JP2004280355A - Moving device and positioning device using the same - Google Patents

Abstract

[PROBLEMS] Ultra-precision positioning that can be downsized, does not cause problems of accuracy and responsiveness, has a simple configuration regardless of the degree of freedom, and can move minutely without complicating control. To provide a moving device suitable for a device or a manipulator.
A moving member (5) and six wires (6a to 6f) having one end joined to the moving member (5) and deformably following the movement of the moving member (5) for holding the moving member (5) at a predetermined position. , Three piezoelectric actuators 7a to 7c respectively joined to the wires 6a to 6c, and a fixing member for fixing the base ends of the piezoelectric actuators 7a to 7c and the ends of the wires 6d to 6f on the side opposite to the moving member 5 side. 2, 3 and 4, the piezoelectric actuators 7a to 7c are arranged so that their displacement directions are parallel to each other, the wires 6a to 6c are provided in parallel with each other, and the wires 6d to 6f are connected to the piezoelectric actuators 7a to 7c. Is provided so as to be orthogonal to the direction of displacement of.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a positioning device used for ultra-precision positioning such as bonding of optical components, a moving device applicable as an ultra-precision manipulator, and a positioning device using the same.
[0002]
[Prior art]
2. Description of the Related Art Recently, ultra-precision positioning technology on the order of nanometers has been required for joining optical components such as joining an optical device and an optical fiber array, and in a semiconductor device manufacturing process. In three-dimensional positioning, movement in three axes of X, Y, and Z and movement of θ _X , θ _Y , and θ _Z around these axes with a maximum of six degrees of freedom are required.
[0003]
Conventionally, in order to realize such multi-free movement, a mechanism in which stages each having one degree of freedom moving in a different direction are overlapped by the required number of degrees of freedom is well known. In this mechanism, the entire movement is constituted by the sum of the movements in different directions on each stage.
[0004]
On the other hand, a parallel link mechanism is known as a technique for realizing the above-described multi-degree-of-freedom movement (for example, Patent Document 1). In this technique, the base member and the end effector are connected by six links, and the length of each link is changed to realize movement of the base member with six degrees of freedom.
[0005]
[Patent Document 1]
JP-A-6-328374
[Problems to be solved by the invention]
In the former technique, each stage only needs to be controlled with one degree of freedom, and since the entire movement is a simple sum of the movements of the respective stages, the control is easy and the movement distance of each stage is increased. As a result, the moving distance of the entire stage is increased, so that it is possible to easily cope with a case where the moving distance is large, but there are the following disadvantages.
[0007]
In other words, because of the structure in which a plurality of stages are stacked, the size and volume of the entire apparatus must be increased. In addition, since the distance between the fixed point and the uppermost stage is long, it is difficult to maintain high rigidity as a whole device, and since a plurality of stages are moved, positioning errors of each stage accumulate. There is a drawback in accuracy. Furthermore, since a plurality of stages are stacked, the mass on the lowermost stage is generally large, and the inertia when the stage moves for positioning becomes large, so it is difficult to realize a fast response speed. is there.
[0008]
On the other hand, the latter technique is unlikely to cause such a problem, and can realize a mechanism that can be moved in multiple degrees of freedom with a relatively compact structure. Since the position error appears as an average value, the accuracy is generally increased, and the inertia mass is small because only the base member is moved, so that a quick response is possible.
[0009]
However, the latter technique has the following disadvantages. That is, when the length of the link changes, the base member generally moves in all six degrees of freedom. To give only a specific moving direction, it is necessary to give a length change to all the links at a certain ratio at the same time. This is less of a problem when six degrees of freedom are required, but is not desirable when the degree of freedom is less than six degrees of freedom. In addition, in order to operate such a parallel link mechanism, it is necessary to provide a universal joint for each link arm. However, small movements may cause backlash and increase the cost. Further, when the moving distance is long, the moving distance of the base member becomes non-linear with respect to the change in the length of each link arm, and the control becomes complicated.
