JPH0740163A - Table transfer device and control method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a table transfer device and a control method therefor capable of correcting the displacement between the left and right sides of a table. [Structure] The table 4 is mounted on the base 2 via the linear guide 3.
Movably supported between the table 4 and the base 2,
Drive mechanisms 5 and 6 for driving the table 4 with respect to the base 2.
Are provided on the left and right sides of the table 4, and the pair of drive mechanisms 5 and 6 are independently driven to provide a difference in the left and right feed amounts of the table 4, thereby adjusting the left and right inclination with respect to the moving direction of the table 4. The feature is that it is possible. Also,
The control is performed by detecting the left and right positions of the table and based on the detected position information. However, the control may be performed after the positioning is completed, or may be performed during the transfer and at the same time as the transfer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a table transfer device used for, for example, a work table of various machine tools, and more particularly to a table transfer device capable of correcting a lateral displacement of the table.

[0002]

2. Description of the Related Art As a conventional table transfer device, for example, one shown in FIG. 12 is known. That is, the table 103 is movably supported on the base 102 via the linear guide portion 101. And base 1
The screw drive mechanism 104 for driving the table 103 with respect to the base 102 was provided between the No. 02 and the table 103.

In order to perform precision feed, the support rigidity of the linear guide portion 101 of the table 103 is increased, and
It is general to provide a position detection means for the table 103 and feed back position information of the table 103 detected by the position detection means to control the positioning.

[0004]

However, in the case of the above-mentioned prior art, although the supporting rigidity of the table 103 is increased, the left side 103L of the table 103 is unavoidable due to the load acting on the table 103 or thermal deformation. And the right side 103R is displaced, and the table 10
Considering the entire surface of No. 3, the entire surface is not positioned with the same accuracy. That is, even if the center of the table 103 is accurately positioned when the table 103 is tilted to the left and right, the errors in the left and right corners of the front end and the left and right corners of the rear end are large due to the tilt.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a table transfer device and a control method therefor capable of correcting the displacement between the left and right sides of a table. Especially.

[0006]

In order to achieve the above object, in the present invention, a table is movably supported on a base through a linear guide, and a table is provided between the base and the table. In a table transfer device provided with a drive mechanism for driving a table with respect to a base, a pair of the drive mechanisms is provided on the left and right sides of the table, and by providing a difference in the left and right feed amounts of the table, the left and right tilts of the table Is adjustable.

The drive mechanism is a screw feed mechanism.

Further, the control is to drive both drive mechanisms in synchronization with each other to move the table to a predetermined position, detect the left and right positions of the table after the completion of positioning, and set the drive mechanism based on the detected position information. You may make a correction to adjust the left and right inclination of the table, or detect the left and right positions of the table while the table is moving and feed back the deviation of the left and right positions to the drive mechanism to determine the left and right positions of the table. The inclination may be adjusted during the movement to be transferred.

[0009]

In the present invention, the drive mechanism provided on the left and right of the table changes the feed amount to the left or right, thereby tilting the table to the right or left to correct the posture.

Further, the attitude control is performed by detecting the left and right positions of the table and based on the detected position information.
This attitude control may be performed after positioning is completed,
It may be carried out during the transfer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

1 to 3 show a table transfer device according to a first embodiment of the present invention.

The table transfer device 1 is composed of a base 2 and a table 4 movably supported by the base 2 via a linear guide portion 3. Between the base 2 and the table 4. , The first for driving the table 4 with respect to the base 2
Second drive mechanisms 5 and 6 are provided.

An infinite sliding type linear guide device as shown in FIG. 6 is used for the linear guide portion 3, and the linear guide device includes a track rail 7 and a large number of balls 8 on the track rail 7. And a moving member 9 that is movably attached to the base 2, and is arranged parallel to each other at both left and right ends of the base 2. In this embodiment, the moving member 9 is a block body having a substantially U-shaped cross section having a central recess 10 opened downward, and the track rail 7 is inserted into the central recess 10. A projecting strip 11 is provided at the upper end of the track rail 7 so as to project to the left and right, and a total of four rows of balls 8 are provided so as to sandwich the projecting strip 11 from above and below. The four rows of balls 8 enhance the support rigidity against loads from above, below, left and right.

