JP2001139300A - Control method for cargo transporter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cargo transporter with simplified driving part and excellent safety. SOLUTION: In the cargo transporter, a motor and an air cylinder are engaged and used as an actuator of the driving part. Supply power to the motor is controlled on the basis of a command signal from a command device and a speed signal from a speed detector, and supply pressure to the air cylinder is controlled through an electricity-air pressure converter on the basis of a motor output signal from a motor output detector, a pressure signal from a pressure detector of the cylinder and the speed signal from the ed detector. The motor thereby outputs driving force constantly, and the cylinder outputs driving force generally in proportion to the output of the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a cargo handling machine having a lifting mechanism such as a link mechanism or a jib mechanism for transporting cargo.

[0002]

2. Description of the Related Art Conventional cargo handling machines are of an electric type using only a motor as an actuator or an air type using only an air cylinder, but those using a motor and an air cylinder in engagement are used. Did not.

[0003]

In the conventional cargo handling machine, in the electric type using a motor as an actuator,
As the load increased, the motor became larger and heavier. In addition, a drive unit corresponding to a motor having a large size needs to have a large gear and the like, and it is generally impossible to divert an existing drive unit. On the other hand, in the pneumatic type using an air cylinder for the actuator, as the load increased, the cylinder became larger and the weight increased. In the event that the cargo falls, the sudden jump of the arm is suppressed by the action of the damper, but this is not a sufficient safety measure.

[0004] The present invention solves the above-mentioned disadvantages. By using a motor and a cylinder engaged with an actuator and using the same, even when the load increases, the driving force is reduced as compared with a cargo handling machine using only a motor. It is an object of the present invention to provide a cargo handling machine capable of reducing the size and weight of the unit, suppressing the arms from jumping up, and sharing parts with existing cargo handling machines.

[0005]

Means for Solving the Problems A motor and an air cylinder are engaged with an actuator of a drive unit, and power supplied to the motor is controlled based on a command signal from a command device and a speed signal from a speed detector. By controlling the supply pressure to the air cylinder through an electric / pneumatic converter based on the motor output signal of the motor output detector, the pressure signal of the cylinder pressure detector, and the speed signal of the speed detector, The motor always produces a driving force, and the cylinder produces a driving force substantially in proportion to the output of the motor. The cylinder is not limited to the air type, but may be a hydraulic cylinder or the like, and the speed signal of the speed detector may be a position signal of a position detector.

[0006]

FIG. 1 is a general view of an embodiment.
The arm 1 of the parallelogram link mechanism is a mechanism for obtaining parallelism in the horizontal and turning directions. The cargo 2 is moved vertically by the drive unit 3. The swivel 4 is supported by a main body plate 5, and a ball screw 6,
A reduction gear 7, a motor 8, a cylinder 9, and a rail guide 10 are provided. The motor 8 is connected to the ball screw 6 via the speed reducer 7, and the driving unit 3 is inserted into the ball screw 6. The cylinder 9 has a tube portion 11 fixed to the main body plate 5 and a rod portion 12 fixed to the movable plate 13. The motor 8 is connected to the cylinder 9 via the speed reducer 7, the ball screw 6, the drive unit 3, and the movable plate 13, and drives the arm 1. The movable plate 13 is fixed to the drive unit 3 and is arranged so as to be able to move up and down along the rail guide 10. The force point 14 of the arm 1 is slidably supported on the movable plate 13, the fulcrum 15 is supported on the main body plate 5, and the action point 16 is supported on the tip of the arm 1. A command device 18 such as a potentiometer provided on an operation lever 17 and a hook 19 for suspending the cargo 2 are provided adjacent to the tip of the arm 1. A speed detector 20 such as a tachogenerator and an electromagnetic brake 21 are connected to a shaft of the motor 8. The control circuit board 22 is provided in the middle of the command device 18, the motor 8, and the cylinder 9, and has a gain circuit (not shown), a phase control circuit (not shown), an integrator (not shown), and a motor output detector ( Not shown), electricity
It is composed of a pneumatic converter (not shown), a pressure detector (not shown), and the like, and is connected to the command device 18, the motor 8, and the cylinder 9 by pipes 23 and electric wires 24. Control circuit board 2
2, a power supply 25 and an air source 26 are supplied. An ascending command is given by tilting the operation lever 17 disposed in the command device 18 upward, a descending command by tilting the operating lever 17 downward, and a stop command by giving it neutral. When the operating lever 17 is tilted upward by the above configuration, the arm 1 is raised, and when the operating lever 17 is tilted downward, the arm 1 is lowered and the cargo 2 is moved up and down. Accordingly, the cargo handling machine 27 can transport the cargo 2 three-dimensionally.

