JP2013111700A - Rotary table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary table device having an automatic alignment part for a work piece on a table, having a short centering time and a simple structure and easy in dustproof design, and to provide an automatic alignment method.SOLUTION: The rotary table device 21 has the table 2 disposed rotatably on a base 21a and automatically aligns the center of the work piece placed on the table 2 with the rotation center of the table 2. The rotary table device 21 for automatic alignment has an A-table 2a, a B-table 2b and a C-table 2c stacked in this order from a side remote from the base 21a, and includes a first movement mechanism 15 disposed on the B-table 2b and moving freely the A-table 2a in the Y-axis direction, a second movement mechanism 16 disposed on the C-table 2c and moving freely the B-table 2b in the X-axis direction, a first drive means moving the A-table 2a in one direction, a second drive means moving the B-table 2b in the other direction, and a rotary drive means rotatively driving the C-table 2c.

Description

  The present invention relates to a rotary table device that automatically aligns the center of a work attached to the upper surface of a table in accordance with the rotation center of the table.

  In a conventional automatic centering device, as disclosed in FIG. 17 of Japanese Patent Application Laid-Open No. 2004-345029, pushers for pushing a workpiece (a ring-shaped workpiece) are arranged to face each other with the workpiece interposed therebetween. When the centering operation start button is pressed, each pusher moves forward, the measuring element built in the tip of each pusher protrudes, measures the distance to the center CL, and confirms that each pusher is in the same position. The pushers of the left and right automatic centering devices are retracted to the origin position. Next, the workpiece is placed, and the distance to the workpiece is measured with each measuring element. At this time, if the workpiece and the center CL coincide with each other, the measurement data is the same, and the difference is “0”. However, if the workpiece core is misaligned, the difference between the two is calculated. Only one pusher moves forward.

  In order to check whether the workpiece has moved to the center by moving the workpiece according to these procedures, temporarily retract each automatic centering device to the home position and advance to the measurement position again. Then, the pushing amount of each measuring element is measured with a Magnescale (registered trademark). Then, considering the distortion due to the clamp, the above-described procedure is repeated until the absolute value of the difference in the push amount becomes a clamp centering accuracy of 0.05 mm or less. Thereafter, the pallet table is rotated every 90 degrees to change the position, the position of the workpiece is adjusted according to the above-described procedure, and the position measurement and adjustment of the workpiece are performed a plurality of times. If it is within the centering accuracy at the time of position measurement and adjustment at the last 360 degrees, the centering of the workpiece is completed.

JP 2004-345029 A (FIGS. 1 to 18, [0046] to [0051])

  However, the automatic centering device described in Patent Document 1 is not efficient because there is no measurement of workpiece deflection, and there is a problem that the centering time is too long because the pusher pushes and the measurement is repeated many times. . Further, the automatic centering device is located in the vicinity of the pallet table, and high-performance devices such as a servo motor, a magnescale, a ball screw, and a linear guide protrude, and there is a problem that a dustproof design is not easy.

  Therefore, the present invention was devised to solve such problems, and has a short centering (alignment) time, a simple structure, and a self-aligning rotary table with a simple dustproof design. It is an object to provide an apparatus.

In order to achieve the solution of the above-described problem, the invention of the rotary table device according to claim 1 is characterized in that a table is rotatably arranged on a base, and a work center placed on the table is defined as a rotation center of the table. The table is laminated in the order of A table, B table, and C table from the side far from the base, and is arranged on the B table. A first moving mechanism that is mounted and guides the A table to be movable in the Y-axis direction along the table surface; and the B table is mounted on the C table. A second moving mechanism in which the C table guides the B table movably along the table surface in the X-axis direction orthogonal to the Y-axis direction;
First driving means for moving the A table in the Y-axis direction, second driving means for moving the B table in the X-axis direction, and rotation driving means for rotating the C table. It is characterized by.

The invention of the rotary table device for self-aligning according to claim 1 according to claim 2 is characterized in that the first eccentric cam in which the first driving means is engaged with the concave portion of the A table, the first eccentric cam, a first spindle formed integrally, and said a first motor for rotating the first spindle, comprising a second eccentric cam and the second drive means is engaged in the recess of the table B, the second a second spindle which is formed in the eccentric cam and integrally, and a second motor for rotating the second spindle, and a third main spindle, wherein the rotary drive means is integrally fixed to the C table, the third And a third motor for rotating the main shaft.

  The invention of the rotary table device according to claim 1 or claim 2 according to claim 3 is a measuring device that measures a shake of a workpiece, a calculation unit that calculates a center misalignment amount of the workpiece from the shake, and the calculation. And a control unit that controls an automatic alignment operation in accordance with the rotation center of the table based on a center misalignment amount of the part, and measures the shake of the workpiece by the measurement device, and the calculation unit based on the measured value The first step of calculating the center misalignment amount in the X-axis direction and the center misalignment amount in the Y-axis direction between the rotation center of the table and the center of the work, and the first drive means move the A table in the Y-axis direction. The second step of correcting the misalignment amount by moving the second table and the third step of correcting the B table by moving the misalignment amount in the X-axis direction by the second driving means are executed. Features.

