JPH06330944A - Static pressure moving guide device - Google Patents

Abstract

PURPOSE:To provide a static pressure moving guide device which is constituted to exert pressurization instead of a magnetic force even in environment being apt to be damaged by magnetism and eliminated a need to form a mechanism part used as a balance between a static pressure floating force and pressurization, and eliminate a fear of environment pollution, in a static moving guide device suitable for precise measurement and precise positioning, especially a static pressure moving guide device using a porous block for a fluid blow-off part. CONSTITUTION:In a static pressure moving guide device wherein a slider S the floating part of which is formed of a porous block 5 is positioned facing a base 3 having high flatness and effects relative movement in a levitation state, the device is formed such that no air leaks through other part than the blow-off part 5a of the porous block 5. An annular recessed groove 6 formed in a manner to surround the blow-off part is formed, and the annular recessed groove 6 is connected to an exhaust device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static pressure movement guide device suitable for precision measurement, precision positioning, etc., and more particularly to a static pressure movement guide device using a porous block for a fluid blowing portion.

[0002]

2. Description of the Related Art FIG. 11 shows a known static pressure movement guide device described in Japanese Patent Application Laid-Open No. 64-6515, in which a slider S having at least a floating portion made of a porous block 1 is used.
However, they face the base 3 having high flatness and relatively move in a floating state. For the porous block 1, a known material used as a filter, an oil-impregnated bearing or the like by sintering metal powder can be used. Alternatively, a ceramic material, alumina, silicon nitride, isotropic graphite, or the like can be used.

Since the porous block 1 has a large number of continuous holes, the outer periphery 1a is sealed with an adhesive or the like, and at the same time, an air supply hole 4 facing the back surface of the porous block 1 is formed in the holder 2. Then, when it is connected to a compressed air source, compressed air blows out from the entire surface 1b of the porous block 1 facing the base 3 and the slider S floats.

In this case, when the load acting on the slider S is small, the flying gap G becomes large and the flow resistance also decreases, so that the rigidity is lowered. Conversely, when the load acting on the slider S is large, the flying gap G becomes large. It becomes smaller and the flow resistance increases,
The rigidity is also strong and stable operation can be obtained. In order to increase the rigidity, there are many methods of attracting between the base 3 and the slider S by magnetic force, as proposed in, for example, Japanese Patent Laid-Open No. 61-290231.

[0005]

By the way, in the conventional method of attracting with a magnet, it is necessary to form the other side with a magnetic material, which is not suitable for an environment where magnetism is disliked. In particular, since the dust of the magnetic substance is adsorbed on the magnet or the magnetic substance on the other side, there are problems that the characteristics become unstable and scratches occur, and it is difficult to clean the dust that has once adhered.

Further, in order to balance the levitation force by the static pressure and the attraction force by the magnet, a mechanism such as a screw or a piezoelectric element for adjusting the gap between the magnet and the magnetic material surface plate is required, and the adjustment work is troublesome. is there.

Still another problem is that the supply fluid for obtaining the static pressure levitation force flows out into the surrounding space, so that it is not suitable for an atmosphere such as a clean room where environmental pollution is disliked.

The technical problem of the present invention is to pay attention to such a problem and to apply a pressure in place of the magnetic force even in an environment where magnetism is disliked, and to balance the static pressure levitation force and the pressure. It is to realize a static pressure movement guide device that does not require the above mechanical parts. In addition, the fluid that generates the static pressure levitation force is
Since it is possible to collect all of them in an exhaust device that generates a pressurizing force that balances the levitation force, the object is to realize a static pressure moving guide device that does not cause environmental pollution by the fluid.

[0009]

FIG. 1 is a sectional view for explaining the basic structure of a static pressure movement guide device according to the present invention. The present invention is directed to a static pressure movement guide device in which a slider S having at least a floating portion made of a porous block 5 faces a base 3 having high flatness and relatively moves in a floating state. According to a first aspect of the present invention, in such a static pressure movement guide device, air is prevented from leaking from a portion other than the blowing portion 5a of the porous block 5, and an area other than the blowing portion 5a is provided.
A recessed region 6 connected to the exhaust device P is provided.