[0010]
The present invention has been made in view of such circumstances, and can be reduced in size, does not cause problems of accuracy and responsiveness, has a simple configuration regardless of the degree of freedom, and does not bring about complicated control. It is an object of the present invention to provide a moving device capable of minute movement and suitable for an ultra-precise positioning device or manipulator, and a positioning device using the same.
[0011]
[Means for Solving the Problems]
In order to solve the above problem, according to a first aspect of the present invention, a moving member and one end thereof are joined to the moving member, and the moving member is deformable following a movement of the moving member. Six wires held in position, one or more piezoelectric actuators respectively joined to one or more ends of the six wires opposite to the moving member side, and a base end of the piezoelectric actuator and A fixing member for fixing an end of the wire to which the piezoelectric actuator is not joined, on the opposite side to the moving member, wherein the displacement of the piezoelectric actuator causes the moving member to move in a predetermined direction. Provide a mobile device.
[0012]
Further, according to a second aspect of the present invention, a movable member and one end which is joined to the movable member at one end thereof and holds the movable member at a predetermined position so as to be deformable following the movement of the movable member. And six piezoelectric actuators respectively joined to ends of the six wires opposite to the moving member side, and a fixing member for fixing a base end of the piezoelectric actuator, A moving device is characterized in that the moving member is caused to move in a predetermined direction by displacement of a piezoelectric actuator.
[0013]
Further, according to a third aspect of the present invention, a movable member and one end which is joined to the movable member at one end thereof and holds the movable member at a predetermined position so as to be deformable following the movement of the movable member. , Three piezoelectric actuators respectively joined to the three ends of the six wires opposite to the moving member side, and a remaining portion where the base end of the piezoelectric actuator and the piezoelectric actuator are not joined. A fixing member for fixing ends of the three wires opposite to the moving member side, wherein the piezoelectric actuators are arranged so that their displacement directions are parallel to each other, and are joined to the piezoelectric actuators. The three wires are provided in parallel with each other along the displacement direction of the piezoelectric actuator, and the remaining three wires are orthogonal to the displacement direction of the piezoelectric actuator. As described above, provided between the moving member and the fixed member, the displacement of the three piezoelectric actuators causes the moving member to move in parallel with the displacement direction of the piezoelectric actuator and / or the driving direction of the piezoelectric actuator. A moving device that causes a rotational movement about an axis perpendicular to the axis.
[0014]
According to the present invention, one end is joined to the moving member, and six wires are used to hold the moving member at a predetermined position so as to be deformable following the movement of the moving member. Since the number of piezoelectric actuators used is large, there is no need to use complicated mechanisms such as universal joints, no complicated control, and basically, a parallel mechanism using one moving member has multiple degrees of freedom. Since movement can be realized, the size of the device can be reduced, and movement with high accuracy and high responsiveness can be realized, which is suitable as an ultra-precise positioning device or manipulator.
[0015]
By joining the piezoelectric actuators to the six wires as in the second aspect, positioning with six degrees of freedom can be realized with a simple configuration. Further, as in the third aspect, the piezoelectric actuator is joined to three of the six wires, and the three wires joined to the piezoelectric actuator are parallel to each other along the driving direction of the piezoelectric actuator. The remaining three wires are provided between the moving member and the fixed member so as to be orthogonal to the driving direction of the piezoelectric actuator. The piezoelectric actuator is displaced, and the moving member is moved in the direction of displacement of the piezoelectric actuator. By causing a parallel movement and a rotational movement about an axis orthogonal to the displacement direction of the piezoelectric actuator, a movement with three degrees of freedom is realized, which is suitable for positioning between the optical device and the optical fiber array.
