JP2004291156A - Clamping device, and vertical direction driving positioning device with tilt function having it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamping device allowing translation and tilt operation in the vertical direction and elimination of positional displacement even when horizontal or downward acceleration works. <P>SOLUTION: The clamping device has three sets of combinations of balls 13-15 placed on supporting members 107-109 and clamp shafts 16-18 having ball receiving sections 16-1 to 18-1 in their lower parts and butting them on the upper parts of the balls. The clamp shafts are formed of the supporting members and shaft sections 16-2 to 18-2 extending upward from there. Holders 104-106 for holding the combinations of the balls and the clamp shafts in the state where the shaft sections are projected upward oscillatably are fixed to the supporting member side. Belleville springs 101-103 for energizing the receiving sections downward are disposed between the receiving sections and the holders. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vertical drive positioning device with a tilt function having a drive function in the vertical direction, that is, a Z-axis direction, and a tilt function, that is, a tilt function.
[0002]
[Prior art]
As a driving device in the Z-axis (vertical) direction used for a positioning stage or the like, it is possible to combine three driving mechanisms to give a translational motion in a vertical direction to a supported body, for example, a table or a suction disk, supported by the driving mechanisms. There has been proposed one that can be used (for example, Patent Document 1).
[0003]
Although this uses a kinematic clamp (a so-called Kelvin clamp), it is a device for positioning, and when a horizontal or downward acceleration exceeding a certain magnitude acts, the upper object may shift.
[0004]
Hereinafter, this will be described with reference to FIGS.
[0005]
(1) In the Kelvin clamp, as shown in FIG. 4A, three spheres 22, 23, and 24 attached to the lower surface of the upper table 20 via shafts are formed on the upper surface of the lower table 21, respectively. The surface of the upper table 20 can be positioned relative to the surface of the lower table 21 by contacting the triangular pyramid (or cone) concave portion 25, the V-shaped groove 26 having a V-shaped cross section, and the flat surface 27. You can do it. In some cases, as shown in FIG. 4B, all three spheres may be configured to contact three sets of V-grooves 26 'formed on the upper surface of the lower table 21'.
[0006]
(2) Such a Kelvin clamp is configured such that the apex of the triangular pyramid of the concave portion 25 is positioned on the axial extension of the V-groove 26 in the case of FIG. Accordingly, even if one surface, for example, the upper table 20 on which the sphere is fixed expands (narrows) between the three spheres due to thermal expansion (or contraction) or the like, or the lower table 21 expands thermally. Even if (or contraction), as shown in FIG. 5, the sphere 22 in contact with the triangular pyramid-shaped concave portion 25 is set as a fixed point, and the sphere 23 in contact with the V-groove 26 moves in the axial direction of the V-groove 26. Then, the sphere 24 in contact with the plane can move to a position determined by the relative positional relationship between the triangular pyramid-shaped concave portion 25 and the V groove 26. In the case of FIG. 4B, three sets of V-grooves 26 'are arranged so as to intersect at one point, and have the same function as that of FIG. 4A.
[0007]
(3) It is assumed that the surface provided with the concave portion and the groove is the lower side, the surface on which each ball is fixed is the upper side, and the lower side supports the upper side in each clamp portion, and horizontal acceleration acts on the lower side. I do. In this case, as shown in FIG. 6 (a), the lower portion is acted on by the friction force μ · F ₁ (where μ is the friction coefficient) due to the weight of the upper portion supported by the clamp portion formed by the V groove 26 and the ball 23. When the horizontal acceleration acting on the side is small, the relative positions of the upper and lower sides are maintained. However, when working the horizontal force F ₂ due to the large horizontal acceleration α at the bottom side, the upper side when the component force F _{2 '(the} component force along the surface direction of the V-groove 26) exceeds the frictional force mu · F ₁ The position shifts. Alternatively, as shown in FIG. 6 (b), when the whole moves downward with an acceleration α ′ exceeding the gravitational acceleration, the upper side cannot follow the lower side and separates. For this reason, in order to apply a greater frictional force, the upper and lower sides are connected by a spring or the like to apply an additional load.