According to a second aspect of the present invention, in the static pressure movement guide device that relatively moves in the floating state as described above, air is not leaked from other than the blowing portion 5a of the porous block 5, and the blowing portion 5a is provided. An annular groove 6 is formed so as to surround the annular groove 6, and the annular groove 6 is connected to the exhaust device P.

According to a third aspect of the present invention, a plurality of static pressure movement guide devices according to the first or second aspect are used and arranged at an angle to each other.

The term "gas" in the present invention includes all fluids. In addition, the porous block 5 is
It may be provided on either the slider side or the base side.

[0013]

According to the present invention, the porous block 5 is provided on the air bearing surface side of the slider S, and the air is not leaked from other than the blowout portion 5a, and the exhaust device is provided in the area other than the blowout portion 5a. With the configuration in which the concave region 6 connected to P is provided, the space between the base 3 and the slider S is sucked with a negative pressure, and the base 3 and the blowing portion 5 are provided.
It acts so that the gap G between it and a becomes narrower. As a result, the flow resistance of the pressurized fluid in the gap G increases, a great rigidity is generated, and the flying height becomes constant.

As described in claim 2, the blowout portion 5a is formed by forming the annular groove 6 so as to surround the blowout portion 5a of the porous block 5 and connecting it to the exhaust device P.
Since all of the fluid blown out from the device is exhausted by the exhaust device P, it does not pollute the surrounding environment and is particularly effective in a clean room or the like.

When the air pressure around the blowing portion 5a is atmospheric pressure as in claim 1, only 5 kg of levitation force can be obtained if the supply pressure is 5 kg. However, as in claim 2, the blowing portion is as follows. When the pressure around 5a is negative, if the supply pressure is 5 kg, a levitation force equivalent to 5 kg + negative pressure can be obtained. As a result, the rigidity is further increased or the supply pressure can be made smaller than 5 kg.

According to a third aspect of the present invention, a plurality of sets of static pressure movement guide devices according to the first or second aspect are used and arranged not at the same plane but at an angle to each other. Since the moving direction of the slider S is restricted to one direction, highly accurate static pressure moving guide is realized.

[0017]

EXAMPLES Next, examples of practical application of the static pressure movement guide device according to the present invention will be described. 2A and 2B are views showing an embodiment of the static pressure movement guide device according to the present invention. FIG. 2A is a vertical sectional view and FIG. 2B is a bottom view of the slider. The slider S may be composed of only the porous block 5 as a whole, but a structure in which the porous block 5 is attached and fixed to the surface of the holder 7 which is usually made of metal or the like facing the base 3 is preferable.

The levitation gap G can be easily controlled by controlling the pressure of the levitation fluid supplied to the porous block 5 or by controlling the exhaust pressure. Therefore, an adjusting mechanism having a complicated structure as in the prior art is not necessary, and the adjusting operation is simple. Also,
As the area of the annular groove 6 increases, the suction force between the air bearing surface and the base 3 increases, and the gap G can be reduced.

However, the flow resistance when the fluid passes through the porous block 5 changes depending on the roughness of the porous block 5 or the size of the porous block 5 in the thickness direction. As a result, the blowing pressure from the porous block 5 changes, so that the gap adjustment can be performed stably and reliably. The roughness of the porous block 5 can be selected depending on the material of the porous block, or the manufacturing method and manufacturing conditions.

FIG. 3 is a sectional view showing another embodiment. In this embodiment, a circular suction region 12 is provided in the center of a disc-shaped holder 71, and a ring-shaped porous block 51 is fitted in a step-shaped recess provided on the outer periphery. In this ring-shaped porous block 51, the inner peripheral side surface and the outer peripheral side surface are sealed with an adhesive or the like. A ring-shaped recess 8 is provided between the suction region 12 and the ring-shaped porous block 51, and the ring-shaped recess 8 is opened to the atmosphere by a through hole 9.

