JP7418808B2 - Tuning fork type vibrator and tuning fork type vibrator adjustment method - Google Patents

Description

The present invention relates to a tuning fork type vibrator and a method for adjusting the tuning fork type vibrator.

Conventionally, a tuning fork type vibrator vibrates two vibrating parts connected by a connecting part in anti-phase to each other, and utilizes the resonance frequency of the anti-phase, which changes the angular velocity and rotation angle. It is used as a vibrating gyroscope for detection, an oscillator for a clock module, etc. (see, for example, Patent Documents 1 to 4). Furthermore, in recent years, extremely small tuning fork type vibrators have been manufactured using MEMS (microelectromechanical system) technology (see, for example, Patent Documents 2 to 4).

In addition, in conventional tuning fork type vibrators, in order to adjust the resonance frequency when two vibrating parts vibrate in opposite phases, the size and density of the vibrating body of each vibrating part, and the elasticity that supports the vibrating body so that it can vibrate. The rigidity of the body is adjusted (for example, see Patent Document 2), and electrostatic force is applied to each vibrating part (see, for example, Patent Document 3 or 4).

Japanese Patent Application Publication No. 2008-283529 Japanese Patent Application Publication No. 2006-162584 Japanese Patent Application Publication No. 2013-253958 Japanese Patent Application Publication No. 2014-178195

In conventional tuning fork type vibrators such as those described in Patent Documents 1 to 4, when the masses and spring constants of the vibrating parts are different, the amplitudes of the vibrating parts when vibrating in opposite phases are not equal. In this case, the vibration energy of each vibrating part escapes to the support body, resulting in a large energy loss (anchor loss), resulting in a small Q value representing the state of vibration. For this reason, for example, as described in Patent Documents 1 to 4, in order to adjust the resonance frequency, methods such as adjusting the rigidity of the elastic body of each vibrating part or applying an electrostatic force to each vibrating part are used. There is. There is also a method of changing the Q value by adjusting the unbalance of the vibrating body by adjusting only the stiffness of a part of the elastic body, but if you adjust the Q value using this method, the resonance frequency will also change at the same time. It will change. As described above, the conventional tuning fork type vibrator has a problem in that it is difficult to adjust the resonance frequency and the Q value independently of each other.

The present invention has been made with attention to such problems, and provides a tuning fork type vibrator and a tuning fork type vibrator adjustment method that can adjust the Q value without substantially affecting the resonance frequency of the opposite phase. The purpose is to provide

In order to achieve the above object, the present inventors conducted a study based on the operating principle of a tuning fork type vibrator. That is, a general tuning fork type vibrator can be represented by the configuration shown in FIG. As shown in FIG. 1(a), the tuning fork type vibrator includes a first vibrating part and a second vibrating part connected by a connecting part (spring constant: _k2 ) made of an elastic member. Further, the first vibrating section includes a first vibrating body (mass: m ₁ ) and a first elastic body (spring constant: k ₁ ) which is connected to a support body so that the first vibrating body can vibrate. Further, the second vibrating section includes a second vibrating body (mass: m ₁ ) and a second elastic body (spring constant: k ₃ ) which is connected to a support body so that the second vibrating body can vibrate.

When the first vibrating part and the second vibrating part vibrate in anti-phase, the mass of the first vibrating body and the mass of the second vibrating body are When the spring constant of the first elastic body and the spring constant of the second elastic body are equal (k ₁ =k ₃ ), the amplitude of the first vibrating body and the amplitude of the second vibrating body become equal. Moreover, at this time, the neutral point between the first vibrating part and the second vibrating part does not move due to vibration.

However, in reality, due to processing errors, etc., the mass of the first vibrating body and the mass of the second vibrating body may differ, or the spring constant of the first elastic body and the spring constant of the second elastic body may differ. There are many. For example, in a typical concentrated mass type MEMS resonator, the size of the vibrating body is larger than that of the elastic body, so that machining errors affect the elastic body more than the vibrating body.