The first and second drive mechanisms 5 and 6 are screw drive mechanisms having exactly the same configuration. Taking the first drive mechanism 5 on the left side as an example for explanation, as shown in FIG. A first screw shaft 52, which is fixed in the axial direction and movably in the rotation direction via support bearings 51, 51 supporting both ends, is fixed on the table 2 in the axial direction with respect to the table 4. From a first ball nut 53 that is screwed to a first screw shaft 52 that is movably mounted in the rotation direction, and a first rotation motor 54 that serves as a rotation drive unit that rotationally drives the first screw shaft 52. It is configured.

The first rotary motor 54 is fixed to the base 2 via a motor fixing bracket 55, and the first ball nut 53 is fixed to the table 4 via a nut fixing bracket 56.
It is fixed on the back. Further, one end of the first screw shaft 52 is connected to the first rotary motor 54 via a coupling 57.

In this embodiment, the first ball nut 53 is provided with a phase difference between the left and right screw grooves at the center of a single nut body 58, as shown in FIG. 5B. The preload is applied by setting the axial gap of the ball 59 interposed between the screw groove 58 and the screw groove of the first screw shaft 52 to be zero or less. Of course, as the first ball nut 53, a double nut type ball nut that applies a preload using a so-called spacer may be used.

On the other hand, the second drive mechanism 6 on the right side has the same structure as that of the first drive mechanism 5, and is fixed in the axial direction and movable in the rotational direction via the support bearings 61, 61. A second screw shaft 62 to be mounted and a second screw screw shaft 62 to be fixed to the table 4 in the axial direction and movably in the rotational direction.
Of the ball nut 63 and a second rotary motor 54 as a rotary drive means for rotationally driving the second screw shaft 62. The leads of the first screw shaft 52 and the second screw shaft 62 are exactly the same.

On the other hand, in order to detect the position of the table 4 with respect to the base 2, linear scales 12L extending along the moving direction of the table 4 are provided at both left and right ends of the table 4.
12R is attached. This linear scale 12
The L and 12R are provided with graduations that can be read after being converted into electrical information such as electrical, magnetic, and optical graduations, and are located at appropriate positions on the base 2, that is, on the left and right of the base 2 in this embodiment. Position sensors 13 that read the scales of the linear scales 12L and R and convert the scales into electrical information at substantially central positions on both sides.
L and 13R are provided.

In this embodiment, the position of the table 4 is read with the origin when the table 4 is located at the right end in the drawing, and the origin sensor 14 is provided at the origin position. However, the origin sensor 14 is not necessary if absolute type position sensors whose absolute positions are known are used as the position sensors 13L and 13R.

The method of detecting the position of the table 4 is not limited to this embodiment, and various other position sensors can be used.

Further, on the base 2, stoppers 15 and 16 are provided in front and rear 2 in order to mechanically restrict runaway of the table 4.
It is provided in various places. A protrusion 17 is formed on the back surface of the table 4 at a position where it can abut the stoppers 15 and 16. The stoppers 15 and 16 are the final fail-safe mechanism, and the runaway detection switches 18 and 19 that electrically stop the driving of the first and second rotary motors 54 and 64 before contacting the stoppers 15 and 16. Is provided and double safety measures are taken.

In the figure, reference numeral 21 denotes a flexible wire harness that bundles the wiring relationship connected between the table 4 and the base 2 so as not to hinder the movement of the table 4.

FIG. 4 shows an example of the main control configuration of the table transfer device of this embodiment.

That is, the transfer amount is input as a command value to the drive control means 20 composed of a computer,
According to this command value, the first and second rotary motors 54, 64
Is calculated, and the first and second rotary motors 54, 6 are calculated.
4 is rotationally driven in synchronization. On the other hand, position information from the left and right position sensors 13L and 13R of the table 4 is input to the drive control means 20, the left and right position information is compared, and the correction amounts of the left and right first and second rotary motors 54 and 64 are calculated. Is configured to be.

