JPH02174570A - Rotary drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary drive device, and particularly to a rotary drive device used in instruments and the like.

(Prior Art) Conventional instruments such as movable magnet instruments and eddy current instruments are known as vehicle instruments.

As disclosed in Japanese Utility Model Application Publication No. 59-85965, etc., a movable magnet type instrument rotates a disc-shaped magnet by an angle using a composite magnetic field of coils wound in a cross-wound manner, and the center of rotation of this magnet is A pointer shaft fixed to the pointer shaft is linked, and the measured value is indicated on the dial by the rotation angle of the pointer fixed to the pointer shaft. In addition, the eddy current type instrument was developed in 1986-7
As disclosed in Japanese Patent No. 4829, etc., the eddy current generated by the rotation of the magnet causes the guide plate to rotate at an angle to a position that maintains balance against the elastic force of the spiral spring, and the rotation of the guide plate A pointer shaft fixed at the center is interlocked, and the measured value is indicated on the dial by the rotation angle of the pointer fixed to the pointer shaft.

(Problems to be Solved by the Invention) In the above-mentioned prior art, since the magnet or the guide plate which is not in contact with the drive source is rotated by the torque generated by the synthetic magnetic field or eddy current, the pointer shaft is There is a problem in that the holding force is small and the pointer tends to swing due to disturbance factors such as vehicle vibration, making the pointer's indication display unstable.

Therefore, an object of the present invention is to provide a rotary drive device with good vibration resistance.

(Means for Solving the Problems) The present invention is a rotational drive device in which an angle sensor is provided on the axis of a rotating shaft of an ultrasonic motor.

(Operation) With the above configuration, the ultrasonic motor is feedhack controlled based on the output of the angle sensor.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

Figures 1 and 2 show a first embodiment of the present invention applied to instruments such as vehicle speedometers and tachometers. A mounting plate 3 is provided at the bottom of the display board 1 via a spacer 2, and the display board 1 and the mounting plate 3 are fixed to the spacer 2 with screws 4 and 5, respectively. There is. 6 is Japanese Patent Publication No. 59-968
Utilizing the principle of traveling waves known from Japanese Patent Publication No. 81, etc.,
This is a traveling wave type ultrasonic motor using flexural vibration disclosed in Japanese Patent Publication No. 2003-100003, and is disposed on the upper part of the mounting plate 3. 7
is a rotating shaft of the ultrasonic motor 6, and this rotating shaft 7 is pushed through a hole 8 of the display board 1, and a pointer 9 is fastened to the upper end by a screw 10.

That is, the rotating shaft 7 is also used as a pointer shaft so that the pointer 9 rotates integrally with the pointer 9. Reference numeral 11 denotes a potentiometer which is an angle sensor located on the axis of the rotating shaft 7 and disposed at the lower part of the mounting plate 3.

The ultrasonic motor 6 is provided with the rotating shaft 7, an elastic body 12 made of a vibrating material such as iron or copper alloy, and electrodes on the upper and lower surfaces of a ceramic substrate, and adjacent sections are arranged alternately in the thickness direction. A piezoelectric body 13 made of polarized piezoelectric ceramic or the like is integrally bonded to the stake 14 using, for example, an epoxy adhesive, and the stator 14
A rotor 15 made of, for example, an aluminum alloy, which is disposed on the upper part of the rotor 15, and a pressure adjusting knob 16 that inserts and locks the lower side of the rotating shaft 7 and elastically abuts against the upper part of the rotor 15. The sleeve of the potentiometer 11 is inserted from the bottom to the top into the hole 17 located on the axis of the rotating shaft 7 and provided in the mounting plate 3, and the outer periphery of the sleeve 18 is inserted. The potentiometer 11 and stator 1
4 is fixed to the mounting plate 3. To elaborate further,
By forming a plurality of cut grooves 20 radially on the upper surface of the elastic body 12, vibrations are transmitted to the upper surface in a good manner.

Potentiometer 1 protruding from the upper part of the sleeve 18
The potentiometer 11 is provided coaxially with the rotary shaft 7 by screwing and coupling the lower male screw portion 22A of the rotary shaft 7 of the ultrasonic mokuro to the female screw portion 22 of the rotary shaft 21 of the first rotary shaft 21. The center hole 23 of the rotor 15 is inserted into the center hole 23 of the rotor 15, and the rotor 15 is in contact with the elastic body 12. An annular and flat slider 24 made of wear-resistant plastic deck or the like is attached to the lower surface of the rotor 15, and an anti-slip sheet 25 made of rubber or the like is attached to the upper surface. A pressure regulating spring 16 is interposed between the non-slip sheet 25 and the stepped portion 26 of the rotating shaft 7, and the pressing force of the pressure regulating spring 16 causes the rotor 15 to be pushed onto the stator 14 via the slider 24. Pressurized contact is made.

