The present invention relates to a safety device of a tiller, in particular, when a tiller such as a tractor plow, a plow, a plough, a plow, a subsoil crusher cultivates a farmland, the impact is reduced when an overload occurs due to obstacles such as stones or rocks. The present invention relates to a safety device of a cultivator, which can be manufactured by a very simple structure by preventing damage and improving work efficiency. To this end, the present invention, the main frame having a tractor connecting portion to be connected to the tractor in front of the tractor, a cultivation unit is rotatably installed on the main frame in the vertical direction to cultivate the land, and the cultivation unit from the main frame In the safety device of the tiller consisting of a cylinder for elastically supporting the rotation, The cylinder is a body into which the rod is inserted to one side； An inner cylinder inserted into one side of the body and formed to be shorter than a moving distance of the pressure plate formed at the rod end, and having an outer diameter smaller than the inner diameter of the body to form a space； A through hole formed in the inner cylinder to communicate an inner side of the inner cylinder with the space part, and formed at a rear portion of the pressing plate when the rod is fully extended； A valve for opening and closing the through hole； Located in the rear portion of the pressure plate and the opening and closing portion for opening and closing the valve by the forward and backward of the pressure plate； and the pressure plate is configured to have a size that the outer diameter is inserted into the inner cylinder.본 발명은 경작기의 안전장치에 관한 것으로, 특히 트랙터용 쟁기, 양련쟁기, 이랑쟁기, 배토기, 심토파쇄기 등의 경작기가 경작지를 경작할 때 돌이나 암석 등의 장애물로 인하여 과부하 발생시 충격을 완화시켜 파손 방지 및 작업 능률을 향상시키며, 아울러 매우 간단한 구조에 의해 제조가 가능한 경작기의 안전장치에 관한 것이다.이를 위하여 본 발명은, 전방에 트랙터와 연결되어 견인되는 트랙터 연결부를 구비하는 메인 프레임과, 상기 메인 프레임에 상하방향으로 회전 가능하게 설치되어 땅을 경작하는 경작부와, 상기 경작부를 메인 프레임으로부터의 회전을 탄성지지하는 실린더로 구성된 경작
