CN100511746C - Piezoelectric actuator - Google Patents

Abstract

A piezoelectric actuator (1) comprising a piezoelectric element (2) having a pair of electrodes formed on the surface of a piezoelectric ceramic as a drive source. The piezoelectric actuator (1) satisfies at least one of following requirements (a) to (c). (a) Variation width W<SUB>C</SUB> of apparent dynamic capacitance C (F) due to temperature variation falls within +-11% in a specific temperature range of -30 to 80 DEG C. (b) Variation width W<SUB>L</SUB> of displacement L (mum) due to temperature variation falls within +-14% in a specific temperature range of -30 to 80 DEG C. (c) Variation width W<SUB>L/C</SUB> of L/C due to temperature variation falls within +-12% in a specific temperature range of -30 to 80 DEG C, assuming that the apparent dynamic capacitance is C (F) and the displacement is L (mum).

Description

Piezoelectric-actuator

Technical field

The present invention relates to utilize the piezoelectric-actuator of the stacked executive component, piezoelectric transformer, supersonic engine, bimorph piezoelectric element, ultrasonic wave sonar, piezoelectric ultrasonic vibrator, piezoelectric buzzer, piezoelectric speaker etc. of reciprocal piezoelectric effect in the big electric field and electrostriction effect.

Background technology

The piezoelectric-actuator that has utilized piezoceramic material is to utilize displacement that reciprocal piezoelectric effect causes that electric energy is converted into the product of mechanical energy, is widely used in electronics and dynamo-electric field.

As the piezoelectric ceramic that above-mentioned piezoelectric-actuator uses, known for example Pb (ZrTi) O ₃System (below be called " PZT system "), BaTiO ₃Deng.The piezoelectric ceramic of PZT system is compared with other piezoelectric ceramic, has high piezoelectric property, accounts at present the major part of the piezoelectric ceramic of practicability.But,, therefore have the problem big to the load of environment owing to contain the higher lead oxide of vapour pressure (PbO).On the other hand, BaTiO ₃Although pottery is not leaded, to compare with PZT, piezoelectric property is lower, and Curie temperature is low to about 120 ℃, therefore has the problem that can not at high temperature use.

Above-mentioned piezoelectric-actuator general at least by the piezoelectric element of the piezoelectric ceramic that is provided with 1 pair of electrode and keep the holding member of this piezoelectric element, at adhesive member that keeps above-mentioned piezoelectric element on this holding member or the isobaric connection member of spring, be used for the lead terminal of above-mentioned piezoelectric element applied voltage and overlayed on resin between above-mentioned 1 pair of electrode or electric insulation component such as silicone oil constitutes.In above-mentioned piezoelectric-actuator, the piezoelectric element that piezoelectric ceramic constitutes is crimped by bonding or casting or spring etc., therefore has been subjected to the binding force (presetting load) of machinery under the state that does not carry out applied voltage.And, in above-mentioned piezoelectric-actuator, during to this piezoelectric-actuator applied voltage, follow voltage to rise, piezoelectric element produces displacement, and therefore above-mentioned mechanical binding force increases (load raises).

Therefore, the displacement of above-mentioned piezoelectric-actuator is owing to presetting load and load rising, and is different with the displacement performance appearance of piezoelectric element itself, and becomes littler value.

Have parameters such as temperature, driving electric field intensity, drive waveforms, driving frequency, Continuous Drive or driving at intermittence in the service condition of above-mentioned piezoelectric-actuator and the drive condition.As the general serviceability temperature scope of above-mentioned piezoelectric-actuator, the occasion in that common living environment is used is to the maximum about-30 ℃～80 ℃, and the occasion as automobile component uses is to the maximum about-40 ℃～160 ℃.And, the amplitude of driving electric field intensity is according to the difference of the purposes of piezoelectric-actuator difference to some extent, in piezoelectric buzzer, ultrasonic wave sonar, piezoelectric speaker etc. is below the 500V/mm, in supersonic engine, piezoelectric transformer, piezoelectric ultrasonic vibrator etc. is below the 1000V/mm, is below the 3000V/mm in stacked executive component.In addition, the occasion that drive waveforms drives in resonance is sinusoidal (sin) ripple, and occasion in addition is various waveforms such as sin ripple, trapezoidal wave, triangular wave, square wave, impulse wave.In addition, about driving frequency, supersonic engine, ultrasonic wave sonar, piezoelectric ultrasonic vibrator etc. are more than the 20kHz, are not enough 20kHz in addition.

The type of drive of above-mentioned piezoelectric-actuator can be categorized as: (1) is controlled displacement with voltage as parameter and is driven method, (2) with the constant voltage that drives and control displacement as parameter and control displacement with iunjected charge as parameter with the permanent energy drives method that drives and (3) and drive method with the permanent electric charge that drives to inject energy.

At this, the relation with regard to the displacement of each driving method and piezoelectric-actuator describes.

For adopting above-mentioned constant voltage to drive the type of drive of the piezoelectric-actuator of method, have following characteristics: the displacement when applied voltage rises and during decline has magnetic hysteresis.In this constant voltage driving method, there is the bigger problem of the fluctuation width of cloth of the displacement in the serviceability temperature scope.

In addition, the type of drive for the piezoelectric-actuator that adopts above-mentioned permanent energy drives method has following characteristics: when injecting energy and rise and the displacement in when decline have magnetic hysteresis.In this perseverance energy drives method, the fluctuation width of cloth of the displacement in the serviceability temperature scope is compared less with above-mentioned constant voltage driving method.

On the other hand, for adopting permanent electric charge to drive the type of drive of the executive component of method,, therefore be dominant can realizing that the most accurate displacement is controlled on this point because the displacement difference when iunjected charge rises and when descending is almost 0.But the problem that exists is: above-mentioned constant voltage driving method of the fluctuation amplitude ratio of the displacement in the serviceability temperature scope and above-mentioned permanent energy drives method are big.

Therefore, as the method for the fluctuation width of cloth of the temperature characterisitic that reduces piezoelectric-actuator and piezoceramic transducer, developed for example following technology.

That is, open the spy and disclose following piezoelectrics in the clear 60-1877 communique: the displacement of the output during with the applied voltage of piezoelectric unit with respect to variations in temperature be piezoelectric unit that increasing function changes, be the piezoelectric unit combination that subtraction function changes and carry out stacked piezoelectrics.

In addition, open in the flat 6-232465 communique, disclose a plurality of piezoceramics layers that displacement performance is different and carried out stacked laminated piezoelectric executive component the spy.

Open in the flat 5-284600 communique the spy, disclose temperature-compensating is connected with piezoelectric ceramic with capacitor or the piezoelectric element that is electrically connected in parallel.

Open the spy and to disclose a kind of piezoelectric element that produces electric charge according to pressure in the flat 7-79022 communique, this piezoelectric element is made of following material: alternately stacked piezoelectric body layer and dielectric layer, the electrostatic capacitance of dielectric layer is greater than the electrostatic capacitance of piezoelectric layer, and the temperature coefficient of dielectric layer has the characteristic opposite with the temperature coefficient of piezoelectric layer.

Open the spy and to disclose a kind of piezoelectric element that produces electric charge according to pressure in the flat 7-79023 communique, wherein, the piezoelectrics material dielectric material that electrostatic capacitance changes with having the temperature characterisitic opposite with the piezoelectrics material is mixed postforming and obtained piezoelectric element.

In addition, open in the flat 11-180766 communique the spy and to disclose the barium titanate series piezoelectric ceramic, this piezoelectric ceramic is the piezoelectric d of measuring with resonance method ₃₃Constant is more than the 300pC/N and in-30 ℃～85 ℃ piezoelectric d ₃₃The little constituent of rate of temperature change.

Opening what disclose barium titanate series in the 2003-128460 communique the spy is the Piezoelektrisches mehrschichtelement of internal electrode with Ni, wherein, and the piezoelectric d that the strain rate of the element when adding the electric field strength of 1kV/mm is calculated ₃₁The rate of temperature change of constant is little.

Yet, can not fully solve in the technology before these because the fluctuation of the placement property of the piezoelectric-actuator that variations in temperature causes etc.

Summary of the invention

The present invention aims to provide the piezoelectric-actuator that a kind of type of drive with piezoelectric-actuator temperature dependency irrelevant, displacement can reduce in view of problem proposes in the past.

The 1st invention is a kind of piezoelectric-actuator, it has the piezoelectric element that forms 1 pair of electrode on the surface of piezoelectric ceramic and constitute as drive source, it is characterized in that: to above-mentioned piezoelectric-actuator applied voltage, be the occasion that the electric field driven condition with uniform amplitude more than the 100V/mm makes its driving with electric field strength, above-mentioned piezoelectric-actuator satisfies at least one important document in the following important document (a)～(c).

(a) the apparent dynamic capacity C[F of following formula (1) expression] the fluctuation width of cloth WC[% that varies with temperature generation]-30 ℃～80 ℃ specific range of temperatures in be ± 11% with interior (wherein, C[F] be the apparent dynamic capacity of this piezoelectric-actuator, when this piezoelectric-actuator is connected with capacitors in series, and during to this piezoelectric-actuator and this capacitor applied voltage, C[F] can be by with the quantity of electric charge Q[C that puts aside in this capacitor] divided by the voltage V[V that is applied on this piezoelectric-actuator] calculate).

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (1)

(wherein, C _MaxBe illustrated in the maximum of-30 ℃～80 ℃ apparent dynamic capacity, C _MinBe illustrated in the minimum value of-30 ℃～80 ℃ apparent dynamic capacity).

(b) the displacement L[μ m of following formula (2) expression] the fluctuation width of cloth W that varies with temperature generation _L[%] is ± 14% with interior (wherein, L[μ m] be the displacement of this piezoelectric-actuator) in-30 ℃～80 ℃ specific range of temperatures.

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (2)

(wherein, L _MaxBe illustrated in the maximum of-30 ℃～80 ℃ displacement, Lmin is illustrated in the minimum value of-30 ℃～80 ℃ displacement).

(c) the fluctuation width of cloth W that varies with temperature generation of the L/C of following formula (3) expression _L/C(%) in-30 ℃～80 ℃ specific range of temperatures be ± 12% with interior (wherein, C[F] be the apparent dynamic capacity of this piezoelectric-actuator, L[μ m] be the displacement of this piezoelectric-actuator, when this piezoelectric-actuator is connected with capacitors in series, and during to this piezoelectric-actuator and this capacitor applied voltage, this C[F] can be by with the quantity of electric charge Q[C that puts aside in this capacitor] divided by the voltage V[V that is applied on this piezoelectric-actuator] calculate).

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (3)

(wherein, (L/C) _MaxBe illustrated in the maximum of-30 ℃～80 ℃ L/C, (L/C) _MinBe illustrated in the minimum value of-30 ℃～80 ℃ L/C).

In addition, the 2nd invention is a kind of electric executive component, it has the piezoelectric element that forms 1 pair of electrode on the surface of piezoelectric ceramic and constitute as drive source, it is characterized in that: to above-mentioned piezoelectric-actuator applied voltage, be the occasion that the electric field driven condition with uniform amplitude more than the 100V/mm makes its driving with electric field strength, above-mentioned piezoelectric-actuator satisfies at least one important document in following important document (j)～(1).

(j) the apparent dynamic capacity C[F of following formula (5) expression] the fluctuation width of cloth W that varies with temperature generation _C[%] in-30 ℃～160 ℃ specific range of temperatures be ± 30% with interior (wherein, C[F] be the apparent dynamic capacity of this piezoelectric-actuator, when this piezoelectric-actuator is connected with capacitors in series and during to this piezoelectric-actuator and this capacitor applied voltage, C[F] can be by with the quantity of electric charge Q[C that puts aside in this capacitor] divided by the voltage V[V that is applied on this piezoelectric-actuator] calculate).

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (5)

(wherein, C _MaxBe illustrated in the maximum of-30 ℃～160 ℃ apparent dynamic capacity, C _MinBe illustrated in the minimum value of-30 ℃～160 ℃ apparent dynamic capacity).

(k) the displacement L[μ m of following formula (6) expression] the fluctuation width of cloth W that varies with temperature generation _L[%] is ± 14% with interior (wherein, L[μ m] be the displacement of this piezoelectric-actuator) in-30 ℃～160 ℃ specific range of temperatures.

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (6)

(wherein, L _MaxBe illustrated in the maximum of-30 ℃～160 ℃ displacement, L _MinBe illustrated in the minimum value of-30 ℃～160 ℃ displacement).

(1) the fluctuation width of cloth W that varies with temperature generation of the L/C of following formula (7) expression _L/C(%) in-30 ℃～160 ℃ specific range of temperatures be ± 35% with interior (wherein, C[F] be the apparent dynamic capacity of this piezoelectric-actuator, L[μ m] be the displacement of this piezoelectric-actuator, when being, this piezoelectric-actuator and electric capacity is connected in series, and during to this piezoelectric-actuator and this capacitor applied voltage, this C[F] can be by with the quantity of electric charge Q[C that puts aside in this capacitor] divided by the voltage V[V that is applied on this piezoelectric-actuator] calculate).

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (7)

(wherein, (L/C) _MaxBe illustrated in the maximum of-30 ℃～160 ℃ L/C, (L/C) _MinBe illustrated in the minimum value of-30 ℃～160 ℃ L/C).

The piezoelectric-actuator of above-mentioned the 1st invention satisfies at least one important document in the above-mentioned important document (a)～(c).That is, in the piezoelectric-actuator of above-mentioned the 1st invention, the fluctuation width of cloth W that varies with temperature generation of above-mentioned apparent dynamic capacity C _C, above-mentioned displacement L the fluctuation width of cloth W that varies with temperature generation _L, or the fluctuation width of cloth W that varies with temperature generation of above-mentioned displacement/dynamic capacity (L/C) _L/CIn at least one in-30 ℃～80 ℃ specific range of temperatures the time in above-mentioned specific scope.

In addition, the piezoelectric-actuator of above-mentioned the 2nd invention satisfies at least one important document in above-mentioned important document (j)～(1).That is, in the piezoelectric-actuator of above-mentioned the 2nd invention, the fluctuation width of cloth W that varies with temperature generation of above-mentioned apparent dynamic capacity C _C, above-mentioned displacement L the fluctuation width of cloth W that varies with temperature generation _L, or the fluctuation width of cloth W that varies with temperature generation of above-mentioned displacement/dynamic capacity (L/C) _L/CIn at least one in-30 ℃～160 ℃ specific range of temperatures the time in above-mentioned specific scope.

Therefore, to vary with temperature the deviation of displacement of generation little for the piezoelectric-actuator of the above-mentioned the 1st and the 2nd invention.That is, even the occasion that above-mentioned piezoelectric-actuator uses under the violent environment of variations in temperature also can be brought into play the displacement of constant.Therefore, above-mentioned piezoelectric-actuator also can perform well in the product that automobile component etc. for example uses under the violent environment of variations in temperature.

Usually, the type of drive of piezoelectric-actuator has following driving method as mentioned above: (1) is controlled displacement with voltage as parameter and is driven method, (2) with the constant voltage that drives and control displacement as parameter and control displacement with iunjected charge as parameter with the permanent energy drives method that drives and (3) and drive method with the permanent electric charge that drives to inject energy.

At this,, describe according to every kind of type of drive of piezoelectric-actuator with regard to the temperature dependency of the displacement of piezoelectric-actuator.

At first, the displacement (Δ L1) of deciding the piezoelectric-actuator of driven is represented with following formula A1.

