JP5089534B2 - Levitation unit and non-contact support device having the same - Google Patents

Description

  The present invention relates to a floating unit that can follow the inclination of a workpiece and a non-contact support device including the same.

  Conventionally, a large number of floating units have been provided, and a flat work (for example, a flat plate such as a liquid crystal panel glass or a substrate, a moving table, etc.) is supported in a non-contact manner by a pressurized gas ejected from the ejection surface of each floating unit. The device is known. An example of the use of such a non-contact support device is a workpiece positioning device. This is because correcting the positional deviation of the workpiece in a non-contact state can reduce the risk of the workpiece being rubbed and damaged by the support surface on the apparatus side during correction.

  By the way, from the viewpoint of improving production efficiency and the like, in recent years, workpieces supported in a non-contact manner have become larger. In such a large-sized workpiece, undulation or the like is likely to occur in part or in whole. On the other hand, in the case of a non-contact support device installed with the upper surface (spout surface) of the floating unit protruding from the unit installation surface, the upper surface of the floating unit is always maintained in a horizontal state. For this reason, as described above, when a swell or the like is generated in the workpiece and tilted, there is a problem that the workpiece collides with and damages the corner of the floating unit disposed below the tilted portion.

Therefore, the present applicant has previously proposed a floating unit in which a main body having a jetting surface is supported in a swingable manner in order to cope with such a problem (see Patent Document 1). According to such a levitation unit, since the upper surface of the levitation unit follows the inclination of the workpiece and the upper surface is parallel to the workpiece, collision between the corner of the levitation unit and the workpiece can be avoided.
JP 2006-319309 A

  However, the present inventors have found that the above-described prior art causes another new problem as described below. In the above prior art, the main body having the ejection surface is made swingable, so that the main body of the levitation unit is tilted when there is no workpiece. The cause of the tilt may be mainly due to the weight of the main body. In addition, the center of swing of the main body may not coincide with the center of gravity of the main body. Then, the following problems arise.

  As shown in FIG. 15, the stage S <b> 1 is placed on the upper surface 93 of the floating unit 92 before the non-contact support device 91 supports the moving table (stage) S <b> 1 as a workpiece in a non-contact manner. At this time, the corner of the main body 94 may collide with the supported surface of the stage S1 and damage the stage S1. In addition, when a part of the stage S1 is tilted due to the undulation, the collision angle becomes large as shown in FIG. 16, and the degree of damage due to the collision becomes larger.

  Further, the estimated flying height of the stage S in the non-contact support device 91 is usually extremely small such as about several μm to several tens of μm. For this reason, when the non-contact support of the stage S by the non-contact support device 91 is performed, as shown in FIG. 17, if the surface accuracy of the supported surface is poor, the gap with the supported surface is larger than the assumed flying height. There is a floating unit 92 (the central floating unit in the figure). In the levitation unit 92, the pressurized gas is released from the widened gap and the levitation force is weakened. At the same time, the reaction from the stage S2 is also weakened, so that the main body 94 is tilted as shown in FIG. Hit the supported surface. If the positional deviation is corrected in this state, the stage S2 is rubbed and damaged. In FIG. 17, the poor surface accuracy of the stage S2 is exaggerated for easy understanding.

  Therefore, the present invention has two functions that seem to contradict each other, that is, the swingability of the main body and the tilt suppression, so that there is a great risk that the swingable main body will inadvertently tilt and the work will be damaged. The main object of the present invention is to provide a floating unit that can be reduced to a low level, and a non-contact support device including the same.

  The present invention employs the following means in order to solve the above problems.

  Means 1. A body having an ejection surface for ejecting pressurized gas is supported by a support, and is a floating unit that supports a workpiece in a non-contact manner by pressurized gas ejected from the ejection surface, wherein the ejection surface is tilted of the workpiece And a tilting suppression mechanism that suppresses tilting of the main body due to its own weight.

  According to this means 1, the main body can follow the tilt of the workpiece by the swing mechanism, and the tilt by the own weight is suppressed by the tilt suppression mechanism. For this reason, unless the force over a self-weight is received from a workpiece | work by the operation | work (work placement, non-contact support, etc.) with respect to a workpiece | work, the main body can suppress the inclination by the own weight. As a result, it is possible to greatly reduce the possibility that the main body will inadvertently tilt due to its own weight and the workpiece will be damaged. For example, since the main body is maintained in a horizontal state when the work is placed on the ejection surface, the possibility that the upper corner of the main body collides with the supported surface of the work and damages the work can be greatly reduced. Even if the surface accuracy of the supported surface of the workpiece is poor and the gap between the workpiece and the supported surface is larger than the assumed flying height, the upper corner of the main body hits the supported surface of the workpiece and the workpiece is rubbed and damaged. The fear can be greatly reduced.

  In addition, as a workpiece | work, the flat plate-shaped workpiece | work with a flat surface (supported surface) which opposes an ejection surface, More specifically, flat plates, such as glass and a board | substrate, a moving table, etc. are assumed.

  Mean 2. The swing mechanism is provided on one of the main body and the support body and on the other side, and the swing mechanism accommodates the sphere part and contacts the upper spherical surface of the accommodated sphere part in an annular shape. An upper abutting portion that contacts the lower spherical portion and a lower abutting portion that abuts in an annular shape, and the tilt suppression mechanism is a spherical surface of the spherical portion accommodated in the accommodating portion. An elastic annular member that comes into contact with the closed space, a closed space that is provided inside the other by the arrangement of the elastic annular member and sealed by the elastic annular member, communicates with the closed space, and can adjust the internal pressure of the closed space And the closed space is disposed at a position where the main body is pushed up by an increase in pressure in the closed space.

