JPH04299079A - Driving method for moving unit and ultrasonic motor - Google Patents

Abstract

PURPOSE:To reversibly drive an ultrasonic motor and a moving unit employing a unilateral vibration as a unique drive source. CONSTITUTION:In a moving unit comprising a base body 1 having vibration imparting face freely vibrating in the normal direction and a mover 2 provided with means for converting the vibration imparted by the vibration imparting face into driving force in a direction different from the vibrating direction, driving is executed with moving control contents satisfying reverse rotation conditions when the moving direction of the mover is reversed. In a ultrasonic motor comprising a stator having vibration imparting face vibrating freely in the normal direction and a rotor abutting through the driving force converting means against the vibration imparting face wherein the driving force converting means comprises an element for converting the vibration imparted by the vibration imparting face into rotary driving force of the rotor, driving is executed with rotation control contents satisfying reverse rotation control conditions when the rotational direction of the rotor is reversed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving device, a method of driving an ultrasonic motor using the principle of operation thereof, and a method of driving an ultrasonic motor.

0002

2. Description of the Related Art Generally, in various industrial fields, predetermined tasks are performed by moving or transporting various objects in predetermined directions.

As means for transferring such objects, the objects are placed on an endless belt conveyor and transferred, or the objects are placed on a self-propelled movable cart and transferred. For example, when manufacturing products using machine tools using a factory automation system, materials to be processed, intermediate products, finished products, etc. are moved along a predetermined route using a combination of belt conveyors, self-propelled transport robots, etc. He was being transported.

[0004] Furthermore, ultrasonic motors have conventionally been used to rotate small objects.

[0005]

[Problems to be Solved by the Invention] Among the conventional transport means mentioned above, the belt conveyor and other transport means have a structure in which the object is transported by moving the transport means itself in a straight line, so it is difficult to bend the transport path. Or, in order to curve the object, multiple belt conveyors are required, the configuration is very complicated, it is sometimes difficult to transfer the object between each belt conveyor, and it is also difficult to reverse the conveying direction. there were. For this purpose, for example, the belt part is divided into multiple parts in the direction of movement, and the ends in the direction of movement are slightly overlapped, so that the belt part can move in a curved manner in a horizontal plane, as in the case of belt conveyors installed at baggage claim areas at airports. Although some devices are formed in this way, the structure is extremely complicated and the cost is high.

Furthermore, although self-propelled transport robots and the like can freely transport objects in a desired direction, they have extremely complicated structures and are extremely expensive.

Furthermore, in order to transfer objects from one location to multiple locations, both belt conveyors and transfer robots must be provided with multiple belt conveyors and transfer robots equipped with drive sources, resulting in complicated configurations. At the same time, the entire system became expensive.

[0008] On the other hand, there has been a desire for an extremely compact ultrasonic motor that has a simple configuration and allows the rotor to rotate in forward and reverse directions.

The present invention has been made in view of these points, and uses vibration in one direction as the only driving source, and can move an object in any direction by the driving force converted from the vibration. The present invention provides a method for driving a moving device that is simple and inexpensive, which can freely reverse the direction of movement of the moving device, and which is capable of rotationally driving an extremely small rotor and has a simple configuration. It is an object of the present invention to provide a method for driving an ultrasonic motor, which is inexpensive and can drive an ultrasonic motor with the rotation direction freely reversible.

0010

[Means for Solving the Problems] In order to achieve the above object, a method for driving a moving device according to claim 1 includes a base body whose vibration imparting surface can freely vibrate in the normal direction of the surface; A moving device having a moving body equipped with a driving force conversion means that converts the vibration received from the vibration imparting surface into a driving force directed in a direction different from the vibration direction of the moving body by vibrating the vibration imparting surface of the base body. The method for driving a moving device for moving a moving object is characterized in that when the moving direction of the moving object is reversed, the moving object is driven with movement control content that satisfies a reversal condition.

A method for driving an ultrasonic motor according to a second aspect of the present invention includes: a stator whose vibration applying surface is freely vibrating in the normal direction of the surface; and a rotor which abuts the vibration applying surface via a driving force converting means. and the driving force converting means,
Driving an ultrasonic motor that rotates a rotor by vibrating the vibration applying surface of the stator, the ultrasonic motor being formed by a conversion element that converts vibration received from the vibration applying surface into a driving force for rotating the rotor. The method is characterized in that when the rotational direction of the rotor is reversed, the rotor is driven with rotation control content that satisfies a reversal condition.

0012

According to the method for driving a moving device according to claim 1, when the base body vibrates, the driving force conversion means of the moving body converts the vibration received from the vibration imparting surface of the base body in a direction different from the vibration direction. , for example, into a driving force directed in the tangential direction of the vibration imparting surface, and the movable body moves in the direction of the driving force. Then, by driving with movement control content that satisfies the reversal condition, the moving direction of the moving body is reversed.

According to the ultrasonic motor according to claim 2,
When the stator vibrates, a conversion element serving as a driving force converting means converts the vibration received from the vibration imparting surface of the stator into a driving force that rotates the rotor, and the rotor rotates. Then, by driving with rotation control content that satisfies the reversal condition, the rotational direction of the rotor is reversed.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6.

