Introduction to Pneumatics andPneumatic Circuit Problems for FPEF Trainer John R. Groot President FPEF John NagohosianFPEF Educational Coordinator John Prisciandaro Dan ButchkoBirmingham Covington School Derby Middle School Birmingham, Michigan Birmingham, MichiganFluid Power Education Foundation3333 N. Mayfair RoadSuite 101Milwaukee, WI 53222Phone: (414) 778-3364 FAX: (414)778-3361http://www.fpef.org Reference Page Fluid Power Educational Foundation http://www.fpef.org/ National Fluid Power Association http://www.nfpa.com/ International Fluid Power Society http://www.ifps.org/ Fluid Power Distributors Association http://www.fpda.org/ Parker Hannifin Corporation http://www.parker.com/ http://www.parker.com/training/ Clippard Minimatic http://www.clippard.com/ Introduction to Pneumatics with Circuit Design Problems for the FPEF Trainer Prepared by:John Prisciandaro and Dan Butchko, Birmingham Public Schools, Birmingham, Michigan Sponsored by: Fluid Power Educational Foundation, 3333 North Mayfair Rd., Milwaukee, WI 53222-3219This FPEF curriculum is designed to be used in Clippard Instrument Laboratory, Inc. and Parkerconjunction with a pneumatic trainer capable of Hannifin Corp., who allowed the use of their technicaldemonstrating the principles and circuits outlined in reference manuals and application problems, whichthe curriculum. The FPEF website provides links to provided much of the information in this manual;the manufacturers that have produced and madeavailable a trainer capable of being used with the Mike Pierno, Engineering Technology departmentcurriculum. This combination provides a head at Seaholm High School, Birmingham Publiccomprehensive and hands-on introduction to School District, whose program has been in existencePneumatics and Fluid Power capabilities.: for many years, and has actively participated in numerous FPEF sessions. Mike has been responsibleThe Fluid Power Educational Foundation, with its for “turning on” hundreds of students to the fluidmembers, have designed this training panel and power/motion control industry and was recentlymanual to help technical teachers and industrial awarded the honor of Key School by the FPEF.trainers facilitate a hands-on experience withpneumatics. The FPEF is grateful to its members for About the FPEFtheir hard work and financial support that has made The FPEF promotes technical education that integratesthis effort possible. Special thanks to John fluid power. The Foundation is always striving toNagohosian-Educational Coordinator, John Groot- raise the level of competence of young people enteringPresident, and Paul Gant-Treasurer, who initiated and our industry and improve visibility for fluid powerguided the project along with their legwork, expertise technology. For information regarding teacherand resources. training sessions, and other activities of the FPEF, contact:John Prisciandaro and Dan Butchko, who preparedthis manual, are Engineering Technology teachers in The Fluid Power Educational Foundationthe Birmingham Public School District, 3333 N. Mayfair RoadBirmingham, Michigan. Both John and Dan have Milwaukee, WI 53222-3219been involved in previous FPEF sponsored activities, Telephone #414-778-3364 Fax #414-778-3361including teacher training sessions, and developing www.fpef.organd presenting unique methods of integreting fluidpower applications in science and technology courses. Fluid Power Educational Foundation Introduction to PneumaticsPneumatic Transmission of EnergyThe reason for using pneumatics, or any other type of energy transmission on amachine, is to perform work. The accomplishment of work requires the applicationof kinetic energy to a resisting object resulting in the object moving through adistance. In a pneumatic system, energy is stored in a potential state under the formof compressed air. Working energy (kinetic energy and pressure) results in apneumatic system when the compressed air is allowed to expand. For example, atank is charged to 100 PSIA with compressed air. When the valve at the tank outletis opened, the air inside the tank expands until the pressure inside the tank equals theatmospheric pressure. Air expansion takes the form of airflow.To perform any applicable amount of work then, a device is needed which cansupply an air tank with a sufficient amount of air at a desired pressure. This deviceis positive displacement compressor. What a Positive Displacement Compressor Consists ofA positive displacement compressor basically consists of a movable member insidea housing. The compressor has a piston for a movable member. The piston isconnected to a crankshaft, which is in turn connected to a prime mover (electricmotor, internal combustion engine). At inlet and outlet ports, valves allow air toenter and exit the chamber. How a Positive Displacement Compressor WorksAs the crankshaft pulls the piston down, an increasing volume is formed within thehousing. This action causes the trapped air in the piston bore to expand, reducing itspressure. When pressure differential becomes high enough, the inlet valve opens,allowing atmospheric air to flow in. With the piston at the bottom of its stroke, inletvalve closes. The piston starts its upward movement to reduce the air volume whichconsequently increases its pressure and temperature. When pressure differentialbetween the compressor chamber and discharge line is high enough, the dischargevalve opens, allowing air to pass into an air receiver tank for storage. 