JPH0690573A - Ultrasonic motor equipment - Google Patents

Abstract

PURPOSE:To detect the number of rotations of a rotor easily and to extract the detected information out of the device easily by providing a brush mechanism in a stator and a pattern section in a rotary member. CONSTITUTION:When an ultrasonic motor 40 is driven and then a rotary member 50 is rotated, a pattern section 56 is rotated. At that time, a brush 62 oscillates the pattern section 56, so the brush is brought into contact with a conductive section 58 of the pattern section 56 and an insulated section 60 alternately. If voltage is preliminarily generated in an encoder circuit device 72, current flows intermittently in a circuit having the brush mechanism 70, the pattern section 56 and the encoder circuit device. The waveform of this current corresponds to a speed of rotation of the pattern section 56. Based on the waveform of the current, the encoder circuit device 72 computes the number of rotations of the rotary member 50. Since the encoder is formed nearer to the stator 41 than to a rotor 12, leads can be extracted easily from the encoder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor for rotating a rotor by utilizing ultrasonic vibration, and in particular, it can detect the number of rotations.

[0002]

2. Description of the Related Art In recent years, ultrasonic motors have been developed which use ultrasonic vibrations to rotate a rotor. The ultrasonic motor has a very high electro-mechanical conversion efficiency and can generate a large driving torque even at a low speed. Above all, a composite oscillator ultrasonic motor that stably generates a rotating torque even at a low speed and is easy to control is expected to be used in various fields. Conventionally, as this type of ultrasonic motor, an ultrasonic motor 1 having a structure shown in FIG. 3 is used.
0 is known. The ultrasonic motor 10 shown in FIG. 3 has a rotor 1 on one surface (sliding surface) of a cylindrical stator 24.
2 is abutted to the stator 24,
First piezoelectric element 16 that generates torsional vibration in the circumferential direction
And a second piezoelectric element that vibrates in the axial direction. The rotor 12 has a spring member 26 and a stator 24.
The stator bottom 14 of the stator 24, the stator holder 16, and the stator head 22 are pressed by the center bolt 3
The rotor 12 is rotatably connected to the stator head 22. In the ultrasonic motor of this configuration, by combining the vibrations of both piezoelectric elements 16 and 20, the sliding surface of the stator is moved so as to draw a Lissajous figure, and the rotor 12 that presses and touches the sliding surface is moved. I try to rotate it. When utilizing the rotational driving force of the ultrasonic motor 10, as shown in FIG. 3, for example, the ultrasonic motor 10 is supported and fixed to the mounting member 34 by the flange 32, and the ultrasonic motor 10 is internally mounted. A cylindrical rotating member 36 that is arranged is provided so as to be rotatable with respect to the mounting member 34.
The rotary member 36 is connected to the rotary member 36 by, for example, the spokes 28 to form an ultrasonic motor device. In this state, when the rotor 12 rotates, the rotating member 36 also rotates in conjunction with this. Therefore, the ultrasonic motor device having the configuration shown in FIG. 3 is preferably used as a winding device for roll screens, blinds and the like.

[0003]

By the way, in the ultrasonic motor device, in order to control the rotation of the rotor 12 or the rotating member 36, it is necessary to detect the rotational speed of the rotor 12 or the rotating member 36. As means for detecting the rotation speed of the rotor 12 or the rotating member 36, the rotor 1
2, an encoder having a magnetized portion outside the magnetized portion, and a magnetic detection sensor arranged to face the magnetized portion, or a commercially available encoder is provided at the rotor 12 or further ahead of the rotor 12 (spring member 26 side). It may be considered that the rotary member 36 is mounted and used at the position.

