CN114483786A

CN114483786A - Split type air foot

Info

Publication number: CN114483786A
Application number: CN202011263833.9A
Authority: CN
Inventors: 张雯
Original assignee: Shanghai Micro Electronics Equipment Co Ltd
Current assignee: Shanghai Micro Electronics Equipment Co Ltd
Priority date: 2020-11-12
Filing date: 2020-11-12
Publication date: 2022-05-13
Anticipated expiration: 2040-11-12
Also published as: CN114483786B

Abstract

The invention discloses a split type air foot, and belongs to the technical field of photoetching equipment. The split type air foot comprises: the pneumatic foot plate is provided with a vacuum groove on the bottom surface, and a downward preloading force is provided by vacuumizing the vacuum groove; the air floatation mechanism is arranged on the air foot plate and is used for providing upward air buoyancy; the preloading mechanism comprises a preloading force transmission frame arranged on the gas pedal plate and a sealing plate arranged at the bottom of the preloading force transmission frame, the sealing plate is used for sealing the vacuum groove, and the preloading force transmission frame is used for transmitting the preloading force to the gas pedal plate; a seal separation structure is disposed between the gas foot plate and the seal plate, the seal separation structure being configured to effect disengagement of the seal plate from the gas foot plate while maintaining the vacuum groove sealed. The split air foot provided by the invention realizes vertical decoupling of the preloading force transmission frame while ensuring sealing of the vacuum groove, and is beneficial to reducing deformation of the air foot plate.

Description

Split type gas foot

Technical Field

The invention relates to the technical field of photoetching equipment, in particular to a split type gas foot.

Background

In semiconductor lithography equipment, air foot is usually used to provide air-floating support for the motion stage, so as to ensure frictionless motion of the motion stage on the corresponding platform. An air floatation mechanism and a preloading mechanism are simultaneously arranged on an air foot plate of the air foot, wherein the air floatation mechanism of the air foot provides upward air buoyancy, and the preloading mechanism of the air foot provides downward preloading force, so that air floatation balance is ensured; the air floatation rigidity of the air foot is adjusted by changing the magnitude of the air buoyancy and the preload.

Although the existing split type air foot is formed by dividing the air floating mechanism and the preloading mechanism into two independent components, the preloading mechanism still needs to provide an upward pressing force to press a sealing ring between the preloading mechanism and an air foot plate, so that good sealing is maintained, and vacuumizing is facilitated to output preloading force, namely the preloading mechanism and the air foot plate are still in rigid connection, and the preloading force generated by the preloading mechanism can act on the whole air foot plate to cause deformation, so that the air floating support is not stable enough, and a motion table can not move stably.

Disclosure of Invention

The invention aims to provide a split type air foot which can reduce the deformation of an air foot plate and ensure stable air floatation support.

In order to realize the purpose, the following technical scheme is provided:

a split-type air-foot for supporting a motion stage for frictionless motion on a work platform, the split-type air-foot comprising:

the pneumatic foot plate is provided with a vacuum groove on the bottom surface, and a downward preloading force is provided by vacuumizing the vacuum groove;

the air floatation mechanism is arranged on the air foot plate and used for providing upward air buoyancy;

the preloading mechanism comprises a preloading force transmission frame arranged on the gas pedal plate and a sealing plate arranged at the bottom of the preloading force transmission frame, the sealing plate is used for sealing the vacuum groove, and the preloading force transmission frame is used for transmitting the preloading force to the gas pedal plate;

a seal separation structure is disposed between the gas foot plate and the seal plate, the seal separation structure being configured to effect disengagement of the seal plate from the gas foot plate while maintaining the vacuum groove sealed.

As a preferred embodiment of the above split type air foot, the seal separation structure includes:

the blocking piece is movably arranged between the groove top of the vacuum groove and the sealing plate; sealing grooves are formed on the side wall of the sealing plate, the side wall of the vacuum groove and the bottom surface of the blocking piece;

and the sealing glue is filled in the sealing groove so as to realize the sealing of the vacuum groove.