[0008]
[Patent Document 1]
JP-A-10-79344 (page 2, FIG. 9)
[0009]
[Problems to be solved by the invention]
By the way, in a Z-axis (vertical) direction positioning device, an upper side (for example, a rotary table) is supported using three sets of Z-axis driving mechanisms, and a tilt (tilt) operation is given in addition to a Z-axis translation operation. May be required. On the other hand, if the upper and lower couplings are Kelvin clamps described above, a tilt operation for giving a tilt can be performed. However, when these three sets of Z axes are installed on a horizontal positioning table (XY table), if the horizontal positioning table moves at a large acceleration for the reason described in the above (3), the upper part is moved upward. The sides will shift. If the upper and lower sides are connected by a spring or the like in order to prevent this, a load is applied to the Z-axis drive mechanism correspondingly, and the capacity of the Z-axis drive mechanism needs to be increased. And the load by the spring increases as the driving amount (stroke) in the Z-axis direction increases.
[0010]
Therefore, an object of the present invention is to make a kinematic clamp (so-called Kelvin clamp) rigid so that translation and tilting operations in the vertical (Z-axis) direction are enabled, and the position is shifted even when horizontal or downward acceleration acts. An object of the present invention is to provide a clamp device that can eliminate the problem.
[0011]
Another object of the present invention is to provide a vertical drive positioning device with a tilt function provided with the clamp device.
[0012]
[Means for Solving the Problems]
According to the present invention, a plurality of combinations of a ball placed on a support member and a clamp shaft having a receiving portion of the ball at a lower portion and having the receiving portion contact the upper portion of the ball are provided, The clamp shaft includes the receiving portion and a shaft portion extending upward from the receiving portion. The combination of the ball and the clamp shaft is provided on the support member side with the shaft portion protruding upward so as to swing. A clamp device is provided, wherein a holder for holding is fixed, and a spring member for urging the receiving portion downward is interposed between the receiving portion and the holder.
[0013]
In the clamp device according to the present invention, the combination of the ball and the clamp shaft is three, and the first ball of the first set is housed in a pyramid or conical recess provided on the first support member. The second set of second balls is accommodated in a V-groove provided in the second support member so as to extend in a predetermined direction, and the third set of third balls is set in the third set. Characterized by being placed on the plane of the supporting member.
[0014]
In the clamp device according to the present invention, the combination of the ball and the clamp shaft is three sets, and the first ball of the first set is housed in the first V-groove provided in the first support member. The second set of second balls is housed in a second V-groove provided in the second support member, and the third set of third balls is provided in the third support member. The first to third support members may be configured to be accommodated in a third V-groove such that extensions of the first to third V-grooves intersect at a single point.
[0015]
In the above-described clamp device, as a first aspect, the first to third sets of shaft portions are each attached to the same upper member, and the first to third support members are vertically movable independently. With this configuration, it is possible to provide a clamp device in which the upper member can be vertically moved and tilted.
[0016]
In the above-mentioned clamp device, as a second mode, the first to third sets of shafts are respectively attached to the same upper member, and the first to third support members are connected to one common support member. Can be provided.
[0017]
According to the present invention, there is also provided a vertical drive positioning device with a tilt function provided with the clamp device according to the first aspect, wherein the first to third support members are vertically moved. There is provided a vertical drive positioning device with a tilt function, wherein a drive mechanism is provided on a base member.
[0018]
The vertical drive positioning device with tilt function according to the present invention is provided with a slide wedge mechanism as the first to third drive mechanisms.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
A preferred embodiment of a clamp device according to the present invention and a vertical drive positioning device with a tilt function using the same will be described with reference to FIGS.
[0020]
FIG. 1 shows an embodiment in which the clamp device according to the present invention is realized by improving the aforementioned Kelvin clamp. Of the three sets of clamps that make up the Kelvin clamp, FIG. 1A shows a first set of a concave part (or a concave part by a cone) 107a formed by a pyramid such as a triangular pyramid and a ball 13 housed therein. 1 (b) shows a second set of the V-groove 108a and the ball 14 accommodated therein, and FIG. 1 (c) shows a third set of the plane and the ball 15 placed thereon. Is shown. All of the first to third sets have the same structure except for the structure of the part where the sphere is placed.