ΔL1＝D33×EF×L0 A1

In the formula, D33: dynamic strain amount [m/V], EF: maximum field intensity [V/m] and L0: the length [m] of the piezoelectric ceramic before the applied voltage.In addition, it is the occasion that the high pressure of the scope of 0～3000V/mm and the degree of not destroying insulation drives that the dynamic strain scale is shown in constant amplitude extra electric field intensity, with the displacement performance of the piezoelectric ceramic that produces on the direction that the applied voltage direction parallels, represent with following formula A2.

D33＝S/EF＝(ΔL1/L0)/(V/L0) A2

In the formula, S: maximum strain amount.In addition, D33 not only has interdependence to temperature, and electric field strength is also had interdependence.

Can know that from above-mentioned formula (A1) with (A2) displacement of piezoelectric-actuator (Δ L1) is long-pending proportional with dynamic strain amount D33 that exists with ... extra electric field intensity and extra electric field intensity.

In addition, there are the relation of following formula A3 and A4 in energy and electric charge and apparent dynamic capacity and applied voltage.

W＝1/2×C×V ² A3

Q＝C×V A4

In the formula, W: energy [J], C: apparent dynamic capacity [F], V: applied voltage [V] and Q: electric charge [C].

At this, when common piezoelectric-actuator is connected with capacitors in series, and when driving with the electric field strength 0～3000V/mm and the electric field strength of uniform amplitude of scope of not destroying the degree of insulation, apparent dynamic capacity C[F] be defined as the value that obtains divided by being applied to the voltage on the executive component with the quantity of electric charge of putting aside in the capacitor.Apparent dynamic capacity C comprise dielectric composition, the polarization reversal composition of piezoelectric ceramic at least and come self poling be rotated into the charging charge of branch, from the leakage current of the DC resistance component of piezoelectric ceramic.And apparent dynamic capacity C not only has interdependence to temperature, and electric field strength is also had interdependence.

Therefore, the displacement (Δ L2) of the piezoelectric-actuator of the occasion of permanent energy drives (W: constant) is by shown in the following formula A5, with the D33/C that exists with ... driving electric field intensity ^0.5With driving electric field intensity (=driving voltage/L0) long-pending proportional.

ΔL2＝D33×(2×W/C) ^0.5A5

At this, have following characteristics: when causing that owing to variations in temperature fluctuation takes place apparent dynamic capacity C, according to above-mentioned formula A3, driving electric field intensity self also fluctuates.

In addition, the displacement (Δ L3) of executive component of occasion that drives (Q: constant) at permanent electric charge is by shown in the following formula A6, with the D33/C that exists with ... driving electric field intensity and driving electric field intensity (=driving voltage/L0) long-pending proportional.

ΔL3＝D33×(Q/C) A6

At this, has following characteristics: again variations in temperature is arranged and cause that when fluctuation took place C, according to above-mentioned formula A4, extra electric field intensity self also fluctuateed.

Therefore, for the displacement fluctuation width of cloth of the executive component that reduces the serviceability temperature scope, preferably exist with ... D33, the D33/C of driving electric field intensity ^0.5, D33/C etc. temperature dependency less.

In addition, certainly, preferably as D33, the D33/C of displacement performance ^0.5, D33/C absolute value bigger.

Secondly, the apparent dynamic capacity of the occasion that drives with regard to permanent energy drives and permanent electric charge and the relation of driving voltage describe.

In the occasion of permanent energy drives (W: constant), the voltage that is carried in piezoelectric-actuator and applies on drive circuit (terminal voltage) is by shown in the following formula A7, with 1/C ^0.5Proportional.

V＝(2×W/C) ^0.5 A7

The terminal voltage of the occasion of permanent electric charge driving (Q: constant) is by shown in the following formula A8, and is proportional with 1/C.

V＝Q/C A8

When terminal voltage fluctuateed, in order to ensure the reliability of the proof voltage of piezoelectric-actuator and drive circuit, the design of carrying out the terminal voltage upper limit was necessary.In the design of executive component, be subjected to the restriction that distance can not reduce between the positive and negative electrode in order to prevent discharge between the electrode or side leakage or insulation breakdown.Therefore, the place of the lower limit of the terminal voltage in the serviceability temperature scope, placement property reduces.Therefore in circuit design, there is the problem of maximization and expensiveization for the proof voltage that improves circuit element.

Therefore, for the displacement performance that improves executive component and make drive circuit miniaturization and cost degradation, preferably exist with ... the 1/C of driving electric field intensity ^0.5, 1/C temperature dependency little.

In addition, if apparent dynamic capacity C converges to certain value, then terminal voltage also converges to certain value, if the D33/C when therefore driving electric field intensity is constant ^0.5Temperature dependency little, the temperature dependency of the displacement of the executive component in the control of then permanent energy can reduce.And if the temperature dependency of the D33/C when driving electric field intensity is constant is little, the temperature dependency of the displacement of the executive component of then permanent electric charge control can reduce.

Like this, in order to reduce the temperature dependency of piezoelectric-actuator, preferably in the serviceability temperature scope, have dynamic strain amount D33, apparent dynamic capacity C, the D33/C that produces under the electric field driven condition of constant amplitude ^0.5, and the fluctuation of D33/C less.

In the piezoelectric-actuator of above-mentioned the 1st invention, as described above, the fluctuation width of cloth W that varies with temperature generation of above-mentioned apparent dynamic capacity C _C, above-mentioned displacement L the fluctuation width of cloth W that varies with temperature generation _L, or the fluctuation width of cloth W that varies with temperature generation of above-mentioned displacement/apparent dynamic capacity (L/C) _L/CIn at least one in-30 ℃～80 ℃ specific range of temperatures respectively ± 11% with interior, ± 14% with interior and ± 12% with interior small range in.

In addition, in the piezoelectric-actuator of above-mentioned the 2nd invention, as described above, the fluctuation width of cloth W that varies with temperature generation of above-mentioned apparent dynamic capacity C _C, above-mentioned displacement L the fluctuation width of cloth W that varies with temperature generation _L, or the fluctuation width of cloth W that varies with temperature generation of above-mentioned displacement/apparent dynamic capacity (L/C) _L/CIn at least one in-30 ℃～160 ℃ specific range of temperatures respectively ± 30% with interior, ± 14% with interior and ± 35% with interior small range in.

Therefore, the piezoelectric-actuator and the type of drive such as constant voltage driving, permanent energy drives and permanent electric charge driving of above-mentioned the 1st invention and the 2nd invention are irrelevant, and the temperature dependency of displacement is less.That is,, still can bring into play placement property about equally even if serviceability temperature changes.

Such as previously discussed, according to the present invention, can provide the piezoelectric-actuator that can reduce with the type of drive of piezoelectric-actuator temperature dependency irrelevant, displacement.

Description of drawings

Fig. 1 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 1.

Fig. 2 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression embodiment 1.

Fig. 3 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 1.

Fig. 4 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 2.

Fig. 5 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression embodiment 2.

Fig. 6 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 2.

Fig. 7 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 3.

Fig. 8 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression embodiment 3.

Fig. 9 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 3.

Figure 10 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 4.

Figure 11 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression embodiment 4.

Figure 12 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 4.

Figure 13 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 5.

Figure 14 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression embodiment 5.

Figure 15 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression embodiment 5.

Figure 16 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 1.

Figure 17 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression comparative example 1.

Figure 18 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 1.

Figure 19 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 2.

Figure 20 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression comparative example 2.

Figure 21 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 2.

Figure 22 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 3.

Figure 23 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression comparative example 3.

Figure 24 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 3.

Figure 25 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 4.

Figure 26 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression comparative example 4.

Figure 27 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 4.

Figure 28 is the curve chart of temperature dependency of apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 5.

Figure 29 is the curve chart of temperature dependency of displacement of the piezoelectric-actuator of expression comparative example 5.

Figure 30 is the curve chart of temperature dependency of displacement/apparent dynamic capacity of the piezoelectric-actuator of expression comparative example 5.

Figure 31 is the curve chart of the temperature dependency of expression apparent dynamic capacity embodiment 6, piezoelectric-actuator (embodiment 1) and dynamic capacity.

Figure 32 is the curve chart of the temperature dependency of expression apparent dynamic capacity embodiment 6, piezoelectric-actuator (embodiment 4) and dynamic capacity.

Figure 33 is the curve chart of the temperature dependency of expression apparent dynamic capacity embodiment 6, piezoelectric-actuator (comparative example 1) and dynamic capacity.

Figure 34 is the curve chart of relation of the dynamic strain amount of 20 ℃ of the pole strength amplitude of expression each piezoelectric-actuator among the embodiment 7, that obtained by embodiment 1～embodiment 5 and temperature.

Figure 35 is the d of expression veneer among the embodiment 8, that made by embodiment 5 ₃₁The driving electric field intensity of measured value, 1000～2000V/mm shown in the embodiment 5 of temperature characterisitic the time the dynamic strain amount respectively with the curve chart of the result after 20 ℃ the value standardization.

Figure 36 is the key diagram of an example of the formation of expression piezoelectric-actuator of the present invention.

Figure 37 is the summary description figure of formation of the piezoelectric-actuator of expression embodiment 1.

Figure 38 is the key diagram of formation of the piezoelectric element of expression embodiment 1.

Figure 39 is the key diagram of formation of the piezoelectric element (veneer) that is made of a slice piezoelectric ceramic of expression embodiment 1.

Figure 40 is the key diagram that piezoelectric element (veneer) and internal electrical pole plate is carried out stacked state of expression embodiment 1.

Embodiment

Below, describe with regard to embodiment of the present invention.

The piezoelectric-actuator of above-mentioned the 1st invention satisfies above-mentioned important document (a)～(c).

In the above-mentioned important document (a), if the apparent dynamic capacity of above-mentioned piezoelectric-actuator is made as C[F], the varying with temperature of apparent dynamic capacity of then following formula (1) expression and the fluctuation width of cloth WC[% that produces] be in ± 11%-30 ℃～80 ℃ specific range of temperatures in.

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (1)

In above-mentioned important document (a), the capacitor that is arranged on 25 ℃ when above-mentioned piezoelectric-actuator and for example temperature is connected in series, and during to above-mentioned piezoelectric-actuator and above-mentioned capacitor applied voltage, above-mentioned apparent dynamic capacity can be by with the quantity of electric charge Q[C that puts aside in the above-mentioned capacitor] divided by the voltage V[V that is applied on the above-mentioned piezoelectric-actuator] calculate.

In the above-mentioned important document (b), if the displacement of above-mentioned piezoelectric-actuator is made as L[μ m], the fluctuation width of cloth W that varies with temperature generation of the displacement L of then following formula (2) expression _LIn-30 ℃～80 ℃ specific range of temperatures, be in ± 14%.

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (2)

In addition, in the above-mentioned important document (c), the apparent dynamic capacity of above-mentioned piezoelectric-actuator is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m] time, the fluctuation width of cloth W that varies with temperature generation of the L/C of then following formula (3) expression _L/CIn-30 ℃～80 ℃ specific range of temperatures, be in ± 12%.

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (3)

In above-mentioned important document (c), the capacitor that is arranged on 25 ℃ when above-mentioned piezoelectric-actuator and for example temperature is connected in series, and during to above-mentioned piezoelectric-actuator and above-mentioned capacitor applied voltage, above-mentioned apparent dynamic capacity can be by with the quantity of electric charge Q[C that puts aside in the above-mentioned capacitor] divided by the voltage V[V that is applied on the above-mentioned piezoelectric-actuator] calculate.

Do not satisfy any one occasion in the above-mentioned important document (a)～(c) at above-mentioned piezoelectric-actuator, promptly in the time of-30 ℃～80 ℃, above-mentioned fluctuation width of cloth W _CDepart from ± 11% with interior scope, above-mentioned fluctuation width of cloth W _LDepart from ± 14% with interior scope and above-mentioned fluctuation width of cloth W _L/CDepart from ± 12% occasion with interior scope, the temperature dependency of the above-mentioned piezoelectric-actuator when temperature is-30 ℃～80 ℃ might increase.

Above-mentioned piezoelectric-actuator preferably satisfy above-mentioned important document (a) and above-mentioned important document (b) these two.

In this occasion, can further reduce the temperature dependency of above-mentioned piezoelectric-actuator.

In addition, above-mentioned piezoelectric-actuator preferably satisfies whole important documents of above-mentioned important document (a)～(c).

In this occasion, can further reduce the temperature dependency of above-mentioned piezoelectric-actuator.

In addition, in above-mentioned piezoelectric-actuator, the above-mentioned fluctuation width of cloth WC[% that varies with temperature generation of dynamic capacity] preferably be in ± 12% in-40 ℃～80 ℃ specific range of temperatures.

In addition, the above-mentioned fluctuation width of cloth WL that varies with temperature generation of above-mentioned displacement L preferably is in ± 14% in-40 ℃～80 ℃ specific range of temperatures.

In addition, the above-mentioned fluctuation width of cloth W that varies with temperature generation of L/C _L/CIn-40 ℃～80 ℃ specific range of temperatures, be in ± 13% preferably.

Like this, in-40 ℃～80 ℃ temperature range, above-mentioned fluctuation width of cloth W _C, fluctuation width of cloth W _L, fluctuation width of cloth W _L/CIn the time of in above-mentioned specific like that scope, even in-40 ℃～80 ℃ specific range of temperatures, the temperature dependency of the displacement of above-mentioned piezoelectric-actuator also can reduce.

Above-mentioned piezoelectric-actuator preferably satisfies following important document (d).

(d) if above-mentioned apparent dynamic capacity is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m], the L/C of then following formula (4) expression ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5Be ± 12% with interior (wherein, L/C in-30 ℃～80 ℃ specific range of temperatures ^0.5Displacement L[μ m for above-mentioned piezoelectric-actuator] with above-mentioned apparent dynamic capacity C[F] the ratio of square root).

W _L/C ^0.5(％)＝[{2×(L/C ^0.5) _max/((L/C ^0.5) _max+(L/C ^0.5) _min)}—1]×100

(4)

(in the formula, (L/C ^0.5) _MaxL/C when the expression temperature is-30 ℃～80 ℃ ^0.5Maximum, (L/C ^0.5) _MinL/C when the expression temperature is-30 ℃～80 ℃ ^0.5Minimum value).

Do not satisfy the occasion of above-mentioned important document (d), i.e. L/C at above-mentioned piezoelectric-actuator ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5Exceed in-30 ℃～80 ℃ specific range of temperatures ± 12% occasion, the temperature dependency of the displacement of above-mentioned piezoelectric-actuator might increase.

In addition, L/C ^0.5The above-mentioned fluctuation width of cloth W that varies with temperature generation _L/C ^0.5In-40 ℃～80 ℃ specific range of temperatures, be in ± 12% preferably.

In this occasion, even in-40 ℃～80 ℃ temperature range, also can reduce the temperature dependency of the displacement of above-mentioned piezoelectric-actuator.

Above-mentioned piezoelectric-actuator preferably satisfies following important document (e).

(e) in-30 ℃～80 ℃ specific range of temperatures, be more than the 250pm/V by the dynamic strain amount of calculating divided by electric field strength in the strain of extra electric field direction with above-mentioned piezoelectric-actuator.

Do not satisfy the occasion of above-mentioned important document (e) at above-mentioned piezoelectric-actuator, the occasion of promptly above-mentioned dynamic strain amount not enough 250pm/V in-30 ℃～80 ℃ specific range of temperatures, the displacement of above-mentioned piezoelectric-actuator might reduce.

In addition, above-mentioned dynamic strain amount is more than the 250pm/V in-40 ℃～80 ℃ specific range of temperatures preferably.

In this occasion, in-40 ℃～80 ℃ temperature range, the displacement of above-mentioned piezoelectric-actuator also can increase.

Secondly, above-mentioned piezoelectric-actuator preferably satisfies following important document (f).

