JPH01222671A - Ultrasonic motor and manufacture thereof - Google Patents

Abstract

PURPOSE:To suppress the generation of an audible sound by composing a vibration absorber layer between a moving element and a frictional material. CONSTITUTION:The vibrator of an ultrasonic motor is formed by adhering fixedly a vibrating element 2 of resilient material, such as metal or the like to the surface of a piezoelectric element 1. The moving element of the vibrator is formed by securing a frictional material 4 made of engineering plastic to the surface of a moving element 3 as a body through a vibration absorber layer 5, and bringing the surface of the material 4 into pressure contact with the surface of the element 2. Thus, a high frequency electric field of a resonance frequency is applied to the element 1 to generate a traveling wave of ultrasonic wave vibration at the elements 1 and 2. In this case, the moving element made of the material 4, the layer 5 and the element 3 in contact with each other at the traveling wave head of the element 2 is integrally driven by the frictional force with the element 2. An unnecessary vibration generated at the material 4 is absorbed by the layer 5, thereby suppressing the generation of an audible sound.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic motor using a piezoelectric ultrasonic vibrator.

3.

2. Description of the Related Art In general, an ultrasonic motor has a configuration in which a vibrating body to which a piezoelectric body is attached is in pressure contact with a moving body. Electrical input to the piezoelectric body causes the piezoelectric body and the vibrating body to move as shown in FIG. This method generates a traveling wave of ultrasonic vibration, and uses the frictional force between the vibrating body and the moving body to drive the moving body to obtain mechanical energy. In FIG. 5, 1 is a piezoelectric body, and a vibrating body 2 is adhesively fixed to the surface of the piezoelectric body. 3 is a moving object;
A friction material 4 is fixed to the surface thereof. By applying electrical input to the piezoelectric body 1, a traveling wave of ultrasonic vibration in the incoming direction is generated in the vibrating body 2. Each mass point of the vibrating body 2 moves in an ellipse as shown in B, and each wave crest has the property of moving laterally in the opposite direction to the direction of the traveling wave. The trough portion of a traveling wave has the property of moving laterally in the same direction as the traveling wave. Therefore, the movable body 3 placed on the surface of the vibrating body 2 contacts only the upper part of the wave crest, and is driven in the C direction by the frictional force with the vibrating body 2.

In such an ultrasonic motor, metals such as iron, stainless steel, and aluminum are used as materials for the vibrating body 2 and the movable body 3. The vibrating body 2 and the movable body 3 are in pressure contact, and in order to reduce wear on their frictional contact surfaces and obtain stable mechanical energy for a long period of time, and to obtain a larger frictional force, the movable body It has been proposed that a friction material 4 made of engineering plastic be fixedly installed on the contact surface with the vibrating body 2 of No. 3.

Problems to be Solved by the Invention However, when metals such as iron, stainless steel, and aluminum are used as the materials for the vibrating body 2 and the movable body 3, contact between the vibrating body 2 and the movable body 3, which are vibrating ultrasonic waves, , there is a problem that the moving body 3 vibrates and resonates, producing audible sounds.

When a hard friction material 4 such as engineering plastic is used, the contact between the friction material 4 and the vibrating body 2 that is vibrating ultrasonic waves causes the friction material 4 and the movable body 3 to vibrate and resonate, producing an audible sound. There is a problem with this occurring.

In view of these problems, the present invention provides an audible sound emission 5.\-
1. The purpose of the present invention is to obtain an ultrasonic motor that is free of energy and generates no noise.

Means for Solving the Problems In order to achieve the above object, the ultrasonic motor of the present invention has a vibration absorbing material layer fixed to the surface of a moving body, and a friction material further fixed to the upper surface of the vibration absorbing material layer. The structure is such that the material and the vibrating body are in contact with each other.

Furthermore, another ultrasonic motor of the present invention has a structure in which a vibration absorbing material layer is fixed between a movable body and a power load body.

In particular, the vibration absorbing material layer may have a structure in which metal thin layers and plastic thin layers are alternately laminated or a flexible resin layer.

In other words, the movable body and the friction material or the movable body and the power load body are bonded and fixed using a flexible adhesive.

Further, as the flexible adhesive, an adhesive material made of a woven or non-woven fabric impregnated with a flexible resin is used.

Effect According to the above configuration, by configuring the vibration absorbing material layer between the movable body and the friction material, the vibration resonance of the friction material generated by the contact between the vibrating body and the friction material is absorbed by the vibration absorbing material layer. Therefore, unnecessary vibrations are prevented from being transmitted to the moving body, and as a result, the generation of audible sound is suppressed.

