Working machine lifting device of tractor

A working machine lifting device of a tractor, comprising:

• an externally installed hydraulic cylinder for lifting a working machine and controlling the attitude of it;
• a valve casing having a first surface;
• a hydraulic valve for supplying hydraulic oil to the cylinder;
• and
• a pipe disposed in the valve casing so as to communicate ports of the hydraulic valve to each other.

A working machine lifting device of a tractor, comprising:

• an externally installed hydraulic cylinder;
• a cylinder cover covering the outer periphery of the cylinder so as to protect the cylinder;
• a lift arm rotated by operation of the cylinder, the lift arm having a portion onto which an upper portion of the cylinder cover is attached;
• and
• a lower link vertically rotated by rotation of the lift arm and connected to a working machine.

A working machine lifting device of a tractor, comprising:

• an externally installed hydraulic cylinder having a piston rod;
• a lift arm rotated by operation of the cylinder, the lift arm having a longitudinally intermediate attaching portion onto which the cylinder is attached, and a slot formed in the attaching portion;
• a roller provided on a tip of the piston rod and slidably inserted in the slot;
• and
• a lower link vertically rotated by rotation of the lift arm and connected to a working machine.