JP2004025360A - Three-dimensional operation mechanism for minute work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional minute operation mechanism for three-dimensionally minutely operating a matter to be operated by use of piezoelectric elements, which can realize the three-dimensional operation of the matter to be operated with a minimized number of piezoelectric elements, is free from the fear of breaking the piezoelectric elements by operating reaction, and has no free space or sliding part which causes an error. <P>SOLUTION: This device has a receiving base 4 supported on a base 2 by three or more radially arranged support legs 5. Each support leg 5 has driven members 12 pressed in the respective axial directions of piezoelectric elements by the respective piezoelectric elements concerned 3, and each driven member is located on the radially outside of the base 2. Each driven member 12 is integrally connected to the base 2 through an axially deflecting parallel plate spring group 20 arranged radially at intervals. Each driven member 12 is integrally connected to the receiving base 4 through a deflecting member 21 deflected in the radial direction and tangential direction. The matter to be operated 1 such as finger, needle, fork or the like which is three-dimensionally operated to perform a minute work is stationarily mounted on the receiving base 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-operation device used for precision positioning and micro-machining, and more particularly to an apparatus for three-dimensionally operating an operation target using a piezoelectric element.
[0002]
[Prior art]
As a three-dimensional minute operation mechanism using a piezoelectric element as a driving source, there is one disclosed in Japanese Patent Application Laid-Open No. H6-170761. In this publication, a receiving base for fixing an object to be operated, such as a finger, and a base are connected by six piezoelectric elements whose both ends are pivotally connected, and different operating voltages are applied to these six piezoelectric elements. This realizes a three-dimensional operation of the object.
[0003]
Since the piezoelectric element can control minute deformation by voltage control, it is possible to accurately control the micro operation.However, when the reaction force acts on the piezoelectric element as bending stress or tensile stress, the piezoelectric element is damaged. Therefore, it is necessary to consider that the reaction force acts as a compressive force in the axial direction of the piezoelectric element. In addition, the number of piezoelectric elements required for causing the object to perform a desired operation is preferably as small as possible, and the drive control system is simplified, so that the entire apparatus can be manufactured at low cost. Also, the mechanism for converting the axial expansion and contraction movement of the piezoelectric element into a free three-dimensional movement of the object to be operated must have a structure that is as simple as possible and has no play space that causes an error. It is. Therefore, for example, when a pivot structure using a shaft and a hole or a pivot structure using a sphere and a concave spherical surface is used, an unavoidable play space on the sliding surfaces causes an error. In the micro operation device, the desired operation itself of the object to be operated is very small. Therefore, even if the error due to these play gaps is small, the ratio of the error amount to the original operation amount becomes very large.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide an operation mechanism for performing a three-dimensional micro operation on an object to be operated by using a piezoelectric element as a drive source under the above-described various constraint conditions. A three-dimensional operation of the object to be operated can be realized, there is no risk of damaging the piezoelectric element due to an operation reaction force, and there are play gaps and sliding parts between members constituting the operation mechanism, which cause errors. It is an object of the present invention to provide a three-dimensional micro operation mechanism.
[0005]
[Means for Solving the Problems]
The three-dimensional operation mechanism for fine work according to the invention of claim 1 of the present application includes a receiving table 4 supported on the base 2 by three or more support legs 5 arranged radially. Each support leg 5 includes a passive member 12 that is pushed by the corresponding piezoelectric element 3 in the axial direction of the corresponding piezoelectric element, and each passive member is positioned radially outward from the base 2. Each passive member 12 and the base 2 are integrally connected by a group of parallel leaf springs 20 that are radially spaced and that bend in the axial direction, and that each passive member 12 and the pedestal 4 are They are integrally connected by a flexure member 21 that flexes in a tangential direction. An object 1 such as a finger, a needle, a fork or the like, which operates in a three-dimensional direction and performs a fine work, is fixedly mounted on the receiving table 4.
[0006]
The parallel leaf spring group 20 preferably includes three or more leaf springs including a leaf spring arranged at intervals in the radial direction and a leaf spring arranged symmetrically with respect to the pressing position of the piezoelectric element 3. It is formed.
[0007]
According to a second aspect of the present invention, the bending member 21 of the three-dimensional operation mechanism for fine work includes a leaf spring 37 which is connected in series and is bent in a radial direction and leaf springs 38 and 39 which are bent in a tangential direction. This is a three-dimensional operation mechanism formed by groups.
[0008]
The cradle 4 is supported by three or more support legs 5 arranged in the radial direction, and each of the support legs is individually driven in the axial direction by the piezoelectric element 3. Therefore, by individually controlling the voltages applied to the three piezoelectric elements 3, the cradle 4 can be tilted in a free direction, whereby the tips of the fingers and tools fixed to the cradle 4 can be moved. It can swing freely in a two-dimensional plane perpendicular to the axis. By applying the same voltage to three or more piezoelectric elements, the pedestal 4 can be moved in the axial direction, and the tips of the fingers, tools, and works fixed to the pedestal 4 can be three-dimensionally combined. Can be exercised arbitrarily.
