CN115899081A - Air foot - Google Patents

Abstract

The invention relates to the technical field of semiconductor equipment, in particular to a gas foot. The air floatation mechanism of the air foot comprises an air outlet main pipeline, at least two first branch pipeline groups and air outlet pipelines, wherein the at least two first branch pipeline groups are communicated with the air outlet main pipeline, the first branch pipeline groups are connected with the air outlet pipelines and are arranged in parallel through all the air outlet pipelines, the lengths of paths through which positive pressure air discharged from the air outlet main pipeline flows from the first branch pipeline groups to the air outlet pipelines are the same, and the distribution uniformity of the positive pressure air discharged from the air outlet main pipeline can be ensured. Meanwhile, the arrangement of ruby falling is omitted, so that the flow of positive pressure gas at the gas outlet of the gas outlet pipeline is ensured to be larger, the gas buoyancy is ensured to be larger, and the manufacturing difficulty and cost of the gas foot are reduced. In conclusion, through the structure, the uniform and large air buoyancy of the air foot can be realized, the reliability of the air foot is ensured, and the manufacturing difficulty and the manufacturing cost of the air foot are also reduced.

Description

Qi foot

Technical Field

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

Background

As shown in fig. 1, the air foot 100 can provide an air bearing support for the precision motion stage to ensure frictionless motion of the precision motion stage on the support platform. The air foot 100 comprises an air foot plate 3, an air floating mechanism 1 and a pre-tightening mechanism (not shown in the figure), wherein the air floating mechanism 1 and the pre-tightening mechanism are arranged in the air foot plate 3, air passages are arranged in the air floating mechanism 1 and the pre-tightening mechanism, and air ports are arranged on the surfaces of the air foot plate 3 of the air floating mechanism 1 and the air passages of the pre-tightening mechanism.

When the air foot 100 works, positive pressure air is introduced into an air passage of the air floating mechanism 1, an air film is formed between the air foot 100 and the supporting platform, and the air film enables the air foot 100 to be supported by air buoyancy, so that the air foot 100 can move on the supporting platform without friction; meanwhile, negative pressure gas is introduced into the pre-tightening mechanism, the negative pressure gas enables the air foot 100 to be acted by vacuum pre-tightening force opposite to the direction of the air buoyancy, the sizes of the air buoyancy and the vacuum pre-tightening force are adjusted, and the air floatation rigidity of the air foot 100 can be adjusted.

The existing air floating mechanism 1 comprises an air outlet main pipeline 11 and a plurality of air outlet pipelines 13 which are arranged on an air foot plate 3, wherein the air outlet pipelines 13 are communicated with the air outlet main pipeline 11 and are arranged along the length direction of the air outlet main pipeline 11, and air outlets 131 are formed on the surface of the air foot 100 plate 13 of the air outlet pipelines 13. Positive pressure gas is introduced into one end of the main gas outlet pipeline 11, the gas outlet pipeline 13 close to the positive pressure gas source has high pressure, and the gas outlet pipeline 13 far away from the positive pressure gas source has low pressure, so that the gas flow of different gas outlet pipelines 13 is uneven, and the stable support of the gas film on the gas foot 100 cannot be realized.

In order to solve the above problems, ruby is provided at the air outlet 131 at different positions, and round holes with different diameters of less than 0.2mm are provided in the ruby to form a narrow flow passage, so as to ensure the uniformity of the air buoyancy at different positions.

However, this method increases the cost of the gas foot 100, and on the other hand, the flow rate of the positive pressure gas is small due to the narrow flow passage, so that the gas buoyancy is small, and the reliability of the gas foot 100 is poor.

Therefore, it is necessary to invent an air foot to solve the irreconcilable contradiction between the magnitude of air buoyancy and the uniformity of air buoyancy.

Disclosure of Invention

The invention aims to provide an air foot, which can realize uniform and larger air buoyancy of the air foot and ensure the reliability of the air foot.