  According to this means 2, the inclination of the main body with respect to the support is arbitrarily adjusted by rotating the spherical part in an arbitrary direction within the accommodating part. Thereby, the operation | movement in which a main body can rock | fluctuate in any direction is realizable. And since a rocking | fluctuation mechanism is comprised using a spherical surface, smooth rocking | fluctuation operation | movement is realizable. Further, in a state where the support is fixed by being installed on a non-contact support device or the like, when the internal pressure of the closed space in the main body or the support body is increased from the atmospheric pressure through the internal pressure adjusting passage, the main body is attached to the support body by the internal pressure. It is pushed up against. Thereby, since the contact force with the spherical body portion is increased at the upper contact portion or the lower contact portion and the frictional resistance is increased at the same time, it is possible to suppress the tilt due to the weight of the main body.

  Means 3. At least one of the upper contact portion and the lower contact portion is a spherical bearing portion.

  According to the means 3, since at least one of the contact portions provided in the housing portion is a spherical bearing portion, the main body can be swung using the spherical bearing. Thereby, the smoother swinging motion of the main body can be realized.

  Means 4. The internal pressure adjusting passage is provided separately from the gas passage provided in the main body so as to supply pressurized gas to the ejection surface.

  According to this means 4, since the internal pressure adjusting passage is provided separately from the gas passage, the internal pressure of the closed space is adjusted without being affected by the pressurized gas supplied to the ejection surface. Thereby, the internal pressure adjustment of closed space can be performed easily.

  Means 5. The elastic annular member is provided on the upper surface of the spherical surface of the spherical body portion.

  According to this means 5, since the elastic annular member is provided on the spherical surface of the spherical body portion, even if the internal pressure of the closed space is increased and the main body is pushed up, the elastic annular member can be prevented from being further crushed. . Thereby, it can suppress that the performance as an elastic member falls by repeating further crushing and a return to the original state of an elastic annular member with pressure regulation of closed space.

  Means 6. The elastic annular member is provided below the spherical surface of the spherical body portion, and the spherical contact portion of the elastic annular member is the lower contact portion.

  According to this means 6, since the spherical contact portion of the elastic annular member is the lower contact portion, the elastic annular member is further crushed when the internal pressure of the closed space is increased and the main body is pushed up. . Since the contact between the elastic annular member and the spherical surface is a line contact, and the increased crushing force is concentrated on the contact portion, the frictional resistance is higher than in the case of surface contact. For this reason, the tilt suppression effect by the increase in frictional resistance can be improved.

  Mean 7 A body having an ejection surface for ejecting pressurized gas is supported by a support, and is a floating unit that supports a workpiece in a non-contact manner by pressurized gas ejected from the ejection surface, wherein the ejection surface is tilted of the workpiece A swing mechanism that allows the main body to swing freely so as to follow the body, and has an elastic force that can be elastically deformed with respect to the follow-up force to the workpiece while suppressing tilting due to its own weight, and tilts by its own weight And a tilt suppressing member provided so as to be able to contact the main body to be contacted.

  According to this means 7, the main body can follow the inclination of the workpiece by the swing mechanism. In addition, the tilt suppression member abuts against the main body so that the main body does not tilt due to its own weight or does not tilt more than a certain amount even if the main body tilts, thereby suppressing tilting due to the weight of the main body. In this case, the tilt suppressing member has an elastic force that can be deformed with respect to a force that follows the tilt of the workpiece while suppressing the tilt with respect to the tilt of the main body due to its own weight. For this reason, the tilt suppressing member is elastically deformed with respect to the following force to the workpiece larger than the weight of the main body, and the following tilt of the main body is not inhibited by the tilt suppressing member. Thus, the means 7 can greatly reduce the possibility that the main body will inadvertently tilt due to its own weight and the workpiece will be damaged.

  Means 8. The swing mechanism includes a spherical portion provided on one of the main body and the support, and a receiving portion that is provided on the other side and receives the spherical portion while being in contact with the spherical surface of the spherical portion. The tilt suppressing member is a cylindrical member that is provided on a shaft portion extending from the spherical body portion and is capable of coming into contact with the lower surface of the main body to be tilted by its own weight.

  According to the means 8, the inclination of the main body with respect to the support body is arbitrarily adjusted by rotating the spherical body portion in an arbitrary direction within the housing portion. Thereby, the operation | movement in which a main body can rock | fluctuate in any direction is realizable. Further, since the tilt suppressing member is a cylindrical member provided at the shaft portion of the support body, it is not necessary to make a new work on the main body in order to obtain the tilt suppressing effect. For this reason, the manufacturing cost of the levitating unit which has a system | strain suppression function can be reduced.

  Means 9. A non-contact support device in which a plurality of floating units according to any one of means 1 to 8 are installed on a base.

  According to this means 9, by providing a plurality of floating units capable of suppressing tilting, it is possible to obtain a non-contact support device that can greatly reduce the risk of the workpiece being damaged.

  Hereinafter, first to third embodiments embodying the present invention will be described with reference to the drawings.

[First Embodiment]
First, an outline of a non-contact support apparatus having a large number of floating units will be described with reference to FIG. In the present embodiment, it is assumed that the non-contact support device is used as a stage positioning device, and FIG. 3 is a plan view showing the non-contact support device. In the following description, “upper and lower” refers to upper and lower with respect to the vertical direction.

  As shown in FIG. 3, the non-contact support device 11 includes a base 12. The upper surface of the base 12 is a floating unit installation surface, and a large number of floating units 13 are installed on the installation surface. The levitation units 13 are arranged at equal intervals in the front, rear, left and right so as to form a lattice shape as a whole in plan view. The number of the levitation units 13 is appropriately increased or decreased in consideration of the flat area of the stage that is supported in a non-contact manner, the ease of bending / swelling, and the like.

  Here, the stage is a moving table used for glass or substrate manufacturing, and this corresponds to a “workpiece”. The “workpiece” is not limited to the moving table, and may be a flat plate such as a glass for a liquid crystal panel or a substrate.

  A part of the upper surface of each levitation unit 13 is an ejection surface 14 from which pressurized gas (here, pressurized air is used) is ejected. Since each levitation unit 13 is the same, the same plane is formed by the upper surface. When pressurized air is ejected from the ejection surface 14 after placing the stage on the upper surface of each levitation unit 13, the placed stage is supported in a non-contact manner with a minute interval. For this reason, if the position shift of the stage is corrected in such a state, the position shift of the stage is corrected without rubbing against the upper surface of the floating unit 13.

