JP3383401B2 - Ultrasonic motor and ultrasonic motor drive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a conduction support portion of an ultrasonic motor which frictionally drives a moving body by an oscillating wave utilizing expansion and contraction motion of a piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 11, a fixed base 201 is provided with a central portion of a vibrating body portion 203 of an ultrasonic motor and a vicinity of a node portion of a secondary vibration mode in the radial direction. The protrusion 212 is supported and fixed by means such as adhesive bonding or screwing. For example, Japanese Patent Laid-Open No. 62-293977 discloses such a conventional structure.

Further, as shown in FIG. 12, a piezoelectric element 30
The conductive structure of the electrode pattern of No. 4 is the piezoelectric element 304.
There is known a structure in which the lead wire 313 is joined to the electrode pattern closest to the central axis. For example, the actual Kaihei 2-572
Japanese Patent Publication No. 89 discloses such a conventional structure.

[0004]

However, in the structure of the conventional ultrasonic motor, for example, according to the structure having the projection 212 of the fixed base 201 as shown in FIG. When the node of the secondary vibration mode is fixed by fixing the vibrating body 203 and the fixing base 201, the fixing area becomes large, so that the vibration is attenuated and the electro-mechanical conversion efficiency is improved as a whole. There was a problem such as a decrease.

Further, a piezoelectric element 304 as shown in FIG.
According to the structure in which the lead wire 313 is joined to the electrode pattern closest to the central axis, the supporting force is insufficient because the node portion of the secondary vibration mode is not fixed in the radial direction of the vibrating body portion 303. Therefore, there is a problem that the electro-mechanical conversion efficiency is reduced and extra vibration is generated due to the influence of the primary vibration mode, which hinders the drive due to self-excited oscillation. Further, conventionally, it is difficult to attach the lead wire 313 to the vicinity of the central portion, and it is necessary to connect the lead wire 313 as many as the number of electrode patterns provided on the piezoelectric element 304, which hinders vibration. Was there.

Therefore, an object of the present invention is to obtain a compact and highly efficient ultrasonic motor by reliably supporting and conducting the vibrating body portion and the piezoelectric element.

[0007]

In order to solve the above-mentioned problem that the motor efficiency is lowered by the support structure and the conductive structure of the vibrating body portion, the present invention provides a vibrating conductive support member in an ultrasonic motor. The vibrating body part is arranged between the body part and the vicinity of the node other than the center part of the piezoelectric element and the lead substrate to provide a supporting means, and the electrode pattern of the piezoelectric element and the electrode pattern of the lead substrate are electrically connected to each other. We realized a compact and highly efficient ultrasonic motor by reliably supporting and conducting the piezoelectric element.

[0008]

In the ultrasonic motor configured as described above, the lead substrate 108 is attached to the fixed base 101 in FIG.
Are arranged. A piezoelectric element 104 having a plurality of electrode patterns formed thereon is joined to the vibrating body 103,
Guided by the central shaft 102, it is fixedly supported near the central portion so as to be integrated with the fixed base 101 on which the lead substrate 108 is arranged. The moving body 105 is guided to rotate by the central shaft 102, and the vibrating body section 10 is driven by the pressing member 106.
3 is pressure-contacted, and is in contact with the vibrating body portion 103 at a predetermined pressure so as to be rotatable.