As a preferred embodiment of the split air foot, the air foot plate is provided with an accommodating groove and the vacuum groove which are sequentially communicated from top to bottom, so that the air foot plate forms a hollow frame structure; the preload force transmission frame is arranged in the accommodating groove.

As a preferred embodiment of the split type air foot, a groove top of the vacuum groove and a groove wall of the accommodating groove form a step; the barrier extends horizontally from the side wall of the vacuum groove to the outside of the step.

As a preferred embodiment of the above split type air foot, the blocking member is a sheet structure, and the width of the blocking member is greater than the width of the sealant.

As a preferable embodiment of the split type air foot, the sealing plate has an inverted T-shaped structure, the sealing plate includes a connecting portion and a sealing portion, the connecting portion is connected to the bottom of the preload force transmission frame, the sealing portion is located in the vacuum chamber, and the blocking member is located between a top surface of the sealing portion and a top surface of the vacuum chamber.

As an preferable implementation manner of the above split type air foot, the accommodating groove includes a first accommodating groove and a second accommodating groove which are sequentially communicated from top to bottom, the preloading force transfer frame is located in the first accommodating groove, and the groove top of the vacuum groove and the groove wall of the second accommodating groove form the step.

As a preferred embodiment of the above split type air foot, the preload force transmission frame is connected with the air foot plate through a preload force transmission column; the preload force transmission frame is provided with a first groove, the air foot plate is provided with a second groove, the first groove and the second groove are arranged at intervals in the vertical direction, and two ends of the preload force transmission column in the axial direction are movably arranged in the first groove and the second groove respectively.

As a preferred embodiment of the split air foot, a connection point of the preload force transmission column and the preload force transmission frame, a connection point of the preload force transmission column and the air foot plate, and a center of the air floating mechanism are all located on a same straight line perpendicular to the working platform.

In a preferred embodiment of the above split air foot, there is a gap in the horizontal direction between the preload force transmission column and each of the groove wall of the first groove and the groove wall of the second groove.

In a preferred embodiment of the split air foot, two end faces of the preload force transmission column arranged along the axial direction are both arc-shaped faces, and the groove top of the first groove and the groove bottom of the second groove are both flat faces, so that the preload force transmission column forms point contact with both the first groove and the second groove.

As a preferred embodiment of the above split air foot, an adaptor is disposed on a top portion of the preload force transmission frame, the adaptor extends obliquely upward along a direction away from the preload force transmission frame, and the first groove is disposed on the adaptor.

As a preferred embodiment of the split air foot, an air guide groove is arranged on the bottom surface of the air foot plate, the air guide groove is arranged between the air floating mechanism and the vacuum groove, and air output by the air floating mechanism can enter the air foot plate through the air guide groove, so that the air floating mechanism is isolated from the vacuum groove.

In a preferred embodiment of the split type air foot, the working platform has ferromagnetism, and a magnet array is further arranged at the bottom of the sealing plate, so that a preload force is provided by the magnetic force between the magnet array and the working platform.

Compared with the prior art, the invention has the beneficial effects that:

according to the split type air foot provided by the invention, the sealing separation structure is arranged between the air foot plate and the sealing plate, so that the sealing is ensured, and the separation of the sealing plate and the air foot plate is realized at the same time, namely, the vertical decoupling of the preloading force transmission frame is realized, the rigid connection between the preloading mechanism and the air foot plate is avoided, the deformation of the air foot plate is favorably reduced, and the stable air floatation support is ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

Fig. 1 is a first schematic structural diagram of a split type air foot according to an embodiment of the present invention;

FIG. 2 is a second schematic structural diagram of a split type air foot according to an embodiment of the present invention;

FIG. 3 is a top view of a split-type gas foot in accordance with an embodiment of the present invention;

FIG. 4 is a bottom view of a split pneumatic foot according to an embodiment of the present invention;

FIG. 5 is a first exploded view of a split type air foot according to an embodiment of the present invention;

