Endoscope and treatment tool elevating mechanism

A treatment tool elevating mechanism that is to be attached to a distal-end-portion main body of an endoscope and that changes a lead-out direction of a treatment tool, the endoscope comprising

• an operation section at which an operating member is provided,
• an insertion section that is provided on a distal end side of the operation section and that is to be inserted into a subject, and
• the distal-end-portion main body that is positioned at a distal end of the insertion section,
• the treatment tool elevating mechanism comprising:
• an elevator-housing-space forming member that is detachably attached to the distal-end-portion main body and that forms an elevator housing space;
• a proximal end wall portion that is provided at the distal-end-portion main body or the elevator-housing-space forming member and at which a lead-out port for the treatment tool opens;
• a first wall portion that extends from the proximal end wall portion to a distal end side of the distal-end-portion main body, the first wall portion being provided at a position on one direction side of a first direction perpendicular to a longitudinal axis of the distal-end-portion main body with respect to the lead-out port;
• a second wall portion that is provided at the elevator-housing-space forming member and that forms, together with the proximal end wall portion and the first wall portion, the elevator housing space, the second wall portion facing the first wall portion at a position on another direction side opposite to the one direction side with respect to the lead-out port;
• a treatment tool elevator that is disposed in the elevator housing space and that is rotatable between a lying position and an elevated position about a rotary shaft parallel to the first direction, the treatment tool elevator having an elevator main body portion rotatably held by the rotary shaft, an elevator distal end portion provided on a distal end side of the elevator main body portion, and a wire connection portion provided at the elevator distal end portion;
• and
• an operating wire that is connected to the wire connection portion and that rotates the treatment tool elevator,
• wherein, when viewed in a second direction perpendicular to both the longitudinal axis and the first direction, a wire distal end portion of the operating wire connected to the wire connection portion is positioned on the another direction side with respect to the elevator main body portion,
• wherein the second wall portion has:
• a first wall surface facing the first wall portion at least a portion of which has a shape along a trajectory of the wire connection portion that rotates about the rotary shaft;
• and
• a second wall surface facing the first wall portion that is provided at a position on the one direction side with respect to the first wall surface and that has a shape extending along a trajectory of the elevator main body portion that rotates about the rotary shaft,
• wherein a curvature of the operating wire is substantially similar to a curvature of the second wall surface, and
• wherein the second wall surface overlaps at least a portion of the wire distal end portion in the first direction when viewed in the second direction.