[0016]
In the moving device according to the third aspect, it is preferable that the moving device further includes a restricting member that restricts relative movement of the three piezoelectric actuators other than the driving direction. Further, in any of the above aspects, the piezoelectric actuator may have a configuration having a piezoelectric element, or may have a configuration having a piezoelectric element and a displacement enlarging mechanism for enlarging the displacement of the piezoelectric element. The wire preferably has a relatively large diameter central portion and a relatively small diameter deformed portion located on both sides of the central portion.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a moving device capable of moving in three degrees of freedom according to the first embodiment of the present invention, and this moving device is used as a positioning device. The moving device 1 has a fixed base 2 and fixed walls 3 and 4 which are joined so as to extend vertically from the fixed base 2 and are orthogonal to each other. Is composed. In the plane on which the fixed base 2 is placed, the direction in which the fixed wall 3 is arranged is X, the direction in which the fixed wall 4 is arranged is Y, the direction extending perpendicularly from the XY plane is Z, and the direction of rotation around X, Y, Z is shown. Are θ _X , θ _Y , and θ _Z , respectively.
[0018]
Above the space defined by the fixed base 2 and the fixed walls 3, 4, a rectangular moving member 5 to which a component to be positioned is attached is arranged. The moving member 5 is arranged so that the main surface is parallel to the fixed base 2 and the other two pairs of surfaces are parallel to the fixed wall 3 and the fixed wall 4 at the illustrated reference position.
[0019]
Three piezoelectric actuators 7a, 7b, 7c are fixed to the upper surface of the fixed base 2 with their longitudinal directions coinciding with the Z direction. Each of the piezoelectric actuators 7a, 7b, 7c is composed of a joint 8a, 8b, 8c to which a wire to be described later is joined, and piezoelectric elements 9a, 9b, 9c below the joints.
[0020]
One end of three wires 6a, 6b, 6c is joined to the lower main surface facing the fixed base 2 and one end of one wire 6d is joined to the surface facing the fixed wall 3 of the moving member 5. One end of each of the two wires 6e and 6f is joined to a surface facing the fixed wall 4. That is, six wires are joined to the moving member 5.
[0021]
When the moving member 5 is at the reference position, the wires 6a, 6b, 6c extend linearly downward from the moving member 5 in the Z direction, and the other ends thereof are connected to the joining portions 8a of the piezoelectric actuators 7a, 7b, 7c, respectively. , 8b, 8c. The wire 6d extends linearly in the Y direction, the other end is joined to the fixed wall 3, and the wires 6e, 6f extend linearly in the X direction, and the other end is joined to the fixed wall 4.
[0022]
The wires 6a to 6f have sufficient rigidity to hold the moving member 5 at a predetermined position, and have a material and a material so as to be elastically deformable following the movement when the moving member 5 moves. The wire diameter and shape are determined.
[0023]
Feeding lines 10a, 10b, 10c are connected to the piezoelectric elements 9a, 9b, 9c, respectively, and these feeding lines 10a, 10b, 10c are connected to a power supply 11. The power supply 11 is connected to a controller 12, which controls the displacement of the piezoelectric elements 9a, 9b, 9c. An operation unit 13 is connected to the controller 12.
[0024]
The piezoelectric actuators 7a, 7b, 7c are displaced in the Z direction by applying a voltage to the piezoelectric elements 9a, 9b, 9c, respectively. The piezoelectric elements 9a, 9b, 9c have a length necessary to secure a desired displacement. The piezoelectric elements 9a, 9b, 9c are not particularly limited, but in order to obtain a large displacement, for example, a laminated type in which electrodes and piezoelectric ceramic layers are alternately laminated can be used.
[0025]
In the positioning device configured as described above, the moving member 5 is moved with three degrees of freedom from the reference position shown in FIG. 1 to position the member attached to the moving member. At the time of positioning, an operation signal is output from the operation unit 13 to the controller 12, and the displacement of the piezoelectric actuators 7a, 7b, 7c (that is, the displacement of the piezoelectric elements 9a, 9b, 9c) so that the moving member 5 performs a desired movement. Thereby, the moving member 5 is driven in a desired direction. In this case, wire 6d, 6e, the 6f because it is fixed, three directions in the XY plane of the moving member 5, i.e. the X direction, Y direction, in the theta _Z direction is constrained. Accordingly, the moving member 5, three piezoelectric actuators 7a, 7b, by 7c, Z direction, theta _X direction, will be positioned by moving in three degrees of freedom theta _Y direction.