FIG. 6 is an exploded view of the split type air foot according to the embodiment of the present invention;

FIG. 7 is a cross-sectional view taken along plane A-A of FIG. 4;

FIG. 8 is an enlarged view of a portion of FIG. 7 at B;

FIG. 9 is a schematic view of a barrier according to an embodiment of the present invention;

FIG. 10 is a schematic view of the sealant of an embodiment of the present invention after curing;

FIG. 11 is an assembly view of the preload force transfer post and preload force transfer frame and the gas pedal in an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of another split type air foot in the embodiment of the invention;

fig. 13 is a bottom view of another split pneumatic foot in accordance with an embodiment of the present invention.

Reference numerals:

10. a gas foot plate; 20. an air floatation mechanism; 30. a preload mechanism; 40. a flexible reed;

11. a first accommodating groove; 12. a second accommodating groove; 13. a vacuum tank; 14. a boss; 15. a vent hole; 16. a vacuum air exhaust hole; 17. a gas guide groove; 18. a first interface; 19. a second interface; 31. a preload force transfer frame; 32. a sealing plate; 33. a barrier; 34. sealing glue; 35. a preload force transfer post; 36. an adapter; 37. a magnet;

141. a second groove; 361. a support portion; 362. a transmission section;

3621. a first groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that are conventionally placed when the products of the present invention are used, and are used only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements to be referred to must have specific orientations, be constructed in specific orientations, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

FIG. 1 is a first schematic structural diagram of a split-type air foot according to an embodiment of the present invention; FIG. 2 is a second schematic structural diagram of a split type air foot according to an embodiment of the present invention; FIG. 3 is a top view of a split-type gas foot in accordance with an embodiment of the present invention; FIG. 4 is a bottom view of a split pneumatic foot according to an embodiment of the present invention; FIG. 5 is an exploded view of the first split type air foot according to the embodiment of the present invention; FIG. 6 is an exploded view of the split type air foot according to the embodiment of the present invention; FIG. 7 is a cross-sectional view taken along plane A-A of FIG. 4; FIG. 8 is an enlarged view of a portion of FIG. 7 at B; as shown in fig. 1 to 8, the present embodiment is directed to providing a split type air foot for supporting a motion platform to make frictionless motion on a work platform, the split type air foot includes an air foot plate 10, an air floating mechanism 20 and a preloading mechanism 30, a vacuum groove 13 is formed on a bottom surface of the air foot plate 10, a certain space is formed between the vacuum groove 13 and the work platform, and a downward preloading force can be provided by vacuuming the vacuum groove 13; the air floatation mechanism 20 is arranged on the air foot plate 10 and used for providing upward air buoyancy, and the whole split type air foot keeps balance under the action of the air buoyancy and the pre-loading force, so that stable air floatation support is realized; the preload mechanism 30 includes a preload force transfer frame 31 provided on the gas foot plate 10 and a sealing plate 32 provided at the bottom of the preload force transfer frame 31, the sealing plate 32 is used to seal the vacuum groove 13 and ensure smooth completion of vacuum-pumping, and the preload force transfer frame 31 is used to transfer the preload force generated by vacuum-pumping to the gas foot plate 10. A seal separation structure is provided between the gas foot plate 10 and the seal plate 32, and the seal separation structure is configured to achieve separation of the seal plate 32 from the gas foot plate 10 while maintaining the seal of the vacuum groove 13. Specifically, referring to fig. 7 and 8, the sealing separation structure includes a blocking member 33 and a sealant 34, the blocking member 33 is movably disposed between the top of the vacuum chamber 13 and the sealing plate 32, a sealing groove is formed on the sidewall of the sealing plate 32, the sidewall of the vacuum chamber 13 and the bottom surface of the blocking member 33, and the sealant 34 is filled in the sealing groove to realize the sealing of the vacuum chamber 13.

