JPH04117111A - Magnetic levitation conveyor - Google Patents

Abstract

PURPOSE:To realize a system in which a guiding force generating means attracts a guide rail in the linear section of a conveying path by setting the horizontal gap, at a specific section of the conveying path, larger than that at the linear section. CONSTITUTION:In a linear section A, a pair of levitation rails 2L, 2R are suspended from the ceiling face of a frame 1 and a pair of guide rails 3L, 3R are laid on the inside faces at the right and left of the frame 1. Only the levitation rails 2L, 2R are installed at a curved section B. In such constitution, levitation/guide electromagnets 7a-7d magnetically attract the lower faces of the levitation rails 2L, 2R in the linear section A of a conveying path thus levitate a truck 5 and lateral movement thereof is limited within the lateral dimensions of the levitation rails 2L, 2R. Furthermore, guide electromagnets 8a-8d magnetically attract the side faces of the guide rails 3L, 3R thus regulating the lateral movement of the truck 5 strictly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetically levitated conveyance device in which a cart travels along a conveyance path in a suspended state to convey articles and the like.

"Prior Art" In recent years, as semiconductor integrated circuits have become highly integrated and miniaturized, the clean rooms in which they are manufactured are required to have a high degree of cleanliness. In order to minimize the generation of dust in such a lean room, a magnetic levitation type transport system is ideal for transporting Noricon wafers, etc., in which the cart floats on the transport path, i.e., travels in a non-contact manner. It is attracting attention because of its popularity.

FIG. 3 to FIG. 6 are diagrams showing an example of a conventional magnetic levitation type conveyance device. In these figures, is a box-shaped frame provided along the conveyance path, and an opening la extending along the conveyance path is formed in the upper surface of the frame. On the ceiling surface of this frame l, a pair of floating rails 2L and 2R made of steel are installed along the conveyance path, and similarly on the left and right inner surfaces of the frame l,
A pair of guide rails 3L made of steel.

3Rs are each constructed. Reference numeral 5 denotes a cart that runs on the conveyance path, and this cart 5 includes four levitation/guidance electromagnets 78 to 78 facing the lower surfaces of the levitation rails 2L and 2H, respectively.
7d, and four guiding electromagnets 88 to 8d facing each side of the guiding rules 3L and 3R, respectively.

Furthermore, although not shown, there is a vertical gap Gv between the rechargeable battery, the levitation/guidance electromagnets 78 to 7d, and the lower surfaces of the levitation rails 2L and 2R, and the guide electromagnet 88.
Based on the detection signals from the gap sensors and these gear sensors, which detect the horizontal gap channels between ~8d and each side of the guide rails 3L and 3R, the floating/guiding electromagnets 78~7d and the guiding electromagnets are activated from the battery. electromagnet 8
A current control circuit is provided to control the excitation current supplied to each of the electrodes 8 to 8d, and to keep the vertical gap Gv and horizontal gap Gh constant at all times.

Here, as shown in FIG. 6, the levitation/guiding electromagnet 7a is composed of a U-shaped primary core 7A and coils 7B and 7C wound around this core 7A. The magnetic poles of the carriage 5 are arranged in a manner that they are aligned in the width direction of the carriage 5. In addition, other levitation/guidance electromagnets 7b to 7
d is similarly configured. The floating/guiding electromagnets 78 to 7d magnetically attract the lower surfaces of the levitation rails 2L and 2H, so that the cart 5 levitates, and further, within the width dimension of the levitation rails 2L and 2R. , its movement in the width direction is restricted. Furthermore, guiding electromagnets 88 to 8
d magnetically attracts each side surface of the guide rails 3L and 3R, thereby firmly restricting movement of the cart 5 in the width direction.

In addition, a primary coil 15.15 of a linear inductor motor is attached to the inner bottom surface of the frame l at a predetermined interval, and a primary coil 15 is attached to the trolley 5 northward across a predetermined gap from the primary coil 15. Opposing secondary conductor 16
or installed.

In this case, the secondary conductor 16 may or may not have an iron core. Further, a loading platform 1g is attached to the upper surface of the truck 5 via a support 17, and a cargo 19 is loaded onto the loading platform 17.

In such a configuration, the levitation/guiding electromagnets 78 to 7
When an excitation current is supplied to the guide electromagnets 88 to 8d, the trolley 5 floats up. On the other hand, when an alternating current is supplied to the primary coil 15 of the linear induction motor, this secondary coil I5 A traveling magnetic field in the direction of arrow F shown in the figure above is generated, and as a result, the truck 5 is accelerated in the direction of arrow F every time it passes above the primary coil 15, and travels by inertia in other sections. As a result, the truck 5 continuously travels in a floating state while alternately repeating acceleration and coasting. In addition, when positioning and stopping the truck 5 at a station, the primary coil 15 in front of that station is excited in the opposite phase to generate a traveling magnetic field in the opposite direction to the arrow F, thereby sufficiently decelerating the truck 5. After that, the cart 5 is stopped by a positioning electromagnet or the like.

