JP2009077545A - Driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable driver which facilitates connection of the electrode film of a piezoelectric element and a wiring member, and ensures stabilized conduction. <P>SOLUTION: The driver comprises: a plurality of planar piezoelectric elements 3 each having an electrode film formed on the opposite sides; conductive diaphragms sandwiched between the plurality of piezoelectric elements; a planar conductive member 5 for electrically conducting the piezoelectric element and the diaphragm; a rodlike drive member 1 connected with one of the plurality of piezoelectric elements; a driven member 8 friction engaging with the drive member movably; and supporting members 2 and 7 for supporting the drive member and holding electric conduction of the piezoelectric element and the planar conductive member by pressing the piezoelectric element, the diaphragm and the planar conductive member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power feeding structure of a driving device using a piezoelectric element.

  Various types of power feeding structures have been proposed for conventional driving devices using piezoelectric elements. As an example, a conventional driving device will be described with reference to FIG.

  FIG. 6 is a side view of a conventional drive device.

  A cylindrical driving member 140 is coupled to one surface of the vibration generating member 100, and a driven member 180 is frictionally engaged with the driving member 140. The drive member 140 is held by a support member (not shown).

  The vibration generating member 100 includes disk-shaped piezoelectric elements 110 and 120 and a vibration plate 130 bonded to the inner surface of the piezoelectric elements 110 and 120.

  Electrode films are formed on both surfaces of the piezoelectric elements 110 and 120.

  The diaphragm 130 is made of a disk-shaped metal plate having a slightly larger diameter than the piezoelectric elements 110 and 120. The diaphragm 130 is electrically connected to the electrode films of the piezoelectric elements 110 and 120.

  Lead wires 150 and 151 are connected to the vibration generating member 100 by soldering. The lead wire 150 is soldered to the electrode film of one piezoelectric element 110. The lead wire 151 is connected to the diaphragm 130. Further, the electrode film of one piezoelectric element 110 and the electrode film of the other piezoelectric element 120 are electrically connected by a lead wire 152.

  In the driving apparatus using such a piezoelectric element, the piezoelectric elements 110 and 120 vibrate by applying an appropriate voltage between the lead wires 150 and 151 of the vibration generating member 100. This vibration causes the driving member 140 fixed to one surface of the vibration generating member 100 to vibrate, and the driven member 180 frictionally engaged with the driving member 140 is moved along the driving member 140.

  FIG. 7 is a diagram showing another conventional example. In the structure of FIG. 7, the piezoelectric element 210 and the extraction electrode 250 are bonded and pressurized with an adhesive 260, and the protrusions 212 of the electrode film 211 and the extraction electrode 250 are utilized using the unevenness of the surface of the electrode film 211 of the piezoelectric element 210. To maintain conductivity.

  FIG. 8 is a diagram showing another conventional example. In the structure of FIG. 8, the connection electrode 313 is formed on the electrode film 311 formed on the surface of the piezoelectric element 310, and the bump 360 of solder composition is formed thereon. Then, the lead conductive member 350 is placed on the bump 360 and is heat-pressed by the heater 370 to maintain conductivity. In FIG. 8, 320 is a piezoelectric element, and 330 is a diaphragm.

These are described, for example, in Patent Document 1 as known examples.
JP 2003-125492 A

  However, in the power feeding method of the drive device shown in FIG. 6, the lead wire is easily bent due to the handling of the lead wire and repeatedly bent at the base of soldering. In addition, there is a limit to reducing the thickness of the solder fillet.

  In the method shown in FIG. 7, there is a possibility that the bonded portion is loosened and the adhesive bond is peeled off. Furthermore, since the adhesive curing time is required, the manufacturing operation takes time.

  In the method shown in FIG. 8, the process is complicated and the productivity is lowered.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a reliable driving device that facilitates the connection between the electrode film of the piezoelectric element and the wiring member and ensures stable energization. It is to be.