In order to achieve the purpose, the invention adopts the following technical scheme:

an air foot comprises an air floatation mechanism, wherein the air floatation mechanism comprises an air outlet main pipeline, at least two first branch pipeline sets and air outlet pipelines, the at least two first branch pipeline sets are communicated with the air outlet main pipeline, the first branch pipeline sets are connected with the air outlet pipelines, all the air outlet pipelines are arranged in parallel, and the lengths of paths from the air outlet main pipeline to the air outlet pipelines are the same; and throttle valves are arranged at the joint of the air outlet main pipeline and each first branch pipeline group and the joint of the first branch pipeline group and the air outlet pipeline.

As a preferred scheme, the first branch pipeline group includes at least two stages of first branch pipelines, the first branch pipeline of the first stage is communicated with the main gas outlet pipeline, the first branch pipeline of the previous stage is connected with at least two first branch pipelines of the next stage along the gas flowing direction, the number of the first branch pipelines of the next stage connected with the first branch pipeline of the same stage is the same, and the output end of the first branch pipeline of the last stage is connected with a gas outlet pipeline.

As a preferable scheme, two first branch pipelines of each previous stage and two first branch pipelines of the next stage corresponding to the first branch pipeline of each previous stage are symmetrically arranged with the first branch pipeline of the previous stage as a center line.

As a preferred scheme, the throttle valve is a first throttle valve, the first throttle valve includes a first plugging end, a second plugging end and a third plugging end which are connected, the first plugging end is communicated with the main gas outlet pipeline, the second plugging end and the third plugging end are respectively communicated with the first branch pipelines of the two first stages, the first throttle valve is provided with a first channel and a second channel which are communicated, the first channel is arranged on the first plugging end, and the second channel penetrates through the second plugging end and the third plugging end;

the cross-sectional area of the first channel is more than 1.5 times of the cross-sectional area of the main gas outlet pipeline and the cross-sectional area of the pipeline of the first branch pipeline group.

As a preferable scheme, the air floating mechanism further includes:

the second throttling valve comprises a fourth plugging end, a fifth plugging end and a sixth plugging end which are connected, the fourth plugging end is communicated with the first branch pipelines of the previous stage, the fifth plugging end and the sixth plugging end are respectively communicated with the first branch pipelines of the two subsequent stages, a third channel and a fourth channel which are communicated with each other are formed in the second throttling valve, the third channel is formed in the fourth plugging end, and the fourth channel penetrates through the fifth plugging end and the sixth plugging end;

the ratio of the cross-sectional area of the third channel to the cross-sectional area of the flow passage of the first branch pipeline of the previous stage is 1/4 to 3/4, and the ratio of the cross-sectional area of the fourth channel to the cross-sectional area of the flow passage of the first branch pipeline of the next stage is 1/4 to 3/4.

As a preferable aspect, the first branch pipe group includes:

and the at least two first branch pipelines are communicated with the main gas outlet pipeline, and the output end of each first branch pipeline is connected with a gas outlet pipeline.

As a preferable scheme, the air foot further comprises a pre-tightening mechanism, the pre-tightening mechanism comprises an air suction main pipeline, at least two second branch pipeline sets and air suction pipelines, the at least two second branch pipeline sets are communicated with the air suction main pipeline, the second branch pipeline sets are connected with the air suction pipelines, all the air suction pipelines are arranged in parallel, and the lengths of paths through which air sucked from the air suction pipelines flows to the air suction main pipeline through the second branch pipeline sets are the same.

As a preferred scheme, the second branch pipeline group includes at least two stages of second branch pipelines, the second branch pipelines of the second stage are communicated with the main air suction pipeline, the second branch pipelines of the previous stage are connected with at least two second branch pipelines of the next stage along the air flow direction, the number of the second branch pipelines of the next stage connected with the second branch pipelines of the same stage is the same, and the output end of the second branch pipeline of the last stage is connected with an air suction pipeline.

As a preferable scheme, two second branch pipes of the next stage corresponding to the second branch pipe of each previous stage are provided, and the two second branch pipes of the next stage are symmetrically arranged with the second branch pipe of the previous stage as a center line.

