Device for adjusting height of cutter of lawn mower

The invention relates to a device for adjusting height of a cutter of a lawn mower. The device comprises a rear rack, a rear wheel, a transmission shaft, and a cutter connected with the rear rack, and also comprises a screw rod nut mechanism, an angular connection rod, a left and right support plate, a front and rear connection piece and a connection rod, wherein the angular connection rod is arranged at the rear part of the rear rack; an angle end of the angular connection rod is hinged with the rear rack; the two ends of the angular connection rod are respectively connected with a rear wheel shaft and a nut of the screw rod nut mechanism; the middle part of the left and right support plate can be rotatably sheathed on the transmission shaft; the rear end of the left and right support plate is connected with the rear rack, and the front end of the left and right support plate is connected with the rear wheel shaft; the rear end of the front and rear connection piece is hinged with a rear wheel shaft, and the front end of the front and rear connection piece is fixedly connected with a front rack; the two ends of the connection rod are respectively hinged with the front rack and the cutter; and a parallelogram is formed by the hinged joints of the connection rod and the front end of the left and right support plate as well as the connection rod and the rear end of the left and right support plate. As a four-bar mechanism is utilized in the device provided by the invention, the purpose that the rack and the height of the cutter can be adjusted at the same time through the screw rod nut mechanism; the adjustment can be finished by a ratchet wrench, and the height adjustment of the cutter can be conveniently realized, thus the device is not only convenient and reliable, but also simple and feasible.