Further, when the battery power is consumed and there is no longer enough power to levitate the cart 5, an automatic charging device is connected to charge the battery.

"Problems to be Solved by the Invention" By the way, in the above-mentioned conventional magnetic levitation conveyance device, the guide electromagnets 88 to 8d and the guide rails 3L and 3R
are facing each other with a small horizontal gap Gh, so
Movement of the cart 5 in the width direction is strictly regulated at all times, so that the loading and unloading of the luggage 19 by the transfer device and the connection of the automatic charging device can be performed smoothly. However, when the conveyance path is curved or branched,
It is said that it is not possible to secure enough space between the guide electromagnets 88 to 8d and the guide rails 3L and 3R, and they come into contact with each other, making it practically impossible to run around curves or branch out. There was a problem.

This invention was made in view of the above-mentioned circumstances, and it is possible to firmly restrict the movement of the bogie in the width direction in straight sections and ensure sufficient guiding rigidity, as well as to prevent traveling in curved sections and branch sections. The purpose of the present invention is to provide a magnetic levitation type transport device that enables the following.

"Means for Solving the Problems" The present invention provides a levitation rail of a predetermined width constructed along a conveyance path, a guide rail constructed along the levitation rail, and a levitation rail constructed along the conveyance path. The device is installed on a trolley traveling on the platform, detects a vertical gap between the platform and the lower surface of the levitation rail, and magnetically attracts the levitation rail according to this vertical gap to keep the levitation rail within the predetermined width dimension. levitation/guiding force generating means for levitating the cart while restricting movement in the width direction of the cart and a side surface of the guide rail provided on the cart; magnetically attracting the guide rail according to the
and a guiding force generating means for regulating movement of the cart in the width direction, the horizontal gap in a specific section such as a curved section or a branch section of the conveyance path being smaller than the horizontal gap in a straight section of the conveyance path. The present invention is characterized in that the guide force generating means is configured to attract the guide rail only in a substantially straight section of the conveyance path.

"Operation" According to the above-mentioned configuration, in the straight section of the conveyance path,
As the guide force generating means attracts the guide rail, movement of the cart in the width direction is strongly restricted, but in specific sections such as curved sections or branch sections of the conveyance path,
Sufficient space is secured between the guiding force generating means and the guiding rail, and the floating/guiding force generating means attracts the floating rail, so that the movement of the cart in the width direction is controlled by the width of the floating rail. It is loosely regulated within the range of , and in this state the bogie runs on curves or branches.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway plan view showing the external structure of an embodiment of the present invention, and FIG. 2 is a block diagram showing the electrical structure of a truck 5 according to the same embodiment.

In FIG. 1, a frame l provided along the conveyance path
In the straight section A, a pair of levitation rails 2L are installed on the ceiling surface of the frame L, as in the conventional case.

2R, and a pair of guide rails 3L and 3R are respectively installed on the left and right inner surfaces of the frame l. On the other hand, in the curve section B, the guide rail 3
L and 3R have been removed, and only the floating rails 2L and 2R are installed.

Next, in FIG. 2, reference numeral 9 denotes a power switch for connecting the battery lO to the current control circuits 11 and 13;
a-12d is a gap sensor attached to the above-mentioned levitation/guiding electromagnets 78 to 7d, respectively, for detecting the vertical gap Gv (see Fig. 5) between the levitation rails 2L and 2R; The aforementioned guiding electromagnets 88-8
These are gap sensors attached to each of the guide rails 3L and 3R for detecting the horizontal gap Gh (see FIG. 1) between the guide rails 3L and 3R. Above gap sensor l 2a-12d
, 14a to +4d are configured, for example, by sh current type sensors. Current control circuit 11 is gap sensor 1
Based on the detection signal 2a=I2d, the excitation current supplied to the levitation/guiding electromagnets 78 to 7d is controlled so that the vertical gap Gv is always constant. Similarly, the current control circuit 13 controls the gap sensor 14a-
Based on the detection signal of 14d, guiding electromagnets 8a to 8d
The excitation current is controlled such that the horizontal gap Gh is always constant. Here, a current limiting circuit 20 is inserted between the guide electromagnets 88 to 8d and the battery 10 to limit the excitation current to the guide electromagnets 88 to 8d to a certain value or less. That is, when the trolley 5 is traveling in the curved section B shown in FIG. An attempt is made to increase the excitation current supplied to the electromagnets 88 to 8d. However, in this curve section B, each of the guiding electromagnets 8a to 8d is originally
There is no need to operate these guiding electromagnets 8.
If an excessive excitation current continues to be supplied to the coils 8 to 8d, those coils will be fired and the battery IO will be wasted. A current control circuit 20 is provided for the purpose of preventing such an excessive excitation current from being supplied.

