JPS6253182A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To augment torque, increase speed, improve durability and to reduce a frictional sound by forming a contacting section in a body brought into pressure-contact with an elastic vibrator by a specific material having predetermined hardness. CONSTITUTION:An elastic vibrator 24 is brought into contact with a sliding body 22 unified with a shaft 21 for transmitting driving force over the outside through a frictional material 23. A piezoelectric vibrator 25 is fitted to the elastic vibrator 24. The frictional material 23 constitutes a contacting section between the elastic vibrator 24 and a body brought into pressure-contact with the vibrator 24, the sliding body 22, and consists of an ABS group resin, a styrene resin, an acrylic resin, a polyethylene resin, a polyamide resin, a fluoroplastic, a polyester resin, a vinylidene chloride resin, a polysulfonic resin and polyphenylene sulfide having hardness of 40-120 in R type Rockwell hardness or one kind or two kinds of mixtures in these copolymer.

Description

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

[Technical background of the invention and its problems] As shown in the configuration diagram in FIG. ), an elastic wave (3) is generated and propagates on the surface of the elastic vibrator (2) in the direction of the arrow. At this time, the elastic wave (3) at the mass point on the surface of the elastic vibrator (2) is the first
Elliptical motion with longitudinal and transverse amplitudes as shown in Figure 0 (4)
, and when propagating in the direction of the arrow above, it is rotating counterclockwise. This elastic wave (3) has a vertex (5) for each wavelength, and the elastic vibrating body (2) has a sliding body (6).
When pressed into contact with the sliding body (6), the top of the elastic wave (5
) is in contact with the elastic vibrating body (2), so the elliptical motion (4
) generates frictional force in the direction of the arrow, that is, an elastic wave (3)
Move in the opposite direction to the Buddhist temple. Normally, in a linear ultrasonic motor based on the principle shown in Fig. 10, the piezoelectric vibrator (1) is B
Piezoelectric ceramic such as aTiO3 or PZT is used, and the elastic vibrating body (2) is made of scrap metal or plastic.

The ultrasonic motor, whose exploded view is shown in FIG. 11 and front view shown in FIG. V
1 = 'J o sin wt is supplied, and V2 whose phase is changed by 90'' from vl to the voltage oscillator (11b).
= Vocos wt, the piezoelectric vibrator (IIC) has V3--V with a further 90° phase change, sin wt, the piezoelectric vibrator (11d) has V4-- with a further 90" phase change than (11c) Vocos Add a voltage of wt,
By driving each piezoelectric vibrator, the elastic vibrator (1
The sliding body (16) brought into pressure contact with 2) performs a rotational movement.

In such linear or rotary ultrasonic motors,
In order to increase the propagation efficiency of elastic waves, elastic vibrator (2) (1
For 2), metals having a high Young's modulus are often used. However, if, for example, metal is used for the sliding bodies (6) (16) and a driving force is obtained by bringing them into direct contact with the elastic vibrating bodies (2) (12), the vibrations of elastic waves and frictional force will cause noise and heat. If rubber or the like is used to eliminate the above-mentioned noise, the problem is that the rubber absorbs the vibrations of elastic waves and frictional force, making it impossible to obtain sufficient driving force. .

In addition, the Acoustical Society of Japan's 1985 Spring Leather Research Presentation Collection No. 1-2-1.1-2-2.1-2-3 describes an elastic vibrating body and an object brought into pressure contact with it. An ultrasonic motor using vinyl, polycarbonate, polypropylene, or Duracon for the contact part is described. All of these are thermoplastic resins, and vinyl in particular has problems such as the physical properties changing significantly due to heat generation due to friction when used for long periods of time or when driven at high speeds and high rotations, and the disadvantage that initial characteristics cannot be maintained. There is. Polypropylene also has the same problem of physical property change due to heat, and polycarbonate is weak against repeated loads and lacks durability when exposed to vibrations of elastic waves for a long time. Duracon has an extremely low *m coefficient, so the elastic wave I! i! There is a problem of not being able to give or receive enough power. As described above, the material of the contact portion between the elastic vibrating body and the object to which the vibrating body is pressurized is subject to significant restrictions in actual use.

[Purpose of the Invention] The object of the present invention is to provide an ultrasonic motor with high torque, high speed, low friction noise, and excellent durability by using II friction material having an appropriate hardness range. be.