As a preferable scheme, the air outlets of the air outlet pipelines and the air inlets of the air suction pipelines are uniformly and alternately arranged in a horizontal plane.

The invention has the beneficial effects that:

the air floatation mechanism of the air foot comprises an air outlet main pipeline, at least two first branch pipeline groups and air outlet pipelines, wherein the at least two first branch pipeline groups are communicated with the air outlet main pipeline, the first branch pipeline groups are connected with the air outlet pipelines and are arranged in parallel through all the air outlet pipelines, the lengths of paths through which positive pressure air discharged from the air outlet main pipeline flows from the first branch pipeline groups to the air outlet pipelines are the same, and the distribution uniformity of the positive pressure air discharged from the air outlet main pipeline can be ensured. Meanwhile, the setting of ruby dropping is cancelled, so that the flow of positive pressure gas at the gas outlet of the gas outlet pipeline is ensured to be larger, the gas buoyancy is ensured to be larger, and the manufacturing difficulty and cost of the gas foot are also reduced.

To sum up, through above-mentioned structure, can realize the even and great gas buoyancy of sufficient gas, guarantee the reliability of sufficient gas, still reduced the manufacturing degree of difficulty and the cost of sufficient gas.

Drawings

FIG. 1 is a schematic diagram of a prior art pneumatic foot;

FIG. 2 is a first schematic structural diagram of a pneumatic foot according to a first embodiment of the present invention;

FIG. 3 is a first schematic structural diagram of an air floating mechanism according to a first embodiment of the present invention;

fig. 4 is a schematic structural diagram of an air floating mechanism according to a first embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a first throttle valve provided in accordance with an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a second throttle valve provided in the first embodiment of the invention;

FIG. 7 is a schematic structural diagram of a pretensioning mechanism provided in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a pneumatic foot according to the first embodiment of the present invention;

FIG. 9 is a schematic structural diagram of an air floating mechanism according to a second embodiment of the present invention;

fig. 10 is a schematic structural view of a pneumatic foot provided in the third embodiment of the present invention.

In the figure:

100-qi foot;

1-an air floating mechanism; 11-main outlet gas pipeline; 12-a first set of branch lines; 121-first branch line; 122-second stage first branch line; 123-a third-stage first branch pipeline; 124-four stage first branch pipeline; 13-gas outlet pipeline; 131-an air outlet; 14-a first throttle valve; 141-a first plug end; 142-a second plug end; 143-a third plug end; 144-a first channel; 145-a second channel; 15-a second throttle valve; 151-fourth plug end; 152-a fifth splicing end; 153-sixth plug end; 154-a third channel; 155-fourth channel;

2-pre-tightening force mechanism; 21-a main inspiration line; 22-a second group of branch lines; 221-stage second branch line; 222-a second branch line; 223-third stage second branch line; 224-fourth stage second branch line; 23-an aspiration line; 231-suction port; 24-a pipe with a square shape;

3-air foot plate.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings.

In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. 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 expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. 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. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

Example one

As shown in fig. 2, the air foot 100 can provide air bearing support for the precision motion stage to ensure frictionless motion of the precision motion stage on the support platform. The air foot 100 comprises an air foot plate 3, an air floating mechanism 1 and a pre-tightening mechanism (not shown in the figure), wherein the air floating mechanism 1 and the pre-tightening mechanism are arranged in the air foot plate 3, air passages are arranged in the air floating mechanism 1 and the pre-tightening mechanism, and air ports are arranged on the surfaces of the air foot plate 3 of the air floating mechanism 1 and the air passages of the pre-tightening mechanism.

When the air foot 100 works, positive pressure air is introduced into an air passage of the air floating mechanism 1, an air film is formed between the air foot 100 and the supporting platform, and the air film enables the air foot 100 to be supported by air buoyancy, so that the air foot 100 can move on the supporting platform without friction; meanwhile, negative pressure gas is introduced into the pre-tightening mechanism, the negative pressure gas enables the air foot 100 to be acted by vacuum pre-tightening force opposite to the direction of the air buoyancy, the sizes of the air buoyancy and the vacuum pre-tightening force are adjusted, and the air floatation rigidity of the air foot 100 can be adjusted.

