JPH0779026A - Piezoelectric actuator and its manufacture - Google Patents

Abstract

PURPOSE:To provide a piezoelectric actuator which has a simple construction, is easy to obtain at a low cost and shows a large displacement. CONSTITUTION:A spiral first electrode 12a and second electrode 12b are wound alternately on the longitudinal outer circumference of a rod-shaped piezoelectric ceramic 11 so as to have respective certain inclinations from the direction of a cross-section perpendicular to the longitudinal direction and not to cross each other. The spiral first and second electrodes 12a and 12b are connected respectively to two land electrodes 13a and 13b for lead wire connection which are provided 180 degrees apart from each other on the one side end of the longitudinal outer circumference of the rod-shaped piezoelectric ceramic 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric actuator for converting electric energy into mechanical energy such as displacement or force, and more particularly to a piezoelectric actuator using a rod-shaped piezoelectric ceramic and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, this type of piezoelectric actuator is
It functions as a functional element that uses the electric field induced strain of piezoelectric ceramics, and requires minute and precise positioning accuracy, for example, for wire drive units and pin drive units in impact type dot printers, semiconductor manufacturing equipment, scanning tunneling microscopes, etc. It is applied to the equipment that is used. This positioning accuracy is usually on the order of submicrons.

In general, a piezoelectric actuator utilizing a displacement amount in the longitudinal direction is obtained by applying an electrode paste printing technique and a ceramic green sheet laminating technique.
It is configured as a laminated type in which internal electrode layers and piezoelectric ceramic layers facing each other are alternately laminated in multiple layers.

FIG. 4 is a perspective view showing the basic structure of a conventional laminated piezoelectric actuator. In this laminated piezoelectric ceramic actuator, in order to prevent the lead-out portion of the internal electrode 42 from being piezoelectrically inactive when the internal electrode 42 and the external electrode 44 are connected, the internal electrode 42 is exposed on each side surface during the lamination process. A glass insulating layer 43 is provided every other layer, and an external electrode 44 is arranged on the glass insulating layer 43.

In this laminated piezoelectric ceramic actuator, when electric energy is supplied from the drive circuit, the piezoelectric ceramic sheet 41 and the internal electrodes 42 are formed by the piezoelectric vertical effect.
The displacement and driving force generated in the stacking direction with

[0006]

In the case of the above-mentioned laminated piezoelectric actuator, its structure is very complicated, and in the manufacturing process, a green sheet is formed, internal electrodes are printed, laminated, sintered, and a glass insulating layer is formed. , External electrode formation, etc.
It requires long-term complicated and stepwise processes. Therefore, the conventional laminated piezoelectric actuator has a problem that it is difficult to manufacture it at a good yield and at a low cost.

Further, in the case of the conventional laminated piezoelectric actuator, since the laminating direction and the displacement direction are structurally coincident with each other, in order to obtain a large displacement amount, the number of laminated ceramic sheets and internal electrodes is increased. It is necessary to increase the number to make the structure long in the stacking direction.

However, if the number of laminated layers is increased, problems such as delamination and cracks occur in the steps of debinding and sintering, so that the laminated length is usually 20 mm.
The degree is limited. Therefore, in order to obtain a large displacement amount, it is necessary to bond a plurality of laminated piezoelectric actuators in series, but such a configuration has a problem in that it is disadvantageous in terms of cost.

The present invention has been made to solve the above problems, and the technical problem thereof is that the piezoelectric actuator is simple in construction, can be easily and inexpensively obtained, and has a large displacement amount, and its manufacture. To provide a method.

[0010]

According to the present invention, the outer peripheral surface of the rod-shaped piezoelectric ceramic in the length direction is inclined with respect to the cross-sectional direction orthogonal to the length direction and does not intersect. A piezoelectric actuator provided with spirally-wound first electrodes and spirally-wound second electrodes that are alternately continuous is provided.

