JP4180128B2 - Magnetic levitation transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic levitation transport apparatus suitable for transporting a transported object in a narrow and long vacuum atmosphere such as a vacuum pipe of a semiconductor manufacturing apparatus or a surface analysis apparatus.
[0002]
[Prior art]
Conventionally, when transporting a transported object in a vacuum pipe, a belt driving device is provided in the vacuum pipe, and the transported object is directly placed on the belt, or the transported object is transported by placing the transported object on a belt via a pallet, As shown in FIGS. 1 and 2, a method is known in which a magnetically levitated conveying device a conveys a conveyed product b between a vacuum chamber c and a vacuum pipe d connected thereto.
[0003]
The magnetic levitation transfer device a includes a traveling body h that is screwed into a ball screw g that is rotated by a motor f provided on a transportation platform e, and the traveling body h is equidistant in the circumferential direction of the vacuum pipe d. The four electromagnets i provided have a configuration in which the levitated body j provided in the pipe d is levitated. When the traveling body h travels along the rail k on the transport table e, the magnetic force of the electromagnet i The floating body j floats in the pipe d and travels with the traveling body h. A hand m is attached to one end of the levitating body j via an arm l, and a transported object b is placed on the hand m to be transported.
[0004]
[Problems to be solved by the invention]
In the above belt-driven conveying method, since there is a friction sliding portion, fine dust is released from the sliding portion and may adhere to the conveyed product b in the vacuum pipe d. In addition, there is a disadvantage in that gas is released from the sliding portion and the vacuum pressure fluctuates. Further, since a driving system for driving the belt exists in the pipe, a pipe is provided with a gate valve in the pipe d. There was a disadvantage that could not be closed.
[0005]
On the other hand, in the above magnetic levitation transfer device a, the electromagnet and the traveling body h to which the electromagnet is attached move around the vacuum pipe d, and therefore a port cannot be provided in the vacuum pipe d in the middle of the transfer path. Moreover, the conveyed product b cannot be conveyed linearly from one end of the pipe d to the other end while the floating body j is positioned in the pipe d. The gap between the outer surface of the pipe d and the electromagnet i is usually as narrow as about 1 mm, and the cylindrical surface of the outer surface of the pipe d must be increased for the movement of the electromagnet i. Therefore, there is a limitation that the magnetic levitation transfer device cannot be used for long pipes. The gap is usually detected by a gap detector provided in the traveling body h, which is a magnetic resistance between the magnetic body provided in the levitating body j and a coil or a transformer that generates magnetic flux. If a non-magnetic plate is interposed between the detectors, the limit is to detect a gap of about 2 to 3 mm. Therefore, the thickness of the vacuum pipe d cannot be increased, and the pipe strength is weak. There was a drawback that it could not be used as a long vacuum conveyance path.
[0006]
The present invention provides a magnetic levitation transport apparatus that can reciprocate in a vacuum pipe provided with a port in the middle to transport a transported object by a single floating body, and that can use a long vacuum pipe as a transport path. It is the purpose.
[0007]
[Means for Solving the Problems]
In the present invention, a traveling body that is formed of a non-magnetic material and that reciprocates along the pipe is provided above the horizontal pipe, and the floating body is accommodated inside the pipe. In a magnetic levitation transport device that levitates the levitated body by means of magnetic levitation means comprising a magnet provided on the traveling body, a hand for holding a conveyed product extending in the axial direction of the pipe is provided before and after the levitated body, An electromagnet in which a port is provided in the middle of the traveling path of the levitating body, a lifting platform is provided for temporarily lifting and lowering the transported object, and a pair of the magnetic levitation means are provided before and after the traveling body. And a permanent magnet provided at a position corresponding to each electromagnet of the levitation body, and each pair of electromagnet and permanent magnet is provided separated from each other at symmetrical positions across the apex of the pipe. A pair of posture stability at symmetrical positions across the lowest point By providing the weight, and so as to achieve the first object. The floating body is provided with a target magnet that constitutes a means for measuring the gap with the traveling body, the magnetic flux detection type gap detector that constitutes the measuring means is provided on the traveling body, and the magnetic pole surface of the target magnet is provided. By making it larger than the measurement area of the gap detector, the second object is achieved. In addition, it is preferable that a moving body that moves linearly in the horizontal direction along the pipe is provided, and the traveling body is attached to the moving body so as to be movable in the vertical direction. The above object can be achieved more appropriately by adopting the structure of claims 2 to 4.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. In FIGS. 3 and 4, reference numeral 1 is a vacuum pipe formed of a nonmagnetic material such as SUS, and 2 is an external upper part of the pipe 1. A traveling body 3 that reciprocates along the line 3 indicates a floating body housed inside the pipe 1. In the illustrated example, a timing belt 6 that linearly travels parallel to the guide 5 by a drive motor 4 is provided above the outside of the pipe 1, and a moving body 7 including a controller attached to the timing belt 6 is provided with support columns 8 and 8. Thus, the traveling body 2 was provided.
[0009]
As shown in FIGS. 4 and 5 , the traveling body 2 is a swinging base having a cross section that is suspended along a traveling base 2 a and a damper 9 and a spring 10 and is curved substantially along the outer surface of the pipe 1. And at least four electromagnets 12a, 12b, 12c, 12d constituting the magnetic levitation means 11 on the lower surface of the swing base 2b, and the same number of gap detectors 13a, 13b, 13c as the electromagnets. , 13d.
[0010]
As shown in FIGS. 4 and 5 , the levitated body 3 is formed of a non-magnetic material such as a hollow cylinder, and has at least four permanent magnets 14a, 14b, 14c constituting the magnetic levitation means 11 on the upper surface thereof. , 14d, weights 15a, 15b for stabilizing the posture of the floating body 3 are provided on the lower surface thereof, and arms 16a, 16b are formed to extend in front of and behind the floating body 3, and a conveyed product A is provided at the tip of each arm. For example, the holding hands 17a and 17b branched into two forks are provided. The permanent magnets 14 are provided on the front surfaces of the floating body 3 before and after the floating body 3 as a pair, each being shifted by 45 ° in the circumferential direction from the apex of the pipe 1 as shown in FIG. Two posture stabilization weights 15 were provided on the lower surface of the side, shifted by 45 ° from the lowest point of the pipe 1. Each electromagnet 12 of the traveling body 2 is provided to face each permanent magnet 14 through the shell of the pipe 1.
[0011]
As a means for measuring the gap between the opposing electromagnets 12 and the permanent magnets 14, target magnets 18 a, 18 b, 18 c, and 18 d made of permanent magnets are provided in the vicinity of each permanent magnet 14 of the levitated body 3, and the running The body 2 was provided with magnetic flux detection type gap detectors 13a, 13b, 13c, and 13d facing these target magnets 18. The magnetic pole surface 20 at the end face of each target magnet 18 is formed to have a significantly wider area, for example, 10 times or more than the measurement area of each gap detector 13, and the opposing positional relationship between the target magnet 18 and the gap detector 13 is initially set. The gap detector 13 can sufficiently capture the magnetic flux for measurement even if it is slightly deviated from the set position.
[0012]
As shown in FIG. 7, the magnetic force of each electromagnet 12 is controlled by a power amplifier 19 that is PID-controlled with a set value detected by the gap detector 13. When yawing, the detection signal from each detector 13 is calculated to correct the necessary magnetic force of the electromagnet 12, and its posture is corrected horizontally according to the piping axis. The swing base 2b of the traveling body 2 is provided with two wheels 2d that rotate in contact with the peripheral surface of the pipe 1 to prevent the electromagnet 12 and the like from abnormally approaching or contacting the outer peripheral surface of the pipe 1. did.
[0013]
In the middle of the pipe 1, as shown in FIG. 3, a port 22 having a lifting platform 21 is provided below, and the transported object A that the lifting platform 21 holds with the bifurcated hand 17 of the floating body 3. It was temporarily received and descended into the port 22, and after the floating body 3 passed over the port 22, it was raised again and the conveyed product A was delivered to the floating body 3. In this case, the elevation area of the lifting platform 21 is formed so that it can pass between the two forks of the hand 17. Delivery chambers 27, 27 are connected to both ends of the pipe 1 via valves 23 and bellows 24, and a delivery platform such as a lifting platform for delivering the conveyed product A to and from the floating body 3 is connected to each delivery chamber 27. Means 29 were provided. For example, as shown in FIG. 6, vacuum chambers 25 and 26 such as an analysis chamber and a process chamber are connected to the delivery chamber 27, and the transported object A is transported between the delivery means 29 and the vacuum chambers 25 and 26. For this purpose, a superconducting transfer arm device 28 is provided in the delivery chamber 27.
[0014]
The floating body 3 in the pipe 1 is controlled by the gap detector 13 when the electromagnet 12 of the traveling body 2 is excited, and floats to a predetermined position. The timing belt 6 causes the moving body 7 and the traveling body 2 to move horizontally. When traveling, the levitated body 3 is attracted by the magnetic coupling between the permanent magnet 14 and the electromagnet 12 and moves magnetically levitating in the pipe 1 while being controlled in posture by the gap detector 13. When the transported object A is transported between the delivery chambers 27 provided via the valve 23 and the bellows 24 at both ends of the pipe 1, for example, as shown in the plan view of FIG. 6, the delivery prepared in the delivery chamber 27. Even if the transported object A can be mounted on the levitated body 3 by the means 29, when the levitated body 3 conveys the conveyed object A to the other delivery chamber 27, the levitated body 3 cannot change its direction in the pipe, so that the levitated body 3 remains as it is. However, in the apparatus of the present invention, the transported object holding hand 17 is provided before and after the floating body 3 in the traveling direction, and a port is provided in the middle of the pipe 1. Since the elevator 21 that moves up and down from 22 is provided, the transported object A can be transferred from one hand 17a to the other hand 17b of the levitated body 3 in the pipe 1, and the transfer means 29 can transfer it at the transport destination. Can offload Okubutsu A from floating member 3.
[0015]
This will be further described. First, the transported object A is placed on the transfer means 29 of one transfer chamber 27 and lifted, and as shown in FIG. When the floating body 3 is moved so as to advance below the object A and the delivery means 29 is lowered, the conveyed object A is placed on one hand 17a (see FIG. 8B). Next, as shown in FIG. 8C, the levitated body 3 is moved until the transported object A is positioned above the lifting platform 21 of the port 22, and the lifting platform 21 is raised to receive the transported product A on the platform. When the floating body 3 is slightly moved away as shown in FIG. 8 (d), the elevator 21 is lowered. Then, once the floating body 3 is reversely run over the port 22, the elevator 21 is raised (see FIGS. 8E and 8F), and the other hand 17b advances further below the elevator 21. The levitation body 3 is moved so as to perform (see (g) of FIG. 8). Thereafter, when the elevator 21 is lowered, the transported object A placed thereon is transferred to the other hand 17b, and the floating body 3 is advanced as shown in FIG. When the delivery means 29 is raised when the transported object A is positioned on the delivery means 29, the transported article A is transferred from the floating body 3 to the delivery means 29, and the transport is completed to prepare for the next transport. As a result, the floating body 3 moves backward (see (i) of FIG. 8).
[0016]
The levitation body 3 is lifted by a permanent magnet 14 provided above it and an electromagnet 12 of the traveling body 2 above the outer periphery of the pipe 1. The electromagnet 12 and the permanent magnet 14 are symmetrical with respect to the apex of the pipe 1. Since there is no magnet in the lower part of the floating body 3 and the weight 15 for posture stabilization is provided at a symmetrical position with the lowest point of the pipe 1 in between, the middle of the pipe 1 is provided. Even if the port 22 is provided on the side surface or the lower part, there is no hindrance to the traveling of the levitated body 3, and a plurality of the ports 22 can be provided as necessary. For example, an exhaust port can be provided in the middle of the piping.