[0026]
For example, the moving member 5 can be moved in the Z direction by displacing the piezoelectric actuators 7a, 7b, 7c in the same direction with the same length. In addition, the moving member 5 can be moved in the _θY direction by displacing the piezoelectric actuators 7b and 7c in the same direction with the same length or by displacing the piezoelectric actuator 7a. Further by displacing one is causing or any displacement in the opposite direction and a piezoelectric actuator 7b and 7c, it is possible to move the moving member 5 in the theta _X direction. Then, by appropriately combining these movements, a desired movement can be achieved. In this case, the wires 6a to 6f have a rigidity capable of holding the moving member 5 at a predetermined position, and are elastically deformable following the moving member 5, so that the moving member 5 maintains a predetermined rigidity while maintaining the required rigidity. Can be moved. Such a wire is preferably a wire having a circular cross section so that it can be deformed in all directions, and a spring material having high rigidity and capable of large elastic deformation is preferable.
[0027]
By moving the moving member 5 with three degrees of freedom in this way, positioning of the member attached to the moving member 5 with three degrees of freedom is realized. Such positioning with three degrees of freedom is extremely suitable for positioning when joining optical components such as joining an optical device and an optical fiber array.
[0028]
In addition, it is possible to achieve three degrees of freedom of movement with a parallel mechanism basically using one moving member 5 without using a complicated mechanism such as a universal joint and without complicating the control. As a result, the size of the apparatus can be significantly reduced. For example, the fixed base 2 has a size of 40 mm × 30 mm, a height of 40 mm, and the moving member 5 has a size of 10 mm × 12 mm × thickness of 3 mm, so that it is possible to realize an ultra-compact size that cannot be compared with a conventional multi-stage positioning device. In this case, the moving amount of the moving member 5 is estimated to be about 15 μm when a voltage of 150 V is applied to the piezoelectric element, for example. In addition, since the structure is simple and only one moving member 5 needs to be arranged, it is possible to realize highly accurate and highly responsive movement.
[0029]
When the displacement is not sufficient with only the piezoelectric element, it is effective to use the displacement enlarging mechanism. As an example of the displacement magnifying mechanism, there is a mechanism as shown in FIG. The displacement magnifying mechanism 20 includes a base member 21, hinges 22 connected to both ends of the piezoelectric element 9, connected to each hinge 22, extending to the side of the piezoelectric element, and extending to the center of the piezoelectric element 21. , Two arms 23 for expanding the displacement of the piezoelectric element 9, and a displacement output unit 24 for externally outputting the displacement of the arm 23. Each arm 23 is connected to the base member 21 near the hinge 22. Therefore, when the piezoelectric element 9 extends as shown by the arrow A, the base end of the arm 23 is displaced via the hinge 22 as shown by the arrow B. As a result, a displacement as shown by an arrow C perpendicular to the displacement direction of the piezoelectric element 9 occurs at the tip of the arm 23. This displacement is about ten times the displacement of the piezoelectric element 9. The displacement output unit 24 is connected to the arm 23 and outputs the displacement to the outside. Since the displacement output unit 24 is connected to the base member 21 via the parallel spring 25, the displacement can be transmitted quickly according to the change in the displacement of the piezoelectric element 9. When a larger displacement is required, the present moving device can be mounted on the coarse moving stage, and rough movement can be performed by the coarse moving stage, and fine moving can be performed by the present moving device.
[0030]
Further, as the wires 6a to 6f, straight wires can be used as shown in FIG. 1, but from the viewpoint of increasing the rigidity of the moving member 5 and increasing the positioning accuracy, as shown in FIG. A structure having a relatively large-diameter central portion 31 and relatively small-diameter deformable portions 32 located on both sides of the central portion 31 may be employed. In the case of such a structure, the rigidity of the entire wire can be increased by the central portion 31 and only the deformed portion 32 can be deformed, so that the axial rigidity of the wire can be further increased. In this case, since there are two deforming portions 32, it is possible to sufficiently follow the movement of the moving member 5.
