JPS58207289A - Controller for winding of mobile travelling body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention r! :Relates to a hoisting control device for a mobile traveling body.

In conventional traveling moving objects such as cranes for single-hole cargo handling, squirrel cage induction motors are used as motors for jasper, traversing, and traveling, which are driven by variable voltage and variable frequency power sources. However, due to the characteristics of this squirrel cage induction motor, even if a starting command is given, the starting torque does not reach the required torque necessary to lift the load at once. Therefore, when using a squirrel cage induction motor for hoisting, and when starting it with a weighed load, the starting torque does not reach the required lifting torque even if a starting command is given, that is, the starting torque does not reach the lifting torque. If it is too small, the load will drop once, which may be dangerous for work. In order to solve this problem, in order to make the hoisting motor generate all the required hoisting torque at the time of starting, it is necessary to detect the torque of the motor, detect the slippage of the motor, detect the magnetic flux of the motor, or control the vector of the magnetic flux and current of the motor. Methods such as the following have been proposed, but all of these methods require separate, regular cracks 11, making the device complex and difficult to maintain.

The present invention has been made in view of this, and uses a variable voltage variable frequency power supply to start the motor in such a way that a squirrel-cage induction motor is used as the hoisting amount, and the load is lifted safely to the disaster victim. The output frequency and output voltage of the inverter are applied to the servo lifter of the servo lifter brake, and the drawbacks of the conventional system are solved with a simple configuration.

The invention will be described below based on illustrated embodiments.

Figure 1 is an example of applying the invention to an overhead crane operated by an operating device. In the figure, the overhead crane is equipped with a hoisting electric motor M l , a traversing electric motor M 2 , and a traveling electric motor M 3 , and each of the electric motors M as shown in FIG.

M2. M3 each has a hoisting inverter I1. At the crossroads, each motor is controlled by a variable voltage variable frequency inverter. A control device C8 is connected to these inverters, and each inverter I1. I2. I
3 is activated, and the control VCLL selectively activates the inverters for winding up and down, traversing, and traveling in response to commands from the operating device (gontrol in the driver's cab, pendant switch, etc.). A variable voltage with a variable frequency is supplied to drive the t excitation.

In addition, the operating device is equipped with all the speed setting devices for each of the inverters, and each inverter is connected to a group of resistors and a multi-function brake to absorb the regenerated power generated due to a sudden change in frequency.

Next, the winding portion will be explained.

The hoisting motor M1 is a rectangular induction motor, and the other shaft of the motor is connected to the drum 12 of a servo lifter brake CB, and the other -R1 is connected to the hoisting drum 5DK via a reduction gear ff1Gk.

Also, a variable voltage variable frequency inverter 11 is connected between the primary side of the hoisting motor M1 and the power supply, and the primary fllll'? of the servo lifter brake CB is connected. Connect each to the secondary side of the inverter.

The operation of the device configured as described above will be explained first by giving a hoisting command by pressing a hoisting button such as a push button switch using the operating device C. If this time is 1t-o, the hoisting inverter 1 operates through the control device @C8'i, and the output frequency F1 of the inverter increases the output voltage V from the lowest values Fo and Vo, and 11
In time the husband k Ftl, Vtl Ic is reached.

The motor starting torque TO is smaller than the maximum load torque Tm.

At t-tl, the motor torque Ttl is larger than the maximum load torque Tm. At this time t1, if the inverter is set so that it can apply electricity to the motor of servo 7 and CB at the inverter output frequency Ftl and output voltage Vtl to release the operating brake, then after time t1 the electric motor M1 Startup starts and completes at time t2.

Fig. 6: Characteristics of motor torque T1 inverter output frequency F1 inverter output voltage V during time t-0 (when operating device commands) t-tl (when brake is released) t-t2 (when motor startup is completed) It is clear from the above explanation that at t-o, the motor starting torque TO is smaller than the required torque TmL to output the load, so the servo lifter brake tl'lFo,V.

Depending on the situation, it is not released and the full load is retained and the cart does not descend once. At t-t2, the motor torque becomes tl>tm, and at the same time Ftl.

When Vtl is applied, servo 7 CB is released for the first time, and the hoisting motor of the crane starts to start and hoist the load. As the output frequency and output voltage of the inverter increase over time, the braking force is gradually relaxed, and t-t2
When this happens, the brake completely applies the inverter's output frequency to the motor of the servo lifter brake, and releases the brake after the motor torque exceeds the maximum load torque, so there is no risk of the load once dropping, ensuring safety. What are the advantages, such as being able to increase the amount of energy and the equipment is simple? have

[Brief explanation of drawings]

Figure 1 is a block diagram of a crane device to which the invention is applied, Figure 2 is a block diagram of a hoisting device, and Figure 3 is a graph of motor torque, inverter output frequency, outgoing voltage, and rotational speed over time. This is an explanatory diagram showing the change in temperature.・-・Reducer D...Hoisting device, ram Patent applicant Hitachi Kiko Kuri Co., Ltd. Agent Hayashi
1 person outside Akira Wei

Claims (1)

[Claims] In hoisting control of a moving body in which the drive motor is controlled by an inverter, the output frequency and output voltage of the inverter are applied to a servo lifter brake directly connected to the hoisting motor VC, and the hoisting motor is When the starting torque exceeds the required torque for lifting the load, the brake is released so that the load can be safely lifted without falling even if the starting torque of the motor is smaller than the required torque for lifting the load. A hoisting control device for a mobile traveling body, characterized in that an IC is used to perform hoisting.