JP2001211673A - Manufacturing method of vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately position electromechanical transducers on an elastic unit and improve performances of a vibration actuator. SOLUTION: This manufacturing method of a vibration actuator excited by applying driving signals to electrode patterns formed on surfaces of electromechanical transducers attached to an elastic unit, includes an electrode forming process (#101) in which whole surface electrodes are formed on at least one side surfaces of the electromechanical transducers, an attachment process (#102) in which the electromechanical transducers are attached to one surface or both surfaces of the elastic unit, an electrode pattern forming process (#103) in which electrode patterns are formed on the whole surface electrodes formed on the electromechanical transducers in a noncontact manner, and an adjustment process (#104) in which the electrode patterns formed in the electrode pattern forming process are re-processed to adjust the performances of the vibration actuator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention manufactures a vibration actuator which joins an electromechanical transducer to an elastic body and applies a drive signal to an electrode pattern formed on the surface of the electromechanical transducer to excite the vibrating actuator. The present invention relates to a method for manufacturing a vibration actuator.

[0002]

2. Description of the Related Art Conventionally, this type of vibration actuator has
By joining an electromechanical transducer such as a piezoelectric element to an elastic body, and applying alternating voltages having different phases to the electromechanical transducer, a plurality of vibrations, for example, a longitudinal vibration and a flexural vibration are generated harmoniously. -Bending types are known.
Japanese Patent Application Laid-Open No. Hei 7-298651 proposes a vibration actuator in which electromechanical transducers are alternately joined to the front and back surfaces of an elastic body in order to improve performance such as driving force and driving efficiency.

[0003]

However, the above-mentioned conventional vibration actuator requires an operation of joining a plurality of electromechanical transducers in accordance with an AC voltage applied to the elastic body, and requires mechanical or optical operation. In the simplest case, the position was visually checked. However, when the position was incorrect, the vibration characteristics were changed, and the performance was likely to be reduced.

[0004] In particular, when an electromechanical conversion element is bonded to the front and back surfaces of an elastic body as in Japanese Patent Application Laid-Open No. 7-298651, the positioning of the front and back surfaces must be accurate.
When the joining operation is difficult and the positioning on the front and back surfaces is inaccurate, the performance may be degraded.

It is also conceivable to use a positioning jig or the like in the assembling work in order to accurately position the electromechanical transducer. In other words, if some kind of positioning means is used for a part of the manufacturing apparatus, the positioning can be adjusted more accurately. However, not only does the development cost of the positioning means increase, but also the positioning work must be performed each time. Another problem arises that it is not suitable for mass production.

[0006] Even if the ideal positioning and joining were achieved, it was inevitable that the characteristics of the vibration actuator would vary due to manufacturing errors of each part.

An object of the present invention is to provide a method of manufacturing a vibration actuator capable of accurately positioning an electromechanical transducer with respect to an elastic body, and thereby improving the performance of the vibration actuator. It is.

[0008]

In order to solve the above-mentioned problems, according to the present invention, an electromechanical transducer is joined to an elastic body, and an electrode pattern formed on a surface of the electromechanical transducer is formed. An electrode forming step (# 101) of forming a full-surface electrode on at least one surface of the electromechanical conversion element, the method comprising the steps of: A joining step (# 102) of joining the other surface of the electromechanical transducer element opposite to the one face to both faces or one face of the electromechanical transducer element, and the entire surface formed on the electromechanical transducer element An electrode pattern forming step (# 103) of forming an electrode pattern on an electrode is a method of manufacturing a vibration actuator.

According to a second aspect of the present invention, in the method of manufacturing a vibration actuator according to the first aspect, an adjusting step of adjusting the performance of the vibration actuator by reworking the electrode pattern formed in the electrode pattern forming step. (# 1
04).

According to a third aspect of the present invention, in the method of manufacturing a vibration actuator according to the first aspect, the electrode pattern forming step is performed by non-contact processing. It is.

[0011] The invention of claim 4 is the invention of claims 1 to 3.
In the method for manufacturing a vibration actuator according to any one of the above, the vibration actuator may have a radially symmetric elongation vibration mode that expands and contracts in a radial direction, and a non-axisymmetric plane that bends axisymmetrically in the same plane. A method for manufacturing a vibration actuator, comprising: a vibrator that simultaneously generates a vibration mode.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in more detail. (First Embodiment) FIG. 1 is a process diagram showing a first embodiment of a method of manufacturing a vibration actuator according to the present invention. FIGS. 2 and 3 show a vibration actuator 10 manufactured by the manufacturing method according to the first embodiment. It is the front view and top view shown. The manufacturing method according to the first embodiment includes an electrode forming step # 101, a joining step # 102, an electrode pattern forming step # 103,
Adjusting step # 104.

