JPS5943903B2 - Stop positioning device for linear induction motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a linear induction motor (hereinafter referred to as 1.
(abbreviated as M), for more details, 1. This relates to a stop positioning device for M.

Since L and I-M have a simple and robust structure, small-sized ones are being used in various automatic control devices, physical distribution devices, or transportation systems for peripheral terminal devices connected to computers.

By the way, conventionally, this kind of glue: 1. This is because the stop positioning of M is performed by the frictional force caused by mechanical contact between the movable part and the guide rail.

(2) A complicated braking mechanism with friction plates is required.

2. The stopping position of the movable part changes due to wear of the friction plate.

3. Frictional heat adversely affects mechanical parts.

4. Friction produces bad odors, smoke, and noise.

Problems such as these occur, and it is particularly inconvenient to apply it to office equipment.

The object of the present invention has been made in view of the drawback of oblique operation, and the object thereof is to realize a stop positioning device with a simple structure.

Another object of the present invention is to realize a stop positioning device that can reliably stop a movable part at a predetermined stop position in a non-contact manner.

A further object of the present invention is to realize a stop positioning device that can reliably stop a secondary conductor plate without adding any special mechanism.

According to the present invention, the traveling magnetic field generating coils wound around the primary iron core are connected in parallel.

1. In M, when a secondary conductor plate is detected at a position between the coils that is located at approximately the same interval as the secondary conductor plate using a part of the traveling magnetic field generating coil, single-phase AC is applied only to the coil. The above object is achieved by energizing and positioning the secondary conductor plate between the coils.

The present invention will be explained below using the drawings.

FIG. 1 shows the characteristics of the present invention: 1. FIG. 2 is a diagram of the operating principle of the M stop positioning device (diagram of the principle of force generation by a single-phase alternating current magnetic field).

In the figure, 1 and 1 are a pair of fixed primary cores, and 2 is At
This is a secondary conductor plate of a predetermined length made of a good conductor such as Cu.

A groove 3 is provided in the primary iron core 1, and magnetic pole parts 4 and 5 are formed on both sides of the groove 3.

The magnetic pole area of the magnetic pole part 5 is set to be larger by an appropriate amount than the magnetic pole area of the magnetic pole part 4, and each magnetic pole part 4 is provided with a single-phase coil 6.
is wrapped.

The graph shown at the bottom of the figure is a magnetic flux density distribution diagram when a DC voltage is applied to the single-phase coil when no secondary conductor plate is present.

The secondary conductor plate 2 is shown by arrow A between the primary cores 1 and 10.

It is movable in the A' direction.

Now, when a single-phase alternating current is applied to the single-phase coil 6, a magnetic flux loop F as shown by the dotted line in the figure is formed, but since it is an alternating magnetic field, the direction of the magnetic flux also alternates.

At this time, the phase of the magnetic flux in the air gap 7 between the magnetic pole parts 4, 4 is 180 degrees ahead of the phase of the magnetic flux in the air gap 8 between the magnetic pole parts 5, 5, and 180 degrees ahead of the phase of the magnetic flux in the air gap 8. This means that the magnetic flux density in the air gap 8 is
(the magnetic pole area of the magnetic pole part 5 is smaller than the magnetic flux density of the magnetic pole part 4
(because it is wider than the magnetic pole area).

When the secondary conductor plate 2 is inserted into the gap of such a magnetic circuit configuration, the following force is generated in the secondary conductor plate 2.

That is, when the tip of the secondary conductor plate 2 is at position a,
A force in the direction of arrow A' is generated.

This is because the phase of the magnetic flux in the air gap 8 lags behind the inlet side due to the eddy current induced inside the primary iron cores 1, 1, so a traveling magnetic field is formed on the secondary conductor plate 2 facing the inlet side. This is for the purpose of

Next, as the tip of the secondary conductor plate 2 approaches the position, the density of the eddy current I08 induced at the tip gradually increases as shown in Figure 2, and the phase of the magnetic flux at the tip increases. begins to lag, the advancing magnetic field on the secondary conductor plate 2 is canceled out, and the force in the direction of arrow A' becomes weaker.

Next, when the tip of the secondary conductor plate 2 comes to the 0 dimension position, it will be affected by the magnetic flux of the air gap 7, and the magnetic flux at the tip of the secondary conductor plate 2 and the part in the air gap 8 will be affected. Since the phase difference with the magnetic flux is 180 degrees or more, a traveling wave in the direction of arrow A is formed on the secondary conductor plate 2, and a force in the same direction is generated.

