JP7169851B2 - Vibration wave motor and lens device using vibration wave motor - Google Patents

Description

The present invention relates to a vibration wave motor for relatively moving a vibrator and a friction member, and a lens apparatus using the vibration wave motor.

As disclosed in Patent Document 1, for example, a conventional vibration wave motor unit has a rolling member sandwiched between a guide wall of a fixed guide member and a rectilinear guide groove of a movable member to move a moving portion. It has a straight guide configuration.

Japanese Patent Application Laid-Open No. 2017-200400

However, in the vibration wave motor unit of Patent Document 1, when the amount of movement of the movable member increases, it becomes necessary to lengthen the guide wall of the guide member in the driving direction, resulting in an increase in the size of the vibration wave motor unit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vibration wave motor that does not increase in size even when the amount of movement is increased.

The vibration wave motor of the present invention comprises: an oscillator comprising a piezoelectric element and a diaphragm; a friction member which is in pressure contact with the oscillator by pressure of a pressure means and moves relative to the oscillator; guide means disposed on the opposite side of the contact surface that press-contacts and guides the relative movement; a held portion held by a member, the guide groove portion being arranged at a position overlapping with the friction member when viewed in the direction of pressure applied by the pressure means; and near the relatively moving ends of the friction member, they are arranged on both sides of the guide groove when viewed from the pressing direction.

It is possible to provide a vibration wave motor that does not increase in size even when the amount of movement is increased.

1 is an exploded view of a vibration wave motor 100 of the present invention; FIG. 2 is a bottom view showing the vibration wave motor 100 of the present invention; FIG. FIG. 3 is a cross-sectional view of the vibration wave motor 100 of the present invention taken along the cross-sectional line IIIA-IIIA of FIG. 2; FIG. 3 is a cross-sectional view of the vibration wave motor 100 of the present invention taken along the cross-sectional line IIIB-IIIB of FIG. 2; FIG. 3 is a cross-sectional view of the vibration wave motor 100 of the present invention taken along the cross-sectional line IIIC-IIIC of FIG. 2; FIG. 3 is a sectional view of the vibration wave motor 100 of the present invention taken along the section line IIID-IIID of FIG. 2; It is a figure which shows the imaging device to which the vibration wave motor 100 of this invention is applied.

(Example)
An example, which is a preferred embodiment of the present invention, will be described below with reference to FIGS. 1 and 2. FIG. In the drawings, the direction of relative movement between the oscillator 104 and the friction member 101, which will be described later, is the X direction. The orthogonal direction is defined as the Y direction.

FIG. 1 shows a developed view of a vibration wave motor 100 (ultrasonic motor) according to an embodiment of the present invention. A vibration wave motor 100 in this embodiment is mainly composed of a vibrator 104, a friction member 101, guide means, fixing means, pressure means, and the like.

The vibrator 104 is composed of a vibrating plate 102 and a piezoelectric element 103, which are vibrating bodies having elasticity. The piezoelectric element 103 is fixed to the diaphragm 102 with a known adhesive or the like. A flexible substrate 105 is crimped to the piezoelectric element 103 at a bonding portion 105a. By applying a high-frequency voltage to the piezoelectric element 103 via the flexible substrate 105, the vibrator 104 vibrates at a frequency in the ultrasonic range ( ultrasonic vibration).

The vibrator 104 is held by a first holding member 106 which is a vibrator holding member. The vibrator 104 is fixed to the first holding member 106 with a known adhesive or the like, but the method is not limited as long as it is fixed. The first holding member 106 is connected to the second holding member 107 via rolling elements (a first roller 108 a and a second roller 108 b ) and leaf springs 109 , which will be described later.

The vibrator 104 presses into contact with the friction member 101 and moves relative to the friction member 101 by ultrasonic vibration. This relative movement is realized by guiding the vibrator 104 in the X direction by guide means composed of a fixed guide member 115, a movable guide member 117, and the like. The guide means is arranged on the opposite side of the contact surface 101a where the vibrator 104 makes pressure contact with the friction member 101 . The second holding member 107 and the movable guide member 117 are fixed with screws (not shown) or the like, but the method is not limited as long as they are fixed. A plurality of rolling members 116 in the form of rolling balls are provided between the fixed guide member 115 and the movable guide member 117 .

