JP2006258505A - Tuning fork vibrator for vibrating gyroscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce drive vibrations leaking to detection legs 12 by suppressing the vertical asymmetricity of distortions in a body part caused by the constraint of a supporting member due to its fixation. <P>SOLUTION: Vertical asymmetricity in drive vibrations (distortions) in the body part 10 is caused by changes in a stress distribution caused by the junction of a tuning-fork vibrator 1 to a package by the supporting member. Grooves 10j and 10k in the longitudinal direction of drive legs 11 are provided for both side regions of a supporting member fixation region 1a in the bottom surface of the body part 10 to be joined to the supporting member. A constraint region by the supporting member is restricted in the region between the grooves 10j and 10k by this structure, and the body part 10 in a region outside the grooves 10j and 10k freely expands and contracts without being affected by the supporting member 2. Since most parts of the body part 10 are therefore not affected by the constraint action of the supporting member 2, the vertical asymmetricity in distortions in the body part 10 is suppressed to reduce drive vibrations leaking to the detection legs 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tuning fork type vibratory gyroscope in which a tuning fork type vibrator formed by coupling a driving leg and a detection leg at a body part is accommodated in a package, and more particularly to a tuning fork type vibrator that supports the body part using a package as a fulcrum. .

  This type of tuning fork type vibration gyro is described in Patent Document 1 or Patent Document 2. FIG. 7 is a view showing a tuning fork type vibration gyro described in Patent Document 1. In FIG. FIG. 8 is a view showing a tuning fork type vibration gyro described in Patent Document 2. In FIG. The basic structure and operation of the tuning fork type vibration gyro described in Patent Document 1 or Patent Document 2 will be described with reference to FIG. FIG. 9 is a diagram showing a tuning fork type vibrator for a vibration gyro. FIG. 9 (A) shows a state when there is no rotation input to the tuning fork type vibration gyro, and FIG. 9 (B) shows a tuning fork type vibration gyro. Represents the state when there is a rotation input. In the figure, 111a and 111b are excitation drive legs (excitation drive side arms in Patent Document 1), and 112a and 112b are vibration detection legs (vibration detection side arms in Patent Document 1). The excitation drive legs 111a and 111b are paired with each other and vibrate in opposite phases. The drive legs 111a and 111b for excitation are referred to as drive legs 111 (drive side arms in Patent Document 1). The vibration detection legs 112a and 112b are paired with each other and vibrate in opposite phases. The vibration detection legs 112a and 112b are referred to as detection legs 112 (detection side arms in Patent Document 1). The trunk | drum 10 is a rectangular parallelepiped, The planar shape (shape of the upper surface 10a) is a square (it does not necessarily need to be a square). Each surface of the body 10 has a top surface represented by reference numeral 10a, a bottom surface (not shown in the figure) represented by reference numeral 10b, an end surface on the drive leg 111 side represented by reference numeral 10c, and an end surface on the detection leg 112 side (in the figure). (Not shown) is represented by reference numeral 10d, one side surface is represented by reference numeral 10e, and the other end face (not shown) is represented by reference numeral 10f. The upper surface 10a and the bottom surface 10b are called main surfaces. In the tuning fork type vibration gyro of Patent Document 1 or Patent Document 2, one non-excitation drive leg (non-excitation drive side arm in Patent Document 1) is provided between the excitation drive legs 111a and 111b. Further, one non-vibration detection leg (non-vibration detection side arm in Patent Document 1) is provided between the vibration detection legs 112a and 112b, but the non-excitation drive leg and the non-vibration detection leg are Since it is provided for stabilizing the vibration and is not necessary in the explanation of the principle, it is omitted in the tuning fork type vibration gyro of FIG.

