JP4376943B2 - Ultrasonic motor and electronic device with ultrasonic motor - Google Patents

Description

  The present invention relates to an ultrasonic motor in which piezoelectric vibration members are laminated, and more particularly, to an improvement in an ultrasonic motor of a type that does not use holding means for lamination of piezoelectric vibration members.

  Recently, in the field of micro motors, attention has been focused on ultrasonic motors that move a moving body using a piezoelectric vibrator that vibrates when a voltage is applied.

  In particular, an ultrasonic motor using a stretching vibration and a bending vibration (double mode vibrator) of a rectangular piezoelectric vibrator is used for various applications because the synthetic body vibrates the moving body linearly, rotationally, etc. In addition, for applications that require high output, a type in which piezoelectric vibrators are laminated is used (see Japanese Patent Laid-Open No. 7-184382).

  FIG. 10 shows an ultrasonic motor of a type in which rectangular piezoelectric vibrators are stacked.

  That is, the basic vibrator of this ultrasonic motor is a piezoelectric vibrator 61, 62 that has been subjected to a predetermined polarization process to vibrate in dual mode, and output extraction members 71, 72 provided at the tips of the piezoelectric vibrators 61, 62. The piezoelectric vibrators 61 and 62 are electrodes provided on both surfaces. The piezoelectric vibrators 61 and 62 are arranged in three rows in the vertical direction and in two rows in the horizontal direction, and the six piezoelectric vibrators are coupled to the coupling means 67a and 67b. , Is held by.

  FIG. 11 is a block diagram relating to the basic structure of the ultrasonic motor.

  According to this, the piezoelectric vibrators 61 and 62 are applied with voltages from the respective electrodes 81 and 82 to vibrate in a double mode, and transmit this combined vibration to the output take-out members 71 and 72. , 72 is moved.

  And since an output is taken out by the several output taking-out members 71 and 72, a high output is obtained.

  However, according to the ultrasonic motor, since only a part of the piezoelectric vibrators 61 and 62 is fixed by the coupling means 67, the vibration direction varies between the piezoelectric vibrators 61 and 62. Further, since the vibration motion is suppressed at the fixed portions of the piezoelectric vibrators 61 and 62, there is a technical problem that the vibration motion is lost and the output cannot be extracted effectively.

  Further, if the coupling means 67 as a separate member is used for fixing the piezoelectric vibrators 61 and 62, it leads to an increase in the size and complexity of the entire motor configuration, and the manufacturing process is a process of attaching the coupling means 67. Adding complexity.

  On the other hand, each of the piezoelectric vibrators 61 and 62 that vibrate in a double mode vibrates forcibly because the piezoelectric vibrators 61 and 62 apply a voltage to a predetermined polarization-treated portion in order to switch the moving direction of the motor by bending vibration. Compared to the above, there is a technical problem that it is impossible to increase the stretching vibration that is urged.

  Accordingly, the present invention has been made to solve the above technical problem, and prevents variation in the vibration direction and vibration loss of the stacked piezoelectric vibrators, thereby reducing the size and simplifying the stacked structure. An object of the present invention is to provide an ultrasonic motor and an electronic apparatus with an ultrasonic motor that can increase the output of synthetic vibration.

  In order to solve the above problems, an ultrasonic motor according to the present invention is an ultrasonic motor having a vibrating body portion in which a plurality of piezoelectric materials having electrodes are laminated, and a movable portion that operates by vibration of the vibrating body portion. It has the electrode pattern for voltage application which conduct | electrically_connects with all the electrodes of the said several piezoelectric material in one surface of a part.

  Preferably, the voltage applying electrode pattern includes an electrode projecting toward a vibration node generated by the vibrating body portion.

  According to this, since the vibration body portion is configured by laminating a plurality of piezoelectric members, the performance variation of each vibration body portion can be reduced. In addition, a small and highly reliable ultrasonic motor can be realized. Further, since conduction can be obtained in the vicinity of the node between the electrode on the laminated surface and the vibrating body portion, the conduction structure can be simplified, and vibration loss can be reduced with little influence from the conduction structure (such as a lead wire).