1 Fluid Power Educational Foundation Introduction to PneumaticsControl of Pneumatic EnergyWorking energy transmitted pneumatically must be directed and under completecontrol at all times. If not under control, useful work will not be done and machineryor machine operators might be harmed. One of the advantages of transmittingenergy pneumatically is that energy can be controlled relatively easily by usingvalves. Control of PressurePressure in a pneumatic system must be controlled at two points - after thecompressor and after the air receiver tank. Control of pressure is required after thecompressor as a safety for the system. Control of pressure after an air receiver tankis necessary so that an actuator receives a steady pressure source without wastingenergy. Control of Pressure after A CompressorIn a pneumatic system, energy delivered by a compressor is not generally usedimmediately, but is stored as potential energy in air receiver tank in the form ofcompressed air.In most instances, a compressor is designed into a system so that it operatesintermittently. A compressor usually delivers compressed air to a receiver tank untilhigh pressure is reached, then it is shut down. When air pressure in the tankdecreases, the compressor cuts in and recharges the tank. Intermittent compressoroperation in this manner is a power saving benefit for the system.A common way of sensing tank pressure and controlling actuation and de-actuationof relatively small (2-15 HP) compressors, is with a pressure switch. Pressure SwitchSystem pressure is sensed with a spring-loaded piston within the switch housing.When pressure in the system is at its low level, the spring pushes the piston down. Inthis position a contact is made causing an electrical signal to turn on the compressor.As pressure in the receiver tank rises, it forces the piston upward. With systempressure at its high level, the piston breaks the electrical contact shutting down thecompressor. 2 Fluid Power Educational Foundation Introduction to Pneumatics Safety Relief ValveMaximum pressure developed by a compressor is designed to be regulated by acontrol system which senses discharge or tank pressure. In case of an emergency,such as the failure of a control system to function properly, a positive displacementcompressor system is generally equipped with a safety relief valve.A safety relief valve is a normally closed valve. The poppet of the safety relief valveis seated on the valve inlet. A spring holds the poppet firmly on its seat. Air cannotpass through the valve until the force of the spring biasing the poppet is overcome.Air pressure at compressor outlet is sensed directly on the bottom of the poppet.When air pressure is at an undesirably high level, the spring will be compressed, thepoppet will move off its seat, and air will exhaust through the valve.A safety relief valve on a compressor is not intended to operate frequently. A safetyrelief valve is designed only to be a safety device. Many times safety relief valvesare equipped with whistles or horns to alert personnel that something has failed or aproblem exists. Pressure RegulatorIn a pneumatic system, energy that will be used by the system and transmittedthrough the system is stored as potential energy in an air receiver tank in the form ofcompressed air. A pressure regulator is positioned after a receiver tank and is usedto portion out this stored energy to each leg of the circuit.A pressure regulator is a normally open valve.With a regulator positioned after a receiver tank, air from the receiver can expand(flow) through the valve to a point downstream. As pressure after the regulator rises,it is sensed in an internal pilot passage leading to the underside of the piston.This piston has a large surface area exposed to downstream pressure and for thisreason is quite sensitive to downstream pressure fluctuations. When downstreampressure nears the preset level, the piston moves upward pulling the poppet towardits seat. The poppet, once it seats, does not allow pressure to continue buildingdownstream. In this way, a constant source of compressed air is made available toan actuator downstream. 