[0009]
The group of parallel leaf springs 20 connecting the base 2 and the passive member 12 of each support leg constitutes a parallel link mechanism. When the passive member 12 is pushed by the piezoelectric element 3, the passive member 12 is mainly It moves in the axial direction and does not apply bending force to the piezoelectric element. The moving stroke of the piezoelectric element 3 is at most about several tens of microns, and the passive member 12 moves in the axial direction by setting the extending direction of the parallel leaf spring group 20 to the radial direction or the radial direction inclined in the axial direction. In this case, the amount of movement in the radial direction can be made sufficiently small, and the minute movement in the radial direction can be absorbed by shearing deformation of the connecting members 23 and 24 for fixing the piezoelectric element and the passive member and the adhesive layer. Therefore, both ends of the piezoelectric element that pushes and drives the passive member 12 can be fixed to the passive member 12 and the base 2 with an adhesive or the like, and a sliding portion or a pin is provided between the passive member 12 and the piezoelectric element 3. It is possible to adopt a structure that does not interpose a connection structure such as a joint portion where an error may enter.
[0010]
The passive member 12 and the pedestal 4 are integrally connected by a flexible member (composite leaf spring group of the embodiment) 21, and a sliding portion or a pin connection is also provided between the passive member 12 and the pedestal 4. Since there is no connecting structure having an unavoidable play space such as a part, the movement of the passive member 12 is accurately transmitted to the finger 1 or the tool fixed to the receiving table 4.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be further described with reference to embodiments shown in the drawings. FIG. 1 shows an example in which a needle finger 1 is supported by the structure of the present invention, and details of each part are shown in FIGS.
[0012]
In the drawing, reference numeral 2 denotes a base, which is a member attached to an arm tip or a moving base of a handling device for conveying or manipulating minute articles, or a table or a processing head of a fine processing machine. Reference numeral 3 denotes three piezoelectric elements arranged in parallel with each other, 4 denotes a pedestal for mounting an operation target, and 5 denotes a base 2 and a pedestal 4 which are located on the extension of each piezoelectric element 3 in the axial direction (extension and contraction direction). The needle finger 1, which is a support leg that is connected to the moving object, is fixed to the receiving table 4. The base 2 has a structure in which a base flange 7 and a front flange 8 are integrally provided at both ends of a column 6, and three piezoelectric elements 3 are provided at positions that divide the circumference into three equal parts. It is fixed and mounted parallel to the column 6. Hereinafter, in this specification, the direction of the central axis of the column 6 is referred to as the axial direction, the direction extending around the central axis is referred to as the radial direction, and the direction perpendicular to the radial direction in a plane perpendicular to the central axis is referred to as the tangential direction (see FIG. 4). ).
[0013]
A strain gauge 9 for feeding back the displacement is attached to each piezoelectric element. The front flange 8 is provided with a radial cutout 10 at an extension of the piezoelectric element 3.
[0014]
As shown in FIGS. 5 and 6, each support leg 5 includes a substrate 11 fixed to the base 2, a passive member 12 integrally connected to the substrate by a group of parallel leaf springs 20 in oblique radial directions, A base bracket 13 integrally connected to the member 12 by a composite leaf spring group 21 with first and second connecting plates 23 and 24 interposed therebetween. The substrate 11 is fixed to the front flange 8 of the base with bolts 26, and a cutout 14 in the radial direction similar to that provided on the front flange 8 is provided in an extended upper portion of the piezoelectric element 3.
[0015]
The mounting blocks 28 and 29 are fixed to both ends of the piezoelectric element 3 with an adhesive, and the mounting block 28 at the base end is fixed to the base flange 7 with bolts 31. The mounting block 29 at the distal end is fixed to the passive member 12 with a stud 33 via a screw block 32. The screw block 32 is provided with a cross hole 34 for rotating the screw block 32.
[0016]
The parallel leaf spring group 20 that connects the substrate 11 and the passive member 12 includes four strip leaf springs 36 that are parallel to each other. Both ends of each band leaf spring are fitted and adhered to grooves obliquely cut into the substrate 11 and the passive member 12. The four strip springs are arranged parallel to the outside and the inside at intervals in the radial direction, and are arranged symmetrically in the tangential direction with the connecting portion of the piezoelectric element 3 interposed therebetween. The bending direction of each band spring 36 is an axial direction or an axial direction inclined radially inward.