  Further, in an ultrasonic motor that moves a movable body that is in contact with a vibrating body portion formed by laminating a plurality of piezoelectric vibrating members, a voltage applying electrode pattern that is electrically connected to an electrode provided on a laminated surface of the piezoelectric vibrating members is provided. The electrode wiring member is integrally laminated on the piezoelectric vibration member.

  According to this, since the electrode wiring member is also integrally laminated on the piezoelectric vibrating member, the structure and manufacturing of the vibrating body portion are simplified, and downsizing and high efficiency can be realized.

  As described above, according to the structure of the vibrator part of the present invention, it is possible to realize an ultrasonic motor that is simple to manufacture (easily polarized), small in size, high in efficiency, and small in individual performance variations.

  Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to FIGS.

{Embodiment 1}
FIG. 1 shows a first embodiment in which the present invention is applied to an ultrasonic motor.

  In the present embodiment, as shown in FIG. 1, the vibration body portion 10, the output extraction portion 17 as the vibration transmission member of the present invention provided at the edge of the vibration body portion 10, and the output extraction portion 17 are applied. A movable body 20 as a movable body of the present invention that is in contact with the movable body 20 and a pressurizing mechanism 18 that pressurizes the movable body 20 and the output extraction unit 17 are configured.

  The moving body 20 includes a rotating member 21 having a rotating bearing 21 a, a fixing member 23 provided facing the rotating member 21, and a rotating shaft 22 that is installed on the fixing member 23 and penetrates the rotating bearing 21 a of the rotating member 21. It is composed of

  The output take-out part 17 has a rectangular parallelepiped shape and is made of a material having rigidity.

  The pressurizing mechanism 18 includes a fixing member 18 a provided to face the vibrating body portion 10 and a pressurizing member 18 b that pressurizes the vibrating body portion 10 to the moving body 20.

  FIG. 2 shows the plane of each laminated layer of the vibrating body portion and the side surface of the vibrating body portion.

  As shown in FIGS. 2A to 2D, the vibrating body portion 10 is integrally laminated with the piezoelectric material 11 as a piezoelectric bending vibration member of the present invention that bends and vibrates when a voltage is applied. The piezoelectric material 12 as the piezoelectric expansion / contraction vibration member of the present invention that undergoes stretching vibration, the piezoelectric material 13 laminated on the piezoelectric material 12, and the electrode pattern provided between the piezoelectric material 13 and the piezoelectric material 12 16, an electrode pattern 15 provided between the piezoelectric material 12 and the piezoelectric material 11, an electrode pattern 14 provided on a surface of the piezoelectric material 11 facing the laminated surface of the piezoelectric material 12, and the piezoelectric material 11 It is comprised from the electrode wiring member 31 as an electrode wiring member of this invention laminated | stacked integrally on the electrode pattern 14 surface.

  Here, as shown in FIGS. 2B and 2C, the piezoelectric materials 11 and 12 have a planar rectangular shape and are processed into dimensions that set a predetermined resonance frequency, and are made of a ferroelectric material such as titanic acid. Barium and lead zirconate titanate are used.

  The piezoelectric material 11 further divides the rectangular body into four smaller rectangular bodies in the cross direction, and polarizes so that the pair of rectangular bodies in the diagonal direction have the same polarity and the pair of rectangular bodies in the side direction also have the same polarity. .

  On the other hand, in the piezoelectric material 12, almost the entire rectangular body is polarized to the same polarity.

  Further, as shown in FIG. 2B, the electrode patterns 14a and 14b are fixed by being divided into four corresponding to the polarized portions of the piezoelectric material 11, and a pair of electrodes 14a and 14b in the diagonal direction. Are simultaneously energized.

  Further, each electrode pattern 14a, 14b is provided with a protruding portion so as to reach a long edge portion close to the rectangular surface of the piezoelectric material 11.