[0021]
The first clamp 10 shown in FIG. 1A is housed in the first support member 107 having a conical (or pyramid) concave portion (hereinafter simply referred to as a concave portion) 107a formed on the upper surface, and the concave portion 107a. The first ball 13 provided has a receiving portion 16-1 of the ball 13 at a lower portion and a shaft portion 16-2 extending upward, and the receiving portion 16-1 is brought into contact with the upper portion of the ball 13. A clamp shaft 16, a holder 104 fixed to the first support member 107 and holding a combination of the ball 13 and the clamp shaft 16 in a state where the shaft portion 16-2 is swingably protruded upward; A disc spring 101 is interposed between the upper side of the receiving portion 16-1 and the inner surface side of the holder 104 to bias the receiving portion 16-1 downward.
[0022]
The second clamp 11 shown in FIG. 1B includes a second support member 108 having a V-shaped groove 108a formed on an upper surface, a second ball 14 housed in the V-shaped groove 108a, The clamp shaft 17 having the receiving portion 17-1 at the lower portion and having the shaft portion 17-2 extending upward and having the receiving portion 17-1 contact the upper portion of the ball 14 and the second support member 108 A holder 105 for holding a combination of the ball 14 and the clamp shaft 17 in a state where the shaft portion 17-2 is swingably protruded upward and an upper surface of the receiving portion 17-1 and an inner surface of the holder 105. And a disc spring 102 for urging the receiving portion 17-1 downward interposed therebetween.
[0023]
The third clamp 12 shown in FIG. 1C includes a third support member 109, an upper surface thereof, that is, a third ball 15 placed on a plane, and a receiving portion 18-1 of the ball 15. A clamp shaft 18 having a shaft portion 18-2 provided at a lower portion and extending upward, and a receiving portion 18-1 abutting on an upper portion of the ball 15, and a shaft portion 18-fixed to a third support member 109. A holder 106 for holding the combination of the ball 15 and the clamp shaft 18 in a state in which the ball 2 and the clamp shaft 18 are protruded upward so as to be able to swing, and an interposition between the upper side of the receiving portion 18-1 and the inner surface side of the holder 106. And a disc spring 103 for urging the receiving portion 18-1 downward.
[0024]
Each of the receiving portions 16-1 to 18-1 has a concave portion formed by a pyramid or a cone on the lower surface side, and the spheres 13 to 15 are accommodated in the concave portion. Each of the holders 104 to 106 has a diameter larger than the diameter of the shaft portions 16-2 to 18-2 so that the shaft portions 16-2 to 18-2 can be swingably inserted into the upper portion thereof. The plate member has an opening, and this plate member functions as a spring retainer for pressing the disc spring against the receiving portion, and applies a necessary load to the holder. Strictly speaking, in order to be able to give relative movement to each holder, the opening of the spring retainer is made larger than the sum of the diameter of the shaft part and the moving distance of the relative movement, and the relative movement accompanying the tilting operation is made. Is configured to allow. A disc spring that gives a required load is mounted, and a spring that does not exceed the elastic limit of the spring even when the clamp shaft is inclined is used.
[0025]
When the above three sets of clamps are used as one clamp device, for example, the shaft portions 16-2 to 18-2 are attached to one upper member 110 as a member to be clamped. On the other hand, the lower members 111, 112, and 113 to which the support members 107 to 109 are attached are also configured by one member. In the second clamp 11, the extension of the V-shaped groove 108 a formed in the second support member 108 intersects the vertex of the concave portion 107 a formed in the first support member 107 in the first clamp 10. Needless to say, the configuration is as follows. Of course, the support members 107 to 109 may be constituted by one member from the beginning. Then, when the support members 107 to 109 are formed of one member, and the first to third V-grooves are formed on the upper surface of this one member so as to intersect at one point, it is shown in FIG. Needless to say, it is possible to provide a clamping device having the same function as the above. In any case, the clamp device having the above-described configuration has a structure in which the first to third clamps 10 to 12 have the same functions as those shown in FIG. 4A and FIG. And the upper side are rigidized, so that even if horizontal or downward acceleration acts, it is possible to eliminate the displacement of each other.
[0026]
On the other hand, when a vertical drive positioning device with a tilt function is configured using the three sets of clamps 10 to 12 shown in FIGS. 1A to 1C, the lower members 111 to 113 of each set are respectively Z-shaped. What is necessary is just to comprise so that a shaft drive mechanism can drive independently in the up-down direction.
