JP2010190705A - Three-axis detecting angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-axis detecting angular velocity sensor whose output signals do not fluctuate and are improved in accuracy even when an impulsive load in any of an X-axis direction, a Y-axis direction, and a Z-axis direction is applied to the acceleration sensor. <P>SOLUTION: This three-axis detecting angular velocity sensor is so constituted as to damp unwanted vibrations in the directions of the three axes of the X-axis, Y-axis, and Z-axis of its angular velocity detecting element 20 by a vibration isolating member 71. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In particular, the present invention relates to a triaxial detection angular velocity sensor capable of detecting angular velocities in the triaxial directions of the X axis, the Y axis, and the Z axis.

  Conventional angular velocity sensors of this type have been configured as shown in FIG.

  FIG. 15 is a perspective view of a conventional angular velocity sensor.

  In FIG. 15, reference numeral 1 denotes an angular velocity detection element. This angular velocity detection element 1 is provided with four vibration parts 2 erected in the Z direction, and a piezoelectric element 3 is provided on the outer surface of the vibration part 2. The connection part 4 which connects the lower part of the part 2 integrally is provided. Reference numeral 5 denotes a weight portion, and the weight portion 5 is fixed to the lower surface of the connection portion 4 in the angular velocity detecting element 1. Reference numeral 6 denotes a metal vibration-proof member. The metal vibration-proof member 6 is fixed to the lower surface of the weight portion 5 and has a trapezoidal hole 7 extending from the upper side to the lower side. Or the support part 8 extended toward the Y-axis direction is provided. Further, a fixing portion 9 is provided on the outer peripheral side of the metallic vibration-proof member 6, and the outer peripheral side of the support portion 8 is connected and fixed by the fixing portion 9. Reference numeral 10 denotes a case. The case 10 fixes the lower surface of the fixing portion 9 of the metal vibration isolating member 6 to the upper surface, and is provided with a rectangular parallelepiped hole 11 located below the angular velocity detecting element 1. ing. Reference numeral 12 denotes a vibration isolating member made of silicon gel. The vibration isolating member 12 is filled in the hole 11 in the case 10 and further filled in the hole 7 in the metallic vibration isolating member 6. The vibration isolating member 12 made of silicon gel is provided in the Z-axis direction of the angular velocity detecting element 1.

  Next, the operation of the conventional angular velocity sensor configured as described above will be described.

  When an AC voltage is applied to the piezoelectric element 3 in the angular velocity detection element 1, as shown in FIG. 16, the four vibrating portions 2 in the angular velocity detection element 1 are driven to vibrate in the diagonal direction of the cross section and in different directions. In this state, when an angular velocity around the Z-axis is generated in the angular velocity detecting element 1, a Coriolis force of F = 2 mV × ω is generated in a direction perpendicular to the vibration driving direction as shown in FIG. Vibrate. The angular velocity generated in the angular velocity detecting element 1 can be detected by amplifying the charge generated in the piezoelectric element 3 in the vibration section 2 by this vibration and converting it into a voltage.

  Here, considering a case where an impact load in the Z-axis direction is applied to the angular velocity sensor from the outside, in the conventional angular velocity sensor, a vibration isolating member 12 made of silicon gel is provided in the Z-axis direction of the angular velocity detecting element 1. Therefore, the unnecessary vibration generated by the impact load is attenuated by the viscoelasticity of the vibration isolation member 12. Therefore, fluctuations in the output signal from the angular velocity sensor can be prevented due to the impact load in the Z-axis direction.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2000-213942 A

  However, in the above-described conventional configuration, the vibration isolating member 12 made of silicon gel is provided only in the Z-axis direction of the angular velocity detecting element 1, so that unnecessary vibration in the Z-axis direction can be attenuated. When the impact load is applied in the direction or the Y-axis direction, the angular velocity detection element vibrates in the X-axis direction or the Y-axis direction due to the impact load, and the output signal from the angular velocity sensor changes. Had problems.

