JP2001050271A - Static-pressure linear guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static-pressure linear guide device that is compact and light, experiences fewer shearing stresses, is free of adhesion of magnetic substance dust among others, and is almost insusceptible to external moment loads. SOLUTION: A pad 10 carries air bearing parts 15 for jetting out compressed air to a magnetic guide rail 13 to support the pad 10 in a noncontact way, and magnet parts 12 for pulling the pad 10 to the guide rail 13 with magnetic attraction. The magnet parts 12 are situated in the practical center in directions perpendicular to, or transversely of, the moving directions of the pad 10, and the air bearing parts 15 are on both sides of the magnet parts 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-precision machine tool, a processing device, a measuring device, an inspection device, a semiconductor manufacturing device, and the like, which are used for moving these samples, tools, detectors and the like. More specifically, the compact linear guide device can be reduced in size and weight, can suppress the occurrence of shear stress, can prevent the adhesion of dust and the like of the magnetic material, and can reduce the moment load from the outside. The present invention relates to a static pressure linear guide device which is hardly affected.

[0002]

2. Description of the Related Art In high-precision machine tools, processing apparatuses, measuring apparatuses, inspection apparatuses, semiconductor manufacturing apparatuses, and the like, it is necessary to position these samples, tools, detectors, and the like with high precision. For this reason, for example, a static pressure linear guide device having almost no friction is used as a positioning device for a mounting table for a sample or the like.

[0003] This static pressure linear guide device is provided with a static pressure gas bearing device (pad) that moves by moving a movable body in a non-contact manner with respect to a guide rail. This static pressure gas bearing device (pad) has an air bearing portion that blows compressed air between a movable body that is a mounting table for a sample or the like and the guide rail to support the movable body without contacting the guide rail. And a magnet unit that generates a magnetic attraction force by a permanent magnet or the like between the movable body of the mounting table and the guide rail to bring the movable body closer to the guide rail.

FIG. 4 shows an example of this static pressure linear guide device. A guide rail 2 extends perpendicularly to the plane of the drawing on the base 1, and a movable table 3 is slidably fitted on the upper surface of the guide rail 2. The movable table 3 is provided with table-side rails 4 and 4 so as to face both sides of the guide rail 2.

On the lower surfaces of the table side rails 4, 4,
Vertical air bearing portions 5 and 5 made of porous material are provided, and horizontal air bearing portions 6 and 6 made of porous material are provided on the side surfaces of the table side rails 4 and 4, respectively. These air bearings 5 and 6 blow out compressed air to the side surfaces of the base 1 and the guide rails 2 to move the movable table 3.
Are supported in a non-contact manner.

At both ends of the base 1, a pair of suction rails 7, 7 extend, respectively.
The movable table 3 is provided at both ends thereof with a pair of magnets 8 and 8 made of a permanent magnet or a yoke.
The magnet parts 8, 8 are attached to the attraction rail 7,
The magnetic table 7 generates a magnetic attraction force so that the movable table 3 approaches the base 1.

As a result, the floating force of the compressed air ejected from the air bearing portions 5, 5, 6, 6 and the magnetic attraction force of the magnet portions 8, 8 are balanced, and the movable table 3
Move in a non-contact manner with respect to the guide rail 1.

[0008]

However, in the static pressure linear guide device shown in FIG. 4, air bearings 5, 5, 6, and 6 for ejecting compressed air are arranged at substantially the center of the movable table 3. On the other hand, magnet portions 8 for generating magnetic attraction are arranged at both ends of the movable table 3,
Since they are relatively separated from each other, there is a problem that it is difficult to reduce the size and weight.

The levitation force mainly depends on the movable table 3.
The magnetic attraction force is generated downward at both ends of the movable tail table 3 while the magnetic attraction force is generated upward at the center of the movable table 3. 3 may be deformed.
As a result, there is a problem that a predetermined bearing gap between the guide rail 1 and the movable table 3 cannot be obtained, and bearing performance is reduced.

Further, since the magnet portions 8, 8 are provided at both ends of the movable table 3 and generate magnetic attraction to the attraction rails 7, 7 at both ends, the magnets 8, 8 are movable from the outside. When a moment load is applied to table 3,
When the movable table 3 swings, the gap between the magnet parts 8, 8 and the attraction rails 7, 7 fluctuates significantly. As a result, in the gap between the narrowed magnet portions 8, 8 and the attraction rails 7, 7, the magnetic attraction force sharply increases, and the load capability is reduced by the increased magnetic attraction force. is there.

Further, since the magnet portions 8 are provided at both ends of the movable table 3, there is a problem that dust or the like of a magnetic material adheres to the permanent magnets of the magnet portions 6 and 6 from the outside.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and can be reduced in size and weight, can suppress the generation of shear stress, and can reduce the generation of magnetic dust. An object of the present invention is to provide a static pressure linear guide device which can prevent adhesion and is hardly affected by an external moment load.

