JPH0715986A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To suppress the resonance vibrations of grooves by providing a torus- shaped vibrating body in which a plurality of grooves which are composed of first grooves and second grooves which are formed in parallel so as to be adjacent are formed side by side in the circumferential direction. CONSTITUTION:A vibrating body 20 is formed to be a nearly torus shape, and a plurality of groove groups 25 are formed along the circumferential direction on its surface. Each groove group 25 is composed of one pair of grooves 21, 22 whose directions are formed in parallel. The grooves 21, 22 are formed in parallel with every extension line 1 to the radial direction of the vibrating body 20 which is passed through the central part of each groove group 25. Consequently, when oscillating waves which advance in the circumferential direction are generated at the vibrating body 20, the grooves 21, 22 are vibrated. Since the direction of the grooves 21, 22 with reference to the advance direction of the oscillating waves is different at this time, identical vibrations are not caused at the grooves 21, 22. Thereby, it is possible to restrain the individual grooves 21, 22 from resonancing with the oscillating waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor having a groove formed in a vibrating body improved.

[0002]

2. Description of the Related Art Ultrasonic motors are, for example, Japanese Patent Publication 1-40.
There is one disclosed in Japanese Patent No. 597. This kind of ultrasonic motor is composed of a vibrating body and a moving body that are in pressure contact with each other. A piezoelectric element or the like for generating vibration is attached to the vibrating body and is excited to generate a progressive vibration wave. The moving body is frictionally driven by this vibration wave. Such an ultrasonic motor has an advantage that it can obtain a high torque even at a low speed, and is put to practical use in various devices such as a camera.

FIG. 9 is a plan view showing the structure of an example of a vibration body of a conventional ultrasonic motor. As shown in FIG. 9, the vibrating body 10 is formed in a substantially annular shape, and a plurality of grooves 11 are formed on the surface thereof along the circumferential direction.
These grooves 11 are formed to increase the amplitude of vibration of the vibrating body 10. The groove 11 is a direction substantially perpendicular to the traveling direction (circumferential direction) of the vibration wave, in other words, the vibrating body 10.
Is formed so as to face the radial direction (radial direction) of. That is, as shown in FIG. 9, the groove 11 is formed parallel to the extension line 1 passing through the center of the vibrating body 11 in the radial direction.

The grooves 11 of the vibrating body 10 are formed one by one by rotating a groove forming member such as a grindstone and sequentially cutting the surface of the vibrating body 10. General vibrating body 10
About 100 grooves are formed in the groove.

[0005]

However, in the above-described conventional ultrasonic motor, when the vibration wave is generated in the vibrating body 10, the groove 11 of the vibrating body 10 may resonate.
Due to this resonance, there is a problem that abnormal noise is generated when the ultrasonic motor is driven.

The present invention has been made to solve the above-mentioned problems, and when a vibration wave is generated in a vibrating body by improving the shape of the groove of the vibrating body of the ultrasonic motor. The purpose of the present invention is to suppress the resonance of the groove and reduce the generation of abnormal noise when the ultrasonic motor is driven.

[0007]

In order to achieve the above-mentioned object, a first solution of the ultrasonic motor according to the present invention has a ring-shaped vibrating body in which a plurality of grooves are arranged side by side in the circumferential direction. In the ultrasonic motor, the plurality of grooves have a first groove and a second groove that are adjacent to each other and are formed in parallel.

A second solving means of the ultrasonic motor is that a groove group consisting of the first groove and the second groove includes a first groove group and a second groove group having different groove depths. It is characterized by having.

A third solving means of the ultrasonic motor is characterized in that the groove depths of the first groove and the second groove are different.

[0010]

In the first solution of the ultrasonic motor, the vibrating body is formed with the grooves having parallel directions. Further, in the second or third solving means of the ultrasonic motor, grooves having different depths are formed in the vibrating body. Therefore, the vibration state of each groove at the time of generation of the vibration wave can be made different, so that the resonance of the groove can be suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultrasonic motor according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of a vibrating body of an ultrasonic motor according to the present invention. In the figure, (a) shows a plan view, and (b)
Shows a perspective view.