Further, according to the present invention, in the above-mentioned piezoelectric actuator, the outer peripheral surface of the rod-shaped piezoelectric ceramic in the length direction is inclined with respect to the cross-sectional direction orthogonal to the length direction and does not intersect. Thus, the spiral first notch groove and the spiral second notch groove are alternately provided, and the spiral first electrode and the spiral second electrode are rod-shaped, respectively. A piezoelectric actuator made of a metal material filled in the first notch groove and the second notch groove so as to substantially match the outer peripheral surface of the piezoelectric ceramic is obtained.

On the other hand, according to the present invention, the end portions of the two metal electrode wires are fixed to one end portion of the outer peripheral surface in the lengthwise direction of the rod-shaped piezoelectric ceramic at a predetermined distance, and the two metal electrode wires are fixed. While the wire is being supplied, the two metal electrode wires and the rod-shaped piezoelectric ceramic are relatively moved along the central axis direction of the rod-shaped piezoelectric ceramic, so that the length is provided on the outer peripheral surface of the rod-shaped piezoelectric ceramic. A piezoelectric including an electrode forming step of forming spiral first electrode lines and spiral second electrode lines that are alternately inclined so as not to intersect each other with respect to a cross-sectional direction orthogonal to the direction. An actuator manufacturing method is obtained.

Further, according to the present invention, the two printing portions for printing the electrode paste fixed at a predetermined distance are respectively brought into contact with one end portion of the outer peripheral surface in the longitudinal direction of the rod-shaped piezoelectric ceramic, and the electrode paste is printed. By relatively moving the two printing portions and the rod-shaped piezoelectric ceramic along the central axis direction of the rod-shaped piezoelectric ceramic while supplying
On the outer peripheral surface of the rod-shaped piezoelectric ceramic, a spiral first metal paste and a spiral second metal paste, which are respectively inclined with respect to a cross-sectional direction orthogonal to the length direction and are alternately continuous so as not to intersect each other, are formed. A method of manufacturing a piezoelectric actuator including a metal paste forming step of forming a metal paste is obtained.

Further, according to the present invention, the two cutting portions for cutting fixed at a predetermined distance are respectively brought into contact with one end portion of the outer peripheral surface in the longitudinal direction of the rod-shaped piezoelectric ceramic, and the two cutting portions are brought into contact with each other. And the rod-shaped piezoelectric ceramic are relatively moved along the central axis direction of the rod-shaped piezoelectric ceramic so that the outer peripheral surface of the rod-shaped piezoelectric ceramic is inclined with respect to the cross-sectional direction orthogonal to the length direction. Have,
In addition, a groove forming step of forming a spiral first notch groove and a spiral second notch groove that are alternately continuous so as not to intersect each other, and a metal material is applied to the entire outer peripheral surface of the rod-shaped piezoelectric ceramic. The metal material application step and the one in which the metal material is filled in the spiral first and second cutout grooves from the outer peripheral surface of the rod-shaped piezoelectric ceramic are left so as to substantially coincide with the outer peripheral surface of the rod-shaped piezoelectric ceramic. To remove the spiral first metal paste and the spiral second metal paste in the spiral first notch and in the spiral second notch, respectively. A method of manufacturing a piezoelectric actuator including a step of removing a metal material for forming a piezoelectric actuator is obtained.

In addition, according to the present invention, in the method for manufacturing a piezoelectric actuator according to any one of the above, further, the spiral first metal paste and the spiral second metal paste are dried and heat-treated, respectively. A method of manufacturing a piezoelectric actuator including an electrode forming step of forming a spiral first electrode and a spiral second electrode is obtained.

[0016]

The piezoelectric actuator of the present invention and the method for manufacturing the same will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing a piezoelectric actuator according to an embodiment of the present invention. This piezoelectric actuator has a spiral first first outer peripheral surface of the rod-shaped piezoelectric ceramic 11 that is inclined with respect to a cross-sectional direction orthogonal to the lengthwise direction and that is alternately continuous so as not to intersect. Electrode 12a (hereinafter, referred to as first spiral electrode 12a) and second spiral electrode 12b (hereinafter, referred to as
The second spiral electrode 12b) is wound around.

