JPH09131631A - Working machine provided with x-y table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-Y table by which an actual positional change of a workpiece can be correctly grasped and also capable of correctly transferring loaded workpiece along the bottom rail group and improving the processing accuracy by making such contrivance that plural driving means for driving the bottom table may exert no bad influence on the positional control of mutual counterparts. SOLUTION: Such constitution is provided that the detecting part 18a of a Y-axis linear encoder 18 is installed in such a place where approximately center of Y shaft rail groups 15, 16 (concretely a center rail 16) makes reciprocating linear movement in one body with a Y-table 14 and also on the basis of detected result of this linear encoder 18, two sets of Y-axis linear motor 17 (second driving means) make positional control of the Y-table 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a top table and a bottom table, which are capable of reciprocating linear movement in two directions orthogonal to each other, on the basis of position data detected by respective linear encoders. The present invention relates to a processing machine with an XY table in which a desired processing shape can be set for an object.

[0002]

2. Description of the Related Art An XY table mounted on a laser beam machine or the like usually slidably supports the X table (upper table) on which a workpiece is mounted via a suction table or the like. A pair of X-axis rails (upper rails), a first drive unit such as a linear motor that linearly moves the X table back and forth along these X-axis rails, and a first linear encoder that detects X table position data. A Y table (lower table) on which the X-axis rail group is placed, and a pair of Y-axis rails (lower rail) extending in a direction orthogonal to the X-axis rail group and slidably supporting the Y table, and The second drive means such as a linear motor for linearly reciprocating the Y table along the Y-axis rail and the second linear encoder for detecting the position data of the Y table. Here, in the first linear encoder, a light emitting element and a light receiving element are provided on an X table to configure a detection unit, and a scale unit (linear scale) fixed to one X-axis rail is irradiated with light from the light emitting element. Since the reflected light is captured by the light receiving element, the position of the moving X table can be detected in real time, and the distance between the pair of X axis rails is relatively small, so The position of the X table can be grasped almost accurately without considering the relative position with the shaft rail.

However, since the distance between the pair of Y-axis rails is wide, if the position of the Y-table is judged only by the relative position with respect to one Y-axis rail, the position control of the Y-table on the side of the other Y-axis rail is large. An error may occur. Therefore, conventionally, as the second linear encoder, two linear encoders that detect the position data of the Y table from the relative position with respect to each Y-axis rail are installed, and the detection results of each linear encoder respectively correspond to each Y-axis. It is configured to be output to different linear motors (the second driving means) that drive the Y table along the rails. That is, in each of these two linear encoders, a light emitting element and a light receiving element are provided on the Y table to form a detection unit, and the light of each light emitting element is applied to the graduations fixed to the pair of Y-axis rails. Since the reflected light is set to be captured by each corresponding light receiving element, the Y table can be accurately position-controlled on any Y-axis rail side.

In general, in this type of XY table,
Between the X table and each X-axis rail, and between the Y table and each Y
Compressed air is designed to be supplied from the air nozzles provided on the table side between the shaft rails, and the compressed air sent in this way forms an air gap to move each table along the rails. The frictional force at the time of the work is greatly reduced, so that the workpiece can be smoothly transferred in the X-axis direction and the Y-axis direction.

Further, in order to perform micron-precision machining on a workpiece using such an XY table, it is necessary to eliminate the effects of expansion and contraction due to temperature changes as much as possible. As a material for the X-axis rail, the Y-axis rail, and the like, a stone material such as granite having excellent mechanical strength and a small thermal expansion coefficient is suitable.

[0006]

By the way, in the conventional XY table of this type, as described above, two linear encoders each having a scale portion fixed to a pair of Y-axis rails (lower rails) are used. By doing so, the accurate position of the Y table (lower table) is grasped, but in reality, each position is determined according to the end of the Y table (upper table) on the Y table. Since there is a large difference in the load applied to the Y-axis rail, the position control during movement of the Y-table will be driven longer for the side with the larger load. Therefore, the position control on one Y-axis rail side will be completed. However, there is a phenomenon that the posture is changed by the position control on the other Y-axis rail side.
As a result, a slight displacement occurs in the work piece transferred by a predetermined amount along the Y-axis rail group, which is a factor that deteriorates the processing accuracy.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to allow the mounted work piece to be accurately transferred along the lower rail group and improve the working accuracy. To provide a processing machine with a table.