  The present invention solves the above-mentioned conventional problems, and the output signal fluctuates regardless of the impact load applied to the angular velocity sensor in the X-axis direction, the Y-axis direction, or the Z-axis direction. An object of the present invention is to provide a three-axis detection angular velocity sensor with improved output signal accuracy.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, an angular velocity detecting element capable of detecting angular velocities in the three axial directions of the X axis, the Y axis, and the Z axis, and an upper surface or a lower surface of the angular velocity detecting element are provided. An IC electrically connected to the angular velocity detecting element and provided with an IC electrode pad; the angular velocity detecting element and the IC are housed inside; and the IC electrode pad in the IC and electrically connected by a lead wire A case provided with a connection electrode pad, and a resin vibration isolating member is filled inside the case, and the vibration isolating member allows the angular velocity detecting element 3 in the X-axis direction, the Y-axis direction, and the Z-axis direction. In this configuration, unnecessary vibrations in the axial direction are attenuated, and according to this configuration, the vibration isolating member prevents the angular velocity detection element in the three axial directions of the X-axis direction, the Y-axis direction, and the Z-axis direction. As a result, the angular velocity detecting element does not vibrate in the X-axis direction or the Y-axis direction even when an impact load is applied in the X-axis direction or the Y-axis direction. This has the effect of stabilizing the output signal.

  In the invention according to claim 2 of the present invention, in particular, the vibration isolating member is provided over the three axial directions of the X-axis, Y-axis, and Z-axis in the angular velocity detecting element. Since the angular velocity detection element is provided across the three axes of the X, Y, and Z axes, the angular velocity is detected regardless of the impact load in the X, Y, or Z directions due to the viscoelasticity of the vibration isolation member. Unnecessary vibration generated in the element can be attenuated, thereby having the effect of stabilizing the output signal from the angular velocity detecting element.

  The invention according to claim 3 of the present invention is a resin vibration-proof member made of urethane gel or silicon gel, and according to this configuration, the resin vibration-proof member is made of urethane gel or silicon gel. Therefore, after filling the case that accommodates the angular velocity detecting element in a liquid state, the vibration isolating member can be cured, whereby the vibration isolating member can be easily attached to the X axis, the Y axis, and the angular velocity detecting element. It has the effect that it can be provided over the three axes of the Z axis.

  The triaxial detection angular velocity sensor of the present invention is provided with an angular velocity detection element capable of detecting angular velocities in the triaxial directions of the X axis, the Y axis, and the Z axis, and in contact with an upper surface or a lower surface of the angular velocity detection element. An IC electrically connected to the detection element and provided with an electrode pad for IC, and the electrode pad for connection which accommodates the angular velocity detection element and IC inside and is electrically connected to the IC electrode pad and lead wire in the IC The case is filled with a resin vibration-proof member inside the case, and the vibration-proof member eliminates the need for the three axial directions of the angular velocity detecting element in the X-axis direction, the Y-axis direction, and the Z-axis direction. According to this configuration, unnecessary vibrations in the three axial directions of the angular velocity detecting element in the X-axis direction, the Y-axis direction, and the Z-axis direction are prevented by the vibration isolating member. As a result, the angular velocity detecting element will not vibrate in the X-axis direction or the Y-axis direction due to the impact load even when an impact load is applied in the X-axis direction or the Y-axis direction. The angular velocity sensor having a stable output signal can be provided.

  Hereinafter, a three-axis detection angular velocity sensor according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a perspective view of an angular velocity sensor according to an embodiment of the present invention, FIG. 2 is a side sectional view of the angular velocity sensor, FIG. 3 is a side sectional view of the angular velocity sensor element in the angular velocity sensor, and FIG. FIG. FIG. 5 is a side sectional view of a portion where the piezoelectric body of the angular velocity sensor element in the angular velocity sensor is provided, and FIG. 6 is a circuit diagram of the angular velocity sensor.

