JPS6077684A - Actuator - Google Patents

Abstract

PURPOSE:To accelerate the response speed and to improve the accuracy of an actuator by laminating piezoelectric effect ceramics, amplifying the distortions of the ceramics, and removing them. CONSTITUTION:The first and second drivers 7, 8 are composed by laminating piezoelectric ceramics. When the first driver 7 is energized, an output shaft 25 is pushed by the distortion. The second driver 8 is rotated by the displacement of the output shaft 25 around the recess 30 of the body 21 as a center. Then, when the first driver 7 is interrupted and the second driver 8 is energized, the output shaft 25 is pressed. The first driver 7 is rotated around the recess 29 of the body 21 as a center by the displacement of the shaft 25 to the original state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator that can be used as a motion source for an arm of an industrial robot or the like by utilizing the strain of a laminated piezoelectric effect cephmic.

For example, actuators in industrial robots generally use motors or hydraulic/pneumatic equipment to output rotational or linear motion.

However, in addition to the above-mentioned 7 units being large and heavy, there are other types that use a motor.
Since the startup of rotation is slow, there is a problem of slow response speed and poor accuracy.In addition, in those using hydraulic and pneumatic equipment, there is a problem of friction loss or Due to pressure fluid leakage, etc., there are problems with slow response speed and poor accuracy.

The present invention has been made in view of the above circumstances, and its purpose is to provide an actuator with high response speed and high precision.

The present invention is based on the fact that a laminated piezoelectric effect cephmic causes distortion when a voltage is applied, and this distortion can be amplified and extracted as a large amount of displacement.

An embodiment of the present invention will be described below based on the drawings.

First, the laminated piezoelectric effect ceramic used in this example will be explained with reference to FIG.

Kono Piezoelectric Effect Ceramic 11-t, recently developed and used by NEC Corporation, is a device made by laminating and sintering cefmic plates 2 and internal electrode plates 3 alternately. After cutting the internal electrode plate 3 into a shape and size, the internal electrode plate 3 exposed on the entire circumference is covered with insulating material 4 every other layer on both left and right sides.
It is electrically insulated and has external electrodes 5 and 6 formed on both left and right sides. Therefore, every other layer of the internal electrode plate 31-1 is electrically connected to the external electrode plate 5 and
C is connected. Wood piezoelectric effect Cefmic 1 differs from conventional piezoelectric effect Cefmic 1 in that it generates mass-market distortion even when the applied voltage is low (for example, even at 100 μm), and does not deteriorate at all even when voltage is repeatedly applied (according to central testing). According to the authors, no deterioration was observed even when the voltage pass μ'fe was continuously applied more than 500 million times.2 On the other hand, this piezoelectric effect Cefmic 1 has the same characteristics as the conventional piezoelectric effect Cefmic 1, which has a layered structure. It is difficult to make the thickness too thick, and the limit is about 9 sheaths. By the way, the Cefmic plate 2 of this piezoelectric effect Cefmic 1 is made of a binary solid solution ceramic of magnesium/lead niobate and lead titanate, (1~X)Pb (
Among Mg1/s Nb2/s) Os -PbTiO3, for example, one in which X is close to 65 is used.

