JPH07110084B2 - Magnetic levitation carrier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation carrier device for levitation of a carrier or carrier arm from a track for non-contact movement.

[0002]

2. Description of the Related Art Several magnetic levitation transfer devices have been proposed in the prior art in which a transfer means (for example, a transfer table) on which an object to be transferred is levitated by magnetic force and which moves in a non-contact state with respect to a track. ing.

For example, there is a magnetic levitation transfer device of the type in which an electromagnet is used to levitate the transfer table from the track, and the distance between the transfer table and the track is measured by a sensor or the like to control the current supplied to the electromagnet. The type using such an electromagnet allows precise control, and is a very useful technique in itself.

[0004]

However, when levitating by an electromagnet, its control is complicated, power consumption increases, and the size of the apparatus must be increased. Therefore, it is desirable to use a permanent magnet as much as possible. There is also a request.

In response to this demand, there are a magnetic levitation transfer device of the type in which the transfer means is levitated by the attractive force of a permanent magnet, and a magnetic levitation transfer device of the type in which the repulsion force is used to levitate.

However, the levitation force by the permanent magnet is more unstable than that by the electromagnet, and in the conventional magnetic levitation transfer device using the permanent magnet, both the type using the attraction force and the type using the repulsion force are used. However, there is a problem in that the vertical relative positions of the permanent magnets are very strict, and when the permanent magnets are not at the predetermined relative positions, the carrier table cannot be floated and held.

The present invention has been proposed in view of the above-mentioned demands or problems in the prior art. A permanent magnet can be used, a stable levitation force can be obtained, and a permissible relative position in the vertical direction. The purpose of the present invention is to provide a magnetic levitation transport device having a large range.

[0008]

As a result of various researches by the inventors, when two permanent magnets are arranged as shown in FIG. 1, a very stable levitation force and a stable levitation force can be obtained. It has been found that the tolerance in the range where the state is maintained, that is, the relative positional relationship between the two magnets in the vertical direction is very large.

The magnetic levitation transfer apparatus of the present invention is a magnetic levitation transfer apparatus for levitating a transfer arm (reference numeral 14 in FIG. 2) from a track (reference numeral 16 in FIG. 2) and moving it in a non-contact manner. A permanent magnet (reference numeral 2 in FIG. 1 and reference numeral 22 in FIG. 2) is made to extend in the transfer arm movement direction to the reference numeral 16R in FIG.
A permanent magnet (reference numeral 1 in FIG. 1 and reference numeral 20 in FIG. 2) is provided near the end of the transfer arm on the side closer to the reference numeral 22) in FIG. 2, and the permanent magnet (reference numeral 1 in FIG. Sign 2 of 2
0) center line (reference numeral 1C in FIG. 1) is orthogonal to the center line (reference numeral 2C in FIG. 1) of the permanent magnets (reference numeral 2 in FIG. 1, reference numeral 22 in FIG. 2) provided on the trajectory, and The permanent magnets provided (reference numeral 2 in FIG. 1, reference numeral 22 in FIG. 2) coincide with the upper edge portion (reference numeral 2S in FIG. 1), and both permanent magnets (reference numeral 1 in FIG. 1,
2, the reference numerals 20 and 22 in FIG. 2 are set to have polarities so as to attract each other.

In carrying out the present invention, it is preferable that an electromagnet for attracting the transfer arm is provided at an end of the transfer arm opposite to the permanent magnet.

Further, an auxiliary magnet (42) is provided in the middle of the transfer arm (14), and an auxiliary magnet (44) is also provided at a portion on the track corresponding to the auxiliary magnet (42). It is preferable that the auxiliary magnets (42, 44) have polarities so as to repel each other in order to exert an auxiliary buoyancy on 14).

