Maanshan Zhicheng Mechanical and Electrical Co., Ltd. and Zhongye Huatian Engineering Technology Co., Ltd. jointly developed a cold flying shear unit. The flying shear is a double crank connecting rod structure with a maximum shear knife of 4500 kN, fastening speed of the shearer is 1 m~1.5 m/sec, and the length of the fixed length is 6 m. Unlike the previous fixed cold shear, the flying shear can realize moving shear without the need of the fixed-scale shear. Fixed length, so it has a high working efficiency. It can meet the demand of 800-1.2 million tons of profiles and bars workshop per year.

　　Then the small edition will introduce the common troubleshooting of cold flying shear to you.

　　1. Loosening of locking nuts for four post tie rods of cold flying shear

　　Reasons: When assembling the cold shear, the lengths of the four pillar tie rods are uneven and have not been adjusted to the same level, resulting in the uneven force of the four pillar tie rods, which makes one or two of the pull rod nuts easy to loosen.

　　Solution: Re-adjust the four tie rods to the same level, if the length is different, add gaskets appropriately.

　　2. The gap between upper and lower shears is variable and unstable.

　　Reasons: The copper sleeve matched with the four columnar tie rods of cold shear is worn seriously, which increases the gap between the columnar and copper sleeve, and causes the change of the gap between upper and lower cutting edges.

　　Solution: Replace the copper sleeve of the column.

　　3. The coincidence degree of upper and lower cutting edges has changed.

　　Reasons: The wear of the copper bush of the mandrel at the connection between the upper cutter seat and the crankshaft bearing seat of the cold shear is serious.

　　Solution: Replace the mandrel and mandrel copper sleeve, and the clearance between mandrel and copper sleeve is controlled within 0.1-0.18 mm.

　　4. The coincidence degree of upper and lower cutting edges decreases

　　Reasons: The locking nuts at both ends of the four pull rods connecting the upper and lower tool holders are loose.

　　Solution: After tightening the locking nuts at both ends of the tie rod, the anti-loosening block is welded beside it.

　　5. Loosening of fastening bolts of bearing seat in moving crankshaft of lower cutter base

　　Cause: The copper bush of the mandrel at the connection between the lower cutter seat and the bearing seat is worn seriously. The shear force is uploaded to the bearing seat, resulting in loosening or fracture of the connecting bolt of the bearing seat.

　　Solution: Check the gap between the mandrel and the copper bush regularly. The gap should be controlled below 3.5mm. If the gap exceeds this value, the mandrel and the copper bush should be replaced in time.

　　In addition, the oil outlet of the dry oil lubrication pipeline should be inspected at any time to ensure the normal operation of the whole lubrication system.