Therefore, a case will be considered in which the spring constant of the first elastic body and the spring constant of the second elastic body are different. As shown in Figure 1(d), the spring constant of the first elastic body is larger than the spring constant of the second elastic body (the first elastic body is harder than the second elastic body). , the average value of the spring constant of the first elastic body and the spring constant of the second elastic body is k ₀ , then the spring constant k ₁ of the first elastic body is k ₁ = k ₀ + ΔK, the spring constant of the second elastic body k ₃ can be expressed as k ₃ =k ₀ -ΔK. Here, ΔK is the amount of deviation of the spring constant from the average value _k0 .

At this time, the resonance frequency ω when the first vibrating part and the second vibrating part vibrate in opposite phases is expressed by equation (1). Further, the amplitudes of the first vibrating body and the second vibrating body are expressed by an amplitude vector X [amplitude of the first vibrating body, amplitude of the second vibrating body] in equation (2).

From equation (2), the amplitude of the first vibrating body is larger than the amplitude of the second vibrating body. Therefore, the reaction force exerted on the support body by the first vibrating part and the second vibrating part is larger in the first vibrating part than in the second vibrating part, and the reaction forces become unbalanced. As a result, anchor loss occurs, and the Q value becomes smaller than when the spring constants are equal (cases in FIGS. 1(b) and 1(c)). Further, at this time, the neutral point between the first vibrating part and the second vibrating part vibrates in the same phase as the harder vibrating body (in the case of ΔK>0, the first vibrating body).

As a result of consideration based on the above operating principle of the tuning fork type vibrator, the present inventors have arrived at the present invention. That is, the tuning fork type vibrator according to the present invention includes a first vibrating part and a second vibrating part, a connecting part connecting the first vibrating part and the second vibrating part, and a connecting part connected to the connecting part. , an adjustment vibration part that vibrates along the vibration direction of the first vibration part and the second vibration part, and the first vibration part includes a first vibration body, a support body, and the first vibration body. and a first elastic body connected to the second vibrating body, and the second vibrating part includes a second vibrating body and a second elastic body connected to the support and the second vibrating body, The spring constant of the elastic body is k ₀ +ΔK, and the spring constant of the second elastic body is k ₀ −ΔK (k ₀ is the spring constant of the first elastic body and the spring constant of the second elastic body). where ΔK is the deviation from the average value of the spring constant), and the adjusting vibrating part is connected at a neutral point between the first vibrating part and the second vibrating part of the connecting part. , the adjusting vibrating section includes a third vibrating body, a third elastic body having one end connected to the third vibrating body, and a connecting portion connecting the connecting portion and the third elastic body, The adjusting vibration section is characterized in that the resonance frequency is adjusted by applying an electrostatic force to the third elastic body , and the tuning fork type vibration in which the first vibration section and the second vibration section vibrate in opposite phases to each other. It is a child.

In the tuning fork type vibrator according to the present invention, when the first vibrating part and the second vibrating part are vibrated in opposite phases, the mass related to the vibration of the first vibrating part and the mass related to the vibration of the second vibrating part are different from each other. Even if they are aligned, if the spring constant of the first vibrating part and the spring constant of the second vibrating part are different, for example, as shown in equation (2), the amplitude of the vibration of the first vibrating part and the amplitude of the vibration of the second vibrating part are different. The amplitudes are not equal. At this time, since the adjustment vibrating part connected to the connecting part is provided so as to be able to vibrate along the vibration direction of the first vibrating part and the second vibrating part, the adjustment vibration part of the first vibrating part and the second vibrating part is The balance excites the vibration of the adjustment vibration section. In this way, by coupling the adjustment vibration section with the first vibration section and the second vibration section, the shape of the vibration mode (the amplitude of the first vibration section and the second vibration section) can be varied. Thereby, it is possible to reduce the amplitude imbalance, reduce the anchor loss, and suppress the decrease in the Q value.

