Relocation and electrical renovation of large sleepers
Our factory has a sleeper produced by Qinghai Heavy Machinery, model CQ61200, installed in 1989. The processing diameter is 2 000 mm and the length is 10 000 mm. Due to long-term use, electrical aging is severe and production is barely maintained. In the early stage of the factory process adjustment, to relocate this equipment, it also proposed a plan for electrical transformation. The original machine tool spindle electrical drag uses the FD drag system. The main problems of the speed control system are: 1Because there are two rotating motors with the same capacity as the speed regulating motor and one amplifier and exciter, there are many devices. It has the disadvantages of large area, low efficiency, high power consumption and high noise. 2 Due to the method of adjusting the excitation current, the response time of the DC motor is slow, the running precision is poor, and the speed regulation width is small. 3 The speed control system is complicated, resulting in low reliability of the control system and large maintenance workload, resulting in low production efficiency. 1. Determination of the electrical transformation plan The electrical part of the CW61200 sleeper is divided into tool holder control, spindle motor control, spindle shift control, and tailstock control. The following is a separate explanation of the program. (1) Tool holder control: The machine has two front and rear tool holders, each of which can be moved to the full distance. Each tool holder of the machine has a control panel, which can control the start of the spindle, acceleration and deceleration, and the forward and reverse movement of the tool holder. The original machine tool uses the tow wire to introduce the three-phase electricity into the junction box under the tool holder, and also uses the junction box. The tow line transmits the button signal for controlling the spindle back to the main control cabinet. Since the tow line moves in the pit, the pit is in front of the machine tool, and inevitably, the chip is dropped into the pit. For a long time, the chip will hinder the sliding of the wire on the wire, causing electrical failure such as an open circuit. This transformation specifically addresses this problem by applying a closed steel towline to protect the cable. In the actual transformation process, the installation of the steel towline needs to take into account the travel of the two tool holders, and whether the height of the steel towline affects The operator uses various factors such as the machine tool. (2) Selection of spindle motor driver: The original spindle motor is controlled by the Generator set. This set of equipment is relatively backward nowadays. When used, the noise is large, and the generator set must be constantly running and consumes a lot of energy. This transformation specifically proposed to replace the generator set with the Continental 590 DC drive. Main motor power 75kW, rated voltage 220V, rated current 384A, rated excitation voltage 220V, rated excitation current 11A. According to this, the Continental 590-380A DC drive unit was selected. The rated output current of the device is 380A, the maximum output current is 418A, the input voltage is AC380V, and the maximum output voltage is 400V, which can fully meet the requirements of power and withstand voltage. (3) Selection of spindle line reactor: Continental 590 DC drive is essentially a three-phase full-control bridge reversible rectifier power supply. According to the operating experience, the line reactor must be installed in the following situations to ensure reliable operation of the rectifier. 1 There is no rectifier transformer on the AC side of the rectifier module, and the line reactor should be installed. 2 DC converter should be equipped with line reactor. For more information, please download the attachment or view Metalworking (Cold Processing), Issue 19, 2013: Heat Gun,Heat Shrink Gun,Cordless Heat Gun,Electric Heat Gun Ebic Tools Limited , http://www.ebictools.com