  Next, details of the floating unit 13 will be described with reference to FIGS. 1 and 2. FIG. 1 is a partial sectional view of the levitation unit. The configuration of the levitation unit will be described with reference to FIG. 2 is also a partial cross-sectional view of the levitation unit as in FIG. 1, but FIG. 2 will be referred to in the description of the tilt suppression mechanism described later.

  As shown in FIG. 1, the levitation unit 13 includes a main body 20 and a support body 30 that supports the main body 20 in a swingable manner. First, the detailed configuration of the main body 20 is as follows. A main body 21 of the main body 20 has a cylindrical shape, and a bearing port 22 is formed on a side surface thereof. The bearing port 22 communicates with one end of a gas passage 23 formed inside the main body 21. Further, the upper surface of the main body 21 is formed flat, and a housing groove 24 having a circular shape in plan view is formed on the upper surface. A flow groove 25 is formed on the bottom surface of the housing groove 24. The other end of the gas passage 23 communicates with the flow groove 25. Therefore, the flow groove 25 communicates with the bearing port 22 via the gas passage 23. And the porous body 26 formed in the disk shape according to the accommodation groove 24 is densely accommodated in the accommodation groove 24. In the accommodated state, the upper surface of the porous body 26 is flush with the upper surface of the main body 21, and the upper surface of the main body 20 of the floating unit 13 is formed by both.

  The porous body 26 is made of a fluororesin such as a sintered trifluoride resin or a sintered tetrafluoride resin. However, in addition to fluororesin, synthetic resin materials such as sintered nylon resin and sintered polyacetal resin, metal materials such as sintered aluminum, sintered copper, and sintered stainless steel, and materials such as sintered carbon and sintered ceramics It may be used.

  In the main body 20 having such a configuration, when pressurized air is supplied to the bearing port 22, the pressurized air reaches the flow groove 25 and further the bottom surface of the porous body 26 through the gas passage 23. The pressurized air passes through the micropores of the porous body 26 and is ejected from the upper surface of the porous body 26. Therefore, the upper surface of the porous body 26 is the ejection surface 14 of the levitation unit 13.

  Next, the levitation unit 13 includes a swing mechanism, so that the main body 20 is swingable and supported by the support 30. First, as a configuration on the support body 30 side, the support body 30 has a main shaft portion 31, and an attachment shaft portion 32 is provided at a base end portion thereof. A screw portion 33 is formed on the outer surface of the attachment shaft portion 32, and the screw portion 33 is used to attach to the base 12 of the non-contact support device 11 described above. A spherical body portion 35 is provided on the distal end side of the main shaft portion 31 via a neck portion 34 whose cross section gradually decreases. Note that the central axis of the main shaft portion 31 coincides with the vertical center line passing through the centers of the mounting shaft portion 32, the neck portion 34, and the spherical body portion 35, which is the center line of the entire floating unit 13. Each part and each member constituting the levitation unit 13 are provided on the basis of this center line.

  On the other hand, as a configuration on the main body 20 side, a mounting recess 27 having a circular opening is provided at the center of the lower surface of the main body 21. A threaded portion is formed on the inner surface of the mounting recess 27. A spherical bearing member 28 is provided in the mounting recess 27. The spherical bearing member 28 has a cylindrical shape whose outer shape matches the mounting recess 27, and a threaded portion is formed on the outer surface thereof. By screwing this threaded portion into the threaded portion of the mounting recess 27, the spherical bearing member 28 is mounted on the main body 21 in a state of being accommodated in the mounting recess 27. On the inner surface of the spherical bearing member 28, a spherical bearing portion 28 a that can abut on the spherical surface of the spherical body portion 35 is formed. The spherical body 35 is substantially entirely encapsulated by the spherical bearing member 28. However, the top of the spherical portion 35 is exposed to the outside of the spherical bearing member 28 through the hole 28b formed in the upper surface of the spherical bearing member 28. An O-ring 29 as an elastic annular member is accommodated in a concave space formed by the hole 28b and the top of the spherical portion 35. The inner surface of the hole 28b is formed in a tapered shape that is inclined inward from the upper surface opening. The O-ring 29 is crushed when the spherical bearing member 28 is attached to the main body 21, and is disposed in the main body 20 in close contact with the bottom surface of the mounting recess 27, the spherical surface of the top of the spherical body portion 35, and the inner surface of the hole 28b. ing.

  In this embodiment, the spherical bearing portion 28 a of the spherical bearing member 28 is a housing portion for the spherical body portion 35. The upper half of the spherical bearing portion 28a (the portion that contacts the upper hemisphere of the spherical portion 35) corresponds to the upper contact portion, and the lower half (the portion that contacts the lower hemisphere of the spherical portion 35) corresponds to the lower contact portion.

  As described above, the main body 20 having the spherical bearing member 28 is supported by the support body 30 in a state where the main body 20 is swingable by the spherical bearing of the spherical portion 35. Thereby, the main body 20 can be tilted following the tilt of the stage. A frictional resistance is generated at a portion where the O-ring 29 is in close contact with the spherical surface of the spherical body portion 35. Further, since the main body 20 is pushed up by the crushing force W (arrow in FIG. 1) of the O-ring 29, a frictional resistance is also generated at the lower portion of the spherical bearing portion 28a (A portion surrounded by a one-dot chain line in FIG. 1). By these frictional resistances, tilting of the main body 20 (slope due to its own weight) is suppressed to some extent.

  However, since the effect of suppressing the tilting of the main body 20 cannot be sufficiently obtained only by this degree of frictional resistance, the main body 20 tilts. Therefore, the levitation unit 13 according to the first embodiment includes a tilt suppression mechanism that suppresses tilting of the main body 20. This tilt suppression mechanism can adjust the internal pressure of the main body 20 to increase the frictional resistance of the portion A, thereby sufficiently suppressing the tilt of the main body 20.