Further, in the tuning fork type vibrator according to the present invention, by adjusting the resonant frequency of the adjustment vibration section, the degree of coupling between the adjustment vibration section, the first vibration section, and the second vibration section can be adjusted. The vibration mode (amplitude of the first vibration section and the second vibration section) can be freely adjusted. Thereby, it is possible to adjust the absorption amount of vibrational energy due to the difference in amplitude between the first vibrating part and the second vibrating part, and the Q value can be freely adjusted. At this time, since the mass and spring constant related to the vibration of the first vibrating part and the mass and spring constant related to the vibration of the second vibrating part are not changed, the Q value is can only be adjusted.

The tuning fork type vibrator according to the present invention can be used, for example, in a gyroscope. In a gyroscope, it is necessary to match the resonance frequencies and Q values of two orthogonal vibration modes. For this purpose, it is desirable to be able to adjust the resonance frequency and Q value of each axis independently. In the tuning fork type vibrator according to the present invention, in a state where the out-of-phase resonant frequency in the X direction and the out-of-phase resonant frequency in the Y direction of the gyroscope are aligned, and without affecting those resonant frequencies, The Q value of the vibration in the X direction and the Q value of the vibration in the Y direction can be made equal.

In the tuning fork type vibrator according to the present invention, the adjustment vibrating part is connected to the connecting part at a neutral point between the first vibrating part and the second vibrating part of the connecting part . The vibration energy due to the difference in amplitude between the vibrating part and the second vibrating part can be absorbed best, and the difference in amplitude can be reduced to zero. Furthermore, the adjustment range of the Q value can be made the largest.

The tuning fork type vibrator according to the present invention may be made of a MEMS vibrator, and may be configured to be able to adjust the resonance frequency of the adjustment vibrating section using electrostatic force. In this case, it can be configured extremely small.

The method for adjusting a tuning fork type vibrator according to the present invention is characterized in that the resonant frequency of the adjusting vibration section of the tuning fork type vibrator according to the present invention is adjusted by the electrostatic force . According to the method for adjusting a tuning fork type vibrator according to the present invention, only the Q value can be freely adjusted with almost no effect on the negative phase resonance frequency.

According to the present invention, it is possible to provide a tuning fork type vibrator and a tuning fork type vibrator adjustment method that can adjust the Q value with almost no effect on the negative phase resonance frequency.

(a) Principle diagram showing the configuration of a general tuning fork type vibrator, (b) and (c) Explanatory diagram showing what happens when it vibrates in opposite phases, (d) Inverse diagram when the spring constants at both ends are different. FIG. 3 is an explanatory diagram showing a situation when the device vibrates in phase. FIG. 1 is a principle diagram showing the configuration of a tuning fork type vibrator according to an embodiment of the present invention. FIG. 2 is a plan view showing an example of a tuning fork type vibrator including a MEMS vibrator according to an embodiment of the present invention. FIG. 3 is an explanatory diagram showing the vibration states of four natural modes of vibration (a) mode 1, (b) mode 2, (c) mode 3, and (d) mode 4 of the tuning fork type vibrator shown in FIG. 2; . In the simulation results of _the tuning fork type vibrator _shown in _FIG . b) It is a graph showing a change in the amplitude ratio x ₁ /x ₂ of the first vibrating body and the second vibrating body. The amplitude of the first vibrating body with respect to the ratio (ω _inner /ω _mid ) of the resonance frequency ω _mid of the opposite phase and the resonance frequency ω _inner of the adjustment vibration part in the simulation results of the tuning fork type vibrator shown in FIG. It is a graph which shows the change of the ratio ( _x2 / _x1 ) with the amplitude of a 2nd vibrating body, and the change of Q value. In the simulation results of the tuning fork type vibrator shown in Figure 3, the applied voltage when an electrostatic force is applied to the third elastic body (corresponding to "Inner electrode"), and the static force applied to the first elastic body or the second elastic body. It is a graph showing (a) change in negative phase resonance frequency and (b) change in Q value with respect to applied voltage (corresponding to "Sense electrode") when electric power is applied.

Embodiments of the present invention will be described below based on drawings and examples.
2 to 7 show a tuning fork type vibrator according to an embodiment of the present invention.
As shown in FIG. 2, the tuning fork type vibrator 10 includes a first vibrating part 11, a second vibrating part 12, a connecting part 13, and an adjusting vibrating part 14.

