JP2006271065A - Driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device, capable of stably providing a pressing force from a vibrating body to a driven body. <P>SOLUTION: A vibration actuator 1A (driving device) comprises a vibrating body 10A which vibrates according to input signals, a driven body 30 which is driven by the vibration of the vibrating body 10A, and a pressing member 50A which presses the vibrating body 10A against the driven body 30. The pressing member 50A presses the vibrating body 10A against the driven body 30 while contacting the vibrating body 10A at a plurality of positions. The vibrating body 10A and the pressing member 50A contact together, in the plane parallel to the vibration plane of the vibrating body 10A, at a plurality of positions, including two positions C1 and C2 sandwiching a straight line L1, that passes an abutting point P1 between the vibrating body 10A and the driven body 30, while the straight line L1 extends in a direction in which a pressing force FP1 at the abutting point P1 acts. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive device that uses vibration of a vibrating body.

  There is a drive device that vibrates a vibrating body by applying an AC voltage to a piezoelectric element or the like, and drives the driven body with a frictional force by repeating contact and separation with the vibrating body. As a technique relating to such a drive device, there are techniques described in Patent Document 1 and Patent Document 2 (hereinafter also referred to as first and second conventional techniques, respectively).

  As shown in FIG. 21, the driving device (piezoelectric actuator) 900A described in Patent Document 1 vibrates in a state where a central part of a vibrating body (vibrating plate) 910A is fixed and supported by an elongated support member 950A. It has a structure in which the body 910A is pressed against the driven body (rotor) 930A by a protrusion 911A provided at one end thereof. The driven body 930A is rotationally driven by the vibration operation of the vibrating body 910A. Further, the support member 950A supports the vibration plate 910A with its elastic force biased toward the rotor 930A. The support member 950A has an elongated shape so as not to inhibit the vibration of the vibrating body, and is fixed near a node (for example, the center) of the vibrating body 910A.

  As shown in FIG. 22, the driving device (vibration motor) 900B described in Patent Document 2 applies a pressing force by the pressure lever 950B to the vibrating body (vibrator) 910B at one point AP1 to extract the driving force. The vibrating body 910B is pressed against the driven body (sliding roller) 930B via the portion 911B to rotate the driven body 930B. In order to prevent rattling of the vibrating body 910B, the vibrating body 910B is sandwiched on both sides of the vibrating body 910B in a state where the biasing force of the backlash spring 941B is applied, and can be slid by friction. It is configured.

JP 2000-333480 A JP 2000-324864 A

  However, in the drive device according to the first conventional technique, the vibrating body 910A is fixedly supported by the elongated support member 950A. Therefore, when the driving force is applied, the reaction force from the driven body 930A is applied to the support member 950A. A large bending moment is applied, and the support member 950A is deformed by this bending moment. Therefore, the vibrating body 910A escapes from the driven body 930A, and it is difficult to stably apply the pressing force from the vibrating body 910A to the driven body 930A.

  Further, in the driving device according to the second conventional technique, the vibrating body 910B is sandwiched between the both side portions with the biasing force of the loosening spring 941B, and is frictionally slidable. Therefore, in order to set the pressing force from the vibrating body 910B to the driven body 930B to a desired value, it is necessary to determine the applied pressure according to the magnitude of the frictional force. However, since the magnitude of the frictional force varies depending on the assembly state at the time of manufacture, it is difficult to stably apply the pressing force from the vibrating body to the driven body.

  As described above, in each of the above conventional techniques, there is a problem that it is difficult to stably apply the pressing force from the vibrating body to the driven body.

  Therefore, an object of the present invention is to provide a drive device that can stably apply a pressing force from a vibrating body to a driven body.

  In order to solve the above-mentioned problem, the invention of claim 1 is a drive device, comprising: a vibrating body that vibrates according to an input signal; a driven body that is driven by vibration of the vibrating body; A pressing member that presses against the driven body, and the pressing member presses the vibrating body toward the driven body in contact with the vibrating body at a plurality of positions, and the vibrating body and the pressing member Means a straight line passing through a contact point between the vibrating body and the driven body in a plane parallel to the vibration surface of the vibrating body and extending in a direction in which the pressing force at the contact point acts. The plurality of positions including two positions are in contact with each other.

  According to a second aspect of the present invention, in the drive device according to the first aspect of the invention, the pressing member is in contact with the vibrating body so as to be separated.

  According to a third aspect of the present invention, in the drive device according to the first or second aspect of the invention, the pressing member and the vibrating body are in contact at two contact portions, and one of the two contact portions. In this case, both the pressing member and the vibrating body are in contact with each other so as to constrain the relative translational movement of the two and enable the relative rotational movement of the two, of the two contact portions. On the other hand, the two are in contact with each other so as to restrain the relative rotational movement.

  According to a fourth aspect of the present invention, in the drive device according to the third aspect of the present invention, in the one of the two contact portions, a V-groove provided in one of the two and the other of the two An arcuate convex portion provided on the surface is in contact.