  1 to 6, reference numeral 20 denotes an angular velocity detection element capable of detecting angular velocities in the three axes directions of the X axis, the Y axis, and the Z axis. The angular velocity detection element has step portions 20 a on both sides of the upper surface, A plurality of element electrode pads 20b are provided on the stepped portion 20a. Further, as shown in FIG. 3, the angular velocity detecting element 20 has a mass portion 21 made of Si in a rectangular parallelepiped shape. Further, the angular velocity detecting element 20 is provided with a first X-axis direction support member 22 made of Si, and the first X-axis direction support member 22 has an upper portion on one side surface of the mass portion 21. In addition to supporting, an outer driving piezoelectric body 23 made of a pair of PZTs is provided outside the upper surface, and an inner driving piezoelectric body 24 made of a pair of PZTs is further provided inside the upper surface. Further, on the upper surface of the first X-axis direction support member 22, an outer detection piezoelectric member 25 is provided between the pair of outer drive piezoelectric members 23. An inner detection piezoelectric body 26 is provided between them. Further, the angular velocity sensor element 20 is provided with a second X-axis direction support member 27 made of Si, and the second X-axis direction support member 27 is the first X-axis direction of the mass portion 21. While supporting the upper part of one side opposite to the side on which the support member 22 is provided, an outer driving piezoelectric body 28 made of a pair of PZTs is provided outside the upper surface, and an inner driving piezoelectric material made of a pair of PZTs inside the upper surface. A body 29 is provided. Further, on the upper surface of the second X-axis direction support member 27, an outer detection piezoelectric body 30 is provided between the pair of outer drive piezoelectric bodies 28. The inner detection piezoelectric body 31 is provided between them.

  The angular velocity sensor element 20 is provided with a first Y-axis direction support member 32 made of Si, and the first Y-axis direction support member 32 supports an upper portion of one side surface of the mass portion 21. In addition, an outer drive piezoelectric body 33 made of a pair of PZT is provided outside the upper surface, and an inner drive piezoelectric body 34 made of a pair of PZT is further provided inside the upper surface. Further, on the upper surface of the first Y-axis direction support member 32, an outer detection piezoelectric body 35 is provided between the pair of outer drive piezoelectric bodies 33. An inner detection piezoelectric body 36 is provided between them. Further, on the upper surface of the first Y-axis direction support member 32, an outer monitor piezoelectric body 37 is provided outside the outer drive piezoelectric body 33 and is positioned outside the inner drive piezoelectric body 34. An inner monitor piezoelectric body 38 is provided.

  The angular velocity sensor element 20 is provided with a second Y-axis direction support member 39 made of Si. The second Y-axis direction support member 39 is the first Y-axis in the mass portion 21. While supporting the upper part of one side opposite to the side on which the direction support member 32 is provided, an outer driving piezoelectric body 40 made of a pair of PZTs is provided outside the upper surface, and further, an inner driving made of a pair of PZTs is placed inside the upper surface. A piezoelectric body 41 is provided. Further, an outer detection piezoelectric body 42 is provided on the upper surface of the second Y-axis direction support member 39 so as to be positioned between the pair of outer drive piezoelectric bodies 40, and An inner detection piezoelectric body 67 is provided between them. Further, a pair of inner monitor piezoelectric bodies 43 are provided on the upper surface of the second Y-axis direction support member 39 so as to be located outside the pair of inner drive piezoelectric bodies 41.

  Further, as shown in FIG. 5, the outer drive piezoelectric body 23 and the outer detection piezoelectric body 25 located on the upper surface of the first X-axis direction support member 22 are formed of the first X-axis direction support member 22 made of Si. Provided on the upper surface of the common GND electrode 44 made of an alloy thin film of Pt and Ti provided on the upper surface, and provided with a drive electrode 45 on the upper surface of the outer drive piezoelectric member 23 and a detection electrode on the upper surface of the outer detection piezoelectric member 25. 46 is provided.

  The outer driving piezoelectric members 23, 28, 33, 42, the inner driving piezoelectric members 24, 29, 34, 41, the outer detecting piezoelectric members 25, 30, 35, 42, and the inner detecting piezoelectric members 26, 31, 36, 43. Is electrically connected to the element electrode pad 20b by a circuit pattern (not shown).