(f) the above-mentioned fluctuation width of cloth WC[% that varies with temperature generation of above-mentioned apparent dynamic capacity C] be in ± 35% in-30 ℃～160 ℃ specific range of temperatures.

In addition, above-mentioned piezoelectric-actuator preferably satisfies following important document (g).

(g) the above-mentioned fluctuation width of cloth WL that varies with temperature generation of the displacement L of above-mentioned piezoelectric-actuator is in ± 14% in-30 ℃～160 ℃ specific range of temperatures.

In addition, above-mentioned piezoelectric-actuator preferably satisfies following important document (h).

(h) if apparent dynamic capacity is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m], the above-mentioned fluctuation width of cloth W that varies with temperature generation of L/C then _L/CIn-30 ℃～160 ℃ specific range of temperatures, be in ± 35%.

In addition, above-mentioned piezoelectric-actuator preferably satisfies following important document (i).

(i) if apparent dynamic capacity is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m], L/C then ^0.5The above-mentioned fluctuation width of cloth W that varies with temperature generation _L/C ^0.5In-30 ℃～160 ℃ specific range of temperatures, be in ± 20%.

Satisfy the occasion of any one the above important document in above-mentioned (f)～(i) important document at above-mentioned piezoelectric-actuator, can further improve the temperature dependency of above-mentioned piezoelectric-actuator.Promptly in this occasion, can in being-30 ℃～160 ℃ broader temperature range, temperature reduce the temperature dependency of the displacement of above-mentioned piezoelectric-actuator.

Secondly, in above-mentioned the 2nd invention, above-mentioned piezoelectric-actuator satisfies above-mentioned important document (j)～(1).

In the above-mentioned important document (j), if the apparent dynamic capacity of above-mentioned piezoelectric-actuator is made as C[F] time, the fluctuation width of cloth W that varies with temperature generation of the apparent dynamic capacity of then following formula (5) expression _C[%] is in ± 30% in-30 ℃～160 ℃ specific range of temperatures.

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (5)

(wherein, C _MaxBe illustrated in the maximum of-30 ℃～160 ℃ apparent dynamic capacity, C _MinBe illustrated in the minimum value of-30 ℃～160 ℃ apparent dynamic capacity).

In above-mentioned important document (j), the capacitor that is arranged on 25 ℃ when above-mentioned piezoelectric-actuator and for example temperature is connected in series, and during to above-mentioned piezoelectric-actuator and above-mentioned capacitor applied voltage, above-mentioned apparent dynamic capacity can be by with the quantity of electric charge Q[C that puts aside in the above-mentioned capacitor] divided by the voltage V[V that is applied on the above-mentioned piezoelectric-actuator] calculate.

In the above-mentioned important document (k), if the displacement of above-mentioned piezoelectric-actuator is made as L[μ m] time, the fluctuation width of cloth W that varies with temperature generation of the displacement L of then following formula (6) expression _LIn-30 ℃～160 ℃ specific range of temperatures, be in ± 14%.

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (6)

(in the formula, L _MaxBe illustrated in the maximum of-30 ℃～160 ℃ displacement, Lmin is illustrated in the minimum value of-30 ℃～160 ℃ displacement).

In the above-mentioned important document (1), if the apparent dynamic capacity of above-mentioned piezoelectric-actuator is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m] time, the fluctuation width of cloth W that varies with temperature generation of the L/C of then following formula (7) expression _L/CIn-30 ℃～160 ℃ specific range of temperatures, be in ± 35%.

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (7)

(in the formula, (L/C) _MaxBe illustrated in the maximum of-30 ℃～160 ℃ L/C, (L/C) _MinBe illustrated in the minimum value of-30 ℃～160 ℃ L/C).

In above-mentioned important document (1), the capacitor that is arranged on 25 ℃ when above-mentioned piezoelectric-actuator and for example temperature is connected in series, and during to above-mentioned piezoelectric-actuator and above-mentioned capacitor applied voltage, above-mentioned apparent dynamic capacity can be by with the quantity of electric charge Q[C that puts aside in the above-mentioned capacitor] divided by the voltage V[V that is applied on the above-mentioned piezoelectric-actuator] calculate.

Do not satisfy any one occasion in above-mentioned important document (j)～(1) at above-mentioned piezoelectric-actuator, promptly when temperature is-30 ℃～160 ℃, above-mentioned fluctuation width of cloth W _CDepart from ± 30% with interior scope, above-mentioned fluctuation width of cloth W _LDepart from ± 14% with interior scope and above-mentioned fluctuation width of cloth W _L/CDepart from ± 35% occasion with interior scope, the temperature dependency of the above-mentioned piezoelectric-actuator when temperature is-30 ℃～160 ℃ might increase.

Above-mentioned piezoelectric-actuator preferably satisfy above-mentioned important document (j) and above-mentioned important document (k) these two.

In this occasion, can further reduce the temperature dependency of above-mentioned piezoelectric-actuator.

Above-mentioned piezoelectric-actuator preferably satisfies whole important documents of above-mentioned important document (j)～(1).

In this occasion, can further reduce the temperature dependency of above-mentioned piezoelectric-actuator.

In addition, in above-mentioned piezoelectric-actuator, the above-mentioned fluctuation width of cloth W that varies with temperature generation of apparent dynamic capacity _C[%] is in ± 35% in-40 ℃～160 ℃ specific range of temperatures preferably.

In addition, the fluctuation width of cloth W that varies with temperature generation of above-mentioned displacement L _LIn-40 ℃～160 ℃ specific range of temperatures, be in ± 14% preferably.

In addition, the above-mentioned fluctuation width of cloth W that varies with temperature generation of L/C _L/CIn-40 ℃～160 ℃ specific range of temperatures, be in ± 35% preferably.

Like this, in-40 ℃～160 ℃ temperature range, above-mentioned fluctuation width of cloth W _C, fluctuation width of cloth W _L, fluctuation width of cloth W _L/COccasion in above-mentioned like that specific scope is even also can reduce the temperature dependency of the displacement of above-mentioned piezoelectric-actuator in-40 ℃～160 ℃ temperature range.

Above-mentioned piezoelectric-actuator preferably satisfies following important document (m).

(m) if above-mentioned apparent dynamic capacity is made as C[F], the displacement of above-mentioned piezoelectric-actuator is made as L[μ m], the L/C of then following formula (8) expression ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5In-30 ℃～160 ℃ specific range of temperatures, be in ± 20%.

W _L/C ^0.5(％)＝[{2×(L/C ^0.5) _max/((L/C ^0.5) _max+(L/C ^0.5) _min)}—1]×100 (8)

(in the formula, (L/C ^0.5) _MaxBe illustrated in-30 ℃～160 ℃ the interior L/C of specific range of temperatures ^0.5Maximum, (L/C ^0.5) _MinBe illustrated in-30 ℃～160 ℃ the interior L/C of specific range of temperatures ^0.5Minimum value).

Do not satisfy the occasion of above-mentioned important document (m), i.e. L/C at above-mentioned piezoelectric-actuator ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5Exceed in-30 ℃～160 ℃ specific range of temperatures ± 20% occasion, the temperature dependency of the displacement of above-mentioned piezoelectric-actuator might increase.

In addition, L/C ^0.5The above-mentioned fluctuation width of cloth W that varies with temperature generation _L/C ^0.5In-40 ℃～160 ℃ specific range of temperatures, be in ± 20% preferably.

In this occasion,, also can reduce the temperature dependency of the displacement of above-mentioned piezoelectric-actuator even in-40 ℃～160 ℃ temperature range.

Above-mentioned piezoelectric-actuator preferably satisfies following important document (n).

(n) in-30 ℃～160 ℃ specific range of temperatures, be more than the 250pm/V by the dynamic strain amount of calculating divided by electric field strength in the strain of extra electric field direction with above-mentioned piezoelectric-actuator.

Do not satisfy the occasion of above-mentioned important document (n) at above-mentioned piezoelectric-actuator, the occasion of promptly above-mentioned dynamic strain amount not enough 250pm/V in-30 ℃～160 ℃ specific range of temperatures, the displacement of above-mentioned piezoelectric-actuator might reduce.

In addition, above-mentioned dynamic strain amount is more than the 250pm/V in-40 ℃～160 ℃ temperature range preferably.

In this occasion, even in-40 ℃～160 ℃ temperature range, the displacement of above-mentioned piezoelectric-actuator also can increase.

In addition, in the above-mentioned the 1st and the 2nd invention, above-mentioned piezoelectric-actuator has the piezoelectric element that forms 1 pair of electrode on the surface of piezoelectric ceramic and constitute as drive source.

Above-mentioned piezoelectric ceramic preferably constitutes by containing at least a alkali metal containing piezoelectric ceramic that is selected among Li, K and the Na.

In this occasion, in temperature is that leakage current when driving under the hot environment more than 80 ℃ more increases, and temperature is that the fluctuation width of cloth of above-mentioned " apparent dynamic capacity " more than 80 ℃ is that the fluctuation width of cloth of " electrostatic capacitance " and " dynamic capacity " more than 80 ℃ is bigger than temperature also.Therefore, in this occasion, by make the fluctuation width of cloth that limits as parameter with apparent dynamic capacity satisfy the above-mentioned important document (a) of above-mentioned the 1st invention and/or (c), above-mentioned important document (j) and/or (1) of above-mentioned the 2nd invention, can bring into play for example driving surely and decide the above-mentioned action effect that the temperature dependency of the displacement of electric charge driving reduces more significantly.

In addition, above-mentioned piezoelectric ceramic is preferably: in the whole serviceability temperature scope of above-mentioned piezoelectric-actuator (for example temperature-30 ℃～160 ℃), be 1 * 10 than resistance ⁶More than the Ω m.At this moment, can prevent because the destruction of the above-mentioned piezoelectric ceramic that resistance heating causes.More preferably: above-mentioned piezoelectric ceramic is 1 * 10 than resistance in the above-mentioned serviceability temperature scope of above-mentioned piezoelectric-actuator ⁸More than the Ω m.In this occasion, the life-span of above-mentioned piezoelectric-actuator can prolong more.

In addition, above-mentioned piezoelectric ceramic is preferably not leaded.

In this occasion, can make the above-mentioned piezoelectric-actuator that does not contain the big lead of carrying capacity of environment.That is, can improve above-mentioned piezoelectric-actuator to environmentAL safety.

In addition, above-mentioned piezoelectric ceramic is preferably: by with general formula { Li _x(K _1-yNa _y) _1-x{ Nb _{1-z- w}Ta _zSb _wO ₃(in the formula, 0≤x≤0.2,0≤y≤1,0≤z≤0.4,0≤w≤0.2, x+z+w〉0) the isotropism perovskite-type compounds of expression constitutes as the polycrystal of principal phase, and the crystal orientation piezoelectric ceramic that is in state of orientation by the particular crystal plane that constitutes this multicrystal each crystal grain constitutes simultaneously.

In this occasion, the piezoelectric-actuator that can easily realize satisfying the piezoelectric-actuator of above-mentioned important document (a)～(i) and satisfy above-mentioned important document (j)～(n) important document.

Above-mentioned crystal orientation piezoelectric ceramic is by being potassium-sodium niobate (K with a kind of of isotropism perovskite-type compounds _1-yNa _yNbO ₃) as basic composition, and the Ta of the part amount of being prescribed of the Li of the part amount of being prescribed of A bit element (K, Na) displacement and/or B bit element (Nb) and/or Sb displacement and the material that obtains constitutes.In above-mentioned general formula, " x+z+w〉0 " expression contains at least a getting final product among Li, Ta and the Sb as substitutional element.

In addition, in above-mentioned general formula, K that contains in " y " expression crystal orientation piezoelectric ceramic and the ratio of Na.In crystal orientation piezoelectric ceramic of the present invention, as A bit element, at least one that contains K or Na gets final product.Promptly K and the ratio y of Na are not particularly limited, can get the arbitrary value below 1 more than 0.In order to obtain high placement property, the value of y is preferably more than 0.05 below 0.75, more preferably more than 0.20 below 0.70, more preferably more than 0.35 below 0.65, be preferably again more than 0.40 below 0.60, more more preferably more than 0.42 below 0.60.

The K of " x " expression Li displacement A bit element and/or the replacement amount of Na.When the part of K and/or Na is replaced by Li, the piezoelectric property that can be improved etc., improve Curie temperature with and/or promote the effect of densification.The value of X specifically is preferably more than 0 below 0.2.Surpass at 0.2 o'clock in the x value, placement property reduces, and is therefore unsatisfactory.The x value is preferably more than 0 below 0.15, more preferably more than 0 below 0.10.

The replacement amount of the Nb of " z " expression Ta displacement B bit element.When the part of Nb is replaced by Ta, the effect of the placement property that can be improved etc.The value of z specifically is preferably more than 0 below 0.4.The z value surpasses at 0.4 o'clock, and Curie temperature reduces, and the piezoelectric of using as household electrical appliance and automobile uses comparatively difficulty, and is therefore unsatisfactory.The z value is preferably more than 0 below 0.35, more preferably more than 0 below 0.30.

In addition, the replacement amount of the Nb of " w " expression Sb displacement B bit element.When the part of Nb is replaced by Sb, the effect of the placement property that can be improved etc.The value of w specifically is preferably more than 0 below 0.2.The w value surpasses at 0.2 o'clock, placement property with and/or Curie temperature reduce, so unsatisfactory.The w value is preferably more than 0 below 0.15.

In addition, in the above-mentioned crystal orientation piezoelectric ceramic, along with dropping to low temperature from high temperature, the variation of cube crystalline substance → regular crystal (the 1st crystalline phase transition temperature=Curie temperature), regular crystal → iris (the 2nd crystalline phase transition temperature), iris → rhombohedral crystal (the 3rd crystalline phase transition temperature) takes place in crystalline phase.In the temperature province that is higher than the 1st crystalline phase transition temperature, become a cube crystalline substance, so the placement property disappearance, and, becoming iris in the temperature province that is lower than the 2nd crystalline phase transition temperature, the temperature dependency of displacement and apparent dynamic electrostatic capacitance increases.Therefore, preferably by making the 1st crystalline phase transition temperature be higher than the serviceability temperature scope and the 2nd crystalline phase transition temperature is lower than the serviceability temperature scope, can make piezoelectric ceramic is regular crystal in whole serviceability temperature scope.

But, as the potassium-sodium niobate (K of the basic composition of above-mentioned crystal orientation piezoelectric ceramic _{1- y}Na _yNbO ₃), according to " American Ceramic Society's magazine: Journal of American CeramicSociety ", the U.S., nineteen fifty-nine, p.438～443 and No. 2976246 specifications of United States Patent (USP) the 42nd volume [9], along with dropping to low temperature from high temperature, the variation of cube crystalline substance → regular crystal (the 1st crystalline phase transition temperature=Curie temperature), regular crystal → iris (the 2nd crystalline phase transition temperature), iris → rhombohedral crystal (the 3rd crystalline phase transition temperature) takes place in crystalline phase.And the 1st crystalline phase transition temperature when " y=0.5 " is that about 420 ℃, the 2nd crystalline phase transition temperature are that about 190 ℃, the 3rd crystalline phase transition temperature are-150 ℃ approximately.Therefore, the temperature province of regular crystal is 190～420 ℃ a scope, and is inconsistent with-40 ℃～160 ℃ of the serviceability temperature scope of industrial products.

On the other hand, in the above-mentioned crystal orientation piezoelectric ceramic, for the potassium-sodium niobate (K of basic composition _{1 -y}Na _yNbO ₃), the amount of the substitutional element by making Li, Ta, Sb changes, and can freely change the 1st crystalline phase transition temperature and the 2nd crystalline phase transition temperature.