In such a configuration, in the straight section A of the conveyance path, the levitation/guidance electromagnets 78 to 7d are connected to the levitation rail 2L.
, 2H magnetically attracts the lower surfaces of the trolley 5, and its movement in the width direction is further restricted within the range of the width of the floating rails 2L, 2R. Furthermore, the guide electromagnets 88 to 8d magnetically attract each side surface of the guide rails 3L and 3R, so that movement of the cart 5 in the width direction is firmly regulated. In this state, the truck 5 is propelled by the traveling magnetic field generated by the primary coil 15 of the linear induction motor (see FIG. 3) and travels in a straight line.

On the other hand, along the curved section of the conveyance path, the guide rails 3R and 3L are removed and become L, so the guide electromagnet 78
Enough space was secured on the sides of ~7d, and the levitation/
By magnetically attracting the guide electromagnets 8a to 8d or the lower surfaces of the levitation rails 2R and 2L, the movement of the cart 5 in the width direction is gently regulated within the width dimension of the levitation rails 2L2R. In this state, the trolley 5 travels around a curve.

In addition, in the above-mentioned embodiment, the case where the guide rails 3L and 3R are removed in the curved section B of the conveyance path is explained as an example, but the guide rails 3L and 3R in the curved section B are removed.
Horizontal gap Gh between 3R and guide electromagnets 78 to 7d
is sufficiently smaller than the straight section A, and the guide electromagnets 78 to 7d attract the guide rails 3L and 3R only in the straight section A, and in the curved section B, the bow suction force is extremely large. It doesn't matter if it doesn't work. Further, although the case where the present invention is applied to the curved section B has been described as an example, the present invention may be applied to a branch section where sufficient space must be secured on the sides of the guide electromagnets 78 to 7d.

Furthermore, it goes without saying that it may be applied to a magnetic levitation type conveyance device having a structure as shown in FIG.

"Effects of the Invention" As explained above, according to the present invention, in the straight section of the conveyance path, the movement of the cart in the width direction is firmly regulated by suctioning the guiding force generating means or the guiding rail. On the other hand, in specific sections such as curved sections or branch sections of the conveyance path, sufficient space is secured between the guiding force generating means and the guiding rail, and the levitation/guiding force generating means By suctioning, the movement of the cart in the width direction is gently regulated within the range of the width of the floating rail, and in this state the cart runs in curves or branches, so that the width of the cart is Movement in the direction is strongly regulated, sufficient guiding rigidity is obtained, and it is also possible to travel in curved sections and branched sections.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing the outer U configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of the trolley of the same embodiment, and FIG. 3 is a conventional magnetic levitation conveyance system. 4 is a plan view showing the external structure of the magnetic levitation transfer device; FIG. 5 is a front sectional view showing the external structure of the magnetic levitation transfer device; FIG. Figure 6 is a front sectional view showing the configuration of the levitation/guiding electromagnet of the magnetic levitation transfer device;
FIG. 7 is a front sectional view showing another configuration example of a magnetic levitation type conveyance device to which the present invention can be applied. 2L, 2R... Levitation rail, 3L, 3R-...
Guide rail, 5... Cart, 78-7d... Levitation/guidance electromagnet, 88-8
a... Guide electromagnet, 12a to 12d, 14a to 14d... Gap sensor, 11.13... Current limiting circuit, 20... Current limiting circuit, ch - Horizontal gap.

Claims (1)

[Scope of Claims] A floating rail having a predetermined width dimension installed along the conveyance path; a guide rail installed along the floating rail; and a guide rail provided on a cart running on the conveyance path, Detecting a vertical gap between the lower surface of the levitation rail, magnetically attracting the levitation rail according to the vertical gap, and moving the cart in the width direction within the predetermined width dimension. detecting a horizontal gap between a levitation/guiding force generating means that levitates the truck while regulating the amount of the truck, and a side surface of the guide rail provided on the truck, and adjusts the guide rail according to the horizontal gap; a guiding force generating means that magnetically attracts and restricts movement of the trolley in the width direction, and the horizontal gap in a specific section such as a curved section or a branch section of the conveyance path is replaced by a straight line of the conveyance path. A magnetic levitation type conveyance device, characterized in that the horizontal gap is larger than the horizontal gap in the section, and the guide force generating means attracts the guide rail only in a substantially straight section of the conveyance path.