Next, in FIGS. 2 and 6 showing the actuator according to the present invention, 7 and 8 are first and second driving bodies, which are used to extract the strain of the piezoelectric effect cephmic described above as a relatively large displacement. Its concrete structure is shown in FIGS. 4 and 5. That is, Figure 4 and @
In Fig. 5, reference numeral 9 denotes a metal cylindrical body, and a connector 1 that also serves as a plug body is connected to a female thread 10 formed on one end side of this cylindrical body 9.
1 are screwed together and fixed with a lock nut 12. 1
Reference numeral 6 is an insulating cylinder made of, for example, polyaceter μ resin, which is layered in the hollow interior of the cylinder 9 and has a small fc friction coefficient. These piezoelectric effect cefmics 1 are mutually bonded to the insulating tube 13 and are slidable relative to the insulating tube 13. Reference numeral 14 denotes an electric wire with low electrical resistance, in which a silver wire is used, and the electrodes of the same polarity of the external electrodes 5 and 6 are electrically connected at one point by the equal VC when soldered. This electric wire 14 is brazed with a slack left between the piezoelectric ceramics 1. In addition, the electric wire 14 is a piezoelectric effect cefmic 1
The space 8 created when the wire is inserted into the insulating tube 13 is used for wiring. Then, one piezoelectric effect cephmic 10 and both external electrodes 5 and 6 located on the connector 11 side
Lead wires 15 and 16 connected to the cylindrical body 9 are led out to the outside of the cylindrical body 9, so that when the lead wires 15 and 16 are connected to a power source, each piezoelectric effect cefmic 1 is connected in parallel to the power source. . Note that 17 is a ceramic insulating plate provided between the piezoelectric effect cefmic 1 and the connector 11. Reference numeral 18 denotes a plunger as an actuating part, and this plunger 18 is slidably inserted inside the other end of the tube 9, and its insertion end is brought into contact with the piezoelectric effect ceramic 1 via a ceramic insulating plate 19. ing.

The actuator of the present invention further amplifies and outputs the displacement taken out from the drive body configured as described above. It is constructed by fastening lids 22 and 23 with screws 24 to both upper and lower sides in the drawing of a short cylindrical body 21.

25Vi output 8 (1yc output shaft, supported in the center of the upper lid body 22 via a bearing 26 so that it can reciprocate in the vertical direction wJ, and a bottom rod 27 is screwed to the lower end located at 20 yen of the base. 28 is an annular projection protruding from the circumferential surface of the body 21, and the upper and lower surfaces 1IllllI of this are provided with, for example, six hemispherical recesses 129 and 30. are formed at equal intervals. 31 is a hemispherical recess formed in the upper part of the output shaft 25 so as to correspond to each time F!A 29 and to be located above these;
Reference numeral 32 denotes a hemispherical recess formed in the lower part of the iron 27 so as to correspond to each of the four parts 60 and to be located below these parts.

Six each of the first and second driving bodies 7 and 8μ are arranged radially in a vertical positional relationship in the base body 20, and the spherical tip of the plunger 18 on the center side is inserted into the recesses 61 and 62, respectively. Connector 1 with mated
One spherical tip is fitted into the recesses 29 and 60, respectively. As a result, the first driving body 7 has a configuration in which the plunger 18 side on the center side is tilted diagonally upward and both ends are rotatably connected to the output shaft 25 and the body 21, respectively, and the second gwJ With respect to the handle a, the plunger 18 side on the center side of the cane is tilted diagonally downward, and both ends are connected to the rod 2.
7 and the fuselage '211C times 111ilrr function is connected.

Next, the operation of the above structure will be explained. In this embodiment, the first and second driving bodies 7 and 8 are basically energized alternately. First, when the first driving body 7 is energized, a predetermined voltage is applied to each piezoelectric effect ceramic 1, and each piezoelectric effect ceramic 1 is distorted so as to extend in the stacking direction.
This distortion is minute in each piezoelectric effect ceramic 1, but since a large number of piezoelectric effect ceramics 1 are stacked,
The sum of the strains of the large number of piezoelectric cephmics 1 acts on the plunger 18, so that the plunger 18 is strongly pressed against the piezoelectric cephmic 1 and is linearly displaced in the direction of arrow A.

Then, since the first driving body 7 is disposed in an upwardly inclined manner, the displacement of the plunger 1B in the direction of the arrow causes a component force that tries to push up the output shaft 25, and as a result, the first driving body 7 The driving body 7 rotates in the direction of arrow B around the recess 29 of the body 21 and linearly displaces the output shaft 25 so as to advance in the direction of arrow C. By this displacement of the output shaft 25 in the direction of arrow C, the second driving body 8 is rotated in the direction of the arrow about the four parts 60 of the body 21 while pushing the plunger 18 into the cylinder body 9. The state after the output shaft 25 advances is shown by the two-dot chain line in FIG. The piezoelectric effect Cefmic 1 returns to its original state as if shrinking, and
A predetermined voltage is applied to the piezoelectric effect cefmic 1 of the second driving body 8 and the plunger 18 is distorted in the same manner as described above.
is strongly pressed by the piezoelectric effect Cefmic IK and is linearly displaced in the direction of arrow E.

