JPH0648521A - Controller of carrying-in/out crane for automatic warehouse - Google Patents

Abstract

PURPOSE:To make an effective use of the regenerative powder of the driving motor of an elevating carriage with regenerative resistance without consuming it in a controller of carrying-in/out crane for automated warehouse. CONSTITUTION:To respective inverters 24-26, DC power is supplied from a common 3-phase bridge type rectifying circuit 27. Respective motors 21-23 are controlled by the respective inverters 24-26. A controller 33 makes a traveling motor 21 carry out power running at the time of regenerative braking and controls the traveling motor 21 so that it may be driven by the regenerative power of the elevating motor 22. When the regenerative power of the elevating motor 22 is higher than the power necessary to drive the traveling motor 21, the controller 33 makes the traveling motor 21 carry out power running and makes a fork motor 23 carry out generative braking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a loading / unloading crane of an automatic warehouse.

[0002]

2. Description of the Related Art Conventionally, as a loading / unloading crane for an automated warehouse, a lifting / carrying carriage provided with a running fork for loading and unloading cargo, and the crane itself can travel along a loading / unloading shelf. Is widely used. In such a loading / unloading crane control device, dedicated motors are respectively provided for traveling the crane, driving the lifting carriage, and driving the fork.
Each motor is controlled by a speed control controller according to the type of the motor.

In recent years, in order to speed up the loading and unloading work and reduce the power consumption, an induction motor is used for each of the motors and speed control is performed as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-18209. Various types of controllers using an inverter have been proposed.

When an inverter is used, a DC power supply is required, but a crane for loading and unloading has a large power consumption and cannot use a battery. Therefore, a commercial AC power supply that was once converted to DC by a rectifier circuit
It is used as a DC power source for inverters. The rectifier circuit is provided for each inverter so that the operation of each inverter does not affect other inverters.

[0005]

By the way, when lowering an elevating carriage carrying a heavy load, in order to prevent the elevating carriage from suddenly descending to collapse the load or damage the crane, It is necessary to cause the drive motor of the carriage to perform restraint braking. Suppressive braking is braking that prevents the motor from being driven from the load side and becoming overspeed, and generally regenerative braking is used.

When regenerative braking is performed by an induction motor controlled by an inverter, a regenerative resistor is usually provided in the inverter, and the regenerative resistor absorbs regenerative power (power consumption).

However, when the load is heavy or the descending distance of the lifting carriage is long, the power consumption of the regenerative resistor also increases as the regenerative power increases, so the power capacity of the regenerative resistor must be increased. I have to. Then,
There has been a problem that the external dimensions of the regenerative resistor become large, and the control device that houses the resistor also becomes large and takes up installation space.

Further, in order to save electric power in the automatic warehouse, it is required that the regenerative electric power is not wastefully consumed by the regenerative resistor but is recovered and used effectively. The present invention has been made to solve the above problems, and an object thereof is to recover and effectively utilize regenerative electric power of a drive motor for a lifting carriage without using a regenerative resistor. An object is to provide a control device for a loading / unloading crane with a simple configuration.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention enables a crane itself having an elevating carriage provided with a running fork for loading and unloading to travel along a shelf for loading and unloading. In the control device for the loading / unloading crane of the automated warehouse, the fork motor that drives the running fork, the lifting motor that drives the lifting carriage up and down, the traveling motor that drives the crane itself, and the regenerative power of the lifting motor. When the regenerative electric power recovery means that collects the energy and supplies the regenerative electric power to at least one of the traveling motor and the fork motor and the lifting motor is performing the regenerative braking, the traveling motor is caused to perform power running or the fork motor is subjected to the dynamic braking. The gist of the present invention is to provide a motor control unit that causes the regenerative power to be completely consumed.

[0010]

Therefore, according to the present invention, when the lift motor is performing regenerative braking, the traveling motor performs power running or the fork motor performs dynamic braking to completely consume the regenerative electric power generated by the regenerative braking. It is like this.

Therefore, it is not necessary to provide a special means such as a regenerative resistor to absorb the regenerative electric power. Also, in order to divert the regenerative electric power of the lifting motor to the power running of the traveling motor,
Looking at the entire work of the loading / unloading crane, it is possible to save power by the amount of power required for the power running of the traveling motor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a perspective view of the automated warehouse in this embodiment.