  In order to solve the above-described problems and achieve the object, a driving apparatus according to the present invention includes a plurality of piezoelectric elements formed in a flat plate shape and having electrode films formed on both surfaces, and the plurality of piezoelectric elements. A sandwiched conductive diaphragm; a plate-like conductive member for energizing the piezoelectric element and the diaphragm; a rod-like drive member connected to one of the plurality of piezoelectric elements; and the drive A driven member frictionally engaged with the member, supporting the driving member, and pressing and sandwiching the piezoelectric element, the diaphragm, and the plate-like conductive member, And a support member that maintains electrical continuity between the piezoelectric element and the plate-like conductive member.

  In the driving apparatus according to the present invention, the support member presses and sandwiches the piezoelectric element, the diaphragm, and the plate-like conductive member using an elastic member having an elastic force. And

  In the drive device according to the present invention, the elastic member is a leaf spring shape portion formed on the plate-like conductive member.

  In the driving apparatus according to the present invention, the elastic member is made of a synthetic polymer material.

  In the driving device according to the present invention, the plate-like conductive member is a flexible printed board.

  In the driving apparatus according to the present invention, the plate-like conductive member is a thin plate having a crimp terminal to which a lead wire is crimped.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the reliable drive device which made the connection of the electrode film of a piezoelectric element, and a wiring member easy, and ensured the stable electricity supply.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is an exploded perspective view showing the configuration of the driving apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram showing a power feeding structure.

  The columnar (rod-like) driving member 1 frictionally engaged with the driven member 8 is inserted into the hole 2b of the supporting portion 2a of the supporting member 2 and the hole 2d of the supporting portion 2c, and moves in the longitudinal direction of the driving member 1. Held possible. A vibration generating member 3 using a plurality of plate-like piezoelectric elements is coupled to one end face of the driving member 1.

  The vibration generating member 3 includes two disk-shaped piezoelectric elements 3b and 3c, and a vibration plate 3a sandwiched and bonded between the two piezoelectric elements. Electrode films 3b-1 and 3c-1 are formed on both surfaces of the two piezoelectric elements 3b and 3c. In the present embodiment, there are two piezoelectric elements, but the same applies to a structure in which three or more are stacked, and the shape may be other than a circular plate.

  The diaphragm 3a is made of a disk-shaped metal plate having a slightly larger diameter than the two piezoelectric elements 3b and 3c. The diaphragm 3a is joined to an electrode film in contact with the diaphragm 3a of the two piezoelectric elements 3b and 3c so as to be conductive.

  A conductor portion 5a of a substantially glasses-like flexible printed circuit board (hereinafter abbreviated as FPC) 5 inserted through the drive member 1 is soldered to the terminal portion 3a-1 of the vibration plate 3a of the vibration generating member 3. .

  The FPC 5 includes conductor portions 5b and 5c connected to each other by a conductor at a position corresponding to a substantially glasses-shaped lens. A hole through which the drive member 1 passes is provided at the center of one conductor portion 5b, and the conductor portion 5b is inserted through the drive member 1 so that the electrode film 3b-1 (see FIG. 2 on the back side of the paper).

  The other conductor 5c is bent in a U shape and is disposed so as to contact the electrode film 3c-1 on the other outer surface of the vibration generating member 3. An elastic member 4a having a ring-shaped elastic force is inserted through the drive member 1 between the FPC 5 bent into a U-shape and the support portion 2a. Between the FPC 5 and the holding member 7, there is provided an elastic member 4b having a ring-shaped (or a disk shape without holes) elastic force.

  By attaching the holding member 7 to the support member 2 with a set screw 7s, the vibration generating member 3, the FPC 5, and the elastic members 4a and 4b are sandwiched between the support member 2 and the holding member 7, and the elastic members 4a and 4b are compressed. Held in a state. The elastic members 4a and 4b are made of a synthetic polymer material (rubber). Other materials can be used as long as the electrode films 3b-1, 3c-1 and the conductor portions 5b, 5c can be pressurized stably. Selected. Incidentally, the pressing force can also be adjusted by adjusting the method of stopping the set screw 7s by inserting a tightening torque or a washer. The electrode films 3b-1 and 3c-1 of the vibration generating member 3 and the conductor portions 5b and 5c of the FPC 5 are pressed and brought into close contact with each other by the repulsive force of the compression.

