JP2001112275A - Ultrasonic motor and flow control valve using the ultrasonic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve by an ultrasonic motor for preventing a vibration propagation to a cylinder of a control valve body, connected to a vibrator by effectively operating a vibration generated at the vibrator as a rotary force. SOLUTION: In a flow control valve, utilizing an ultrasonic motor having a rotor 3 rotating by a vibration of a vibrator 10 via a driver 4 and a valve disc 5 changing in its opening of a valve port 8 by a rotation of the rotor 3 with suitable urging means in a control valve body 1 formed in a sealed structure through welding or the like with the vibrator 10, a cylinder 7 and a body 9, the vibrator 10 is formed of two vibrator 10a formed by connecting a piezoelectric element 2a or an electrostatictive element to the upper surface of an elastic element 6a, and a vibrator 10b formed by connecting a piezoelectric element 2b or an electrostrictive element to the lower surface of an elastic element 6b made into a recess shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor capable of effectively using the vibration generated by a vibrator as a rotational force, and a flow control valve or a pressure control valve using the ultrasonic motor. The present invention relates to a flow control valve that effectively uses vibration generated by a vibrator as a rotational force and prevents propagation of vibration to a cylinder or the like of a control valve body joined to the vibrator.

[0002]

2. Description of the Related Art In general, when an ultrasonic motor for driving a piezoelectric element with a high-frequency voltage in an ultrasonic region is combined with a control valve,
A control valve that is small and has excellent controllability can be configured.
FIG. 4 shows an example of a conventional control valve using an ultrasonic motor, which has been filed by the present applicant in Japanese Patent Application No. 10-331937. Hereinafter, the prior art will be described with reference to FIG.

A conventional control valve includes a vibrator 10 in which a piezoelectric element 2 is joined to an upper surface of an elastic body 6, a cylinder 7 having an inflow pipe 12 on a side surface, a valve port 8 and an outflow pipe 13. The control valve body 1 is formed by joining the elastic body 6, the cylinder 7, and the body 9 to each other in a closed structure by welding or the like. The control valve body 1 accommodates a rotor 3, a driver 4 and a valve body 5, and the rotor 3 is pressed against the driver 4 by an appropriate urging means. Further, the valve element 5 is capable of controlling the opening of the valve port 8 by rotating together with the rotor 3.

[0004] The thrust spring 14 applies a thrust load to the driver 4 and the body 9 and rotates together with the rotation of the rotor 3 and the valve element 5. In addition, a cylindrical hole formed at the center of the valve body 5 includes:
A spring 15 is inserted, and the ball 16 is brought into contact with a recess 17 formed in the center of the body 9 via the spring 15. The thrust spring 14
Since the spring force is set to be larger than that of the spring 15, the lower surface of the valve body 5 is constantly pressed against the body 9 and also pressed toward the driver 4 via the rotor 3.

The valve element 5 has a stopper piece formed by projecting a part of the outer peripheral portion outward, and the stopper piece reaches the valve port 8 at a reference position (fully closed state) of the valve element 5. At this time, the rotation of the rotor 3 is stopped by abutting against a stopper pin 18 implanted and fixed to the body 9.

Next, the operation of the prior art will be described.
The driving mechanism of the related art is an ultrasonic motor in which the driving element 4 is vibrated by the piezoelectric element 2 and the rotor 3 is rotated. Although the description of the operation principle is omitted, it is a so-called standing wave driven ultrasonic motor. In the prior art, the gap between the valve port 8 of the body 9 and the flow groove of the valve element 5 is changed by rotating the valve element 5 using the rotational movement of the rotor 3, and the flow rate to the valve port 8 is reduced. To control.

[0007]

As described above, in the conventional control valve using an ultrasonic motor, the vibrator 10, the cylinder 7, and the body 9 are joined by welding or the like in order to form a sealed structure. However, the vibration of the vibrator 10 is
In the case of the vibration having the following, since the position of the nodal circle is located closer to the center than the outer diameter of the vibrator 10, some vibration displacement occurs at the outer peripheral portion where the cylinder 7 is attached. Therefore, the vibration generated by the vibrator 10 propagates as a transverse wave or a longitudinal wave to the cylinder 7 that is joined to the vibrator 10 by welding or the like to form a sealed structure, and the vibration concentrates on the tip of the cylinder. Becomes Further, since the body having the valve port 8 is joined to the distal end of the cylinder 7 by welding or the like, the vibration transmitted to the distal end is restrained by welding or the like, and the driver disposed on the vibrator Therefore, there is a problem that the rotor 3 that rotates due to the friction drive with the above-mentioned structure is difficult to rotate.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make the vibration generated by a vibrator work effectively as a rotational force. It is an object of the present invention to provide an ultrasonic motor for preventing vibration from propagating to a cylinder or the like of a control valve body joined to the control valve and a control valve using the ultrasonic motor.

That is, the first invention of the present application is the oscillator 1
The configuration of No. 0 is obtained by joining a vibrator 10a in which a piezoelectric element 2a or an electrostrictive element is joined to an upper surface of an elastic body 6a, and joining a piezoelectric element 2b or an electrostrictive element to the bottom of an elastic body 6b having a concave shape. Formed by two vibrators of the vibrator 10b,
The ultrasonic motor is characterized in that a driver 4 is provided on the lower surface of the elastic body 6b.