However, in these methods, it is difficult for the lead wires of the encoder to be pulled out to the mounting member 34 side to which the ultrasonic motor 10 is mounted, because it is difficult for them to be blocked by the spokes 28 or the like. I had no choice but to pull it out from the end that was not attached.
Therefore, the lead wire becomes long (2 to 3 m when used in a general roll screen), and the workability of assembling the ultrasonic motor 10 becomes extremely poor. Furthermore, since the lead wire is pulled out in the direction away from the ultrasonic motor, it is more inconvenient to arrange the lead wire for transmitting the information detected by the encoder to the drive circuit device of the ultrasonic motor. It was inferior. Further, especially when a commercially available encoder is used, the manufacturing cost is increased.

The present invention has been made to solve the above problems, and it is possible to detect the number of rotations of a rotor of an ultrasonic motor by a simple method and easily extract the detected information to the outside of the ultrasonic motor device. The structure is made possible to improve workability and reduce manufacturing cost.

[0006]

An ultrasonic motor device of the present invention comprises a rotor and a cylindrical stator, and the stator has a first piezoelectric element vibrating in the circumferential direction of the stator.
An ultrasonic wave including an ultrasonic motor in which a second piezoelectric element that vibrates in the axial direction of the stator is incorporated, a mounting member to which the ultrasonic motor is mounted, and a rotating member that interlocks with the rotor. In the motor device, an encoder is formed. And
The encoder is composed of (1) pattern unit and (2) brush mechanism. (1) The pattern portion is formed on the rotating member. The pattern portion is divided into a conductive portion and an insulating portion. (2) The brush mechanism is formed on the stator. The brush mechanism contacts the pattern unit. When the pattern portion is rotating, the brush mechanism alternately slides on the conductive portion or the insulating portion formed on the pattern portion.

[0007]

The ultrasonic motor device of the present invention comprises a brush type encoder composed of a brush mechanism formed on the stator and a pattern portion formed on the rotating member. The number can be detected.
Further, since the encoder is formed on the stator, the lead wire connected to the encoder is pulled out of the ultrasonic motor device without being hindered by the rotor, and the mounting member on the side where the ultrasonic motor is mounted is attached. Can be pulled from. Therefore, the lead wire from the encoder can be shortened. Furthermore, since the lead wire used to drive the ultrasonic motor and the lead wire connected to the encoder can be gathered or bundled, the handling is easy and the workability is further improved, The manufacturing cost can be reduced.

[0008]

An embodiment of the present invention will be described below with reference to FIG. The ultrasonic motor 40 shown in FIG. 1 is roughly composed of a cylindrical stator 41 and a ring-shaped rotor 12,
The stator 41 includes the stator bottom 44 and the first piezoelectric element 1
6, the stator holder 18, the second piezoelectric element 20, and the stator head 22 are connected in series. The first piezoelectric element 16 is a piezoelectric element that vibrates in the circumferential direction of the stator 41, and the second piezoelectric element 20 is a piezoelectric element that vibrates in the axial direction of the stator 41. The rotor 12 is a bearing (not shown)
It is rotatably connected to the stator 41 by a center bolt 52 via. Further, the elastic force of the spring member 26 locked by the nut 27 screwed to the center bolt 52 causes the rotor 12 to move the rotor 12 to the end surface (sliding surface) of the stator head 22.
It is pressed against.

In the ultrasonic motor 40 of this structure, an alternating voltage is applied to both piezoelectric elements 16 and 20, and the ultrasonic vibrations of each are combined to move the sliding surface of the stator 41 so as to draw a Lissajous figure. Then, the rotor 12 pressing and touching the sliding surface is continuously rotated in a fixed direction. Furthermore, the stator bottom 4
4, a reduced diameter portion 42 and a mounting end portion 38 are formed, and an end surface of the mounting end portion 38 is adhesively fixed to a mounting member 46. Supporting and fixing the stator 41 to the mounting member 46 is not limited to bonding,
Various means such as screwing may be used. Also, the reduced diameter portion 4
2 to the mounting end 38 may be integrally formed with the stator bottom 44, or may be integrally formed with the center bolt 52 from which the center of the stator 41 is extracted.