[0008]

The above-mentioned object of the present invention is to mount an upper table on which a workpiece is mounted, an upper rail group for supporting the upper table so as to be capable of reciprocating linear movement, and mounting the upper rail group. An XY table including a placed lower table and a lower rail group that extends in a direction orthogonal to the upper rail group and supports the lower table so as to be capable of reciprocating linear movement in a direction orthogonal to the moving direction of the upper table. At least two linear motors that drive the lower table so as to be capable of reciprocating linear movement along the lower rail group are provided at intervals, and at least two linear encoders that detect position data of the lower table are provided. The linear motor group is provided at a substantially intermediate position for dividing the linear motor group of the base in a direction along the lower rail, and the linear motor group is based on the detection result of the linear encoder. It is accomplished by configuring to perform the position control of the lower table.

[0009]

As described above, if the detection unit of the linear encoder for detecting the position data of the lower table is installed at a position where it linearly moves reciprocally in the approximate center of the lower rail group integrally with the lower table, this detection is performed. Since the position data of the lower table detected by the section is the average of the relative position with the lower rail at the right end and the relative position with the lower rail at the left end in the direction of movement, It is possible to accurately grasp the actual change in the position of the workpiece. And
In this way, if the plurality of linear motors (the second driving means) that drive the lower table are synchronized to perform the position control based on the detection result of one linear encoder, one linear motor Since the phenomenon that the lower table whose position is controlled to change the posture by the position control of the other linear motor does not occur, the positional deviation of the transferred workpiece can be avoided and the processing accuracy is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a front view of an XY table according to the present embodiment, FIG. 2 is a side view of the XY table with a part omitted, and FIG. 3 is an overall side view of a laser processing machine including the XY table. 4 is a side view of a portion corresponding to FIG. 3 of the safety cover that covers the laser processing machine, FIG. 5 is a side view of the Y-axis linear motor incorporated in the XY table shown in FIGS. 1 and 2, and FIG. 6 is the XY. FIG. 7 is a cross-sectional view showing the legs of the X table of the table, FIG. 7 is a plan view showing the air blowing surface of the legs of the X table shown in FIG. 6, and FIG. 8 is a plan view showing the suction table of the XY table. 9A and 9B are explanatory views showing the support structure of the suction table shown in FIG.

The XY table according to this embodiment is adopted in the laser processing machine shown in FIG. That is, this laser processing machine includes a processing machine main body 1 for guiding a laser beam (YAG laser) supplied from a laser oscillator 5 by an optical system including a lens group, a beam splitter, and the like, and irradiating the workpiece, and a mounted object. An XY table 2 that can transfer a workpiece (glass substrate) in two directions orthogonal to each other by a linear motor, a surface plate (base plate) 3 on which the processing machine body 1 and the XY table 2 are mounted, and the surface plate 3 And a vibration isolation table 4 on which a laser beam is mounted. A safety cover 7 (see FIG. 4) having a cover frame 6 shown by a chain line in FIG. Covering. In addition, reference numeral 21 in FIG. 1 denotes an optical surface plate on which the processing machine body 1 is mounted.
It is supported by the surface plate 3 via 2.

