JP2009296801A - Oscillatory wave drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oscillatory wave drive device that obtains a stable spring performance of a frictional contact spring. <P>SOLUTION: In an oscillator composed of a contact spring having a vibrator and a beam structure, a joint of the contact spring is fusion-joined entirely by laser welding at least in one direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibrator or a moving element of a vibration wave driving device configured by a vibrating body or a moving body and a contact spring having a beam structure.

  A conventional vibration wave driving device, particularly a linear ultrasonic motor, includes a form in which a protrusion is bonded to a flat plate disclosed in Patent Document 1. Since the principle is already well known, the description is omitted. The configuration of the vibration type driving device 101 will be described with reference to FIG.

  In the figure, reference numeral 103 denotes a plate-like elastic member, and a piezoelectric element 104 is bonded to one side. A friction member 105 is bonded to the other surface by bonding to form the vibrator 102. The linear slider 112, which is a moving element, is brought into pressure contact with the friction member 105 and moved relative thereto.

Since the protrusion is not formed by removal processing, but formed as a separate member, it is possible to obtain a stable and highly accurate vibrator or vibration wave driving device with reduced performance degradation due to processing strain.
JP-A-77-143771

  The vibration wave drive device in which the vibrator is formed in a rectangular flat plate shape, and the friction member is bonded to one surface on the flat plate, presses the linear slider that is a moving element against the vibrator that generates vibration, In this configuration, power is supplied to the vibrator to generate vibration, and the linear slider is moved relative to the vibration. Therefore, in order to transmit vibration generated by the vibrator to the moving element stably and effectively, it is desirable that the friction contact portion of the vibrator or moving element has a contact spring structure and that the contact spring is firmly joined. For example, when the contact spring is arranged in a beam shape and laser welding is used for the joining, the metals are melted and joined, and the members are integrally formed so that the driving force can be transmitted efficiently. Further, since heat is locally applied, melt bonding is possible without causing deformation of the parts.

  Further, in order for the contact spring to function effectively and to exhibit stable performance, it is desirable that the spring performance does not vary. For this purpose, it is desirable that the contact surface between the vibrator and the contact spring has no gap that affects the spring deformation. However, in laser welding, it is difficult to join the entire contact surface of the two members due to its characteristics, and a minute gap is formed in addition to the joined portion, resulting in unstable spring performance. Furthermore, if the entire contact surface is to be melt-bonded, it is necessary to apply a great amount of welding heat, such as increasing the number of welding points or continuous welding. For this reason, the parts may be deformed, the spring performance of the contact spring may vary, and phenomena such as unstable relative movement of the linear slider may occur. It is impossible to take advantage of the advantages of laser welding, such as low thermal effects.

  The vibration wave driving device of the present invention includes a vibrating body or a moving body and a contact spring having a beam structure, and the vibrator or moving element of the vibration wave driving device has at least one contact spring joint in at least one direction. One contact portion is melt-bonded by laser welding over the entire surface, so that stable performance can be obtained with little variation. Therefore, in order to prevent a gap from being generated in a portion that affects the spring deformation of the contact surface between the vibrating body or the moving body and the contact spring, a recess or protrusion is formed on one member or both members, and melt bonding is performed. The contact interface of the part was eliminated.

  As described above, according to the vibration wave driving device of the present invention, at least one junction of the contact springs in the vibrator or moving element of the vibration wave driving device, which is configured by the contact spring having the vibrating body or the moving body and the beam structure, is provided. In the direction, at least one contact portion is melt-joined by laser welding on the entire surface, so that stable performance with little variation is obtained.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  FIG. 1 is an external perspective view of a vibration wave driving device 1 according to a first embodiment of the present invention, FIG. 2 (a) is a sectional side view, and FIG. 2 (b) is a deformation view of a contact spring (deformation shape). Is indicated by a broken line). The vibration wave driving device 1 includes a vibrator 2 and a linear slider (not shown) that is a moving element. In addition to these members, a pressure member for bringing the vibrator 2 and the linear slider into pressure contact, a conduction member for supplying power to the vibrator 2, and the like are required. Since these members are the same as those in the prior art, description thereof is omitted.

  The vibrator 2 includes a laminated piezoelectric element 4 that is an electro-mechanical conversion element formed in a rectangular thin plate shape, an elastic member 3 that is joined and integrated with one end face of the laminated piezoelectric element 4, and an elastic member 3 The contact spring member 5 functions as a friction material to be joined to the contact spring.

  The vibrator 2 of the vibration wave driving device 1 according to the present embodiment excites two bending vibration modes having substantially the same frequency, and relatively moves the linear slider via the contact spring member 5. 3 (a) and 3 (b) schematically show the two mode shapes that are the vibration modes of the vibrator.

  The laminated piezoelectric element 4 is formed by laminating and integrating a plurality of thin plate-like piezoelectric element films having electrodes on the surface.

