Mold clamping mechanism and injection molding machine

A second metal mold 15 has a through hole 31 that extends in the movement direction of the second metal mold 15 . A first metal mold 14 has an internal threaded portion 34 that extends on a common line with the through hole 31 and has an opening at the surface of the first metal mold 14 facing the second metal mold 15 . A bolt 39 formed by a shaft 37 and a head 38 is employed. The shaft 37 is passed through the through hole 31 in such a manner that the head 38 is arranged at the opposite side to the first metal mold 14 with respect to the second metal mold 15 , and the distal end of the shaft 37 is located at the same side as the first metal mold 14 with respect to the second metal mold 15 . When the second metal mold 15 is held in contact with the first metal mold 14 , the bolt 39 is rotated by an electric motor 45 through the head 38 . In this manner, an external thread 41 , which is formed at the distal end of the shaft 37 , is threaded to the internal threads 36 of the internal threaded portion 34 . This presses the second metal mold 15 against the first metal mold 14.