[Summary of the Invention] An ultrasonic motor according to the present invention includes an elastic vibrating body equipped with a piezoelectric vibrator, and an object brought into pressure contact with the elastic vibrating body, and drives the piezoelectric vibrator to generate the In an ultrasonic motor that induces elastic waves on an elastic vibrating body to operate an object brought into pressurized contact with the elastic vibrating body or the elastic vibrating body itself, a contact portion of the object brought into pressurized contact with the elastic vibrating body. Rockwell hard IR type 40-120 ABS resin,
It is formed from one or a mixture of two or more of styrene resin, acrylic resin, polyethylene resin, polyamide resin, fluorine resin, polyester resin, vinylidene chloride resin, polysulfone resin, polyphenylene sulfide, and copolymers thereof. It is characterized by this.

[Embodiments of the invention] Example 1 An example of the actual flow of a rotary ultrasonic motor will be described.

As shown in the front sectional view in Fig. 1 and the exploded view in Fig. 2, the sliding body (22) integrated with the shaft (21) for transmitting the driving force to the outside is suitable for those that require large torque. Generally, metal is used in consideration of rigidity, durability, workability, etc. Also, the elastic vibrating body (24) is in contact with the sliding body (22) via the integrated friction material (23).
) (outer diameter: 60 mm, inner diameter: 50 tur) is made of metal such as duralumin, and a piezoelectric vibrator (25) (using PZT) is attached to the elastic vibrating body (24). The *m material (23) is an elastic vibrating body (24) and an object brought into pressure contact with the elastic vibrating body (24), that is, lS! spindle (
22) and has a Rockwell hardness of R type 4.
ABS resin with hardness of 0 to 120.

Styrene resin, acrylic resin, polyethylene resin.

Polyamide resin, fluorine resin, polyester resin, j
! It consists of vinylidene chloride resin, polysulfone 84m, polyphenylene sulfide, and one or a mixture of two or more of these copolymers.

The absorber (26) disposed in contact with the piezoelectric vibrator (25) is for preventing the vibration of the piezoelectric vibrator (25) from being transmitted to the case (27), the sealing lid (28), etc. In addition, (29) and (30) are bearings, (31)
is a mounting base, and (32) is a spring. Friction material (23)
An ultrasonic motor as shown in Fig. 1 was made by assembling these using ABS resin, and A was used as a friction 0 (23).
Figure 3 shows the rotational speed of the sliding body (22) with respect to the drive voltage of the ultrasonic motor when the hardness of the BS resin (Rockwell hardness R type) is changed, and Figure 4 shows the torque characteristics with respect to the drive voltage.
As shown in the figure. Figure 5 also shows that the driving voltage of the ultrasonic motor is 2.
Friction material (23) 161 in case of 0V! The rotation speed of the sliding body (22) with respect to the hardness (Rockwell hardness R type)
Fig. 6 shows the torque characteristics under the same conditions. As mentioned above, from the characteristics of both rotation speed and torque, the Rockwell hardness R type that can be used as an ultrasonic motor is 40 to 120, and 30
In this case, both the rotation speed and torque characteristics decrease. Further, those exceeding 120 generate noise during operation, and those exceeding 125 deteriorate torque characteristics. This tendency was observed in A, which was used as a friction material in the example.
Not only BS resin, polyamide resin, polystyrene resin, copolymer of polyethylene resin and styrene resin, but also polyethylene resin, polyphenylene sulfide, polyamide resin, acrylic resin, fluorine resin, polyester resin, vinylidene chloride resin, polysulfone It was confirmed that the same effect can be applied to resins, copolymers thereof, and mixtures of two or more thereof. In the embodiment shown in FIGS. 1 and 2, the friction material (23
) is attached to the sliding body (22) and integrated, but it is also possible to just insert it between the sliding body (22) and the elastic vibrating body (24), or it can be attached to the elastic vibrating body. Similar effects can be obtained with other configurations.

Example 2 An example of a linear ultrasonic motor will be described.

In the configuration shown in FIG. 9, the elastic vibrating body is made of 5-mm brass, two piezoelectric vibrators are attached to both ends of the elastic vibrating body, aluminum is used as the sliding body, and friction is applied to the aluminum. Fix the material and apply 1! The Jm material is attached to the elastic vibrator so as to sandwich the PZT from both sides in the attachment direction. PZ of a linear ultrasonic motor with such a configuration
Figure 7 shows the relationship between the hardness of the sliding body and the moving speed for each material when a voltage of 200cm is applied to T, and Figure 8 similarly shows the relationship between the hardness and the thrust force given by 13. .

