JPH0353192A - Positioning device - Google Patents

Abstract

PURPOSE:To realize free movement or the like by providing a first member with driving units which displace contact parts to a second member in the direction, where the second member is pushed away from the first member, and the movement direction by plural actuators. CONSTITUTION:Driving units consisting of contact parts 3, pushing-up piezoelectric elements 4, and moving piezoelectric elements 5 are stored in a driving unit frame 6 and are attached to a first member 1. Four driving units are provided, and contact parts 3 of driving units are pressed to a second member 2 by elements 4 in four positions to lift the second member, and contact surfaces of members 1 and 2 are separated to support only contact parts 3 by the member 2. Contact parts 3 are moved by a required extent in an arbitrary direction in a plane by elements 5 of driving units. Elements are contracted, and surfaces of two members 1 and 2 are brought into contact with each other and are fixed, and contact parts 3 are returned to original positions by elements 5, thereby completing positioning.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positioning device used in precision instruments.

(Traditional technology) In the past, as a positioning device that uses actuators such as a piezoelectric element, this is the principle of hinge L6 and 17 as shown in the mechanism that directly drives the movable portion with a piezoelectric element and Fig. 5. Arm 20. A device is known that uses a displacement amplifying mechanism that moves the piezoelectric element 19 to amplify minute displacements of the piezoelectric element 11. Also, as shown in FIG. 6, a pair of clamp levers 24, 24,
24. It has a moving piezoelectric element 22 that moves 24,
Clamp levers 24, 24 are fixed by piezoelectric elements 23 for fixation.
The moving piezoelectric element 2 is moved and clamped alternately.
A mechanism for uniaxial positioning using an inchworm-like method of expanding and contracting 2 is also known. In Fig. 6, the clamp levers 24, 24 are fixed to the frame 21, and 24'
, 24' are shown separated. Although the drawings are not shown, as a method for controlling a multi-axis movement mechanism,
There is a mechanism in which the movable part is supported by a leaf spring and made to move slightly by a piezoelectric element (Japanese Patent Application Laid-Open No. 62-214412).
. In addition, as shown in FIG. 7, there is an XY two-axis moving mechanism that uses an inchworm-like method to pull the metal fitting 32 downward using a piezoelectric element (not shown) on a plane, and clamps the expanding and contracting moving part using the piezoelectric element 31. (Society of Precision Engineering, Autumn Proceedings of 1986, P247). Furthermore, as shown in FIG. 8, there is also a mechanism that performs translation and rotation using an inchworm-like method (Society for Precision Engineering, 1985 Spring Proceedings P305).

(Problems to be Solved by the Invention) In a method in which a movable part is directly driven by an actuator such as a piezoelectric element, the movement range is limited by the maximum displacement amount of the actuator. When a piezoelectric element is used, even if a laminated piezoelectric element with a large displacement is used, the movement range is limited to about several +11 meters. The method shown in Figure 5 using a displacement magnification mechanism can obtain a displacement magnification rate up to several tens of times higher than that of direct drive, but the displacement magnification mechanism reduces rigidity and is easily susceptible to displacement and vibration due to external forces. The problem is that you end up doing it.

In the example of Japanese Patent Publication No. 62-214412 that uses a leaf spring for support, the displacement of the leaf spring is limited, so the travel distance and rotation angle are restricted, and in the case of multiple degrees of freedom, the mechanism becomes complicated and the rigidity is reduced. descend. In the case of the inchworm mechanism as shown in Figure 6,
Usually, many items move only on one axis, but when two or more axes are combined, the structure becomes complicated and the rigidity decreases.
This causes problems in terms of vibration and accuracy. In the inchworm mechanism shown in FIG. 6, there is a possibility that the fixation may be released due to failure of the actuator or the like. Furthermore, the rigidity during fixation is reduced due to the complexity of the fixing mechanism. Furthermore, the clamping operation may cause minute movements and errors. Figures 6 to 8 If the surface slides during movement, as in the inchworm mechanism, there is a possibility of seizure between parts, stick-slip, etc. Also, when used in an ultra-high vacuum device or when cleaning the air. When high temperature is required, there is a problem of dust generation. Furthermore, in the case of the various fine movement mechanisms described above, if there is no need for fine movement after positioning, the unnecessary fine movement mechanism cannot be removed. In addition, there is no conventional fine movement mechanism that can move with three degrees of freedom in XYe in one operation.

The objects of the present invention are to be able to move over a large stroke without any restrictions on the amount of movement, to have high rigidity when fixed, to prevent release of fixing or misalignment due to actuator failure, to require no energy when fixing, and to prevent sliding. No parts, XY in one movement
The object of the present invention is to provide a positioning device that can move with e3 degrees of freedom.

(Means for Solving the Problems) The positioning device of the present invention is composed of a first member and a second member, and is a positioning device that performs positioning by moving a second member with respect to the first member. It is controlled by a contact part with the second member and a plurality of actuators that expand and contract such as piezoelectric elements, and the contact part can be displaced by the actuator in the direction of pushing the second member away from the first member and in the direction of movement. The first member is provided with a drive unit having the following structure, and the first member and the second member are in contact with each other at a surface when they are fixed,
The actuator displaces the contact portion of the drive unit with the second member in the pushing direction to separate the contact surfaces of the first member and the second member, and the actuator moves the contact portion of the drive unit in-plane. The present invention is characterized in that it includes a moving mechanism for displacing in the moving direction.

In the positioning device, the first member and the second member may be pressed and fixed by the elastic force of a spring, or the first member and the second member may be moved between the first member and the second member by an attractive force of a magnet, or A pressing means for pressing and fixing by repulsive force may be provided.

(Function) In the present invention, the contact portion of the drive unit is pressed against the second member by the push-up mechanism, the second member is lifted, the contact surfaces of the first member and the second member are separated, and only the contact portion is The second member is supported by the second member, and the contact portion is moved by the required amount in any direction within the plane by the movement mechanism of the drive unit, thereby moving the second member by the required amount in any direction. After that, positioning is performed by retracting the push-up mechanism to bring the surfaces of the two members into contact and fixing them, and returning the contact portion separated from the second member to the initial position by the moving mechanism. Alternatively, after changing the order of the stroke and moving the contact part by the necessary amount in advance, lift the second member, move the contact part and the second member to their original positions, and then Positioning can also be performed by touching and fixing. If the stroke is large, the required amount of movement can be achieved by repeating the above steps. By moving the moving mechanism by the required amount, it becomes possible to perform arbitrary precise positioning. By making the contact part movable in two directions, X and Y, one movement can move the
The axis can move in two degrees of freedom. Furthermore, by moving the contact portions in different directions using individual drive units, rotational movement of the e-axis is possible.

Further, by changing the amount of movement of each drive unit, the center of rotation during rotational movement can be arbitrarily set. With this configuration, 2
Two members can be positioned simultaneously. Actuators such as piezoelectric elements used in the push-up mechanism and the moving mechanism operate only when moving, and when fixed, the members come into surface contact and are fixed by frictional force. Since the two members are fixed by surface contact over a wide area, the rigidity during fixation is high.

When the actuator is fixed, it is not operating, so even if a failure occurs in the actuator, there is no fear that the fixation will be released or the position will go out of order. Furthermore, since no energy is consumed during fixation, there is no need to worry about heat generation. Furthermore, since there is no sliding movement between the various members during movement, there is no generation of dust, which can be a problem in vacuum environments or in places where air cleanliness is required. Also, since there is no sliding, there is no sticking or slipping. When performing mutual positioning between two planes, by providing a unitized drive unit at the four corners of one plane, the fine movement device can be easily controlled, and if movement is not required after positioning, the drive It is also easy to remove the parts. This allows the device to be used as a jig for precise positioning of components during manufacturing and adjustment of precision equipment, and for removing the drive unit after positioning.