  The body 10, the excitation drive legs 111 a and 111 b, and the vibration detection legs 112 a and 112 b are made of one piezoelectric single crystal, and are cut out from a single plate-like piezoelectric single crystal. Examples of the piezoelectric single crystal include quartz crystal, lithium niobate, and langasite. The body 10, the excitation drive legs 111 a and 111 b and the vibration detection legs 112 a and 112 b have the same thickness. In a state where the excitation drive legs 111a and 111b are not excited, that is, in a stationary state, the axes of the excitation drive legs 111a and 111b and the axes of the vibration detection legs 112a and 112b are respectively on the end surfaces 10c and 10d of the body part 10. It is vertical. The axes of the excitation drive leg 111a and the vibration detection leg 112a are on the same axis. Similarly, the axes of the excitation drive leg 111b and the vibration detection leg 112b are on the same axis. The excitation driving legs 111a and 111b are symmetrical and the vibration detecting legs 112a and 112b are also symmetrical with respect to a plane that passes through the center of gravity of the body portion 10 and is parallel to the end face 10e. Excitation drive legs 111a and 111b and vibration detection legs 112a and 112b are provided with drive electrodes and detection electrodes, respectively (the illustration of these electrodes is omitted).

  When an AC voltage for excitation is applied to the drive electrode in the tuning fork type vibration gyro having the structure shown in FIG. 9, the excitation drive legs 111a and 111b are opposite to each other in the plane parallel to the upper surface 10a, that is, reversed. Vibrates in phase. This vibration is drive vibration in the tuning fork type vibration gyro. The drive vibration is vibration in a plane parallel to the main surface (the upper surface 10a and the bottom surface 10b) of the trunk portion 10, and such vibration in a plane parallel to the main surface is referred to as in-plane vibration. In-plane vibration is indicated by arrows Ha and Hb in FIG. In this state, when the rotation of the angular velocity ω is input around the input shaft in FIG. 9B, a Coriolis force is generated in proportion to the leg end velocity due to the leg vibration. It becomes the vibration of the same frequency. This vibration is referred to as Coriolis vibration in the sense of vibration based on Coriolis force. When the leg vibrates so that the displacement of the leg end is in the range of ± a, the absolute value of the leg end velocity is zero when the displacement of the leg end is ± a, and the displacement of the leg end is zero. It becomes the maximum at the time of. In the tuning fork type vibration gyro having the structure shown in FIG. 9, when the rotation of the angular velocity ω is inputted around the input shaft shown in FIG. Each occurs. The Coriolis vibrations Ca and Cb are vibrations in a direction perpendicular to the main surface of the body portion 10, and their phases are opposite to each other. The vibration in the direction perpendicular to the main surface of the body portion 10 is referred to as surface vertical vibration.

  Since the body portion 10 is plate-shaped, it has extremely high rigidity against vibration in a direction parallel to the main surface, that is, in-plane vibration, and vibration in a direction perpendicular to the other main surface, that is, surface vertical vibration. Shows relatively low rigidity. Therefore, among the vibrations generated in the excitation drive legs 111a and 111b, the drive vibrations Ha and Hb that are in-plane vibrations hardly propagate to the vibration detection legs 112a and 112b, and the other surface vertical vibrations are Coriolis vibrations. Ca and Cb propagate to the vibration detection legs 112a and 112b with high efficiency. The Coriolis vibrations propagated to the vibration detection legs 112a and 112b are detected vibrations Da and Db in the tuning fork type vibration gyro. The tuning fork type vibration gyro detects the angular velocity ω by taking out the voltage appearing on the vibration detection legs 112a and 112b as an electric signal with the detection electrodes by the detection vibrations Da and Db.

  In the tuning fork type vibration gyro, the drive vibration component appearing on the vibration detection legs 112a and 112b is noise, and the detected vibration component (Da, Db) is a signal. Therefore, since the ratio of the drive vibration component to the detected vibration component (Da, Db) in the vibration detection legs 112a, 112b becomes a signal-to-noise ratio (S / N ratio), in order to detect the angular velocity ω with high accuracy, It is necessary to reduce the drive vibration component that leaks and appears in the vibration detection legs 112a and 112b. The drive vibration component leaking to the vibration detection legs 112a and 112b becomes a bias for the signal component [detected vibration component (Da, Db)]. If this bias is unstable, the detection accuracy of the angular velocity ω is lowered.

