JPH0775353A - Vibrating motor - Google Patents

Abstract

PURPOSE:To obtain a vibrating motor which does not require very strict dimensional precision, which is easy to design and manufacture, of which the direction of rotation of a rotor can be changed easily relatively and which is excellent in a rotational efficiency. CONSTITUTION:A stator part 20 comprises two piezoelectric elements 22 and 24, two electrode plates 26 and 28 for impressing a high-frequency AC voltage of a prescribed frequency on these elements, first, second and third metal block bodies 30, 32 and 34 so disposed as to hold these parts from outside and a coupling bolt 36 for tightening the metal block bodies. In the vicinity of the end face of the third metal block body 34, a plurality of slanting slit grooves 38 are formed so that the node of longitudinal vibration be positioned at the center thereof. When the piezoelectric elements 22 and 24 are made to vibrate, the longitudinal vibration is generated in the whole of the stator part 20 and torsional vibration is generated simultaneously by the action of the slanting slit grooves 38. Thereby resultant elliptical vibration of the longitudinal vibration and the torsional vibration occurs on the surface 12 of contact with a rotor and a rotor part 10 can be driven to rotate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration motor for rotating a rotor portion by vibrating a piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, a bolt tightening Langevin type ultrasonic motor is well known, for example, Japanese Patent Laid-Open No. 61-496.
There is known a piezoelectric motor using a cantilever torsional ultrasonic transducer according to Japanese Unexamined Patent Publication No. 70, an ultrasonic motor according to Japanese Unexamined Patent Publication No. 63-217984, and the like.

However, in the conventional motors of this type, there is a problem that the rotor can rotate only in one direction, and the structure is complicated and expensive.

FIG. 9 is a diagram showing an example of a conventional bolted Langevin type ultrasonic motor. In the ultrasonic motor shown in the figure, metal block bodies 104 and 106 having different lengths are arranged at both ends of two piezoelectric elements 100 and 102, and both block bodies 104 and 106 are piezoelectric elements by a bolt 108 at the center thereof. It is fixed so that 100 and 102 are tightened.

In this ultrasonic motor, when a high frequency AC voltage is applied from the AC power supply 110 to the piezoelectric elements 100 and 102, longitudinal vibration occurs due to vibration in the thickness direction of the piezoelectric elements 100 and 102, and torsion occurs due to the twisting of the bolt 108. Vibration is generated, and elliptical vibration, which is a combination of longitudinal vibration and torsional vibration, is generated on the end faces of the block bodies 104 and 106, and a rotational driving force can be obtained by this elliptic vibration.

On the end face of the block body 106 described above, a disk 112 is arranged biased toward the block body 106 by a spring 114, and a rotary shaft 116 of the disk 112 is supported by a bearing 118. There is. Therefore, the disk 112
By contacting the end surface of the block body 106, the rotational force obtained by the combined vibration is transmitted to the disk 112, and the rotational output can be taken out from the rotary shaft 116.

By the way, the above-described bolt tightening Langevin type ultrasonic motor generates elliptical vibration by utilizing the torsional vibration generated by tightening the bolt, but directly generates the elliptic vibration without using the tightening of the bolt. A vibration motor for driving is also known in the past, and is disclosed in Japanese Patent Laid-Open No.
There are vibration motors disclosed in JP-A-355679 and JP-A-5-146179.

Each of these vibration motors has a piezoelectric element having a plurality of voltage application regions divided in the rotation direction of the rotor, and applies high-frequency AC voltages having different phases to the respective regions. As a result, bending vibration is directly generated in the metal block body sandwiching the piezoelectric element, and elliptical vibration is generated in the rotor contact surface.

[0009]

However, in the conventional bolted Langevin type ultrasonic motor shown in FIG. 9, rotation output cannot be effectively generated unless the resonance points of longitudinal vibration and torsional vibration are matched. Therefore, one block body 104 is formed in a short shape, and the other block body 106 is formed.
Need to be formed in a long shape to match the resonance points. Moreover, since bolts are used to generate torsional vibration, it is necessary to strictly control the pitch, tightening load, and various dimensional accuracy, which makes designing and manufacturing difficult.

Further, since the torsional vibration is generated by utilizing the tightening of the bolt, only one-direction elliptical vibration can be generated on the end face of the block body 106, and the rotating shaft 116 cannot be driven in both forward and reverse directions. There was a problem.