[0017]
The four band springs 36 constitute a parallel link mechanism in the radially outer and inner directions. When the piezoelectric element 3 pushes the passive member 12 in the axial direction, the inner and outer band plates 36 are moved. The spring 36 flexes in the same shape and translates the passive member 12. If the extending direction of the band spring 36 is exactly the radial direction, the passive member 12 will not be displaced in the radial direction during this axial movement, but as shown in the illustrated embodiment, the band spring 36 is inclined. In this case, the passive member 12 also moves in the radial direction along with the axial movement. As described above, the radial movement can be set to a size that can be absorbed by the adhesive layer between the piezoelectric element 3 and the mounting blocks 28 and 29 and the shear deformation of the screw block 32. That is, by making the direction of the band spring 36 closer to the radial direction, the radial movement accompanying the axial movement of the passive member 12 can be reduced to a negligible degree.
[0018]
The passive member 12 and the first connecting plate 23 of the composite leaf spring group are connected to each other by two short leaf springs 38 which are spaced apart in the radial direction with their faces tangential. The first connecting plate 23 and the second connecting plate 24 are connected to each other by four parallel band springs 37 whose surfaces are in oblique radial directions. The second connecting plate 24 and the base bracket 13 are connected to each other by two short leaf springs 39 that are provided with a surface in a tangential direction and are spaced apart in a radial direction. Both ends of these leaf springs 37, 38, and 39 are formed by cutting the passive member 12 and the first connecting plate 23, the first connecting plate 23 and the second connecting plate 24, and the second connecting plate 24 and the base bracket 13. Both ends are fitted and adhered. Note that the arrangement of the four band springs 37 connecting the first connecting plate 23 and the second connecting plate 24 is substantially the same as the arrangement of the band springs 36 of the parallel leaf spring group 20, and their inclination directions are opposite. It is.
[0019]
By the connection via the leaf springs 37, 38, 39, the axial movement of the passive member 12 is transmitted to the base bracket 13, while the inclination of the base bracket 13 in each direction is absorbed by the composite leaf spring group 21.
[0020]
The three supporting legs 5 having the above-described structure are arranged at positions where the circumference around the center axis of the base 2 is divided into three equal parts so that the passive member 12 is located radially outside the substrate 11. ing. One pedestal 4 is fixed to three pedestal brackets 13 of three support legs by screws 41. An object to be operated such as a finger, a tool, or a work is fixed to the receiving table 4 by an appropriate fixing structure. In the example shown in FIG. 1, the needle finger 1 having a sharp tip is fixed by a fixing screw 41 screwed to a fixing bracket 40 integrated with the receiving table.
[0021]
In the above structure, the tip of the needle finger 1 is advanced and retracted in the axial direction by applying the same voltage to the three piezoelectric elements 3 arranged at a position where the circumference around the central axis of the base 2 is equally divided into three. Can be. When a high voltage is applied to only one piezoelectric element, the tip of the needle finger 1 oscillates in the direction opposite to the radiation direction, and the oscillating operation in the radiation direction controls the voltage applied to the three piezoelectric elements 3. Thus, the direction and amount of the shake can be controlled. Therefore, the tip of the needle finger 1 can be three-dimensionally operated by a combination of the above operations.
[0022]
Since the passive member 12 fixed to the piezoelectric element 3 is supported by the group of parallel leaf springs 20 constituting the parallel link mechanism, no bending stress or large shear stress is applied to the piezoelectric element 3. Since the passive member 12 and the piezoelectric element 3 and the base 2 and the pedestal 4 are connected by an adhesive or screw fastening structure in which a sliding portion or a pin connecting portion does not exist, a play gap which causes an error in a minute motion. Therefore, an object such as a finger, a tool, or a work mounted on the receiving table 4 can be accurately moved in a desired three-dimensional space by controlling the piezoelectric element 3.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the overall configuration of an embodiment. FIG. 2 is a longitudinal sectional view of the apparatus of FIG. 1. FIG. 3 is a longitudinal sectional view of a support structure of the apparatus of FIG. 1. FIG. FIG. 5 is a side view showing one support leg. FIG. 6 is a plan view showing one support leg.
DESCRIPTION OF SYMBOLS 1 Needle finger 2 Base 3 Piezoelectric element 4 Cradle 5 Support leg 12 Passive member 20 Parallel leaf spring group 21 Composite leaf spring group 37 Band leaf spring 38 Short leaf spring 39 Short leaf spring

Claims (2)

A pedestal (4) supported on the base (2) with three or more support legs (5) arranged radially is provided, and each support leg is pushed in the axial direction by a corresponding piezoelectric element (3). Passive members (12), each passive member being located radially outward from the base (2), and each passive member and the base (2) being flexed in an axial direction spaced apart in a radial direction. The passive members and the pedestal (4) are integrally connected by a flexible member (21) that bends in a radial direction and a tangential direction, and is connected to the pedestal. A three-dimensional operation mechanism for fine work in which the object (1) is fixed. The said flexible member is formed of the leaf spring group (21) which contains the leaf spring (37) and the leaf spring (38,39) which bend in the tangential direction connected in series. A three-dimensional operating mechanism according to claim 1.

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