In the tuning fork type vibration gyro of Patent Document 1 and Patent Document 2, the tuning fork vibrator is supported at the center of gravity by a support member made of quartz glass (the holding body in Patent Document 1). Its center of gravity is in the middle of the torso.
JP 2001-255152 A JP 2001-208545 A Japanese Patent No. 2518600 JP 2000-337880 A JP2002-243451

  FIG. 3 is a schematic diagram showing fluctuations in distortion appearing in the vibrator when the body of the tuning fork vibrator is supported by a support member. FIGS. 3A and 3B show distortions appearing on the body 10 when drive vibration is applied to the body in a state where the body is not supported by the support member. 3C and 3D show the case where the center of gravity of the body portion 10 is supported by the support member 2 and when the body portion 10 is mounted on the package substrate 30 and driving vibration is applied to the body portion 10. The distortion that appears in the part appears. 3C and 3D, the support member 2 is fixed to the center of gravity of the body portion 10 and the package substrate 30.

  FIG. 3A shows the case where stresses due to the vibration displacements α1 and β1 of the legs in the opposite directions are generated in the trunk portion 10 by the driving vibration excited by the driving legs. Strains a1 and b1 are generated, and strains c1 and d1 in opposite directions are generated in the lower portion of the body portion 10, indicating that a1 = b1 = c1 = d1. FIG. 3 (B) shows that when the stress caused by the vibration displacements α2 and β2 of the legs opposite to each other is generated in the trunk portion 10 by the driving vibration excited by the driving legs, the upper portions of the trunk portion 10 are opposite to each other. Strains a2 and b2 are generated, and strains c2 and d2 in opposite directions are generated in the lower portion of the body portion 10, indicating that a2 = b2 = c2 = d2.

  On the other hand, FIG. 3C shows a case where stress due to the vibration displacements α1 and β1 of the legs opposite to each other is generated in the upper portion of the trunk portion 10 due to the driving vibration excited by the driving legs. Strains a1 and b1 that are opposite to each other are generated, and strains c1 and d1 that are opposite to each other are generated at the lower portion of the body portion 10. This indicates that a1 = b1> c1 = d1. Further, FIG. 3D shows that when stress due to vibration displacements α2 and β2 of legs opposite to each other is generated in the trunk portion 10 by the driving vibration excited by the driving legs, the upper portion of the trunk portion 10 is opposite to each other. Directional strains a2 and b2 are generated, and strains c2 and d2 in opposite directions are generated in the lower portion of the body portion 10, which indicates that a2 = b2> c2 = d2.

  As shown in FIGS. 3C and 3D, when the body 10 of the tuning fork vibrator is supported by the support member 2, the strain at the upper part of the body 10 and the distortion at the lower part thereof are different in magnitude. As a result, the upper and lower asymmetry of the trunk distortion occurs. When a vertical asymmetry is generated in the distortion of the body portion 10, vibration in a direction orthogonal to the drive vibration, that is, a plane vertical vibration component is generated in the body portion. This surface vertical vibration component appears on the vibration detection leg as leakage drive vibration and is in the same vibration direction as the detection vibration. Therefore, the surface vertical vibration component becomes a noise component with respect to the detection vibration and reduces the detection accuracy of the angular velocity.

  In a tuning fork type vibration gyro, it is inevitable to employ a vibrator mounting structure in which a vibrator is mounted on a package. Patent Document 1 discloses a structure in which a cylindrical support member is fixed to the center of gravity of a tuning fork vibrator with an adhesive or the like to support the vibrator. In the vibrator mounting structure adopted in the tuning fork type vibration gyro of Patent Document 1, the tuning fork type vibrator is supported on the same principle as the vibrator mounting structure shown in the schematic diagram of FIG. Appearing on the vibration detection leg as leakage drive vibration, and becomes a noise component with respect to the detected vibration, and the angular velocity detection accuracy is lowered. The structure described in Patent Document 3 has been proposed as a structure for suppressing drive vibration from leaking to the vibration detection leg.

