JP2019039997A - Vibration wave motor and driving device - Google Patents

Abstract

To provide a vibration wave motor and a driving device that can be down-sized and thinned in a pressure direction for a vibrator, and that can attenuate vibration which may be a noise source.SOLUTION: A vibration wave motor comprises: a vibrator; a contact member that frictionally contacts with the vibrator; pressure means that generates applied pressure to the vibrator; and transmission means that transmits the applied pressure to the vibrator, and in the vibration wave motor, the vibrator and the contact member relatively move due to vibration generated in the vibrator. The transmission means comprises a protruding part that protrudes in parallel to a pressure direction for the vibrator and a vibration attenuation member that is arranged around the protruding part, the applied pressure is transmitted to the vibrator through the protruding part and the vibration attenuation member, and first applied pressure transmitted by the protruding part is larger than second applied pressure transmitted by the vibration attenuation member.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a driving device incorporated in a vibration wave motor, an optical apparatus, and the like.

  2. Description of the Related Art Conventionally, a vibration wave motor (ultrasonic motor) is known in which a vibrator that periodically vibrates when a high-frequency voltage is applied is pressed against a contact member, whereby the vibrator and the contact member move relatively. Patent Document 1 includes a vibrator that vibrates ultrasonically by an applied high-frequency drive voltage, a contact member that frictionally contacts the vibrator, and a pressurizing unit that pressurizes the vibrator against the contact member. An ultrasonic motor in which a vibrator and a contact member move relatively is disclosed.

  When the movable part is affected by acceleration due to a sudden acceleration / deceleration movement or the like, a moment in the pitch direction may be generated with respect to the moving direction. As a result, a gap is formed between the V-groove constituting the guide mechanism of the movable part and the ball urged by the V-groove. When the ball hits the V-groove in the gap, the movable part vibrates and noise is generated. Will occur. In the ultrasonic motor of Patent Document 1, a vibration damping member is disposed between the vibrator holding member and the moving plate in order to suppress the generation of this gap and attenuate the vibration of the movable part.

Japanese Patent Laying-Open No. 2015-104144

  However, in the ultrasonic motor of Patent Document 1, the thickness of the movable portion increases by the thickness of the vibration damping member, which hinders downsizing and thinning. Further, in the ultrasonic motor of Patent Document 1, since the pressurizing means, the vibrator, and the friction member are arranged in series along the pressurizing direction with respect to the vibrator, the size and thickness of the pressurizing direction are reduced in the first place. Is difficult.

  An object of the present invention is to provide a vibration wave motor and a driving device that can be reduced in size and thickness in a pressurizing direction with respect to a vibrator and can attenuate vibration that becomes a noise source.

  A vibration wave motor according to one aspect of the present invention includes a vibrator, a contact member that frictionally contacts the vibrator, a pressurizing unit that generates a pressure force on the vibrator, and the pressure force applied to the vibrator. A vibration wave motor, wherein the vibrator and the contact member move relative to each other by vibration generated in the vibrator, wherein the transmission means is a direction in which the vibrator is pressurized. And a vibration damping member disposed around the convex part, and the pressure is transmitted to the vibrator via the convex part and the vibration damping member, The first pressurizing force transmitted by the convex portion is larger than the second pressurizing force transmitted by the vibration damping member.

  According to the present invention, it is possible to provide a vibration wave motor and a drive device that can be reduced in size and thickness in the pressurizing direction with respect to the vibrator and can attenuate vibrations that become noise sources.

1 is a perspective view of a vibration wave motor of Example 1. FIG. 1 is an exploded perspective view of a vibration wave motor according to Embodiment 1. FIG. FIG. 3 is a top view of the vibration wave motor according to the first embodiment. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a figure explaining the shape of the vibration damping member of Example 1. FIG. FIG. 3 is a schematic view around a vibration damping member of Example 1. FIG. 6 is a schematic view around a vibration damping member of Example 2. 6 is a schematic view around a vibration damping member of Example 3. FIG. 6 is a perspective view of a lens driving device according to Embodiment 4. FIG. 6 is a perspective view of a lens unit according to Embodiment 4. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted. In each embodiment, the relative movement direction of the vibrator and the contact member is the X-axis direction, orthogonal to the X-axis, the direction in which the vibrator is pressed against the contact member (pressurization direction) is the Y-axis direction, and the X-axis. A direction orthogonal to the direction and the Y-axis direction is taken as a Z-axis direction. In addition, the coordinate system of each Example is for convenience of explanation, and the present invention is not limited to this.