As shown in fig. 2, the air floating mechanism 1 includes an air outlet main pipeline 11, at least two sets of first branch pipeline groups 12 and air outlet pipelines 13, at least two sets of first branch pipeline groups 12 are communicated with the air outlet main pipeline 11, the first branch pipeline groups 12 are connected with the air outlet pipelines 13, the air outlet main pipeline 11 is connected in parallel through all the air outlet pipelines 13, positive pressure gas is introduced into the air outlet main pipeline 11, the path length from the air outlet main pipeline 11 to the air outlet pipelines 13 through the first branch pipeline groups 12 is the same, and the uniformity of the flow distribution of the positive pressure gas from the air outlet main pipeline 11 can be ensured. Meanwhile, the arrangement of falling ruby is omitted, so that the flow of positive pressure gas at the gas outlet 131 of the gas outlet pipeline 13 is ensured to be larger, the gas buoyancy is ensured to be larger, and the manufacturing difficulty and cost of the gas foot are reduced.

The junction of main pipe way 11 and every first branch pipeline group 12 of giving vent to anger, and the junction of first branch pipeline group 12 and gas outlet pipe way 13 all is equipped with the choke valve, and the malleation is gaseous can play certain cushioning effect in the choke valve to buffer the velocity of malleation gas along the extending direction of main pipe way 11 of giving vent to anger, and then play even malleation gas flow's effect, guarantee the pressure intensity uniformity of the malleation gas of every gas outlet 131.

In summary, through the structure, the uniform and large air buoyancy of the air foot 100 can be realized, the reliability of the air foot 100 is ensured, and the manufacturing difficulty and the cost of the air foot 100 are also reduced.

As a preferable scheme, the air floating mechanism 1 can be realized by 3D printing or molecular diffusion welding and other processes, so that the air floating mechanism 1 is simple and convenient to manufacture.

As shown in fig. 3, in the embodiment, the number of the first branch pipeline sets 12 is two, two first branch pipeline sets 12 are symmetrically distributed on two sides of the main gas pipeline 11 by taking the main gas pipeline 11 as a central line, and the first branch pipeline set 12 includes four stages of first branch pipelines: first branch pipeline 121 of one-level, second grade first branch pipeline 122, tertiary first branch pipeline 123 and level four first branch pipeline 124, first branch pipeline 121 of one-level is linked together with main pipeline 11 of giving vent to anger, along malleation gas flow direction, two first branch pipelines 122 of second grade are connected to first branch pipeline 121 of one-level, two tertiary first branch pipelines 123 are connected to second grade first branch pipeline 122, two first branch pipelines 124 of level four are connected to tertiary first branch pipeline 123, the first branch pipeline 124 output of level four all is connected with air outlet pipe 13. The two second-stage first branch pipelines 122 are symmetrically distributed on two sides of the first-stage first branch pipeline 121 by taking the first-stage first branch pipeline 121 as a central line, the two third-stage first branch pipelines 123 are symmetrically distributed on two sides of the second-stage first branch pipeline 122 by taking the second-stage first branch pipeline 122 as a central line, the two fourth-stage first branch pipelines 124 are symmetrically distributed on two sides of the third-stage first branch pipeline 123 by taking the third-stage first branch pipeline 123 as a central line, 16 air outlet pipelines 13 are arranged in total, air outlets 131 of the 16 air outlet pipelines 13 are uniformly distributed in a horizontal plane, uniform and large air buoyancy can be provided, and the reliability of the air foot 100 is ensured.

In other embodiments, the first branch pipe set 12 may also be three, four or more, the number and layout of the air outlets 131 may be adjusted by adjusting the number of the first branch pipe set 12, the number of the first branch pipe set 12 may be increased to match a precision motion stage with a larger size, and the number of the first branch pipe set 12 may be decreased to match a precision motion stage with a smaller size.

In other embodiments, the number of stages of the first branch pipeline may be two, three, five or more, and the number of stages of the first branch pipeline is at least two, which can ensure that there are more air outlets 131 to cover a larger area, and ensure the reliability of the air foot 100.

As shown in fig. 3, two first branch pipelines of the next stage corresponding to each first branch pipeline of the previous stage are provided, and the first branch pipelines of the two next stages are symmetrically arranged with the first branch pipeline of the previous stage as a central line, so that the first branch pipelines are all arranged in a horizontal plane, the thickness of the air foot plate 3 is ensured to be light and thin, and the space occupied by the air foot plate 3 is small.

In other examples, as shown in fig. 4, the number of the last stage first branch pipes (the fourth stage first branch pipe 124 in this embodiment) may be three, and the three fourth stage first branch pipes 124 are uniformly arranged by using the outlets of the third stage first branch pipes 123, so that the gas outlet pipes 13 can be uniformly distributed, and the gas foot 100 can be ensured to provide uniform gas buoyancy. In other examples, the last stage first branch line may be four, five or more.

As shown in fig. 3, the air floating mechanism 1 further includes a first throttle valve 14 and a second throttle valve 15, the first throttle valve 14 and the second throttle valve 15 are three-way valves, the first throttle valve 14 can realize the quick assembly and disassembly of the air outlet main pipeline 11 and the first branch pipelines 121 of two first levels, the second throttle valve 15 can realize the quick assembly and disassembly of the first branch pipelines of the previous level and the first branch pipelines of two next levels, which is convenient for the operator to quickly assemble the air floating mechanism 1, and can realize the quick replacement of each part of the air floating mechanism 1, thereby ensuring the long-term better use effect of the air floating mechanism 1.

As shown in fig. 5, the first throttle valve 14 includes a first plugging end 141, a second plugging end 142, and a third plugging end 143, which are connected to each other, the first plugging end 141 is communicated with the main gas outlet pipe 11, the second plugging end 142 and the third plugging end 143 are respectively communicated with the two first-stage first branch pipes 121, a first passage 144 and a second passage 145, which are communicated with each other, are formed on the first throttle valve 14, the first passage 144 is formed on the first plugging end 141, the second passage 145 penetrates through the second plugging end 142 and the third plugging end 143, and positive pressure gas discharged from the main gas outlet pipe 11 respectively enters the first-stage first branch pipes 121 on both sides through the first passage 144 and the second passage 145.

Preferably, the cross-sectional area of the first channel 144 is more than 1.5 times the cross-sectional area of the main gas outlet pipeline 11 and the cross-sectional area of the pipeline of the first branch pipeline group 12, and the positive pressure gas can play a certain buffering role in the first channel 144 with a larger cross-sectional area to buffer the speed of the positive pressure gas along the extending direction of the main gas outlet pipeline 11, so as to play a role in equalizing the flow rate of the positive pressure gas, and ensure the consistency of the pressure of the positive pressure gas at each gas outlet 131.

As shown in fig. 6, the second throttle valve 15 includes a fourth plugging end 151, a fifth plugging end 152 and a sixth plugging end 153, which are connected to each other, the fourth plugging end 151 is communicated with the first-stage first branch pipeline 121, the fifth plugging end 152 and the sixth plugging end 153 are respectively communicated with the two second-stage first branch pipelines 122, a third channel 154 and a fourth channel 155, which are communicated with each other, are formed on the second throttle valve 15, the third channel 154 is formed on the fourth plugging end 151, the fourth channel 155 penetrates through the fifth plugging end 152 and the sixth plugging end 153, and positive pressure gas discharged from the first-stage first branch pipeline 121 enters the second-stage first branch pipelines 122 at both sides through the third channel 154 and the fourth channel 155.

