JP2009168788A - Gyro sensor vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gyro sensor vibrator, which uses curved secondary oscillating attitude of a rod for driving and detecting, with high accuracy, easy supporting, simple structure, and enhanced practicality. <P>SOLUTION: In the gyro sensor vibrator, a main constituent of which is a straight rod consisting practically of elastic material, the rod concerned includes a driving electrode exciting secondary flexing oscillation with both free ends piezoelectrically in a first plane containing the long axis thereof, and a detecting electrode detecting piezoelectrically oscillation caused by Coriolis force generated along a second plane perpendicular to the plane when the rod rotates around the rotating axis parallel to the long axis. In addition , the driving electrode and the detecting electrode are deployed at opposite side of the gravity center of the rod. Also, at least the gravity center of the rod is supported elastically. Moreover, a direction of piezoelectricity of the rod is shifted to 90 degree at both sides of the gravity center. Furthermore, the rod is equipped with buffers at sections near both ends. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sensor vibrating body that outputs an electrical signal proportional to a rotational angular velocity in a vibrating gyroscope.

  Vibrating gyroscopes are small, simple, and consume little power, so they are widely used as small sensors such as vehicles, robots, and cameras for motion measurement and attitude control. Various types of vibrating bodies used as angular velocity sensors have been proposed and compete for performance such as downsizing, improvement in sensitivity and accuracy, and multi-axis detection direction. A rod using the primary bending vibration was first put into practical use, but gradually a tuning fork type vibration body made of a piezoelectric material or a vibration body considered to be a deformation thereof is gradually becoming dominant. However, depending on the application, another type of sensor vibrating body having different advantages may be required.

  The following documents are exemplified for the prior art of the gyro sensor vibrating body using the bending vibration of the rod (or elongated plate) made of an elastic body.

JP 61-191916 A Japanese Utility Model Publication No.59-40813 Journal of the Acoustical Society of Japan, Vol. 56, No. 1 (2000), pp. 47-55, “Piezoelectric Gyro Sensor Using a Longitudinal First-Bending Quadratic Dual Mode Rectangular Vibrator” Yoshiro Tomikawa Takashi Goto Sumio Sugawara

  Since the above Patent Documents 1 and 2 are gyro sensor vibrating bodies using the primary bending vibration of the rod, these are collectively referred to as Conventional Example 1, and the Non-Patent Document 1 is a gyro sensor using the secondary bending vibration of the rod. Since it is a vibrating body, this will be referred to as Conventional Example 2.

  An outline of the gyro sensor vibrating body of the conventional example 1 is shown in FIG. (A) is a perspective view showing main vibration (fundamental driving fundamental vibration), (b) is detected vibration caused by Coriolis force that appears when the vibrating body rotates around a rotation axis parallel to the long axis of the rod. It is a top view which shows (amplitude is proportional to a rotation angular velocity). Reference numeral 1 denotes a rod-like vibrating body made of an elastic body (piezoelectric material) having a rectangular cross section, 2 denotes a long axis thereof, and 2a denotes a vibration state of a long axis. The vibration state is a primary bending vibration for both driving and detection, and has two nodes. Reference numeral 11 denotes four support lines fixed to the main vibration node position N on the side surface of the rod-shaped vibrating body 1. The vibration surface of the main vibration is in the vertical direction, and the vibration surface of the detected vibration is in the horizontal direction. The main vibration is excited by piezoelectric elements or electrode films (not shown) provided on the upper and lower surfaces of the rod 1, and the voltage due to the detected vibration is detected by the piezoelectric elements or electrode films (not shown) provided on the side surfaces of the rod 1. Is done.

  The main points of the gyro sensor vibrating body of Conventional Example 2 are shown in FIG. This sensor vibrating body has a longitudinal vibration of the rod-shaped vibrating body 1 as a main vibration, and the second bending of the rod due to the Coriolis force that appears by the rotational movement of the vibrating body around the rotation axis in the direction perpendicular to the long axis of the rod 1. Vibration is detected vibration. A plan view of FIG. 8A and a side view of FIG. 8B (viewed from the long axis direction of the rod-shaped vibrating body 1) represent the substantially structure. (C) is a plan view showing the vibration state (when extended) of the main vibration, (d) is a plan view showing the electrode arrangement and input / output characteristics of the main vibration, and (e) is a plan view showing the vibration state of the detected vibration. (F) is a top view which shows the electrode arrangement | positioning and the output characteristic of a detection voltage.

  In FIG. 8, 1 is a rod-shaped vibrating body, 12 is a supporting column, 13 is an adhesive, and the upper end of the supporting column 12 is placed on the lower surface of the center of the rod-shaped vibrating body 1 (made of piezoelectric ceramics or quartz and has an elongated flat plate shape). Glued. Reference numeral 14 denotes a vibration state of the main vibration (only shown when extended), and 15 denotes a vibration state of the detected vibration (only one side is shown). The resonance frequencies of both vibration modes are set so that the side ratios of the bars are appropriately selected to be in a degenerate relationship so that the detected amplitude is maximized. (D) shows the drive electrode film 8 that divides the plate surface into four. (There is a counter electrode on the back of the plate.) Due to the symmetry of the vibration mode of the main vibration, the drive voltages applied to the four drive electrodes are all the same. This is shown by blackening each electrode terminal 5. (F) shows the case where the same electrode 8 is used for detection, but the partial expansion and contraction of the plate surface is opposite on both sides of the long axis 2 as shown in FIG. Different as shown. That is, assuming that the drive voltage is V and the detection voltage appearing on one electrode due to bending vibration is ΔV, a voltage V + ΔV is generated in the black electrode terminal 5, and V−ΔV is generated in the white electrode terminal 5. appear. Therefore, the necessary detection voltage 2ΔV can be detected by differentially connecting these electrodes.

  In both of the conventional examples 1 and 2, the sensor vibrating body may have a simple shape (a rectangular parallelepiped), so that high-precision machining can be performed, which has an advantage that leads to high-precision detection operation. However, there are the following problems. In Conventional Example 1, the distortion of the rod surface due to the detected vibration at the fixed point N of the support line 11 is not zero. Moreover, since the bar's center of gravity is an antinode, it cannot be used as a support. In the conventional example 2, the center of gravity position G of the rod can be supported and the mechanical stability is good. However, the surface distortion does not become zero due to expansion and contraction due to the main vibration, and the center of gravity rotates due to the detection vibration. When supported using an adhesive, the Q value of the vibrating body cannot be sufficiently increased.

  The object of the present invention is to make use of the advantages of a rod-shaped vibrating body that is simple in shape and easy to obtain machining accuracy, and is applied to a simple support structure that is not easily affected by vibration distortion and has high rotation detection accuracy and is practical. A gyro sensor vibrator is provided.

In order to achieve the above object, the gyro sensor vibrating body of the present invention includes any of the following features (1) to (15).
(1) A substantially straight rod made of an elastic material as a main body, and the rod is a drive electrode that piezoelectrically excites secondary bending vibrations at both ends in a first plane including the major axis thereof; A detection electrode for piezoelectrically detecting vibration caused by a Coriolis force generated along a second plane which is a plane orthogonal to the plane when the rod rotates around a rotation axis parallel to the major axis; That.
(2) In addition to the above (1), the elastic material is a material having piezoelectricity, and the drive electrode and the detection electrode are a drive electrode film and a detection electrode film formed on the surface of the rod. .
(3) In addition to (1) or (2) above, the drive electrode and the detection electrode are respectively disposed on the opposite sides of the center of gravity.
(4) In addition to any of the above (1) to (3), the rod is supported on the base by an elastic support member so that the cross section at the center of gravity can be inclined slightly in any direction. is being done.
(5) In addition to (4) above, the rod is also supported by another elastic support member in the vicinity of the node position excluding the center of gravity.
(6) In addition to any of the above (1) to (5), the support member that supports the center of gravity and the other two support members that respectively support the other two node positions excluding the center of gravity are all provided. It is formed of a conductor and serves as a three-terminal lead line necessary for the drive electrode and the detection electrode.
(7) In addition to any of the above (1) to (6), in order to limit the movement of the rod at least around the long axis, a shock absorber at a position closer to the end than the center of gravity Was established.
(8) In addition to the above (7), the contact portion of the shock absorber with the rod is made of a rubber material.
(9) In addition to any of the above (2) to (8), the rod made of a piezoelectric material has a piezoelectric direction that is substantially 90 ° different on both sides of the center of gravity. It consists of two parts.
(10) In addition to (9) above, the support member is attached to a coupling member that couples the two portions.
(11) In addition to (9) or (10) above, each of the two parts is made of a bar having a substantially square cross-sectional shape.
(12) In addition to either (9) or (10) above, each of the two parts is made of a bar having a rectangular cross-sectional shape.
(13) In addition to any of the above (1) to (12), the support member or the other support member may be elastic by a leaf spring.
(14) In addition to any of the above (1) to (12), the support member or the other support member may be elastic by a wire.
(15) In addition to any of the above (1) to (12), the support member or the other support member may be elastic by a rubber material.

