Mold clamping mechanism and injection molding machine

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