JP2012143155A - Oscillatory wave driving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurence of abnormal noise and unstable relative movements of a driven body.SOLUTION: An oscillatory wave driving apparatus 8 includes: an electromechanical conversion element 3; an oscillator 7 having an elastic member 1, which is joined to the electromechanical conversion element 3 and is provided with protruding members 2a, 2b at the side opposite to the side which the electromechanical conversion element 3 is joined; and a linear slider 4 which makes frictional contact with the protruding member 2a, 2b and moves relative to the elastic member 1 by oscillating the oscillator 7. The protruding members 2a, 2b are formed by part of the elastic member 1, and clearance parts 5a, 5b are provided on a surface, which faces the electromechanical conversion element 3, at the protruding members 2a, 2b.

Description

  The present invention relates to a vibration wave drive device, and in particular, a vibration wave drive that vibrates an elastic member joined to an electro-mechanical conversion element and relatively moves a driven body by supplying power to the electromechanical conversion element. Relates to the device.

  2. Description of the Related Art Conventional vibration wave driving devices, particularly linear vibration wave motors, include a vibration wave driving device having a configuration in which a protruding member is joined to a flat plate as disclosed in Patent Document 1. The configuration of the vibration wave driving device will be described with reference to FIG.

  FIG. 14 is a side view showing a configuration of a conventional driving device 801. In the figure, reference numeral 101 denotes a plate-like elastic member. A piezoelectric element 301 is bonded to one surface, and projecting members 201a and 201b, which are friction materials, are bonded to the other surface. The protruding members 201a and 201b may be joined by fitting or screwing. The elastic member 101, the piezoelectric element 301, and the protruding members 201a and 201b constitute a vibrator 701.

  The linear slider 401, which is a driven body, is brought into pressure contact with the protruding members 201a, 201b, which are friction materials of the vibrator 701, and relative movement is performed.

  The protruding members 201a and 201b are not formed by removing the elastic member 101, but are formed by joining the elastic member 101 as separate members. As a result, a decrease in performance due to processing strain is suppressed, and a stable and highly accurate vibrator and vibration wave driving device can be obtained.

Japanese Patent Application Laid-Open No. 7-143771

  By the way, in the conventional vibration wave driving device 801, the elastic member 101 and the piezoelectric element 301 constituting the vibrator 701 are formed in a substantially rectangular flat plate shape, and friction is applied to one surface of the flat plate elastic member 101. A protruding member 201 that is a member is provided. The linear slider 401 is brought into pressure contact with the projecting members 201a and 201b, and the elastic member 101 is vibrated by supplying power to the piezoelectric element 301. The linear slider 401 receives the vibration via the projecting members 201a and 201b. Perform relative movement.

  In such a configuration, the linear slider 401 may bounce upon receiving vibration generated by the vibrator 701, which causes problems such as generation of abnormal noise and unstable movement of the linear slider 401. .

  An object of the present invention is to provide a technique for reducing the size of a vibration wave driving device and stabilizing the driving performance.

  The vibration wave driving device according to the present invention includes an electro-mechanical conversion element, and an elastic member that is bonded to the electro-mechanical conversion element and has a protruding member on a side opposite to the side to which the electro-mechanical conversion element is bonded. And a driven body that makes frictional contact with the protruding member and that moves relative to the elastic member by vibrating the vibrator, and the protruding member is a member of the elastic member. It is formed from a part, and a gap portion is provided on a surface of the protruding member facing the electro-mechanical conversion element.

  According to the present invention, it is possible to reduce the size of the vibration wave driving device and stabilize the driving performance.

It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on the 1st Embodiment of this invention from the downward direction. It is a sectional side view of the vibration wave drive device concerning a 1st embodiment. It is side sectional drawing which shows the protrusion member of the left side in an elastic member, a clearance gap, and a penetration part. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 2nd Embodiment from the downward direction. It is a sectional side view of the vibration wave drive device concerning a 2nd embodiment. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 3rd Embodiment from the upper direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 4th Embodiment from upper direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 5th Embodiment from the upper direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 5th Embodiment from the downward direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 6th Embodiment from upper direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 6th Embodiment from the downward direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 7th Embodiment from upper direction. It is a perspective view which shows the state which looked at the external appearance of the vibration wave drive device which concerns on 7th Embodiment from the downward direction. It is a side view which shows the structure of the conventional drive device.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective view showing the appearance of the vibration wave driving device 8 according to the first embodiment of the present invention as viewed from below, and FIG. 2 is a side sectional view of the vibration wave driving device 8. .

