JP6954597B2 - Magnetic levitation transfer device - Google Patents

Description

The present invention relates to a transport device used in a clean environment, such as a semiconductor manufacturing device and a food manufacturing device, and is characterized in that the transport table is floated and transported in a non-contact manner by using a magnetic force. It is about the device.

For example, in a semiconductor manufacturing apparatus, a conveying apparatus for moving an article such as a semiconductor wafer in a vacuum container is used. In the transfer device used in such a semiconductor manufacturing device, in order to maintain the cleanliness inside the vacuum container, it is necessary to reduce the dust generation due to the movement of the transfer table to the utmost limit, and in order to reduce the dust generation, the transfer device is used. It is effective to float and hold the table in a non-contact manner and move it.

Patent Document 1 presents a magnetic levitation transfer device as shown in FIG. 7 as an example of a magnetic levitation transfer device that floats, holds, and moves a transfer table by applying magnetic force. The magnetic levitation transport device of Patent Document 1 is a levitation body 911 in which a permanent magnet 912 is mounted in a container 910.
Movable guide 915 and guide 91 with an electromagnet 917 attached to the outside of the container 910.
A drive mechanism 916 for moving the 5 is provided so that the levitation body 911 follows the movement of the guide 915 by the magnetic interaction between the permanent magnet 912 and the electromagnet 917.
Further, a position sensor 919 is attached to the guide 915, and the exciting current of the electromagnet 917 is controlled by a control means (not shown) to levitate the levitation body 911 by the permanent magnet 912 and the electromagnet 917. As a result, a magnetic levitation transfer device that floats and holds in a non-contact manner and is movable in a non-contact manner is shown.

However, such a magnetic levitation transfer device requires an electromagnet, a position sensor, and a control means, and has a problem that the device becomes large-scale, complicated, and expensive.

As a method for solving such a problem, in Patent Document 2, as shown in FIG. 8, a mounting table 970 on which parts are mounted, a support portion 971 for supporting the mounting table 970, and a support portion 971 are provided below the support portion 971. A buoyancy receiving portion 973 having a first magnet means 973a for obtaining a buoyancy, and a towed portion 972 having a second magnet means 972a attracted below the support portion 971 or the support portion 971. The first magnet means 97 includes a first magnet means 973a, a third magnet means 961d arranged to face the second magnet means 972a, and a fourth magnet means 963.
3a, a component configured so that the mounting table 970 can be moved by moving the fourth magnet means 963 while attracting the second magnet means 972a while floating the mounting table 970 by the magnetic force of the third magnet means 961d. The transport device is shown.

According to Patent Document 2, the mounting table 970 has a first magnet means 973a and a third magnet means 961.
Since it floats by the magnetic force acting during d, no electromagnet or control means is required, and the magnetic levitation transfer device can be configured with a simple structure.

As described above, the magnetic levitation transfer device shown in Patent Document 2 has an excellent structure capable of realizing magnetic levitation transfer only with a permanent magnet without using an electromagnet or a control means. However, the parts are placed by the magnetic force of the first magnet means 973a provided on the buoyancy receiving portion 973 and the third magnet means 961d provided on the towing vehicle movably provided on the outside of the housing. Since the pedestal 970 is levitated, in order to maintain the cleanliness inside the housing, the first magnet means 973a and the third magnet means 961d face each other across the wall of the housing. I had to do it. For this reason, the structure of the housing becomes complicated, and there is a problem that the cross-sectional structure of the housing must be designed and manufactured each time according to the magnetic levitation transfer device.

Japanese Unexamined Patent Publication No. 63-133803 Japanese Unexamined Patent Publication No. 2003-168716

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic levitation transfer device which is composed of only permanent magnets and can be easily incorporated into a housing.

The invention according to claim 1 in the magnetic levitation transport device of the present invention
A transport device used in a clean environment, a magnetic levitation mechanism having a base and a transport base that is levitated and held from the base by magnetic force, and a magnetic feed that moves the transport base in a non-contact manner. In a magnetic levitation transfer device having a mechanism
The magnetic levitation mechanism comprises a first magnet pair for urging the carrier upward and a second magnet pair for urging the carrier downward, the first magnet pair and the second magnet. Each pair is composed of a magnet on the transport base side and a magnet on the base side that repel each other.
The magnet on the transport table side and the magnet on the base side of the first magnet pair and the second magnet pair are all configured by arranging a plurality of magnet pieces in the moving direction of the transport table. It is characterized by.

According to the present invention, by providing a first magnet pair for urging the carrier upward and a second magnet pair for urging the carrier downward, objects having different weights are placed on the carrier. However, since the fluctuation of the levitation amount of the transport table can be suppressed to be small, the magnetic levitation mechanism can be configured only with a permanent magnet.
Further, since all the magnets constituting the first magnet pair for urging the transport table upward and the magnets constituting the second magnet pair for urging the transport table downward are independent magnets, so that the magnet specifications are used. Can be individually adjusted to achieve the desired levitation characteristics, and by using magnets with different temperature characteristics for the magnets that make up the first magnet pair and the magnets that make up the second magnet pair, the temperature It is possible to reduce the change in levitation characteristics due to the change.
Further, since the magnets constituting the first magnet pair and the second magnet pair are arranged in the moving direction of the transport table as a magnet piece, even if the transport distance becomes long, it can be dealt with only by increasing the number of magnet pieces used. .. Further, since it is not necessary to separate the transport base side magnet and the base side magnet constituting the first magnet pair and the second magnet pair by the housing wall or the like, the entire magnetic levitation mechanism can be put in the housing. It becomes.
As a result, a magnetic levitation mechanism having a size according to the application and plan can be easily manufactured, and the entire magnetic levitation mechanism can be put in the housing, so that a magnetic levitation mechanism that can be easily incorporated into the housing can be provided.