Land electrodes 13a and 13b are provided at one end of the rod-shaped piezoelectric ceramic 11, and the first spiral electrode 12a and the second spiral electrode 12b are connected to the land electrodes 13a and 13b, respectively. ing.

When manufacturing such a piezoelectric actuator, for example, as an electrode forming step, the ends of two metal electrode wires are separated from one end of the outer peripheral surface in the lengthwise direction of the rod-shaped piezoelectric ceramic 11 with a predetermined distance. By fixing and relatively moving the two metal electrode wires and the rod-shaped piezoelectric ceramic 11 along the central axis direction of the rod-shaped piezoelectric ceramic 11 while supplying the two metal electrode wires, a unique first The first and second spiral electrodes 12a and 12b are obtained.

Alternatively, as a metal paste forming step, first, a 2 for electrode paste printing is fixed at a predetermined distance.
The two printed portions are brought into contact with one end of the outer peripheral surface in the length direction of the rod-shaped piezoelectric ceramic 11, and the two printed portions and the rod-shaped piezoelectric ceramic 11 are provided along the central axis direction of the rod-shaped piezoelectric ceramic 11 while supplying the electrode paste. As described above, the spiral first metal paste and the spiral second metal paste are alternately formed, and then the spiral first metal paste and the spiral first metal paste are spirally formed in the electrode forming step. The first spiral electrodes 12a and 12b are respectively obtained by drying and heat-treating the second metal paste in the shape of a circle.

In such a piezoelectric actuator, when positive and negative voltages are applied to the first and second spiral electrodes 12a and 12b via the land electrodes 13a and 13b, respectively, the spiral electrodes 12a and 12b are connected to each other. When a voltage is applied to the ceramic portion in, the ceramic portion generates a strain of extension in the direction of the electric field due to the piezoelectric vertical effect.
Although the electric field direction of the applied voltage is slightly deviated from the length direction of the rod-shaped piezoelectric ceramic 11, the spiral electrodes 12a, 12
Since b is wound around the outer peripheral surface of the rod-shaped piezoelectric ceramic 11 in the length direction, the strain directions of the elongation are averaged and the displacements coincide with the length direction of the rod-shaped piezoelectric ceramic 11. The magnitude of this displacement is proportional to the product of the piezoelectric constant, which is the material constant of the rod-shaped piezoelectric ceramic 11, the number of turns in each spiral electrode 12a, 12b, and the applied voltage. Therefore,
If the length of the rod-shaped piezoelectric ceramic 11 is increased, the number of windings of the spiral electrodes 12a and 12b can be increased, so that the displacement amount of the piezoelectric actuator can be easily increased.

Next, the method for manufacturing the piezoelectric actuator will be described in more detail with reference to some specific examples.

Example 1 In Example 1, first, as a raw material, Pb (Ni _0.5 Nb _0.5 ) _0.5 Ti _0.35 Zr _0.15
It has a chemical composition of O ₃ and a longitudinal effect piezoelectric constant of 6
Piezoelectric ceramic material powder of 35 × 10 ⁻¹² [m / V] is press-molded and then sintered at 1200 ° C. in the atmosphere to obtain a diameter of 10 [mm] and a length of 7 as shown in FIG.
A rod-shaped piezoelectric ceramic 11 of 7 [mm] was manufactured.

Next, land electrodes 13a and 13b having a diameter of 2 [mm] for attaching two lead wires are attached at positions 180 degrees apart from each other at one end of the outer peripheral surface in the longitudinal direction of the rod-shaped piezoelectric ceramic 11. Formed. After that, the two print heads installed so as to correspond to the intervals between the land electrodes 13a and 13b are fixed in contact with each other, and while supplying the electrode paste, the rod-shaped piezoelectric ceramic 11 is rotated around the central axis in the longitudinal direction. While the rod-shaped piezoelectric ceramic 11 is being rotated, the rod-shaped piezoelectric ceramic 11 is moved along the central axis direction (here, the two print heads may be rotated around the rod-shaped piezoelectric ceramic 11), and the line width of 0. 5 [m
m], the pitch of the rod-shaped piezoelectric ceramic 11 is 5 [m
m], the electrode paste is spirally wound 14 times to form the land electrodes 13a and 13b, respectively.
A spiral first electrode paste and a second electrode paste connected to each other were formed.