First, a vibration actuator 10 manufactured by the manufacturing method of the first embodiment will be described with reference to FIG. 2 or FIG. The vibration actuator 10 includes a vibrator 11, a relative motion member 51 that generates relative motion between the vibrator 11, and a pressing member 32 that presses and contacts the vibrator 11.
And pressurizing means 31 having The pressing means 31 generates a pressing force between the vibrator 11 and the relative motion member 51.

The vibrator 11 includes an elastic body 12 and an elastic body 12.
And an electromechanical transducer 13 which is an electromechanical transducer mounted on one plane. The elastic body 12 is formed in a rectangular flat plate shape. The dimensions of each part of the elastic body 12 are the primary longitudinal vibration L1 and the fourth-order bending vibration B4.
The natural frequencies are set so as to be substantially the same.

An electromechanical transducer 13 to be described later is bonded to one plane of the elastic body 12 by bonding or the like. Two grooves in the width direction of the elastic body 12 are provided on the other plane of the elastic body 12 at a predetermined distance from each other in the relative movement direction (the left-right direction in FIG. 2). A sliding member having a rectangular cross-sectional shape is fitted into these grooves and adhered by an epoxy-based adhesive, and a part of the sliding member is mounted so as to protrude from the elastic body 12 in a protruding manner. The protruding sliding material functions as the driving force extracting portions 12a and 12b. Therefore, the elastic body 12 comes into contact with the relative motion member 51 via the driving force extracting portions 12a and 12b made of these sliding members.

FIG. 3 shows a longitudinal vibration L1 generated in the vibrator 11.
It is explanatory drawing which shows bending vibration B4. The driving force output members 12a, 12b are positioned to match the loop position m _1, m ₄ is located outside of the four loop position m ₁ ~m ₄ fourth-order bending vibration B4 generated in the elastic member 12 Is provided. The driving force output portions 12a, 12b need not in a position to exactly match the loop position m _1, m ₄ bending vibration B4, may be in the vicinity of the antinode position.

The electromechanical transducer 13 is made of a thin plate-like piezoelectric material. This electromechanical transducer 13 has input regions 13a, 13a to which an A-phase drive signal is inputted.
The input regions 13b and 13d to which the driving signal of the phase B is shifted by (π / 2) from the phase of the phase A by (π / 2) are formed. Each of the input areas 13a to 13d is, as shown in FIG.
Five nodal positions n _{1 of} bending vibration B4 generated in elastic body 12
Desirably it is accurately formed into four regions partitioned by ~n _5. That is, since the input region 13a~13d be deformed by input of the driving signal are both, which does not cross the nodal position n ₁ ~n ₅ is a fixed point, input region 1
Deformation of 3a~13d is not to be inhibited by the nodal positions n ₁ ~n _5. Therefore, each of the input areas 13a to 13d
Electric energy input to the elastic body 1 with maximum efficiency
2 because it is converted into mechanical energy.

At the node positions n ₂ and n ₄ of the bending vibration B4, detection areas 13p and 13p 'for outputting electric energy by the longitudinal vibration L1 generated by the vibrator 11 are provided in a semicircular shape. Thereby, the vibration state of the longitudinal vibration L1 generated by the vibrator 11 is detected.

Each of the input areas 13a to 13d and each of the detection areas 1
Electrode patterns 15a to 15d, 15p, and 15p 'are formed on the surfaces of 3p and 13p', respectively.
Therefore, it is possible to input a drive signal to each of the input regions 13a to 13d independently, and to output a detection signal independently from each of the detection regions 13p and 13p '.

Next, a method of manufacturing the vibration actuator according to the first embodiment will be described. Electrode forming step # 101
Is a step of forming the entire surface electrode 15 on at least one surface of the electromechanical transducer 13. Electromechanical transducer 1
Numeral 3 is a thin rectangular shape made of a piezoelectric material such as PZT (lead zirconate titanate), quartz, barium titanate, or the like. The electrode 15 is formed, for example, by printing an ink containing a metal such as silver by a screen printing method, by forming a metal such as nickel by electroless plating, or by forming a metal plate by a bonding method such as bonding. It is obtained by doing. In this embodiment, a full-surface electrode is also formed on the back surface so that grounding can be obtained when the electrode is joined to the elastic body.