Y=0.4～0.6 when being maximum for piezoelectric property has been carried out Li, Ta, the replacement amount of Sb and the multiple regression (multiple regression) of crystalline phase transition temperature measured value and has been analyzed, and the results are shown in following formula B1, formula B2.

Know that from formula B1 and formula B2 the Li replacement amount has the effect that makes the 1st crystalline phase transition temperature raise and the 2nd crystalline phase transition temperature is reduced.In addition, Ta and Sb have the effect that makes the 1st crystalline phase transition temperature reduce and the 2nd crystalline phase transition temperature is reduced.

The 1st crystalline phase transition temperature=(388+9x-5z-17w) ± 50[℃] (formula B1)

The 2nd crystalline phase transition temperature=(190-18.9x-3.9z-5.8w) ± 50[℃] (formula B2)

Therefore the 1st crystalline phase transition temperature is the temperature of piezoelectricity complete obiteration, and dynamic capacity sharply increases in its vicinity, is preferably more than (environment for use ceiling temperature+60 of product ℃).The 2nd crystalline phase transition temperature only is the temperature that crystalline phase changes, piezoelectricity does not disappear, therefore be set in can not produce the temperature dependency of displacement or dynamic capacity in the dysgenic scope and get final product, so be preferably below (environment for use lower limit temperature+40 of product ℃).

On the other hand, the environment for use ceiling temperature of product is different according to purposes, is respectively 60 ℃, 80 ℃, 100 ℃, 120 ℃, 140 ℃, 160 ℃ etc.The environment for use lower limit temperature of product is respectively-30 ℃ ,-40 ℃ etc.

Therefore, because the 1st crystalline phase transition temperature shown in the above-mentioned formula B1 is preferably more than 120 ℃, so " x ", " z ", " w " preferably satisfy (388+9x-5z-17w)+50 〉=120.

And, because the 2nd crystalline phase transition temperature shown in the formula B2 is preferably below 10 ℃, so " x ", " z ", " w " preferably satisfy (190-18.9x-3.9z-5.8w)-50≤10.

That is, in above-mentioned crystal orientation piezoelectric ceramic, above-mentioned general formula: { Li _x(K _1-yNa _y) _1-x{ Nb _{1 -z-w}Ta _zSb _wO ₃In x, y and the z relation that preferably satisfies following formula (9) and formula (10).

9x—5z—17w≥—318 (9)

—18.9x—3.9z—5.8w≤—130 (10)

In addition, there is the occasion that the isotropism perovskite-type compounds (a KNN based compound) only represented by above-mentioned general formula constitutes in above-mentioned crystal orientation piezoelectric ceramic and adds other element on one's own initiative or by the occasion of other element substitution.

In the former occasion, preferably only constitute by a KNN based compound, as long as but can keep the crystal structure of isotropism Ca-Ti ore type and various characteristicses such as sintering characteristic, piezoelectric property are had no adverse effects, then also can contain other element or other phase.Be especially in use in the raw material of making above-mentioned crystal orientation piezoelectric ceramic, the sneaking into of containing the purity that can buy from market is 99% to 99.9% the raw material of industry of impurity is inevitable.For example, at the Nb of one of raw material of above-mentioned crystal orientation piezoelectric ceramic ₂O ₅In, as the impurity from raw ore or manufacture method, some occasion contains the Ta of maximum not enough 0.1wt%, the F of maximum not enough 0.15wt%.In addition, will narrate in embodiment 1 described later, in the occasion of the use Bi of manufacturing process, it is sneaked into is inevitable.

Occasion the latter, for example can have the temperature dependency that reduces apparent dynamic capacity, the effect that improves displacement by adding Mn, but also has the effect that lowers dielectric loss tan δ, improves mechanical quality coefficient Qm, therefore, can obtain Ideal Characteristics as the driving executive component of resonance.

In addition, in above-mentioned crystal orientation piezoelectric ceramic, constitute the isotropism perovskite-type compounds represented with above-mentioned general formula and be in state of orientation as the particular crystal plane of multicrystal each crystal grain of principal phase.Wherein, the particular crystal plane that is orientated in the above-mentioned crystal grain is preferably cube (pseudo-cubic) { the 100} face of plan.

In addition, so-called " intend cube { HKL} " is meant that the structure of isotropism perovskite-type compounds is generally regular crystal, iris, three prismatic crystals etc., with cube crystalline phase than slightly distortion, but because this distortion just little by little, therefore is taken as cube crystalline substance and represents with Miller index.

In this occasion, can further increase the displacement of above-mentioned piezoelectric-actuator, can reduce the temperature dependency of apparent dynamic capacity simultaneously.

In addition, { the 100} face carries out the occasion of planar orientation, average orientation F (HKL) expression based on Lao Tegaierding (Lotgering) method that the degree of planar orientation can be represented with following mathematical expression 1 for intending cube.

Mathematical expression 1

$F\left(\mathrm{HKL}\right)=\frac{\frac{{\mathrm{\&Sigma;}}^{,}I\left(\mathrm{HKL}\right)}{\mathrm{\&Sigma;I}\left(\mathrm{hkl}\right)}-\frac{{\mathrm{\&Sigma;}}^{,}{I}_0\left(\mathrm{HKL}\right)}{\mathrm{\&Sigma;}{I}_0\left(\mathrm{hkl}\right)}}{1-\frac{{\mathrm{\&Sigma;}}^{,}{I}_0\left(\mathrm{HKL}\right)}{\mathrm{\&Sigma;}{I}_0\left(\mathrm{hkl}\right)}}\&times;100(\%)$

In addition, in mathematical expression 1, ∑ I (hk1) is the summation to the X-ray diffraction intensity of all crystal faces (hk1) of crystal orientation piezoelectric ceramic mensuration, and ∑ I0 (hk1) is the summation to the X-ray diffraction intensity with all crystal faces (hk1) of measuring with the same no orientation ceramic of forming of crystal orientation piezoelectric ceramic.And, ∑ ' I (HKL) is the summation of X-ray diffraction intensity of the particular crystal plane (HKL) of crystallographical equivalent that the crystal orientation piezoelectric ceramic is measured.∑ ' I ₀(HKL) be summation to the X-ray diffraction intensity of particular crystal plane (HKL) with crystallographical equivalent of measuring with the same no orientation ceramic of forming of crystal orientation piezoelectric ceramic.

Therefore, constituting multicrystal each crystal grain for there not being the occasion of orientation, average orientation F (HKL) is 0%.And in (HKL) face occasion parallel-oriented with respect to the mensuration face that constitutes multicrystal all crystal grains, average orientation F (HKL) is 100%.

Usually, the ratio of the crystal grain of orientation is many more, can obtain high characteristic more.For example, make particular crystal plane carry out the occasion of planar orientation, in order to obtain high piezoelectric property etc., the average orientation F (HKL) based on Lao Tegaierding (Lotgering) method that is represented by above-mentioned mathematical expression 1 is preferably more than 30%, more preferably more than 50%, more preferably more than 70%.In addition, make the preferably vertical face of particular crystal plane of its orientation with polaxis.For example, be the occasion of regular crystal in the crystallization of above-mentioned perovskite-type compounds, make the particular crystal plane of its orientation be preferably cube { the 100} face of plan.

That is, above-mentioned crystal orientation piezoelectric ceramic is preferably: cube { degree of orientation of 100} face is more than 30% to the plan that is obtained by Lao Tegaierdingfa, and in 10 ℃～160 ℃ temperature range, crystallization is regular crystal (22 of a claim the).

In addition, make particular crystal plane carry out the occasion of axle orientation, the degree of its orientation can not be used the degree of orientation same with planar orientation (mathematical expression 1) definition.But,, can adopt the average orientation (the axle degree of orientation) of the Lotgering method that relates to (HKL) diffraction to represent the degree that axle is orientated to carry out the occasion of X-ray diffraction perpendicular to the face of axis of orientation.In addition, particular crystal plane roughly carry out fully axle orientation formed body the axle degree of orientation and particular crystal plane is roughly carried out the axle degree of orientation that the formed body of planar orientation measures fully is same degree.

Secondly, just use the characteristic of the piezoelectric-actuator of above-mentioned crystal orientation piezoelectric ceramic to describe.

At the piezoelectric-actuator that above-mentioned crystal orientation piezoelectric ceramic is used for drive source, can will in-30 ℃～160 ℃ temperature range, in electric field strength, be more than the 100V/mm and the dynamic strain amount D33 that produces under the electric field driven condition with uniform amplitude below the electric field strength that can not destroy insulation is controlled to be more than the 250pm/V.If will form and technology is further optimized, then can be controlled to be more than the 300pm/V, and then be more than the 350pm/V, further be more than the 400pm/V again, further be more than the 450pm/V again, further be more than the 500pm/V.

In addition, the fluctuation width of cloth of displacement (the fluctuation width of cloth of=dynamic strain amount) is if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 14%.If will form and technology is further optimized, then can be controlled to be ± below 12%, and then be below ± 10%, further be below ± 8%.

In addition, in-30 ℃～80 ℃ temperature range, the fluctuation width of cloth (the fluctuation width of cloth of=dynamic strain amount) of the displacement that produces under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm is if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 14%.If will form and technology is further optimized, then can be controlled to be ± below 12%, and then be below ± 9%, further be below ± 7%, further be below ± 5% again, further be below ± 4% again.Therefore, can obtain deciding the little executive component of temperature dependency of the displacement of driven.

In addition, at the piezoelectric-actuator that above-mentioned crystal orientation piezoelectric ceramic is used for drive source, in-30 ℃～160 ℃ temperature range, the fluctuation width of cloth of the apparent dynamic capacity that produces under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm is if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 35%.If will form and technology is further optimized, then can be controlled to be ± below 32%, and then be below ± 30%, further be below ± 28%.

In addition, in-30 ℃～80 ℃ temperature range, the fluctuation width of cloth of the apparent dynamic capacity that produces under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm is if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 11%.If will form and technology is further optimized, then can be controlled to be ± below 9%, and then be below ± 7%, further be below ± 5%, further be below ± 4% again.Therefore, decide the occasion that electric charge drives and drives surely, can obtain the little executive component of temperature dependency of terminal voltage.

In addition, at the piezoelectric-actuator that above-mentioned crystal orientation piezoelectric ceramic is used for drive source, in-30 ℃～160 ℃ temperature range, the fluctuation width of cloth of the displacement/apparent dynamic capacity that under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm, produces if with

(maximum-minimum value)/2 are fiducial value, then can be controlled to be ± below 35%.If will form and technology is further optimized, then can be controlled to be ± below 30%, and then be below ± 25%.

In addition, in-30 ℃～80 ℃ temperature range, if the fluctuation width of cloth of the displacement/apparent dynamic capacity that produces under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm is a fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 12%.If will form and technology is further optimized, then can be controlled to be ± below 9%, and then be below ± 7%.Therefore, can obtain deciding the little executive component of temperature dependency of displacement in the electric charge driving.

In addition, at the piezoelectric-actuator that above-mentioned crystal orientation piezoelectric ceramic is used for drive source, in-30 ℃～160 ℃ temperature range, displacement/(the apparent dynamic capacity) that under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm, produces ^0.5The fluctuation width of cloth if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 20%.If will form and technology is further optimized, then can be controlled to be ± below 15%.

In addition, in-30 ℃～80 ℃ temperature range, displacement/(the apparent dynamic capacity) that under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm, produces ^0.5The fluctuation width of cloth if be fiducial value with (maximum-minimum value)/2, then can be controlled to be ± below 12%.If will form and technology is further optimized, then can be controlled to be ± below 9%, and then be below ± 7%.Therefore, can be driven surely in the little executive component of temperature dependency of displacement.

In addition, displacement generation the whole of source of above-mentioned piezoelectric-actuator are made of above-mentioned crystal orientation piezoelectric ceramic, but in the scope of the placement property that does not influence piezoelectric-actuator, also the piezoelectric ceramic that above-mentioned general formula (1) can be represented and other piezoelectric ceramic make up and constitute piezoelectric-actuator.For example,, the above volume of 50% in the piezoelectric ceramic is made of the crystal orientation piezoelectric ceramic of above-mentioned general formula (1) expression, and remaining less than 50% is made of barium titanate series piezoelectric ceramic etc. in the occasion that is stacked executive component.

Secondly, narrate with regard to piezoelectric ceramic and the semiconductor element executive component that forms that is connected in parallel with positive temperature characterisitic.

State in the use in the piezoelectric-actuator of piezoelectric ceramic formation, in-30 ℃～80 ℃ temperature range, the displacement, apparent dynamic capacity, displacement/apparent dynamic capacity, displacement/(the apparent dynamic capacity) that under electric field strength is the electric field driven condition with uniform amplitude more than the 100V/mm, produce ^0.5Fluctuation less, can access the good executive component of temperature characterisitic.But in-30 ℃～160 ℃ temperature range, although the fluctuation of displacement is less, apparent dynamic capacity might increase.

In order to investigate its reason, measured dynamic capacity behind the leakage current composition of removal piezoelectric-actuator, dynamic capacity does not increase in the temperature province more than 80 ℃ yet as a result.Can know that promptly above-mentioned piezoelectric ceramic is in the temperature province that is higher than 80 ℃, leakage current has very big increase.This is because the value when being 25 ℃ than the value of resistance with temperature is compared, and approximately reduces by 2 causes about the order of magnitude.Temperature is that 25 ℃ ratio resistance has 10 ¹⁰The value that Ω m is above.

Therefrom know, in order to reduce the fluctuation width of cloth of apparent dynamic capacity of-30 ℃～160 ℃ temperature province, will be lower at about temperature province resistance below 80 ℃, increase such semiconductor element and be electrically connected surpassing about 80 ℃ high-temperature area resistance with the executive component parallel connection with positive temperature coefficient of resistance, and dispose according to the temperature mode about equally of the temperature of PTC resistor and piezoelectric element and to get final product.Like this, below 80 ℃ the time, flow through than multiple current in the PTC resistor, more than 80 ℃ the time, flow through electric current in the PTC resistor hardly, so the fluctuation width of cloth of the apparent dynamic capacity of executive component can reduce.Its result can be in the temperature range of-30 ℃～160 ℃ broadness, obtain deciding electric charge drives and drive surely in the little and little piezoelectric-actuator of temperature dependency displacement of temperature dependency of terminal voltage.

Promptly, above-mentioned piezoelectric-actuator is preferably: comprise the PTC resistor with positive temperature coefficient of resistance, and this PTC resistor is electrically connected with the above-mentioned piezoelectric ceramic with negative temperature coefficient of resistance is in parallel, is configured (15 of claims the) according to the temperature of above-mentioned PTC resistor and the temperature position relation about equally of above-mentioned piezoelectric ceramic simultaneously.

At this, so-called temperature about equally is meant that the above-mentioned piezoelectric ceramic (piezoelectric element) of above-mentioned piezoelectric-actuator when driving is in 40 ℃ with the temperature difference of PTC resistor, more preferably in 30 ℃, more preferably in 20 ℃, further be preferably in 10 ℃.

In addition, the position of configuration relation has: the occasion that above-mentioned PTC resistor and piezoelectric ceramic dispose in contact, the occasion that the PTC resistor is set between the lead terminal of piezoelectric-actuator and be the occasion etc. that disposes the PTC resistor on the connector at the parts different with piezoelectric-actuator.

In addition, the resistance-temperature characteristic of PTC resistor preferably, the semiconductor element of the barium titanate series that resistance value sharply rises when surpassing about 80 ℃ high temperature.That is, above-mentioned PTC resistor is barium titanate-base semiconducting preferably, and has positive temperature coefficient of resistance in temperature is temperature province more than 80 ℃.(16 of claims the).

