JPH04117112A - Magnetic levitation conveyor - Google Patents

Abstract

PURPOSE:To realize traveling of a truck on a curved section or a branch section by detecting the fact that the truck is located in a specific section, transmitting the detected fact to the truck and then interrupting power supply to a guide force generating means based on thus transmitted fact. CONSTITUTION:Photointerrupters 20, 21 and a truck position detecting circuit 23, disposed on the side of a conveying path, detect the fact that a truck 5 is located in a curved section B and a truck detection signal representing the fact is transmitted to the truck 5 by radio. A receiver disposed on the truck 5 side receives the truck detection signal and then a relay is turned OFF to interrupt power supply to guide electromagnets 8a-8d which are thereby disabled. Consequently, the levitation/guide electromagnets 8a-8d attract the lower faces of the levitation rails 2R, 2L magnetically to realize smooth traveling of the truck on a curved section with lateral movement thereof being regulated moderately within the range of lateral dimensions of the levitation rails 2L, 2R.

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. Because it is necessary to minimize the generation of dust, the transport device for transporting Noricon wafers, etc. in the lean room is a magnetically levitated transport device that floats on a cart or transport path, that is, travels in a non-contact manner. It is attracting attention as being ideal.

FIG. 4 to FIG. 7 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 1a extending along the conveyance path is formed in the upper surface of the frame. On the ceiling surface of this frame 1, 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 1, steel A pair of guide rails 3L configured by.

3Rs are each constructed. Reference numeral 5 denotes a cart that runs on the conveyance path, and this cart 5 includes floating rails 2L, 2H.
four levitation/guidance electromagnets 78 facing each lower surface of the
7d, and four guiding electromagnets 8a to 8d facing each side of the guiding rails 3L and 3R are provided. Furthermore, although not shown, a rechargeable battery and a levitation/
The vertical gap Gv between the guide electromagnets 78 to 7d and the lower surfaces of the levitation rails 2L and 2H, and the guide electromagnet 8
A gap sensor detects the horizontal gap channel between 8 to 8d and each side of the guide rails 3L and 3R, and based on the detection signals of these gap sensors, the floating/guiding electromagnets 78 to 7d and The excitation current supplied to each of the guide electromagnets 88 to 8d is controlled to keep the vertical gap Gy and horizontal gap Gh constant.
An I flow control circuit is provided.

Here, as shown in FIG. 7, 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 8a 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, the primary coils 15, 15, etc. of the linear inductor motor are attached to the inner bottom surface of the frame l at predetermined intervals, and the primary coils 15, 15, etc. Opposing secondary conductors 16 are attached.

In this case, the secondary conductor 16 may or may not have an iron core. Further, on the upper surface of the trolley 5, a support 1 is provided.
A loading platform 18 is attached via the loading platform 7, and 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 15 A traveling magnetic field is generated in the direction of arrow F shown in the figure above, and as a result, the trolley 5
5, it is accelerated in the direction of arrow F, and in other sections it runs by inertia. As a result, the trolley 5 alternately accelerates and coasts in a floating state, but travels continuously. 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 across a slight horizontal gap, 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 8a 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, and also 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 floating ball rail is installed in a bogie traveling on the platform, detects the vertical gap between the floating ball rail and the lower surface of the floating rail, magnetically attracts the floating ball rail according to the vertical gear, and magnetically attracts the floating ball rail within the predetermined width dimension range. detecting a horizontal gap between a levitation/guiding force generating means that levitates the trolley while restricting movement in the width direction of the trolley within the trolley and a side surface of the guide rail provided on the trolley; , magnetically attracting the guide rail according to this horizontal gap;
A guiding force generating means for restricting movement of the cart in the width direction; and a detecting means provided in a specific section of the conveyance path such as a curved section or a branch section, and detecting that the cart is located within the specific section. and a transmission means for transmitting the detection result of the detection means to the trolley, and a switching means for cutting off the supply of power to the guiding force generation means based on the detection result transmitted by the transmission means. In addition, the horizontal gap in the specific section is set to be smaller than the horizontal gap in the 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 ensured between the guiding force generating means and the guide rail, and it is detected that the bogie is located in a specific section, this detection result is transmitted to the bogie, and based on the transmitted detection result, Since the power supply to the guiding force generating means is cut off, the guiding force generating means becomes inactive, and as a result, the levitation/guiding force generating means attracts the levitation rail, thereby causing the carriage to move in the width direction. The bogie travels in a curve or in a divergent manner while being loosely regulated within the width of the floating rail.

