JP4221512B2 - Moving table equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a moving table device such as an XYθ table device or an XY table device used in a manufacturing apparatus such as a semiconductor device or a micromachine.
[0002]
[Prior art]
Conventionally, the XY table device has a structure in which an X table and a Y table, which are moving tables, are stacked on a fixed table, and the XYθ table device further stacks a θ table, which is a moving table, on the Y table. Had a structure.
[0003]
For this reason, it is difficult to reduce the height and weight of the entire moving table. In addition, since the entire moving table is heavy, it is difficult to increase the speed of movement. Furthermore, the moving table is supported by a table below the guide or bearing, but the guide or bearing can only support a part of the moving table, so if the moving table becomes large, the moving table will bend due to its own weight. There was a problem.
[0004]
Since the conventional moving table has such a problem, there are few examples of the moving table device for heavy loads.
[0005]
Therefore, one moving table is arranged on the fixed table, and the moving table is supported by a large number of balls accommodated in the pockets of the cage arranged between the two tables. A moving table device that can be moved in the X direction, the Y direction, and the θ direction has been proposed (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-8-257854 gazette
[Problems to be solved by the invention]
In the moving table device described in Patent Document 1, the above-described problem in the conventional moving table device is solved.
[0008]
However, since a large number of balls having a relatively small diameter are accommodated in the pocket of the cage, the balls in the pocket may be displaced in one direction and may be bitten.
[0009]
An object of the present invention is to provide a moving table device that solves the above-described problems and can effectively prevent a ball from getting caught in a pocket of a cage.
[0010]
[Means for Solving the Problems and Effects of the Invention]
The moving table device according to claim 1 is a plurality of rectangular fixed tables, a rectangular moving table disposed so as to be movable above the fixed table, and a plurality of rectangular ball receiving pockets provided on an upward surface of the fixed table. A square retainer, a plurality of balls accommodated in pockets of each retainer and movably supporting the movable table with respect to the fixed table; and a moving means for moving the movable table with respect to the fixed table. Each cage is attached to the upward surface of the fixed table so as to be movable in a direction parallel to the surface.
[0011]
The cage is preferably attached to the upward surface of the fixed table so as to be movable in all directions parallel to the surface.
[0012]
The moving range of the cage with respect to the fixed table is appropriately determined according to the size of the table and the like, but it is necessary that at least the pocket portion of the cage does not come off the fixed table. Further, the moving range does not need to be so large, for example, it can be moved about 1 to several mm in all directions.
[0013]
According to the moving table device of the first aspect, it is possible to prevent the ball in the pocket from being offset in one direction and causing the biting by moving the cage with respect to the fixed table.
[0014]
According to a second aspect of the present invention, in the moving table device according to the first aspect, at least two pin holes are provided in one of the fixed table and the cage, and the other is fitted with a gap with respect to the pin hole. The pin is provided in a fixed shape.
[0015]
The pin holes and pins are usually circular. The size of the gap between the pin hole and the pin is appropriately determined according to the size of the table, and is, for example, 1 to several mm in diameter.
[0016]
According to the moving table device of claim 2, the pin provided in either one of the fixed table or the retainer is fitted with the pin provided in a fixed shape on the other side with a gap, thereby fixing the fixed table. The cage can be moved with respect to the ball to prevent the ball from getting caught, and the movement of the cage relative to the fixed table is restricted within a desired range by having at least two pin hole and pin combinations. can do.
[0017]
According to a third aspect of the present invention, there is provided a movable table device comprising: a rectangular fixed table; a rectangular movable table disposed movably above the fixed table; and a plurality of rectangular ball receiving pockets provided on an upward surface of the fixed table. A square retainer, a plurality of balls accommodated in pockets of each retainer and movably supporting the movable table with respect to the fixed table; and a moving means for moving the movable table with respect to the fixed table. In addition, the inner peripheral surface of the pocket of each cage can be elastically deformed.