The XY table 2 has a shaft hole 9a provided in the central portion of the bottom surface and a large number of suction holes 9b communicating with the vacuum pump 8, and the mounted workpiece is placed through the suction hole 9b group. A suction table 9 that can be sucked and fixed by sucking air, and an X table 10 that rotatably supports the suction table 9 by inserting a columnar support shaft 10a into the shaft hole 9a of the suction table 9. , A pair of parallel X-axis rail portions 11a slidably supporting the X-table 10 on both side edges and having a concave sectional shape, and the X-axis installed inside the support table 11. An X-axis linear motor 12 that linearly reciprocates the X table 10 along the rail portion 11a, an X-axis linear encoder 13 that detects position data of the X table 10, and a Y on which the support base 11 is mounted.
The table 14, three Y-axis rails 15 and 16 extending in a direction orthogonal to the X-axis rail portion 11a and slidably supporting the Y-table 14, and these Y-axis rail groups 15 and 1
A Y-axis linear motor 17 that linearly moves the Y table 14 back and forth along a line 6, and a Y-axis linear encoder 18 that detects position data of the Y table 14 are mainly configured. However, the X table 10 and each X-axis rail portion 11
Between a, and the Y table 14 and the Y-axis rails 15 and 16
An air gap is formed by blowing compressed air from an air nozzle provided on the table side between them respectively, and by reducing the frictional force by these air gaps, the workpiece is moved in the X-axis direction and the Y-axis direction. It can be transferred smoothly.

In order to eliminate the influence of expansion and contraction due to the temperature change as much as possible, in this embodiment, the adsorption tables 9 and X are used.
Table 10, support 11, Y table 14, and Y
Granite called Indian Black is used as the stone material for the shaft rail groups 15 and 16, and Granite called Rustenburg is used as the stone material for the surface plate 3.

The laser beam machine having such an XY table 2 drives and controls the XY table 2 to move the workpiece mounted on the suction table 9 with high positional accuracy in the horizontal plane. Therefore, by moving the workpiece along a predetermined locus with respect to the spot-shaped laser beam (beam spot) emitted from the tip (objective lens) of the optical system of the processing machine body 1, A desired processing pattern by beam irradiation can be drawn on the workpiece. Specifically, in a manufacturing process of a liquid crystal display element for full-color display, a product in which a stripe-shaped transparent electrode extending in one direction and a color filter laminated on the electrode are formed on a glass substrate is processed. The color filter is mounted on the suction table 9 and the beam spot is emitted from the processing machine main body 1 while the workpiece is appropriately transferred by the XY table 2, whereby the color filters are arranged at a constant pitch interval in the direction orthogonal to the longitudinal direction thereof. Can be removed with.

Since the linear motors 12 and 17 incorporated in the XY table 2 generate a strong magnetic force for driving a heavy object, in this embodiment, a CRT for a monitor or a monitor arranged in the periphery is used. In order to prevent the magnetic forces of the linear motors 12 and 17 from adversely affecting the machine, the safety machine 7 mainly made of a ferromagnetic material covers the laser machine. That is, the safety cover 7 is, as shown in FIGS.
4 is an iron plate, a degaussing plate, and the like. Specifically, the part A in FIG. 4 is the place where the stainless steel plate of SUS304 is attached, and the parts a and c are the inside of the stainless steel plate of SUS304 and the stainless steel plate of SUS430. It is a two-layer structure where a degaussing plate is attached to enhance the degaussing effect. Among these, the claw part is a double-opening cover that can be opened and closed. In addition, the d part has the same configuration as the claw part on the outside of the colored acrylic plate. It is a part of the three-layer structure. Thus, if the laser processing machine is covered with the safety cover 7 having a degaussing effect, and a strong magnetic force is expected in the vicinity of the linear motors 12 and 17, the degaussing effect is enhanced by forming a two-layer structure. There is no fear that the magnetic forces of 12 and 17 will adversely affect the peripheral equipment, and the optical system of the processing machine main body 1 can be easily adjusted by opening the double-opening cover of the c. Further, when directly confirming whether or not the laser beam is properly applied to the workpiece, if the both-sided covers of the section D are opened, it is possible to perform visual confirmation safely through the colored acrylic plate.

Next, the detailed structure of the XY table according to this embodiment will be described.

As shown in FIG. 8, a large number of suction holes 9b communicated with the vacuum pump 8 are provided on the upper surface of the suction table 9, and the vacuum pump 8 is provided through the suction holes 9b.
By sucking air with, the suction table 9 can suck and fix the mounted workpiece.