  An appropriate voltage is applied to the vibration generating member 3 through the FPC 5 to cause vibration, and the drive member 1 is vibrated in the longitudinal direction. The driven member 8 frictionally engaged with the driving member 1 moves along the driving member.

  In order to stabilize the electrical connection between the FPC 5 and the electrode film, the contact pressure may be concentrated by making the pattern of the conductor portion of the FPC a striped pattern, multiple points, or the like. Further, the shape of the FPC 5 may be arbitrarily configured as long as the conductivity with the electrode film can be maintained.

  FIG. 3 is an exploded perspective view showing the driving apparatus of the second embodiment, and FIG. 4 is a view showing a power feeding structure of the second embodiment.

  Since the second embodiment has substantially the same configuration as the first embodiment, the differences will be mainly described.

  In the second embodiment, lead wires are used instead of the FPC of the first embodiment.

  A lead wire 16a for applying a voltage to the electrodes on the inner side surfaces of the piezoelectric elements 13b and 13c of the vibration generating member 13 is crimped and joined to a substantially U-shaped lead wire crimping portion 13u formed on the diaphragm 13a.

  Between the one surface of the vibration generating member 13 and the support member 2a, a thin plate-like ring-shaped conductive member 15a and a ring-shaped elastic member 4a to which a lead wire 16b is crimped are both inserted into the drive member 1. Yes. Between the other surface of the vibration generating member 13 and the holding member 7, a thin plate-like, ring-shaped (a thin plate-like shape without holes) with a lead wire 16 c may be bonded to a ring-shaped (circle without a hole). A plate-like elastic member 4b may be provided.

  By attaching the holding member 7 to the support member 2 with a set screw 7s, the vibration generating member 13, the conductive members 15a and 15b, and the elastic members 4a and 4b are sandwiched between the support member 2a and the holding member 7, and the elastic members 4a and 4b. Is held in a compressed state. The electrode film of the vibration generating member 13 and the conductive members 15a and 15b are pressed and brought into close contact with each other by the repulsive force of the compression.

  The conductive members 15a and 15b may have any shape as long as they can maintain conductivity with the electrode film of the vibration generating member 13. Further, if the conductive members 15a and 15b are provided with protrusions or the like to concentrate the contact pressure, the conductivity can be further improved.

  FIG. 5 is an exploded perspective view showing the configuration of the driving apparatus of the third embodiment.

  Since the third embodiment has substantially the same configuration as the second embodiment, the differences will be mainly described.

  In the third embodiment, the conductive members 15a and 15b of the second embodiment have a spring property.

  A lead wire 16a for applying a voltage to the electrodes on the inner side surfaces of the piezoelectric elements 13b and 13c of the vibration generating member 13 is crimped and joined to a substantially U-shaped lead wire crimping portion 13u formed on the diaphragm 13a.

  Between the one surface of the vibration generating member 13 and the support member 2a, a thin plate-like, substantially ring-shaped conductive member 25a to which a lead wire 16b is crimped is inserted into the drive member 1. A plate spring-shaped portion 25a-1 is formed on the conductive member 25a, and elasticity is imparted in the thickness direction of the conductive member 25a. Between the other surface of the vibration generating member 13 and the holding member 7, there is provided a conductive member 25b having a thin plate shape and a substantially ring shape (or a thin plate shape without a hole) to which a lead wire 16c is crimped. The conductive member 25b is formed with a leaf spring-shaped portion 25b-1, and has elasticity in the thickness direction of the conductive member 25b.

  By attaching the holding member 7 to the support member 2 with a set screw 7s, the vibration generating member 13 and the conductive members 25a and 25b having spring properties are sandwiched between the support member 2a and the holding member 7, and the conductive member 25a having spring properties. 25b are held in a compressed state. The electrode film of the vibration generating member 13 and the conductive members 25a and 25b are pressed and brought into close contact with each other by the repulsive force of the compression.