The joining step # 102 is a step of joining the electromechanical transducer 13 to both or one surface of the elastic body 12. As the elastic body 12, stainless steel, steel, phosphor bronze or Elinvar material, brass, aluminum, or the like is used, and a metal material having a large resonance sharpness is preferable. In this embodiment, one electromechanical transducer 1 is provided on the surface of the elastic body 12.
3 was joined by an adhesive such as epoxy.

The electrode pattern forming step # 103 is a step of forming electrode patterns 15a to 15d, 15p and 15p 'on the entire surface electrodes 15 formed on the electromechanical transducer 13. Each of the electrode patterns 15a to 15d, 15p, 15
p ′ is formed by non-contact processing means such as laser processing or electric discharge processing. For this reason, no mechanical stress or the like is applied to the elastic body 12, the electromechanical transducer 13, and the like. In addition, the electromechanical transducer 13 is often made of ceramics, and may be damaged or cracked by machining with a blade such as a milling machine or a lathe.
Non-contact processing means is preferred.

The adjusting step # 104 includes the electrode patterns 15a to 15d, 1 formed in the electrode pattern forming step # 103.
5p and 15p 'are reworked and the vibration actuator 10
This is a step of adjusting the performance of the device. Each step of the above manufacturing method #
Due to 101 to # 103, even if the electrode patterns 15a to 15d, 15p, and 15p 'are formed at ideal positions, the characteristics of the vibration actuator 10 vary due to manufacturing errors of the respective components. Is inevitable. Therefore, in the first embodiment, the electrode patterns 15a to 15a to
After forming 15d, 15p, and 15p ', the performance was adjusted while applying the electrical probe to measure the vibration characteristics and again applying the processing by the processing means described above.

As described above, according to the first embodiment, the electrode pattern is formed after the entire surface electrode is formed on the electromechanical transducer and joined to the elastic body. In order to assemble, there is no longer any constraint such as the necessity of a positioning jig or the like in the assembling work. In other words, there is no inaccurate alignment such as visual alignment or optical position detection,
The possibility of damaging the performance of the vibration actuator has been eliminated. Further, the cost for developing accurate positioning means is not required, and a manufacturing method suitable for mass production can be realized.

Further, since the electromechanical transducer can be formed at an ideal position with respect to the elastic body, the characteristics of the electromechanical transducer can be maximized, and the performance of the vibration actuator can be improved. .

Further, since the electrode shape can be adjusted again in the adjustment step, even if there is a manufacturing error in each part, the electrode shape is adjusted according to the variation in the characteristics of the vibration actuator, and the vibration actuator is adjusted. Characteristics can be adjusted. Therefore, the characteristics of the completed vibration actuator do not vary.

(Second Embodiment) FIGS. 4 to 6 are process diagrams showing a second embodiment of a method of manufacturing a vibration actuator according to the present invention. FIG. 4 shows an electrode forming step # 101, and FIG. FIG. 6 is a view showing an electrode pattern forming step # 103. FIG. 7 is a diagram illustrating a vibration actuator manufactured by the manufacturing method according to the second embodiment. In the embodiments described below, parts performing the same functions as those in the above-described first embodiment are denoted by the same reference numerals or the same reference numerals at the end, and overlapping drawings and descriptions are appropriately omitted.

First, the vibration actuator will be described with reference to FIG. The vibrator 21 of this vibration actuator is formed by bonding electromechanical transducers 23 and 24 having the same thickness to both sides of an elastic body 22 made of a metal plate or the like by using an adhesive or the like. Electromechanical transducer 2
Nos. 3 and 24 are obtained by forming a piezoelectric material such as PZT into a donut plate shape and polarizing the entire surface in the plate thickness direction [FIG.
(B)]. The donut plate shape of the vibrator 21 is designed and manufactured such that the resonance frequencies of the radially symmetric elongation vibration mode (R, 1) and the non-axisymmetric in-plane vibration mode ((1, 1)) are substantially equal. .

The electromechanical conversion elements 23 and 24 are
Both sides have full-surface electrodes 25B and 26B (see FIGS. 4 and 6).
The electrodes on the opposite side are the electrodes 25A-1, 25A-2 or the electrodes 26A-1, 26A-2 which divide the whole in the diameter direction into approximately two. Two electrodes 25
AC voltages having different phases are input to A-1, 26A-1 or the electrodes 25A-2, 26A-2. The electromechanical transducers 23 and 24 have electrodes 25A-1 and 26A- on the surface opposite to the surface facing the elastic body 22.
1 or the arrangement of the electrodes 25A-2 and 26A-2 respectively match. That is, the electrodes 25A and 26A are
Two electromechanical transducers 2 arranged on both sides of
At positions overlapping the stacking directions of 3, 24, the directions of division substantially match.

