A drive frame 34 as a cylindrical molded article has a drive frame main body 34a, three first cam grooves 34c, three second cam grooves 34d, three high-density regions H, and three cam pins 43. The cam pins 43 are disposed in the circumferential direction between first center lines X1 which are positioned in the center in the circumferential direction between adjacent high-density regions H, and the high-density regions H.