JPH01318501A - Magnetic levitation carrier - Google Patents

Abstract

PURPOSE:To reduce the curvature of a carrying path by fixing the complex magnet of a carriage rotatably along the longitudinal direction of a guide rail. CONSTITUTION:A guide rail 21 composed of ferromagnetic material is burried in the under face of the upper wall of a rail frame 20. A carrier 22 is provided with a complex magnet 24 and a base 25 therefore. The complex magnet 24 is fixed rotatably to the base 25 through a base 26 and a pin 27 with a predetermined gap being held with respect to the guide rail 21. The complex magnet 24 comprises three yokes 28 arranged along the longitudinal direction of the guide rail 21 and an electromagnet 30 wound with an electromagnet coil 29 of one of the three yokes 28. Since the complex magnet rotates when the carrier passes through the curved guide rail section, the curvature of the guide rail can be reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic levitation conveyance device for conveying small items such as documents, and is particularly suitable for accelerating and decelerating a conveyance vehicle. The present invention relates to a magnetic levitation transport device.

(Prior Art) In recent years, as part of office automation and factory automation, it has become common practice to move slips, documents, cash, products, etc. between multiple locations within a building using a conveyor device.

The conveyance device used for such purposes must be capable of moving the conveyed object quickly and quietly, and
Semiconductor factories are required to be dust-free. For this reason, in this type of transport device, the transport vehicle is supported on the guide rail in a non-contact manner. Among them,
The method of magnetically supporting the transport vehicle in a non-contact manner is excellent in following the guide rails and in preventing noise and dust generation.

However, in the case where the transport vehicle is supported by magnetic force, if all of this magnetic force is to be provided by an electromagnet, the electromagnet must be constantly energized, which inevitably increases current consumption.

Therefore, the present applicant previously proposed a so-called zero power feedback control method in which a permanent magnet provides most of the magnetomotive force required for a composite electromagnet, thereby reducing power consumption.

This control method attempts to control the gap between the magnetic force of the permanent magnet and the weight of the transport vehicle so that the weight of the transport vehicle is always balanced even if the weight of the transport vehicle changes. It is possible to perform magnetic levitation without passing any current, and the battery capacity mounted on the transport vehicle can be reduced in size.

FIG. 5 shows its specific configuration. That is, in the same figure, the conveyance path consists of a track frame 1 whose cross section is in the shape of an inverted cross-section, and a track frame 1 made of a ferromagnetic material buried in a separate position on the lower surface of the upper wall of the track frame 1.
A book guide rail 2, an emergency guide rail 3 each having a cross-section shaped like an opening and attached to the inner surface of the side wall of the track frame 1 with their open sides facing each other, and two guide rails 2 of the track frame 1. and a stator 4 of a linear induction motor, which is disposed in the middle of the motor and is mounted at a predetermined distance in the longitudinal direction. In addition, the conveyance vehicle 5, which is freely movable along this conveyance path, has composite electromagnets (magnetic support units) 7 disposed on the upper part of the conveyance vehicle frame 6 with a predetermined gap between each of the guide rails 2 described above. , these composite electromagnets 7 are fixed, and the guide rail 2 is
A flat base 8 is attached, which is placed so as to face the lower surface of the base. As shown in FIGS. 6 and 7, the composite electromagnet 7 consists of yokes 9 placed on both sides of the guide rail 2 with a predetermined gap, and electromagnetic coils 10 wound around the yokes 9, respectively. two sets of electromagnets 11 and a permanent magnet 12 arranged between two yokes 9.
The magnetic flux formed by the two sets of electromagnets 11 is added to each other by connecting the two electromagnetic coils 10 in series.

Note that an optical gap sensor 13 is attached to the composite electromagnet 7 to detect the gap length between the composite electromagnet 7 and the lower surface of the guy/trail 2.

In addition, the transport vehicle 5 is driven by a linear system in which the stator 4 serving as the primary side is arranged discretely at an appropriate distance on the transport path side, and the reaction plate serving as the secondary side conductor is arranged on the transport vehicle side. It uses an induction motor drive system (
(See Japanese Patent Application Laid-open No. 102105/1983).

(Problem to be Solved by the Invention) However, according to the above conventional method, the composite electromagnet 7
Because they are installed at right angles, the outer dimensions of the transport path and transport vehicle become larger.

This disturbs the laminar flow of air in the clean room of a semiconductor manufacturing factory, for example, and this affects the quality of semiconductor products. Furthermore, since the composite electromagnet 7 is fixed, there is a problem in that when traveling along a curved section of the conveyance path, the radius must be increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic levitation type transport device that reduces the installation space and the cost of the system by reducing the outer dimensions of the transport vehicle and the lfl transport path.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a conveyance path on which ferromagnetic guide rails are laid, and rails arranged along the conveyance path at predetermined intervals along the longitudinal direction. A composite electromagnet that generates a magnetic force between a secondary stator, a secondary conductor that is combined with this stator to form a linear induction motor, and a guide rail, and adjusts the current flowing through this composite electromagnet. A magnetic levitation type vehicle equipped with a control WJ device, a secondary conductor, a composite electromagnet, and a control device, levitated by the magnetic force, and travels along a conveyance path by forming a linear induction motor. In the conveyance device, a composite electromagnet is placed along the length of the guide rail on the conveyance vehicle, is rotatably attached, and is inserted in the middle as a yoke structure that divides the magnetic flux into two equal parts. It is characterized in that it is configured to be added to the magnetic flux of the permanent magnet.