The first vibrating part 11 includes a first vibrating body 11a (mass: m ₁ ) and a first elastic body 11b (spring constant: k ₀ +ΔK) which connects the first vibrating body 11a to the support body 1 so as to vibrate. have. The second vibrating part 12 includes a second vibrating body 12a (mass: m ₁ ) and a second elastic body 12b (spring constant: k ₀ −ΔK), which is connected to the support body 1 so that the second vibrating body 12a can vibrate. have. Here, the masses of the first vibrating body 11a and the second vibrating body 12a are equal. Further, the one having a larger spring constant is defined as the first elastic body 11b, and the first elastic body 11b is harder than the second elastic body 12b. k ₀ is the average value of the spring constant of the first elastic body 11b and the spring constant of the second elastic body 12b, and ΔK is the amount of deviation from the average value k ₀ of the spring constant.

The connecting part 13 connects the first vibrating part 11 and the second vibrating part 12 so that they can vibrate. The connecting portion 13 is made of an elastic member, and connects the first vibrating portion 11 and the second vibrating portion 12 so that they vibrate in opposite phases. In a specific example shown in FIG. 2, the connecting portion 13 is formed by connecting two exactly the same elastic members (spring constant k _c ), and one of the elastic members is connected to the first vibrating body of the first vibrating portion 11. 11a is connected, and the second vibrating body 12a of the second vibrating section 12 is connected to the other elastic member.

The adjustment vibrating part 14 includes a third vibrating body 14a (mass: m ₃ ), a third elastic body 14b (spring constant: k 3 ) whose one end is connected to the third vibrating body 14a, and a connecting part 13 and a third vibrating body 14a (mass: m ₃ ). It has a connecting portion 14c (mass: m ₄ ) connected to the elastic body 14b. The connecting portion 14c connects the connecting position of the two elastic members of the connecting portion 13 (the neutral point between the first vibrating portion 11 and the second vibrating portion 12) and the other end of the third elastic body 14b. The adjustment vibration unit 14 is provided with a third vibrating body 14a that can vibrate along the vibration direction of the first vibrating body 11a and the second vibrating body 12a. Further, the adjustment vibration section 14 is configured to be able to adjust the spring constant of the third elastic body 14b. Thereby, the adjustment vibration section 14 can adjust its own resonance frequency.

In a specific example, the tuning fork type vibrator 10 is made of a MEMS vibrator manufactured using MEMS technology, as shown in FIG. The tuning fork type vibrator 10 shown in FIG. 3 can be manufactured using an SOI wafer. In the tuning fork type vibrator 10, a first vibrating part 11, a second vibrating part 12, a connecting part 13, and an adjustment vibrating part 14 are formed on a device layer of an SOI wafer by photolithography and etching, and a support body is formed on a handle layer. 1 is formed. Further, an electrode 15 is formed in the device layer for adjusting the spring constant by applying an electrostatic force to the third elastic body 14b of the adjustment vibration section 14. Note that the light gray part in FIG. 3 is the device layer, and the black part is the part removed by etching.

Next, the effect will be explained.
In the tuning fork type vibrator 10, since the spring constant of the first elastic body 11b and the spring constant of the second elastic body 12b are different, when the first vibrating part 11 and the second vibrating part 12 are vibrated in opposite phases, The amplitude of the first vibrating body 11a and the amplitude of the second vibrating body 12a are not equal. At this time, since the adjustment vibrating part 14 connected to the connecting part 13 is provided so as to be able to vibrate along the vibration direction of the first vibrating body 11a and the second vibrating body 12a, the first vibrating body 11a and the second vibrating body 12a The unbalance of the two vibrating bodies 12a excites the vibration of the adjustment vibrating section 14. In this way, the adjustment vibrating section 14 is coupled with the first vibrating body 11a and the second vibrating body 12a, thereby changing the shape of the vibration mode (the amplitude of the first vibrating body 11a and the second vibrating body 12a). can be done. Thereby, it is possible to reduce the amplitude imbalance, reduce the anchor loss, and suppress the decrease in the Q value.

