Creative hydraulic lift school science experiment kit
In recent years, due to the rapid development of construction scale, there are more and more high-rise buildings, and the use of lifting platforms on construction sites has become more and more extensive. What are the principles of such a convenient tool? After studying this section of the experiment, you may understand the mystery.
The purpose of the experiment:
1. Know the principles of the simple lifting platform.
2. Learn the relevant knowledge of air pressure and hydraulic pressure.
The lifting platform relies on the expansion and folding of the quadrilateral support frame to complete the lifting of the cargo platform. Its power is to push the quadrilateral support through air pressure. Expand and collapse. It makes high-altitude operations more efficient and safer.
The instability of the quadrilateral: After the length of the four sides of the quadrilateral is determined, the shape of the quadrilateral can still change, for example, it can be a rectangle, a rhombus, etc. Therefore, "the four sides of a quadrilateral are determined, and its shape is uncertain". The angle can still be changed. Because of the instability of the quadrilateral, it is easy to deform, and it is flexible to expand and has a large stroke, so the expansion and folding of the bracket is more convenient!
Air pressure is the atmospheric pressure acting on a unit area. The power of the lifting platform is a kind of pneumatic transmission principle. The pneumatic transmission uses compressed gas as the working medium and transmits power or information by the pressure of the gas. The power transmission system transports compressed gas to pneumatic actuators through pipelines and control valves, and converts the pressure energy of the compressed gas into mechanical energy to perform work.
Hydraulic transmission uses liquid as a working medium to transmit power. In this experiment, the syringe can be regarded as an executive component of a hydraulic system. After water is injected into the syringe, it is equivalent to a hydraulic cylinder, which converts the pressure of the liquid into mechanical energy.
Experimental steps:
1. Know the experimental equipment: quadrilateral bracket, plastic box, plastic box with holes, hoses, syringes, syringes with holes, figurines, screws, nuts, foam glue, long screws.
2. Fix the quadrilateral bracket to the plastic box with holes with screws to form the bottom of the lifting platform.
3. Use a long screw to fix the upper end of the quadrilateral bracket to the plastic box (when the long screw passes through the bracket and one side of the plastic box, insert the syringe into the screw, fix it to the middle position, and screw the other side with a nut. , In this way, the whole bracket part of the lifting platform is assembled.
4. Connect one end of the hose to the syringe with a hole, and the other end to the syringe. The bracket and the power unit (syringe) together form a complete elevator system. Of course, water can also be injected into the syringe. When the syringe is pushed, the water is pushed into the syringe with a hole, thereby driving the bracket to rise, which becomes a hydraulic lifting platform system.
Tip: When assembling the bracket, don't forget to put a washer between the screws to avoid the bracket being too loose and affecting the experimental results. The screws between the plastic box and the bracket should not be tightened too tightly, otherwise the bracket will not move.
Knowledge expansion: The early appearance of elevators should be traced back to ancient China and European countries. At that time, tools such as wheel wheels were used to transport people and goods vertically. The modern elevator is the product of the invention of the steam engine in the nineteenth century. 1845 hydraulic lifts birth, when the liquid used is water. In 1853, the American Elisha Otis Elishaotis invented an automatic safety device to greatly improve the safety of wire rope traction elevators. March 23, 1857, New York, a five-storey stores in the US to install a passenger elevator use Otis safety device header
machine. Since then, the use of elevators has been widely accepted and developed rapidly. The initial elevator was driven by a steam engine, so the building must be equipped with a boiler room. In 1880.
machine officially appear. Since then, the use of elevators has been widely accepted and developed rapidly.