The ultrasonic motor 40 is arranged in a rotating member 50 which is cylindrical and made of a conductor. Rotating member 50
Is rotatably supported by a mounting member 46 by a bearing 48. Further, a donut-shaped rubber member 54 is interposed between the rotor 12 and the rotating member 50. The rubber member 54 transmits the rotational driving force of the rotor 12 to the rotating member 50, and thus the rotor 12 and the rotating member 51 are integrally linked. Fitting holes 13, 13 are formed on the outer peripheral surface of the rotor 12, and the rubber member 5 is inserted in the fitting hole 13.
A protrusion (not shown) formed on the inner peripheral surface of the rubber plate 4 is inserted so that the rubber member 54 and the rotor 12 do not slip. Further, in order to transmit the rotational driving force of the rotor 12 to the rotating member 50, the rubber member 54 is not limited to being interposed, but the rotor 12 and the rotating member can be interposed by interposing metal spokes or donut-shaped plates. It goes without saying that 50 may be interlocked.

Further, as shown in FIG. 1, the ultrasonic motor 4
In order to support and fix 0 to the mounting member 46, if the end face of the stator 41 is fixed after forming the reduced diameter portion 42 in the stator bottom 44, fixing by the flange formed in the vibration node of the ultrasonic motor. The ultrasonic motor 40 can be fixed to the mounting member 46 without adversely affecting the vibration of the ultrasonic motor without using the method.

Further, in the ultrasonic motor device of this embodiment, a brush type encoder is formed. The encoder is a brush mechanism 70 provided on the reduced diameter portion 42 of the stator 41.
And a pattern portion 56 formed on the rotary member 50, and the brush mechanism 70 is formed of a brush 62 and a brush connector 64. The brush 62 is the brush connector 6
4 is planted in contact with the pattern portion 56. The brush 62 is made of a conductor having elasticity, and phosphor bronze or the like can be applied. A lead wire 76 that connects to the encoder circuit device 72 is connected to the brush connector 64.

Further, the pattern portion 56 formed on the rotating member 50 rotates integrally with the rotating member 50 and is periodically divided into a conductive portion 58 and an insulating portion 60 as shown in FIG.

A lead terminal 68 connected to the lead wire 66 is in contact with the end of the rotary member 50. The lead wire 66 is connected to the encoder circuit device 72. Thus, if the brush 62 had been in contact with the conductive portion 58, then from the encoder circuitry 72, the leads 76,
A series of circuits including the brush connector 64, the brush 62, the conductive portion 58, the rotating member 50, the lead terminal 68, and the lead wire 66 is formed. That is, if a voltage is generated in the encoder circuit device 72, a current flows through the circuit. However, if the brush 62 was not in contact with the conductive portion 58, i.
When in contact with 0, no current flows through the circuit. When the rotating member 50 is rotating, the rotating member 50 slides on the lead terminals 68.

In the ultrasonic motor device having this structure, when the rotating member 50 is rotated by driving the ultrasonic motor, the pattern portion 56 is also rotated. Then, the brush 62 slides on the pattern portion 56, so that the brush 62 alternately contacts the conductive portion 58 and the insulating portion 60. Therefore, at this time, if a voltage is generated in the encoder circuit device 72, a current intermittently flows in the circuit including the brush mechanism 70, the pattern portion 56, and the encoder circuit device 72. Since the waveform of this current corresponds to the rotation speed of the rotating pattern portion, the encoder circuit device 7
2 calculates the number of rotations of the rotating member 50 based on the waveform of this current. Further, the obtained rotation speed information is transmitted to the drive circuit device of the ultrasonic motor as an electric signal to control the ultrasonic motor.

