KR100791592B1 - Linear manipulator with piezoelectric device - Google Patents

Abstract

A linear manipulator with a piezoelectric device is provided to improve resolution of the linear manipulator by moving a mover in two step displacement. A linear manipulator with a piezoelectric device includes a first clamp instrument(10), a second clamp instrument(40), an operating instrument(20), a first standard part(31), a second standard part(32), and a bottom part(30). The first and the second clamps are placed at a predetermined distance from each other and support and transfer a mover(50) in a lower part of the mover. The operating instrument is placed between the first and the second clamps. The first standard part connects the first clamp instrument to the operating instrument. The second standard part connects the second clamp instrument to the operating instrument. The bottom part is connected with the first and second standard parts and one end of the operating instrument, and is fixed to the ground.

Description

Linear Manipulator with Piezoelectric Device

1A is a schematic diagram of a conventional self-supporting driver.

FIG. 1B is a configuration diagram for explaining the operation of the self-worm driver shown in FIG. 1A.

2 is a schematic diagram of an adjusting apparatus using a conventional piezoelectric element drive.

3 is a perspective view of a linear driver using a piezoelectric element according to the present invention.

4A to 4C are configuration diagrams for describing an operation principle of a linear driver using a piezoelectric element.

5A and 5B are diagrams for explaining the operation of the clamp mechanism.

6A and 6B are configuration diagrams for explaining the operation of the drive mechanism.

7 is a configuration diagram of a linear driver using a piezoelectric element according to the present invention connected to a power source.

8A is a voltage waveform diagram applied to a linear driver using a piezoelectric element according to the present invention for moving the mover to the right.

8B is a voltage waveform diagram applied to a linear driver using a piezoelectric element according to the present invention for moving the mover to the left.

9A to 9G are diagrams for explaining a process of moving a mover by performing a single stroke by a linear driver using a piezoelectric element according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear driver using a piezoelectric element, and more particularly to a linear driver using a piezoelectric element capable of moving two step displacement by performing one stroke (cycle).

Piezoelectric devices (piezoelectric devices) are semiconductor devices whose length varies in proportion to the input voltage, and since their length can be finely adjusted linearly, they are used in various applications such as drivers of ultra-precision machinery. . Among such conventional application devices, a conventional linear driver, in which a predetermined number of piezoelectric elements are installed and operated by adjusting the length thereof, will be described with reference to the drawings.

1A is a schematic diagram of a conventional inchworm type motor, in which first and second clamps C1 and C2 having piezoelectric elements arranged in a direction perpendicular to a traveling direction, and first and second clamps ( It consists of a motor frame MF having a piezoelectric element positioned between C1 and C2 and arranged in parallel with the traveling direction. The self-assembly-type driver configured as described above moves along the guideway G as each piezoelectric element is driven to increase and decrease in length. This operation will be described in detail with reference to the drawings as follows.

FIG. 1B is a configuration diagram for explaining the operation of the self-worm driver shown in FIG. 1A.

First, in order to move the insect repellent driver placed on the guideway G from the equilibrium state, the first clamp C1 is extended to the length of the piezoelectric element and is thus fixed to the wall of the guideway G (step S1). Then, the piezoelectric element of the motor frame MF extends with respect to the first clamp C1, so that the second clamp C2 located at the other end of the motor frame MF is along the length G along the guide path G. ), (Step S2). At this time, the length of the piezoelectric value of the second clamp C2 is increased, and accordingly, the second clamp C2 is fixed to the wall of the guide path (step S3). In the state where the second clamp C2 is fixed to the wall of the guide road, the piezoelectric element of the first clamp C1 contracts again, so that the first clamp C1 is separated from the guide road G (step S4). Then, the piezoelectric element of the motor frame MF contracts with respect to the second clamp C2, so that the first clamp C1 located at the end of the motor frame MF along the guide path G has a length L. FIG. Move by (step S5). Then, the length of the piezoelectric value of the first clamp C1 is increased, and accordingly, the first clamp C1 is fixed to the wall of the guide path (step S6). After that, the step S1 and the subsequent steps are repeated. In other words, the conventional self-learning driver repeatedly performs the process of step S6 in step S1 as one stroke.

