JP2005176479A - Oscillating body and oscillating wave actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein energy losses during oscillation with a oscillating body are large since a resin-made circuit substrate is interposed between an elastic body of the oscillating body and an electromechanical energy transducer. <P>SOLUTION: The oscillating body is composed of the electromechanical energy transducer and the elastic body 1 and excites oscillation by supplying power to the electromechanical energy transducer. The elastic body 2 is made of ceramics. The power is supplied to the electromechanical energy transducer 5 by forming a wiring pattern 2b on the surface of the elastic body being in contact with the electromechanical energy transducer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vibration body and a vibration wave actuator such as a vibration wave motor using the vibration body, and more particularly to a vibration body to which electric power is supplied via a wiring pattern.

  Conventionally, a vibrating body using a circuit board has been devised to supply electric power to a piezoelectric element of a vibrating body, such as, for example, Japanese Patent No. 3170634 and Japanese Patent Laid-Open No. 7-193291.

  FIG. 6 is a cross-sectional view of a vibrating body 41 constituting a rod-like vibration wave motor which is one of conventional vibration wave actuators. As shown in the figure, the rod-shaped vibrating body includes a metal first elastic body 42 and a second elastic body 43, a laminated piezoelectric element 45 disposed between them, and a sandwiching portion 46d of the circuit board 46 as shown in the figure. The shafts 44 and nuts 47 in the center are tightened between the elastic bodies 42 and 43 to form an integral structure.

  The laminated piezoelectric element 45 is an element in which a plurality of piezoelectric ceramic layers (hereinafter referred to as piezoelectric layers) having an electromechanical energy conversion element function and electrode layers are alternately stacked and laminated. The wiring pattern 46e of the clamping part 46a of the circuit board 46 shown in FIG. 7 is clamped by an elastic body and directly brought into contact with the plurality of electrodes exposed on the surface, thereby enabling electrical connection. Then, electric power can be supplied to the vibrating body 1 from an external power source via the circuit board 46.

  The circuit board 46 is provided with a wiring pattern 46e for conducting electrical connection, a linear wiring pattern 46f connected to the wiring pattern 46e, and a wiring pattern 46g for a terminal part on a base part 46d which is a base of the board. Conventionally, the base material portion 46d of the circuit board 46 is made of an insulating and flexible polyimide resin, and the wiring patterns 46e, 46f, and 46g are made of copper foil.

  In some cases, the wiring pattern portions 46e, 46f, and 46g of the circuit board 46 are bonded to the base portion 46d by an epoxy adhesive or directly bonded.

  When an AC voltage for driving is applied to the laminated piezoelectric element 45 via the circuit board 46, two regions are expanded and contracted in the thickness direction due to the special electrode pattern configuration of the electrode layer inside the laminated piezoelectric element 45. Repeatedly, bi-directional bending vibrations are excited in the vibrating body.

Then, the bending vibration in the two directions causes the vibrating body to generate an elliptical motion on the contact surface 42a, and the contact body that is in pressure contact with the contact surface 42a is caused by the frictional force generated by the elliptical motion of the vibrating body. It moves relative to it. The contact surface 42a of the elastic body 42 is plated with a hard wear-resistant metal (electroless nickel) as a friction material.
Japanese Patent No. 3170634 Japanese Unexamined Patent Publication No. 7-193291

  Conventionally, however, as described above, since the vibration body sandwiches the circuit board 46e made of resin, it is simple and reliable as a means for supplying power, but the vibration attenuation during vibration is large and the energy loss is large. It was. Therefore, the vibration wave motor that is one of the vibration wave actuators using such a vibration body has caused a reduction in motor efficiency and motor performance.

  Furthermore, the vibration wave motors installed in recent digital devices have been required to be smaller and have higher performance, and the smaller the vibrating body, the more negatively the conventional circuit board is sandwiched. It was predicted that the performance of the vibration wave motor would be deteriorated.

  In addition, the contact body that is in pressure contact with the elastic body of the vibrating body wears the contact surface of the elastic body. However, the hard metal by conventional plating is a metal although it is hard, so the wear resistance is insufficient. Met.

