The shearing machine is very important in modifying the size of the plate. In practical applications, we often encounter various types of plates, many of which are trimmed by this equipment. So how does the device adjust the unbalanced current problem?
1. Use auto-converter for compensation: usually install auto-converter on the current transformer on one side of the transformer, connect LH output end to the input end of the converter, when changing the ratio of auto-converter At this time, the output current of the converter can be equal to the secondary current of the LH without the converter, so that the current flowing into the CNC or NC shearing machine differential relay is zero or close to zero.
2. Use the balance coil of the intermediate converter for magnetic compensation: usually, the main coil or differential coil is wound on the iron core of the intermediate converter of the shearing machine, which is connected to the differential current. Besides, a balance coil and a second coil is connected to the side with the smaller secondary current. You should correctly choose the number of turns of the balance coil so that the magnetic potential energy generated by the balance coil completely cancels the magnetic potential generated by the differential coil.
3. The differential relay with magnetic braking characteristics is adopted: the differential relay of the transformer is based on the fast saturation converter, adding a set of braking coils, and the shearing machine uses the short-circuit current in the event of an external fault to achieve braking so that the starting current of the relay increases with the increase of the braking current, it can reliably avoid the unbalanced current during the external short circuit of the transformer, and improve the sensitivity of the internal fault of the transformer.
The current imbalance of the shearing machine can be adjusted in the above manner, which can improve the operating efficiency of the equipment and also extend the service life of the machine.
What to do with hydraulic clamping of shears
The hydraulic shearing machine can cut the boards reasonably according to the user’s requirements. For the boards of the specified size, this kind of equipment is mainly used for operation, and some too longboards can be shortened. What should we do at this time in the case of hydraulic clamping?
1. The valve stuck phenomenon caused by burrs and dirt molded into the hydraulic components to slide and cooperate with the gap is usually called mechanical clamping. When the liquid flows through the gap between the valve core and the valve body, the radial force acting on the valve core causes the valve core to jam, which is called hydraulic clamping.
2. The shearing machine can reduce the occurrence of clamping by improving the processing accuracy of the valve core and the valve body hole, and improving the shape and position accuracy. At present, the shape accuracy of the valve core and valve body holes, such as roundness and cylindricity, can be controlled within 0.003mm, and hydraulic clamping will generally not occur when this accuracy is reached. The hydraulic machine opens several appropriate pressure-equalizing grooves on the surface of the valve core, and the voltage groove and the outer circle of the valve core are concentric. The tapered shoulder is adopted, and the small end of the shoulder faces the high-pressure area, and the kidney spool is radially centered in the valve hole.
3. Make the valve core or valve body hole vibrate with high frequency and small amplitude in the axial or circumferential direction. Carefully remove the burrs on the valve core shoulder and the tip of the valve hole sinking groove to prevent the shearing machine from damaging the valve core outer circle and the valve body hole. Improve the cleanliness of the oil.
If you encounter the problem of hydraulic clamping while using the shears, you must stop working at this time and adjust the internal accessories in time. Strengthen the lubrication of equipment to prevent hydraulic clamping.