  The contact spring member 5, which is a friction material, needs to have a high coefficient of friction and excellent wear resistance. In this embodiment, the heat resistance is ensured by heat-treating the stainless steel.

  As the material of the elastic member 3, stainless steel, which is a material excellent in vibration characteristics, can be used. In this embodiment, the same kind of martensitic stainless steel is used for the contact spring member 5 and the elastic member 3. Since the welding is performed by locally applying heat by laser welding, it is possible to join without reducing the wear resistance of the frictional contact portion and without reducing the vibration characteristics of the elastic member. Moreover, since the same kind of material is used, welding can be easily performed.

  In the vibration wave drive device 1 of the present embodiment, the linear slider is brought into pressure contact with the vibrator 2 that generates vibration, power is supplied to the vibrator 2 to generate vibration, and the linear slider moves relative to the vibration. It is the structure to perform. For this reason, a phenomenon may occur in which abnormal noise is generated due to the linear slider bouncing the vibration generated by the vibrator 2 or the relative movement of the linear slider becomes unstable. Therefore, it is necessary to provide an elastically deforming portion that effectively receives the vibration generated by the vibrator in the vicinity of the frictional contact portion of the vibrator 2 or the linear slider.

  Therefore, the elastic member 3 of the present embodiment is provided with a spring function by forming a recess 6 by half-etching and arranging the contact spring member 5 in the form of a double-supported beam. The recess 6 may be formed by cutting or press forging. A hole that penetrates other than the recess may be used, and the hole may be formed by press punching or etching. In the present embodiment, a small rectangular elastic member 3 of 10 × 5 mm is used, the laminated piezoelectric element 4 is bonded with an adhesive, and an elastic member in which a recess is formed is used to secure a bonding area.

  In the present invention, the groove 7 is formed in the vicinity of the recess 6 for imparting the spring function of the elastic member 3. The portion where the elastic member 3 and the contact spring member 5 are melt-bonded is limited by the groove 7, and the portions other than the two members that are melt-bonded are greatly separated, so that the spring performance of the contact spring member 5 is stabilized. FIG. 4 shows a top view when the contact spring member 5 is disposed on the elastic member 3 and joined by laser welding. The broken line is a contact interface between the two members, and the melt-bonded portion 8 is indicated by a broken-line circle. 9 indicated by a solid circle is a portion irradiated with the laser. Laser welding has different characteristics in terms of its laser irradiation area and fusion bonding area. This is because if two components are stacked as in the present embodiment and laser is irradiated from one component side, the thermal energy of the laser is not transmitted 100% to the position where bonding is desired, and the heat diffuses. Therefore, in this embodiment, since the contact area between the two parts is limited by the recess 6 and the groove 7, the entire surfaces are joined. In addition, since unnecessary portions are removed, welding heat hardly diffuses, and welding with low energy becomes possible, so that deformation of parts can be suppressed. In the configuration in which the contact spring member 5 is arranged like a double-supported beam as in the present embodiment, the spring performance depends on the state of the support position of the contact spring member 5. For this reason, it is desirable that there is no gap between the contact surfaces of the two parts, and in particular, there should be no gap in the direction of the arrow 10 (direction intersecting the contact spring) that greatly affects the deformation direction 11 of the contact spring member 5. . In the present embodiment, the entire surface is joined in the direction 10 intersecting the deformation direction of the contact spring by the recess 6 and the groove 7 without any gap. On the other hand, with respect to the mode shown in FIG. 3 (a), the bending is performed without any gap, so that the rigidity of the vibrator is also stabilized.

  Further, as shown in FIG. 5, by increasing the contact width of the contact spring member 5, the contact surface pressure with the linear slider can be lowered and the durability can be improved. FIG. 6 shows a top view when the contact spring member 5 having a wide contact width is arranged and joined. Since the width is increased, the number of welding points is increased, and the central fusion bonded portion 8 is entirely bonded in a direction 10 intersecting with the contact spring deformation direction as indicated by a broken-line circle. As shown in FIG. 7, a plurality of locations may be joined all over, or all of them may be joined all over. In FIG. 8, the contact surface 14 (indicated by a broken square line) of the elastic member 3 with the contact spring member 5 is discretely arranged, and the direction perpendicular to the moving direction of the linear slider is also restricted. Since the part where heat at the time of welding diffuses is reduced, welding heat can be suppressed, and unmelted parts can be reduced. The joints that are discretely arranged may be circular, and in this case, the shape of the melted joint is circular, so that the heat of fusion can be further suppressed and unmelted parts can be reduced. Further, these grooves and dents may be provided on the contact spring side, and the melt-bonded portion may be regulated by a protrusion. It can be adjusted according to the presence or absence of deformation due to the thermal effect on the elastic member or the contact spring member and the specification of the vibration wave driving device.

