JPH11136973A - Vibration type drive equipment and apparatus equipped with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide certain static rigidity and good follow-up performance for vibration displacement by providing an elastic sliding portion for one of vibrating body and contact body and forming the portion other than the sliding surface in an elastic sliding portion to an irregular shape. SOLUTION: Rotation of a moving body 1 is transmitted to a drive target of the equipment through an output gear 5. An elastic sliding member 1a is formed to a stepped ring shape as a whole. Also, the elastic sliding member 1a is made from a plate material of austenite-based stainless steel JIS SUS304 by giving press work to the combination of drawing and burring processes. However, on the outer peripheral surface (portion other than sliding surface 1b) at the elastic sliding member 1a, honeycomb type irregularity having many hexagon-shaped recesses is formed by etching process before press work. By forming this kind of the elastic sliding member 1a, the mass can be reduced while securing a required static rigidity and the dynamic rigidity can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-type driving device in which a contact body is brought into pressure contact with a vibrating body in which vibration is excited, and these are relatively moved (slid).

[0002]

2. Description of the Related Art As a vibration type driving device as described above,
For example, there is one proposed in Japanese Patent Application Laid-Open No. H8-103088. FIG. 6 of the present application shows a sliding portion in the driving device proposed in the above publication.

In this figure, reference numeral 62 denotes a vibrating body,
1 is a moving body (contact body). An elastic sliding member 61 a is attached to the moving body 61, and a lower end surface (sliding surface) of the elastic sliding member 61 a is in pressure contact with a friction material 62 a attached to the vibrating body 62.

Here, the elastic sliding member 61a pressed against the friction material 62a is required to have abrasion resistance unlike other parts. Therefore, in the driving device shown in FIG. It is a separate member of high.

The elastic sliding member 61a also has the property of a spring, that is, has a static softness.
Since the sliding surface of the elastic sliding member 61a flexes to some extent with respect to the vibration displacement generated in 2 (the friction material 62a), the contact state with the friction material 62a is made uniform, thereby preventing noise generation and efficiency reduction. .

[0006]

However, if the elastic sliding member 61a having a spring property causes an arbitrary vibration deformation different from the vibration displacement, the effect of preventing noise generation and the effect of preventing a decrease in efficiency are reduced. The moving member 61a is required to have not only a spring property but also a followability to a vibration displacement.

Here, the above-mentioned arbitrary vibration is caused by the elastic sliding member 6.
This tends to occur when the natural frequency of 1a is low, that is, when the dynamic rigidity is low. Therefore, generally, the elastic sliding member 61
a preferably has a natural frequency that is at least two to three times the frequency of the vibrating body 62.

The above can be easily understood by considering the case where an automobile runs on a bumpy road. If the mass of the wheel and tire hanging under the suspension spring is large, the natural frequency of the vertical movement of the tire is small,
The tire cannot follow the unevenness of the road, and the riding comfort becomes worse. On the other hand, if the static stiffness of the suspension spring is set too high, the tires will spring on roads with small irregularities, resulting in a rough ride. That is,
When the static stiffness of the suspension spring is the same, the smaller the unsprung load, the better the tire follows the road surface.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration type driving device having an elastic sliding member which has a certain degree of static stiffness and has good followability to vibration displacement.

[0010]

In order to achieve the above object, according to the present invention, there is provided a vibration type driving device in which a vibrating body which is excited and a contacting body which comes into contact with the vibrating body relatively slide. An elastic sliding portion is provided on one of the body and the contact body, and a portion of the elastic sliding portion other than the sliding surface is formed in a concavo-convex shape or has a multilayer structure made of a different material.

That is, by forming a portion other than the sliding surface into a honeycomb shape or a corrugated shape, or by forming a multilayer structure in which a low-density layer such as a resin is sandwiched between rigid layers of a metal material or the like. The sliding part has a high static stiffness against bending etc. (that is, a large second moment of area) compared to the mass. Conversely, it has a small mass and high dynamic stiffness while securing a certain static stiffness. To get
The followability of the elastic sliding portion to the vibration displacement is enhanced so that the noise and the efficiency of the vibration type driving device can be reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a rod-shaped vibration type motor (vibration type driving device) according to a first embodiment of the present invention.
In this vibration type motor, an upper vibrating body 2 and a lower vibrating body 8 fastened by bolts 4 and an elastic sliding member 1a sliding on an upper sliding surface 2a of the upper vibrating body 2 are integrally fixed. And a moving body (contact body) 1.
Between the vibrators 2 and 8, a piezoelectric element 3 for driving (for electric-mechanical energy conversion) and for a sensor (for mechanical-electric energy conversion) and an electrode plate 7 are sandwiched. Also,
An insulating sheet 9 that electrically insulates the lower vibrating body 8 and the bolt 4 is interposed between the lower vibrating body 8 and the bolt 4. Further, the elastic sliding member 1a is fixed to the moving body 1 by a method such as adhesive, electric resistance welding, laser welding, electron beam welding, brazing, or the like.

