JP2016092911A - Vibration wave motor and optical equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a vibration wave motor more compact without lowering output nor driving efficiency.SOLUTION: A vibration wave motor according to the present invention has a vibrator which vibrates with an applied high-frequency voltage; a vibrator fixed member to which the vibrator is fixed; pressing means of pressing a slide part formed at the vibrator; a slide member against which the slide member is pressed by the pressing means; a vibrator support member which holds the vibrator and is driven relatively to the slide member; and a coupling member which couples the vibrator fixed member and vibrator support member together, the vibrator support member and coupling member being fastened at least in a part of a projection region formed by projecting the vibrator fixed member on a plane having its normal in a pressing direction of the pressing means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration wave motor applied to an optical apparatus and the like, and more particularly to an ultrasonic motor driven by ultrasonic vibration.

  2. Description of the Related Art Conventionally, a vibration wave motor that drives a sliding member by pressing a vibrator that periodically vibrates by application of a high-frequency voltage to the sliding member is known.

  In the prior art disclosed in Patent Document 1, a diaphragm of a vibration wave motor is fixed to a support member via a spacer, and a vibrator unit composed of these members is fixed to a slide part.

JP 2012-213271 A

  In the configuration of Patent Document 1, when the vibrator unit is fixed to the slide part, the fixing part provided with the hole for receiving the screw is fastened to the slide part with a screw or the like. The fixing portion of the support member protrudes from the outer shape of the diaphragm and is exposed and attached to the slide component. Therefore, the problem that a vibration wave motor will enlarge arises.

  Accordingly, an object of the present invention is to solve the above-described problems, and is to realize downsizing of a vibration wave motor without reducing output and driving efficiency.

  The vibration wave motor of the present invention includes a vibrator that vibrates by an applied high-frequency voltage, a vibrator fixing member to which the vibrator is fixed, a pressurizing unit that pressurizes a sliding portion formed on the vibrator, The sliding member whose sliding portion is pressed by the pressure means, the vibrator supporting member that holds the vibrator and is driven relative to the sliding member, and the vibrator fixing member and the vibrator supporting member are connected to each other. The vibrator supporting member and the coupling member are fastened at least in a part of the projection area in which the vibrator fixing member is projected on a plane whose normal is the pressurizing direction of the pressurizing unit. It is characterized by being.

  According to the present invention, it is possible to reduce the size of the vibration wave motor without reducing the output and the driving efficiency.

FIG. 1A is a cross-sectional view of a main part of an ultrasonic motor according to an embodiment of the present invention, and FIG. 1A is perpendicular to the relative driving direction of a vibrator and a sliding member and is parallel to a pressing direction by a pressing member. FIG. 1B is a cross-sectional view of the ultrasonic motor cut by a plane, and FIG. 1B shows the ultrasonic motor cut by a plane parallel to the relative driving direction of the vibrator and the sliding member and the pressing direction by the pressing member. FIG. The principal part perspective view of the vibrator | oscillator of the ultrasonic motor in the Example of this invention is shown. The principal part disassembled perspective view of the components which comprise the ultrasonic motor by the Example of this invention is shown. The figure which looked at the fastening part of the connection member of an ultrasonic motor and vibrator support member in the example of the present invention from the pressurization direction is shown. The principal part sectional drawing showing the state in which the ultrasonic motor of this invention was integrated in the lens barrel of a direct acting drive is shown. The principal part sectional view showing the state where the ultrasonic motor of the present invention was built in the lens barrel of rotation type drive is shown.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of each embodiment, in order to facilitate understanding in relation to the drawings, the relative movement direction of the vibrator and the sliding member is defined as “X axis” and will be described. Further, the direction in which the vibrator is pressed against the sliding member by the pressure spring is defined as “Z axis”, and the direction perpendicular to the X axis and the Z axis is defined as “Y axis”.

  FIG. 1 is a sectional view of an essential part of an ultrasonic motor as a vibration wave motor representing an embodiment of the present invention. FIG. 1A is a cross-sectional view when the ultrasonic motor is cut along a plane perpendicular to the relative driving direction of the vibrator and the sliding member of the ultrasonic motor and parallel to the pressing direction of the pressing member. YZ cross section). FIG. 1B is a cross-sectional view (XZ cross section) when the ultrasonic motor is cut along a plane parallel to the relative driving direction of the vibrator and the sliding member and the pressing direction of the pressing member. In addition, although the present embodiment will be described by taking an example of a direct drive type and a rotary drive type ultrasonic motor, application to other types is also possible.

  FIG. 2 is a perspective view of a main part of the vibrator of the ultrasonic motor in the embodiment of the present invention.

