JPS63140161A - Positioning table - Google Patents

Abstract

PURPOSE:To secure smooth feed of a nut by making the nut movable in two axial directions along a plane perpendicular to the axial direction of a feed screw, and enabling it to follow tilting of the feed screw in two directions. CONSTITUTION:A rectilinear guide bearing 11 movably supporting a table 3, and a feed screw 9 laid along the moving direction of the table 3 are provided. Also, a nut 7 is screwed on the feed screw 9, and held by a nut holding member 20. Further, an oscillating frame 16 is provided to support the nut holding member 20, so as to be movable in the axial direction as well as passable through the axial center of the nut 7 and oscillatable around the perpendicular axial center thereto. In addition, there is provided a fixing member 15 for supporting the oscillating frame 16 in such a way that said oscillating frame 16 can freely oscillate around the center of an axis which is substantially perpendicular to the supporting axis of the nut holding member 20 as well as freely move in the direction of said axis. With this constitution, the nut can be smoothly fed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a positioning table, and more particularly to an improvement in the mounting structure of a nut screwed onto the feed screw in a positioning table in which the table is moved by a feed screw. It is.

Conventional technology In positioning tables using conventional feed screws,
As shown in FIG. 3, the table 32 is supported movably along the idle rail 31 via an air bearing, and a feed screw 33 is arranged in parallel along the idle rail 31, and the feed screw 33 is driven by a servo motor. A nut 35 screwed onto the feed screw 33 is attached to the table 32, and the nut 35 is attached as shown in FIGS. 4(a), (b), ( e)
, as shown in (d), a round shaft 36 and a square shaft 37 are provided on both upper and lower sides of the nut 35 perpendicularly to the axial direction of the feed screw 33.
The round shaft 36 is supported so as to be movable in its axial direction via a ball 38 and to be swingable around α, the tangent of the ball 38, and the square shaft 37 is supported on the axis of the feed screw 33. A structure in which a side surface 37a parallel to a plane perpendicular to the center is supported via a ball 39 so as to be movable in a plane is known.

With this structure, the nut 35 is movable up and down and rotates around the square shaft 3 around the point of contact with the ball 38 of the round shaft 36.
The nut 35 can be moved and driven smoothly by absorbing deviations in the relative positions of the guide rail 31 and the feed screw 33.

Problems to be Solved by the Invention However, with the configuration of the positioning table described above, the nut 35 can follow the axial runout of the feed screw 33 vertically and horizontally, but it cannot follow the inclination of the axial center of the feed screw 33. There is a problem that tracking is not perfect because it is restrained.
Therefore, there is a problem in that yawing or pitching occurs when the table 32 is moved. Furthermore, in the above configuration, the support for the rotational torque of the feed screw 33 is the only point of contact between the round shaft 36 above the nut 35 and the ball 38, and therefore, the reaction force of the rotation torque of the feed screw 33 is applied to the feed screw 33. There was a problem with the left and right swing of the 33.

The present invention solves the above-mentioned conventional problems by making it possible for the nut to move in the axial direction of the feed screw, move on a perpendicular plane, and follow the inclination of the feed screw in any direction. Send? The purpose is to provide a high positioning table of 11 degrees.

Means for Solving the Problems In order to achieve the above object, a positioning table according to the present invention includes a table, a linear guide bearing that movably supports the table, and a positioning table disposed along the direction of movement of the table. A feed screw that can be driven by a transmission, a nut screwed onto the feed screw, a nut holding member holding the nut, and a shaft that swings and rotates around an axis that passes through the axis of the nut and is perpendicular to the axis. a rocking frame that supports the nand holding member so as to be movable in the center direction; and a mounting member that supports the swing frame so as to be swingable and movable in the axial direction.

Function According to the above structure of the present invention, the nut is supported by the mounting member in a state where it is restricted only in the feeding direction and rotational direction by the feed screw, and has completely four degrees of freedom.
Even if there is an error in the parallelism between the linear guide bearing and the feed screw or the straightness of the feed screw, smooth nut feeding can be ensured.
High table feeding accuracy can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 2, reference numeral 1 denotes a base, on which a movable table 3 movably supported by thrust air bearings 2 at four corners is disposed. An X guide rail extending in the X direction is provided on the base 1, and an X table 5 movable along the X guide rail is provided below the movable table 3. This X table 5
At both ends in the X direction, air bearings 6 that are guided 1113 along the X guide rail are disposed. Further, at one end of the X table 5 in the X direction, a pole nut 7 is arranged to be screwed into a ball screw 9 which is rotationally driven by a DC servo motor 8 disposed at one end of the idle rail 4 (X) in 11j. It is set up. Furthermore, the X table 5
A Y guide rail 10 is disposed along the Y direction, and an air bearing 1 is guided to move along the Y guide rail 10.
1 is disposed on the lower surface of the movable table 3. Also, there is a D on the side of this Y7 hood rail 10 parallel to this.
Ball screw 13 rotationally driven by C servo motor 12
A ball nut (not shown) disposed on the lower surface of the movable table 3 is screwed into the movable table 3. The X-table 5 is also supported by a thrust air bearing 14 so as to be movable on the base 1.