In this occasion, the semi-conductive insulating properties of the PTC under the temperature more than 80 ℃ improves more, so the leakage current that flows through in the parallel circuits of executive component and PTC element can reduce.In addition, therefore the barium titanate-base semiconducting that resistance value sharply rises more than 80 ℃ the time can not contain lead as executive component, so be more preferably owing to do not contain the additive lead of Curie temperature to elevated temperature excursions yet.

And then, at executive component is airtight assembly (package) type, and semiconductor element is arranged on the occasion of airtight component internal, the insulating resins that use in the executive component etc. are the meeting thermal decomposition when long-time the use, might consume the oxygen of airtight component internal, so even the semiconductor element of the barium titanate series of the preferred reducing resistance that resistance value does not also reduce under low oxygen concentration atmosphere.

In addition, if the resistance value of PTC resistor is lower, the voltage that then is applied on the executive component also reduces, thus the resistance value of PTC resistor preferably the impedance than the piezoelectric-actuator of piezoelectricity executive component when driving is fully big.

In addition, follow the driving of piezoelectric-actuator, PTC resistor self-heating or do not generate heat that all it doesn't matter.Following the occasion of self-heating, for example,, can make its effect of playing temperature heater, the use lower limit temperature of executive component is raise by easily heat conduction being given the position configuration PTC resistor of piezoelectric element.That is, narrow down, can reduce the fluctuation width of cloth of the apparent dynamic capacity etc. of executive component in fact by making operating temperature range.Particularly the semiconductor element of barium titanate series is owing to being the stationary temperature heater that resistance value sharply rises under its Curie temperature, so be suitable for the PTC resistor.

On the other hand, in the occasion of not following self-heating, the electric current that flows through in the parallel circuits of executive component and semiconductor element reduces, and therefore can suppress the rising of circuit cost.

In addition, above-mentioned piezoelectric-actuator is preferably: have stacked by a plurality of piezoelectric ceramic and the stack-up dielectric ceramic that forms as above-mentioned piezoelectric ceramic, and be used for Fuelinjection nozzle (17 of claims the).

In this occasion, can bring into play the characteristic of above-mentioned piezoelectric-actuator to greatest extent.

Secondly, about an example of the formation of piezoelectric-actuator of the present invention, use Figure 36 to describe.

As shown in the drawing like that, piezoelectric-actuator 1 can be by the piezoelectric element 2 that for example has piezoelectric ceramic, keep the retaining member 4 of piezoelectric element, the transmission member 5 of accommodating the outer cover component 3 of piezoelectric element etc. and transmitting the displacement of piezoelectric element to constitute.

As piezoelectric element 2, as described later as shown in Figure 38, for example can use the piezoelectric element of piezoelectric ceramic 21 and internal electrode 22 and the 23 alternately laminated a plurality of and cascade types that constitute etc.

In addition, as piezoelectric element, can use piezoelectric element (diagram slightly) by a slice piezoelectric ceramic being sandwiched in the veneer that constitutes in 2 internal electrodes.

In addition, be formed with 1 pair of outer electrode 25 and 26 in the side of piezoelectric element 2, adjacent 2 internal electrodes 22 in piezoelectric element 2 are electrically connected with different mutually outer electrode 25 and 26 with 23.

Such as shown in figure 36, in piezoelectric-actuator 1, transmission members such as piston 5 are configured in an end of the stacked direction of piezoelectric element 2.Between outer cover 3 and transmission member 5, dispose disk spring 55, piezoelectric element 2 is applied preset load.Transmission member 5 can activity can be delivered to the outside with its displacement along with the displacement of piezoelectric element 2.In addition, outer cover 3 is provided with moving through hole 31 and 32.In this moving through hole 31 and 32, be inserted with the terminal (lead-in wire) 61 and 62 that is used for supplying with electric charge, by packing ring 31 and 32 air-tightness that keep in the outer cover 3 from the outside.Terminal 61 and 62 be arranged on piezoelectric element 2 on outside terminal 25 and 26 be electrically connected.

And for example as shown in Figure 36, between piston component 5 and outer cover 3, dispose O shape ring 35, the bubble-tight while in keeping outer cover 3, form and make piston component 5 flexible movable structures.

Above-mentioned piezoelectric-actuator can be used in for example Fuelinjection nozzle etc.In addition, as above-mentioned piezoelectric-actuator, stacked executive component, piezoelectric transformer, supersonic engine, bimorph piezoelectric element, ultrasonic wave sonar, piezoelectric ultrasonic vibrator, piezoelectric buzzer, piezoelectric speaker etc. are arranged.

(embodiment 1)

Secondly, describe with regard to embodiments of the invention.

In this embodiment, make piezoelectric element, use this piezoelectric element to make piezoelectric-actuator with piezoelectric ceramic.

In this embodiment, such as shown in figure 37 as the model of piezoelectric-actuator, make the piezoelectric-actuator 11 that uses anchor clamps 8.

That is, this routine piezoelectric-actuator 11 has with the Piezoelektrisches mehrschichtelement 2 of piezoelectric ceramic as drive source, and this piezoelectric element 2 is fixed by anchor clamps 8.

Anchor clamps 8 have the piston (connecting elements) 82 of the displacement of the transmission piezoelectric element 2 that is used to accommodate the outer cover 81 of piezoelectric element 2 and is connected with piezoelectric element 2.Piston 82 is connected on the guider 83 by disk spring 85.Be provided with pedestal portion 815 in outer cover 81, piezoelectric element 2 is configured in the pedestal portion 815.The piezoelectric element 2 of configuration is fixing by the head 821 of piston 82 in the pedestal portion 815.At this moment, can apply from 85 pairs of piezoelectric elements 2 of disk spring and preset load.In addition, the end of the opposition side of the head 821 of piston 82 (determination part 88) can the activity along with the displacement of piezoelectric element 2.

At this, describe with regard to the applying method that presets load.Presetting load can obtain by following method: insert columned pressure bar (omitting diagram) in the space of piston 82 and dump bolt 84, with A Musila (Amsler) type testing machine guider 83 is applied correct load.Then, in order to keep presetting load, under the state that has applied load, dump bolt 84 and outer cover 81 are fixed.Then, remove above-mentioned pressure bar.

In addition, in this embodiment, the reason of making the model of piezoelectric-actuator is the temperature characterisitic for the displacement of estimating piezoelectric-actuator.Be set to elongated shape by its shape, piezoelectric element 2 can be arranged on the inside of thermostat, and determination part 88 is arranged on the outside (about 25 ℃ of=temperature) of thermostat.In the evaluation of temperature characterisitic described later, for piezoelectric-actuator shown in Figure 37 11, the part that will be lower than dotted line is arranged on the inside of thermostat.At this moment, in piezoelectric-actuator,, in piezoelectric-actuator, be provided with heat-insulating material 86 in order to prevent moving of the part of heat more than dotted line.

The model of such piezoelectric-actuator and piezoelectric-actuator shown in Figure 36 are of equal value on function.

In addition, such as shown in figure 38, in this embodiment, piezoelectric element 2 is alternately laminated and Piezoelektrisches mehrschichtelement that form constitutes by piezoelectric ceramic 21 and internal electrical pole plate 22 and 23.In addition, on the both ends of the stacked direction of piezoelectric element 2, dispose alumina plate 245.

In addition, be formed with two outer electrodes 25 and 26 according to the mode of clamping piezoelectric element on the side of piezoelectric element 2, outer electrode 25 is connected with 62 with lead-in wire 61 with 26.

In addition, internal electrical pole plate 22 and 23 with outer electrode 25 and 26 between be electrically connected with the outer electrode 25 and 26 ways of connecting of different potentials respectively according to adjacent two internal electrodes 22 and 23 in the piezoelectric element 2.

In addition, in this routine piezoelectric element 2,,, in the represented figure of Figure 38, omitted stacked number for the ease of mapping by adding up to 40 piezoelectric ceramic 21 stacked and constitute.

Secondly, the manufacture method of piezoelectric-actuator that should be routine describes.

At first, according to following such piezoelectric element of making.

(1) NaNbO ₃Synthesizing of flakelike powder

Weighing Bi ₂O ₃Powder, Na ₂CO ₃Powder and Nb ₂O ₅Powder makes it become Bi in stoichiometric proportion _2.5Na _3.5Nb ₅O ₁₈Composition, they are carried out wet mixed.Then, the NaCl that this raw material is added 50wt% carries out 1 hour dry type and mixes as flux.

Secondly, the mixture that obtains is put into platinum crucible,, under the condition of 1100 ℃ * 2hr, heat again after flux is melted fully, carry out Bi with the condition heating of 850 ℃ * 1hr _2.5Na _3.5Nb ₅O ₁₈Synthetic.In addition, programming rate is made as 200 ℃/hr, and it is cold that cooling is made as stove.After the cooling, flux is removed from reactant, obtained Bi by hot wash _2.5Na _3.5Nb ₅O ₁₈Powder.The Bi that obtains _2.5Na _3.5Nb ₅O ₁₈Powder is so that { the 100} face is the flakelike powder of flourishing face (developedplane).

Then, to this Bi _2.5Na _3.5Nb ₅O ₁₈Flakelike powder adds synthetic NaNbO ₃The Na of institute's necessary amount ₂CO ₃Powder also mixes, and as flux, carries out 950 ℃ * 8 hours heat treatment with NaCl in platinum crucible.

In the resulting reactant except containing NaNbO ₃Also contain Bi beyond the powder ₂O ₃, therefore from reactant, behind the removal flux, put it into NHO ₃(1N), make the Bi that generates as unnecessary composition ₂O ₃Dissolving.Then, this solution is filtered to separate NaNbO ₃Powder washs with 80 ℃ ion exchange waters.The NaNbO that obtains ₃Powder is that cube { the 100} face is that flourishing face, particle diameter are that 10～30 μ m and asperratio are about 10～20 flakelike powder to intend.

Make as described below and have { Li _0.07(K _0.43Na _0.57) _0.93{ Nb _0.84Ta _0.09Sb _0.07O ₃The crystal oriented ceramic of forming.

Weighing purity is the Na more than 99.99% ₂CO ₃Powder, K ₂CO ₃Powder, Li ₂CO ₃Powder, Nb ₂O ₅Powder, Ta ₂O ₅Powder, Sb ₂O ₅Powder makes it become { Li from 1mol _0.07(K _0.43Na _0.57) _0.93{ Nb _0.84Ta _0.09Sb _0.07O ₃Stoichiometric composition in cut the NaNbO of 0.05mol ₃And the composition that obtains as medium, carries out 20 hours wet mixed with organic solvent with the Zr ball.Then,, carry out 20 hour case of wet attrition as medium with the Zr ball with organic solvent again, obtain the pre-burning thing powder that average grain diameter is about 0.5 μ m by carrying out pre-burning in 5 hours at 750 ℃.

NaNbO with this pre-burning thing powder and above-mentioned sheet ₃According to pre-burning thing powder: NaNbO ₃The ratio of=0.95mol:0.05mol carries out weighing, makes it become { Li _0.07(K _0.43Na _0.57) _0.93{ Nb _0.84Ta _0.09Sb _0.07O ₃Composition, as medium, carry out 20 hours wet mixed with organic solvent with the Zr ball, obtain pulverizing slurry.Then, behind slurry interpolation adhesive (polyvinyl butyral resin) and plasticizer (butyl phthalate), carry out again mixing in 2 hours.

Then, use banded building mortion, the slurry that mixes is configured as the band shape that thickness is about 100 μ m.By this band being carried out stacked and crimping and rolling, obtain the thick sheet-like formed body of 1.5mm that is then.Then, the sheet-like formed body that will obtain in atmosphere is that 600 ℃, heating time are that 5 hours, programming rate are that 50 ℃/hr, cooling rate are that the cold condition of stove is carried out degreasing with heating-up temperature.And then, the sheet-like formed body after the degreasing is imposed CIP with the pressure of 300MPa handle, in oxygen, carry out 5 hours sintering then in 1110 ℃.Like this, be made into piezoelectric ceramic (crystal orientation piezoelectric ceramic).

For the piezoelectric ceramic that obtains, calculate sintered density and adopt 1 pair of face parallel of above-mentioned mathematical expression to calculate plan cube { the average orientation F (100) of 100} face based on Lao Tegaierdingfa with zone face (tape surface).

And then, by the piezoelectric ceramic that obtains is carried out grinding and grinding and processing, the piezoelectric ceramic 21 of the disc shaped test piece of thick 0.485mm, diameter 11mm that making its top and bottom as shown in figure 39 are parallel with zone face, (Sumitomo Metal Mining Co., Ltd makes to its top and bottom printing Au roasting electrode paste (gold baking electrodepaste), ALP3057) also after drying, adopt netted band oven to carry out 850 ℃ * 10 minutes roasting, on piezoelectric ceramic 21, form the electrode 20 of thick 0.01mm.And then, in order to remove several microns jut of the electrode peripheral part that forms inevitably because of printing, the disc shaped test piece that obtains is processed into diameter 8.5mm by the cylinder grinding.Subsequently, on above-below direction, impose polarization and handle, obtain on piezoelectric ceramic 21, having formed the piezoelectric element (veneer) 20 of whole electrode 210.

Under 25 ℃ temperature, the piezoelectric strain constant (d that adopts resonance antiresonance method that the piezoelectric element 20 that obtains is measured as piezoelectric property ₃₁), electromechanical coupling factor (kp), mechanical quality coefficient (Qm) and as the permittivity (ε of dielectric property ₃₃ ^t/ ε ₀), dielectric loss (tan δ).

In addition, same, by measuring the temperature characterisitic of permittivity, try to achieve the 1st crystalline phase transition temperature (Curie temperature) and the 2nd crystalline phase transition temperature.In addition, at the 2nd crystalline phase transition temperature is occasion below 0 ℃, because the fluctuation width of cloth of the permittivity of a temperature side high than the 2nd crystalline phase transition temperature is very little, so the occasion that can not confirm in the peak position of permittivity, the temperature that permittivity is bent is as the 2nd crystalline phase transition temperature.

Secondly, adopt the above-mentioned piezoelectric element that obtains to make the piezoelectric element of cascade type, use this piezoelectric element to constitute piezoelectric-actuator, estimate.

Such as shown in figure 40, at first, carry out the internal electrical pole plate 22 (23) of the above-mentioned piezoelectric element that obtains like that 20 and the SUS system of thick 0.02mm, the diameter 8.4mm with the projection that is used to be connected on the outer electrode described later alternately laminated.At this moment, the projection of internal electrical pole plate 22 (23) disposes to replace different directions on stacked direction, and each layer is all according to equidirectional configuration internal electrical pole plate 22 (23).Like this, add up to 40 piezoelectric ceramic 21 alternately laminated with the internal electrical pole plate 22 (23) of 41 of totals, and then in the top and bottom of duplexer the alumina plate (insulation board) of stacked thick 2mm, diameter 8.5mm, such as shown in figure 38, be made into the piezoelectric element 2 of cascade type.

Then, the outer electrode 25 and 26 of rectangular SUS system is welded on the projection of above-mentioned internal electrode 22 and 23, itself and piezoelectric element parallel connection are electrically connected, prepare lead terminal 61 and 62 then, outer electrode 25 and 26 is electrically connected with lead terminal 61 and 62.

In addition, in order to ensure the internal electrical pole plate 22 of the projection of internal electrical pole plate 22 and 23 and opposite polarity and 23 and the Au electrode of the piezoelectric element of opposite polarity between state of insulation, between the projection of the identical battery lead plate of the polarity of duplexer side, insert the resin system insulating component (omitting diagram) of configuration broach shape, apply silicone grease in the above, with the retaining member 4 lining duplexers of insulated tube formation, make the piezoelectric element 2 of cascade type again.