Further, the invention according to claim 2 of the present invention is the invention of at least one of the plurality of magnet pieces on the transport base side and the plurality of magnet pieces on the base side, which constitute the first magnet pair. The plurality of magnet pieces are characterized in that the end faces intersecting the moving direction of the transport table are inclined with respect to the moving direction.

End faces of a plurality of magnet pieces of the first magnet pair for urging the carrier upward, at least one of a plurality of magnet pieces on the carrier side and a plurality of magnet pieces on the base side, intersecting the moving direction. Was tilted with respect to the moving direction so that the shape of the surface facing the magnet on the other side was a substantially parallel quadrilateral shape. As a result, fluctuations in the levitation force when the transfer table moves and passes each other are reduced, so that it is possible to provide a magnetic levitation transfer device having more stable levitation characteristics and transfer characteristics.

Further, the invention according to claim 3 of the present invention is the invention of at least one of the plurality of magnet pieces on the transport base side and the plurality of magnet pieces on the base side, which constitute the second magnet pair. The plurality of magnet pieces are characterized in that the end faces intersecting the moving direction of the transport table are inclined with respect to the moving direction.

The end faces of the second magnet pair that biases the carrier downward, at least one of the plurality of magnet pieces on the carrier side and the plurality of magnet pieces on the base side, intersecting the moving direction. Was tilted with respect to the moving direction so that the shape of the surface facing the magnet on the other side was a substantially parallel quadrilateral shape. As a result, fluctuations in the levitation force when the transfer table moves and passes each other are reduced, so that it is possible to provide a magnetic levitation transfer device having more stable levitation characteristics and transfer characteristics.

Further, the invention according to claim 4 in the present invention is the magnet piece and the transport table on the base side of at least one of the first magnet pair and the second magnet pair. It is characterized in that the lengths of the magnet pieces on the side in the moving direction of the transport table are different.

In the present invention, of at least one of the first magnet pair and the second magnet pair,
Since the lengths of the opposing base side magnet pieces and the transport base side magnet pieces are different, the end faces of multiple magnet pieces do not pass each other at the same time when the transport base moves, so the levitation force fluctuates when the magnet pieces are switched. And since the cogging force is dispersed and generated, it is possible to provide a magnetic levitation transfer device having more stable levitation characteristics and transfer characteristics.

Further, in the invention according to the fifth aspect of the present invention, the first magnet pair is provided on both end sides of the width in the direction orthogonal to the transport table moving direction, respectively, and the base of the two first magnet pairs. The width interval in the direction orthogonal to the transport table moving direction of the magnet on the table side and the width interval in the direction orthogonal to the transport table moving direction of the magnet on the transport table side of the two first magnet pairs are different. The two magnets having a narrower width spacing are located between the two magnets having a wider width spacing.

In the present invention, first magnet pairs for urging the carrier upward are provided on both ends in the width direction of the carrier, and for example, the width interval between the two magnets on the base side is the width of the two magnets on the carrier side. Wider than the width interval,
The two magnets on the carrier side with a narrow width interval are inserted between the two magnets on the base side with a wide interval.
As a result, when the carrier is urged to shift in the width direction due to some external force or the like,
Since this urging force is reduced by the repulsive force of the transport base side magnet and the base side magnet, a more stable magnetic levitation transport device can be provided.

Further, in the invention according to claim 6 in the present invention, the second magnet pair is provided on both end sides of the width in the direction orthogonal to the transport table moving direction, respectively, and the base of the two second magnet pairs. The width interval in the direction orthogonal to the transport table moving direction of the magnet on the table side and the width interval in the direction orthogonal to the transport table moving direction of the magnet on the transport table side of the two second magnet pairs are different. The two magnets having a narrower width spacing are located between the two magnets having a wider width spacing.

In the present invention, second magnet pairs for urging the carrier downward are provided on both ends in the width direction of the carrier, and for example, the width interval between the two magnets on the base side is the width of the two magnets on the carrier side. Wider than the width interval,
The two magnets on the carrier side with a narrow width interval are inserted between the two magnets on the base side with a wide interval.
As a result, when the carrier is urged to shift in the width direction due to some external force or the like,
Since this urging force is reduced by the repulsive force of the transport base side magnet and the base side magnet, a more stable magnetic levitation transport device can be provided.

Further, in the invention according to claim 7 of the present invention, the magnetic feed mechanism includes a cylindrical pinion magnet having a rotation axis orthogonal to the moving direction of the transport table, and a plurality of magnet pieces of the transport table. The length of the rack magnet, which is composed of rack magnets arranged in the moving direction and is composed of the plurality of magnet pieces, in the moving direction of the carrier is the said of the magnet on the carrier side of the first magnet pair. It is characterized in that it is shorter than the length of the transport table in the moving direction.

In the present invention, the length of the rack magnets constituting the magnetic feed mechanism in the moving direction of the carrier is shorter than the length of the magnets on the carrier side of the first magnet pair in the moving direction of the carrier, so that the carrier moves. When tilted in the direction, the transport base is urged in the direction in which the tilt is reduced by the repulsive force of the transport base side magnet and the base side magnet of the first magnet pair.
As a result, even when the transport table is tilted in the moving direction, it is possible to avoid suction of the transport table and reduce the tilt, and it is possible to provide a more stable magnetic levitation transport device.

Further, in the invention according to claim 8 of the present invention, the magnetic feed mechanism is provided by providing the first magnet pair on both end sides of a width in a direction orthogonal to the transport table transport direction and moving the transport table. Is arranged closer to the center of the width of the carrier than the first magnet pair provided on both ends of the width of the carrier.