Further, the tuning fork type vibrator 10 can adjust the degree of coupling between the adjusting vibrating section 14, the first vibrating body 11a, and the second vibrating body 12a by adjusting the resonance frequency of the adjusting vibrating section 14. The vibration mode (the amplitude of the first vibrating body 11a and the second vibrating body 12a) can be freely adjusted. Thereby, it is possible to adjust the absorption amount of vibrational energy due to the difference in amplitude between the first vibrating body 11a and the second vibrating body 12a, and the Q value can be freely adjusted. At this time, since the mass of the first vibrating body 11a and the spring constant of the first elastic body 11b, as well as the mass of the second vibrating body 12a and the spring constant of the second elastic body 12b are not changed, the resonance frequency of the opposite phase is almost the same. Only the Q value can be adjusted without affecting it.

In order to investigate the effect of adjusting the Q value of the tuning fork type vibrator 10 shown in FIG. 2, numerical calculations were performed. First, numerical calculations were performed for the case where the resonant frequency of the adjustment vibrating section 14 was sufficiently far from the resonant frequency when the first vibrating section 11 and the second vibrating section 12 were vibrated in opposite phases. The mass m ₁ of the first vibrating body 11a and the second vibrating body 12a, the average value k ₀ of the spring constant of the first elastic body 11b and the spring constant of the second elastic body 12b, the amount of deviation ΔK of each spring constant, the connecting portion The spring constant k _c of each of the 13 elastic members, the mass m ₃ of the third vibrating body 14a, the spring constant k ₃ of the third elastic body 14b, and the mass m ₄ of the connecting portion 14c were set as follows.

m ₁ = 1
m ₃ =0.01
m ₄ =0.0001
k ₀ =1
k _c =2
_k3 =0.05
ΔK=0.01

If ΔK=0, the in-phase resonance frequency f1 where all the vibrators move in the same direction is 1 (rad/s), and the anti-phase resonance frequency f2 is 1 (rad/s). .7321 (rad/s), the resonant frequency f3 of the third vibrating body 14a is 2.2361 (rad/s), and the resonant frequency f4 of the connecting portion 14c is 201.25 (rad/s). Similarly, when ΔK=0.01, four eigenmodes as shown in FIGS. 4(a) to 4(d) appear, and the amplitude of each part of each mode is as follows. Here, the amplitude of the first vibrating body 11a is x ₁ , the amplitude of the second vibrating body 12a is x ₂ , the amplitude of the third vibrating body 14a is x ₃ , and the amplitude of the connecting portion 14c is x ₄ .

In mode 1, the resonant frequency is 201.25 (rad/s), and almost only the connecting portion 14c vibrates. In mode 2, the resonant frequency is 1.0 (rad/s), all the vibrators are moving approximately in parallel, and the mode is the same phase. In mode 3, the resonant frequency is 1.7321 (rad/s), the first vibrating body 11a and the second vibrating body 12a vibrate in opposite directions, and are in a reverse phase mode. In this reverse phase mode, the magnitudes of the amplitudes of the first vibrating body 11a and the second vibrating body 12a are different, and it is considered that anchor loss occurs. In mode 4, the resonant frequency is 2.2292 (rad/s), which is sufficiently far from the resonant frequency of mode 3 (1.7321 (rad/s)). Therefore, mode 3 and mode 4 are linked. Almost only the third vibrating body 14a is vibrating.

Next, numerical calculations were performed for the case where the resonant frequency of the adjustment vibrating section 14 was made close to the resonant frequency when the first vibrating section 11 and the second vibrating section 12 were vibrated in opposite phases. Each constant was set as follows (only _k3 was changed).

m ₁ = 1
m ₃ =0.01
m ₄ =0.0001
k ₀ =1
k _c =2
_k3 =0.03023
ΔK=0.01

If ΔK=0, the in-phase resonance frequency f1 is 1 (rad/s), the anti-phase resonance frequency f2 is 1.732 (rad/s), and the third The resonant frequency f3 of the vibrating body 14a is 1.739 (rad/s), and the resonant frequency f4 of the connecting portion 14c is 200.75 (rad/s). The amplitude of each part of each mode is as follows.

