JP2018197163A5 - - Google Patents

Description

Magnetic levitation transfer device

The present invention relates to a transport apparatus used in a clean environment such as a semiconductor manufacturing apparatus and a food manufacturing apparatus, and more particularly, a magnetic levitation transport characterized by using a magnetic force to levitate and transport a transport base in a non-contact manner. It relates to the device.

For example, in a semiconductor manufacturing apparatus, a transfer device that moves an article such as a semiconductor wafer in a vacuum vessel is used. In a transfer device used in such a semiconductor manufacturing apparatus, in order to maintain the cleanliness in the vacuum container, it is necessary to reduce the dust generation due to the movement of the transfer table to the limit. It is effective to move the table while keeping it floating without contact.

As an example of a magnetic levitation conveyance device that floats, holds, and moves a conveyance table in a non-contact manner by applying magnetic force, Patent Document 1 discloses a magnetic levitation conveyance device as shown in FIG. The magnetic levitation transport device of Patent Document 1 is a levitation body 911 in which a permanent magnet 912 is attached in a container 910.
, And a movable guide 915 and a guide 91 with an electromagnet 917 attached to the outside of the container 910.
And a drive mechanism 916 for moving 5, and the floating 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) so that the levitated body 911 is levitated by the permanent magnet 912 and the electromagnet 917. This shows a magnetic levitation transport device that can float and hold in a non-contact manner and can move in a non-contact manner.

However, such a magnetic levitation transport apparatus requires an electromagnet, a position sensor, and a control means, and there is a problem that the apparatus becomes large and complicated and expensive.

As a method for solving such a problem, in Patent Document 2, as shown in FIG. 8, a mounting table 970 for mounting components, a support portion 971 for supporting the mounting table 970, and a lower portion of the support portion 971 are provided. A buoyancy receiving portion 973 having a first magnet means 973a for obtaining a high buoyancy, and a towed portion 972 having a supporting portion 971 or a second magnet means 972a to be attracted provided below the supporting portion 971, A first magnet means 973a, a third magnet means 961d and a fourth magnet means 963 arranged opposite to the second magnet means 972a.
3a, a component configured to move the mounting table 970 by moving the fourth magnet unit 963 while attracting the second magnet unit 972a while floating the mounting table 970 by the magnetic force of the third magnet unit 961d A transport device is shown.

According to Patent Document 2, the mounting table 970 includes a first magnet unit 973a and a third magnet unit 961.
Since it is levitated by the magnetic force acting during d, no electromagnet or control means is required, and the magnetic levitating and conveying apparatus can be configured with a simple structure.

As described above, the magnetic levitation transport apparatus disclosed in Patent Document 2 has an excellent structure that can realize magnetic levitation transport using only permanent magnets without using electromagnets or control means. However, the component on which the component is placed by the magnetic force of the first magnet unit 973a provided in the buoyancy receiving portion 973 and the third magnet unit 961d provided on the towing vehicle movably provided outside the casing. Since the table 970 is floated, in order to maintain the cleanliness in the housing, the first magnet means 973a and the third magnet means 961d are opposed to each other across the wall portion of the housing. There was a need to do. For this reason, the structure of the housing has become complicated, and there has been a problem that the cross-sectional structure of the housing has to be designed and manufactured in accordance with the magnetic levitation transport device.

JP 63-133803 A JP 2003-168716 A

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 transport apparatus that is composed of only permanent magnets and can be easily incorporated into a casing.

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

According to the present invention, when objects to be conveyed having different weights are placed on the conveyance table by providing the first magnet pair that urges the conveyance table upward and the second magnet pair that urges the conveyance table downward. However, since the fluctuation of the flying height of the transfer table can be suppressed, a magnetic levitation mechanism can be configured with only permanent magnets.
In addition, since the magnets constituting the first magnet pair that biases the transport table upward and the magnets that constitute the second magnet pair that biases the transport table downward are all independent magnets, It is possible to achieve a desired levitation characteristic by individually adjusting the temperature of the first magnet pair and the second magnet pair by using magnets having different temperature characteristics. It is possible to reduce the change in the flying 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, even if the transport distance becomes long, it can be dealt with only by increasing the number of magnet pieces used. . In addition, since it is not necessary to separate the carrier-side magnet and the base-side magnet that constitute the first magnet pair and the second magnet pair by a housing wall or the like, the entire magnetic levitation mechanism can be placed 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 casing, so that a magnetic levitation mechanism that can be easily incorporated into the casing can be provided.

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

End surfaces of the first magnet pair urging the transfer table upward, intersecting the moving direction of at least one of the plurality of magnet pieces on the transfer table side and the plurality of magnet pieces on the base side Was inclined with respect to the moving direction, and the shape of the surface facing the counterpart magnet was a substantially parallelogram shape. As a result, the levitation force fluctuation or the like when the transport table moves and passes each other is reduced, so that a magnetic levitation transport apparatus with more stable levitation characteristics and transport characteristics can be provided.

