JPH0236703A - Magnetic levitation carrier - Google Patents

Abstract

PURPOSE:To reduce the number of controller by securing fixed poles applied with electromagnetic coils and electromagnetic conversion elements with regular intervals and switching the fixed pole and the electromagnetic conversion element selectively corresponding to the motion of a movable body. CONSTITUTION:Fixed poles 2-1 to 2-6 applied with electromagnetic coils 20 are secured with regular intervals along a rail 40. Electromagnetic conversion elements 3-1 to 3-6 are arranged in the levitation gaps between the fixed poles 2-1 to 2-6 and a movable body 1. A switching judgement means 55 performs selection of the fixed poles 2-1 to 2-6 and the electromagnetic conversion elements 3-1 to 3-6 corresponding to the motion of the movable body 1. At this time, a levitation calculating means 54 calculates the levitation based on the output of a selected electromagnetic conversion element. A levitation control means 53 supplies current corresponding to the calculated levitation to the electromagnetic coil of a selected fixed pole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a magnetic levitation conveyance device that levitates and moves a movable body in a non-contact manner using controlled magnetic attraction force.

[Conventional technology]

An example of a conventional magnetic levitation transfer device is shown in FIG. A fixed magnetic pole 2.2 around which electromagnetic coils 20 and 20' are wound is arranged along a rail 40 that defines the moving direction of the movable body 1. Further, a displacement sensor for detecting the distance (flying height) from the fixed magnetic pole to the movable body is similarly arranged near each of the fixed magnetic poles.

The movable bodies can be stably levitated and moved by the magnetic attraction force of each individually controlled electromagnet.

[Problem to be solved by the invention]

However, since the magnetic levitation conveyance device with the above-mentioned conventional configuration individually controls the current supplied to the electromagnets, that is, the electromagnetic coils 20 and 20', the number of control circuits and displacement sensors equal to the number of magnetic poles is required, and the rails are long. As the distance increases, more control circuits and displacement sensors are required, resulting in increased costs.

The present invention has been made in view of the above-mentioned points, and the displacement sensors and control devices of the conveyor line for magnetically levitating a movable body are not always fully functional, and when the movable body passes a certain magnetic pole. Focusing on the function of the magnetic pole, we selected and switched the magnetic pole and displacement sensor respectively as the movable body moves, and only needed to install a control device equal to the number of control axes that function at all times. This type of inexpensive magnetic levitation transport device is constructed by a magnetic conversion element and a function generator.

It is about providing.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a magnetic levitation conveyance device consisting of fixed magnetic poles 2-1, 2-2, 2-3, . A group of fixed magnetic poles 2-1, 2-2, and 2-2 are fixed at equal intervals along the rail 40 at appropriate intervals.
2-3, . . . and magnetoelectric conversion elements 3-1, 3-2, 3-3 in the floating air gap of the movable body 1.

... is arranged, and the fixed magnetic pole 2-1.2-2.2-3
, . . . The group of electromagnetic coils 20 wound on each of
The selected electromagnetic coil 20 is supplied with a current commanded by the levitation control means 53 by the power amplifier 6, and the supplied current is detected and sent to the levitation height calculation means 54. The guided and selected magnetoelectric transducer 3 is electrically coupled to a detector 11, and the output of the detector 11 is configured to be guided to the switching determining means 55 and the flying height calculating means 54.

[Effect]

By configuring the magnetic levitation transport device as described above, when a current is supplied to the electromagnetic coil 20, a magnetic attraction force acts on the movable body 1, and the movable body 1 levitates.

The flying height is calculated by the flying height calculation means 54 from the current supplied at this time and the magnetic flux density in the flying gap detected by the magnetoelectric conversion element 3 and the detector 11, and the flying height is input to the flying height control means 53. adjusts and controls the current supplied to the electromagnetic coil 20 of the power amplifier 6 to stably levitate the movable body 1.

As the movable body 1 moves along the rail 40, the state of movement is determined by the switching determination means 55 by comparing the outputs of the magnetoelectric conversion elements 3 located before and after the movable body 1,
The electromagnetic coil 20 and the magnetoelectric transducer 3 are switched by the selection switching means 51 and the selection switching means 52 according to a command from the switching judgment means, and the magnetic levitation control axis is switched. As a result, the movable body 1 stably floats on the rail 40 while magnetically attracted.
can move along.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

2 and 3 are views showing the magnetic levitation conveyance device according to the present invention, and FIG. ), FIG. 2(b) is a side view, and FIG. 3 is a diagram showing the system configuration of the magnetic levitation transfer device. Fixed magnetic poles 2-1, 2-2, 2-k, and 2'-1 around which T-magnetic coils 20 and 20' are wound
, 2'-2, . . . 2'-k, . . . are fixed along the rail 40 at appropriate intervals. In FIG. -2,...2'-k...
... are omitted), each fixed magnetic pole and movable body 1
Magnetoelectric conversion elements 3-1, 3-2,...3 are placed in the air gaps of
-k...and 3'-1, 3'-2,...3'-
k... (In FIG. 2(b), magnetoelectric conversion elements 3'-1, 3'-2,...3'-k,
... are omitted). The magnetoelectric conversion elements 3-1, 3
-2.

