JPH0597389A - Monitoring of anomaly of electromagnetic brake for stopping crane - Google Patents

Abstract

PURPOSE:To secure the resonable operation of a crane which maintains and improves the precision in the transport and operation of articles by a crane without requiring a large quantity of man's labor by monitoring the anomaly of an electromagnetic brake by comparing the slip quantity of the electromagnetic brake and a previously set slip quantity by a sequencer. CONSTITUTION:A position detector 4 reads out the position at the time point when the switch such as contactor 5a and limit switch 5b is turned OFF and sets the position into a sequencer 6. Then, the position detector 4 reads out the position at the time point when the revolution of an electric motor 2 used for traveling, hoist, suspension, etc., becomes zero and sets the position into the sequencer 6. Then, difference between the position at the time point when the switch is turned OFF and the position at the time point when the revolution of the electric motor 2 becomes zero is set as the slip quantity of an electromagnetic brake 5, and this slip quantity is compared with a previously set slip quantity by the sequencer, and if a deflection or a prescribed difference exists between both, an alarm S is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane used for moving an article in the front-rear direction, left-right direction, up-down direction, tilting direction, etc., and is used for monitoring abnormality of an electromagnetic brake when the movement is stopped. The present invention relates to an abnormality monitoring method for a stop electromagnetic brake.

[0002]

2. Description of the Related Art Cargo handling machines used for moving goods include hoisting units such as chain blocks, hoists and table lifters, cranes such as jib cranes, wall cranes, overhead cranes and bridge cranes. ,
There are various types such as mobile cranes such as truck cranes and wheel cranes.

[0003] For example, in an overhead crane, a ladle crane used for moving and operating a ladle is provided with a girder that moves along the ceiling, a main club and an auxiliary club installed on the girder, and the main club. There is also a structure having a main winding hook (ladle hook) and an auxiliary winding hook provided on the auxiliary club.

Similarly, in an overhead crane, a steel ingot crane used to transport an ingot holds a steel rod that moves along the ceiling, a club provided in the digit, and a steel ingot provided in the club. There is a structure having a tongue and an auxiliary winding hook provided on the club.

[0005]

In a crane used for carrying or operating such articles as a ladle and steel ingot, the accuracy of carrying or operating is maintained / improved, and the operation of the crane that does not rely on human labor is rationalized. However, there was a problem that early detection and repair of abnormal crane parts were required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and monitors the slip amount of an electromagnetic brake used for deceleration, among acceleration / deceleration control during traveling by a crane, hoisting and lowering. By doing so, the occurrence of abnormal electromagnetic brakes due to such an increase in the amount of slip of the electromagnetic brakes is monitored, and the electromagnetic brakes are always kept in a normal state to maintain or improve the accuracy of transportation of goods by a crane or manual operation. The objective is to rationalize crane operation, which does not rely on much, and to enable early detection and repair of abnormal parts of the electromagnetic brake.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a contactor and a limit switch provided for an electromagnetic brake when monitoring an abnormality during braking of an electromagnetic brake used for stopping traveling such as traveling by a crane and hoisting or lowering. The position detector reads the position at the time when the switch is turned off into the sequencer, and then the position detector reads the position at the time when the motor rotation becomes zero into the sequencer.
The difference between the position at the time when the switch provided for the electromagnetic brake is turned off and the position at the time when the rotation of the motor becomes zero is taken as the slip amount of the electromagnetic brake, and this slip amount and the preset slip amount In order to solve the above-mentioned conventional problems with the configuration of the invention relating to the abnormality monitoring method for the electromagnetic brake for crane stop, Is used as a means.