When the self-leavening driver performs one cycle, the piezoelectric element of the motor frame MF moves only as much as the length L. That is, the distance or displacement of the conventional insect repellent drive by performing one stroke is one step. One step is the resolution of the insect insect driver. Therefore, if the insect insect driver drives one stroke in n steps, its resolution is 1 / n times.

On the other hand, as another example of a linear driver using a piezoelectric element, an adjusting device using a piezoelectric element drive described in US Patent No. 5,424,597 may be mentioned. This will be described with reference to FIG. 2.

As shown in FIG. 2, a conventional apparatus using a piezoelectric element drive includes a translation unit 1 and 2 having two piezoelectric elements attached thereto, and a link 3 and 4 supporting each of the translation unit 1 and 2. And it supports and consists of several elements (the detailed description is omitted).

However, the adjusting device using the piezoelectric element drive alternately moves the driven elements 8 by the length of the piezoelectric element constituting each of the translating parts, as the translational parts 1 and 2 alternately perform linear motions. . In other words, similar to the operation of the conventional insect drive, the adjustment device using the piezoelectric element drive performs one stroke so that the distance or displacement of the driven element 8 moves by one step. Therefore, one step becomes the resolution of the adjusting device using the piezoelectric element drive, and the resolution is 1 / n times when one stroke is driven by n steps.

Therefore, since only one step can be moved by performing a linear drive using a conventional piezoelectric element and the resolution thereof is also small, there is a limit to moving the driven element finely.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems as described above, and to provide a linear driver using a piezoelectric element capable of moving two step displacement by performing one stroke (cycle).

The present invention is to provide a linear driver using a piezoelectric element having a high resolution by performing two strokes to move two step displacements.

To this end, the linear actuator using the piezoelectric element according to the present invention is located at a predetermined distance from each other, the first clamp device and the second clamp device for supporting and moving the mover from the bottom of the mover, the first and second clamp A drive device positioned between the first reference device, the first reference device connecting the first clamp device and the drive device, the second reference device connecting the second clamp device and the drive device, and the first and second devices. This is achieved by including a base portion connected to one end of the drive device and fixed to the bottom.

Here, while the clamp device of any one of the first clamp device or the second clamp device supporting the mover is separated from the mover and the other clamp device supports the mover, the driving device is the other one. Perform a half stroke to move the mover one step with the clamping device of. Further, after the mover moves one step, if the one clamp device supports the mover and the other clamp device is separated from the mover, the drive device returns to its original position and the one clamp device And half the stroke to move the mover one step further.

The configuration and operation of a linear driver using a piezoelectric element according to the present invention will be described in detail with reference to the drawings.

3 is a perspective view of a linear driver using a piezoelectric element according to the present invention, which is located at a predetermined distance from each other, and includes a first clamp device 10 for supporting and moving the mover 50 under the mover 50; First reference for connecting the second clamp device 40, the drive device 20 positioned between the first and second clamps 10, 40, and the first clamp device 10 and the drive device 20. Of the second reference unit 32 connecting the unit 31, the second clamp device 40, and the driving device 20, and the first and second reference units 31 and 32 and the driving device 20. One end is connected to the bottom portion 30 is fixed to the bottom.

Here, the first clamp device 10 includes a first piezoelectric element 11 installed so that its longitudinal direction is horizontal, first and second body portions connecting both ends of the first piezoelectric element 11; On the opposite side of the first support portion 12, which is connected to one end of the first and second body portions in the same direction, and supports the mover 11, and the first piezoelectric element 11 around. It is positioned and connects the other end of the first and second body portion and consists of a first hinge portion connected to the first reference portion 31.

In the same structure as the first clamp device 10, the second clamp device 40 connects both ends of the second piezoelectric element 41 and the second piezoelectric element 41 so that the longitudinal direction thereof is horizontal. The second and second body parts 42 and the second piezoelectric element 41 which connect the third and fourth body parts, one end in the same direction as the third and fourth body parts, and support the mover 11. The second support portion 42 is located on the opposite side of the first support portion 42 and connects the other ends of the third and fourth body portions and is connected to the second reference portion 32.