  The mass portion 21 is supported by the first X-axis direction support member 22, the second X-axis direction support member 27, the first Y-axis direction support member 32, and the second Y-axis direction support member 39. By doing so, the drive frequency in the X-axis direction is 39 kHz, the drive frequency in the Y-axis direction is 41 kHz, and the drive frequency in the Z-axis direction is 40 kHz. That is, the driving frequency of the mass portion 21 is set to be different in the X-axis direction, the Y-axis direction, and the Z-axis direction, and the driving frequency in the Z-axis direction is set to a central value.

  The first X-axis direction support member 22, the second X-axis direction support member 27, the first Y-axis direction support member 32, and the second Y-axis direction support member 39 are as shown in FIG. In addition, there are four holes 19 between them, and an outer peripheral portion 69 in which the outer peripheral side is integrally connected is provided.

  Reference numeral 47 denotes a bottomed rectangular cylindrical frame made of Si. The frame 47 includes the first X-axis direction support member 22, the second X-axis direction support member 27, and the first Y-axis direction support member 32. And the outer peripheral part 69 connected with the 2nd Y-axis direction supporting member 39 is supported.

  Reference numeral 48 denotes an IC. The IC 48 is in contact with the outer bottom surface of the angular velocity sensor element 20, and a plurality of IC electrode pads 48a are provided on both sides of the upper surface. The IC electrode pads 48a are connected to the angular velocity detection element. 20 is electrically connected to the element electrode pad 20b and the lead wire 48b.

  Further, as shown in FIG. 6, the IC 48 includes a drive circuit 49 and a detection circuit 50, and the drive circuit 49 includes a Z-axis direction drive circuit 51a and a Y-axis direction drive circuit 51b. It is what. Further, the Z-axis direction drive circuit 51a performs differential output signals from the outer monitor piezoelectric body 37 in the first Y-axis direction support member 32 and the inner monitor piezoelectric body 43 in the second Y-axis direction support member 39. Values are input to the outer drive piezoelectric bodies 23, 28, 33, 40 and the inner drive piezoelectric bodies 24, 29, 34, 41 via the IV converter 52, the band pass filter 53 and the AGC circuit 54 in the Z-axis direction drive circuit 51a. Thus, the mass portion 21 is driven to vibrate with a constant amplitude in the Z-axis direction. Similarly, the Y-axis direction drive circuit 51 b outputs from the inner monitor piezoelectric body 38 in the first Y-axis direction support member 32 and the inner monitor piezoelectric body 43 in the second Y-axis direction support member 39. By inputting the differential value of the signal to the outer driving piezoelectric bodies 33 and 40 and the inner driving piezoelectric bodies 34 and 41 via the IV converter 52, the band pass filter 56 and the AGC circuit 57 in the Y-axis direction driving circuit 51b, The mass portion 21 in the angular velocity sensor element 20 is driven to vibrate with a constant amplitude in the Y-axis direction.

  The detection circuit 50 includes a Y-direction Coriolis force detection circuit 58 and an X-direction Coriolis force detection circuit 59. The Y-direction Coriolis force detection circuit 58 is outside the first Y-axis direction support member 32. The output signals of the detection piezoelectric member 35 and the inner detection piezoelectric member 36 are input to the IV converter 60, and the output signals of the outer detection piezoelectric member 42 and the inner detection piezoelectric member 43 in the second Y-axis direction support member 39 are IV converted. After the input to the detector 61 and the difference between the two, the synchronous detector 62 detects the angular velocity around the X axis by synchronous detection at the drive frequency in the Z-axis direction. The X-direction Coriolis force detection circuit 59 includes an IV converter 63 for inputting output signals of the outer detection piezoelectric body 25 and the inner detection piezoelectric body 26 in the first X-axis direction support member 22, and a second X-axis. The differential value of the output signal from the IV converter 64 that receives the output signals from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 in the direction support member 27 is obtained by the synchronous detector 65 at the drive frequency in the Z-axis direction. By detecting synchronously, the angular velocity around the Y axis is detected. Further, similarly to these, the synchronous detector 66 detects the angular velocity around the Z-axis by performing synchronous detection at the drive frequency in the Y-axis direction.