The automated warehouse 1 is erected up front and rear, and has a pair of shelves 3a and 3b having a plurality of storage sections 2 in the length direction (left and right direction in FIG. 2) and the height direction (however, the front side shelf 3b is the highest. Only the lower stage is shown). Of the storage sections 2 of the shelves 3a and 3b, one of the lowermost and end portions is a home position 4 for loading and unloading a load.

In addition, a stacker and a stacker are provided between the shelves 3a and 3b.
A crane 5 is provided. The crane 5 includes a traveling platform 7 that travels on rails 6 laid on the ground, a pair of masts 8 standing from both ends of the traveling platform 7, and a mast 8
It is provided with an up-and-down carriage 9 and the like which is vertically movable. Further, the lifting carriage 9 is provided with a running fork 10 movable in the front-rear direction.

On the traveling platform 7, the crane 5 is mounted on the shelves 3a, 3b.
A traveling motor 21 is provided to drive the vehicle along the direction. Further, the mast 8 is provided with an elevating motor 22 for vertically moving the elevating carriage 9.
Further, the lift carriage 9 is provided with a fork motor 23 for driving the fork 10.

A control device 11 for controlling the motors 21-23 is provided on the mast 8. Further, a computer 12 (not shown in FIG. 2) for warehousing / outgoing management is installed at a place away from the automatic warehouse 1. The computer 12 and the control device 11 respectively include
As shown in FIG. 3, optical communication devices 12a and 11a are additionally provided. That is, the computer 12 and the control device 11
Means that data required for warehousing / delivery management is exchanged by optical communication using the optical communication devices 12a and 11a.

FIG. 1 shows a block circuit diagram of the control system of this embodiment. The motors 21 to 23 are induction motors, and their speeds are controlled by dedicated inverters 24 to 26, respectively.

The rectifier circuit 27 converts a commercial three-phase AC power supply 28 into DC, and supplies it to each of the inverters 24 to 26 as a DC power supply. The rectifier circuit 27 is a well-known three-phase bridge rectifier circuit that is composed of six diodes D connected by the Gretz connection, as shown in FIG. Further, no regenerative resistor is provided in each of the inverters 24 to 26.
Therefore, when the motors 21 to 23 perform regenerative braking,
The regenerative current flowing from each of the motors 21 to 23 into each of the inverters 24 to 26 flows out to the rectifier circuit 27 without power consumption in each of the inverters 24 to 26. However, in that case, since the reverse bias is applied to each diode D of the rectifier circuit 27, the regenerative current does not flow into the three-phase AC power supply 28. That is, each motor 21
The regenerated electric powers of 23 are blocked by the rectifier circuit 27 and are not returned to the three-phase AC power supply 28.

The pulse encoder 29 outputs a pulse according to the rotation of the traveling motor 21, the pulse encoder 30 outputs a pulse according to the rotation of the lifting motor 22, and the pulse encoder 31 outputs a pulse according to the rotation of the fork motor 23. Is output. Therefore, the pulse output from the pulse encoder 29 corresponds to the traveling movement of the traveling platform 7. The pulse output from the pulse encoder 30 corresponds to the vertical movement of the vertical carriage 9. Further, the pulse output from the pulse encoder 31 corresponds to the movement of the fork 10.

A traveling table 7 is provided for each storage 2 of the shelves 3a, 3b.
Stop positions for the lift carriage 9 and the fork 10 are predetermined, and a plurality of sensors (not shown in FIG. 2) are provided at appropriate positions on the shelves 3a and 3b corresponding to the stop positions. . Also, the fork 10
A sensor (not shown in FIG. 2) for detecting whether or not the load is securely placed is provided on the top. The sensor group 32 is composed of the plurality of sensors.

The controller 33, based on the detection signals from the sensor group 32 and the pulses from the pulse encoders 29 to 31, the moving speeds and current positions of the traveling platform 7, the lifting carriage 9 and the forks 10, and the current position on the forks 10. Detect the loading state of the load. Then, the controller 33 makes the detection result equal to the instruction from the computer 12 transmitted via the optical communication devices 12a and 11a.
The motors 24 to 26 are drive-controlled by controlling the inverters 21 to 23. In addition, the controller 33
Detects the abnormality of the crane 5 or the load based on the detection signal from the sensor group 32 and the pulse from each of the pulse encoders 29 to 31, and the content of the abnormality is detected by the optical communication devices 11a and 1a.
Contact the computer 12 via 2a.