Preferably, the ratio of the cross-sectional area of the third channel 154 to the cross-sectional area of the flow path of the primary first branch line 121 is 1/4 to 3/4, and the ratio of the cross-sectional area of the fourth channel 155 to the cross-sectional area of the flow path of the secondary first branch line 122 is 1/4 to 3/4. The positive pressure gas can play a certain role of buffering in the three channels 154 and the fourth channel 155 with larger cross-sectional areas so as to buffer the speed of the positive pressure gas along the extending direction of the main gas outlet pipeline 11, and further play a role of equalizing the flow of the positive pressure gas, and ensure the pressure consistency of the positive pressure gas of each gas outlet 131. Preferably, the ratio of the cross-sectional area of the third passage 154 to the cross-sectional area of the flow passage of the primary first branch line 121 is preferably 1/2, and the ratio of the cross-sectional area of the fourth passage 155 to the cross-sectional area of the flow passage of the secondary first branch line 122 is preferably 1/2.

Preferably, the first throttle valve 14 and the second throttle valve 15 can be realized by a 3D printing process, and the valve structure can be placed in a pipeline with a small aperture by 3D printing.

As shown in fig. 7, the structure of the pre-tightening mechanism 2 is substantially the same as that of the air floating mechanism 1, wherein the pre-tightening mechanism 2 includes a main air suction pipeline 21, at least two second branch pipeline groups 22 and air suction pipelines 23, the at least two second branch pipeline groups 22 are communicated with the main air suction pipeline 21, the air suction pipelines 23 are connected to the second branch pipeline groups 22, all the air suction pipelines 23 are arranged in parallel, and the lengths of the paths through which the air sucked from the air suction pipelines 23 flows from the second branch pipeline groups 22 to the main air suction pipeline 21 are the same. The uniformity of the negative pressure developed from the air line 23 can be ensured. Meanwhile, the arrangement of falling ruby is eliminated, so that the flow of negative pressure gas in the gas suction port 231 of the gas pipeline 23 is ensured to be larger, the vacuum pre-tightening force is ensured to be larger, and the manufacturing difficulty and cost of gas foot are reduced.

As the preferred scheme, the pre-tightening mechanism 2 can be realized through processes such as 3D printing or molecular diffusion welding, so that the pre-tightening mechanism 2 is simple and convenient to manufacture, and a valve structure is placed in a pipeline with a small aperture through 3D printing.

As a preferred scheme, the second branch pipeline group 22 includes at least two stages of second branch pipelines, the second branch pipelines of the second stage are communicated with the main air suction pipeline 21, along the air flowing direction, the second branch pipeline of the previous stage is connected with at least two second branch pipelines of the next stage, the number of the second branch pipelines of the next stage connected with the second branch pipeline of the same stage is the same, and the output end of the second branch pipeline of the last stage is connected with the air suction pipeline 23, so that uniform and large vacuum pretightening force can be provided, and the reliability of the air foot 100 is ensured.

As shown in fig. 7, in the present embodiment, the number of the second branch pipe sets 22 is two, two second branch pipe sets 22 are symmetrically distributed on two sides of the air suction pipe 23 by taking the air suction pipe 23 as a center line, and the second branch pipe set 22 includes four stages of second branch pipes: one-level second branch pipeline 221, second grade second branch pipeline 222, tertiary second branch pipeline 223 and level four second branch pipeline 224, one-level second branch pipeline 221 is linked together with main pipeline 11 of giving vent to anger, along the positive pressure gas flow direction, two second grade second branch pipelines 222 are connected to one-level second branch pipeline 221, two tertiary second branch pipelines 223 are connected to second grade second branch pipeline 222, two level four second branch pipelines 224 are connected to tertiary second branch pipeline 223, level four second branch pipeline 224 output all is connected with out gas pipeline 13. The two second-stage second branch pipelines 222 are symmetrically distributed on two sides of the first-stage second branch pipeline 221 by taking the first-stage second branch pipeline 221 as a central line, the two third-stage second branch pipelines 223 are symmetrically distributed on two sides of the second-stage second branch pipeline 222 by taking the second-stage second branch pipeline 222 as a central line, the two fourth-stage second branch pipelines 224 are symmetrically distributed on two sides of the third-stage second branch pipeline 223 by taking the third-stage second branch pipeline 223 as a central line, 16 air outlet pipelines 13 are arranged, air suction ports 231 of the 16 air outlet pipelines 13 are uniformly distributed in a horizontal plane, uniform and large vacuum pre-tightening force can be provided, and reliability of the air foot 100 is guaranteed.