3 Fluid Power Educational Foundation Introduction to Pneumatics Common Types of CylindersThere are many different cylinder types. The most common are listed below:Single acting cylinder - a cylinder in which air pressure is applied to the movableelement (piston) in only one direction.Spring return cylinder - a cylinder in which a spring returns the piston assembly.Ram cylinder - a cylinder in which the movable element is the piston rod.Double acting cylinder - a cylinder in which air pressure may be alternately appliedto the piston to drive it in either direction.Double acting – double rod cylinder - Double acting cylinder with apiston rod extending form each end. The piston rods are connected tothe same piston. Double rod cylinders provide equal force and speed inboth directions. 4 Fluid Power Educational Foundation Introduction to Pneumatics Sizing a CylinderTo determine the size cylinder that is needed for a particular system, certainparameters must be known. First of all, a total evaluation of the load must be made.This total load is not only the basic load that must be moved, but also includes anyfriction and the force needed to accelerate the load. Also included must be the forceneeded to exhaust the air from the other end of the cylinder through the attachedlines, control valves, etc. Any other force that must be overcome must also beconsidered as part of the total load. Once the load and required force characteristicsare determined, a working pressure should be assumed. This working pressure thatis selected MUST be the pressure seen at the cylinder's piston when motion is takingplace. It is obvious that cylinder's working pressure is less than the actual systempressure due to the flow losses in lines and valves.With the total load (including friction) and working pressure determined, thecylinder size may be calculated using Pascal's Law. Force is equal to pressure beingapplied to a particular area. The formula describing this action is: Force = Pressure * AreaForce is proportional to pressure and area. When a cylinder is used to clamp orpress, its output force can be computed as follows: F = P * AP = pressure (PSI (Bar) (Pascal's))F = force (pounds (Newtons))A = area (square inches (square meters))These pressure, force and area relationships are sometimes illustrated as shownbelow to aid in remembering the equations.F=P*A F FP = -- P A A 5 FA = -- P Fluid Power Educational Foundation Introduction to Pneumatics Directional Control ValvesTo change the direction of airflow to and from the cylinder, we use a directionalcontrol valve. The moving part in a directional control valve will connect anddisconnect internal flow passages within the valve body. This action results in acontrol of airflow direction. Valve flow diagrams are reprinted courtesy of Parker Hannifin Corporation.The typical Passage A Passage Bdirectional controlvalve consists of a Spoolvalve body withfour internal flow Valve Bodypassages within thevalve body and a Pressure Exhaustsliding spool. Passage PassageShifting the spool alternately connects a cylinder port to supply pressure or theexhaust port. With the spool in the position where the supply pressure is connectedto port A and port B is connected to the exhaust port, the cylinder will extend. Then,with the spool in the other extreme position, supply pressure is connected to port Band port A is connected to the exhaust port, now the cylinder retracts. With adirectional control valve in a circuit, the cylinder's piston rod can be extended orretracted and work performed.AB ABP Ex P Ex 6 Fluid Power Educational Foundation Introduction to Pneumatics Functional Types of Directional Control ValvesOne method of classifying a directional control valve is by the flow paths that areset up in its various operating conditions. Important factors to be considered are thenumber of individual ports, the number of flow paths the valve is designed for andinternal connection of ports with the movable part. Two-Way Directional ValveA two-way directional valve consists of two ports connected to each other withpassages, which are connected and disconnected. In one extreme spool position, portA is open to port B; the flow path through the valve is open. In the other extreme,the large diameter of the spool closes the path between A and B; the flow path isblocked. A two-way directional valve gives an on-off function.Flow Path Open Flow Path Closed 7 Fluid Power Educational Foundation Introduction to Pneumatics Three-Way Directional ValveA three-way directional valve consists of three ports connected through passageswithin a valve body that are shown here as port A, port P and port Ex. If port A isconnected to an actuator, port P to a source of pressure and port Ex is open toexhaust, the valve will control the flow of air to (and exhaust from) Port A.The function of this valve is to pressurize and exhaust one actuator port. When thespool of a three-way