In mode 1, the resonant frequency is 200.76 (rad/s), and almost only the connecting portion 14c vibrates. In mode 2, the resonant frequency is 0.99624 (rad/s), all the vibrators are moving approximately in parallel, and the mode is the same phase. In mode 3, the resonant frequency is 1.7321 (rad/s), the first vibrating body 11a and the second vibrating body 12a vibrate in opposite directions, and are in a reverse phase mode. In this reverse phase mode, the amplitudes of the first vibrating body 11a and the second vibrating body 12a become close to each other, and the amplitude of the third vibrating body 14a also becomes large. This means that the adjustment vibration section 14 (third vibrating body 14a) vibrates in conjunction with the main vibrating section (first vibrating body 11a and second vibrating body 12a). This means that the amplitude of the main vibration section has changed due to the change in the amplitude of the vibration. As a result, unbalance is reduced and anchor loss is reduced. In mode 4, the resonance frequency is 1.7386 (rad/s), and almost only the third vibrating body 14a vibrates.

Next, when only the spring constant k ₃ of the third elastic body 14b is changed, the magnitudes of the amplitudes x ₁ to x ₄ of each vibrating body in mode 3 are determined and shown in FIG. 5(a). Further, the amplitude ratio x ₁ /x ₂ of the first vibrating body 11a and the second vibrating body 12a is determined and shown in FIG. 5(b). In addition, in FIGS. 5A and 5B, when the resonance frequency when the first vibration section 11 and the second vibration section 12 are vibrated in opposite phases is equal to the resonance frequency of the adjustment vibration section 14. The amount of change in _k3 was set to 0%.

As shown in FIG. 5(a), it was confirmed that x ₁ and x ₂ had opposite signs, and that the first vibrating section 11 and the second vibrating section 12 were vibrating in opposite phases. Further, it was confirmed that the amplitude x ₄ of the connecting portion 14c remains almost zero and does not change even if the spring constant k ₃ of the third elastic body 14b is changed. Further, the vibration of the third vibrating body 14a has a magnitude relationship between the resonance frequency when the first vibrating part 11 and the second vibrating part 12 are vibrated in opposite phases and the resonant frequency of the vibration of the adjustment vibrating part 14. It was confirmed that the phase was reversed. In addition, as shown in FIG. 5(b), by changing the spring constant _k3 of the third elastic body 14b and changing the resonance frequency of the adjustment vibrating part 14, the first vibrating body 11a and the second vibrating body It was confirmed that the amplitude ratio of the first vibrating body 11a and the second vibrating body 12a can be changed, including the case where the amplitudes of the vibrating bodies 12a are equal.

A simulation was performed using the finite element method (FEM) using the tuning fork type vibrator 10 shown in FIG. In the simulation, the amplitudes and Q values of the first vibrating body 11a and the second vibrating body 12a were determined when the resonant frequency ω _inner of the adjustment vibrating section 14 was changed. Through simulation, _{the ratio (ω inner / ω mid} ), the change in the ratio (x ₂ /x ₁ ) between the amplitude of the first vibrating body 11a and the amplitude of the second vibrating body 12a and the change in the Q value were determined and shown in FIG. 6. Note that the ratio k ₁ /k ₂ between the spring constant k ₁ of the first elastic body 11b and the spring constant k ₂ of the second elastic body 12b is 1.23.

