JP2004230521A - Small displacement support device - Google Patents

Abstract

An object of the present invention is to provide a small displacement support device capable of easily finely adjusting the attitude of a table.
In a minute displacement support device having a table for supporting an object and an alignment means for adjusting the attitude of the table by minute displacement of the table, the alignment means includes an electrostrictive element and the electrostrictive element. And moving means for shifting the expansion / contraction starting point of the electrostrictive element. A clamp mechanism for maintaining the posture of the table after alignment is provided.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a small displacement support device for supporting an object (for example, a small displacement support device that performs measurement or processing that requires high resolution on a workpiece or a workpiece).
[0002]
[Prior art]
Conventionally, the displacement of a table for mounting objects is divided into linear movement and rotational movement, and they are controlled separately, or displacement control is performed using a table with an alignment function composed of multiple actuators. Had gone.
[0003]
For example, in a micromanipulator described in Patent Document 1, a pair of hand modules includes a parallel link mechanism having six degrees of freedom, and an end effector including a base member and a handpiece mounted on a base. And six links and springs connecting the base member and the base. The six links form a group of three links each, and the connection points of the links connect the base member and the base body by a spring as a pivot connection. Each of the six links can be expanded and contracted by a piezoelectric element.
[0004]
In the movable plate supporting device described in Patent Literature 2, two plates are provided above and below, and the movable upper plate is supported by being connected to the lower plate using at least three support mechanisms. Each of the support mechanisms includes a first link, a second link, and a free-rotating joint that rotatably connects the first link and the second link. The end of each first link is connected to the lower plate using a pin joint and via a negative actuation electromagnetic disc brake and a rotary spring damper. On the other hand, the end of each second link is connected to the upper plate via a ball joint and connected to the power supply via each negative-acting power disc brake release switch.
[0005]
Patent Document 3 shows a displacement enlarging mechanism. The arm is attached to the fixed base via a hinge. An actuator is provided that can press a part of the arm against the elastic force of the spring to displace the distal end side of the arm in a predetermined displacement direction. The arm is maintained in a state where the arm is tilted by a predetermined tilt angle toward the near side in the displacement direction by a spring in a state where the actuator is not extended and retracted.
[0006]
Patent Document 4 shows a parallel link mechanism. In this parallel link mechanism, the movable plate is controlled by three rotary actuators via a universal joint and their control devices.
[0007]
[Patent Document 1]
JP-A-6-170761
[Patent Document 2]
JP-A-9-19883
[Patent Document 3]
JP 2001-22445 A
[Patent Document 4]
JP-A-11-94968
[Problems to be solved by the invention]
The support surface of the table is generally configured to be maintained in a horizontal position. However, depending on the position of the center of gravity of the load, an uneven load may be applied to the table surface, or the elastic force of the plate spring structure supporting the table may be used. In addition, there is a problem that the table surface is tilted due to unevenness due to a manufacturing error or the like.
[0012]
Further, when the table is aligned with two axes of linear displacement and rotational displacement, a complicated mechanism including a plurality of actuators is required. In this case, it is difficult to reduce the size of the device, and a high device manufacturing cost is required.
[0013]
Furthermore, with a complicated structure, the table tends to have low rigidity. In such a case, not only a heavy object cannot be mounted, but also it is weak against external force such as vibration.
[0014]
SUMMARY OF THE INVENTION An object of the present invention is to provide a small displacement support device that can easily finely adjust the attitude of a table.
[0015]
[Means for Solving the Problems]
An example of the solution of the present invention is as follows.
[0016]
(1) In a minute displacement support device having a table for supporting an object and an alignment means for adjusting the attitude of the table by minute displacement of the table, the alignment means includes an electrostrictive element and the electrostrictive element. A small displacement support device having a moving means for moving the starting point of expansion and contraction of an electrostrictive element.