As shown in FIG. 1, the vibrating body 20 is formed in a substantially annular shape like the vibrating body 10 shown in the conventional example, and a plurality of groove groups are formed along the circumferential direction on the surface thereof. 25 are formed at equal intervals. The groove group 25 includes a pair of grooves 21 and 22 formed in parallel with each other. Groove 2
Reference numerals 1 and 22 are formed parallel to the extension line 1 in the radial direction of the vibrating body 20 passing through the center of the groove group 25. Therefore, unlike the groove 11 of the vibrating body 10 of FIG. 9, the grooves 21 and 22 do not face the radial direction of the vibrating body 20, respectively.

FIG. 2 is a perspective view showing the construction of an embodiment of a groove forming member for forming the groove group 25 of the vibrating body 20. As shown in FIG. 2, the groove forming member 30 has a pair of notch members 31 and 32 formed in a substantially disc shape such as a grindstone capable of grinding or cutting the member. A spacer 35 is provided between the notch members 31 and 32 to secure an appropriate gap and arrange the two in parallel. Further, holders 36 (36a, 36b) for holding the cut members 31, 32 are provided outside the cut members 31, 32, respectively.

In FIG. 3, the vibrating body 2 is formed by the groove forming member 30.
FIG. 6 is a perspective view showing a state when a groove group 25 is formed in 0. As shown in FIG. 3, the vibrating body 20 is mounted on a holding base 41 and further fixed by a fastener 42 so as not to move. The holding table 41 is rotatably supported. The rotation axis of the groove forming member 30 is the vibrating body 20.
Are arranged so as to be perpendicular to the axial direction of the vibrating body 20 so that they can rotate (direction A in the figure), approach and separate from the vibrating body 20 (direction B in the figure), and It is movably supported in the radial direction (direction C in the figure).

FIG. 4 is a flow chart for explaining a process of forming the groove group 25 on the vibrating body 20. An embodiment of a method of processing the vibrating body 20 will be described below with reference to FIGS. 3 and 4. First, step S1 in FIG.
Then, the processing of the groove group 25 is started. At this time, the count number Z for counting the number of groove groups 25 formed in the vibrating body 20 in FIG. 3 is set (initialized) to 0. Next, proceeding to step S2 in FIG. 4, the groove forming member 30 in FIG. 3 receives a driving force from a driving unit (not shown) and is rotated in the A1 direction in FIG. At this time, the groove forming member 30 is the same as the vibrating body 2.
0 is on the right side in the drawing and is in a state of non-contact with the vibrating body 20.

Next, in step S3 of FIG. 4, the groove forming member 30 is moved at an appropriate moving speed in the radial direction of the vibrating body 20 (direction C1 in FIG. 3). As a result, the surface of the vibrating body 20 is cut, and the groove group 25 is formed (step S4 in FIG. 4). That is, the grooves 21 and 22 are formed at the same time.

When the formation of the groove group 25 is completed, the process proceeds to step S5 of FIG. 4 and the groove forming member 30 is returned to the initial position. That is, in FIG. 3, the groove forming member 30 is moved in the direction B2 in the drawing to release the cut into the vibrating body 20, and is also moved in the direction C2 in FIG.
Returned to position 1

Next, the process proceeds to step S6 in FIG. 4, 1 is added to the count number Z, and the process proceeds to the next step S7.
In step S7, the count number Z finally becomes the vibrating body 2
It is determined whether or not the value of the number X of the groove groups 25 formed in 0 has been reached. When the count number Z reaches the number X of the groove group 25, it is determined that the formation of the groove group 25 on the vibrating body 20 is completed, the process proceeds to step S10, and the processing of the groove group 25 is completed. In step S7, the count number Z is the number X of the groove groups 25.
If the value is smaller, the process proceeds to the next step S8. In step S8, the holding table 41 is rotated by a predetermined angle, that is, (360 / X) °. Accordingly, the vibrating body 20 that forms the next groove group 25 with respect to the groove forming member 30.
The position of is set.