  In FIG. 1 and FIG. 2, the vibration wave driving device 8 includes a vibrator 7 and a linear slider 4 that is a driven body. In addition to these members, a pressure member for bringing the vibrator 7 and the linear slider 4 into pressure contact and a power supply member for supplying power to the vibrator 7 are necessary. Since it is the same as that of a conventional vibration wave driving device, illustration and description are omitted.

  The vibrator 7 includes a laminated piezoelectric element (electro-mechanical conversion element) 3, an elastic member 1, and two projecting members 2a and 2b. The laminated piezoelectric element 3 is an electro-mechanical conversion element formed in a rectangular thin plate shape. That is, the laminated piezoelectric element 3 is formed by laminating and integrating a plurality of thin plate-like piezoelectric element films having electrodes on the surface. The elastic member 1 is bonded to one surface of the multilayer piezoelectric element 3 and operates integrally with the multilayer piezoelectric element 3. The protruding members 2a and 2b are formed integrally with the elastic member 1 on the surface opposite to the surface to which the laminated piezoelectric element 3 of the elastic member 1 is bonded, and function as a friction material.

  The vibrator 7 of the vibration wave driving device 8 in the present embodiment excites two bending vibration modes having substantially the same frequency, and relatively moves the linear slider 4 as a driven body via the protruding members 2a and 2b. .

  As a material of the elastic member 1, for example, stainless steel having excellent vibration characteristics is used. Specifically, the rectangular plate-like elastic member 1 is formed by cutting a cylindrical stainless steel rod. At that time, the cylindrical stainless steel rod is cut so that the planar direction of the plate-like elastic member 1 is perpendicular or parallel to the axial direction of the cylindrical stainless steel rod. That is, in the case of an anisotropic material such as a stainless steel rod, the performance as a vibrator is more stable by cutting out on a surface perpendicular or parallel to the axial direction.

  The two protruding members 2a and 2b, which are friction materials, need to be made of a material having a high friction coefficient and excellent wear resistance. In this embodiment, the two protruding members 2a and 2b are formed from the elastic member 1 by cutting. That is, the elastic member 1 is made of a material that has been heat treated to ensure wear resistance, and the protruding members 2 a and 2 b are cut out based on the elastic member 1.

  Two gap portions 5a and 5b are formed by cutting on the surface of the elastic member 1 to be bonded to the laminated piezoelectric element 3 at the same position as the planar direction position where the protruding members 2a and 2b are formed. In addition, two penetrating portions 6a and 6b are formed by cutting in the periphery of the projecting members 2a and 2b in the planar direction. The through portions 6a and 6b are configured to penetrate in the plate thickness direction (thickness direction). The gap portions 5a and 5b and the through portions 6a and 6b are shown in detail in FIG. FIG. 3 is a side cross-sectional view showing the left protrusion member 2a, the gap 5a, and the penetrating portion 6a in the elastic member 1. The through portions 6a and 6b surround the three directions of the projecting members 2a and 2b, and the projecting members 2a and 2b are connected to the elastic member 1 integrally in the remaining one direction.

  The projecting members 2a and 2b are formed in a cantilever structure by the gap portions 5a and 5b and the through portions 6a and 6b. For example, the through portions 6a and 6b are formed by press punching, and the gap portions 5a and 5b are formed by press forging. Moreover, you may form the penetration parts 6a and 6b and the clearance gaps 5a and 5b by the removal process by cutting, an etching, and a half etching process. Moreover, you may form penetrating part 6a, 6b and clearance gap part 5a, 5b combining these.

  In the vibration wave driving device 8 according to the present embodiment, the linear slider 4 is brought into pressure contact with the vibrator 7 that generates vibrations, and the vibrator 7 is fed with power to generate vibrations. 4 performs relative movement. Then, by providing the gap portions 5a and 5b and the through portions 6a and 6b, the projecting members 2a and 2b (elastically deforming portions) are respectively perpendicular to the plane direction of the elastic member 1 (the direction of the arrow 10 shown in FIG. 3). ) Can be elastically deformed. Therefore, the vibration generated by the vibrator 7 is effectively received by the linear slider 4 and the linear slider 4 is prevented from jumping. Thereby, generation | occurrence | production of the noise by the linear slider 4 jumping and the unstable relative movement of the linear slider 4 can be avoided. Further, the configuration of the vibrator 7 is simple, and the vibration wave driving device 8 can be downsized.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  Since the configuration of the second embodiment is basically the same as the configuration of the first embodiment, in the description of the second embodiment, the same parts as the configuration of the first embodiment are used. Are denoted by the same reference numerals, and the description of the first embodiment is used, and only different portions will be described.