  According to a fifth aspect of the present invention, in the drive device according to the first aspect of the invention, the pressing member is bonded to the vibrating body with any of a rubber-based adhesive, a silicone-based adhesive, and an epoxy-based adhesive. It is characterized by being.

  According to a sixth aspect of the present invention, in the driving device according to any one of the first to fifth aspects, the pressing member and the vibrating body are in surface contact.

  According to a seventh aspect of the present invention, in the drive device according to any one of the first to sixth aspects, the pressing member is rotatable around a predetermined rotation center axis in the plane. And

  According to an eighth aspect of the present invention, in the drive device according to the seventh aspect of the invention, the vibrating body is pressed against the driven body by an elastic force of an elastic member attached to the pressing member. The distance between the point of application to the pressing member and the predetermined rotation center axis is greater than the distance between the contact point and the predetermined rotation center axis.

  According to the first to eighth aspects of the invention, the vibrating body is pressed against the driven body by the pressing member in contact with the pressing member at a plurality of positions, and is in contact with the driven body. The vibrating body can be stably pressed against the driven body and held. In particular, the vibrating body and the pressing member are in contact with each other at a plurality of positions including two positions sandwiching a straight line extending in the direction in which the pressing force acts through a contact point in a plane parallel to the vibration surface of the vibrating body. Therefore, the vibrating body is held more stably.

  In particular, according to the second aspect of the present invention, the pressing member is in contact with the vibrating body so as to be separated from the vibrating body and is not firmly fixed to the vibrating body. Can be suppressed.

  According to the invention described in claim 3, it is possible to stabilize the relative positional relationship between the vibrating body and the pressing member.

  Furthermore, according to the invention described in claim 5, since the pressing member is bonded to the vibrating body with any of a rubber adhesive, a silicone adhesive, and an epoxy adhesive, The rigidity improvement can be suppressed, and the fluctuation of the resonance frequency of the vibrating body 1 can be suppressed.

  According to the eighth aspect of the present invention, an appropriate pressing force can be generated with a smaller elastic force by the lever principle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
FIG. 1 is a diagram showing a vibration actuator 1A (drive device) according to a first embodiment of the present invention. FIG. 2 is a diagram showing a vibrating body 10A used in the vibration actuator 1A, and FIG. 3 is a diagram showing a piezoelectric element 11 (or 12) used in the vibrating body 10A.

  As shown in FIG. 1, the vibration actuator 1A includes a vibrating body 10A that is a drive source, a driven body (rotor) 30 that is driven by the vibrating body 10A, and a pressing member 50A that presses the vibrating body 10A against the driven body. And an elastic member 60 attached to the pressing member 50A.

  As shown in FIG. 2, the vibrating body 10 </ b> A is configured as a truss-type vibration generator using two piezoelectric elements 11 and 12. The vibrating body 10 </ b> A includes two piezoelectric elements 11, 12, a chip member 13, and a base member 14. As will be described later, the vibrating body 10A vibrates in response to application of an input signal (specifically, a high frequency voltage (high frequency signal)).

  The two piezoelectric elements 11 and 12 are arranged so as to intersect at right angles, and the end portions on the intersecting side of the piezoelectric elements 11 and 12 are joined to the chip member 13. The other ends of the piezoelectric elements 11 and 12 are joined to the base member 14. The tip member 13 is preferably formed of a material (for example, a metal material such as a cemented carbide) that can stably obtain a high coefficient of friction and obtain high wear resistance. The base member 14 is preferably formed of a material that is easy to manufacture and has high strength (for example, a metal material such as stainless steel). The piezoelectric elements 11 and 12 and the members 13 and 14 are bonded using an adhesive.

  As shown in FIG. 3, the piezoelectric element 11 is a laminated piezoelectric element, and has a structure in which a plurality of ceramic thin plates 21 and electrodes 22 and 23 having piezoelectric characteristics are alternately laminated. The ceramic thin plates 21 and the adjacent electrodes 22 and 23 are fixed with an adhesive or the like. Every other electrode 22 and electrode 23 are alternately arranged between the plurality of ceramic thin plates 21. The electrode 22 is connected to the drive power supply 26 via the signal line 24, and the electrode 23 is connected to the drive power supply 26 via the signal line 25.

  The piezoelectric element 11 is a displacement element that expands and contracts in the stacking direction according to a change in applied voltage. Specifically, when a voltage having a predetermined sign is applied between the signal line 24 and the signal line 25 to the piezoelectric element 11, an electric field corresponding to the applied voltage is generated in the stacking direction of the ceramic thin plates 21, and all ceramics The thin plate 21 deforms in the same direction (specifically, extends). Conversely, when a voltage having an opposite sign is applied to the piezoelectric element 11 between the signal line 24 and the signal line 25, the piezoelectric element 11 contracts. Therefore, when an AC voltage is applied, the piezoelectric element 11 repeats expansion and contraction according to the cycle of the AC voltage. Further, when the frequency of the drive AC voltage matches the resonance frequency of the piezoelectric element 11, a larger vibration is excited.