Further, as shown in FIG. 9, a shaft hole 9a for inserting the support shaft 10a of the X table 10 is provided at the center of the bottom surface of the suction table 9, and the shaft around the support shaft 10a is provided. Between the outer gap, that is, between the outer wall surface of the support shaft 10a and the inner wall surface of the shaft hole 9a, a gap is maintained by mixing a large number of resin balls (resin spacers) 19a with grease slightly larger than the gap of the shaft gap. Agent 19 is filled. However, the support shaft 10a is a convex body made of stainless steel, and the inner wall portion of the shaft hole 9a is also formed in a bearing structure made of stainless steel. The support shaft 10a rotatably supports the suction table 9 through the gap maintaining agent 17, and when positioning the workpiece suction-fixed on the suction table 9 with respect to the X table 10 with high accuracy. The motor 20 shown in FIG.
The suction table 9 is driven by the support shaft 10a
Can be appropriately rotated about the rotation center. Further, while the gap of the axial gap is 15 to 16 μm, the gap maintaining agent 19 disperses the resin balls 19 a having a diameter of 20 μm before the filling, so that the resin balls 19 a are crushed after the filling. In this state, they are dispersed in the axial gap, so that even if strict size control is not performed, the axial gap is always kept uniform, and there is no play in the vicinity of the rotation center of the suction table 9. It is like this. When the positioning for rotating the suction table 9 is completed, the X table 10 can suck and fix the suction table 9 by sucking air from the air nozzle on the upper surface side.

As shown in FIG. 2, the X-table 10 has a support base 1 having a pair of parallel X-axis rail portions 11a.
An X-axis linear motor 12 for reciprocally moving the X-table 10 along the X-axis rail portion 11a is installed inside the support base 11 slidably. The linear motor 12 is composed of a coil 12a integrated with the X table 10, a magnet 12b and a yoke 12c extending in parallel with the X-axis rail portion 11a, and the X output from the X-axis linear encoder 13. Based on the position data of the table 10, the position of the X table 10 is controlled via the coil 12a which is a movable part. Further, in this X-axis linear encoder 13, a light-emitting element and a light-receiving element are integrated with the X-table 10 to form a detection section 13a, and a scale section (linear scale) 13b fixed to one X-axis rail 11a has a light-emitting element. The light is emitted and the reflected light is captured by the light receiving element, and the position of the moving X table 10 can be detected in real time.

In this embodiment, since the X table 10 is slidably supported by the pair of parallel X-axis rail portions 11a provided on both side edges of the support base 11,
It is easy to give a high degree of parallelism to the pair of X-axis rail portions 11a, and when the support base 11 is installed on the Y table 14, the positional accuracy of the rail portion 11a group is easily increased. be able to. Moreover, in this embodiment, the point of action P of the magnetic driving force generated by the X-axis linear motor 12 is made to substantially coincide with the center of gravity of the X table 10 driven by the linear motor 12, so that the X table 10 is started. There is no risk of rattling at the time of stopping, and it is possible to improve the processing accuracy.

Next, the support structure and driving method of the Y table 14 on which the support base 11 is mounted will be described. The Y table 14 has both side edges slidable by a pair of Y axis main rails 15. The center rail (Y-axis auxiliary rail) 16 is slidably supported by the center rail (Y-axis auxiliary rail) 16.
The Y table 14 is reciprocated along the shaft rail groups 15 and 16. As shown in FIG. 5, each of the pair of linear motors 17 has a coil 17 a integrated with the Y table 14 and Y-axis rail groups 15 and 16.
The pair of linear motors 17 are constituted by a magnet 17b and a yoke 17c extending in parallel with the coil 1 which is a movable part based on the position data of the Y table 14 output from the Y-axis linear encoder 18.
The position of the Y table 14 is controlled via 7a. Further, in the Y-axis linear encoder 18, a light emitting element and a light receiving element are integrally formed in a substantially central portion of the Y table 14 to form a detecting portion 18a, and a scale portion (linear scale) 18b fixed to the center rail 16 emits light. The light of the element is irradiated and the reflected light is captured by the light receiving element, and the position of the moving Y table 14 can be detected in real time.

