JP2008142860A - Device and method for correcting rotary angle of pallet table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for correcting a rotary angle of a pallet table wherein high precision processing is performed by precisely correcting an error of a rotary angle at the time of rotating a pallet table used for a 5-shaft machining center and the like. <P>SOLUTION: The device comprises a pair of sensors 16, 16 detecting a very fine spacing changing by rotation between a pallet 2 rotating while mounting a heavy workpiece 5 and a rotary table 3 supporting the pallet and rotating around a base point 4 as a center. A deviation of the sensors 16, 16 is indexed and an angle is corrected, so as to eliminate an indexing error. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pallet table disposed in, for example, a 5-axis machining center, and corrects a rotation angle error when rotating a heavy workpiece and corrects the rotation angle of the pallet table that can set the workpiece at the correct rotation position. The present invention relates to an apparatus and a method.

Many of the pallets arranged in the machine tool are mounted with a workpiece and rotate mainly along a horizontal plane, and a so-called tilting table is used as a pallet inclined in the vertical direction. On the other hand, there is a demand for a pallet table that is formed integrally with a machine tool instead of installing a separate pallet table with the increase in the number of axes of the machining center. Not disclosed. Examples of the pallet in the 5-axis machining center include those disclosed in “Patent Document 1”, which is different from the present invention.
Utility model registration No. 3099831 (Fig. 1)

  An example of a 5-axis machining center is shown in FIG. The column 8 is mounted on the bed 9 and moves in the Y-axis direction. The main shaft 10 is mounted so as to move along the column 8 in the Z-axis direction and move along the axis (A-axis). On the other hand, the pallet table 1 is rotatably supported by a pallet table support base 6 supported on a table base 7 so as to be movable in the X-axis direction. And a rotating table 3 that rotates about a base point 4 on a pallet table support base 6.

  As shown in FIG. 1, the workpiece 5 is processed by the main shaft 10 in a state of being mounted on the pallet 2 arranged along the horizontal plane, but from the position of FIG. 1 as shown in FIG. 2 as necessary. It may also be processed in a state rotated by 90 °. Of course, there are many cases where machining is performed at an angular position in the middle from the horizontal side to the vertical side.

When the work 5 is mounted on the pallet 2 in the state shown in FIG. 1, the weight of the work 5 acts on the upper surface of the pallet 2, so that the work 5 is stably supported, but the position rotated 90 ° as shown in FIG. Alternatively, the weight of the workpiece 5 does not act only on the upper surface of the pallet 2 at a position in the middle, and a moment force acts on the workpiece 5 so as to move away from the upper surface of the pallet 2.
Since each component of the pallet table 1 is processed with high accuracy and is rigid, the pallet table 1 is stably supported by the pallet 2 even in the state of FIG. 2, but the moment force acts as described above. For this reason, the work 5 is subjected to a force to move away from the upper surface of the pallet 2. Therefore, in theory, even if the pallet table 1 is rotated 90 ° accurately, the rotation angle may not be 90 °, and correction is necessary to correctly maintain the 90 ° angular position.

  The present invention was invented in view of the above circumstances, and the rotation angle of a pallet table that corrects the rotation angle so that the pallet table is always set at an accurate angular position even when the pallet table is at an arbitrary rotation position. It is an object of the present invention to provide a correction apparatus and method.

  In order to achieve the above object, the present invention provides a pallet for rotating a workpiece (workpiece) mounted thereon and a pallet that rotatably supports the pallet and that is centered on a base point. A rotation angle correction device for a pallet table having a rotary table that rotates from the side to the vertical surface side, wherein the device reduces a minute gap amount generated between the pallet side and the rotary table side by rotation of the pallet table. A pair of sensors arranged opposite to each other at a position 180 ° apart on the rotary table side to detect, and a rotation angle correction means for correcting a rotation angle by obtaining a deviation between the sensors. And

  The invention of claim 2 is a rotation angle correction method by the rotation angle correction device of the pallet table of claim 1, wherein the method calculates the deviation of the pair of sensors at a plurality of rotation angle positions of the rotation table. The rotation angle of the rotary table is corrected each time by the deviation angle corresponding to the deviation.

  According to the “pallet table rotation angle correction device” of claim 1 of the present invention, since the rotation angle error is corrected by the deviation of the pair of sensors, the pallet table is set at the correct rotation position at all rotation angles. , Accurate workpiece machining can be performed.

  Further, according to the “pallet table rotation angle correction method” of claim 2 of the present invention, the amount of rotation angle to be corrected is obtained each time by detecting the deviation of the minute gap amount that changes depending on the rotation angle. The pallet table can be set at the correct rotational position. As described above, highly accurate workpiece machining can be performed.