Now, when the compressed air is supplied in order of the air supply port 10 and the annular groove 11 and the compressed air blows out from the lower surface of the ring-shaped porous block 51, it passes through the gap G between the base 3 and the outer peripheral side. While escaping into the atmosphere, the ring-shaped recess 8 and the through hole 9 flow out into the atmosphere in this order. At the same time, since the suction region 12 is exhausted by the exhaust pump P, the suction surface 71
A suction force acts between a and the base 3 to narrow the levitation gap G, increase the rigidity, and keep the levitation gap G constant.

In the embodiment of FIG. 2 corresponding to claim 2, since the fluid blown out from the porous block 5 is collected by the exhaust device P, there is no fear of environmental pollution of the surroundings. In the corresponding embodiment of FIG. 3, since the fluid blown out from the ring-shaped porous block 51 flows out to the surroundings,
A fluid that does not cause environmental pollution should be selected and used.

FIG. 4 is a plan view and a front view illustrating an application of the static pressure movement guide device according to the present invention. For example, this is an example suitable for flatness measurement, and has a high flatness.
An XY table 13 is placed on 31. XY
The static pressure movement guide device 14 illustrated in FIG. 2 is attached to the lower surface of the table 13 at four places, and the X-direction drive motor Mx is connected via the X-direction drive shaft 15, and Y
The Y-direction drive motor My is connected via the direction drive shaft 16.

The slider 17 is slidable in the Y direction with respect to the XY table 13, and the slider 18 is
It is slidable in the X direction with respect to the XY table 13. It should be noted that pipes for air supply and exhaust of each static pressure movement guide device 14 are omitted.

A probe such as a dial gauge is installed on the surface plate 31, an object to be measured is mounted on the XY table 13, and the object is moved in the XY directions. You can measure the degree. As in this embodiment, the XY table 13 is provided on the plane via a plurality of static pressure movement guide devices.
By moving in any direction, the state in the plane direction can be accurately measured.

FIG. 5 is an example in which the present invention is applied to support in the rotational direction, and is a plan view and a front view of a lapping machine. Both upper and lower surfaces of the lap surface plate 32 are highly accurately flat-finished, and on the base 20 supporting the rotary shaft 19 of the lap surface plate,
Porous blocks 14 according to the present invention are arranged upward at an equidistant position from the rotary shaft 19 with an interval of 120 degrees. The porous block in this embodiment is also shown in FIGS.
The circular shape is applied.

In this apparatus, the work holding jig 21 to which the work W is attached is placed on the lapping plate 32 and is rotatably supported as in the known lapping machine. When the lap surface plate 32 rotates in this state, the lap surface plate 32 is rotated.
However, since the static pressure movement guide device 14 of the present invention levitates only a minute gap and rotates stably, the work W can be planarized with high precision in the μm range.

When the flatness of the machined surface of the lap surface plate 32 decreases after a long period of use, the correction by the correction device corrects the support by the porous block of the present invention with high accuracy and stability. Therefore, it is possible to finish the machined surface of the lapping plate with high precision in the sub μm range.

As is apparent from the above embodiments, the static pressure movement guide device according to the present invention may be mounted upward or downward with respect to the base having high flatness. Further, the static pressure movement guide device may be attached to the fixed side or the movable side.

FIG. 6 shows another embodiment of the porous block according to the present invention, where (a) is a plan view and (b) is a front view.
(C) is a bottom view and (d) is a dd sectional view in (a). In this embodiment, an escape groove 22 is provided at the center of the rectangular porous block 52 on the air bearing surface side, and elongated blow-out portions 5a, 5a are formed on both sides thereof. And
Rectangular annular recessed grooves 6, 6 are formed so as to surround the blowout portions 5a, 5a and are connected to the exhaust holes 23, 23.

Further, elongated air supply grooves 24, 24 are formed at positions directly behind the air supply parts 5a, 5a, and all surfaces other than the air supply grooves 24, 24 and the air supply parts 5a, 5a are all formed. It is sealed with resin or adhesive. Therefore, when the back surface of this porous block is attached to a holder, the air supply grooves 24, 24 are connected to a pressure air source, the exhaust holes 23, 23 are connected to an exhaust device, and the base is placed on a flat base, the blowout part Compressed air is blown out from 5a and 5a and floats up, and the annular concave grooves 6 and 6 around it are exhausted, so that suction force is generated between the porous block and the base.