  FIG. 4 is a perspective view showing the appearance of the vibration wave driving device 8a according to the second embodiment as viewed from below, and FIG. 5 is a side sectional view of the vibration wave driving device 8a.

  In the second embodiment, the projecting members 2c and 2d are configured separately from the elastic member 1a, and the projecting members 2c and 2d are joined to the elastic deformation portions 11a and 11b of the elastic member 1a, respectively. The protruding members 2c and 2d are made of a wear-resistant material. Each of the elastic deformation portions 11a and 11b is configured integrally with the elastic member 1a, and is surrounded by three through portions 6a and 6b in the planar direction of the elastic member 1a. Further, in the same manner as in the first embodiment, gaps 5a and 5b are formed below the elastically deforming portions 11a and 11b (side facing the laminated piezoelectric element 3). Thereby, the elastic deformation parts 11a and 11b can be easily elastically deformed with respect to the elastic member 1a.

  That is, to form the protruding members 2a and 2b integrally with the elastic member 1 as in the first embodiment, the elastic member 1 is subjected to removal processing such as cutting. There is a concern about the deterioration of the performance as a vibrator due to distortion. On the other hand, in the second embodiment, the projecting members 2c and 2d are formed of a member separate from the elastic member 1a. Thereby, it is not necessary to perform removal processing for forming the protruding members 2c and 2d on the elastic member 1a, and the plate thickness accuracy of the plate material can be utilized in the elastic member 1a.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.

  Since the configuration of the third embodiment is basically the same as the configuration of the second embodiment, in the description of the third embodiment, the same parts as the configuration of the second embodiment are used. Are denoted by the same reference numerals, and the description of the second embodiment is used, and only different portions will be described.

  FIG. 6 is a perspective view showing the appearance of the vibration wave driving device 8b according to the third embodiment as viewed from above.

  In the third embodiment, the gap portions 5a and 5b in the second embodiment are not provided, and the elastic member 1b has a uniform thickness except for the through portions 6a and 6b. That is, the elastic deformation portions 11c and 11d to which the protruding members 2c and 2d of the elastic member 1b are joined have the same thickness as the entire elastic member 1b. Then, gaps 5c and 5d are formed in the upper layer or all the layers of the laminated piezoelectric element 3a. The gap portions 5c and 5d are provided at the same positions as the positions occupied by the elastic deformation portions 11c and 11d and the through portions 6a and 6b in the planar direction of the multilayer piezoelectric element 3a.

  As described above, in the third embodiment, since it is not necessary to form the gaps 5a and 5b in the elastic member 1b, it is only necessary to form the through portions 6a and 6b by press punching. Can be simplified. The through portions 6a and 6b may be formed by cutting or etching.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.

  Since the configuration of the fourth embodiment is basically the same as the configuration of the second embodiment, in the description of the fourth embodiment, the same parts as the configuration of the second embodiment are used. Are denoted by the same reference numerals, and the description of the second embodiment is used, and only different portions will be described.

FIG. 7 is a perspective view showing the appearance of the vibration wave driving device 8c according to the fourth embodiment as viewed from above.

  In the fourth embodiment, the elastic deformation portions 11e and 11f having the same thickness as the elastic member 1c are subjected to a bending process, and the lower end portions (release ends) of the elastic deformation portions 11e and 11f of the elastic member 1c. A gap is formed between the piezoelectric element 3 and the laminated piezoelectric element 3. Then, the protruding members 2c and 2d are joined to the upper end portions of the elastically deforming portions 11e and 11f, respectively.

  In forming the elastically deformable portions 11e and 11f, first, the penetrating portions 6a and 6b are formed by using any one of processing methods such as press punching, cutting, and etching, and then bending is performed by pressing.

  By bending the elastically deforming portions 11e and 11f, a gap is formed between the lower end portions of the elastically deforming portions 11e and 11f and the laminated piezoelectric element 3, so that it is elastic as in the second embodiment. There is no need to perform the process of providing the gap portions 5a and 5b in the deformed portions 11a and 11b, respectively. Further, unlike the third embodiment, there is no need to perform a process of providing the gap portions 5c and 5d in the laminated piezoelectric element 3a.

  In particular, when a press punching method is used to form the elastically deformable portions 11e and 11f of the elastic member 1c, it is possible to continuously perform punching and bending with a progressive press machine. It will be advantageous.