  As shown in FIG. 2C, the electrode pattern 15 is provided on almost the entire rectangular surface of the piezoelectric material 12 so as to reach the center of one long edge portion of the pair of long sides of the piezoelectric material 12. Protrusions are provided. As shown in FIG. 2D, the electrode pattern 16 is fixed to almost the entire surface of the piezoelectric material 13, and has a long edge portion in a direction opposite to the electrode pattern 15 out of a pair of long sides of the rectangular surface of the piezoelectric material 12. Protrusion is provided to reach the center.

  As shown in FIGS. 2A and 2E, the electrode wiring member 31 includes a piezoelectric material 31a and voltage application electrode patterns 31b provided at portions corresponding to the protruding portions of the electrode patterns 14, 15, and 16. 31c, 31d, 31e.

    Each voltage application electrode pattern 31b, 31c, 31d, 31e reaches a long edge portion adjacent to the rectangular surface, is further extended to the side surface of the vibrating body portion 10, and is connected to each electrode pattern 14, 15, 16 (See FIG. 2 (e)).

  Next, based on FIGS. 1-4, the usage method of this Embodiment is demonstrated.

  FIG. 3 shows a block diagram of the ultrasonic motor according to the present embodiment, and FIG. 4 shows a vibration mode of the piezoelectric material according to the present embodiment.

  First, when it is desired to rotate the rotating member 21 of the moving body 20 clockwise, a voltage may be applied to the voltage applying electrode patterns 31b, 31d and 31e as shown in FIG.

  At this time, the electrode patterns 14a, 15 and 16 are energized. Here, the piezoelectric material 11 between the electrode patterns 14a and 15 causes bending vibration in the lateral direction as shown in FIG. 4A, while the piezoelectric material 12 between the electrode patterns 15 and 16 corresponds to B in FIG. As shown, it causes stretching vibration in the vertical and horizontal directions.

  Here, the vibration direction of each piezoelectric material 11 is kept constant, and the vibration motion is not limited. In addition, since the piezoelectric material 12 is applied with a voltage almost over the entire surface, it causes a large stretching vibration.

  Since the piezoelectric materials 11 and 12 are integrated, the bending vibration and the stretching vibration of the piezoelectric materials 11 and 12 are combined, and the short edge portion of the rectangular surface performs elliptical motion counterclockwise.

  The output take-out part 17 fixed to the short edge of the rectangular surface expands the elliptical motion and presses against the rotating member 21 of the moving body 20 at a predetermined timing.

  Therefore, the rotating member 21 of the moving body 20 that is press-contacted at a predetermined timing receives a frictional force each time it contacts and rotates in the clockwise direction.

  Further, when it is desired to rotate the rotating member 21 of the moving body in the counterclockwise direction, a voltage may be applied to the voltage applying electrode patterns 31c, d, e as shown in FIG.

  At this time, the electrode patterns 14b, 15 and 16 are energized. Here, the piezoelectric material 11 between the electrode patterns 14b and 15 causes bending vibration in the opposite phase to A in FIG. 4, while the piezoelectric material 12 between the electrode patterns 15 and 16 is as shown in FIG. 4B. Causes stretching vibration.

  Since the piezoelectric materials 11 and 12 are integrated, the bending vibration and the stretching vibration of the piezoelectric materials 11 and 12 are combined, and an elliptical motion is performed clockwise at the short edge portion of the rectangular surface.

  Therefore, the rotating member 21 of the moving body 20 that contacts at a predetermined timing receives a frictional force each time the output take-out portion 17 is pressed and rotates counterclockwise.

  As described above, according to the present embodiment, by holding the piezoelectric material 11 without using the fixing means, the vibration motion is not limited, and the vibration direction is kept constant. The loss of the vibration motion of each piezoelectric material 11 and the variation in the vibration direction are prevented.

  In addition, since the expansion and contraction motion is forcibly excited by the piezoelectric material 12, the expansion and contraction vibration can be increased, and the combined vibration of the expansion and contraction vibration and the bending vibration is formed by laminating each piezoelectric material that vibrates in double mode. High output can be obtained compared to the above.

  In addition, since a voltage is applied between the electrode patterns 14 and 15 and between the electrode patterns 15 and 16, the electrode pattern 15 is used as a reference to simplify the device configuration.