FIG. 7 shows a holder 72 for holding this porous block 52.
Mounted on the holder, as shown in (a).
In the 72, an air supply passage 25 that connects between the air supply grooves 24, 24 on the back surface of the porous block and the pressurized air source is formed. Further, as shown in (b), an exhaust passage 26 connecting the exhaust holes 23 of the porous block and the exhaust device P.
Are formed. In addition, the base 3 with high flatness,
A mounting hole 27 for mounting to another base with bolts is formed.

FIG. 8 shows another embodiment of the porous block. (A) is a plan view, (b) is a front view, (c) is a bottom view, and (d) is d-d in (c). FIG. In this embodiment, 2 is provided on the air bearing surface side of the rectangular porous block 53.
Book-shaped elongated blowing portions 5a, 5a are formed, and a common annular groove 6 is formed so as to surround both blowing portions 5a, 5a. That is, the two sets of annular recessed grooves 6, 6 shown in FIG. 6 are close to each other and integrally communicate with each other to form a letter V shape, and an exhaust hole 28 is formed in the center recessed groove 6a.

On the back surface of the porous block, air supply grooves 29, 29 are formed directly behind the two blow-out portions 5a, 5a, and communicate with each other in an H-shape by the communication groove 29a.
Then, the blowing portions 5a, 5a and the H-shaped groove 29,
Portions other than 29a are sealed with an adhesive or the like.

Therefore, when the back surface of the porous block is attached to the holder, the H-shaped air supply grooves 29 and 29a are connected to the pressure air source, and the exhaust hole 28 is connected to the exhaust device, the blowout portions 5a and 5a are ejected. The compressed air is blown out to generate a levitation force, and the common groove 6 around it is exhausted, so that a suction force is generated between the porous block and the base. The dimensions of each part in this embodiment are as illustrated.

FIG. 9 shows an example in which the static pressure movement guide device of FIGS. 6 to 8 is applied to a one-way guide device, (a) is a plan view,
(B) is a front view. The base in this example is
A left-right symmetrical mountain-shaped rail 33 is formed on one side, and a flat rail 34 is formed in parallel therewith.

On the lower surface of the table 313, two front and rear porous blocks 54, 54 are attached at positions parallel to the left slope of the mountain-shaped rail 33, and two front and rear porous blocks at positions parallel to the right slope. Blocks 5s and 5s are attached. Further, front and rear porous blocks 56, 56 are attached at positions corresponding to the flat rails 34. Each of the porous blocks 54 to 56 is shown in FIG.
Although the porous block as shown in FIG. 8 is sufficient, it may be attached to the holder as shown in FIG.

As described above, when the rail is provided on one side and the static pressure movement guide device is opposed to both slopes of the rail, the table 313 is floated by the left and right porous blocks 54 and 55. At the same time, the lateral movement is restricted. In addition, the flat porous block 56 on the right side is
Although the regulation force in the in-plane direction does not occur, the force for floating the table 313 occurs. Therefore, according to this embodiment, the table 313 is guided by the mountain-shaped rails 33 and can float and move only in the direction of the mountain-shaped rails 33.

In order to make the rigidity of the table 313 uniform and to stabilize the levitation, the area of the two sets of the mountain-shaped rail porous blocks 54 and 55 in the plane direction and the flat porous block on the right side are set. The area of 56 is preferably designed to be the same.

In this embodiment, instead of the flat porous block 56, it is possible to use a mountain-shaped rail as in the left side and guide with two mountain-shaped rails, but the dimensional change in the rail interval direction. And dimensional error,
The stable movement of the table 313 may be hindered.

When two sets of tables in which the mountain rails and the flat rails are combined in parallel as described above are orthogonally overlapped, they function as an XY table.