...3-k... and 3'-1, 3'-2,...
...3''-k... is selected by the multiplexer 5 according to a command from the microcomputer 30, and is coupled to the detector 11, and the output of the detector 11 is sent to the microcomputer 30 and the function generator 13. The group of electromagnetic filters 20 is guided by a signal from the microcomputer 30.
The power amplifier 6 supplies current as selected by the multiplexer 4 and in response to a signal from the control device 12 . The current I supplied at this time is guided to the function generator 13. The microcomputer 30 also includes a CPU 31, l1032, RAM 33, and RO.
It is composed of M34.

In the above configuration, a current generator that supplies the electromagnetic filter 20;
Fixed magnetic poles 2-1, 2-2,...2-k...
・and the magnetic flux density B generated in the gap g of the movable body 1 and the movable body 1
The relationship between the magnetic attraction force F acting on the magnetic attraction force F and the air gap g
The relationship between the magnetic attraction force F and the current I have the characteristics shown in FIGS. 4(a), 4(b), and 4(c), respectively. That is, F=B'' F=t/g (1=constant) F=kz I'' (g=constant) (where ks, km, and ks are constants of proportionality). Therefore, the relationship between the air gap g, the current I, and the magnetic flux density B can be defined as g=K(I/B'') where K is a proportionality constant.

Therefore, by inputting the supplied current and the magnetic flux density B to the function generator 13, the flying height (gap g) is calculated. The control device 12 compares the calculated flying height with the target flying height and controls the current supplied to the electromagnetic coil 2o.
To stably magnetically levitate a movable body 1.

As the movable body 1 moves, fixed magnetic poles 2-1, 2-2, ..., 2-k, etc. function to stabilize the floating body 1.
The electromagnetic coil 20 and the magnetoelectric conversion element 3-1, respectively.
3-2,...3-k... to multiplexer 4
and switching by multiplexer 5. Magnetoelectric conversion element 3-
1, 3-2, . . . 3-k, . . . The details of the switching are shown in FIG.

As shown in FIG. 5, magnetoelectric conversion elements 3-1, 3-2.・
...3-9... are arranged at equal intervals in the direction of movement, and the length of the movable body 1 in the direction of movement is determined by the magnetoelectric conversion elements 3-1, 3.
-2, 3-9, . Magnetoelectric transducer elements 3-1, 3-2,...3 immediately in front of the direction of movement of
-9... is selected in advance to prepare for switching of the control axis due to movement, so a total of three magnetoelectric transducers are always selected. Therefore, the detector is also 11-1.11-2.1
Prepare 3 items 1-3. Correspondingly, analog multiplexers of 5-1.5-2.5-3 are also prepared, and each detector 11-1.11-2゜1.1-
3 and magnetoelectric conversion elements 3-1, 3-2,...3-9
Switch the combination of electrical connections of groups of... In other words, a certain magnetoelectric conversion element 3 that functions for magnetic attraction and levitation of the movable body 1 stops functioning for magnetic attraction and levitation when the movable body 1 passes through the movable body 1. While disconnecting the element 3 and the detector 11, the magnetoelectric conversion element 3, which is located immediately in front of the moving direction of the movable body 1 and is scheduled to function to magnetically attract and levitate the movable body 1, is removed.
and the detector 11. Therefore, it is determined by the arrangement order of the magnetoelectric transducers to be selected for each of the three detectors 11. For example, when the movable body 1 is in state 1 in FIG. 5, the magnetoelectric transducers 3-1, 3-2.
3-3 are detectors 11-1.11-2.11-3 respectively
is selected by multiplexer 5-1.5-2.5-3,
It functions to magnetically attract and levitate the movable body 1. Now movable body 1
moves to the right in the figure, and the magnetoelectric transducer 3-1 moves toward the movable body 1.
When state 2 is reached, where the magnetic attraction levitation no longer functions,
Cut off the connection between the magnetoelectric conversion element 3-1 and the detector 11-1,
The magnetoelectric conversion element 3-4 and the detector 11-1 are connected. By performing this operation as the movable body 1 moves, the magnetoelectric conversion elements are sequentially switched. In addition, electromagnetic coil 2
The same applies to the selection switching of 0.

Next, the detection of the passing state of the movable body 1 and the switching command operation will be described. In FIG. 6(a), fixed magnetic pole 2,
In state 1 in which the electromagnetic coil 20 and the magnetoelectric transducer 3 are functioning to magnetically attract and levitate the movable body 1, the magnetic flux density B at the levitation gap g detected by the cooperation of the magnetoelectric transducer 3 and the detector 11 is:
Control device 1 for stably levitating the movable body 1 by magnetic attraction
2 (see Figure 3), it reaches a certain level. Now, when the movable body 1 moves to the right as shown in FIG. 6(b), the magnetic flux leaking into the air increases and the detected magnetic flux density begins to decrease (state 2). Furthermore, as shown in FIG. 5(C), when the movable body 1 passes directly under the magnetoelectric conversion element 3-1, the magnetic flux leaks even more. Therefore, as shown in FIG. 7, from a certain upper limit Bu of the detected magnetic flux density,
If a change to a certain lower limit value Bl is detected, the movable body 1
It is possible to judge the passing state of

In FIG. 5, passage detectors 36-1, 36-2, 3
6-3 performs the above-mentioned detection from the output of the detector 11-1.11-2.11-3 and sends a passing signal to the microcomputer 30. microcomputer 3
0 detects a passing signal and sends a switching signal to the detector 11, magnetoelectric transducer 3, and multiplexer 5 that are to perform selection switching.

A flowchart for executing the above control is shown in FIG.

In FIG. 8, Sl to S8 indicate each processing step. In step S1, as an initial setting, the number of the current magnetoelectric transducer 3 selected by each detector 11 is stored in the memory <1), (2),
(3) is memorized.

Next, in step S2, it is determined whether a passing signal has been input, and the process waits until it is input. If the passing signal is input, the process moves to the next step S3, and the number of the detector 11 that has issued the passing signal is stored in the memory P. Step S4
Now, the number A(P) of the detector 11 that emitted the passing signal stored in this memory P and the memories (1), (2), (3)
) The numbers A(1) and A(2) of the detector 11 stored in
) and A(3) to determine the direction of movement of the movable body 1. The number A(P) of the detector 11 that emitted the passing signal is the number A(1), A(2), A( If it is smaller than any one of 3), the process moves to step S5, and if it is larger, the process moves to step S6. In steps S5 and S6, a selection switching signal is sent to increase or decrease the selection address of number P of the multiplexer 5), the magnetoelectric transducer 3 and the detector 1.
Execute the switching of 1. In steps S7 and S8, the number of the magnetoelectric transducer 3 (A(P)-3, A(P)+3) is changed to the memory corresponding to the number of the switched detector 11.
) in step S2 in preparation for the next switching decision.
Return to However, in this example, the numbers of @electrical conversion elements 3 that select each detector 11 are in 3 increments (for example, the detector 11-1 is selected from the magnetoelectric conversion elements 3-1.3-4.3-
7. Select... (see Figure 5)), movable body 1
It varies depending on the number of magnetoelectric transducers 3 that function constantly to magnetically attract and levitate. Further, the selection and switching of the electromagnetic coil 20 can be performed in the same manner as described above by branching and guiding the selection switching signal of the magnetoelectric transducer 3 to the multiplexer 4 that selects and switches the electromagnetic coil 20 configured in the same manner as described above. Due to the above circumstances, the movable body 1 is stably floated and movement controlled.

〔Effect of the invention〕

As explained above, according to the present invention, an expensive displacement sensor is not used, a relatively inexpensive magnetoelectric transducer is used, and in order to individually control the conventional control axes, the number of grave poles is installed. It is sufficient to provide only the necessary control device to function at all times, and an excellent effect can be obtained in that this type of conveying device can be provided at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the system configuration of a magnetic levitation transport device according to the present invention, and FIG. 2 is a diagram showing a magnetic levitation transport device which is an embodiment of the present invention. A cross-sectional view showing the arrangement (A cross-sectional view of A in FIG. 3B), a side view of FIG. , FIGS. 4(a), (b), and (c) respectively show the movable body 1.
FIG. FIG. 6(a) is a diagram showing the detailed configuration of the switching section of the magnetoelectric conversion element. (b) and (C) are diagrams showing the relationship between the fixed magnetic pole and the movable body as the flexible body moves, Figure 7 is a diagram showing the movable body and the state of change in magnetic flux density, and Figure 8 is magnetic levitation. FIG. 9 is a flowchart of the control process of the conveyance device, and is a diagram showing an example of the configuration of a conventional magnetic levitation conveyance device. Applicant Ebara Research Institute, Inc. Agent Patent attorney Takashi Kumagai (1 other person) No. 2 No. 4 Figure a/ Be1!2 Condition (b> (C) Figure 6 Figure 7 Figure 7 8 Figure A-A l1ft of course Figure 9

Claims (2)

[Claims] (1) A movable body, a group of electromagnets fixed to the rail at equal intervals along a rail that defines the direction of movement thereof, and a displacement detection means for detecting the levitation gap between each electromagnet of the electromagnet group and the movable body. a control device that uses the detected displacement as an input to stably levitate the movable body; a power amplifier that supplies current to the electromagnet; and a switching judgment unit that commands switching of the electromagnet that functions as the movable body moves. , a first selector that selects the electromagnet according to a signal from the switching determination means and guides the current supplied by the power amplifier to the selected electromagnet.
1. A magnetic levitation conveyance apparatus comprising: a selection switching means; and a second selection switching means for selecting the detection means based on a signal from the switching determination means and guiding the selected detection means to the control means. (2) The displacement detection means detects the magnetic flux density generated in the floating air gap between the movable body and the electromagnet, and includes a magnetoelectric conversion element disposed in the air gap, and a combination of the detected magnetic flux density, the current supplied to the electromagnet, and the movable body. 2. The magnetic levitation conveyance apparatus according to claim 1, further comprising a flying height calculation means that stores a relationship between flying heights and calculates the flying height from the magnetic flux density and the current.