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

End surfaces of the second magnet pair urging the transfer table downward, and intersecting the moving direction of at least one of the plurality of magnet pieces on the transfer table side and the plurality of magnet pieces on the base side Was inclined with respect to the moving direction, and the shape of the surface facing the counterpart magnet was a substantially parallelogram shape. As a result, the levitation force fluctuation or the like when the transport table moves and passes each other is reduced, so that a magnetic levitation transport apparatus with more stable levitation characteristics and transport characteristics can be provided.

In the invention according to claim 4 of the present invention, the magnet piece on the base side and the transport table of at least one of the first magnet pair and the second magnet pair. The magnet pieces on the side are different in length in the moving direction of the carriage.

In the present invention, 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 carrier-side magnet pieces are different, the end faces of multiple magnet pieces do not pass each other when the carrier is moved, so the levitation force fluctuations when the magnet pieces are switched In addition, since the cogging force is generated in a distributed manner, a magnetic levitation conveyance apparatus with more stable levitation characteristics and conveyance characteristics can be provided.

In the invention according to claim 5 of the present invention, the first magnet pair is provided on both ends of the width in the direction orthogonal to the transporting table moving direction, and the bases of the two first magnet pairs are provided. The width interval in the direction orthogonal to the transfer table movement direction of the magnet on the table side and the width interval in the direction orthogonal to the transfer table movement direction of the magnet on the transfer table side of the two first magnet pairs are different, The two magnets having a narrower width interval are between the two magnets having a wider width interval.

In the present invention, the first magnet pair for urging the transport table upward is provided on both ends in the width direction of the transport table, for example, the width interval between the two magnets on the base side is the same as that of the two magnets on the transport table side. Wider than the width interval,
It was set as the structure where two magnets of the conveyance stand side with a narrow width space | interval enter between two magnets of the base side with a wide width space | interval.
As a result, when the carriage is biased so as to be displaced in the width direction by some external force or the like,
Since this urging force is reduced by the repulsive force of the carrier-side magnet and the base-side magnet, a more stable magnetic levitation carrier device can be provided.

In the invention according to claim 6 of the present invention, the second magnet pair is provided on both ends of the width in the direction orthogonal to the transporting table moving direction, and the base of the two second magnet pairs is provided. The width interval in the direction orthogonal to the transfer table movement direction of the magnet on the table side is different from the width interval in the direction orthogonal to the transfer table movement direction of the magnet on the transfer table side of the two second magnet pairs, The two magnets having a narrower width interval are between the two magnets having a wider width interval.

In the present invention, the second magnet pair for urging the transport table downward is provided on both ends in the width direction of the transport table. For example, the width interval between the two magnets on the base side is set between the two magnets on the transport table side. Wider than the width interval,
It was set as the structure where two magnets of the conveyance stand side with a narrow width space | interval enter between two magnets of the base side with a wide width space | interval.
As a result, when the carriage is biased so as to be displaced in the width direction by some external force or the like,
Since this urging force is reduced by the repulsive force of the carrier-side magnet and the base-side magnet, a more stable magnetic levitation carrier device can be provided.

In the invention according to claim 7 of the present invention, the magnetic feed mechanism includes a cylindrical pinion magnet having a rotation axis perpendicular to the moving direction of the transport table, and a plurality of magnet pieces of the transport table. The rack magnets are arranged in the moving direction, and the length of the rack magnets made of the plurality of magnet pieces in the moving direction of the transfer table is the length of the magnet on the transfer table 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 magnet constituting the magnetic feed mechanism in the direction of movement of the carrier is shorter than the length of the magnet on the side of the carrier of the first magnet pair in the direction of movement of the carrier. When inclined in the direction, the transfer table is biased in a direction in which the inclination is reduced by the repulsive force of the transfer table side magnet and the base side magnet of the first magnet pair.
Thereby, even when the conveyance table is inclined in the moving direction, it is possible to reduce the inclination by avoiding the adsorption of the conveyance table, and it is possible to provide a more stable magnetic levitation conveyance device.

  According to an eighth aspect of the present invention, the magnetic feed mechanism according to the eighth aspect of the present invention, wherein the first magnet pair is provided on both ends of the width in the direction orthogonal to the transporting table transporting direction, and the transporting table is moved. Is arranged closer to the center of the width of the transfer table than the first magnet pair provided on both ends of the width of the transfer table.