The controller 11 stores the controller 33 and the inverters 24 to 26 of the above control system. Next, the operation of the present embodiment configured as described above will be described.

At the time of unloading the load, the computer 12 loads the load on which shelf 3a, 3b, in which row (indicating the position of the storage unit 2 in the length direction) and in which stage (the storage unit in the height direction). 2) is shown) and whether or not to take out from the storage unit 2 at the position 2) is calculated. Subsequently, the computer 12 outputs a command signal for guiding the lift carriage 9 of the crane 5 to the storage unit 2 obtained by calculation, that is, a travel control command signal of the traveling platform 7 and a lift control command signal of the lift carriage 9. create.

Each command signal is converted into an optical signal by the optical communication device 12a and transmitted. The optical communication device 11a is
The optical signal from the optical communication device 12a is received, the optical signal is reconverted into each command signal, and the command signal is output to the controller 33 in the control device 11.

The controller 33 detects the current position of the traveling platform 7 based on the detection signal from the sensor group 32 and the pulse from the pulse encoder 29. Then, the controller 33 drives and controls the traveling motor 21 by controlling the inverter 24 so that the current position of the traveling platform 7 becomes a position corresponding to the target storage unit 2 series based on the traveling control command signal. .

The controller 33 also includes a sensor group 32.
The current position of the up-and-down carriage 9 is detected based on the detection signal from the pulse encoder 30 and the pulse from the pulse encoder 30. Then, the controller 33 controls the drive of the lift motor 22 by controlling the inverter 25 so that the current position of the lift carriage 9 corresponds to the target stage of the storage section 2 based on the lift control command signal. .

As a result, the traveling platform 7 travels up to the target storage section 2 and the lift carriage 9 is raised to the step of the target storage section 2. Then, the controller 33 drives and controls the fork motor 23 by controlling the inverter 26 based on the detection signal from the sensor group 32 and the pulse from the pulse encoder 31. That is, the fork 10 is extended to the intended storage part 2 and a load is placed thereon, and then the fork 10 is drawn into the lifting carriage 9.
The load is stored in the crane 5.

Next, in order to move the load accommodated in the crane 5 to the home position 4 and take it out, the traveling platform 7 is used.
While traveling to the home position 4, the elevating carriage 9 is lowered to the lowest stage of the shelves 3a, 3b.

That is, the controller 33 controls the traveling motor 21 and the lifting motor 22 by controlling the inverters 24 and 25 in the same manner as described above. However,
By causing the lift motor 22 to perform regenerative braking, it is possible to prevent the lift carriage 9 from being suddenly lowered to collapse the load or damage the crane 5.

Here, the controller 33 controls the inverters 24 and 25 so that the drive times of the traveling motor 21 and the lifting motor 22 become equal. Then, the regenerative current flowing from the lifting motor 22 to the inverter 25 flows out to the rectifier circuit 27 without power consumption in the inverter 25, but is blocked by the rectifier circuit 27 and is blocked by the three-phase AC power supply 28.
Will not be returned to. Therefore, the regenerative current from the lifting motor 22 flows into the inverter 24, is used to drive the traveling motor 21, and is consumed. That is, the lifting motor 2
The traveling motor 21 is driven by the regenerative electric power of 2.

When the regenerative electric power of the lifting motor 22 cannot be completely consumed by the traveling motor 21, that is, the traveling motor 2
If the regenerative electric power of the lifting motor 22 is larger than the electric power required for driving No. 1, the fork motor 23 is caused to perform dynamic braking.

That is, a direct current is supplied to the primary winding of the fork motor 23 via the inverter 26 to excite the primary side. Then, the fork motor 23 works as a rotary armature type AC generator, not as an induction motor, and internally consumes the supplied power, so that the fork motor 23 is braked.