  FIG. 9 is an external perspective view of the vibration wave driving device 1 in which the number of welding points is increased in a direction intersecting the contact spring deformation direction, and FIG. 10 is a cross-sectional side view. As described above, in the configuration in which the contact spring member 5 is arranged in the form of a double-supported beam as in the present embodiment, the spring performance depends on the support state of the contact spring member 5. Therefore, the number of welded joints 8 is increased in a direction crossing the spring deformation direction 11, and more stable spring performance can be obtained.

  FIG. 11 shows an external perspective view of the vibration wave driving device 1 according to the second embodiment of the present invention. As in the first embodiment, the vibration wave driving device 1 includes a vibrator 2 and a linear slider 12 that is a moving element. In this embodiment, a contact spring member 5 is provided on the linear slider 12. FIG. 12 shows a cross-sectional view of the linear slider 12. The contact spring member 5 is disposed so as to cover the friction sliding surface side of the linear slider 12 and the lower half of both side surfaces, and the linear slider 12 and the contact spring member 5 are melt-bonded by laser welding from both side surface directions. In the present embodiment, fusion bonding is performed in parallel with the deformation direction 11 of the contact spring member 5. The groove 7 provided in the linear slider 12 is melt-bonded over the entire surface in the deformation direction 11 of the contact spring member 5 without any gap, so that stable spring performance can be obtained.

  FIG. 13 shows a cross-sectional view of the moving member of the rotary vibration wave driving device. The present invention can be used not only in a vibration wave driving apparatus in which the moving element moves relative to the direction orthogonal to the vibrator, but also in a rotary vibration wave driving apparatus. In the present embodiment, a cylindrical contact spring member 5 is arranged on the side surface of the circular movable element 13 and is joined from the side surface direction of the movable element 13 by laser welding. The contact spring member 5 uses an end face of a cylindrical portion formed by press drawing as a friction sliding portion. The material is stainless steel, which is hardened by heat treatment to ensure wear resistance. In the present embodiment, the contact spring member 5 is disposed in a cantilever shape, and the state of the melt-bonded portion is very important because the contact spring member 5 is deformed so as to draw an arc by contact with the vibrator. By providing the groove 7 on the side surface of the movable element 13, the entire surface is melt-bonded in a direction intersecting with the direction 11 of deformation of the contact spring member 5, and stable spring performance can be obtained.

The perspective view of the vibration wave drive device in 1st Embodiment of this invention. The cross-sectional side view and contact spring deformation | transformation figure of the vibration wave drive device in 1st Embodiment. The perspective view which shows typically two vibration modes of the vibration wave drive device in 1st Embodiment. FIG. 3 is a top view of the vibrator according to the first embodiment. The perspective view of the vibration wave drive device which made the friction sliding area of the friction contact member of the vibrator | oscillator in 1st Embodiment wide. FIG. 3 is a top view of the vibration wave driving device in which the frictional sliding area of the frictional contact member of the vibrator in the first embodiment is widened. FIG. 3 is a top view of the vibration wave driving device in which the frictional sliding area of the frictional contact member of the vibrator in the first embodiment is widened. FIG. 3 is a top view of a vibration wave driving device in which fusion joint portions between a frictional contact member and an elastic member of the vibrator in the first embodiment are discretely arranged. The perspective view of the vibration wave drive device which increased the number of welding points of the friction contact member and elastic member of a vibrator in a 1st embodiment. Sectional side view of the vibration wave drive device in which the number of welding points between the frictional contact member and the elastic member of the vibrator in the first embodiment is increased. FIG. 6 is a perspective view of a vibration wave driving device in a second embodiment. Sectional drawing of the linear slider in 2nd Embodiment. Sectional drawing of the slider of the vibration wave drive device in 3rd Embodiment. The figure which shows the vibration wave drive device in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Vibration-wave drive device 2,102 Vibrator 3,103 Elastic member 4,104 Piezoelectric element 5 Contact spring member 6 Depression 7 Groove 8 Melt joint part 9 Laser irradiation part 10 Direction crossing the deformation direction of a contact spring 11 Contact Spring deformation direction 12, 112 Linear slider 13 Moving element 14 Contact surface 105 Friction contact member

Claims (4)

  The contact portion of the contact spring in the vibrator or moving element of the vibration wave driving device constituted by the vibrating body or moving body and the contact spring having a beam structure is melt-bonded in at least one direction and at least one contact portion is melt-bonded on the entire surface. The vibration wave drive device characterized by the above-mentioned.   2. The vibration wave driving device according to claim 1, wherein a direction in which the entire contact portion is melt-bonded intersects or is parallel to a contact spring deformation direction.   3. The vibration wave driving device according to claim 1, wherein there are a plurality of contact portions in which the entire contact portion is melt-bonded.   4. The vibration wave driving device according to claim 1, wherein the fusion bonding is performed by laser welding.

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