[0018]
The entire inner peripheral surface of the pocket may be elastically deformable, or a part of the inner peripheral surface of the pocket may be elastically deformable.
[0019]
According to the movable table device of the third aspect, the inner peripheral surface of the pocket of the cage is elastically deformed, so that it is possible to prevent the balls in the pocket from being offset in one direction and causing biting.
[0020]
According to a fourth aspect of the present invention, there is provided the movable table device according to the third aspect, wherein each retainer has an elastic damper on the inner periphery of the pocket, and the inner peripheral surface of the damper is elastically deformable. It is what.
[0021]
For example, rubber is used as the elastic body constituting the damper.
[0022]
The damper may be provided on the entire inner periphery of the pocket, or may be provided on a part of the inner periphery of the pocket.
[0023]
According to the movable table device of the fourth aspect, the cage has an elastic damper on the inner periphery of the pocket, so that the inner peripheral surface of the pocket can be elastically deformed to prevent the ball from being caught. it can.
[0024]
According to a fifth aspect of the present invention, there is provided the movable table device according to the third aspect, wherein a slit is formed in a portion near the inner periphery of the pocket of each cage made of a rigid body, and a thin wall that is elastically deformable in a portion closer to the inner periphery than the slit A portion is formed.
[0025]
Preferably, a plurality of slits and thin portions are formed.
[0026]
According to the movable table device of the fifth aspect, the slit is formed in the inner peripheral portion of the pocket of the cage made of a rigid body, and the thin wall portion that can be elastically deformed is formed in the inner peripheral portion of the slit. As a result, the inner peripheral surface of the pocket can be elastically deformed to prevent the ball from being caught.
[0027]
According to a sixth aspect of the present invention, the movable table device according to the first or second aspect is characterized in that the inner peripheral surface of the pocket of each cage is elastically deformable.
[0028]
According to the moving table device of claim 6, the cage moves relative to the fixed table, and the inner peripheral surface of the pocket of the cage is elastically deformed, so that the ball in the pocket is offset and bites in one direction. Can be prevented.
[0029]
In the movable table device according to any one of claims 1 to 6, it is desirable that the pockets of the cages have a rectangular shape and the corners of the pockets are curved surfaces having a radius of curvature larger than the ball radius, for example, cylindrical surfaces.
[0030]
In this way, it is possible to prevent the ball from shifting to the corner of the pocket and to further enhance the effect of preventing the ball from getting caught.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to an XYθ table apparatus will be described with reference to the drawings.
[0032]
1 and 2 show the overall configuration of the moving table device, and FIGS. 3 and 4 show a part of the enlarged view.
[0033]
As shown in FIG. 1 and FIG. 2, the moving table device includes a lower fixed table (1), an upper movable table (2) disposed above the fixed table (1), and a fixed table (1). A plurality of cages (3) attached to the plurality, and a plurality of cages (4) accommodated in the ball accommodation pockets (4) of the cages (3) and movably supporting the movable table (2) relative to the fixed table (1) And a moving device (6) as moving means for moving the moving table (2) relative to the fixed table (1).
[0034]
Both tables (1) and (2) have a rectangular outer shape when viewed from above, and a rectangular opening (7) (8) is formed at the center.
[0035]
The moving device (6) includes fluid pressure cylinders (10) which are four actuators respectively corresponding to the outer four sides of both tables (1) and (2). The base end of the cylinder body (10a) of each cylinder (10) is pivotally attached to a bracket (11) fixed to the outer surface of the fixed table (1), and the tip of the piston rod (10b) moves. The bracket (12) fixed to the outer surface of the table (2) is rotatably attached. Then, by appropriately driving these four cylinders (10), the moving table (2) moves the X and Y directions, which are horizontal directions perpendicular to the fixed table (1), and the vertical axis. It can be moved in any of the θ directions that are the rotation directions around the center.
[0036]
For example, the outer dimensions of both tables (1) and (2) are 1100 mm × 1350 mm, and the moving stroke of the moving table (2) is ± 2 mm in the X and Y directions and ± 0.15 ° in the θ direction.