  Reference numeral 101 denotes a diaphragm, and the bonded portion 101a is fixed to the bonding convex portion 102a of the base 102 by bonding or the like.

  A piezoelectric element 103 is fixed to the vibration plate 101 with a known adhesive or the like. The piezoelectric element 103 is set so that when a high frequency voltage is applied, the vibration plate 101 generates vibrations such as ultrasonic vibrations and resonates in the longitudinal direction and the lateral direction, respectively. The vibration plate 101 and the piezoelectric element 103 constitute the vibrator 100.

  As the diaphragm 101 of the vibrator 100 resonates in the longitudinal direction and the lateral direction, as shown in FIG. 2, the tip of the sliding portion 101b formed on the diaphragm 101 has an elliptical motion as shown in the figure. R is generated. By changing the frequency and phase of the high-frequency voltage applied to the piezoelectric element 103, the rotational direction and ellipticity ratio of the elliptical motion R can be appropriately changed to cause the vibrator 100 to generate a desired motion. Therefore, when the slider 104, which is a sliding member as the counterpart component, and the sliding portion 101b of the diaphragm 101 are in frictional contact, a driving force is generated in the vibrator 100, and the vibrator 100 is moved along the X-axis direction. It can be driven relative to the slider 104. The slider 104 is fixed to a unit support member 116 described later by a screw 117 shown in FIG. Reference numeral 105 denotes a vibrator support member, which is connected to a base 102 as a vibrator fixing member on which the vibrator 100 is fixed by a connecting member 301 as described later.

  A pressure plate 106 is configured to press and hold the piezoelectric element 103 described above along the pressure direction (Z-axis direction) shown in FIG. 1 with an elastic member 107 interposed therebetween as will be described later.

  Reference numeral 108 denotes a pressure spring. The pressure spring 108 is incorporated between the spring holding member 109 and the spring ground plate 110, and a pressure spring unit 118 serving as pressure means is constituted by these members. Since the tip diameter large portion 109a above the Z-axis of the spring holding member 109 is assembled into the fitting portion 110a of the spring base plate 110 by light press-fitting, the unit state can be maintained against the spring force of the pressure spring 108 after assembly. . Bayonet protrusions 110b are formed on the outer diameter portion of the spring base plate 110 at several places in the circumferential direction. In the assembled state, the bayonet protrusion is demarcated by the bayonet engaging portion 105 a formed on the vibrator support member 105 in the pressure direction. At this time, the tip pressing portion 109b below the Z-axis of the spring holding member 109 applies a pressing force for biasing the vibrator 100 to the slider 104 via the pressing plate 106 and the elastic member 107 by the biasing force of the pressing spring 108. Occur. Accordingly, the vibrator 100 and the slider 104 can be brought into pressure contact and brought into frictional contact.

  A moving plate 111 is fixed to the contact portion 105 b of the vibrator support member 105 with a screw 113. The vibrator support member 105 has a screw hole 105c through which the screw 113 passes. The moving plate 111 receives the ball 112, and has a plurality of V-groove portions 111a extending in the relative movement direction (X-axis direction) between the vibrator and the friction member and having a V-shaped cross section. A guide portion is configured to guide the member 105 in the relative movement direction of the vibrator and the friction member (FIG. 1).

  Reference numeral 115 denotes a cover plate, which is fixed to the unit support member 116 with a known screw or the like. The cover plate 115 also constitutes a part of the guide portion described above, and the relative movement direction (X-axis direction) between the vibrator and the friction member provided at a position facing the V groove portion 111a of the moving plate 111 described above. And a V-groove 115a having a V-shaped cross section. The above-described ball 112 is sandwiched between the V-groove 111a and the V-groove 115a. Therefore, the vibrator support member 105 including the vibrator 100 is driven and moved relative to the slider 104 along the relative movement direction of the vibrator and the friction member.

  Next, the connection between the base 102 and the vibrator support member 105 of the present invention will be described with reference to FIGS.

  FIG. 3 is an exploded perspective view of the main part of the parts constituting the ultrasonic motor according to the embodiment of the present invention.

  FIG. 4 is a view of the fastening portion between the connecting member and the vibrator support member in the ultrasonic motor according to the embodiment of the present invention as seen from the pressing direction (Z-axis direction).

