JP2624493B2 - Linear induction motor conveyor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding drive control of a transfer device using a double-sided linear induction motor, the impact applied to a secondary conductor (transport vehicle) is reduced, and the secondary conductor (transport vehicle) is stopped and positioned. A linear induction motor transport device in which a primary stator is opposed to a secondary conductor so as to sandwich the secondary conductor, a speed sensor for detecting the speed of the secondary conductor, and a detection speed of the speed sensor. If the speed is lower than a predetermined speed, one side of the stator is selectively excited to accelerate and decelerate, and if the speed exceeds a predetermined speed, both sides of the stator are excited to be driven. .

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear induction motor transport device, and more particularly, to drive control of a transport device using a double-sided linear induction motor.

The linear induction motor is one in which the primary side, the secondary side, and the gap of the rotary induction motor are linearly stretched, respectively, and generates an AC moving magnetic field on the primary side to act on the secondary side made of a good electric conductor. As a result, an eddy current is generated, and the repulsive force generated on the primary side and the secondary side is used as the thrust, and the electric energy can be directly converted into linear kinetic energy.

One type of such linear induction motor is a two-sided linear induction motor in which the primary side is opposed to the secondary side so as to sandwich the secondary side from both sides, and is small and has excellent maintainability. And transport of documents in offices.

[Prior Art] FIG. 11 is a conceptual configuration diagram of a transfer apparatus using such a double-sided linear induction motor. In the figure, reference numerals 1 and 2 denote primary-side stators (iron core coils), which are opposed to each other with the secondary-side conductor 3 interposed therebetween. Reference numeral 4 denotes a carrier, which is connected to and integrated with the secondary conductor 3. Support members 5 and 6 are provided on both side surfaces of the transport vehicle 4, and the vehicles are rotatably attached to the support members 5 and 6. Reference numerals 7 and 8 denote rails provided on the support members 5 and 6 of the carrier 4 on which wheels slide, and are arranged in parallel with the stators 1 and 2.

By the way, a linear induction motor generally has a feature that a large thrust is obtained when the vehicle starts or when the speed is low, and a large braking force is obtained when the linear motor is stopped. FIG. 12 shows these relationships in a characteristic diagram. In FIG. 12, the vertical axis indicates thrust, and the horizontal axis indicates speed. The (+) of the speed indicates acceleration, and the (-) indicates braking (deceleration).

[Problems to be Solved by the Invention] However, because of these characteristics, a large impact is applied to the transport vehicle 4 at the time of starting, and it is difficult to perform stop positioning in addition to the impact at the time of stopping. That is, since the thrust is large, if the timing for stopping the excitation of the stators 1 and 2 is a little earlier, the speed becomes too fast, and if the timing is a little slower, the motor moves in the opposite direction. Therefore, in the final positioning, a single-phase coil for positioning is provided in advance, and the single-phase coil is excited, or the carrier 4 is mechanically sandwiched and stopped. If the speed is too fast, it cannot be reliably stopped at a predetermined position.

The present invention has been made in view of such a point, and an object of the present invention is to provide a linear induction motor transfer device that can perform a highly accurate stop positioning control with a small impact applied to a transfer vehicle.

[Means for Solving the Problems] FIG. 1 is a block diagram showing the principle of a linear induction motor transport device according to the present invention, and the same parts as those in FIG. 11 are denoted by the same reference numerals. In the figure, 9 is a speed sensor for detecting the speed of the secondary conductor 3, and 10 is an excitation control unit for controlling drivers 11 and 12 for exciting the stators 1 and 2 in accordance with the detection signals of these speed sensors 9. A plurality of speed sensors 9 are attached along the stator 1.

[Operation] The speed sensor 9 detects the moving speed of the secondary conductor 3 in a non-contact manner, for example, and applies the detection signal to the excitation control unit 10.
When the detected speed is equal to or lower than a predetermined speed at the time of starting or stopping, that is, when the thrust is large, one of the driver 11 for exciting the stator 1 and the driver 12 for exciting the stator 2 is provided. Is selectively driven to accelerate and decelerate to a weak thrust, and when the detected speed exceeds a predetermined speed, the drivers 11 and 12 are simultaneously driven to increase the thrust to excite the stators 1 and 2 simultaneously. .

FIG. 2 is an operation explanatory diagram of FIG. In FIG. 2, for example, the thrust when only one of the stators 1 is excited is half that when both of the stators 1 and 2 are excited. However, the secondary conductor 3 receives the repulsive force from the stator 1 and approaches the stator 2 side. If the distance L between the stators 1 and 2 is increased to avoid the secondary conductor 3 coming into contact with the stator 2 due to such repulsive force, the magnetic loss increases, the magnetic flux passing through the secondary conductor 3 decreases, and the thrust increases. Becomes smaller. However, such a repulsive force has a characteristic that it increases in proportion to the moving speed of the secondary conductor 3.
Therefore, when the speed is low, the repulsive force is small, and the amount 1 by which the secondary conductor 3 moves toward the stator 2 becomes small. Here, the interval L between the stators 1 and 2 is generally set in consideration of the thickness of the secondary conductor 3 and the play caused by the component accuracy and the assembly accuracy of the carrier and the rail, but (L / 2)> l And the secondary conductor 3 is not damaged.