  1 to 3 are a perspective view, an exploded perspective view, and a top view of the vibration wave motor 100, respectively. 4 and 5 are cross-sectional views taken along lines AA and BB in FIG. 3, respectively. FIG. 6 is a diagram illustrating the shape of the vibration damping member.

  The vibration wave motor 100 is a linear motion type linear actuator and generates a driving force in the X-axis direction. The vibration wave motor 100 is connected to the driven portion by inserting a connecting projection provided on the driven portion into the groove-shaped driving force extracting portion 16a shown in FIG. Can be driven in the direction.

  First, the mechanism by which the vibration wave motor 100 generates a driving force will be described. As shown in FIG. 2, the vibration wave motor 100 includes a vibrator 3 including a piezoelectric element 1 and a vibration plate (elastic plate) 2 that are fixed to each other with an adhesive or the like. The flexible substrate 19 is mechanically and electrically connected to the piezoelectric element 1 with an anisotropic conductive paste or the like, and applies a two-phase high-frequency voltage to the piezoelectric element 1. The piezoelectric element 1 generates periodic vibrations in an ultrasonic region when a high frequency voltage is applied. At this time, the diaphragm 2 resonates in each of the longitudinal direction (X-axis direction) and the short-side direction (Y-axis direction), and the two protrusions (convex parts) 2 a provided on the diaphragm 2 are Elliptic motion is performed on the xy plane. By changing the frequency and phase of the high-frequency voltage applied to the piezoelectric element 1, it is possible to appropriately change the rotation direction and ellipticity ratio of the ellipse to generate a desired movement. The vibrator 3 can generate a driving force that moves relative to the slider 4 by making frictional contact with a slider (contact member) 4 fixed to the base member 12. That is, the vibrator 3 can move relative to the slider 4 in the X-axis direction.

  Next, connection of the vibrator 3, the base 11 that holds the vibrator 3, and the base holding frame 15 will be described. As shown in FIG. 2, the diaphragm 2 has holes 2 b at two locations separated in the X-axis direction. The base 11 has a fixing pin 11a at a position facing the two holes 2b. The pin 11a is inserted into the hole 2b and then fixed with an adhesive or the like. The base holding frame 15 is connected to the move plate 16 by screws and to the base 11.

  At each end of the base 11 in the X-axis direction, the base 11 is disposed on the inner side and the base holding frame 15 is disposed on the outer side with the roller member 13 interposed therebetween. The leaf spring 14 is fixed to the base holding frame 15 by adhesion or the like, and is in contact with the roller member 13 so as to be elastically biased in the X-axis direction. The roller member 13 elastically biases the base 11 in the X-axis direction. That is, the base 11 is biased to the base holding frame 15 via the roller member 13. The base 11 is not only urged in the X-axis direction with respect to the base holding frame 15 but can be moved in the Y-axis direction by the rolling of the roller member 13. That is, the base holding frame 15 is configured to be equalized in the X axis direction and the Y axis direction.

  With the above configuration, the base 11 and the base holding frame 15 are free from play in the X-axis direction, which is the driving direction, and almost generate sliding resistance due to the rolling operation of the roller member 13 in the Y-axis direction. Connection that is not possible can be realized.

  Next, a pressurizing configuration in which the vibrator 3 is brought into friction contact with the slider 4 will be described. When the vibrator 3 is pressed against the slider 4 by one pressurizing means, it is necessary to arrange the pressurizing means immediately above the vibrator 3. In this case, the thickness of the vibration wave motor 100 in the pressing direction increases.