Subsequently, each electrode paste is dried and then heat-treated to form a first spiral electrode 12a, respectively.
A piezoelectric actuator was prepared by molding the first spiral electrode 12b.

When a direct current voltage was applied to this piezoelectric actuator and the amount of displacement was examined, the results shown in Table 1 were obtained.

[0027]

[Table 1]

From Table 1, in the case of this piezoelectric actuator, 8.5 to 32.5 when a voltage of 0.5 to 2 [kV] is applied.
It can be seen that a large displacement amount of [μm] can be obtained.

(Embodiment 2) In the embodiment 2, after the rod-shaped piezoelectric ceramic 11 having the land electrodes 13a and 13b is prepared by the same procedure as that of the embodiment 1, the respective land electrodes 13a and 1b are formed.
3b each have a width of 0.2 [mm] and a thickness of 0.05 [m.
m], the ends of the first metal electrode wire and the second metal electrode wire are fixed by soldering, respectively, and then the rod-shaped piezoelectric ceramic 11 is lengthened while supplying the first and second metal electrode wires. The rod-shaped piezoelectric ceramic 11 is moved along the central axis direction while rotating about the central axis in the direction (here, the first and second metal electrode wires are also moved around the rod-shaped piezoelectric ceramic 11). The rod-shaped piezoelectric ceramic 11 may be spirally wound at a pitch of 3 [mm] with a winding number of 22 times so as to be inclined 5 degrees with respect to the cross-sectional direction orthogonal to the length direction. Thus, a piezoelectric actuator having the first spiral electrode 12a and the second spiral electrode 12b was produced.

When a DC voltage was applied to this piezoelectric actuator and the amount of displacement was examined, the results shown in Table 2 were obtained.

[0031]

[Table 2]

From Table 2, in the case of this piezoelectric actuator, 14.5 to 57.
It can be seen that a large displacement amount of 5 [μm] can be obtained. still,
Compared to the first embodiment, the second embodiment obtains a larger displacement amount with the same applied voltage, but this is because the number of windings is large.

(Third Embodiment) In the third embodiment, the diameter 10 having the land electrodes 13a and 13b is obtained by the same procedure as in the first embodiment.
After forming the rod-shaped piezoelectric ceramic 11 having a length of [mm] and a length of 76.2 [mm], the width a [m] is applied to each land electrode.
m], the ends of the first metal electrode wire and the second metal electrode wire are fixed by soldering, respectively, and then the rod-shaped piezoelectric ceramic 11 is lengthened while supplying the first and second metal electrode wires. The rod-shaped piezoelectric ceramic 11 is moved in a direction along the central axis direction while rotating around the central axis in the direction,
The rod-shaped piezoelectric ceramic 11 is spirally wound at a pitch p [mm] at an angle of θ with respect to a cross-sectional direction orthogonal to the longitudinal direction, and is formed by winding n times.
A piezoelectric actuator having the spiral electrode 12a and the second spiral electrode 12b was prepared. Where the first and second
Rod-shaped piezoelectric ceramics 11 of spiral electrodes 12a, 12b
The distance (distance) in the length direction of (p / 2-a) [m
m].

Incidentally, FIG. 2 is a plan development view of the piezoelectric actuator shown for explaining the formation positions of the spiral electrodes 12a and 12b on the outer peripheral surface of the rod-shaped piezoelectric ceramic 11. Each of the spiral electrodes 12a and 12b has a linear shape that is diagonally parallel in the developed view.

Therefore, in accordance with such a manufacturing method, the above-mentioned electrode parameters (a, θ, p, n) are variously changed to produce piezoelectric actuators having different specifications.
When a direct current voltage was applied to these piezoelectric actuators and the amount of displacement was examined, the results shown in Table 3 were obtained.