In the table transfer device having the above structure,
According to the command value, the first and second screw shafts 52 and 62 are completely synchronously driven by the first and second rotary motors 54 and 64 by a predetermined amount, and the first and second screw shafts 52 and 62 are rotated. The first and second ball nuts 53 and 63 that are screwed together are reciprocally moved by the same amount.

However, the load acting on the table 4, thermal deformation, and the like inevitably cause a positional deviation between the left side and the right side of the table 4. Considering the entire surface of the table 4, the entire surface has the same accuracy. Not positioned. That is, even if the center of the table 4 is accurately positioned when the table 4 is tilted to the left and right, the left and right corners of the front end and the left and right corners of the rear end have large front and rear errors due to the tilt.

Therefore, the left and right positions of the table 4, that is, the central positions of the left and right sides of the table 4 in this embodiment are constantly monitored by the position sensors 13L and 13R, the left and right position information is compared, and the positions are deviated. Only, the amount of rotation of the first and second rotary motors 54 and 64 is corrected, the deviation of the left and right feed amounts is corrected, and the inclination of the table 4 is corrected.

The correction of the left / right positional deviation may be performed at the stop position. However, in this embodiment, the left / right positional deviation is constantly monitored and corrected while the table 4 is moving, and yawing of the table 4 is performed. Is being prevented.

Therefore, even when working while the table 4 is moving, precise work is possible, and further,
Even when stopped, the entire surface of the table 4 is accurately positioned in an instant.

This table transfer device enhances the positioning accuracy on the entire surface of the table 4, and as its evaluation method, the table central position O and the four corner positions A, B, which have the largest error when tilted to the left and right, When the positioning accuracy was measured at 5 points of C and D, extremely high positioning accuracy was obtained.

7 and 8 show a table transfer device according to the second embodiment of the present invention.

The table transfer device of the second embodiment is an XY table which supports a table 31 so as to be movable in the X-axis and Y-axis directions orthogonal to each other, and has a first linear guide on a first base 32. The second base 34 is movably supported in the linear direction (hereinafter referred to as the Y-axis direction) via the portion 33, and the second base 34 is provided on the second base 34 via the second linear guide portion 35. A direction orthogonal to the moving direction of the base 34 (hereinafter referred to as the X-axis direction)
The table 31 is movably supported.

Then, the first base 32 and the second base 34
A single screw shaft 36Y2 is arranged as a Y-direction drive mechanism 36Y in the Y-axis direction, and an X-direction drive mechanism 36X in the X-axis direction is provided between the second base 34 and the table 31.
As the two screw shafts 36XL and 36XR are arranged.

In the case of this embodiment, the left and right positional deviations are corrected by the two screw shafts 36XL2 and 36XR2 only in the X-axis direction. You may make it correct | amend the position gap on either side as a structure. This embodiment is applied when the positional deviation does not matter in the Y-axis direction.

Since the first linear guide portion 33 and the second linear guide portion 35 use the same endless sliding type linear guide device as in the first embodiment, the description thereof will be omitted.

The Y-direction drive mechanism 36Y is a screw drive mechanism, and is a screw shaft which is fixed on the first base 32 through support bearings 36Y1 supporting both ends thereof in the axial direction and movably in the rotational direction. 36Y2 and the second base 3
4, the ball nut 36 screwed to the screw shaft 36Y2 that is fixed in the axial direction and movably in the rotational direction.
Y3 and a rotation motor 3 for driving the screw shaft 36Y2 to rotate.
6Y4.

The X-direction drive mechanisms 36XL and 36XR are provided with a pair of independent drive mechanisms on the left and right and are arranged in parallel with each other.