(Function) Since the composite electromagnet is arranged along the longitudinal direction of the guide rail and is rotatably attached, it rotates according to the curved portion of the conveyance path when traveling along the curved portion. Therefore, the radius of curvature of the conveyance path can be reduced, and the installation space can be reduced.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a sectional view showing a composite electromagnet of an embodiment of the invention, and Fig. 3 is a plan view taken along line A-A in Fig. 2. shows.

In FIG. 1, the conveyance path includes a track frame 20 whose overall structure is the same as the conventional track frame 1 described above, but with a smaller width;
It is made of ferromagnetic material and is buried in the lower surface of the upper wall of the track frame 20,
and two guide rails 21 whose width is smaller than the conventional guide rail 2 described above, an emergency guide rail 3 attached to the inner surface of the side wall of the track frame 20, and a stator 4 attached to the track frame 20. It consists of In addition, the transport vehicle 22 that can freely travel along this transport path includes two sets of composite electromagnets 24 arranged on the upper part of the transport vehicle frame 23 with a predetermined gap between each of the guide rails 21 described above.
A flat base 25 is attached to fix these composite electromagnets 24 and to face the lower surface of the guide rail 21. As shown in FIGS. 2 and 3, the composite electromagnet 24 is connected to the guide rail 21 described above.
The guide rails 25 are rotatably attached to the base 25 via a base 26 and a pin 27, and arranged at the center and both sides along the longitudinal direction of the guide rail 21. An electromagnet 30 consisting of three yokes 28 and an electromagnetic coil 29 wound around at least one of these three yokes 28, and two permanent magnets arranged between the three yokes 28, respectively. The magnetic flux formed by energizing the electromagnetic coil 29 is divided into approximately two equal parts, added to the magnetic flux of each permanent magnet 31, and the magnetic flux is divided into two approximately equal parts between the guide rail 21 and the guide rail 21. They form a closed loop of independent magnetic flux. Note that two optical gap sensors 13 are attached to the composite electromagnet 24 between the yoke 28.

Next, the operation of the magnetic levitation type conveyance device configured as above will be explained. First, on a straight conveyance path, the conveyance vehicle 22
Each composite type [[Ei24 does not rotate because the magnetic force acting between it and the guide rail 21 becomes equal. In other words,
The center axes of the composite electromagnet 24 and the guide rail 21 are parallel to each other when viewed from above, and the carrier 22 travels in a straight line. Next, on the curved conveyance path, each composite type 1i52 of the conveyance vehicle 22
In No. 4, the present inventor found that by making the dimension between the outer sides of the yoke 28 larger than the width of the guide rail 21, the yoke 28 rotates so that the magnetic force is balanced according to the curve of the guide rail 21. That is, even if each composite electromagnet 24 is attached to the carrier 22, when traveling along a curved portion of the guide rail 21, each composite electromagnet 24 rotates according to the curved portion. Therefore, even if the radius of curvature of the guide rail 21, that is, the radius of curvature of the transport path is made small, the transport vehicle 22 can travel.

In addition, the conveyance path is usually installed by combining unit conveyance paths manufactured separately, but in this case, due to expansion due to temperature and adjustment allowance based on the dimensional tolerance of the unit conveyance path, etc.
Appropriate gaps (indicated by G in FIG. 2) are required between adjacent ones. However, since the composite electromagnet 24 forms two independent closed loops of magnetic flux, one of the closed loops is maintained even when passing through this gap, and problems caused by disappearance of magnetic force can be eliminated. .

[Effects of the Invention] As explained above, according to the present invention, since the composite electromagnet is rotatably attached to the conveyance vehicle, the radius of curvature of the curved portion of the conveyance path can be made small. This makes it possible to reduce the installation space of the conveyance path, make effective use of the entire installation space, and reduce costs. Furthermore, since the composite electromagnet is attached along the longitudinal direction of the transport path, the outer shape of the transport vehicle can be made smaller than before.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a composite electromagnet according to an embodiment of the present invention, and FIG.
4 is an explanatory diagram showing the operation of an embodiment of the present invention; FIG. 5 is a sectional view of a conventional magnetic levitation conveyance device; 6 is a plan view showing a composite electromagnet of a conventional magnetic levitation type transfer device, and FIG. 7 is a sectional view taken along the line A--A in FIG. 6 in the direction of the arrow. 20... Track frame, guide rail 22... Transport vehicle, 24... Composite electromagnet 27... Pin, 28...
・Yoke 29...Electromagnetic coil 31...Permanent magnet agent Patent attorney Nori Chika Ken Yudo Daishimaru Ken Figure 1 Figure 5 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7

Claims (1)

[Claims] (1) A conveyance path on which a ferromagnetic guide rail is installed,
A primary stator disposed along the conveyance path at a predetermined interval along the longitudinal direction, a secondary conductor that is combined with the stator to form a linear induction motor, and the guide rail. A composite electromagnet that generates a magnetic force, a control device that adjusts the current flowing through the composite magnet, the secondary conductor, the composite electromagnet, and the control device are mounted, and the magnetic field levitates due to the magnetic force and the linear induction In a magnetically levitated conveyance device comprising a conveyance vehicle that travels along the conveyance path by formation of a motor, the composite electromagnet is disposed on the conveyance vehicle along the longitudinal direction of the guide rail and is rotatable. What is claimed is: 1. A magnetic levitation type conveyance device, characterized in that the magnetic levitation type conveyance device is configured so that the magnetic flux is added to the magnetic flux of a permanent magnet inserted in the middle as a yoke structure that divides the magnetic flux into approximately two equal parts.