[0017]
(2) The alignment means has a pair of link plates, and the electrostrictive element is arranged between the pair of link plates. The alignment means is moved by moving a part of the link plate of the alignment means by the moving means. The above-mentioned minute displacement support device, wherein the starting point of expansion and contraction of the electrostrictive element is shifted.
[0018]
(3) The above-mentioned minute displacement support device provided with a clamp mechanism for maintaining the posture of the table after alignment.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
According to one embodiment of the present invention, a table has a surface for mounting an object (hereinafter, referred to as a table surface). This table surface is typically a flat surface that is kept horizontal.
[0020]
Alignment means for supporting the table from below the table and finely adjusting the attitude of the table is provided. The alignment means preferably comprises a link mechanism having an elastic hinge portion using a spring, and has a pair of link plates and an electrostrictive element (for example, a piezo actuator) provided between them.
[0021]
Each link plate of the alignment means has a vertical cross section in the shape of a square, and the bent portion is configured as an elastic hinge portion formed by a spring.
[0022]
Due to expansion and contraction of an electrostrictive element such as a piezo (piezoelectric) actuator, both the table surface and the object mounted thereon are displaced by the alignment means for fine adjustment. For example, by applying an external force to the electrostrictive element by the moving means in the direction of expansion and contraction of the electrostrictive element, the starting point of expansion and contraction of the electrostrictive element is shifted in the direction of expansion and contraction of the electrostrictive element. Thereby, the displacement (linear movement and rotational movement) of the table surface is controlled with high accuracy.
[0023]
After finely adjusting the attitude of the table to a desired state by the alignment means, it is preferable to lock the table by a clamp mechanism while maintaining the attitude. Various clamp mechanisms can be employed.
[0024]
【Example】
FIG. 1 is a side view showing a minute displacement support device provided with an alignment unit according to one embodiment of the present invention.
[0025]
The small displacement support device has a table 1 for supporting an object and an alignment means 2 for finely adjusting the attitude of the table 1 by giving a small displacement to the table 1.
[0026]
The alignment means 2 includes an electrostrictive element 3 and a moving means 4 for moving the electrostrictive element 3 in the direction of expansion and contraction of the electrostriction element 3 to shift the starting point of expansion and contraction of the electrostriction element 3 in the direction of expansion and contraction of the electrostriction element 3. Having.
[0027]
The alignment means 2 has a pair of link plates 5, and the electrostrictive element 3 is arranged substantially horizontally between the pair of link plates 5.
[0028]
The moving means 4 shifts the starting point of the expansion and contraction of the electrostrictive element 3 in the direction of expansion and contraction of the electrostrictive element 3 by moving the bent portion 5 a of the link plate 5 in the expansion and contraction direction (horizontal direction) of the electrostriction element 3.
[0029]
When the electrostrictive element 3 is extended, a force is applied to the link plate 5, and the force acts to push the table 1 upward. Conversely, when the electrostrictive element 3 contracts, a force acts to lower the table 1 downward.
[0030]
The ratio of the displacement of the table 1 to the amount of extension of the electrostrictive element 3 can be determined by the angle θ between the table 1 and the link plate 5.
[0031]
Preferably, the electrostrictive element 3 is one that extends evenly in the left-right direction from the center thereof, and the moving means 4 has a pressing pin 4a and an elastic spring 4b, and the bending of the link plate 5 by the pressing pin 4a. By applying an external force to the portion 5a in the direction of expansion and contraction of the electrostrictive element 3, the starting point of expansion and contraction of the electrostrictive element 3 is shifted from the center. As a result, the table surface 1a of the table 1 has a different left / right ascent amount balance, and a rotational motion is given.
[0032]
If the moving means 4 having the pressing pin 4a and the elastic spring 4b is attached to both of the pair of link plates 5, the rotation control in the direction in which the electrostrictive element 3 is pressed becomes easy, but as shown in FIG. Even if only one side of the pair of link plates 5 is used, the rotation direction can be controlled within the range of the displacement amount by changing the strength of the elastic spring between the left and right sides in advance.