The second invention of the present application provides a vibrator 10 in which a piezoelectric element 2 or an electrostrictive element is joined to an upper surface of an elastic body 6, a cylinder 7 having an inflow pipe 12 on a side surface, and a valve port. 8 and the body 9 provided with the outflow pipe 13 are each formed in a sealed structure by welding or the like, and the control valve body 1 is provided.
A rotor 3 that rotates through a driver 4 by the vibration of a vibrator 10 and a valve body 5 that changes the degree of opening of the valve port 8 by a suitable urging means for rotating the rotor 3 are provided therein. A control valve using an ultrasonic motor, comprising: a vibrator 10 having a piezoelectric element 2a or an electrostrictive element joined to an upper surface of an elastic body 6a; and an elastic body 6b having a concave shape. A flow control valve characterized in that it is formed of two vibrators, a vibrator 10b having a piezoelectric element 2b or an electrostrictive element joined to a bottom surface.

[0011]

According to the present invention, the vibrator 10 in which the piezoelectric element 2b or the electrostrictive element is joined to the outside of the elastic body 6b.
and a vibrator 10 comprising a vibrator 10a formed by joining a piezoelectric element 2a or an electrostrictive element to an elastic body 6a on the upper side of the vibrator 10b.
b) a valve element 5 for applying an electric signal in the ultrasonic range to b and controlling the flow rate via a rotor 3 pressed against an internal driving element 4
Rotates while sliding on the body 9.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of the present invention. The flow control valve in the present embodiment, like the conventional product,
The control valve main body 1 includes a vibrator 10, a cylinder 7 having an inflow pipe 12 on a side surface, and a body 9 having a valve port 8 and an outflow pipe 13. Are respectively joined to a closed structure by welding or the like.
The control valve body 1 accommodates a rotor 3, a driver 4 and a valve body 5, and the rotor 3 is pressed against the driver 4 by an appropriate urging means. Further, the valve element 5 is capable of controlling the opening of the valve port 8 by rotating together with the rotor 3. The inflow pipe 12 may be connected to the body 9 (not shown) instead of being attached to the side of the cylinder 7.

The difference between the vibrator 10 according to the present invention and the conventional vibrator will be described. The vibration mode of the vibrator 10 to the driver 4 of the present invention is the same as that of the related art, and the rotational direction is switched by controlling the positional relationship between the node of the vibration generated by the vibration of the vibrator 10 and the driver 4. The rotor 3 is driven by the driver 4.
Is to rotate. 19 is the piezoelectric element 2
B is a through hole provided to achieve an electric power supply means such as a lead wire (not shown).

In the present invention, the structure of the vibrator 10 includes a vibrator 10a in which a piezoelectric element 2a or an electrostrictive element is joined to an upper surface of an elastic body 6a, and a piezoelectric element The element 2b or the transducer 10b formed by joining the electrostrictive elements is formed by two transducers.

The operation of the vibrator 10 will be described. FIG. 3 schematically shows an example in which the piezoelectric elements 2a and 2b are divided into four parts and the vibrator 10 vibrates in a half mode, that is, when one node of vibration occurs. 3A is a diagram viewed from the piezoelectric element side of the vibrator 10a, FIG. 3B is a schematic vibration diagram viewed from the cross-sectional direction of the vibrator 10a, and FIG. 3C is a diagram viewed from the piezoelectric element side of the vibrator 10b. FIG. 3D is a schematic view of the vibration viewed from the cross-sectional direction of the vibrator 10b, and FIG. 3E is a vibrator 10a and 10b.
5A and 5B are schematic diagrams of the vibration of the vibrator 10 synthesized in the cross section viewed from the cross-sectional direction. A solid line indicates a deformed state when an (+) voltage of an AC voltage is applied, and a dotted line indicates a deformed state when a (-) voltage is applied. ing.

In FIG. 3A, the piezoelectric element 2a is divided into four parts, and all areas have the same polarity. Here, when current is applied only to the areas 20 and 21 of the piezoelectric element 2a, a node of vibration is generated at the position of N1, and as shown in FIG.
23 vibrate in opposite phases. FIG.
The piezoelectric element 2b in FIG.
It is divided and all areas have the same polarity. Here, when current is applied only to the areas 26 and 27 of the piezoelectric element 2b, a node of vibration is generated at the position of N3, and as shown in FIG.
5 will oscillate in opposite phase. Here, the vibrator 10
FIG. 3 (e) shows a schematic vibration diagram of the vibrator 10 synthesized by a and 10b. That is, the vibrators 10a and 10b vibrate so that the phases are opposite to each other in the up-down direction.