  Therefore, the tilt suppression mechanism will be described in detail next. Here, FIG. 2 which is explanatory drawing for demonstrating inclination suppression other than FIG. 1 is referred suitably. First, the tilt suppression mechanism has the following configuration. A pressure port 41 is provided on a side surface of the main body 21 at a location different from the bearing port 22. The pressurizing port 41 communicates with one end of an internal pressure adjusting passage 42 formed in the main body 21 separately from the gas passage 23. The other end of the internal pressure adjusting passage 42 opens at the bottom surface of the mounting recess 27 and communicates with a closed space K <b> 1 formed inside the O-ring 29. As shown in FIG. 2, when pressurized gas (also referred to as pressurized air is used here) is supplied to the pressure port 41, the pressure in the closed space K1 is increased through the internal pressure adjusting passage 42. Increased above atmospheric pressure. In this pressurized state, the closed space K1 is sealed by the O-ring 29. Therefore, it is possible to adjust the pressure in the closed space K <b> 1 (internal pressure of the main body 20) depending on whether the pressurization port 41 is opened to the atmosphere or pressurized air is supplied to the pressurization port 41.

  In such a configuration, when pressurized air is supplied to the pressure port 41 to pressurize the closed space K1, an upward force is applied to the main body 20 as indicated by an arrow in FIG. And pushed up. If it does so, the frictional resistance in A part will increase compared with before pressurization, and the inclination suppression effect of the main body 20 will also become large compared with before pressurization. Thereby, it becomes possible to suppress the tilting of the main body 20 sufficiently.

  Here, as described above, the main body 20 is swingably supported so as to follow the inclination of the stage. For this reason, the extent to which the closed space K1 is pressurized is such that the tilt of the main body 20 can be suppressed. Since the load (about 10 to 100 kg) applied to one levitation unit 13 due to the placement of the stage, non-contact support, etc. is significantly different from the weight of the main body 20 (about 1 kg), if the degree of pressurization is that level, The swing function is not disturbed. That is, if the stage is placed or the stage is supported in a non-contact manner, the main body 20 is pressed downward by the stage, so that the above-described pressurization of the main body 20 by pressurization has little influence on the swing function.

  Next, the operation performed by the levitation unit 13 in the non-contact support apparatus 11 provided with the levitation unit 13 described in detail above will be described with reference to the drawings as appropriate.

  First, the operation of placing the stage on the upper surface of the levitation unit 13 will be described with reference to FIG. As shown in FIG. 4, when the stage S is placed on the upper surface of the main body of the levitation unit 13 (the upper surface of the main body 21 and the upper surface of the porous body 26), pressurized air is supplied to the pressure port 41. Keep it. Then, the main body 20 is prevented from being tilted as described above, and the upper surface of the main body of the levitation unit 13 is maintained in a horizontal state. Thereby, when the stage S is placed, it is possible to greatly reduce the possibility that the upper corner of the main body collides with the supported surface of the stage S (the surface facing the ejection surface 14) and the stage S is damaged.

  Further, if a part of the stage S is inclined due to undulation or the like, the supported surface of the inclined portion is not parallel to the upper surface of the main body of the floating unit 13 that is maintained horizontally. In this case, since the closed space K1 is only pressurized to such an extent that the tilt of the main body 20 can be suppressed, the main body 20 is subjected to a load that greatly exceeds the weight of the main body 20 when the stage S is placed. Inclination follows the inclination of the stage S. In this regard, since the horizontal upper surface of the main body and the supported surface of the inclined stage S are in a non-parallel state, the stage S can hit the corner of the upper part of the main body, but the stage S can be compared with the conventional technique in which the main body 20 tilts. A significant reduction in the risk of damaging the skin can be expected.

  Next, the operation of the main body 20 following and tilting the stage S tilted during non-contact support will be described with reference to FIG. In FIG. 5, the stage inclination and flying height are exaggerated for easy understanding. During the non-contact support of the stage S, pressurized air is supplied to the bearing port 22 and the pressure port 41. Thereby, pressurized air is ejected from the upper surface of the porous body 26 to support the stage S in a non-contact manner, and the main body 20 is prevented from being tilted by its own weight. During such non-contact support, undulation or the like may occur, and a part of the stage S may be inclined as shown in FIG. In this case, in the levitation unit 13 disposed below the inclined portion, the pressurized air is released to the outside through a gap that is widened with the stage S due to the inclination. In the portion where the gap is widened, the levitation force on the stage S does not sufficiently act, and the reaction that the main body 20 receives from the stage S becomes small. Then, the main body 20 is pushed up by the crushing force W of the O-ring 29 and the internal pressure of the closed space K1, and the main body 20 is inclined following the inclination of the stage S. As a result, as shown in FIG. 5B, the supported surface of the stage S and the upper surface of the main body of the levitation unit 13 are in a parallel state, and the risk of the stage S colliding with the upper corner of the main body and being damaged is reduced. Can be made.

  Although illustration is omitted, even if the surface accuracy of the supported surface of the stage S is poor and the gap between the upper surface and the stage S is larger than the assumed flying height in some floating units 13, Inclination of the main body 20 of the levitation unit 13 is suppressed. As a result, in use as a positioning device, the possibility that the corner of the upper part of the main body hits the stage S and the positional deviation is corrected in that state, and the stage S is rubbed and damaged can be greatly reduced.

  From the above description, the first embodiment has the following excellent effects.

  In the levitation unit 13, the main body 20 is swingable by a swing mechanism and can follow the inclination of the stage S. In addition, by increasing the pressure in the closed space K1 and increasing the frictional resistance at the spherical bearing portion (A portion), tilting of the main body 20 due to its own weight is suppressed. For this reason, unless the main body 20 receives a force exceeding its own weight due to the placement of the stage S or non-contact support, the upper surface of the main body of the levitation unit 13 is maintained in a horizontal state. As a result, the possibility that the main body 20 will inadvertently tilt due to its own weight and damage the stage S can be greatly reduced. For example, when the stage S is placed, or when the clearance between the stage S is increased in some floating units 13 due to poor surface accuracy of the stage S, the stage S is caused by a collision with the upper corner of the main body. The risk of injury can be greatly reduced.