Next, when the tip of the secondary conductor plate 2 moves to position d, a large eddy current ■ appears at the tip, as shown in FIG.

7 is induced, the phase of the magnetic flux at the tip begins to lag, and the phase difference between the magnetic flux at the tip and the magnetic flux in the portion S in the air gap 8 becomes 180 degrees again, and the magnetic flux advances onto the secondary conductor plate 2. No magnetic field is formed and the force is zero.

Next, when the tip of the secondary conductor plate 2 moves from position d to position e, the phase of the magnetic flux at the tip further lags, and the phase difference between the magnetic flux at the tip and the magnetic flux at the portion within the air gap 8 is It will be 180 degrees or less.

Therefore, a force in the direction of arrow A' is generated on the secondary conductor plate 2.

This force is maximum when the tip of the secondary conductor plate 2 is at position e.

When the tip of the secondary conductor plate 2 passes the position e, the force generated on the secondary conductor plate 2 decreases and becomes zero at the position f.

This is because the force at the tip (in the direction of arrow A) and the force at the rear end (in the direction of arrow A') of the secondary conductor plate 2 having a predetermined length are balanced.

When the tip of the secondary conductor plate 2 passes the position f, the force at the rear end of the secondary conductor plate 2 (in the direction of arrow A') changes from the force at the tip (in the direction of arrow A').
direction), and a force in the direction of arrow A is generated on the secondary conductor plate 2.

An embodiment of the stop positioning device according to the present invention utilizing such an operating principle is shown in FIGS. 4 and 5.

4 shows a side view of the device of the present invention, and FIG. 5 shows a top view thereof.

In each figure, 9 indicates the traveling magnetic field generating coil wound around each magnetic pole of the primary iron cores 1, 1 arranged on both sides of the secondary conductor plate 20, and 10 and 10' indicate the position of the secondary conductor plate 2. A photodetector consisting of a light projector and a light receiver for detection; 11 is a guide rail provided continuously on the upper part of the primary core as shown in FIG. 4; 12 is a guide rail that freely rotates on the guide rail 11; Possible wheels 13 are carriers connected to the secondary conductor plate 2.

As can be seen with reference to FIG. 5 of the illustrated stop positioning device, the length of the secondary conductor plate 2 is set shorter than the length of the primary iron core 1.1.

Further, the traveling magnetic field generation phase and stop positioning coils 6 and 6', which form part of the traveling magnetic field generating coil 9 wound around the primary iron cores 1 and 1, are arranged at intervals approximately equal to the length of the secondary conductor plate 2. A coil provided at a certain distance is selected.

In other words, the arrangement of the coils 6 and 6' is such that, as explained in the operating principle diagram of FIG. is not formed, that is, A.

Coils are selected that are set at positions where the forces in the A' direction are both zero.

Each coil 6,6' is wired so as to generate a magnetic flux loop as shown by the broken line 14 in FIG.

Further, the photodetectors 10.10' are respectively arranged at positions indicated by position d in FIG.
is connected to a drive circuit shown in FIG. 7, which will be described later.

The operation of this embodiment will be explained step by step below.

FIG. 6 is a wiring diagram of the stop positioning device according to the present invention.

All numbers in the figure refer to FIG. 5.

This embodiment shows a case where a three-phase AC power source is connected.

What is important here is that the coils wound around the primary core applied to the stop positioning device of the present invention are connected in parallel to each phase power source.

That is, in the present invention, as described above, the coils 6 forming part of the traveling magnetic field generating coil and arranged at predetermined intervals.
．． Since single-phase alternating current is applied to 6' IC at a predetermined timing to stop and position the secondary conductor plate between both coils 6 and 6', it is necessary that the traveling magnetic field generating coil is connected to each phase. Connected in parallel to the power supply.

FIG. 7 shows a drive circuit for a stop positioning device according to the present invention.

In the figure, 15 and 16 are reverse phase application switching relays, 17
18 is a relay for generating a traveling magnetic field, 18 is a stop positioning relay, 19 is an inverter, 20 is a start/stop signal input terminal, and other numbers refer to FIG. 5.