  The piezoelectric element 12 has the same configuration as that of the piezoelectric element 11, and expands and contracts in the stacking direction in accordance with the change in applied voltage.

  Thus, the piezoelectric elements 11 and 12 can be vibrated by applying an alternating voltage. Then, as described below, by controlling the applied voltage, the tip member 13 can be moved so as to draw an elliptical orbit (including a circular orbit) or a linear orbit.

  FIG. 4 is a diagram illustrating a driving operation by the vibrating body 10A. As shown in FIG. 4, the moving operation of the chip member 13 can be controlled by making the drive frequency in the drive AC voltage for the piezoelectric elements 11 and 12 of the vibrating body 10A the same and controlling the phase difference. .

  For example, by applying a high frequency AC voltage having the same frequency and the same phase to the two piezoelectric elements 11 and 12, the piezoelectric elements 11 and 12 always vibrate in the same direction, as shown in FIG. As shown, the tip member 13 is driven in the vertical direction.

  Further, by applying a high-frequency AC voltage having the same frequency and “reverse phase” to the two piezoelectric elements 11 and 12, the piezoelectric elements 11 and 12 always vibrate in opposite directions, and FIG. As shown, the tip member 13 is driven in the left-right direction.

  Then, by applying a high-frequency alternating voltage of the same frequency having a phase difference of 90 degrees (deg) to the two piezoelectric elements 11 and 12, as shown in FIG. Is driven to draw an elliptical orbit (ideally a perfect circle). Further, by changing the phase difference between the two drive voltages to various values, it is possible to make the elliptical orbital shape elongated.

  The vibrating body 10 </ b> A drives the driven body 30 using a vibrating operation on a plane including such an elliptical orbit (also referred to as a vibrating plane).

  Refer to FIG. 1 again. As shown in FIG. 1, the driven body 30 is supported by a rotating shaft 71 protruding from a base plate (base portion) 70, and is a disk that rotates around the rotating shaft 71 (specifically, the central axis AR1). It is a shaped member. The driven body 30 is in contact with the vibrating body 10A at a part of the outer periphery (specifically, the contact point P1). As will be described later, in the contact operation between the driven body 30 and the vibrating body 10A, the elliptical motion or the like of the tip member 13 is converted into the rotational motion of the driven body 30, and the driven body 30 is rotationally driven.

  Further, the pressing member 50A has an L shape (more precisely, a shape in which the right and left sides are inverted). The rotating shaft 72 protruding from the base plate 70 passes through a hole provided on one end side (the upper end side of the vertical portion) of the L-shaped pressing member 50A. The pressing member 50A is pivotally supported by the rotating shaft 72. Has been. The pressing member 50A can rotate around the rotation shaft 72 (specifically, the rotation center axis AR2).

  Further, a cutout portion 59 is provided on the other end side (the tip portion of the horizontal portion) of the L-shaped pressing member 50A. Further, a projecting portion 73 projects from the base plate 70. An elastic member 60 (here, a coil spring) is spanned between the notch 59 and the protrusion 73. That is, the notch 59 and the protrusion 73 function as an attachment portion for the coil spring.

  In addition, two arc-shaped convex portions 51 and 52 are provided in the vicinity of the horizontal center portion of the L-shaped pressing member 50A, and the vibrating body 10A and the pressing member 50A include these two convex portions 51 and 52. Contact is made at each contact point (contact position) C1, C2. In a state where the vibrating body 10A and the pressing member 50A are in contact with each other at two contact points C1 and C2, the elastic member 60 is extended beyond its natural length, and the elastic member 60 has the pressing member 50A on the central axis AR2. An urging force is applied in a direction to rotate clockwise about the axis. As a result, the urging force by the elastic member 60 is transmitted to the vibrating body 10A via both contact points C1 and C2, and is converted to a pressing force (also referred to as “pressing force”) FP1 by the vibrating body 10A to the driven body 30. Is done. Thus, the pressing member 50 </ b> A presses the vibrating body 10 </ b> A toward the driven body 30 by the elastic force of the elastic member 60. By applying such pressing force, the driven body 30 can be driven with a greater force by the vibrating body 10A.

  FIG. 5 is a conceptual diagram illustrating a driving state of the driven body 30. In FIG. 5, each component is modeled.

  When the tip member 13 exists on the upper side of the elliptical orbit PB, the tip member 13 of the vibrating body 10A moves from the contact start position to the contact end position in a state of frictional contact with the driven body 30, thereby rotating the direction DX. Is transmitted (FIG. 5A). When the tip member 13 is present below the elliptical orbit PB, the tip member 13 moves toward the contact start position with the tip member 13 away from the driven body 30 (FIG. 5B), and again in FIG. The state returns to the same state as in (a) (FIG. 5C). Thereafter, the same operation is repeated, and the driven body 30 is driven in the rotational direction DX by the frictional force generated between the tip member 13 and the driven body 30. That is, the driven body 30 is driven by a frictional force generated between the driven body 30 and the vibrating body 10A while repeating contact with the vibrating body 10A and separation from the vibrating body 10A according to the vibration operation of the vibrating body 10A.