  Reference numeral 301 denotes a connecting member, which is made of, for example, a stainless steel plate having spring properties. The connection member 301 is formed with a screw hole portion 301 a for fastening with the vibrator support member 105. The moving plate 111 fixed to the vibrator support member 105 is formed with a female screw portion 111 b, and the connecting member 301 and the vibrator support member 105 are fastened by a set screw 113. The screw hole portion 301a, the female screw portion 111b, and the screw hole 105c formed in the vibrator support member 105 constitute a fastening portion 303 (FIG. 1B). As shown in FIGS. 3 and 4, the fastening portion 303 is formed at two locations in the longitudinal direction (X-axis direction) of the vibrator 100, so that the vibrator support member 105 and the connecting member 301 can be more securely fastened. To. Further, the connecting member 301 has screw holes 301 c formed at four bent portions 301 b and is fastened by screws 302 to the screw hole portions 102 b formed on the base 102.

  As described above, the coupling member 301 having the frame structure and the vibrator support member 105 are fastened at the two screw hole portions 301a in the X-axis direction. As shown in FIG. 4, the outer shape portion 301 d around the screw hole portion 301 a is in a projection region viewed from the Z-axis direction of the base 102, that is, on a plane having a normal to the pressurizing direction of the pressurizing means. It is almost in the projection area where is projected. When viewed from the Z-axis direction in FIG. 4, the outer portion 301 d is present in the outer region of the bonded portion 101 a formed on the diaphragm 101 described above. That is, the overall length of the vibrator 100 in the X-axis direction is substantially the same as the overall length of the base 102, the connecting member 301, and the vibrator support member 105. By adopting this configuration, the length of the relative movement direction (X-axis direction) between the vibrator and the friction member of the fastening portion 303 described above can be shortened, and downsizing of the ultrasonic motor as the vibration wave motor can be realized. .

  The base 102 and the vibrator 100 described above need to be assembled first. After this assembly is completed, the connection between the vibrator 100 and the vibrator support member 105 is completed by fastening the connection member 301 and the base 102 with the screw 302.

  At this time, as described above, the connecting member 301 has a frame structure and is made of a stainless steel thin plate or the like, so that it has flexibility in the pressurizing direction (Z-axis direction). As a result, even when there is an error in the height of the vibrator in the Z-axis direction due to component tolerance or the like when the vibrator 100 is pressed by the pressurizing unit 118 serving as a pressurizing means, the error is reduced. It is possible to generate a necessary pressing force against the slider 104 by absorbing the same. The ultrasonic motor which is the vibration wave motor of the present invention is completed by the configuration described above.

  FIG. 5 is a cross-sectional view of a principal part showing a state when the ultrasonic motor of the present invention is incorporated in a lens barrel of an optical device as a linear drive type. In this figure, the same reference numerals are given to components that are the same as those in the above embodiment. Reference numeral 501 denotes a first lens holding member that holds the first lens 502, and reference numeral 503 denotes a third lens holding member that holds the third lens 504. The outer peripheral portion of the third lens holding member 503 has a cylindrical portion 503a, and is fastened to the first lens holding member 501 with a screw or the like (not shown) at the distal end portion 503b. A unit receiving portion 503c to which the above-described ultrasonic motor is fixed is provided at a part of the outer diameter portion of the cylindrical portion 503a, and is detachably fixed by a known screw or the like. A second lens holding member 505 that holds the second lens 506 is disposed on the inner diameter portion of the cylindrical portion 503a. The second lens 506 is moved along the optical axis C by an ultrasonic motor that is a vibration wave motor of the present invention as a focusing lens. At this time, since the second lens holding member 505 is slidably received by the known guide bar 507 and the bearing portion 505a, the second lens can be moved along the optical axis C. Yes. The connection between the second lens holding member 505 and the above-described vibrator support member 105 includes, for example, an engagement pin 105 d provided on the vibrator support member 105 and an engaged portion 505 b provided on the second lens holding member 505. The engagement may be performed by a known rack or an engagement pin.

  FIG. 6 is a cross-sectional view of an essential part showing a state when the ultrasonic motor according to the embodiment of the present invention is incorporated in a lens barrel of an optical apparatus as a rotational drive type. The components constituting the ultrasonic motor are almost the same as those of the above-mentioned direct acting type, but the slider 104 described above is configured in a straight line in which the direction of the optical axis C is the longitudinal direction. The sixth slider 601 is formed in a ring shape that can rotate around the optical axis C. Reference numeral 602 denotes an ultrasonic motor unit, which is composed of the components of the ultrasonic motor described in the above-described embodiments. However, the cover plate 115 and the unit support member 116 described above are not formed in a circular shape in accordance with the rotational drive. It is. A known cam ring 603 is fixed to the slider 601. Reference numeral 604 denotes a rectilinear guide cylinder, which is disposed on the inner peripheral portion of the cam ring 603 so as to be relatively rotatable. The straight guide tube 604 is fixed to a mount 605 that is attached to and detached from the camera body by a known bayonet. A cam follower fixed to each photographing lens group described later is slidably inserted in a cam groove (not shown) formed in the cam ring 603 and a straight guide groove (not shown) formed in the straight guide tube 604. Reference numeral 606 denotes an exterior cylinder, which constitutes an external part disposed on the outer peripheral portion of the cam ring 603 described above. Reference numeral 607 denotes a first photographing lens group, which is held by the first lens group barrel 608, and a cam pin 609 is fixed to the rear end in the optical axis direction. Reference numeral 610 denotes a second photographic lens group, which is held by the second lens group barrel 611 and has a cam pin 612 fixed to the rear end in the optical axis direction. Reference numeral 613 denotes a third photographing lens group, which is held by the third lens group barrel 614 and has a cam pin 615 fixed to the rear end in the optical axis direction.