  According to a third aspect of the present invention, the rotary table device according to a third aspect of the present invention is the first clamper that integrally fixes the A table, the B table, and the C table, and the B table and the C table that are fixed integrally. A second clamper that fixes the C table and the base together, and the first step fixes the first clamper and the second clamper, opens the third clamper, and The second step is characterized in that the first clamper is opened, the third clamper and the third clamper are fixed, and the third step is that the first clamper and the second clamper are opened and the third clamper is fixed.

  According to the first aspect of the present invention, the table is stacked in the order of the A table, the B table, and the C table from the side far from the base, and the first moving mechanism that guides the A table so as to be movable in the Y-axis direction; 1 drive means is provided between the A table and the B table, a second moving mechanism for guiding the B table so as to be movable in the X-axis direction, and a second drive means are provided between the B table and the C table. Therefore, it is possible to provide a rotary table device that has a simple structure and high reliability and performs automatic alignment.

According to the invention of claim 2, the first driving means rotates the first eccentric shaft, the first eccentric cam engaged with the recess of the A table, the first main shaft integrally formed with the first eccentric cam, and the first main shaft. And the second driving means rotates the second main shaft, a second eccentric cam that is integrally formed with the second eccentric cam, and a second main shaft that is integrally formed with the second eccentric cam. The rotation driving means includes a third main shaft integrally fixed to the C table, and a third motor that rotates the third main shaft. Automatic alignment is possible, and alignment time can be shortened.
Further, since the first eccentric cam is formed integrally with the first main shaft and the second eccentric cam is formed integrally with the second main shaft and housed in the table, the dust-proof design can be facilitated. Moreover, since it can be accommodated in a rotary table device that automatically aligns, a dustproof design can be facilitated.

  According to the third aspect of the present invention, the deflection of the workpiece is measured by the measuring device, and the calculation unit calculates based on the measured value, and the amount of misalignment in the X-axis direction between the rotation center of the table and the center of the workpiece, Y A first step for determining the amount of misalignment in the axial direction, a second step for correcting the A table by moving the amount of misalignment in the Y axis direction by the first driving means, and a second step for correcting the B table by X. By performing the process including the third step of moving and correcting the axial misalignment amount, the work can be automatically aligned without any repetitive operation, so that the centering operation can be easily performed in a short time. In addition, since the automatic centering portion for automatic centering can improve the centering accuracy of the workpiece, the processed product can also achieve a higher processing accuracy.

  According to the invention of claim 4, the first step fixes the first clamper and the second clamper and opens the third clamper, and the second step opens the first clamper, the third clamper and the third clamper. In the third step, the first clamper and the second clamper are opened, and the third clamper is fixed, so that automatic alignment with higher accuracy, faster operation, and efficiency can be achieved.

It is a top view of a vertical grinding machine. It is a front view of a vertical grinding machine. It is a left view of a vertical grinding machine. It is a longitudinal cross-sectional view of a rotary table apparatus. It is an expanded sectional view of the AA line shown in FIG. 4, and is a schematic diagram made easy to understand. It is an expanded sectional view of the BB line shown in FIG. 4, and is a schematic diagram made easy to understand. It is sectional drawing of CC line shown in FIG. (A), (b), (c) is a schematic diagram and a process diagram showing an operation principle of an automatic alignment unit that aligns the center of the workpiece W fixed on the upper surface of the table with the rotation center of the table.

Hereinafter, embodiments of the present invention will be described from an overall view of a vertical grinding machine.
As shown in FIG. 1, a rotary table device 21 having an automatic alignment unit 20 is disposed in the center of the vertical grinding machine 10.
As shown in FIG. 2, the table 2 of the rotary table device 21 is laminated in three layers in the order of an A table 2a, a B table 2b, and a C table 2c from the top. A grindstone shaft head 3 is attached to the cross slide 7 in the upper right part of the front surface, and a grindstone shaft 3 a having a grindstone 3 b fixed to the tip is attached to the rotation shaft of the grindstone shaft head 3. In addition, a measuring device 8 that measures the deflection of the workpiece W is disposed on the left side of the grindstone shaft head 3 in order to grasp the amount of misalignment of the workpiece W. The measuring device 8 includes a main body with a probe 8a attached to the tip, a guide 8b movable up and down, and a transport device 8c.

As shown in FIG. 3, the grindstone shaft head 3 of the vertical grinding machine 10 is moved in the vertical (Z ₁ axis) direction and the left and right (X ₁ axis: see FIG. 2) direction while rotating the grindstone shaft 3a. A Z ₁ axis driving device and an X ₁ axis driving device (not shown) by a servo motor, a ball screw, a nut and the like are arranged. Further, the rotary table device 21 which is a work holding member incorporates the automatic alignment unit 20 of the present invention, and a third servo motor C3 which is a rotation driving means for controlling the rotation of the rotary table device 21 (FIG. 4). Reference) is arranged. Furthermore, a first servo motor C1 and a second servo motor C2, which are first and second drive means for the automatic alignment unit 20 described later, are arranged. This vertical grinding machine 10 has a 5-axis control NC grinding machine when the 3 (C 1, C 2, C 3) axes are aligned with the 2 (X ₁ , Z ₁ ) axis control axes of the grinding wheel axis head 3 of the main body. Become.