The conductive support member 109 is disposed between the lead substrate 108 and the vicinity of the nodes other than the central portions of the vibrating body portion 103 and the piezoelectric element 104, and supports the vibrating body portion 103 and the piezoelectric element 104. The electrodes are arranged so that the electrode pattern of the piezoelectric element 104 and the electrode pattern of the lead substrate 108 are electrically connected. The drive circuit 107 applies a drive signal to the electrode pattern on the lead substrate 108. When the drive signal is applied, a vibration wave is generated in the vibrating body portion 103 and the piezoelectric element 104, and the pressing member 106 causes the moving body 105 to make a rotational motion via a frictional force.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (1) First Embodiment FIGS. 1 and 2 are a block diagram and a sectional view of a first embodiment of an ultrasonic motor according to the present invention. A lead substrate 108 is arranged on the fixed base 101. The vibrating body portion 103 is joined to a piezoelectric element 104 having a plurality of electrode patterns formed thereon, is guided by the central shaft 102, and is located near the central portion so as to be integrated with the fixed base 101 on which the lead substrate 108 is arranged. It is fixedly supported. It should be noted that the lead substrate 108 is preliminarily formed with an electrode pattern for conducting the plurality of electrode patterns provided on the piezoelectric element 104.

The moving body 105 is rotatably guided by the central shaft 102, and is rotatable by contacting the vibrating body portion 103 with a predetermined pressure by a pressing member 106 having one end fixed to the central shaft 102. . The pressing member 106 can use an elastic body such as a coil spring or a leaf spring, and these may be used together.

The broken line in FIG. 2 represents the operation in the secondary vibration mode, and the point 114 where the two broken lines intersect is
The vibrating body portion 103 and the piezoelectric element 104 show one node portion 114 formed in the radial direction other than the central portion. FIG. 3 is a plan view showing the node position of the first embodiment of the ultrasonic motor of the present invention. Similarly, the piezoelectric element 104 bonded to the vibrating body section 103 is attached to the piezoelectric element 104 in the radial direction. This is a representation of one node 114 that is formed in a portion other than the central portion.

The conductive support member 109 is made of a conductive elastic body, and is located near the one node 114 formed in the vibrating body portion 103 and other than the central portion of the piezoelectric element 104 and the lead substrate 108.
And the vibrating body portion 103 and the piezoelectric element 104.
The electrode pattern of the piezoelectric element 104 is electrically connected to the electrode pattern of the lead substrate 108. In addition, in FIG.
Also, the conduction support member 109 is arranged in the vicinity of one node 114 formed in the piezoelectric element 104 in the radial direction other than the central portion. Here, as the conduction support member 109, a connector formed in advance in an annular shape may be used, or a linear connector may be arranged in an annular shape by the conduction support member guide 115. Since the conductive support member 109 is brought into pressure contact with the fixed base 101 on which the lead substrate 108 is arranged by the vibrating body portion 103, the elastic force at the time of pressure contact is applied from the pressure member 106 and a drive circuit (not shown). It is set in advance so as to have an appropriate value depending on the magnitude of the driving voltage.

The drive circuit (not shown) is the vibrating body section 1.
03 and the piezoelectric element 104 have a driving signal having one node portion other than the central portion in the radial direction in the lead substrate 10.
No. 8 electrode pattern or lead substrate 108 electrode pattern provided with lead wires 113 for inputting drive signals
Apply to. When the drive signal is applied, a vibration wave is generated in the vibrating body portion 103 and the piezoelectric element 104, and the pressing member 106 causes the moving body 105 to make a rotational motion via a frictional force.

(2) Second Embodiment FIG. 4 is a plan view of a second embodiment of the ultrasonic motor of the present invention. On the lead substrate 108, a lead substrate electrode pattern 116 for short-circuiting a plurality of electrode patterns of the piezoelectric element 104 (broken line) and electrically connecting them through the conduction supporting member 109 is formed in advance. The conduction support member 109 is disposed between the lead substrate 108 and a vibrating body portion 103 and the piezoelectric element 104 (broken line) in the vicinity of one node portion other than the central portion in the radial direction. While supporting the piezoelectric element 104, the piezoelectric element 104 (broken line)
Is arranged so that the electrode pattern of the lead substrate 108 and the lead substrate electrode pattern 116 of the lead substrate 108 are electrically connected. The conductive support member 109 uses conductive silicone rubber for the conductive portion 109a and insulating silicone rubber for the insulating portion 109b, and the conductive portions 109a and the insulating portion 109b are alternately laminated and arranged on both sides. Surface insulation 10
9c is a connector constituted by supporting insulating silicone rubber. The conductive portion 109a is formed in such a size that only the electrode pattern of the piezoelectric element 104 (broken line) contacts.