  In addition, since each electrode pattern 14 is energized by energizing only the electrode surface 31b of the electrode wiring member 31, there is no need to individually wire each electrode pattern 14, and the piezoelectric materials 11 and 12 Can be polarized at a time.

  In addition, since the displacement of the combined vibration of the piezoelectric materials 11 and 12 is increased by the output take-out portion 17, the rotating member 21 that is in pressure contact with the tip of the output take-out portion 17 is rotated by receiving a larger frictional force.

  Further, since the output take-out portion 17 is pressed against the rotating member 21 at a predetermined timing by the combined vibration of the piezoelectric materials 11 and 12, a frictional force is applied, so that the rotating member 21 is rotated.

{Embodiment 2}
FIG. 5 shows a second embodiment in which the present invention is applied to an ultrasonic motor. As shown in FIG. 5, the main part of the present embodiment includes a vibrating body portion 10, an output extracting portion 17 as a vibration transmitting member of the present invention provided at an edge of the vibrating body portion 10, and an output extracting portion. The movable body 20 as a movable body of the present invention that is in contact with 17, and a pressurizing mechanism (not shown) that pressurizes the movable body 20 and the output extraction unit 17.

  The moving body 20 has a guide groove (not shown), and a linear motion member 21 that linearly moves in a predetermined direction, and a regulation member (not shown) that controls the motion direction of the linear motion member 21 paired with the guide groove. ).

  The output extraction unit 17 has the same configuration as that of the first embodiment, and a pair of output extraction units 17 are provided on the lower surface of the vibrating body unit 10 at equal distances from the center to the left and right.

  The pressurizing mechanism is configured to pressurize the vibration node portion on the upper surface of the vibrating body portion 10 downward.

  FIG. 6 shows the plane of each laminated layer of the vibrating body portion and the side surface of the vibrating body portion.

  As shown in FIGS. 6A to 6G, the vibrating body portion 10 is integrally laminated with a piezoelectric material 11 as a piezoelectric bending vibration member of the present invention that flexurally vibrates when a voltage is applied, and the piezoelectric material 11. The piezoelectric material 12 as a piezoelectric expansion / contraction vibration member of the present invention that stretches and vibrates, the piezoelectric material 13 as the piezoelectric expansion / contraction vibration member of the present invention laminated integrally with the piezoelectric material 12, and the piezoelectric material 13 integrally. The piezoelectric material 44 as the piezoelectric bending vibration member of the present invention to be laminated, the piezoelectric material 45 as the piezoelectric bending vibration member of the present invention laminated integrally with the piezoelectric material 44, and the piezoelectric material laminated on the piezoelectric material 45. 46, and between each piezoelectric material 11, the electrode patterns 14 and 48 as the first electrode of the present invention, the electrode pattern 16 as the second electrode of the present invention, and the electrode as the reference electrode of the present invention Patterns 15, 47, 49 and piezoelectric material 1 And a electrode wire member 31 as an electrode wiring member of the present invention which is laminated on the electrode pattern 14 side.

  Here, as shown in FIG. 6B, the piezoelectric material 11 has substantially the same configuration as that of the first embodiment. However, the piezoelectric material 11 further divides the rectangular body into four equal parts in the lateral direction. Thus, polarization processing is performed alternately so as to have opposite polarities, and electrode patterns 14a and 14b are provided on one rectangular surface corresponding to the portions to be polarized.

  Each of the electrode patterns 14a and 14b has a protruding portion that reaches one long edge portion.

  On the other hand, as shown in FIG. 6D, the piezoelectric material 13 is subjected to the same polarization process in the reverse direction to the piezoelectric material 12.

  Further, as shown in FIGS. 6E and 6F, the piezoelectric materials 44 and 45 are subjected to polarization processing with a reverse polarity at a portion corresponding to the portion subjected to the polarization processing of the piezoelectric material 11.

  The electrode pattern 48 provided between the piezoelectric materials 44 and 45 has substantially the same configuration as that of the electrode pattern 14, but the protruding portion of the piezoelectric material 45 is provided on the side opposite to the protruding portion of the electrode pattern 14 a.