As shown in FIG. 3, vertical grinding machine 10 includes a bed 1 which is a base, a guide base 1a placed on the bed 1 is placed on the guide base 1a, by the X ₁ axis drive unit A saddle 5 that moves in the left-right direction, a cross slide 7 that is mounted on the saddle 5 and moves up and down by the Z ₁ axis driving device, a grindstone shaft head 3 fixed to the front of the cross slide 7, and a grindstone shaft A rotary table device 21 having a built-in automatic aligning portion 20 of the present invention is disposed below the grindstone 3b. The rotary table device 21 is composed of a grindstone 3b of the grindstone shaft 3a attached to the head 3.

Further, as shown in FIG. 3, a high-power panel 9 is disposed on the back surface of the vertical grinding machine 10, and the control unit 9a housed in the high-power panel 9 has five axes (X ₁ , Z ₁ , C1, In addition to performing NC control of C2 and C3), workpiece measurement performed by the measuring device 8 and automatic alignment control performed by the automatic alignment unit 20 are performed. In addition, the workpiece measurement of the measuring device 8 includes a calculation unit (not shown) for calculating the amount of eccentricity from the measured value, and a storage unit (not shown) for storing numerical values, programs, etc. ) And an operation input unit of the operation panel 9b.
In addition to a series of grinding processes and measurements, the control unit 9a controls the automatic alignment unit 20 and the like, and a small amount of eccentricity of the workpiece W is controlled by the first eccentric cam 11s of the first main spindle 11 and the second main spindle 12. The second eccentric cam 12s is rotated by rotation control, and the work W is moved in the X-axis direction and the Y-axis direction to control the misalignment.
The calculation unit (not shown) instantaneously calculates the misalignment amount from the measured value of the shake of the measuring device 8.
The storage unit (not shown) stores workpiece information, grinding information, and input information from the operation panel 9b.
The operation input unit is an input unit that is input by an operator from the numeric keypad of the operation panel 9b. The numerical value of the NC program is changed and controlled based on the calculated numerical value.

<Configuration of rotary table device 21>
With reference to FIGS. 4-7, the structure of the rotary table apparatus 21 which has the self-aligning part 20 of this invention is demonstrated in detail for every site | part. FIG. 4 is a longitudinal sectional view of the rotary table device 21.
As shown in FIG. 4, it comprises a table 2 in which three layers are stacked in the order of an A table 2a, a B table 2b, and a C table 2c from the top, and an automatic alignment unit 20 incorporated therein. The automatic alignment unit 20 automatically aligns the workpiece center c0 attached in the vicinity of the center on the table 2 with the rotation center c1 of the table 2 and corrects it so that there is no misalignment.

<Configuration of Table 2>
As shown in FIG. 4, the configuration of the table 2 is a disc-like structure in which the upper A table 2 a, the middle B table 2 b, and the lower C table 2 c are stacked in three layers in order from the top. If the adapter 2d is included, it is laminated in four layers.
The A table 2a is slidable in one direction, for example, the Y-axis (front-rear) direction, and the B table 2b is slidable in the other direction, for example, the X-axis (left-right) direction, or is integrally fixed and stacked. In addition, a substantially ring-shaped B liner 2m that is divided is sandwiched between the A table 2a and the B table 2b, and a space of the recess a corresponding to the thickness of the B liner 2m is secured.
A first moving mechanism 15 described later is provided in the space between the A table 2a and the B table 2b, and the A table 2a is slidable in the Y-axis direction, for example.
Further, the substantially ring-shaped C liner 2n divided between the B table 2b and the C table 2c is also sandwiched, and a space of the concave portion c corresponding to the thickness of the C liner 2n is secured.
In a space between the B table 2b and the C table 2c, a second movement mechanism 16 described later is provided, and the B table 2b is slidable in the X-axis direction, for example.

<Configuration of the first spindle 11>
As shown in FIG. 4, the 1st main axis | shaft 11 is formed from a solid material, and is arrange | positioned in the center of A table 2a. A first eccentric cam 11s formed integrally with the upper end portion 11a of the first main shaft 11 is engaged with a third bearing 11b which is a bearing. The first main shaft 11 is rotatably supported by a total of three locations including a fourth bearing 11c and a fifth bearing 11d.
The lower part of the first main shaft 11 is mounted between the outer peripheral surface of the first main shaft 11 and the upper inner peripheral surface 11k of the lower housing 11g via a lower housing 11g fixed to the lower surface 12p of the central housing 12g. The 1st motor C1 made is arrange | positioned. The first motor C1 includes a first stator C1a and a first rotor C1b, and the first stator C1a is mounted on the upper inner peripheral surface 12k of the lower housing 11g.
A first encoder C1c for detecting the rotation angle is disposed below the first motor C1.

<Configuration of the second spindle 12>
As shown in FIG. 4, the 2nd main axis | shaft 12 is formed in the cylindrical shape, and is engaged with the center of B table 2b. A second eccentric cam 12s formed integrally with the upper end portion 12a of the second main shaft 12 is engaged with a sixth bearing 12b which is a bearing. The second main shaft 12 is inserted through the third main shaft 13 in a state where the first main shaft 11 is inserted and a gap is provided on the outer periphery. A seventh bearing 12c, which is a bearing, is disposed below the second main shaft 12, and is supported at both ends at the upper and lower ends in a freely rotatable manner.
Further, the lower part of the second main shaft 12 is mounted between the outer peripheral surface of the second main shaft 12 and the upper inner peripheral surface 12k of the central housing 12g via a central housing 12g fixed to the lower surface 14p of the upper housing 14. The second motor C2 thus arranged is arranged. The second motor C2 includes a second stator C2a and a second rotor C2b, and the second stator C2a is mounted on the upper inner peripheral surface 12k of the central housing 12g. Further, a two-encoder C2c for detecting a rotation angle is disposed below the second motor C2.

<Configuration of the third spindle 13>
As shown in FIG. 4, the third main shaft 13 is provided with a through hole at the center, the first main shaft 11 and the second main shaft 12 are inserted, and the adapter 2 d is inserted in a state where a gap is provided on the outer periphery. Via the C table 2c. The third main shaft 13 is rotated by a first bearing 13b that is a large bearing provided on the outer periphery of the adapter 2d and a second bearing 13c that is a medium-sized bearing provided on the reduced diameter portion 13d of the third main shaft 13. Both ends are supported freely.
The third main shaft 13 is rotatably driven by the third motor C3 of the rotation driving means mounted between the outer peripheral surface 13e of the third main shaft 13 and the upper inner peripheral surface 13k of the housing 13g. Is done.
The third motor C3 includes a third stator C3a and a third rotor C3b, and is mounted on the upper inner peripheral surface 13k of the housing 13g.
The third motor C3 drives the rotation of the workpiece W by highly accurate position control. A third encoder C3c for detecting a rotation angle is disposed below the third main shaft 13.

The cores of the first main shaft 11, the second main shaft 12, and the third main shaft 13 are the rotation center c1.
Moreover, the 1st motor C1, the 2nd motor C2, and the 3rd motor C3 are servo motors, and a synchronous built-in motor (Direct Drive Motor) is suitable.
In addition, here, the third main shaft 13 is rotated by the rotational drive of the third motor C3 to perform the grinding process. However, at least one of the first motor C1 and the second motor C2 is synchronized with the third motor C3 so that one You may control so that grinding may be performed in cooperation with a spindle motor. As a result, power can be increased. Furthermore, since the third motor C3 can be reduced in size and saved in energy, CO ₂ can be reduced.

<Configuration of first moving mechanism>
FIG. 5 is an enlarged cross-sectional view taken along the line AA shown in FIG. 4 and is a schematic diagram in which the eccentric amount of the cam is greatly exaggerated for easy understanding. As shown in FIG. 5, the first moving mechanism 15 includes two guide rails 15a and three guide nuts (Y-axis sliding members) 15ab slidably attached to the respective guide rails 15a. It is configured. Moreover, the 1st moving mechanism 15 is arrange | positioned in the space of the recessed part a formed by the substantially ring-shaped B liner 2m divided | segmented between the A table 2a and the B table 2b.

<Configuration of first driving means 15E>
As shown in FIG. 5, the first drive means 15E is provided in a recess b formed on the lower surface of the A table 2a, except for the first motor C1 (not shown).
The first drive means 15E includes a first eccentric cam 11s engaged with the recess b of the A table 2a, a first main shaft 11 formed integrally with the first eccentric cam 11s, and a first main shaft 11 that rotates the first main shaft 11. 1 motor 1C (see FIG. 4), and the amount of eccentricity of the first eccentric cam 11s is set to MAX, and the A table 2a is moved in the Y-axis direction.
The first drive unit 15E is a conversion mechanism in which the first eccentric cam 11s is formed integrally with the first main shaft 11, and converts the rotation (rotational movement) of the first eccentric cam 11s into a linear movement in the Y-axis direction. is there. For this purpose, a third bearing 11b is mounted on the outer periphery of the first eccentric cam 11s formed integrally with the first main shaft 11, and an X-axis slider 15d is mounted on the outer periphery of the third bearing 11b. The X-axis slider 15d is formed in a rectangular shape, and X-axis guides 15e and 15e are disposed on end faces in the front-rear (Y-axis) direction via needle rollers 15g with a cage. The X-axis guides 15e and 15e are fixed to the lower surface of the A table 2a, and are free of gaps (backlash) by the wedge 15f. Thereby, the movement in the left-right (X-axis) direction is absorbed, and only the movement in the Y-axis direction is transmitted to the A table 2a and slides in a small amount.

  As shown in FIG. 5, the X-axis guide 15e, the wedge 15f, the needle rollers 15g, and the X-axis slider 15d serve as the X-axis direction regulating means 15c. The X-axis direction restricting means 15c transmits the eccentric amount t in the Y-axis direction of the first eccentric cam 11s to the A table 2a and restricts the eccentric amount t in the X-axis direction to escape in the left-right direction. The eccentricity t is preferably 0.50 mm, for example. Since the movement amount is ± 0.50 mm, MAX is 1.00 mm.

<Configuration of second moving mechanism>
FIG. 6 is an enlarged cross-sectional view taken along the line BB shown in FIG. 4 and is a schematic diagram in which the eccentric amount of the cam is greatly exaggerated for easy understanding. As shown in FIG. 6, the second moving mechanism 16 includes two guide rails 16a and three guide nuts (X-axis sliding members) 16ab that are slidably attached to the respective guide rails 16a. It is configured. Moreover, the 2nd moving mechanism 16 is arrange | positioned in the space of the recessed part c formed by the substantially ring-shaped C liner 2n divided | segmented between the B table 2b and the C table 2c.