[0013]

In order to achieve the above object, a static pressure linear guide device according to the present invention blows out compressed air to a magnetic material base to support a movable body in a non-contact manner. An air bearing portion, and a magnet portion for bringing the movable body closer to the base made of a magnetic material by magnetic attraction force on the movable body side, and a floating force of the air bearing portion by compressed air, In a static pressure linear guide device for floating and moving the movable body in a non-contact manner with respect to the base while balancing the magnetic attraction force, the magnet unit is disposed substantially at the center of the movable body. The air bearing portion is disposed on both sides thereof.

As described above, according to the present invention, since the magnet portion is disposed substantially at the center of the movable body and the air bearing portions are disposed on both sides of the movable portion, the ejection of the compressed air and the generation of the magnetic attraction force are prevented. Can be configured on the same plane, and miniaturization and weight reduction can be achieved.

Further, by disposing the magnet portion substantially at the center of the movable body and disposing the air bearing portions on both sides thereof,
The magnet portion and the air bearing portion are arranged relatively close to each other so that the ejection of the compressed air and the generation of the magnetic attraction force can be performed at relatively close positions. Therefore, generation of moment due to shear stress in the movable body can be extremely reduced,
The possibility of deformation of the movable body can be almost eliminated.

Further, since the magnet portion is disposed substantially at the center of the movable body, and the air bearing portions are disposed on both sides thereof, and the two are disposed relatively close to each other, a moment load is externally applied to the movable body. In addition, even when the movable body swings, the gap between the magnet portion and the base hardly fluctuates. Therefore, in the gap between the magnet portion and the base, the magnetic attraction force does not suddenly increase, the load capacity does not decrease, and there is almost no influence from the external moment load.

Further, since the magnet portion is disposed substantially at the center of the movable body and the air bearing portions are disposed on both sides thereof,
It is possible to effectively prevent dust and the like of the magnetic material from adhering to the permanent magnet and the like of the magnet unit.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a static pressure linear guide device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a side view of a hydrostatic gas bearing device (pad) of a hydrostatic linear guide device according to a first embodiment of the present invention, and FIG. 1B is a side view of FIG. It is a top view of the static pressure gas bearing device (pad) shown to a). FIG. 2 (a)
FIG. 2 is a side view of the static pressure linear guide device according to the first embodiment of the present invention, and FIG. 2B is a front view of the static pressure linear guide device shown in FIG.

As shown in FIG. 1, a pair of bottomed holes 11, 11 are formed at substantially the center in the direction (width direction) perpendicular to the traveling direction of the hydrostatic gas bearing device (pad) 10. A pair of magnets 1 made of a permanent magnet or a yoke is provided in the bottomed hole 11.
2 and 12 are stored.

The magnet portion 12 generates a magnetic attraction force on the guide rail 13 by a permanent magnet or the like, and
0 is made to approach the guide rail 13.
Further, since the magnet portion 12 is housed in the bottomed hole 11 as described above, it is possible to prevent intrusion of magnetic powder and the like from the outside.

The bottom of the bottomed hole 11 has a spacer 1
4 is provided, whereby the gap between the magnet part 12 and the guide rail 13 is adjusted, so that the magnetic attraction force can be easily adjusted.

On both sides in a direction (width direction) perpendicular to the traveling direction of the pad 10, air bearing portions 15, 1 made of porous material are provided.
5 are provided. The air bearing 15 blows out compressed air to the guide rail 13 to support the pad 10 in a non-contact manner.

The guide rail 13 is made of a magnetic material to obtain a magnetic attraction. The base material is made of a non-magnetic material such as an aluminum alloy, ceramics, stone, or the like, while only a portion necessary for the magnetic attraction is made of a magnetic material. May be formed as a separate part by bolt fixing or adhesive fixing.

By combining the two hydrostatic gas bearing devices (pads) thus configured in an L-shape and disposing them on the upper surface and side surfaces of the guide rail 13 as shown in FIG. The device can be configured. Thus, L
The upper pad 10a and the horizontal pad 10b configured in a character shape can float and move on the upper surface and the side surface of the guide rail 13 without contact.

The guide rail 13 only needs to improve the machining accuracy of a total of three surfaces, the upper surface and the side surface serving as the bearing surface, and the bottom surface serving as the mounting surface, and it is necessary to consider the parallelism of the opposing surfaces. Therefore, the number of parts can be reduced, and the cost can be reduced.

As described above, in the present embodiment, the magnet portion 12 is disposed substantially at the center of the pad 10 in the width direction and the air bearing portions 15 are disposed on both sides thereof. The generation of the suction force can be configured on the same plane, and the size and weight can be reduced.