[0016] That is, the conductive portion 1 of the conduction supporting member 109
The pitch of 09a is at least 1 with respect to the electrode pattern having the shortest arc length in the circumferential direction of the portion where the electrode pattern of the piezoelectric element 104 and the conductive support member 109 are in contact with each other.
One or more conductive portions 109a are formed so as to be in contact with each other.

Further, the conductive portion 109 of the conductive support member 109.
The a pitch is formed such that at this position, the circumferential clearance of the electrode pattern of the piezoelectric element 104 is such that at least one insulating portion 109b of the conductive support member 109 is in contact with the narrowest portion. There is. Further, by forming the width of the connector in the radial direction to be narrower than the gap between the plurality of electrode patterns formed on the piezoelectric element,
Prevent short circuit between electrodes.

The conduction support member 109 described here is used.
5 may be used even if the conduction support member 509 formed in advance in an annular shape as shown in FIG. 5 is used, or the linear conduction support member 609 as shown in FIG. 6 is arranged in an annular shape. I do not care. Here, in both the annular conductive support member 509 and the linear conductive support member 609, the conductive portions 509a and 609a, the insulating portions 509b and 609b,
The dimensions, materials, and shapes of the insulating portions 509c and 609c on both side surfaces are the same as those of the conduction support member 109 described in the second embodiment.

(3) Third Embodiment FIG. 7 is a sectional view of a first embodiment of the ultrasonic motor driving apparatus of the present invention. A structure in which an output shaft 110 that operates integrally with a moving body 105 of the ultrasonic motor and a power transmission member 111 that operates based on the operation of the output shaft 110 are provided by using the ultrasonic motor described in the above embodiment. By doing so, the output from the motor is taken out, and the ultrasonic motor drive device can be realized.

With such a structure, in particular,
Even when vibrating the vibrating body portion 103 and the piezoelectric element 104 so as to have one node portion other than the central portion in the radial direction, the ultrasonic wave is small and highly efficient without lowering the electromechanical conversion efficiency. A motor drive device can be realized.

(4) Fourth Embodiment FIG. 8 is a sectional view of a fourth embodiment of the ultrasonic motor according to the present invention. A lead substrate 108 is arranged on the fixed base 101. The vibrating body portion 103 is joined to a piezoelectric element 104 having a plurality of electrode patterns formed thereon, is guided by the central shaft 102, and has a fixed base 101 on which a lead substrate 108 is arranged.
It is fixedly supported near the center so as to be integrated with.
It should be noted that the lead substrate 108 is preliminarily formed with an electrode pattern for conducting the plurality of electrode patterns provided on the piezoelectric element 104.

The moving body 105 is rotatably guided by the central shaft 102, and can be rotated by contacting the vibrating body portion 103 with a predetermined pressure by a pressing member 106 having one end fixed to the central shaft 102. . The pressing member 106 can use an elastic body such as a coil spring or a leaf spring, and these may be used together.

The broken line in FIG. 8 represents the operation of the primary vibration mode in which there is no node in the radial direction of the vibrating body portion 103 and the piezoelectric element 104, and the central axis 10
2 shows a state in which there is no node other than the fixed portion between 2 and the vibrating body portion 103. Further, FIG. 9 is a plan view showing the node position of the fourth embodiment of the ultrasonic motor of the present invention,
Similarly, the piezoelectric element 104 bonded to the vibrating body portion 103
In addition, one knot 2 formed near the center in the radial direction
14 is represented.