In the present invention
The first magnet pair composed of the base side magnet and the transport base side magnet urges the transport base upward by a repulsive force. On the other hand, in the magnetic feed mechanism including the rack magnet and the pinion magnet, the carrier is urged downward by the attractive force between the rack magnet and the pinion magnet.
If the carrier is tilted for some reason, the carrier will rotate around approximately the center of the width, with one end of the width moving upwards and the other moving downwards. The magnets on the base side and the magnets on the transport base side of the first magnet pair on the end side that have moved downward are close to each other, and a force that urges the transport base more strongly upward and reduces the inclination of the transport base acts. .. On the other hand, in the magnetic feed mechanism, as the distance between the rack magnet and the pinion magnet approaches, the attractive force increases and a force that increases the inclination of the transport table is generated.
In the present invention, the magnetic feed mechanism is arranged between the two first magnet pairs provided on both ends of the width of the transport table. Therefore, when the transport table is tilted, the distance between the rack magnet and the pinion magnet is increased due to the tilt. Since the amount in which the base-side magnet of the first magnet pair provided on the end side of the width of the transfer table and the magnet on the transfer table side are in close proximity to each other is always larger than the approach amount, the transfer table is tilted by the magnetic feed mechanism. The force for reducing the inclination of the transport table by the first magnet pair becomes larger than the force for increasing the force, and the transport table is returned to the horizontal position.
As a result, even when the transport table is tilted in the width direction, it is possible to avoid suction of the transport table and reduce the tilt, and it is possible to provide a more stable magnetic levitation transport device.

As described above, in the magnetic levitation transfer device according to the present invention,
By providing a first magnet pair that biases the carrier upward and a second magnet pair that biases the carrier downward, the magnetic levitation mechanism can be configured with only permanent magnets.
Since the magnet pieces of the magnet pair are arranged in the direction of movement, even if the transport distance is long, it is possible to easily manufacture a magnetic levitation mechanism of a size according to the application and plan simply by increasing the number of magnet pieces used.
Since it is not necessary to separate the transport base side magnet and the base side magnet by the housing wall, it is possible to provide a magnetic levitation mechanism that can be easily incorporated into the housing.

It is a figure which shows the structure of the Example of this invention, (a) is a plan view, (b) is a front view. It is a perspective view which shows the structure of this Example. It is a cross-sectional view which shows the structure of this Example, (a) is a cross-sectional view of the AA position in FIG. It is sectional drawing of the BB position in 1 (b). It is a figure which shows the effect by the end face shape of the magnet piece of the 1st magnet pair, (a) is a plan view which shows the shape of a magnet piece, (b) is a graph which shows the change of the repulsive force by the change of the end face shape, (c). ) Is a graph showing the change in cogging force due to the change in the end face shape. In the front view explaining the arrangement of magnets of a pair of magnets, (a) is a normal time, and (b) is a time when an outlier occurs. It is a graph which shows the analysis result of the urging force by a 1st magnet pair and a 2nd magnet pair. It is a figure which shows the structure of the magnetic levitation transfer apparatus according to Patent Document 1. It is a figure which shows the structure of the magnetic levitation transfer apparatus according to Patent Document 2.

An embodiment of the magnetic levitation transport device according to the present invention will be described in detail with reference to FIGS. 1 to 5.
First, the appearance and schematic structure of the magnetic levitation transfer device according to the present embodiment will be described with reference to FIGS. 1 and 2. In the description of this embodiment, the direction indicating arrow symbol is shown in FIG.
The direction of X is described as "moving direction X", the direction of Y is described as "width direction Y", and the direction of Z is described as "height direction Z".

As shown in FIGS. 1 and 2, the magnetic levitation transport device according to the present embodiment has a substantially plate-shaped base 1.
In the same manner as 0, the transport base 20 and the transport base 20 which are substantially plate-shaped, on which the object to be transported is placed, floated and held from the base 10, and transported in the longitudinal direction of the base 10, that is, in the moving direction X, are non-existent. It is composed of a magnetic feed mechanism 50 and the like that convey by contact.

A first magnet pair 30 for urging the carrier 20 upward and a second magnet pair 40 for urging the carrier downward are provided on both ends of the magnetic levitation transport device in the width direction, respectively. There is. Further, a magnetic feed mechanism 50 composed of a rack magnet 51 and a pinion magnet 52 is provided at a position from the center of the two first magnet pair 30 and the second magnet pair 40 provided on both end sides in the width direction Y. It is provided.

As shown in FIG. 3A, the first magnet pair 30 for urging the carrier 20 upward is the pedestal 81.
It is composed of a base side magnet 31 attached to the upper surface side of the base 10 and a transport base side magnet 32 attached to the lower surface side of the transport base 20 via the above. Since the base side magnet 31 and the transport base side magnet 32 are arranged so as to repel each other, the transport base side magnet 32 of the first magnet pair 30 is made of the base side magnet 31 of the first magnet pair 30. Being urged upwards.

Further, the second magnet pair 40 that urges the transport base 20 downward is a base attached to the lower surface of the top plate 83 fixed to the upper surface of the side plate 82 fixed to both side ends of the upper surface of the base 10. It is composed of a side magnet 41 and a transport base side magnet 42 attached to the upper surface side of the transport base 20. Since the base side magnet 41 and the transport base side magnet 42 are arranged so as to repel each other, the transport base side magnet 42 of the second magnet pair 40 is a second magnet attached to the lower surface of the top plate 83. It is urged downward by the base side magnet 41 of the pair 40.

As shown in FIG. 3A, the base-side magnets 31, 41 and the transport base-side magnets 32, 42 of the first magnet pair 30 and the second magnet pair 40, respectively, have a plurality of magnet pieces 31a, respectively. 41
A plurality of a, 32a, 42a are arranged in the moving direction X, and the first magnet pair 30 and the second magnet pair 30 are arranged.
The base-side magnets 31 and 41 of the magnet pair 40 are arranged over substantially the entire length of the base 10 in the moving direction X. Similarly, the transport base side magnets 32 and 42 of the first magnet pair 30 and the second magnet pair 40 are arranged over substantially the entire length of the transport base 20 in the moving direction X.

As described above, in the magnetic levitation transfer device according to the present invention, the magnets constituting the first magnet pair 30 and the second magnet pair 40 are made into a plurality of magnet pieces arranged in the moving direction X, and thus the purpose of use and the like. Therefore, even if the transport distance is changed, it can be dealt with simply by increasing or decreasing the number of magnet pieces used, and flexible correction can be made.

Further, in the magnetic levitation transfer device transfer table according to the present invention, as shown in FIG. 3 (b), the transfer table 2
It has a rack magnet 51 composed of a plurality of magnet pieces 51a arranged in the moving direction X on the lower surface of 0, and a plurality of rotating axes in a direction parallel to the width direction Y orthogonal to the moving direction X. The transport table 20 is moved in a non-contact manner by the magnetic feed mechanism 50 composed of the arranged pinion magnets 52.

The rack magnets 51 are arranged so that the polarities of the adjacent individual magnet pieces 51a are different from each other. Further, the cylindrical side surface portion of the substantially cylindrical pinion magnet 52 is divided into a plurality of regions arranged in the circumferential direction, and the adjacent regions are magnetized so as to have different polarities from each other.

The rack magnet 51 and the pinion magnet 52 face each other through a gap, and when a plurality of pinion magnets 52 are rotated by a rotating means (not shown), the rack magnet 51 is attracted by the magnetic attraction of the rack magnet 51 and the pinion magnet 52. Moves in the moving direction X, and the transport base 20 to which the rack magnet 51 is attached is moved in a non-contact manner.

In the magnetic levitation transfer device according to the present invention, a magnetic levitation mechanism for levitation of a transfer table on which an article is placed and conveyed is attached, and a first magnet pair 30 for urging the transfer table upward and a transfer table are attached downward. It is configured to have a second magnet pair 40 to be driven.

A structure in which the carrier is urged in both the upper and lower directions to raise the carrier is also described in Patent Document 2 whose schematic configuration is shown in FIG. 8, and the buoyancy receiving portion 973 is the first magnet means. 973
A configuration is shown in which the repulsive force of a and the third magnet means 961d is urged upward, and the repulsive force of the upper lower surface 961e of the guide portion 961 and the upper surface 973b of the buoyancy receiving portion is urged downward. However, Patent Document 2 does not describe the function and effect of downward urging due to the repulsive force of the upper lower surface 961e and the upper surface 973b of the buoyancy receiving portion.

The magnetic levitation transport device according to the present invention also has a configuration in which the transport base 20 is urged upward and downward, and the functions and effects of this configuration in the present invention will be described below.

The first function of this configuration is to raise the transport table by upward urging, and to prevent the transfer table 20 from rising too much due to downward urging and coming into contact with the top plate 83 or the like.

However, a more important second function of this configuration is the adjustment of the levitation characteristics of the carrier 20. The first magnet pair 3 when the carrier 20 is configured to be urged in both the upper and lower directions.
The analysis result of the urging force characteristic of the 0 and the second magnet pair 40 and the levitation characteristic of the transport table 20 obtained as a result will be described with reference to FIG.

FIG. 6 shows the results of tentatively setting and analyzing dimensional specifications such as the size of the first magnet pair 30 and the second magnet pair 40 and the distance between magnets, and the horizontal axis is the base side of the first magnet pair 30. The distance between the magnet 31 and the transport base side magnet 32, and the vertical axis is the generated urging force. The urging force is indicated by the “upward urging force” that urges the carrier 20 generated on the first magnet pair 30 upward, which is indicated by the broken line in the graph of FIG. 6, and the one-dot chain line in the graph of FIG. The "downward urging force" that urges the carrier 20 generated on the second magnet pair 40 downward, and the "total urging force" that is the sum of the upward urging force and the downward urging force drawn by the solid line in the graph of FIG. I asked. The total urging force is the urging force actually received by the transport table 20 by the first magnet pair 30 and the second magnet pair 40.

In this analysis, the weights of multiple magnets to be analyzed, the carrier, the base, etc. are not taken into consideration. Further, the downward urging force generated on the second magnet pair 40 has a negative value because the transport table 20 is urged downward.

As described in the graph of FIG. 6, the upward urging force generated in the first magnet pair 30 is about 10 kN when the distance between the magnets is 10 mm, and about 15 kN when the distance between the magnets is 6 mm.
Similarly, the downward urging force generated in the second magnet pair 40 is about -7k when the distance between the magnets is 10 mm.
N is generated, and when the distance between magnets is 6 mm, about -5 kN is generated. As a result, the total urging force obtained by adding the upward urging force and the downward urging force is about 3.4 kN when the distance between the magnets is 10 mm, and 9.5 kN when the distance between the magnets is 6 mm.

The above analysis result of "total urging force" shows that when the carrier 20 is pushed downward at 3.4 kN, the distance between magnets is balanced at a position of 10 mm, and when it is pushed at 9.5 kN, the distance between magnets is balanced at 6 mm.
It means that. From this equilibrium behavior, when the transport table 20 is pushed downward at 4.8 kN, the distance between the magnets becomes 9 mm.
From the above, the force applied to the transport table 20 changes from 3.4 kN to 4.8 kN, that is, 1.4.
When kN is increased, the distance between magnets is reduced from 10 mm to 9 mm, that is, by 1 mm.

By the way, if the transport table 20 is simply levitated, only the upward urging by the first magnet pair 30 may be sufficient. Therefore, for example, when the magnetic characteristics of the first magnet pair 30 are adjusted, specifically, the magnetic force is weakened so that the urging force when the distance between the magnets is 10 mm becomes 3.4 kN, which is the same as the total urging force. Asked for an upward force. This result is entered in FIG. 6 as "calculation_upward urging force" with a two-dot chain line.