The preloading mechanism 30 outputs the preloading force in a vacuum preloading mode, wherein the vacuum preloading mode is that the vacuum groove 13 is vacuumized to form negative pressure to generate the preloading force, so that the sealing performance of the vacuum groove 13 needs to be effectively ensured; in this embodiment, the sealant 34 is filled into the sealing groove by pouring, and after the sealant 34 is cured, the sealant can be tightly bonded to the sidewall of the sealing plate 32, the sidewall of the vacuum groove 13, and the bottom surface of the blocking member 33, thereby sufficiently sealing the vacuum groove 13; meanwhile, the top surface of the blocking member 33 is in non-fixed contact with the top of the vacuum chamber 13, i.e. there is no fixed connection in any way, and the blocking member 33 can be freely separated from the top of the vacuum chamber 13. When the preloading force transmission frame 31 and the sealing plate 32 are subjected to downward preloading force, the blocking piece 33 can be pulled through the sealant 34, so that the blocking piece 33 is separated from the groove top of the vacuum groove 13, namely the sealing plate 32 is separated from the air foot plate 10, and the vertical decoupling of the preloading force transmission frame 31 is realized, so that the preloading force transmission frame 31 has vertical freedom of movement; the sealant 34 can elastically deform, so that the preload transmitted to the sealing separation structure can be absorbed by the sealant 34, the preload is prevented from directly acting on the air foot plate 10 through the sealing plate 32, the deformation of the air foot plate 10 is reduced, and the stable support of the air foot is ensured. In conclusion, the arrangement of the sealing and separating structure in the embodiment avoids the rigid connection between the sealing plate 32 and the gas foot plate 10 in the vertical direction, and realizes the vertical decoupling of the preloading force transmission frame 31 while ensuring the sealing; in this embodiment, the vertical direction is a direction perpendicular to the working platform, i.e., a vertical direction.

Specifically, the air foot plate 10 is provided with a containing groove and a vacuum groove 13 which are sequentially communicated from top to bottom, so that the air foot plate 10 forms a hollow frame structure; the preload force transmission frame 31 is disposed in the accommodating groove. With continued reference to fig. 8, a step is formed between the groove top of the vacuum groove 13 and the groove wall of the accommodating groove; optionally, a barrier 33 extends horizontally from the sidewall of the vacuum groove 13 out of the step. Further, the width of the blocking part 33 is larger than that of the sealant 34, so that the sufficient blocking effect of the blocking part 33 is ensured; further optionally, in this embodiment, the side wall of the sealing plate 32 and the groove wall of the receiving groove are located on the same vertical plane, that is, the blocking member 33 may be overlapped on the sealing plate 32 once protruding out of the step, so that when the blocking member 33 is stably placed, an enough space for the sealing groove is provided, and it is ensured that the sealant 34 is sufficient.

FIG. 9 is a schematic view of a barrier according to an embodiment of the present invention; FIG. 10 is a schematic view of the sealant of an embodiment of the present invention after curing; referring to fig. 1, 4 and 10, since the vacuum groove 13 is a cavity structure on the bottom surface of the gas foot plate 10, the sealant 34 is finally cured to form a ring-shaped structure; accordingly, referring to fig. 9, the barrier 33 is also a loop-like structure. In this embodiment, the blocking member 33 is also a sheet structure, that is, the size of the blocking member 33 in the thickness direction is small, so that the blocking member can conveniently and smoothly separate from the air foot plate 10 while avoiding occupying the vertical space of the vacuum chamber 13. Optionally, the barrier 33 is made of paper tape.

Further, referring to fig. 8, the sealing plate 32 is an inverted T-shaped structure, and specifically includes a connecting portion connected to the bottom of the preload force transmission frame 31 and a sealing portion located in the vacuum groove 13 to support the blocking member 33, that is, the blocking member 33 is located between the top surface of the sealing portion and the groove top of the vacuum groove 13. Specifically, optionally, referring to fig. 7 and 8, the accommodating grooves include a first accommodating groove 11 and a second accommodating groove 12 which are sequentially communicated from top to bottom, the second accommodating groove 12 is communicated with the first accommodating groove 11 and the vacuum groove 13, the preload force transfer frame 31 is located in the first accommodating groove 11, and a step is formed between the groove top of the vacuum groove 13 and the groove wall of the second accommodating groove 12; further alternatively, the sealing plate 32 is located in the second accommodation groove 12 and the vacuum groove 13. Further, the connecting portion of the sealing plate 32 and the sealing portion are of an integrated structure.

Referring to fig. 2 and 7, the preload force transmission frame 31 is connected to the gas pedal 10 through the preload force transmission post 35; FIG. 11 is an assembly view of the preload force transfer post and preload force transfer frame and the gas pedal in an embodiment of the present invention; specifically, referring to fig. 11, the preload force transmission frame 31 is provided with a first groove 3621, the gas pedal 10 is provided with a second groove 141, the first groove 3621 and the second groove 141 are vertically spaced, and two ends of the preload force transmission column 35 along the axial direction are movably disposed in the first groove 3621 and the second groove 141, respectively. The movable connection between the preload force transmission frame 31 and the gas pedal 10 is realized through the preload force transmission column 35, so that the preload force is transmitted from the preload mechanism 30 to the gas pedal 10, the preload force transmission frame 31 is decoupled in the x direction, the y direction and the z direction, the preload force is accurately and effectively transmitted in the vertical direction, and the force transmission deviation is avoided. Referring to fig. 2 and 7, the x, y and z directions described herein can be understood as three coordinate directions in a three-dimensional coordinate system in space, wherein x and y are two directions perpendicular to each other in a horizontal plane, and the z direction is a vertical direction, i.e., a vertical direction.

Referring to fig. 3, the connection point of the preload force transmission column 35 and the preload force transmission frame 31, the connection point of the preload force transmission column 35 and the air foot plate 10, and the center C of the air floating mechanism 20 are all located on the same straight line perpendicular to the working platform, so that the acting point of the preload force on the air foot plate 10 and the acting point of the air floating force coincide with each other, thereby ensuring the stability of the air floating support and avoiding unnecessary deformation of the air foot plate 10 caused by the preload force acting on other positions of the air foot plate 10. Further, the axis of first recess 3621, the axis of second recess 141 and the axis of preload force transfer post 35 coincide with each other; the connection point of the preload force transmission column 35 and the preload force transmission frame 31, the connection point of the preload force transmission column 35 and the air foot plate 10 and the center of the air floating mechanism 20 are all located on the axis of the preload force transmission column 35, so that the structural design is further optimized, and the effective transmission of force is ensured. In order to ensure the stable operation of the whole motion platform, a plurality of air floating mechanisms 20 are arranged; specifically, the preload force transmission columns 35 and the air bearing mechanisms 20 correspond one-to-one in number; accordingly, the number of preload force transfer columns 35, first recesses 3621 and second recesses 141 also correspond one-to-one. The preload force on the preload force transmission frame 31 can be decomposed into a plurality of component forces according to the number of the preload force transmission columns 35, each component force is balanced with the air buoyancy of the air floating mechanism 20 at the corresponding position, and therefore uniform and stable air floating support of the whole air foot is achieved. Further, referring to fig. 11, the preload force transmission column 35 has a horizontal clearance with both the groove wall of the first recess 3621 and the groove wall of the second recess 141 to increase the movement space of the preload force transmission column 35; furthermore, two end faces of the preload force transmission column 35 axially arranged are both arc-shaped faces, and the groove top of the first groove 3621 and the groove bottom of the second groove 141 are both planes, so that the preload force transmission column 35 and the grooves form point contact; the above arrangement can improve the degree of decoupling of the preload force transmission frame 31.

