Method for testing the tightness of converter brake by using inverter torque control

Abstract

The present invention relates to the field of converter structure, and in particular to a method for testing the tightness of a converter brake by using a frequency converter torque control. A method for testing the tightness of a converter brake by using a frequency converter torque control is characterized by: performing the following steps in sequence: 1) detecting whether the sum of the braking torques of four brakes is normal; 2) detecting whether the braking torque of a single brake is normal. The present invention is easy to operate and reduces labor intensity.

Description

Technical Field

[0001] The invention relates to the field of converter structure, and in particular to a method for testing the tightness of a converter brake by using a frequency converter torque control. Background Art

[0002] At present, there is no direct test method for the tightness of the converter brake in China. Equipment maintenance personnel adjust the brake tightness according to the brake scale or experience. Due to the low accuracy of the scale and large differences, the brake is often not tight and the braking force is insufficient. Moreover, after the converter is loaded with molten iron, it is a variable torque load (zero position is the minimum, about ±90° is the maximum). If the brake is loose, it may not be reflected in time in production. After the brake is worn out after a period of use, the braking force decreases, and the brake tightness needs to be checked and adjusted regularly. Occasionally, the brake of domestic converters is loose, and the converter overturns to splash out the molten steel, causing significant economic losses. Summary of the invention

[0003] In order to overcome the defects of the prior art and provide a converter auxiliary testing means which is easy to operate and reduces labor intensity, the present invention discloses a method for testing the tightness of a converter brake by using a frequency converter torque control.

[0004] The present invention achieves the purpose of the invention through the following technical solutions:

[0005] A method for testing the tightness of a converter brake by using a frequency converter torque control is characterized by: performing the following steps in sequence:

[0006] ① Check whether the sum of the braking torques of the four brakes is normal:

[0007] After the converter is tilted to zero position, the four inverters for converter tilting are set to torque control mode, the brakes are closed, and the torque setting of each inverter is 1.5 times the rated torque of the motor. Then the converter is shaken forward and reverse in turn. If the converter does not move, it is determined that the braking torque of the four brakes is normal and the converter can be produced normally.

[0008] ② Check whether the braking torque of a single brake is normal:

[0009] After the test result of the sum of the braking torques of the four brakes is normal, the converter is tilted to zero position, and the four converter tilting inverters are all set to torque control mode, the brake is closed, the brake of the motor to be tested is released and then closed again, that is, only a single brake is opened, and the torque setting of the four inverters is 1.5 times the rated torque of the motor. The motor to be tested is first run in the forward direction, that is, only a single motor is run, and then the brake of the motor to be tested is released and closed again, and the motor to be tested is run in the reverse direction. If the pulse count of the speed feedback encoder of the motor to be tested in the forward and reverse operation is greater than the set value, it is judged that the brake of the motor to be tested is too loose;

[0010] Note: Using the gear backlash, the program protection is the same as method 1;

[0011] The method for testing the tightness of a converter brake by using a frequency converter torque control is characterized in that it also includes:

[0012] ③ Make the torque output of each motor increase at a certain slope to protect the equipment and mitigate the impact.

[0013] The method of using inverter torque control to test the tightness of the converter brake is characterized in that: in step one and step two, the adjustable torque of tilting a single brake is 1 to 2 times the rated torque of its motor, and the brake test is set with program protection. When the tilting time exceeds 2 seconds, or the tilting angle exceeds 5°, or the motor speed is greater than 5 Hz, the test is automatically stopped.

[0014] The present invention can effectively detect whether the tightness of the converter brake is appropriate, and has the following beneficial effects:

[0015] Equipment maintenance personnel can use the present invention to assist them in adjusting the brake clearance;

[0016] Production operators can use this method to test the brake tightness once every shift or every day to find out and deal with it in time;

[0017] The present invention does not need to dismantle the motor coupling, nor does it generate new equipment costs. It can be tested by only using the production gap, which takes up very little time.