<Configuration of Second Driving Unit 16E>
As shown in FIG. 6, in the second drive means 16E, the components other than the second motor C2 (not shown) are provided in a recess d formed on the lower surface of the B table 2b.
The second drive means 16E includes a second eccentric cam 12s engaged with a recess of the B table, a second main shaft 12 formed integrally with the second eccentric cam 12s, and a second motor that rotates the second main shaft 12. 2C, and the amount of eccentricity of the second eccentric cam 12s is set to MAX, and the B table 2b is moved in the X-axis direction.
The second drive means 16E is a conversion mechanism that converts the rotation (rotational motion) of the second eccentric cam 12s formed integrally with the second main shaft 12 into a linear motion in the X-axis direction. For this purpose, a sixth bearing 12b is mounted on the outer periphery of the second eccentric cam 12s formed integrally with the second main shaft 12, and a Y-axis slider 16d is mounted on the outer periphery of the sixth bearing 12b. The Y-axis slider 16d is formed in a rectangular shape, and Y-axis guides 16e and 16e are arranged on the end surfaces in the left and right (X-axis) direction via needle rollers 16g with a cage. The X-axis guides 16e and 16e are fixed to the lower surface of the B table 2b, and are free of gaps (backlash) by the wedge 16f. Thereby, the movement in the front-rear (Y-axis) direction is absorbed, only the movement in the X-axis direction is transmitted to the B table 2b, and only the B table 2b slides.

  As shown in FIG. 6, the Y-axis guide 16e, the wedge 16f, the needle rollers 16g, and the Y-axis slider 16d serve as the Y-axis direction restricting means 16c. The Y-axis direction regulating means 16c transmits the eccentric amount t in the X-axis direction of the second eccentric cam 12s to the B table 2b, and the eccentric amount t in the Y-axis direction is released and regulated in the front-rear direction. The eccentricity t is preferably 0.50 mm, for example, as described above. When the first main shaft 11 and the second main shaft 12 are rotated by 90 degrees, the movement amount is ± 0.50 mm, and when the first main shaft 11 and the second main shaft 12 are rotated by 180 degrees, the movement amount is MAX1.00 mm.

<Configuration of first clamper>
As shown in FIG. 4, the first clamper B1 is stored in the C table 2c and fixed to the adapter 2d. The cylinder rod B1a passes through the B table 2b, and the head of the cylinder rod B1a whose diameter is increased is engaged with the A table 2a. Once the first clamper B1 is turned on, the three layers of the A table 2a, B table 2b, and C table 2c are fixed to the adapter 2d and clamped (fixed) together. When the first clamper B1 is turned OFF, the three layers of the A table 2a, the B table 2b, and the C table 2c are unclamped from the adapter 2d.
As shown in FIG. 7, the first clampers B <b> 1 (☆ marks) are arranged uniformly by a total of four in a plan view.
The structure of the first clamper B1 is formed with a cylinder chamber in which a plurality of disc springs (not shown) are built, and the cylinder rod B1a is pulled by the biasing force of the disc spring. The first clamper B1 is a clamper device that uses the biasing force of the disc spring.
Therefore, the A table 2a, the B table 2b, and the C table 2c are clamped by the adapter 2d by the urging force of the disc spring, and the table 2 is integrally clamped (see FIG. 4). Once the hydraulic pressure is supplied to the cylinder chamber (not shown) of the first clamper B1, each table is unclamped by deflecting the disc spring against the urging force of the disc spring.

<Configuration of second clamper>
As shown in FIG. 4, the second clamper B2 is stored in the C table 2c as described above, and is fixed to the adapter 2d. Further, the enlarged head of the cylinder rod B2a is engaged with the B table 2b, and the B table 2b and the C table 2c are clamped by the adapter 2d. Once the hydraulic pressure is supplied to the cylinder chamber of the second clamper B2, the disc spring is deflected against the urging force of the disc spring, and the second clamper B2 and the C table 2c are unclamped.
As shown in FIG. 7, a total of four second clampers B2 (* marks) are alternately arranged with four of the first clampers B1 (* marks). Since the structure of the second clamper B2 is the same as that of the first clamper B1, description of the overlapping structure is omitted.

<Configuration of third clamper>
As shown in FIG. 4, the third clamper B3 is a brake. The third clamper B3 is disposed on the upper surface of the flange portion 13h of the housing 13g mounted on the upper surface of the base 21a. Specifically, the third clamper B3 is a disc brake, and clamps or opens the both sides of the ring-like disc 2f with a brake pad on a flange portion 2e provided on the outer periphery of the adapter 2d for unclamping. Clamping and unclamping are controlled by hydraulic pressure ON / OFF.
As shown in FIG. 7, a total of two third clampers B3 are arranged on the left and right (*).

<Configuration of Raflocator>
As shown in FIG. 4, the raflocator 2h is a block that guides the fixing position when the workpiece W is fixed to the upper surface of the jig plate 2g fixed to the upper surface of the A table 2a. On this upper surface, a position locator and a clamper are provided in accordance with the size to be used when the work W is placed. If a careful work and a high-precision work W are brought into contact with the raflocator 2h, the rotation of the third spindle 13 is performed. The workpiece W can be positioned and fixed at a position close to the center c1, for example, a position close to the center of the table 2 (0.02 to 0.05 mm).