On the other hand, when the stators 1 and 2 are simultaneously excited, the repulsive force from each of the stators 1 and 2 is canceled, so that the secondary conductor 3 is stabilized at an intermediate position between the stators 1 and 2, and The vehicle travels according to the output moving magnetic field.

In this way, the stators 1 and 2
By controlling the excitation of 2, the thrust at the time of starting or stopping is reduced, the impact applied to the secondary conductor 3 is also reduced, and the stop position of the secondary conductor 3 can be set with high accuracy.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a block diagram showing one embodiment of the present invention.
The same components as those in the drawings are denoted by the same reference numerals. In the figure, reference numeral 13 denotes a position sensor for detecting the position of the transport vehicle 4, and two position sensors are provided above the rail 7 with an interval corresponding to the length of the support member 5. Similarly to the position sensor 13, a plurality of speed sensors 9 (four in this embodiment) are arranged at predetermined intervals above the rails 7. As the speed sensor 9 and the position sensor 13, for example, photocouplers are used. A comb-shaped shutter 14 is integrated with the support member 5 so as to pass through the photocouplers.

In such a configuration, the speed sensor 9 and the position sensor 13 output pulses corresponding to the movement of the shutter 14, that is, the traveling of the carrier 4. Thereby, the traveling speed of the transport vehicle 4 can be obtained from the pulse width of the output pulse of the speed sensor 9. Since all the output pulses of the position sensor 13 are turned off, the transport vehicle 4 is provided with the position sensor 13. It is possible to detect that the vehicle has passed a predetermined position, and since the output pulses of the position sensor 13 are all kept off, the carrier 4 moves to the predetermined position where the position sensor 13 is provided. It can detect that it is stopped.

FIG. 4 is a circuit diagram of a station controller for driving and controlling the apparatus of FIG. In the figure, reference numeral 15 denotes a driving coil constituting the stator 1, 16 denotes a driving coil constituting the stator 2, and 17 denotes a coil for positioning. The coil 15 is driven by a driver 18 in three-phase excitation in a predetermined phase order according to acceleration and deceleration, the coil 16 is driven by a driver 19 in three-phase excitation in a predetermined phase order according to acceleration and deceleration, and the coil 17 is driven by a driver. At 20, selective excitation is performed using two of the three phases.

Reference numeral 21 denotes an input terminal of a three-phase AC power supply, and each driver 18 to
It is connected to a rectifier circuit 22 as well as to 20.
The rectifier circuit 22 supplies a power supply voltage to each unit. Reference numeral 23 denotes a motor control processor, a timer 24 for managing various time relationships, a counter 25 for confirming the position of the carrier,
A memory (RAM) 26 for temporarily storing various data such as data for monitoring the traveling speed of the carrier is provided. Reference numeral 27 denotes a setting switch for setting a state of a rail such as a curve or a slope in the processor 23.

An output signal of the speed sensor 9 is directly input to the processor 23 and a control signal SEL output from the processor 23.
Are also selectively input to the processor 23 via a multiplexer 28 controlled by The processor 23 sends the phase order designation signal DV1 to the driver 18, sends the phase order designation signal DV2 to the driver 19, and sends the positioning control signal D2 to the driver 20.
Send V3. Further, the processor 23 includes a register bank 29.
Data is also exchanged with the main control processor 30 via.

The register bank 29 has flags 29a and 29b indicating the timing of data transfer, and the processor 30
Register 29c for storing data to be transmitted to 3, processor
A register 29d for storing data to be transmitted from 23 to the processor 30 is provided. The processor 30 is provided with a memory (RAM) 31 for temporarily storing data to be transferred. A bus 32 connects the plurality of station controllers and the linear motor controller 33 configured as described above in common.

FIG. 5 is a configuration diagram of a transport system composed of a plurality of stations. In the figure, reference numeral 34 denotes a system controller for controlling the entire system, which is connected to the linear motor controller 33. The stators 1 and 2 of each station are arranged in common along the rails 7 and 8, respectively. The stators 1 and 2 of each station are provided with phase sequence designation signals DV1 and DV2 from the respective motor control processors 23.
Is added, and the carrier 4 is excited to be accelerated or decelerated.

FIG. 6 is an explanatory diagram of transmission and reception of commands between the linear motor controller 33 and each station. Indicates the case of an acceleration / deceleration station.
33 transmits the acceleration / deceleration control command SPC and the station status detection command SNS, and the station returns a confirmation response. Indicates the stop station, and the linear motor controller 33 outputs the stop control command ST
P and the station status detection command SNS are transmitted, and a confirmation response is returned from the station. Indicates a start station, and the linear motor controller 33 transmits a start control command STR. Shows a case of a station related to a series of traveling of the transport vehicle 4, and the linear motor controller 33 sends a station state detection command.
SNS is transmitted, and a confirmation response is returned from the station.