The drive device 20 includes a third piezoelectric element 21 and a third piezoelectric element having a longitudinal direction in a direction perpendicular to the longitudinal direction of the first piezoelectric element 11 and the second piezoelectric element 41. Fifth and sixth body portions connecting both ends of the 21, third hinge portions connecting one end positioned in the same direction of the fifth and sixth body portions and connected to the first reference portion 31; The fourth piezoelectric element 21 is positioned on the opposite side of the third hinge portion and connects the other ends of the fifth and sixth body portions, and consists of a fourth hinge portion connected to the second reference portion 32.

Here, the first and second support portions 12 and 42 are formed in a predetermined shape, preferably a semi-cylindrical protrusion to support the mover 50 to make line contact with the mover.

The principle of the linear driver configured as described above will be described with reference to FIGS. 4A to 4C.

First, as shown in FIG. 4A, when the linear driver is in an equilibrium state, the first and second piezoelectric elements 11 and 41 of the first and second clamp devices 10 and 40 maintain the equilibrium length, and The first and second supports 12, 42 support the mover 50, and the third piezoelectric element 21 of the drive device 20 also maintains an equilibrium length, so that the drive device 20 has a first length. And the second clamp device 10, 40.

When the shape of the second clamp device 10 and the drive device 40 of the linear driver changes in the equilibrium state of FIG. 4A (actually, the second and third piezoelectric elements 41 and 21 are stretched, and accordingly, the second support). The additional move away from the mover and towards the first and second reference drive; as described in detail below), the mover 50 moves to the right by one step ST 1 relative to the bottom 30. do. That is, as shown in FIG. 4B, the height of the second clamp is lowered (substantially the second piezoelectric element is stretched) so that the second support part 42 is separated from the mover 50. The drive device 20 then pulls the first and second reference portions (substantially the third piezoelectric element 21 stretches), so that the first and second clamp devices 10, 40 are bottomed 30. ) Contraction (approaching toward the bottom 30). In this case, since the first clamp device 10 supports the mover 50, the mover 30 may move the first clamp device (ie, the distance of the first reference part 31 relative to the bottom part 30). 10) to the right. Here, if the distance moved by the mover 30 is defined as one step ST1, the mover 50 moves by one step ST1 by performing an operation in which the driving device 20 contracts.

As shown in FIG. 4B, in the state where the mover 30 has moved one step, the second and third piezoelectric elements 41 and 21 of the linear driver return to their original lengths and the first support of the first clamp device 10. When the 12 moves away from the mover (substantially the first piezoelectric element 11 is stretched), the mover 50 moves by one step ST 1 to the right with respect to the bottom 30. That is, as shown in FIG. 4C, the second clamp device 40 returns to its original length (substantially the length of the second piezoelectric element 41 is reduced), and the second support portion 42 supports the mover 50. The first support of the first clamp device 10 is separated from the mover (substantially the length of the first piezoelectric element 11 is increased). Then, the third piezoelectric element 21 of the drive device 20 returns to its original length, whereby the first and second reference portions to which the first and second clamp devices 10 and 40 are fixed are bottom portion 30. Away from At this time, since the second clamp device 40 supports the mover 50, the mover 50 is moved by the distance that the second reference part connected to the second clamp device 40 moves based on the bottom part 30. Move to the right with the second clamp device 40 (substantially the third piezoelectric element 21 is reduced). Here, if the distance moved by the mover 30 is defined as one step ST1, the mover 50 moves by one step ST1 by performing the operation of the driving device 20 to return.

Therefore, the linear driver using the piezoelectric element according to the present invention moves the mover two steps by performing one stroke.

On the other hand, the rollers 51 positioned above and below the mover 50 maintain the vertical position of the mover when the first and second support portions of the first and second clamp devices support and drop.

Up to now, although the operation of the linear driver using the piezoelectric element according to the present invention has been schematically described, the operation of the linear driver with the operation of the hinge positioned substantially between the first and second clamp device and the drive device is shown in FIG. The explanation is as follows.