  As described above, the vibrating body 10A is pressed against the driven body 30 with an appropriate pressing force FP1 by the pressing member 50A and the elastic member 60 in order to increase the driving force. The pressing force FP1 from the vibrating body 10A to the pressing member 50A is a force having an appropriate magnitude, and the vibration period of the vibrating body 10A cannot follow the expansion / contraction operation of the pressing member 50A due to the elastic force of the elastic member 60. Since the chip member 13 of the vibrating body 10A repeats contact and separation against the driven body 30 against the pressing force FP1 by the pressing member 50A because it is short (that is, has a very high frequency). it can. Therefore, it is possible to perform the driving operation as described above.

  Here, as shown in FIG. 1, in a plane parallel to the vibration surface of the vibration body 10A (for example, the paper surface of FIG. 1), the vibration body 10A and the pressing member 50A are two pieces sandwiching a straight line L1 (described below). Contact is made at contact points C1 and C2. The straight line L1 is a straight line that passes through the contact point P1 between the vibrating body 10A and the driven body 30 and extends in the direction in which the pressing force FP1 at the contact point P1 acts. The pressing force FP1 acts in a direction along the straight line L1 perpendicular to the straight line L2 (described below). The straight line L2 is a straight line connecting the central axis AR2 of the pressing member 50A and the contact point P1.

  According to such contact holding at the three points C1, C2, and P1, the vibrating body 10A can be stably pressed against the driven body 30, and the vibrating body 10A can be stably held. is there.

  As shown in FIG. 18, it is assumed that a local bending moment is applied to one fixed joint portion FC (first comparative example). In the vibration actuator 200A according to the first comparative example, an elongated convex portion 91 provided near the horizontal center portion of the pressing member 250A is fixed to the vibrating body 10A. As shown in FIG. 19, in such a first comparative example, since a local bending moment is generated in the elongated convex portion 91, the convex portion 91 is deformed by the driving reaction force from the driven body 30. The vibrating body 10A moves (from the position indicated by the two-dot chain line BL to the position indicated by the solid line SL), and “escape” of the vibrating body 10A with respect to the driven body 30 occurs. Therefore, the driving force for the driven body 30 becomes unstable.

  On the other hand, in the above embodiment, the pressing member 50A presses the vibrating body 10A toward the driven body 30 in a state where the pressing member 50A is in contact with the vibrating body 10A at two positions. Specifically, the vibrating body 10A is contact-supported at three or more points (in this case, three points C1, C2, P1) of two or more points (in this case, two points) of the pressing member 50A and the contact point P1 (in this case, three points C1, C2, P1). (See FIG. 1). According to such a configuration, the deformation of the member due to the local application of a bending moment can be prevented, so that “escape” as in the first comparative example (or the first conventional technique) described above can occur. Can be reduced. That is, it is possible to stably press and hold the vibrating body 10A against the driven body 30.

  Further, as shown in FIG. 20, it is assumed that the pressure applied by the spring 260 is applied to the vibrating body at one point AP2 and the vibrating body 10A is pressed against the driven body 30 (second comparative example). . In the vibration actuator 200B according to the second comparative example, the vibration body 10A is applied with the biasing force of the rattling spring 241B in order to suppress the rattling in the left-right direction in FIG. It is sandwiched and held (clamped) on both sides. The vibrating body 10A slides in the vertical direction in FIG. 20 against a frictional force having a magnitude corresponding to the clamping force by the loosening spring 241B. Here, the clamping force by the rattling spring 241B varies depending on the assembly state at the time of manufacture, and there is a situation that the variation is large. Further, the friction coefficient of the contact portion between the vibrating body 10A and the springing spring 241B and the friction coefficient of the contact portion between the vibrating body 10A and the side wall portion 250B are different depending on the surface condition in each contact portion and vary. large. For this reason, the frictional force (maximum static frictional force and dynamic frictional force) also varies greatly. Due to the presence of such a variation factor “friction force according to the clamping force and the friction coefficient”, it is difficult to stably apply a desired pressing force from the vibrating body 10 </ b> A to the driven body 30.

  On the other hand, in the above embodiment, the pressing member 50A presses the vibrating body 10A toward the driven body 30 in a state where the pressing member 50A is in contact with the vibrating body 10A at two positions. As a result, the vibrating body 10A is contact-supported at three or more points (in this case, three points C1, C2, P1) of two or more points (in this case, two points) of the pressing member 50A and the contact point P1. Therefore, it is not necessary to sandwich the vibrating body 10A by applying a clamping force as in the second comparative example (or the second conventional technique). Therefore, since the fluctuation factor “friction force according to the clamping force and the friction coefficient” can be eliminated, the pressing force from the vibrating body 10 </ b> A to the driven body 30 can be stably applied.

