JP3420254B2 - Vibration wave drive device and device provided with vibration wave drive device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention excites vibration in a vibrating body by expanding and contracting a vibration generating element such as a piezoelectric element.
Ri by the vibration generated by the synthesis, the vibration wave driving apparatus and a vibration wave moving the moving member in contact with the vibrating body
The present invention relates to a device including a drive device .

[0002]

2. Description of the Related Art Generally, the basic structure of a pencil type motor is
A vibrating body and the plurality of piezoelectric elements are laminated sandwiched between the metal block as the elastic material block is composed of the moving body and which is pressed by a spring force to the vibrating member by applying an alternating electric field to these piezoelectric elements to excite two standing waves having different phases, a synthesis to generate vibration, such as a jump rope to the vibrating body by, causing the relative movement by frictional contact with the surface of the vibrating body, and the moving body to pressure-contact to I am trying.

In a pencil type motor having such a structure, a vibrating body is usually fixed to a fixed side, and a moving body functions as a so-called rotor. Rotational output of the rotor is provided coaxially and makes frictional contact. , For example, is transmitted to a rotation output member having a gear portion on the outer circumference.

Further, since the vibration of the vibrating body has a certain regularity, it vibrates as a whole and is complicated. Therefore, the vibrating body is fixed to a position where it does not affect the vibration with respect to the fixing member. In many cases, the end of the body is fixed to the fixing member.

FIG. 6 is an enlarged cross-sectional view of a conventional pencil type motor. A is a piezoelectric element 3, 4, 5, 6 for driving and a sensor for a sensor between metal blocks 1 and 2 as elastic blocks. By laminating the piezoelectric element 7 with the electrode plate 8 interposed therebetween and fastening the metal blocks 1 and 2 with fastening bolts 9, a compressive stress is applied to the piezoelectric elements 3, 4, 5 and 6. clamping a fixed vibrator.

Reference numeral 10 denotes a rotor that abuts on the end surface of the metal block 1, 11 is a rotation output member that is provided coaxially with the rotor 10 and has a gear portion 11a on the outer periphery that abuts, and 12 is an insertion fit to the rotation output member 11. Radial bearings, 13
Is a fixed member in which a cylindrical portion 13a fitted to the inner race portion of the radial bearing 12 is formed on a fixed flange portion 13b.

These rotor 10, rotation output member 11,
The radial bearing 12 and the fixing member 13 are the vibrating body A.
Of the fastening bolt 9 extending through the metal block 1 is coaxially arranged around the shaft portion 9a formed at the tip portion of the fastening bolt 9, and the pressure spring 14 is inserted into the inner diameter portion of the cylindrical portion 13a of the fixing member 13. One end of the pressure spring 14 has the cylindrical portion 13a.
Is in contact with the tip spring receiving portion 13c.

The pressure spring 14 applies a pressing force between the rotation output member 11 and the rotor 10 and between the rotor 10 and the metal block 1. The pressure spring 14 contacts the other end of the pressure spring 14 and is fastened. The bolt 9 is elastically mounted between the bolt 9 and the spring stop member 15 fixed to the tip of the shaft 9a to generate a pressing force.

On the other hand, in the fixing member 13, a screw (not shown) is screwed into the screw hole 13d of the fixing flange portion 13b to vibrate.
The body A is fixed. Further, although the spring stop member 15 is prevented from coming off by the washer 16, it is also proposed that the spring stop member 15 is tightened with a nut instead of the washer 16.

However, since the conventional pencil type motor described above has a structure in which the fixing member 13 and the fastening bolt 9 of the vibrating body A are elastically connected via the pressure spring 14, the vibrating body A is fixed to the fixing member 9. Since it is supported by a spring, the vibrator A oscillates in a wavy manner during driving of the motor, which causes a problem that normal driving cannot be performed. This is because the mass of the metal blocks 1 and 2 is the rotor 10 formed of a light metal such as aluminum or the rotation output member 1 formed of plastic.
Since it is much larger than that of No. 1, it occurs remarkably, and as a result, the shaft center of the bolt 9 and the shaft center of the motor are deviated, and the rotor 10 and the metal block 1 contact unevenly, resulting in uneven contact. This will cause unevenness in pressurization and greatly affect the characteristics of the motor.

The occurrence of such a shaft center mismatch between the bolt 9 and the motor occurs not only due to the abnormal vibration of the vibrating body A, but also due to a mechanical cause. This makes the pencil motor smaller, for example, 10 mm in diameter and 1 in length.
When the diameter of the shaft 9a of the bolt 9 is about 1 mm and the diameter of the shaft 9a is about 1 mm, and a screw portion is provided at the tip of the shaft 9a to restrict the position of the spring stop member 15 by the nut, the nut is used as the shaft. It is also generated when the shaft portion 9a is bent or twisted by receiving a turning force when it is screwed onto the shaft 9a.