On the other hand, in a conventional vibration motor which directly generates an elliptical vibration by bending vibration without utilizing bolt tightening, it is necessary to apply a plurality of high frequency AC voltages having different phases to each voltage application region in the piezoelectric element. Because there is
There has been a problem that the drive circuit of the motor becomes complicated, leading to high cost.

The present invention was created in view of the above points, and its purpose is to have a relatively gentle dimensional accuracy, to facilitate designing and manufacturing, and to change the rotor rotating direction relatively easily. Another object of the present invention is to provide a vibration motor capable of achieving high rotation efficiency.

[0013]

In order to solve the above problems, the invention of claim 1 is a vibration motor having a stator part and a rotor part, wherein the stator part is polarized in the direction of the rotation axis of the rotor part. A piezoelectric element that generates longitudinal vibration, an electrode that applies a high-frequency alternating voltage to the piezoelectric element, and the piezoelectric element are attached and fixed to both sides of the piezoelectric element so as to sandwich the piezoelectric element. A first block body and a second block body, each of which has at least one slit groove that is inclined with respect to the rotation axis and is formed on at least one of the positions; and a longitudinal vibration generated by the piezoelectric element. , The torsional vibration generated by the slit groove portion of the block body is combined, and the elliptical vibration is generated on the rotor contact surface of the stator portion to rotate the rotor portion. And drives.

The invention of claim 2 is characterized in that, in the invention of claim 1, the rotational driving direction of the rotor portion is changed by changing the inclination direction of the slit groove.

According to a third aspect of the invention, in the invention of the first or second aspect, at least one of the first block body and the second block body in which the slit groove is formed further has the slit groove as an end. It is configured by being divided into a third block body formed in the portion and a fourth block body having no slit groove, and when the third block body and the fourth block body are assembled. The slit groove is formed at a position including the node of the vertical vibration.

[0016]

Since the piezoelectric element used in the vibration motor according to claim 1 is polarized in the direction of the rotation axis of the rotor portion, by applying a high frequency AC voltage to this piezoelectric element, the first and second block bodies are longitudinally aligned. Vibration can be generated. Further, the inclined slit groove formed in the first or second block body is located at a position including the node of the vertical vibration described above. Therefore, when the slit groove portion vertically vibrates, the directions of expansion and contraction at the node are opposite. As a result, the length of the slit groove in the vertical direction (rotational axis direction) also expands and contracts due to the vertical vibration, the inclination of the slit groove also changes due to the vertical vibration, and as a result, torsional vibration occurs in the slit groove portion. Thus, when the longitudinal vibration and the torsional vibration are generated, elliptical vibration that is a combination of these vibrations is generated on the rotor contact surface of the stator portion, and the rotor portion is driven to rotate in one direction.

In the invention of claim 1, since the torsional vibration is generated by forming the slit groove,
Moreover, since the torsional vibration is generated by utilizing the longitudinal vibration, it is not always necessary to match the resonance points of the longitudinal vibration and the torsional vibration which are independently generated, and it is possible to easily realize an efficient motor. In addition, since the tightening with bolts is not used to generate torsional vibration,
Design and manufacturing are easy without the need to strictly control the pitch, tightening load and various dimensional accuracy.

Furthermore, since it is sufficient to apply a single-phase high-frequency AC voltage to the piezoelectric element, the structure of the piezoelectric element and the motor drive circuit is relatively simple, and the cost does not increase.

Further, in the vibration motor of claim 2,
The rotational driving direction of the rotor portion is changed by changing the inclination direction of the slit groove described above. That is, the torsional vibration generated when the slit groove expands and contracts in the rotation axis direction depends on the inclination direction of the slit groove, and two types of block bodies having opposite inclination directions of the slit groove are prepared. As a result, the rotor portion can be driven in the normal rotation or the reverse rotation.

According to the second aspect of the present invention, since it is only necessary to prepare two block bodies having different slit groove inclination directions, the rotation direction of the rotor portion can be easily changed.

Particularly, in the conventional bolted Langevin type ultrasonic motor, the rotation direction cannot be changed unless the bolt is changed, whereas in the present invention, only the block body is changed. It is easy to share and the cost can be reduced.