Next, in step S9, the groove forming member 30 is formed.
The cutting depth is adjusted. The cutting members 31 and 32 of the groove forming member 30 are those in which the abrasive grains on the surface thereof are appropriately crushed during processing and new cutting edges are sequentially generated, so that the outside diameter of the cutting members 31 and 32 is increased as the groove group 25 is processed. Gradually decreases in size. Therefore, it is performed to correct the amount. In addition, when the decrease in the outer diameter of the cut members 31 and 32 is slight, the step S9 may be skipped. The cutting depth is adjusted by moving the groove forming member 30 in the B1 direction in FIG. 3 by an appropriate amount. When this adjustment is completed, the process returns from step S9 to step S3, and the above-described groove group 25 is formed again.

FIG. 5 shows the groove forming member 3 for the vibrating body 20.
It is a top view which shows the moving direction of 0. In the above processing method, the groove forming member 30 is moved in the C direction shown in FIG. 5 (from the outer ring side of the vibrating body 20 to the inner ring side), but the present invention is not limited to this, and the groove forming member 30 may be moved in the D direction in FIG. It is also possible to move the groove forming member 30 (from the inner ring side to the outer ring side). Alternatively, in the direction E in FIG. 5 (the groove forming member 30 is moved from the outer ring side of the vibrating body 20 to the inner ring side, and further to the outer ring side opposite to the vibrating body 20 via the central portion of the vibrating body 20). It is also possible to move the groove forming member 30.

In the vibrating body 20 formed in this way,
When a vibration wave traveling in the circumferential direction is generated, each groove 21, 22 vibrates. Here, since the directions of the grooves 21 and 22 are different from the traveling direction of the vibration wave, the grooves 21 and 22 are different.
The same vibration does not occur in. Thereby, it is possible to suppress the resonance of the grooves 21 and 22 due to the vibration wave.

FIG. 6 is a perspective view showing a second embodiment of the vibrating body of the ultrasonic motor and the groove forming member for forming the vibrating body according to the present invention. In the following description of the other embodiments, the same parts as those in the first embodiment will be designated by the same reference numerals, and redundant description will be omitted as appropriate. The vibrating body 20A shown in FIG.
Similar to the groove group 25 of the vibrating body 20 shown in FIG. 1, a plurality of groove groups 25a including a pair of 21a and 22 formed in parallel are formed along the circumferential direction. Where the groove 21
The depth of a is formed deeper than the depth of the groove 22 by δ.

In order to form the groove group 25a, in the groove forming member 30A, in comparison with the groove forming member 30 of FIG. A member 31a is provided. Therefore, the groove 21a is formed by the cutting member 31a, and at the same time, the groove 22 is formed by the cutting member 32.

FIG. 7 is a perspective view showing a third embodiment of a vibrating body of an ultrasonic motor and a groove forming member for forming the vibrating body according to the present invention. The groove group 25 of the vibrating body 20 of FIG. 1 and the groove group 25a of the vibrating body 20A of FIG. 6 are composed of two grooves, whereas the groove group 25b of the vibrating body 20B of FIG. 7 is formed.
Is composed of three grooves 21 to 23 whose directions are parallel to each other. The groove 22 located in the center of the groove group 25b is
It faces the radial direction of the vibrating body 20B.

Further, in order to form the groove group 25b,
The groove forming member 30B is further provided with a notch member 33 as compared with the groove forming member 30 of FIG. Furthermore, the notch members 31 and 32 and the notch member 3
Spacers 35a and 35b are provided between the cut members 31 to 33 so that 2 and 33 are arranged in parallel at appropriate intervals.

FIG. 8 is a perspective view showing a fourth embodiment of a vibrating body of an ultrasonic motor and a groove forming member for forming the vibrating body according to the present invention. The vibrating body 20C shown in FIG.
Similar to the vibrating body 20B of FIG. 7, a groove group 25c including three grooves 21a, 22 and 23a formed in parallel is formed. The groove depths of the grooves 21a and 23a on both sides of the groove group 25c are formed deeper than the groove depth of the central groove 22.