[0012]

Problems to be solved by the present invention is to challenge it to solve the above-By mounting the fixing member and vibrating body is made through a spring member in the middle, that the abnormal vibration is generated to the vibrating body In addition to the above, there is a non-uniformity in contact between the parts that are in frictional contact with each other and a non-uniformity in pressurization due to the mismatch between the bolt and the shaft center of the motor due to the deformation of the parts that occurs during the assembly of the parts.

[0013]

SUMMARY OF THE INVENTION A vibration wave drive device of the present invention is an electric drive device between a pair of elastic body blocks forming a vibrating elastic body.
Interposed mechanical energy conversion element, and a conclude member to penetrate between the elastic body block, the pair of elastic blocks
A vibrating body in which the electro-mechanical energy conversion element is sandwiched and fastened, a sleeve portion into which an end portion of the fastening member is inserted and fixed to fix the vibrating body , and the sleeve.
A fixing member having a fixing flange portion integrally formed with the moving member, a moving member arranged coaxially with the vibrating body on the outer peripheral side of the fastening member and contacting an elastic body block of the vibrating body, and the fastening member. through the spring receiving portion by being disposed between the moving member possess a pressure spring to pressure contact the moving member relative to the elastic body block, the end portion of the fastening member and the solid
The sleeve portion and wherein Rukoto directly fixed constant member.

[0014]

In the vibration wave driving device of the present invention, since the vibrating body and the fixing member are directly fixed to each other, abnormal vibration does not occur even if a portion of the vibrating body having a large mass is separated from the fixing member. A large tilt of the member is suppressed, and a discrepancy between the shaft center of the motor and the shaft center of the moving member is suppressed, so that the moving member abuts the vibrating body accurately and evenly.

[0015]

[Embodiment 1] FIG. 1 is a sectional view showing Embodiment 1 of a vibration wave motor as a vibration wave driving device according to the present invention. In this embodiment, members having the same structures as those of the conventional example shown in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, a threaded portion 20a is formed at the tip of a fastening bolt 20 for fastening the metal blocks 1 and 2 as elastic blocks, and a width across flat portion 20b is formed under the threaded portion 20a. Further, a stopper step portion 20c is formed below the two-face width portion 20b.

Reference numeral 21 denotes a pressure sleeve which is engaged with the inner race portion of the radial bearing 12 and is inserted between the inner circumference of the rotor 10 and the outer circumference of the fastening bolt 20, and a spring bearing is provided inside the insertion end. The part 21a is formed. The pressure spring 14 is loaded in the pressure sleeve 21 with one end of the pressure spring 14 abutting against the spring receiving portion 21a.

Reference numeral 22 denotes a fixing member, which is a screw hole 2 for attachment.
A sleeve 22c for fixing to a flange portion 22b having 2a
Is integrally formed, and the fixing sleeve 22c is inserted until it comes into contact with the stopper step portion 20c of the fastening bolt 20. In addition, the fixing sleeve 22 of the fixing member 22
The insertion end of c contacts the stopper step portion 20c on the inner peripheral side and contacts the other end of the pressure spring 14 on the outer peripheral side to generate a predetermined spring force on the pressure spring 14, thereby causing the rotor 10 and the metal to rotate. A pressing force is generated between the block 1 and the block 1.

Further, the fixing sleeve 22 of the fixing member 22
The inner surface of c is formed in an outer shape that matches the width across flats 20b of the fastening bolt 20, and the fixing member 22 is formed by the fastening member 22.
It cannot rotate with respect to 0. After fitting the fixing member 22 to the fastening bolt 20, the nut 23 is tightened.
Screwed to the screw portion 20a of the fixing member 22 and the fastening bolt 2
0 is directly fixed, and the rotor 10, the rotation output member 11, the radial bearing 12, the pressure sleeve 21, and the pressure spring 14 are prevented from coming off.

In the vibration wave motor according to this embodiment having the above structure, the fastening bolt 20 is directly fixed to the fixing member 22, so that the metal blocks 1 and 2 having a large mass in the whole motor are also fixed to this fixing member 22. Since it is fixed directly to the motor, it is not elastically fastened with the fastening bolt via the pressure spring as in the past, so it does not vibrate while the motor is driving.
It is possible to prevent abnormal vibration of the body A, and to suppress the abnormal vibration, so that the small diameter portion of the fastening bolt 20 is less likely to fall during driving, and therefore the radial bearing 12 is prevented.
By this, this fall can be absorbed and partial contact between the rotor 10 and the metal block 1 can be prevented.

[Embodiment 2] Second Embodiment FIG. 2 is a sectional view showing a second embodiment of the present invention.

In this embodiment, a resin bearing 24 made of a resin made of a low friction material is used in place of the radial bearing in the embodiment shown in FIG. 1, and a disc spring 25 is provided between the rotor 10 and the rotation output member 11. Is installed.

In the pencil type motor having the above-described structure, even if the small diameter portion of the fastening bolt 20 falls, the spring force of the disc spring 25 presses the rotor 10 against the metal block 1.
It is possible to prevent uneven pressure from being applied to one side of the rotor 10.