  Reference numeral 67 denotes a case made of a bottomed rectangular cylindrical ceramic. The case 67 houses the angular velocity sensor element 20 and the IC 48 inside, and is provided with a plurality of connection electrode pads 68 on the upper surface. The IC electrode pad 48 a in the IC 48 and the connection electrode pad 68 in the case 67 are electrically connected by a lead wire 70.

  Reference numeral 71 denotes a vibration isolating member made of urethane gel. The vibration isolating member 71 is filled inside the case 67 and the vibration isolating member 71 is connected to the X-axis, Y-axis, and Z-axis of the angular velocity detecting element 20. It is provided over the axial direction.

  Next, a method for assembling the three-axis detection angular velocity sensor according to the embodiment of the present invention configured as described above will be described.

  First, a common GND electrode 44 made of an alloy thin film of Pt and Ti is formed by vapor deposition on the upper surface of a substrate (not shown) made of Si prepared in advance, and then made of a PZT thin film on the upper surface of the common GND electrode 44. Outside drive piezoelectric bodies 23, 28, 33, 40, inside drive piezoelectric bodies 24, 29, 34, 41, outside detection piezoelectric bodies 25, 30, 35, 42, inside detection piezoelectric bodies 26, 31, 36, 43, outside monitor The piezoelectric body 37 and the inner monitor piezoelectric bodies 38 and 67 are formed by vapor deposition.

  Next, the outer drive piezoelectric bodies 23, 28, 33, 40, the inner drive piezoelectric bodies 24, 29, 34, 41, the outer detection piezoelectric bodies 25, 30, 35, 42, the inner detection piezoelectric bodies 26, 31, 36, 43 The drive electrode 45, the detection electrode 46, and the monitor electrode (not shown) made of an alloy thin film of Ti and Au are formed on the upper surfaces of the outer monitor piezoelectric member 37 and the inner monitor piezoelectric members 38, 67.

  Next, while applying a voltage to the common GND electrode 44 side and grounding the drive electrode 45, the detection electrode 46 and the monitor electrode (not shown), the outer drive piezoelectric bodies 23, 28, 33, 40, the inner drive Piezoelectric bodies 24, 29, 34, 41, outer detection piezoelectric bodies 25, 30, 35, 42, inner detection piezoelectric bodies 26, 31, 36, 43, outer monitor piezoelectric bodies 37 and inner monitor piezoelectric bodies 38, 67 are polarized. .

  Next, by removing unnecessary portions in the base material (not shown), the mass portion 21, the first X-axis direction support member 22, the second X-axis direction support member 27, and the first Y-axis direction. The angular velocity detection element 20 including the support member 32, the second Y-axis direction support member 39, the outer peripheral portion 69, and the frame body 47 is formed.

  Next, the angular velocity detecting element 20 is bonded to the upper surface of the IC 48 with an adhesive (not shown).

  Next, after a supporting jig (not shown) is installed inside the case 67 prepared in advance, an IC 48 in which the angular velocity detecting element 20 is integrally bonded to the jig (not shown) is further mounted. Put.

  Next, after the element electrode pad 20b in the angular velocity detection element 20 and the IC electrode pad 48a in the IC 48 are electrically connected by bonding a lead wire 48b, the connection between the IC electrode pad 48a in the IC 48 and the case 67 is performed. The lead electrode 70 is electrically connected to the electrode pad 68.

  Next, the inside of the case 67 is filled with a vibration isolating member 71 made of liquid urethane gel until the middle of the outer surface of the IC 48 is hidden, and then cured by heating at about 100 ° C. for about 1 hour. .