As shown in FIG. 6, it was confirmed that the Q value could be adjusted by adjusting the resonance frequency ω _inner of the adjustment vibration section 14. In addition, if there is no anchor loss when the first vibrating part 11 and the second vibrating part 12 are vibrated in opposite phases, the reaction force applied to the first vibrating body 11a and the reaction force applied to the second vibrating body 12a are equal and cancel each other out, so k ₁ ×x ₁ =k ₂ ×x ₂ . Since k ₁ /k ₂ =1.23, it is assumed that the Q value becomes the maximum value when x ₂ /x ₁ =1.23. As shown in FIG. 6, it was confirmed that the Q value shows the maximum value when x ₂ /x ₁ = 1.21, and a result very close to the assumption was obtained. From this result, it can be said that by adjusting the resonant frequency ω _inner of the adjustment vibration unit 14, the value of x ₂ /x ₁ can be changed and the anchor loss due to the difference in spring constant can be reduced.

Next, a MEMS vibrator was actually manufactured and the Q value was adjusted. In order to change the spring constant of the third elastic body 14b of the adjustment vibration section 14, an electrostatic force was applied to the third elastic body 14b. At this time, the changes in the resonance frequency and the Q value when the first vibrating section 11 and the second vibrating section 12 are vibrated in opposite phases with respect to the applied voltage are determined, and the results are shown in FIG. 7(a). and (b) (“Inner electrode” in each figure). Note that in FIGS. 7A and 7B, electrostatic force is applied to the first elastic body 11b or the second elastic body 12b in order to directly change the spring constant of the first elastic body 11b or the second elastic body 12b. The changes in the negative phase resonance frequency and Q value with respect to the applied voltage when applied are also shown ("Sense electrode" in each figure).

As shown in FIG. 7(a), when the spring constant of the first elastic body 11b or the second elastic body 12b is directly changed, the resonance frequency of the opposite phase changes greatly, whereas the spring constant of the third elastic body 14b It was confirmed that even if the constant was changed, the anti-phase resonance frequency hardly changed. Moreover, as shown in FIG. 7(b), compared to directly changing the spring constant of the first elastic body 11b or the second elastic body 12b, it is better to change the spring constant of the third elastic body 14b. It was confirmed that the rate of change in value was large. From these results, by changing the spring constant of the third elastic body 14b, it is possible to change the resonance frequency of the adjustment vibration section 14 and adjust the Q value without almost affecting the resonance frequency of the opposite phase. It can be said that it can be done.

1 Support body 10 Tuning fork type vibrator 11 First vibrating part 11a First vibrating body 11b First elastic body 12 Second vibrating part 12a Second vibrating body 12b Second elastic body 13 Connecting part 14 Adjustment vibrating part 14a Third vibration Body 14b Third elastic body 14c Connection portion 15 Electrode

Claims (4)

A first vibrating part and a second vibrating part,
a connecting part connecting the first vibrating part and the second vibrating part;
an adjusting vibration part connected to the connecting part and vibrating along the vibration direction of the first vibration part and the second vibration part,
The first vibrating section includes a first vibrating body and a first elastic body connected to a support body and the first vibrating body,
The second vibrating section includes a second vibrating body and a second elastic body connected to the support body and the second vibrating body,
The spring constant of the first elastic body is k ₀ +ΔK, and the spring constant of the second elastic body is k ₀ −ΔK (k ₀ is the spring constant of the first elastic body and the spring constant of the second elastic body). is the average value of the spring constant, and ΔK is the deviation from the average value of the spring constant),
The adjusting vibrating part is connected at a neutral point between the first vibrating part and the second vibrating part of the connecting part,
The adjustment vibrating part includes a third vibrating body, a third elastic body having one end connected to the third vibrating body, and a connecting part connecting the connecting part and the third elastic body,
The adjusting vibrating part is a tuning fork type in which the first vibrating part and the second vibrating part vibrate in opposite phases to each other, and the adjusting vibrating part adjusts the resonance frequency by applying an electrostatic force to the third elastic body. vibrator. 2. The tuning fork type vibrator according to claim 1, further comprising an electrode for applying said electrostatic force . The tuning fork type vibrator according to claim 1 or 2, comprising a MEMS vibrator. 4. A method for adjusting a tuning fork type vibrator, comprising adjusting the resonance frequency of the adjusting vibration section of the tuning fork type vibrator according to any one of claims 1 to 3 , using the electrostatic force .