  In the levitation unit 13, the main body 20 is swingable by a spherical bearing. Therefore, the main body 20 can be tilted in an arbitrary direction, and a smooth swinging operation can be realized.

  In the above-described levitation unit, the internal pressure adjusting passage 42 serving as a passage for the pressurized air that pressurizes the closed space K1 is provided separately from the gas passage 23. Therefore, the influence of the pressurized air supplied for non-contact support is exerted. The internal pressure can be adjusted without receiving it. Thereby, adjustment of an internal pressure can be performed easily.

  In the levitation unit 13, since the O-ring 29 is disposed at a position where it comes into contact with the upper spherical surface of the sphere 35, the O-ring 29 is further crushed even when the main body 20 is pushed up to suppress tilting. Can be avoided. Thereby, it can suppress that the further crushing and the return to the original state are repeated with the pressure adjustment of the closed space K1, and the performance of the O-ring 29 deteriorates.

  The first embodiment is not limited to the contents described above. Other possible embodiments are listed below.

  In the above-described embodiment, the degree of pressurization of the closed space K1 is set to such an extent that the tilt can be suppressed. However, if the pressurization degree is further increased, the certainty of tilt suppression is increased, and thus the swing function of the main body 20 is hindered. It is also possible to increase the degree of pressurization to the extent. In such a case, if the pressure of the closed space K1 is appropriately adjusted (for example, pressurization is stopped or the degree of pressurization is reduced) when the swing function of the main body 20 is required, the swing function is hindered. Can be eliminated.

  In the above embodiment, the closed space K1 is constantly pressurized. However, after the stage S is placed, the supply of pressurized air to the pressure port 41 is shut off, and the pressurization of the closed space K1 is stopped. You may adjust to an air release state.

  In the above embodiment, the pressurizing port 41 is provided on the side surface of the main body 21, but the pressure port 41 may be provided on the lower surface of the main body 21. Further, the pressurizing port 41 and the internal pressure adjusting passage 42 may be provided in the support 30. In this case, one end of the internal pressure adjusting passage 42 opens at the top of the spherical portion 35.

  In the above embodiment, the bearing port 22 and the pressurizing port 41 are provided separately, but as shown in FIG. 6, a common port 51 in which both the ports 22 and 41 are shared is provided. It is good also as a structure. In this case, the main body 21 is provided with a common passage 52 connected to the gas passage 23 and the internal pressure adjusting passage 42. By doing so, the manufacturing process can be reduced.

  As a configuration of the swing mechanism that is supported by the support 30 so that the main body 20 can swing, a spherical bearing portion that has a hemispherical concave shape on the lower surface of the main body 21 as shown in FIG. 53 may be formed. In this case, the O-ring 29 is accommodated in the groove formed in the spherical bearing portion 53. In addition, an auxiliary member 54 that assists in supporting the main body 21 that is swingable is integrally provided below the main body 21. The auxiliary member 54 includes an accommodation recess 55 that accommodates the spherical lower portion of the spherical portion 35, and a spherical contact portion 56 that abuts the spherical portion 35 in the entire circumferential direction. The main body 21 is prevented from falling off from the spherical portion 35 by the contact of the spherical contact portion 56. In such a configuration, when the internal pressure of the main body 20 is increased, the frictional resistance between the spherical contact portion 56 and the spherical surface of the spherical body portion 35 is increased, and the tilt of the main body 20 is suppressed. In this alternative example, the auxiliary member 54 is also a part of the main body 20, and the spherical bearing portion 53 and the accommodating concave portion 55 of the auxiliary member 54 constitute an accommodating portion of the spherical portion 35. The spherical contact portion 56 corresponds to the lower contact portion.

  In addition, in place of the above-described hemispherical spherical bearing portion 53, as shown in FIG. 7B, a concave portion 57 having a tapered surface is formed, and the upper portion of the spherical portion 35 is accommodated in the concave portion 57. It is good. In this case, when the spherical upper surface of the spherical portion 35 abuts against the tapered surface of the recess 57, the main body 21 can swing.

  In the above-described embodiment, as the configuration of the swing mechanism, the spherical bearing portion 28a is provided on the main body 20 side and the spherical portion 35 is provided on the support 30 side. However, the configuration may be reversed. That is, a configuration in which a spherical body portion is provided on the main body 20 side and a spherical bearing portion is provided on the support body 30 side may be employed. In this case, although not shown, a shaft portion extending downward is provided on the lower surface of the main body 21, and a spherical body portion is provided at the tip of the shaft portion. In such a configuration, the O-ring 29 that suppresses the tilt of the main body 20, the internal pressure adjusting passage 42, the closed space K, and the like are provided on the support 30 side. And if the internal pressure of the closed space K in the support body 30 is raised, the main body 20 will be pushed up with respect to the support body 30 by the internal pressure. Thereby, since the contact force with the spherical body portion is increased on the upper side of the spherical bearing portion and the frictional resistance is increased at the same time, the tilt of the main body 20 can be suppressed.

  In the above embodiment, the upper surface of the porous body 26 and the upper surface of the main body 21 are flush with each other, but the porous body 26 is provided with the upper surface protruding from the upper surface of the main body 21. It may be.

  In the above-described embodiment, the case where the non-contact support device 11 is used as a positioning device for the stage S is described. However, other applications such as a transfer device for a workpiece (the stage S, a flat plate, etc.) are used. Alternatively, the non-contact support device 11 may be used.

[Second Embodiment]
The second embodiment is different from the first embodiment in the configuration of the floating unit. For this reason, below, it demonstrates centering on the difference in a structure about the floating unit, and the difference in operation | movement of the floating unit resulting from it, and attaches | subjects the same code | symbol about a common part, and abbreviate | omits description. In addition, the description of common effects and other examples is omitted.