Therefore, the ultrasonic motor device of this embodiment can always detect the rotational speed of the rotating member 50 or the rotor 12, so that the ultrasonic motor is controlled by feeding back the rotational speed to the ultrasonic motor. You can also do
Further, since the encoder is formed closer to the stator 41 than the rotor 12 of the ultrasonic motor 40, the lead wire connected to the encoder can be easily pulled out from the mounting plate 46 to which the ultrasonic motor 40 is mounted. You can Therefore, the length of the lead wire can be shortened, and the workability in assembling the ultrasonic motor 40 is significantly improved. In particular, the wiring tube 80 for passing the lead wire 76 connected to the brush mechanism 70 and the ultrasonic motor 40
Since it is possible to share a wiring line for passing a lead wire (which is connected to both piezoelectric elements 16 and 20) for driving the device, it is possible to simplify the manufacturing or mounting process and achieve cost reduction. You can also Furthermore, since a simple brush type encoder is used integrally with the ultrasonic motor device, the manufacturing cost can be reduced. Moreover, since the brush type encoder is used, it is very inexpensive. In this embodiment, the stator 41
The reduced diameter portion 42 is formed on the reduced diameter portion 42, and the reduced diameter portion 42 is formed on the reduced diameter portion 42.
However, the present invention is not limited to this, and it is sufficient that the brush mechanism 70 does not rotate with the rotor 12 and is formed as a fixed member. However, as is apparent from FIG. 1, since the brush mechanism 70 is formed in the reduced diameter portion 42, it is not necessary to increase the diameter of the rotating member 50 to form the encoder, and the ultrasonic motor device can be downsized. Can be planned. In the present embodiment, an example in which a conductor is used as the material of the rotating member 50 has been described. The member 50 does not have to be a conductor.

[0017]

The ultrasonic motor device of the present invention comprises a brush type encoder integrally formed of a brush mechanism formed on the stator and a pattern portion formed on the rotating member. Alternatively, since it is possible to detect the rotation speed of the rotor, it is possible to perform control such as feeding back the rotation speed to the ultrasonic motor. Furthermore, since the encoder is formed closer to the stator than the rotor of the ultrasonic motor, the lead wire connected to the encoder can be easily pulled out from the mounting plate on which the ultrasonic motor is mounted. Therefore, the length of the lead wire can be shortened, and the workability in assembling the ultrasonic motor is significantly improved. In particular, the lead wire connected to the encoder and the lead wire for driving the ultrasonic motor (connected to the first piezoelectric element and the second piezoelectric element) can be collected or bundled. The manufacturing or mounting process can be simplified, and the cost can be reduced. Further, since the brush type encoder, which is integrated with the ultrasonic motor device and is simple and inexpensive, is used, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an ultrasonic motor device of this embodiment.

FIG. 2 is a perspective view of a pattern portion.

FIG. 3 is a cross-sectional view of a conventional ultrasonic motor device.

[Explanation of symbols]

 10 Ultrasonic Motor 12 Rotor 16 First Piezoelectric Element 20 Second Piezoelectric Element 24 Stator 34 Mounting Member 36 Rotating Member 40 Ultrasonic Motor 41 Stator 46 Mounting Member 50 Rotating Member 56 Pattern Part 58 Conductive Part 60 Insulating Part 62 Brush 64 Brush Connector 70 Brush mechanism

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshio Takahashi 1-7 Yukiya Otsukacho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Yoichi Kimura 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alp Su Electric Co., Ltd.

Claims (1)

[Claims] 1. A rotor and a cylindrical stator,
An ultrasonic motor in which a first piezoelectric element that vibrates in the circumferential direction of the stator and a second piezoelectric element that vibrates in the axial direction of the stator are incorporated in the stator, and an attachment to which the ultrasonic motor is attached. In an ultrasonic motor device comprising a member and a rotating member that interlocks with the rotor, a pattern portion formed on the rotating member and divided into a conductive portion and an insulating portion, and the pattern portion formed on the stator An ultrasonic motor device, wherein an encoder including a brush mechanism that comes into contact with the ultrasonic motor is formed.