Therefore, at the joint between the elastic body 6a of the vibrator 10a and the elastic body 6b of the vibrator 10b, the vibrations of both are canceled out, so that the joint of the cylinder 7 joined to the elastic body 6b is Therefore, the vibration generated by the vibrator 10 does not propagate to the cylinder 7 as a transverse wave or a longitudinal wave. On the other hand, rotor 3
Rotates according to the positional relationship between the node of the vibration generated by the vibrator 10 b and the driver 4. To reverse the rotor 3
Electric current is applied only to areas 20 and 22 of the piezoelectric element 2a to generate a vibration node at the position N2.
In b, by energizing only the areas 24 and 26 to generate a node of vibration at the position of N4, the positional relationship between the driver 4 and the node becomes opposite to that described above. 3 can be reversed. In addition, the area 23 or 27 can be used as a signal to a self-excited circuit or a microcomputer circuit for performing a stable oscillation operation by using a voltage generated by the vibration of the vibrator 10 as a feedback signal.

The thrust spring 14 applies a thrust load to the driver 4 side and the body 9 side and rotates together with the rotation of the rotor 3 and the valve body 5. Spring 15 into the cylindrical hole
Is inserted, the ball 16 abuts against the concave portion 17 at the center of the body 9 via the spring 15, and the thrust spring 14 is set to have a larger spring force than the spring 15. The present invention and the conventional product are exactly the same in that the lower surface is pressed against the body 9 and also pressed against the driver 4 via the rotor 3.

FIG. 2 is a sectional view showing a second embodiment of the present invention. This is a shape in which a brim is provided on the vibrator 10b.
A gap is provided with the outer circumference of b, and the outer circumferential surface of the cylinder 7 is bonded at the outer circumference of the collar. That is, a collar is provided to more clearly define a node of vibration in the shape of the vibrator.

In FIG. 3, the piezoelectric elements 2a and 2
b has the same polarization direction at the time of bonding to the elastic body 6a and the elastic body 6b.
In other words, the present invention can be realized even when bonding is performed with the polarization direction reversed, and the energization area is made the same in the vertical direction.

Although not particularly shown, the present invention can be realized by dividing the piezoelectric element 2 into even numbers. Further, the present invention can be realized even if the polarization direction of the piezoelectric element 2 is set to the same polarity, and all the areas are connected in series so as to match each vibration mode. Further, the bonding surface and the number of the piezoelectric elements 2 are not restricted.

The vibrator exemplified in the embodiment may be one in which the elastic body 6b and the cylinder 7 are integrated, or one in which the elastic body 6b, the cylinder 7 and the driver 4 are integrated. In these inventions, there is an advantage that the vibrator 6 can be manufactured by a low-cost method such as pressing or forging.

[0023]

As described above, according to the present invention, the construction of the vibrator is performed in two sets, so that the vibration generated by the vibrator is prevented from propagating to the tip of the cylindrical portion and the rotation of the rotor is ensured. The effect of having the advantage that can be achieved is enormous. Reference numeral 19 denotes a through hole provided in the piezoelectric element 2b for achieving an electric power supply means such as a lead wire (not shown). Rotation can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a vibration mode of a vibrator 10.

FIG. 4 is a sectional view showing a conventional flow control valve using an ultrasonic motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Control valve body 2, 2a, 2b Piezoelectric element 3 Rotor 4
Driver 5 Valve body 6, 6 a, 6 b Elastic body 7 Cylinder 8 Valve port 9 Body 10, 10 a, 10 b Vibrator 11 Sectional position generated by vibrator 10 12 Inflow pipe 13
Outflow pipe 14 Thrust spring 15 Spring 16 Ball 17 Depression formed in the center of body 9 18 Stopper pin 19 Through hole 20, 21, 22, 23 Areas of piezoelectric element 2a 24, 25, 26, 27 Piezoelectric element 2b Each area

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[Procedure amendment]

[Submission date] October 4, 1999 (1999.10.
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Ultrasonic motor and ultrasonic motor
Flow control valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H062 AA07 BB33 CC05 DD01 EE07 FF41 5H680 AA18 BB16 DD01 DD22 DD23 DD53 DD92 EE07 FF02 GG41

Claims (2)

[Claims] 1. A vibrator 1 comprising a piezoelectric element 2a or an electrostrictive element joined to an upper surface of an elastic body 6a.
2a of the vibrator 10b formed by joining a piezoelectric element 2b or an electrostrictive element to the bottom surface of an elastic body 6b having a concave shape.
An ultrasonic motor formed of two vibrators and provided with a driver 4 on a lower surface of the elastic body 6b. 2. A vibrator 10 in which a piezoelectric element 2 or an electrostrictive element is joined to an upper surface of an elastic body 6, a cylinder 7, and a body 9 having a valve port 8 are each formed in a sealed structure by welding or the like. The control valve body 1 is provided, and the rotor 3 is rotated in the control valve body 1 via the driver 4 by the vibration of the vibrator 10.
And a control valve using an ultrasonic motor provided with a valve element 5 that changes the opening of the rotor 3 with respect to the valve port 8 by an appropriate urging means. The piezoelectric element 2a is provided on the upper surface
Alternatively, the vibrator is formed of two vibrators, a vibrator 10a formed by joining an electrostrictive element and a vibrator 10b formed by joining a piezoelectric element 2b or an electrostrictive element to the bottom surface of an elastic body 6b having a concave shape. And flow control valve.