  As shown in FIG. 6A, the electrode wiring member 31 includes a piezoelectric material 31a as a main body, an electrode application pattern 31b provided in a portion corresponding to the protruding portions of the electrode patterns 14a and 14b, and an electrode pattern 48a. 48b, the electrode application pattern 31c provided at the portion corresponding to the protruding portion of 48b, the electrode pattern 31d provided at the portion corresponding to the protruding portion of the electrode patterns 15, 47, 49, and the protruding portion of the electrode pattern 16 It is comprised from the electrode pattern 31e provided in the corresponding site | part.

  Each of the electrode patterns 31b, 31c, 31d, and 31e reaches the adjacent long edge portion of the rectangular surface of the piezoelectric material 31a, and is further extended to the side surface of the vibrating body portion 10, so that each electrode pattern 14, 15, 16, 44, 47, 48, and 49 (see FIG. 6H).

  Next, the usage method of this Embodiment is demonstrated based on FIGS.

  FIG. 7 shows a block diagram of the main part when the moving body 20 of the present embodiment is moved in the left direction, and FIG. 8 shows the operation of the vibrator part according to the present embodiment.

  First, when it is desired to linearly move the linear motion member 21 of the moving body 20 in the right direction, a voltage may be applied to the electrode application patterns 31c, 31d, and 31e as shown in FIG. At this time, the electrode patterns 15, 16, 47, 48, 49 are energized, and the piezoelectric materials 44, 45 between the electrode patterns 47, 48, 49 undergo bending vibration in the vertical direction as shown in FIG. On the other hand, the piezoelectric materials 12 and 13 between the electrode patterns 15, 16 and 47 cause stretching vibration in the vertical and horizontal directions as shown in FIG.

  And since each piezoelectric material 44, 45, 12, 13 is united, the bending vibration and expansion-contraction vibration of each piezoelectric material 44 are synthesize | combined, and each site | part of the lower surface of the vibrating body part 10 is elliptical motion counterclockwise. I do.

  A pair of output extraction portions 17a and 17b fixed to the lower surface of the vibrating body portion 10 expands the elliptical motion and presses against the linear motion member 21 of the moving body 20 at a predetermined timing.

  Therefore, the linear motion member 21 of the moving body 20 that is press-contacted at a predetermined timing receives a frictional force each time it abuts and linearly moves in the right direction.

  In order to move the linear motion member 21 of the moving body 20 leftward, as shown in FIG. 6A, a voltage may be applied to the electrode application patterns 31b, 31d, and 31e.

  At this time, as shown in FIG. 7, the electrode patterns 14, 15, 16, 47 are energized, and voltages are applied to the piezoelectric materials 11, 12, 13 between the electrode patterns 14.

  Here, the piezoelectric material 11 causes bending vibration having a phase difference of 180 ° from that of A in FIG. 8, while the piezoelectric materials 12 and 13 between the electrode patterns 15 and 16 have vertical and horizontal directions as shown in B of FIG. 8. Causes stretching vibration.

  And since each piezoelectric material 11, 12, 13 is united, the bending vibration and expansion-contraction vibration of each piezoelectric material 11, 12 are synthesize | combined, and each site | part of the lower surface of the vibrating body part 10 carries out elliptical motion clockwise. Do.

  Therefore, the linear motion member 21 of the moving body 20 that is press-contacted at a predetermined timing receives a frictional force each time it abuts and linearly moves in the left direction.

  As described above, in particular, according to the present embodiment, since the piezoelectric materials 13 and 45 are further laminated, a large synthetic vibration can be obtained, and the linear motion member 21 is linearly moved at a higher output.

  Further, since the output take-out portion 17 is pressed against the linear motion member 21 at a predetermined timing by synthetic vibration and a frictional force is applied, the linear motion member 21 is linearly moved.

  Alternatively, the vibrating body unit 10 may be pressurized and installed on the fixed surface so that the ultrasonic motor itself moves linearly. At this time, the vibrating body portion 10 causes the output extraction portions 17a and 17b to elliptically move by synthetic vibration, and the output extraction portions 17a and 17b receive a frictional force every time they come into pressure contact with the fixed surface. Move linearly on the fixed surface.

