Printing head for 3D printer

The utility model relates to the technical field of printers. The utility model discloses a printing head for a 3D printer. The device comprises a conveying pipe, the conveying pipe is of a hollow structure with an opening in the bottom end. The top end of the conveying pipe is of a sealed structure; a matched piston is connected into the conveying pipe in a sliding manner; a convex rod is fixedlyconnected to the center of the upper surface of the piston; the other end of the convex rod penetrates through the top of the conveying pipe and extends upwards; the convex rod is in sliding connection with the top of the material conveying pipe; the top of the conveying pipe is fixedly connected with a bracket; a motor is fixedly installed at the other end of the support, an output shaft of themotor is connected with a cam, a matched roller is fixedly installed at the end, close to the cam, of the protruding rod, two sliding rods symmetrical about the protruding rod are fixedly connected tothe upper surface of the p