  According to the present invention, there is an effect that a gyro sensor vibrating body having one or more of the following effects can be provided. That is, by using the secondary bending vibration of the rod for both driving and detection, the advantages of the rod-shaped vibrating body that is simple in shape and easy to obtain machining accuracy can be utilized, and the performance can be highly stabilized. In addition, the drive electrode and the detection electrode are arranged on the opposite sides of the bar center of gravity, so that the drive voltage mixed as noise in the detection voltage can be reduced. In addition, by supporting the bar center of gravity, a support structure with good balance and very little influence of strain could be realized. Moreover, the strength of the vibrating body could be practically increased by providing the movement limiting member. In addition, by combining vibrating pieces with different piezoelectric directions across the center of gravity, an electrode arrangement with improved efficiency in both driving and detection could be achieved. Moreover, the support structure which has high strength and hardly disturbs the detection vibration can be obtained by devising the support member.

  First, Example 1 will be described as the best mode, and various examples and modifications that are judged to be extremely good from several viewpoints will be described with reference to the drawings.

FIG. 1 shows the structure and operation of the first embodiment of the present invention. (A) is a plan view, (b) is a front view, (c) is a left side view showing the shape of the support member, (d) is a vibration state of basic vibration, (e) is a vibration state by Coriolis force, (f ) Is a sectional arrangement view of the drive electrode film, and (g) is a sectional arrangement view of the detection electrode.
The rod-shaped vibrating body 1 is horizontally supported on the base 3 by a leaf spring-like support member 4 at the position of the center of gravity G at the center of the rod. Although the base 3 is not illustrated, it is more preferable as a high-accuracy gyro sensor that it is a part of an airtight (vacuum) container that houses the vibrating body. The rod-shaped vibrating body 1 is made of a quartz material that is a piezoelectric elastic material, and the X, Y, and Z axes that are crystal axes are substantially oriented in the directions shown in FIGS. May vary slightly due to adjustment of characteristics.

  The drive (excitation) electrode and the detection electrode are essential, but their planar shapes are not shown. The operation requires three terminals: a drive terminal, a detection terminal, and a common terminal (ground terminal). In this embodiment, a metal bonded to a metal film (not shown) provided on the surface of the center of gravity of the rod-like vibrator 1. The leaf spring-like support member 4 is used as a common terminal, and the drive terminal and the detection terminal are each connected to the terminal column 6 via a lead wire 7 which is thinner and more flexible than the electrode terminal (pad) 5 provided on the surface of the two vibration nodes. Are connected to an external circuit (not shown).