  Therefore, in this embodiment, the vibrator 3 is pressed against the slider 4 by using a plurality of pressurizing units arranged around the vibrator 3. Specifically, four tension coil springs (pressurizing means) 6 which are elastic members are arranged at four corners of the pressurization sheet metal (first transmission member) 5, and the first ends of the tension coil springs (first transmission members) 5 The second end is hung on the move plate 16 to press the vibrator 3 against the slider 4. By arranging the tension coil springs 6 at the four corners of the pressurizing sheet metal 5 and dispersing the applied pressure, it is possible to achieve a reduction in size and thickness.

  The pressure metal plate 5 has two convex portions 5 a that protrude in parallel with the Y-axis direction, which is the urging direction (pressure direction) of the tension coil spring 6, and abut against the plate member 10. The two convex portions 5a are arranged along the Z axis. The convex portion 5 a has a curved surface shape, and is in contact with the plate member 10 at the contact portion 7. A butyl rubber (vibration damping member) 8 is disposed around the convex portion 5a as shown in FIG.

  A felt 9 is disposed between the vibrator 3 and the plate member (second transmission member) 10 as an elastic member having flexibility. Two protrusions 2 a of the diaphragm 2 are in contact with the slider 4. The slider 4 is fixed to the base member 12 by fastening screws 23 and 24. The ball base 17 is disposed on the side opposite to the vibrator 3 with respect to the slider 4. Three rolling balls 18 are arranged between the ball base 17 and the move plate 16.

  As described above, in this embodiment, since the vibrator 3 is brought into frictional contact with the slider 4 using the four tension coil springs 6 arranged around the vibrator 3, the vibration wave motor 100 can be reduced in size. Thinning can be realized.

  Since the pressing metal plate 5 is elastically biased in the Y-axis direction by the tension coil springs 6 at the four corners, the two convex portions 5a are in contact with the plate member 10 at the contact portion 7, so that FIG. 5 and FIG. It has a degree of freedom around the axis C connecting the two contact portions 7 shown in FIG. That is, the pressure sheet metal 5 can always press the plate member 10 with the contact portion 7 while being equalized and driven around the axis C (E direction in FIG. 4).

  The pressure applied by the tension coil spring 6 is transmitted to the plate member 10 through both the convex portion 5 a of the pressurizing sheet metal 5 and the butyl rubber 8, and is further transmitted to the vibrator 3 through the felt 9. Since the flexible felt 9 abuts on the vibrator 3, the surface of the vibrator 3 can be pressed with a uniform force as a whole without inhibiting the drive vibration of the vibrator 3.

  Next, a configuration for guiding straight in the driving direction will be described. The ball base 17 is fixed to the base member 12 with a screw 25 through a pressing metal plate 20. The ball base 17 and the move plate 16 are formed with V-shaped grooves for rolling the three rolling balls 18 in the X-axis direction that is the driving direction. In this embodiment, three V-shaped grooves are formed on the move plate 16, and two V-shaped grooves are formed on the ball base 17.

  In this embodiment, the moving plate 16 is biased to the ball base 17 via the three rolling balls 18 while the vibrator 3 is pressed against the slider 4 by the four tension coil springs 6. When the vibrator 3 generates a driving force in the X-axis direction, the three rolling balls 18 roll along a V-shaped groove extending on the X-axis, and the move plate 16 smoothly guides in the X-axis direction. Is done.

  The move plate 16 is fixed to the base holding frame 15 with screws 21 and 22. The move plate 16 has a groove-shaped driving force extraction portion 16a extending in the Z-axis direction orthogonal to the driving direction. The move plate 16 is guided in the X-axis direction by the driving force generated by the vibrator 3 via the base 11 and the base holding frame 15. It is possible to transmit the driving force of the vibration wave motor 100 to the driven portion by inserting the connecting projection provided on the driven portion into the driving force extracting portion 16a.

