Detection device for tooth shape size of cross-shaped key

The invention discloses a detection device for a tooth shape size of a cross-shaped key. According to the detection device, a backlight source is placed on a U-shaped objective table; a fixed plate is vertically and fixedly arranged on the side face of the objective table; a 90-degree rotary air cylinder is mounted in the center of the fixed plate; a handle of the cross-shaped key is fixedly arranged on a clamp; an air pump is connected with the 90-degree rotary air cylinder by a solenoid valve; a CCD (Charge Coupled Device) camera is located above a tooth-shaped part of the cross-shaped key to be detected; the camera is connected with a computer host by an image acquisition card; a display is connected with the computer host; a PLC (Programmable Logic Controller) is connected with the computer host. According to the detection device disclosed by the invention, the backlight source is used for clearly showing a tooth-shaped outline of the key in the view field of the camera; image interferences are removed by image processing; the boundary of the tooth-shaped image is positioned and the distance between opposite sides of a tooth shape is calculated. A 90-degree rotary mechanism is used for realizing the all-directional image acquisition on the tooth shape of the key and whether a product is qualified or not is judged according to the distance between image sampling points and a pre-set threshold value, and furthermore, the problem of a traditional detection manner that online detection can not be carried out in real time is solved.