JPH04304946A - Movable table - Google Patents

Abstract

PURPOSE:To provide a movable table capable of effectively canceling out the shift of a drive direction with respect to the guide face of the movable table and an amount of rattling. CONSTITUTION:A first table 1 and a second table 3 are stacked one atop the other on a foundation table 1 and a plurality of balls 4 are assembled between each table. Plate springs 15, 15, which are parallel to the surface of each table, are provided between the first table 2 and its driving means 10 and between the second table 3 and its driving means 11. Movement of each table 2, 3 due to the shift of the drive direction and rattling is converted into a parallel movement to the surface of each table by the balls 4, resulting in the deformation of each plate spring 15. Deformation of each plate spring cancels out any inconvenient movement of each table 2, 3 thereby correcting the direction of movement of each table.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable table used for precise inspection and processing of articles.

0002

[Prior Art and its Problems] A conventional XY table movably supports one movable table (for example, a Y table) by a pair of guides provided on a base table.
The other movable table (for example, the This is done by engaging a ball screw shaft placed in the table with a nut attached to each movable table.

However, in the structure in which the ball screw shaft is integrally connected to each movable table as described above, the axis of the ball screw shaft (the driving direction of the movable table) may be tilted or misaligned with respect to the guiding direction of each guide. If the two do not match exactly, the inclination of the movable table may cause wobbling in the guidance of the movable table, a delay or advance between the movable table and the drive means, and errors such as pitching or yawing may easily occur.

In particular, in a structure in which a movable table is supported by a pair of guides separated by a distance, it is practically difficult to accurately obtain the flatness between the two guides and the center height of both. Accurately matching the guide direction with the axis of the ball screw shaft is an extremely difficult task.

[0005] Therefore, the present invention solves the above problems, and even if there is a deviation or play in the drive direction of the movable table with respect to the guide surface, the deviation or play can be effectively absorbed and the table can be moved with high precision. The aim is to provide a mobile table that makes it possible.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a first means of the present invention provides a movable table provided on a support table that is moved in a straight line by a drive means, in which the movable table and the drive The structure is such that the means are connected via an elastic member having high rigidity in the moving direction of the movable table.

A second means of the present invention is that, in the above structure, the movable table is supported by a plurality of balls rolling on the surface of the support table, and the elastic member is attached to a plate parallel to the surface of the support table. It has a springy structure.

[0008]

[Operation] In the first means, the driving force of the driving means is transmitted to the movable table without delay due to the rigidity of the elastic member,
Move both together.

Furthermore, if there is play in the guide portion of the movable table or a positional shift between the movable table and the driving means, the elastic member deforms and absorbs the play or shift.

On the other hand, in the second method, since the movable table is guided along the surface of the support table by rolling balls, the movement of the movable table caused by deviation or wobbling in the driving direction with respect to the guide surface is prevented by the support table. translated into motion parallel to the table surface. Therefore, the movement of the movable table deforms the leaf spring and is absorbed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the movable table of the embodiment is constructed by sequentially stacking a first table 2 and a second table 3, which are movable tables, on a base table 1. In this case, the base table 1 becomes the support table for the first table 2, and the first table 2 becomes the support table for the second table 3.

Between the base table 1 and the first table 2, and between the first table 2 and the second table 3, there are a plurality of balls 4 that make point contact with the surfaces of the opposing tables.
and thin plate-like retainers 5 and 6 that hold the balls. Each cage 5, 6 is formed into a rectangular shape corresponding to the shape of the first table 2 and second table 3, but has a slightly elongated shape in the direction of movement of each table, and has a shape that extends over its entire surface. , a large number of pockets 7 are formed to store the balls 4 in a rollable manner. While held by the holders 5 and 6, the ball 4 is placed on the first table 2 or the second table.
It is distributed almost uniformly over the entire lower surface of the table 3, and is set so as to receive the load of each table equally.

Further, one side of the base table 1 and the first table 2 each has an integral extension portion 8 extending outward.
, 9 are provided. The surface of each of these extensions 8 and 9 is
A driving means 1 is formed on a surface having highly accurate parallelism to the ball guide surfaces of each table 1 and 2, and drives the first table 2 to move straight on the extension part 8 of the base table 1.
A driving means 11 is installed on the extension 9 of the first table 2 to move the second table 3 straight in a direction orthogonal to the first table.

Each of the driving means 10 and 11 includes a ball screw shaft 12 horizontally suspended on the extension parts 8 and 9 along the moving direction of each table 2 and 3, and a ball screw shaft of a servo motor, a stepping motor, etc. 12 and a drive motor 13 that rotates.
and a slider 14 that slides while engaging with the ball screw shaft 12, and the slider 14 is connected to the first table 2 and the second table 3 via a leaf spring 15.