≪Operation principle of automatic alignment part≫
As shown in FIG. 4, the operation principle of the automatic alignment unit 20 that matches the workpiece center c0 attached to the upper surface of the table 2 with the rotation center c1 of the table 2 will be described in the order of steps.
While the operator operates a lift, a crane, etc., the work W is placed on the raflocator 2h on the upper surface of the jig plate 2g, and the work W is fixed while being pressed against the raflocator 2h.
However, in a series of work exchange operations performed without taking much time, the work center c0 does not coincide with the rotation center c1 of the third main shaft 13 even if it abuts against the raflocator 2h, and a small amount (0.02 to 0.02). 0.05 mm) misalignment occurs. Therefore, automatic centering is performed by the automatic alignment unit 20 of the present invention to eliminate a slight amount of misalignment.
The procedure of automatic alignment is performed in a process including a first process of workpiece measurement, a second process of automatic alignment 1, and a third process of automatic alignment 2.

In Table 1, the A table 2a, the B table 2b, and the C table 2c are arranged on the base 21a, and the operations of the first clamper B1, the second clamper B2, and the third clamper B3 in each process are arranged in a list. It is a thing. As shown in Table 1, in the first step, the first clamper and the second clamper are fixed and the third clamper is released, and in the second step, the first clamper is released and the third clamper and the third clamper are fixed. In the third step, the first clamper and the second clamper are opened and the third clamper is fixed.
In addition, when the rotation of the main shaft is one rotation or more, it is described as rotation, and when it is less than one rotation, it is described as rotation.

[Table 1]

<First step>
FIGS. 8A, 8B, and 8C are a schematic diagram and a process diagram showing the operation principle of the automatic alignment unit. As shown in FIG. 8A, in the first step, the deflection of the workpiece W fixed on the upper surface of the table 2 is measured. Specifically, the control unit 9a lowers the probe 8a attached to the measuring device 8 (see FIG. 2), rotates the third main shaft 13 by the rotational drive of the third motor C3, and rotates the workpiece W while rotating the workpiece W. The runout of the inner or outer peripheral surface of W is measured.
In this case, as shown in “work measurement” in the first step of Table 1, the first clamper B1 and the second clamper B2 are clamped, and the third clamper B3 is unclamped. The measured value of the shake of the workpiece W is transferred to a calculation unit (not shown) in the control unit 9a (see FIG. 3), and is instantaneously calculated to obtain the coordinate value (x, y) of the workpiece center c0.
The following steps 2 and 3 will be described assuming that the work center c0 is, for example, in the second quadrant and the numerical value of the coordinate value (−x, y) is (−0.05, 0.03), for example.

<Second step>
As shown in “Automatic alignment 1, Y axis” in the second step of Table 1, the first clamper B1 is unclamped (released) to free the A table 2a, and the second clamper B2 is clamped to the B table. 2b and C table 2c are fixed. The third clamper B3 serves as a clamp.
When a movement command is input to the first moving mechanism 15, a rotation command is immediately input to the first motor C1, and the first main shaft 11 is rotated by −19.9 degrees corresponding to −0.03 mm, for example.
As shown in FIG. 5, the A table is formed by the cooperation of the first driving means 15 </ b> E by the first eccentric cam 11 s formed integrally with the upper end portion 11 a of the rotated first main shaft 11 and the first moving mechanism 15. 2a is moved in the Y-axis direction by the amount of y (−0.03 mm).
As shown in FIG. 8B, the misalignment in the Y-axis direction is eliminated by the movement of the y amount (−0.03 mm). A closed loop that is confirmed by a linear scale may be used.

<Third step>
As shown in “automatic alignment 2, X axis” in the third step of Table 1, the second clamper B2 is further unclamped (released) to make the B table 2b free.
When a movement command is input to the second movement mechanism 16, a rotation command is immediately input to the second motor C2, and the second main shaft 12 is rotated by 25.8 degrees corresponding to, for example, 0.05 mm.
As shown in FIG. 6, the B table is obtained by the cooperation of the second driving means 16 </ b> E by the second eccentric cam 12 s formed integrally with the upper end portion 12 a of the rotated second main shaft 12 and the second moving mechanism 16. 2b is moved in the X-axis direction by the amount of x (+0.05 mm).
As shown in FIG. 8C, the misalignment in the X-axis direction is also eliminated by moving the x amount (+0.05 mm). That is, since the center of the workpiece W is (0, 0), the automatic alignment operation is terminated. The target value for automatic alignment is set to ± 0.002 mm.

<4th process>
The first clamper B1 and the second clamper B2 are clamped (fixed) to integrate the table 2, and the third clamper B3 is opened to unclamp, and the third main shaft 13 is rotated by driving the third motor C3. The table 2 fixed integrally to the third spindle 13 via the adapter 2d and the workpiece W fixed to the upper surface of the table 2 are rotated to perform external grinding, internal grinding, or end grinding of the workpiece W. .

