JPH0724953Y2 - Ultrasonic linear motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an ultrasonic linear motor suitable as a drive source for electronic devices and precision machines.

[Prior Art] In electronic devices and precision machines, actuators that require a small space for mounting and enable precise positioning are required. Particularly when linear movement is required, a linear motor is more preferable than a rotary actuator because a movement direction conversion mechanism is unnecessary.

Therefore, the applicant of the present invention has provided a linear motor shown in FIG. 5 which is suitable as a drive source for electronic devices and precision machines (see, for example, Japanese Patent Application No. 63-106702).

In FIG. 5, 1 and 2 are leg portions, 3 is a body portion that connects one ends of these leg portions 1 and 2, and these are elastic members formed in a U-shape to form a vibrating body 4. There is. The legs 1 and 2 have a square cross section, a lower end surface A formed in a flat shape, and an equal length from the lower end surface A to the body portion 3. Further, the upper end of the body 3 is chamfered, and the chamfered surface 5 has a piezoelectric element (vibration element) 6,
7 is attached using an adhesive or the like.

The piezoelectric elements 6 and 7 are adapted to expand and contract in a direction orthogonal to the chamfered surface 5 by a voltage applied from a power source (not shown).

The vibrating body 4 is configured such that the rails 8 are guided by the legs 1 and 2 to move.

The rail 8 is provided with legs 1, 2 of the vibrating body 4 along the longitudinal direction.
The guide groove 9 for guiding the guide groove 9 is formed. The guide groove 9 has a flat tread 9a with which the lower end surfaces A of the legs 1 and 2 come into contact, and the side surfaces of the legs 1 and 2 are Guide surfaces 9b, 9b for guiding are formed perpendicular to the tread surface 9a.

In the linear motor configured as described above, when the vibrating body 4 is vibrated by either the piezoelectric element 6 or the piezoelectric element 7, the chamfered surface 5 is inclined with respect to the axes of the legs 1 and 2. Since the legs 1 and 2 are vibrated, the legs 1 and 2 vibrate in the axial direction and in the direction orthogonal to the axis. Therefore, depending on the frequency, the legs 1 and 2 alternately expand and contract, and the lower end surface A of the extended leg is displaced so as to move in the backward direction with respect to the longitudinal direction of the rail 8. repeat. In this vibration mode, the extending leg has a higher surface pressure on the tread 9a of the rail 8 than the contracting leg, so that the extending leg, that is, the leg whose lower end moves in the backward direction, The tread 9a of the rail 8 will be pushed with great force. Therefore, the vibrating body 4 advances due to the reaction force of the leg portion moving in the backward direction.

Further, in order to move the vibrating body 4 backward, the vibrating body 4 is vibrated by the piezoelectric element (6 or 7) on the side opposite to that when moving forward. Then, the lower end surface A of the extended leg is vibrated so as to move in the forward direction, and the vibrating body 4 is moved backward by the reaction force of the leg moving in the forward direction.

That is, at the lower ends of the legs 1 and 2, the longitudinal vibration in the axial direction and the lateral vibration in the direction orthogonal to the axis are combined into elliptical vibration, whereby the vibrating body 4 moves on the tread surface 9a of the rail 8. To do.

In the linear motor configured as described above, the structure of the vibrating body 4 is simple, and a linear driving force can be obtained by simply vibrating the vibrating body 4. Further, since the structure is simple, it can be constructed extremely compactly and can be used as a drive source for equipment such as electronic equipment and precision machinery having a very small mounting space.

[Problems to be Solved by the Invention] However, in the conventional ultrasonic linear motor described above,
When the legs 1 and 2 move, the side surfaces of the legs 1 and 2 inevitably come into contact with the guide surface 9b of the rail 8 that restricts lateral displacement with respect to the traveling direction. There is a drawback in that frictional resistance is generated between the guide surface 9b and the guide surface 9b and this becomes a running resistance of the vibrating body 4. Further, the longitudinal vibration of the legs 1 and 2 also causes a frictional resistance between the side surfaces of the legs 1 and 2 and the guide surface 9b of the rail 8, which also causes a running resistance of the vibrating body 4. was there.

The present invention has been made in view of the above circumstances, and prevents the lateral displacement with respect to the traveling direction and the generation of frictional resistance between the leg portion and the rail to prevent the running resistance of the vibrating body. It is an object of the present invention to provide an ultrasonic linear motor that can reduce the noise.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention is configured so that the rail and the base ends of at least two leg portions made of an elastic material, the tips of which contact the rail, are elastic. A vibrating body configured by connecting with a body made of a material, and a mounting surface formed at both ends of the vibrating body in the axial direction of the vibrating body inclining with respect to the axial direction of the body,
A vibrating element which is mounted on the mounting surface and vibrates in a direction intersecting with the axial direction of the body portion, and a vibration which the vibrating element applies in a direction intersecting with the axial direction of the body portion, The vibration is divided into a component parallel to the direction and a component orthogonal to the direction and transmitted to the legs, and the vibrating body is linearly moved relative to the rail in the axial direction of the body,
A groove portion is formed on the upper surface of the rail along the length direction of the rail, and an inner side surface of the groove portion is formed so as to gradually spread from the groove bottom side to the opening side of the groove portion, and the inner surface of the groove portion serves as a guide surface. , Forming a convex portion having a guide surface of a shape matching the guide surface of the rail at the tip of the leg portion, and contacting only the guide surface of the convex portion of the leg portion and the guide surface of the groove portion of the rail. The leg of the vibrating body is brought into contact with the rail to define the traveling direction of the vibrating body.