Next, the operation of the rotary drive device having the above configuration will be explained. First, the ring-shaped piezoelectric body 13 is divided into 2n pieces in the circumferential direction, and divided into n-1 pieces on the left and right, which are polarized so that adjacent ones have opposite polarities, and are spaced apart from each other without polarity. One of the remaining two pieces is 172 times the size of each of the 2(n-1) pieces, and the other is 372 times the size, and one piece is sandwiched between two sets of (nl) pieces each. Two sets of (n-1) pieces arranged and divided into two have their respective electrodes connected in parallel, and AC voltage de with a phase difference of 90° is applied.
is applied by the drive circuit 27.

The control circuit 28 receives a measurement signal a corresponding to a measurement event such as vehicle speed or engine rotational speed, and an angle signal S from the potentiometer 11, and compares both signals a and b. The drive circuit 27 is controlled by the control signal.

When the rotation angle of the rotating shaft 7 corresponding to the measurement signal a input to the control circuit 28 is larger than the angle signal input from the potentiometer 11, the drive circuit 27 is controlled based on the control signal C from the control circuit 28. An AC high-frequency voltage d having a phase faster than the other by 90 degrees is applied to the piezoelectric body 13, and a counterclockwise traveling wave is created in the elastic body 12, and the voltage contacts the elastic body 12 under pressure. The rotor 15 rotates in the clockwise direction due to mutual frictional force, and the rotating shaft 7 and pointer 9 rotate integrally with the rotor 15 in the open rotation direction via the pressure adjustment spring 16, and the rotation of the potentiometer 11 causes the rotor 15 to rotate clockwise. The shaft 21 rotates coaxially with the rotating shaft 7 via the male and female screw portions 22 and 228. When the angle signal from the potentiometer 11 coincides with the rotation angle corresponding to the measurement signal a due to the rotation of the rotating shaft 7 in the open rotation direction, the AC voltage d is cut off by the control signal C from the control circuit 2, and the rotation starts. The shaft 7 is held in pressurized contact with the stake 14 by a pressure adjusting spring 16. On the other hand, when the rotation angle of the rotating shaft 7 corresponding to the measurement signal a is smaller than the angle signal A, one of the electrodes separated from the drive circuit 27 based on the control signal C receives an AC high frequency voltage that is 90 points slower in phase than the other. e
is applied to the piezoelectric body 13, which generates a traveling wave in the opening rotation direction, and the rotor 1, which is in pressure contact with the elastic body 12,
5 rotates in the counterclockwise direction, the rotating shaft 7 and the pointer 9 rotate in the counterclockwise direction integrally with the rotor 15 via the pressure regulating spring 16, and the rotating shaft 21 of the potentiometer 11 is coaxial with the rotating shaft 7. Rotate as . In this way, the rotating shaft 7
is driven by an ultrasonic motor 6 and controlled by a potentiometer 11 in a feed bank manner.

In this manner, in the above embodiment, the rotating shaft 7 rotates integrally with the rotor 15 and the rotating shaft 21 of the potentiometer 11 via the pressure adjusting spring 16, and the rotor 15 always rotates in pressurized contact with the stator 14. Since the rotating shaft 7 is configured to stop or stop, a sufficient holding force is always applied to the rotating shaft 7, and the pointer 9 can stably display instructions without swinging due to disturbance factors such as vehicle vibration. At the same time, the transmission torque loss can be reduced, and the potentiometer 11 is directly connected to the axis of the rotating shaft 7 of the small ultrasonic motor (j) for feed-hack control, so it is compact, has no response delay, and has high precision. Become a meter.

FIG. 3 shows a second embodiment of the present invention, which was published in Japanese Patent Laid-open No. 59
This shows a case where a traveling wave type ultrasonic motor 6A using stretching vibration proposed in Publication No. 96881 etc. is used, and the same parts as in the above embodiment are given the same reference numerals.The outer circumferential surface 29A of the rotor 15A is The tapered surface 29A of the rotor 15Δ is pressed into contact with the tapered surface 29 of the elastic body 12A due to the pressing force of the matching spring 16 against the circumferential surface 29.

Also, the screw IOA that fixes the pointer 9 to the rotating shaft 7 is
The rotary shaft 7 and the rotary shaft 21 are connected to each other without using the threaded portion 22. Furthermore, there is no male thread 19 on the outer peripheral surface of the sleeve 18 of the potentiometer 11, and the center hole 30 of the elastic body 12A is press-fitted and fixed to the outer peripheral surface of the sleeve 18.

