Steelmaker's personal technical summary

In the cold rolling operation area of ​​the xx Jingtang project department, he has experienced many large-scale special inspections during this period of time. Have a certain degree of understanding of the mechanical equipment of cold rolling and retreating. Combining several specific items of mechanical special maintenance, several common elements are summarized, namely gap, coaxiality and level. Handling these elements is of great help to the quality of the equipment we have overhauled. The following is a summary of the significance of each element in equipment overhaul.

Gap is also an item that is often overlooked. Although it looks small, if it is not handled properly, or it is not adjusted to the extent allowed by the error, it may affect normal production and even cause an accident. For example, the double-cutting shear edge gap of the inlet section is adjusted according to the different thickness of the strip. In general, the strip thickness is above 0.50mm, and the cutting edge clearance should generally be adjusted to about 0.20~0.30mm. It is not appropriate if the gap is too large or too small. Because the gap is too large, it is easy to cause the strip to be cut off smoothly. If the clearance is too small, the upper and lower cutting edges are prone to friction and damage the cutting edge. In addition, the gap between the brush roller housings on the cleaning section is also important. For example, in the special maintenance in May, the adjustment of the clearance of the cleaning section 1#brush 2# brush roller bearing seat. Due to the uneven thickness of the bearing pad, the brush roller bearing seat is excessively vibrated during operation and the gap changes due to thermal expansion and contraction during the production process. The specific adjustment method is to measure the gap of the brush roller bearing seat with the feeler gauge after the temperature is lowered after the shutdown, and then adjust the gap by adding 0.2 mm gasket on the large operation side according to the gap value. It can be raised and lowered normally to meet production requirements. In general, the brush bearing housing requires that the sum of the gaps on both sides is within the error range of 0.35 to 0.45 mm. If the bearing housing clearance is too large, the vibration of the brush roller during operation is too large. Due to the high rotation speed of the brush roller and the large load, the vibration is large for a long time, which may cause the brush roller to break. It can be seen that it is important to adjust the gap of the brush roller housing to the standard state. Finally, the gap between the end faces of the toothed coupling between the tension roller and the reduction gearbox is also included. The gap between the drive motor of the looper bottom roller and the end faces of the gearbox coupling of the reduction gearbox. In general, the clearance between the small motor and the toothed contact is guaranteed to be 6mm, and the error tolerance is ±0.05mm. The gap between the large motor and the toothed contact is guaranteed to be 10mm, and the error tolerance is ±0.05mm. After the export looper 1# tower 1# bottom roller motor is replaced, the tooth gap between the motor and the speed reducer is adjusted. Adjust the motor with the gearbox as the reference, use the dial indicator to make the coaxiality of the two hands, calculate the error value according to the dial gauge reading, and determine the thickness of the gasket. Raise the motor as a whole. That is, the radial error is adjusted to 0.3 to 0.5 mm. The gap between the end faces of the two hands is then measured with a feeler gauge and a gauge block. Control the gap value between 5.5 and 6.5mm. If the gap is too large, the transmission torque is unstable, which affects the normal operation of the gearbox. If the gap is too small, vibration occurs at high speed, and the end faces of the two handles are easily collided. Therefore, the adjustment of the end face clearance of the tooth is also an important parameter.

Coaxiality, also known as radial error. This factor is an important parameter when adjusting the furnace rolls. After replacing the furnace roll, after the bearing seat is installed, the horizontal and coaxiality of the furnace roll should be adjusted to ensure that the center line of the furnace roll coincides with the center of the bearing seat after the bearing is mounted on the bearing, that is, the two cores are coaxial. Before adjusting the coaxiality, you should first adjust the level of the roller with a level. Ensure that the roller level is about the same time, start to adjust the axial error, select four corresponding points a, b, c, d in the clockwise direction on the end face of the bearing seat. Under the theoretical situation, when the dial indicator turns over a week The readings of these four points should satisfy a+c=b+d. As long as one set of corresponding values ​​is read, another set of values ​​can be known. This is a very important conclusion in the adjustment of the axial error. It is practical, convenient, and accurate in practice. Can reduce a lot of time and improve work efficiency. Based on these two sets of data, the deviation of the bearing housing and the thickness of the foot gasket can be determined. First, in the vertical direction, if point a is used as the zero point of the measurement, the furnace roller is rotated, and when the dial indicator is rotated to point c, the reading is positive s, then the front and rear of the bearing housing are high and low. It is necessary to add a gasket to the rear foot or reduce the gasket of the front foot. This can be determined according to the actual situation. On the contrary, if the reading is negative, the bearing seat is low in front and high in the front, and the adjustment method is opposite to the former. In the same horizontal direction, the horizontal balance is achieved by adjusting the diagonal top wire on the foot of the bearing housing. The amount of adjustment of the top wire is still s/2. In short, this method uses a dial gauge to measure the error of the end face of the bearing seat, and determines the adjustment direction and the thickness of the gasket according to the measured data, thereby achieving the purpose of adjusting the coaxiality.

Level or parallelism. This factor has an important influence on whether the strip runs off. If the rollers are not parallel during operation, it will inevitably affect the tendency of the strip to walk. If the strip is too misaligned, it will affect the welding effect. When the tail is severe, the tail and the leader cannot be docked at all. For example, in the special maintenance project for cold rolling and retreating equipment in June, the parallelism of the 1# auxiliary pinch roller in the entrance area was adjusted. Due to the small tightening bolts of the pinch roller bearing housing, vibration occurs during long-term work, causing the upper roller bearing housing to loosen and the displacement to change. When the upper pressing roller is pressed, the two rollers are not parallel. The pressing force of the driving side hydraulic cylinder is larger than that of the operating side, and the strip runs away from the driving side. The adjustment method is that the upper pressing roller is removed, the level of the bottom roller is measured by a level meter, and the error is calculated according to the value to determine the thickness of the gasket. Flatten the bearing housing until the horizontal error reaches 0.03 to 0.08 mm. Then, use a steel wire to pull out a straight line parallel to the bottom roller, install the upper pressure roller, and adjust the bearing seat until the upper pressure roller is parallel to the steel wire. Fasten the bearing top wire to prevent loosening again.

I have not been working for a long time. Although I have a certain understanding of the cold rolling and retreating equipment, there are still many things to learn. Including the ability to handle, solve problems, etc. on the equipment... Learning is the property we carry with us. Where we are, our knowledge is with us. There is no end to learning. Only by continually studying hard can we give us unlimited wisdom; we can bring us real happiness. In the future work, we must work hard to learn from the masters, constantly improve our professional skills, and strive to learn from each other. It is the fundamental way to survive in such fierce competition, so as to better adapt to the development of the enterprise. need.