Compound machines in construction

compound machines in construction. Today the machines are part of everyday life of human beings. Since these do not only refer to the machines used in the construction level, are distinguished tambén coffee machines, lawn mowers, computers, etc. Almost everything around us today is made up of machines. The machines are pieces whether mobile and immobile that can transform energy through the interactions of the same. Using the personan machines can modify the direction and magnitude of applied force X.

There are two types of machine: simple machines and complex machines. Simple machines can be, a lever, cables, wheels, etc.., Which are used to obtain a force greater than that applied by the person. The complex machine that has the simple difference, have an engine that is responsible for either extract energy, electrical, chemical, kinetic, etc.., Into mechanical energy. It also has different mechanisms that convert energy from the engine. Another type of machine is the frame, this ensures the connection between all elements or objects. Has a very rigid structure that supports the mechanisms and the motor. The machines have a safety mechanism to protect the person handling the machine to potential hazards that can cause this. There are also generating machines, unlike those with motor, which transforms the main, these generate it. For these reasons is that machines are known as generators. Of these there is a wide range, some of the best known are the compressors and pumps. The machines can be classified depending on the engine it has, or the energy source that works in: • thermal machines. • hydraulic machines. • electrical machines. Can also be classified depending on the mechanism has: • alternative machines. • Machines reaction. • rotating machines. May also exist machines fixed frame and movable frame, depending on the kind of frame that holds.

SPARK PLUG.

Spark plugs are the last component of the ignition system in charge of providing the necessary ignition spark to combustion of the mixture within the combustion chamber. This type of spark plugs cold, hot, tapered seat, short range and long range.

For the spark plug is free of impurities such as oil, water, dust, do not have damage to its structure, the vehicle must carry adequate and properly installed.
The two main functions of the spark plugs are:
1) The ignite the air-fuel mixture (which is where the plug is the last step in the ignition circuit). This transmits power that transforms fuel into working energy. The spark plug voltage takes charge of the coil and produces a high voltage spark to ignite the fuel-air mixture compressed within each cylinder.
2) The removal of heat from the combustion chamber: The spark plug works as a heat exchanger, removing unwanted thermal energy in the combustion chamber to the engine cooling system.
The parts of a spark plug are: screw terminal, is where you connect the spark plug, the insulator prevents spark jumps in wet conditions, the insulation (which must withstand about 40,000 volts as well as thermal shock, the inner can withstand temperatures of 2,500 degrees, and the outside temperatures below zero), the metal (which is where you give the hex wrench to tighten or loosen the spark plug, the measure may be 5/8 or 13/16 inches ), the metal body, head, the water line, the center electrode, gasket that prevents leakage of gases and the resistance element, which reduces interference with radio and TV (not all the lead plugs) , huacha (board), the tip of the insulator, the thread (which varies from 10 to 18 mm), the center electrode and side electrode.
The different engines require spark plugs with different temperature range. The old or low-performance engines are cold, so they require a hot plug (with low heat dissipation) prevents the formation of deposits at the end of the insulating material of the plug. However, new or high performance engines are very hot and require spark plugs dissipate the excessive heat generated in them.


Each spark plug manufacturers have a coding through which one can know the temperature range, whether or not the spark plug has resistance, type of electrode (platinum or copper, etc.).
To change depends on the type spark plugs and the number of electrodes and the quality of mainly gas. Regularly spark plugs with a copper electrode is changed every 10,000 km. But there copper plugs that can last several electrodes functioning properly to 20.000 km per electrode (ie, up to 80.000 kmpara plugs 4 electrodes).
To be installing is very important to follow the torque provided by the manufacturer. A loose spark plug can cause leakage of flue gases, and if too tight can damage the threads on the engine head.

About Piston

The piston function is to transform the thermal energy developed in the combustion into mechanical energy through the reciprocating motion inside cylinders. They must be able to withstand the extreme conditions which exist within it. The piston also should be light to avoid passing on excessive inertia to increase engine vibration and be able to provide sealing the cylinder so that the gases do not escape impairing the operation of the engine.

                                                                    PISTON


 







The pistons are cast in one piece and can be made of cast iron, steel and aluminum alloys. Cast iron piston less wear and can be used with fewer gaps due to expand less than aluminum. Instead of aluminum pistons are much more light and have a heat transfer coefficient greater. Therefore piston engines employing casting require more cooling water and cooling jackets plates of reduced thickness. The piston can be made ​​in her head in her lap material and be constructed in another to join in one piece thanks to a weld.

The piston head is responsible to withstand the high pressures and temperatures while the skirt has the function of transmitting the motion to the crank. Requires binding of a bearing so that it can transmit the movement without excessive friction.