Instead of the disc spring 25 of the second embodiment described above, a compression coil spring 26 may be provided coaxially with the axis of the motor as shown in FIG. 3, or a plurality of compression coil springs may be provided as shown in FIG. 27 are arranged at equal pitch on the same circumference,
Alternatively, as shown in FIG. 5, the same effect can be obtained by providing a soft sheet 28 made of a soft material such as rubber or felt.

The pencil type motor of each of the above-described embodiments can be used as a drive source for various devices, for example, as a motor of an autofocus (AF) device of a camera, and a rotation output member. By engaging a gear with 11 and using this gear as an input member of the gear transmission mechanism, the AF is transmitted via the output member of the gear transmission mechanism.
Drive the mechanism.

[0026]

As described above, according to the present invention,
Electro-mechanical between a pair of elastic blocks forming a vibrating elastic body
The energy conversion element is interposed and the fastening member is made of these elastic bodies.
It penetrates between the blocks and between the pair of elastic blocks
Vibration that is clamped by sandwiching the electro-mechanical energy conversion element
The moving body and the end of the fastening member for fixing the vibrating body.
The sleeve part that is inserted and fixed, and the sleeve part
A fixing member having a fixing flange portion formed physically,
The vibrating body is coaxially arranged on the outer peripheral side of the fastening member and
Moving member in contact with elastic block of moving body, and the fastening portion
Is placed between the material and the moving member to form the spring receiving portion.
Pressure contact of the moving member with the elastic block through
An end portion of the fastening member and the fixing portion.
Since the sleeve portion of the wood has to be fixed directly, before
Since the fastening member relative to the serial fixing member is firmly fixed rather than supported via a spring member as in the prior art, resulting in axial center of the movable member is a shaft center and, for example, a rotor of the motor during the motor drive It is possible to minimize the deviation and the collapse of the fastening member, prevent uneven contact between the moving member and the vibrating body, uneven pressure, etc., and suppress abnormal rotation of the motor to ensure normal rotation. Further, since the end portion of the fastening member is fixed to the fixing member having the fixing flange,
The vibrating body itself can be firmly fixed. Since the fixing member can firmly support the vibrating body, it is possible to stabilize the axial position of the vibrating body, and the deviation of the axis of the moving body causes uneven pressure on the contact portion between the vibrating body and the moving member. It can be prevented from occurring.

Further, even if the fastening member falls down, by providing an elastic member such as a compression spring between the rotation output member and the moving member, it is possible to further suppress unevenness in contact with the moving member, unevenness in pressure and the like. Therefore, the efficiency of the motor can be improved. Further, since the pressure spring applies the spring force to the moving member via the bearing member, it does not become a load when the moving member moves.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a vibration wave motor as a vibration wave driving device according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of a vibration wave motor as a vibration wave driving device according to the present invention.

FIG. 3 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 4 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 5 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 6 is a diagram showing a conventional vibration wave motor.

[Explanation of symbols]

1, 2 ... Metal block, 3, 4, 5, 6 ...
Piezoelectric element for driving 7 Piezoelectric element for sensor 8 ...
Electrode plates 9, 20 ... Fastening bolts 10 ...
Rotor 11 ... Rotation output member 12 ...
Radial bearing

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-211075 (JP, A) JP-A-2-228273 (JP, A) JP-A-2-119580 (JP, A) JP-A-4- 210786 (JP, A) JP 2-184274 (JP, A) JP 63-103675 (JP, A) JP 2-269483 (JP, A) JP 2-228275 (JP, A) Jitsukaihei 2-75995 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02N 2/00

Claims (3)

(57) [Claims] 1. A electricity between a pair of the elastic body blocks constituting the vibrating elastic member - interposed mechanical energy conversion element, and a conclude member to penetrate between the elastic body block, the pair of elastic
Sandwiching the electro-mechanical energy conversion element between body blocks
And the vibrating body fastened together , and a sleeve portion for inserting and fixing the end portion of the fastening member to fix the vibrating body , and
A fixing member having a fixing flange portion integrally formed with the sleeve ; a moving member arranged on the outer peripheral side of the fastening member coaxially with the vibrating body and contacting an elastic body block of the vibrating body; through the spring receiving portion by being disposed between the member and the mobile member have a the pressure spring to pressure contact the moving member relative to the elastic body block, of the fastening member
Vibration wave driving apparatus in which the sleeve portion of the end portion and said fixing member and said Rukoto directly fixed. 2. The rotation of the moving member according to claim 1.
The rotation output member for taking out the moving member and the spring receiver
Is placed so as to be coaxial with the vibrating body, and
An oscillatory wave drive device characterized in that an elastic member is provided between the transfer output member and the moving member . 3. The vibration wave driving device according to claim 2 is used as a drive source, and a gear that meshes with the rotation output member is provided.
A device equipped with a vibration wave drive device, which outputs through a transmission mechanism using A as an input member .