[0031]
In the case of the device shown in FIG. 1, the three piezoelectric actuators 7a, 7b, 7c are long, and there is a possibility that the rigidity of the moving member 5 cannot be sufficiently secured in this state. In such a case, as shown in FIG. 4, it is preferable to provide a restraining member 33 such as a leaf spring that restrains the relative movement of the three piezoelectric actuators 7a, 7b, 7c in directions other than the displacement direction. Specifically, three restraining members 33 are provided so as to sequentially connect the joints 8a, 8b, 8c of the piezoelectric actuators 7a, 7b, 7c, and the displacement of the piezoelectric elements 9a, 9b, 9c in the Z direction is prevented. Without interfering with each other, it is possible to maintain their relative positions in a plane perpendicular to the Z direction.
[0032]
Next, a second embodiment of the present invention will be described.
In the first embodiment, the moving device of the parallel mechanism that causes the moving member 5 to move in three degrees of freedom has been described. However, a moving device capable of moving in six degrees of freedom will be described here. FIG. 5 is a perspective view showing a moving device capable of moving in six degrees of freedom. The device configuration of the moving device 1 'in FIG. 5 is basically the same as that of the moving device in FIG. 1, and the same components are denoted by the same reference numerals and description thereof will be omitted.
[0033]
The present embodiment is different from the first embodiment in that the piezoelectric actuators 7d, 7e, 7f are provided also on the wires 6d, 6e, 6f, which are not provided with the piezoelectric actuator in the first embodiment.
[0034]
The piezoelectric actuator 7d is fixed to the fixed wall 3 with its longitudinal direction (displacement direction) coincident with the Y direction, and the piezoelectric actuators 7e and 7f are fixed with their longitudinal directions (displacement direction) coincident with the X direction. It is fixed to the wall 4. Each of the piezoelectric actuators 7d, 7e, and 7f includes bonding portions 8d, 8e, and 8f to which wires described later are bonded, and piezoelectric elements 9d, 9e, and 9f below the bonding portions. Feeding lines 10d, 10e, 10f are connected to the piezoelectric elements 9d, 9e, 9f, respectively, and these feeding lines 10d, 10e, 10f are connected to a power supply 11.
[0035]
In thus configured mobile device, first embodiment Z direction movement was possible at the mobile device, theta _X direction, theta _Y direction, of course, X piezoelectric actuator 7d, 7e, by 7f direction, Y-direction, you can also move the moving device 5 in the theta _Z direction, movement of six degrees of freedom can be realized. For example, the moving member 5 can be moved in the X direction by displacing the piezoelectric actuators 7e and 7f in the same direction with the same length. Further, by displacing the piezoelectric actuator 7d, the moving member 5 can be moved in the Y direction. Furthermore, by displacing the piezoelectric actuator 7e, either displacing or these in the opposite direction to 7f, it is possible to move the moving member 5 in the theta _Z direction. Then, these movements and Z directions, theta _X-direction, by appropriately combining the movement of the theta _Y direction, thereby enabling a desired movement of six degrees of freedom.
[0036]
Although the moving device of the present embodiment is larger than the moving device of the first embodiment having three degrees of freedom, the moving device can be sufficiently reduced in size compared to the multistage stage type conventionally used as a positioning device. In addition, while maintaining the effects of the first embodiment, movement with six degrees of freedom is possible, and positioning with six degrees of freedom is possible.
[0037]
Note that the present invention is not limited to the above embodiment, and can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the positioning device having three degrees of freedom and six degrees of freedom has been described. However, by appropriately adjusting the number of piezoelectric actuators, movement of any degree of freedom from one degree of freedom to six degrees of freedom is realized. be able to. Further, in the above embodiment, the case where the present invention is applied as an ultra-precision positioning device has been mainly described. However, if an operation hand is attached to a moving member, the present invention can be applied to a multi-degree-of-freedom ultra-precision manipulator. .