[0036]

[Table 3]

From Table 3, in the case of this piezoelectric actuator, by changing the electrode parameters relating to a, θ, p, and n as various specifications I, II, and III, 500 [V] to 2 can be obtained.
It can be seen that a large displacement amount of 8.5 to 54 [μm] can be obtained under the voltage application condition of [kV]. However, the electrode interval in the piezoelectric actuator of specification I is 0.8 [mm], and there is a possibility of causing a short circuit between the electrodes under this voltage interval with an excessive voltage application condition. Therefore, measurement at an applied voltage of 2 [kV] Is avoiding.

By the way, the piezoelectric actuator of the present invention and the manufacturing method thereof can be modified as described below.

That is, as shown in FIG. 3, in this piezoelectric actuator, the outer peripheral surface of the rod-shaped piezoelectric ceramic 21 in the lengthwise direction is inclined with respect to the cross-sectional direction orthogonal to the lengthwise direction and intersects. So that the metal materials Z ₁ and Z ₂ are respectively provided in the spiral first notch groove H ₁ and the spiral second notch groove H ₂ which are continuously provided alternately so as not to exist. The first spiral electrode 31a and the second spiral electrode 31b corresponding to the above-described respective embodiments are filled by filling the outer peripheral surface of 21 so as to be substantially aligned with each other.
And are constructed.

In the case of manufacturing this piezoelectric actuator, first, in a groove forming step, two cutting portions for cutting fixed at a predetermined distance are respectively formed on one end portion of the outer peripheral surface in the longitudinal direction of the rod-shaped piezoelectric ceramic 21. Contact with 2
The two cut portions and the rod-shaped piezoelectric ceramic 21 are relatively moved along the central axis direction of the rod-shaped piezoelectric ceramic 21, and the outer peripheral surface of the rod-shaped piezoelectric ceramic 21 is cross-sectionally orthogonal to its lengthwise direction. First spiral notch grooves H ₁ and second spiral notch grooves H ₂ are formed so as to have an inclination and are continuous so as not to intersect each other.

Next, as a metal material applying step, a metal material is applied to the entire outer peripheral surface of the rod-shaped piezoelectric ceramic 21, and then, as a metal material removing step, the rod-shaped piezoelectric ceramic 21.
The metal material applied to the outer peripheral surface of the rod-shaped piezoelectric ceramic 21 is filled in the spiral first and second cutout grooves H ₁ and H ₂ so as to substantially match the outer peripheral surface of the rod-shaped piezoelectric ceramic 21. By removing them, a spiral first metal paste and a spiral second metal paste are obtained. Finally, as an electrode forming step, the spiral first metal paste and the spiral second metal paste are dried and heat-treated to form a first spiral electrode 31a and a second spiral electrode 31b, respectively. To do.

This piezoelectric actuator also includes the first and second piezoelectric actuators.
When positive and negative voltages are applied to the spiral electrodes 31a and 31b of the respective electrodes via the land electrodes, a voltage is applied to the ceramic portion between the spiral electrodes 31a and 31b, and the ceramic portion causes the direction of the electric field due to the piezoelectric longitudinal effect. Generates strain in elongation.

In the case of the piezoelectric actuators of the above-mentioned respective embodiments, the electrodes are formed on the surface of the ceramic portion, and the electric field thereof is orthogonal to the length direction of the rod-shaped piezoelectric ceramic 11 in the vicinity of the surface. In the case of this embodiment, the electric field component in the lengthwise direction of the rod-shaped piezoelectric ceramic 21 is increased by forming the notch grooves H ₁ and H _2, and the efficiency of the electric field induced strain is higher than that of the previous embodiments. Will get better. Further, the metal paste material is applied to the entire rod-shaped piezoelectric ceramic 21 and the metal adhering to the ceramic surface other than the inside of the notch grooves H ₁ and H ₂ is removed, whereby the metal can be easily filled.

Therefore, the method of manufacturing this piezoelectric actuator will be described in detail below with reference to specific examples.

