Automatic scribing device for side edges of plates

An air cylinder is fixed above the side edge of a plate through a supporting frame, a marking pen for marking is fixed at the front end of the air cylinder, the air cylinder is connected with a two-position five-way electromagnetic valve through a flexible air pipe, a meter counting wheel is placed on the marked composite plate, and the meter counting wheel is connected with the marking pen. A control part of the electromagnetic valve and the meter counting wheel is connected with a programmable logic controller (PLC), a touch screen is communicated with the PLC, a scribing position and a scribing length are input on the touch screen, and a required line segment can be scribed on the side edge of a plate. The marking device can automatically mark a marking line with a required length at any position on the side edge of a plate according to processing requirements, and an original manual marking mode is improved into an automatic positioning mode of mechanical marking, so that the laborcost is saved, the labor