  Next, with reference to FIG. 4 and FIG. 7, the vibration of the pressurization sheet metal 5 which is a movable part is demonstrated. FIG. 7A is a schematic diagram of FIG. 4 and shows the periphery of the butyl rubber 8 in a simplified manner. FIG. 7B simply shows the behavior of the natural vibration of the diaphragm 2 during driving. During driving, the vibrator 3 is vibrated by applying a high-frequency voltage to the piezoelectric element 1, and the pressure metal plate 5 generates a driving force. The vibrator 3 is pressed by the slider 4 through the felt 9 and the plate member 10. Since the vibration of the vibrator 3 is attenuated by the felt 9 and the plate member 10, it is difficult to transmit to the pressure metal plate 5. However, it is difficult to completely attenuate the vibration when the vibrator 3 is driven. Therefore, the vibration from the vibrator 3 that could not be attenuated is transmitted from the contact portion 7 to the pressurization sheet metal 5 to excite the pressurization sheet metal 5. If the pressure sheet metal 5 generates natural vibration by this excitation, it may cause noise.

  In the present embodiment, the butyl rubber 8 is disposed around the convex portion 5 a of the pressure sheet metal 5 in order to suppress the excitation of the pressure sheet metal 5. Since the butyl rubber 8 is tightly sandwiched between the plate member 10 and the pressure sheet metal 5 in the Y-axis direction that is the pressure direction, the vibration of the pressure sheet metal 5 can be attenuated. Moreover, since the vibration of the plate member 10 can also be attenuated, the vibration transmitted from the contact portion 7 to the pressure metal plate 5 can be suppressed. Moreover, since the butyl rubber 8 is arrange | positioned in the space formed between the pressurization sheet metal 5 and the plate member 10, the thickness of a pressurization direction is not increased.

  In order to further suppress the excitation of the pressure sheet metal 5, in the present embodiment, the convex portion 5a of the pressure sheet metal 5 is disposed at a position overlapping the vibration node 2c in the Y-axis direction which is the pressure direction. . With this configuration, the pressure sheet metal 5 abuts on the plate member 10 at a position where vibration from the vibration plate 2 is difficult to be transmitted, so that transmission of vibration to the pressure sheet metal 5 can be suppressed.

  Further, the butyl rubber 8 is disposed at a position overlapping the protrusion 2 a of the diaphragm 2 in the Y-axis direction that is the pressing direction. With this configuration, the vibration transmitted from the protrusion 2a that slides on the slider 4 during driving can be further attenuated, and the excitation of the pressure metal sheet 5 can be suppressed.

  The main role of the pressure metal sheet 5 is to always press the vibrator 3 against the slider 4 with a desired pressure so that the vibrator 3 generates a stable driving force. Therefore, it is necessary to attenuate the vibration of the pressure sheet metal 5 on the assumption that the pressure sheet metal 5 can reliably press the vibrator 3 against the slider 4. Therefore, in the present embodiment, the pressure F1 transmitted from the convex portion 5a to the vibrator 3 is larger than the pressure F2 (the resultant force of the pressure F2a and the pressure F2b) transmitted from the butyl rubber 8 to the vibrator 3. Is set. By setting in this way, a configuration that does not hinder equalization driving around the axis C of the pressure sheet metal 5 is realized.

  Next, a configuration in which the pressure metal plate 5 stably presses the vibrator 3 will be described with reference to FIGS. The axis C connecting the contact portions 7 of the two convex portions 5a passes through the position where the pressing force F1 by the convex portions 5a acts. The center position where the pressing force F1 acts is a position D shown in FIG. Further, the pressing force F2 by the butyl rubber 8 is a resultant force of the pressing forces F2a and F2b, and the center position where the pressing force F2 acts is also the position D. That is, in the XZ plane, the center of the pressurizing force F1 overlaps the center of the pressurizing force F2. Due to the positional relationship between the pressurizing forces F1 and F2, equalization driving around the axis C of the pressure metal sheet 5 is not inhibited by the butyl rubber 8. For this reason, even if the butyl rubber 8 is disposed, the two convex portions 5 a always abut against the plate member 10, and the pressure metal plate 5 can stably press the vibrator 3.

  With reference to FIG. 8, the vibration wave motor 101 of the present embodiment will be described. The vibration wave motor 101 of the present embodiment includes a plate member 10 a having a shape different from that of the plate member 10 of the vibration wave motor 100 of the first embodiment. Since other configurations are the same as those of the vibration wave motor 100 of the first embodiment, the description thereof is omitted.