  The purpose of the invention according to the present application is to prevent a decrease in efficiency and performance of the vibration body and the vibration wave motor due to vibration attenuation caused by sandwiching the circuit board in the vibration body, and to improve the efficiency and performance of the vibration wave motor. An object of the present invention is to provide a highly reliable vibrator capable of extending the life of a vibration wave motor.

  A first configuration that realizes the object of the invention according to the present application includes an electromechanical energy conversion element and one or a plurality of elastic bodies, and a vibration body that excites vibrations by supplying electric power to the electromechanical energy conversion element. The one or more elastic bodies are made of ceramics, a wiring pattern is formed on the surface of the elastic body in contact with the electromechanical energy conversion element, and power is supplied to the electromechanical energy conversion element. Is the body.

  A second configuration that realizes the object of the invention according to the present application includes an electromechanical energy conversion element and one or a plurality of elastic bodies, and a vibration body that excites vibrations by supplying electric power to the electromechanical energy conversion element. 1, wherein one or a plurality of the elastic bodies are made of ceramics, move relative to the elastic bodies, and contact the pressurized contact bodies with the surfaces of the elastic bodies.

  A third configuration for realizing the object of the invention according to the present application is a combination of the first and second configurations, and includes an electromechanical energy conversion element and one or a plurality of elastic bodies. In the vibrating body that excites vibrations by supplying the one or more elastic bodies, one or a plurality of the elastic bodies are made of ceramics, and a wiring pattern is formed on one surface in contact with the electromechanical energy conversion element. It is a vibrating body that contacts with a contact body that moves relative to the elastic body and makes pressure contact.

  A fourth configuration for realizing the object of the invention according to the present application includes the vibrating body according to the first configuration, and a contact body that is in pressure contact with the surface of the elastic body moves relative to the elastic body. This is a vibration wave actuator characterized by the following.

A fifth configuration that realizes the object of the invention according to the present application includes the vibrating body according to the second configuration, and a contact body that is in pressure contact with the surface of the elastic body moves relative to the elastic body. Vibration wave actuator characterized by.
A sixth configuration that realizes the object of the invention according to the present application includes the vibrating body according to the third configuration, and a contact body that is in pressure contact with the surface of the elastic body moves relative to the elastic body. A vibration wave actuator characterized by that.

  According to a seventh configuration for realizing the object of the invention according to the present application, in the first to third aspects, the electromechanical energy conversion element includes a plurality of layers of materials having an electromechanical energy conversion element function in which a plurality of electrode regions are formed. It is an electromechanical energy conversion element.

  According to an eighth configuration for realizing the object of the invention according to the present application, in the first to sixth aspects, the elastic body is made of alumina, silicon carbide, silicon nitride, zirconia, or ceramics mainly composed of these. This is a vibrating body or a vibration wave actuator.

  According to a ninth configuration for realizing the object of the invention according to the present application, in the first, third, fourth, and sixth, the wiring pattern formed on the surface of the elastic body has a conductive metal attached. The vibration body or the vibration wave actuator is characterized.

  According to the above configuration, energy loss of the vibrating body and the vibration wave actuator can be reduced, and high efficiency and high performance can be achieved. Further, the vibration wave actuator in which the contact body that is in pressure contact with the surface of the elastic body made of ceramic moves relative to the elastic body improves the wear resistance of the friction material, and the vibration wave motor It is possible to improve the service life of the battery. In particular, it is suitable for a small vibrating body and a vibration wave motor.

  According to the present invention, since the wiring pattern is formed on the surface of the elastic body made of ceramics, the conventional circuit board can be eliminated and the energy loss of the vibrator can be reduced. Furthermore, the ceramic itself is also a material with little attenuation, and energy loss of the vibrator can be reduced. As a result, the efficiency and performance of the vibration wave motor can be improved. At the same time, since the elastic body is made of ceramic, the wear resistance of the contact portion is also improved, and the durability time of the vibration wave motor can be improved conventionally.