  In the present embodiment, the protruding members 2c and 2d, which are separate members, are joined to the upper end portions of the elastic deformation portions 11e and 11f, respectively. Instead of this, the upper end portions of the elastically deforming portions 11e and 11f may be used as the projecting members without joining the projecting members 2c and 2d, which are separate members. That is, the heat-treated stainless steel is used for the elastic member 1c, whereby the wear resistance of the upper end portions of the elastically deforming portions 11e and 11f is ensured and used as a protruding member.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described.

  Since the configuration of the fifth embodiment is basically the same as the configuration of the second embodiment, the description of the fifth embodiment is the same as the configuration of the second embodiment. Are denoted by the same reference numerals, and the description of the second embodiment is used, and only different portions will be described.

  FIG. 8 is a perspective view showing the appearance of the vibration wave drive device 8d according to the fifth embodiment as viewed from above, and FIG. 9 shows the vibration wave drive device 8d according to the fifth embodiment. It is a perspective view which shows the state which looked at the external appearance from the downward direction.

  In the fifth embodiment, the elastic member 1d is provided with elastic deformation portions 11g and 11h, and the two protruding members 2c and 2d are joined to the elastic deformation portions 11g and 11h, respectively. Around the elastic deformation portions 11g and 11h, through portions 6c, 6d, 6e and 6f having the same shape are formed in the elastic member 1d. The through portions 6c and 6d are arranged in the direction perpendicular to the moving direction of the linear slider 4 in the plane direction of the elastic member 1d so as to sandwich the elastic deformation portion 11g. The through portions 6e and 6f are arranged in a direction perpendicular to the moving direction of the linear slider 4 in the plane direction of the elastic member 1d so as to sandwich the elastic deformation portion 11h. As shown in FIG. 9, gaps 5e and 5f are formed below the elastically deforming portions 11g and 11h (on the side facing the laminated piezoelectric element 3), respectively. Thereby, the elastic deformation portions 11g and 11h can be easily elastically deformed according to the vibration of the protruding members 2c and 2d.

  The protruding members 2a and 2b in the first embodiment and the elastically deforming portions 11a to 11f in the second to fourth embodiments have a cantilever structure (a structure supported on one side). Therefore, in the moving direction of the linear slider 4, there is a possibility that a difference in rigidity occurs between the pair of protruding members and the elastically deforming portion. On the other hand, in the fifth embodiment, since the elastically deforming portions 11g and 11h each have a double-supported structure (a structure supported by two opposing sides), such a rigidity difference does not occur.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described.

  Since the configuration of the sixth embodiment is basically the same as the configuration of the fifth embodiment, in the description of the sixth embodiment, the same parts as the configuration of the fifth embodiment are used. Are denoted by the same reference numerals, and the description of the fifth embodiment is used, and only different portions will be described.

  FIG. 10 is a perspective view showing the appearance of the vibration wave driving device 8e according to the sixth embodiment as viewed from above. FIG. 11 shows the vibration wave driving device 8e according to the sixth embodiment. It is a perspective view which shows the state which looked at the external appearance from the downward direction.

  In the sixth embodiment, the elastic deformation portions 11i and 11j of the elastic member 1e are provided with through portions 61a to 61d together with the through portions 6c to 6f. The through portions 61a and 61b are arranged in a direction parallel to the moving direction of the linear slider 4 in the plane direction of the elastic member 1e so as to sandwich the elastic deformation portion 11i. The through portions 61c and 61d are arranged in a direction parallel to the moving direction of the linear slider 4 in the plane direction of the elastic member 1e so as to sandwich the elastic deformation portion 11j. As shown in FIG. 11, gaps 5g and 5h are formed below the elastically deforming portions 11i and 11j (on the side facing the laminated piezoelectric element 3), respectively, and the elastically deforming portions 11i and 11j are formed as protruding members 2c. It is easily elastically deformed in response to 2d vibration. At the same time, by appropriately setting the shapes of the through portions 61a to 61d, the elastic deformation portions 11i and 11j can have desired spring rigidity, and the vibration wave driving device 8e is brought into an optimum driving state. be able to.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described.

  Since the configuration of the seventh embodiment is basically the same as the configuration of the second embodiment, in the description of the seventh embodiment, the same parts as those of the second embodiment are used. Are denoted by the same reference numerals, and the description of the second embodiment is used, and only different portions will be described.

  FIG. 12 is a perspective view showing the appearance of the vibration wave driving device 8f according to the seventh embodiment as viewed from above, and FIG. 13 shows the vibration wave driving device 8f according to the seventh embodiment. It is a perspective view which shows the state which looked at the external appearance from the downward direction.