[0037]
Details of the retainer (4) portion are shown in FIGS.
[0038]
A rectangular annular spacer (13) is fixed to the upper surface of the fixed table (1) at the peripheral edge of the opening (7) to prevent intrusion of dust and the like into the cage (3). A plurality of rectangular plates (lower plates) (14) made of wear-resistant material are fixed on the upper surface of the fixed table (1). As the wear-resistant material constituting the plate (14), for example, a material obtained by quenching and grinding steel is used. The upper surface (14a) of the plate (14) is a horizontal upward cage mounting surface and a ball contact surface.
[0039]
At the position corresponding to the lower plate (14) on the lower surface of the moving table (2), the same number of the same wear-resistant material plates (upper plates) (15) are fixed. The lower surface (15a) of the plate (15) is a horizontal downward ball contact surface.
[0040]
A rigid cage (3) is placed on each lower plate (14) of the fixed table (1). The cage (3) has a square pocket (4) formed on the square plate excluding the periphery, and the four corners (4a) of the pocket (4) are connected to the adjacent sides. The curved surface has a radius of curvature larger than the ball radius (cylindrical surface in this example). The cage (3) has a slightly smaller planar size than the plates (14) and (15), and moves on the upper surface (14a) of the plate (14) in all directions parallel to the upper surface (14a). It has become possible.
[0041]
Circular pin holes (16) penetrating up and down the retainer (3) are formed in two places of the retainer (3), for example, in the vicinity of two adjacent apexes. Two circular pins (17) are formed on the upper surface of the fixed table (1) at the same interval as the pin holes (16). The pin (17) has a lower part fixed to the fixed table (1) and protrudes upward through the lower plate (14). The outer diameter of the pin (17) is slightly smaller than the inner diameter of the pin hole (16), and each pin (17) is fitted in the pin hole (16) with a gap. By appropriately determining the difference between the inner diameter of the pin hole (16) and the outer diameter of the pin (17), each cage (3) can be moved individually within a predetermined range on the lower plate (14). It has become. The difference between the inner diameter of the pin hole (16) and the outer diameter of the pin (17) is, for example, about 1 mm.
[0042]
A plurality of balls (5) are accommodated in the pockets (4) of the respective cages (3) with a slight gap and are placed on the lower plate (14). The outer diameter of the ball is slightly larger than the height of the cage (3), and the upper part of the ball (5) protrudes slightly above the cage (3). ) Is placed.
[0043]
In this moving table device, the moving table (2) can be moved in the X, Y, and θ directions only by arranging one moving table (2) above the fixed table (1). Therefore, the height of the entire moving table device can be reduced and the weight of the moving part can be reduced. Further, a plurality of cages (3) are arranged between the tables (1) and (2), and the moving table is provided by a large number of balls (5) accommodated in the pockets (4) of these cages (3). Since (2) is supported, the movement of the moving table (2) is light, and no deflection occurs even when the moving table (2) is enlarged. Therefore, a large load moving table device can be realized.
[0044]
Furthermore, by moving each cage (3) individually with respect to the fixed table (1), it is possible to prevent the ball (5) in the pocket (4) from being offset in one direction and causing biting. it can. Furthermore, since the corner (4a) of the pocket (4) is curved, the ball (5) is prevented from being displaced to the corner (4a) of the pocket (4), and the ball (5) The effect of preventing biting can be further enhanced.
[0045]
However, the corner (4a) of the pocket (4) is not necessarily a curved surface. Further, the number of the cages (3) and the shapes of the cages (3) and the pockets (4) are not limited to those in the above embodiment. Further, in the above embodiment, each retainer (3) is provided with one pocket (4), but one retainer may be provided with two or more pockets. May be different.
[0046]
5 and 6 show two modifications of the cage (3). 5 and 6, the same parts as those in the above embodiment are denoted by the same reference numerals.
