JPH0619339Y2 - Ultrasonic linear motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a linear motor using a piezoelectric vibrator or an electrostrictive vibrator.

"Prior art and its problems" Various types of motors using piezoelectric vibrators and electrostrictive vibrators have been proposed in the past, but JP-A-58-148682 discloses a transverse wave and a longitudinal wave excited at the interface of the vibrator. Has proposed a motor which obtains a driving force by the traveling wave synthesized by the above. A motor that uses this ultrasonic vibration obtains its traveling wave by combining longitudinal and transverse waves.Therefore, the electrostrictive element is subjected to a specific polarization process, and these two or more frequency voltages with different phases are applied. Must be applied to the oscillator. Therefore, the manufacturing process is complicated and the power supply circuit is also complicated.

[Purpose of Invention] The present invention aims to obtain a novel ultrasonic linear motor that operates according to a different operation principle from the ultrasonic motors described above, is easy to manufacture, and does not require a special vibrator. And

[Outline of the Invention] The linear motor of the present invention is provided with a plurality of drive feet, one for each of the adjacent ones of the elastic base, with different resonance frequencies between adjacent ones. When vibration is applied by the corresponding piezoelectric vibrator or electrostrictive vibrator,
One of the driving feet adjacent to each other flexurally resonates according to the positive flexural deformation of the elastic base, while the other driving foot does not flexurally vibrate itself due to the negative flexural deformation of the elastic base, As a result, it was made paying attention to obtaining a linear driving force.

That is, according to the present invention, at least two driving feet having different resonance frequencies are provided in the abdomen between the nodes of the elastic base body having at least three flexural fluctuation nodes, each node being supported by a rigid body. A piezoelectric vibrator or an electrostrictive vibrator corresponding to each driving foot is provided on the elastic base, which flexibly deforms the elastic base in a positive / negative relationship and gives vibration to each driving foot. A feature is that a predetermined frequency voltage is applied to the electrostrictive vibrator.

The positive or negative flexural deformation between the nodes of the elastic substrate and the flexural resonance of each driving foot change depending on the specific resonance frequency of each driving foot and the frequency of the frequency voltage applied to the piezoelectric vibrator or the electrostrictive vibrator. Therefore, by changing the frequency, it is possible to adjust the moving speed and change the moving direction of the moving element having the elastic base and the driving foot.

"Embodiment of the Invention" The present invention will be described below with reference to illustrated embodiments. 1 and 2 show one embodiment of an ultrasonic linear motor according to the present invention. The mover 10 includes an elastic base 11 and two drive legs 12 and 13. The elastic base body 11 is for flexural vibration, and has at least three flexural vibration nodes F1, F2, F3 at a predetermined interval L.
F1, F2 and F3 are supported by the rigid frame body 14. Therefore, the elastic substrate 11 is flexibly deformed (changed) when a predetermined frequency voltage is applied to each node. Also, drive foot 1
2 and 13 are intermediate points of the nodes F1, F2, F3 of the elastic base 11,
That is, they are fixed to the belly portion, and their lower end surfaces come into contact with the running surface 20. And, in the elastic substrate 11,
Piezoelectric vibrators or electrostrictive vibrators (hereinafter simply referred to as vibrators) 15 and 16 corresponding to the drive feet 12 and 13 are provided. Adhesion of these elements can be performed by using, for example, an epoxy resin adhesive.

The mover 10 is made of an elastic material such as aluminum, brass,
It is composed of an elastic material (acoustic material) capable of favorably transmitting vibration, such as stainless steel, iron, a synthetic resin material, a ceramic material, a glass material, or a composite material combining these materials.

The vibrators 15 and 16 are composed of laminated piezoelectric or electrostrictive elements or single-plate piezoelectric or electrostrictive elements.
When a drive frequency voltage is applied, the drive frequency expands and contracts at a frequency corresponding to the frequency of the frequency voltage. Then, this expansion / contraction (vibration) causes the elastic base 11 to be flexibly deformed in either the positive or negative direction, and is amplified and transmitted to the drive legs 12 and 13.

