JP4724448B2 - Vibration wave driving device and apparatus provided with the vibration wave driving device - Google Patents

Description

  The present invention relates to a vibration wave driving device and a device including the vibration wave driving device.

  A vibration wave motor or the like as a vibration wave drive device includes a circular vibrating body in which driving vibration is formed and a circular contact body that is in pressure contact with the vibrating body. A driving force is obtained by relatively moving the contact body.

  In general, the vibrating body includes an elastic body and a piezoelectric element as an electro-mechanical energy conversion element disposed on the elastic body. For example, a piezoelectric element having two driving phases is disposed at a position spatially having a phase difference of 90 ° with respect to the elastic body, and a two-phase having a phase difference of 90 ° with respect to the two driving phases. By applying an alternating signal, two bending vibrations are generated on the elastic body. The contact body is moved relative to the vibrating body by the driving vibration obtained by combining the two bending vibrations. A circular friction member for obtaining an appropriate frictional force is bonded, applied, or formed on the contact portion of at least one of the vibrating body and the contact body.

  Since the contact surface of this friction member is a continuous body in the circumferential direction and the circumference does not change, the shape of the contact surface is distorted by the input of vibration. If the contact surface is twisted due to this distortion, it causes an increase in wear, an increase in sliding loss, and occurrence of squealing.

  Therefore, by using sheet metal pressing, as shown in FIG. 12, the friction member is divided into a plurality of friction member elements, and the vibration wave formed so that each friction member element can be deformed independently. A drive device has been proposed (see, for example, Patent Document 1).

In FIG. 12, this vibration wave driving device includes a circular vibrating body 3 (see FIG. 13) in which a driving vibration is formed, and a circular contact body 5 (see FIG. 13) in pressure contact with the vibrating body. In addition, a circular friction member 2 for obtaining an appropriate frictional force is formed at the contact portion of the vibrating body 3. Since the friction member 2 is divided into a plurality of friction member elements by slits in the circumferential direction, distortion of the shape of the contact surface can be prevented. Further, as shown in FIG. 13, a plurality of the friction members 2 are arranged concentrically on the vibrating body 3, so that the contact area between the friction member 2 and the contact body 5 is large and the contact surface pressure is low. The durability of the wave drive device is high.
JP 2002-315364 A

  However, in the vibration wave driving device described in Patent Document 1, each friction member 2 is in strong contact with the contact body 5 only at a limited portion near the outer periphery, as shown in FIG. Yes. In order to increase the contact area between the friction member 2 and the contact body 5 in order to improve the durability of the vibration wave driving device, as shown in FIG. 14 (a), the friction member 2 arranged concentrically. The number of must be increased.

  In the vibration wave driving device, the processing accuracy of the stacked components, particularly the processing accuracy of the fitting surface, greatly affects the static and dynamic rigidity of the friction member 2, and is reflected in the performance of the vibration wave driving device. Therefore, in the case of mass production, it is not preferable to increase the number of parts to be stacked.

  An object of the present invention is to provide a vibration wave driving device capable of improving durability without increasing the number of parts and a device including the vibration wave driving device.

To achieve the above object, the vibration wave driving apparatus according to claim 1 is provided with a vibrating body driving vibration is formed, and a contact body for the vibrating member in pressure contact through a friction member against In the vibration wave driving device that rotates the contact body relative to the vibrating body by the driving vibration, the friction member is divided in a circumferential direction with respect to an axis of rotation of the friction member to be a plurality of friction member elements. Each of the friction member elements is arranged between a fixed portion at both ends arranged in the radial direction with respect to the axis of rotation, one supporting portion, an inner-end supported beam-like elastic portion, a connecting portion, an outer peripheral side The both-end supported elastic part and the other support part are continuously formed, the contact surface formed on the inner-end supported end-like elastic part, and the outer-end supported end-like elastic part and by contact surfaces are arranged on two concentric circles, the contact surface of the outer diameter side , And the contact surface on the inner diameter side, characterized in that the separate spring properties and is configured to be respectively deformed in the radial direction and axial direction relative to the axis of rotation of the rotary.

  According to the present invention, the circular friction member fixed to the contact portion in one of the vibrating body and the contact body is divided into the plurality of friction member elements in the circumferential direction of the friction member, and the plurality of friction member elements are the vibration body. And a plurality of contact surfaces that contact the contact portion on the other side of the contact body, and can be deformed in the normal direction of the contact surface and the radial direction of the friction member by independent spring characteristics, without increasing the number of parts. Durability can be improved.

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

  A vibration wave motor as a vibration wave driving device according to an embodiment of the present invention includes a circular vibration body in which drive vibration is formed, and a circular contact body that is in pressure contact with the vibration body. Here, if the contact portion between the vibrating body and the contact body is circular, the vibrating body and the contact body do not necessarily have to be circular. The vibration body includes an elastic body and an electro-mechanical energy conversion element disposed on the elastic body, and forms drive vibration in the elastic body using the electro-mechanical energy conversion element as a drive source. A driving force is obtained by moving the contact body relative to the vibrating body by the driving vibration of the vibrating body. A circular friction member shown in FIG. 1 to be described later for obtaining an appropriate frictional force is formed in the contact portion of at least one of the vibrating body and the contact body.

  FIG. 1 is a partial perspective view of a friction member of a vibration wave driving device according to an embodiment of the present invention.

  In FIG. 1, arrow A indicates the circumferential direction of the friction member, and arrow B indicates the radial direction of the friction member. This is the same in other drawings.

  The friction member 11 is radially divided into a plurality of friction member elements. In this figure, five friction member elements are illustrated. Each friction member element includes a double-supported beam-like elastic portion 12 including two contact surfaces, a support portion 13 that supports the double-supported beam-like elastic portion 12, and a connecting portion 14 that connects the two contact surfaces. Is done. The fixing portion 15 of the friction member 11 is joined to the base portion 16 by bonding with an adhesive, metal brazing, welding, press-fitting, shrinking, or the like.

  The friction member element can be deformed in the normal direction of the contact surface (hereinafter referred to as “axial direction”) and the radial direction by independent spring characteristics. The amount of deformation in the axial direction is managed by the rigidity of the portion protruding from the fixed portion 15 on the inner diameter side and the outer diameter side, and is a parameter that determines the contact area between the opposing contact surfaces.

  If the axial rigidity is too high, the contact body jumps, the contact becomes unstable, and abnormal noise is generated. If the axial rigidity is too low, the required rotational speed cannot be obtained, and excessive input is required to obtain a sufficient output. Therefore, it is important to appropriately manage the axial rigidity in order to obtain a stable contact.

  The amount of deformation in the radial direction is controlled by the rigidity of the portion extending in the direction perpendicular to the periphery of the contact surface, and the mass movement obtained by the vibration direction (that is, axial amplitude and radial amplitude) of the opposing contact surface. By substantially matching (direction), the radial slip between the contact surfaces can be reduced and stable contact can be obtained.

  Since the cantilever-like elastic part 12, the support part 13, and the connecting part 14 are a continuous body between the fixed parts 15, their behavior and influence are comprehensively determined by static and dynamic finite element analysis in the design. It is essential to grasp it.

  By dividing the friction member 11 in the circumferential direction, the wear powder passes through the opening and is discharged. Further, by applying an adhesive substance to the surface other than the contact surface of the base 16 or the friction member 11, it is possible to prevent the abrasion powder from being fixed to the adhesive substance and discharged to the outside. it can.

  The friction member 11 is manufactured by press working using a martensitic stainless steel plate having a thickness of 0.1 mm as a material. First, radial slits are punched into the round plate from the contact surface side. The stress concentration at the edge portion can be alleviated by the sagging of the edge portion generated by punching from the contact surface side. Next, a step between the fixed portion 15 and the contact surface is formed by ironing in the axial direction from the side opposite to the contact surface.

  According to the configuration of FIG. 1, the friction member 11 is radially divided into a plurality of friction member elements, and each friction member element has two contact surfaces and has an independent spring property in the axial direction and the radial direction. Since it is deformable, the durability can be improved without increasing the number of parts.

  FIG. 2 is a partial perspective view of a first modification of the friction member 11 of FIG.

  The friction member 11 in FIG. 2 is different from the friction member 11 in FIG. 1 in that it has a buffer member 17 provided between the connecting portion 14 and the base portion 16.

  The buffer member 17 is made of a material having a viscous damping such as a resin, and absorbs unnecessary vibration generated in the friction member 11. The buffer member 17 may be installed between the support part 13 and the base part 16, and may be apply | coated to surfaces other than a contact surface.

  The two contact surfaces of the double-supported beam-like elastic portion 12 are such that the displacement direction of the contact surface on the outer diameter side (arrow C) is perpendicular to the contact surface than the displacement direction of the contact surface on the inner diameter side (arrow D) Managed. The specific design value varies depending on the input vibration wave. The displacement direction of the contact surface is managed by using the angle formed by the contact surface of the double-supported beam-like elastic portion 12 and the support portion 13 as a parameter. The displacement direction of the contact surface may be managed by the plate thickness of the friction member 11 or the shape of the connecting portion 14.

  In the case of a general vibrating body supported on the inner diameter side of the contact surface, the vibration wave amplitude increases as the diameter increases, so the rigidity on the inner diameter side is made larger than that on the outer diameter side depending on the length of the radially extending portion. ing.

  According to the configuration of FIG. 2, the displacement direction of the contact surface on the outer diameter side (arrow C) is managed so as to be perpendicular to the contact surface with respect to the displacement direction of the contact surface on the inner diameter side (arrow D). Therefore, it is possible to reduce the radial slip between the contact surfaces and obtain a stable contact.

  FIG. 3 is a partial perspective view of a second modification of the friction member 11 of FIG.

  The friction member 11 of FIG. 3 differs from the friction member 11 of FIG. 1 in that the friction member element has a plurality of contact surfaces in the circumferential direction.

  Since the friction member element has the cantilever-like overhanging portion 31 in the circumferential direction of the both-end supported elastic portion 12, due to intermittent contact due to the friction member element being divided in the circumferential direction, It is possible to prevent the friction member element from being broken. Although the friction member 11 has a complicated shape, it can be manufactured in two steps, a punching process and a ironing process, like the friction member 11 of FIG.

  According to the configuration of FIG. 3, since there are a plurality of contact surfaces in the circumferential direction, it is easy to generate distortion following the input vibration wave of the opposing contact surfaces, and stress concentration can be reduced. Furthermore, the radial contact area can be increased.

  FIG. 4 is a partial perspective view of a third modification of the friction member 11 of FIG.

  The friction member 11 in FIG. 4 differs from the friction member 11 in FIG. 1 in that the connecting portion 14 has an arc shape.

  The friction member element has a plurality of contact surfaces in the radial direction. The curvature of the arc of the connecting portion 14 and the axial position of the arc are manipulated by the shape of the female die in the ironing process.

  According to the configuration of FIG. 4, the vibration direction of the plurality of contact surfaces can be managed by manipulating the curvature of the arc of the arcuate connecting portion 14 and the axial position of the arc.

  FIG. 5 is a partial perspective view of a fourth modification of the friction member 11 of FIG.

  The friction member 11 of FIG. 5 differs from the friction member 11 of FIG. 1 in that the connecting portion 14 is disposed in the same plane as the contact surface. The support part 13 and the connection part 14 have spring properties in the axial direction and the radial direction.

  According to the configuration of FIG. 5, since the connecting portion 14 is disposed in the same plane as the contact surface, the ironing process is unnecessary, and the friction member can be formed only by punching.

  6 and 7 are partial perspective views of a fifth modification of the friction member 11 of FIG.

  The friction member 11 shown in FIGS. 6 and 7 is different from the friction member 11 shown in FIG. 1 in that two rows of contact surface groups are fixed by a ring connecting portion 61.

  The frictional members 11 are arranged in the circumferential direction and the radial direction by arranging two rows of contact surface groups, which are each divided radially, on the concentric circles at positions shifted in the circumferential direction and fixed by the ring connecting portion 61. Both have a plurality of contact surfaces.

  According to the configuration of FIGS. 6 and 7, since the two contact surface groups are arranged at positions shifted from each other in the circumferential direction, the contact is not intermittent and a stable contact can be obtained.

  FIG. 8 is a partial perspective view of a sixth modification of the friction member 11 of FIG.

  The friction member 11 shown in FIG. 8 is different from the friction member 11 shown in FIG. 1 in that the friction member 11 includes two friction members 11a and 11b.

  The friction members 11a and 11b are stacked such that the positions of the friction member elements do not overlap each other in the circumferential direction.

  A male die that punches radial slits needs to have a certain degree of strength in order to ensure durability that can withstand tens of thousands of uses. On the other hand, in order to increase the contact area, it is desirable to reduce the slit width of the friction member. However, if the male mold does not have a sufficient thickness, the strength and durability of the male mold are significantly reduced.

  According to the configuration of FIG. 8, the two friction members are stacked while shifting the position of the friction member elements, so that it is possible to widen the slit width of each friction member and ensure sufficient strength of the male mold. Can do.

  FIG. 9 is a partial perspective view of a seventh modification of the friction member 11 of FIG.

  The friction member 11 in FIG. 9 is different from the friction member 11 in FIG. 1 in that it includes a reinforcing member 91 laminated on the friction member 11.

  The reinforcing member 91 serves to reinforce the friction member 11. The number of reinforcing members 91 is not limited to one and may be plural.

  According to the configuration of FIG. 9, when a friction member is manufactured from a flat plate having a constant thickness, the rigidity of the friction member can be adjusted by a simple method when a desired rigidity cannot be obtained.