Further, in the invention of claim 3, the block body in which the slit groove is formed is further divided into a third block body and a fourth block body, and the slit groove is provided at one of the ends. Is formed. Therefore, the slit groove described above can be formed only by cutting the end portion of the block body, which facilitates manufacturing.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing the overall construction of an embodiment to which the vibration motor of the present invention is applied.

The vibration motor of this embodiment shown in FIG. 1 includes a rotor portion 10 which is rotationally driven in a fixed direction, and a rotor portion 1 of the rotor portion 10.
0 and a stator portion 20 that is rotationally driven by elliptical vibration generated on the rotor contact surface 12 that is one end surface. The rotor portion 10 includes a disc 14 that comes into contact with the rotor contact surface 12 at a constant pressure, and a rotation output shaft 16 attached to the center of rotation of the disc 14. Therefore, when elliptical vibration occurs on the rotor contact surface 12 of the stator portion 20, the disc 14 of the rotor portion 10 causes the rotation output shaft 16 to rotate.
Is driven to rotate in one direction.

In addition, the stator portion 20 is formed with ring-shaped piezoelectric elements 22 and 24 using a piezoelectric material such as ceramics, and electrodes arranged so as to be in full contact with both sides of one piezoelectric element 24. The plates 26 and 28, and the first metal block body 30, the second metal block body 32, and the third metal block body 30 arranged so as to sandwich the piezoelectric element 22, the electrode plate 26, the piezoelectric element 24, and the electrode plate 28 from both sides. And the coupling bolts 36 for fastening and fixing the first metal block body 30 and the third metal block body 34 located at both ends.

Further, one end surface of the third metal block body 34 serves as the rotor contact surface 12 described above, but the other end surface is in contact with the second metal block 32, and the other end surface has an end portion. A plurality of diagonal slit grooves 38 are formed so as to coincide with each other. Therefore, after the stator portion 20 is assembled, the second metal block body 32 and the third metal block body 34 are integrated with each other, and a plurality of diagonal slit grooves 38 are formed in the vicinity of the substantially central portion thereof. .

The piezoelectric elements 22 and 24 described above are used as electrodes during polarization, for example, those obtained by polishing and removing silver or nickel surfaces after polarization is completed.

FIG. 2 is a perspective view showing a state where the stator portion 20 is assembled. As shown in the figure, the assembled stator portion 20 includes a third metal block body 34, a second metal block body 34, and a second metal block body 34.
The metal block body 32, the piezoelectric element 22, the electrode plate 26, the piezoelectric element 24, the electrode plate 28, and the first metal block body 30 of FIG. The external connection terminals 40 have a shape in which the external connection terminals 42 project from the other electrode plate 28.

The two external connection terminals 40 and 42 are for applying a high frequency AC voltage having a constant frequency to the piezoelectric element 24. Further, with respect to the other piezoelectric element 22, the end surface of the second metal block body 32 electrically connected to the external connection terminal 42 via the coupling bolt 36 shown in FIG. 1 acts as an electrode plate. A high frequency AC voltage having a constant frequency is applied by the second metal block 32 and the external connection terminal 40.

FIG. 3 is an exploded perspective view showing the detailed structure of the stator portion 20 and the assembled state.

A screw hole is formed at the center of each of the first metal block body 30 and the third metal block body 34 described above, so that the male screw groove formed on the coupling bolt 36 is screwed. Has become. Further, a bolt insertion hole 32a having an inner diameter substantially equal to the outer diameter of the coupling bolt 36 is formed at the center of the second metal block body 32. Each of the piezoelectric element 22, the electrode plate 26, the piezoelectric element 24, and the electrode plate 28 has a bolt insertion hole 22a, 26a, 24a, which has an inner diameter larger than the outer diameter of the coupling bolt 36.
28a is formed. These bolt insertion holes 22
The inner diameters of a, 26a, 24a and 28a are the piezoelectric elements 22,
When the electrode plate 26, the piezoelectric element 24, and the electrode plate 28 are assembled, the outer diameter of the collar 44, which is inserted into the outer side of the coupling bolt 36, is formed to be substantially the same.

To assemble the stator portion 20, first, one end of the coupling bolt 36 is screwed onto the first metal block body 30 to be fixedly mounted, then the collar 44 is inserted, and then the electrode is provided on the outer peripheral side of the collar 44. The plate 28, the piezoelectric element 24, the electrode plate 26, and the piezoelectric element 22 are sequentially inserted. Next, the second metal block body 32 is inserted into the connecting bolt 36, and finally the third metal block body 34 is connected to the connecting bolt 36.
The other members are fastened and fixed by the first and third metal block bodies 30 and 34 by being screwed to the other end.

In this embodiment, when connecting and fixing,
Since no adhesive is used to fix the laminated surface of each member, it is possible to prevent variations in resonance frequency from one motor to another and to prevent the Q value from decreasing, thereby improving the performance and reliability of the vibration motor. it can.

As shown in FIG. 3, the piezoelectric elements 22 and 24 are arranged so that their polarization directions are different from each other. When high-frequency AC voltages of the same polarity are applied, one expands and the other contracts. become. However, since the high frequency AC voltage having the opposite polarity is applied with the electrode plate 26 in common, when one piezoelectric element 22 extends, the other piezoelectric element 24 is applied.
Also extends, and when one piezoelectric element 22 contracts, the other piezoelectric element also contracts. As a result, the amplitude value in the vertical direction (longitudinal direction of the coupling bolt 36) of the entire stator portion 20 can be set to a large value.

FIG. 4 is a view showing details of the oblique slit groove 38 formed in the third metal block body 34 of the stator portion 20. FIG. 3A shows a side view of the third metal block body 34.
It is shown that 8 is arranged so as to partially contact the lower end face of the third metal block body 34. Since the oblique slit grooves 38 can be formed by cutting from the lower side or the lateral direction of the third metal block body 34, the formation thereof can be performed relatively easily. Although slightly difficult to cut, the second and third metal block bodies 32 and 34 are formed of one metal block body, and a diagonal slit groove 38 is formed by inserting a blade laterally near the middle thereof. You may do it.

Further, FIG. 6B shows a view of the third metal block body 34 from the lower side, and as an example, the diameter 3
A state where 12 oblique slit grooves 38 are formed in the 5 mm metal block body 34 is shown.

FIG. 5 is a view for explaining the vertical direction of the oblique slit groove 38, that is, the position of the rotor in the rotation axis direction.

As shown in FIG. 7A, the oblique slit groove 38 is formed so that its center coincides with the position of the vertical vibration node shown in FIG. (B) of the figure shows the positions of the nodes and antinodes of the longitudinal vibration. In the figure, and correspond to the positions of the nodes, and both end surfaces of the stator portion 20 correspond to the antinode positions, respectively. The one node is located at the center of the oblique slit groove 38, and the other node is located at the piezoelectric element 2.
It corresponds to 2 and 24 respectively.

By thus aligning the center of the oblique slit groove 38 with the position of the node of the longitudinal vibration, the oblique slit groove 38 expands and contracts in different directions with the center as a boundary. Moreover, since the inclination direction of the oblique slit groove 38 and the vibration direction of the longitudinal vibration are different, when such expansion and contraction occurs, a phenomenon occurs in which the central portion is rotated in a certain angle range to rotate in a certain angle range. . As a result, vibration in the torsional direction is generated in the oblique slit groove 38 portion of the third metal block body 34, and this vibration is also propagated to the other metal block bodies 30 and 32.
Torsional vibration will occur in the whole of. Therefore, the vertical vibration directly generated by the piezoelectric elements 22 and 24 and the torsional vibration generated by the action of the oblique slit groove 38 are combined, and elliptical vibration in a certain direction is generated on the rotor contact surface 12, and this elliptic vibration is generated. Thus, the rotor unit 10 is rotationally driven in one direction.

FIG. 5 (c) shows an outline of the torsional vibration generated in the stator portion 20. The frequency of the high frequency AC voltage applied to the piezoelectric elements 22 and 24 so as to generate this torsional vibration at the resonance frequency is shown in FIG. It is desirable to decide. However, in general, the resonance frequency also differs due to the difference in the longitudinal elastic coefficient, the lateral elastic coefficient, and the like. Therefore, longitudinal vibration and torsional vibration of the same order are not generated by the resonance frequency of the same frequency, and longitudinal vibration and torsional vibration of different resonance orders occur when the piezoelectric elements 22 and 24 are vibrated by the resonance frequency of a certain frequency. Therefore, the frequency of this high frequency AC voltage must be set.

For example, three metal block bodies 30, 3
The primary resonance frequency of the longitudinal vibration when 2, 34 are formed of aluminum and the diameter of the stator portion 20 is 35 mm and the length L is 90 mm (the lengths of the piezoelectric elements 22 and 24 are also converted to aluminum). When f01 and the secondary resonance frequency f02 are calculated,

[Equation 1] Further, when the primary resonance frequency f11, the secondary resonance frequency f12, and the tertiary resonance frequency f13 of the torsional vibration are calculated,

[Equation 2] Here, v0 and v1 are propagation velocities of vibrations in the vertical and horizontal directions of the metal block body 30 and the like, and were calculated as 5100 m / s and 3000 m / s, respectively.

As described above, the resonance frequency has different values for the longitudinal vibration and the torsional vibration. For example, the secondary resonance frequency of the longitudinal vibration and the tertiary resonance frequency of the torsional vibration are each 56 k.
Hz and 51 kHz, which are relatively close. Therefore, in the present embodiment, 50 kHz is used as the frequency of the high-frequency AC voltage so that resonance occurs in both longitudinal vibration and torsional vibration at the same frequency.

Actually, the applicant of the present invention prototyped and confirmed a vibration motor having the above-mentioned design values. It was confirmed that elliptical vibration was generated on the rotor contact surface 12 and the rotor portion 10 could be rotationally driven in one direction. Has been. Moreover,
Compared with the conventional bolted Langevin type vibration motor, the generated driving torque is about 5 to 10 times larger,
It has been confirmed that the rotation efficiency is also good. At this time, the width of the oblique slit groove 38 was 2 mm, and the length of the rotor in the rotation axis direction was 7 mm.

The rotation direction of the rotor portion 10 can be reversed by reversing the inclination direction of the oblique slit groove 38. For example, when the oblique slit groove 38 is formed in the inclined direction shown in FIG. 5 and the vibration motor is rotated by the secondary resonance mode for longitudinal vibration and the tertiary resonance mode for torsional vibration, the rotor unit 10 rotates clockwise. Driven to rotate. On the other hand, it has been confirmed that the rotor portion 10 is rotationally driven in the counterclockwise direction when the inclination directions are set to opposite directions while keeping the shape of the oblique slit grooves 38 substantially the same. It is possible to set the rotation direction of the rotor unit 10 only by the inclination direction of 38.

Accordingly, if two kinds of the third metal block bodies 34 in which the oblique slit grooves 38 have the opposite inclination directions are prepared, the rotation direction of the motor is set to the opposite direction depending on which one is used. It is possible to reduce the manufacturing cost by sharing the parts. This difference is clear compared to the conventional bolted Langevin type motor, in which both the connecting bolt and the two metal block bodies had to be replaced.

Further, in the vibration motor of this embodiment,
Elliptical vibration is also generated on the stator end surface opposite to the rotor contact surface 12. That is, since elliptical vibration is also generated in the lower end surface shown in FIG. 5, by using this end surface as the rotor contact surface 46, it is possible to make a vibration motor that drives two rotor portions to rotate simultaneously.

In the case of the vibration mode shown in FIG. 5 and the inclination direction of the oblique slit groove 38, the rotor portion 10 in contact with the rotor contact surface 12 is rotationally driven in the clockwise direction, and at the same time, the other rotor contact surface 46. The rotor portion that comes into contact with is driven to rotate counterclockwise. When the slanting direction of the oblique slit groove 38 is reversed, the rotor portion 10 in contact with the rotor contact surface 12 is rotationally driven in the counterclockwise direction, and at the same time, the rotor portion in contact with the other rotor contact surface 46 is in contact. Will be driven to rotate in the clockwise direction.
By changing the resonance mode, it is possible to drive the two rotor parts to rotate in the same direction, and a combination of rotation directions can be set as necessary.

As described above, in the vibration motor of this embodiment, the oblique slit groove 38 is formed so that the center of the vibration motor is located at the node of the vertical vibration, so that the torsional vibration is generated simultaneously with the vertical vibration. Since it is not necessary to match the resonance points of the longitudinal vibration and the torsional vibration, it is possible to easily realize an efficient motor.

Further, since the connecting bolt 36 is simply used for tightening the first and third metal block bodies 30, 34, it is not necessary to strictly control the pitch, tightening load and various dimensional accuracy, and the designing and manufacturing are performed. Will be easier.

Further, since the piezoelectric elements 22 and 24 are all polarized in the same direction, they can be operated by applying a single-phase high-frequency AC voltage, and the piezoelectric elements and the motor drive circuit can be operated. The structure is relatively simple, and the cost does not increase.