<5th process>
After the grinding process is completed, the operator loosens the fixture of the workpiece W, and rotates the second spindle 12 by the reverse drive of the second motor C2 during the workpiece W replacement operation to lower the workpiece W to the floor. The B table 2b is moved by an amount x (−x) of a slight misalignment that cannot be seen even by visual observation, and the position of the B table 2b is returned to the original position.
Further, the first spindle 11 is rotated by the reverse drive of the first motor C1, and the A table 2a is moved by a slight misalignment y amount (+ y) that cannot be seen even by visual observation, so that the position of the A table 2a is restored. Return to.
Thereby, the slight misalignment of the A table 2a and the B table 2b is eliminated, and the original state without the misalignment is restored.
In this way, by returning the positions of the A table 2a and the B table 2b to the original positions each time, there is no accumulation of misalignment between the A table 2a and the B table 2b.
In addition, you may divide this 5th process into 2 processes of this 5th process and a 6th process.
As described above, the operation principle of the automatic alignment unit 20 of the present invention is extremely unique, and is smooth and simple without repeating each operation.

The operation and effect of the rotary table device 21 having the automatic alignment unit 20 of the present invention will be described.
1) In the present invention, the first step of measuring the misalignment of the workpiece W with the measuring device, and instantaneously calculating it by the calculation unit to identify the misalignment position (x, y) of the workpiece W; Since the second step of moving the table 2a in the Y direction by the y value and the third step of moving the second B table 2b in the X direction by the x value, the misalignment of the workpiece W can be eliminated. As a result, there is a remarkable effect that the centering (alignment) time is short because each operation is not repeated.
Further, the time required for automatic alignment by the automatic alignment unit 20 of the present invention is within about 120 seconds including measurement. Since the self-aligning portion 20 of the present invention does not repeat, there is no extension. Therefore, production planning is easy and there is no risk of disturbing the progress of the scheduling.
2) Servo motors and sensors for automatic alignment, and high-performance devices such as rolling guides are not exposed anywhere on the top surface of the table 2, and high positions such as servo motors and linear guides All the performance devices are mounted in a cylindrical rotary table device 21. Therefore, the dust-proof design for preventing the intrusion of dust may be a design of a single cylindrical cover that is easy to manufacture, the structure is simple, and the dust-proof design is easy. In addition, it is possible to provide a turntable device having an automatic alignment unit that is easy to design for dust prevention.

The present invention can be variously modified and changed within the scope of the technical idea.
For example, as a feature of the present invention, the two A tables 2a and B tables 2b are moved in the Y direction (second step) and the X direction (third step), but the order of these steps may be interchanged. Further, the first moving mechanism 15 and the second moving mechanism 16 may be interchanged.
The B liner 2m may be provided integrally with the A table 2a, and the C liner 2n may be provided integrally with the B table 2b.
For example, the first clamper B1 integrally fixes the A table 2a and the B table 2b, and the second clamper B2 integrally fixes the B table 2b and the C table 2c. The first clamper B1 fixes the A table 2a, the B table 2b, and the C table 2c integrally, and the second clamper B2 fixes the A table 2a and the B table 2b integrally. It doesn't matter. Furthermore, the brake of the third clamp B3 may be a brake device of another type.

FIGS. 8A, 8B, and 8C are drawn with exaggerated eccentricity for easy understanding. Actually, the eccentric amount of the A table 2a and the B table 2b is a minute amount of 0.10 mm or less, but FIG. 8 is exaggerated by enlarging it several hundred times.
For example, in the case of machining with an NC lathe, it is necessary to rotate the workpiece W at a high speed because the cutting tool that is the cutting edge of the lathe is fixed. The work W on the table 2 may be rotated at a low speed. Therefore, even if there is such a small amount of eccentricity, there is no influence on the machining accuracy.

2 Table 2a A table (upper)
2b B table (middle)
2c C table (lower)
2d Adapter 2e Flange 2f Disk 10 Vertical grinding machine 11 First spindle 11a Upper end 12 Second spindle 12a Upper end 13 Third spindle 15 First moving mechanism 15a Guide rail 15ab Guide nut (Y-axis sliding member)
15b First eccentric cam 15c X-axis direction restricting means 15d X-axis slider 15E First drive means 15f Wedge 15g Needle roller 16 Second moving mechanism 16a Guide rail 16ab Guide nut (X-axis sliding member)
16b Second eccentric cam 16c Y-axis direction restricting means 16d Y-axis slider 16E Second drive means 16f Wedge 16g Needle roller 17 Retainer 18 End cover 20 Automatic alignment part 21 Rotary table device (work holding member)
21a base (for rotary table device)
B1 1st clamper B2 2nd clamper B3 3rd clamper (brake)
C1 first motor (first driving means)
C2 Second motor (second drive means)
C3 Third motor (rotation drive means)
c0 Center of workpiece c1 Center of rotation t Eccentricity W Workpiece

In order to achieve the solution of the above-described problem, the invention of the rotary table device according to claim 1 is characterized in that a table is rotatably arranged on a base, and a work center placed on the table is defined as a rotation center of the table. The table is laminated in the order of A table, B table, and C table from the side far from the base, and is arranged on the B table. A first moving mechanism that is mounted and guides the A table to be movable in the Y-axis direction along the table surface; and the B table is mounted on the C table. A second moving mechanism in which the C table guides the B table movably along the table surface in the X-axis direction orthogonal to the Y-axis direction;
A first driving means for moving the table A to the Y-axis direction, and a second driving means for moving the table B into the X-axis direction, Bei example and a rotary drive means for rotating the C table, The first driving means includes a first main shaft disposed at the center of the lower surface of the A table, and the second driving means includes a cylindrical second main shaft through which the first main shaft is inserted, and the rotational driving. The means includes a third main shaft having a through hole through which the second main shaft is inserted .