In other embodiments, the second branch pipe group 22 may be three, four or more, the number and layout of the suction ports 231 may be adjusted by adjusting the number of the second branch pipe group 22, the precision motion stage with a larger size may be matched by increasing the number of the second branch pipe group 22, and the precision motion stage with a smaller size may be matched by decreasing the number of the second branch pipe group 22.

In other embodiments, the number of the second branch pipes may be two, three, five or more, and the number of the second branch pipes is at least two, so that more air inlets 231 can be provided to cover a larger area, and the reliability of the air foot 100 can be ensured.

As a preferred scheme, the number of the second branch pipelines of the next stage corresponding to each second branch pipeline of the previous stage is two, the two second branch pipelines of the next stage are symmetrically arranged by taking the second branch pipeline of the previous stage as a central line, and the second branch pipelines do not additionally occupy the space of the air foot plate 3 in the thickness direction, so that the second branch pipelines are all arranged in the horizontal plane, and the thickness of the air foot plate 3 is ensured to be minimized.

In other examples, the number of the second branch pipes of the last stage (the fourth-stage second branch pipe 224 in this embodiment) may be three, and the three fourth-stage second branch pipes 224 are uniformly arranged by using the outlets of the third-stage second branch pipes 223, so that the air inlets 231 can be uniformly distributed, and the air foot 100 can be ensured to provide uniform vacuum pre-tightening force.

Preferably, as shown in fig. 8, the air floating mechanism 1 and the pre-stressing mechanism 2 are relatively independent in space and do not interfere with each other, and the air outlets 131 of the air outlet pipelines 13 and the air inlets 231 of the air suction pipelines 23 are uniformly and alternately arranged in a horizontal plane, so as to avoid the air foot 100 from generating large deformation under the combined action of the air buoyancy and the pre-stressing force. Preferably, the number and shape of the air outlets 131 and the air inlets 231 are the same, and the air foot 100 can avoid the problem of local depression of the conventional air foot 100.

Example two

As shown in fig. 9, the structure of the air foot 100 is basically the same as that of the air foot 100 of the first embodiment, and the main differences between the two are as follows: the structure of first branch pipeline group 12, specifically, first branch pipeline group 12 includes two at least one-level first branch pipelines 121, and one-level first branch pipeline 121 is linked together with main pipeline 11 of giving vent to anger, and the output of every one-level first branch pipeline 121 is connected with out gas pipeline 13, this kind of air foot 100 simple structure, convenient preparation.

EXAMPLE III

In the present embodiment, as shown in fig. 10, the structure of the air foot 100 is basically the same as that of the air foot 100 of the first embodiment, and the main differences are as follows: the structure of pretightening force mechanism 2, specifically, pretightening force mechanism 2 includes back shape pipeline 24, and back shape pipeline 24 is linked together with main pipeline 21 of breathing in, and a plurality of pipelines 23 of breathing in set up on back shape pipeline 24 along the circumference of back shape pipeline 24, simple structure, convenient preparation.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (10)

1. The air foot comprises an air floatation mechanism (1), and is characterized in that the air floatation mechanism (1) comprises an air outlet main pipeline (11), at least two groups of first branch pipeline groups (12) and air outlet pipelines (13), wherein the at least two groups of first branch pipeline groups (12) are communicated with the air outlet main pipeline (11), the first branch pipeline groups (12) are connected with the air outlet pipelines (13), all the air outlet pipelines (13) are arranged in parallel, and the lengths of paths through which gas exhausted from the air outlet main pipeline (11) flows from the first branch pipeline groups (12) to the air outlet pipelines (13) are the same; and throttle valves are arranged at the connection part of the air outlet main pipeline (11) and each first branch pipeline group (12) and the connection part of the first branch pipeline group (12) and the air outlet pipeline (13).