The static pressure movement guide device using the mountain rail and the static pressure movement guide device using the flat rail in FIG. 9 can be separately used independently. Further, in place of the mountain-shaped rail of FIG. 9, a V groove may be provided on the base 35 side as shown in FIG. 10, and two left and right porous blocks 54, 55 may be arranged in a V shape on the table 313 side. it can.

In each of the above embodiments, compressed air is used as an example of the supply fluid, but the fluid is not limited to air as long as it has a pressure.

[0044]

As described in claim 1, the air is not leaked from portions other than the blow-out portion 5a of the porous block 5 and the recessed area 6 connected to the exhaust device P is provided. 3 and the recessed region 6 are sucked by a negative pressure to act so as to narrow the gap G between the base 3 and the blowing portion 5a, resulting in a strong rigidity and a constant flying height. To do.

Further, since the magnet is not required, the static pressure movement guide device can be realized even in an environment where magnetism is disliked, and the trouble due to magnetic dust and the troublesome cleaning can be eliminated. Unlike a device that uses a magnet, it is not necessary to provide a complicated adjusting mechanism, and balance adjustment is easy.

As described in claim 2, the blow-out portion 5a is formed by forming the annular groove 6 so as to surround the blow-out portion 5a of the porous block 5 and connecting it to the exhaust device P.
All of the fluid blown from the exhaust device P is reliably exhausted by the exhaust device P, so that it does not pollute the surrounding environment. Further, since the outside of the blowing portion 5a has a negative pressure, the rigidity is further increased or the supply pressure can be reduced.

According to a third aspect of the present invention, a plurality of sets of static pressure movement guide devices according to the first or second aspect are used, and the static pressure movement guide devices are arranged not at the same plane but at an angle to each other. Since the movement direction of is regulated in one direction, highly accurate static pressure movement guide is possible.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a basic configuration of a static pressure movement guide device according to the present invention.

FIG. 2 is a vertical cross-sectional view showing an embodiment of the static pressure movement guide device according to the present invention and a bottom view on the slider side.

FIG. 3 is a sectional view showing an embodiment of a static pressure movement guide device according to the present invention.

FIG. 4 is a plan view and a front view illustrating an application of the static pressure movement guide device according to the present invention.

5A and 5B are a plan view and a front view showing an example in which the static pressure movement guide device according to the present invention is applied to a lapping device.

FIG. 6 is a view showing another embodiment of the porous block according to the present invention.

FIG. 7 is a vertical cross-sectional view showing a state in which a porous block is attached to a holder.

FIG. 8 is a view showing another embodiment of the porous block.

9 is a plan view and a front view showing an example in which the porous block of FIGS. 6 to 8 is applied to a one-way guide device.

FIG. 10 is a cross-sectional view showing an example in which the present invention is applied to a static pressure movement guide device with a guide groove.

FIG. 11 is a cross-sectional view of a conventional static pressure movement guide device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Porous block 3 Base with high flatness 5 Porous block 5a Blowing part S Slider P Exhaust device 6 Recessed area (annular groove)

Claims (3)

[Claims] 1. A porous block (5) having at least a floating portion.
In the static pressure movement guide device in which the slider (S) consisting of the flat block (3) faces the base (3) having high flatness and moves relatively in the floating state, air is blown from other than the blowout part (5a) of the porous block (5). A static pressure movement guide device, characterized in that it does not leak, and that a recessed region (6) connected to the exhaust device (P) is provided in a region other than the blowout part (5a). 2. A porous block (5) having at least a floating portion.
In the static pressure movement guide device in which the slider (S) consisting of the flat block (3) faces the base (3) having high flatness and moves relatively in the floating state, air is blown from other than the blowout part (5a) of the porous block (5). In addition to providing a leakproof structure, an annular groove (6) is formed so as to surround the blowout portion, and the annular groove (6) is provided.
A static pressure movement guide device characterized by being connected to an exhaust device. 3. A static pressure movement guide device comprising a plurality of static pressure movement guide devices according to claim 1 or 2, which are arranged at an angle to each other.