Appearance inspection device of crimp terminal

An appearance inspection device of a crimp terminal, which inspects an appearance by capturing an image of the appearance while applying illumination light onto a crimp terminal crimped on a tip of an electric wire, the device comprising:

• a terminal set unit that is set at a fixed position of an image capturing space;
• an illumination unit for applying illumination light onto the crimp terminal disposed on the terminal set unit in a predetermined direction;
• and
• a camera that captures an image of the crimp terminal disposed on the terminal set unit in a predetermined direction,
• wherein the illumination unit includes a planar gradation light source having a brightness that gradually changes from one side on an illumination surface toward another side,
• wherein the camera is disposed at a position at which the planar gradation light source appears, as a reflected image on a surface of the crimp terminal, on an image obtained by the camera capturing the image of the crimp terminal,
• wherein the terminal set unit is set at a center of an image capturing space of the camera, and the crimp terminal is inserted and set at a posture at which a front end of the crimp terminal is directed toward a front, an upper surface of an electric-wire caulked portion of the crimp terminal is directed upward, and right and left side surfaces of the crimp terminal are directed toward right and left sides,
• wherein the camera comprises an upper camera that is disposed over the top of the terminal set unit and captures the image of the crimp terminal disposed on the terminal set unit, from the top is provided as the camera,
• wherein the planar gradation light source includes right and left gradation light sources disposed at positions diagonally above and, respectively, on the right and left sides to avoid a top of the terminal set unit as an image capturing optical path of the camera, at a posture at which a flat illumination surface is parallel to an axial direction of the crimp terminal, and
• wherein a gradation direction in each of the right and left gradation light sources is set such that the brightness of the illumination surface in each of the right and left gradation light sources gradually changes in a right-left direction while the brightness in a direction parallel to the axial direction of the crimp terminal is maintained to have a predetermined value.