{Third embodiment}
FIG. 9 shows a block diagram in which the present invention is applied to an electronic apparatus using an ultrasonic motor as a drive source.

  In the present embodiment, a laminated piezoelectric element 51, a vibrating body 52 that vibrates integrally with the laminated piezoelectric element 51, a moving body 53 that is periodically pressed against the vibrating body 52, and a moving body 53 A transmission mechanism 54 that operates integrally, an output mechanism 55 that is moved based on the operation of the transmission mechanism 54, and a pressurizing mechanism 56 that pressurizes the vibrating body 52 and the moving body 53.

  Here, as the transmission mechanism 54, for example, a transmission wheel such as a gear train or a friction wheel is used.

  The output mechanism 55 includes a shutter drive mechanism and a lens drive mechanism in a camera, a pointer in an electronic timepiece or a measuring instrument, an arm in a robot, and a cutting tool feed mechanism and a machining member feed mechanism in a machine tool. Is used.

  In addition, as an electronic device in this embodiment, preferably, an electronic timepiece, a measuring instrument, a camera, a printer, a printing machine, a machine tool, a robot, a moving device, and the like can be realized.

  Furthermore, if an output shaft is attached to the moving body 53 and a power transmission mechanism for transmitting torque from the output shaft is provided, an ultrasonic motor drive device can be realized.

(A) is explanatory drawing which shows the planar structure of Embodiment 1 which applied this invention to the ultrasonic motor, (b) is explanatory drawing which shows a cross-sectional structure. FIG. 2 is an explanatory diagram illustrating a planar structure of each laminated layer and a side surface of a vibrating body portion related to FIG. 1. FIG. 2 is a block diagram related to FIG. 1. It is explanatory drawing which shows the aspect of the vibration concerning FIG. (A) is explanatory drawing which shows the planar structure of Embodiment 2 which applied this invention to the ultrasonic motor, (b) is explanatory drawing which shows a cross-section. It is explanatory drawing which shows the planar structure of each laminated layer concerning FIG. 5, and the side surface of a vibrating body part. It is explanatory drawing which shows the block diagram of the principal part when moving the mobile body concerning FIG. 5 to the left direction. It is explanatory drawing which shows the aspect of the vibration concerning FIG. It is explanatory drawing which shows Embodiment 3 which applied this invention to the electronic device. It is explanatory drawing which shows the structure of the perspective direction of the ultrasonic motor of the laminated structure concerning a prior art. FIG. 11 is a block diagram of a basic structure related to FIG. 10.

Explanation of symbols

10 vibrator 11 piezoelectric material (piezoelectric bending vibration member)
12 Piezoelectric material (Piezoelectric stretching vibration member)
14 Electrode pattern (first electrode)
15 Electrode pattern (reference electrode)
16 Electrode pattern (second electrode)
17 Output extraction part (vibration transmission member)
20 Mobile body (movable body)
31 Electrode wiring member (electrode wiring member)

Claims (5)

A vibrating body portion in which a plurality of piezoelectric materials having electrodes are laminated; a movable portion that operates by vibration of the vibrating body portion;
In the ultrasonic motor having a voltage application electrode pattern that is electrically connected to all the electrodes of the piezoelectric material at the end surface of the vibrating member in the stacking direction of the piezoelectric material,
The ultrasonic motor according to claim 1, wherein the voltage applying electrode pattern is connected to a protruding portion that reaches the edge of the piezoelectric material from each of the electrodes. The ultrasonic motor according to claim 1,
The ultrasonic motor according to claim 1, wherein the voltage applying electrode pattern includes an electrode projecting toward a vibration node generated by the vibrating body portion. The ultrasonic motor according to claim 1 or 2,
An ultrasonic motor, wherein an electrode wiring member provided with the voltage applying electrode pattern is integrally laminated on the piezoelectric vibration member.   The ultrasonic motor according to claim 3, wherein the electrode wiring member is made of a piezoelectric material. An electronic apparatus with an ultrasonic motor, comprising the ultrasonic motor according to claim 1.

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