Injection system for die casting machine

An injection system for a die casting machine, comprising an accumulator, an injection cylinder, a pressurization cylinder and a valve module connected via an oil pipeline;

• wherein in a slow injection phase of the injection cylinder, the valve module is adapted for dynamic switching between a phase of an oil pump of the oil pipeline supplying oil alone and a phase of the oil pump and the accumulator jointly supplying oil;
• in a fast injection phase, a braking phase and a tracking phase, the valve module is configured to make a rod chamber of the injection cylinder to be conductive with the oil pump of the oil pipeline and an oil tank, to form a first A-type half-bridge structure;
• and
• in a pressurization injection phase, the valve module is configured to make a rod chamber of the pressurization cylinder to be conductive with the oil pump of the oil pipeline and the oil tank to form a second A-type half-bridge structure;
• wherein the valve module comprises a switching valve V4, a switching valve V5, a switching valve V6, a switching valve V8, a switching valve V12, a servo valve 7, a servo valve V9 and a unidirectional valve V11 and a unidirectional valve V13;
• an output end of the oil pump is connected to the rod chamber of the injection cylinder via the unidirectional valve V11 and the servo valve V9 connected in series in sequence to form a first oil pipeline;
• the output of the oil pump is connected to the accumulator via the switching valve V12 to form a second oil pipeline;
• the output of the oil pump is connected to a non-rod chamber of the injection cylinder via the unidirectional valve V11, the unidirectional valve V13, the switching valve V8 and the switching valve V5 connected in series in sequence to form a third oil pipeline;
• and
• the accumulator is connected to the non-rod chamber of the injection cylinder via the switching valve V4 and the switching valve V5 connected in series in sequence to form a fourth oil pipeline;
• the oil tank is connected to the rod chamber of the injection cylinder via the servo valve V7 to form a fifth oil pipeline;
• the accumulator is connected to a non-rod chamber of the pressurization cylinder via the switching valve V4 to form a sixth oil pipeline;
• the output of the oil pump is connected to the rod chamber of the pressurization cylinder via the unidirectional valve V11, the servo valve V9 and the switching valve V6 connected in series in turn to form an eighth oil pipeline;
• in the fast injection phase and the braking phase, the accumulator supplies oil to the non-rod chamber of the injection cylinder via the fourth oil pipeline that is conductive, and pressure oil in the rod chamber of the injection cylinder flows back to the oil tank along the fifth oil pipeline that is conductive;
• and
• the first oil pipeline and the fifth oil pipeline are conducted to form a third A-type half-bridge structure, and opening degrees of the servo valve V7 and the servo valve V9 are controlled to regulate an injection speed of the injection cylinder;
• in the tracking phase, the oil pump and the accumulator supply oil to the non-rod chamber of the injection cylinder via the third oil pipeline that is conductive and the conductive fourth oil pipeline, respectively;
• the oil pump further replenishes the accumulator with oil via the second oil pipeline;
• and the pressure oil in the rod chamber of the injection cylinder flows back to the oil tank along the fifth oil pipeline;
• and
• the first oil pipeline and the fifth oil pipeline are conducted to form a fourth A-type half-bridge structure, and opening degrees of the servo valve V7 and the servo valve V9 are controlled to regulate the injection speed of the injection cylinder;
• the oil tank is connected to the rod chamber of the pressurization cylinder via the servo valve V7 and the switching valve V6 connected in series in sequence to form a seventh oil pipeline;
• in the pressurization injection phase, the accumulator supplies oil to the non-rod chamber of the pressurization cylinder via the sixth oil pipeline that is conductive;
• the pressure oil in the rod chamber of the injection cylinder and in the rod chamber of the pressurization cylinder flows back to the oil tank along the seventh oil pipeline and the fifth oil pipeline that are conducive;
• and
• the eighth oil pipeline and the seventh oil pipeline are conducted to form a fifth A-type half-bridge structure, and the opening degrees of the servo valve V9 and the servo valve V7 are controlled to regulate a pressurized pressure of the pressurization cylinder.