Vibrator 104 moves relative to friction member 101 , and friction member 101 is fixed to first base member 114 with screws 118 . Furthermore, a fixed guide member 115 is also fixed to the first base member 114 by screws 119 . The first base member 114, screws 118, and screws 119 constitute fixing means for holding the friction member 101 and the guide means. Note that the description of the fixing member in the claims corresponds to the first base member 114 .

A spring 110 provides a pressure force for pressing the oscillator 104 into contact with the friction member 101 . The springs 110 connect the biasing member 111 and the movable guide member 117 at four points, and pressurize the vibrator 104 against the friction member 101 by the pressing force of the plurality of springs 110 . The biasing member 111 has a projection 111a in the -Z direction, and the projection 111a abuts against the base plate 112 to transmit the pressure. A cushioning member 113 attached to the base plate 112 is arranged on the opposite side of the surface of the base plate 112 that contacts the biasing member 111 . The base plate 112 and the buffer member 113 are arranged between the piezoelectric element 103 and the biasing member 111 to prevent direct contact between the biasing member 111 and the piezoelectric element 103 and prevent damage to the piezoelectric element 103 . The spring 110 , the biasing member 111 , the base plate 112 , the cushioning member 113 , and the like constitute the pressurizing means, and the description of the pressurizing means in the claims corresponds to the spring 110 .

In the vibration wave motor 100 of the present invention, the vibrator 104, the first holding member 106, the second holding member 107, the spring 110, the biasing member 111, the base plate 112, the buffer member 113, and the movable guide member 117 are A moving unit 121 is configured (see FIG. 3A). The moving part 121 can move in the X direction relative to the friction member 101 . A configuration in which the moving portion 121 is fixed and the friction member 101 moves is also possible.

Next, the configuration of the vibration wave motor 100 of the present invention will be described with reference to FIGS. 2 and 3(A) to (D). FIG. 2 is a bottom view of the vibration wave motor 100 viewed from the -Z direction. 3A is a cross-sectional view taken along the cross-sectional line IIIA-IIIA in FIG. 2, FIG. 3B is a cross-sectional view taken along the cross-sectional line IIIB-IIIB, FIG. 3C is a cross-sectional view taken along the cross-sectional line IIIC-IIIC, FIG. (D) is a cross-sectional view along the cross-sectional line IIID-IIID.

First, the configuration of the vibration wave motor 100 will be described with reference to FIG. The movable guide member 117 is provided with four spring hooks 117b for engaging the springs 110, and the springs 110 are hooked on the spring hooks 117b. The movable guide member 117 is provided with a movable guide groove portion 117a that guides the rolling member 116 in the X direction. Similarly, the fixed guide member 115 is provided with a fixed guide groove portion 115a that guides the rolling member 116 in the X direction. The rolling member 116 rolls while being sandwiched between the fixed guide groove portion 115a and the movable guide groove portion 117a by the pressing force of the spring 110, so that the movable guide member 117 maintains a low load on the fixed guide member 115. It can move straight in the X direction.

A first base member 114 holds the fixed guide member 115 and the friction member 101 . The fixed guide member 115 has four held portions 115b, and is fixed to the first base member 114 at the held portions 115b. A friction member 101 is arranged in the +Z direction of the fixed guide member 115 . The fixed guide groove portion 115a of the fixed guide member 115 is arranged at a position overlapping the friction member 101 when viewed from the -Z direction.

The held portions 115b provided near the X-direction end of the fixed guide groove portion 115a are arranged on both sides of the fixed guide groove portion 115a in the Y direction. By arranging the fixed guide groove portion 115a at such a position, even when the length of the fixed guide groove portion 115a is extended in order to increase the amount of relative movement between the vibrator 104 and the friction member 101, the fixed guide groove portion 115a and the object to be held can be maintained. Part 115b does not interfere. Therefore, even if the amount of relative movement between the vibrator 104 and the friction member 101 is increased, it is not necessary to avoid the fixed guide groove portion 115a in the Z direction or the Y direction. With this configuration, it is possible to provide the vibration wave motor 100 that does not increase in size even when the amount of relative movement between the vibrator 104 and the friction member 101 is increased.