Then, for the Au electrode of the piezoelectric element 2 that improves cascade type and the adaptation between the battery lead plate, under 25 ℃ temperature, stacked direction is applied the compression stress 30 seconds (pressure aging) of 150MPa.Under 25 ℃ temperature, stacked direction is applied the compression stress of 30MPa again, under this state, apply the sine wave 30 minutes (voltage is aging) that electric field strength is the amplitude of 0～1500V/mm with the frequency of 40Hz.Then, such as shown in figure 37, the piezoelectric element 2 of cascade type is fixed on the anchor clamps 8, on the stacked direction of piezoelectric element 2, with 16.4Mpa to preset load crimp spring constant be the disk spring 85 of 2.9N/ μ m.Like this, making piezoelectric-actuator 11 as shown in Figure 37.

Then, to resulting piezoelectric-actuator carry out that applied voltage is 485,728, (electric field strength is that the trapezoidal wave of 0～1000V/mm, 0～1500V/mm, 0～2000V/mm) uniform amplitude drives the temperature characterisitic of mensuration displacement and apparent dynamic capacity-40 ℃～160 ℃ temperature range in to 970V.

The mensuration of displacement adopts the displacement transducer of electrostatic capacitive, is 0.5Hz and 10Hz, voltage rise time to be that 150 μ s, voltage are that 150 μ s, duty ratio are to measure the displacement of being observed under the trapezoidal wave drive condition of 50:50 fall time in frequency.

The mensuration of apparent dynamic capacity is as follows, be to be connected in series in piezoelectric-actuator under 25 ℃ the state with the capacitor of 878 μ F in temperature always, at applied voltage is that 485V, 728V, 970V, frequency are 0.05Hz, voltage rise time to be that 1ms, voltage are to be to be under the trapezoidal wave drive condition of constant voltage of 10s 10s, voltage (OFF) time of cutting off 1ms, voltage (ON) time of connecting fall time, measure the terminal voltage of the capacitor of being observed, calculate by following formula 11 and obtain.

Apparent dynamic capacity={ (V (connection)-(V (cut-out)) * 878 μ F)/{ applied voltage-(V (connection)-V (cut-out)) } (11)

(in the formula, apparent dynamic electrostatic capacitance [F], applied voltage [V], V (connection): connect capacitor terminal voltage [V], V (cut-outs) behind the beginning 10s: cut off the capacitor terminal voltage [V] that begins behind the 10s from voltage) from voltage.

That is,, try to achieve the savings electric charge (electric charge of the savings electric charge+leakage of=executive component) of capacitor,, be the apparent dynamic capacity of executive component its applied voltage divided by executive component based on the terminal voltage of capacitor.At this, owing to is connected with capacitors in series and the voltage that executive component applies is decreased, but maximum reduction amplitude is the very little value of 0.3V, so the voltage on being judged as applied voltage and being applied to executive component is identical.

In addition, obtain the fluctuation width of cloth in the temperature range of the fluctuation width of cloth in-30 ℃～80 ℃ the temperature range and-30 ℃～160 ℃ from the value of being measured.Here, the so-called fluctuation width of cloth is to be the value of fiducial value with (maximum-minimum value)/2.

The relative density of the crystal oriented ceramic that obtains in the present embodiment is more than 95%.In addition, intend cube that { the 100} face is orientated abreast with respect to zone face, and cube { average orientation of 100} face reaches 88.5% to the plan of measuring according to Lao Tegaierdingfa.And, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 86.5pm/V, electromechanical coupling factor kp are 48.8%, mechanical quality coefficient Qm is 18.2, permittivity (ε ₃₃ ^t/ ε ₀) be 1042, dielectric loss tan δ is 6.4%.In addition, the 1st crystalline phase transition temperature (Curie temperature) of being tried to achieve by the temperature characterisitic of permittivity is that 282 ℃, the 2nd crystalline phase transition temperature are-30 ℃.

Secondly, the characteristic of the piezoelectric-actuator that obtains with regard to this example is narrated.

Displacement/apparent dynamic capacity, displacement/(apparent dynamic capacity) that displacement that apparent dynamic capacity of measuring and frequency are 0.5Hz and calculating are tried to achieve ^0.5, dynamic strain amount D33 is shown in table 1, Fig. 1, Fig. 2 and Fig. 3.

In addition, apparent dynamic capacity, frequency are displacement, displacement/apparent dynamic capacity, displacement/(the apparent dynamic capacity) of 0.5Hz ^0.5The fluctuation width of cloth in-30 ℃～80 ℃ temperature range and the fluctuation width of cloth in-30 ℃～160 ℃ temperature range are shown in table 12, table 13, table 14, table 15 respectively.

As seeing from table 1, Fig. 1, Fig. 2, Fig. 3, table 11, table 12, table 13, table 14, in this routine piezoelectric-actuator, the minimum value of the dynamic strain amount D33 in-30 ℃～80 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, D33=303pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 3.8%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 3.2%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 6.9%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1500V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 5.3%.

Secondly, the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, D33=303pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 7.7%.

The maximum of the fluctuation width of cloth of dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 28.9%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 27.8%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 13.8%.

(embodiment 2)

The firing temperature of the sheet-like formed body after degreasing is made as 1105 ℃, and according to step similarly to Example 1, making has { Li _0.07(K _0.45Na _0.55) _0.93{ Nb _0.82Ta _0.10Sb _0.08O ₃The crystal oriented ceramic of forming.To the crystal oriented ceramic that obtains, under condition similarly to Example 1, estimate sintered density, average orientation and piezoelectric property.In addition, make the stacked executive component of 40 piezoelectric elements, estimate the characteristic of executive component according to similarly to Example 1 step.

The relative density of the crystal oriented ceramic that present embodiment obtains is more than 95%.In addition, intend cube that { the 100} face is orientated abreast with respect to zone face, and cube { average orientation of 100} face reaches 94.6% to the plan of measuring according to Lao Tegaierdingfa.And, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 88.1pm/V, electromechanical coupling factor kp are 48.9%, mechanical quality coefficient Qm is 16.6, permittivity (ε ₃₃ ^t/ ε ₀) be 1071, dielectric loss tan δ is 4.7%.In addition, the 1st crystalline phase transition temperature (Curie temperature) of being tried to achieve by the temperature characterisitic of permittivity is that 256 ℃, the 2nd crystalline phase transition temperature are-35 ℃.

The characteristic of the piezoelectric-actuator of present embodiment is shown in table 2, Fig. 4, Fig. 5, Fig. 6, table 11, table 12, table 13 and table 14.

As from these table and figure saw, in this routine piezoelectric-actuator, the minimum value of the dynamic strain amount D33 in-30 ℃～80 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are 20 ℃ occasion at the driving electric field amplitude, D33=355pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 8.0%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 6.3%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm and 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 7.8%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 6.7%.

Secondly, the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are 20 ℃ occasion at the driving electric field amplitude, D33=355pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 13.8%.

The maximum of the fluctuation width of cloth of dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 31.4%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 26.8%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 13.3%.

(embodiment 3)

The firing temperature of the sheet-like formed body after degreasing is made as 1105 ℃, and according to step similarly to Example 1, making has { Li _0.065(K _0.45Na _0.55) _0.935{ Nb _0.83Ta _0.09Sb _0.08O ₃The crystal oriented ceramic of forming.To the crystal oriented ceramic that obtains, under condition similarly to Example 1, estimate sintered density, average orientation and piezoelectric property.And, make the stacked executive component of 40 piezoelectric elements according to similarly to Example 1 step, estimate the characteristic of executive component.

The relative density of the crystal oriented ceramic that present embodiment obtains is more than 95%.In addition, intend cube that { the 100} face is orientated abreast with respect to zone face, and cube { average orientation of 100} face reaches 93.9% to the plan of measuring according to Lao Tegaierdingfa.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 95.2pm/V, electromechanical coupling factor kp are 50.4%, mechanical quality coefficient Qm is 15.9, permittivity ( ₃₃ ^t/ ε ₀) be 1155, dielectric loss tan δ is 5.2%.In addition, the 1st crystalline phase transition temperature (Curie temperature) of being tried to achieve by the temperature characterisitic of permittivity is that 261 ℃, the 2nd crystalline phase transition temperature are-12 ℃.

The characteristic of the piezoelectric-actuator of this example is shown in table 3, Fig. 7, Fig. 8, Fig. 9, table 11, table 12, table 13 and table 14.

As from these table and figure saw, in this routine piezoelectric-actuator, the minimum value of the dynamic strain amount D33 in-30 ℃～80 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are 80 ℃ occasion at the driving electric field amplitude, D33=347pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 5.6%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 5.2%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 8.6%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1500V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 6.9%.

Secondly, the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are 80 ℃ occasion at the driving electric field amplitude, D33=347pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 11.5%.

The maximum of the fluctuation width of cloth of dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 34.6%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 27.1%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 10.9%.

(embodiment 4)

In this example, make the crystal orientation piezoelectric ceramic of forming similarly to Example 1, with this crystal orientation piezoelectric ceramic making piezoelectric-actuator with the step different with embodiment 1.

That is the NaNbO that at first embodiment 1 is made, ₃Flakelike powder and aschistic NaNbO ₃Powder, KNbO ₃Powder, KTaO ₃Powder, LiSbO ₃Powder and NaSbO ₃Powder carries out weighing, makes it become { Li _0.07(K _0.43Na _0.57) _0.93{ Nb _0.84Ta _0.09Sb _0.07O ₃Composition, carry out 20 hours wet mixed as solvent with organic solvent.

Behind slurry interpolation adhesive (polyvinyl butyral resin) and plasticizer (dibutyl phthalate), carry out again mixing in 2 hours.

And, NaNbO ₃The use level of flakelike powder is set at, and a KNN synthetic by initiation material is solid solution (ABO ₃) the 5wt% of A bit element be from NaNbO ₃The amount that flakelike powder is supplied with.In addition, aschistic NaNbO ₃Powder, KNbO ₃Powder, KTaO ₃Powder, LiSbO ₃Powder and NaSbO ₃Powder is that the purity that adopts solid phase method, be about to contain ormal weight is 99.9% K ₂CO ₃Powder, Na ₂CO ₃Powder, Nb ₂O ₅Powder, Ta ₂O ₅Powder with and/or Sb ₂O ₅The mixture of powder is pulverized reactant with ball mill then and is made 750 ℃ of heating 5 hours.

Secondly, with banded building mortion the slurry that mixes is configured as the band shape that thickness is about 100 μ m.By this band being carried out stacked and crimping and rolling, obtain the sheet-like formed body of thick 1.5mm then.Secondly, the sheet-like formed body that will obtain in atmosphere is that 600 ℃, heating time are that 5 hours, programming rate are that 50 ℃/hr, cooling rate are that the cold condition of stove is carried out degreasing with heating-up temperature.And then, after sheet-like formed body after the degreasing imposed CIP and handle with the pressure of 300MPa, in oxygen, be that 1130 ℃, heating time are that 5 hours, intensification and cooling rate are under the condition of 200 ℃/hr, in the process of heating time, apply 35kg/cm at firing temperature ²The hot pressed sintering of pressure (3.42MPa).Like this, be made into piezoelectric ceramic (crystal orientation piezoelectric ceramic).

The relative density of the crystal oriented ceramic that present embodiment obtains is more than 95%.In addition, intend cube that { the 100} face is orientated abreast with respect to zone face, and cube { average orientation of 100} face reaches 96% to the plan of measuring according to Lao Tegaierdingfa.And, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 96.5pm/V, electromechanical coupling factor kp are 51.9%, mechanical quality coefficient Qm is 15.2, permittivity (ε ₃₃ ^t/ ε ₀) be 1079, dielectric loss tan δ is 4.7%.In addition, the 1st crystalline phase transition temperature (Curie temperature) of being tried to achieve by the temperature characterisitic of permittivity is that 279 ℃, the 2nd crystalline phase transition temperature are-28 ℃.

The characteristic of the piezoelectric-actuator of this example is shown in table 4, Figure 10, Figure 11, Figure 12, table 11, table 12, table 13 and table 14.

As from these table and figure saw, in this routine piezoelectric-actuator, the minimum value of the dynamic strain amount D33 in-30 ℃～80 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are 50 ℃ occasion at the driving electric field amplitude, D33=427pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 7.2%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 6.1%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 8.0%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 6.7%.

Secondly, the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is the occasion of 50 ℃ of 1000V/mm, temperature at the driving electric field amplitude, D33=427pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 9.4%.

The maximum of the fluctuation width of cloth of dynamic capacity is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 28.4%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 32.4%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 19.5%.

(embodiment 5)

In the present embodiment, make the composition { Li that has at 1mol embodiment 3 _0.065(K _0.45Na _0.55) _0.935{ Nb _0.83Ta _0.09Sb _0.08O ₃China and foreign countries have added the piezoelectric ceramic (crystal orientation piezoelectric ceramic) of the composition of Mn0.0005mol, make piezoelectric-actuator with this piezoelectric ceramic.

At first, weighing purity is the Na more than 99.99% ₂CO ₃Powder, K ₂CO ₃Powder, Li ₂CO ₃Powder, Nb ₂O ₅Powder, Ta ₂O ₅Powder, Sb ₂O ₅Powder and MnO ₂Powder becomes from { Li it _0.07(K _0.43Na _0.57) _0.93{ Nb _0.84Ta _0.09Sb _0.07O ₃Cut the NaNbO of 0.05mol in the composition of 1mol+Mn 0.0005mol ₃And the composition that obtains as medium, carries out 20 hours wet mixed with organic solvent with the Zr ball.Then,, carry out 20 hour case of wet attrition as medium with the Zr ball with organic solvent again, obtain the pre-burning thing powder that average grain diameter is about 0.5 μ m by carrying out pre-burning in 5 hours at 750 ℃.

In the step afterwards, the firing temperature of the sheet-like formed body after degreasing is made as 1105 ℃, and according to step similarly to Example 1, making has { Li _0.065(K _0.45Na _0.55) _0.935{ Nb _0.83Ta _0.09Sb _0.08O ₃The crystal oriented ceramic of the composition of 1mol+Mn 0.0005mol.

For the crystal oriented ceramic that obtains, with condition evaluating sintered density, average orientation and voltage characteristic similarly to Example 1.And, make the stacked executive component of 40 piezoelectric elements according to similarly to Example 1 step, estimate the characteristic of executive component.And, with the amplitude of electric field strength be 2V/mm (± 1V), sinusoidal wave, frequency is the electrostatic capacitance of the condition evaluating executive component of 1kHz.

The relative density of the crystal oriented ceramic that present embodiment obtains is more than 95%.And intend cube that { the 100} face is orientated abreast with respect to zone face, and cube { average orientation of 100} face reaches 89.6% to the plan of measuring according to Lao Tegaierdingfa.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 99.1pm/V, electromechanical coupling factor kp are 52.0%, mechanical quality coefficient Qm is 20.3, permittivity (ε ₃₃ ^t/ ε ₀) be 1159, dielectric loss tan δ is 2.7%.Therefrom know, add Mn and have the effect that improves Qm, reduces tan δ.

In addition, the 1st crystalline phase transition temperature (Curie temperature) of being tried to achieve by the temperature characterisitic of permittivity is that 263 ℃, the 2nd crystalline phase transition temperature are-15 ℃.

The characteristic of the piezoelectric-actuator of present embodiment is shown in table 5, Figure 13, Figure 14, Figure 15, table 11, table 12, table 13 and table 14.