[Operation] In such an ultrasonic linear motor, a direction intersecting with the axial direction of the body part is formed on the mounting surface formed at both ends of the vibrating body in the axial direction of the body part in a manner inclined with respect to the axial direction of the body part. A vibrating element that vibrates in the direction of the body, and the vibration applied by the vibrating element in the direction intersecting the axial direction of the body part is divided into the vibrations of the component parallel to the axial direction of the body part and the component orthogonal to the leg part. Since the vibration is transmitted, the elliptical vibration can be generated at the tip of the leg due to the longitudinal vibration and the lateral vibration of the leg, whereby the vibrating body moves linearly in the axial direction of the body relative to the rail.

Then, the inner side surface of the groove is formed so as to gradually spread from the groove bottom side to the opening side of the groove formed in the length direction of the rail upper surface, and the inner surface of the groove is used as a guide surface and at the tip of the leg portion. A convex portion having a guide surface having a shape matching the guide surface of the rail is formed, and only the guide surface of the convex portion and the guide surface of the groove portion are brought into contact with each other to bring the leg portion of the vibrating body into contact with the rail and Since the traveling direction is regulated, the vibrating body can be moved on the rail while only the guide surface of the leg is in contact with the guide surface of the rail. There is no unnecessary frictional resistance between them.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. However, in these figures, the elements common to those shown in FIGS. 4 to 5 are designated by the same reference numerals to simplify the description.

In these figures, 11 is a vibrating body and 21 is a rail.

The vibrating body 11 is formed by integrally forming parallel leg portions 12 and 13 and a body portion 14 connecting these leg portions in a U-shape. Piezoelectric element on surface 5
16,17 are attached. The legs 12 and 13 have a square cross section, and the lower end surface (guide surface) B
Are formed so as to project in a V shape from the left and right side surfaces of the leg portions 12 and 13 toward the axis of the leg portions. Therefore, the leg portions 12 and 13 have a structure in which a V-shaped convex portion is formed at the tip end portion, and the guide surface is formed at the lower end surface of the convex portion. Torso
Reference numeral 14 is formed integrally with the leg portions 12 and 13, and its cross section is formed in a square shape like the leg portions. The leg portions 12 and 13 and the body portion 14 are usually made of aluminum material. The piezoelectric elements 16 and 17 are made of laminated piezoelectric actuators or single-plate piezoelectric ceramics, and are configured to expand and contract by an alternating voltage applied from a power source (not shown). The direction of expansion and contraction is orthogonal to the chamfered surface 5. The chamfered surface 5 is fixed to the chamfered surface 5 with an adhesive.

Then, the dimensions of the vibrating body 11 are appropriately designed, but in the illustrated example, both the leg portions 12 and 13 and the body portion 14 are formed in 5 mm □,
The pitch of the legs 12, 13 is 30 mm, and the height from the tip of the lower end surface B of the legs 12, 13 to the upper surface of the body 14 is 15 mm. Further, as the material of the leg portions 12, 13 and the body portion 14, it is preferable to form an elastic material having appropriate rigidity and elasticity. In addition to the above aluminum, duralumin,
A metal material such as iron, brass or stainless steel, an inorganic material such as alumina, glass or silicon carbide, a polyimide resin, or an organic material such as nylon can be used.

On the other hand, the rail 21 is made of a rigid material such as iron and has a rectangular cross section, and a guide surface 22 for restricting the moving direction of the vibrating body 11 is formed on the upper surface thereof.
The guide surface 22 is formed by the inner surface of a V-shaped groove portion formed along the length direction of the central portion of the upper surface of the rail 21.
The V-shaped groove portion is formed in such a size that the lower end surfaces (guide surfaces) B of the leg portions 12 and 13 can come into close contact with each other. That is, the rail
The inner side surface of the groove portion forming the guide surface 22 of the groove 21 is formed so as to gradually widen on the opening side rather than the groove bottom side of the groove portion.

Further, the vibrating body 11 is formed by a connecting member (not shown).
It is pressed against the rail 21 with a predetermined force.