The magnetic levitation transfer apparatus of the present invention is a magnetic levitation transfer apparatus for levitating a transfer table (reference numeral 60 in FIG. 9) from a track (reference numeral 16 in FIG. 9) and moving it in a non-contact manner. A permanent magnet (reference numeral 2 in FIG. 1 and reference numeral 22 in FIG. 9) is made to extend in the carrier moving direction (reference numeral 16L in FIG. 9), and the permanent magnet (reference numeral 2 in FIG. 1 and FIG. 9) provided on the track is provided.
The permanent magnet (Fig.
No. 1, reference numeral 20 in FIG. 9 is provided, and the center line (reference numeral 1C in FIG. 1) of the permanent magnet (reference numeral 1 in FIG. 1, reference numeral 20 in FIG. 9) provided on the carrier is the permanent magnet provided on the track. A permanent magnet (reference numeral 2 in FIG. 1, reference numeral 2 in FIG. 1) orthogonal to the center line (reference numeral 2C in FIG. 1) of the magnet (reference numeral 2 in FIG. 1) and provided on the track.
The upper edge portion (reference numeral 2S in FIG. 1) of the reference numeral 22 in FIG. 9 corresponds to both permanent magnets (reference numerals 1 and 2 in FIG. 1, reference numeral 2 in FIG.
The polarities of 0 and 22) are set so as to attract each other.

Further, the magnetic levitation transfer apparatus of the present invention is a magnetic levitation transfer apparatus for levitating a transfer table (reference numeral 60 in FIG. 10) from a track (reference numeral 16 in FIG. 10) and moving it in a non-contact manner. A permanent magnet (reference numeral 16W in FIG. 10) in the moving direction of the carrier (reference numeral 2 in FIG. 1, reference numeral 22 in FIG. 10)
And a permanent magnet (reference numeral 1 in FIG. 1, reference numeral 20 in FIG. 10) on the side surface of the carrier near the permanent magnet (reference numeral 2 in FIG. 1, reference numeral 22 in FIG. 10) provided on the track. A permanent magnet (see reference numeral 1 in FIG. 1 and reference numeral 2 in FIG. 10) provided on the carrier table.
0) center line (reference numeral 1C in FIG. 1) is orthogonal to the center line (reference numeral 2C in FIG. 1) of the permanent magnets (reference numeral 2 in FIG. 1, reference numeral 22 in FIG. 10) provided on the trajectory, and The permanent magnets (reference numeral 2 in FIG. 1 and reference numeral 22 in FIG. 10) are arranged so as to coincide with the upper edge portion (reference numeral 2S in FIG. 1) of both permanent magnets (reference numerals 1, 2 and 9 in FIG. 1). The reference numerals 20, 22) are set so that their polarities are attracted to each other.

In addition to this, in carrying out the present invention,
It is preferable that the carrier includes rail cars and passenger cars for other transportation means, and is used for levitating traveling in various transportation means such as railways.

[0015]

According to the present invention having the above-described structure, the relative positional relationship between the permanent magnet provided on the carrying arm or the carrying table and the permanent magnet provided on the track is as shown in FIG. Become.

As is apparent from FIG. 1, the permanent magnets 1 and 2 are arranged so as to be orthogonal to each other, and their center lines (or extension lines thereof) 1C and 2C are orthogonal to each other. The polarities of the permanent magnets 1 and 2 are as shown in the figure, and a magnetic attraction force acts between the permanent magnets 1 and 2 in the horizontal direction. In addition, in FIG. 1, all the S poles and the N poles may be replaced.

In FIG. 1, the permanent magnet 1 is always pulled by a member (not shown) to the left side in FIG. 1, that is, the side opposite to the permanent magnet 2 in the horizontal direction.
It does not move by being sucked to the side. Here, in FIG. 1, the center line 1C of the permanent magnet 1 is the upper edge 2S of the permanent magnet 2.
Is consistent with Even if the permanent magnet 1 is moved vertically (in the direction of arrow V) in this state, a magnetic repulsive force or a restoring force acts to return to the arrangement shown in FIG. In other words, in the arrangement shown in FIG. 1, the magnetic attraction force and the repulsion force between the permanent magnets 1 and 2 have the effect of maintaining their relative positional relationship. Therefore, if the permanent magnet 1 is arranged at the bottom of the carrier arm 14 or the carrier table 60 and the permanent magnet 2 is located on the side surface of the track, the carrier arm 1
4 or the carriage 60 maintains a very stable floating state in the vertical direction V.