  10 and 11 are partial perspective views of an eighth modification of the friction member 11 of FIG.

  The friction member 11 shown in FIGS. 10 and 11 differs from the friction member 11 shown in FIG. 1 in that the contact surfaces are arranged on a plurality of different concentric circles.

  The friction member 11 is composed of two friction members 11a and 11b. The friction member 11a has two rows of contact surfaces disposed on two concentric circles on the inner peripheral side and the outer peripheral side, and the friction member 11b is disposed so as to straddle the two rows of contact surfaces of the friction member 11a. It has one row of contact surfaces. Note that the friction member may have a single plate structure as long as the contact surfaces are arranged on a plurality of different concentric circles. As shown in FIG. 11, the contact surface of the friction member 11 is in contact with the contact surface of the friction member 11 ′ in contact in the entire region in the radial direction.

  Since the hardness of the contact surface of the friction member 11 is set higher than the hardness of the contact surface of the friction member 11 ′ to be abutted, the amount of wear of the contact surface of the friction member 11 is very small. For this reason, the main cause of the performance deterioration of the vibration wave driving device is deterioration of the contact surface property, for example, flatness due to wear of the friction member 11 ′ to be contacted.

  10 and 11, the contact surface of the friction member 11 contacts the contact surface of the friction member 11 ′ in contact with the entire surface in the radial direction. It can be mitigated and performance deterioration of the vibration wave drive device can be prevented.

It is a fragmentary perspective view of the friction member of the vibration wave drive device concerning an embodiment of the invention. It is a fragmentary perspective view of the 1st modification of the friction member of FIG. It is a fragmentary perspective view of the 2nd modification of the friction member of FIG. It is a fragmentary perspective view of the 3rd modification of the friction member of FIG. It is a fragmentary perspective view of the 4th modification of the friction member of FIG. It is a fragmentary perspective view of the 5th modification of the friction member of FIG. It is a fragmentary perspective view of the 5th modification of the friction member of FIG. It is a fragmentary perspective view of the 6th modification of the friction member of FIG. It is a fragmentary perspective view of the 7th modification of the friction member of FIG. It is a fragmentary perspective view of the 8th modification of the friction member of FIG. It is a fragmentary perspective view of the 8th modification of the friction member of FIG. It is a figure which shows the shape of the friction member of the conventional vibration wave drive device, (a) is a front view, (b) is a fragmentary sectional view. It is sectional drawing of the friction member of FIG. It is sectional drawing of the friction member of FIG. 12, (a) is a general view, (b) is the elements on larger scale.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Friction member 12 Dual-supported elastic part 13 Support part 14 Connection part 15 Fixed part

Claims (5)

A vibrating body in which driving vibration is formed;
And a contact body for pressure contact via the friction member against the vibration member,
In the vibration wave driving device that rotates the contact body relative to the vibrating body by the driving vibration,
The friction member is divided in a circumferential direction with respect to an axis of rotation of the friction member, and a plurality of friction member elements are arranged,
Each of the friction member elements includes one supporting portion, an inner peripheral side cantilevered elastic portion, a connecting portion, and an outer peripheral side cantilever beam between fixed portions at both ends arranged in a radial direction with respect to the axis of rotation. A cylindrical elastic part and the other support part are formed continuously,
The contact surface formed on the inner peripheral side cantilever-like elastic portion and the contact surface formed on the outer peripheral side cantilever-like elastic portion are arranged on two concentric circles,
The vibration characterized in that the contact surface on the outer diameter side and the contact surface on the inner diameter side are configured to be deformable in an axial direction of rotation and a radial direction with respect to the axis of rotation by independent springiness, respectively. Wave drive device. The vibration wave drive according to claim 1 , wherein the displacement direction of the contact surface on the outer diameter side is configured to be perpendicular to the contact surface from the displacement direction of the contact surface on the inner diameter side. apparatus. The friction member is
Adjacent to each of the friction member elements having the contact surface on the outer diameter side and the contact surface on the inner diameter side arranged in a circumferential direction with respect to the rotation axis of the friction member,
Another friction member element in which the contact surface formed on the double-supported beam-like elastic portion is disposed at a position corresponding to the contact surface on the outer diameter side and the contact surface on the inner diameter side. The vibration wave driving device according to claim 1, wherein: The vibration wave driving device according to claim 1 , wherein a buffer member that absorbs unnecessary vibration is installed in the connecting portion . A vibration wave driving apparatus according to any one of claims 1 to 4, driven to the driven by the driving force obtained by relatively moving the contact member relative to the vibrating member by driving the vibration A device characterized by comprising a body.

Images