In this "calculation_upward urging force" in which the magnetic characteristics are adjusted by using only the first magnet pair as the magnet pair, when the carrier 20 is pushed downward at 3.4 kN as shown in the graph of FIG. 6, the magnets are separated from each other. It balances at a distance of 10 mm, and when pushed at 4.8 kN, it balances at a distance of 6 mm between magnets.
Therefore, the force applied to the transport table 20 changes from 3.4 kN to 4.8 kN, that is, 1.4 k.
When N increases, the distance between magnets decreases from 10 mm to 6 mm, that is, 4 mm.

From the above, in the analysis result in which the dimensional specifications of the magnet pair shown in FIG. 6 are tentatively set, the transport table 20 is used.
When the force applied to the carrier 20 is increased by 1.4 kN, the distance between the magnets changes by 4 mm when the carrier 20 is levitated only by the magnet pair that biases the carrier 20 upward, but the first magnet pair 30 that biases the carrier 20 upward. By providing the second magnet pair 40 that urges downward, the amount of change in the distance between magnets can be suppressed to 1 mm.

In this way, the first magnet pair 30 for urging the transport table 20 upward and the second magnet pair 40 for urging the transfer table 20 downward are provided, and the upward urging force on the transfer table 20 is applied by the downward urging force. By partially canceling out, it is possible to obtain the effect that the fluctuation of the floating amount of the transport table 20 can be suppressed to be small even when the objects to be transported having different weights are placed on the transfer table 20, and as a result, only the permanent magnet is used. It is possible to configure a magnetic levitation mechanism that can stably float and hold.

The above-mentioned urging force behavior characteristics are characteristic values when the dimensional specifications of the magnet pair are temporarily set to specific values, and the behavior of the urging force is required by adjusting the dimensional specifications of the magnet pair in various ways. It is possible to match with.

In particular, in the magnetic levitation transfer device according to the present invention, all of the magnets of the first magnet pair 30 for urging the transfer table 20 upward and the magnets of the second magnet pair 40 for urging the transfer table 20 downward are all included. Since it is an independent magnet, the size of each magnet and the distance between the magnets should be changed individually to adjust the upward urging force and the downward urging force, and the levitation characteristics of the conveyor should be adjusted to the desired specifications. Is possible.

It is known that the attractive force and the repulsive force of the magnet change depending on the temperature, and generally, the attractive force and the repulsive force decrease as the temperature rises. Therefore, even in the magnetic levitation transfer device according to the present invention, when the temperature of the magnet used rises due to a change in the environmental temperature or the like, the repulsive force of the first magnet pair 30 that biases the transfer table 20 upward and the transfer table 20 The repulsive force of the second magnet pair 40, which urges the magnet downward, is reduced.

The transport table 20 that is floated and held has an upward urging force by the first magnet pair 30 and a downward urging force by the second magnet pair 40, the weight of the transport table 20, and the object to be transported. The amount of levitation is determined by the downward urging due to the weight of the magnet. Of these urging forces, the upward urging force of the first magnet pair 30 and the downward urging force of the second magnet pair 40 both decrease as the temperature rises, so the balance between the urging forces in both directions is roughly maintained. Dripping. However, the downward urging force due to the weight of the transport table 20 and the weight of the object to be transported does not change with the temperature rise, and as a result, the floating amount of the transport table 20 decreases due to the temperature rise.

However, in the magnetic levitation transfer device according to the present invention, the first method of urging the transfer table 20 upward.
Since all of the magnets of the magnet pair 30 and the magnets of the second magnet pair 40 that urge the carrier 20 downward are independent magnets, the magnets constituting the first magnet pair 30 are attracted by the temperature rise. Power,
It is possible to select a grade having a small reduction rate of the repulsive force, and to select a grade having a large reduction rate of the attractive force and the repulsive force due to the temperature rise for the magnets constituting the second magnet pair 40. As a result, the decrease in the upward urging force due to the first magnet pair 30 due to the temperature rise is suppressed, and the decrease in the downward urging force due to the second magnet pair 40 becomes large. Combined with the downward urging force due to the weight of the object to be transported, it is possible to adjust the balance due to the urging force in both directions, and it is possible to reduce the change in levitation characteristics due to temperature changes.

Further, in the magnetic levitation transfer device according to the present invention, the first magnet pair 30 and the second magnet pair 40
Regarding each, at least one of the magnet pieces 31a and 41a of the base side magnets and the magnet pieces 32a and 42a of the transport base side magnets constituting each magnet pair is as shown in FIG. 4 (a). The end face intersecting the moving direction X is inclined with respect to the moving direction X, that is, the surface facing the magnet piece on the other side has a substantially parallel four-sided shape. The above-mentioned "end face intersecting with the moving direction X" will be hereinafter referred to as "moving direction end face".

Generally, when two magnets formed by arranging magnet pieces side by side are arranged so as to repel each other, the magnets move and the direction of movement of the magnet piece on one side is above the end face of the magnet piece on the other side. When the end faces pass, that is, when the end faces in the moving direction of both magnet pieces pass each other, FIG. 4 (b)
As shown in, the repulsive force of the magnet pair fluctuates. At the same time, as shown in FIG. 4C, a force in the moving direction X called a cogging force is generated in a direction in which the end faces in the moving direction of both magnet pieces are separated from each other.

In the graphs of FIGS. 4 (b) and 4 (c), the horizontal axis indicates the amount of movement of the magnet pieces, and the central position of the horizontal axis is the position where the end faces in the moving direction of both magnet pieces pass each other. When the end face in the moving direction is inclined, the center of the slope is a position where they pass each other.