The vibrator 20 is driven by a drive voltage generator including an oscillator, a phase shifter, an amplifier, etc.
The first AC voltage is applied to 6A-1. In addition, a second AC voltage having a phase electrically different from the first AC voltage by (π / 2) is applied to the electrodes 25A-2 and 26A-2. The electrodes 25B and 26B on the back surface are connected to the GND potential.

The vibrator 20 controls the frequency of the AC voltage to 2
By approaching the resonance frequency of the two vibration modes,
Resonating in two modes, radially symmetric elongational vibration and non-axisymmetric in-plane vibration occur simultaneously. And the vibrator 21
Causes an elliptical motion as a displacement obtained by combining two vibrations at the position of the driving force extracting portion. At this time, the vibrator 21
A frictional force is generated between the sliding surface of the relative moving member and the relative moving member in the moving direction of the relative moving member, and a linear driving force of the relative moving member can be obtained.

The phase difference between the first and second AC voltages is π / 2
, The straight traveling direction can be reversed. Further, by moving the driving frequency closer to or farther from the resonance frequency of the vibrator, it is possible to increase or decrease the speed of the straight running operation. The speed can be increased or decreased by increasing or decreasing the AC voltage.

Next, a method of manufacturing the vibration actuator according to the second embodiment will be described. The electrode forming step # 101 includes:
As shown in FIG. 4, this is a step of forming full-surface electrodes 25 on both surfaces of the electromechanical transducer 23. The electrode 25 is formed by printing of silver or the like or electroless plating of nickel or the like. 4A and 4C are a front view and a back view showing the electromechanical transducer 23, and FIG. 4B is a side view. The electrodes 25A and 25B on the front and rear surfaces are all full-surface electrodes in the same manner, and an identification mark 27 for identifying the direction of polarization (arrow A) is provided on one surface (here, the front surface). This identification mark 27 can be formed by a writing instrument, printing, or the like.

In the joining step # 102, as shown in FIG.
In this step, the electromechanical transducers 23 and 24 having the entire electrodes 25 and 26 formed in the electrode forming step # 101 are joined to both surfaces of the elastic body 22. In this step # 102, the jig 61
The electromechanical transducer 23, the elastic body 22, and the electromechanical transducer 24 are laminated in this order. After the lamination, the back surfaces of the electromechanical transducers 23, 24 (identification marks 27, 28) are formed in order to form an electrode pattern. ), It is not necessary to be aware of the orientation of each component.

The electrode pattern forming step # 103 is a step of forming an electrode pattern on the entire electrodes 25A, 26A on the surfaces formed on the electromechanical transducers 23, 24, as shown in FIG.

In this step # 103, the joining step # 102
After completion of the bonding, the non-contact processing means 62, 62, such as laser processing or electric discharge processing, automatically divides the lowermost surface and the uppermost surface full-surface electrodes 25A, 26A into two equal parts, and forms electrode patterns 25A-1, 25A-2 and electrode pattern 26A-
1, 26A-2 is formed.

This electrode pattern forming step # 103
At this time, it is also possible to change the area of the electrode pattern and adjust the characteristics of the vibration actuator within a certain range by using an electric detection means (for example, impedance measurement) together (adjustment step # 104).

FIG. 8A shows electromechanical transducers 83 and 8.
4 is a diagram showing a case where an electrode pattern is formed on the elastic member 4 and then the elastic member 82 is laminated. The lamination order is as follows. First, the electromechanical transducer 83 is set face down on the jig 61,
The elastic body 82 is set thereon, and further, the electromechanical transducer 84 is set face up thereon. At this time, the matching of the electrode patterns of the electromechanical transducer 83 and the electromechanical transducer 84 is visually checked or special positioning means is required.

Further, as shown in FIG. 8B, if the deformed portions d are formed in the electromechanical transducers 83b and 84b,
Although the position at the time of lamination can be adjusted, the characteristics are changed because the shape is not point symmetric, and when setting the jig 61b having the alignment portion e of the irregularly shaped portion d,
It is unavoidable that the orientation must be matched and that the relationship between the irregularly shaped portion and the electrode pattern varies due to manufacturing errors of the parts.