  The rod-shaped vibrating body 1 is excited by the excitation electrode in a secondary bending vibration mode in the horizontal plane (in the XY plane) as shown in FIG. In the bent secondary mode, the center of gravity G does not move. If there are two other nodes (nodes) and the rod-shaped vibrating body is sufficiently thin and has a uniform cross section, the position is approximately 13.2% of the total length of the rod from both end faces. (In the bending primary mode of the rod, the two nodes are located at about 22.4% from both end faces, so in the secondary mode, it is closer to the end face.) As shown in FIG. When rotational motion is performed at an angular velocity Ω around the rotational axis parallel to the major axis 2, the Coriolis force causes secondary bending vibration in the vertical plane (in the YZ plane) as shown in FIG. The amplitude is proportional to Ω. By detecting the deformation due to this vibration in a piezoelectric manner like other gyro sensors, it is possible to know the component in the major axis direction of the rotational angular velocity.

  A leaf spring-like support member 4 made of a metal material provided at the center of gravity G shown in FIG. 1C keeps the surface of the magnetic head parallel to the surface of the magnetic disk in an HDD device or the like and is adapted to it. This is an application of a spring member, sometimes called a gimbal spring, that is used for holding. The support member 4 is formed by punching or etching a thin metal plate having a spring property. The inner frame 4a, the middle frame 4b, and the outer frame 4c are each provided with two vertical shafts 4d and a horizontal shaft 4e which are constricted portions. And is fixed to the base 3 with a spring surface upright. 4f is a mounting hole used if necessary. The rod-shaped vibrating body 1 (represented by a cross section) is inserted into the hole of the inner frame 4a up to the position of the center of gravity, and is fixed to the metal film on the surface with an appropriate amount of solder or (conductive) adhesive. A narrow frame-shaped hatched portion shown as the fixing portion 4g represents a portion where the solder or the like gets wet from the metal film on the surface of the vibrating body.

  The center of gravity G of the rod-shaped vibrating body 1 does not move in the secondary bending vibration mode, but the cross section including the center of gravity G should be able to be slightly inclined in both the horizontal and vertical directions in the drive and detection operations. I must. The support member 4 of the present embodiment makes it possible to incline the inner frame 4a without causing friction loss by elastic deformation obtained by adding a slight bend of the middle frame 4b to the twist of the vertical shaft 4d and the horizontal shaft 4e. . Another important point is that, in the free vibration of the above mode, theoretically, no bending moment is generated in the cross section including the center of gravity (only the shearing force acts). Therefore, the expansion / contraction strain of the material is close to zero on the surface of the rod near the center of gravity, and even if solder or adhesive is attached to this portion, the Q value of the rod-shaped vibrating body 1 is less likely to be reduced if the range is narrow. Therefore, the center of gravity G of the rod-shaped vibrating body 1 and the support member 4 can be firmly fixed without impairing the function as a sensor, and a sensor vibrating body that is strong against external force can be configured. (In the primary bending vibration mode used in Conventional Example 1, the bending distortion and displacement at the center of gravity are maximum, and in Conventional Example 2, the maximum value of surface distortion due to excitation stretching vibration occurs on the surface of the center of gravity. And there is no convenient point on the bar, such as the center of gravity of this embodiment.)

  Next, the arrangement of drive (excitation) electrodes and detection electrodes will be described. As shown in the cross-sectional view of FIG. 1 (f), the driving electrode films 5a and 5b are arranged on the four side surfaces around the rod-shaped vibrating body 1 (for ease of illustration, the electrode films are drawn away from the surface of the rod). ) The electrode film 5a drawn in white is a common electrode, and the painted drive electrode film 5b is supplied with a drive voltage from an output terminal of an external oscillation circuit (not shown). An electric field E is generated in the cross section of the rod-shaped vibrator 1, and the rod-shaped vibrator 1 is bent in a horizontal plane. Sectional drawing (g) shows electrode films 5a and 5b for detection. If a voltage is applied between them, a horizontal electric field E is generated and the rod-shaped vibrating body 1 is bent in the vertical plane. Conversely, when the rod is bent in the vertical plane, the detection voltage is detected between the two electrodes due to the piezoelectric inverse effect. Therefore, the detection electrode film 5c is connected to the detection terminal. The detection terminal is connected to an external detection circuit (not shown) and an input terminal of the oscillation circuit. The common electrode film 5a is connected to the support member 4 and grounded. Note that FIG. (G) may be used as the drive electrode, and FIG. (F) may be used as the detection electrode, or the rod-like vibrator 1 may be rotated 90 ° around the long axis 2 to drive the drive in a vertical plane. The detection may be a bend in a horizontal plane.

  The drive electrode and the detection electrode are preferably arranged at different positions on the surface of the rod-shaped vibrating body 1. However, in the present invention using the secondary bending vibration mode for both driving and detection, each electrode is connected to the center of gravity G. It is good to arrange | position separately on the side surface of the rod located in the mutually opposite side on both sides. That is, the electrode arrangement is as shown in (f) in the majority of one side of the center of gravity G, and the electrode arrangement is as shown in (g) in the majority of the other side of the center of gravity G (up to almost half length possible). This is because the distribution of the bending moment on the long axis is point-symmetric with respect to the center of gravity, and on each side of the center of gravity, the bending moment has the same sign, and the maximum curvature part with high drive / detection efficiency is separated on both sides of the center of gravity. This is due to what is happening. It is preferable that the drive electrode film 5b and the detection electrode film 5c are provided on the opposite sides of the center of gravity G and separated from each other to some extent because the possibility that the drive signal is picked up by the detection electrode and becomes noise is reduced. In addition, the drive terminal and the detection terminal can be easily provided on the opposite side with the center of gravity G interposed therebetween, and the arrangement configuration is rational. (In the conventional example 1, it is not impossible to dispose the drive electrode and the detection electrode so as to sandwich the center of gravity of the rod. However, since the maximum distortion with the largest driving or detection effect occurs including the position of the center of gravity, the portion is driven.・ There is a disadvantage that it does not belong to one or both of the detection electrodes and cannot be used effectively.)

  In Example 1, the rod-shaped vibrating body 1 was a rod having a square cross section. This is because the natural frequency of the bending vibration in the horizontal direction is set equal to the natural frequency of the bending vibration in the vertical direction, and the detection voltage is maximized by resonance. Such setting of dimensional conditions can be achieved with a high yield by high-precision machining such as lapping because the rod may have a simple rectangular parallelepiped shape as compared with a tuning fork or the like. In order to determine the directionality when the cross section is close to a square, for example, an appropriate chamfering process may be performed on the edge on the + X side of the end face of the bar. It can be corrected by slightly increasing the length). In addition, in order to stabilize the detection operation, the natural frequency of the detection mode is intentionally deviated from the drive frequency by a predetermined amount. It can be set accurately and the characteristics can be stabilized.

  Next, modifications of several types of support structures, which can be applied to the first embodiment and other embodiments described later, instead of the gimbal spring structure shown in FIG. 1 (c) will be described. FIGS. 2A to 2E are views showing examples of various leaf spring-like support members 4 and support structures used in the gyro sensor vibrating body of the present invention.

FIGS. 2A and 2B show substantially the same effect as the gimbal spring, but the projecting dimension amount around the rod-shaped vibrating body 1 is slightly reduced at least in a certain direction. (C) is a three-sided view of a support structure in which the support member 4 is separated into left and right support springs to reduce the size. The end portion 4g of the support member on one side is bonded (conductively) to the side surface of the rod-shaped vibrating body 1. The inverted U-shaped spring part is separated from the surface of the bar. (C) shows a spring part having a spiral shape and a spring surface that is parallel to the rod-like vibrator 1 (slightly separated from the surface of the vibrator) to reduce the lateral width of the sensor vibrator. (D) is the same as the previous example except that the spring portion has a bellows-shaped bent shape.
The various springs shown in FIG. 2 including the gimbal spring shown in FIG. 1C can be used not only to support the center of gravity G of the rod-shaped vibrating body 1 but also to support nodes (node points). Further, for example, in the case of a support member in which the bonding portion 4g is out of the surface of the spring portion or the center of the spring shape as shown in (c), the bonding portion 4g is slightly from the center of gravity G or the node point N position. Come off. These support members 4 can also be used as lead wires for drive and detection electrodes.

  FIG. 3 illustrates several other types of support structures that do not use a leaf spring. (A), (b), and (c) are cross-sectional views of the support store part, and (d) is the end face of the rod-shaped vibrator 1. It is the side view seen from the side. (A) is a support structure using the support wire 11. The support structure often used in the conventional bar-shaped quartz crystal was a soldered nail head wire with a head shaped like a nail head on the surface of the node position of the vibrator. It was a fragile structure. In the present invention, the strength is dramatically increased by using a support wire penetrating the vibrating body. Reference numeral 1c denotes, for example, a conical concave portion provided from both sides at the center of gravity or node point position of the rod-shaped vibrating body, and 1d denotes a through hole connecting them. A metal film connected to the electrode film is formed on the inner surface of the recess and the hole. The support wire 11 is provided with a flange 1a serving as a stopper at the intermediate portion, and the support wire 11 is fixed by solder or conductive adhesive 11b in the vicinity of the through hole 1d. Since it vibrates in an orthogonal plane, the truly stationary center of gravity or node point is not on the surface of the rod-shaped vibrating body 1 but only at the center. This configuration is intended to support the point exactly, and supports the cross section including the center of gravity or the contact point so as to be tiltable in any direction.

  (B) illustrates a structure in which the rubber material 4h is filled in the conical holes 1c provided on both side surfaces of the rod-shaped vibrating body 1 and the headed support wire 11 is embedded therein as in the previous example. The elastic deformation of the rubber material 4h facilitated the inclination of the bar cross section in any direction. In (c), instead of providing a conical hole, a rubber material 4h is raised in a dome shape on the side surface, and the nail head wire 11 is embedded therein. In the embodiment of the support structure using these support lines, the length of the support line may be selected so as to resonate with the vibration frequency of the vibrating body 1, thereby reducing the vibration resistance. In (d), a support line is not used, but a rubber O-ring having a circular cross section, for example, is fitted around the center of gravity or node point of the rod-shaped vibrator 1, and a part of the periphery of the rubber ring 4i is a substrate (not shown). This structure is supported by the upper holding member 4j. In these embodiments, when no conductive filler is mixed in the rubber material 4h or the rubber ring 4i, a flexible lead wire connected to the electrode terminal is provided at another position.

  FIG. 4 is a partial perspective view showing Embodiment 2 of the present invention. In the second embodiment, the rod-shaped vibrating body 1 made of a quartz material is divided into two at the center of gravity, one end is rotated by 90 ° around the major axis, and the end faces are butted and rejoined. As can be seen from the directions of the crystal axes shown in the vicinity of the vibrating piece a and the vibrating piece b shown by the two-dot chain line in FIG. The coupling member 10 is made of a thin metal plate, has a bowl shape, and the inner surface thereof is a metal film for bonding (not shown or may be connected to a common electrode film) provided on the vibrating piece a and the vibrating piece b. Bonded with a thin layer of solder or adhesive. As described in the paragraph 0018 of the first embodiment, the vicinity of the center of gravity does not move, and only a slight rotation occurs and distortion is small. On the other hand, it is possible to adopt the cross-sectional arrangement shown in FIG. 1 (f), which is considered to have good electro-mechanical conversion efficiency for both the drive electrode and the detection electrode, and the merit of improving detection sensitivity and noise resistance. There is. It should be noted that if the vibrating piece a and the vibrating piece b are both square and the same cross section, joining is easy and accurate, but a slight difference may be provided. Moreover, you may use materials other than a metal for a joining member.

FIG. 5 shows a third embodiment of the present invention, in which (a) is a perspective view of a coupling member, (b) and (c) are perspective views showing electrode arrangement on one side of a sensor vibrating piece, and (d) and (e), respectively. ) Is a diagram illustrating a vibration state of a basic vibration or a detection vibration of the sensor vibrating body.
In the third embodiment, the resonator element a and the resonator element b are plate members having a rectangular cross section and a considerably large side ratio. The connecting member 10 shown in the perspective view (a) is made of synthetic resin, ceramics or metal material, and has orthogonal slits. Each resonator element is a plate-like piezoelectric body as shown in a perspective view (b) or (c). For example, an X-axis 128 ° rotation Y plate of lithium niobate is used. (B) and (c) show two types of connection of drive or detection electrodes. Such a plate material is inserted and fixed into the slit of the coupling member 10 from both sides to be integrated. FIG. 5E shows the vibration state of the drive, and FIG. 5F shows the vibration state at the time of detection in which the vibration surface is orthogonal.

  As described above, since the bar-shaped vibrating body 1 is elastically supported at its center of gravity, for example, it can be said that the rod-shaped vibrating body 1 is more favorably supported than a cantilevered supporting structure used for a tuning fork type vibrating body. However, there is a risk of damage if excessive impact acceleration or rotational impact is applied. Example 4 illustrates a structure that provides safety to prevent such an accident. 6A and 6B show a shock absorber structure according to the fourth embodiment. FIG. 6A is a partial cross-sectional view including a sensor vibrating body. FIGS. 6B and 6C are perspective views of a shock absorber according to another embodiment. .

  In FIG. 6 (a), reference numeral 9 denotes a shock absorber, which limits the movement of the rod-shaped vibrating body 1 in the axial direction or the rotational movement around the center of gravity within a predetermined range, It is provided to prevent damage to the support system and connection system. Reference numerals 9a and 9b denote buffer member holders which are fixed on the substrate 3. 9c is a buffer member, which is made of a flexible rubber material, and in soft contact with the rod-shaped vibrating body at the time of excessive impact. The buffer member holding body 9a is installed close to the end face of the rod for limiting the translational movement in the axial direction, and the buffer member holding body 9b is for limiting the rotational movement so as not to disturb the vibration as much as possible even if it contacts the vibrating body 1. Is provided so as to surround the position of the node point (node). The connection terminal (position where the lead wire was attached) moved closer to the center of gravity than in FIG. The perspective views (b) and (c) further simplify the structure, and a shock absorber having a rubber material 9c with a recess therein in which the end of the rod-like vibrating body 1 is inserted with a predetermined gap around it. 9 is shown. The holding body is not shown. In the shock absorber 9 of (b), the side surface of the rod-shaped vibrating body 1 is in contact with the buffer member 9c, and in (c), the edge of the rod-shaped vibrating body is in contact with the buffer member holding body 9.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments. For example, the features of the respective embodiments may be arbitrarily combined, or other elements including conventional techniques may be introduced. Further, as a material constituting the rod-shaped vibrating body, materials other than those exemplified, for example, a constant elastic metal material, ceramics, or other piezoelectric materials (such as langasite and lithium tantalate) may be used.

  Since the present invention provides a gyro sensor vibrating body having high shape accuracy and a practical support structure, the industrial applicability is great.

  Fig. 1 shows a first embodiment of the present invention, (a) is a plan view, (b) is a front view, (c) is a left side view, (d) is a vibration state of basic vibration, and (e) is a vibration state by Coriolis force. , (F) is a cross-sectional arrangement view of the drive electrode film, and (g) is a cross-sectional arrangement view of the detection electrode.   (A)-(e) is a figure which shows the Example of the various support springs and support structure which are used for the gyro sensor vibrating body of this invention.   (A)-(d) is sectional drawing which shows the Example of the other various support structure used for the gyro sensor vibrating body of this invention.   It is a fragmentary perspective view which shows Example 2 of this invention.   Fig. 4 shows a third embodiment of the present invention, in which (a) is a perspective view of a coupling member, (b) and (c) are perspective views showing electrode arrangement on one side of the sensor vibrating piece, and (d) and (e) are sensors. It is a figure which shows the vibration mode of the fundamental vibration or detection vibration of a vibrating body.   The buffer structure in Example 4 of this invention is shown, (a) is a fragmentary sectional view containing a sensor vibrating body, (b), (c) is a perspective view of the buffer body which is another Example, respectively.   The gyro sensor vibrating body of the prior art example 1 is shown, (a) is a perspective view and a vibration state of main vibration, and (b) is a plan view and a vibration state of detection vibration.   Conventional Example 2 shows a gyro sensor vibrating body, wherein (a) is a schematic plan view, (b) is a side view, (c) is a plan view showing the vibration state of the main vibration, and (d) is its electrode arrangement and output characteristics. (E) is a plan view showing the vibration state of the detected vibration, and (f) is a plan view showing the electrode arrangement and output characteristics.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bar-shaped vibrating body 1a Vibrating piece a, 1b Vibrating piece b, 1c recessed part, 1d through-hole 2 Vibrating body long axis 2a Long-axis vibration mode 3 Base 4 Support member 4a inner frame, 4b middle frame, 4c outer frame, 4d vertical axis, 4e horizontal axis, 4f mounting hole, 4g fixing part 4h rubber material, 4i rubber ring, 4j holding member 5 electrode terminal 5a common electrode film, 5b drive electrode film, 5c detection electrode film 6 terminal column 7 lead wire 8 8a, 8b Electrode film 9 Shock absorber 9a, 9b Buffer material holder, 9c Buffer member 10 Coupling member 11 Support line 11a flange part, 11b Solder 12 Support column 13 Adhesive 14 Drive vibration state 15 Detected vibration state G Vibration body Center of gravity N Vibration node (node point)
E Electric field Ω Angular velocity

Claims (15)

  A substantially straight rod made of an elastic material is used as a main body, the rod is a drive electrode that piezoelectrically excites secondary bending vibrations at both ends in a first plane including the major axis, and the rod is A detection electrode that piezoelectrically detects vibration caused by a Coriolis force generated along a second plane that is a plane orthogonal to the plane when rotating around a rotation axis parallel to the long axis; A gyro sensor vibrating body.   2. The gyro sensor according to claim 1, wherein the elastic material is a piezoelectric material, and the drive electrode and the detection electrode are a drive electrode film and a detection electrode film formed on a surface of the rod. Vibrating body.   The gyro sensor vibrating body according to claim 1, wherein the drive electrode and the detection electrode are respectively disposed on opposite sides of the center of gravity.   The said bar | burr is supported by the base by the elastic support member so that the cross section in the gravity center position can make a minute inclination in arbitrary directions, The base in any one of Claim 1 thru | or 3 characterized by the above-mentioned. Gyro sensor vibrating body.   The gyro sensor vibrating body according to claim 4, wherein the bar is supported by another elastic support member even in the vicinity of a node position excluding the center of gravity.   The supporting member that supports the center of gravity and the other two supporting members that respectively support the other two node positions excluding the center of gravity are all formed of a conductor, and the three terminals necessary for the drive electrode and the detection electrode are drawn out. 6. The gyro sensor vibrating body according to claim 1, wherein the gyro sensor vibrating body is a line.   7. The shock absorber according to claim 1, wherein a shock absorber is provided at a position closer to the end than the center of gravity in order to limit movement of the rod at least around the long axis. Gyro sensor vibrating body.   The gyro sensor vibrating body according to claim 7, wherein a contact portion of the shock absorber with the rod is formed of a rubber material.   9. The bar according to claim 2, wherein the bar made of a piezoelectric material is composed of two portions whose directions of piezoelectricity are substantially different by 90 degrees on both sides of the center of gravity. Gyro sensor vibrating body.   The gyro sensor vibrating body according to claim 9, wherein the support member is attached to a coupling member that couples the two portions.   11. The gyro sensor vibrating body according to claim 9, wherein each of the two parts is made of a bar material having a substantially square cross-sectional shape.   11. The gyro sensor vibrating body according to claim 9, wherein each of the two portions is made of a bar member having a rectangular cross-sectional shape.   The gyro sensor vibrating body according to any one of claims 1 to 12, wherein the supporting member or the other supporting member is elastic by a leaf spring.   The gyro sensor vibrating body according to claim 1, wherein the support member or the other support member is elastic by a wire.   The gyro sensor vibrating body according to claim 1, wherein the support member or the other support member is elastic by a rubber material.

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