  In the present invention
The first magnet pair composed of the base-side magnet and the transport-side magnet biases the transport base upward by a repulsive force. On the other hand, in a magnetic feed mechanism composed of a rack magnet and a pinion magnet, the conveyance table is biased downward by an attractive force between the rack magnet and the pinion magnet.
  When the conveyance table is inclined for some reason, the conveyance table rotates around the approximate center of the width, and one of both end portions of the width moves upward and the other moves downward. The base-side magnet of the first magnet pair on the end side moved downward and the magnet on the transport base are close to each other, and a force is exerted to urge the transport base more strongly and reduce the inclination of the transport base. . On the other hand, in the magnetic feed mechanism, when the distance between the rack magnet and the pinion magnet approaches, a force that increases the attraction force and increases the inclination of the transport table is generated.
  In the present invention, since the magnetic feed mechanism is disposed between the two first magnet pairs provided on both ends of the width of the carriage, when the carriage is inclined, the distance between the rack magnet and the pinion magnet is increased by the inclination. The amount of proximity between the base side magnet of the first magnet pair provided on the end side of the width of the transport table and the magnet on the transport table is always greater than the approaching amount, so the inclination of the transport table by the magnetic feed mechanism The force for reducing the inclination of the conveyance table by the first magnet pair is larger than the force for increasing the angle, and the conveyance table is returned to the horizontal level.
  Thereby, even when the conveyance table is inclined in the width direction, it is possible to reduce the inclination while avoiding adsorption of the conveyance table, and it is possible to provide a more stable magnetic levitation conveyance device.

From the above, in the magnetic levitation transport device according to the present invention,
By providing a first magnet pair that urges the carrier table upward and a second magnet pair that urges the carrier table downward, a magnetic levitation mechanism can be configured with only permanent magnets,
Since the magnets of the magnet pair are arranged in the moving direction, even if the transport distance is long, a magnetic levitation mechanism with a size according to the application and plan can be easily manufactured just by increasing the number of magnet pieces used.
Since it is not necessary to separate the carrier-side magnet and the base-side magnet at the housing wall, a magnetic levitation mechanism that can be easily incorporated into the housing can be provided.

It is a figure which shows the structure of the Example of this invention, (a) is a top view, (b) is a front view. It is a perspective view which shows the structure of a present Example. It is sectional drawing which shows the structure of a present Example, (a) is sectional drawing of the AA position in FIG.1 (b) which shows the structure of a magnetic levitation mechanism, (b) is a figure which shows the structure of a magnetic feed mechanism. It is sectional drawing of the BB position in 1 (b). It is a figure which shows the effect by the end surface shape of the magnet piece of a 1st magnet pair, (a) is a top view which shows the shape of a magnet piece, (b) is a graph which shows the change of the repulsive force by a change of end surface shape, (c ) Is a graph showing changes in cogging force due to changes in the end face shape. It is a front view explaining arrangement | positioning of the magnet of a magnet pair, (a) is normal time, (b) is a time of deviation | shift occurrence. It is a graph which shows the analysis result of the energizing force by the 1st magnet pair and the 2nd magnet pair. It is a figure which shows the structure of the magnetic levitation conveyance apparatus by patent document 1. FIG. It is a figure which shows the structure of the magnetic levitation conveyance apparatus by patent document 2. FIG.

Embodiments of a magnetic levitation transport apparatus according to the present invention will be described in detail with reference to FIGS.
First, the external appearance and schematic structure of the magnetic levitation transport apparatus according to the present embodiment will be described with reference to FIGS. In the description of this embodiment, a direction indication arrow symbol is shown in FIG.
The direction of X is described as “movement direction X”, the direction of Y as “width direction Y”, and the direction of Z as “height direction Z”.

As shown in FIGS. 1 and 2, the magnetic levitation transport apparatus according to the present embodiment has a substantially plate-like base 1.
0, which is also substantially plate-shaped, places the object to be transported, is lifted and held from the base 10, and is transported in the longitudinal direction of the base 10, that is, in the moving direction X. It comprises a magnetic feed mechanism 50 that carries by contact.

A first magnet pair 30 for urging the conveying table 20 upward and a second magnet pair 40 for urging the conveying table downward are provided on both ends in the width direction of the magnetic levitation conveying apparatus. Yes. Further, a magnetic feed mechanism 50 composed of a rack magnet 51 and a pinion magnet 52 is located at a position from the center of the two first magnet pairs 30 and the second magnet pair 40 provided on both end sides in the width direction Y. Is provided.

As shown in FIG. 3A, the first magnet pair 30 that urges the transfer table 20 upward is a pedestal 81.
The base side magnet 31 attached to the upper surface side of the base 10 and the transport base side magnet 32 attached to the lower surface side of the transport base 20. Since the base-side magnet 31 and the carrier-side magnet 32 are arranged so as to repel each other, the carrier-side magnet 32 of the first magnet pair 30 is caused by the base-side magnet 31 of the first magnet pair 30. It is urged upward.