Embodiments of the “pallet table rotation angle correction apparatus and method” of the present invention will be described in detail below with reference to the drawings.
As shown in FIG. 3, the pallet table 1 includes a pallet 2 on which a workpiece 5 is mounted and a rotary table 3. The rotary table 3 includes a pallet rotating mechanism unit 3a that rotatably supports the pallet 2, and a pallet rotating mechanism unit. 3a is composed of a rotating arm portion 3b that rotates around a base point 4. In addition, in FIG. 3, although the connection structure of the pallet rotation mechanism part 3a and the rotation arm part 3b is not clearly shown, the rotation arm part 3b is integrally connected to both sides of the pallet rotation mechanism part 3a, and the base point on the fixed side. 4 has a structure in which the pallet 2 and the entire rotary table 3 are rotated around the center.

The pallet 2 is a disk-shaped object on which the work 5 is mounted, and is rotatably supported on the sliding surface 11 of the main body case 12 via the pallet rotation mechanism 3a of the rotary table 3 as shown in FIG.
The pallet rotating mechanism 3a of the rotary table 3 includes a main body case 12 fixed to the rotating arm 3b side and a worm wheel 14 and a pallet 2 that mesh with a worm gear 13 housed therein and fixed to the pallet 2 side. It comprises what has an encoder 15 etc. for detecting and controlling rotation.

  As shown in FIGS. 3 and 4, a sensor 16 is disposed between the pallet 2 side and the main body case 12 side. As shown in FIG. 3, the sensor 16 includes a pair of sensors 16, 16 disposed at opposite positions that are 180 ° apart on the main body case 12 side. The pallet 2 is supported on the rotary table 3 side via the sliding surface 11 as described above. However, as shown in FIGS. 1 and 2, a moment due to the weight of the work 5 acts by the rotation of the pallet table 1. A minute gap S is formed between the pallet 2 side and the rotary table 3 side. The sensors 16 and 16 are for detecting the minute gap amount.

The minute gap S changes depending on the rotational position of the pallet table 1, and the amount of the minute gap between the pair of left and right sensors 16, 16 also changes. When the deviation of the minute gap amount between the left and right sensors 16, 16 is obtained, this deviation changes as indicated by line A with respect to the indexing angle as shown in FIG.
On the other hand, when the indexing angle and the indexing error due to the rotation of the pallet table 1 are obtained, the result is as shown by line B in FIG. When the A line and the B line are compared and combined, the result is as shown in FIG.

  Based on the above results, the change in the indexing angle caused by the rotation of the pallet table 1 is obtained by obtaining the deviation of the sensor 16 and correcting only the angle corresponding to this deviation. In the present invention, this correction is performed by a rotation angle correction means (not shown). Therefore, the pallet table 1 is corrected to the correct rotation angle position by performing correction during rotation of the pallet table 1 by the rotation angle correction means.

  The rotation angle may be corrected each time the pallet table 1 is rotated. However, in practice, deviations at several rotation angles are obtained in advance by the work 5 to obtain a correction curve, and this correction curve is used as a base. It is convenient to perform correction for each rotation angle. Of course, it is not limited to this.

  Although the rotation angle can be corrected accurately as described above, the arrangement of the sensor 16 is not limited to the position described above, and an appropriate position can be obtained by the shape of the pallet 2 and the rotary table 3. desirable.

  The present invention is applied to a rotating pallet table, but the format is not limited, and the present invention can be applied to all rotating tables, and the range of use is wide.

1 is an overall schematic diagram of a 5-axis machining center to which a pallet table rotation angle correction apparatus and method according to the present invention are applied. 1 is an overall schematic diagram of a 5-axis machining center to which a pallet table rotation angle correction apparatus and method according to the present invention are applied. The axis sectional view showing the outline structure of the pallet table in the present invention. The elements on larger scale which show the attachment state of the sensor in this invention. The diagram which shows the relationship between the indexing precision of a sensor and an indexing angle (rotation angle). The diagram which shows the relationship between the index angle of a pallet table, and its index error. The diagram which shows the correlation of FIG.5 and FIG.6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pallet table 2 Pallet 3 Rotating table 3a Pallet rotating mechanism part 3b Rotating arm part 4 Base point 5 Work 6 Pallet table support stand 7 Table stand 8 Column 9 Bed 10 Spindle 11 Sliding surface 12 Body case part 13 Worm gear 14 Worm wheel 15 Encoder 16 sensors

Claims (2)

  A pallet table rotation angle correction apparatus comprising: a pallet that rotates with a workpiece (workpiece) mounted thereon; and a rotary table that rotatably supports the pallet and rotates the pallet from a horizontal plane side to a vertical plane side. The apparatus is arranged opposite to a position separated by 180 ° on the rotary table side in order to detect a minute gap amount generated between the pallet side and the rotary table side by rotation of the pallet table. A rotation angle correction device for a pallet table, characterized in that a rotation angle correction means for correcting a rotation angle by obtaining a deviation between the sensors is provided.   A rotation angle correction method using a rotation angle correction apparatus for a pallet table according to claim 1, wherein the method obtains a deviation of the pair of sensors at a plurality of rotation angle positions of the rotation table, and a deviation angle corresponding to the deviation. A rotation angle correction method for a pallet table, wherein the rotation angle of the rotation table is corrected each time.

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