[0027]
As the Z-axis drive mechanism, for example, a so-called slide wedge type as shown in FIG. 2 can be used. FIG. 2 shows a case in which the Z-axis drive mechanism 40 is applied to the first clamp 10, but exactly the same clamp is used in each of the second and third clamps 11 and 12.
[0028]
In FIG. 2, a Z-axis drive mechanism 40 is horizontally slidable on a base member 50 and has a horizontal moving block 61 having an inclined surface on an upper surface side, and an inclined surface corresponding to the inclined surface of the horizontal moving block 61. A vertical movement block 62 having a lower surface side and capable of moving up and down by the horizontal movement of the horizontal movement block 61; a motor 63 acting as a drive source for moving the horizontal movement block 61; And an air cylinder 64 for applying a pressing force in the horizontal direction.
[0029]
The horizontal moving block 61 has a slide member 61-1 on a lower surface side that can slide at least one horizontal guide member 50-1 provided on the base member 50. The horizontal movement block 61 is also provided with at least one guide member 61-2 on the inclined surface. On the other hand, a slide member 62-1 that can slide the guide member 61-2 is provided on the inclined surface of the vertical movement block 62. A block body 50-2 is provided on the base member 50 so as to extend upward in correspondence with the back surface of the vertical movement block 62, and extends vertically on the side of the vertical movement block 62 in the block body 50-2. An existing vertical guide member 50-3 is provided. A slide member 62-2 that can slide the guide member 50-3 is provided on the back surface of the vertical movement block 62. Between the output shaft of the motor 63 and the horizontal movement block 61, a ball screw mechanism 65 for converting the rotational movement of the output shaft into a horizontal movement is provided.
[0030]
With the above structure, when the motor 63 rotates in one direction, this is converted into a horizontal motion, and the horizontal moving block 61 moves horizontally in the right direction in FIG. 2, and as a result, the vertical moving block 62 moves upward. I do. On the other hand, when the motor 63 rotates in the opposite direction, this is converted into a horizontal motion, and the horizontal moving block 61 horizontally moves to the left in FIG. 2, and as a result, the vertical moving block 62 moves downward.
[0031]
The air cylinder 64 is used for the following reason. A vertical force acts on the vertical moving block 62 due to the upper member 110 and, in some cases, a work placed thereon and other loads, and a horizontal component acts on the horizontal moving block 61. Since a high-output motor is required to cover this horizontal component only with the output of the motor 63, the horizontal component is received by bringing the output shaft 64-1 of the air cylinder 64 into contact with the horizontal movement block 61. Thus, the output of the motor 63 can be reduced.
[0032]
In any case, three sets of clamps 10 to 12 in which the Z-axis driving mechanisms 40, 70, 80 having the above-described structure are combined are arranged on the base member 50 as shown in FIG. Of course, also in this case, in the second clamp 11, the extension of the V-shaped groove 108a formed in the second support member 108 is formed by the extension of the recess 107a formed in the first support member 107 in the first clamp 10. It goes without saying that it is configured to intersect the vertex. On the other hand, when the Z-axis drive positioning device is of the type shown in FIG. 4B, all three sets of clamps have the V-groove 108a shown in FIG. And driven by the Z-axis drive mechanism described above. Of course, also in this case, the three sets of clamps are arranged so that the extension lines of the three V-grooves intersect at one point. In any case, the upper member 110 of the three sets of clamps 10 to 12 is the same member, and if the three sets of clamps 10 to 12 have the same amount of vertical movement, the upper part 110 performs a translational operation, and there is a difference in the amount of movement. This causes a tilt operation.
[0033]
As described above, the kinematic clamp (the so-called Kelvin clamp) is made rigid to enable the translation and tilt operation in the Z-axis direction, and to eliminate the displacement even when horizontal or downward acceleration acts. A Z-axis drive positioning device with a tilt function can be provided. The above-described Z-axis drive mechanism is merely an example, and is not limited to the slide wedge type, and may be realized by a known drive mechanism such as a simple air cylinder or a ball screw.
[0034]
In some cases, the structure may be such that the positional relationship between the upper side and the lower side is reversed.