  FIG. 8 is a view corresponding to FIG. 7A and simply shows the periphery of the butyl rubber 8 of the vibration wave motor 101. The plate member 10a has inclined surfaces 10a1 and 10a2 on the XY plane. When the butyl rubber 8 has a shape having a uniform thickness in the Y-axis direction, the charge amount of the butyl rubber 8 is different from that of the first embodiment due to the inclined surfaces 10a1 and 10a2, and the charge amount increases as the distance from the convex portion 5a increases in the X-axis direction. Get smaller. That is, due to the inclined surfaces 10a1 and 10a2, the pressurizing force F2 decreases in the X-axis direction, which is the moving direction of the vibration wave motor 101, as the distance from the convex portion 5a increases.

  With the above configuration, the load is reduced in the equalization driving of the pressure sheet metal 5 that rotates in the direction of arrow E, so that it is easy to rotate. That is, smoother equalization driving is possible, and driving loss can be reduced, so that the vibration wave motor 101 with high driving efficiency can be provided.

  With reference to FIG. 9, the vibration wave motor 102 of the present embodiment will be described. The vibration wave motor 102 according to the present embodiment includes a pressure sheet metal 50 having a shape different from that of the pressure sheet metal 5 of the vibration wave motor 100 according to the first embodiment. Since other configurations are the same as those of the vibration wave motor 100 of the first embodiment, the description thereof is omitted.

  FIG. 9 is a diagram corresponding to FIG. 7A, and simply shows the periphery of the butyl rubber 8 of the vibration wave motor 102. The pressure sheet metal 50 has inclined surfaces 50a and 50b on the XY plane. When the butyl rubber 8 has a shape having a uniform thickness in the Y-axis direction, the charge amount of the butyl rubber 8 is different from that of the first embodiment due to the inclined surfaces 50a and 50b, and the charge amount increases as the distance from the convex portion 5a increases in the X-axis direction. Get smaller. That is, due to the inclined surfaces 50a and 50b, the pressurizing force F2 decreases as the distance from the convex portion 5a increases in the X-axis direction, which is the moving direction of the vibration wave motor 102, as in the second embodiment.

  With the above configuration, the load is reduced in the equalization driving of the pressure sheet metal 50 that rotates in the direction of arrow E, so that it is easy to rotate. That is, smoother equalization driving can be performed and driving loss can be reduced, so that the vibration wave motor 102 with high driving efficiency can be provided.

  In each embodiment, the contact portion 7 is composed of a convex portion provided on the pressure sheet metal and a flat portion provided on the plate member that contacts the convex portion. You may be comprised by the provided convex part and the plane part provided in the pressurization sheet metal 5 contact | abutted to this convex part. That is, it is only necessary that one of the pressure sheet metal and the plate member has a convex portion and the other has a plan view in contact with the convex portion.

  Further, in each embodiment, the pressurizing sheet metal 5 pressurizes the vibrator 3 via the felt 9 and the plate member 10. The projection 5a of the pressure metal plate 5 can pressurize the vibrator 3 without the vibration wave motor hindering the driving vibration of the vibrator 3, and the vibration from the vibrator 3 can be obtained only by interposing the butyl rubber 8 therebetween. If it is possible to attenuate sufficiently, the felt 9 and the plate member 10 may be omitted from the components. In this case, the vibration wave motor can be further reduced in thickness.

  In each embodiment, butyl rubber is used as the vibration damping member. However, other vibration-proof rubber (vibration-proof member) may be used as long as the effects described in each embodiment can be realized. Examples of the anti-vibration rubber include nitrile rubber, chlorobrene rubber, and ethylene propylene rubber.

  With reference to FIGS. 10 and 11, the lens driving device 300 of the present embodiment will be described. FIG. 10 is a perspective view of the lens driving device 300, and FIG. 11 is a perspective view of the lens unit 200.

  Since the lens driving device 300 is the lens driving device 300 in which the vibration wave motor 100 of the first embodiment is mounted on the lens unit 200, the description of the same parts as those of the first embodiment is omitted.

