JP2007078065A - Hydrostatic bearing linear motion slide system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slide-way which can be easily detached, attached and cleaned. <P>SOLUTION: In a hydrostatic linear motion slide-way system 1, a ceramic lever-like guide-way 2 having a square or rectangular cross-section is mounted on a support 4 having a V-shaped cross-section with a damping pad 5 interposed between a lower surface of the guide-way 2 and the support 4, and the slide-way 3 is slidably mounted on an upper inverted V-shaped surface of the lever-like guide-way. The slide-way 3 having a bottom surface with a substantially V-shaped cross-section includes a pair of ceramic static pads 7a, 7b arranged on one side of the substantially V-shaped bottom surface and a ceramic static pad 7c arranged on the other side of the substantially V-shaped bottom surface. The ceramic static pads are provided with water supply pots 81. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrostatic bearing linear motion slide system in which a ceramic slideway (also called a carriage) can be moved linearly on a granite guideway using a hydrostatic water bearing. The hydrostatic bearing linear motion slide system is easy on the environment and can be used for worktables and tool tables of machine tools.

  As hydrostatic fluid bearings for hydrodynamic bearing linear motion slide systems, hydrostatic gas bearings that use air, hydrostatic oil bearings that use lubricating oil, and hydrostatic water bearings that use water have been proposed. In the field, hydrostatic oil bearings are mainly used, and hydrostatic gas bearings are mainly used for hydrostatic air bearing rotary systems for rotating bodies such as spindles and rotary tables (for example, Patent Document 1). And Patent Document 2).

  On the other hand, since inspection equipment and measuring equipment for semiconductor manufacturing equipment are required to be small and accurate, a ceramic slide-way is used on a ceramic or granite guideway using a static pressure air bearing. The mainstream is a hydrodynamic gas bearing linear motion slide system that can move linearly. For example, an alumina ceramic movable table (slide-way) that can move on a ceramic or granite base in the guide direction of an alumina ceramic guide member (guide-way), and the movable table A static pressure gas bearing linear guide device comprising: an air bearing portion supported and guided by gas; and a suction force applying portion that sucks the movable body against the base, wherein the suction force applying portion is the base There has been proposed a static pressure gas bearing linear guide device that includes a suction rail portion fixed to a table, and whose thermal expansion coefficient is substantially the same as the thermal expansion coefficient of the base material ceramic or granite. (For example, refer to Patent Document 3 and Patent Document 4.)

  The hydrostatic bearing direct acting slide system is easier to the environment than the hydrostatic oil bearing direct acting slide system, and the water is sent because the gap between the slideway and the guideway is about half (7 to 10 μm). There is an advantage that the horsepower of the pump can be smaller than the horsepower of the pump used in the hydrostatic oil bearing (for example, see Non-Patent Document 1).

  Such a hydrostatic bearing linear motion slide system has opposing slide-way bearing surfaces, receives bearing rails along and between them, and each bearing surface is in contact with that surface. In a linear motion hydrostatic bearing with a similar symmetrical pocket inside, where pressurized water diverges to create a thin film of water in the gap between the rail and the carriage surface, self-change of load on both sides of the bearing Compensating method, wherein each bearing surface is provided with a pressurized fluid receiving groove having a geometrical shape that can be expressed analytically at a distance from the corresponding pocket in the longitudinal direction, and arranged on the opposite side from each groove. Pockets on the opposite surface when fluid is supplied to the exterior of the surface and the resistance to fluid flow from the groove is such that the bearing is in a normal equilibrium position and the gap is not loaded by an external force. To the ratio of the resistance to the fluid flow, so that when an external force is applied, a differential pressure is established in the opposing pockets to compensate for the applied load and the fluid flow is regulated. There has been proposed a self-compensating hydrostatic bearing linear motion slide system that self-compensates the load in proportion to the change in the bearing gap caused by the applied load (see, for example, Patent Document 5).