2. The gas foot according to claim 1, wherein the first branch line set (12) comprises at least two first branch lines, the first branch line of a first stage is communicated with the main gas outlet line (11), the first branch line of a previous stage is connected with at least two first branch lines of a subsequent stage along the gas flow direction, the first branch lines of the subsequent stage connected with the first branch line of the same stage are the same in number, and the output end of the first branch line of the last stage is connected with a gas outlet line (13).

3. The pneumatic foot according to claim 2, wherein there are two first branch lines of each preceding stage corresponding to the following stages, and the two first branch lines of the following stages are symmetrically arranged with the first branch line of the preceding stage as a center line.

4. The gas foot according to claim 3, wherein the throttle valve is a first throttle valve (14), the first throttle valve (14) comprises a first plug end (141), a second plug end (142) and a third plug end (143) which are connected, the first plug end (141) is communicated with a main gas outlet pipeline (11), the second plug end (142) and the third plug end (143) are respectively communicated with the first branch pipelines of the two first stages, the first throttle valve (14) is provided with a first channel (144) and a second channel (145) which are communicated, the first channel (144) is provided on the first plug end (141), and the second channel (145) penetrates through the second plug end (142) and the third plug end (143);

the cross-sectional area of the first channel (144) is more than 1.5 times of the cross-sectional area of the main gas outlet pipeline (11) and the cross-sectional area of the pipeline of the first branch pipeline group (12).

5. The air foot according to claim 4, characterized in that the air-floating mechanism (1) further comprises:

the second throttling valve (15) comprises a fourth plugging end (151), a fifth plugging end (152) and a sixth plugging end (153) which are connected, the fourth plugging end (151) is communicated with the first branch pipelines of the previous stage, the fifth plugging end (152) and the sixth plugging end (153) are respectively communicated with the first branch pipelines of the two subsequent stages, a third channel (154) and a fourth channel (155) which are communicated are formed in the second throttling valve (15), the third channel (154) is formed in the fourth plugging end (151), and the fourth channel (155) penetrates through the fifth plugging end (152) and the sixth plugging end (153);

the ratio of the cross-sectional area of the third passage (154) to the cross-sectional area of the flow passage of the first branch line of the preceding stage is 1/4 to 3/4, and the ratio of the cross-sectional area of the fourth passage (155) to the cross-sectional area of the flow passage of the first branch line of the succeeding stage is 1/4 to 3/4.

6. The air foot according to claim 1, characterized in that the first branch line set (12) comprises:

and the at least two first branch pipelines are communicated with the main gas outlet pipeline (11), and the output ends of the first branch pipelines are connected with a gas outlet pipeline (13).

7. The air foot according to any one of claims 1 to 6, characterized in that the air foot further comprises a pre-tightening mechanism (2), the pre-tightening mechanism (2) comprises a main air suction pipeline (21), at least two second branch pipeline sets (22) and air suction pipelines (23), the at least two second branch pipeline sets (22) are communicated with the main air suction pipeline (21), the second branch pipeline sets (22) are connected with the air suction pipelines (23), all the air suction pipelines (23) are arranged in parallel, and the lengths of the paths through which air sucked from the air suction pipelines (23) flows from the second branch pipeline sets (22) to the main air suction pipeline (21) are the same.

8. The gas foot according to claim 7, characterized in that the second branch pipe group (22) comprises at least two stages of second branch pipes, the second branch pipes of the second stage are communicated with the main gas suction pipe (21), the second branch pipes of the previous stage are connected with at least two second branch pipes of the next stage along the gas flow direction, the number of the second branch pipes of the next stage connected with the second branch pipes of the same stage is the same, and the output end of the second branch pipe of the last stage is connected with a gas suction pipe (23).

9. The pneumatic foot according to claim 8, wherein the number of the second branch lines of each preceding stage is two, and the second branch lines of the two following stages are symmetrically arranged with respect to the center line of the second branch line of the preceding stage.

10. The gas foot according to claim 7, characterized in that the gas outlets (131) of the gas outlet pipelines (13) and the gas inlets (231) of the gas suction pipelines (23) are evenly staggered in a horizontal plane.

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