An output gear 5 for transmitting the rotation of the moving body 1 to the outside is engaged with the moving body 1 so as to be integrally rotatable. Further, between the output gear 5 and the moving body 1, the lower sliding surface 1b of the elastic sliding member 1a is connected to the sliding surface 2a of the upper vibrating body 2.
There is provided a coil spring 6 for generating a pressurizing force for bringing the pressure contact into contact with the coil spring 6.

In the motor configured as described above, when two frequency signals having phases different from each other are applied to the driving piezoelectric element 3 via the electrode plate 7, vibration is excited in the vibrating bodies 2 and 8, and the upper vibrating body is excited. The vibration displacement of the sliding surface 2a of the sliding surface 2
The elastic sliding member 1a and the moving body 1 are transmitted by friction between the members a and 1b, and these are rotationally driven. The rotation of the moving body 1 is transmitted via an output gear 5 to an object to be driven by the apparatus (such as a photosensitive drum of a copying machine). The magnitude of the vibration displacement generated on the sliding surface 2a of the upper vibrator 2 is adjusted by the thickness of the constricted portion 2b of the upper vibrator 2. FIG. 2 shows a specific shape of the elastic sliding member 1a. As can be seen from FIG. 2A, the elastic sliding member 1a is formed in a stepped ring shape as a whole. Also, the elastic sliding member 1a
Is austenitic stainless steel JIS SUS304
Is pressed by combining squeezing and burring.

However, on the outer peripheral surface (the portion other than the sliding surface 1b) of the elastic sliding member 1a, honeycomb-shaped irregularities having a large number of hexagonal recesses are formed by etching before pressing. I have.

By forming the elastic sliding member 1a in this manner, it is possible to reduce the mass and increase the dynamic rigidity while securing the required static rigidity. The elastic sliding member 1a
The thickness of the small-diameter portion near the sliding surface 1b may be reduced by ironing to further increase the dynamic rigidity.

Moreover, by leaving the sliding surface of the elastic sliding member 1a as a flat surface portion similar to the conventional one, the sliding surface 2a of the upper vibrating body 2 is excessively worn or damaged due to unevenness of the sliding surface. Can be prevented.

In this embodiment, the case where the elastic sliding member 1a is formed so that the uneven surface is on the outer peripheral side is described. However, the elastic sliding member 1a may be formed so that the uneven surface is on the inner peripheral side. In addition, irregularities may be provided on both inner and outer peripheral surfaces.

Further, in this embodiment, the elastic sliding member 1
Although a case has been described where a is formed by pressing a plate material, it may be formed by another processing method, for example, a processing method using a pipe material.

The uneven surface may be formed by rolling or knurling after forming into a ring shape. Further, the elastic sliding member may be formed together with the uneven surface using a casting method such as lost wax. Further, the ring shape and the uneven surface can be simultaneously formed by spinning.

In this embodiment, the elastic sliding member 1a
Although the case where SUS304 having high wear resistance is used as the material of the above has been described, similarly, martensitic stainless steel (such as JIS SUS420J) or precipitation hardening type stainless steel (such as JIS SUS631) having high wear resistance may be used. . The second moment of area and the dynamic rigidity may be increased by using a material having a low specific gravity, such as titanium, magnesium alloy, or aluminum alloy, as thick as possible to increase the thickness. If the ratio of the Young's modulus to the specific gravity is substantially the same, a material having a lower specific gravity can increase the dynamic rigidity with the same mass.

In the present embodiment, the case where the elastic sliding member 1a, which is a separate member, is attached to the moving body 1 has been described. You may.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
4 shows a specific shape of an elastic sliding member of the vibration type motor according to the embodiment. The elastic sliding member 1 according to the present embodiment
a 'is also attached to the moving body 2 as in the first embodiment.

The elastic sliding member 1a 'is formed by leaving a sliding portion consisting of the sliding surface 1b' as a flat shape and forming the other portion in a wavy shape continuous in the circumferential direction. The elastic sliding member 1a 'may be formed by pressing a plate material having a corrugated shape in advance, or may be formed by pressing a deformed pipe. Alternatively, the ring may be corrugated by knurling.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
2 shows a specific configuration of an elastic sliding member of the vibration type motor according to the embodiment. The elastic sliding member 1 according to the present embodiment
a ″ is also attached to the moving body 2 as in the first embodiment.

As shown in detail in FIG. 5, the elastic sliding member 1a ″ is formed between two metallic materials (rigid layers) 11, 11 by a low-density material formed of a material having a lower density than these metallic materials. It has a three-layer structure sandwiching the density member 12. Thereby, a material for the elastic sliding member having high rigidity can be produced for the mass.

Then, this material is press-processed, and FIG.
The elastic sliding member 1a ″ having the shape shown in FIG.