Further, in a hydrostatic bearing device that uses water as a working fluid, a method for preventing sticking between the slide way and the guideway sliding surface, the operation of the apparatus main body incorporating the hydrostatic bearing device being suspended. A method for preventing sticking of a hydrostatic bearing device is also proposed in which a working fluid is supplied to the sliding surface at a predetermined pressure (see, for example, Patent Document 6).
JP-A-5-243355 JP 2000-6018 A JP 2000-136824 A JP 2004-60748 A JP-A-6-213235 JP 2000-27864 A By Alexander H. Slocum et al, Pregnancy esign of self-compensated, water-hydrostatic bearings magazine "Precision Engineering 17", pp. 173-185, 1995

  The hydrostatic bearing linear motion slide system is environmentally friendly, and it is expected to be widely used in the market for more than 10 years as a next generation linear motion slide system that requires no oil. As can be understood from the fact that it is as old as 1995, in the field of machine tools, there is only one example (see Non-Patent Document 1) used for a ceramic grinding apparatus. In addition, the static pressure water bearing rotary table system is adopted, and the semiconductor manufacturing polishing equipment that has been tried to be marketed is due to the fact that the precision of the processing work is not high and the hydrostatic water bearing is clogged. It has failed in practical use. The reason why the ceramic grinding device has been put to practical use is that the processing dimensional accuracy required by the market is rough, plus or minus 100 to 1000 μm, and strict processing dimensional accuracy (plus or minus 1 to 2 μm) as in a semiconductor manufacturing polishing apparatus is required. It is presumed that there was not.

This hydrostatic bearing direct acting slide system requires a lot of cleaning effort to prevent clogging of the ceramic slideway pad part, and once every three weeks, the grinding machine is stopped to clean the slideway. When it is necessary to prepare for the next work piece when it is not in operation, it is washed with water so that the surface of the guideway is prevented from drying and grinding dust and ceramic powder spilled by grinding are not fixed to the guideway. At the same time, it is necessary to remove the slide way and wash it with water. In this water cleaning, since the hydrostatic bearing structure has a shape in which a rod-shaped guide rail is held by a slide way having a U-shaped cross section, it takes much time to remove, attach and clean the slide way.

The present invention is a hydrostatic bearing direct acting slide system capable of providing a machining work with machining dimensional accuracy within plus or minus 50 μm, and is easy to remove, attach and clean ceramic slideways. It is an object of the present invention to provide a hydrostatic bearing direct acting slide system having a structure.

  In the first aspect of the present invention, a lower surface of a granite or ceramic bowl-shaped guideway having a square or rectangular cross section is placed on a V-shaped cross section of a support base via a rubber damping pad. The lower cross-section is substantially V-shaped on the reverse V-shaped plane of the upper surface of the ceramic, and a recess for attaching the slide way driving means is provided on one side of the substantially V-shaped bottom surface, and the ceramic is sandwiched between the recesses. At least a pair of static pressure pads are provided in the direction of movement of the slide way, and a ceramic static pressure pad is provided in the direction of movement of the ceramic slide way on the other side of the substantially V-shaped bottom surface. The pressure pad is provided with a water supply pipe capable of adjusting the pressure. When the substantially V-shaped bottom surface of the slideway slides on the right-side hills of the guideway, the water supply pump Water supplied to the water supply pipe is supplied from the ceramic pad to the right angle hill surface of the guide way, and the ceramic slide way can float from the right angle hill surface of the guide way. A bearing direct acting slide system is provided.

  The invention according to claim 2 is characterized in that the hydrostatic bearing direct acting slide system has a V-shaped support base made of granite, ceramic, or cast iron. A hydrostatic bearing direct acting slide system is provided.

  According to a third aspect of the present invention, the slope angle formed by the horizontal line and the upper side of the V-shaped support base that supports the saddle-shaped guideway is such that the side of the slideway on which the concave portion for mounting the slideway driving means is provided rises. The hydrostatic bearing linear motion slide system according to claim 1 or 2, characterized in that the side is 55 to 65 degrees and the gradient angle on the other side is 35 to 25 degrees. is there.

  The gap between the saddle-shaped guideway and the slideway is maintained at 7 to 10 μm by the tensile strength of the damping pad and the pressure balance of the water supplied to the ceramic hydrostatic pad surface. The bottom surface of the ceramic slide way has an inverted V shape, and the ceramic static pressure pad is provided only on the bottom surface. Therefore, the ceramic slide way can be removed from the saddle-shaped guideway or attached to the saddle-shaped guideway. Installation is easy and cleaning is also easy.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a sectional view of a hydrostatic bearing direct acting slide system according to the present invention, FIG. 2 is a perspective view of the slide way seen from the bottom side, and FIG. 3 is a ceramic using the hydrostatic bearing direct acting slide system. It is a front view of a manufactured work piece end face grinding apparatus.