FIG. 2 is a block diagram showing a control system.
When the operator tilts the operation lever 17 up or down, a potentiometer (not shown) connected to the operation lever 17 built in the command device 18 continuously generates a command signal 28 corresponding to the tilt angle. appear. Command signal 28
Is a power supply 31 to the motor 8 via a gain circuit 29 and a phase control circuit 30, a motor output detector 33 that uses a motor voltage value as a motor output signal 32, and an electric / pneumatic converter 34 such as an electro-pneumatic proportional valve. And the supply pressure 35 to the cylinder 9. The speed detector 20 feeds back the speed signal 38 to the addition points 36 and 37,
A part thereof is fed back to the addition point 36 as a torque deviation signal 40 by the integrator 39. Pressure detector 41 feeds back pressure signal 42 to summing point 37. Motor 8
Is engaged with the cylinder 9 via the speed reducer 7, the arm 8 is driven by the motor 8 and the cylinder 9, and the cargo 2 hooked on the hook 19 attached to the command device 18 is raised or lowered. Therefore, the motor 8 always produces a driving force, and the cylinder 9 produces a driving force substantially in proportion to the output of the motor 8.

FIG. 3 is an output characteristic diagram at the time of stop. The X axis is the weight W of the cargo 2. The Y axis is the output P. Pa
Indicates the output corresponding to the weight of the arm 1. Line A is the output of cylinder 9. The line B is the output of the motor 8. The line C is an output obtained by combining the motor 8 and the cylinder 9. Operation lever 1
7 is neutralized, a stop command signal 28 is output from a potentiometer (not shown), and the arm 1 is stopped by the motor 8 and the cylinder 9. When there is no cargo 2, the weight of the arm 1 is always reduced by the motor. 8 is output, and when there is cargo 2, the supply power 31 and the supply pressure 3 are set according to the weight of the cargo 2.
5 changes.

FIG. 4 is an output characteristic diagram at the time of rising. The X axis is the weight W of the cargo 2. The Y axis is the output P. Pa
Indicates the output corresponding to the weight of the arm 1. Line A is the output of cylinder 9. The line B is the output of the motor 8. The line C is an output obtained by combining the motor 8 and the cylinder 9. Operation lever 1
7 is tilted upward, a potentiometer (not shown) outputs an ascending command signal 28 corresponding to the tilt angle, and the motor 8
Then, the arm 1 is raised by the output of the cylinder 9. The motor 8 is controlled so that the rising command signal 28 and the speed signal 38 become equal.
And the pressure supplied to the cylinder 9 is varied so that the motor output signal 32 and the pressure signal 42 become equal. Therefore, the supply power 3 according to the weight of the cargo 2
1 and the supply pressure 35 are both variable. Further, the supply pressure 35 to the cylinder 9 feeds back the speed signal 38 to suppress the supply pressure 35 at the time of light load, thereby suppressing the hunting phenomenon.

FIG. 5 is an output characteristic diagram at the time of lowering. The X axis is the weight W of the cargo 2. The Y axis is the output P. Pa
Indicates an output P corresponding to the weight of the arm 1. Line A is cylinder 9
The output when the load 2 is zero to Wn is zero. The line B is the output of the motor 8, and when the load 2 is zero to Wn, the output Pa is equal to or less than the own weight of the arm 1 and when the load 2 is Wn, the output Pa is the own weight of the arm 1. The line C is an output obtained by combining the motor 8 and the cylinder 9. When the operating lever 17 is tilted downward, a lowering command signal 28 corresponding to the tilt angle is output from a potentiometer (not shown), and the arm 1 is lowered by the output of the motor 8 and the cylinder 9. The power supply 31 to the motor 8 is varied so that the descending command signal 28 is equal to the speed signal 38, and the supply pressure 35 to the cylinder 9 is varied so that the motor output signal 32 is equal to the pressure signal 42. Therefore, both the supply power 31 and the supply pressure 35 are varied according to the weight of the cargo 2.

The characteristic diagrams shown in FIGS. 3, 4 and 5 vary depending on the output characteristics of the motor 8 and the cylinder 9, and are not necessarily straight lines.

The operations of lowering, grasping, raising, stopping, and separating will be described with reference to FIGS. 1, 2, 3, 4, and 5. FIG.

In the case of lowering, the operator grasps the operating lever 17 and tilts it down, and a potentiometer (not shown) outputs a lowering command signal 28 corresponding to the tilting angle. The descending command signal 28 is supplied with power 31 supplied to the motor 8 via a gain circuit 29 and a phase control circuit 30, and at the same time, a motor output detector 33 and an electric / pneumatic converter 34 such as an electropneumatic proportional valve. Supply pressure 35 to the cylinder 9 is supplied. The speed detector 20 feeds back the speed signal 38 to the summing point 36 and the summing point 37, and a part of the speed signal 38 is converted into a torque deviation signal 40 by the integrator 39.
Feedback to The pressure detector 41 feeds back the pressure signal 42 to the summing point 37. Therefore, the motor 8 is controlled so that the descending command signal 28 and the speed signal 38 become equal.
Supply power 31 to the cylinder 9 so that the motor output signal 32 and the pressure signal 42 become equal.
5 changes the arm 1 and the command device 18 to the position where the cargo 2 is hooked on the hook 19 with the characteristics shown in FIG.