The flexible substrate 105 has an extending portion 105b extending in the -X direction and a bending portion 105c bending the extending flexible substrate 105 in the +X direction. In the second holding member 107, the bending reaction force from the flexible substrate 105 generated in the Z direction by the bending portion 105c is received by the flexible substrate contact portion 107a (U-turn flexible substrate receiving portion).

In order to increase the amount of relative movement between the vibrator 104 and the friction member 101, it is necessary to increase the length of the extension portion 105b of the flexible substrate 105. FIG. Along with this, the length of the flexible substrate contact portion 107a for receiving the reaction force of the bent portion 105c of the flexible substrate 105 also increases. When the moving part 121 is positioned near the -X direction end of the movable range, the flexible substrate contact part 107a protrudes most in the -X direction. In the conventional configuration, if the first base member 114 is formed in a shape expanded in the -X direction so as to avoid the flexible substrate contact portion 107a at this position, the held portion 115b becomes large in the X direction. put away.

In the vibration wave motor 100 of the present invention, the held portion 115b of the fixed guide member 115 is arranged closer to the friction member 101 than the flexible substrate contact portion 107a when viewed from the pressure direction. Even if the amount of relative movement between the vibrator 104 and the friction member 101 is increased, the flexible substrate contact portion 107a extending in the driving direction and the held portion 115b do not interfere with each other. With this configuration, it is not necessary to form the held portion 115b on the outside in the X direction, and it is possible to provide the vibration wave motor 100 that does not increase in size even when the amount of movement is increased.

Next, the configuration of the vibration wave motor 100 will be described with reference to FIG. 3(A). The spring 110 generates a pressure force to press the oscillator 104 into contact with the friction member 101 . The biasing member 111 has a spring hook portion 111b, and the movable guide member 117 also has a spring hook portion 117b. The pressurizing force of the spring 110 becomes an urging force that presses the vibrator 104 against the friction member 101 in the Z direction via the base plate 112 and the buffer member 113 . Then, the contact portion 102a of the diaphragm 102 comes into contact with the friction member 101 in a pressurized state, and is in a pressurized contact state.

In this pressurized contact state, when a two-phase drive voltage is applied to the piezoelectric element 103, two-phase ultrasonic vibration is excited in the diaphragm 102, causing an elliptical motion in the contact portion 102a. It is efficiently transmitted to the friction member 101 . As a result, the moving part 121 can move in the X direction relative to the friction member 101 and the first base member 114 on the fixed side.

The fixed guide member 115 is arranged on the opposite side of the vibrator 104 with the friction member 101 interposed therebetween, and guides the relative movement of the vibrator 104 and the friction member 101 in the X direction. A guide member fixing portion 114a (first fixing portion) is provided on the first base member 114, and a fixed guide member 115 is fixed by a screw 119 (see FIG. 3D). A friction member fixing portion 114 c is provided on the first base member 114 , and the friction member 101 is fixed with screws 118 .

Next, connecting means for connecting the first holding member 106 and the second holding member 107 will be described. The rolling elements are composed of a first roller 108a and a second roller 108b. The first roller 108a and the second roller 108b are arranged between the first holding member 106 and the second holding member 107. there is Furthermore, a plate spring 109 having a predetermined biasing force in the X direction, which is the relative movement direction of the vibrator 104, is arranged between the second holding member 107 and the second roller 108b. The first roller 108a and the second roller 108b are movable in the pressing direction (Z direction) of the spring 110. As shown in FIG. Due to the biasing force of the plate spring 109, the first holding member 106 is biased in the -X direction via the second roller 108b, and the second holding member 107 is biased in the +X direction. With this configuration, the first roller 108a is urged between the first holding member 106 and the second holding member 107 and held without falling.

With the configuration as described above, there is no backlash in the X direction, which is the moving direction of the moving part 121, and the rolling elements can move freely in the pressing direction of the spring 110. It becomes possible to connect without disturbing. In the present invention, the leaf spring 109 is used as the elastic member constituting the connecting means between the first holding member 106 and the second holding member 107. I don't mind.

The biasing force of the plate spring 109 is set to be greater than the inertial force due to acceleration/deceleration that occurs when the vibrator 104 starts and stops driving. With this configuration, the vibrator 104 and the second holding member 107 do not undergo relative displacement in the movement direction due to inertial force during driving, and stable drive control can be achieved.