FIG. 6 is a view showing the structure of a vibration motor in which the coupling bolt 36 is replaced with another member. Connecting bolt 3
As shown in FIG. 1, the reference numeral 6 designates a second metal block body 30, 34 which is screwed into the first and third metal block bodies 30 and 34 and is present in the middle thereof.
The metal block body 32, the piezoelectric element 22, the electrode plate 26, the piezoelectric element 24, and the electrode plate 28 are simply tightened from both sides. Therefore, any member other than the coupling bolt 36 may be used as long as it can be similarly tightened, and it is not necessary to screw it to the metal block bodies 30 and 34.

FIG. 6A shows one connecting bolt 48 and two.
A vibration motor is shown which performs the above-mentioned tightening with one nut 50, 52. In this case, through holes are formed in the first and third metal block bodies 30 and 34, and the metal block bodies 30 and 34 are attached to the nut 5 from the outside.
Tighten with 0,52.

In this way, the connecting bolt 48 is formed without forming screw holes in the first and third metal block bodies 30, 34.
By tightening each member with the two nuts 50 and 52, the strain generated in the metal block bodies 30 and 34 can be suppressed to a minimum. That is, when the screw holes are formed in the metal block bodies 30 and 34 and the screw holes are screwed into the coupling bolts 36 to tighten the whole, local stress acts on the screw holes. , Complicated distortion occurs. On the other hand, when the nuts 50 and 52 are tightened from the outside of the metal block bodies 30 and 34, a tentative tightening stress acts from the outer side toward the inner side, which acts on the metal block bodies 30 and 34. The applied stress is relatively simple, and the generated strain is not complicated. Therefore, stable output characteristics are easily obtained.

Further, FIGS. 6B and 6C show a case where a connecting rod 54 is used in place of the connecting bolt 48 and one end thereof is swaged to perform the above-mentioned tightening. After each component is inserted into the connecting rod 54 in order, one end thereof is caulked as shown in FIG.

As described above, since the vibration motor of this embodiment does not generate the torsional vibration by utilizing the tightening with the bolts, any method may be used for tightening each member. Therefore, as shown in FIG. 6, it suffices to use commonly used nuts 50 and 52 or simply crimp the connecting rod 54, which can reduce the cost of parts and simplify the manufacturing process. You can also

FIG. 7 is a view showing another embodiment of the present invention, and an exploded perspective view of the stator portion 20 corresponding to FIG. 3 is shown. This vibration motor has a structure in which one piezoelectric element 22 in the vibration motor shown in FIG. 3 is replaced with an insulating plate 56. In the vibration motor shown in FIG. 3, in order to increase the amplitude of vertical vibration, two piezoelectric elements 2 are used.
2 and 24 are used, but a large amplitude, that is, a large driving force is not always required depending on the application, and thus when the small driving force is sufficient, the vibration motor shown in FIG. 7 is used. Since this vibration motor generates longitudinal vibration only by the piezoelectric element 24, the rotation driving force is about half that of the vibration motor shown in FIG.

The structure shown in FIG. 1 can be applied to the rotor portion 10 and its assembled state as it is.

FIG. 8 is a diagram showing another embodiment of the present invention. The figure (a) is a side view of the stator part 20, and the figure (b) is a sectional view on the AA line.

A characteristic of the vibration motor of this embodiment is that a plurality of vertical slit grooves 58 are formed in the second metal block body 32. It is preferable that the vertical slit groove 58 is formed so as not to reach the nodes of the vertical vibration and the torsional vibration. For example, in the example shown in FIG. 5, the vertical slit groove 58 is formed so as to be located between the node of longitudinal vibration and the node of torsional vibration.

By thus forming the vertical slit groove 58 in a part of the metal block body 32, the weight is reduced in the portion where the vertical slit groove 58 is formed, and the vertical slit groove 58 causes vertical vibration. It will be magnified and a larger elliptical vibration will occur on the rotor contact surface 12.
Therefore, the rotor portion 10 contacting the rotor contact surface 12
Is driven to rotate with a larger driving force.

The vertical slit groove 58, together with the above-mentioned oblique slit groove 38, also has a function of enhancing the heat radiation effect. In particular, since the vibration motor has a problem of low heat radiation performance, providing the slit groove has a great effect of also improving heat radiation performance.

