A lead delivery apparatus for a cast on strap machine is arranged to deliver a predetermined volume of molten lead to a mould. The apparatus includes a first needle valve, a second needle valve, and a housing. The housing has a reservoir including an inlet and an outlet. The reservoir inlet is in fluid communication with a molten lead supply. The reservoir is supplied with molten lead during use such that the molten lead in the reservoir is maintained at a constant height.

A lead delivery apparatus for a cast on strap machine is arranged to deliver a predetermined volume of molten lead to a mould. The apparatus includes a first needle valve, a second needle valve, and a housing. The housing has a reservoir including an inlet and an outlet. The reservoir inlet is in fluid communication with a molten lead supply. The reservoir is supplied with molten lead during use such that the molten lead in the reservoir is maintained at a constant height.

A lead delivery apparatus for a cast on strap machine is arranged to deliver a predetermined volume of molten lead to a mould. The apparatus includes a first needle valve, a second needle valve, and a housing. The housing has a reservoir including an inlet and an outlet. The reservoir inlet is in fluid communication with a molten lead supply. The reservoir is supplied with molten lead during use such that the molten lead in the reservoir is maintained at a constant height.

A lead delivery apparatus for a cast on strap machine is arranged to deliver a predetermined volume of molten lead to a mould. The apparatus includes a first needle valve, a second needle valve, and a housing. The housing has a reservoir including an inlet and an outlet. The reservoir inlet is in fluid communication with a molten lead supply. The reservoir is supplied with molten lead during use such that the molten lead in the reservoir is maintained at a constant height.

A method of manufacturing a mold by a machine tool, the method including predicting a thermal fatigue life of a mold which is made of a mold material having a hardness H and on which heating during contact with a workpiece and cooling after contact with a workpiece are repeated, the method including a step for obtaining a thermal stress maximum value σ.sub.h_MAX among a plurality of thermal stress values at a position x on the mold and a temperature T.sub.h at the thermal stress maximum value, wherein the temperature at the thermal stress maximum value σ.sub.h_MAX is a temperature lower than a maximum temperature among the plurality of temperatures, the machine tool manufactures the predetermined mold shape from a mold material having one of the plurality of hardnesses in which the thermal fatigue life was obtained based on the thermal stress maximum value, the yield strength, and the contraction.

A mold temperature control system that controls temperature of mold in a diecasting machine, includes temperature sensors that detect mold temperatures of individual parts of the mold, flow controllers that control instantaneous flow rates of cooling water that cools the parts of the mold, and a control device that acquires the mold temperatures detected by the temperature sensors, computes deviations between target mold temperature and the current mold temperatures at every production cycle, converts the deviations into flow rate values, and transmits the flow rate values to the flow controllers.

A mold temperature control system that controls temperature of mold in a diecasting machine, includes temperature sensors that detect mold temperatures of individual parts of the mold, flow controllers that control instantaneous flow rates of cooling water that cools the parts of the mold, and a control device that acquires the mold temperatures detected by the temperature sensors, computes deviations between target mold temperature and the current mold temperatures at every production cycle, converts the deviations into flow rate values, and transmits the flow rate values to the flow controllers.

A die casting machine of an embodiment includes: a holding furnace holding molten metal; a sleeve located outside the holding furnace and having a molten metal supply port passing through a mold; a plunger sliding through the sleeve and including a plunger rod and a plunger tip fixed to a tip of the plunger rod; a molten metal supply pipe supplying the molten metal into the sleeve and attachable to and detachable from the molten metal supply port; and a moving mechanism detaching the molten metal supply pipe from the molten metal supply port when the plunger is sliding.

A die casting machine of an embodiment includes: a holding furnace holding molten metal; a sleeve located outside the holding furnace and having a molten metal supply port passing through a mold; a plunger sliding through the sleeve and including a plunger rod and a plunger tip fixed to a tip of the plunger rod; a molten metal supply pipe supplying the molten metal into the sleeve and attachable to and detachable from the molten metal supply port; and a moving mechanism detaching the molten metal supply pipe from the molten metal supply port when the plunger is sliding.

A die casting machine of an embodiment includes: a holding furnace holding molten metal; a sleeve located outside the holding furnace and having a molten metal supply port passing through a mold; a plunger sliding through the sleeve and including a plunger rod and a plunger tip fixed to a tip of the plunger rod; a molten metal supply pipe pushed against the sleeve to cover the molten metal supply port and supplying the molten metal into the sleeve; and a pushing force variable mechanism reducing a pushing force for the sleeve in the molten metal supply pipe when the plunger is sliding.