  The conductive members 25a and 25b have a spring property, and may have any shape as long as the conductivity and the electrode film of the vibration generating member 13 can be maintained.

  As described above, according to the above-described embodiment, the electrical connection between each electrode film and the conductive member is performed by the crimping connection by pressurization of the electrode film and the conductive member. Will deteriorate and will not break.

  Furthermore, since soldering to the adhesive or electrode film is not required, the connection work is easy, and the supporting means for supporting the vibration generating member and the pressing means for crimping connection can be made common. Can be reduced.

  In addition, when electrical connection with each electrode film and the diaphragm is performed by an integrated flexible printed board, there is no need to apply excessive force to the joint because of the flexibility. Furthermore, since the crimping surface can be formed by the conductor portion of the flexible printed circuit board, a large-area crimping surface can be easily formed without using other components.

  Furthermore, even when the electrical connection with each electrode film or diaphragm is made with a thin plate having a crimp terminal to which a lead wire is crimped, the junction between the thin plate portion, which is a conductor portion, and the lead wire becomes a crimp terminal. Therefore, excessive force is not applied to the joint. Further, by forming a portion having a spring property in the thin plate portion, it can also serve as an elastic member that pressurizes the joint portion, and the number of parts can be further reduced.

It is a disassembled perspective view which shows the structure of the drive device of the 1st Embodiment of this invention. It is a figure which shows the electric power feeding structure in the drive device of 1st Embodiment. It is a disassembled perspective view which shows the structure of the drive device of the 2nd Embodiment of this invention. It is a figure which shows the electric power feeding structure in the drive device of 2nd Embodiment. It is a disassembled perspective view which shows the structure of the drive device of the 3rd Embodiment of this invention. It is a figure which shows the electric power feeding structure in the drive device using the conventional piezoelectric element. It is a figure which shows the other conventional electric power feeding structure. It is a figure which shows other conventional electric power feeding structures.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive member 2 Support member 2a, 2b Support part 2b, 2d Hole 3 Vibration generating member 3a Diaphragm 3b, 3c Piezoelectric element 4a, 4b Elastic member 5 Flexible printed circuit board (FPC)
5a, 5b, 5c Conductor part 7 Holding member 7s Set screw 8 Driven member 13 Vibration generating member 13a Diaphragm 13u Lead wire crimping part 15a, 15b Conductive member 16a, 16b, 16c Lead wire 25a, 25b Conductive having spring property Member 100 vibration generating member 110, 120 piezoelectric element 130 diaphragm 140 driving member 150, 151, 152 lead wire 180 driven member 210 piezoelectric element 211 electrode film 212 electrode film convex part 250 extraction electrode 260 adhesive 310 piezoelectric element 311 electrode film 313 Connection electrode 350 Extraction electrode 360 Bump 370 Heater

Claims (6)

A plurality of piezoelectric elements formed in a flat plate shape and electrode films formed on both sides;
A conductive diaphragm sandwiched between the plurality of piezoelectric elements;
A plate-like conductive member for energizing the piezoelectric element and the diaphragm;
A rod-shaped drive member connected to one of the plurality of piezoelectric elements;
A driven member frictionally engaged with the driving member in a movable manner;
The piezoelectric element, the diaphragm, and the plate-like conductive member are pressed and sandwiched while supporting the driving member, thereby providing electrical continuity between the piezoelectric element and the plate-like conductive member. A supporting member to hold;
A drive device comprising:   The driving device according to claim 1, wherein the support member presses and sandwiches the piezoelectric element, the diaphragm, and the plate-like conductive member using an elastic member having an elastic force. .   The drive device according to claim 2, wherein the elastic member is a leaf spring-shaped portion formed on the plate-like conductive member.   The drive device according to claim 2, wherein the elastic member is made of a synthetic polymer material.   The drive device according to claim 1, wherein the plate-like conductive member is a flexible printed board.   The drive device according to claim 1, wherein the plate-like conductive member is a thin plate having a crimp terminal to which a lead wire is crimped.

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