[0033]
The object mounting table surface 1a formed on the table 1 is generally a flat surface that is maintained horizontally.
[0034]
Each of the pair of link plates 5 has a vertical cross section in the shape of a letter "", and the bent portion 5a is formed as an elastic hinge portion formed of a spring.
[0035]
The upper and lower ends of each link plate 5 are connected to the lower surface of the table 1 and the base 8 via elastic spring members 7, respectively. The table 1 is elastically supported on a base 8 by a link mechanism 2 including a pair of ring plates 5.
[0036]
When an object with an imbalanced center of gravity is mounted on the table surface 1a of the table 1, a difference occurs in the load of the force applied to the left and right spring members 7, and the table surface 1a cannot be kept horizontal. At this time, by operating the moving means 4, the state of the table surface 1a can be finely adjusted to recover the horizontal state.
[0037]
After aligning the table 1 in such a manner, it is preferable to provide a clamp mechanism 10 for the purpose of enhancing the function of maintaining the table 1 so that the table 1 is less likely to move against an unexpected external force.
[0038]
FIG. 2 shows an example of such a clamp mechanism 10.
[0039]
As shown in FIG. 2, the clamp mechanism 10 has a pair of side support plates 11 that are substantially the same width as the table 1 on both sides of the base 8 and are vertically arranged. Is screwably mounted. A movable body 13 is arranged between the screws 12. The movable body 13 is fixed to the lower surface of the table 1 via an elastic spring 14. That is, the movable body 13 is attached to the table 1 so as to be integrated as a unit by the elastic spring 14. Then, the movable body 13 is fixed at a desired position by sandwiching the movable body 13 from both sides with both screws 12. As a result, the table 1 is clamped. Thus, the table 1 can be locked without disturbing the aligned position of the table 1. In this way, the rigidity of the table 1 can be increased.
[0040]
When the two screws 12 are loosened and the tips of the screws 12 are separated from the end surface of the moving body 13, the table 1 is unlocked.
[0041]
The alignment means including the link plate 5 and the like shown in FIG. 1 has a large direction dependency on the reaction force (rigidity) to an external force, but the clamp mechanism 10 of FIG. Thus, the table 1 can be restrained around six axes without affecting the attitude of the table 1, and the overall rigidity can be increased.
[0042]
【The invention's effect】
According to the present invention, fine movement alignment can be realized with a simple structure and at low cost. Further, more accurate measurement and processing can be realized.
[0043]
According to the present invention, since the moving means moves the electrostrictive element of the alignment means to shift the expansion / contraction starting point of the electrostrictive element, the attitude of the table can be easily finely adjusted.
[0044]
Further, when a clamp mechanism is provided to enable the table to be clamped, the table can be restrained around six axes without affecting the attitude of the table, and the overall rigidity can be increased.
[Brief description of the drawings]
FIG. 1 is a side view showing a minute displacement support device provided with an alignment unit according to one embodiment of the present invention.
FIG. 2 shows a clamp mechanism of the small displacement support device shown in FIG.
[Explanation of symbols]
Reference Signs List 1 Table 2 Alignment means 3 Electrostrictive element 4 Moving means 4a Pressing pin 4b Elastic spring 5 Link plate 7 Elastic spring member 8 Base 10 Clamp mechanism 11 Side support plate 12 Screw 13 Movable body 14 Elastic spring

Claims (3)

A table for supporting an object, and a micro-displacement support device having alignment means for adjusting the attitude of the table by micro-displacement of the table;
A micro-displacement support device, characterized in that the alignment means has an electrostrictive element and a moving means for moving the electrostrictive element to shift the expansion / contraction starting point of the electrostrictive element. The alignment means has a pair of link plates, and an electrostrictive element is disposed between the pair of link plates. The moving means moves a part of the link plate of the alignment means to thereby reduce the power of the alignment means. 2. The small displacement support device according to claim 1, wherein a starting point of expansion / contraction of the strain element is shifted. 3. The small displacement support device according to claim 1, further comprising a clamp mechanism for maintaining a posture of the table after the alignment.

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