  With the configuration described above, a photographing lens barrel using a rotary ultrasonic motor is completed. In this state, when the slider 601 is rotated around the optical axis C by the driving force generated by the ultrasonic motor, the integrally fixed cam ring 603 is also rotated around the optical axis C. Along with this movement, the first, second, and third photographic lens groups are driven forward and backward to the positions defined by the optical design by the cam grooves and the linear guide grooves, respectively. The photographing magnification of the photographing lens can be changed.

  In the above-described embodiments, the zooming operation of the taking lens has been described. Similarly, the focusing operation of the focusing lens can be performed.

  Specific examples of the ultrasonic motor, which is the vibration wave motor according to the present invention, and the lens barrel of the optical apparatus incorporating the ultrasonic motor have been described in detail, but the present invention is not limited to the above-described embodiments, and is claimed. Any form can be adopted as long as it is shown in the range described in the section.

  The drive control of the optical device can be performed with high accuracy while achieving the miniaturization of the optical device.

100 vibrator 101 diaphragm 102 base 103 piezoelectric element 104 slider 105 vibrator support member 106 pressure plate 107 elastic member 108 pressure spring 109 spring holding member 110 spring ground plate 111 moving plate 112 ball 113 screw 115 cover plate 116 unit support member 301 Connecting member 302 Screw 303 Fastening portion 501 First lens holding member 502 First lens 503 Third lens holding member 504 Third lens 505 Second lens holding member 506 Second lens 507 Guide bar 601 Slider 602 Ultrasonic motor Unit 603 Cam ring 604 Straight guide tube 605 Mount 606 Exterior tube 607 First shooting lens group 608 First lens group barrel 609, 612, 615 Cam pin 610 Second shooting lens group 611 Second lens group barrel 613 Third shooting Lens group 614 third lens unit barrel C light axis

Claims (8)

A vibrator that vibrates by an applied high-frequency voltage;
A vibrator fixing member to which the vibrator is fixed;
A pressurizing means for pressurizing the sliding portion formed on the vibrator;
A sliding member to which the sliding portion is pressed by the pressurizing means;
A vibrator support member that holds the vibrator and is driven relative to the sliding member;
A connecting member that connects the vibrator fixing member and the vibrator support member;
In a vibration wave motor having
The vibrator support member and the connecting member are fastened at least in a projection area in which the vibrator fixing member is projected onto a plane whose normal is the pressurizing direction of the pressurizing unit. Vibration wave motor.   2. The vibration wave motor according to claim 1, wherein the vibrator support member and the connecting member are fastened at two locations along a direction in which the vibrator support member is driven relative to the sliding member. A vibration wave motor characterized by   3. The vibration wave motor according to claim 1, wherein the connecting member has a frame structure.   4. The vibration wave motor according to claim 1, wherein the pressurizing unit is attached to the vibrator support member. 5.   5. The vibration wave motor according to claim 1, wherein the vibrator fixing member and the vibrator supporting member are arranged in a direction in which the vibrator supporting member is driven relative to the sliding member. A vibration wave motor characterized by having substantially the same overall length.   6. The vibration wave motor according to claim 1, wherein the vibration wave motor is an ultrasonic motor in which the vibrator generates ultrasonic vibration. The vibration wave motor according to any one of claims 1 to 6,
A lens holding member that is engaged with the vibrator support member of the vibration wave motor and holds a lens;
A guide bar extending in the direction of the optical axis of the lens and slidably received by the lens holding member;
The lens holding member moves along the guide bar when the vibration wave motor linearly drives in the direction of the optical axis. The vibration wave motor according to any one of claims 1 to 6,
A cam ring fixed to the sliding member of the vibration wave motor;
A lens barrel that is attached to the inner periphery of the cam ring via a cam pin and holds the lens;
And the vibration wave motor rotates around the optical axis of the lens to move the lens barrel in the direction of the optical axis.

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