The second magnet pair 40 that urges the transport table 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 consists of a side magnet 41 and a carriage base magnet 42 attached to the upper surface side of the carriage 20. Since the base-side magnet 41 and the carriage-side magnet 42 are arranged so as to repel each other, the carriage-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 and 41 and the transport base side magnets 32 and 42 of the first magnet pair 30 and the second magnet pair 40 are respectively a plurality of magnet pieces 31a, 41
a, 32a, 42a are arranged in the moving direction X, and the first magnet pair 30 and the second magnet
The base side magnets 31 and 41 of the magnet pair 40 are arranged over substantially the entire length in the movement direction X of the base 10. Similarly, the transport table side magnets 32 and 42 of the first magnet pair 30 and the second magnet pair 40 are arranged over substantially the entire length in the movement direction X of the transport table 20.

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

Further, in the magnetic levitation transfer device transfer stand according to the present invention, as shown in FIG.
A rack magnet 51 composed of a plurality of magnet pieces 51a arranged in the movement direction X on the lower surface of 0, and a rotation axis in a direction parallel to the width direction Y orthogonal to the movement direction X. The carrier 20 is moved in a non-contact manner by the magnetic feed mechanism 50 including the pinion magnets 52 arranged.

The rack magnets 51 are arranged so that the polarities of the adjacent magnet pieces 51a are different from each other. 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 is magnetized so that adjacent regions have different polarities.

The rack magnet 51 and the pinion magnet 52 are opposed to each other through a gap. When the plurality of pinion magnets 52 are rotated by a rotating means (not shown), the rack magnet 51 is caused by the magnetic attractive force of the rack magnet 51 and the pinion magnet 52. Moves in the moving direction X, and the carriage 20 to which the rack magnet 51 is attached is moved in a non-contact manner.

In the magnetic levitation transport apparatus according to the present invention, the magnetic levitation mechanism for levitating the transport base on which the article is placed and transported is attached, and the first magnet pair 30 for biasing the transport base upward and the transport base are attached downward. The second magnet pair 40 is configured to be energized.

A structure for urging the transfer table in both upward and downward directions to lift the transfer table is also described in Japanese Patent Application Laid-Open No. H11-228260, 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 it is urged upward by the repulsive force of a and the third magnet means 961d and urged downward by the repulsive force of the upper lower surface 961e of the guide portion 961 and the upper surface 973b of the buoyancy receiving portion. However, Patent Document 2 does not describe the function and effect of downward biasing by the repulsive force of the upper lower surface 961e and the upper surface 973b of the buoyancy receiving portion.

The magnetic levitation transport apparatus according to the present invention is configured to bias the transport base 20 upward and also downward, and the function and effect of this structure in the present invention will be described below.

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

However, the more important second function of this configuration is the adjustment of the flying characteristics of the carriage 20. 1st magnet pair 3 at the time of setting it as the structure which urges | biases the conveyance stand 20 to both upward and downward directions
The characteristics of the urging force of the zero and second magnet pair 40 and the resulting analysis result of the floating characteristics of the transport table 20 will be described with reference to FIG.

FIG. 6 is a result 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 the magnets, and the horizontal axis is the base side of the first magnet pair 30. The distance between magnets of the magnet 31 and the carriage side magnet 32 is the urging force generated on the vertical axis. The urging force is indicated by a dashed line in the graph of FIG. 6 and “upward urging force” for urging the carrier 20 generated in the first magnet pair 30 indicated by a broken line in the graph of FIG. The “total urging force” obtained by adding the “lower urging force” for urging the carrier 20 generated in the second magnet pair 40 downward and the upper urging force and the lower urging force indicated by a solid line in the graph of FIG. " 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 the plurality of magnets to be analyzed and the carrier, base, etc. are not considered. Further, the downward urging force generated in the second magnet pair 40 has a negative value because it urges the transport table 20 downward.

As shown in the graph of FIG. 6, the upward biasing force generated in the first magnet pair 30 is generated about 10 kN when the distance between the magnets is 10 mm, and is generated 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 −7 k when the distance between the magnets is 10 mm.
N is generated, and approximately -5 kN is generated when the distance between the magnets is 6 mm. As a result, the total urging force obtained by adding the upper urging force and the lower urging force becomes an upward urging force of 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 analysis result of the above “total urging force” shows that when the carrier 20 is pressed downward at 3.4 kN, the distance between the magnets is balanced at a position of 10 mm, and when pressed at 9.5 kN, the distance between the magnets is balanced at 6 mm.
It means that. From this balancing behavior, the distance between the magnets is 9 mm when the carrier 20 is pushed downward at 4.8 kN.
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 increases, the distance between the magnets decreases from 10 mm to 9 mm, i.e. by 1 mm.