As from these table and figure saw, in this routine piezoelectric-actuator, the minimum value of the dynamic strain amount D33 in-30 ℃～80 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are the occasion of 50 ℃ and 80 ℃ at the driving electric field amplitude, D33=355pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 10.4%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 4.9%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 10.7%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 7.2%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1000V/mm, temperature are the occasion of 50 ℃ and 80 ℃ at the driving electric field amplitude, D33=355pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 11.8%.

The maximum of the fluctuation width of cloth of dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 26.9%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 21.3%.

Displacement/(apparent dynamic capacity) ^0.5The maximum of the fluctuation width of cloth be the occasion of 1000V/mm at the driving electric field amplitude, the fluctuation width of cloth is ± 12.4%.

Know by this result, add the effect that Mn has the fluctuation width of cloth of the apparent dynamic capacity in the temperature range that reduces-30 ℃～160 ℃.

In addition, the electrostatic capacitance for this routine piezoelectric-actuator describes.

The electrostatic capacitance of the piezoelectric-actuator of this example is the value less than apparent dynamic capacity in-30 ℃～160 ℃ scope.And the fluctuation width of cloth in-30 ℃～80 ℃ scope is ± 4.8%, and the fluctuation of the apparent dynamic capacity when being 1000V/mm with electric field strength is roughly the same.On the other hand, the fluctuation width of cloth in-30 ℃～160 ℃ scope is ± 5.2%, becomes much smaller than the value of the fluctuation width of cloth of apparent dynamic capacity.Can think that the difference of this dynamic capacity and electrostatic capacitance is that the difference of electric field strength determines.

Therefore can think, the reason of the difference of the fluctuation width of cloth is: in the temperature province of the high temperature more than 80 ℃, in electric field strength is that 1000V/mm is when above, owing to making apparent dynamic capacity, the increase of leakage current increases, but then, when electric field strength is 2V/mm, almost there is not leakage current, electrostatic capacitance does not increase.

Know from above, in this routine piezoelectric-actuator, by making driving electric field intensity, can in the temperature range of-30 ℃～160 ℃ broadness, lower the fluctuation width of cloth of apparent dynamic capacity less than 1000V/mm.Can think that its level that may reach can reach the temperature characterisitic same degree with the dynamic capacity of veneer.

(comparative example 1)

In this comparative example, be to use the example of stacked executive component of PZT material of regular crystal of the intermediate characteristic (semi-rigid) of soft system and hard system, this stacked executive component is suitable for the stacked executive component that the automobile fuel injection valve is used.At this, so-called soft system is meant that Qm is the material below 100, and so-called hard is to be meant that Qm is the material more than 1000.The stacked executive component that Fuelinjection nozzle is used is used for deciding voltage control or control or decide electric charge control surely, and drives by trapezoidal wave and to make valve opening and closing, thereby controls the spraying of fuel.Characteristic to executive component requires the temperature characterisitic of the displacement in displacement performance height and each control mode little.

Weighing PbO powder, ZrO ₂Powder, TiO ₂Powder, SrCO ₃Powder, Y ₂O ₃Powder, Nb ₂O ₅Powder, Mn ₂O ₃Powder makes it become (Pb _0.92Sr _0.09) { (Zr _0.543Ti _0.457) _0.985(Y _0.5Nb _0.5) _0.01Mn _0.005O ₃Composition, as medium, carry out wet mixed with water with the Zr ball.Then, carry out pre-burning in 7 hours at 790 ℃, again with organic solvent as medium, carry out case of wet attrition with the Zr ball, obtain the slurry that average grain diameter is about the pre-burning thing powder of 0.7 μ m.

Behind this slurry interpolation adhesive (polyvinyl butyral resin) and plasticizer (BBP(Butyl Benzyl Phthalate), carry out mixing in 20 hours with the Zr ball again.

Secondly, the slurry that mixes is configured as the band shape that thickness is about 100 μ m,, obtains the sheet-like formed body of thick 1.2mm, then, in atmosphere, the sheet-like formed body that obtains is carried out degreasing then by this band is carried out stacked and thermo-compressed with banded building mortion.And then, the sheet-like formed body after the degreasing is disposed on the MgO plate in the aluminium oxide saggar, in atmosphere, carry out 2 hours sintering in 1170 ℃.In the later step, use Ag to stick with paste and carry out roasting as electrode material, in addition, identical with embodiment 1.

The relative density of the piezoelectric ceramic of this comparative example is more than 95%.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 158.0pm/V, electromechanical coupling factor kp are 60.2%, mechanical quality coefficient Qm is 540, permittivity (ε ₃₃ ^t/ ε ₀) be 1701, dielectric loss tan δ is 0.2%.

The executive component characteristic of this comparative example is shown in table 6, Figure 16, Figure 17, Figure 18, table 15, table 16, table 17, table 18.

As from these table and figure saw, the minimum value of the dynamic strain amount D33 of the piezoelectric-actuator of this comparative example in-30 ℃～70 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

To be 2000V/mm and 1500V/mm, temperature at the driving electric field amplitude be-30 ℃ occasion to the minimum value of dynamic strain amount D33, is 553pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 5.6%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 14.5%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 10.5%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

To be 2000V/mm and 1500V/mm, temperature at the driving electric field amplitude be-30 ℃ occasion to the minimum value of dynamic strain amount D33, is 553pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, is ± 11.1%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 33.5%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 23.7%.

(comparative example 2)

This comparative example 2 is to use the example of stacked executive component of PZT material of the rhombohedral crystal of soft system, and the stacked executive component of usefulness is determined in the position that this stacked executive component is suitable for less semiconductor-fabricating device of variation of ambient temperature etc.The position determines that the stacked executive component of usefulness is to use in the little place of variation of ambient temperature, so demanding displacement performance, but does not require that temperature characterisitic is good.

Weighing PbO powder, ZrO ₂Powder, TiO ₂Powder, SrCO ₃Powder, Y ₂O ₃Powder, Nb ₂O ₅Powder makes it become (Pb _0.895Sr _0.115) { (Zr _0.57Ti _0.43) _0.978(Y _0.5Nb _0.5) _0.01Nb _0.012O ₃Composition, as medium, carry out 20 hours wet mixed with water with the Zr ball.Then, carried out pre-burning 5 hours, carry out case of wet attrition as medium with the Zr ball with water again at 875 ℃.This slurry is added adhesive (polyvinyl alcohol), be the 1wt% of preburning powder, adopt spray dryer to carry out drying and granulation then.

Secondly, obtain the formed body of diameter phi 15mm, thick 2mm by the dry type press forming with mould.Then, the disk shape formed body that obtains is carried out degreasing in atmosphere.And then after the sheet-like formed body after the degreasing imposed CIP and handle with the pressure of 200MPa, be disposed on the MgO plate in the aluminium oxide saggar, in atmosphere, carry out 2 hours sintering in 1260 ℃.Later step is identical with comparative example 1.

The relative density of the piezoelectric ceramic of this comparative example is more than 95%.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 212.7pm/V, electromechanical coupling factor kp are 67.3%, mechanical quality coefficient Qm is 47.5, permittivity (ε ₃₃ ^t/ ε ₀) be 1943, dielectric loss tan δ is 2.1%.

The executive component characteristic of this comparative example is shown in table 7, Figure 19, Figure 20, Figure 21, table 15, table 16, table 17, table 18.

As from these table and figure saw, the minimum value of the dynamic strain amount D33 of this routine piezoelectric-actuator in-30 ℃～70 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 2000V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 482pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, and the fluctuation width of cloth is ± 23.7%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 37.9%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 15.5%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 2000V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 482pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, is ± 38.5%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 63.5%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 2000V/mm and 1500V/mm at the driving electric field amplitude, is ± 33.1%.

(comparative example 3)

This comparative example 3 is to use the example of stacked executive component of PZT material of the regular crystal of soft system, and this stacked executive component is suitable for the knock sensor that automobile is used.Knock sensor is to utilize the piezoelectric effect of piezoelectric ceramic that petrolic detonation is converted into voltage and detect, not as the function of executive component.

Weighing PbO powder, ZrO ₂Powder, TiO ₂Powder, SrTiO ₃Powder, Sb ₂O ₃Powder makes it become (Pb _0.95Sr _0.05) { (Zr _0.53Ti _0.47) _0.978Sb _0.022O ₃Composition, as medium, carry out 20 hours wet mixed with water with the Zr ball.Then, carried out pre-burning 5 hours, carry out case of wet attrition as medium with the Zr ball with water again at 825 ℃.In the later step,, identical with comparative example 2 except sintering temperature is made as 1230 ℃.

The relative density of the piezoelectric ceramic of this comparative example is more than 95%.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 203.4pm/V, electromechanical coupling factor kp are 62.0%, mechanical quality coefficient Qm is 55.8, permittivity (ε ₃₃ ^t/ ε ₀) be 2308, dielectric loss tan δ is 1.4%.

The executive component characteristic of this comparative example is shown in table 8, Figure 22, Figure 23, Figure 24, table 15, table 16, table 17, table 18.

As from these table and figure saw, the minimum value of the dynamic strain amount D33 of the piezoelectric-actuator of this comparative example in-30 ℃～70 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 663pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, is ± 10.4%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 17.9%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 10.2%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 663pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, is ± 14.8%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 32.3%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 18.4%.

(comparative example 4)

This comparative example 4 is to use the example of stacked executive component of PZT material of the regular crystal of semi-rigid system, and this stacked executive component is suitable for the supersonic engine of high output.Supersonic engine makes the piezoelectric ceramic ring that sticks on the stator drive to count 10kHz resonance, and makes the rotor rotation that is crimped on the stator.For the executive component characteristic, the temperature characterisitic of displacement performance of having relatively high expectations and good displacement.

Weighing PbO powder, ZrO ₂Powder, TiO ₂Powder, SrCO ₃Powder, Sb ₂O ₃Powder, MnCO ₃Powder makes it become (Pb _0.965Sr _0.05) { (Zr _0.5Ti _0.5) _0.96Sb _0.03Mn _0.01O ₃Composition, as medium, carry out wet mixed with water with the Zr ball.Then, carried out pre-burning 5 hours, carry out case of wet attrition as medium with the Zr ball with water again at 875 ℃.In the later step,, identical with comparative example 2 except sintering temperature is made as 1230 ℃.

The relative density of the piezoelectric ceramic of this comparative example is more than 95%.To temperature is that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d ₃₁Constant is that 136.9pm/V, electromechanical coupling factor kp are 57.9%, mechanical quality coefficient Qm is 850, permittivity (ε ₃₃ ^t/ ε ₀) be 1545, dielectric loss tan δ is 0.2%.

The executive component characteristic of this comparative example is shown in table 9, Figure 25, Figure 26, Figure 27, table 15, table 16, table 17, table 18.

As from these table and figure saw, the minimum value of the dynamic strain amount D33 of the piezoelectric-actuator of this comparative example in-30 ℃～70 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 409pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, is ± 6.0%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 15.8%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 11.5%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are-30 ℃ occasion at the driving electric field amplitude, is 409pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, is ± 15.2%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 36.7%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 22.7%.

(comparative example 5)

Comparative example 5 is to use the example of stacked executive component of PZT material of the regular crystal of hard system, and this stacked executive component is suitable for highly sensitive angular-rate sensor.Angular-rate sensor have make the piezoelectric ceramic tuning fork with the executive component function of counting the kHz frequency resonance and driving and the sensor function that detects angular speed the two.For the characteristic of executive component, displacement performance can be lower, but require the temperature characterisitic of displacement little.

Weighing PbO powder, ZrO ₂Powder, TiO ₂Powder, ZnO powder, MnCO ₃Powder, Nb ₂O ₅Powder makes it become Pb{ (Zr _0.5Ti _0.5) _0.98(Zn _0.33Nb _0.67) _0.01Mn _0.01O ₃Composition, as medium, carry out wet mixed with water with the Zr ball.Then, carry out pre-burning in 5 hours, carry out case of wet attrition as medium with the Zr ball with water again at 800 ℃.In the later step,, identical with comparative example 2 except sintering temperature is made as 1200 ℃.

The relative density of the piezoelectric ceramic of this comparative example is more than 95%.In addition, be that the evaluation result of 25 ℃ piezoelectric property is piezoelectric d to temperature ₃₁Constant is that 103.6pm/V, electromechanical coupling factor kp are 54.1%, mechanical quality coefficient Qm is 1230, permittivity (ε ₃₃ ^t/ ε ₀) be 1061, dielectric loss tan δ is 0.2%.

The executive component characteristic of this comparative example is shown in table 10, Figure 28, Figure 29, Figure 30, table 15, table 16, table 17, table 18.

As from these table and figure saw, the minimum value of the dynamic strain amount D33 of the piezoelectric-actuator of this comparative example in-30 ℃～70 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are 20 ℃ occasion at the driving electric field amplitude, is 295pm/V.The minimum value of this dynamic strain amount D33 is less than the 303pm/V of embodiment 1.

The maximum of the fluctuation width of cloth of displacement is the occasion of 2000V/mm at the driving electric field amplitude, is ± 3.2%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 14.3%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 13.9%.

And the minimum value of the dynamic strain amount D33 in-30 ℃～160 ℃ temperature range and the fluctuation of above-mentioned characteristic are as described below.

The minimum value of dynamic strain amount D33 is that 1500V/mm, temperature are 20 ℃ occasion at the driving electric field amplitude, is 295pm/V.

The maximum of the fluctuation width of cloth of displacement is the occasion of 1500V/mm at the driving electric field amplitude, is ± 11.1%.

The maximum of the fluctuation width of cloth of apparent dynamic capacity is the occasion of 1500V/mm at the driving electric field amplitude, is ± 32.4%.

The maximum of the fluctuation width of cloth of displacement/apparent dynamic capacity is ± 24.5% in the occasion of driving electric field amplitude 1500V/mm.

(embodiment 6) leakage current separates with electric capacity

In this embodiment, whether is as embodiment 5 because the increase of leakage current causes in the reason that rises more than 80 ℃ in order to study apparent dynamic capacity shown in embodiment 1～5 like that, the piezoelectric ceramic (veneer) that uses embodiment 1, embodiment 4 and comparative example 1 to make, the temperature characterisitic of evaluation dynamic capacity.

At this, the mensuration of dynamic capacity is as follows, in the triangular wave extra electric field intensity that with the frequency is 1Hz is the 2000V/mm (occasion that 0～970V) high voltage drives, measure amount of polarization by following formula A9 from amount of polarization-voltage magnetic hysteresis loop, based on this, calculate the iunjected charge amount when driving under the high electric field, and as dynamic capacity.

Dynamic capacity C=Q/V A9

In the formula, V: applied voltage (=970V), Q: maximum charge [C].

The veneer that embodiment 1 and embodiment 4 made repeatedly during applied voltage, has caused the phenomenon of the null offset of amount of polarization owing to leakage current in the temperature province more than 80 ℃.Therefore, in order to estimate magnetic hysteresis loop, voltage-amount of polarization characteristic that 10 times applied voltage observed is repeatedly revised, so that voltage=0 the time, amount of polarization=0, and obtain magnetic hysteresis loop by removing leakage current with the model that is parallel with linear resistance.The dynamic capacity of being tried to achieve by this magnetic hysteresis loop is different with apparent dynamic capacity, obtains divided by applied voltage with removing charging charge behind the leakage current, that come from medium composition and polarization reversal composition and polarization rotation composition.Draw this magnetic hysteresis loop repeatedly 10 times, with the mean value of maximum amount of charge as amount of polarization.

On the other hand, even the veneer that comparative example 1 is made applied voltage does not repeatedly have the phenomenon of the null offset of amount of polarization yet.In the evaluation of magnetic hysteresis loop, with above-mentioned similarly repeatedly the mean value of the maximum amount of charge that observed for 10 times of applied voltage as amount of polarization.

