Open/close mold hydraulic loop system with mold protection

The invention provides an open/close hydraulic loop system with mold protection. The system is characterized by comprising a close mold steering valve which is connected with a system oil feeding end, and a differential valve connected with the close mold oil cylinder; the close mold steering valve is combined with the differential valve, so that the open/close mold time can be reduced, and the production efficiency can be improved. The system comprises an open mold back pressure valve which is connected with the system oil feeding end, so that the mold can be opened at slow speed, and rapid rebound of a moving platen caused by transient release of the clamping force produced by the machine hinge deformation is avoided, and products are prevented from damage by pulling or the mold is prevented from damage. The system comprises a low pressure mold protective valve which is connected with a system oil return end; thus, when the mold is closed fast, if foreign bodies exist in the mold, and when the pressure is s