By the way, if the carrier 20 is simply levitated, only upward biasing by the first magnet pair 30 may be used. Therefore, for example, when the magnetic characteristics of the first magnet pair 30 are adjusted, specifically, the magnetic force is weakened so that the biasing force when the distance between the magnets is 10 mm is 3.4 kN which is the same as the total biasing force. The upward urging force was calculated. The results are shown in FIG. 6 as “calculated_upward biasing force” with a two-dot chain line.

In this “calculation_upward biasing force” in which the magnetic characteristics are adjusted with only the first magnet pair as the magnet pair, as shown in the graph of FIG. 6, when the carrier 20 is pushed downward at 3.4 kN, the distance between the magnets When the distance is 10mm, the balance is 6mm when the distance between magnets is 6mm.
Accordingly, the force applied to the transport table 20 changes from 3.4 kN to 4.8 kN, that is, 1.4 kN.
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.
When the force applied to the carrier increases by 1.4 kN, the distance between the magnets changes by 4 mm when the carrier 20 is lifted by only the magnet pair that biases upward, but the first magnet pair 30 that biases the carrier is upward. When the second magnet pair 40 that biases downward is provided, the amount of change in the distance between the magnets can be suppressed to 1 mm.

As described above, the first magnet pair 30 that urges the conveyance table 20 upward and the second magnet pair 40 that urges the conveyance table 20 downward are provided, and the upward urging force to the conveyance table 20 is reduced by the downward urging force. By partially canceling, it is possible to suppress the variation in the flying height of the transport table 20 even when the objects to be transported having different weights are placed on the transport 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.

Note that the above behavioral characteristics of the urging force are characteristic values when the dimensional specification of the magnet pair is temporarily set to a specific value, and the behavior of the urging force can be changed to the required characteristics by variously adjusting the dimensional specification of the magnet pair. It is possible to match.

In particular, in the magnetic levitation transport apparatus according to the present invention, all of the magnets of the first magnet pair 30 that biases the transport base 20 upward and all the magnets of the second magnet pair 40 that biases the transport base 20 downward. Since the magnets are independent, the size of each magnet, the distance between the magnets, etc. can be individually changed to adjust the upper biasing force and the lower biasing force to adjust the floating characteristics of the carriage to the desired specifications. Is possible.

In addition, it is known that the attractive force and repulsive force by a magnet will change with temperature, and generally, as the temperature increases, the attractive force and repulsive force decrease. Therefore, even in the magnetic levitation transport apparatus according to the present invention, when the temperature of the magnet used increases due to a change in the environmental temperature or the like, the repulsive force of the first magnet pair 30 that biases the transport base 20 upward and the transport base 20. Both of the repulsive forces of the second magnet pair 40 that urges the magnet downward are reduced.

The transport table 20 that is levitated and held includes an upward biasing force by the first magnet pair 30, a downward biasing force by the second magnet pair 40, the weight of the transport table 20, and a placed object to be transported. The flying height is determined by the downward bias by the weight of the. Of these urging forces, the upward urging force by the first magnet pair 30 and the downward urging force by the second magnet pair 40 both decrease as the temperature rises, so that the balance by the urging forces in both directions is roughly maintained. Be drunk. However, since 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 due to the temperature rise, the flying height of the transport table 20 decreases as a result of the temperature rise.

However, in the magnetic levitation transport apparatus according to the present invention, the first that biases the transport base 20 upward.
Since the magnet of the magnet pair 30 and the magnet of the second magnet pair 40 that urges the carrier 20 downward are all independent magnets, the magnets constituting the first magnet pair 30 are attracted by the temperature rise. Power,
It is possible to select a material type with a small reduction rate of the repulsive force and a material type with a large reduction rate of the attractive force and the repulsive force due to the temperature rise of the magnets constituting the second magnet pair 40. As a result, the lowering of the upward biasing force by the first magnet pair 30 due to the temperature rise is suppressed, and the lowering of the downward biasing force by the second magnet pair 40 becomes large. Combined with the downward urging force due to the weight of the conveyed object, it is possible to adjust the balance due to the urging force in both directions, and to reduce the change in the floating characteristics due to the temperature change.

In the magnetic levitation transport apparatus according to the present invention, the first magnet pair 30 and the second magnet pair 40 are also used.
As shown in FIG. 4 (a), 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, The shape in which the end surface intersecting the moving direction X is inclined with respect to the moving direction X, that is, the surface facing the counterpart magnet piece is a substantially parallelogram shape. The “end surface intersecting the moving direction X” will be referred to as “moving direction end surface” hereinafter.

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

In the graphs of FIG. 4B and FIG. 4C, the horizontal axis indicates the amount of movement of the magnet piece, and the central position of the horizontal axis is the position where the moving direction end faces of both magnet pieces pass each other. In addition, when the moving direction end surface is inclined, the center of the inclined surface is a passing position.

