Resumo de Pneumatics In Automation

DEFINITTION FOR AUTOMATION:

Automation is the technology by which a process or procedure is accomplished without human assistance. It is implemented using a program of instructions combined with a control system that executes the instructions.

AUTOMATION TYPES:

Device level:
This is the lowest level in our automaton hierarchy. it includes the actuators, sensors and other hardware components that comprise the machine level.

Machine level:
Hardware at the device level is assembled into individual machines.
Examples include CNC machine tools and similar production equipment, industrial robots, powered conveyors.

Cell or system level:
This is the manufacturing cell, which operates under instructions from the plant level. Functions include part dispatching and machine loading, coordination among machines and material handling system and collecting and evaluating inspection data.

Plant level:
This is the factory or production system level. It receives instructions from the corporate information system and translates them into operational plants for production. Likely functions include process planning, inventory control, purchasing, shop floor control and quality control.

Enterprise level:
This is the highest level, consisting of the corporate information system. It is concerned with all of the functions necessary to manage the company: marketing and sales, design, research, aggregate planning and master production scheduling.

RESONS FOR AUTOMATION:
· Greater accuracy of work and reliability of operation.
· Reducing production time in comparison with manually operated machines.
· Sequences of work are controlled and regulated by special devices in the machines.

DEFINITION FOR CONTROL:
Control is the process of beginning, ending or influencing a work operation in anyway, by means of an impulse.

A number of control elements arranged in series are known as a
Control chain.
TYPES OF CONTROL:

· If the machine services guidance from a master component which it traces, the process is known as guidance control.
· If the control system is based on a interchangeable impulse generator which can be programmed, the system of automation is known as program control.

Some of the types are as follows,

Guidance control

§ Program control
§ Time-pattern control
§ Path- pattern control
§ Mechanical control
§ Hydraulic - Pneumatic control
§ Pneumatic control
§ Numerical control

Here we are choosing Hydraulic - Pneumatic control system with reference to our topic.
COMPARISON OF PNEMAUTICS AND HYDRAULICS:

The difference between hydraulics and pneumatics essentially lies in the properties and behavior of the different media, the liquid hydraulic oil and the gaseous air. The medium carries the energy present in the pump or in the compressor, to the operating devices, cylinder or motor. There are advantages and disadvantages associated with these Medias.

PNEUMATICS:
Medium: air(gas)

HYDRAULICS:
Medium: liquids

ADVANTAGES:
Air is available everywhere. Return piping can be dispensed with. Air has a comparatively high flow speed in the piping and valves. Compressed air can be stored well in the container. Easy assembly with plug fasteners and flexible pipes possible.
DISADVANTAGES:
Air must be treated; leakage losses are costly because of continues energy less, above 6 bar, technical safety control is necessary.

ADVANTAGES:
The low compressibility of oil can be practically neglected. Extremely high pressures for greater forces can be produced with small cylinder dimensions.

DISADVANTAGES:
Hydraulic oil is expensive. Return pipes are necessary. Leakage loss i.e. loose pipes pollute the surrounding.

APPLICATIONS OF PNEUMATICS:
· Where many operations are to be performed quickly and well controlled with small force, example automatic or semi-automatic machines.
· Where the machines given under must be quickly resettable for objects with different measurements, example gluing and assembling units in the furniture manufacturing.
· Where external cleanliness is demanded, example filling and packing machines in food industries.

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