Next, the configuration of the vibration wave motor 100 will be described with reference to FIG. 3(B). The flexible substrate 105 is joined to the piezoelectric element 103 (not shown) at the joining portion 105a. The extending portion 105b extends along the −X direction from the joint portion 105a. The bent portion 105c is formed when the extending portion 105b is folded back from the -X direction to the +X direction and inverted. The flexible substrate 105 is fixed by the flexible fixing portion 114d of the first base member 114 at the fixing portion 105d. When the moving portion 121 moves in the X direction, the position of the bending portion 105c moves, thereby absorbing the distance variation between the flexible fixing portion 114d and the guide member fixing portion 114a. With this configuration, even if the moving portion 121 moves in the X direction, the load applied to the flexible fixing portion 114d and the guide member fixing portion 114a is reduced.

Since the flexible substrate 105 is folded back at the bent portion 105c, a folding reaction force is generated in the Z direction. The second holding member 107 is provided with a flexible substrate abutting portion 107a for receiving this folding reaction force. By abutting the flexible substrate 105 on the flexible substrate abutting portion 107a, it is possible to maintain the shape of being folded back from the −X direction to the +X direction at the bending portion 105c. The flexible substrate abutting portion 107a is a portion of the moving portion 121 that protrudes most in the -X direction.

Next, the configuration of the vibration wave motor 100 will be described with reference to FIG. 3(C). In the Z direction, a fixed guide groove portion 115a is formed at a position where the fixed guide member 115 and the friction member 101 overlap, and a movable guide groove portion 117a is formed at a position where the movable guide member 117 and the friction member 101 overlap. A rolling member 116 is sandwiched between the fixed guide groove portion 115a and the movable guide groove portion 117a by the pressing force of the spring 110. As shown in FIG. With this configuration, the movable guide member 117 is guided straight in the X direction with respect to the fixed guide member 115 .

A spherical protrusion 107b is formed on the second holding member 107 . The driven member (the focus lens 3 described later) is connected to the spherical protrusion 107b via the connecting member 122. At this time, the connecting member 122 imparts an urging force in the +Z direction to the spherical protrusion. 107b. This configuration allows the second holding member 107 and the driven member to move integrally in the X direction.

Next, the configuration of the vibration wave motor 100 will be described with reference to FIGS. 2 and 3D. The first base member 114 is fixed to the second base member 123 by four screws 120 at base member fixing portions 114b (second fixing portions). In the vicinity of the end of relative movement between the vibrator 104 and the friction member 101, the flexible substrate contact portion 107a of the second holding member 107 is connected to the guide member fixing portion 114a of the first base member 114 and the base member fixing portion. 114b. This configuration eliminates the need to increase the size of the first base member 114 in the X direction in order to avoid interference with the flexible substrate contact portion 107a of the second holding member 107, thereby providing the vibration wave motor 100 that does not increase in size. be able to.

As described above, in the vibration wave motor 100 of the present invention, the fixed guide groove portion 115a is provided at a position overlapping the friction member 101 when viewed from the pressure direction. The held portions 115b provided near the ends in the X direction of the fixed guide groove portion 115a are arranged on both sides of the fixed guide groove portion 115a in the Y direction. With this configuration, interference between the fixed guide groove portion 115a and the base member fixing portion 114b can be avoided, and the vibration wave motor 100 can be miniaturized even when the amount of relative movement between the vibrator 104 and the friction member 101 is increased.

Further, when viewed from the pressure direction, the guide member fixing portion 114a for fixing the fixed guide member 115 is arranged at a position closer to the friction member 101 than the flexible substrate contact portion 107a. As a result, interference between the flexible substrate abutting portion 107a and the guide member fixing portion 114a can be avoided, and the vibration wave motor 100 can be miniaturized even when the amount of relative movement between the vibrator 104 and the friction member 101 is increased.

