Assembly and Maintenance of Length Shears in Round Steel Production Line
Abstract: This paper introduces the production situation of the second bar operation in the No. 2 Steel Rolling Plant. Since the production line has been put into operation, it has mainly produced various types of round steel products. With the accelerated production rhythm and the increasing output, the cold shear system has become unstable, and there are often failures and shutdowns. After careful investigation by the technicians in our workshop, the cold shear clutch is frequently damaged during operation and the amount of thin oil in the cold shear system is too small. To solve the problem, technical transformation was carried out, and the cold shear clutch and brake assembly method was innovated, which effectively improved the stability of the equipment. Through the transformation and optimization of the cold shearing system in the second zone of the bar operation, the stability of the equipment is improved, the smooth production is ensured, and the maintenance of the staff is greatly reduced, and the labor intensity is reduced.
1. Overview of production status
The second bar production line of Xuangang No. 2 Steel Rolling Plant is one of the key projects for Xuangang to upgrade equipment level, plan product structure and realize the third leap. It was completed and put into operation in September 2014. The production line is designed by MCC Jingcheng, the heating furnace is contracted by MCC Southern Weishi Furnace Industry Co., Ltd., the Italian Danieli Company is responsible for the technical design of the rolling line, and the Danieli China Company is responsible for the equipment design of the entire line, the rolling line The technological design, equipment and equipment are at the domestic level. The designed products include round steel with a diameter of φ14～φ90mm and ribbed steel bar with a diameter of φ20～50mm. The product structure is mainly round steel. The entire production line is equipped with 18 Danieli short stress line rolling mills And four KOCKS three-high reducing and sizing rolling mills, the original process design is that the Danieli rolling mill provides different intermediate material types according to the size of the finished product, and the finished product is rolled by the KOCKS rolling mill. The main varieties include carbon steel, alloy structural steel, spring steel, bearing steel, etc. With the implementation of the company's "general to excellent, excellent to special" production and operation policy, it has become the consensus of leaders at all levels to seek benefits from variety steel and market from variety steel. With the implementation of the company's production and operation policy of "general to excellent, excellent to special", it has become the consensus of leaders at all levels to seek benefits from variety steel and market to variety steel, and the second bar operation area production line is the company's variety steel Demonstration of the production line, do a good job in round steel production, and ensure the quality of round steel shearing has become an urgent matter.
2. Introduction of sizing shears and clutch usage
The fixed cold shear of Xuangang's high-strength bar production line, scientific name fixed-length shear, is the key equipment for cutting the finished double-length bar into the fixed-length bar, and the fixed-length shear is also an important equipment to ensure the cutting accuracy of the finished product.
During the working process of the cold shear, because the action between the brake and the clutch is required to be highly responsive and the action frequency is relatively fast, the friction plates and steel discs are seriously worn. After the friction plates and steel plates are worn to a certain extent, the it is replaced. Since clutches and brakes are provided with release springs, the entire set of clutches and brakes must be removed every time the friction plates or steel discs are replaced so that the position of the release springs does not deviate, so as to ensure the assembly accuracy of the friction plates and steel plates. Due to frequent disassembly and assembly of the whole set of clutches and brakes, the bottom sub-ports and bolt bottom buckles will be damaged, which will reduce the assembly accuracy of the equipment and increase the difficulty of maintenance. Cold shear damage accidents often occur in high-strength bar production lines. The traditional disassembly and assembly process is very cumbersome, taking more than 6 hours, and the maintenance work is labor-intensive.
3. Technical scheme of clutch transformation
In order to solve this technical problem, the quick replacement method of clutch brake friction plate and steel disc adopts the following technical solutions:
A method for quick replacement of friction plates and steel discs of clutches and brakes. The tools used include hexagonal inner hexagonal compression bolts of the friction plates (drill 8mm threaded holes every 120 degrees on the circular casings on both sides of the heat dissipation ports of each layer of the clutch and brake). , a total of 3 drilled), compression bolt support seat and support seat fixed hexagon socket bolt (select 8*60 full-button hexagon socket head bolt as the bearing seat fixing bolt), Ф14*100 cone head hexagonal friction plate compression bolt (The length of the cone head part is 10mm, and the unthreaded length above the cone head is 10mm), the compression bolt support seat (the overall size of the support seat is 75 × 40 × 40, and the bottom is milled with 40 × 20 × 30 grooves, concave The size of the groove matches the circular shell on both sides of the heat dissipation port. The upper center is drilled with a Ф10×20 through hole to pass through the fixing bolt of the support seat, and the Ф14×40 threaded through hole is set around it to support the friction plate. bolt).
The compression bolt support seat is sleeved on the circular shell on both sides of the heat dissipation port, the compression bolt support seat is fixed on the heat dissipation port shell with the support seat fixing bolt, and the friction plate compression bolt is screwed into the support seat with Ф14×40 thread in the through hole. In this way, as long as the friction plate pressing bolts are tightened, the friction plate and steel plate can be fixed. When the outer friction plate and steel plate are removed, the inner friction plate and steel plate will not be displaced due to the absence of pressure. When installing, follow the above steps in reverse. In this way, the clutch and brake can quickly replace the friction plates and steel discs layer by layer online.
4. Quick replacement method of clutch brake friction plate and steel disc
A 40×20×30 groove is milled at the bottom of the compression bolt support seat, and its size matches the circular shell on both sides of the cooling vent. The unthreaded part and the taper head of the hexagon socket head cap bolt of the friction plate are machined by a lathe, and its axis is parallel to the axis of the bolt. Because the surface roughness of the friction plate and the steel plate must be guaranteed during the replacement process, the threaded part of the compression bolt cannot directly contact the friction plate and the steel plate. It ensures that the surface of the friction plate is not damaged and can be pressed and fixed to the friction plate. The specific implementation of the utility model: first, the airbags of the clutch and brake are degassed, and the fixing bolts of the support seat can be passed through the through holes of the support seat, and are connected with the 8mm threaded holes on the circular casing on both sides of the heat dissipation port of each layer of the clutch or brake. connected to secure the support base. The friction plate pressing bolt is screwed into the threaded through hole of the support seat, and the friction plate can be compressed after gradually screwing in, so as to ensure that the release spring will not deviate due to the loosening of the friction plate. At this time, after the clutch and brake are exhausted, remove the clutch airbag, and then remove the friction plates and steel discs one by one.
5. Solve the problem that the amount of thin oil in the cold shear system is too small
The original design of the cold shear thin oil system has no spare pump; the pipeline is connected with 1.5 inches, and the flow rate is too small, which may lead to the shutdown of the cold shear because the flow rate cannot meet the specified requirements; the oil pump inlet adopts a single filter element, which cannot realize the online replacement of the filter element and cannot guarantee the equipment. quality of oil used. In view of the small flow of thin oil in the cold shear system, we discussed in our workshop and decided to connect the cold shear thin oil system with the thin oil station of the kockes rolling mill system, and throw away the original system, thus solving the problem of low flow of the cold shear thin oil system. , so as to ensure the normal operation of the equipment.
6. Conclusion
Through the implementation of a series of transformations, the stable operation of the cold shear system in the second zone of the bar operation has been effectively guaranteed, and the accident time has been reduced. Compared with before and after the implementation, the damage accidents of the cold shear clutch have been reduced. The quick replacement method of clutch brake friction plates and steel discs is the first design at home and abroad. It is quick and convenient to replace the clutch brake friction plates and steel discs. Since there is no need to disassemble and assemble the clutch brake as a whole, the service life of the clutch brake is greatly prolonged. The method has the advantages of strong practicability, reliable work, simple operation, simple maintenance and low cost.
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