  Further, when the two contact points C1 and C2 between the vibrating body 10A and the pressing member 50A sandwich the straight line L1 (a straight line extending in the direction of the pressing force), the vibrating body 10A is more stably supported by the pressing member 50A. Can be retained.

  FIG. 6 is a diagram for considering the rotational moment around the contact point C1. The rotational moment around the contact point C1 will be considered with reference to FIG.

  As shown in FIG. 6A, when the reaction force F1 of the pressing force FP1 acting on the point P1 is decomposed into a central component F1r and its orthogonal component F1θ, only the component F1θ contributes to the rotational moment around the point C1. . Further, as shown in FIG. 6B, when the points C1 and C2 are present on one side of the straight line L1 without sandwiching the straight line L1, the counterclockwise around the point C1 by the component F1θ of the reaction force F1. Rotational moment around works. At this time, since the vibrating body 10A and the pressing member 50A are not bonded at the point C2 and can be separated from each other, a drag force for canceling the rotational moment due to the force F1θ cannot be generated at the point C2. As a result, the vibrating body 10A is rotated counterclockwise around the point C1 and becomes unstable.

  On the other hand, in the above embodiment, as shown in FIG. 6A, the two contact points C1 and C2 exist at positions sandwiching the straight line L1, and the point C1 is set by the component F1θ of the reaction force F1. A clockwise rotational moment works at the center. In this case, a rotational moment that cancels the clockwise rotational moment caused by the component F1θ of the reaction force F1 can be generated by the normal force at the point C2. Therefore, the rotational moment about the point C1 has a balanced relationship and can be stably held.

  The same argument holds for the rotational moment around the point C2, and the presence of the two contact points C1 and C2 between the straight line L1 makes it possible to hold the vibrating body 10A more stably. is there.

  Furthermore, in the above-described embodiment, the pressing member 50A presses the vibrating body 10A toward the driven body 30 in a state where the pressing member 50A is in contact with the vibrating body 10A at the two contact points C1 and C2. A relatively large vertical drag is generated at the contact points C1 and C2, the static friction force (maximum static friction force) that can be generated at the contact points C1 and C2 is a relatively large value, and the vibrating body 10A at the contact points C1 and C2 And “slip” between the pressing member 50 </ b> A are less likely to occur. In order to more reliably prevent the occurrence of this “slip”, each tangent at each of the contact points C1 and C2 is configured to be nearly parallel to the tangent at the point P1 (or the straight line L2). Is preferred.

  Moreover, in the said embodiment, 10 A of vibrating bodies and 50 A of press members are contacting so that separation | separation is possible. According to this, since both the vibrating body and the pressing member are not firmly fixed, it is possible to suppress the influence on the vibration characteristics that may occur when both are firmly fixed. In particular, in the vibration actuator 1A, it is possible to increase the amplitude of the chip member 13 by using the resonance phenomenon of the vibrating body 10A. In this case, since it is required to set the resonance frequency of the vibrating body 10A to an appropriate value, it is particularly important to suppress the influence on the vibration characteristics.

  If it is assumed that the vibrating body 10A and the pressing member 50A are firmly fixed using an adhesive, the rigidity of the vibrating body 10A is improved, and the resonance frequency of the vibrating body 10A varies, resulting in a desired Setting it to a value can be difficult.

  On the other hand, according to the above embodiment, the vibrating body 10A and the pressing member 50A are not firmly fixed with an adhesive or the like at the contact points C1 and C2. In other words, the pressing member 50 </ b> A presses the vibrating body 10 </ b> A toward the driven body 30 in a state where the pressing member 50 </ b> A contacts the vibrating body 10 </ b> A so as to be separated. Therefore, compared with the case where the vibrating body 10A and the pressing member 50A are firmly fixed using an adhesive, it is possible to suppress the influence on the vibration characteristics of the vibrating body 10A due to the rigidity improvement or the like. Such a configuration is particularly useful when increasing the vibration of the vibrating body 10A using a resonance phenomenon.

  Further, as in the above-described embodiment, the direction of the pressing force FP1 is preferably close to the direction of the normal line (a straight line perpendicular to the tangent line L4 (FIG. 1)) L3 at the contact point P1. In short, it is preferable to arrange the rotation shaft 72 (rotation center axis AR2) of the pressing member 50A at a position close to the tangent L4. Specifically, as shown in FIG. 7, the angle between the straight line L1 and the straight line L3 (also expressed as the angle between the straight line L2 and the straight line L4) α is 30 degrees (deg) or less (ideal Is more preferably 0 degree). According to this, since the normal L3 direction component of the pressing force FP1 can be increased as compared with the case where the angle α is relatively large, the elastic force of the elastic member 60 is efficiently converted into the normal component of the pressing force FP1. Can be converted.

  In the above embodiment, as shown in FIG. 8, the distance D2 between the point B1 of the elastic force exerted by the elastic member 60 on the pressing member 50A and the rotation center axis AR2 is equal to the contact point P1 and the rotation center axis AR2. Is greater than the distance D1. For example, D2 / D1 = 2.7 is set here.