By providing a spring between the first member and the second member and applying pressure between the movable members using the elastic force of the spring, stronger fixation can be obtained. The friction between the contact portion and the movable member during movement also increases, allowing movement in a vertical plane or in an upside-down state with the second member disposed below the first member. Even in the case of a high-speed push-up operation by the piezoelectric element, the moving member does not separate from the contact portion due to the inertia of the movement, allowing stable operation. Since it does not affect the surroundings magnetically or electrically, it can also be used in electron beam exposure equipment and electron beam annealing equipment.

By providing a magnet on one moving member and using a material that is attracted to the magnet on the other member, or providing a magnet on the other member that is attracted to the magnet and applying pressure by the attractive force of the magnet, it is possible to use a spring. Similar to pressurization, a stronger fixation can be obtained. Even if magnets are provided on both moving members and the contact surfaces of the moving members are pressurized by the repulsive force of those magnets, stronger fixation can be obtained as in the case of suction. The friction between the push-up part and the movable member during movement also increases, making it possible to move in a vertical plane or in an upside-down state with the second member disposed below the first member. Even in the case of a high-speed push-up operation by the piezoelectric element, the moving member does not separate from the contact portion due to the inertia of the movement, allowing stable operation. Furthermore, it is possible to eliminate limitations on the maximum movement stroke, which is a problem when using springs.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention. - It is a cross-sectional view taken along the A cross section. In FIG. 1, a first member 1 with a drive unit is fixed and a second member 2
Move and position. In this embodiment, a laminated piezoelectric element is used as the actuator. A drive unit consisting of the contact portion 3, the piezoelectric element 4 for pushing up, and the piezoelectric element 5 for movement is housed in a drive unit frame 6 and attached to the first member 1. In this embodiment, there are four drive units, and the contact portion 3 of the drive unit is pressed against the second member 2 by the piezoelectric elements for pushing up at four locations, the second member 2 is lifted, and the first member 1 and the second member 2 are lifted up. The contact surfaces of the second member 2 are separated so that the second member 2 is supported only by the contact portion 3, and the contact portion 3 is moved in any desired direction within the plane by the moving piezoelectric element 5 of the drive unit. After moving the second member 2 by the required amount in an arbitrary direction, the pushing-up piezoelectric element 4 is contracted to bring the surfaces of the two members into contact and fixation, and the second member 2 is separated from the second member 2. Positioning is performed by returning the contact portion 3 to its initial position using the moving piezoelectric element 5. Also, after changing the order in the stroke and moving the contact part 3 by the necessary amount in advance, lift the second member 2, return the contact part 3 and the second member 2 to their original positions, and move the two members together. Positioning can also be performed by touching and fixing the surfaces in between.

In this embodiment, each set of drive units is housed in the drive unit frame 6, but they may be housed directly in the first member 1. By making the drive unit separate from the first member as in this embodiment, the drive unit can be removed when the positioning mechanism is not required. FIG. 2 is a cross-sectional view taken along section line A-A in FIG. 1 and viewed from above. Each drive unit includes a push-up piezoelectric element 4 and two XY moving piezoelectric elements 5, and is movable in any direction within the XY plane. If the four contact parts 3 move in the same way, the second member 2 will
Move according to the movement. The second member 2 can be rotated by moving the four contact parts 3 in different directions so that the second member 2 rotates.

At this time, by changing the amount of movement of each drive unit, it is possible to set an arbitrary rotation center position.

FIG. 3 shows a positioning system in which a spring 7 is provided between the first member 1 and the second member 2 in the above-mentioned positioning device, and by applying pressure between the movable members by the elastic force of the spring, more firm fixation is achieved. It is a device. By applying pressure using the elastic force of the spring 7, the frictional force between the contact portion and the moving member during movement also increases.