Therefore, the regenerative electric power of the lifting motor 22 which cannot be consumed by the traveling motor 21 is used for the dynamic braking of the fork motor 23 and consumed. As described above, in the present embodiment, the rectifier circuits conventionally provided for the respective inverters 24 to 26 are integrated into one rectifier circuit 27, and the common rectifier circuit 27 supplies DC power to the respective inverters 24 to 26. I am trying to do it. Then, when the lift motor 22 performs regenerative braking, the traveling motor 21 is caused to perform power running,
The traveling motor 21 is driven by the regenerative electric power of the lifting motor 22. When the regenerative electric power of the lifting motor 22 is larger than the electric power required to drive the traveling motor 21, the fork motor 23 is made to perform the dynamic braking.

As a result, the regenerative power of the lifting motor 22 is
Since it is consumed by the traveling motor 21 and the fork motor 23, it is not necessary to provide a regenerative resistor in the inverter 24. Further, since the rectifier circuits conventionally provided for the respective inverters 24 to 26 are integrated into one rectifier circuit 27, two rectifier circuits can be omitted. for that reason,
The controller 11 can be made smaller by the amount of the regenerative resistor and the rectifier circuit that are omitted.

Further, since the regenerative electric power of the lifting motor 22 which has been conventionally consumed by the regenerative resistor is diverted to drive the traveling motor 21, it is possible to save the electric power of the entire automatic warehouse 1 accordingly.

The present invention is not limited to the above embodiment, and for example, as disclosed in Japanese Utility Model Laid-Open No. 58-117488, the traveling motor 21 and the fork motor 23 are formed by a single inverter. Switching control may be performed. FIG. 5 shows a block circuit diagram of the control system in that case. The output of the inverter 41 is the controller 33
It is switched by a switching circuit 42 controlled by, and is selectively supplied to the motors 21 and 23 to be driven. Also in this case, as in the above-described embodiment, the traveling motor 21 is driven by the regenerative electric power of the lifting motor 22.
To drive.

The rectifier circuit 27 may be replaced with another type of rectifier circuit such as a three-phase half-wave rectifier circuit or a three-phase full-wave rectifier circuit instead of the three-phase bridge rectifier circuit. Furthermore, 3
The phase AC power supply 28 may be replaced with a single phase AC power supply, and the rectifier circuit 27 may use an arbitrary type rectifier circuit for single phase accordingly.

In addition, each of the motors 21 to 23 can use not only an induction motor but also other types of motors such as a DC motor and a servo motor. The inverters 24 to 26,
It is also possible to replace 41 with another suitable type of motor control controller such as a cycloconverter.

[0039]

As described above in detail, according to the present invention, the regenerative energy of the drive motor for the lifting carriage can be recovered and used effectively without using the regenerative resistor, and can be used effectively. There is an excellent effect that the control device can be provided with a simple configuration.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a control system of an embodiment embodying the present invention.

FIG. 2 is a perspective view showing an automated warehouse in one embodiment.

FIG. 3 is a block circuit diagram showing a communication transmission state between the computer 12 and the control device 11 of the automated warehouse 1 in one embodiment.

FIG. 4 is a circuit diagram of a rectifier circuit 27 according to an embodiment.

FIG. 5 is a block circuit diagram of a control system of another embodiment.

[Explanation of symbols]

10 ... Running fork, 9 ... Lifting carriage, 5
... Crane, 3 ... Shelf, 23 ... Fork motor, 22 ... Lifting motor, 21 ... Traveling motor, 24-26, 41 ... Inverter as regenerative power recovery means, 27 ... Rectifier circuit as regenerative power recovery means, 33 ... Motor Controller as control means, 12 ... Computer as motor control means

Claims (1)

[Claims] 1. A control device for a loading / unloading crane of an automatic warehouse, wherein a crane equipped with a lifting / lowering carriage provided with a running fork for loading and unloading is capable of traveling along a shelf for loading / unloading. , A fork motor that drives a running fork, an elevating motor that elevates and lowers an elevating carriage, a traveling motor that travels the crane itself, and / or at least one of a traveling motor and a fork motor that recovers regenerative power from the elevating motor. When the regenerative power is being supplied from the regenerative power recovery means and the lifting motor, the traveling motor is made to perform power running or the fork motor is dynamically braked so that the regenerative power is completely consumed. A control device for a loading / unloading crane for an automatic warehouse, comprising: a motor control means.