  According to such a configuration, an appropriate pressing force can be generated with a smaller elastic force by the principle of the lever.

<2. Second Embodiment>
In the first embodiment, the case where the vibrating body 10A is held at the three points of the contact point P1 and the two contact points C1 and C2 is illustrated, but the present invention is not limited to this. For example, the vibrating body may be held by the contact surface between the vibrating body and the pressing member in addition to the contact point P1. The vibration actuator 1B according to the second embodiment relates to such a modification.

  FIG. 9 is a diagram showing a vibration actuator 1B according to the second embodiment. As shown in FIG. 9, the vibration actuator 1B is the same as that of the first embodiment except that the vibration body 10B is provided instead of the vibration body 10A and the pressure member 50B is provided instead of the pressure member 50A. Hereinafter, in order to avoid duplication of description, the description will focus on differences from the vibration actuator 1A.

  As shown in FIG. 9, in the vibration actuator 1B, the lower side of the vibrating body 10B and the upper side of the horizontal portion of the pressing member 50B are continuously in contact with each other in the contact region CR. The vibrating body 10B and the pressing member 50B extend in a direction in which the pressing force FP1 at the contact point P1 acts through the contact point P1 in a plane parallel to the vibration surface of the vibration body 10B (for example, the paper surface of FIG. 9). The contact is made at two or more positions across the straight line L1. As described above, by holding the contact between the continuous contact region CR sandwiching the straight line L1 and the contact point P1, the pressing force FP1 against the driven body 30 can be stably applied.

  Note that the shape of the contact region CR between the vibrating body and the pressing member is not limited to a straight line as shown in FIG. 9, but may be a curve as shown in FIG. FIG. 10 is a diagram illustrating a vibration actuator 1C according to a modification of the second embodiment. A vibration actuator 1C according to the modification of FIG. 10 is the same as that of the second embodiment except that a vibration body 10C is provided instead of the vibration body 10B, and a pressing member 50C is provided instead of the pressing member 50B.

  Such vibration actuators 1B and 1C can obtain the same effects as those of the vibration actuator 1A.

<3. Third Embodiment>
FIG. 11 is a diagram illustrating a vibration actuator 1D according to the third embodiment. As will be described later, according to the vibration actuator 1D, “slip” between the vibrating body and the pressing member can be prevented more reliably, in other words, the relative displacement between the vibrating body and the pressing member can be generated. Can be more reliably prevented.

  As shown in FIG. 11, the vibration actuator 1D is the same as the first embodiment except that the vibration body 1OD includes a vibration body 10D and the pressure member 50D instead of the pressure member 50A. Hereinafter, in order to avoid duplication of description, the description will focus on differences from the vibration actuator 1A.

  The vibrating body 10D has a base member 14D. Unlike the above-described base member 14, the base member 14D has arcuate convex portions 15 and 16 on the pressing member 50D side. The pressing member 50 </ b> D has a V-groove portion 53 instead of the convex portion 51, and has a flat portion 54 instead of the convex portion 52. The convex portion 15 of the vibrating body 10D is in contact with both surfaces VS1 and VS2 of the V groove of the V groove portion 53 of the pressing member 50D, and the convex portion 16 of the vibrating body 10D is in contact with the flat portion 54 of the pressing member 50D. is doing. As described above, the pressing member 50D and the vibrating body 10D include two contact portions (specifically, a contact portion constituted by the V groove portion 53 and the convex portion 15, and a flat portion 54 and the convex portion 16). Contact portion).

  The relative motion between the vibrating body 10D and the pressing member 50D has a total of 3 degrees of freedom including 2 translational freedom degrees and 1 rotational degree of freedom in a plane parallel to the vibration surface of the vibrating body 10D. Of these three degrees of freedom, two translational degrees of freedom are constrained (restricted) when the convex portion 15 contacts the V-groove portion 53. Further, when the convex portion 16 contacts the flat portion 54, the remaining one degree of freedom of rotation is constrained. As a result, the relative positional relationship between the vibrating body 10D and the pressing member 50D is geometrically determined.

  In other words, in one of the two contact portions (specifically, the contact portion between the convex portion 15 and the V groove portion 53), both the pressing member 50D and the vibrating body 10D are relative to each other. They are in contact so as to constrain translational motion and allow relative rotational movement of the two. Further, in the other of the two contact portions (specifically, the contact portion between the convex portion 16 and the flat portion 54), both are in contact with each other so as to restrain relative rotational motion.

  According to such a configuration, it is possible to stabilize the relative positional relationship between the vibrating body 10D and the pressing member 50D without being affected by the frictional force between the vibrating body 10D and the pressing member 50D. Therefore, even when subjected to external vibration and impact, it is possible to prevent the relative displacement of the vibrating body 10D from occurring. Further, the position adjustment of the vibrating body 10D can be easily performed during assembly adjustment.