First, since the structure and operation | movement of the 1st clamp device 10 and the 2nd clamp device 40 are the same, the operation | movement is demonstrated taking the 1st clamp 10 as an example.

5A and 5B are diagrams for explaining the operation of the clamp mechanism.

As shown in FIG. 5A, when the first clamp device 10 is in an equilibrium state, the first piezoelectric element 11 maintains the predetermined length L1, and the first support 12 and the first hinge Maintaining a state away from the first piezoelectric element 11 on the basis of the first piezoelectric element (11). At this time, as shown in FIG. 5B, when the first clamp device 10 is operated and its length is increased, the first clamp device 10 is referred to as a “horizontal equilibrium state” indicated by a dotted line on the basis of the first reference unit 31. Its position changes from " horizontally stretched state " That is, when the first piezoelectric value is extended to the length (L2), the position of the body portion fixing the both ends of the first piezoelectric element 11 is far from the first reference portion 31 and accordingly the first support portion 12 and the first hinge approach toward the first piezoelectric element 11. At this time, since the first hinge is fixed to the first reference portion 31, the first piezoelectric element 11 extends in the horizontal direction and moves vertically to approach the first hinge, and the body portion moves with the horizontal movement. A vertical movement approaching the first hinge is performed. In addition, the first support 12 moves vertically approaching the first hinge as the body portion operates.

As described so far, the first clamp device 10 repeatedly operates the "horizontal equilibrium state" and the "horizontal stretch state".

Meanwhile, the operation of the driving device 20 together with the hinge will be described below.

6A and 6B are configuration diagrams for explaining the operation of the drive mechanism.

As shown in FIG. 6A, when the driving device 20 is in an equilibrium state, the third piezoelectric element 21 maintains the predetermined height H1, and the third hinge and the third hinge connected to the first reference part 31 are formed. The fourth hinge connected to the second reference part 32 maintains a state away from the third piezoelectric element 21 based on the third piezoelectric element 21. At this time, as shown in FIG. 6B, when the driving device 20 is operated and its length is increased, the driving device 20 is represented by a solid line from the "vertical equilibrium state" indicated by the dotted line on the basis of the bottom part 30. Its position is changed to "vertically stretched state". That is, when the third piezoelectric element 21 is extended to the length (H2), the body portion fixing both ends of the third piezoelectric element 21 is extended to both sides with respect to the third piezoelectric element 21. At this time, since the body portion located at one end of the third piezoelectric element 21 is fixed to the bottom portion 30, the body portion located at the other end of the third piezoelectric element 21 is doubled in the vertical direction with respect to the bottom portion 30. Relatively far away. As the body moves vertically, the third hinge connected to the first reference part 31 and the fourth hinge connected to the second reference part 32 move vertically simultaneously with the horizontal movement toward the third piezoelectric element 21. . At this time, the bottom part 30 and the first and second reference parts 31 and 32, which are fixed at two places, perform only horizontal movement toward the third piezoelectric element 21. Accordingly, the first and second reference units 31 and 32 may perform only the movement of horizontally moving the first and second clamp mechanisms 10 and 40.

As described so far, the drive device 20 repeatedly operates the "vertical equilibrium state" and the "vertical stretch state".

Accordingly, the first clamp device 10 and the drive device 20 are connected to each other through the first reference unit 31, and the second clamp device 40 and the drive device 20 are connected to the second reference unit 32. Since the first and second clamp devices 10 and 40 and the driving device 20 are controlled with a time difference, since the first and second clamp devices 10 and 40 are connected to each other, the movement of the mover 30 may be controlled.

The process of moving the mover by controlling the linear driver using the piezoelectric element according to the present invention configured as described above will be described below.

7 is a configuration diagram of a linear driver using a piezoelectric element according to the present invention connected to a power source.

The first and second clamp devices 10, 40 and the drive device 20 are semiconductor devices controlled by voltage, and include first, second, and third piezoelectric elements 11, 41, and 21. Therefore, the first piezoelectric element 11 is connected to the voltage VL, the second piezoelectric element 41 is connected to the voltage VR, and the third piezoelectric element 21 is connected to the voltage VM.