In the positioning table having the overall configuration as described above, the mounting structure of the pole nut 7 to the X table 5 will be explained in detail with reference to FIGS. 1(a), (b), and (c). Furthermore, the mounting structure of the pole nut screwed onto the ball screw 13 to the moving table 3 has a similar structure.
Explanation will be omitted.

Reference numeral 15 denotes a mounting member fixed to one end of the X-table 5, and a pair of horizontal swinging bins 17 protruding inward from both side support pieces 15a are attached to both sides of the swinging frame 16. It is fitted into the drilled support hole 18, and a ball 19 is interposed between them, and the swinging frame 1G is supported by the horizontal swinging bin 17 so that it can move left and right and swing around the bin axis. ing. A support hole 22 is bored in the swing frame 16 substantially perpendicularly to the axis of the horizontal swing bin 17 . On the other hand, the ball nut 7 is attached to the nut holding member 20.
The ball nut 7 is fitted and held in the nut holding member 20 and fixed with a bolt 24.
A vertical swing pin 21 is projected perpendicularly to the axis of the bolt, and this vertical swing pin 21 is fitted into the support hole 22, and a ball 23 is interposed between them, so that the nut holding member 20 is vertically It is supported by a swing pin 21 so that it can move up and down and swing around the axis of the bottle.

In the above configuration, by operating the DC servo motors 8 and 12, the moving table 3 is moved to the X guide rail 4.
Positioning is performed by moving in the X direction and Y direction using the X guide rail 10 as a guide.

At this time, when moving and driving the X table 5, even if the ball screw 9 is not exactly parallel to the X guide rail 4 or the ball screw 9 is not sufficiently straight, the pole nut 7 will not be able to hold the nut holding member 20. and swing frame 16
Since it is movable up and down and left and right through the ball screw 9 and is also swingable around the horizontal swing bin 17 and the vertical swing bin 21, it is possible to prevent the ball screw 9 from swinging or tilting its axis.
To smoothly follow and move an X table 5 without applying any force other than in the moving direction. Therefore, the feeding of the X-table 5 is smooth and highly accurate, and the straightness is not impaired. A similar effect can be obtained by adopting a mechanism.

The present invention is not limited to the above embodiments.

For example, in the above embodiment, a combination of a ball screw and an air bearing is used as the feed fil+1, but other feed screws or linear guide bearings may also be used. Further, in the above embodiment, the feed screw is disposed on the fixed side and the nut is disposed on the movable table side, but the arrangement may be reversed.

Effects of the Invention According to the positioning table of the present invention, as described above, the nut can be moved in two directions along the plane perpendicular to the axial direction of the feed screw.
It is movable in the pongee direction and can also follow the inclination of the feed screw pongee in two directions, and has four degrees of freedom, so it is possible to adjust the parallelism between the feed screw and the linear guide bearing and the feed. Even if there is an iv% difference in the straightness of the screw itself, smooth nut feeding can be ensured, and as a result, high table feeding accuracy can be ensured.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, and FIG. 1 (
a) is a front view of the main part, Figure 1 (1+) is a longitudinal side view of the same,
Fig. 1(e) is a sectional view taken along line f-1 in Fig. 1(b), Fig. fi2 is an exploded perspective view of the entire positioning table, Figs.
The figures show a conventional example, and FIG. 3 is a perspective view of the moving mechanism, FIG. 4(a) is a longitudinal side view of the main part, FIG. is a sectional view taken along the line ■-■ in the same figure (b),
FIG. 4(d) is a sectional view taken along the line ■-■ in FIG. 4(b). 3...Moving table 5...X table 6...Air bearing 7...Pole nut 9... ......Ball screw 15...Mounting member 16...Swinging frame 17...Horizontal swinging bin 20 ......Nut holding member 21...
...Vertical swing pin. 2nd Patent Attorney Toshio Nakao (1 person) Figure 1 (
C) 7 - ball nut 9, ball nut 15, mounting member 16, movable frame 17, main rv-oscillating engine 20, fi...
r...Vertical violent movement Figure 2

Claims (1)

[Claims] a table, a linear guide bearing that movably supports the table, a feed screw that is rotatably driven along the moving direction of the table, a nut that is screwed onto the feed screw, and holds the nut. a nut holding member; a swinging frame that supports the nut holding member so as to be able to swing around an axis that passes through the axis of the nut and is perpendicular to the axis and to move in a wheel center direction; and an axis that supports the nut holding member; a mounting member that supports the swing frame so as to be able to swing around an axis that passes through the frame, is perpendicular thereto, and is substantially perpendicular to the support axis of the nut holding member, and is movable in the axial direction. A positioning table characterized by: