The mouldboard plough is a type of agricultural tool for ploughing the land, which is a fully suspended mouldboard plough, consisting of a heavy blade at the end of a beam, usually tied to a group of livestock or motor vehicles that pull it, or driven by human power, used to break up clods of soil and plough grooves in preparation for sowing. Pen "Fun" Pavilion www.biquge.info

The traditional Chinese ploughshare is an evolution of the ancient wooden ploughing tool. It was founded in the legendary Shennong period, about 5,000 years ago. The rake is a wooden stick with a crank head, and the rake is a horizontal wood at the end of the rake. Originally operated by a single person, it developed into a "coupling tillage" method in which two people were opposite each other and operated together, and then developed into a man-pulled type in which one person pushed the plow in the rear, a human-powered traction type with a rope pulling forward, and finally an ox-pulled instead of human-powered traction, thus completing the evolution to the plough (Fig. 1). China's use of cattle to plough the land began at the latest during the reign of Wu Ding and Emperor Yi of the Yin Dynasty. In the Shang Dynasty, the ploughshares were made of wood, and bronze ploughshares appeared in the Western Zhou Dynasty. During the Warring States period, iron ploughshares were used, and there were curved ploughshares called "Goku" at the time. By the Tang Dynasty, a well-structured animal-powered mouldboard plough had been formed. The plough described in the late Tang Dynasty Tortoise Meng's writings is basically the same as the traditional animal-powered plough used in modern times (Fig. 2). The improvement of the plough after the Tang Dynasty was the addition of knives, i.e., coulters, in the Yuan Dynasty. In the early 50s of the 20th century, China began to produce and promote Western-type animal plows and improved paddy field plows; In 1957, the tractor-towed five-share plough was produced; Production of suspended plows in the early 60s; By the mid-70s, there were more than 30 models of dryland and paddy field mouldboard plough series, which were matched with tractors with a traction force of 5~25 kilowatts.

Saxon ploughs with wooden ploughshares and walls appeared in Europe in the 8th century. At the beginning of the 16th century, it developed into a large animal plough pulled by a dozen horses. In 1730, the Dutch plough with wooden plough walls was introduced to England and was improved to become the famous Joséhan plough in Europe. In 1785, the production of iron ploughshares began in England. In 1788, T. Jefferson of the United States proposed a mathematical model of the hyperbolic parabolic plow body surface. In 1851, Britain made a balance-type two-way plough pulled by a steam engine driven by a wire rope, which was the beginning of replacing human and animal power with mechanical power. In 1868, the United States began to use a three-layer composite steel plate with a soft middle layer and a hard outer layer to make the plough wall, so that it has the necessary strength and wear resistance. Until the end of the 19th century, when tractors with internal combustion engines appeared, the mouldboard plough remained one of the most important supporting agricultural tools. In 1922, the first suspended mouldboard plough was made in England, which made the plough and tractor one, and finally changed the way the tractor pulled the animal plough.

According to the different traction power, it is divided into animal plough and mechanical plough. The mechanical plough is divided into traction plow, suspended plough and semi-suspended plough according to different attachment methods; According to different uses, there are general plows, deep ploughs, land ploughs, paddy field plows, mountain ploughs, orchard ploughs, etc. In addition, it can also be divided into two-way plow, amplitude modulation plow, etc. according to the different structures; According to the number of operating plough bodies, it is divided into single plough, double plough, triple plough, etc.; According to the weight of the plough and the type of soil adapted, it can be divided into heavy plow, medium plough and light plough. On the basis of the mouldboard plough, the addition of components such as rotary tillage, soil loosening or leveling can form various types of combine tillers.

The two-way plough is a mouldboard plough that can make the mound always turn in the same direction of the field during the round trip of the cultivated land. Originally, it was designed to make it always turn down when plowing slopes, so it was also called mountain plow. It has a variety of types: some use only one plough body, which can be turned to the left or converted to the right, such as the pendulum two-way plough created in China in the 70s of the 20th century (Fig. 3); European and American countries have developed the balance type, key type and rolling type and other two-way plough, is no longer used, since the 60s focus on the development of the flip type two-way plough (Fig. 4), the plough is equipped with two kinds of plough body in the opposite direction of the plough, used alternately in the round trip, its ploughing quality is better, but the weight of the plough is large.

The main working part of the mouldboard plough is the plough body, in addition to the coulter, stubble mulcher and safety device.

The plough body is composed of a ploughshare, a plough wall, a plough side plate (or plow bed), a plow support, etc. (Fig. 5), and the working surface of the ploughshare and the plough wall constitutes the surface of the plough body. When ploughing, the mound rises, breaks and flips along the surface of the plough body. The tillage performance of the mouldboard plough mainly depends on the type and parameters of the surface of the plough body: the channeling plough body makes the soil rise upwards and then turn into the furrow; The rolling plough body makes the soil roll over in place. The plough body with steep and short curved surface has strong soil crushing performance, but poor soil turning ability. The opposite is true for ploughshares with gentle, longer and more twisted surfaces. The cross-section of the soil ploughed by the ordinary mouldboard plough body is rectangular. In the early 70s, France developed a mouldboard plough body with a roughly diamond-shaped soil cross-section, which is called a diamond-shaped plough body. Its advantage is that the longitudinal spacing of each plough body on the multi-plough can be reduced by about 1/3 compared with the ordinary, so as not to cause soil congestion.

There are two kinds of coulters, straight coulters and disc knives, which are installed on the side of uncultivated land in front of the plough body, and are used to cut the soil vertically, so that the soil that the plow body ploughs up is neat, and the furrow is clear after ploughing, which is conducive to improving the quality of cultivated land.

The function of the stubble mulching device is to plow the soil on the upper part of the uncultivated side before the soil is ploughed up and turned into the furrow, and then covered by the plough ploughed soil mound, so that most of the surface weeds can be buried underneath. There are four types of mulching machines: mouldboard type, corner cutting type, disc type and mulching board type (Fig. 6). The mouldboard stubble mulcher is also called a small front plow. In order to avoid damage caused by the plough when it encounters underground obstacles, a safety device is often installed on the mouldboard plow. The whole machine type safety device is installed between the pull rod and the pull ring of the traction plow, there are two kinds of pin type and spring type, and the pin is cut off or the spring is compressed when encountering obstacles, so that the plow is disengaged from the tractor. Monocoque safety device is installed on the plow column of each plow body, there are various types such as pin type, spring type, rolling type, when a plow body encounters an obstacle, the plow body can automatically lift upwards and cross the obstacle. After crossing the obstacle, some can be automatically reset, and some need to be manually reset.