The conduction support member 109 is made of a conductive elastic body and is arranged between the lead substrate 108 and the vicinity of the node portion 214 formed in the vibrating body portion 103 and the central portion of the piezoelectric element 104. It is arranged so as to support the portion 103 and the piezoelectric element 104 and to electrically connect the electrode pattern of the piezoelectric element 104 and the electrode pattern of the lead substrate 108. Note that, in FIG. 9, the conduction support member 109 is disposed near the node portion 214 formed near the central portions of the vibrating body portion 103 and the piezoelectric element 104. Here, as the conduction support member 109, even if a connector formed in advance in an annular shape is used, a linear connector is used as the conduction support member guide 1.
Depending on 15, it may be arranged in an annular shape. The conduction support member 109 is used as the lead substrate 1.
Since the fixed base 101 on which 08 is arranged and the vibrating body portion 103 are brought into pressure contact with each other, the elastic force at the time of pressure contact has an appropriate value depending on the magnitude of the drive voltage applied from the pressing member 106 and the drive circuit (not shown). Is set in advance so that

The drive circuit (not shown) is the vibrating body section 1.
03 and the piezoelectric element 104 are provided in the electrode pattern of the lead substrate 108 or the electrode pattern of the lead substrate 108 for inputting a drive signal such that one node 214 is provided near the center in the radial direction. It is applied to the lead wire 113. By applying the drive signal, the vibrating body 1
03 and the piezoelectric element 104 generate a vibration wave, and the pressure member 10
6 causes the moving body 105 to make a rotational movement via a frictional force. In addition, in the present embodiment, as in the first embodiment described above, in the radial direction of the vibrating body portion 103 and the piezoelectric element 104, one node portion is provided in addition to the central portion.
It can also be applied to an ultrasonic motor that produces a rotational motion in the next vibration mode.

Also in this embodiment, the plurality of electrode patterns of the piezoelectric element 104 are short-circuited and electrically connected to the piezoelectric element 104 through the conduction support member 109 as described in the second embodiment. A lead substrate 108 having a lead substrate electrode pattern 116 for the purpose and a conduction support member 109 made of conductive and insulating silicone rubber are used to form a conduction support structure with a plurality of electrode patterns provided on the piezoelectric element 104. It's also easy. further,
Conduction support member 109 using conductive silicone rubber
Alternatively, the conduction support member 509 formed in an annular shape or the linear conduction support member 609 may be arranged in an annular shape.

(5) Fifth Embodiment FIG. 10 is a sectional view of a second embodiment of the ultrasonic motor driving apparatus of the present invention. Using the ultrasonic motor shown in the fourth embodiment, an output shaft 110 that operates integrally with the moving body 105 of the ultrasonic motor and a power transmission member 111 that operates based on the operation of the output shaft 110 are provided. With the structure, the output from the motor is taken out, and the ultrasonic motor drive device can be realized.

With this structure, in particular,
Even when vibrating so that the vibrating body portion 103 and the piezoelectric element 104 have a node portion only near the center portion in the radial direction,
As in the third embodiment, a compact and highly efficient ultrasonic motor driving device can be realized without lowering the electromechanical conversion efficiency.

Therefore, the ultrasonic motor drive device according to the present invention can be applied to the drive unit of electronic equipment such as the focus drive, diaphragm drive, shutter drive device and timepiece pointer drive device of a camera. Further, it can be used for an arm axis of a machine tool such as a robot.

[0030]

According to the ultrasonic motor of the present invention, the conductive support member is disposed between the lead substrate and the vicinity of the node portion other than the central portion of the vibrating body portion and the piezoelectric element to form the vibrating body portion and the piezoelectric element. With a simple structure in which the electrode pattern of the piezoelectric element and the electrode pattern of the lead substrate are electrically connected while being fixedly supported, the contact state between the moving body and the vibrating body at the time of driving the motor becomes good. Further, the stability of the vibrating body is improved, the sliding noise at the time of driving the motor can be reduced, and the motor performance can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of an ultrasonic motor according to the present invention.