When the magnet piece is a simple rectangular shape and the surface facing the counterpart magnet is a simple rectangle, the repulsive force fluctuation and cogging force generated in the magnet pair are shown in FIGS. 4 (b) and 4 (c), respectively. The curve is indicated by a broken line as “no inclination of both magnet end faces”. The repulsive force changes greatly when the moving end faces of both magnet pieces pass each other, and the change of the cogging force is also large.

On the other hand, for example, when the moving direction end face of the magnet piece 31a of the base side magnet 31 is inclined so that the face facing the counterpart magnet piece has a substantially parallelogram shape, “the one magnet end face is inclined”.
As shown by the solid line, 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 values of the cogging force are generated is widened.

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

In the magnetic levitation transport apparatus according to the present invention, since 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 provide a magnetic levitation transfer apparatus that can reduce the fluctuation of the levitation force and the cogging force when the transfer table moves and the end surfaces of both the magnet pieces pass each other, and have more stable levitation characteristics and transfer characteristics.

Moreover, in the magnetic levitation conveyance apparatus by this invention, as shown to Fig.4 (a), the length L1 of the moving direction X of the magnet piece 31a of the base side magnet 31 of the 1st magnet pair 30, for example, and conveyance are carried out. Side magnet 32
The length L2 in the moving direction X of the magnet piece 32a is a different length.

If the length of the magnet piece 31a of the base-side magnet 31 and the length of 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 are moved at a specific position. Magnet piece 3
The movement direction end face of 1a and the movement direction end faces of the magnet pieces 32a of all the transport side magnets 32 pass at the same time, and a large levitation force fluctuation and cogging force are generated at this specific position.

On the other hand, if the magnet piece 31a of the base side magnet 31 and the magnet piece 32a of the conveyance side magnet 32 are made into different lengths, the conveyance stand 20 will move, and the movement direction end surface of a certain specific magnet piece 31a will have a certain specific surface. At the moment when the movement direction end face of the magnet piece 32a passes, the movement direction end face of the magnet piece 31a adjacent to a certain magnet piece 31a and the magnet piece 32a adjacent to a certain magnet piece 32a.
The moving direction end faces of do not match.

When the carriage 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 magnet piece 31a adjacent to the specific magnet piece 31a and the specific magnet piece 3
The moving direction end surfaces of the magnet pieces 32a adjacent to 2a pass each other. Thereafter, the transport table 20 is moved to 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
1a and 32a pass each other sequentially.

As described above, in the magnetic levitation transport apparatus according to the present invention, the magnet pieces 31a of the base-side magnet 31 and the magnet pieces 32a of the transport-side magnet 32 have different lengths.
Further, the end surfaces of the plurality of magnet pieces 31a and 32a of both of the transfer side magnets 32 pass one after another, and the fluctuation of the levitation force and the cogging force due to the passing of the end faces on the moving direction side of the magnet pieces 31a and 32a are generated in a distributed manner. Don't be. Thereby, it is possible to provide a magnetic levitation conveyance apparatus with more stable levitation characteristics and conveyance 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 is used.
, 42a, the same effect can be obtained. 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 are provided. The lengths may be different lengths.

Further, in the magnetic levitation transport apparatus according to the present invention, as shown in FIG. 5A, two first magnet pairs 30 are provided on both ends in the width direction Y of the transport base 20, for example, The width interval between the two base-side magnets 31 constituting one magnet pair 30 is made wider than the width interval between the two carrier-side magnets 32, and the two carrier-side magnets 32 with a narrow width interval are both spaced apart. Is between the two large 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 interval of the base-side magnet 31 and the width interval of the transport-base magnet 32. In order to clarify the arrangement state of the base-side magnet 31 and the carriage-side magnet 32, the width end portion side is enlarged and not shown in the vicinity of the width center portion.

When the carriage 20 is in the center of the width of the base 10, that is, when there is no shift in the width direction Y, the two carriage-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 (hereinafter referred to as “one side”) of the magnetic levitation transport apparatus and the right side of the magnetic levitation transport apparatus (hereinafter referred to as “below”). Each of the base side magnets 31 and the transport base side magnets 32 constituting the first magnet pair 30 (described as “the other side”) are slightly shifted in the width direction Y and face each other. A repulsive force is generated in the base side magnet 32.

At this time, since the carrier 20 is in the center of the width, the distance between the base-side magnet 31 and the carrier-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. Accordingly, the repulsive force F1 for urging the carrier 20 generated in the base-side magnet 31 and the carrier-side magnet 32 of the first magnet pair 30 on the one side to the other side, and the first magnet pair 30 on the other side. The repulsive force F2 for urging the transfer table 20 generated in the base-side magnet 31 and the transfer table-side magnet 32 to one side is equal.

The carrier 20 is moved in the width direction Y by the repulsive force F1 received by the carrier-side magnet 32 of the first magnet pair 30 on one side and the repulsive force F2 received by the carrier-side magnet 32 of the first magnet pair 30 on the other side. However, 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 conveying table 20 is urged in the width direction Y. There is no power to do.