In the ultrasonic linear motor configured as described above, the lower end surfaces B of the leg portions 12 and 13 are V-shaped from the left and right side surfaces of the leg portions 12 and 13 toward the axis of the leg portions 12 and 13. The rail 1 is projected to be in close contact with the lower end surface B of the leg portions 12, 13 and the leg portion 1
Since the guide surface 22 that guides 2, 13 is formed,
12 and 13 are vibrated by the piezoelectric elements 16 and 17 and their lower end surface B
When elliptically vibrates, the lower end surface B drives on the guide surface 22 of the rail. Therefore, the frictional resistance is not generated between the guide surface 22 of the rail 21 and the legs 12 and 13 due to the traveling and vertical vibration of the legs 12 and 13. Therefore, the running resistance of the vibrating body 14 caused by the frictional resistance between the legs 12 and 13 and the rail 21 can be eliminated.

In addition, in the above-mentioned embodiment, a rail having a rectangular cross section is used.
The guide surface 22 having a V-shaped cross section is formed on the guide 21. As shown in FIG. 3, a long plate is bent into a V-shaped guide surface.
22 may be formed.

Further, although the groove-shaped guide surface is formed on the rail 21 side, the guide surface may be formed so as to project from the rail 21, and the lower end surface of the leg portion may be formed in the groove shape.

Further, the lower end surfaces B of the legs 12 and 13 and the guide surface 2 of the rail 21.
Although the shape of 2 is formed in a V shape, it is needless to say that it may be formed in a shape that is curved in an arc shape or a trapezoidal shape.

[Effects of the Invention] As described in detail above, the present invention is arranged on both ends of the vibrating body in the axial direction of the body in the axial direction of the body on the mounting surface formed to be inclined with respect to the axial direction of the body. A vibration element that vibrates in the intersecting direction, and the vibration applied by the vibrating element in the direction intersecting the axial direction of the body portion is divided into vibrations of a component orthogonal to the component parallel to the axial direction of the body portion and Since it is transmitted to the legs, longitudinal vibration and lateral vibration of the legs can generate elliptical vibration at the tips of the legs, which allows the vibrating body to move straight relative to the rail in the axial direction of the body. Can be exercised.

Further, according to the present invention, the inner surface of the groove is formed so as to gradually spread from the groove bottom side to the opening side of the groove formed in the length direction of the rail upper surface, and the inner surface of the groove is used as the guide surface.
A convex portion having a guide surface having a shape matching the guide surface of the rail is formed at the tip end portion of the leg portion, and only the guide surface of the convex portion and the guide surface of the groove portion are brought into contact with each other so that the leg portion of the vibrating body is set on the rail. Since the abutting contact defines the traveling direction of the vibrating body, the vibrating body can be moved on the rail while only the guide surface of the leg is in contact with the guide surface of the rail, which is caused by the traveling and longitudinal vibration of the leg. Since the vibrating body can travel without generating unnecessary frictional resistance between the rail and the leg portion, the running resistance of the vibrating body, which has been a problem in the past, can be removed, and the vibrating body can smoothly travel. You can

Further, in particular, according to the present invention, since the guide surface of the rail is brought into contact with only the vibrating surface of the leg portion, it is possible to suppress the reduction of the driving force due to the frictional force other than the surface generating the elliptical vibration.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are views showing an embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a side view, and FIG. 3 is another rail. FIG. 4 is a front view and FIG. 5 is a side view, showing a perspective view and FIGS. 4 to 5 as a conventional example. 5 ... Mounting surface, 11 ... Vibrator, 12,13 ... Legs, 16,17 ...
… Piezoelectric element (vibration element), 21 …… Rail, 22 …… Guide surface, B …… Lower end surface (guide surface)

Claims (1)

[Scope of utility model registration request] 1. A vibrating body composed of a rail, a vibrating body formed by connecting at least two leg portions made of an elastic material, the base ends of which are brought into contact with the rail with a body portion made of an elastic material. A mounting surface formed at both ends in the axial direction of the body portion of the body inclined with respect to the axial direction of the body portion, and a vibration element mounted on the mounting surface and vibrating in a direction intersecting the axial direction of the body portion. The vibrating body is configured to divide the vibration applied by the vibrating element in a direction intersecting the axial direction of the body part into the vibrations of the component parallel to the axial direction of the body part and the component orthogonal to the vibrating body. Is configured to be linearly moved relative to the rail in the axial direction of the body, and a groove is formed on the upper surface of the rail along the length of the rail, from the groove bottom side to the opening side of the groove. The inner surface of the groove is formed so that it gradually expands, and the inner surface of the groove is used as a guide surface. In addition, a convex portion having a guide surface having a shape matching the guide surface of the rail is formed at the tip portion of the leg portion, and only the guide surface of the convex portion at the tip of the leg portion and the guide surface of the groove portion on the rail upper surface are formed. The ultrasonic linear motor is characterized in that the traveling direction of the vibrating body is regulated by bringing the legs of the vibrating body into contact with the rails by contacting with each other.