  In addition, in this 3rd Embodiment, although the case where a V-groove part was provided in pressing member 50D was illustrated, it is not limited to this. For example, a V-groove portion may be provided on the vibration body side. FIG. 12 is a view showing a vibration actuator 1E according to such a modification.

  A vibration actuator 1E according to the modification of FIG. 12 is the same as that of the second embodiment except that a vibration body 10E is provided instead of the vibration body 10D, and a pressing member 50E is provided instead of the pressing member 50D.

  In the vibration actuator 1E according to this modification, unlike the vibration actuator 1D according to the third embodiment, the V-groove portion 17 is provided in the base member 14E, and the convex portion 51 in contact with the V-groove portion 17 is the pressing member. 50E. Further, the base member 14E has a convex portion 16E, and the pressing member 50E has a flat portion 54E. In this modification, the convex portion 16E is provided instead of the convex portion 16, and the flat portion 54E is provided instead of the flat portion 54. However, the same convex portion 16 and flat portion 54 as in the third embodiment are provided. You may do it.

  Such a vibration actuator 1E can provide the same effect as that of the vibration actuator 1D.

<4. Fourth Embodiment>
In the said 3rd Embodiment, although the case where the generation | occurrence | production of the relative movement of a vibrating body and a press member was prevented using a V-groove part was illustrated in this 4th Embodiment using an adhesive agent, The case where the relative movement with a pressing member is prevented is illustrated.

  FIG. 13 is a diagram illustrating a vibration actuator 1F according to the fourth embodiment.

  As shown in FIG. 13, the vibration actuator 1F has substantially the same configuration as the vibration actuator 1A. However, in the vibration actuator 1A according to the first embodiment, the vibrating body 10A and the pressing member 50A are in contact with each other in a separable manner, whereas in the vibration actuator 1F according to the fourth embodiment, an adhesive is used. The relative motion between the vibrating body 10A and the pressing member 50A is restricted.

  FIG. 14 is an enlarged view showing the vicinity of a contact point C1 between the base member 14 and the convex portion 51. In the portion where the lower flat portion of the base member 14 and the convex portion 51 are in contact with each other, an adhesive is embedded in the gap between them. In such a state, both are adhered.

  Similarly, in a portion where the convex portion 52 of the pressing member 50A and the lower flat portion of the base member 14 are in contact with each other, an adhesive is embedded in the gap between the two, and both are bonded.

  According to such a configuration, the same effect as in the first embodiment can be obtained, and the relative positional relationship between the vibrating body and the pressing member can be stabilized.

  However, in the first embodiment, the vibrating body 10A and the pressing member 50A are detachably contacted, whereas in the fourth embodiment, the vibrating body 10A and the pressing member 50A are made of an adhesive. It is glued. Therefore, as described above, it is conceivable that the vibration body 10A is integrated with the pressing member 50A to improve the rigidity, and thereby the resonance frequency of the vibration body 10A varies. It is preferable to minimize the variation of the resonance frequency due to such rigidity improvement.

  In order to suppress the fluctuation of the resonance frequency due to such rigidity improvement, it is preferable to use an adhesive having a small elastic coefficient as an adhesive for bonding the vibrating body 10A and the pressing member 50A. For example, it is preferable to use any of a rubber adhesive, a silicone adhesive, and an epoxy adhesive. If another expression is used, it is preferable to use an adhesive having a longitudinal elastic modulus of 500 MPa or less. Using such an adhesive makes it difficult for vibration between the vibrating body 10A and the pressing member 50A to be transmitted through the portion of the adhesive, so that improvement in rigidity of the vibrating body 10A can be suppressed. Therefore, it is possible to suppress fluctuations in the resonance frequency of the vibrating body 10A due to the improvement in rigidity.

  In addition, in this 4th Embodiment, although the case where the vibrating body 10A and the pressing member 50A were adhere | attached by 2 points | pieces C1 and C2 was illustrated, it is not limited to this. For example, when the vibrating body 10B and the pressing member 50B are in continuous contact as in the second embodiment, an adhesive may be sandwiched and bonded over the entire contact region CR.

  15 and 16 are views showing a vibration actuator 1G according to such a modification. FIG. 16 is an enlarged view showing the vicinity of the contact region CR.

  As shown in FIG. 15, the vibration actuator 1G has a configuration substantially similar to that of the vibration actuator 1B (FIG. 9). However, as shown in FIG. 16, in the vibration actuator 1G, the vibrating body 10B and the pressing member 50B are not in detachable contact with each other, but the vibrating body 10B and the pressing member 50B are bonded using an adhesive. The relative motion of both is constrained. Such a vibration actuator 1G can provide the same effects as those of the vibration actuator 1F.

  Moreover, in this vibration actuator 1G, the case where the vibrating body 10B and the pressing member 50B are bonded to each other by applying an adhesive to the entire region of the contact region CR is exemplified. An adhesive may be applied and bonded to only a part (for example, only two portions corresponding to the convex portions 51 and 52 in FIG. 1).