Furthermore, in the vicinity of the end of the relative movement range between the vibrator 104 and the friction member 101, the flexible substrate contact portion 107a of the second holding member 107 is connected to the guide member fixing portion 114a of the first base member 114 and the base member fixing portion. 114b. With this configuration, interference with the flexible substrate contact portion 107a of the second holding member 107 can be avoided, and the size of the vibration wave motor 100 can be reduced even when the amount of relative movement between the vibrator 104 and the friction member 101 is increased.

(Application example)
FIG. 4 shows the configuration of an imaging device to which the vibration wave motor 100 of the present invention is applied. In addition, in this description, the case where the vibration wave motor 100 is mounted in the imaging apparatus will be described, but this does not limit the present invention. Also, an imaging apparatus in which the imaging lens 1 and the camera body 2 are integrated will be described, but the imaging lens 1 may be an interchangeable lens.

As shown in FIG. 4, the main body of the imaging device is composed of an imaging lens 1 and a camera body 2 . Inside the imaging lens 1, the vibration wave motor 100 is fixed to a lens barrel (corresponding to the second base member 123). Further, the focus lens 3 is connected to the vibration wave motor 100 , and the focus lens 3 can be moved in a direction substantially parallel to the optical axis 5 by moving the vibrator 104 constituting the vibration wave motor 100 . During imaging, the focus lens 3 moves in a direction substantially parallel to the optical axis 5, and the subject image is formed at the position of the imaging element 4, making it possible to generate a focused image.

3 Focus lens (lens)
100 Vibration wave motor 101 Friction member 101a Contact surface 102 Diaphragm 103 Piezoelectric element 104 Vibrator 105 Flexible substrate 105a Joint portion 105b Extension portion 105c Bending portion 107 Second holding member (holding member)
107a Flexible substrate contact portion 110 Spring (pressure means)
114 first base member (fixing member)
114a guide member fixing portion (first fixing portion)
114b base member fixing portion (second fixing portion)
115 fixed guide member (guide means)
115a fixed guide groove (guide groove)
115b held portion 116 rolling member (guide means)
117 movable guide member (guide means)
123 second base member (lens barrel)

Claims (8)

a vibrator comprising a piezoelectric element and a diaphragm;
a friction member that is in pressure contact with the vibrator and moves relative to the vibrator due to the pressure of the pressure means;
a guide means disposed on the opposite side of the contact surface that makes pressure contact and guides the relative movement;
a fixing member that holds the friction member and the guide means,
The guide means has a guide groove portion and a held portion held by the fixed member,
The guide groove portion is arranged at a position overlapping the friction member when viewed from the direction of pressure applied by the pressure means,
The vibration wave motor, wherein the held portion is arranged on both sides of the guide groove portion when viewed from the pressure direction in the vicinity of the relative movement end portion of the vibrator and the friction member. . a flexible substrate;
a holding member that holds the vibrator and the flexible substrate,
The flexible substrate has a joint portion that is joined to the piezoelectric element, an extension portion that extends from the joint portion along the direction of the relative movement, and a bending portion that inverts and folds the extension portion,
The holding member has a flexible substrate abutting portion that abuts on the extending portion and the bent portion,
2. The vibration wave motor according to claim 1, wherein the held portion is arranged at a position closer to the friction member than the flexible substrate contact portion when viewed from the pressing direction. The fixing member has a first fixing portion for fixing the guide means, and a second fixing portion for fixing to a second base member holding the fixing member,
3. The vibration wave motor according to claim 2, wherein the second fixing portion is arranged at a position farther from the friction member than the flexible substrate contact portion when viewed from the pressing direction. . 3. The flexible substrate abutting portion enters between the first fixing portion and the second fixing portion when the vibrator is positioned in the vicinity of the relative movement end portion. The vibration wave motor described in . The guide means is composed of a fixed guide member, a movable guide member, and a rolling member, the fixed guide member being fixed to the fixed member, and the rolling member being held in the guide groove. 5. The vibration wave motor according to any one of claims 1 to 4. 6. The vibration wave motor according to claim 5, wherein the vibrator moves integrally with the movable guide member. 7. The vibration wave motor according to claim 1, wherein the vibration wave motor is an ultrasonic motor that vibrates at a frequency in an ultrasonic range. a vibration wave motor according to any one of claims 1 to 7;
a lens driven by the vibration wave motor,
An image pickup apparatus, wherein the second base member that holds the fixed member is a lens barrel.

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