Further, by arranging the magnet portion 12 substantially at the center in the width direction of the pad 10 and arranging the air bearing portions 15 on both sides thereof, the magnet portion 12 and the air bearing portion 15 are arranged relatively close to each other. Thus, the ejection of the compressed air and the generation of the magnetic attraction force can be performed at relatively close positions. Therefore, generation of a moment due to shear stress in the pad 10 can be extremely reduced, and the risk of deformation of the pad 10 can be almost eliminated.

Further, since the magnet portion 12 is disposed substantially at the center of the pad 10 in the width direction and the air bearing portions 15 are disposed on both sides thereof, and both are disposed relatively close to each other, the pad 10 is externally provided. , The gap between the magnet portion 12 and the guide rail 13 hardly changes. Therefore, in the gap between the magnet part 12 and the guide rail 13, the magnetic attraction force does not increase rapidly, the load capacity does not decrease, and the influence of the moment load from the outside is hardly affected. Absent.

Further, since the magnet portion 12 is disposed substantially at the center of the pad 10 in the width direction and the air bearing portions 15 are disposed on both sides thereof, dust and the like of the magnetic substance adhere to the permanent magnets and the like of the magnet portion 12. Can be effectively prevented.

FIG. 3A is a side view of a static pressure linear guide device according to a second embodiment of the present invention.
FIG. 3B is a front view of the static pressure linear guide device shown in FIG.

In the second embodiment, a triangular table 17 is slidably provided above a V-shaped guide rail 16.
7, two hydrostatic gas bearing devices (pads) 10,
10 is interposed. The table may be formed in a V-shape, and the guide rail may be formed in a triangular shape.

As described above, also in the present embodiment, the ejection of the compressed air and the generation of the magnetic attraction force can be formed on the same plane, and the size and weight can be reduced. Further, generation of a moment due to shear stress in the pad 10 can be extremely reduced.
The possibility of zero deformation can be almost eliminated. Furthermore, there is almost no influence of the moment load from the outside. Further, it is possible to effectively prevent the dust and the like of the magnetic material from adhering to the permanent magnet and the like of the magnet unit 12.

The present invention is not limited to the above-described embodiment, but can be variously modified.

[0035]

As described above, according to the present invention,
Since the magnet portion is arranged substantially at the center of the movable body and the air bearing portions are arranged on both sides thereof, the ejection of the compressed air and the generation of the magnetic attraction force can be configured on the same plane. The weight can be reduced.

Further, by arranging the magnet portion substantially at the center of the movable body and arranging the air bearing portions on both sides thereof,
The magnet portion and the air bearing portion are arranged relatively close to each other so that the ejection of the compressed air and the generation of the magnetic attraction force can be performed at relatively close positions. Therefore, generation of moment due to shear stress in the movable body can be extremely reduced,
The possibility of deformation of the movable body can be almost eliminated.

Further, since the magnet portion is disposed substantially at the center of the movable member, and the air bearing portions are disposed on both sides thereof, and the two members are disposed relatively close to each other, a moment load is externally applied to the movable member. In addition, even when the movable body swings, the gap between the magnet portion and the base hardly fluctuates. Therefore, in the gap between the magnet portion and the base, the magnetic attraction force does not suddenly increase, the load capacity does not decrease, and there is almost no influence from the external moment load.

Further, since the magnet portion is disposed substantially at the center of the movable body and the air bearing portions are disposed on both sides thereof,
It is possible to effectively prevent dust and the like of the magnetic material from adhering to the permanent magnet and the like of the magnet unit.

[Brief description of the drawings]

1A is a side view of a hydrostatic gas bearing device (pad) of a hydrostatic linear guide device according to a first embodiment of the present invention, and FIG. 1B is a side view of FIG. The top view of a static pressure gas bearing device (pad).

FIG. 2A is a side view of the static pressure linear guide device according to the first embodiment of the present invention, and FIG. 2B is a front view of the static pressure linear guide device shown in FIG.

FIG. 3A is a side view of a static pressure linear guide device according to a second embodiment of the present invention, and FIG. 3B is a front view of the static pressure linear guide device shown in FIG.

FIG. 4 is a front view of a conventional static pressure linear guide device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hydrostatic gas bearing device (pad, movable body) 11 Bottomed hole 12 Magnet part 13 Guide rail (base) 14 Spacer 15 Air bearing part 16 V-shaped guide rail 17 Triangular table

Claims (1)

[Claims] 1. An air bearing for blowing a compressed air to a base made of a magnetic material to support the movable body in a non-contact manner, and bringing the movable body closer to the base made of a magnetic material by magnetic attraction. The movable body is provided on the side of the movable body, and a floating force of the air bearing unit by the compressed air and a magnetic attraction force of the magnet unit are balanced to float the movable body to the base in a non-contact manner. A static pressure linear guide device for moving by moving, wherein the magnet portion is disposed substantially at the center of the movable body, and the air bearing portions are disposed on both sides thereof.