Further, since the permanent magnet 1 has a function of returning to the arrangement shown in FIG. 1, even if the permanent magnet 1 slightly moves in the vertical direction V, its levitation force is not affected at all, and the permanent magnets 1 and 2 are not affected. It was found that the permissible variation range in the relative positional relationship of was extremely large. Therefore, the problem that the relative positional relationship in the vertical direction of the conventional permanent magnet is very strict is solved.

[0019]

EXAMPLES Examples of the present invention will be described below with reference to FIGS.

FIG. 2 shows an embodiment of the present invention.

The magnetic levitation transport apparatus, generally designated by reference numeral 10, has a partition wall 12, and a transport arm 14 is provided inside the partition wall 12.
And a track 16 are provided. And the transfer arm 1
A table 18 for placing an object to be transferred (not shown) such as a wafer is provided above the tip of the table 4.

On the other hand, below the tip of the transfer arm 14,
A permanent magnet 20 made of ferrite is provided. The permanent magnet 20 has a relative positional relationship as shown in FIG. 1 with respect to the permanent magnet 22 made of ferrite provided on the right side surface 16R of the track 16 in FIG. In other words, the permanent magnet 20 corresponds to the permanent magnet 1 in FIG. 1, and the permanent magnet 22 corresponds to the permanent magnet 2 in FIG. That is, the center line of the permanent magnet 20 (corresponding to the center line 1C of FIG.
2 and a center line of the permanent magnet 22 (corresponding to the center line 2C of FIG. 1: not shown in FIG. 2) are orthogonal to each other, and a center line of the permanent magnet 20 (center line of FIG. 1). Compatible with 1C:
2 (not shown in FIG. 2) coincides with the upper edge of the permanent magnet 22 (corresponding to the upper edge 2S of FIG. 1: not shown in FIG. 2).
In addition to this, the polarities of the permanent magnets 20 and 22 also correspond to those of the magnets 1 and 2 in FIG. That is, the permanent magnets 20, 2
Since the opposite polarities of No. 2 are different, a magnetic attractive force acts.

An end 24 made of a magnetic material is formed on the opposite side of the permanent magnet 20 in the transfer arm 14.
The end portion 24 is separated from the door-shaped portion 26 of the partition wall 12 by the electromagnet 2.
8 is facing. When the electromagnet 28 is excited, a magnetic attraction force acts on the end 24 of the magnetic body. Then, when the electromagnet carrier 30 travels on the rail 32 to move the electromagnet 28 in the traveling direction of the carrier arm 14, that is, in the direction perpendicular to the paper surface of FIG. 2, the carrier arm 14 also moves accordingly.

As will be described later, a linear motor can be used instead of the electromagnet 28. Further, a plurality of electromagnets 28 may be arranged instead of the electromagnet transporting trolley 30 and the rail 32, and a predetermined electromagnet may be selectively excited.

A stopper 34 is provided near the end 24 of the transfer arm 14 to prevent the arm 14 from going too far to the right in FIG. On the other hand, the permanent magnet 36 provided in the middle of the arm 14 has a permanent magnet 38,
Since the polarities are arranged so as to be attracted to each other, the arm 14 is always biased to the left in FIG.

A permanent magnet 42 is provided at still another position of the transfer arm 14, and a permanent magnet 44 is provided at a position below and below it. Since the opposite surfaces have the same polarity, repulsive force acts and acts as an auxiliary levitation force for the arm 14. Similarly, a permanent magnet 46 is provided below the partition wall 12 and at a position facing the permanent magnet 20 in order to exert a magnetic repulsion force to obtain an auxiliary floating force of the arm 14. The polarity is set to be the same as the polarity of the facing surface of the permanent magnet 20.

According to this embodiment, the permanent magnets 20, 22 are
The magnetic attractive force acting between them is balanced with the magnetic attractive force acting between the permanent magnet 36 and the permanent magnets 38, 40 and the magnetic attractive force acting on the end 24 by the electromagnet 28. In other words, the current supplied to the electromagnet 28 is controlled so that the equilibrium state of the magnetic attraction force in the lateral direction H is achieved. On the other hand, the weight loaded on the arm 14 and the table 18 is the same as the permanent magnet 20 as described in FIG.
22 and the magnetic restoring force acting between the permanent magnets 42, 4
The balance is maintained by the magnetic repulsion force (auxiliary levitation force) that acts between the magnetic pole 4 and the permanent magnets 20 and 46.

In this state, when the electromagnet 28 is moved to the front in the direction perpendicular to the paper surface of FIG. 2, the transfer arm 1 is moved as described above.
4 also moves accordingly. Here, even if vibration occurs in the vertical direction V, the magnetic restoring force acting between the permanent magnets 20 and 22 acts. And, as explained in connection with FIG. 1, the range in which this magnetic restoring force acts is wide,
The relative positional relationship between the permanent magnets 20 and 22 on which the magnetic restoring force acts is relatively wide. Therefore, even if the arm 14 and the table 18 move in the vertical direction V, the floating state or the non-contact state is preferably maintained.

Similarly, since the magnetic attraction force in the horizontal direction H is in an equilibrium state, the horizontal direction H is generated when the transfer arm 14 travels.
There is no bias towards. Even if the equilibrium state of the magnetic attraction force is disturbed in the lateral direction H, the electromagnet 2
This can be dealt with by controlling the current supplied to No. 8.

Next, description will be made with reference to FIGS.

While FIG. 2 shows the overall outline,
3 to 7 show the embodiment more specifically and in detail. Here, corresponding members are designated by the same reference numerals in FIGS. 2 to 7.

FIGS. 3 to 5 show the track 16 in detail. 3-5, the track 16 is shown slightly wider than that of FIG. Further, in FIGS. 3 to 5, the table 18 is not provided on the transfer arm 14, and a transfer target such as the wafer W (FIG. 5) is directly placed on the arm 14. Further, the installation positions of the permanent magnets 42, 44 provided in the middle of the transfer arm 14 for giving an auxiliary levitation force are slightly different between FIG. 2 and FIGS.

In FIG. 3, an arrow M indicates the traveling direction of the transfer arm 14. Then, in FIG. 4, an arrow f
Reference numeral ₁ denotes a levitation force that opposes the weight applied to the transfer arm 14 based on the magnetic restoring force between the permanent magnets 20 and 22. The arrow f ₂ indicates the force that pulls the arm 14 toward the side wall 16 s of the track 16 by the magnetic attraction force between the permanent magnets 20 and 22, and the arrow f ₃ indicates the permanent magnets 42 and 44.
A magnetic repulsive force or an auxiliary levitation force acting between them is shown, and an arrow f ₄ shows an attraction force by the electromagnet 28.

6 and 7 show an embodiment in which the end 24 of the transfer arm 14 is changed. Vertical direction V (FIG. 6) and arm 1
4, a plurality of magnetic material members 48 are provided to prevent swinging in the traveling direction M (FIG. 7) of the electromagnet 28.
The suction force (Fig. 2) acts on multiple points.

The embodiment shown in FIGS. 3 to 7 is substantially the same as the embodiment shown in FIG. 2 in terms of its structure and operation and effect, and there is no essential difference, so that the description will be omitted.

FIG. 8 shows an electromagnet transfer carriage 30 and a rail 3.
2 shows an embodiment in which a plurality of electromagnets 28 are arranged instead of 2, and a predetermined electromagnet is selectively excited.

The electromagnet 28 has a traveling direction M of the transfer arm 14.
A plurality of them are arranged (only one is shown in FIG. 8), and each electromagnet is provided with one proximity sensor 50. When the sensor 50 detects that the arm 14 and its end 24 are close to each other, the output of the sensor 50 is sent to the control unit 52. Then, the control unit 52 outputs an electric signal to excite the corresponding electromagnet 28, and the electric signal is sent to the coil of the electromagnet via the amplifier 54.