FIG. 4 shows the positioning device described above, in which the second member 2 is provided with a magnet 8, and the first member 1 is pressurized by the attraction force of the magnet using a material that is attracted to the magnet. Similar to pressure, it is a positioning device that provides stronger fixation. The frictional force between the push-up part and the moving member during movement also increases due to the pressurization caused by the attractive force of the magnet.

(Effects of the Invention) The advantages of the present invention are as follows. That is, there is no restriction on the amount of movement, and large stroke movement is possible, and arbitrary precise positioning can be performed up to the limit of the resolution of the actuator. It is possible to move with three degrees of freedom in XYe in one operation, and the rotation center of the e-axis can be set arbitrarily. Since the first member and the second member are fixed in surface contact over a wide area between the two members, the rigidity at the time of fixation is high. Since the actuator is not operating when the actuator is fixed, even if a failure occurs in the actuator, there is no risk of the actuator being unfixed or being misaligned. Additionally, this allows no energy to be consumed during fixation, and there is no need to worry about heat generation. Since there is no sliding movement between the various parts during movement, there are no problems such as dust generation or burn-in, which can occur in precision equipment or in a vacuum. When performing mutual positioning between 2,000 planes, by providing a unitized drive unit at the four corners of one plane, the fine movement device can be easily controlled, and if no movement is required after positioning, It is also easy to remove the drive unit. This results in
This device can also be used as a jig for precise positioning between components during manufacturing and adjustment of precision equipment, and removing the drive unit after positioning.

By applying pressure between the movable members using the elastic force of a spring or the like, stronger fixation can be obtained. The friction between the push-up part and the movable member during movement also increases, making it possible to move in a vertical plane or in an upside-down state with the second member disposed below the first member. Even in the case of a high-speed push-up operation by the piezoelectric element, the moving member does not separate from the contact portion due to the inertia of the movement, allowing stable operation. Since it does not affect the surroundings magnetically or electrically, it can also be used in electron beam equipment, etc.

By applying pressure with a magnet, stronger fixation can be obtained, similar to applying pressure with a spring. The friction between the push-up part and the movable member during movement also increases, making it possible to move in a vertical plane or in an upside-down state with the second member disposed below the first member. Even in the case of a high-speed push-up operation by the piezoelectric element, the moving member does not separate from the contact portion due to the inertia of the movement, allowing stable operation. Furthermore, it is possible to eliminate limitations on the maximum movement stroke, which is a problem when using springs.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, FIG. 3 is a diagram of an embodiment fixed by the force of a spring, and FIG. , a diagram of an embodiment fixed by the force of a magnet, FIG. 5 is a diagram of a conventional example of a moving device using a displacement magnification mechanism, and FIG. 6 is a diagram of a conventional example of a shaft fine movement device using an inchworm mechanism. 7 is a diagram of a conventional example of an XY two-axis fine movement device using an inchworm mechanism, and FIG. 8 is a diagram of a conventional example of a translational and rotational fine movement device using an inchworm mechanism.

Claims (1)

[Claims] 1. A positioning device that moves and positions a second member relative to a first member, comprising: a contact portion with the second member;
The first member includes a drive unit that is configured by an actuator that expands and contracts, and is capable of displacing the contact portion in the direction of pushing and moving the second member with respect to the first member by the actuator, When the and second member are fixed, they are in surface contact, and the actuator displaces the contact portion of the drive unit with the second member in the direction of pushing them apart, thereby causing the first member and the second member to separate. A positioning device characterized by comprising a moving mechanism that separates the contact surface and causes the actuator to displace the contact portion of the drive unit in the in-plane direction. 2. Patent claim 1, which includes a pressing means for pressing and fixing the first member and the second member using the elastic force of a spring.
The positioning device described. 3. The positioning device according to claim 1, further comprising a pressing means for pressing and fixing the first member and the second member between the first member and the second member using the attractive force or repulsive force of a magnet.