Tool replacing device

A tool exchange device comprising:

• a first coupling member attached to one of a body side of an apparatus and a tool side and having a first coupling surface;
• and
• a second coupling member attached to the other of the body side and the tool side and having a second coupling surface capable of being in contact with the first coupling surface,
• wherein the first coupling member includes, on the first coupling surface,
• a first pin,
• a second pin, and
• an auxiliary projection,
• the second coupling member includes, on the second coupling surface,
• a first hole that allows the first pin to enter and exit,
• a second hole that allows the second pin to enter and exit, and
• an auxiliary hole that allows the auxiliary projection to enter and exit,
• a first gap in a direction parallel to the second coupling surface is provided each between the first pin and the first hole and between the second pin and the second hole,
• a second gap in a direction parallel to the second coupling surface is provided between the auxiliary projection and the auxiliary hole, and
• the second gap is larger than the first gap.