valve is in one extreme position, the pressure passage isconnected with the actuator passage. When in the other extreme position, the spoolconnects the actuator passage with the exhaust passage.AAP Ex P Ex 8 Fluid Power Educational Foundation Introduction to Pneumatics Four-Way Directional ValvePerhaps the most common directional valve in simple pneumatic systems consists ofpressure port, two actuator ports and one or more exhaust ports. These valves areknown as four-way valves since they have four distinct flow paths or \"ways\" withinthe valve body.A common application of four-ported four-way directional valve is to causereversible motion of a cylinder or motor. To perform this function, spool connectsthe pressure port with one actuator port. At the same time, the spool connects theother actuator port with the exhaust port. This is a four-ported four-way valve. Passage A Passage B SpoolValve Body Pressure Exhaust Passage Passage AB AB P Ex P Ex AB AB P Ex P Ex 9 Fluid Power Educational Foundation Introduction to PneumaticsFive-Port / Four-Way Directional ValveFour-way valves are also available with five external ports, one pressure port, twoactuator ports, and two exhaust ports. Such valves provide the same basic control offlow paths as the four-ported version, but have individual exhaust ports. In the fluidpower field this is referred to as a \"five-ported, four-way valve.\" This type of valvebrings all flow paths to individual external ports. The pressure port is connected tosystem pressure after a regulator. Actuator ports are connected to inlet and outletports of a cylinder or motor. Each exhaust port serves an actuator port. AB Ex1 P Ex2 5-Ported, 4-Way Valve AB Ex1 P Ex2 10 Fluid Power Educational Foundation Introduction to Pneumatics Schematic Symbols for Directional ValvesA directional valve is a valve that directs the flow of air in one with or another. Itdoesn't throttle or meter the airflow, and it doesn't change the pressure of the air. Itjust changes the direction of the airflow in some way. The ANSI symbol fordirectional valves are the most complicated of all the fluid power symbols, but someof the most important, so let us start with directional valves, see how the symbolsystem works. A typical directional valve symbol is made up of three parts:Left Actuator Valve Action Right ActuatorThe actuators are the devices or methods that cause the valve to shift from oneposition to another. The valve action refers to the combinations of positions andflow paths which the valve offers. Position BoxesEvery valve provides two or more usable positions, each position providing one ormore flow paths. For example, the familiar single solenoid spring return valveprovides two usable positions, one position occurring when the solenoid is incommand of the valve, the other position occurring when the spring is in commandof the valve. The ANSI symbol for a directional valve is built around a series ofboxes or rectangles, one box for each usable position of the valve. A 2-Position valve is shown by two boxes. A 3-Position valve is shown by three boxes. 11 Fluid Power Educational Foundation Introduction to PneumaticsMost air moves are either 2-position or 3-position valves, but it would be possible tohave an unusual valve with four or five or even six positions. In any case, therewould be a box to represent each position of the valve. Valve PortsEvery valve port, which appears on the outside of the valve, is supposed to beshown on the symbol. But the ports are shown on only one of the boxes, the box thatrepresents the flow paths that exist at the start of the machine cycle. Some examplesare: A 2-position 2-port valve A 2-position 3-port valve A 3-position 4-port valve Flow PathsEach box contains a group of lines that represent the flow paths the valve provideswhen it is in that position. If a port is blocked, we show that by the symbol .If two ports are connected and air can flow, this is shown by a line drawn betweenthe two ports. 2 1In the example above, the left box shows the conditions that exist at the start of thecycle. Port 1 is blocked, and port 2 is blocked. When the valve is shifted, the flowcondition shown in the right hand box exists. Port 1 is open to port 2. 12 Fluid Power Educational Foundation Introduction to PneumaticsThe direction in which air flows during a normal operating cycle is shown byputting arrowheads at the ends of the flow paths next to the ports where the air willcome out. 2 Example #1 - At the start of the cycle, the flow path from port 1 to port 2 is blocked. When the valve shifts, flow is from port 1 to port 2. 