The top surface of the preload force transfer frame 31 is flush with the top surface of the gas pedal 10 to achieve stable placement of the preload force transfer frame 31 in the first receiving groove 11. With the above arrangement, in order to achieve the movable connection between the preload force transfer frame 31 and the gas pedal 10, still referring to fig. 7 and 11, an adapter 36 is disposed on the top of the preload force transfer frame 31, the adapter 36 extends obliquely upward in a direction away from the preload force transfer frame 31, and the first recess 3621 is disposed on the adapter 36, so as to ensure that the first recess 3621 is vertically spaced from the second recess 141. Further, referring to fig. 2, 5 and 11, the bosses 14 are provided on the top surface of the gas foot plate 10, and the second grooves 141 are provided on the bosses 14, so that the strength and structure of the gas foot plate 10 are prevented from being adversely affected by slotting on the top surface of the gas foot plate 10. Alternatively, the adaptor 36 includes a support portion 361 and a transfer portion 362, the support portion 361 connects the transfer portion 362 and the preload force transfer frame 31, and the first groove 3621 is provided on a bottom surface of the transfer portion 362; further, the supporting portion 361 is a wedge-shaped structure, and the wedge-shaped structure design can avoid interference with the air foot plate 10 during extension, and can improve the overall connection strength of the adaptor 36.

The air floating mechanism 20 and the air foot plate 10 are of an integrated structure, the air floating mechanism 20 can be formed by processing the air foot plate 10, so that the manufacturing is convenient, the integrity and strength requirements of a split type air foot are met, and the good coplanarity of the air floating surface and the consistency of the air buoyancy force borne by the air foot plate 10 are ensured. In this embodiment, referring to fig. 1, 3 and 4, the air foot plate 10 has a rectangular structure, and four air floating mechanisms 20 are provided, where the four air floating mechanisms 20 are respectively located at four top corners of the air foot plate 10, so as to make the stress of the air foot plate 10 uniform. Further, the vacuum groove 13 is disposed at the center of the air foot plate 10 and has a "middle" shape, so as to be as close to the air floating mechanism 20 at the four corners as possible, thereby uniformly and smoothly transmitting the preload force to the four corners of the air foot plate 10. Further, the sealant 34 and the barrier 33 are also conformal designed along the outer contour of the vacuum groove 13. Further, the cross section of the preload force transmission frame 31 is rectangular, and four adapters 36 and four preload force transmission columns 35 are provided on the preload force transmission frame 31 and located at the four corners of the preload force transmission frame 31 to match with the four air floating mechanisms 20.

Referring to fig. 3, the gas pedal 10 is further provided with a flexible spring plate 40, which is mainly used for positioning the preload force transmission frame 31 in the horizontal plane, so as to ensure the relative stability of the installation position; the flexible springs 40 have high stiffness in the horizontal direction but low stiffness in the vertical direction, thus providing some vertical freedom while ensuring that the preload mechanism 30 does not move horizontally relative to the gas plate 10. Alternatively, in the case where the preload force transmission frame 31 has a rectangular configuration, the number of the flexible spring pieces 40 is three, and the three flexible spring pieces 40 are respectively located on three sequentially connected three sides of the preload force transmission frame 31. The split air foot provided by the embodiment can realize the relative stability of the installation position of the preloading force transmission frame 31 and the decoupling between the preloading force transmission frame 31 and the air foot plate 10 through the movable connection between the preloading force transmission frame 31 and the air foot plate 10 and the comprehensive action of the flexible spring pieces 40, thereby ensuring the accurate transmission of the preloading force along the vertical direction and providing stable air floatation support.

Referring to fig. 7, the first receiving groove 11 is an inverted cone structure, and accordingly, the longitudinal section of the pre-load force transfer frame 31 is also an inverted cone structure adapted to the first receiving groove 11; different from traditional split type air foot, there is not rigid connection between split type air foot's the preload force transfer frame 31 that this embodiment provided and the air foot board 10, consequently, the setting that adopts the toper structure can be when preloading power is too big, makes the air foot board 10 carry on spacingly and support preloading force transfer frame 31, avoids sealed glue 34 excessively to drag and causes vacuum chamber 13's sealed inefficacy.