This X-direction drive mechanism 36XL, 36X
R is a screw shaft 36XL that is mounted on the second base 34 via support bearings 36XL1 and 36XR1 that support both ends in the axial direction and is movable in the rotational direction.
2, 36XR2 and the screw shaft 36X fixedly attached to the table 31 in the axial direction and movably in the rotational direction.
Ball nut 36XL3 screwed to L2, 36XR2
36XR3 and a rotation motor 36XL4 as a rotation driving means for rotating the screw shafts 36XL2 and 36XR2.
It is composed of 36XR4.

On the other hand, the table 3 for the second base 34
In order to detect the position of 1, the linear scales 37L and 37R extending along the moving direction of the table 31 are attached to the left and right ends of the table 31 in the same manner as in the first embodiment, and are attached to the second base 34. Position sensors 38L, 3 provided
The position information is detected by 8R.

Also in this second embodiment, the position of the table 4 is read with the right end in the X-axis direction as the origin, and the origin sensor 38 is provided at the origin position.

The table 3 is mounted on the second base 34.
In order to mechanically control the runaway of 1
0 are provided at two front and rear positions, and a protrusion 41 is formed on the back surface of the table 4 at a position where it can abut against the stoppers 40, 40. Runaway detection switches 42 and 43 for electrically stopping the driving of 36L4 and 36R4 are provided. The runaway detection switches 42 and 43 are also provided on the first base 32.

On the other hand, in the figure, 44 and 45 are the table 3
Between the table 31 and the second base 34 and between the second base 34 and the first base 34 so as not to hinder the movement of the first and second bases 34.
It is a flexible wire harness that bundles wiring relationships connected between the bases 32.

The rest of the configuration and operation are the same as in the first embodiment, so a description thereof will be omitted.

Here, an example of a control system of the table transfer device will be described with reference to FIGS. 9 to 11.

FIG. 9 shows an example of the control system configuration when the left and right screw axes L and R are separate. That is, the motor drivers DL and DR of the drive motors ML and MR for the left and right screw shafts L and R, and the positioning units PL and PR.
And a controller CL, CR, and scales SL, SR for detecting left and right positions, and a comparator CP for comparing signals from the scales SL, SR is provided between the controllers CL, CR. In addition, each motor ML,
The MR has a pulse generator PG.

Feed command signals for the left and right screw shafts L and R are sent from the controllers CL and CR to the positioning unit PL,
It is output to PR. And the left and right scales SL, SR
The scale values Li and Ri read by are fed back to the left and right controllers CL and CR and the positioning units PL and PR.

FIG. 10 shows a control flowchart of the system of FIG.

This system includes controllers CL and CR.
When the side can perform synchronous control, controller CL, CR
The left and right drive motors M by the synchronous positioning command from
L, MR are driven, and after positioning is completed, each screw axis L, R
Is designed to be corrected.

First, the scale S of the left and right screw axes L and R
The values of L and SR are read (step 1).

Next, the command value I and the scale value Li of the left screw shaft L are compared (step 2). If they match, the process proceeds to step 3, and if they do not match, the process proceeds to step 4.

In step 3, the scale values Li and Ri of the left and right screw axes L and R are compared. If they match, the process ends, and if they do not match, the process proceeds to step 5.

In step 5, it is compared whether or not the left scale value Li is larger than the right scale value Ri, and Li>
If it is Ri, proceed to step 6 and set the right-hand screw axis R to the difference 1
Feed by 1/2, and if Li <Ri, go to step 7 to return the right-hand screw axis R by 1/2 of the difference, and then step 6,
Both step 7 returns to step 2.

On the other hand, in step 4, the command value I and the scale value Li are compared. If the command value I> scale value Li, the process proceeds to step 8 to feed the left screw shaft L by the difference, and the command value I <scale. If the value is Li, the process proceeds to step 9, and the left screw axis L is returned by the difference, and then both step 8 and step 9 return to step 2.

In this way, the above procedure is repeated until the left and right scale values Li and Ri finally match, and the table is positioned with high accuracy.

FIG. 11 shows a case where the left and right screw axes L and R are controlled by one controller Co.