In addition, by configuring a vibration absorbing material layer between the moving body and the power load body, unnecessary vibrations generated in the moving body are absorbed by the vibration absorbing material layer, so that unnecessary vibrations are not transmitted to the power load body. As a result, the generation of audible sounds is suppressed.

In particular, as the vibration absorbing material layer, a flexible resin layer or
By configuring a layer in which thin metal layers and thin plastic layers are laminated alternately, unnecessary vibrations are absorbed in the flexible resin layer portion or the alternately laminated portion of thin metal layers and thin plastic layers. As a result, the generation of audible sounds is suppressed.

In addition, 7. By using a manufacturing method that uses a flexible adhesive to bond and fix a movable body and a friction material or a movable body and a power load body, unnecessary vibrations are absorbed in the flexible adhesive layer, resulting in audible noise. It is possible to easily manufacture an ultrasonic motor in which generation of .

Furthermore, by using an adhesive made of woven or non-woven fabric impregnated with flexible resin as the flexible adhesive,
At the same time as suppressing the occurrence of flexibility, it is easy to configure the thickness of the adhesive layer to be uniform, and the mechanical strength of the adhesive layer is increased, making it more suitable for moving objects and power load objects. Large torque can be transmitted.

Embodiment (Embodiment 1) An example of the structure of the main part of the ultrasonic motor of the present invention is shown in FIG. The vibrating part is a vibrating part I*2 made of an elastic material such as metal and fixed to the surface of the piezoelectric body 1 by adhesive.

In the movable part, a friction material 4 made of engineering plastic is fixed to the surface of a movable body 3 as a main body via a vibration absorbing material layer 5. The structure is such that the surface of the friction material 4 and the surface of the vibrating body 2 are brought into pressure contact. By applying a high-frequency electric field having a resonant frequency to the piezoelectric body 1, a traveling wave of ultrasonic vibration as described above is generated in the piezoelectric body 1 and the vibrating body 2.

At this time, the friction material 4, the vibration absorbing material layer 5, the movable body 3, and the moving part that are in contact at the head of the traveling wave of the vibrating body 2 are integrated and driven by the frictional force with the vibrating body 2. 0 Unnecessary vibration is transmitted to the friction material 4 due to the contact of the ultrasonic vibration between the vibrating body 2, which is generating ultrasonic vibration, and the friction material 4 that is in contact with its surface, and unnecessary resonance occurs. Unwanted vibrations are absorbed by the vibration absorbing material layer 6 and are not transmitted to the moving body 3, resulting in the effect of suppressing the generation of audible sounds.

There are no particular restrictions on the vibration absorbing material layer 5, but the thickness may be 1
A configuration can be used in which thin layers of metal, each having a thickness of less than 1 mm, are alternately laminated with thin layers of plastic, each having a thickness of less than 1 mm.

In this case, the metal layer can be made of iron, aluminum, lead, stainless steel, etc., and the plastic can be ordinary plastics such as polyester resin, polyethylene resin, urethane resin, or epoxy resin.

9/, -7 Moreover, as the vibration absorbing material layer 5, a scorchable resin layer can be used. The material is not particularly limited, but unsaturated synthetic rubber, urethane rubber, silicone rubber, polyester rubber, flexible epoxy resin, etc. can be used.

Furthermore, the flammable resin layer 5 can be obtained by a method of adhesively fixing the friction material 4 and the movable body 3 using a flammable adhesive. In particular, by using an adhesive material in which woven or non-woven fabric is impregnated with visible resin, it is possible to suppress the generation of audible noise, and at the same time, it is possible to use ceramic fibers that transmit large torsion to the moving object by improving mechanical strength. .

The present invention will be explained in more detail below using specific examples.

A disc-type ultrasonic motor with a diameter of 40mm and a thickness of 8M as shown in FIG. 2 was constructed. In FIG. 2, the vibrating part of the ultrasonic motor has a circumferential array of a large number of protrusion segments 21 having the same diameter on the surface of a disk-shaped piezoelectric ceramic 1 on which electrodes are attached. It is constructed by adhesively fixing the back surface of the stainless steel vibrating body 2 using a hard epoxy resin adhesive. The protrusion segment 21 is the vibrating body 2
It is provided to make it easier to vibrate mechanically and to increase the amplitude. The corresponding moving part is constructed by fixing a vibration absorbing material layer 5 between a stainless steel moving body 3 and a friction material 4. Although the vibrating body part and the movable part are not shown, they are pressed against each other by appropriate spring tightening means, and the protruding segment part 21 of the vibrating body and the friction material 4 are in contact with each other.