That is, in this embodiment, the Y table 14
In addition to the pair of Y-axis main rails 15 supporting both side edge portions of the Y-table 14, the center portion of the Y-table 14 is supported by the center rail 16 located between the both main rails 15. Even if the center rail 16 is located near the central portion of the Y table 14,
Since the Y table 14 receives the load of 0, there is no fear that the Y table 14 is bent, and even when the X table 10 is located on the side edge portion of the Y table 14, the load of the X table 10 is applied to one Y axis main rail 15 Since the center rail 16 and the center rail 16 are dispersed and received, the air gap between the upper surface of the remaining Y-axis main rail 15 and the Y table 14 does not undesirably widen. It should be noted that the arrow in FIG. 1 indicates the compressed air blown out by the Y table 14, and as can be seen from this arrow, there is an air gap between the upper surface and both side surfaces of each Y-axis main rail 15 and the Y table 10. And an air gap is formed between the upper surface of the center rail 16 and the Y table 10.

Further, in the present embodiment, the detecting portion 18a of the Y-axis linear encoder 18 for detecting the position data of the Y table 14 is installed at a position where the Y table 14 and the center rail 16 are reciprocally linearly moved integrally with the Y table 14. Therefore, the position data of the Y table 14 detected by the detector 18a is obtained by averaging the relative positions of the pair of Y-axis main rails 15 supporting both side edges of the Y table 14. Therefore, it is possible to accurately grasp the actual position change of the mounted workpiece. And like this,
When the position control based on the detection result of one Y-axis linear encoder 18 is performed in synchronization with the two Y-axis linear motors 17, the Y table 14 position-controlled by one of the linear motors 17 is used. Since the phenomenon that the posture is changed by the position control of the other linear motor 17 does not occur, the positional deviation of the transferred workpiece can be avoided and the processing accuracy is improved.

Here, the X table 10 and the Y table 14
The shape of the air blowing surface that blows the compressed air toward the X-axis rail portion 11a group and the Y-axis rail group 15 and 16 will be described with reference to FIGS. Although these drawings show the air blowing surface (rail facing surface) 10b of the leg portion of the X table 10, the surface facing the upper surface of the X-axis rail portion 11a group of the X table 10 and the Y table 14 are shown. Among them, the surface facing the upper surface and both side surfaces of the Y-axis main rail group 15 or the surface facing the upper surface of the center rail 16 is also an air blowing surface having substantially the same shape. Now, the air blowing surface 10b of the illustrated X table 10
In addition to exposing a large number of air nozzles 10c, an exhaust groove 10d extending across adjacent air nozzles 10c is provided, so that the air is supplied to the air gap through the air nozzles 10c. The compressed air has a relatively wide gap, and these exhaust grooves 10
Attempts to flow through d, resulting in a stable compressed air discharge flow path. In particular, since a similar exhaust groove is provided on the air blowing surface of the Y table 14 to stabilize the discharge passage of the compressed air, by moving the X table 10 on the Y table 14, either one of the Y tables is moved. Even when the air gap on the upper surface side of the shaft main rail 15 becomes slightly wide, there is no possibility that a large amount of compressed air will flow into it from another place and an irregular air flow will be generated. It is possible to avoid the occurrence of vibration due to the irregular air flow in the.

In this embodiment, the air blowing surface is
An example is shown in which an exhaust groove extending across adjacent air nozzles is provided. However, the plane shape of the exhaust groove provided around each air nozzle is a square shape with the air nozzle as the center or a square shape. By setting it in a V shape, it is possible to further stabilize the discharge passage of the compressed air.

Next, the Y-axis rail group 1 in this embodiment
The mounting structure of 5, 16 will be described. Y table 1
The pair of Y-axis main rails 15 and the center rail 16 that slidably support 4 are mounted on the upper surface of the surface plate 3 by inserting the rail bottom into the mounting grooves 3a. Since it is designed to be positioned in the width direction on the inner wall surface, even if an external force is applied to the rails 15 and 16 in the width direction as the X table 10 supported on the Y table 14 moves. Since the position of the rails 15 and 16 is regulated by the surface plate 3, there is no fear that the rails 15 and 16 will be displaced.