Various modifications and changes are possible without being limited to the embodiment described above, and these are also within the equivalent scope of the present invention. (1) As shown in FIG. 9, when an electromechanical transducer is joined to the front and back surfaces of a vibration actuator having the same configuration as that of the first embodiment, the same operation as in the second embodiment may be performed. (2) In the electrode pattern forming step # 103, in order to make the characteristics at the time of actual driving less variable,
This may be performed after attaching the vibration actuator to the support member. The electrode pattern forming step # 103 is
As described above, only the adjustment step # 104 may be performed after attaching to the support member.

[0041]

As described in detail above, the present invention has the following effects. (1) Since the electrode pattern is formed after the entire electrode is formed on the electromechanical transducer and joined to the elastic body, the joining can be performed without being conscious of the position of the electrode pattern. Becomes unnecessary, and the assembly cost can be reduced. At this time, since the electrode pattern is formed later, the shape of the electromechanical transducer is not changed for positioning, so that the characteristics of the vibration actuator do not change. (2) A plurality of electrode patterns formed on the same surface of the elastic body can be formed at accurate positions according to vibration characteristics, or
The electrode patterns formed on the front and back surfaces of the elastic body can be accurately matched on the front and back surfaces, and the performance of the actuator can be improved. At this time, mass production can be performed at low cost without the need for a device such as a positioning means. (3) Since the electrode pattern can be adjusted by the adjusting step, it is possible to provide a vibration actuator that cancels performance variations caused by various manufacturing errors generated in each component and exhibits performance within a certain range.

[Brief description of the drawings]

FIG. 1 is a process chart showing a first embodiment of a method for manufacturing a vibration actuator according to the present invention.

FIG. 2 is a front view showing a vibration actuator manufactured by the manufacturing method according to the first embodiment.

FIG. 3 is a plan view showing the vibration actuator 10 manufactured by the manufacturing method according to the first embodiment.

FIG. 4 is a view showing an electrode forming step # 101 of the method for manufacturing a vibration actuator according to the second embodiment.

FIG. 5 is a view showing a joining step # 102 of the method of manufacturing the vibration actuator according to the second embodiment.

FIG. 6 is a view showing an electrode pattern forming step # 103 of the method of manufacturing the vibration actuator according to the second embodiment.

FIG. 7 is a diagram illustrating a vibration actuator manufactured by a manufacturing method according to a second embodiment.

FIG. 8 is a diagram showing a comparative example of a method of manufacturing a vibration actuator (a case where an electrode pattern is formed on an electromechanical transducer and then laminated on an elastic body).

FIG. 9 is a front view showing another vibration actuator manufactured by a manufacturing method according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration actuator 11, 21 Vibrator 12, 22 Elastic body 13, 23, 24 Electromechanical conversion element 15, 25, 26 Electrode pattern 61 Jig 62 Processing means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H680 AA00 BB01 BB13 CC02 CC10 DD01 DD15 DD23 DD24 DD53 DD55 DD72 DD82 DD85 DD95 EE24 FF08 FF11 FF16 FF17 FF21 FF23 FF25 FF26 FF33 GG02 GG20 GG23 GG24 GG25 GG27

Claims (4)

[Claims] An electromechanical transducer is joined to an elastic body,
In a method for manufacturing a vibration actuator for applying a drive signal to an electrode pattern formed on a surface of the electromechanical transducer to excite the same, a full-surface electrode is formed on at least one surface of the electromechanical transducer. An electrode forming step of bonding; a bonding step of bonding the other surface of the elastic body opposite to the one surface to the both surfaces or one surface of the elastic body, respectively; A method for manufacturing a vibration actuator, comprising: an electrode pattern forming step of forming an electrode pattern on an entire surface electrode formed on an element. 2. The method of manufacturing a vibration actuator according to claim 1, further comprising an adjustment step of adjusting the performance of the vibration actuator by reworking the electrode pattern formed in the electrode pattern formation step. A method of manufacturing a vibration actuator. 3. The method for manufacturing a vibration actuator according to claim 1, wherein the electrode pattern forming step is performed by non-contact processing. 4. One of claims 1 to 3
In the manufacturing method of the vibration actuator described in the paragraph, the vibration actuator simultaneously generates a radially symmetric elongation vibration mode that expands and contracts in a radial direction and a non-axisymmetric in-plane vibration mode that bends non-axisymmetrically in the same plane. A method of manufacturing a vibration actuator, comprising: