Basic Pneumatics Module 1: Introduction to Pneumatics PREPARED BY Academic Services August 2011 © Applied Technology High Schools, 2011 ATM 1132 – Basic Pneumatics Module 1: Introduction to Pneumatics Module Objectives After the completion of this module, the student will be able to: Identify the common uses of pneumatic systems. Identify the main advantages of a pneumatic system. Identify the main disadvantages of a pneumatic system. Understand how to to construct a pneumatic circuit. Explain the structure and signal flow of a pneumatic system. Explain the meaning of Pascal’s law. Calculate the force exerted by a pneumatic cylinder. Module Contents Topic Page No. 1 Introduction 3 2 Applications of Pneumatics 4 3 Advantages and disadvantages 6 4 Signal flow in Pneumatics 7 5 Pascal’s law 9 6 Supplementary resources 10 7 References 10 8 Worksheet 12 Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 1 Introduction 1.1 What Does the word Pneumatics Mean? The word Pneumatics comes from the Greek word pneuma, which means 'breath or wind'. It is basically the use of under pressure gas that helps in performing a certain work in science and technology. 1.2 Definition of pneumatics Pneumatics is the transmission and control of forces and movements by means of compressed air. (The use of compressed air as a medium to do work). 1.3 What is the fluid power? Fluid power is the energy transmitted and controlled by means of a pressurized fluid, either liquid or gas. The term fluid power applies to both hydraulics and pneumatics. Hydraulics use liquids (oil or water) under pressure while pneumatics use compressed air or other neutral gases. Pneumatics technology has for some considerable time been used in carrying out the simplest mechanical tasks, but nowadays has played a vital and important role in automation and development of sophisticated technologies. Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 2 Applications (Uses) of Pneumatics: 2.1 Some of the pneumatic applications in our life: A Pneumatic device is used to dismantle an automobile tire A pneumatic device is used in an automobile painting A heavy duty pneumatic jackhammer A pneumatic filling machine A dental drill is one of the uses of the pneumatic technology Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics A pneumatic device is used to fill the tire with compressed air to adjust the tire pressure. 2.2 Other applications of pneumatics: 2.2.1 industrial applications Pneumatic systems are used in many industrial applications such as: Material handling Clamping Shifting Positioning Branching of material flow Packaging Filling Transfer of materials Sorting of parts Stamping and embossing of components 2.2.2 Industrial processes Pneumatic systems are used in carrying out machining and some industrial processes such as: Drilling Turning Milling Sawing Finishing Forming Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 3 Advantages and disadvantages of pneumatics: 3.1 Advantages: 1- Air is available everywhere in unlimited quantities. 2- Air can be easily transported in pipelines, even over large distances. 3- Compressed air can easily be stored in a reservoir/tank. 4- Compressed air is relatively insensitive to temperature fluctuations. 5- Exhaust air is clean. 6- The running cost is relatively inexpensive. 7- Compressed air is a very fast working medium. 8- Overload safe. 3.2 Disadvantages: 1- Compressed air requires good preparation. Dirt and condensates should be removed. 2- Variable speeds. As air is compressible; it is difficult to achieve uniform and constant piston speed. 3- Low Forces compared to Hydraulics. 4- Noisy operation. This problem has now, however been largely solved due to the development of sound absorption material and silencers. Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 4 Structure and signal flow of pneumatic systems Pneumatic systems consist of an interconnection of different groups of elements. These groups of elements form a control path for signal flow, starting from the signal section (input) through to the actuating section (output). Control elements control the actuating elements in accordance with the signals received from the processing elements. 4.1 Primary levels of the pneumatic system: Fig. 1.1: Pneumatic signal flow and the corresponding control elements Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 4.2 Practical example on pneumatic elements signal flow 0Z Fig. 1.2 : Example of pneumatic control elements shown in a practical circuit Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 5. Pascal’s Law As explained earlier in the Basic Hydraulics course Pascal’s law states that: “The pressure in a confined fluid is transmitted equally to the whole surface of its container” Accordingly, the pressure at any point in a body of fluid is the same in any direction as shown in Fig. 1.3. Mathematical formula Fig. 1.3 F P A Where: P is the pressure in Pascal (Pa) F is the force in Newton (N) A is the cross sectional area in m2 Notes: 1 bar = 100000 Pa 1 Kg = 10 N 1 m2 = 10000 cm2 5.1 Solved example Calculate the Extension force of the pneumatic cylinder shown in Fig. 1.4 If you are given the followings: Piston area (A) = 0.03 m2 Pressure (P) = 6 bar Solution F=P×A F = (6 × 100000) × 0.03 = 18000 N = 1800 Kg Fig. 1.4 Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics 6. For further reading, you can use the following links: 1- www.Fest-didactic.com 2- http://www.eng2all.com/vb/t28932.html 3- http://www.logiclab.hu/lesson.php?fe=2 7. Supplementary recourses 1- Pneumatics video from Festo. 2- FluidSIM software. 8. References 1- Festo manuals and workbook TP101 2- Festo manuals and textbook TP101 Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics Student’s notes ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ ............................................................................................................ Module 1: Introduction to Pneumatics ATM 1132 – Basic Pneumatics Worksheet 1 List three applications of pneumatics ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… State three advantages of pneumatics ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………. List any two disadvantages of pneumatics ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………. Write down the mathematical formula of Pascal’s law ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… If you need to lift a car of 1000 Kg (10000N) by a pneumatic cylinder of piston area equal 0.04 m2. What is the value of the pressure in this case? ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… What is the approximate value of the pressure used in pneumatic systems? ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… Module 1: Introduction to Pneumatics