  FIG. 10 (FIG. 1 in Patent Document 3) shows a rotational speed sensor 10 (tuning fork type vibration gyro) described in Patent Document 3. The rotational speed sensor 10 includes a housing 11, double ended (ie, H-type) tuning fork 13, and a rotational speed detection circuit 21. The housing 11 includes a lid 12, a base portion 14, and a mounting structure 15. The tuning fork 13 is etched from a single crystal of piezoelectric material. This material may be quartz, lithium niobate or other piezoelectric material.

  FIG. 11 (FIG. 3 in Patent Document 3) shows the tuning fork 13 described in Patent Document 3. The main body 16 of the tuning fork 13 has a surrounding frame 30 and an internal cavity 33. The tuning fork 13 includes excitation tines 31 and 32 and pickup tines 44 and 45. The tuning fork 13 also has a single dedicated mounting base 57 in the cavity 33. The mounting base 57 is spaced from the inner peripheral surface 18 of the frame 30, is surrounded by the mounting base 57, and is disposed at the center thereof. The mounting base 57 is coupled to the inner peripheral surface 18 by a suspension device 59 formed by cross bridges 61 and 62 and suspension bridges 64 to 67. The peripheral surface 71 of the mounting base 57 is spaced from the inner peripheral surface 18 of the main body 16 by an opening 73 in the + Y direction and by an opening 74 in the −Y direction.

  FIG. 12 (FIG. 4 in Patent Document 3) shows a base portion 14 and a mounting structure 15 of the housing 11 described in Patent Document 3. The attachment structure 15 is a pedestal 94. The pedestal 94 has substantially the same dimensions as the mounting surface 59 of the tuning fork 13. Returning to FIGS. 10 and 11, the tuning fork 13 is attached to the pedestal 94. The back surface 70 of the mounting base 57 is a single dedicated mounting surface of the tuning fork 13. This surface is fixed to the mounting surface 76 of the pedestal 94. This fixing is preferably performed by a conventional thermoplastic adhesive or epoxy resin. Thus, the tuning fork 13 is mounted in the housing 11 only at the single dedicated mounting surface 70. A suspension device 59 couples the mounting base 57 to the frame 30. The pedestal 94 may be made of stainless steel, aluminum, nickel alloy monel 400 or ceramics. It may be “garded” separately from the polished silicon or quartz wafer and then fixed to the base 14 using an epoxy resin. In the tuning fork type vibration gyro of Patent Document 3, the vibrator mounting structure is composed of a pedestal 94, a suspension device 59, and a mounting base 57.

  In the vibrator mounting structure described in Patent Document 3, since the internal cavity 33 is provided in the main body 16 of the tuning fork 13, it is necessary to perform a deep etching process on the main body 16 of the tuning fork 13. When the tuning fork 13 is made of a material for which an efficient etching method has not been established, for example, langasite, the vibrator mounting structure of the cited document 3 cannot be applied. Further, the vibrator mounting structure of the cited document 3 is provided with a suspension device 59 in the internal cavity 33. Therefore, the structure is complicated, expensive, and difficult to downsize.

  In the vibrator mounting structures of Patent Documents 1 and 2 listed above, as shown in FIG. 3, since the tuning fork vibrator is supported by the support member 2, distortion asymmetry occurs in the vibrator. Drive vibration leaks to the detection legs, which hinders improvement in angular velocity detection accuracy of the tuning fork type vibration gyro, and also impairs stability of detection accuracy. Further, the vibrator mounting structure described in Patent Document 3 cannot be applied to a tuning fork vibrator made of a material for which an efficient etching method has not been established, such as Langasite, and the structure is complicated and expensive. Also, miniaturization is difficult. In Patent Document 4, as shown in FIG. 5, the resonance frequency and leakage vibration are adjusted by cutting the base of the vibration leg at an angle. Moreover, in patent document 5, as shown in FIG. 6, in order to adjust mass balance, the ridgeline of the vibration leg is ground. Thus, in Patent Document 4 and Patent Document 5, since adjustment is performed after the tuning fork type vibrator is completed, there is a degree of freedom in adjustment amount, but the adjustment man-hours are increased, and the production cost of the vibrator is high. Become.