In addition, it is several 40 that the dynamic capacity of the veneer of trying to achieve like this be multiply by the sheet of elements of executive component, and the result that the apparent dynamic capacity of the executive component made from embodiment 1, embodiment 4 and comparative example 1 is compared is shown in Figure 31, Figure 32 and Figure 33 respectively.

As known to Figure 31, Figure 32 and Figure 33, (the apparent dynamic capacity of executive component) of comparative example 1 is roughly consistent with the value of (dynamic capacity of veneer * 40), but in embodiment 1 and embodiment 4, (the apparent dynamic capacity of executive component) has very big-difference with the value of (dynamic capacity of veneer * 40).(the apparent dynamic capacity of executive component) rises in the high-temperature area more than 80 ℃, still the value constant of (dynamic capacity of veneer * 40).The fluctuation width of cloth of relevant (dynamic capacity of veneer * 40) in-30 ℃～160 ℃ temperature range is ± 7.6% in embodiment 1, be ± 2.2% in embodiment 4.

Know from above, if piezoelectric-actuator of the present invention reduces the leakage current of about high temperature more than 80 ℃ or the leakage current below 80 ℃ is increased, then in the temperature range of-30 ℃～160 ℃ broadness, even driving electric field intensity is the high electric field driven of 2000V/mm, the fluctuation width of cloth of apparent dynamic capacity also can reduce.Can think that its level that may reach can reach the temperature characterisitic same degree with the dynamic capacity of veneer.

The regulation of the lower limit of (embodiment 7) dynamic strain amount

Shown in embodiment 5, like that,, in the temperature range of-30 ℃～160 ℃ broadnesses, can reduce the fluctuation width of cloth of apparent dynamic capacity by making driving electric field intensity less than 1000V/mm.But if reduce driving electric field intensity, the dynamic strain amount also reduces.In this embodiment, obtain the dynamic strain amount of executive component of the present invention in the occasion that has reduced driving electric field intensity.

The relation of the driving electric field intensity of the executive component that embodiment 1～5 makes and 20 ℃ dynamic strain amount is shown in Figure 34.Can know, be the place of 100V/mm in the lower limit as the necessary driving electric field intensity of executive component, and the dynamic strain amount is more than the 250pm/V.

The regulation of the temperature characterisitic of (embodiment 8) dynamic strain amount in low electric field

In the present embodiment, obtain under the low driving electric field intensity that is lower than 1000V/mm the fluctuation width of cloth of the displacement of the occasion that the dynamic strain amount is little.

For this reason, must reduce the applied voltage of piezoelectric-actuator is measured, for the piezoelectric-actuator that this embodiment makes, when electric field strength deficiency 500V/mm, displacement is little, measures the precision possible deviation.In addition, the evaluation of its temperature characterisitic is difficult more.

Therefore, if measure the piezoelectricity transverse strain constant d of veneer ₃₁Although, the supposition difficulty of the absolute value of displacement then, the supposition of the temperature characterisitic of displacement is possible, therefore in the present embodiment, adopts resonance-antiresonance method to implement the piezoelectricity transverse strain constant d of veneer ₃₁Mensuration.

The piezoelectric d of the veneer that embodiment 5 is made ₃₁Dynamic strain amount under the driving electric field intensity of 1000～2000V/mm that the measured value of the temperature characterisitic of constant and embodiment 5 obtain is the Figure 35 that the results are shown in to compare after 20 ℃ the value standardization respectively.The piezoelectric d of relevant veneer in-30 ℃～80 ℃ temperature range ₃₁The fluctuation width of cloth of constant is ± 7.8% in embodiment 5.In addition, the piezoelectric d of relevant veneer in-30 ℃～160 ℃ temperature range ₃₁The fluctuation width of cloth of constant is ± 7.8% in embodiment 5.The fluctuation of the dynamic strain amount under this value and the driving electric field intensity of 1000～2000V/mm is identical or be less value.

Know that from above even make driving electric field intensity be lower than 1000V/mm, executive component of the present invention also can reduce the fluctuation width of cloth of displacement in the temperature range of-30 ℃～160 ℃ broadness.

Table 11

Table 12

Table 13

Table 14

Table 15

Table 16

Table 17

Table 18

Claims (21)

1. piezoelectric-actuator, it has the piezoelectric element that forms 1 pair of electrode on the surface of piezoelectric ceramic and constitute as drive source, it is characterized in that: to described piezoelectric-actuator applied voltage, it with electric field strength the occasion that the electric field driven condition with uniform amplitude more than the 100V/mm makes its driving, described piezoelectric-actuator satisfies at least one important document in the following important document (a)～(c)

(a) following formula, (1) the fluctuation width of cloth WC[% that varies with temperature generation of Biao Shi apparent dynamic capacity C] be in ± 11% in-30 ℃～80 ℃ specific range of temperatures, wherein, C is the apparent dynamic capacity of described piezoelectric-actuator, when described piezoelectric-actuator is connected with capacitors in series, and during to described piezoelectric-actuator and described capacitor applied voltage, C can be by calculating divided by the voltage V that is applied on the described piezoelectric-actuator with the quantity of electric charge Q that puts aside in the described capacitor

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (1)

Wherein, C _MaxBe illustrated in the maximum of-30 ℃～80 ℃ apparent dynamic capacity, C _MinBe illustrated in the minimum value of-30 ℃～80 ℃ apparent dynamic capacity;

(b) the fluctuation width of cloth W that varies with temperature generation of the displacement L of following formula (2) expression _L[%] is in ± 14% in-30 ℃～80 ℃ specific range of temperatures, and wherein, L is the displacement of described piezoelectric-actuator,

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (2)

Wherein, L _MaxBe illustrated in the maximum of-30 ℃～80 ℃ displacement, L _MinBe illustrated in the minimum value of-30 ℃～80 ℃ displacement;

(c) the fluctuation width of cloth W that varies with temperature generation of the L/C of following formula (3) expression _L/CIn-30 ℃～80 ℃ specific range of temperatures, be in ± 12% (%), wherein, C is the apparent dynamic capacity of described piezoelectric-actuator, L is the displacement of described piezoelectric-actuator, when described piezoelectric-actuator is connected with capacitors in series, and during to described piezoelectric-actuator and described capacitor applied voltage, described C can be by calculating divided by the voltage V that is applied on the described piezoelectric-actuator with the quantity of electric charge Q that puts aside in the described capacitor

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (3)

Wherein, (L/C) _MaxBe illustrated in the maximum of-30 ℃～80 ℃ L/C, (L/C) _MinBe illustrated in the minimum value of-30 ℃～80 ℃ L/C,

The unit of described apparent dynamic capacity C is F, and the unit of described quantity of electric charge Q is C, and the unit of described voltage V is V, and the unit of the displacement L of described piezoelectric-actuator is μ m;

Described piezoelectric ceramic is by with general formula: { Li _x(K _1-yNa _y) _1-x{ Nb _1-z-wTa _zSb _wO ₃The isotropism perovskite-type compounds of expression constitutes as the polycrystal of principal phase, while is made of the crystal orientation piezoelectric ceramic that the particular crystal plane that constitutes described multicrystal each crystal grain is in state of orientation, in the following formula, 0＜x≤0.2,0≤y≤1,0＜z≤0.4,0＜w≤0.2, x+z+w〉0.

2. piezoelectric-actuator according to claim 1 is characterized in that: satisfy described important document (a) and described important document (b) the two.

3. piezoelectric-actuator according to claim 1 is characterized in that: the whole important documents that satisfy described important document (a)～(c).

4. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (d),

(d) L/C of following formula (4) expression ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5, in-30 ℃～80 ℃ specific range of temperatures, be in ± 12%, wherein, L/C ^0.5Be the displacement L of described piezoelectric-actuator and the ratio of the square root of described apparent dynamic capacity C,

W _L/C ^0.5(％)＝[{2×(L/C ^0.5) _max/((L/C ^0.5) _max+(L/C ^0.5) _min)}—1]×100

(4)

In the formula, (L/C ^0.5) _MaxBe illustrated in-30 ℃～80 ℃ L/C ^0.5Maximum, (L/C ^0.5) _MinBe illustrated in-30 ℃～80 ℃ L/C ^0.5Minimum value.

5. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (e),

(e) in-30 ℃～80 ℃ specific range of temperatures, be more than the 250pm/V by the dynamic strain amount of calculating divided by electric field strength in the strain of extra electric field direction with described piezoelectric-actuator.

6. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (f),

(f) described fluctuation width of cloth W _C[%] is in ± 35% in-30 ℃～160 ℃ specific range of temperatures.

7. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (g),

(g) described fluctuation width of cloth W _L[%] is in ± 14% in-30 ℃～160 ℃ specific range of temperatures.

8. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (h),

(h) described fluctuation width of cloth W _L/C[%] is in ± 35% in-30 ℃～160 ℃ specific range of temperatures.

9. piezoelectric-actuator according to claim 1 is characterized in that: also satisfy following important document (i),

(i) described fluctuation width of cloth W _L/C ^0.5[%] is in ± 20% in-30 ℃～160 ℃ specific range of temperatures.

10. piezoelectric-actuator, it has the piezoelectric element that forms 1 pair of electrode on the surface of piezoelectric ceramic and constitute as drive source, it is characterized in that: to described piezoelectric-actuator applied voltage, it with electric field strength the occasion that the electric field driven condition with uniform amplitude more than the 100V/mm makes its driving, described piezoelectric-actuator satisfies at least one important document in following important document (j)～(1)

(j) the fluctuation width of cloth W that varies with temperature generation of the apparent dynamic capacity C of following formula (5) expression _C[%] is in ± 30% in-30 ℃～160 ℃ specific range of temperatures, wherein, C is the apparent dynamic capacity of described piezoelectric-actuator, when described piezoelectric-actuator is connected with capacitors in series, and during to described piezoelectric-actuator and described capacitor applied voltage, C can be by calculating divided by the voltage V that is applied on the described piezoelectric-actuator with the quantity of electric charge Q that puts aside in the described capacitor

W _C(％)＝[{2×C _max/(C _max+C _min)}—1]×100 (5)

Wherein, C _MaxBe illustrated in the maximum of-30 ℃～160 ℃ apparent dynamic capacity, C _MinBe illustrated in the minimum value of-30 ℃～160 ℃ apparent dynamic capacity;

(k) the fluctuation width of cloth W that varies with temperature generation of the displacement L of following formula (6) expression _L[%] is in ± 14% in-30 ℃～160 ℃ specific range of temperatures, and wherein, L is the displacement of described piezoelectric-actuator,

W _L[％]＝[{2×L _max/(L _max+L _min)}—1]×100 (6)

Wherein, L _MaxBe illustrated in the maximum of-30 ℃～160 ℃ displacement, Lmin is illustrated in the minimum value of-30 ℃～160 ℃ displacement;

(l) the fluctuation width of cloth W that varies with temperature generation of the L/C of following formula (7) expression _L/C(%), in-30 ℃～160 ℃ specific range of temperatures, be in ± 35%, wherein, C is the apparent dynamic capacity of described piezoelectric-actuator, L is the displacement of described piezoelectric-actuator, when described piezoelectric-actuator is connected with capacitors in series, and during to described piezoelectric-actuator and described capacitor applied voltage, described C can by with the quantity of electric charge Q that puts aside in the described capacitor divided by the voltage V[V that is applied on the described piezoelectric-actuator] calculate

W _L/C[％]＝[{2×(L/C) _max/((L/C) _max+(L/C) _min)}—1]×100 (7)

Wherein, (L/C) _MaxBe illustrated in the maximum of-30 ℃～160 ℃ L/C, (L/C) _MinBe illustrated in the minimum value of-30 ℃～160 ℃ L/C,

The unit of described apparent dynamic capacity C is F, and the unit of described quantity of electric charge Q is C, and the unit of described voltage V is V, and the unit of the displacement L of described piezoelectric-actuator is μ m;

Described piezoelectric ceramic is by with general formula: { Li _x(K _1-yNa _y) _1-x{ Nb _1-z-wTa _zSb _wO ₃The isotropism perovskite-type compounds of expression constitutes as the polycrystal of principal phase, while is made of the crystal orientation piezoelectric ceramic that the particular crystal plane that constitutes described multicrystal each crystal grain is in state of orientation, in the following formula, 0＜x≤0.2,0≤y≤1,0＜z≤0.4,0＜w≤0.2, x+z+w〉0.

11. piezoelectric-actuator according to claim 10 is characterized in that: satisfy described important document (j) and described important document (k) these two.

12. piezoelectric-actuator according to claim 10 is characterized in that: the whole important documents that satisfy described important document (j)～(1).

13. piezoelectric-actuator according to claim 10 is characterized in that: also satisfy following important document (m),

(m) L/C of following formula (8) expression ^0.5The fluctuation width of cloth W that varies with temperature generation _L/C ^0.5[%] is in ± 20% in-30 ℃～160 ℃ specific range of temperatures, wherein, and L/C ^0.5Be the displacement L of described piezoelectric-actuator and the ratio of the square root of described apparent dynamic capacity C,

W _L/C ^0.5(％)＝[{2×(L/C ^0.5) _max/((L/C ^0.5) _max+(L/C ^0.5) _min)}—1]×100

(8)

Wherein, (L/C ^0.5) _MaxBe illustrated in-30 ℃～160 ℃ the interior L/C of specific range of temperatures ^0.5Maximum, (L/C ^0.5) _MinBe illustrated in-30 ℃～160 ℃ the interior L/C of particular range ^0.5Minimum value.

14. piezoelectric-actuator according to claim 10 is characterized in that: also satisfy following important document (n),

(n) by with described piezoelectric-actuator dynamic strain amount that the strain of extra electric field direction is calculated divided by electric field strength in-30 ℃～160 ℃ specific range of temperatures for more than the 250pm/V.

15. piezoelectric-actuator according to claim 10, it is characterized in that: comprise PTC resistor with positive temperature coefficient of resistance, described PTC resistor is electrically connected with the described piezoelectric ceramic with negative temperature coefficient of resistance is in parallel, is configured according to the temperature of described PTC resistor and the temperature position relation about equally of described piezoelectric ceramic simultaneously.

16. piezoelectric-actuator according to claim 15 is characterized in that: described PTC resistor is a barium titanate-base semiconducting, has positive temperature coefficient of resistance in temperature is temperature province more than 80 ℃.

17., it is characterized in that according to claim 1 or 10 described piezoelectric-actuators: described piezoelectric-actuator have stacked by a plurality of described piezoelectric ceramic and the Piezoelektrisches mehrschichtelement that forms as described piezoelectric element, and be used for Fuelinjection nozzle.

18. according to claim 1 or 10 described piezoelectric-actuators, it is characterized in that: described piezoelectric ceramic constitutes by containing the piezoelectric ceramic that is selected from a kind alkali metal containing among Li, K and the Na at least.

19. according to claim 1 or 10 described piezoelectric-actuators, it is characterized in that: described piezoelectric ceramic is not leaded.

20., it is characterized in that according to claim 1 or 10 described piezoelectric-actuators: in described crystal orientation piezoelectric ceramic, described general formula: { Li _x(K _1-yNa _y) _1-x{ Nb _{1-z- w}Ta _zSb _wO ₃In x, y and the z relation that satisfies following formula (9) and formula (10),

9x—5z—17w≥—318 (9)

—18.9x—3.9z—5.8w≤—130 (10)。

21. according to claim 1 or 10 described piezoelectric-actuators, it is characterized in that: cube { degree of orientation of 100} face is more than 30% to the plan that the employing Lao Tegaierdingfa of described crystal orientation piezoelectric ceramic measures, and in 10 ℃～160 ℃ temperature range, crystallization is a regular crystal.

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