This leaf spring 15 is formed in a vertically elongated shape in the direction of movement of each table so as to have high rigidity in the direction in which each table 2, 3 is driven, and is fixed to the side surface of each table 2, 3. It extends horizontally over the upper surfaces of the tool 16 and the slider 14, and the sides on both sides are bolted to the mounting tool 1.
6 and the slider 14.

With the plate spring 15 mounted in this manner, the slider 14 is attached to the plate spring 15 by the drive of the ball screw shaft 12.
When the slider 14 moves, the movement of the slider 14 is transmitted to each table 2, 3 without delay and has enough rigidity to move both together, and each table 2, 3 can be deformed in the vertical direction. The elastic force is given as follows.

As shown in FIGS. 3 and 4, the slider 14 includes a nut 17 that engages with the ball screw shaft 12, and a guide member 18 formed by two inclined surfaces 19 and 20 whose opposite sides intersect at an acute angle. The guide member 18 is sandwiched between two fixing members 21 and 22 arranged opposite to each other.

The fixing members 21 and 22 have inner surfaces formed with inclined surfaces 23 and 24 that fit into the inclined surfaces 19 and 20 of the guide members, and between the inclined surfaces 23 and 24 and the inclined surfaces 19 and 20, , a plurality of needle rollers 27 each rolling in the moving direction of the slider 14 are incorporated to slidably support the guide member 18. Further, the fixing members 21 and 22 are fixed to the respective extension parts 8 and 9 while pressing the guide member 18 from both sides, and apply a predetermined preload to the needle roller 27 by the pressing force. As a result, the gap in the sliding portion between the guide member 18 and the fixed members 21 and 22 is reduced to zero,
This eliminates rattling in the lateral direction of the table, which causes yawing.

Further, on the upper surfaces of the reference table 1 and the first table 2, regulating frames 25 and 26 are provided for regulating the movements of the cages 5 and 6, respectively. This regulatory frame 25, 26
When the first or second table 2, 3 moves within the range of the upper surface of the reference table 1 and the first table 2, it is always located below each table 2, 3, and the table is moved by a plurality of balls 4. I am starting to support it.

In the movable table of the embodiment having the above structure, when the first table 2 or the second table 3 is driven by the operation of the driving means 10, 11, the balls 4 rolling between each table cause The first table 2 and the second table 3 are the reference table 1 and the first table 2, respectively.
guided along the surface of the

In this case, the driving force of the drive means 10, 11 is transmitted to each table 2, 3 without delay by the leaf spring 15, which has high rigidity in the direction of movement of each table 2, 3.

[0023] Furthermore, if there is a deviation between the guiding direction of each table 2, 3 and the driving direction of the driving means 10, 11, or if there is any wobble in the guide surface in the lateral direction with respect to the table's advancing direction, the deviation or The movement of the tables 2 and 3 caused by the rattling is converted into movement parallel to the surfaces of the reference table 1 and the first table 2, respectively, by the guidance by the ball 4 and the pressing force of the leaf spring 15. However, when the first or second tables 2, 3 try to move as described above, the leaf spring 15, which is stretched parallel to the surfaces of the reference table 1 and the first table 2, deforms in the width direction, causing Absorbs inconvenient movements of tables 2 and 3. Therefore, it is possible to prevent pitching and yawing during movement of the table, and it is possible to accurately move each table 2, 3 along the driving direction.

Note that the above-mentioned leaf spring 15 may be constructed by combining a plurality of leaf springs.

[0025]Furthermore, the leaf spring can be replaced with an elastic member having another structure as long as it has enough rigidity to transmit the driving force to the table without delay and elasticity to deform the table in the vertical direction.

[0026]

As described above, the first means of the present invention is that an elastic member is provided between the movable table and the driving means to absorb movement of the table due to misalignment or rattling with respect to the guide surface. , pitching and yawing can be prevented, and the table can be moved with high precision.

[0027] Furthermore, in the second means of the invention,
Movement of the table due to misalignment or rattling relative to the guide surface is converted into movement along the surface of the support table, and this is absorbed by the leaf spring, so undesirable movement of the table can be reliably absorbed with a simple structure. can.

[Brief explanation of drawings]

[Fig. 1] Perspective view of the embodiment

[Figure 2] Partially cutaway plan view of the same as above

[Figure 3] Cross-sectional view taken along line III-III in Figure 2

[
Figure 4: Cross-sectional view taken along line IV-IV in Figure 2

[Explanation of symbols]

1. Basic table 2　1st table 3 Second table 4 Ball 10, 11 Driving means 15 Leaf spring

Claims (2)

[Claims] 1. A movable table in which a movable table provided on a support table is moved in a straight line by a drive means, wherein the movable table and the drive means are connected via an elastic member having high rigidity in the direction of movement of the movable table. A mobile table featuring 2. The movable table according to claim 1, wherein the movable table is supported by a plurality of balls rolling on the surface of the support table, and the elastic member is a leaf spring parallel to the surface of the support table. moving table.