(Embodiment 4) In Embodiment 4, the procedure is the same as that of Embodiment 1, and the sectional shape is a ring shape and the diameter is 10 [m.
m], a length of 76.2 [mm], and an inner diameter of 7 [mm] are formed.
2 mm in diameter and 0.2 in depth at positions 0 degrees apart
A [mm] notch for a land electrode was formed.

Next, two cutting blades for cutting are set on each groove edge at intervals matching in the notch groove for each land electrode, and then the rod-shaped piezoelectric ceramic 21 is placed around the central axis in the length direction. While rotating, it is moved along the central axis direction (here, the two cutting blades may also be rotated around the rod-shaped piezoelectric ceramic 21), and the length thereof is provided on the outer peripheral surface of the rod-shaped piezoelectric ceramic 21. Each has an inclination of θ degrees with respect to the cross-sectional direction orthogonal to the direction, and has a pitch p
[Mm], number of windings n in shape on the outer peripheral surface, width A [m
m] and depth B [mm], V-shaped first and second notch grooves H ₁ and H ₂ were formed in a spiral shape. Further, after applying the metal paste material to the entire outer peripheral surface of the rod-shaped piezoelectric ceramic 21, the spiral first and second notch grooves H ₁ and H ₂ are substantially aligned with the outer peripheral surface of the rod-shaped piezoelectric ceramic 21. By removing the metal paste material so as to be left, the spiral first metal paste and the second metal paste are obtained. Finally, by drying and heat-treating the spiral first metal paste and the spiral second metal paste, respectively, the first spiral electrode 31a and the second spiral electrode as shown in FIG. 3 are obtained. A piezoelectric actuator having an electrode 31b was created.

Therefore, the above-mentioned electrode parameters (A, B, θ, p, n) related to the groove shape according to this manufacturing method are used.
By variously changing as in the case of Example 3,
When several piezoelectric actuators having different specifications were prepared and a direct current voltage was applied to these piezoelectric actuators to examine the displacement amount, the results shown in Table 4 were obtained.

[0048]

[Table 4]

From Table 4, in the case of this piezoelectric actuator, when the electrode parameters for A, B, θ, p, and n are changed, it is possible to apply the voltage of 500 [V] to 1 [kV] to 10.
It was found that a large displacement amount of 2 to 67.5 [μm] can be obtained. Here, compared to the case of Example 3, a larger displacement amount was obtained in Example 4 under the same electrode parameter conditions. This is due to the influence of the electric field due to the groove on the ceramic and the ring. This is due to the influence of the hollow portion in the length direction that is piezoelectrically inactive (the effect of removing the ceramic portion) due to the cross-sectional shape of the shape.

In the piezoelectric actuators of Examples 1 to 3 described above, the shape of the piezoelectric ceramic 11 was a columnar shape having a circular cross section, but in each of these Examples, the shape is also a cross section. It may be a hollow cylinder having a ring shape. Further, the shape of the piezoelectric ceramic may be a polygonal column whose cross-sectional shape is a polygon other than the above-mentioned circle or ring. Further, the shape of the piezoelectric ceramic can be applied even if it changes in the length direction as long as its cross-sectional shape changes in a similar manner.

[0051]

As described above, according to the present invention, since the two electrodes for voltage application are spirally provided on the outer peripheral surface of the piezoelectric ceramic, the piezoelectric actuator having a large displacement amount can be facilitated. It can be configured simply. This piezoelectric actuator has an advantage that it can be provided at a low cost because the manufacturing process is simple.

[Brief description of drawings]

FIG. 1 is a perspective view showing a piezoelectric actuator according to an embodiment of the present invention.

FIG. 2 is a development view showing a piezoelectric actuator according to a third embodiment of the invention.

FIG. 3 is a side view showing a piezoelectric actuator according to a fourth embodiment of the present invention.

FIG. 4 is a perspective view showing a conventional laminated piezoelectric actuator.

[Explanation of symbols]

11, 21 Rod-shaped piezoelectric ceramics 12a, 12b, 31a, 31b Spiral electrodes 13a, 13b Land electrode 41 Piezoelectric ceramic 42 Internal electrode 43 Glass insulating layer 44 External electrodes H ₁ , H ₂ Notched groove parts Z ₁ , Z ₂ Metal material

Claims (6)

[Claims] 1. A spiral-shaped first outer peripheral surface of a rod-shaped piezoelectric ceramic, which has an inclination with respect to a cross-sectional direction orthogonal to the length direction, and which is alternately continuous so as not to intersect. A piezoelectric actuator in which an electrode and a spiral second electrode are wound and provided. 2. The piezoelectric actuator according to claim 1, wherein an outer peripheral surface of the rod-shaped piezoelectric ceramic in a longitudinal direction has an inclination with respect to a cross-sectional direction orthogonal to the longitudinal direction and does not intersect. A spiral first notch groove and a spiral second notch groove that are alternately continuous to each other are provided, and the spiral first electrode and the spiral second electrode are respectively A piezoelectric actuator comprising a metal material filled in the first notch groove and the second notch groove so as to substantially coincide with the outer peripheral surface of the rod-shaped piezoelectric ceramic. 3. An end portion of two metal electrode wires is fixed to one end portion of the outer peripheral surface in the length direction of the rod-shaped piezoelectric ceramic at a predetermined distance, and the two metal electrode wires are supplied while being supplied. By relatively moving the two metal electrode wires and the rod-shaped piezoelectric ceramic along the central axis direction of the rod-shaped piezoelectric ceramic, a cross-sectional direction orthogonal to the length direction is formed on the outer peripheral surface of the rod-shaped piezoelectric ceramic. The first spirals each having an inclination with respect to each other and alternately continuing so as not to intersect with each other.
2. A method for manufacturing a piezoelectric actuator, comprising: an electrode forming step of forming the electrode wire and the spiral second electrode wire. 4. Two printing parts for printing electrode paste fixed at a predetermined distance are respectively brought into contact with one end of the outer peripheral surface in the longitudinal direction of the rod-shaped piezoelectric ceramic, and the electrode paste is supplied while the two parts are provided. By relatively moving one printed portion and the rod-shaped piezoelectric ceramic along the central axis direction of the rod-shaped piezoelectric ceramic, the outer peripheral surface of the rod-shaped piezoelectric ceramic with respect to the cross-sectional direction orthogonal to the length direction. A piezoelectric actuator, comprising: a metal paste forming step of forming a spiral first metal paste and a spiral second metal paste, each of which has an inclination and is continuous so as not to intersect with each other. Production method. 5. A cutting tool 2 fixed at a predetermined distance.
The two cut portions are respectively brought into contact with one end of the outer peripheral surface in the length direction of the rod-shaped piezoelectric ceramic, and the two cut portions and the rod-shaped piezoelectric ceramic are relatively moved along the central axis direction of the rod-shaped piezoelectric ceramic. By doing so, the outer peripheral surface of the rod-shaped piezoelectric ceramic is inclined with respect to the cross-sectional direction orthogonal to the length direction, and is spirally continuous with the first notch groove and the spiral notch that intersect each other. Second of the shape
A groove forming step of forming a notch groove, a metal material applying step of applying a metal material to the entire outer peripheral surface of the rod-shaped piezoelectric ceramic, and a spiral-shaped first metal material applied from the outer peripheral surface of the rod-shaped piezoelectric ceramic. By removing the material filled in the first and second notch grooves so as to remain substantially in conformity with the outer peripheral surface of the rod-shaped piezoelectric ceramic, the inside of the spiral first notch groove and the spiral A spiral first metal paste and a spiral second metal paste in the second groove.
And a metal material removing step of forming the metal paste of 1. 6. The method of manufacturing a piezoelectric actuator according to claim 4, further comprising drying the spiral first metal paste and the spiral second metal paste,
Heat-treated to form a spiral first electrode and a spiral second electrode, respectively.
A method for manufacturing a piezoelectric actuator, comprising: