This is called a twist car. Can you give me some information?
You can often see a kind of car for children to play in the square. The way it moves forward is very special. , people sit on it and just twist the steering wheel to move it forward and backward, which is very fun. The bicycles and tricycles we usually see, no matter how you shake the front of the bike, they will just sway in place and cannot move forward even half a step. Why can turning the steering wheel left and right on a twisty car make it move forward?
Out of curiosity, we also bought one. When we got home, we carefully observed and studied, and found that the reason why the twisty car can move forward is Its special structure.
The twist car is also called a swing car. When it officially applied for a patent, it was called a children's fitness and entertainment car. Since its advent in 2002,
it has become instantly popular due to its peculiar movement method, and some people even named it one of the "Top Ten Inventions in the World in 2002". It has three pairs of wheels.
It has three pairs of wheels. The front pair of steering wheels are small and suspended in the air. They only serve to avoid collision with the car body when the ground is uneven; the last are two load-bearing wheels, and people sit directly above them. It bears most of the force, and the rider's line of gravity also passes through it; the two wheels in the middle that are coaxial with the steering wheel are the driving wheels, and their special working method makes the The car is moving forward.
When starting to move, turn the handlebar to one side. The handlebar and the driving wheel are welded together as a whole, so the wheels will also turn to the same side.
At this time, the wheel will participate in two kinds of motion: in the tangential direction of the trajectory, the wheel has a tendency to move backwards driven by the rotation axis.
The friction force given by the ground along the The opposite direction of the tangent line is forward; on the other hand, in the direction pointing to the center of the circle, the wheel makes a circular motion, and the ground provides centripetal force for its friction effect, and the direction points to the center of the rotation circle. The two friction effects combine to push the car forward
and the car accelerates.
When the wheel rotates past the center line, the direction of the tangential speed turns to the front of the tangential line, and the friction force will then turn to the rear, hindering the movement of the car
. But the car has already accumulated kinetic energy in the initial stage, and it can continue to move forward by inertia. During this period, the car decelerates.
Then when the person turns the steering wheel in the opposite direction, the wheel starts to rotate backward, and the friction force moves forward, and the acceleration process of the front begins to repeat. It can be seen that the twist car moves forward by friction. It accelerates and decelerates alternately during movement. It cannot accelerate all the time like other cars, so the speed is not too fast and is very suitable for children's cars. requirements for safety. This may be one of the reasons why it became so popular.
Seeing the twisting car swaying from side to side and meandering forward, we may think of an animal - a snake. All snakes can crawl forward in this way. When crawling, the snake body makes horizontal wavy bends on the ground, causing the back side of the bend to exert force on the rough ground.
The reaction force of the ground pushes the snake body forward. I think the physics of how a twister and a snake move forward should be the same. Fake
If we don’t take into account people’s psychological aversion to snakes, and don’t consider that it is just a children’s toy, but only consider the similarity of the two principles, the twisting car is called “twisting car” "Snake driving" seems to be more suitable