The number of the vertical slit grooves 58 formed in the second metal block 32 is not limited to eight, but may be one or more. Further, in the example shown in FIG. 8, it is formed so that the positions of the nodes of the longitudinal vibration and the torsional vibration are not applied, but the positions of the nodes may be included. When the vertical slit groove 58 is formed separately, or when the first and third metal block bodies 30,
It is possible to form it at 34.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made within the scope of the gist of the present invention.

For example, in the above-described embodiment, the case where the oblique slit groove 38 is formed at the position of one node of vertical vibration has been described as an example, but when the vertical vibration includes a plurality of nodes, two slits are formed. The oblique slit groove 38 may be formed in each of the above nodes. In this case, it is necessary to determine the inclination direction so that the oblique slit grooves 38 formed at the positions of the nodes amplify the torsional vibrations with each other.

[0066]

As described above, according to the invention of claim 1,
Since the torsional vibration is generated by forming the slit groove and this torsional vibration is generated by utilizing the longitudinal vibration, it is not always necessary to match the resonance points of the longitudinal vibration and the torsional vibration that are independently generated. Without, it is possible to easily realize an efficient motor. Further, since the torsional vibration is not generated by utilizing the tightening by the bolt, it is not necessary to strictly control the pitch, the tightening load and various dimensional accuracy, and the design and the manufacturing are easy.
Furthermore, since it is sufficient to apply a single-phase high-frequency AC voltage to the piezoelectric element, the structure of the piezoelectric element and the motor drive circuit is relatively simple, and the cost does not increase.

According to the second aspect of the invention, the rotation direction of the rotor portion can be easily changed only by preparing two block bodies having different slit groove inclination directions.
Other parts can be easily shared and the cost can be reduced.

According to the third aspect of the present invention, the block body in which the slit groove is formed is further divided into two block bodies, and the slit groove is formed at one of the end portions of the block body. Since the above-mentioned slit groove can be formed only by cutting the end portion of, the manufacturing becomes easy.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment to which a vibration motor of the present invention is applied.

FIG. 2 is a perspective view showing an assembled state of the stator section shown in FIG.

FIG. 3 is an exploded perspective view showing a detailed structure of a stator portion and an assembled state.

FIG. 4 is a view showing details of an oblique slit groove formed in a third metal block body of a stator part.

FIG. 5 is a diagram for explaining the vertical position of an oblique slit groove.

6 is a diagram showing a structure of a vibration motor in which the coupling bolt shown in FIG. 3 is replaced with another member.

FIG. 7 is a diagram showing another embodiment of the present invention.

FIG. 8 is a diagram showing another embodiment of the present invention.

FIG. 9 is a diagram showing an example of a conventional bolted Langevin type ultrasonic motor.

[Explanation of symbols]

 10 rotor part 20 stator part 22,24 piezoelectric element 26,28 electrode plate 30 first metal block body 32 second metal block body 34 third metal block body 36 coupling bolt 38 diagonal slit groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Miyamoto 20 Oyamazuka, Oiwa Town, Toyohashi City, Aichi Honda Electronics Co., Ltd.

Claims (3)

[Claims] 1. A vibration motor having a stator part and a rotor part, wherein the stator part is polarized in a rotation axis direction of the rotor part, and a piezoelectric element for generating longitudinal vibration; and a high-frequency alternating voltage applied to the piezoelectric element. And an electrode for applying the piezoelectric element are fixedly attached to both sides of the piezoelectric element so as to sandwich the piezoelectric element, and at least one slit groove inclined with respect to the rotation axis at a position including the node of the longitudinal vibration is at least A first block body and a second block body formed on one side, and the longitudinal vibration generated by the piezoelectric element and the torsional vibration generated by the slit groove portion of the block body are combined, A vibration motor, wherein the rotor portion is rotationally driven by generating elliptical vibration on a rotor contact surface of the stator portion. 2. The vibration motor according to claim 1, wherein the rotational driving direction of the rotor portion is changed by changing the inclination direction of the slit groove. 3. The third block according to claim 1, wherein at least one of the first block body and the second block body having the slit groove is further provided with the slit groove at an end thereof. A body and a fourth block body not having the slit groove, and a position including the longitudinal vibration node when the third block body and the fourth block body are assembled. A vibration motor, wherein the slit groove is formed in the.