1 Example #2 - At the start of the cycle, the flow path 2 from port 1 to port 2 is blocked. When the valve shifts, port 1 is opened to port 2, but during some part of the cycle air flows from port 1 to port 2, and 1 during another part of the cycle air flows from port 2 to port 1.Typical Symbols for Valve Actions Two- Position Valves2-Way, Blocked 2-Way, Open atat start of cycle start of cycle3-Way, Blocked 3-Way, Open atat start of cycle start of cycle2-Inlet Selector Distributor (Diverter)4-Way, 4-portSingle Inlet 4-Way, 5-Port Single Inlet Dual4-Way, 5-port or ExhaustsDual PressureCommonExhaust 13 Fluid Power Educational Foundation Introduction to PneumaticsSymbols for Valve ActuatorsThe symbols for the valve actuators are drawn next to the end of the valve boxes.The rule is that each actuator is drawn next to the box that exists when that actuatoris in command. In the drawing above, when the spring has control of the valve, theflow paths in the left hand box. When the solenoid (the right hand actuator) is incommand, the flow paths in the right hand box exist.There are a series of standard symbols for actuators. These symbols may be drawnon either end of the valve without altering their meaning.Spring Composite ActuatorsManualPush Button If two actuator symbols are drawn side by side, this means that either one can cause the valve to actuate.Lever Either the air pilot OR the spring can cause theMechanical valve to move.Solenoid Typical Actuator CombinationsAir Pilot 2-Position, Double pilot, detented 3-Position, Double pilot, spring centeredAir Pilot(Alternate)Detent 14 Fluid Power Educational Foundation Introduction to Pneumatics Miscellaneous Valve Symbols Check Valve - Allows flow in one direction, but blocks flow in the other direction. In this example flow can go from right to left, but now flow left to right is blocked. Fixed Restriction or orifice - Restricts flow in both directions. Adjustable Restriction - Restricts flow in both directions. Flow Control Valve - (also called speed control valve) allows free flow in one direction but restricts flow in the other direction. In this example free flow is from right to left, restricted flow from left to right. In this example, free flow is from left to right. Restricted flow is from right to left. Shuttle Valve - A three-port valve with two inlets and one outlet. In this example ports 1 and 2 are1 inlets, port 3 the outlet. If pressure is applied3 to port 1, it will appear out port 3, but will not back-flow out port 2. If pressure is applied to port 2, it will appear2 out port 3 but will not back-flow out port 1. When the pressures are removed from ports 1 and 2, port 3 will exhaust back out one of the two inlet ports, but it may exhaust out either of them. Pulse Valve A valve that allows the initial supply of air it receives to pass through it just for a few milliseconds (pulse), then remains closed until the supply pressure is exhausted. 15 Fluid Power Educational Foundation Introduction to Pneumatics Summary Explanation of Valve TerminologyTWO Way Valve, Normally Closed: Flow is from inlet to outlet when the valve is actuated. Fluid in outlet line is trapped when the valve is deactivated.THREE Way Valve, Normally Closed: Flow is from inlet to outlet when the valve is actuated. On deactivation of valve, outlet line is vented to atmosphere.THREE Way Valve, Normally Open: Flow is from inlet to outlet in the deactivated valve condition. Actuation of the valve stops flow from inlet to outlet, the outlet is then exhausted.FOUR Way Valve: From inlet, flow is diverted to one of the outlets; outlet port that is not active is vented to atmosphere. Valve can be either spring return or two-position type.FLOW Control Valve: Allows free flow in one direction and controlled adjustable flow rate in the other direction.SHUTTLE Valve: Allows flow from either input to the output.PULSE Valve: A unitized valve that converts a continuous supply of air into an outlet pulse of air and then remains closed until the supply pressure is exhausted. 16 Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #1Application:Finished parts are accumulating on the end of a conveyor. The parts need to betransferred on to a connecting conveyor that carries them to the final inspectionand packaging stations. The technician needs to be able to activate and thenrelease a transfer device powered by a pneumatic cylinder.Objective:To be able to design and assemble a circuit that extends and retracts a singleacting, spring return cylinder.Circuit Problem:Using the given components and layout, design a schematic circuit which willoperate a spring return cylinder with a two position, spring offset, three-way valve.