[0047]
In these two modifications, the inner peripheral surface of the pocket (4) of the cage (3) is elastically deformable.
[0048]
In the example of FIG. 5 (first modified example), a plurality of slits (20) penetrating up and down the rigid cage (3) are formed in the portion near the inner periphery of the pocket (4). ), The inner peripheral surface of the pocket (4) can be elastically deformed by forming an elastically deformable thin portion (21) in the inner peripheral portion.
[0049]
In the example of FIG. 6 (second modified example), the retainer (3) includes a rectangular annular rigid retainer body (22) and a similarly shaped damper (23) fixed to the inner peripheral surface thereof. The inside of the damper (23) is a pocket (4). The damper (23) is made of an elastic body such as rubber, and the inner peripheral surface of the damper (23), that is, the inner peripheral surface of the pocket (4) is elastically deformable. The four corners (4a) of the pocket (4) are curved surfaces having a radius of curvature larger than the ball radius.
[0050]
In the first and second modified examples, in addition to those shown in FIGS. 3 and 4, the inner peripheral surface of the pocket (4) of the cage (3) is elastically deformed, so that the ball ( It is possible to prevent 5) from being displaced in one direction and causing biting, and the effect of preventing biting of the ball (5) is further improved.
[0051]
However, in the case of the first and second modifications, the corner (4a) of the pocket (4) is not necessarily curved. Each cage (3) may be fixed to the fixed table (1).
[0052]
The configuration of each part of the moving table device is not limited to that of the above embodiment, and can be changed as appropriate.
[0053]
Although the XYθ table device has been described in the above embodiment, the present invention can be applied to other types of moving table devices such as an XY table device.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view of a moving table device showing an embodiment in which the present invention is applied to an XYθ table device.
FIG. 2 is a front view of the moving table device of FIG. 1;
3 is an enlarged vertical sectional view showing a portion of a holder of the moving table device of FIG. 1. FIG.
4 is a plan view of a portion of the retainer of FIG. 3. FIG.
FIG. 5 is a drawing corresponding to FIG. 4 and showing a first modified example of the cage.
FIG. 6 is a drawing corresponding to FIG. 4 and showing a second modified example of the cage.
[Explanation of symbols]
(1) Fixed table
(2) Moving table
(3) Cage
(4) Pocket
(5) Ball
(6) Mobile device
(16) Pin hole
(17) Pin
(20) Slit
(21) Thin part
(23) Damper

Claims (6)

A rectangular fixed table, a rectangular moving table disposed so as to be movable above the fixed table, a plurality of rectangular cages provided on an upward surface of the fixed table and having square ball receiving pockets, and each cage A plurality of balls housed in the pocket and movably supporting the moving table relative to the fixed table, and a moving means for moving the moving table relative to the fixed table,
A movable table device, wherein each retainer is attached to an upward surface of a fixed table so as to be movable in a direction parallel to the surface.   The fixed table or the cage is provided with at least two pin holes, and on the other side, a pin fitted with a gap with respect to the pin hole is fixedly provided. 1 moving table device. A rectangular fixed table, a rectangular moving table disposed so as to be movable above the fixed table, a plurality of rectangular cages provided on an upward surface of the fixed table and having square ball receiving pockets, and each cage A plurality of balls housed in the pocket and movably supporting the moving table relative to the fixed table, and a moving means for moving the moving table relative to the fixed table,
A movable table device characterized in that an inner peripheral surface of a pocket of each cage is elastically deformable.   4. The movable table device according to claim 3, wherein each cage has an elastic damper on the inner periphery of the pocket, and the inner peripheral surface of the damper is elastically deformable.   4. The movement according to claim 3, wherein a slit is formed in a portion near the inner periphery of the pocket of each cage made of a rigid body, and a thin-walled portion that is elastically deformable is formed in a portion closer to the inner periphery than the slit. Table device.   The movable table device according to claim 1 or 2, wherein an inner peripheral surface of a pocket of each cage is elastically deformable.

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