The present invention is based on the driving feet 12 and 13 of the moving element 10 described above.
The resonance frequencies of the elastic base 11 and the elastic base 11 are flexibly vibrated in synchronization with the different resonance frequencies. That is, when one of the nodes between the nodes deforms downward (this is positive), the other vibrators 15 and 16 have different phases so that the other deforms upward (this is negative). The driving voltage of a predetermined frequency is separately applied. The resonance frequencies of the drive legs 12 and 13 can be made different by changing their thickness, material, length, or the like. The resonance frequency is determined in consideration of the frequency of the drive voltage applied to the vibrators 15 and 16. In addition, the direction of flexural deformation of the elastic base 11 is such that the drive feet 12 and 1
Tuned to a resonance frequency of 3. The moving direction of the moving element 10 can be changed by appropriately changing the frequency of the driving voltage of the vibrators 15 and 16, and the moving speed of the moving element 19 can be changed by changing the application amount of the driving voltage. You can In this way, when the different resonance frequencies of the drive feet 12 and 13 are set to be the same as the frequency of the drive voltage applied to the corresponding vibrators 15 and 16, the drive feet 12 and 13 are oscillated most efficiently for linear drive. You can get the power.

The ultrasonic linear motor having the above-described configuration is provided with the vibrators 15 and 16
When driving voltages having different predetermined driving frequencies are simultaneously applied to the moving elements, the mover 10 moves rightward or leftward as shown in FIGS. 2 (A) and 2 (B).

The reason is considered to be as follows. Now oscillator 1
When 5 and 16 are given different driving voltages of predetermined frequencies,
Between the nodes F1 and F2 in the elastic base 11, and between the nodes F2 and F3
Between 1 and 2, depending on the respective given frequencies, the one deforms downward (positive direction) while the other changes upward (negative direction). For example, clauses F1 and F2
It is assumed that the area between the nodes is positively deformed and the area between the nodes F2 and F3 is negatively deformed. Then, at the same time, the driving feet 12 and 13 also vibrate vertically (vertically). Since the same frequency voltage as the resonance frequency is applied to the drive feet 12 and 13, both drive feet 12 and 13 resonate flexibly. The vertical vibration and the flexural vibration are combined into an elliptic motion. But the driving foot 1
In the case of No. 3, since the nodes F2 and F3 of the elastic substrate 11 have a negative relationship, they are in a floating state with respect to the traveling surface 20, and this elliptic motion does not act. Therefore, drive foot 1
Only two elliptic motions act on the running surface 20, and the driving foot 12 becomes a thrust to the left and right. As a result, a linear driving force can be obtained. On the contrary, between the nodes F1 and F2 of the elastic base 11 is negatively deformed,
When the area between F2 and F3 is positively deformed, the opposite relationship is obtained. That is, since the driving foot 12 is in a floating state and only the driving foot 13 is in contact with the running surface 20, only the elliptic movement of the tip of the driving foot 13 acts on the running surface 20. Therefore, the driving foot 13 becomes a thrust to the left and right. As a result, a linear driving force can be obtained. And
The moving direction of the mover 10 can be set by setting the frequency of the drive voltage applied to the vibrators 15 and 16 to be the same as the resonance frequency of the corresponding drive legs 12 and 13.

It should be noted that the above-mentioned operation principle is one reasoning, but the present linear motor can be actually driven, and therefore, even if the operation principle is different from the above, the scope of the present invention is not narrowed. .

"Effects of the Invention" As described above, the ultrasonic linear motor of the present invention has a different operation principle from the conventional ultrasonic motor, and has a very simple structure of the mover and special polarization treatment. It can be constituted by a piezoelectric vibrator or an electrostrictive vibrator which is unnecessary. Further, the moving direction can be changed by changing the frequency of the drive voltage applied to the piezoelectric vibrator or the electrostrictive vibrator, and a novel linear motor that is easy to manufacture and use can be provided.

[Brief description of drawings]

FIG. 1 is a front view showing one embodiment of the ultrasonic linear motor of the present invention, and FIGS. 2 (A) and 2 (B) show the operation principle of the linear motor according to the present invention, which is a modification of the driving foot and the mover. It is a schematic diagram depicting the situation. 10 ... mover, 11 ... elastic base, 12, 13 ... drive foot, 14 ... rigid frame, 15, 16 ... vibrator, 20
…… Running surface, F1, F2, F3 …… Section.

Claims (1)

[Scope of utility model registration request] 1. Having at least three flexural vibration nodes,
An elastic base body in which each node is supported by a rigid body; at least two driving feet fixed to the abdomen between the nodes of the elastic base body and having mutually different resonance frequencies;
And a piezoelectric vibrator or an electrostrictive vibrator provided corresponding to each driving foot, which flexibly deforms the elastic base in a positive / negative relationship and gives vibration to the driving foot, and An ultrasonic linear motor characterized in that a predetermined frequency voltage is applied to the piezoelectric vibrator or the electrostrictive vibrator.