  Alternatively, in the vibration actuator 1C (FIG. 10), the vibrating body 10C and the pressing member 50C may be bonded with their curved contact surfaces.

<5. Other>
Although the embodiments of the present invention have been described above, the present invention is not limited to the contents described above.

  For example, in each of the above embodiments, the case where the driven body 30 is formed as a rotating body (rotor) and rotates is illustrated. However, the present invention is not limited to this, and the present invention is also applied when the driven body moves linearly. It is possible to apply. Specifically, a rectangular driven body guided by a guide may be linearly driven in the left-right direction in FIG.

  Moreover, in the said 3rd Embodiment, although the case where the V groove part 53 (FIG. 11) and the circular-arc-shaped convex part 15 contacted and the translation 2 freedom degree was restrained was illustrated, it is not limited to this. For example, as shown in FIG. 17, an arcuate recess 53H may be provided in place of the V-groove (V-shaped recess) 53 (FIG. 11). In this way, a concave portion is provided on one side of both the vibrating body and the pressing member, and a convex portion is provided on the other side, and the relative translational motion of the both is restricted by bringing the concave portion and the convex portion into contact with each other. You may make it do.

  Moreover, in each said embodiment, although the case where each vibrating body vibrates elliptically was illustrated, it is not limited to this. For example, the vibration by the vibrating body may be simple vibration.

It is a figure which shows the vibration actuator (drive device) which concerns on 1st Embodiment. It is a figure which shows a vibrating body. It is a figure which shows a piezoelectric element. It is a figure which shows the drive operation by a vibrating body. It is a figure which shows the drive state of a to-be-driven body. It is a figure for considering the rotational moment around contact point C1. It is a figure which shows angle (alpha) between the straight line L1 and the straight line L3. It is a figure which considers the rotational moment around the rotation center axis AR2. It is a figure which shows the vibration actuator which concerns on 2nd Embodiment. It is a figure which shows the vibration actuator which concerns on a modification. It is a figure which shows the vibration actuator which concerns on 3rd Embodiment. It is a figure which shows the vibration actuator which concerns on another modification. It is a figure which shows the vibration actuator which concerns on 4th Embodiment. It is the elements on larger scale of FIG. It is a figure which shows the vibration actuator which concerns on another modification. It is the elements on larger scale of FIG. It is the elements on larger scale which show the vibration actuator which concerns on the further modification. It is a figure which shows the vibration actuator which concerns on a 1st comparative example. It is a figure which shows the vibration actuator which concerns on a 1st comparative example. It is a figure which shows the vibration actuator which concerns on a 2nd comparative example. It is a figure which shows the 1st prior art. It is a figure which shows the 2nd prior art.

Explanation of symbols

1A to 1G Vibration actuator 10A to 10E Vibration body 11, 12 Piezoelectric element 13 Chip member 14, 14D, 14E Base member 30 Driven body (rotor)
50A to 50E Pressing member 60 Elastic member 70 Base plate AR2 Center of rotation axis C1, C2 Contact point P1 Current contact

Claims (8)

A driving device comprising:
A vibrating body that vibrates in response to an input signal;
A driven body driven by vibration of the vibrating body;
A pressing member that presses the vibrating body toward the driven body;
With
The pressing member presses the vibrating body against the driven body in a state of contacting the vibrating body at a plurality of positions.
The vibrating body and the pressing member are straight lines passing through a contact point between the vibrating body and the driven body in a plane parallel to the vibration surface of the vibrating body, and a pressing force is applied at the contact point. A drive device characterized by contacting at a plurality of positions including two positions sandwiching a straight line extending in the direction of the movement. The drive device according to claim 1,
The driving device according to claim 1, wherein the pressing member is in contact with the vibrating body so as to be separated. The drive device according to claim 1 or 2,
The pressing member and the vibrating body are in contact at two contact portions,
In one of the two contact portions, both the pressing member and the vibrating body are in contact with each other so as to constrain the relative translational movement of the two and allow the relative rotational movement of the two. In the other of the two contact portions, the two are in contact with each other so as to restrain the relative rotational movement. The drive device according to claim 3, wherein
In the one of the two contact portions, a V-groove provided in one of the two contacts an arcuate convex portion provided in the other of the two. A drive device. The drive device according to claim 1,
The driving device, wherein the pressing member is bonded to the vibrating body with any of a rubber-based adhesive, a silicone-based adhesive, and an epoxy-based adhesive. The drive device according to any one of claims 1 to 5,
The driving device, wherein the pressing member and the vibrating body are in surface contact. The drive device according to any one of claims 1 to 6,
The driving device according to claim 1, wherein the pressing member is rotatable about a predetermined rotation center axis in the plane. The drive device according to claim 7, wherein
The vibrating body is pressed against the driven body by the elastic force of an elastic member attached to the pressing member,
The drive device according to claim 1, wherein a distance between an application point of the elastic force to the pressing member and the predetermined rotation center axis is larger than a distance between the contact point and the predetermined rotation center axis.

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