The 1250 ton cold shear machine is a fixed-length shearing and cutting equipment for rolling pieces coming from the cold bed.

　　Structure of 1250 tons cold shear

　　3.1. Belt drive device: The main motor transfers motion to the flywheel through a triangular belt (the flywheel is connected with the passive pulley), and its transmission ratio is I1 = 2.3. At this point, the flywheel will save energy.

　　3.2. Hydraulic clutch, brake and reducer. When the clutch closes, the flywheel transfers motion to the reducer; when the clutch opens, the braking function will be realized, the reducer will stop working and the flywheel will idle. The speed ratio of the reducer is I1 = 30. Hydraulic clutch brake is an imported component. Hydraulic control system is manufactured in China.

　　3.3. Crankshaft and shearing device. The crankshaft is mounted on the frame with an eccentricity of 105mm. The crank cutter holder is mounted on the crankshaft, and the cutter holder moves up and down in the slideway of the frame. When the clutch closes, the reducer works and drives the crankshaft to rotate. The crank tool holder moves down rapidly from the high position to realize cutting (the blade is installed on the tool holder through the tool holder). After shearing, the crankshaft tool holder moves up with the crankshaft rotation. When moved to high position, the clutch opens and brakes immediately. At this point, the crankshaft stops running. Wait for the next cycle. The opening, closing and braking of clutch are realized by hydraulic system controlled by proximity switch.

　　3.4. The frame and frame are portal frame structures of cast-welded structures. The crankshaft is mounted in a copper alloy bush on the frame of 1250 tons cold shear machine. The tool holder is mounted in the slideway of the frame body. The slideway is made of copper alloy liner and fitted on the slideway. The skateboard has the function of adjusting the clearance between tool holder and slideway. The normal clearance is 0.1 mm to 0.25 mm. Excessive small or large clearance will affect the quality of section.

　　3.5. Blade clamping and replacement device. The blade is mounted on the upper and lower tool holders, the upper tool holder is mounted on the tool holder, the lower tool holder is mounted on the frame of 1250 tons cold shear machine, and the tool holder is mounted on the tool holder, which is pressed by several groups of butterfly springs. Hydraulic cylinders are installed at the rear of each group of butterfly springs. When the blade is replaced, it is controlled by hydraulic force. The piston of the hydraulic cylinder pushes the butterfly spring and loosens the tool seat so that the tool seat can be detached from the tool holder. At this time, the hydraulic cylinder piston in the frame pushes the cutter base more than half. The knife base can be lifted out by the crane. After the new cutter base is hoisted and put in place, the piston of the hydraulic cylinder can pull it into the cutter base and put it in place. At this time, the hydraulic cylinder piston on the butterfly spring rear seat withdraws. The butterfly spring tightens the knife base, thus realizing the replacement of old and new blades.

　　3.6. Material pressing device. Material pressing device is composed of material pressing head, lever and cylinder. Its function is to fix the shear firmly, so as to achieve stable shear. Its compaction is realized by hydraulic system controlled by electrical apparatus. The position of pressing material can be adjusted according to the size of shearing specification, which is completed by hydraulic cylinder.

　　The 1250 ton cold shear is driven by the top motor through the elastic coupling by the first gear reducer, the big gear sleeved on the crankshaft and the right half clutch fixed on the gear to rotate idly. When the cold shear starts to work, the roller of the brake device is sucked by the electromagnet. At this time, the left half clutch mounted on the crankshaft with the sliding key is pushed to the right by the spring and the right half clutch phase is added. By combining, the crankshaft is driven to rotate, and the scissors installed at the right end of the crankshaft can obtain straight up and down motion.

　　The upper cutting edge fixed on the scissors moves in a straight line with the scissors. The lower cutting edge is fixed on the frame and does not move. When the upper cutting edge falls down, the cutting of steel is realized. When the shearing is finished, the controller automatically operates to cut off the electromagnet, the roller of the brake device is pulled up and moved under the action of the spring to release the clutch, the crankshaft stops rotating, the shears are restored to the original maximum position under the action of the balance spring, and the 1250 tons of cold shears are reciprocating in this way to achieve the task of shearing the fixed length and the cutting head.