The present invention relates to a safety device for a cultivator and, more specifically, to a safety device for a cultivator, which reduces an impact when overload occurs in a cultivator such as a plough, a double-lined plough, a furrow plough, a hiller and a deep soil crusher for a tractor, by an obstacle such as a stone, a rock and the like during operation in a farming land to prevent breakage and increase working efficiency, and can be manufactured by a simple structure. To this end, according to the present invention, in the safety device for a cultivator comprising a main frame having a tractor coupling unit disposed on a front side to be connected to a tractor and be pulled, a cultivation unit rotatably installed to the main frame in a vertical direction to cultivate land, and a cylinder elastically supporting the cultivation unit with respect to rotation from the main frame, a rod having a pressing plate fixed thereto and inserted into a cylinder body. The pressing plate comprises: a real pressing plate having an outer diameter smaller than the inner diameter of the cylinder body to be fixed to the rod while forming a separation part between the outer diameter thereof and the inner diameter of the cylinder body； a gap holding plate disposed at the front portion of the rear pressing plate to be fixed to the rod； and a front pressing plate having an outer diameter to maintain airtightness with the inner diameter of the cylinder body, having a plurality of perforated hydraulic moving holes, and fixed to the rod at the front portion of the gap holding plate.COPYRIGHT KIPO 2020본 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 경작기의 안전장치에 있어서, 상기 실린더의 몸체의 내측으로 가압판이 고정된 로드가 삽입되고, 상기 가압판은 외경이 상기 실