On the other hand, a force that shifts the conveying table 20 in the width direction Y, that is, a force in the width direction, is applied. As shown in FIG. When shifted to the side, the distance between the base side magnet 31 of the first magnet pair 30 on one side and the transport side magnet 32 decreases, and the base side magnet 31 and the transport side magnet 31 of the first magnet pair 30 on the other side are transported. The distance of the base side 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, since the repulsive force F4 generated in the first magnet pair 30 on the other side where the distance between the magnets has increased, the repulsive force F3
Becomes larger than the repulsive force F4.

In a state where the transport table 20 is shifted to one side as shown in FIG. 5B, the transport table 20 is moved to the other side due to the repulsive force F4 which attempts to move the transport table 20 to one side. Repulsive force F3
Therefore, the conveyance table 20 is biased to the other side, and the width direction force FY which attempts to shift the conveyance table 20 to one side is offset by this and decreases.

As described above, the two first magnet pairs 30 are respectively provided on both end sides in the width direction Y of the transport table 20, and the interval between the two base-side magnets 31 constituting the two first magnet pairs 30 is set to two. By adopting a configuration in which the two carrier table side magnets 32 that are wider and narrower than the carrier table side magnet 32 are between the two base side magnets 31 that have a wide width interval, the carrier table 20 can be provided. When the force is shifted in the width direction Y, the repulsive force of the two first magnet pairs 30 can reduce the force to shift the transport table 20 in the width direction Y, so that more stable magnetic levitation transfer An apparatus can be provided.

In addition, although the case where the space | interval of the two base side magnets 31 was wider than the space | interval of the two conveyance stand side magnets 32 was demonstrated to the example above, the space | interval of the base side magnet 31 is narrower than the space | interval of the conveyance stand side magnet 32. Even in the case, the same effect can be obtained.

In the above description, the first magnet pair 30 has been described as an example. However, the same effect can be obtained with the second magnet pair 40, and further, both the first magnet pair 30 and the second magnet pair 40 can be obtained. May be applied.

However, in any of the above cases, that is, in the case where the interval between the base side magnets 31 is wider or narrower, or in the case of the first magnet pair 30 or the second magnet pair 40, the transport table 20.
Is greatly shifted, and when the narrower magnet is displaced to the outside than the wider magnet, the first
The repulsive force generated in the magnet pair 30 or the second magnet pair 40 does not generate a biasing force that returns the transport table 20 to the original position, and the stability of the transport table 20 in the width direction is impaired.

In order to avoid this situation, the magnetic levitation transport apparatus according to the present invention has a structure in which a guide roller 84 is provided in a direction facing the side surface of the transport base 20 to mechanically restrict a large deviation of the transport base 20. However, since the guide roller 84 operates only when the conveyance table 20 is largely deviated, and does not operate when the conveyance table 20 is not deviated or when the deviation of the conveyance table 20 is small, dust generation from the guide roller 84 is minimal. It can be suppressed to the limit.

Even when the guide roller 84 and the carriage 20 are brought into contact with each other by a large force in the width direction, a difference is provided between the width interval between the two base-side magnets and the width interval between the two carriage-side magnets, Since both of the two magnets are arranged between the magnets having the wider width interval, the force in the width direction 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.

Instead of the guide roller 84 or in combination with the guide roller 84, magnets having repulsive polarities are provided on the arrangement position of the guide roller 84 and the side surface of the transport table 20, respectively, and the transport table is generated by the repulsive force of the magnet pair. 20 large deviations may be regulated.

Moreover, in the magnetic levitation transport apparatus according to the present invention, as shown in FIGS. 3A and 3B, the total length L4 of the movement direction X of the rack magnet 51 is the transport base side magnet of the first magnet pair 30. The configuration is shorter than the total length L3 of 32 moving directions X.

If the flying height of one side end and the other side end in the moving direction of the transport table 20 is accidentally changed, that is, if the transport table 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 is also provided.
And the carriage side magnet 32 are also close to each other. The proximity between the magnets due to this inclination becomes larger as the total length of the magnet is longer even with the same inclination amount.

In the magnetic levitation transport apparatus 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 inclined, the total length in the moving direction X is increased. The base-side magnet 31 and the transport-base-side magnet 32 of the longer first magnet pair 30 are closer than the rack magnet 51 and the pinion magnet 52. Therefore, the moving direction X of the carrier 20
Even when the inclination with respect to is increased, the base side magnet 31 and the transport base side magnet 32 of the first magnet pair 30 come into contact with each other 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, the base side magnet 31 and the transport base side magnet 32 repels without being attracted, 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 transport apparatus 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 the transport base 20 moves in the moving direction X.
Even when tilted with respect to the rack magnet 51 and the pinion magnet 52, the tilt of the transport table 20 can be reduced, and a more stable magnetic levitation transport device can be provided.

