METHOD AND APPARATUS FOR CONTROLLING TEMPERATURE OF MOLD

PROBLEM TO BE SOLVED: To control the temp. of a mold to constant high temp. with high accuracy by detecting first temp. on the downstream side of a mold cooling circuit and detecting third temp. on the upstream side of a parallel circuit and determining the opening degree of the shunt flow rate control valve on the upstream side of the parallel circuit on the basis of the temp. differences between the first temp. the second temp. of a medium variable and the third temp. SOLUTION: A parallel circuit (or shunt circuit) 4 is provided to a mold cooling circuit 2 cooling a mold 1 and a first temp. detector 12 is provided to the mold cooling circuit 2 on the downstream side of the parallel circuit 4 and a third temp. detector 13 is provided on the upstream side of a shunt point 7. A flow rate control valve 9 controls an opening degree (ratio of shunt quantity) on the basis of the temp. differences between three temps. of the first temp. T detected by the first temp. detector 12, the second temp. T2 (the medium temp. in a heat exchange circuit after the heat exchange with a medium cooling part) detected by a second temp. detector 24 and the third temp. T3 detected by the third temp. detector 13. The opening degree is controlled substantially continuously.