In this connection state, the mover can be moved by applying a voltage while staggering each piezoelectric element. For example, a process of moving the mover to the right based on the linear driver will be described as follows.

As shown in FIG. 8A, when a pulse wave voltage is applied to the first, second, and third piezoelectric elements 11, 41, and 21, the linear driver operates as shown in FIGS. 9A to 9G to move the mover. Move it.

At the time t0, since the voltages VL, VR, VM are not input to the first, second, and third piezoelectric elements 11, 41, 21, the linear driver is in an equilibrium state as shown in Fig. 9A. Will be in.

At the time point t1, when the voltages VL and VM are not input to the first and third piezoelectric elements 11 and 21, and the voltage VR is input to the second voltage element 41, the linear driver is turned on. As shown in 9b, the length of the second clamp device 40 is extended so that the second support is separated from the mover.

When the second support portion of the second clamp device 40 is kept away from the mover, at the time t2, the voltage VL is not input to the first piezoelectric element 11 and the third piezoelectric element 21 is not present. ), When the voltage VM is inputted, the driving device 20 increases in length as shown in FIG. 6B. That is, as shown in FIG. 9C, the drive device 20 is extended to support the mover 50. At the same time, during the process of extending until the drive device 20 supports the mover 50 in the vertical equilibrium state, as shown in FIG. 4B, the first reference part 31 and the second reference part 32 are driven by the drive device ( Go to 20). Therefore, as shown in FIG. 9C, the first clamp device 10 fixed to the first reference portion 31 to support the mover 50 is equal to the distance (Δstep 1 step) together with the mover 50. Move)) to the right.

When the mover 50 keeps moving to the right by Δx, at time t3, the voltage VR applied to the second piezoelectric element 41 is grounded to reduce the length of the second clamp device 40 so that the horizontal Return to equilibrium. That is, as shown in FIG. 9D, the length of the second clamp device 40 is reduced so that the second support 42 supports the mover. Thus, the first and second clamp devices 10, 40 maintain a horizontal equilibrium state, and the drive device 40 maintains a vertically stretched state.

At the time point t4, when the voltage VL is applied to the first piezoelectric element 11, the length of the first clamp device 10 is increased, so that the first support 12 is separated from the mover 50. That is, as shown in FIG. 9E, the first clamp device 10 is kept away from the mover 50 and stretched horizontally.

When the first support part of the first clamp device 10 is kept away from the mover 50, when the voltage VM applied to the third piezoelectric element 21 is grounded at a time point t5, the driving device 20 is grounded. Is changed from the vertically stretched state of FIG. 6B to the vertical equilibrium state of FIG. 6A. While the drive device 20 changes from the vertically stretched state to the vertical equilibrium state, the drive device 20 pushes the first reference part 31 and the second reference part 32 out of itself as shown in FIG. 4C. Therefore, as shown in FIG. 9E, the second clamp device 40 fixed to the second reference portion 32 to support the mover 50 has a distance of Δx together with the mover 50 (one step (1 step). Move)) to the right.

Then, by grounding the voltage VL applied to the first piezoelectric element 11 at time t6, the linear driver moves the mover 50 by 2Δx as shown in FIG. 9F (two steps (2 steps). )) And return to the state of time t0.

Accordingly, the linear driver according to the present invention performs one cycle by operating the first and second clamp devices 10 and 40 and the driving device 20 during the time t6 at the time t0. You can move the mover two steps.

In the meantime, the above example of moving the mover 50 to the right side of the drawing based on the linear driver has been described. However, the order of input of the voltages VL, VR, VM applied to the first and second piezoelectric elements and the driving device is described. If it is input as shown in FIG. 8B, the linear driver may move the mover to the left side of the drawing based on itself. Detailed description thereof will be omitted since the operation of the linear driver is the same as that of FIG. 8B.

The linear driver using the piezoelectric element according to the present invention described so far can move the mover two steps by performing one stroke, thereby doubling the resolution of the conventional linear drive ratio.

Therefore, the linear driver according to the present invention can be used for a joint driver of a small ultra-precision robot manifold, a driver of a small ultra-precision machine, a table driver for an AFM, a driver for a small three-dimensional measuring instrument, and the like.