Using a 0.5ffff thick adhesive sheet made of glass fiber non-woven fabric impregnated with butadiene-based synthetic rubber adhesive,
0.5m thick made of phenolic resin containing inorganic filler
The vibration absorbing material layer 5 was formed by bonding the friction material sheet of ff and the moving body.

The electrodes are arranged so that four traveling waves are excited in the circumferential direction of the vibrating body, and the resonance frequency is approximately 70 KHz.

By inputting power with a voltage of 80 cm, the moving part rotates.

11 /, -7 The ultrasonic motor obtained in this way has a no-load rotation speed of 70
o rpm and starting torque of 800 gf-cyn, and no audible sound was observed during no-load rotation and during rotation with the load continuously increased to 800 gf-cyn.

The thickness is still ○ as the vibration absorbing material layer 5. The output was similar to that of a laminate sheet made by alternately laminating three aluminum metal sheets and polyester resin sheets (thickness: 0.05 mm), and no audible sound was produced.

(Embodiment 2) FIG. 3 shows another configuration example of the main structure of the ultrasonic wave generator of the present invention. Reference numeral 1 denotes a piezoelectric body to which electrodes are adhered, and a vibrating body 2 made of an elastic material of four types is adhesively fixed to the surface of the piezoelectric body. A friction material 4 is adhesively fixed to the metal movable body 3, and the movable body 3 is fixed to the power load body 7 via the vibration absorbing material 1#6. j The structure is such that the surface of the damping material 40 and the surface of the vibrating body 2 are brought into pressure contact. By applying a high-frequency electric field having a resonant frequency to the piezoelectric body 1, the traveling wave of the ultrasonic vibration described above is generated in the piezoelectric body 1 and the vibrating body 2. At this time, the friction material 4, movable body 3, vibration absorbing material layer 6, and power load body 7, which are in contact with each other at the head of the traveling wave of the vibrating body 2, are driven together.

Due to the contact of ultrasonic vibration between the vibrating body 2 generating ultrasonic vibration and the friction material 4 in contact with its surface, unnecessary vibrations are transmitted to the friction material 4 and the movable body 3. Although unnecessary resonance occurs, the unnecessary vibration is absorbed by the vibration absorbing material layer 6 and is no longer transmitted to the power load body 7, resulting in the effect of suppressing the generation of audible sound.

There are no particular restrictions on the vibration absorbing material layer 6, but the thickness may be 1 m.
A configuration can be used consisting of alternating thin layers of metal with a thickness of less than 1'mar and thin layers of plastic with a thickness of less than 1'mar. In this case, as the metal layer, iron, aluminum, lead, stainless steel, etc. can be used, and as the plastic, usual 13/-, such as polyester resin, polyethylene resin, urethane resin, epoxy resin, etc. can be used.

Plastic can be used.

Indeed, a visible resin layer can be used as the vibration absorbing material layer 6. There are no particular restrictions on the material; unsaturated synthetic rubber, urethane rubber, silicone rubber, polyester rubber, scorable epoxy resin, and the like can be used.

Furthermore, the flammable resin layer 6 can be obtained by bonding and defining the vibrating body 3 and the power load body 7 using a flammable adhesive. In particular, by using an adhesive material in which a woven or non-woven fabric is impregnated with a flexible resin, it is possible to suppress the generation of audible noise and at the same time, transmit a large torque to the moving body due to its mechanical strength. Woven or non-woven materials include glass fiber, carbon fiber, and polyester fiber.

Synthetic resin fibers, ceramic fibers, etc. can be used.

The present invention will be explained in more detail below using specific examples.

Diameter 40 myr, thickness s mnr as shown in Figure 4
A disc-type ultrasonic motor was constructed. In FIG. 4, the vibrating part of the ultrasonic motor includes an electrode 142 attached and formed;
-7 On the surface of the disk-shaped piezoelectric ceramic 10, use a hard epoxy resin adhesive to attach the back surface of the stainless steel vibrating body 2, which has a circumferential arrangement of a large number of protrusion segments 21 on the front surface with the same diameter. It is constructed by adhesively fixing it. The protruding segments 1-21 are provided to make the vibrating body 2 easier to vibrate mechanically and to increase the amplitude. The corresponding moving part is
A vibration absorbing material layer 6 is fixed between a stainless steel movable body 3 to which a friction material 4 is adhesively fixed and a power load body 7. Although the vibrating body part and the movable part are not shown, they are pressed against each other by appropriate spring tightening means, and the protruding segment part 21 of the vibrating body and the friction material 4 are in contact with each other.