Then, since the second driving body 8 is arranged to be inclined downward, a component force is generated in the displacement of the plunger 18 in the direction of the arrow E, which tends to push down the Eri output @25. The driving body 8 rotates around the recess 60 of the body 21 in the direction opposite to the arrow C, and positions the output shaft 25 in the direction opposite to the arrow C by the VC degree so as to move the output shaft 25 backward in the direction opposite to the arrow C. Due to the displacement of , the drive body 7 of the cylinder 1 moves in the opposite direction of the arrow B as the plunger 18 is pushed into the cylindrical body 9.
Everything returns to the original state shown in solid lines in FIG. Thus,
The output shaft 25 reciprocates in the direction of arrow C and the direction opposite to arrow C by alternately energizing the first and second drive 1#J pins 7 and 8.

Incidentally, the amount of displacement of the plungers 18 of the first and second driving bodies 7 and 8 is relatively small, and it is extremely difficult to immediately drive an arm or the like of an industrial robot by the plungers 18Vc. However, according to the actuator of the present invention, the displacement of plunger 18 can be amplified and output. To explain this in principle with reference to Fig. 6, the driving body has a VC between energized MiJ O-Y+, and when it moves forward by energization, it rotates by an angle σ around 0 and is positioned at 0-Y211Ji'. The amount of advance displacement of the plunger at that time is ΔX, and the amount of displacement of the output shaft is y.
Then, BINa6Δx/y Therefore, y=Δx/BIN
a and yzru. However, θ is relatively small, and SINθ(1
Therefore, the displacement fk of the plunger 18 can be amplified and extracted as a large reciprocating displacement of the output shaft 25, and the output shaft 25 can directly drive an arm of an industrial robot or the like.

In addition, in the above firearm example, the first and second driving bodies 7 and 81C
Therefore, the output shaft 25 is displaced in the direction of the arrow C and the direction opposite to the arrow C, but for example, the driver 8 of the moth 12 is omitted,
Instead, a spring may be provided that biases the output shaft 25 in the opposite direction of arrow C. As is clear from the above description, the present invention uses a driver to extract the strain of the piezoelectric effect cephmic as a relatively large displacement. Furthermore, since the displacement can be amplified and output, it can be used as a drive source for an arm of an industrial robot, etc. Moreover, since the groove bottom uses the electrostrictive effect of piezoelectric effect ceramic to displace the entire output section, it has various excellent effects such as good response and high degree accuracyf! : It is something that is played.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view schematically showing a piezoelectric effect cefmic, and FIGS. 2 and 3 are longitudinal sectional views and partial plan views of the μ actuator. In the figure, 1 is a piezoelectric effect ceramic, 7.8μ first degree second driving body, 9 is a cylindrical body, 18 is a full force part, 20 is a base body, and 25 is an output shaft (output part). Figure 1 Figure 2 Figure 3 Area Figure 5 Figure 14 t) Figure 40 Figure 6

Claims (1)

[Claims] 1. A base body, an output part provided on this base body so as to be able to reciprocate, and a large number of laminated piezoelectric effect cephmics stored in a stacked state in a cylinder, and the actuating part being actuated by the distortion of these piezoelectric effect cephmics caused by the application of voltage. a driving body for displacing the driving body, the driving body is arranged to be inclined with respect to the reciprocating direction of the output section n11, and one end side and the other end side of the driving body are rotatable to the base body and the output section, respectively. An actuator characterized in that the actuator is connected to transmit the displacement of the cutting part to the output part.