  The lens driving device 300 is disposed inside a lens barrel (not shown) and is used to move a moving lens group such as a zoom lens and a focus lens in the optical axis direction. The lens holding frame 201 holds a moving lens group (not shown). The guide bar 203, the guide bar 204, and the base member 12 of the vibration wave motor 100 are fixed to a lens barrel (not shown).

  The lens holding frame 201 includes a connecting member 202 that is rotatably attached. The connecting member 202 has a connecting protrusion 202 a for connecting to the driving force extracting portion 16 a of the move plate 16. The connecting member 202 is parallel to the rotation direction G around the X′-X ″ axis parallel to the X axis with respect to the lens holding frame 201 and the X′-X ″ axis by a biasing spring 205 which is an elastic biasing member. Elastically biased in the H direction.

  Accordingly, the connecting projection 202a is engaged with the groove-shaped driving force extracting portion 16a, and the connecting member 202 is elastically biased as described above, so that the lens holding frame 201 moves through the connecting member 202. The plate 16 is urged without rattling.

  With the above configuration, when the movable part including the base holding frame 15 of the vibration wave motor 100 is driven, the driving force of the vibration wave motor 100 is transmitted to the lens holding frame 201 via the driving force extraction part 16a. As described above, the vibration wave motor 100 has the butyl rubber 8 disposed around the convex portion 5a of the pressure sheet metal 5 so that the vibration transmitted to the pressure sheet metal 5 can be attenuated and noise can be suppressed. It is. Therefore, the lens driving device 300 can move the lens holding frame 201 along the guide bars 203 and 204 with low noise.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

3 vibrator 4 slider (contact member)
5 Pressurized sheet metal (transmission means)
5a Convex part 6 Tension coil spring (Pressurizing means)
8 Butyl rubber (Transmission means, vibration damping member)
10 Plate member (transmission means)
100-102 Vibration wave motor

Claims (9)

A vibrator,
A contact member in frictional contact with the vibrator;
A pressurizing means for generating a pressure applied to the vibrator;
Transmission means for transmitting the applied pressure to the vibrator,
A vibration wave motor in which the vibrator and the contact member move relatively by vibration generated in the vibrator;
The transmission means includes a convex portion projecting parallel to the pressurizing direction with respect to the vibrator, and a vibration damping member disposed around the convex portion,
The applied pressure is transmitted to the vibrator via the convex portion and the vibration damping member,
The vibration wave motor according to claim 1, wherein the first pressurizing force transmitted by the convex portion is larger than the second pressurizing force transmitted by the vibration damping member. The transmission means includes a first transmission member and a second transmission member along the pressing direction,
2. The vibration wave motor according to claim 1, wherein one of the first transmission member and the second transmission member includes the convex portion, and the other includes a flat portion that contacts the convex portion. An elastic member having flexibility between the second transmission member and the vibrator;
3. The vibration wave according to claim 2, wherein the pressure is transmitted to the vibrator via the second transmission member and the elastic member via the convex portion and the vibration damping member. motor.   The center of the second pressing force overlaps the center of the first pressing force in a plane including the moving direction of the vibration wave motor and the direction orthogonal to the moving direction and the pressing direction. The vibration wave motor according to any one of claims 1 to 3.   5. The vibration wave according to claim 1, wherein the vibrator includes a vibration plate that contacts the contact member, and a piezoelectric element that excites vibration when a voltage is applied thereto. motor. The diaphragm includes a protrusion that frictionally contacts the contact member;
The convex portion is arranged at a position overlapping with a node of the natural vibration of the diaphragm generated when driving vibration is applied to the piezoelectric element in the pressing direction,
The vibration wave motor according to claim 5, wherein the vibration damping member is disposed at a position overlapping the protrusion in the pressing direction.   At least one surface of the vibration damping member is sandwiched between inclined surfaces in the pressurizing direction so that the second pressing force decreases in the moving direction of the vibration wave motor as the distance from the convex portion increases. The vibration wave motor according to claim 1, wherein the vibration wave motor is provided.   The vibration wave motor according to claim 1, wherein the convex portion has a curved surface. The vibration wave motor according to any one of claims 1 to 8,
And a driven part that is driven by the driving force transmitted from the vibration wave motor.