FIG. 2 is a sectional view of the first embodiment of the ultrasonic motor of the present invention.

FIG. 3 is a plan view showing a node position of the first embodiment of the ultrasonic motor of the present invention.

FIG. 4 is a plan view of a second embodiment of the ultrasonic motor according to the present invention.

FIG. 5 is a component diagram showing a first conductive support member of the ultrasonic motor of the present invention.

FIG. 6 is a component diagram showing a second conductive support member of the ultrasonic motor of the present invention.

FIG. 7 is a sectional view of a first embodiment of the ultrasonic motor driving device of the present invention.

FIG. 8 is a sectional view of a fourth embodiment of the ultrasonic motor of the present invention.

FIG. 9 is a plan view showing a node position of a fourth embodiment of the ultrasonic motor of the present invention.

FIG. 10 is a sectional view of a second embodiment of the ultrasonic motor drive device of the present invention.

FIG. 11 is a first sectional view of a conventional ultrasonic motor.

FIG. 12 is a second sectional view of a conventional ultrasonic motor.

[Explanation of symbols]

101,201,301 Fixed base 102,202,302 central axis 103, 203, 303 Vibrating body part 104, 304 Piezoelectric element 105,305 mobile 106,306 Pressure member 107 drive circuit 108 Lead substrate 109, 509, 609 Conductive support member 109a, 509a, 609a Conducting part 109b, 509b, 609b Insulation part 109c, 509c, 609c Both side insulating parts 110 output shaft 111 Power transmission member 212 protrusion 113,313 Lead wire 114, 214 nodes 115 Conduction support member guide 116 Lead board electrode pattern

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-1-144371 (JP, A) JP-A-2-159984 (JP, A) JP-A-63-190571 (JP, A) JP-A-1- 311878 (JP, A) Actual Open Sho 64-30690 (JP, U) Actual Open Flat 2-120767 (JP, U) Actual Open Flat 3-104095 (JP, U) Actual Open Flat 1-134367 (JP, U) Actually open 61-83277 (JP, U) Actually open 2-27672 (JP, U) Actually open 59-109176 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02N 2/00

Claims (4)

(57) [Claims] 1. An ultrasonic motor for frictionally driving a moving body by means of an oscillating wave utilizing expansion and contraction motion of a piezoelectric element, comprising a disk-shaped elastic member fixedly supported near the center by a central shaft (102). A vibrating body part (103), a piezoelectric element (104) joined to the vibrating body part (103) and having a plurality of electrode patterns formed thereon, and a movement arranged so as to come into pressure contact with the vibrating body part (103) A body (105), a pressure member (106) arranged so that the moving body (105) comes into pressure contact with the vibrating body portion (103), a lead substrate (108) having an electrode pattern formed thereon, and a vibration The electrode pattern of the piezoelectric element (104) and the electrode of the lead substrate (108) are arranged between the lead substrate (108) and the vicinity of the nodes other than the central portion of the body portion (103) and the piezoelectric element (104). Pattern Is it an elastic body that conducts ?
And Ranaru conductive support member (109), the vibrating body (103) and the piezoelectric element (104) leads substrate a drive signal for vibrating to have one knuckles than the central portion to the radial direction (108) An ultrasonic motor comprising: a drive circuit (107) for inputting to the electrode pattern of. 2. The ultrasonic motor according to claim 1, wherein the conductive support member (109) is a connector in which a plurality of insulating portions and conductive portions are alternately arranged with a predetermined dimension. 3. The connector according to claim 1, wherein the conductive support member (109) is formed with a width that is narrower in the radial direction than the gap between the plurality of electrode patterns formed on the piezoelectric element (104). Item 3. The ultrasonic motor according to any one of items 2. 4. An output shaft (110) having the ultrasonic motor according to any one of claims 1 to 3, which operates integrally with a moving body (105), and an operation of the output shaft (110). And a power transmission member (111) that operates based on the above.