"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 1 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. Further, in the figure, 20 is a reflective photointerrupter installed at the starting end of the curved section B,
Light is irradiated onto the trolley 5 passing on the conveyance path, and passage of the trolley 5 is detected based on the presence or absence of reflected light.

Similarly, 21 is a reflective photointerrupter installed at the end of the curved section B, and the trolley 5 passing on the conveyance path
The passage of the trolley 5 is detected based on the presence or absence of reflected light. These photo interrupters 20
．． The detection signal 21 is supplied to a truck position detection circuit 23. The cart position detection circuit 23 includes a photointerrupter 20
The flip-flop is configured by an RS flip-flop, etc., which is set when a detection signal indicating the passage of the carriage 5 is supplied from the photointerrupter 21, and reset when a detection signal indicating the passage of the carriage 5 is supplied from the photointerrupter 21. During the period when is set, the bogie 5 is assumed to be located within the curve section B, and a bogie detection signal indicating this is output to the transmitter 24. The transmitter 24 wirelessly transmits the truck detection signal output from the truck position detection circuit 23 to the truck 5.

Next, in FIG. 2, 9 is a power switch for connecting the battery 10 to the current control circuit 11 and I3;
Gap sensors a to 12d are attached to the above-mentioned levitation/guiding electromagnets 78 to 7d, respectively, and are used to detect the vertical gap Gv (see FIG. 5) between the levitation rails 2L and 2R, and 14a to 14d are gap sensors. 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
, l4a to 14d are constituted by, for example, eddy current sensors. The tffi control circuit 11 controls the excitation current supplied to the levitation/guiding electromagnets 7a to 7d based on the detection signals of the gap sensors 12a to +2d, and controls the excitation current so that the vertical gap Gv is always constant. do. Similarly, the current control circuit I3 is connected to the gap sensor +4
Based on the detection signals a to +4d, the guiding electromagnets 88 to
8d, and horizontal gap Gh
The excitation current is controlled so that the current is always constant. Here, between the guiding electromagnets 8a to 8d and the battery 10,
A relay 25 is inserted to cut off the excitation current to the guide electromagnets 88 to 8d. This relay 25 is
It is controlled to be on/off by the receiver 26, and is in the off state during a period when the above-mentioned transmitter 24 is transmitting a bogie detection signal indicating that the bogie 5 is located within the curve section B. That is, when the trolley 5 is running on the curve section B shown in FIG. 1, the horizontal gap ch becomes large, so the current control circuit 13
Based on the detection signal of 4d, each guiding electromagnet 88 to 8d
Try to increase the excitation current supplied to the However, in this curve section B, there is no need to operate each of the guide electromagnets 88 to 8d, and if an excessive excitation current continues to be supplied to these guide electromagnets 88 to 8d, those coils will generate heat. At the same time, the battery 10 is wasted. A relay 25 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 7a to 7d are connected to the levitation rail 2L.
, 2R magnetically attracts the lower surfaces of the trolley 5, and its movement in the width direction is further restricted within the width dimension 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, in the curve section B of the conveyance path, the guide rail 3
Since R and 3L have been removed, the guide electromagnets 78 to 7
Sufficient space is secured on the sides of d.

In addition, the photo interrupter 20.21 and the cart position detection circuit 23 provided on the transport path side detect that the cart 5 is located in the curved section B, and a cart detection signal indicating this is wirelessly transmitted to the cart 5. be done. And trolley 5
When the receiver 26 provided on the side receives this truck detection signal, the relay 25 is turned off, the power supply to the guide electromagnets 88 to 8d is cut off, and the guide electromagnets 88 to 8d are turned off. It becomes operational. As a result, the levitation/guidance electromagnets 8a to 8d are connected to the levitation rail 2R2.
By magnetically attracting the lower surface of the dolly L, the dolly 5 travels around a curve with movement in the width direction of the dolly 5 being gently restricted within the width dimension of the floating rails 2L and 2R.

Next, FIG. 3 is a partially cutaway plan view showing the external configuration of another embodiment of the present invention. In this figure, 30 is a light projector installed at the starting end of curve section B, and 31 is a light receiver installed at the end end of curve section B. They are arranged in a certain positional relationship.

The light receiver 31 supplies a detection signal indicating the presence or absence of light from the light projector 30 to the truck position detection circuit 33.

When the light emitted from the light projector 30 is blocked by the trolley 5, the trolley position detection circuit 33 assumes that the trolley 5 is located within the curve section B based on the detection signal of the light receiver 31, and indicates the fact. A trolley detection signal indicating this is output to the transmitter 24. Even in the above configuration, the position of the cart 5 in the curve section B is detected by the light emitter 30, the light receiver 31, and the cart position detection circuit 33 provided on the conveyance path side, and a cart detection signal indicating this is sent to the cart 5. It is sent wirelessly to the

In addition, in the above-mentioned embodiment, the case where the guide rails 3L and 3R were removed at the curved section of the conveyance path was explained as an example, but the guide rails 3L and 3R at the curved section B,
3R and guide i [Horizontal gap G between stones 78 to 7d
h may be made sufficiently larger than the straight section A so that the guiding electromagnets 78 to 7d attract the guiding rails 3L and 3R only in the straight section A. Further, although the case where the present invention is applied to the curve section B has been described as an example, the present invention may also be applied to a branch section where sufficient space must be secured on the sides of the guide electromagnets 78 to 7d. Furthermore, the eighth
Of course, the present invention may be applied to a magnetic levitation type conveyance device having a structure as shown in the figure.

"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 strongly restricted by the guiding force generating means attracting the guiding rail. On the other hand, in a specific section such as a curved section or a branch section of the conveyance path, sufficient space is ensured between the guiding force generating means and the guide rail, and it is detected that the cart is located in the specific section. , this detection result is transmitted to the trolley, and based on the transmitted detection result, the power supply to the guiding force generating means is cut off, so the guiding force generating means becomes inactive, and as a result, the levitation/guiding force By the generating means suctioning the levitation rail, the movement of the bogie in the width direction is gently regulated within the width dimension of the levitation rail, and the bogie runs in a curve or in a branch, so it can move in a straight line. In the section, the movement of the bogie in the width direction is strongly regulated, sufficient guiding rigidity is obtained, and the advantage is that it is possible to travel on curved sections, branch sections, etc.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing the external 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 another embodiment of the invention. FIG. 4 is a partially cutaway side view showing the external structure of a conventional magnetic levitation transfer device; FIG. 5 is a plan view showing the external structure of the magnetic levitation transfer device. , FIG. 6 is a front sectional view showing the external configuration of the magnetic levitation type transfer device, FIG. 7 is a front sectional view showing the configuration of the levitation/guiding electromagnet of the same magnetic levitation type transfer device, and FIG. 8 is a front sectional view showing the configuration of the magnetic levitation type transfer device. FIG. 2 is a front cross-sectional view showing another configuration example of a magnetic levitation type conveyance device to which the above embodiment can be applied. 2L, 2R・・・Levitation rail, 3L, 3R・
...Guidance rail, 5--Dolly, 7a-7d... Levitation/guidance electromagnet, 88-8a.
Guide electromagnet, 12a-12d, +4a-14d--gi +-/b sensor, 11.13... Current control circuit, 20.21... Reflective photointerrupter, 2
3-... Cart position detection circuit (20 to 23 are detection means), 24... Transmitter (transmission means), 25...
...Relay (switching means), 26...Receiver,
Gh...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 the movement of the cart in the width direction; and a guide force generating means that is provided in a specific section such as a curved section or a branch section of the conveyance path, and the cart is located within the specific section. a detecting means for detecting that the detecting means has detected the detection means; a transmitting means for transmitting the detection result of the detecting means to the bogie; and a power supply to the guiding force generating means is cut off based on the detection result transmitted by the transmitting means. 1. A magnetic levitation type conveyance device, characterized in that the horizontal gap in the specific section is larger than the horizontal gap in a straight section of the conveyance path.