Further, in this embodiment, as described above, XY
The suction table 9, the X table 10, the support table 11, the Y table 14, and the Y-axis rail group 1 which are the components of the table 2.
For materials such as 5,16, Indian Black (a type of granite), which is known as a stone material with a small thermal expansion coefficient and particularly high mechanical strength, is selected, so large tensile force, compression force, bending stress etc. The durability of each component of the XY table 2 to which is added is improved, and each table 10, 14 or the support 11 or each rail group 1 is used even if used for a long time
It is difficult for damage such as cracks to occur in the parts 5 and 16. Moreover, since Rustenburg (a type of granite) known as a stone material having a particularly small coefficient of thermal expansion is selected as the material of the surface plate 3 having a large area on the base of the apparatus, it is a large surface plate 3. However, the amount of expansion and contraction due to temperature change is extremely small.

[0028]

As described above, the XY according to the present invention
The table has a detection unit of a linear encoder that detects the position data of the lower table installed at a position where it linearly moves reciprocally in the approximate center of the lower rail group integrally with the lower table. The position data of the lower table can accurately grasp the actual position change of the mounted work piece, and the multiple driving means that drive the lower table do not adversely affect the position control of the other party. This has an excellent effect that the positional deviation of the workpiece transferred on the table can be avoided and the processing accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of an XY table according to this embodiment.

FIG. 2 is a side view of the XY table with a part thereof omitted.

FIG. 3 is an overall side view of a laser processing machine including the XY table.

FIG. 4 is a side view of a portion corresponding to FIG. 3 of a safety cover that covers the laser beam machine.

5 is a side view of a Y-axis linear motor incorporated in the XY table shown in FIGS.

FIG. 6 is a cross-sectional view showing a leg portion of an X table of the XY table.

FIG. 7 is a plan view showing an air blowing surface of a leg portion of the X table shown in FIG.

FIG. 8 is a plan view showing a suction table of the XY table.

9 is an explanatory view showing a support structure of the suction table shown in FIG.

[Explanation of symbols]

1 Processing Machine Main Body 2 XY Table 3 Surface Plate (Base Plate) 9 Adsorption Table 10 X Table (Upper Table) 11 Support Base 11a X Axis Rail Part 12 X Axis Linear Motor (First Driving Means) 13 X Axis Linear Encoder ( 1st linear encoder) 14 Y table (lower table) 15 Y-axis main rail 16 center rail (Y-axis auxiliary rail) 17 Y-axis linear motor (second drive means) 17a coil 17b magnet 18 Y-axis linear encoder (first) 2 linear encoder) 18a Detection part 18b Scale part (linear scale)

Claims (3)

[Claims] 1. An upper table on which a workpiece is mounted, an upper rail group that supports the upper table so as to be capable of reciprocating linear movement, a lower table on which the upper rail group is mounted, and an orthogonal to the upper rail group. An XY table provided with a lower rail group that extends in the direction of the lower table and supports the lower table so as to be linearly movable back and forth in a direction orthogonal to the moving direction of the upper table,
At least two linear motors for driving the lower table to be capable of reciprocating linear movement along the lower rail group are provided at intervals, and at least two linear encoders for detecting position data of the lower table are provided.
The linear motor group is arranged at a substantially intermediate position dividing the linear motor group in a direction along the lower rail, and the linear motor group is configured to control the position of the lower table based on the detection result of the linear encoder. A processing machine with an XY table. 2. The XY table according to claim 1, wherein the linear encoder includes a detection portion having a light emitting element and a light receiving element, and a scale portion extending in parallel with the lower rail group. With processing machine. 3. The processing machine with an XY table according to claim 1 or 2, wherein the linear encoder is provided in the vicinity of the lower rail in the approximate center of the lower rail group.