[0038]
【The invention's effect】
As described above, according to the present invention, one end is joined to the moving member, and the six wires that deformably hold the moving member at a predetermined position following the movement of the moving member are provided. Since the number of piezoelectric actuators used depends on the degree of freedom, it does not use a complicated mechanism such as a universal joint, does not complicate control, and basically uses a parallel moving member. Since movement with multiple degrees of freedom can be realized by the mechanism, the size of the device can be reduced, and movement with high accuracy and high responsiveness can be realized. With the moving device of the present invention, it is possible to realize an ultra-precision positioning device and an ultra-precision manipulator having an ultra-compact and simple structure.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a moving device capable of moving in three degrees of freedom according to a first embodiment of the present invention.
FIG. 2 is a schematic view showing a displacement enlarging mechanism of a piezoelectric element.
FIG. 3 is a schematic view showing another example of the structure of the wire.
FIG. 4 is a perspective view for explaining a restricting member that restricts a direction other than a displacement direction of the piezoelectric actuator.
FIG. 5 is a perspective view showing a moving device capable of moving with six degrees of freedom according to a second embodiment of the present invention.
[Explanation of symbols]
1, 1 '; moving device 2, fixed tables 3, 4, fixed wall 5, moving members 6a to 6f, wires 7a to 7f, piezoelectric actuators 9a to 9f, piezoelectric elements 10a to 10f, wiring 12, chamber 11, and power supply 12. A controller 13; an operation unit 20;

Claims (8)

A moving member;
One end is joined to the moving member, and six wires that hold the moving member at a predetermined position so as to be deformable following the movement of the moving member;
One or more piezoelectric actuators respectively joined to one or more ends of the six wires opposite to the moving member side;
A fixing member for fixing a base end of the piezoelectric actuator and an end opposite to the moving member side of a wire to which the piezoelectric actuator is not joined,
A moving device, wherein the displacement of the piezoelectric actuator causes the moving member to move in a predetermined direction. A moving member;
One end is joined to the moving member, and six wires that hold the moving member at a predetermined position so as to be deformable following the movement of the moving member;
Six piezoelectric actuators respectively joined to ends of the six wires opposite to the moving member side,
A fixing member for fixing a base end of the piezoelectric actuator,
A moving device, wherein the displacement of the piezoelectric actuator causes the moving member to move in a predetermined direction. A moving member;
One end is joined to the moving member, and six wires that hold the moving member at a predetermined position so as to be deformable following the movement of the moving member;
Three piezoelectric actuators respectively joined to the three ends of the six wires opposite to the moving member side;
And a fixing member for fixing the base end of the piezoelectric actuator and the other end of the remaining three wires to which the piezoelectric actuator is not joined, on the side opposite to the moving member side,
The piezoelectric actuators are arranged so that their displacement directions are parallel to each other. The three wires joined to the piezoelectric actuator are provided in parallel with each other along the displacement directions of the piezoelectric actuators, and the remaining three wires are connected to each other. The wire is provided between the moving member and the fixed member so as to be orthogonal to the displacement direction of the piezoelectric actuator,
The displacement of the three piezoelectric actuators causes the moving member to cause a parallel movement in a displacement direction of the piezoelectric actuator and / or a rotational movement about an axis orthogonal to a driving direction of the piezoelectric actuator. Moving device. The moving device according to claim 3, further comprising a restricting member that restricts relative movement of the three piezoelectric actuators in directions other than the driving direction. The moving device according to claim 1, wherein the piezoelectric actuator has a piezoelectric element. The moving device according to any one of claims 1 to 5, wherein the piezoelectric actuator includes a piezoelectric element and a displacement enlarging mechanism that enlarges a displacement of the piezoelectric element. 7. The wire according to claim 1, wherein the wire has a relatively large-diameter central portion and relatively small-diameter deformed portions located on both sides of the central portion. 8. Moving equipment. A positioning device, wherein the positioning is performed using the moving member of the moving device according to any one of claims 1 to 7.

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