Claims (5)

A first clamp device 10 and a second clamp device 40 positioned apart from each other by a predetermined distance and supporting and moving the mover 50 under the mover 50; A driving device 20 positioned between the first and second clamps 10 and 40, A first reference unit 31 connecting the first clamp device 10 and the driving device 20; A second reference part 32 connecting the second clamp device 40 and the driving device 20; And a bottom portion 30 connected to one end of the first and second reference portions 31 and 32 and the driving device 20 and fixed to a bottom thereof. Here, while the clamp device of any one of the first clamp device or the second clamp device supporting the mover is separated from the mover and the other clamp device supports the mover, the driving device is the other one. Performs a half stroke to move the mover one step with the clamp device of After the mover has moved one step, if the one clamp device supports the mover and the other clamp device is away from the mover, the drive device returns to its original position and with the one clamp device. And a half stroke which moves the mover one step. According to claim 1, The first clamp device 10 is The first piezoelectric element 11, A first hinge part connected to the first piezoelectric element and the first reference part 31; The second clamp device 40 The second piezoelectric element 41, A second hinge part connected to the second piezoelectric element 41 and the second reference part 32; The drive device 20, A third piezoelectric element 21 having a longitudinal direction in a direction perpendicular to the longitudinal direction of the first piezoelectric element 11 and the second piezoelectric element 41; A third hinge part connected to the third piezoelectric element 21 and the first reference part 31; And a fourth hinge portion connected to the third piezoelectric element (21) and the second reference portion (32). According to claim 1, The first clamp device 10 is The first piezoelectric element 11, First and second body portions connecting both ends of the first piezoelectric element 11; A first support part 12 connecting one end located in the same direction of the first and second body parts and supporting the mover 11; A first portion positioned opposite to the first support part 12 around the first piezoelectric element 11 and connecting the other ends of the first and second body parts and connected to the first reference part 31; Including a hinge part, The second clamp device 40 The second piezoelectric element 41, Third and fourth body parts connecting both ends of the second piezoelectric element 41; A second support part 42 connecting one end of the third and fourth body parts in the same direction and supporting the mover 11; A second hinge positioned opposite the first support part 42 around the second piezoelectric element 41 and connecting the other ends of the third and fourth body parts and connected to the second reference part 32; Includes wealth, The drive device 20, A third piezoelectric element 21 having a longitudinal direction in a direction perpendicular to the longitudinal direction of the first piezoelectric element 11 and the second piezoelectric element 41; Fifth and sixth body parts connecting both ends of the third piezoelectric element 21; A third hinge part connected to one end of the fifth and sixth body parts in the same direction and connected to the first reference part 31; And a fourth hinge part positioned opposite to the third hinge part around the third piezoelectric element 21 and connecting the other ends of the fifth and sixth body parts and connected to the second reference part 32. Linear driver using a piezoelectric element characterized in that. The method according to any one of claims 1 to 3, The first clamp device is separated from the support when the length of the first piezoelectric element is increased, The second clamp device is separated from the support when the length of the second piezoelectric element is increased, The driving device moves the first and second reference parts connected to the first and second clamp devices in a vertical direction with respect to the length direction of the third piezoelectric element when the length of the third piezoelectric element is increased. Linear driver using. The method according to any one of claims 1 to 3, The drive device Inputting zero input voltage to the first, second and third piezoelectric elements (t0), (T1) inputting a predetermined voltage to the first piezoelectric element while the input voltage is zero to the second and third piezoelectric elements, While the input voltage is zero to the second piezoelectric element and a predetermined voltage is input to the first piezoelectric element, a predetermined voltage is input to the third piezoelectric element (t3), (T4) grounding input voltages of the first and second piezoelectric elements while a predetermined voltage is input to the third piezoelectric element; A predetermined voltage is input to the third piezoelectric element and a predetermined voltage is input to the second piezoelectric element while the input voltage is 0 to the first piezoelectric element (t5), A step (t6) of inputting a predetermined voltage to the third piezoelectric element while the input voltage is 0 to the first piezoelectric element and a predetermined voltage to the second piezoelectric element is performed. Linear driver used.

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