  The hydrostatic bearing linear motion slide system 1 shown in FIG. 1 has a rubber damping pad on a support base 4 having a V-shaped cross section on the lower surface of a granite or ceramic bowl-shaped guideway 2 having a square or rectangular cross section. 5 through. The support 4 is housed in a cast iron frame 9. A ceramic slide way 3 is slidably mounted on an inverted V-shaped plane on the upper surface of the bowl-shaped guide way 2. The bottom surface (bottom surface) of the slide way 3 has a substantially V-shaped cross section, and a recess 6 for attaching a slide way driving means is provided on one side of the substantially V-shaped bottom surface. At least a pair of the static pressure pads 7a and 7b are provided in the moving direction of the slide way, and the ceramic static pressure pads 7c are provided in the moving direction of the ceramic slide way on the other side constituting the substantially V-shaped bottom surface. . These ceramic hydrostatic pads are provided with a water supply pipe 8 capable of adjusting the pressure, and when the substantially V-shaped bottom surface of the slideway slides on the right-side hills of the guideway, water is supplied by a water supply pump (see FIG. 2). Water supplied to the supply pipe 8 is supplied from the ceramic pads 7a, 7b, 7c to the right-angled mountain surface of the guideway 2, and the ceramic slideway 3 rises from the right-angled mountain surface of the bowl-shaped guideway.

  As shown in FIG. 2, the ceramic hydrostatic pad 7 has a narrow concave outer frame 70a, which is a ceramic hydrostatic pad 7a, 7b, 7c in the central recess 70b, and includes the concave outer frame 70a and the central recess 70b. The water supply pot 81 is provided at the center or 1/3 position. A U-shaped static pressure pad 7e is provided at the tip of the collector 7d having a water collecting hole 7f and surrounding the collector at the center. A water supply pot 81 is also provided in the concave portion of the U-shaped static pressure pad 7e. In addition to the illustrated shape of the ceramic hydrostatic pad 7, ceramic hydrostatic pads disclosed in Patent Document 5, Patent Document 6, Non-Patent Document 1, and the like can also be used. The number of ceramic hydrostatic pads 7 depends on the dimensions of the slide way.

  The water supply pot 81 is connected to the water supply pipe 8, and the tip of the water supply pipe 8 is connected to the pump 83. In FIG. 2, 82 is a drain pipe, 84 is a pressure gauge, 85 is a relief valve, 86 is a anti-pressure valve, and M is a motor. The outer diameter of the water supply pipe 8 connected to the static pressure pad is about 5 to 8 mm.

3. A saddle-shaped guideway 2, a slideway 3, and a V-shaped support base. Examples of ceramic materials for the hydrostatic pad 7 include alumina (Al ₂ O ₃ ) ceramics (thermal expansion coefficient: 4 to 8 × 10 ⁻⁶ / ° C.), mullite (3Al ₂ O ₃ .2SiO ₂ ) ceramics (thermal Examples thereof include expansion coefficient: 5 × 10 ⁻⁶ / ° C., silicon nitride (Si ₃ N ₄ ) ceramics (thermal expansion coefficient: 3 to 4 × 10 ⁻⁶ / ° C.), and the like. Among these, alumina ceramics are preferable because they are inexpensive and have a thermal expansion coefficient close to that of granite. In addition, the cage-shaped guideway 2 can be made of granite (including black granite) (coefficient of thermal expansion of about 6-9 × 10 ⁻⁶ / ° C.), and granite is considered in terms of durability and lubricity. Is preferably used.

The material of the V-shaped support base 4 that supports the bowl-shaped guide way 2 may be ceramic, granite, or cast iron. Cast iron is inexpensive and easy to manufacture. Granite is superior in anti-corrosion properties compared to ceramics. The inclination angle formed by the horizontal line and the upper side of the V-shaped support base is 55 to 65 degrees on the side (α ₁ ) on which the slide way side portion provided with the recess 6 for attaching the slide way driving means is floated. The gradient angle (α ₂ ) on the side is preferably 35 to 25 degrees. In FIG. 1, α ₁ is shown as 60 degrees and α ₂ as 30 degrees.