FIG. 7 is a flowchart illustrating the flow of the operation of the starting station. In this case, first, for example, DV1 is turned on, and only one of the stators is excited in the acceleration direction (). Then, it is confirmed whether or not the speed V has reached the threshold speed _VA of the one-side excitation (). If the threshold speed V _A has been reached, DV2 is also turned on to excite both stators in the acceleration direction (), but if not reached, it is confirmed whether the vehicle has escaped from the corresponding station (). It is also checked whether the station has escaped even when the mode is shifted to the both-side excitation drive. After confirming that the station has escaped, the excitation is turned off and the start operation is completed (). If the vehicle has not escaped from the station, it is checked whether the target speed V1 has been reached (). If the target speed V1 has been reached, the excitation is turned off and the starting operation is terminated, but if not, the one-sided excitation is continued. FIG. 8 shows the relationship between these speeds.

FIG. 9 is a flowchart for explaining the operation flow of the stop station. In this If first velocity V To determine whether decreased to the threshold speed V _B of the side excitation (). DV1 and exciting to drive both sides of the stator in the deceleration braking direction by turning on the DV2 if not reduced to the threshold speed V _B (). Then, it is confirmed whether or not the operation is abnormal by checking whether the vehicle has passed the stop station (). When the vehicle passes the stop station, it is determined that the operation is abnormal, and the excitation is turned off (), and an abnormal end process is performed, and a series of operations is completed. If not passing through the stop station, the speed V is the threshold speed
Continuing the unilateral excitation until reduced to V _B.

Velocity V To determine whether decreased to the threshold velocity V _C of the further positioning the coil excitation if you decrease the threshold velocity V _B (). Drives energized one side of the stator in the deceleration braking direction is turned on for example DV1 only if not reduced to the threshold velocity V _C (). Then, it is confirmed whether or not the operation is abnormal by checking whether the vehicle has passed the stop station (). If the vehicle has passed the stop station, it is determined that the operation is abnormal, the excitation is turned off (), an abnormal end process is performed (), and a series of operations is completed. Velocity V if not passed through the stop station to continue the unilateral excitation until reduced to the threshold speed V _C.

If the speed V is lowered to the threshold speed V _C to excite the positioning coil turns off the DV1 and DV2 (). Then, it is checked whether or not it has stopped (). If it is stopped, the excitation of the positioning coil is turned off, and the operation as the stop station ends (). If the vehicle has not stopped, it is further confirmed whether or not an abnormal operation has occurred based on whether or not the vehicle has passed the stop station (). If the vehicle has passed the stop station, it is determined that the operation is abnormal, the excitation is turned off (), an abnormal end process is performed (), and a series of operations is completed. If it has not passed through the stop station, the excitation of the positioning coil is continued until it stops. FIG. 10 shows the relationship between these speeds.

Since the target speed for acceleration or deceleration at the intermediate station except for the start station and the stop station is relatively high, generally both-side excitation is performed.

[Effects of the Invention] As described above in detail, according to the present invention, the excitation applied to both sides or one side according to the speed of the transport vehicle, so that the impact applied to the transport vehicle is small and the stop positioning with high accuracy is performed. It is possible to provide a linear induction motor transport device capable of performing control.

[Brief description of the drawings]

1 is a block diagram showing the principle of the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, FIG. 3 is a block diagram showing one embodiment of the present invention, and FIG. 4 is a circuit diagram of a station controller of the present invention. FIG. 5 is a block diagram of the transport system of the present invention, FIG. 6 is an explanatory diagram of sending and receiving commands of the present invention, FIG. 7 is a flowchart showing the flow of operation of the starting station, and FIG. Fig. 9, Fig. 9 is a flowchart showing the flow of the operation of the stop station, Fig. 10 is an explanatory diagram of the speed change of the stop station, Fig. 11 is a conceptual configuration diagram of a transfer device using a double-sided linear induction motor, Fig. 12 7 is a thrust characteristic diagram of the linear induction motor. 1 and 3, reference numerals 1 and 2 denote stators, 3 denotes a secondary conductor, 4 denotes a carrier, 9 denotes a speed sensor, and 10 denotes an excitation control unit.

Claims (1)

(57) [Claims] 1. A linear induction motor transport device in which a primary side stator is opposed to a secondary conductor so as to sandwich the secondary conductor, a speed sensor for detecting a speed of the secondary conductor, and a speed sensor for detecting a speed of the secondary sensor. Excitation control means for selectively exciting one side of the stator for acceleration and deceleration when the speed is equal to or less than a speed and for exciting both sides of the stator when the speed exceeds a predetermined speed is provided. Linear induction motor conveyor.