Hydraulic-control Check Valve (with safety valve) (For front scarifier (optional)) 1. Check Valve 2. Screw Plug 3. Valve Body 4. Piston 5. Overflow Valve The hydraulic-control check valve with safety valve is mainly prevent the pressure variation of hydraulic cylinder and protect hydraulic cylinder from occurring abnormal pressure due to the foreign force. When the scraper plate is lifted to max. position, the traction frame is moved to end.
When traction frame has been in place and lifting limit is realized, the hydraulic-control check valve with safety valve installed on the lifting oil cylinder (left) of scraper plate is mainly prevent the work equipment from damaging due to the contact and collision. Operation When operate the operation rod to retract the oil cylinder, the oil enters into A1chamber from oil pump and pushes the check valve (1) and the oil flows to the top piston inside chamber on the head of oil cylinder through B 1 chamber. The oil on the bottom of oil cylinder flows from B 2 chamber to A 2 chamber and back to oil tank.
When operate the operation rod to extend the oil cylinder, the oil flows into the bottom of oil cylinder through B 2 chamber. When the pressure of A 2 chamber and B 2 chamber is increased, the piston (4) is pushed and pushes the check valve (1) to open. The oil on the head of oil cylinder flows to the throttle of check valve (1) from B 1 chamber and back to oil tank from A 1 chamber. When encounters any impact and vibration and the pressure of B 1 chamber is increased to abnormal value of 250 kg/cm 2 or more during the operation of machine, the overflow valve (5) is opened and oil flows to B 2 chamber and back to oil tank, which avoid the impact. 20-112