Method to move an upper mold in relation to a lower mold in a permanent mold casting machine and the permanent mold casting machine used for the method

A method for moving an upper mold in relation to a lower mold in a permanent mold casting machine that introduces molten metal from a holding furnace into a set of the molds via a stoke, the permanent mold casting machine having a set of upper and lower molds in which molten metal is to be introduced to form a casting product, four supporting frames disposed on a base of the machine near respective four corners of the base, a lower mold base placed across upper ends of the four supporting frames, the lower mold being fixedly attached to the lower mold base, a lifting and lowering frame, two lifting and lowering cylinders for lifting and lowering the lifting and lowering frame attached to two of the supporting frames, two guide rods attached to the other two supporting frames that are vertically slidable in the two other supporting frames and fixed to a lower surface of the lifting and lowering frame and having a fastening portion that fixes the lifting and lowering frame in a fixed position in the machine, a mold clamping mechanism attached to the lifting and lowering frame, the upper mold being attached to a lower part of the mold clamping mechanism and the mold clamping mechanism having upper mold lifting and lowering means that carries out the assembly and separation of the upper and lower molds by lifting and lowering the upper mold, relative to the lower mold and the lifting and lowering frame, and a fastening mechanism that engages with the fastening portions of the two guide rods, the method comprising:

• forming a space for setting a core and for taking out a cast product from between the upper and lower molds by lifting the upper mold with the upper mold lifting and lowering means relative to the lifting and lowering frame and by lifting the lifting and lowering frame relative to the lower mold with the two lifting and lowering cylinders;
• lowering the lifting and lowering frame and the attached mold clamping mechanism relative to the lower mold with the two lifting and lowering cylinders to lower the upper mold to a position close to the lower mold;
• fastening the lifting and lowering frame and the attached mold clamping mechanism in the fixed position in the machine by engaging the fastening mechanism with the fastening portions of the two guide rods so they cannot be moved;
• then lowering the upper mold relative to the lower mold with the upper mold lifting and lowering means of the mold clamping mechanism to bring the upper mold into contact with the lower mold and form a mold assembly having a cavity;
• introducing molten metal into the cavity of the assembled mold from the holding furnace via the stoke;
• lifting the upper mold relative to the lower mold after the molten metal in the mold assembly has solidified a predetermined distance with the upper mold lifting and lower means of the mold clamping mechanism to separate the upper mold from the lower mold, while keeping the fastening mechanism engaged with the fastening portions of the two guide rods and the lifting and lowering frame and the attached mold clamping mechanism in the fixed position;
• releasing the fastening mechanism from engagement with the fastening portions of the two guide rods and the lifting and lowering frame and the attached mold clamping mechanism from the fixed position;
• and
• lifting the lifting and lowering frame and the attached clamping mechanism relative to the lower mold with the two lifting and lowering cylinders to further lift the upper mold away from the lower mold and form the space for taking out the cast product.