  Moreover, by applying the present invention to a small vibration wave motor, the processing of ceramics can be eliminated as much as possible, leading to cost reduction. As a result, a highly reliable vibrating body and the like can be provided easily and inexpensively, and the effect of the vibration wave motor is great.

(Embodiment)
FIG. 1 shows a first embodiment according to the present invention. FIG. 1 is a cross-sectional view of a vibration wave motor which is one of new rod-like vibration wave actuators, and its vibration body 1 is composed of an elastic body 2 made of ceramics (alumina) and an elastic body 3 made of metal brass. Further, the laminated piezoelectric element 5 is sandwiched between the shaft 4 and the nut 7 made of steel.

  FIG. 2 shows a wiring pattern 2b formed on one surface in contact with the laminated piezoelectric element 5 of the elastic body 2 made of ceramics. The wiring pattern 2b is formed by printing a conductor made of silver having a thickness of several μm on the surface of ceramic by screen printing, and then baking it. A flat cable 6 is attached to the wiring pattern 2b by soldering. The wiring pattern 2b is brought into direct contact with the electrode on the surface of the laminated piezoelectric element 5 described below, and can be supplied with electric power from an external power source.

  The electromechanical energy conversion element of FIG. 3 is an electromechanical energy conversion element in which a plurality of materials having an electromechanical energy conversion element function in which a plurality of electrode regions are formed are stacked. Show. Electrodes A, A ′, B, and B ′ are formed on one side of the piezoelectric layer of each layer, and electrodes A and AG, A ′ and A′G, B and BG, and B ′ and B ′ are opposed to the top and bottom of the piezoelectric layer. By applying an AC voltage between G, a generating force that becomes a vibration source of the vibrating body is obtained.

  In FIG. 3, the piezoelectric layers 19-1 to 19-n perform conduction of each of the eight types of electrodes A, A ′, B, B′AG, AG ′, BG, B′G independently through the through holes 20. ing.

  In addition, conduction to the outside is obtained by the through-hole 20 formed in the piezoelectric layer 19-1 on the surface, and conduction is performed by contacting the elastic body 2 in which the wiring pattern 2b corresponding to each through-hole is formed. Is called.

  The piezoelectric layer 19-3 has electrodes A, A ′, B, and B ′ formed thereon, and is used for driving. The piezoelectric layer 19-3 has through holes formed in the piezoelectric layer 19-1 and the piezoelectric layer 19-2 and the piezoelectric layer 19. -3 also has a function as a wiring part for connection with electrodes of 3 or less.

  Electrodes A, A ′, B, and B ′ are formed on the piezoelectric layer 19-4, and further, an electrode S for vibration detection is formed. The vibration between the electrode S and the upper and lower electrodes AG is accompanied by vibration. Output as sensor (S phase) is generated by the generated voltage.

  Similarly, the piezoelectric layers 19-5 to 19- (n-1) are divided into four electrodes A, A ', B, B' or AG, AG ', separated by a substantially cross-shaped insulating portion. BG and B′G are formed. In the same piezoelectric layer, the electrodes A and AG and A ′ and A′G facing the central axis are previously polarized in opposite directions. Further, the electrodes B and BG and B ′ and B′G are also polarized in advance in opposite directions.

  These four electrodes A, A ′, B, and B ′ below the piezoelectric layer 19-3 are used for driving the A phase for the electrodes A and A ′, and similarly for the B phase driving for the electrodes B and B ′. .

  In the laminated piezoelectric element 5, the electrodes are divided into four regions in order to effectively use the driving force of the vibration wave motor.

  These piezoelectric layers 19 are laminated and integrated, and then fired to produce the laminated piezoelectric element 5.

  The piezoelectric layer 19-n has a role as an insulating layer, and after the laminated piezoelectric element is fired and integrated, the piezoelectric layers 19-1 and 19-2 are processed together with a double-sided lapping process for smoothing. Also serves as a teenager.

  And each through-hole 20 formed in the piezoelectric layer 19-1 in the surface of the laminated piezoelectric element 5 and the wiring pattern 2b formed in the single side | surface of the elastic body 2 of FIG. In this way, conduction is performed.