In addition, a! The raw materials used were the same as those shown in Example 1 above. The case where a voltage of 200 V was applied to PZT was described above, but when the applied voltage is changed, the moving speed of the sliding body changes almost in proportion to the applied voltage. As is clear from the results shown in Figures 7 and 8, the linear ultrasonic motor has a Rockwell hardness of 40 to 40 to No. 120 shows good results because the moving speed and thrust of the sliding body are large. Also, Figure 7,
Polyethylene resin other than the friction material shown in FIG.

Polyphenylene sulfide, polyamide resin.

Acrylic resin, fluorine resin, polyester resin.

It has been confirmed that similar results can be obtained with vinylidene chloride resin, polysulfone resin, copolymers thereof, and mixtures of two or more thereof.

[Effects of the Invention] According to the present invention, I! has a hardness range of Rockwell hardness R type 40 to 120. By using 11m material,
It is possible to obtain an ultrasonic motor that solves problems such as changes in physical properties of friction materials, noise, and durability.

[Brief explanation of drawings]

1 to 6 show examples of the rotary ultrasonic motor according to the present invention, FIG. 1 is a front cross-sectional view showing the configuration of the iA sonic motor, and FIG. 2 is the ultrasonic motor shown in FIG. 1. An exploded view of the sonic motor, Fig. 3 is a curve diagram showing the rotation speed of the sliding body with respect to the drive voltage of the ultrasonic motor, Fig. 4 is a curve diagram showing the torque characteristics of the sliding body with respect to the drive full'll pressure, and Fig. 5 The figure is a curve diagram showing the relationship between the hardness of the friction material and the rotation speed of the sliding body, Figure 6 is a curve diagram showing the relationship between the hardness of the friction material and the torque characteristic of the sliding body, and Figures 7 and 8 are from this book. An example of a linear ultrasonic motor to be devised is shown. Figure 7 is a curve diagram showing the relationship between the hardness of the aluminum friction material and the moving speed of the sliding body, and Figure 8 is a curve diagram showing the relationship between the hardness of the friction material and the thrust force. 9 is a configuration diagram of a linear ultrasonic motor, FIG. 10 is an explanatory diagram showing the operating principle of an ultrasonic motor, and FIG. 11 is an exploded view of a conventional rotary ultrasonic motor. FIG. 12 is a front view of the super wave motor shown in FIG. 11. (22)...Sliding body (23)...
...mm material (24)...Elastic vibrator (25
)...Piezoelectric vibrator (27)...Case (28)...Sealing lid patent granted
Requested by Hito Marukon Electronic Co., Ltd. Drawing engraving (no changes in content) Front cross-sectional view of the ultrasonic motor Figure 1 Exploded view of the ultrasonic motor Figure 2 Relationship between drive voltage and rotational speed Figure 3 Relationship between drive voltage and torque Figure 4) - IRR Il! Relationship between raw material hardness and rotational speed No. 5 IRR Relationship between friction material hardness and torque 5o 100 IRR Relationship between friction material hardness and moving speed Figure 7 IRR Relationship between friction material hardness and thrust Figure 8 Linear type Ultrasonic motor configuration diagram Figure 9 Figure 10 Figure 11 Figure 12 Procedure correction writing method) % formula % 1. Incident display. 19860 Patent Application No. 191669 2 Name of the invention Ultrasonic motor 3 Relationship with the case of the person making the amendment Patent applicant address 1-1 Saiwai-cho, Nagai City, Yamagata Prefecture Telephone Nagai (0238) 84-2131 (Oi) Representative) Postal code 993 November 260, 1985 (Shipping date) Amendment to proceedings (voluntary) 1985
November 19th

Claims (1)

[Claims] (1) An elastic vibrating body including a piezoelectric vibrator and an object brought into pressure contact with the elastic vibrating body, and driving the piezoelectric vibrator to induce an elastic wave on the elastic vibrating body. In an ultrasonic motor that operates an object brought into pressurized contact with the elastic vibrating body or the elastic vibrating body itself, the contact portion of the object brought into pressurized contact with the elastic vibrating body has a Rockwell hardness of R type 4.
0 to 120 ABS resin, styrene resin, acrylic resin, polyethylene resin, polyamide resin, fluorine resin, polyester resin, vinylidene chloride resin, polysulfone resin, polyphenylene sulfide, and one type of copolymer thereof Or an ultrasonic motor characterized by being formed from a mixture of two or more types.