FIGS. 1 and 2 show an embodiment of a moving device driven by the method of the invention.

[0016] This moving device is a linear type that moves in a straight line, and in the figure, reference numeral 1 is a base body, the upper surface 1a of which is used as a vibration imparting surface. It is formed to vibrate in the vertical direction by a mechanism. This excitation mechanism may be of any configuration; in the case of a large moving device, a vibrating body capable of high output is used, and in the case of a small moving device, a piezoelectric element or the like is used to It is preferable to use sound waves to excite the vibration.

A movable body 2 is placed on the upper surface 1a of the base body 1 with a plurality of blades 3, 3, . . . provided on the lower surface serving as driving force converting means.

The movable body 2 is formed in the shape of a rectangular parallelepiped, and each blade 3 is inclined by an angle θ with respect to a direction perpendicular to the lower surface of the movable body 2, that is, a normal direction to the upper surface 1a of the base body 1. The movable body 2 is moved in the direction of the arrow in FIG. 1 by dividing the external force received from the vertical vibration of the top surface 1a and extracting the force component F directed in the tangential direction of the top surface 1a. Convert it into driving force.

Next, a method for driving a moving body according to the method of the present invention will be explained.

When moving the movable body 2, the upper surface 1a of the base body 1 is vibrated up and down by the vibration mechanism. Each blade 3 of the movable body 2 that has received the vertical vibration of the upper surface 1a converts the external force received from the vibration into a driving force F that moves the movable body 2 in the horizontal direction. is moved in the direction of the arrow.

The moving speed of the movable body 2 may be adjusted by varying the amplitude of the vertical vibration of the upper surface 1a of the base body 1 or by varying the inclination angle θ of the blade 3 with respect to the movable body 2. When reversing the moving direction of the moving body 2, it is preferable to drive the moving body 2 with movement control contents that satisfy the reversal conditions.

For example, when the blade 3 is caused to resonate, the movable body 2 starts moving in the opposite direction to the previous moving direction.

For this purpose, first, the frequency of the base body 1 is changed to match the resonant frequency of the blade 3, and the traveling direction of the moving body 2 is reversed. As for the resonant frequency of the blade 3, the traveling direction is similarly reversed even if the resonant frequency is the primary, secondary or higher resonant frequency.

[0024] Furthermore, in order to return the moving direction of the movable body 2 to its original direction, it is preferable to vary the frequency of the base body 1 to be either larger or smaller than the resonance frequency.

Second, the resonant frequency of the blade 3 itself is varied. For example, since the resonant frequency of the blade 3 is determined by determining factors such as the protruding length and thickness of the blade 3 from the moving body 2, it is preferable to vary these determining factors. In order to vary the protrusion length of the blade 3, it is preferable to provide the blade 3 on the movable body 2 so that the protrusion length can be varied. In order to change the thickness of the blade 3, it is preferable to prepare a plurality of types of blades with different thicknesses and replace the attachment to the movable body 2 as necessary.

Furthermore, when the movable body 2 is to be stopped, it is preferable to stop the vibration of the upper surface 1a of the base body 1.

In FIGS. 3 and 4, the movable body 2 is formed to rotate, and the movable body 2 is formed into a disk or cylinder shape, and a plurality of blades 3, 3, . . . on the lower surface of the movable body 2 are formed. is fixed at a position of a concentric circle O from the center of the moving body 2 so that the driving force is directed in the same tangential direction of the concentric circle O.

With this structure, when the upper surface 1a of the base body 1 is vibrated in the vertical direction, each blade 3 receiving the vibration generates a driving force in the same tangential direction of the concentric circle O. These driving forces move the moving body 2
is rotated. Therefore, an object placed on the movable body 2 can be moved along the circumference around the center of the movable body 2.

In this embodiment as well, the direction of rotation of the movable body 2 can be reversed by causing the blade 3 to resonate, as in the previous embodiment.

FIGS. 5 and 6 show an ultrasonic motor to which the principle of the rotary moving body shown in FIGS. 3 and 4 is applied.

The ultrasonic motor of this embodiment has a stator 11
is formed into a cylindrical shape, and a piezoelectric element 12 that vibrates the stator 11 in the axial direction by ultrasonic waves is provided in the middle of the axial direction. Therefore, the upper surface 11a of the stator 11
becomes the vibration imparting surface. The rotor 13 placed on the upper surface 11a of the stator 11 is formed in substantially the same manner as the moving body 2 shown in FIGS. 3 and 4. That is, the rotor 13
A plurality of blades 1 are provided on the lower surface of the blades 1, which serve as converting elements of a driving force converting means that converts the vibration of the upper surface 11a into a driving force in the rotational direction.
4, 14, . . . are arranged on concentric circles centered on the center of the rotor 13. In addition, in this embodiment, the rotor 1
A central shaft 15 is provided at the center of the stator 11 protruding from the upper surface 11a, and the rotor 13 is loosely fitted onto the central shaft 15 so that the rotor 3 rotates coaxially with the stator 11.