2 to 8 show an embodiment relating to a mechanism for floating the transport arm 14, the present invention can be applied to a mechanism for floating the transport base.
FIG. 9 shows an embodiment in which the carrier 60 is floated. Here, members corresponding to those in the embodiments of FIGS. 2 to 8 are designated by the same reference numerals.

In FIG. 9, a carrier indicated by reference numeral 60 is contained in a partition wall 12 made of a non-magnetic material, and an outer shell member 62 made of a non-magnetic material such as aluminum,
A mounting member 64 for mounting an object to be transferred such as the wafer W;
The outer shell member 62 includes a plate-shaped member 66 provided on one side surface and made of a magnetic material. The plate-shaped member 66 corresponds to the end portion 24 in FIGS. 2 to 8, and the magnetic force (attracting force) of the electromagnet 28 acts.

Linear motors 70 are arranged in a distributed manner on the side opposite to the electromagnet 28, and the linear motors 70 cause the carriage 60 to run in a direction perpendicular to the plane of the paper of FIG. The electromagnet 28 corresponds to the levitating movement of the carrier 60 by selective excitation.

A permanent magnet 20 is provided below the carriage 60, and the permanent magnet 20 is provided with a track 1 in FIG.
6 has a relative positional relationship with the permanent magnet 22 made of ferrite provided on the left side surface 16L. Of the magnetic attraction force and repulsion force (holding force) acting between the permanent magnets 20 and 22, the balance between the load weight in the vertical direction V and the magnetic levitation force, and the magnetic attraction force in the horizontal direction H. The equilibrium is the same as in the case of the embodiment of FIGS.

FIG. 10 and FIG. 11 show an embodiment in which the carrier 60 is floated and run like the embodiment of FIG. 9, but the arrangement of the permanent magnets 20, 22 and the position of the linear motor 70. Are different. That is, in the embodiment of FIG. 9, the permanent magnet 20 is provided at the bottom of the outer shell member 62 of the carrier, whereas in FIG. 10, the permanent magnet 20 is provided at the side surface of the outer shell member 62 of the carrier. Has been. In this connection, the mounting position of the permanent magnet 22 in the vertical direction V is also different between FIG. 9 and FIG. 10, and in the case of FIG. 10, the mounting position is a relatively upper position on the side wall 16W of the track. There is. Further, in FIG. 10, the installation position of the linear motor (linear injection motor) is different from that in FIG. 9 in relation to the mounting position of the permanent magnet 22 being relatively upward.

With respect to other configurations and operational effects, the embodiment of FIGS. 10 and 11 is substantially the same as the case of FIG.

It should be noted that the illustrated embodiment is merely an example, and the present invention is not limited to the illustrated embodiment. For example, although the above-described embodiment is described only for the case of being applied as a transfer means for wafers in semiconductor manufacturing equipment, it is not limited to the transfer stand for wafers and the like, and can be used for running rail cars and vehicles used in various transportation means. It should be noted that the invention is applicable to systems.

[0045]

The effects of the present invention are listed below.

(1) Provided is a magnetic levitation transfer device which can use a permanent magnet and can obtain a stable levitation force.

(2) Even if the transfer arm or the transfer table moves slightly in the vertical direction, its levitation force is not so affected.

(3) The allowable variation range in the vertical relative positional relationship between the transport arm or the transport base and the track is extremely large.

(4) The power consumption is small and the control is simple as compared with the magnetic levitation transport device using the electromagnet.

(5) Since the arrangement of the permanent magnets is completely different from that of the conventional magnetic levitation transport device using permanent magnets,
The degree of freedom in layout is increased, and the overall size and weight of the device can be reduced.

(6) Since it can be moved to various kinds of transfer devices, and in particular, it can be used for a type housed in a partition, it is preferably applied to semiconductor manufacturing equipment.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the operation principle of the present invention.

FIG. 2 is a front view showing an embodiment of the present invention.

FIG. 3 is a main part plan view showing a main part of another embodiment of the present invention.

FIG. 4 is a front view of a main part of the embodiment of FIG.