The start/stop signal input terminal 20 is connected to an output terminal of a two-person canand circuit (not shown).

Each input of the NAND circuit is equipped with a photodetector 10°1 as shown in Figure 5.
Ryokawa force from 0' is input.

Therefore, at the time when the information "1" is output from both photodetectors 10 and 10', that is, when the secondary conductor plate 2 reaches the position shown in FIG. The traveling magnetic field generating relay 17 is opened, while the logic "0" signal closes the stop positioning relay 18 via the inverter 19.

As a result, the supply of current to the traveling magnetic field generating coil 9 is cut off, while single-phase alternating current is supplied to the stop positioning coils 6, 6' arranged at a predetermined interval.

That is, the relay 17 is controlled to be closed only when a traveling magnetic field is generated, and the relay 18 is controlled to be closed only when a stop position is determined.

Although not shown, at the time when one of the photodetectors outputs information "1", that is, when the secondary conductor plate 2 reaches the stop position, the secondary conductor plate is connected to each traveling magnetic field generating coil 9. The relays 15, 16 are switched between open and closed states based on the output from the photodetector in order to supply current in the direction that applies the braking force to the relays 15, 16.

Of course, this negative phase application time is preset to a length that does not change the traveling direction of the secondary conductor plate.

When starting again the secondary conductor plate 2 which has been stopped between the coils 6 and 6', the coils 6 and 6'
The single-phase alternating current supply to the traveling magnetic field generating coil 9 is stopped.
By applying alternating current to each phase, the vehicle can be launched in any direction.

As shown in FIG. 5, the drive circuit shown in FIG. 7 is such that the pitch interval of the traveling magnetic field generation and stop positioning coils 6 and 6' is an odd number of pole lengths, and both coils are used for generating the traveling magnetic field. time, the same phase (in this case, it is 1/2 pole shorter than the secondary conductor plate length & λ coil pitch interval.

). Therefore, in the case of an even number of pole lengths, the drive shown in FIG. 7 may be used, but if a circuit configuration is adopted in which single-phase alternating current is applied in opposite directions to one of them in order to form the magnetic flux loop 14 shown by the dotted line in FIG. , even better.

However, in order to recommend the circuit shown in Fig. 7, which is simple and has fewer circuit components and is inexpensive, the pitch interval of the coils for generating a traveling magnetic field and positioning to stop as shown in Fig. 5 is an odd number of pole lengths, and both coils are If possible, we would recommend a structure that is in phase when generating a magnetic field.

As explained above, according to the present invention, the short secondary conductor shape, 1
．． Non-contact stop positioning of M can be realized at low cost by using a part of the existing traveling magnetic field generating coil without arranging a special stop positioning coil or the like.

[Brief explanation of drawings]

FIG. 1 is a diagram of the operating principle for explaining the stop determination device of the present invention, FIGS. 2 and 3 are diagrams for further explaining FIG. 1, and FIGS. 4 and 5 are diagrams according to the present invention. A side view and a top view of one embodiment of the stop positioning device, FIG. 6 is a wiring diagram of the traveling magnetic field generating coil applied to the present invention, and FIG. 7 is a diagram of the drive circuit connected to the stop positioning device of the present invention. -f11. In the figure, 1 is the primary iron core, 2 is the secondary conductor plate, and 6.
6' is a coil for generating a traveling magnetic field and for positioning a stop;
9 is a traveling magnetic field generating coil, '10.10' is a photodetector,
11 is a conveyor rail, 12 is a wheel, and 13 is a carrier.

Claims (1)

[Claims] 1. A primary coil in which a traveling magnetic field generating coil connected in parallel to a power source is wound over a predetermined length on at least one side of a secondary conductor plate made of a good conductor plate guided and supported by a conveyor rail. A stop positioning device for a linear induction motor that transports the secondary conductor plate along the conveyance rail by disposing a side iron core and sequentially energizing the traveling magnetic field generating coil, the secondary conductor plate A detection device for detecting the secondary side conductor plate is provided at a position corresponding to the traveling magnetic field generating coil placed at an interval approximately equal to the length along the conveyance rail, and a detection signal from the detection device is provided. A stop positioning device for a linear induction motor, characterized in that when the traveling magnetic field generating coil is located at a position corresponding to the detecting device, a single-phase alternating current is applied only to the traveling magnetic field generating coil to stop the secondary conductor plate between the coils.