[0008]

In the abnormality monitoring method for the electromagnetic brake for stopping the crane according to the present invention, the position detector reads the position at the time when the switches such as the contactor and limit switch provided for the electromagnetic brake are turned off by the position detector. After that, the position detector reads the position at the time when the rotation of the electric motor used for traveling, hoisting, hoisting, etc. becomes zero, and the switch for the electromagnetic brake is turned off. As the slip amount of the electromagnetic brake, the difference between the position at and the position at the time when the motor rotation becomes zero is taken as the slip amount of the electromagnetic brake, and this slip amount and the preset slip amount are compared in the sequencer and there is a gap between the two. At certain times or when a predetermined difference occurs between the two, an alarm is issued to monitor the electromagnetic brake for abnormalities. Abnormalities in the electromagnetic brake during operation will be discovered early, and by carrying out appropriate repairs, the accuracy of transportation or operation of items such as ladle and steel ingot will be maintained or improved, and crane operation that does not rely heavily on human labor The rationalization of is realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an abnormality monitoring control system used in an embodiment of an abnormality monitoring method for an electromagnetic brake for stopping a crane according to the present invention, in which reference numeral 1 denotes an article such as a ladle or a steel ingot. An electric motor control panel for performing control when performing left-right front-back movement, vertical movement, tilting or tipping movement, 2 is an electric motor controlled by the electric-motor control panel 1, and 3 is a speed of the electric motor 2. This speed detector 3 is a speed detector for
The structure is such that the speed is obtained by the number of pulses generated per hour.

Reference numeral 4 indicates the position at the time when the switches such as the contactor 5a and the limit switch 5b provided for the electromagnetic brake 5 are turned off, and the position at which the rotation of the electric motor 2 becomes zero thereafter. In this embodiment, the position detector 4 has a structure for detecting the position by the number of integrated pulses from the reference position.

Further, 6 is a sequencer, which inputs the position at the time when the switches such as the contactor 5a and the limit switch 5b provided for the electromagnetic brake 5 are turned off through the position detector 4 and thereafter. The first detector 6a is provided with which the position detector 4 inputs the position at the time when the speed detector 3 detects that the rotation of the electric motor 2 has become zero. The difference between the position when the switches such as the contactor 5a and the limit switch 5b provided for the brake 5 are turned off and the position when the rotation of the electric motor 2 becomes zero is output as the slip amount of the electromagnetic brake 5. To do.

Further, the sequencer 6 compares the slip amount of the electromagnetic brake 5 output from the first control section 6a with a preset slip amount, and when both slip amounts are different or both slip amounts are different. A second controller 6b that outputs an alarm output S when there is a predetermined difference in slip amount,
The adjustment of the difference between the two slip amounts when the alarm output S is issued in the second controller 6b is performed by the set value adjuster 6
It is to be adjusted in c.

In the abnormality monitoring control system of the electromagnetic brake shown in FIG. 1 having such a configuration, the time t ₁ shown in FIG.
Until then, the electric motor 2 rotates at a desired operation speed, and the overhead traveling of the crane at a desired speed, hoisting at a desired speed, lowering at a desired speed, and the like are performed.

After that, when a stop command is issued at time t ₁ in FIG. 2, the switches such as the contactor 5a and the limit switch 5b provided to the electromagnetic brake 5 are turned off at time t ₂ after a short time. However, the position at the time (t ₂ ) when it is turned off is input from the position detector 4 to the first controller 6a of the sequencer 6 and read.

Further, deceleration is continued and the electromagnetic brake 5
When the speed detector 3 detects that the rotation of the electric motor 2 has become zero at the time t ₃ in FIG. 2 due to the braking by the motor, and the rotation of the electric motor 2 becomes zero correspondingly (t ₃ ).
The position at 4 is input to the first controller 6a of the sequencer 6 from the position detector 4 and read.

In the first controller 6a, the position and rotation of the electric motor 2 at the time (t ₂ ) when the switches such as the contactor 5a and the limit switch 5b provided in the electromagnetic brake 5 are turned off are zero. the difference between the position in the became time (t ₃₎ is calculated as the slip amount L of the electromagnetic brake 5 as shown in FIG. 2, it is preset in the second controller 6b of the sequencer 6 and the deceleration distance L The slip amount is compared, and an alarm output S is issued if there is a deviation or a predetermined difference.