When gripping the cargo 2, the operation lever 1
7 is a stop command, the arm 1 and the command device 18 are connected as shown in FIG.
And the hook 19 is hooked on the cargo 2 to grip the cargo 2 on the floor.

In the case of ascending, when the operator inclines the operating lever 17 from neutral to upward, an ascending command signal 28 corresponding to the inclination angle is output. The supply power 31 to the motor 8 is varied so that the rising command signal 28 and the speed signal 38 are equal, and the supply pressure 35 to the cylinder 9 is varied so that the motor output signal 32 and the pressure signal 42 are equal. so,
The arm 1 and the command device 18 are raised with the characteristics shown in FIG.

In the case where the operation lever 17 is stopped in the air, when the operator sets the operation lever 17 to the neutral position from the rising command, a stop command signal 28 is output. The power supply 3 to the motor 8 is controlled so that the motor 8 is stopped immediately by the stop command signal 28.
1 is varied, and the supply pressure 35 to the cylinder 9 is varied so that the motor output signal 32 becomes equal to the pressure signal 42, thereby stopping the arm 1 and the command device 18 with the characteristics shown in FIG.

In the case of unloading the cargo 2, when the operator grasps the operating lever 17 and tilts it downward, a descending command signal 28 corresponding to the tilt angle is output. The power supply 31 to the motor 8 is varied so that the descending command signal 28 and the speed signal 38 are equal, and the supply pressure 35 to the cylinder 9 is variable so that the motor output signal 32 and the pressure signal 42 are equal. Then, the arm 1 and the command device 18 are lowered with the characteristics shown in FIG. 5 until the cargo 2 lands on the floor. Next, when the operation lever 17 is set to a stop command, the arm 1 and the command device 18 are stopped with the characteristics shown in FIG. 3, and the cargo 2 is removed from the hook 19.

[0018]

According to the present invention, since the motor 8 and the cylinder 9 are engaged and used, the reduction gear 7 such as a gear connected to the motor 8 and the drive unit 3 can be reduced in size as compared with an electric cargo carrier. Thus, parts can be shared with existing cargo handling machines. Further, since the dynamic load is reduced by the cushion of the cylinder 9, it is possible to cope with a low arm rigidity. Compared to the air-type cargo handling machine, when the cargo 2 falls, the jump of the arm 1 is held by the electromagnetic brake 21 so that there is almost no jump. Therefore, there is a great effect that the reduction gear 7 and the drive unit 3 can be simplified and downsized, and the cargo handling machine 27 having excellent safety can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a general view of an embodiment.

FIG. 2 is a block diagram showing a control system.

FIG. 3 is an output characteristic diagram during stop.

FIG. 4 is an output characteristic diagram at the time of rising.

FIG. 5 is an output characteristic diagram at the time of falling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arm 2 Cargo material 3 Drive part 4 Revolving table 5 Body plate 6 Ball screw 7 Reduction gear 8 Motor 9 Cylinder 10 Rail guide 11 Tube part 12 Rod part 13 Movable plate 14 Force point 15 Support point 16 Working point 17 Operating lever 18 Command device 19 Hook Reference Signs List 20 speed detector 21 electromagnetic brake 22 control circuit board 23 pipe 24 electric wire 25 power supply 26 air source 27 cargo handling machine 28 command device 29 gain circuit 30 phase control circuit 31 supply power 32 motor output signal 33 motor output detector 34 electricity / Pneumatic converter 35 Supply pressure 36, 37 Additional point 38 Speed signal 39 Integrator 40 Torque deviation signal 41 Pressure detector 42 Pressure signal

Claims (2)

[Claims] In a cargo handling machine for providing a commanding device to a balancing mechanism and transmitting a signal to an actuator by the commanding device to vertically move the cargo and hold it three-dimensionally, a motor and a cylinder are provided for the actuator. The motor is used by engaging and controlling the motor based on a command signal from the command device and a speed signal obtained from a speed detector or a position signal obtained from a position detector, and a motor obtained from a motor output detector. By controlling the cylinder based on the output signal and the pressure signal obtained from the pressure detector of the cylinder, the motor always generates a driving force, and the cylinder generates the driving force substantially in proportion to the output of the motor. A method for controlling a cargo handling machine, comprising: 2. The motor output signal obtained from the motor output detector, the pressure signal obtained from the pressure detector, and the speed signal from the speed detector or the position signal from the position detector. 2. The method for controlling a cargo handling machine according to claim 1, wherein the load state is determined based on the basis, and the cylinder is controlled.