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 3 Part # Component Description Qty 1 1 1 1 2-position, spring offset, 3-way valve 1 2 2 push button actuator1 3 single acting, spring return cylinder NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #2Application:Parts need to be clamped for a drilling operation. The technician needs to activateand deactivate a pneumatic clamp that holds the part in a fixture on the drillingmachine. The clamp must be activated before the drilling cycle begins anddeactivated at the end of the drilling cycle.Objective:To be able to design and assemble a circuit that extends and retracts a doubleacting cylinder.Circuit Problem:Using the given components and layout, design a schematic circuit which willoperate a double acting cylinder with a two position four-way valve.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 3 1 Part # Component Description Qty 1 2 position, 4-way valve 1 2 2 manual actuator 1 1 3 double acting cylinder 111 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #3Application:A large stamping press must have a part in place, the clamps engaged and thesafety guard closed before the press can operate. The pneumatic circuit needed forthis type of machine is designed to minimize potential safety hazards.Objective:To be able to design and assemble an “AND” logic circuit.Circuit Problem:Using the given components and layout, design a schematic circuit which will onlyoperate the cylinder when the three valves are all simultaneously operated,indicating the safety precautions are in place.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 4 31 2 1 Part # Component Description Qty 1 32 1 2-position, spring offset, 3-way valve 51 2 air pilot actuator 2 31 3 manual actuator 3 4 single acting, spring return cylinder 1 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON THE VALVES. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #4Application:Parts are accumulating on a conveyor belt and waiting to be released andtransferred to the next phase of assembly. Technicians at multiple stations need tocontrol the gate release mechanism to have parts sent to their assembly station.Objective:To be able to design and assemble an “OR” logic circuit.Circuit Problem:Using the given components and layout, design a schematic circuit which willoperate one spring return cylinder from any one of three identical valves.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 3 1 1 2 3 4 1 41 Part # Component Description Qty 2 1 2-position, spring offset, 3-way valve 3 2 shuttle valve 2 3 3 push button actuator 3 1 4 Single acting, spring return cylinder 11 N NOTE: ACTUATORS MAY ALREA DY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #5 Application: A plastic thermo-forming machine is capable of heating and forming parts of various thicknesses. The parts must be held in their molded positions while the plastic is curing in its final form. The length of time needed to cure the plastic will vary depending on the thickness. This in turn will require a forming operation that has a variable time delay before the part is automatically released. Objective: To be able to design and assemble a “LIMITED MEMORY” circuit. Circuit Problem: Using the given components and layout, design a schematic circuit which will extend a cylinder for an adjustable period of time, then automatically retract the cylinder. Design and draw schematic diagram. Approved: _______ Connect components to match schematic diagram. Operate and explain circuit to instructor. Approved: _______ Layout of Components Needed: 6 Qty Part # Component Description5 1 2-position, spring offset, 3-way valve 2 4 2 2 volume chamber 1 3 air pilot actuator 11 4 flow control valve 1 5 push button actuator 1 3 6 single acting, spring return cylinder 1 1 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #6Application:A gravel yard has a single conveyor that can transport gravel to two differentloading docks. In order to shift the out feed of the conveyor to the alternate loadingdock the operator must push a button. As a safety precaution, the conveyor willalways be held in the last shifted position.Objective:To be able to design and assemble an “FULL MEMORY” circuit.Circuit Problem:Using the given components and layout, design a schematic circuit that requires theoperator to push one of two buttons that in turn shifts a detented, two position,four-way valve. The valve is air-piloted in both directions and operates a doubleacting cylinder.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 5 Part # Component Description Qty 1 1 2-position, spring offset, 3-way valve 2 4 4 2 2-position, detented, 4-way valve 1 1 1 3 push button actuator 2 4 air pilot actuator 23 2 3 5 double acting cylinder 11 1 111 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #7Application:Boxes are being filled with packing material that is dispensed in a time-releasedquantity. The exact amount of packing material needed is dispensed in one cycle.The operator must not be able to double pack the boxes, which would create anoverflow situation. The operator will push a button to activate the dispensing gate.Once the button is pushed the cycle will continue until completed. A new cyclecannot be started until the first cycle is completed and the push button released.Even if the push button is held down continuously, a new cycle cannot be started.Objective:To be able to design and assemble a “ONE SHOT CYCLE” circuit.Circuit Problem:Using the given components and layout, design a schematic circuit which will onlyoperate the cylinder for one timed cycle. No matter how long the valve is heldshifted, only one cycle of the cylinder will result. The pulse valve controls the timedelay before the retraction of the cylinder. The one shot cycle is a limited memorytime function.