When the magnet piece is a simple square and the surface facing the magnet on the other side is a simple rectangle, the fluctuation of the repulsive force and the cogging force generated in the magnet pair are shown in FIGS. 4 (b) and 4 (c), respectively. The curve is marked with a broken line as "no inclination of both magnet end faces", and the change in repulsive force when the end faces in the moving direction of both magnet pieces pass each other is large, and the change in cogging force is also large.

On the other hand, for example, when the end face of the magnet piece 31a of the base side magnet 31 in the moving direction is inclined so that the surface facing the magnet piece on the other side has a substantially parallel four-sided shape, "one magnet end face is inclined".
The curve is marked with a solid line, and the amount of change in the repulsive force decreases and the range of change becomes wider. Similarly, the amount of change in the cogging force is reduced, and the position interval at which the positive and negative electrode values of the cogging force are generated becomes wide.

Further, in the curve marked by the alternate long and short dash line as "the end faces of both magnets are tilted" when the end faces of both the magnet pieces 31a and 32a of the base side magnet 31 and the transport base side magnet 32 are tilted in the moving direction.
The amount of change in the repulsive force decreases and the range of change becomes wider. Similarly, the amount of change in the cogging force is further reduced, and the interval between the positive and negative electrode values of the cogging force becomes wider.

In the magnetic levitation transport device according to the present invention, the end faces in the moving direction of at least one of the plurality of magnet pieces 32a of the transport base side magnet 32 and the plurality of magnet pieces 31a of the base side magnet 31 are inclined. It is possible to reduce the fluctuation of the levitation force and the cogging force when the transfer table moves and the end faces in the moving direction of both magnet pieces pass each other, and it is possible to provide a magnetic levitation transfer device having more stable levitation characteristics and transfer characteristics.

Further, in the magnetic levitation transport device according to the present invention, as shown in FIG. 4A, for example, the length L1 of the first magnet pair 30 and the length L1 of the magnet piece 31a of the base side magnet 31 in the moving direction X are conveyed. Side magnet 32
The length L2 of the magnet piece 32a in the moving direction X is set to a different length.

If the lengths of the magnet piece 31a of the base side magnet 31 and the magnet piece 32a of the transport side magnet 32 are the same, when the transport base 20 is moved, all the base side magnets 31 will be placed at a specific position. Magnet piece 3
The end faces in the moving direction of 1a and the end faces in the moving direction of the magnet pieces 32a of all the transport-side magnets 32 pass each other at the same time, and a large fluctuation of the levitation force and a cogging force are generated at this specific position.

On the other hand, when the magnet piece 31a of the base side magnet 31 and the magnet piece 32a of the transport side magnet 32 have different lengths, the transport base 20 moves, and the end face in the moving direction of a specific magnet piece 31a is specific. At the moment when the end faces of the magnet pieces 32a in the moving direction pass each other, the end faces of the magnet pieces 31a adjacent to the specific magnet piece 31a in the moving direction and the magnet pieces 32a adjacent to the specific magnet piece 32a
The end faces in the moving direction of are not the same.

When the carrier 20 further moves the distance of the difference between the length L1 of the magnet piece 31a and the length L2 of the magnet piece 32a, the end face in the moving direction of the specific magnet piece 31a and the adjacent magnet piece 31a and the specific magnet piece 3
The end faces of the magnet pieces 32a adjacent to 2a in the moving direction pass each other. After that, the transport base 20 is the magnet piece 31.
Each time the distance of the difference between the length L1 of a and the length L2 of the magnet piece 32a is moved, the adjacent magnet piece 3 is further moved.
1a and 32a pass each other in sequence.

From the above, in the magnetic levitation transport device according to the present invention, the magnet piece 31a of the base side magnet 31 and the magnet piece 32a of the transport side magnet 32 have different lengths, so that the base side magnets 31 arranged in the moving direction X have different lengths.
The end faces of the plurality of magnet pieces 31a and 32a of both the transport side magnet 32 and the magnet pieces 31a and 32a pass each other in sequence, and the levitation force and the cogging force due to the passing of the end faces of the magnet pieces 31a and 32a in the moving direction are dispersed and generated as a large fluctuation. It doesn't become. Thereby, it is possible to provide a magnetic levitation transfer device having more stable levitation characteristics and transfer characteristics.

In the above description, the first magnet pair 30 has been described as an example, but the magnet piece 41a of the second magnet pair 40 has been described as an example.
A similar effect can be obtained with respect to the length of, 42a. Further, for both the first magnet pair 30 and the second magnet pair 40, the magnet pieces 31a and 41a of the base side magnets 31 and 41 and the magnet pieces 32a and 42a of the transport side magnets 32 and 42 The length may be different.

Further, in the magnetic levitation transfer device according to the present invention, as shown in FIG. 5A, two first magnet pairs 30 are provided on both end sides of the transfer table 20 in the width direction Y, for example, two second magnet pairs. The width spacing of the two base side magnets 31 constituting one magnet pair 30 is wider than the width spacing of the two transport base side magnets 32, and the width spacing of the two transport base side magnets 32 having a narrow width spacing is both wide. Is configured to be between two wide base side magnets 31.
5 (a) and 5 (b) are front views of the magnetic levitation transport device for explaining the relationship between the width spacing of the base side magnet 31 and the width spacing of the transport base side magnet 32, but on both end sides. In order to clarify the arrangement state of the base side magnet 31 and the transport base side magnet 32, the vicinity of the center of the width is not described, but the sides of both ends of the width are enlarged.

When the transport base 20 is in the center of the width of the base 10, that is, when there is no deviation in the width direction Y, the two transport base side magnets 32 having a narrow width interval between the two base side magnets 31 having a wide width interval. As shown in FIG. 5A, the first magnet pair 30 on the left side of the magnetic levitation transfer device (hereinafter referred to as “one side”) and the right side of the magnetic levitation transfer device (hereinafter referred to as “one side”). The base side magnet 31 and the transport base side magnet 32 constituting the first magnet pair 30 (described as "the other side") face each other with a slight deviation in the width direction Y, and carry the base side magnet 31. A repulsive force is generated in the pedestal magnet 32.