  First, the difference in configuration of the floating unit in the second embodiment will be described with reference to FIG. FIG. 8 is a partial cross-sectional view of the levitation unit. As shown in FIG. 8, the levitation unit 60 is different in the structure of the swing mechanism, particularly the structure on the main body 20 side. First, a spherical bearing 61 having a hemispherical concave shape is provided at the center of the lower surface of the main body 21. The spherical bearing portion 61 supports the upper portion of the sphere portion 35 of the support 30. In addition, an auxiliary member 62 that assists in supporting the main body 21 that can swing is integrally provided on the lower surface of the main body 21. The auxiliary member 62 is formed with a housing hole 63 that is slightly larger than the opening of the spherical bearing portion 61, and the lower portion of the spherical body portion 35 is housed in the housing hole 63. The lower opening of the accommodation hole 63 is narrowed by the annular protrusion 64 more than the upper opening, and the O-ring 65 is disposed in a groove formed in the annular protrusion 64 in close contact with the lower spherical surface of the sphere 35. Has been. The O-ring 65 abuts on the lower spherical surface of the sphere 35 to prevent the main body 21 from falling off the sphere 35.

  In this embodiment, the auxiliary member 62 is also a part of the main body 20, and the spherical bearing portion 61 and the accommodating hole 63 of the auxiliary member 62 constitute an accommodating portion of the spherical portion 35. Further, the spherical bearing portion 61 corresponds to the upper contact portion, and the spherical contact portion of the O-ring 65 corresponds to the lower contact portion.

  As described above, in the levitation unit 60, the main body 20 is swingably supported by the support body 30 by providing the spherical bearing 61 and the auxiliary member 62. A frictional resistance is generated at the spherical contact portion of the O-ring 65 (the B portion surrounded by the one-dot chain line in FIG. 8). Further, as shown in FIG. 8, since the spherical bearing portion 61 is pressed against the spherical surface of the spherical body portion 35 by the crushing force W of the O-ring 65, a frictional resistance is also generated in the spherical bearing portion 61. These frictional resistances suppress the tilting of the main body 20 to some extent.

  Next, the tilt suppression mechanism will be described. Here, in addition to FIG. 8, FIG. 9, which is a partial cross-sectional view of the levitation unit as in FIG. 8, and is an explanatory diagram for explaining tilt suppression, is appropriately referred to.

  In the levitation unit 60, the internal pressure adjusting passage 42 is formed so that the opposite end of the pressurizing port 41 opens at a portion corresponding to the top of the spherical body portion 35 of the spherical bearing portion 61. A space formed between the spherical bearing portion 61 and the upper spherical surface of the spherical portion 35 and in the accommodation hole 63 of the auxiliary member 62 is a closed space K2, and the internal pressure adjusting passage 42 communicates with the closed space K2. doing. As shown in FIG. 9, when pressurized air is supplied to the pressure port 41, the pressure in the closed space K <b> 2 increases through the internal pressure adjusting passage 42. In this pressurized state, the closed space K2 is sealed by the O-ring 65. Therefore, it is possible to adjust the pressure of the closed space K <b> 2 depending on whether the pressurization port 41 is opened to the atmosphere or pressurized air is supplied to the pressurization port 41.

  When the pressure in the closed space K2 increases, an upward force acts on the main body 20 as shown by an arrow in FIG. If it does so, the frictional resistance in B part will increase compared with before pressurization, and the inclination suppression effect of the main body 20 will also become large compared with before pressurization. Thereby, it becomes possible to suppress the tilting of the main body 20 sufficiently.

  Also by the levitation unit 60 of the second embodiment described above, the tilt of the main body 20 is suppressed by increasing the pressure in the closed space K2. And if this levitation unit 60 is installed in the non-contact support apparatus 11, since the main body upper surface of the levitation unit 60 will be maintained in a horizontal state, operation | movement similar to the levitation unit 13 of 1st Embodiment is attained. . Therefore, the same effect as the first embodiment described above can be obtained.

  However, the following points have excellent effects peculiar to the second embodiment.

  In the levitation unit 60, since the O-ring 65 is in contact with the lower spherical surface of the sphere 35, the O-ring 65 is further crushed when the main body 20 is pushed up to suppress tilting. The contact between the O-ring 65 and the spherical surface at the portion B is a line contact, and the increased crushing force is concentrated on the contact portion. For this reason, the tilt suppression effect can be enhanced with less pressure than in the case of surface contact.

  Note that the second embodiment is not limited to the contents described above. Other possible embodiments are listed below.

  In the above embodiment, the pressurizing port 41 and the internal pressure adjusting passage 42 are provided in the main body 21. However, as shown in FIG. 10, the auxiliary port 62 may be provided. Although not shown, the pressure port 41 is provided in the auxiliary member 62, and the internal pressure adjusting passage 42 is provided across both the auxiliary member 62 and the main body 21 so as to open to the spherical bearing portion 61. It may be.

  As a configuration in which the main body 20 is swingable and supported by the support 30, as shown in FIG. 11A, a recess 71 having a tapered surface is used instead of the hemispherical spherical bearing 61. The upper portion of the spherical body portion 35 may be accommodated in the concave portion 71. In this case, the upper surface of the spherical portion 35 contacts the tapered surface of the recess 71, so that the main body 20 is swingable and supported by the support 30.

  In addition, instead of directly contacting the main body 21 and the sphere 35, as shown in FIG. 11B, a spherical bearing member 72 similar to the spherical bearing member 28 in the first embodiment is provided. It is good also as a structure provided. In this case, an O-ring holding member 73 for holding an O-ring 65 that is in close contact with the lower spherical surface of the sphere 35 is provided on the lower surface of the main body 21.

[Third Embodiment]
This third embodiment also differs from the first embodiment in the configuration of the floating unit. For this reason, the following description will focus on the differences in configuration of the floating unit and the differences in the operation of the floating unit caused thereby, and common portions will be denoted by the same reference numerals and description thereof will be omitted. In addition, explanations of effects and other common examples will be omitted as appropriate.

  First, the structural difference of the levitation unit in the third embodiment will be described with reference to FIG. FIG. 12 is a partial cross-sectional view of the levitation unit. As shown in FIG. 12, in the levitation unit 80, the mounting recess 27 of the main body 21 is formed shallower than in the case of the first embodiment, so that the lower portion of the spherical bearing member 28 is formed on the main body 21. It is attached to the main body 21 in a state protruding from the lower surface.

  Further, the levitation unit 80 has a different configuration especially regarding tilt suppression. That is, instead of the O-ring 29, the pressure port 41, and the internal pressure adjusting passage 42, a tilt collar and a cylindrical collar 81 as a cylindrical member are attached around the main shaft portion 31 and the neck portion 34 of the support 30. Yes. In the support 30, the mounting shaft 32 has a larger cross section than that of the main shaft 31, and the lower surface of the cylindrical collar 81 is supported by the annular step surface 82 formed thereby. The cylindrical collar 81 is formed of a soft resin such as urethane resin or an elastic material such as rubber. The height H2 of the cylindrical collar 81 when not attached to the support 30 is formed to be higher than the height H1 between the lower surface of the spherical bearing member 28 and the step surface 82. For this reason, the cylindrical collar 81 is attached to the support body 30 in a state compressed in the vertical direction, and pressure in the vertical direction is applied to the cylindrical collar 81. Due to this pressurization, the cylindrical collar 81 accumulates a restoring force in the vertical direction (see arrows in the figure), and the upper and lower surfaces thereof are attached in close contact with the lower surface and the step surface 82 of the spherical bearing member 28, respectively.

  Here, the cylindrical collar 81 formed of an elastic material has an elastic force that can be elastically deformed with respect to the follow-up force to the stage while suppressing tilting of the main body 20 due to its own weight. As described in the first embodiment, since the load received from the stage greatly exceeds the weight of the main body 20, the property of having the elastic force as described above can be imparted to the cylindrical collar 81. .

  As described above, the floating unit 80 is provided with the cylindrical collar 81 in close contact with the lower surface on the main body 20 side, and the cylindrical collar 81 suppresses the tilting of the main body 20 and responds to the following force on the stage. It has an elastic force that can be elastically deformed. Therefore, if the levitation unit 80 is installed in the non-contact support device 11, the function of the main body 20 following and tilting the stage can be maintained while the tilt due to the weight of the main body 20 can be suppressed.

  Specifically, when the stage is placed on the upper surface of the main body of the levitation unit 80, the upper surface of the main body is maintained in a horizontal state by the cylindrical collar 81, so that the possibility of the stage being damaged by such an operation can be greatly reduced. If the stage to be mounted is inclined, the cylindrical collar 81 is elastically deformed by receiving a load exceeding the weight of the main body 20 due to the stage mounting, and the main body 20 is inclined following the inclination of the stage S. . As in the first embodiment, in this case, the stage can hit the corner of the horizontal upper part of the main body, but a significant reduction in the possibility of damaging the stage can be expected as compared with the prior art.

  Next, the following operation of the main body 20 during non-contact support will be described with reference to FIG. In FIG. 13, the stage tilt and flying height are exaggerated. As shown in FIG. 13, when a part of the stage S is tilted during the non-contact support of the stage S, the floating unit 80 arranged below the tilted part is a part where the gap with the stage S is widened. The levitation force does not act sufficiently, and the reaction that the main body 20 receives from the stage S is reduced (see the description of the first embodiment with reference to FIG. 5A). Then, the pressurization is reduced on the inclined mountain side of the cylindrical collar 81, and the main body 20 is pushed up by the restoring force of the cylindrical collar 81. On the other hand, on the inclined valley side of the cylindrical collar 81, the main body 20 (specifically, the lower surface of the spherical bearing portion 28) is pressed from above as the mountain side is pushed up, and the cylindrical collar 81 is elastically deformed. In this way, the main body 20 tilts following the tilt of the stage S. As a result, as shown in FIG. 13, the supported surface of the stage S and the upper surface of the main body of the levitation unit 80 are in a parallel state, and the possibility that the stage S collides with the upper corner of the main body and is damaged can be reduced.

  Although illustration is omitted, if the surface accuracy of the supported surface of the stage is poor and the clearance between the upper surface and the stage becomes larger than the assumed flying height in some floating units 80, the main body of the floating unit 80 Inclination 20 due to contact with the cylindrical collar 81 is suppressed. As a result, it is possible to greatly reduce the possibility that the upper corner of the main body hits the stage and the positional deviation is corrected in that state, and the stage is rubbed and damaged.

  As described above, also in the third embodiment, the same effect as that of the first embodiment described above can be obtained. However, the third embodiment has an excellent effect peculiar to the third embodiment in that a cylindrical collar 81 is provided instead of the tilt suppression mechanism having the closed space K or the like. That is, in the levitation unit 80, since the tilt of the main body 20 is suppressed by the cylindrical collar 81 provided on the main shaft portion 31 of the support body 30, unlike the above-described first and second embodiments, the main body 20 is newly provided. There is no need for special work. For this reason, the manufacturing cost of the levitating unit which has a tilt suppression function can be reduced.

  Note that the third embodiment is not limited to the contents described above. Other possible embodiments are listed below.

  In the above embodiment, the cylindrical collar 81 is provided as the tilt suppressing member, but an O-ring may be used instead. In this case, as shown in FIG. 14, a configuration in which an O-ring 86 is provided at the base portion of the sphere 35 in the support 30 is considered as an example. The tilt of the main body 20 is suppressed by the rigidity of the O-ring 86, and the function of following the main body 20 to the stage is obtained by the elastic force. In addition, the tilt suppressing member may be a coil spring or the like.

  In the above embodiment, the cylindrical collar 81 having a height H2 higher than the height H1 on the attached side is provided in a compressed state. However, it is equal to or slightly lower than the height H1. The structure provided with the cylindrical collar 81 of height H2 may be sufficient. Thereby, attachment of the cylindrical collar 81 becomes easy. However, in the configuration in which the cylindrical collar 81 having a low height H2 is attached, the main body 20 tilts to a certain extent until the lower surface of the spherical bearing member 28 comes into contact with the upper surface of the cylindrical collar 81. However, even in such a case, an effect of suppressing tilting that prevents the main body 20 from tilting beyond a certain level can be obtained, and the main body 20 can be maintained in a substantially horizontal state if the height is slightly low. For this reason, it can be an effective means as compared with a configuration in which the cylindrical collar 81 is not provided.

  In the embodiment described above, the lower portion of the spherical bearing member 28 protrudes from the lower surface of the main body 21, but the entire spherical bearing member 28 is housed in the mounting recess 27 as in the first embodiment, and the lower surface of the main body 21. The spherical bearing member 28 may be flush with the lower surface of the spherical bearing member 28.

  In the above embodiment, the stepped surface 82 for supporting the lower surface of the cylindrical collar 81 is formed on the support 30. However, instead of the stepped surface 82, the upper surface of the base 12 included in the non-contact support device 11 (unit installation) The lower surface of the cylindrical collar 81 may be supported by the surface. By doing so, no new work is required for the support body 30, and the tilt suppression function can be easily given to the floating unit only by providing the cylindrical collar 81.

The partial sectional view of the levitation unit in a 1st embodiment. Explanatory drawing for demonstrating the inclination suppression function of a floating unit. The top view which shows a non-contact support apparatus. Operation | movement explanatory drawing explaining a stage mounting operation | movement. Operation | movement explanatory drawing explaining the stage following operation | movement of a main body. The partial sectional view of the levitation unit which is another example (difference of passage composition) of a 1st embodiment. The partial cross section figure of the floating unit which is another example (difference of a rocking | fluctuation mechanism) of 1st Embodiment. The partial sectional view of the levitation unit in a 2nd embodiment. Explanatory drawing for demonstrating the inclination suppression function of a floating unit. The partial sectional view of the levitation unit which is another example (difference of passage composition) of a 2nd embodiment. The partial cross section figure of the floating unit which is another example (difference of a rocking | fluctuation mechanism) of 2nd Embodiment. The partial sectional view of the levitation unit in a 3rd embodiment. Operation | movement explanatory drawing explaining the stage following operation | movement of a main body. The partial cross section figure of the levitating unit which is another example (difference of a tilt suppression member) of 3rd Embodiment. Explanatory drawing explaining one problem at the time of using the conventional floating unit. Explanatory drawing explaining one problem at the time of using the conventional floating unit. Explanatory drawing explaining one problem at the time of using the conventional floating unit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Non-contact support apparatus, 12 ... Base | substrate (base) 13 ... Levitation unit, 14 ... Jetting surface, 20 ... Main body, 23 ... Gas passage, 28a ... Spherical bearing part (accommodating part, upper side contact part, lower side contact) Part), 29 ... O-ring (elastic ring member), 30 ... support, 31 ... main shaft part (shaft part), 35 ... sphere part, 42 ... passage for adjusting internal pressure, 60 ... floating unit, 61 ... spherical bearing part ( Accommodating portion, upper abutment portion) 63... Accommodation hole (accommodating portion), 65... O-ring (elastic annular member, lower abutment portion), 80. Shaped member), K ... closed space, S ... stage (work).

Claims (7)

A main body having an ejection surface for ejecting pressurized gas is supported by a support, and is a floating unit that supports a workpiece in a non-contact manner by pressurized gas ejected from the ejection surface,
A swing mechanism that allows the main body to swing so that the ejection surface follows the tilt of the workpiece;
A tilt suppression mechanism that suppresses tilting of the main body by its own weight;
Equipped with a,
The swing mechanism is
A spherical portion provided on either the main body or the support;
A housing provided on the other side for housing the spherical body portion and having at least an upper contact portion that contacts the spherical upper surface of the received spherical portion in an annular shape and a lower contact portion that contacts the spherical lower surface and the annular shape. And
Have
The tilt suppression mechanism is
An elastic annular member that comes into contact with the spherical surface of the spherical portion housed in the housing portion;
A closed space provided inside the other by the arrangement of the elastic annular member and sealed by the elastic annular member;
An internal pressure adjusting passage that communicates with the closed space and allows the internal pressure of the closed space to be adjusted;
Have
The levitation unit, wherein the closed space is disposed at a position where the main body is pushed up by an increase in pressure in the closed space . The levitation unit according to claim 1 , wherein at least one of the upper contact portion and the lower contact portion is a spherical bearing portion. The internal pressure control passage, the floating unit according to claim 1 or 2, characterized in that provided separately from the gas passage provided in said body to supply pressurized gas to the jet plane. The levitation unit according to any one of claims 1 to 3 , wherein the elastic annular member is provided on a spherical upper surface of the sphere portion. The said elastic annular member is provided in the spherical-surface lower part of the said spherical body part, and the spherical contact part of the said elastic annular member is the said lower side contact part, The Claim 1 thru | or 3 characterized by the above-mentioned. Levitation unit. A main body having an ejection surface for ejecting pressurized gas is supported by a support, and is a floating unit that supports a workpiece in a non-contact manner by pressurized gas ejected from the ejection surface,
A swing mechanism that allows the main body to swing so that the ejection surface follows the tilt of the workpiece;
An inclination suppressing member provided so as to be able to come into contact with the main body, which has an elastic force capable of elastic deformation with respect to the follow-up force to the workpiece while suppressing the inclination due to the own weight of the main body, and to be inclined by the own weight. ,
Equipped with a,
The swing mechanism is
A spherical portion provided on either the main body or the support;
An accommodating portion that is provided on the other side and accommodates the spherical portion in a state of being in contact with the spherical surface of the spherical portion;
The levitation unit , wherein the tilt suppressing member is a cylindrical member that is provided on a shaft portion extending from the spherical body portion and is capable of contacting the lower surface of the main body to be tilted by its own weight . A non-contact support device in which a plurality of levitation units according to any one of claims 1 to 6 are installed on a base.

Images