A glass fiber nonwoven fabric impregnated with a butadiene-based synthetic rubber adhesive has a thickness of o. Using a rsmm adhesive sheet, the vibration absorbing material layer 6 is bonded to the moving body and a friction material sheet made of phenolic resin containing an inorganic filler and having a thickness of 0.5 mm.
was configured.

The electrodes are arranged so that four traveling waves are generated in the circumferential direction of the vibrating body, and the moving part rotates when power is input at a resonance frequency of about 70 KHz and a voltage of 80 V.

The ultrasonic motor obtained in this way has: - No-load rotation speed 7
00 rpm, starting speed 800cl '4: c-foot, no-load rotation, and load 80o g, f-c〃l
No audible sound was observed during rotations that increased continuously up to

Moreover, the thickness of the vibration absorbing layer 6 is ○. In the case of an ultrasonic motor configured with a laminate sheet made by laminating five aluminum metal sheets and polyester resin sheets (0.05 mm thick) alternately, the same output as above can be obtained, and it is almost audible. No occurrence was observed.

Effects of the Invention By configuring the vibration absorbing material layer between the moving body and the friction material, there is an effect that generation of audible sound is suppressed when driving the ultrasonic motor.

In fact, a layer of vibration absorbing material (1
4 has the effect of suppressing the generation of audible sound when driving the ultrasonic motor.

Furthermore, by using the method of configuring the vibration absorbing material layer using a visible adhesive, it is possible to easily manufacture an ultrasonic motor in which generation of audible sound is suppressed.

In addition, by using a method of configuring the vibration absorbing material layer using a flexible adhesive made of woven or non-woven fabric impregnated with flammable resin, it is possible to suppress the generation of audible sound and at the same time Alternatively, it becomes possible to increase the torque transmission force to the power load body.

[Brief explanation of the drawing]

1 and 3 are enlarged cross-sectional views of the main components of the ultrasonic motor of the present invention, FIGS. 2 and 4 are perspective views illustrating an embodiment of the present invention, and FIG. 5 is an ultrasonic motor of the present invention. FIG. 2 is an operation explanatory diagram showing the principle of 1... Piezoelectric body, 2... Vibrating body, 3...
...Moving body, 4...Friction material, 5...Vibration absorber, 6...Vibration absorber, 7...
Power load body.

Claims (1)

Scope of Claims: (1) An ultrasonic vibrating body that generates a traveling wave on its surface and a movable body are brought into pressure contact, and the vibrating body drives the movable body through the frictional force between them. An ultrasonic motor in which a vibration absorbing material layer is fixed to the surface of the movable body, a friction material is further fixed to the upper layer thereof, and the friction material layer and the vibrating body are in contact with each other. (2) An ultrasonic motor in which an ultrasonic vibrating body that generates a traveling wave on its surface and a movable body are brought into pressurized contact and the movable body is driven by the vibrating body through a frictional force between the two; An ultrasonic motor in which a vibration absorbing material layer is fixed between the body and the power load body. (3) The ultrasonic motor according to claim 1 or 2, wherein the vibration absorbing material layer is formed by alternately laminating thin metal layers and thin plastic layers. (4) The ultrasonic motor according to claim 1 or 2, wherein the vibration absorbing material layer is a flexible resin material layer. (5)
A method for manufacturing an ultrasonic motor in which an ultrasonic vibrating body that generates a traveling wave on its surface and a movable body are in pressurized contact with each other, and the vibrating body drives the movable body through the frictional force between the two. A method for manufacturing an ultrasonic motor, comprising adhesively fixing a friction material to the contact surface of the vibrating body using a synthetic adhesive. (6) A method for manufacturing an ultrasonic motor in which an ultrasonic vibrating body that generates a traveling wave on its surface and a movable body are in pressure contact with each other, and the vibrating body drives the movable body through the frictional force between the two. . A method of manufacturing an ultrasonic motor, in which the movable body and the power load body are bonded and fixed using a flexible adhesive. (7) The method for manufacturing an ultrasonic motor according to claim 5 or 6, wherein the flexible adhesive is obtained by impregnating a woven fabric or a nonwoven fabric with the flexible adhesive.