According to the ultrasonic motor of this embodiment, when the piezoelectric element 12 is excited to cause the upper surface 11a of the stator 11 to vibrate ultrasonically, each blade 1 fixed to the lower surface of the rotor 13
4 extracts the ultrasonic vibration as a driving force directed in the tangential direction of the upper surface 11a and in the same tangential direction of the concentric circle O1 of the rotor 13, and these driving forces cause the rotor 13 to
rotates coaxially with the stator 11 about the central axis 15.

Also in the ultrasonic motor of this embodiment, FIG.
As in the case of the moving device shown in FIG.
By causing resonance, the rotational direction of the rotor 13 can be reversed.

For example, each blade 14 is made of phosphor bronze with a radial width of 1.2 mm, a protruding length from the rotor 13 of 1.0 mm, and an included angle between the normal to the lower surface of the rotor 13 and the blade 14 of 30 mm. When the ultrasonic vibrations excited by the piezoelectric element 12 are set to 140.0 KHz, which is the first resonant frequency of the blade 14, and 491.5 KHz, which is the second or third resonant frequency of the blade 14, In each case, the rotor 13 reversed its direction of rotation.

The ultrasonic motor of this embodiment has a stator 11
The rotor 13 can be rotated simply by ultrasonic vibration using the piezoelectric element 12, and the direction of rotation of the rotor 13 can be reversed by resonating the blades 14. It can be formed into a small size. Therefore, it can be used in various industrial fields where the appearance of small motors is desired. For example, it can be provided at the tip of a fiberscope, which is a type of medical equipment, and used as a drive source for various small medical scalpels such as a laser scalpel. Furthermore, since the configuration is simple, there are fewer failures, and costs can be reduced.

Note that the reversal conditions include, as mentioned above, in addition to making the blades 3 and 14 resonate.
Alternatively, it may be another type that can reverse the rotation of the rotor 13.

Furthermore, in each of the embodiments shown in FIGS. 1 to 6, the base body 1 and the stator 11, which serve as upward vibration imparting surfaces,
The moving body 2 and the rotor 13 are placed on the upper surfaces 1a and 11a of the
are placed on each other by their own weight so that they are always in contact with each other, but in addition to their own weight, an appropriate spring or the like may be used to apply a constant contact force to the moving body 2 and the rotor 13. . Alternatively, the movable body 2 and the rotor 13 may be brought into contact with the base body 1 and the stator 11 by magnetic force. In this case, the vibration-applying surface is not limited to a horizontal plane, but may also be a vertical plane or a downwardly facing surface, so that the movable body 2 and the rotor 13 can be brought into contact with the vibration-applying surface and made movable. In particular, this case is extremely suitable for driving the moving body 2 etc. in a zero gravity field such as outer space.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be modified as necessary.

[0039]

[Effects of the Invention] Since the driving method of the moving device and the driving method of the ultrasonic motor of the present invention are configured and operate in this way, each uses vibration in one direction as the only driving source, and converts the vibration from that vibration. Using the driving force, one of the moving devices can move an object in any direction and the direction of movement can be freely reversed, and the other ultrasonic motor can drive an extremely small rotor to rotate in forward and reverse directions. Furthermore,
The moving device and the ultrasonic motor each have a simple configuration and low cost, and both have extremely wide range of applications and have excellent industrial utility value.

[Brief explanation of the drawing]

[Fig. 1] A side view showing the principle of a moving device that is a target of the method of the present invention.

[Figure 2] A perspective view of the moving body in Figure 1 seen from below.

[Fig. 3] A side view showing the principle of a rotating type of moving device that is a target of the method of the present invention.

[Figure 4] A perspective view of the moving body in Figure 3 seen from below.

[Fig. 5] A side view showing one embodiment of an ultrasonic motor that is a target of the method of the present invention.

[Fig. 6] Plan view of Fig. 5

[Explanation of symbols]

1 Base body 1a Top surface 2. Mobile object 3 Blade 11 Stator 11a Top surface 12 Piezoelectric element 13 Rotor 14 Blade

Claims (2)

[Claims] 1. A base body with a vibration-applying surface that can freely vibrate in the normal direction of the surface, and a driving force conversion means that converts vibrations received from the vibration-applying surface into driving force directed in a direction different from the vibration direction. A mobile device having a mobile body comprising:
In the method for driving a moving device for moving a movable body by vibrating the vibration imparting surface of the base body, when the moving direction of the movable body is reversed, the movable body is driven with movement control content that satisfies a reversal condition. How to drive a mobile device. 2. The stator includes a stator having a vibration applying surface that can freely vibrate in the normal direction of the surface, and a rotor that abuts the vibration applying surface via a driving force converting means, the driving force converting means being , an ultrasonic motor formed by a conversion element that converts vibration received from the vibration applying surface into a driving force for rotating the rotor; an ultrasonic motor that rotates the rotor by vibrating the vibration applying surface of the stator; A method for driving an ultrasonic motor, characterized in that when the rotational direction of the rotor is reversed, the motor is driven with rotation control content that satisfies a reversal condition.