  The length of the vibrating body 1 (the length of the shaft 4) is 9.5 mm, the outer diameters of the elastic bodies 2 and 3 are 9 mm, the thicknesses are 1.0 mm and 0.8 mm, respectively, and the diameter of the wiring pattern 2b is 7 mm. . The laminated piezoelectric element 5 has an outer diameter of 6 mm, a thickness of about 1.3 mm, and 22 layers (n is 22 in the figure). The number of layers can be changed arbitrarily according to the motor specifications.

  In FIG. 1, a ferrous metal spring case 9 is joined to an aluminum rotor 8 that has been subjected to alumite treatment by an adhesive or the like. The spring case 9 is provided with a cylinder portion that guides the spring and a flange portion that receives the spring at a lower portion thereof. A compression spring 14 is sandwiched between the flange and the lower portion of the gear 11 to compress the spring 8. The tip is pressed against the contact surface 2 a of the elastic body 2.

  The gear 11 is positioned in the thrust direction by a motor mounting flange 12 positioned by a positioning step provided on the shaft 4 and a nut 13 for fixing the motor mounting flange 12, and rotates and slides at a contact point with the flange 12. A part is formed and is rotatably supported.

  The vibration wave motor configured as described above is driven by applying two-phase AC signals having different phases to the laminated piezoelectric element 5 from an external power source (not shown), and bending vibration in two directions with respect to the longitudinal direction of the shaft 4 is excited in the elastic body. The elastic body generates a bending vibration. At this time, elliptical vibration occurs in the contact portion between the contact surface 2a, which is a friction surface on one side of the elastic body 2, and the rotor 8, whereby the rotor 8, the spring case 9, and the gear 11 rotate together. The spring case 9 is provided with two grooves 9a in the radial direction. Since the grooves 9a and the two protrusions 11a provided on the gear 11 are fitted, the rotational force of the rotor 8 is reduced. It is configured to be transmitted to the gear 11.

  Then, the vibration wave motor is fastened to the mounting base 16 via the flange 12 with a screw 15 and incorporated into the device.

  That is, the elastic body 2 of the vibrating body 1 is made of alumina, which is an insulating ceramic, the contact surface 2a is in contact with the rotor, and the other surface serves as a friction material for applying a frictional force. It serves as a substrate for a wiring pattern to be supplied.

  As a result, there is no need to sandwich a circuit board for attenuating the vibrator as in the prior art, and the vibration wave motor has high motor efficiency and good performance. Further, since the elastic body uses ceramics as a friction material, the wear resistance is improved, and the durability, that is, the life of the vibration wave motor is extended.

  More specifically, there are three reasons for using ceramics for the elastic body. One is that the mechanical properties are advantageous for vibrating bodies. In other words, the vibrating body has conventionally been a metal such as brass, aluminum, or steel, but ceramic is a material with less vibration damping, as is the case with metals, and has a lower specific gravity and a higher Young's modulus. This is advantageous for downsizing.

  Second, ceramic is a material harder than metal, and is optimal as a friction material for sliding parts. The third, unlike metal, is a material that does not have conductivity, so it is easy to use as a circuit pattern substrate.

  However, the reason why ceramics have not been used as an elastic body is that the workability is poor and the machining cost is considerably high. This time, the shape of the elastic body was simplified as much as possible to make it a disk. Furthermore, because the size of the vibrating body has been reduced due to the development of a small vibration wave motor, even if the outer and inner diameters after firing the ceramic are omitted, it becomes a relatively accurate part and the cost does not increase much. It was. For this reason, ceramics was used this time.

The elastic body 2 was produced by mixing 99.5% alumina powder with an organic binder and granulating it into granules, placing it in a powder press mold, press molding, and firing at about 1650 ° C. Of course, ceramics that are generally commercially available and inexpensive are better, but in general, alumina (Al ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), zirconia (ZrO ₂ ) )and so on. In addition, these manufacturers have a small amount of additive components and are used for their respective purposes. In the present invention, ceramics having these as main components may be used. Each ceramic may be selected according to the motor specifications in consideration of cost, wear resistance, and the like. By the way, in this example, importance was put on cost, and alumina with relatively good wear resistance was used.