[0018] The present invention can utilize the production interval time to test the tightness of the converter brake at any time, reduce the time for manual adjustment of the tightness of the brake, reduce the labor intensity of maintenance personnel, and reduce the impact on production. DETAILED DESCRIPTION

[0019] The present invention is further described below by means of specific examples.

[0020] Example 1

[0021] A method for testing the tightness of a converter brake by using a frequency converter torque control is implemented in the following steps:

[0022] ① Check whether the sum of the braking torques of the four brakes is normal:

[0023] After the converter is tilted to zero position, the four inverters for converter tilting are set to torque control mode, the brakes are closed, and the torque setting of each inverter is 1.5 times the rated torque of the motor. Then the converter is shaken forward and reverse in turn, that is, +1.5 times the torque is for forward shaking of the converter, and -1.5 times the torque is for reverse shaking of the converter. If the converter does not move, it is determined that the braking torque of the four brakes is normal and the converter can be produced normally.

[0024] The adjustable torque of a single brake is 1 to 2 times the rated torque of its motor. The brake test is set with program protection. When the tilting time exceeds 2 seconds, or the tilting angle exceeds 5°, or the motor speed is greater than 5 Hz, the test will automatically stop.

[0025] ② Check whether the braking torque of a single brake is normal:

[0026] After the test result of the sum of the braking torques of the four brakes is normal, the converter is tilted to zero position. The four converter tilting inverters are all set to torque control mode, the brake is closed, the brake of the motor to be tested is released and then closed again, that is, only a single brake is opened, and the torque setting of the four inverters is 1.5 times the rated torque of the motor. The motor to be tested is first run in the forward direction, that is, only a single motor is run, and then the brake of the motor to be tested is released and closed again, and the motor to be tested is run in the reverse direction, that is: +1.5 times the torque is for shaking the converter forward, and -1.5 times the torque is for shaking the converter in the reverse direction. If the pulse count of the speed feedback encoder of the motor to be tested in the forward and reverse operation is greater than the set value, it is judged that the brake of the motor to be tested is too loose;

[0027] The adjustable torque of a single brake is 1 to 2 times the rated torque of its motor. The brake test is set with program protection. When the tilting time exceeds 2 seconds, or the tilting angle exceeds 5°, or the motor speed is greater than 5 Hz, the test will automatically stop.

[0028] Step 2: Use gear backlash test;

[0029] ② Make the torque output of each motor increase at a certain slope to protect the equipment and reduce impact.

Claims

1. A method for testing the tightness of a converter brake by using a frequency converter torque control, characterized in that: Follow the steps below to implement: ① Check whether the sum of the braking torques of the four brakes is normal: After the converter is tilted to zero position, the four inverters for converter tilting are set to torque control mode, the brakes are closed, and the torque setting of each inverter is 1.5 times the rated torque of the motor. Then the converter is shaken forward and reverse in turn. If the converter does not move, it is determined that the braking torque of the four brakes is normal and the converter can be produced normally. ② Check whether the braking torque of a single brake is normal: After the test result of the sum of the braking torques of the four brakes is normal, the converter is tilted to zero position, and the four converter tilting inverters are all set to torque control mode, the brake is closed, the brake of the motor to be tested is released and then closed again, that is, only a single brake is opened, and the torque setting of the four inverters is 1.5 times the rated torque of the motor. The motor to be tested is first run in the forward direction, that is, only a single motor is run, and then the brake of the motor to be tested is released and closed again, and the motor to be tested is run in the reverse direction. If the pulse count of the speed feedback encoder of the motor to be tested in the forward and reverse operation is greater than the set value, it is judged that the brake of the motor to be tested is too loose; In step ① and step ②, the adjustable torque of tilting a single brake is 1 to 2 times of the rated torque of its motor. The brake test is set with program protection. When the tilting time exceeds 2 seconds, or the tilting angle exceeds 5°, or the motor speed is greater than 5 Hz, the test will automatically stop.