Referring to fig. 1 and 2, in order to realize the air floating function of the air floating mechanism 20, a vent hole 15 is provided on the bottom surface of the air foot plate 10, and positive pressure gas generated by the air floating mechanism 20 is released from the vent hole 15; accordingly, the air foot plate 10 is provided with a first interface 18 for inputting positive pressure air in the air floating mechanism 20. Further, a vacuum pumping hole 16 is formed in the bottom surface of the gas foot plate 10, the vacuum pumping hole 16 is communicated with the vacuum groove 13, a second interface 19 is formed in the gas foot plate 10, and the second interface 19 is communicated with the vacuum pumping hole 16, so that the vacuum pumping operation of the vacuum groove 13 is realized, and the loading of the preload force is realized. Further, the air foot plate 10 is further provided with an air guide groove 17, the air guide groove 17 is arranged between the air floating mechanism 20 and the vacuum groove 13, positive pressure gas output by the air floating mechanism 20 can enter the air foot plate 10 through the air guide groove 17, a path for the positive pressure gas of the air floating mechanism 20 to flow to the vacuum groove 13 is cut off, and an effective isolation effect between the air floating mechanism 20 and the vacuum groove 13 is achieved. Further, the wall of the air guide groove 17 is provided with air guide holes, and positive pressure gas which flows through enters the air foot plate 10 through the air guide holes; the isolation effect can be adjusted by the limitation of the number and the aperture of the air vents. In this embodiment, referring to fig. 4, the guiding groove is in an L-shaped structure, so as to match with the air floating mechanism 20 distributed at four corners and the vacuum groove 13 in the shape of a Chinese character 'zhong', and play a role of effectively isolating the vacuum groove 13 from the air floating mechanism 20.

FIG. 12 is a schematic structural diagram of another split type air foot in the embodiment of the invention; fig. 13 is a bottom view of another split pneumatic foot in accordance with an embodiment of the present invention. Generally, the working platform of the split air foot is a marble platform, so the preloading mechanism 30 mostly adopts a vacuum preloading mode; however, when the working platform of the split air foot is an iron platform, a steel platform or other working platforms with ferromagnetism, the split air foot of the embodiment can output a certain preload force through the magnetic force, and when the preload force provided by vacuum preload is limited, the magnetic preload mode can be used as a supplement of the preload force. Referring to fig. 12 and 13, in an implementation, the sealing plate 32 may be a magnetic preloading plate, on which a magnet array is disposed, the magnet array includes a plurality of magnets 37 distributed in an array on the magnetic preloading plate, the magnets 37 have magnetism and can generate a magnetic force with the ferromagnetic working platform, so as to form a preloading force, and the preloading force is still transmitted to the air foot plate 10 by the sealing plate 32, the preloading force transmitting frame 31 and the preloading force transmitting column 35, and cooperates with the preloading force generated by vacuum preloading, so as to ensure air bearing balance of the air foot under the action of the preloading force and the air bearing force of the air bearing mechanism 20.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements and substitutions will now be apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. The utility model provides a split type gas foot for support motion platform does frictionless motion on work platform, its characterized in that, split type gas foot includes:

the pneumatic foot plate (10), wherein a vacuum groove (13) is formed in the bottom surface of the pneumatic foot plate (10), and a downward preloading force is provided by vacuumizing the vacuum groove (13);

the air floatation mechanism (20) is arranged on the air foot plate (10) and is used for providing upward air buoyancy;

a preload mechanism (30) comprising a preload force transfer frame (31) provided on the gas foot plate (10) and a sealing plate (32) provided at the bottom of the preload force transfer frame (31), the sealing plate (32) being for sealing the vacuum groove (13), the preload force transfer frame (31) being for transferring a preload force to the gas foot plate (10);

a seal separation structure is provided between the gas foot plate (10) and the seal plate (32), the seal separation structure being configured to effect disengagement of the seal plate (32) from the gas foot plate (10) while maintaining the vacuum groove (13) sealed.