As described above, the details of the present invention have been described by way of examples. However, the present invention is not limited to the matters described in the examples, and various types that can be conceived by those having ordinary knowledge in the field of the present invention. Any design changes that do not depart from the spirit of the present invention, including variations and modifications, are also included in the present invention.

According to the present invention, it is possible to provide a magnetic levitation transport apparatus that is composed of only permanent magnets and can be easily incorporated into a casing.

DESCRIPTION OF SYMBOLS 10 Base 20 Transfer stand 30 1st magnet pair 31 Base side magnet 31a Magnet piece 32 Transfer stand side magnet 32a Magnet piece 40 2nd magnet pair 41 Base side magnet 41a Magnet piece 42 Transfer stand side magnet 42a Magnet piece DESCRIPTION OF SYMBOLS 50 Magnetic feed mechanism 51 Rack magnet 51a Magnet piece 52 Pinion magnet 81 Base 82 Side plate 83 Top plate 910 Container 911 Floating body 912 Permanent magnet 915 Guide element 916 Drive mechanism 917 Electromagnet 919 Position sensor 961 Guide part 961d Third magnet means 961 Upper lower surface 963 Fourth magnet means 970 Placement portion 971 Support portion 972 Towing portion 972a Second magnet means 973 Buoyancy receiving portion 973a First magnet means 973b Upper surface

Claims (8)

A transport device used in a clean environment, a base, a magnetic levitation mechanism having a transport base that is levitated and held by the magnetic force, and a magnetic feed that moves the transport base in a non-contact manner. In a magnetic levitation transport device having a mechanism,
The magnetic levitation mechanism includes a first magnet pair that urges the transport table upward and a second magnet pair that urges the transport table downward, and the first magnet pair and the second magnet. Each of the pairs is composed of a magnet on the side of the carriage and a magnet on the side of the base that repel each other,
The magnets on the transfer platform side and the magnets on the base platform side of the first magnet pair and the second magnet pair are each configured by arranging a plurality of magnet pieces in the moving direction of the transfer table. A magnetic levitation conveyance device. The plurality of magnet pieces on at least one of the plurality of magnet pieces on the side of the carriage and the plurality of magnet pieces on the side of the base constituting the first pair of magnets, 2. The magnetic levitation transport apparatus according to claim 1, wherein the intersecting end faces are inclined with respect to the moving direction. The plurality of magnet pieces of at least one of the plurality of magnet pieces on the transport table side and the plurality of magnet pieces on the base side constituting the second magnet pair are in a moving direction of the transport table. The magnetic levitation conveyance apparatus according to claim 1, wherein the intersecting end faces are inclined with respect to the moving direction. The length of the magnet piece on the base side and the magnet piece on the transfer table side in the transfer table moving direction of at least one of the first magnet pair and the second magnet pair. The magnetic levitation conveyance apparatus according to any one of claims 1 to 3, characterized in that: Providing the first magnet pair on both ends of the width in the direction perpendicular to the direction of movement of the carriage,
The width interval of the two first magnet pairs in the direction orthogonal to the moving direction of the transfer table of the magnets on the base side, and the movement of the transfer table of the magnets on the transfer table side of the two first magnet pairs 5. The two magnets having different width intervals in a direction orthogonal to the direction and having a narrower width interval are between the two magnets having a wider width interval. 6. A magnetic levitation conveyance apparatus described in any of the above. Providing the second magnet pair on both ends of the width in the direction perpendicular to the direction of movement of the carriage,
The width interval of the two second magnet pairs in the direction orthogonal to the moving direction of the transfer platform of the magnets on the base side, and the transfer of the transfer platform of the magnets on the transfer platform side of the two second magnet pairs The width interval in a direction orthogonal to the direction is different, and the two magnets having a narrower width interval are between the two magnets having a wider width interval. A magnetic levitation conveyance apparatus described in any of the above. The magnetic feed mechanism includes a cylindrical pinion magnet having a rotation axis orthogonal to the moving direction of the transfer table, and a rack magnet in which a plurality of magnet pieces are arranged in the moving direction of the transfer table. The length of the rack magnet composed of a plurality of magnet pieces in the moving direction of the transfer table is shorter than the length of the magnet on the transfer table side of the first magnet pair in the moving direction of the transfer table. The magnetic levitation transport apparatus according to any one of claims 1 to 6. The first magnet pair is provided on both ends of the width in the direction orthogonal to the transport table transport direction, and the magnetic feed mechanism for moving the transport table is provided on both ends of the transport table width. The magnetic levitation conveyance apparatus according to any one of claims 1 to 7, wherein the magnetic levitation conveyance apparatus is arranged closer to the center of the width of the conveyance table than the first magnet pair.