  In the seventh embodiment, the elastic member 1f is provided with substantially circular through portions 6g and 6h. The penetrating portion 6g is composed of, for example, six holes arranged in two rows, and each row is arranged in a direction perpendicular to the moving direction of the linear slider 4 in the plane direction of the elastic member 1f so as to sandwich the elastic deformation portion 11k. Placed in. The through portion 6h is also composed of, for example, six holes arranged in two rows, and each row is arranged in a direction perpendicular to the moving direction of the linear slider 4 in the plane direction of the elastic member 1f so as to sandwich the elastic deformation portion 11l. Placed in. As shown in FIG. 13, gaps 5i and 5j are formed below the elastically deforming portions 11k and 11l and the through portions 6g and 6h (sides facing the laminated piezoelectric element 3), respectively. 11l is easily elastically deformed according to the vibration of the projecting members 2c and 2d.

  Although the cross-sectional shape of each of the six holes of the through portions 6g and 6h may be two or more types of cross-sectional shapes, it is preferably substantially circular. Thereby, it can process accurately by removal processes, such as an etching and a press. That is, in general, removal methods such as etching and pressing are conceivable as a method for forming the through portion, but it is difficult to form when the through portion has a corner shape such as a rectangle or a complicated shape having a corner portion. It becomes. For example, etching is a processing method in which a material is immersed and dissolved in an etching solution, so that corners are easily rounded and it is difficult to control the size. Similarly, it is difficult to control the rounded shape at the corners. Also in the press, it is difficult to process a rectangle or a complicated shape in consideration of the durability of the mold. Further, in the vibrator 7f in the present embodiment, the spring rigidity is determined by the shape of the elastic deformation portions 11k and 11l, which greatly affects the performance.

  Therefore, in the present embodiment, the cross-sectional shape of each of the six holes of the through portions 6g and 6h is set to be substantially circular. As a result, the elastically deformable portions 11k and 11l can be formed with high accuracy using either etching or pressing.

  In the present embodiment, the elastic member 1f is formed by etching a stainless plate material into a rectangular shape. That is, there is also a method of forming the elastic member 1f by removing the material on the bulk by cutting or the like. However, in such removal processing, there is a problem that the performance of the vibration wave driving device 8f is deteriorated because stress due to processing is generated as processing strain, and therefore etching processing is performed.

  The thickness accuracy of the elastic member 1f greatly affects the performance of the vibration wave driving device 8f. Therefore, in the present embodiment, the elastic member 1f is formed by processing a plate material having a desired thickness into a required shape by pressing and etching. As a result, the elastic member 1f maintains the highly accurate plate thickness of the plate material.

  In press working, the processing strain can be suppressed as much as possible by using the fine blanking method. In the etching process, the plate thickness accuracy can be maintained without giving processing distortion.

  In the present embodiment, the gaps 5i and 5j on the surface of the elastic member 1f that joins the laminated piezoelectric element 3 are formed by half etching. Thereby, the elastic member 1f which maintained the board thickness precision of a board | plate material, without adding process distortion can be created.

1, 1a Elastic member 2a, 2b, 2c, 2d Projection member 3 Multilayer piezoelectric element (electro-mechanical conversion element)
4 Linear slider 5a, 5b Gap part 6a, 6b Penetration part 7, 7a Vibrator 8, 8a Vibration wave drive device 11a, 11b Elastic deformation part

Claims (6)

A vibrator having an electro-mechanical conversion element and an elastic member bonded to the electro-mechanical conversion element and provided with a protruding member on a side opposite to the side to which the electro-mechanical conversion element is bonded;
A driven body that makes frictional contact with the protruding member and moves relative to the elastic member by vibrating the vibrator;
The protruding member is formed from a part of the elastic member,
A vibration wave driving device, wherein a gap is provided on a surface of the protruding member facing the electro-mechanical conversion element.   2. The vibration wave driving device according to claim 1, wherein the elastic member is made of a stainless steel plate.   The vibration wave driving device according to claim 1, wherein the protruding member is formed by cutting a part of the elastic member.   The vibration wave driving device according to claim 1, wherein the protruding member is formed by pressing a part of the elastic member.   5. The vibration wave driving device according to claim 1, wherein the electro-mechanical conversion element is a laminated piezoelectric element. 6.   5. The vibration wave driving device according to claim 1, wherein two bending vibration modes are excited in the vibrator. 6.

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