2. The split pneumatic foot of claim 1, wherein the seal separation structure comprises:

a blocking piece (33) movably arranged between the groove top of the vacuum groove (13) and the sealing plate (32); sealing grooves are formed on the side walls of the sealing plate (32), the side walls of the vacuum groove (13) and the bottom surface of the barrier (33);

and the sealant (34) is filled in the sealing groove so as to realize the sealing of the vacuum groove (13).

3. The split type air foot according to claim 2, characterized in that the air foot plate (10) is provided with a containing groove and the vacuum groove (13) which are sequentially communicated from top to bottom, so that the air foot plate (10) forms a hollow frame structure; the preloading force transmission frame (31) is arranged in the accommodating groove.

4. The split type pneumatic foot according to claim 3, wherein the groove top of the vacuum groove (13) forms a step with the groove wall of the accommodating groove; the barrier (33) extends horizontally from the side wall of the vacuum groove (13) to the outside of the step.

5. The split pneumatic foot according to claim 2, wherein the blocking member (33) is a sheet structure, and the width of the blocking member (33) is larger than the width of the sealant (34).

6. The split pneumatic foot according to claim 2, wherein the sealing plate (32) has an inverted T-shaped configuration, the sealing plate (32) includes a connection portion connected to a bottom portion of the preload force transmission frame (31) and a sealing portion located in the vacuum groove (13), and the blocking member (33) is provided between a top surface of the sealing portion and a groove top of the vacuum groove (13).

7. The split type air foot according to claim 4, wherein the accommodating grooves comprise a first accommodating groove (11) and a second accommodating groove (12) which are sequentially communicated from top to bottom, the preloading force transmission frame (31) is located in the first accommodating groove (11), and the groove top of the vacuum groove (13) and the groove wall of the second accommodating groove (12) form the step.

8. The split pneumatic foot according to claim 1, characterized in that the preload force transmission frame (31) and the pneumatic foot plate (10) are connected by a preload force transmission column (35); the preload force transmission frame (31) is provided with a first groove (3621), the air foot plate (10) is provided with a second groove (141), the first groove (3621) and the second groove (141) are arranged at intervals in the vertical direction, and two ends of the preload force transmission column (35) in the axial direction are movably arranged in the first groove (3621) and the second groove (141) respectively.

9. The split air foot according to claim 8, characterized in that the connection point of the preload force transfer column (35) and the preload force transfer frame (31), the connection point of the preload force transfer column (35) and the air foot plate (10), and the center of the air floating mechanism (20) are all located on the same line perpendicular to the working platform.

10. The split pneumatic foot according to claim 8, characterized in that a gap exists in a horizontal direction between the preload force transfer column (35) and both the groove wall of the first groove (3621) and the groove wall of the second groove (141).

11. The split air foot according to claim 8, characterized in that both end surfaces of the preload force transmission column (35) arranged along the axial direction are arc-shaped surfaces, and the groove top of the first groove (3621) and the groove bottom of the second groove (141) are flat surfaces, so that the preload force transmission column (35) forms point contact with both the first groove (3621) and the second groove (141).

12. The split pneumatic foot according to claim 8, characterized in that an adapter (36) is provided on the top of the preload force transmission frame (31), the adapter (36) extending obliquely upward in a direction away from the preload force transmission frame (31), and the first groove (3621) is provided on the adapter (36).

13. The split type air foot according to claim 1, characterized in that an air guide groove (17) is arranged on the bottom surface of the air foot plate (10), the air guide groove (17) is arranged between the air floating mechanism (20) and the vacuum groove (13), and the air output by the air floating mechanism (20) can enter the air foot plate (10) through the air guide groove (17), so that the air floating mechanism (20) is isolated from the vacuum groove (13).

14. The split air foot according to any one of claims 1-13, characterized in that the working platform is ferromagnetic, and a magnet array is further provided at the bottom of the sealing plate (32) to provide a preload force by magnetic force between the magnet array and the working platform.