  Finally, after removing the jig (not shown), the anti-vibration member 71 made of liquid urethane gel is filled again into the hole (not shown) by the jig (not shown) made in the anti-vibration member 71. Then, the vibration isolating member 71 is left to stand in a normal temperature atmosphere for about 5 hours to be naturally cured.

  That is, since the resin vibration-proof member 71 is urethane gel, the vibration-proof member 71 can be cured after filling the case 67 containing the angular velocity detection element 20 in a liquid state. The anti-vibration member 71 can be easily provided in the three axial directions of the X-axis, Y-axis, and Z-axis of the angular velocity detecting element 20.

  Next, the operation of the three-axis detection angular velocity sensor according to the embodiment of the present invention constructed and assembled as described above will be described.

  First, a case where an angular velocity around the X axis is first added to the mass portion 21 will be described.

  First, when a positive voltage is applied to the inner drive piezoelectric bodies 24, 29, 34, and 41, and a negative voltage is applied to the outer drive piezoelectric bodies 23, 28, 33, and 40, as shown in FIG. 24, 29, 34, and 41 are extended, and the outer drive piezoelectric bodies 23, 28, 33, and 40 are contracted. As a result, the mass portion 21 moves upward. Next, when a negative voltage is applied to the inner driving piezoelectric bodies 24, 29, 34, and 41, and a positive voltage is applied to the outer driving piezoelectric bodies 23, 28, 33, and 40, the inner driving piezoelectric bodies 24, 29, 34, and 41 shrinks and the outer driving piezoelectric bodies 23, 28, 33, 40 extend, and as a result, the mass portion 21 moves downward. That is, the mass unit 21 is driven to vibrate at a speed V at a drive frequency in the Z-axis direction. The vibration drive of the mass portion 21 is such that the output signals generated from the outer monitor piezoelectric member 37 and the inner monitor piezoelectric member 67 are constant, and the inner drive piezoelectric members 24, 29, 34, 41 and the outer drive piezoelectric member 23. , 28, 33, and 40 are adjusted to control the amplitude of vibration drive.

  Further, when the mass unit 21 rotates at an angular velocity ω around the central axis in the X-axis direction in a state where the mass unit 21 is driven to vibrate at a drive frequency in the Z-axis direction, as shown in FIG. 21 generates a Coriolis force of F = 2 mV × ω in the Y-axis direction. Due to this Coriolis force, the mass portion 21 is driven to vibrate in the Y-axis direction. Therefore, as shown in FIG. 9, for example, as shown in FIG. A positive charge is generated by the expansion of the piezoelectric body 36, and a negative charge is generated by the contraction of the outer detection piezoelectric element 42 and the inner detection piezoelectric element 43 in the second Y-axis direction support member 39. The electric charges generated from the outer detection piezoelectric member 35 and the inner detection piezoelectric member 36 are converted into output signals by the IV converter 60, and the electric charges generated from the outer detection piezoelectric member 42 and the inner detection piezoelectric member 43 are converted into the IV converter 61. 10 to obtain the differential between the two, and then synchronous detection is performed by the synchronous detector 62 at the vibration drive frequency in the Z-axis direction as shown in FIG. It is to detect.

  Next, a case where an angular velocity around the Y axis is added to the mass unit 21 will be described.

  Also in this case, as in the case where the angular velocity around the X axis is detected, the mass portion 21 is angularly rotated around the central axis in the Y axis direction when the mass portion 21 is driven to vibrate in the Z axis direction. As shown in FIG. 11, a Coriolis force of F = 2 mV × ω in the X-axis direction is generated in the mass portion 21 as shown in FIG. Due to this Coriolis force, the mass portion 21 is driven to vibrate in the X-axis direction, so that the outer detection piezoelectric member 23 and the inner detection piezoelectric member 25 in the first X-axis direction support member 22 are extended by this vibration drive. Is generated, and the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 of the second X-axis direction support member 27 are contracted to generate a negative charge. The electric charges generated from the outer detection piezoelectric member 23 and the inner detection piezoelectric member 26 are converted into output signals by the IV converter 63, and the electric charges generated from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 are converted into the IV converter 64. Then, after obtaining the differential between them, as shown in FIG. 12, the synchronous detector 66 performs synchronous detection at the frequency of vibration drive in the Z-axis direction, so that the angular velocity around the Y-axis is obtained. It is to detect.