In this case, the left and right motors ML and MR are driven by a command signal from one controller Co.

When the motors ML and MR are driven, the scale value L read by the left and right scales SL and SR.
i and Ri are the left and right positioning units PL and PR
Be fed back to. At this time, these signals L
i and Ri are also fed back to the D / A conversion unit DA.

In the D / A conversion unit DA, the left screw shaft L
And the scale value Ri of the right-handed screw shaft R are compared, and the difference is given to the right-handed screw shaft R as a correction signal Δi.

Scale values Li, Ri of the left and right screw axes L, R
The left and right motors ML, M
R can be synchronized and driven smoothly.

[0061]

The present invention has the above-described structure and operation, and the drive mechanism provided on the left and right of the table changes the left or right feed amount of the table to adjust the left and right inclination of the movable table. Therefore, it is possible to perform positioning with high accuracy over the entire surface of the table and prevent yawing during transfer.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a main part of a table transfer device according to a first embodiment of the present invention in a state in which a table is greatly advanced.

FIG. 2 is a schematic plan view showing a state in which the transfer amount of the table is smaller than that in FIG.

3 (a) is a front view of the apparatus of FIG. 2, and FIG. 3 (b) is a side view of the apparatus of FIG.

4 is a block diagram showing an example of a main control configuration of the apparatus of FIG.

5 (a) is a partial cross-sectional view of the drive mechanism portion of the apparatus of FIG. 1, and FIG. 5 (b) is an enlarged cross-sectional view of the ball nut of FIG. 5 (a).

6 shows a linear guide device used in the linear guide part of the device of FIG. 1, FIG. 6 (a) is a partially cutaway side view,
FIG. 3B is a front sectional view.

FIG. 7 is a plan view showing an XY table of a table transfer device according to a second embodiment of the present invention.

8 (a) is a front view of FIG. 7, and FIG. 8 (b) is a side view of FIG.

FIG. 9 is a block diagram showing a configuration example of a control system of the table transfer device of the present invention.

10 is a flowchart of the control system of FIG.

FIG. 11 is a block diagram showing a configuration example of a control system different from that of FIG. 9.

FIG. 12 is a plan view of a conventional uniaxial type table transfer device.

[Explanation of reference numerals] 1 table transfer device 2 base 3 linear guide 4 table 5, 6 first and second drive mechanism 52, 62 first and second screw shaft 53, 63 first and second ball Nut 12L, 12R Linear scale 13L, 13R Position sensor

Front page continued (72) Inventor Koichi Yamamoto 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor ▲ Taka ▼ Aki 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Within the corporation

Claims (4)

[Claims] 1. A table transfer device in which a table is movably supported on a base via a linear guide and a drive mechanism for driving the table with respect to the base is provided between the table and the base. By providing a pair of the drive mechanisms on the left and right of the table and independently driving the pair of drive mechanisms to provide a difference between the left and right feed amounts of the table, the left and right tilts of the table with respect to the moving direction can be adjusted. A table transfer device characterized by the above. 2. The table transfer device according to claim 1, wherein the drive mechanism is a screw feed mechanism. 3. A table transfer device in which a table is movably supported on a base via a linear guide and a drive mechanism for driving the table with respect to the base is provided between the tables. , A pair of the drive mechanism is provided on the left and right sides of the table, the both drive mechanisms are synchronously driven to move the table to a predetermined position, and after the positioning is completed, the left and right positions of the table are detected,
A method for controlling a table transfer device, comprising: adjusting a lateral inclination of a table by correcting a drive mechanism based on detected position information. 4. A table transfer device, wherein a table is movably supported on a base via a linear guide, and a drive mechanism for driving the table with respect to the base is provided between the tables. The pair of drive mechanisms is provided on the left and right of the table, the left and right positions of the table are detected while the table is moving, and the deviation between the left and right positions is fed back to the drive mechanism to adjust the left and right tilt of the table during the movement. A method of controlling a table transfer device, characterized in that the table transfer device is transferred while being transferred.