Further, in order to form the groove group 25c,
In comparison with the groove forming member 30B of FIG. 7, the groove forming member 30C is replaced with the cutting members 31 and 33 and has a larger outer diameter than the cutting members 31 and 33, respectively.
a and 33a are provided. Therefore, the notch member 3
Grooves 21a and 23a are formed by 1a and 33a, respectively, and at the same time, the groove 22 is formed by the notch member 32.

The vibrating body 20A of the above second to fourth embodiments.
It is possible to form a groove in each of the grooves 20C to 20C by the same processing method as that of the first embodiment shown in FIGS. 3 and 4 by the groove forming members 30A to 30C.

In the vibrating bodies 20A and 20C, the grooves of the groove groups 25a and 25c are formed in parallel to each other, and the depths of the grooves are different. Therefore, when each groove is vibrated by the vibration wave, the amplitude of the vibration of each groove is different, so that the resonance of the groove can be further suppressed.

The embodiment of the ultrasonic motor according to the present invention has been described above. However, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention. Is. For example, the groove group 25 is formed by one cut of the groove forming member 30, but the cuts 31 and 32, the material of the vibrating body 20, and the cutting depth of the groove forming member 30 into the vibrating body 20. , And the groove group 25 may be formed by repeatedly moving the groove forming member 30 while gradually increasing the cutting depth in accordance with the rotation speed and the moving speed of the groove forming member 30 (second to second). The same applies to the fourth embodiment).

In the embodiment, the groove group 25a (or 25c)
The grooves 21a and 22 (or 21a, 22 and 23a) are formed to have different groove depths.
(Or the groove group 25c) may be formed to have different groove depths. Also, the groove depths of the groove groups 25 or 25b may be different.

[0032]

According to the ultrasonic motor of the first aspect of the present invention, the grooves whose directions are parallel to each other are formed in the vibrating body so that the vibration state of each groove when the vibration wave is generated is different. The resonance of the groove can be suppressed. According to the ultrasonic motor of claim 2 or 3, since the grooves having different groove depths are formed in the vibrating body, the amplitude of vibration of each groove when the vibration wave is generated is made different. The resonance of each groove can be suppressed more effectively. As a result, it is possible to reduce the generation of abnormal noise when the ultrasonic motor is driven.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a vibrating body of an ultrasonic motor according to the present invention.

2 is a perspective view showing a configuration of an embodiment of a groove forming member for forming a groove group 25 of the vibrating body 20. FIG.

FIG. 3 shows a groove group 25 formed on the vibrating body 20 by the groove forming member 30.
FIG. 6 is a perspective view showing a state when the is formed.

FIG. 4 is a flowchart for explaining a process of processing the groove group 25 of the vibrating body 20.

5 is a plan view showing the direction of movement of the groove forming member 30 with respect to the vibrating body 20. FIG.

FIG. 6 is a perspective view showing a second embodiment of a vibrating body of an ultrasonic motor and a groove forming member for forming the vibrating body according to the present invention.

FIG. 7 is a perspective view showing a third embodiment of a vibrating body of an ultrasonic motor and a groove forming member for forming the vibrating body according to the present invention.

FIG. 8 is a perspective view showing a vibrating body of an ultrasonic motor and a groove forming member for forming the vibrating body according to a fourth embodiment of the present invention.

FIG. 9 is a plan view showing the configuration of an example of a conventional vibrator.

[Explanation of symbols]

 20 Vibrators 21, 22 Grooves 25 Groove Group 30 Groove Forming Members 31, 32 Cut Members 35 Spacers 36a, 36b Holder 41 Holding Base

Claims (3)

[Claims] 1. An ultrasonic motor having a ring-shaped vibrating body in which a plurality of grooves are arranged side by side in a circumferential direction, wherein the plurality of grooves are adjacent to each other and are formed into a first groove and a second groove. An ultrasonic motor having a groove. 2. The groove group composed of the first groove and the second groove has a first groove group and a second groove group having different groove depths. The ultrasonic motor according to 1. 3. The ultrasonic motor according to claim 1, wherein the first groove and the second groove have different groove depths.