  Next, a case where an angular velocity around the Z axis is added to the mass portion 21 will be described.

  In order to detect the angular velocity around the Z-axis, the mass unit 21 is driven to vibrate in the Y-axis direction as shown in FIG.

  First, a positive voltage is applied to the outer drive piezoelectric body 33 and the inner drive piezoelectric body 34 in the first Y-axis direction support member 32, and at the same time, the outer drive piezoelectric body 40 and the inner drive piezoelectric element in the second Y-axis direction support member 39. When a negative voltage is applied to the body 41, the outer driving piezoelectric member 33 and the inner driving piezoelectric member 34 are extended, and the outer driving piezoelectric member 40 and the inner driving piezoelectric member 41 are contracted. It moves toward the Y-axis direction support member 32.

  Next, a negative voltage is applied to the outer drive piezoelectric body 33 and the inner drive piezoelectric body 34 in the first Y-axis direction support member 32, and at the same time, the outer drive piezoelectric body 40 and the inner drive in the second Y-axis direction support member 39. When a positive voltage is applied to the piezoelectric body 41, the outer driving piezoelectric body 33 and the inner driving piezoelectric body 34 contract, and the outer driving piezoelectric body 40 and the inner driving piezoelectric body 41 extend, and as a result, the mass unit 21 has the second portion. It moves toward the Y-axis direction support member 39. That is, the mass unit 21 is driven to vibrate at a speed V at a drive frequency in the Y-axis direction. The vibration drive of the mass portion 21 is such that the output signals generated from the inner monitor piezoelectric members 38 and 67 are constant, the outer drive piezoelectric member 33, the inner drive piezoelectric member 34, the outer drive piezoelectric member 40, and the inner drive piezoelectric member. The amplitude of vibration drive is controlled by adjusting the voltage applied to the body 41.

  When the mass unit 21 is driven to vibrate in the Y-axis direction and the mass unit 21 rotates at an angular velocity ω around the central axis in the Z-axis direction, the mass unit 21 has F = 2 mV × ω in the X-axis direction. Coriolis force is generated. Due to this Coriolis force, the mass portion 21 is driven to vibrate in the X-axis direction, so that the outer detection piezoelectric member 23 and the inner detection piezoelectric member 25 in the first X-axis direction support member 22 are extended by this vibration drive. Is generated, and the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 of the second X-axis direction support member 27 are contracted to generate a negative charge. The electric charges generated from the outer detection piezoelectric member 23 and the inner detection piezoelectric member 26 are converted into output signals by the IV converter 63, and the electric charges generated from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 are converted into the IV converter 64. 14 is converted into an output signal, and the difference between the two is obtained. Then, as shown in FIG. 14, the synchronous detection is performed by the synchronous detector 66 at the vibration drive frequency in the Y-axis direction, so that the angular velocity around the Z-axis is obtained. It is to detect.

  Here, considering the case where an impact load in the X-axis direction, the Y-axis direction, and the Z-axis direction is simultaneously applied to the triaxial detection angular velocity sensor from the outside, the triaxial detection angular velocity sensor according to the present invention has a protection made of silicon gel. Since the vibration member 71 is provided over the three axial directions of the angular velocity detection element 1 in the X-axis direction, the Y-axis direction, and the Z-axis direction, the X-axis direction, the Y-axis direction, and the Z-axis direction are affected by the viscoelasticity of the vibration isolation member 71. Whichever of the impact loads is applied, unnecessary vibration generated in the angular velocity detection element 20 is attenuated. Therefore, fluctuations in the output signal generated from the triaxial detection angular velocity sensor can be prevented due to the impact load in the X axis direction, the Y axis direction, and the Z axis direction.