When the alarm output S is issued, the cause of the slip amount of the electromagnetic brake 5 not being a predetermined value is investigated, and the lining of the electromagnetic brake 5 is appropriately repaired.

As shown in Table 1, in a ladle crane for transporting and operating a ladle in one embodiment, as shown in Table 1, when the electromagnetic brake 5 is braked during the main hoisting of the main hoist for raising and lowering the ladle. The set value is set to 10 mm, and the set value of the slip amount at the time of braking the electromagnetic brake 5 at the time of auxiliary lowering of the auxiliary winding for tilting the ladle is set to 13 mm, and the slip at the time of braking the electromagnetic brake 5 at the time of traveling. The set value of the amount was 50 mm.

Further, as also shown in Table 1, the actual value of the amount of slip when the electromagnetic brake 5 is braked when the main hoist is lowered is 6 mm, and the slip when the electromagnetic brake 5 is braked when the auxiliary hoist is lowered. The actual value of the amount is 9 mm, and the actual value of the amount of slippage during braking of the electromagnetic brake 5 during traveling is 30 mm. Therefore, the electromagnetic brake 5 is determined to be normal, but when the above set values are exceeded, The second controller 6b of the sequencer 6 outputs an alarm output S to issue an alarm indicating that the electromagnetic brake 5 is abnormal.

[0020]

[Table 1]

By doing so, it becomes possible to detect the abnormality of the electromagnetic brake 5 early during the traveling by the crane, the main hoisting lowering and the auxiliary hoisting lowering.

[0022]

The abnormality monitoring method for the electromagnetic brake for stopping a crane according to the present invention provides an electromagnetic brake for monitoring abnormality during braking of the electromagnetic brake used for stopping traveling, hoisting, lowering, etc. by a crane. The position detector reads the position at the time when the contactor, limit switch, and other switches are turned off.
After that, the position at the time when the rotation of the electric motor becomes zero is read into the sequencer by the position detector, and at the time when the switch provided to the electromagnetic brake is turned off and when the rotation of the electric motor becomes zero. The difference from the position of the electromagnetic brake is used as the slip amount of the electromagnetic brake, and this slip amount is compared with the preset slip amount in the sequencer to monitor the electromagnetic brake for abnormalities. By monitoring the slip amount of the electromagnetic brake at the time of braking, it becomes possible to detect abnormalities of the electromagnetic brake at an early stage, and by appropriately repairing the brake lining, etc. Maintaining or improving the accuracy of transportation or operation,
It is possible to realize a remarkably excellent effect that the rationalization of the crane operation that does not rely on many human hands is realized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an abnormality monitoring control system adopted in an embodiment of an abnormality monitoring method for a crane stopping electromagnetic brake according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between speed and time at the time of deceleration and braking in an embodiment of the abnormality monitoring method for the electromagnetic brake for stopping a crane according to the present invention.

[Explanation of symbols]

 1 Electric Motor Control Panel 2 Electric Motor 3 Speed Detector 4 Position Detector 5 Electromagnetic Brake 5a Electromagnetic Brake Contactor (Switch) 5b Electromagnetic Brake Limit Switch (Switch) 6 Sequencer 6a First Control Section 6b Second Control Section 6c Set Value Regulator

Claims (1)

[Claims] 1. When monitoring an abnormality during braking of an electromagnetic brake used to stop traveling such as traveling by a crane or hoisting or lowering, when a switch such as a contactor or a limit switch provided for the electromagnetic brake is turned off. Position is read by the position detector to the sequencer, and then the position at the time when the rotation of the motor becomes zero is read by the position detector to the sequencer and the position at the time when the switch provided for the electromagnetic brake is turned off. And the position at the time when the motor rotation becomes zero as the slip amount of the electromagnetic brake.Compare this slip amount with a preset slip amount in the sequencer to monitor the electromagnetic brake for abnormalities. A characteristic method for monitoring abnormalities of electromagnetic brakes for stopping cranes.