The invention according to claim 2 is the rotary table device according to claim 1 , wherein the first driving means includes a first eccentric cam engaged with a recess of the A table, the first eccentric cam, comprising a first motor for rotating the first spindle formed integrally, and said second drive means includes a second eccentric cam engaged with the recess of the table B, the second eccentric cam and integrally and a second motor for rotating the formed second main shaft, the rotary drive means, in that it comprises a third motor for rotating the third main spindle which is fixed integrally with the C table Features.

<Configuration of first driving means 15E>
As shown in FIG. 5, the first drive means 15E is provided in a recess b formed on the lower surface of the A table 2a, except for the first motor C1 (not shown).
The first drive means 15E includes a first eccentric cam 11s engaged with the recess b of the A table 2a, a first main shaft 11 formed integrally with the first eccentric cam 11s, and a first main shaft 11 that rotates the first main shaft 11. 1 motor 1C (see FIG. 4), and the amount of eccentricity of the first eccentric cam 11s is set to MAX, and the A table 2a is moved in the Y-axis direction.
The first eccentric cam 11s of the first drive means 15E is a conversion mechanism that is formed integrally with the first main shaft 11 and converts the rotation (rotational movement) of the first eccentric cam 11s into a linear movement in the Y-axis direction. . For this purpose, a third bearing 11b is mounted on the outer periphery of the first eccentric cam 11s formed integrally with the first main shaft 11, and an X-axis slider 15d is mounted on the outer periphery of the third bearing 11b. The X-axis slider 15d is formed in a rectangular shape, and X-axis guides 15e and 15e are disposed on end faces in the front-rear (Y-axis) direction via needle rollers 15g with a cage. The X-axis guides 15e and 15e are fixed to the lower surface of the A table 2a, and are free of gaps (backlash) by the wedge 15f. Thereby, the movement in the left-right (X-axis) direction is absorbed, and only the movement in the Y-axis direction is transmitted to the A table 2a and slides in a small amount.

In Table 1, the A table 2a, the B table 2b, and the C table 2c are arranged on the base 21a, and the operations of the first clamper B1, the second clamper B2, and the third clamper B3 in each process are arranged in a list. It is a thing. As shown in Table 1, in the first step, the first clamper and the second clamper are fixed and the third clamper is released, and in the second step, the first clamper is released and the second clamper and the third clamper are fixed. In the third step, the first clamper and the second clamper are opened and the third clamper is fixed.
In addition, when the rotation of the main shaft is one rotation or more, it is described as rotation, and when it is less than one rotation, it is described as rotation.

Claims (4)

A rotary table device in which a table is rotatably arranged on a base, and a work center placed on the table is automatically aligned with the rotation center of the table,
The table is laminated in the order of A table, B table, C table from the side far from the base,
A first movement mechanism disposed on the B table, wherein the A table is placed, and the B table guides the A table movably in the Y-axis direction along the table surface;
The second movement is arranged on the C table, the B table is placed, and the C table guides the B table movably along the table surface in the X-axis direction orthogonal to the Y-axis direction. Mechanism,
First driving means for moving the A table in the Y-axis direction;
Second driving means for moving the B table in the X-axis direction;
Rotation driving means for rotating the C table;
A rotary table device comprising: A first eccentric cam in which the first driving means is engaged with a recess of the A table; a first main shaft formed integrally with the first eccentric cam; a first motor that rotates the first main shaft; With
A second eccentric cam in which the second driving means is engaged with a recess of the B table; a second main shaft formed integrally with the second eccentric cam; a second motor that rotates the second main shaft; With
A third spindle that is integrally fixed to the C table, and a third motor that rotates the third spindle;
The rotary table device according to claim 1, further comprising: A measuring device that measures the deflection of the workpiece, a calculation unit that calculates the misalignment amount of the workpiece center from the deflection, and controls the automatic alignment operation according to the rotation center of the table based on the misalignment amount of the calculation unit A control unit,
The measuring device measures the workpiece shake, and the calculation unit calculates the workpiece based on the measured value. A first step to be obtained;
A second step of correcting the A table by moving the misalignment amount in the Y-axis direction by the first driving means;
A third step of correcting the B table by moving the deviation amount in the X-axis direction by the second driving means;
The rotary table device according to claim 1 or 2, wherein the rotary table device is executed. A first clamper that integrally fixes the A table, the B table, and the C table;
A second clamper for integrally fixing the B table and the C table;
A third clamper that integrally fixes the C table and the base;
In the first step, the first clamper and the second clamper are fixed, the third clamper is opened,
In the second step, the first clamper is opened, the third clamper and the third clamper are fixed,
The rotary table device according to claim 3, wherein in the third step, the first clamper and the second clamper are opened, and the third clamper is fixed.

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