  That is, since the vibration isolating member 71 is provided in the three axial directions of the X-axis, Y-axis, and Z-axis in the angular velocity detecting element 20, any one of the X-axis direction, the Y-axis direction, and the Z-axis direction is caused by the viscoelasticity of the anti-vibration member 71. Even if an impact load is applied, unnecessary vibration generated in the angular velocity detecting element 20 can be attenuated, and this has the effect of stabilizing the output signal from the angular velocity detecting element 20.

  In the three-axis detection angular velocity sensor according to the embodiment of the present invention, the vibration isolating member 71 is urethane gel, but silicon gel has the same effect.

  The triaxial detection angular velocity sensor according to the present invention does not cause the output signal to fluctuate even when an impact load in the X axis direction, the Y axis direction, or the Z axis direction is applied to the angular velocity sensor. The three-axis detection angular velocity sensor has the effect of providing a three-axis detection angular velocity sensor with improved output signal accuracy, and is particularly capable of detecting angular velocities in the three-axis directions of the X, Y, and Z axes. It is useful to apply to.

The perspective view of the triaxial detection angular velocity sensor in one embodiment of this invention Side sectional view of the 3-axis detection angular velocity sensor Side sectional view of angular velocity sensor element in the same three-axis detection angular velocity sensor Top view of angular velocity sensor element in the three-axis detection angular velocity sensor Side sectional view of the location where the piezoelectric body of the angular velocity sensor element is provided in the three-axis detection angular velocity sensor Circuit diagram of the 3-axis detection angular velocity sensor Side sectional view showing a state in which the angular velocity detection element in the three-axis detection angular velocity sensor is driven to vibrate in the Z-axis direction. The figure which shows the state which detects the angular velocity around the X-axis of the same 3-axis detection angular velocity sensor Side sectional view showing a state in which the angular velocity detection element in the three-axis detection angular velocity sensor is operated by the Coriolis force in the Y-axis direction Waveform diagram showing the state of synchronous detection of the output signal from the 3-axis detection angular velocity sensor at the drive frequency in the Z-axis direction The figure which shows the state which detects the angular velocity around the Y-axis of the same 3-axis detection angular velocity sensor Waveform diagram showing the state of synchronous detection of the output signal from the 3-axis detection angular velocity sensor at the drive frequency in the Z-axis direction The figure which shows the state which detects the angular velocity around the Z-axis of the same 3-axis detection angular velocity sensor Waveform diagram showing the state of synchronous detection of the output signal from the 3-axis detection angular velocity sensor at the drive frequency in the Y-axis direction A perspective view of a conventional angular velocity sensor The top view which shows the state which the vibration part of the angular velocity detection element in the conventional angular velocity sensor drives by vibration The top view which shows the state which the vibration part of the angular velocity detection element in the conventional angular velocity sensor operate | moves

20 Angular velocity detector 48 IC
48a IC electrode pad 67 Case 68 Connection electrode pad 70 Lead wire 71 Anti-vibration member

Claims (3)

An angular velocity detection element capable of detecting angular velocities in the three directions of the X, Y, and Z axes, an abutting contact with the upper surface or the lower surface of the angular velocity detection element, and electrically connected to the angular velocity detection element and an IC An IC provided with an electrode pad, and a case in which the angular velocity detecting element and the IC are housed inside and a connection electrode pad in the IC is electrically connected to the IC electrode pad by a lead wire. The inside of the case is filled with a resin vibration-proof member, and this vibration-proof member is configured to attenuate unnecessary vibrations in the three axial directions of the angular velocity detecting element in the X-axis direction, the Y-axis direction, and the Z-axis direction. 3-axis detection angular velocity sensor. The triaxial detection angular velocity sensor according to claim 1, wherein the vibration isolating member is provided in the three axial directions of the X axis, the Y axis, and the Z axis in the angular velocity detection element. The triaxial detection angular velocity sensor according to claim 1, wherein the resin vibration-proof member is urethane gel or silicon gel.

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