The lawn mower (also known as the brush cutter) is a portable garden machine powered by a small gasoline engine. The working principle of the lawn mower is that the cutting head installed on the gear box of the lawn mower rotates at a high speed to drive the movement of the high-strength nylon rope fixed on the cutting head. The straw or small shrubs are cut off. At the same time, the nylon rope is gradually cracked and consumed during use.
The mowing head is an indispensable functional part of the lawn mower and also one of the vulnerable parts. Its structure and operating conditions directly affect the consumption of nylon rope, the quality of mowing and the labor intensity of the operator.
At present, the mowing heads used at home and abroad can be divided into two categories according to whether there is a rope storage mechanism. The mowing head without a rope storage mechanism (also known as the mowing disc or turntable) can only use short nylon ropes. In addition to the utilization rate of the nylon rope ≤ 60%, the mowing efficiency also extends beyond the mowing head The consumption of nylon rope decreases. The mowing head with a rope storage mechanism has basically the same structure and principle, which is mainly composed of three parts: a tray seat, a rope storage wheel and a tray cover. The disc cover is fixed on the disc seat by the elastic clip on the disc seat; the rope storage wheel is pressed against the inner wall of the disc cover by a built-in spring and is positioned by pawls; the nylon rope end on the rope storage wheel passes through the disc seat The hole on the top sticks out of the mowing head. Such a structure is not only complicated, but also has many disadvantages. First, the position of the nylon cord on the mowing head is higher (generally ≥30mm), which reduces the mowing effect. Second, when the mowing head is working, the disc cover is closest to the ground, which can easily cause the disc cover to wear out. Once the disc cover is damaged, the mowing head immediately fails. Third, high-speed rotating gears will generate a lot of heat, and the elastic card on the disk seat will be difficult to play a fixed role after being heated. Fourth, the pawl positioning method has fixed requirements for the winding direction of the nylon rope on the rope storage wheel.