[0035]
By providing the above-described three-axis vertical drive positioning device on the X-axis table or the Y-axis table of the XY stage, a stage device that can move in the three X-axis directions is configured. Can be. In this case, the base member 50 serves as an X-axis table or a Y-axis table.
[0036]
【The invention's effect】
According to the present invention, the upper side and the lower side in a kinematic clamp, a so-called Kelvin clamp, are made rigid to enable translation and tilting in the Z-axis direction and to maintain the position even when horizontal or downward acceleration is applied. It is possible to provide a clamp device that can eliminate the displacement.
[0037]
According to the present invention, it is also possible to provide a vertical drive positioning device with a tilt function provided with a clamp device having the above-described effects.
[Brief description of the drawings]
FIG. 1 is a sectional view for explaining three sets of clamps constituting a clamp device according to the present invention.
FIG. 2 is a side view showing a structure of one clamp in a case where a Z-axis drive mechanism is combined with each set of clamps of FIG. 1 to constitute a vertical drive positioning device.
FIG. 3 is a plan view showing a layout of each set when a vertical drive positioning device is configured using a combination of the clamp and the Z-axis drive mechanism shown in FIG. 2;
FIG. 4 is a view for explaining two examples of a conventional Kelvin clamp.
FIG. 5 is a diagram for explaining an operation of absorbing a shift based on thermal expansion of a support member in a conventional Kelvin clamp.
FIG. 6 is a diagram for explaining a problem when a horizontal acceleration and a downward acceleration are applied in the conventional Kelvin clamp.
[Explanation of symbols]
10, 11, 12 First, second, third clamps 13 to 15 Balls 16 to 18 Clamp shafts 16-1, 17-1, 18-1 Receiving parts 16-2, 17-2, 18-2 Shafts 40, 70, 80 Z-axis drive mechanism 50 Base member 50-1, 50-3, 61-2 Guide member 61 Horizontal moving member 62 Vertical moving member 61-1, 62-1, 62-2 Slide member 63 Motor 64 Air Cylinder 65 Ball screw mechanism 101, 102, 103 Disc spring 104-106 Holder 107, 108, 109 First, second, third support member 110 Upper member 111, 112, 113 Lower member

Claims (7)

A plurality of combinations of a ball placed on a support member and a clamp shaft having a receiving portion of the ball at a lower portion and having the receiving portion abutting on an upper portion of the ball are provided. And a shaft portion extending upward therefrom, and a holder for holding a combination of the ball and the clamp shaft in a state where the shaft portion is protruded upward so as to be swingable on the support member side. A clamp device which is fixed and has a spring member interposed between the receiving portion and the holder for urging the receiving portion downward. 2. The clamp device according to claim 1, wherein the combination of the ball and the clamp shaft is three, and the first ball of the first set is a concave portion formed by a pyramid or a cone provided on a first support member. And a second set of second balls is accommodated in a V-groove provided in the second support member so as to extend in a predetermined direction, and a third set of third balls is A clamping device, wherein the clamping device is placed on a plane of the third support member. 2. The clamp device according to claim 1, wherein the combination of the ball and the clamp shaft is three sets, and the first ball of the first set is a first V-groove provided on a first support member. 3. , The second set of second balls is accommodated in a second V-groove provided in the second support member, and the third set of third balls is provided in the third support member. The clamp device is housed in a third V-groove, and the first to third support members are configured such that extensions of the first to third V-grooves intersect at one point. 4. The clamp device according to claim 2, wherein the first to third sets of shafts are respectively attached to the same upper member, and the first to third support members are vertically movable independently. 5. A clamp device, wherein the upper member is configured to be vertically movable and tiltable by being configured. 4. The clamp device according to claim 2, wherein the first to third sets of shaft portions are respectively attached to the same upper member, and the first to third support members are configured by one common support member. 5. A clamping device characterized by the following. A vertical drive positioning device with a tilt function, comprising the clamp device according to claim 4, wherein first to third drive mechanisms for vertically moving the first to third support members are provided on a base member. A vertical drive positioning device with a tilt function. The vertical drive positioning device with a tilt function according to claim 6, further comprising a slide wedge mechanism as the first to third drive mechanisms.

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