FIG. 5 is a perspective view showing a main part of the embodiment shown in FIGS.

FIG. 6 is a front view showing another embodiment of the present invention.

FIG. 7 is a plan view of the embodiment of FIG.

FIG. 8 is a block diagram showing an example of a traveling unit used in the embodiment of the present invention.

FIG. 9 is a front view showing still another embodiment of the present invention.

FIG. 10 is a front view showing another embodiment of the present invention.

11 is a plan view of the embodiment of FIG.

[Explanation of symbols]

10 ... Magnetic levitation transport device 12 ... Partition wall 14 ... Transport arm 16 ... Orbit 18 ... Table 20, 22, 36, 38, 40, 42, 44, 46 ...
・ Permanent magnet 24 ・ ・ ・ Transfer arm end 28 ・ ・ ・ Electromagnet 60 ・ ・ ・ Transport base 66 ・ ・ ・ Magnetic material plate member 70 ・ ・ ・ Linear motor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Haruo Yoshida 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Ebara Research Institute Ltd. (72) Inventor Yayoi Mizushima 4-chome, Fujisawa, Kanagawa Prefecture No. 1 Stock company Ebara Research Institute

Claims (6)

[Claims] 1. A magnetic levitation transfer device for levitating a transfer arm (14) from a track (16) for non-contact movement, wherein a permanent magnet (2, 22) is provided on a side surface (16R) of the track in a transfer arm moving direction. And a permanent magnet (1, 20) is also provided near the end of the transfer arm near the permanent magnet (2, 22) provided on the track, and the permanent magnet (1, 20) provided on the transfer arm. Center line (1C) of the permanent magnet (2, 22) provided on the track is orthogonal to the center line (2C) of the permanent magnet (2, 22) and the upper edge (2S) of the permanent magnet (2, 22) provided on the track.
The magnetic levitation transport device is characterized in that both permanent magnets (1, 2, 20, 22) have polarities set so as to attract each other. 2. The magnetic levitation transfer apparatus according to claim 1, wherein an electromagnet for attracting the transfer arm is provided at an end of the transfer arm opposite to the permanent magnet. 3. An auxiliary magnet (42) is provided in the middle of the transfer arm (14), and an auxiliary magnet (44) is also provided at a portion on the track corresponding to the auxiliary magnet (42), and the transfer arm (42) is provided. 3. The magnetic levitation transport apparatus according to claim 1, wherein the auxiliary magnets (42, 44) have polarities so as to repel each other in order to exert an auxiliary buoyancy force on 14). 4. A magnetic levitation transfer device for levitating a carrier (60) from a track (16) and moving it in a non-contact manner, wherein a permanent magnet (2, 22) is provided on a side surface (16L) of the track in the carrier moving direction. The permanent magnets (1, 2,) on the lower side of the carrier near the permanent magnets (2, 22) provided on the track.
20), the center line (1C) of the permanent magnets (1, 20) provided on the carrier is the permanent magnets (2, 2) provided on the track.
2) is orthogonal to the center line (2C) and coincides with the upper edge (2S) of the permanent magnets (2, 22) provided on the track,
A magnetic levitation transport device characterized in that the polarities of both permanent magnets (1, 2, 20, 22) are set so as to attract each other. 5. A magnetic levitation transfer device for levitating a carrier (60) from a track (16) and moving it in a non-contact manner, wherein a permanent magnet (2, 22) is provided on a side wall (16W) of the track in the carrier moving direction. Of the permanent magnets (1, 2, on the side of the carrier near the permanent magnets (2, 22) provided on the track.
20), the center line (1C) of the permanent magnets (1, 20) provided on the carrier is the permanent magnets (2, 2) provided on the track.
The permanent magnets (1, 2, 20, 22) are arranged so as to be orthogonal to the center line (2C) of 2) and to coincide with the upper edge portion (2S) of the permanent magnets (2, 22) provided on the track. ) Is a magnetic levitation transport device whose polarities are set so as to attract each other. 6. The magnetic levitation transfer apparatus according to claim 4, wherein the transfer table includes a vehicle for transportation means.