  Examples of the drive means of the slide way drive means include linear motors, motor drive wires, hydraulic cylinders, air cylinders, servo motor drive ball screws, and the like.

  The material for the vibration damping pad 5 is a liquid adhesive composition in which an acrylic vinyl monomer and a curing agent are mixed with a liquid rubber such as neoprene rubber, isoprene rubber, chloroprene rubber having a functional group such as carboxyl group or hydroxyl group. Things are used. This composition further comprises a polyether polyol, polyisocyanate urethane elastomer, ethylene / propylene / butadiene copolymer rubber, ethylene / propylene / ethylidene norbornene copolymer rubber, hydrogenated styrene / butadiene / styrene block copolymer. Polymer rubber, hydrogenated styrene / isoprene / styrene block copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, soft resin such as low density polyethylene or elastomer, calcium carbonate, titanium oxide, clay Further, it may contain a filler such as asphalt, an antioxidant and the like. For example, JP-A-2004-99651 discloses (A) 100 parts by mass of liquid isoprene having an acid anhydride group, (B) 1 to 4 parts by mass of an amine-based latent curing agent, and (C) an antioxidant. Disclosed is a vibration-damping adhesive composition containing 5 to 5 parts by mass and (D) 0.5 to 5 parts by mass of an acrylic compound. Japanese Patent Application Laid-Open No. 2005-41943 is a resin composition containing at least three components of a vinyl polymer, a polyester resin, and a rubber-like elastic resin containing 1% by mass or more of a unit having a polar group, Disclosed is a resin composition for a vibration damping material in which a polyester resin phase and a rubber-like elastic resin phase are dispersed independently in a vinyl polymer matrix containing 1% by mass or more of units having groups.

  The damping pad 5 may have a laminated structure. For example, after semi-vulcanizing a layer of high damping rubber as a core material and applying a vibration damping adhesive composition to the front and back surfaces of this high damping rubber, it is placed on the support base 4 and a bowl-shaped guide is placed thereon. By embossing the way 2 and then curing it, a damping pad in which the high damping rubber layer and the rubber layer are integrated can be obtained. A thickness of 1 to 5 mm is sufficient for the damping pad 5.

  The surface grinding apparatus shown in FIG. 3 is a ceramic work piece end face grinding apparatus 10 using the hydrostatic bearing linear motion slide system 1. In FIG. 3, w is a ceramic work piece, 8 is a water supply pipe, 11 is a tank for storing hydrostatic water made of pure water containing 0.5% alcohol, and 12 is a stirring blade and a support. A temperature controller having a mostat, 13 a linear motor, 14 a diamond cup wheel type grindstone, 15 a grindstone head, 16 a grindstone shaft, 17 a lifting mechanism, 17 a a lifting plate, 17 b a support A motor 17, a ball screw 18, a column 18, a guide rail 19, a tool table 20 that can be moved back and forth, a cover 21 made of a resin sheet that prevents splashing, and a drain 82. Tubes and 83 are pumps.

  The work piece w is placed on the slide way 3 of the hydrostatic bearing direct acting slide system 1. The slide way 3 is driven in the horizontal direction by a linear motor provided on the lower surface of the slide way 3 by driving the motor 13 so that the end face of the work piece w is a diamond cup wheel type. It can move in the direction of the grindstone 14 (right direction) or move away from the diamond cup wheel type grindstone 14 (left direction). When the slide way 3 is moved left and right, the static pressure water in the tank 11 is supplied from the water supply pot 81 to the ceramic pad 7 on the sliding surface between the bowl-shaped guide way 2 and the slide way 3. The gap between the saddle-shaped guideway 2 and the slideway 3 is kept at about 7 to 10 μm.

  The static pressure water supplied to the ceramic pads 7a, 7b, 7c and the U-shaped static pressure pad 7e is collected by the collector 7d and discharged from the drain pipe 82.

