Punching device and sheet post-processing apparatus

A punching device, comprising:

• a punching member that has a punching blade at a leading end thereof in a first direction and that punches a hole in a sheet by moving in the first direction;
• a pin that penetrates the punching member in a second direction orthogonal to the first direction such that one end portion and an other end portion of the pin protrude in the second direction from the punching member;
• a holder that is coupled to the one end portion and the other end portion and that moves in the first direction together with the punching member by being pressed in the first direction;
• and
• a guide that has a cylindrical shape having an axial direction extending in the first direction and that accommodates the punching member and supports movement of the punching member in the first direction,
• wherein
• the guide has pin insertion holes that penetrate the guide in the second direction and that are elongated in the first direction, the pin insertion holes being formed one on each of opposite sides of the guide in the second direction,
• the one end portion and the other end portion each protrude to outside the guide through one of the pin insertion holes that is positioned on a same side in the second direction,
• the holder has a fitting hole that is circular and penetrates the holder in the first direction, and the guide is fitted into the fitting hole such that the holder is held so as to be movable in the first direction along an outer circumferential surface of the guide,
• the fitting hole has a recessed portion that is recessed outward in a radial direction, and
• the guide has a protruding portion that protrudes outward in the radial direction thereof and is positioned within the recessed portion.