  The wiring pattern on one side of the elastic body 2 may be printed by a metal paste by screen printing as in this example, or may be printed by a metal powder containing an adhesive having a low baking temperature and low cost. . Further, for mass production, a metal may be deposited by a vacuum deposition method, a sputtering method, or the like. The metal to be used is preferably a conductive material. For example, noble metals such as silver, gold, platinum and palladium, nickel, chromium and copper may be used. Further, the thickness of the metal layer to be deposited is not problematic if it is 0.1 to 10 μm in consideration of the roughness of the ceramic surface.

  In this example, the ceramic of the elastic body 2 is subjected to double-sided lapping after forming and firing to reduce the surface roughness on both sides to about several μm, and then the one-side contact surface is further polished to have a roughness of 0.5 μm or more. It has a good finish and improved wear resistance. Then, a silver paste was printed on the other wrap surface to form a wiring pattern.

  In addition to this example, the wiring pattern may be electrically connected to a wire or another circuit board, or a conductive adhesive may be used in addition to soldering. In this example, a laminated piezoelectric element is used. Of course, even a single-plate piezoelectric element has conventionally used a copper plate, but this example is applicable.

1 shows a vibration wave motor incorporating a vibrating body according to an embodiment of the present invention. The wiring pattern formed in the vibrating body of this invention is shown. The laminated piezoelectric element used for the vibration wave motor incorporating the vibrating body of the Example by this invention is shown. A vibrator using a conventional circuit board is shown. 1 shows a conventional circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibration body 2 Elastic body which consists of ceramics 2a Contact surface 2b Wiring pattern 3 Metal elastic body 5 Multilayer piezoelectric element 6 Cable

Claims (9)

  An electromechanical energy conversion element and one or a plurality of elastic bodies, and a vibration body that excites vibrations by supplying electric power to the electromechanical energy conversion element, wherein the one or more elastic bodies are made of ceramics, A vibrating body, wherein a wiring pattern is formed on a surface of the elastic body in contact with a mechanical energy conversion element, and electric power is supplied to the electromechanical energy conversion element.   An electromechanical energy conversion element and one or a plurality of elastic bodies, and a vibration body that excites vibrations by supplying electric power to the electromechanical energy conversion element, wherein one or a plurality of the elastic bodies are made of ceramics and the elastic A vibrating body, wherein the vibrating body moves relative to the body, and a pressed contact body contacts the surface of the elastic body.   An electromechanical energy conversion element and one or a plurality of elastic bodies, and a vibration body that excites vibrations by supplying electric power to the electromechanical energy conversion element, wherein the one or more elastic bodies are made of ceramics, A vibrating body, wherein a wiring pattern is formed on one surface in contact with a mechanical energy conversion element, and a contact body that moves relative to the elastic body and is in pressure contact is in contact with the other surface.   A vibration wave actuator comprising the vibrating body according to claim 1, wherein a contact body that is in pressure contact with a surface of the elastic body moves relative to the elastic body.   A vibration wave actuator comprising the vibrating body according to claim 2, wherein a contact body that pressurizes and contacts the surface of the elastic body moves relative to the elastic body.   A vibration wave actuator comprising the vibrating body according to claim 3, wherein a contact body that is in pressure contact with the surface of the elastic body moves relative to the elastic body.   4. The vibrating body according to claim 1, wherein the electromechanical energy conversion element is an electromechanical energy conversion element in which a plurality of layers having a material having an electromechanical energy conversion element function in which a plurality of electrode regions are formed are stacked.   7. The vibrating body or the vibration wave actuator according to claim 1, wherein the elastic body is made of alumina, silicon carbide, silicon nitride, zirconia, or ceramics mainly composed of these.   7. The vibrating body or the vibration wave actuator according to claim 1, wherein the wiring pattern formed on the surface of the elastic body has a conductive metal attached thereto.

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