Second, the principle is to use the swing of the center of gravity to realize the progress of the car. The detailed explanation is as follows:
A horizontal wooden strip three feet from the ground, four feet long and six inches high. The left end of the wooden strip is cut into the shape of a handlebar, and the right end has three pin-shaped holes. Imagine that these two pieces of wood are arranged in the left and right axes of a rickshaw. Imagine inserting a three-foot-long shaft between two pin-shaped top holes, and hinging a wooden column that can swing along the small shaft in the two holes below the pin shape, and the other end is supported on the ground. This four-legged rickshaw is a wooden cow.
Wooden bull's head: the carriage of a four-wheeled vehicle is equipped with a bull's head, and the two shafts are mounted on the front and rear pillar shafts. The long and short struts are hinged on the strut shafts, and the two shafts are hinged on the vehicle body, and the wheels are rotated by shaking the two shafts to support the ground.
Horse-riding: The carriage of a two-wheeled vehicle is equipped with horse heads, and the front and rear strut shafts are equipped with two shafts. The long and short struts are hinged on the strut shafts, and the two shafts are fixedly connected with the vehicle body. The wheels are rotated by shaking the two shafts to support the ground.
Extended data:
During the Republic of China, some scholars made textual research on this. One theory is that the wooden ox was a "wooden ox cart" used by miners in Sichuan at that time, while the floating horse was a narrow boat called a "fast horse".
There are two main reasons why the image of Mu Niu Liu Ma is ugly: on the one hand, because of the shape of the cow or horse, it is easy to hide in the deep mountains and forests, which is not conducive to being discovered by the enemy; On the other hand, cows and horses can play a confusing role when playing tricks.
And "people don't work hard, cattle and horses don't eat" proves that it is human control. Zhuge Liang, a clever man, made a wooden cow and a flowing horse, a wonderfully coordinated vehicle with wheels and legs.
That is, when people push, the wheels move in the middle, making the four legs move up and down; In the process of cattle and horses moving forward, one leg is pressed by the grain board above, the other two legs are lifted by levers, and people cooperate to shift the center of gravity to the raised leg behind. Under the actual wrist pressure, Mu Niu Liu Ma moved forward by the diameter of a wheel.
In this way, the four legs can move vertically up and down to match the slope of the mountain road. It is precisely because of this that Sima Yi's reconnaissance whistle makes people stunned and amazed.
Another feature of wooden cattle is "anti-theft". That is to say, in the process of transporting grain, if the enemy finds or intercepts it, if it can't resist it, if it abandons the grain and escapes, as long as the sponsor wants Niu Liu to insert the pre-made tenon in the hidden part of the hub (there may be supporting tools for tenon insertion).
Something like an Allen wrench), so that the wheels can't turn and the enemy can't carry them. In this case, the only thing the enemy can do is to burn it.
As for why it was not fully popularized later, it was because with the progress of the times and the attention of the court and the people to the road, the road became wider and flatter, and at the same time, it was found that the round wheel was more practical and faster. Unicycle and two-wheeled scooter widely used in rural areas are later improved and innovative versions. Liu Ma, a cattle herder, gradually withdrew from the historical stage because he was extremely "heavy".
References:
Baidu Encyclopedia-Mu Niu Liu Ma