to claim 1, wherein one surface of the base portion is coupled to the support member using a surface that does not exceed the planar shape of the base portion.   10. The gyro sensor vibrating body according to claim 7, wherein one surface of the base portion is coupled to a support member at an inner portion of the plurality of through holes.   The gyro sensor vibrating body according to claim 1, wherein a hole for attaching a support member is provided in the base portion.   The main material of the base and the six vibrating legs is a single crystal material having at least three-fold rotational symmetry, and the direction of the normal of the one plane is substantially the same as the three-fold rotational symmetry axis of the single crystal material. The gyro sensor vibrator according to claim 1, wherein the gyro sensor vibrator is parallel.   The main material of the base and the six vibrating legs is quartz, the direction of the normal of the one plane is close to the Z axis, the direction of the six radial legs is close to the Y axis, and the 1 The difference between the normal direction of the plane and the Z-axis direction is within 5 degrees, and the difference between the major axis direction of each of the radial legs and the Y-axis direction is within 5 degrees. The gyro sensor vibrating body according to claim 12.   The main material of the base and the six vibrating legs is a silicon single crystal material, and each leg has a piezoelectric film member formed on the surface thereof. The gyro sensor vibrating body according to 1.   12. The main material of the base and the six vibrating legs is an isotropic material, and each leg has a piezoelectric film member formed on the surface thereof. The gyro sensor vibrating body according to claim 1.

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