  Therefore, an object of the present invention is to reduce the drive vibration leaking to the detection leg by suppressing the occurrence of vertical asymmetry of the distortion generated in the vibrator due to the tuning fork vibrator supported by the support member, and thus the tuning fork vibrator. The purpose is to improve and stabilize the angular velocity detection accuracy of the vibrating gyroscope. Another object of the present invention is applicable to a tuning fork vibrator made of a material for which an efficient etching method has not been established, for example, langasite, has a simple structure, and can be downsized. In addition, the production cost is to provide a tuning fork type vibrator that is inexpensive.

  In order to solve the above-mentioned problems, the present invention provides the following means.

(1) A pair of excitation drive legs, a pair of vibration detection legs, and a body part that couples the excitation drive legs and the vibration detection leg, and is interposed between the body part and the package, the body part In the tuning fork vibrator for a vibrating gyroscope having a support member fixed region on the bottom surface of the substrate and a support member fixed to the support member mounting region of the package,
A plurality of grooves are provided on the bottom surface,
The groove is provided on both sides of the support member fixing region on the bottom surface,
The tuning fork vibrator for a vibration gyro, wherein the direction of the groove is the longitudinal direction of the drive leg for excitation.

  (2) The tuning fork vibrator for a vibration gyro according to claim 1, wherein the groove is provided from an end surface on the excitation driving leg side to an end surface on the vibration detection leg side in the trunk portion.

  According to the present invention, it is possible to suppress the occurrence of vertical asymmetry of the distortion generated in the vibrator due to the tuning fork vibrator being fixed to the support member. By suppressing the generation, it is possible to provide a vibrator that can reduce the drive vibration leaking to the detection leg, and consequently improve and stabilize the angular velocity detection accuracy of the tuning fork type vibration gyro. Furthermore, according to the present invention, it can be applied to a tuning fork vibrator made of a material for which an efficient etching method has not been established, for example, langasite, has a simple structure, can be downsized, and can be produced. The cost is to provide a tuning-fork resonator that is inexpensive.

  Next, embodiments of the present invention will be described, and the present invention will be described more specifically with reference to the drawings. FIG. 1 is an exploded perspective view showing a main part of a tuning fork type vibrating gyroscope having a tuning fork type vibrator according to an embodiment of the present invention. FIG. 2 is a perspective view of a tuning fork vibrator (a tuning fork vibrator for a vibration gyro according to an embodiment of the present invention) in which a groove is provided on the bottom surface of the trunk in the tuning fork vibratory gyro of FIG.

  1 and 2, 1 is a tuning fork type vibrator, 1 a is a support member fixing region in the tuning fork type vibrator 1, 2 is a support member, 3 is a package, 10 is a body portion, 10 j and 10 k are bottom surfaces of the body portion 10. , 11a and 11b are excitation drive legs, 11c is a non-excitation drive leg, 12 is a detection leg, 12a and 12b are vibration detection legs, 12c is a non-vibration detection leg, Reference numeral 30 denotes a package substrate, 30a denotes a support member mounting area, and 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, 35a, 35b, 36a, 36b, 37a, and 37b denote terminals.

  In FIG. 1, the tuning fork vibrator 1, the support member 2, and the package 3 are shown in an exploded manner. In a state where the tuning fork vibrator 1, the support member 2, and the package 3 are combined, the lower surface of the support member 2 is fixed to the support member mounting region 30a on the upper surface of the package substrate 30 with an adhesive, and the upper surface of the support member 2 is the tuning fork. The type vibrator 1 is fixed to the support member fixing region 1a on the bottom surface of the body 10 with an adhesive. The center of the support member fixing region 1a is at the center of gravity of the planar shape of the bottom surface of the body portion 10. The state in which the members denoted by reference numerals 1, 2, and 3 are coupled is a state in which the support member 2 supports the position of the center of gravity of the tuning fork vibrator 1 with the support member mounting region 30a as a fulcrum. 1 is a state mounted on the package 3 via the support member 2.

  The drive leg 11 in the tuning fork vibrator 1 includes a non-excitation drive leg 11c in addition to the excitation drive legs 11a and 11b corresponding to the excitation drive legs 111a and 111b in the drive leg 111 of FIG. Similarly, the detection leg 12 in the tuning fork vibrator 1 includes a non-vibration detection leg 12c in addition to the vibration detection legs 12a and 12b corresponding to the vibration detection legs 112a and 112b in the detection leg 112 of FIG. The non-excitation drive leg 11c and the non-vibration detection leg 12c are also provided as the non-excitation drive side arm and the non-vibration detection side arm in the tuning fork type vibration gyro in Patent Documents 1 and 2. 11 and the detection leg 12 are provided for stabilizing the vibration, but it is not important for the operation of the present invention, and the present embodiment can be implemented even if these legs 11c and 12c are omitted as shown in FIG. Hereinafter, further description of the non-excitation drive leg 11c and the non-vibration detection leg 12c will be omitted. The action of the tuning fork vibrator 1 in the tuning fork vibrator gyro shown in FIG. 1 is the same as that of the tuning fork vibrator shown in FIG.

  The tuning fork vibrator 1 of FIG. 1 is a single crystal piezoelectric body made of langasite. This tuning fork vibrator 1 is formed by machining with a grindstone or a wire saw. In the tuning fork vibrator 1, at least one of the drive legs 11a and 11b for excitation is provided with a drive electrode, and at least one of the vibration detection legs 12a and 12b is provided with a detection electrode. is there. The drive electrode and the detection electrode are connected to any of the terminals 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, 35a, 35b, 36a, 36b, 37a, or 37b by bonding wires. However, these bonding wires are also not shown.

  FIG. 2 is a diagram showing a vibrator structure according to the embodiment of the present invention. In FIG. 2, the tuning fork vibrator 1 is shown upside down from FIG. In the embodiment of FIG. 2, grooves 10 j and 10 k are provided on both sides of the support member fixing region 1 a on the bottom surface 10 b of the body portion 10 joined to the support member 2. The direction of the grooves 10j and 10k is the longitudinal direction of the drive leg 11 for excitation.

  4 shows that the vertical asymmetry of the distortion appearing in the trunk 10 of the tuning fork vibrator in the embodiment of FIG. 2 is significantly higher than the vertical asymmetry of the distortion appearing in the trunk 10 of the conventional structure shown in FIG. It is a figure which shows notionally being suppressed. 4 (A) and 4 (B) are diagrams showing the vertical asymmetric distortion appearing on the body 10 in a tuning fork vibrator having a conventional structure, and FIG. 4 (A) is the same as FIGS. 3 (A) and 3 (B). FIG. 4B shows the same contents as FIGS. 3C and 3D. As shown in FIGS. 4A and 4B, in the tuning fork vibrator 1 having a conventional structure, a vertically asymmetric strain is generated in the body portion 10 due to the restraint of the support member 2. In the tuning fork type vibrator 1 according to the embodiment of FIG. 2, the two grooves 10j and 10k shown in FIG. 4C are provided on both sides of the support member fixing region 1a of the body portion 10, so The region is limited to the region between the two grooves 10j and 10k, and the body portion 10 in the region outside the grooves 10j and 10k can freely expand and contract without being affected by the support member 2. As described above, in the embodiment of FIG. 2, since most of the body portion 10 is not subjected to the restraining action of the support member 2, the vertical asymmetry of the strain in the body portion 10 is greatly suppressed.

  As described above, in the embodiment of FIGS. 1 and 2, the vertical asymmetry of the barrel distortion caused by the restraint of the support member 2 against the drive vibration in the barrel 10 is caused by providing a groove on the bottom of the barrel. As a result, the drive vibration leaking to the detection leg 12 is reduced, and the angular velocity detection accuracy of the tuning-fork type vibration gyro is improved and stabilized.

  In the embodiment shown in FIGS. 1 and 2, langasite is used as the piezoelectric crystal material constituting the tuning fork vibrator 1. Langasite is a material for which an efficient etching method has not been established, but the formation of the vibrator in the production of this embodiment can be performed by machining with a grindstone or a wire saw. Since an etching process is not required, this embodiment can be easily realized.

  Although the embodiments of the present invention have been specifically described above with reference to the drawings, it goes without saying that the present invention is not limited to these embodiments.

1 is an exploded perspective view showing a tuning fork type vibration gyro provided with a tuning fork type vibrator having a groove on a bottom surface of a trunk part according to an embodiment of the present invention. FIG. 2 is a perspective view of a tuning fork vibrator having a groove on the bottom surface of the body portion according to the embodiment of the present invention shown in FIG. 1. FIG. 6 is a schematic diagram showing a variation in distortion appearing in a vibrator when the body of a tuning fork vibrator having a conventional structure is supported by a support member. It is a schematic diagram showing the principle by which the vertical asymmetry of the fluctuation | variation of the distortion which appears in a vibrator | oscillator is suppressed when the trunk | drum of the tuning fork type vibrator which is embodiment of this invention is supported by a support member. It is a figure which shows the vibration type gyro adjustment method of patent document 4. FIG. It is a figure which shows the angular velocity sensor of patent document 5, and its characteristic adjustment method. It is a figure which shows the electrode arrangement | positioning and connection state of each leg of a tuning fork type vibration gyroscope described in Patent Document 1. 10 is a diagram showing a piezoelectric vibration gyroscope described in Patent Document 2. FIG. It is a figure explaining the operation principle of the tuning fork type vibrator of the structure which combined the driving leg and the detection leg with the trunk. It is a figure which shows the rotational speed sensor 10 (tuning fork type vibration gyro) of patent document 3. FIG. It is a figure which shows the tuning fork 13 of patent document 3. FIG. It is a figure which shows the base 14 and the attachment structure 15 of the housing 11 described in patent document 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tuning fork type vibrator 1a Support member fixing area in tuning fork type vibrator 1 Support member 3 Package 10 Body 10j, 10k Groove provided on bottom surface 10b of body 10 11 Drive legs 11a, 11b, 111a, 111b Drive for excitation Leg 11c Non-excitation drive leg 12 Detection leg 12a, 12b, 112a, 112b Vibration detection leg 12c Non-vibration detection leg 30 Package substrate 30a Support member mounting region 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b , 35a, 35b, 36a, 36b, 37a, 37b Terminals α1, β1, α2, β2 Vibration displacement of drive legs a1, b1, a2, b2 Distortion on the upper side of the trunk (the side where the support member is not fixed) c1, d1, c2, d2 Strain on the lower side of the trunk (the side on which the support member is fixed)

Claims (2)

A pair of excitation drive legs and a pair of vibration detection legs, and a body part that couples the excitation drive legs and the vibration detection legs, and is interposed between the body part and the package; In a tuning fork vibrator for a vibrating gyroscope having a support member fixed region and a support member fixed to a support member mounting region of the package,
A plurality of grooves are provided on the bottom surface,
The groove is provided on both sides of the support member fixing region on the bottom surface,
The tuning fork vibrator for a vibration gyro, wherein the direction of the groove is the longitudinal direction of the drive leg for excitation.   2. The tuning fork vibrator for a vibration gyro according to claim 1, wherein the groove is provided from an end surface on the excitation driving leg side to an end surface on the vibration detection leg side in the trunk portion.

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