8. By applying the AC voltages d and e from the drive circuit 27, a counterclockwise traveling wave is generated in the elastic body 12A, and the rotor is in pressure contact with the elastic body 12A via the tapered surface 29.29A. 15Δ rotates in the clockwise direction, and the rotation or stopping thereof is controlled by a feed hack based on the angle signal from the potentiometer 11. On the other hand, in this embodiment as well, the rotating shaft 7 rotates integrally with the rotor 15A and the rotating shaft 21 of the potentiometer 11 via the pressure regulating spring 16, and the rotor 15Δ is always in pressure contact with the stake 14A. Since it is configured to rotate or stop at , a sufficient holding force is always applied to the rotating shaft 7, and the pointer 9 can stably display instructions without shaking due to disturbance factors such as vehicle vibration. In addition, since the potentiometer 11 is directly connected to the axis of the pointer shaft 7 of the small ultrasonic motor 6A for feedback control, a highly accurate meter can be obtained with the Combaku I.

Furthermore, in the second embodiment, the inner peripheral surface 29 of the elastic body 12A and the outer peripheral surface 29A of the rotor 15A can both be formed into Taber arc surfaces to obtain substantially the same effects.

FIG. 5 shows a fourth embodiment of the present invention, which was published in Japanese Unexamined Patent Publication No. 60
- This shows a case where a torsion coupler type ultrasonic motor 6B using standing waves proposed in Publication No. 148387 etc. is used, and the same parts as in the above embodiment are given the same symbols and explanations of the same parts are omitted. To explain, the stator 14B of the ultrasonic motor 6B has two piezoelectric bodies 13A and 13B sandwiched between two aluminum disks 3L and 31A, and a torsion connector 32 on the two aluminum disks 3. and these piezoelectric bodies] 3A, 13B, aluminum disk 3L 31
A and the torsion connector 32 are screwed and integrated by a threaded portion 19B of a sleeve 18A of a rotary encoder IIA, which is an angle sensor. This sleeve 188 includes the aluminum disk 3L 31A, the piezoelectric body 13A, 13 from below.
It is inserted into the center of B and screwed into the center of the twist connector 32. The torsion connector 32 has a groove 33 formed on its lower surface to form a pair of crescent moon legs 34, and a beam 35 protruding from one surface diagonally to the groove 33. Further, a rotary shaft 21 of a rotary encoder IIA is mounted on the upper part of the torsion connector 32.
8 protrudes, and the center hole 23 of the rotor 1513 is fitted into this rotating shaft 21A. Rotation axis 2] Δ has In1 rotation +
lQl+ 7 A is kitIllne'; Part 22.2
2A, and the rotor 15A is pressed into contact with the torsion connector 32 by the pressing force of the pressure adjusting spring 16 provided through the step portion 26. For example, when rotating a character wheel with a total of n1 that displays the distance built by a vehicle, when AC type 1 is applied to the piezoelectric bodies 13Δ and 13B, resonance is amplified at the height of the stator 14B. The beam 35 is
Combined with the torsional vibration generated in one of
A star is attached to No. ij (〕r-l, back control is performed. Therefore, in this embodiment, i13 is used, and the rotation axis 7Δ is connected to the pressure regulating spring 1G.
rotor 15 [3 oni rotary encoder 11
The axis of rotation 21△ of △ and the n-body 2F”J %r Ll,'+
1-,) [:l-E1581J,"/Ini/<Data 1413 Since it is configured to rotate in pressurized contact with +i+i width, the rotation axis 7△ has sufficient holding force for The ultrasonic waves of the small jv4 are directly connected to the rotary encoder 11Δ on the axis of the rotary shaft 7Δ of the rotor B), and stable rotational drive is possible. Because of this, four high-precision vessels can be made with one bacuto.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, various types of ultrasonic motors and angle sensors may be selected, and the present invention can be applied to various rotary drive devices such as meters.

〔Effect of the invention〕

The present invention provides vibration resistance 11.4J by installing an angle sensor on the axis of the rotating shaft of the ultrasonic motor. It is possible to provide a rotary drive device with excellent performance.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention;
The figure is an overall longitudinal sectional view, the second figure is an exploded perspective view, and the third figure is an overall longitudinal sectional view showing a second embodiment of the present invention. 6.6Δ, 6B--Ultrasonic motor 7, 7A-(Ultrasonic motor's) rotating shaft 11-Potentiometer (angle sensor) 11A-Rotary encoder (angle sensor'') Patent applicant Hiki Seiki Co., Ltd. Agent Patent attorney Professor Ushiki Godo Patent Attorney Usui 1) Choshibu

Claims (1)

[Claims] (1) A rotary drive device characterized in that an angle sensor is provided on the axis of a rotating shaft of an ultrasonic motor.