NOVELTY - A water-assisted molding water hydraulic proportional system includes water hydraulic pump (8) having outlet, which is driven by a motor (7) and which connects a pressure control valve, reversing valve (12), and nozzle (14); accumulator (10) between the pressure control valve and water hydraulic pump; pressure sensor (16) for returning the pressure to a pressure controller (17) to form close loop control, where pressure controller receives the injection pressure instruction signal given by a computer to control the pressure control valve and further control the injection pressure.    USE - Used for carrying out the water-assisted plastic injection molding to a hollow plastic product.    ADVANTAGE - High-quality water-assisted molding production is achieved.    DETAILED DESCRIPTION - A water-assisted molding water hydraulic proportional system includes a temperature-controlled water tank, water tank temperature sensor, heater, water-temperature controller, water-temperature control instruction, filter, motor (7), water hydraulic pump (8), unloading overflow valve, accumulator (10), electromagnetic proportional reducing valve, two-position two-way electromagnetic reversing valve (12), injection water temperature sensor, nozzle (14), mold, pressure sensor (16), pressure controller (17), and injection pressure control instruction. The inlet of the water hydraulic pump driven by the motor connects the temperature-controlled water tank by the filter. The outlet of the water hydraulic pump connects the inlet of the unloading overflow valve. The outlet of the unloading overflow valve connects the temperature-controlled water tank. The unidirectional valve outlet and the liquid control mouth of the unloading overflow valve connect inlets of the accumulator and the electromagnetic proportional reducing valve. The outlet of the electromagnetic proportional reducing valve connects the inlet of the two-position two-way electromagnetic reversing valve. The pressure sensor is connected between the electromagnetic proportional reducing valve and the inlet of the two-position two-way electromagnetic reversing valve. The outlet of the two-position two-way electromagnetic reversing valve connects the nozzle; and the injection water temperature sensor is connected between them, which returns the temperature of the injection water to the input end of the water-temperature controller. The water tank temperature sensor is set in the temperature-controlled water tank. The sent electric signal is connected to the input end of the water-temperature controller. The water-temperature controller receives the water-temperature control instruction. The output end of the water-temperature controller connects the heater and adjusts the water temperature of the temperature-controlled water tank basing on the water-temperature control instruction. The pressure sensor returns the pressure at the outlet of the electromagnetic proportional reducing valve and connects the electric signal to the input end of the pressure controller. The pressure controller receives the injection pressure control instruction. The output end of the pressure controller connects the proportional electromagnet of the electromagnetic proportional reducing valve. The pressure at the outlet of the electromagnetic proportional reducing valve is the pressure of the injection water. The nozzle controls the water with the temperature and the pressure basing on the water-temperature control instruction and the injection pressure control instruction to enter the molding chamber of the mold, which acts on the plastic meld to carry out the water-assisted injection molding to the hollow plastic product.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic view of water-assisted molding water hydraulic proportional system.    Motor (7)    Water hydraulic pump (8)    Accumulator (10)    Reversing valve (12)    Nozzle (14)    Pressure sensor (16)    Pressure controller (17)