  The column 18 is provided upright from the tool table 20, and the tool table 20 is rotated on the guide rail 19 by a servo motor driven ball screw (not shown). And is movable in the front-rear direction. The grinding wheel head 15 is attached to the column 18 and is moved in the vertical direction by the lifting mechanism 17. The diamond cup wheel type grindstone 14 rotatably supported by the grindstone shaft 16 is rotated around the grindstone shaft by a servo motor (not shown). In the vicinity of the processing point where the cutting edge 14a of the diamond cup wheel-type grindstone contacts the end face of the work piece w, grinding water is supplied from a water outlet hole provided obliquely in the annular groove of the base of the cup wheel-type grindstone A certain coolant is supplied.

  By utilizing the back and forth movement of the tool table 20, the up and down movement of the grindstone head 15, and the left and right movement of the slide way 3, the work piece w and the diamond cup wheel type grindstone 14 can be moved relative to each other. The work piece w end face is cut and ground by a cutting edge 14a of a diamond cup wheel type grindstone. If the time until the next workpiece is processed after grinding is short, water is always supplied so as not to dry the surface of the bowl-shaped guideway and the slide way, so that it can always be kept moist. It is important. When it is a long time until the next work piece is processed after the grinding is finished, the surface of the bowl-shaped guide way and the slide way are washed with water and dried.

  Using a linear motor driven alumina ceramic slideway 3, black granite cage-shaped guideway 2, cast iron support base 4, neoprene rubber damping pad, hydrostatic pressure 0.5 MPa, slideway 20 mm / min The movement height of the irregularities of the alumina ceramic work piece that has been end-face ground under the processing conditions of a moving speed of 100 mm and a rotational speed of the grindstone of 100 rpm is about 20 to 25 μm.

  The hydrostatic bearing direct acting slide system used in the ceramic work piece end face grinding apparatus 10 has been described above as an example. However, the hydrostatic bearing direct acting slide system of the present invention is a plunge processing grinding apparatus. Needless to say, the present invention can be used as a static pressure water bearing linear motion slide system of a work table or a tool table used in a surface grinding apparatus such as a traverse machining grinding apparatus and a lathe.

  In the hydrostatic bearing direct acting slide system of the present invention, the bottom surface of the slide way has an inverted V shape, and the ceramic hydrostatic pad is provided only on the bottom surface. Easy to remove or attach to saddle-shaped guideway. In addition, it is easy to clean the bowl-shaped guideway and slide way.

It is sectional drawing of the hydrostatic bearing direct acting slide system of this invention. It is the perspective view which looked at the slide way from the bottom side. It is a front view of the ceramic work piece end face grinding apparatus using the hydrostatic bearing direct acting slide system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrostatic water bearing direct-acting slide system 2 Sponge-shaped guideway 3 Slideway 4 V-shaped support base 5 Damping pad 7a, 7b, 7c Static pressure pad 8 Water supply piping 10 Ceramic end face grinding device 14 Diamond cup hoi -Rule-shaped whetstone w Ceramic work piece 81 Water supply pot

Claims (3)

  The lower side of a granite or ceramic bowl-shaped guideway made of granite or ceramic having a square section is placed on a support base having a V-shaped section through a rubber damping pad, and an inverted V-shaped upper surface of the bowl-shaped guideway is placed. The lower surface has a substantially V-shaped cross section on the plane, and a recess for attaching the slide way driving means is provided on one side of the substantially V-shaped bottom surface, and the ceramic hydrostatic pad is placed on the slide way across the recess. A ceramic hydrostatic pad is provided on the other side of the substantially V-shaped bottom surface in the moving direction of the ceramic slide way, and pressure can be adjusted to the ceramic hydrostatic pad. Water supply piping is provided, and the water supply pump supplies the water supply piping when the substantially V-shaped bottom surface of the slideway slides on the right-angle hills of the guideway. Water is characterized by being capable emerged from perpendicular Sanryo surface of the ceramic pad than the guideways perpendicular Sanryo supplied to face the ceramic slideways and guideways, static pressure water bearing linear slide system.   2. The hydrostatic bearing linear motion slide according to claim 1, wherein the hydrostatic bearing linear motion slide system has a V-shaped support base made of granite, ceramic, or cast iron. 3. system.   The inclination angle formed by the horizontal line and the upper side of the V-shaped support base supporting the bowl-shaped guideway is 55 to 65 degrees on the side where the slideway side part where the concave part for attaching the slideway driving means is provided is floated. The hydrostatic bearing direct acting slide system according to claim 1 or 2, wherein the other side has a gradient angle of 35 to 25 degrees.

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