At this time, since the transport base 20 is in the center of the width, the distance between the base side magnet 31 and the transport base side magnet 32 of the first magnet pair 30 on one side and the base of the first magnet pair 30 on the other side. The distance between the base side magnet 31 and the transport base side magnet 32 is equal. Therefore, the repulsive force F1 that urges the base side magnet 31 of the first magnet pair 30 on one side and the transport base 20 generated on the transport base side magnet 32 to the other side, and the first magnet pair 30 on the other side. The repulsive force F2 that urges the transport base 20 generated on the base side magnet 31 and the transport base side magnet 32 to one side is equal.

The transport base 20 is in the width direction Y due to the repulsive force F1 received by the transport base side magnet 32 of the first magnet pair 30 on one side and the repulsive force F2 received by the transport base side magnet 32 of the first magnet pair 30 on the other side. Although it is urged, since the repulsive force F1 generated in the first magnet pair 30 on one side and the repulsive force F2 generated in the first magnet pair 30 on the other side are equal, the transport table 20 is urged in the width direction Y. There is no force to do.

On the other hand, under a force that shifts the transport table 20 in the width direction Y, that is, a force in the width direction, for example, as shown in FIG. When displaced to the side, the distance between the base side magnet 31 of the first magnet pair 30 on one side and the transport base side magnet 32 decreases, and the base side magnet 31 of the first magnet pair 30 on the other side and the transport base side magnet 32 are transported. The distance of the pedestal magnet 32 increases.
Since the repulsive force generated in the two magnets is inversely proportional to the square of the distance between the magnets, the repulsive force F3 generated in the first magnet pair 30 on one side where the distance between the magnets has decreased increases. On the other hand, the repulsive force F4 generated in the first magnet pair 30 on the other side where the distance between the magnets has increased decreases, so that the repulsive force F3
Is greater than the repulsive force F4.

In a state where the transport base 20 is displaced to one side as shown in FIG. 5B, the transport base 20 is moved to the other side by the repulsive force F4 that tries to move the transport base 20 to one side. Repulsive force F3
Is larger, so that the carrier 20 is urged to the other side and the width direction force FY that tries to shift the carrier 20 to one side is offset by this and decreases.

Based on the above, two first magnet pairs 30 are provided on both ends of the transport base 20 in the width direction Y, and the distance between the two base side magnets 31 constituting the two first magnet pairs 30 is two. The transport base 20 is configured such that the two transport base side magnets 32, which are wider than the distance between the transport base side magnets 32 and are narrowly spaced, are located between the two base side magnets 31 having a wide width gap. Is subjected to a force that shifts in the width direction Y, the repulsive force of the two first magnet pairs 30 reduces the force that shifts the transport table 20 in the width direction Y, so that more stable magnetic levitation transport is performed. Equipment can be provided.

In the above description, the case where the distance between the two base side magnets 31 is wider than the distance between the two transport base side magnets 32 has been described as an example, but the distance between the base side magnets 31 is narrower than the distance between the transport base side magnets 32. Even in this case, the same effect can be obtained.

Further, although the first magnet pair 30 has been described above as an example, the same effect can be obtained with the second magnet pair 40, and further, with respect to both the first magnet pair 30 and the second magnet pair 40. May be applied.

However, in any of the above cases, that is, whether the distance between the base side magnets 31 is wider or narrower, or whether the first magnet pair 30 or the second magnet pair 40 is used, the transport base 20
Is greatly deviated, and when the narrower magnet shifts to the outside of the wider magnet, the first
The repulsive force generated in the magnet pair 30 or the second magnet pair 40 does not generate an urging force for returning the transport base 20 to the original position, and the stability of the transport base 20 in the width direction is impaired.

In order to avoid this situation, the magnetic levitation transfer device according to the present invention is provided with a guide roller 84 in a direction facing the side surface of the transfer table 20, and has a structure that mechanically regulates a large deviation of the transfer table 20. However, the guide roller 84 operates only when the transport base 20 is largely displaced, and does not operate when the transport base 20 is not displaced or the displacement of the transport base 20 is small. Therefore, dust generation from the guide roller 84 is minimized. It can be suppressed to the limit.

Further, even when the guide roller 84 and the transport base 20 come into contact with each other due to a large width direction force, a difference is provided between the width distance between the two base side magnets and the width distance between the two transport base side magnets, and the width distance is narrower. Since the two magnets are both located between the magnets having a wider width interval, the width direction force is reduced by the repulsive force of the two magnet pairs, and the dust generation from the guide roller 84 is further minimized. It can be suppressed to the limit.

In addition, instead of the guide roller 84 or in combination with the guide roller 84, magnets having polarities repelling each other are provided at the arrangement position of the guide roller 84 and the side surface of the transport table 20, respectively, and the transfer table is provided by the repulsive force of the magnet pair. A large deviation of 20 may be regulated.

Further, in the magnetic levitation transport device according to the present invention, as shown in FIGS. 3 (a) and 3 (b), the total length L4 of the rack magnet 51 in the moving direction X is the transport base side magnet of the first magnet pair 30. The configuration is shorter than the total length L3 of the moving direction X of 32.

If the levitation heights of one side end and the other side end of the transport base 20 are accidentally different from each other in the moving direction, that is, when the transport base 20 is tilted with respect to the moving direction, the rack magnet 51 is tilted. And the pinion magnet 52 are close to each other. At the same time, the base side magnet 31 of the first magnet pair 30
And the magnet 32 on the transport table side are also close to each other. The proximity between magnets due to this inclination becomes larger when the total length of the magnets is longer even with the same amount of inclination.