However, since the low-density material 12 is inferior in abrasion resistance, the three-layer end face of the elastic sliding member 1a ″ is not used as a sliding surface as it is, but as shown in FIG. The elastic sliding member 1a "is bent and formed so that the surface of the metal material 11 becomes the sliding surface 1b". Since the edge of the sliding surface 1b "formed by bending in this manner is rounded,
The sliding surface 1b ″ does not damage the sliding surface of the vibrating body 2 on which the sliding member 1 slides. Also, since the sliding area can be increased, the spring 6 that presses the moving body 1 against the vibrating body 2 can be used. If the force is increased, the frictional force can be increased and the output torque can be increased.

Here, as the low density material 12, for example,
It is desirable to use a metal material or resin having a large number of honeycomb-shaped or noodle-shaped concave portions (including through holes). The shape of the concave portion may be any shape, and may be formed by etching, or may be formed by punching out a through hole by pressing. In addition, the noodle-like material may be made by crushing metal fibers, or may be made by intentionally increasing porosity by sintering. In addition, a resin may be impregnated in the concave portions of the crepe-like material.

Further, it is desirable to use polyethylene, polyester or the like as the resin. In this case, similar to the case where the resin is impregnated into the noodle-like material, the vibration damping ability of the resin itself is high, so that there is also an effect of suppressing the noise of the motor.

In each of the above embodiments, the case where the elastic sliding portion (elastic sliding members 1a, 1a ', 1a ") is provided on the moving body has been described, but the elastic sliding portion is provided on the vibrating body. This is because the deformation due to the vibration displacement is relative.

Further, in each of the above embodiments, the rod-shaped vibration type motor has been described, but the present invention can be applied to a ring-shaped or linear type vibration type driving device.

[0033]

As described above, according to the present invention,
Since the rigidity of the elastic sliding portion provided on the vibrating body or the contacting body can be increased relative to the mass, the dynamic rigidity of the elastic sliding portion is improved, and the elastic sliding portion follows the vibration displacement of the vibrating body. It can have sex. Therefore, the noise is small,
A highly efficient vibration type driving device can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vibration type motor according to a first embodiment of the present invention.

FIG. 2 is a perspective view and a sectional view of an elastic sliding member of the motor.

FIG. 3 is a perspective view of an elastic sliding member in a vibration type motor according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an elastic sliding member in a vibration type motor according to a third embodiment of the present invention.

FIG. 5 is an explanatory view showing a material structure of an elastic sliding member according to the third embodiment.

FIG. 6 is a sectional view of a sliding portion of a conventional vibration type motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moving body 1a, 1a ', 1a "Elastic sliding member 1b, 1b', 1b" Sliding surface 2 Upper vibrating body 3 Piezoelectric element 4 Bolt 5 Output gear 6 Spring 7 Electrode plate 8 Lower vibrating body 9 Insulating sheet

Claims (17)

[Claims] 1. A vibration-type driving device in which a vibrating body in which vibration is excited and a contact body that comes into contact with the vibrating body relatively slide, wherein an elastic sliding portion is provided on one of the vibrating body and the contact body. A vibratory drive device characterized in that portions of the elastic sliding portion other than the sliding surface are formed in an uneven shape. 2. The vibration-type driving device according to claim 1, wherein the uneven shape is a shape that increases the rigidity of the elastic sliding portion. 3. The vibration type driving device according to claim 1, wherein the uneven shape is a honeycomb shape. 4. The vibration type driving device according to claim 1, wherein the uneven shape is a wave shape. 5. The vibration-type driving device according to claim 1, wherein the uneven shape is formed by etching. 6. The vibration-type drive device according to claim 1, wherein the uneven shape is formed by rolling. 7. The vibration-type driving device according to claim 1, wherein the uneven shape is formed by knurling. 8. The vibration type driving device according to claim 1, wherein the elastic sliding portion is formed by press working, and the uneven shape is formed before the press working. . 9. The vibration type driving device according to claim 1, wherein said elastic sliding portion is formed by casting together with said uneven shape. 10. The vibration type driving device according to claim 1, wherein said elastic sliding portion is formed by spinning together with said uneven shape. 11. The vibration according to claim 1, wherein the elastic sliding portion is constituted by a separate member attached to one of the vibrating body and the contact body. Mold drive. 12. A vibration type driving device in which a vibrating body excited by vibration and a contact body that comes into contact with the vibrating body relatively slide, wherein an elastic sliding portion is provided on one of the vibrating body and the contact body. A vibration type driving device, characterized in that a portion of the elastic sliding portion other than the sliding surface has a multilayer structure made of a different material. 13. The vibration type driving device according to claim 12, wherein the elastic sliding portion has a structure in which a low-density layer having a lower density than the rigid layer is sandwiched by the rigid layer. 14. The vibration type driving device according to claim 13, wherein said rigid layer is formed of a metal material. 15. The vibration type driving device according to claim 12, wherein the low density layer is formed of a metal material having a plurality of concave portions. 16. The vibration type driving device according to claim 12, wherein the low density layer is formed of a resin. 17. A device comprising the vibration type driving device according to claim 1 as a driving source.