[0017]
Further, by making the magnetic pole surface of the target magnet 18 paired with each gap detector 13 sufficiently larger than the measurement surface of the detector 13, even if the levitated body 3 is shaken, the target magnet is placed on the gap detector 13. The magnetic flux from 18 can be reliably captured, and even if a non-magnetic pipe 1 is present in the middle, a gap within about 6 mm can be accurately detected, and the gap detection limit is increased to increase the pipe 1. It becomes possible to increase the wall thickness of. If the thickness of the pipe 1 is thick, the cylinder accuracy is improved even with a long pipe, and the long pipe can be used as a transport path, and the transport distance can be increased.
[0018]
In addition, a long-distance transfer device can be configured by continuously connecting the devices shown in FIG.
[0019]
【The invention's effect】
As described above, according to the present invention, the traveling body that reciprocates along the outside of the pipe of the non-magnetic material is provided, and the levitated body accommodated inside the pipe is moved by the levitating means of the levitating body and the traveling body. Since it is levitated, a port can be provided in the lower part or side surface of the pipe without interfering with the running of the traveling body, and a carrying object holding hand is provided before and after the floating body and the floating body of the pipe is traveled. Since a port is provided in the middle of the path and a lifting platform for holding and moving the transported object is provided there, the transported object can be transported by reciprocating one floating body in the vacuum pipe. Since the target magnet with a sufficiently large magnetic pole area than the magnetic flux measurement surface of the gap detector provided in the floating body is provided on the levitated body, the gap detection limit of the gap detector can be improved and the thickness of the pipe can be increased. Use long vacuum piping for the transport path There are effects such that it constitutes a long conveying distance by.
[Brief description of the drawings]
FIG. 1 is a side view of a conventional magnetic levitation transport apparatus. FIG. 2 is a sectional view taken along line 2-2 of FIG. 1. FIG. 3 is a cut side view of an embodiment of the present invention. FIG. 5 is an enlarged plan view of the main part of FIG. 3. FIG. 6 is an external plan view of an embodiment of the present invention. FIG. 7 is a control block diagram of the apparatus of the present invention. Figure [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum piping, 2 Running body, 3 Levitation body, 11 Magnetic levitation means, 12 * 12a * 12b * 12c * 12d Electromagnet, 13, * 13a * 13b * 13c * 13d Gap detector, * 14 * 14a * 14b * 14c * 14d Permanent magnet, 15a / 15b Posture stabilization weight, 17a, 17b Hand, 18 / 18a / 18b / 18c / 18d Target magnet, 20 Magnetic pole surface, 21 Lift platform, 22 port, A

Claims (4)

A traveling body that is formed of a non-magnetic material and that reciprocates along the pipe is provided above the horizontal pipe, and a floating body is accommodated inside the pipe so that the floating body and the traveling body In a magnetic levitation transport apparatus for levitating the levitated body by means of magnetic levitation means comprising a provided magnet,
A hand for holding the transported object extending in the axial direction of the pipe is provided before and after the floating body, and a port is provided in the middle of the travel path of the floating body of the pipe, and the transported object is temporarily held there to move up and down A pair of electromagnets provided in front of and behind the traveling body and permanent magnets provided at positions corresponding to the electromagnets of the levitation body. And a permanent magnet separated from each other at symmetrical positions across the top of the pipe, and a pair of posture stabilizing weights disposed at symmetrical positions across the lowest point of the floating body Levitation transport device.   The floating body is provided with a target magnet that constitutes a means for measuring a gap with the traveling body, and the traveling body is provided with a magnetic flux detection type gap detector that constitutes the measuring means, and the magnetic pole surface of the target magnet is disposed on the gap The magnetic levitation transport apparatus according to claim 1, wherein the magnetic levitation transport apparatus is larger than a measurement area of the detector.   The magnetic levitation transport apparatus according to claim 1, wherein a moving body that moves linearly in the horizontal direction along the pipe is provided, and the traveling body is attached to the moving body so as to be movable in the vertical direction.   2. The magnetic levitation transport according to claim 1, wherein the levitated body is formed of a thin hollow cylindrical body, and a space as large as possible is formed between the inner surface of the pipe and the diameter of the pipe. apparatus.

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