In the magnetic levitation transport device according to the present invention, the total length L4 of the rack magnet 51 is made shorter than the total length L3 of the transport base side magnet 32 of the first magnet pair 30, so that when the transport base 20 is tilted, the total length of the moving direction X is X. The base side magnet 31 and the transport base side magnet 32 of the first magnet pair 30 having a longer length are closer to each other than the rack magnet 51 and the pinion magnet 52. Therefore, the moving direction X of the transport table 20
Even when the inclination with respect to the magnet becomes large, the base side magnet 31 and the transport base side magnet 32 of the first magnet pair 30 come into contact first, and the rack magnet 51 and the pinion magnet 52 do not come into contact with each other.

In the first magnet pair 30, the base side magnet 31 and the transport base side magnet 32 repel each other, so even if the base side magnet 31 and the transport base side magnet 32 come into contact with each other, the base side magnet 31 and the transport base side magnet 31 The 32 does not attract and repels, and the repulsive force urges the transport table 20 in a direction in which the inclination is reduced.

As described above, in the magnetic levitation transfer device according to the present invention, the total length L4 of the rack magnet 51 is made shorter than the total length L3 of the transfer table side magnet 32 of the first magnet pair 30, so that the transfer table 20 moves in the moving direction X.
Even when the rack magnet 51 and the pinion magnet 52 are tilted with respect to the other, the tilt of the transport table 20 can be reduced by avoiding the attraction of the rack magnet 51 and the pinion magnet 52, and a more stable magnetic levitation transport device can be provided.

Although the details of the present invention have been described above by way of examples, the present invention is not limited to the matters described in the examples, and various types that can be conceived by a person having ordinary knowledge in the field of the present invention. Even if there is a design change to the extent that it does not deviate from the gist of the present invention, including modification and modification, it is included in the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a magnetic levitation transfer device that is composed of only permanent magnets and can be easily incorporated into a housing.

10 Base 20 Transport stand 30 First magnet pair 31 Base side magnet 31a Magnet piece 32 Transport stand side magnet 32a Magnet piece 40 Second magnet pair 41 Base side magnet 41a Magnet piece 42 Transport stand side magnet 42a Magnet piece 50 Magnetic feed mechanism 51 Rack magnet 51a Magnet piece 52 Pinion magnet 81 Pedestal 82 Side plate 83 Top plate 910 Container 911 Floating body 912 Permanent magnet 915 Guide 916 Drive mechanism 917 Electromagnetic magnet 919 Position sensor 961 Guide part 961d Third magnet means 961 Upper and lower surface 963 Fourth magnet means 970 Mounting part 971 Support part 972 Torn part 972a Second magnet means 973 Fleet receiving part 973a First magnet means 973b Upper surface

Claims (7)

A transport device used in a clean environment, a magnetic levitation mechanism having a base and a transport base that is levitated and held from the base by magnetic force, and a magnetic feed that moves the transport base in a non-contact manner. In a magnetic levitation transfer device having a mechanism, the magnetic levitation mechanism comprises a first magnet pair that urges the transfer table upward and a second magnet pair that urges the transfer table downward. The magnet pair 1 and the second magnet pair are each composed of a magnet on the transport base side and a magnet on the base side that repel each other, and the transport of the first magnet pair and the second magnet pair. The magnet on the base side and the magnet on the base side are both configured by arranging a plurality of magnet pieces in the moving direction of the transport table, and at least one of the first magnet pair and the second magnet pair. A magnetic levitation transfer device, characterized in that the lengths of the magnet pieces on the base side and the magnet pieces on the transfer table side in the moving direction of the transfer table of one of the magnet pairs are different . The plurality of magnet pieces on the transport table side and the plurality of magnet pieces on the base side, which form the first magnet pair, are the same as the moving direction of the transport table. The magnetic levitation transfer device according to claim 1, wherein the intersecting end faces are inclined with respect to the moving direction. The plurality of magnet pieces on the transport table side and the plurality of magnet pieces on the base side, which form the second magnet pair, are the same as the moving direction of the transport table. The magnetic levitation transfer device according to claim 1 or 2, wherein the intersecting end faces are inclined with respect to the moving direction. The first magnet pair is provided on both end sides of the width in a direction orthogonal to the transport table moving direction, and is orthogonal to the transport table moving direction of the magnet on the base side of the two first magnet pairs. The width interval in the direction and the width interval in the direction orthogonal to the transport table moving direction of the magnet on the transport table side of the two first magnet pairs are different, and the two magnets having the narrower width interval have the width. The magnetic levitation transfer device according to any one of claims 1 to 3 , wherein the magnet is located between the two magnets having a wider interval. The second magnet pair is provided on both end sides of the width in a direction orthogonal to the transport table moving direction, and is orthogonal to the transport table moving direction of the magnet on the base side of the two second magnet pairs. The width spacing in the direction and the width spacing in the direction orthogonal to the transport table movement direction of the magnet on the transport table side of the two second magnet pairs are different, and the two magnets having the narrower width interval have the width. The magnetic levitation transfer device according to any one of claims 1 to 4 , wherein the magnet is located between the two magnets having a wider interval. The magnetic feed mechanism comprises a cylindrical pinion magnet having a rotation axis orthogonal to the moving direction of the transport table, and a rack magnet in which a plurality of magnet pieces are arranged in the moving direction of the transport table. The length of the rack magnet made of the magnet pieces in the moving direction of the carrier is shorter than the length of the magnet on the carrier side of the first magnet pair in the moving direction of the carrier. The magnetic levitation transfer device according to any one of claims 1 to 5. The first magnet pair is provided on both ends of the width in a direction orthogonal to the transport direction, and the magnetic feed mechanism for moving the transport is provided on both ends of the width of the transport. The magnetic levitation transfer device according to any one of claims 1 to 6 , wherein the magnetic levitation transfer device is arranged closer to the center of the width of the transfer table than the first magnet pair.

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