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 8 4 7 Part # Component Description Qty 1 1 122 1 2-position, spring offset, 3-way valve 211 1 2 flow control valve 2 1 3 air pilot actuator 2 3 53 4 pulse valve 1 1 11 6 5 2-position, detented, 4-way valve 1 1 6 push button actuator 1 7 mechanical actuator 1 8 double acting cylinder 1 1 NOTE: ACTUATORS MAY ALREADY BE 1 ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #8Application:The machine head of a precision grinder needs to continuously reciprocate over acylinder head surface being finished. The speed of the stroke must be controlled inboth directions.Objective:To be able to design and assemble an “AUTOMATIC CAM CYCLING” circuit.Circuit Problem:Using the given components and layout, design a schematic circuit thatautomatically cycles the continuous reciprocation of a cylinder. Limit valveslocated at the full extension and retraction of the cylinder are mechanically (cam)operated. Flow control valves that control the flow of the exhaust air leaving thecylinder (bleeding out) govern the speed of the operation. The cycle is started andstopped the shifting of toggle valve.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 8 7 7 Part # Component Description Qty 1 1 1 1 2-position, spring offset, 3-way valve 2 4 11 2 2-position, 3-way valve 1 1 11 3 2-position, detented, 4-way valve 1 4 flow control valve 25 4 5 air pilot actuator 2 1 6 manual actuator 1 3 7 mechanical actuator 2 1 8 double acting cylinder 151 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. 26 11 Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #9Application:The material transfer portion of a progressive die machine needs to be manuallyindexed by the operator shifting a valve. When this happens, the locator pins arereleased and the sheet metal roll advances to the next die. The locating pins canonly be released while the sheet metal roll is advancing.Objective:To be able to design and assemble a “ONE CYCLE – THEN RESET” circuit.Circuit Problem:Using the given components and layout, design a schematic circuit that will extenda double acting cylinder while simultaneously extending a spring return cylinder.The spring return cylinder is operated when a cam follower is actuated and canonly operate during the extension of the double acting cylinder. When the doubleacting cylinder is fully extended it actuates a cam follower that causes it to retractand be ready for another cycle (reset). When the double acting cylinder retracts, noaction occurs upon actuating the cam follower.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 5 7 8 Part # Component Description Qty 1 16 1 1 2-position, detented, 4-way valve 13 1 6 2 flow control valve 214 1 3 2-position, spring offset, 3-way valve 3 2 2 3 4 air pilot actuator 2 1 1 1 1 3 5 push button actuator 1 1 1 6 mechanical actuator 2 1 7 double acting cylinder 1 8 single acting, spring return cylinder 1 4 1 NOTE: ACTUATORS MAY ALREADY BE ASSEMBLED ON A VALVE. Fluid Power Educational Foundation An Introduction to Pneumatics Pneumatics Problem #10Application:A power door opening system must be controlled with a timed cycle. Operatorsneed to activate the door cycle from both inside and outside by pushing a button.The door needs to remain open for an adjustable time period before itautomatically closes. The operators must also have a means to keep the door opencontinuously when needed.Objective:To be able to design and assemble a “DOOR OPENER – DELAY SHUT” circuit.Circuit Problem:Using the given components and layout, design a schematic circuit which allowstwo valves to start a cycle that extends a cylinder for an adjustable time period andthen retracts it. The adjustable time delay is controlled be a “limited memory”circuit. A third valve (toggle valve) must have the ability to extend the cylinderand keep the cylinder extended until the operator wants it retracted.Design and draw schematic diagram. Approved: _______Connect components to match schematic diagram.Operate and explain circuit to instructor. Approved: _______Layout of Components Needed: 7 Part # Component Description Qty1 9 10 1 2-position, 3-way valve 1 1 2 4 2 2-position, spring offset, 3-way valve 1 1 1 3 2-position, spring offset, 4-way valve 2 1 8 6 4 flow control valve 1 15 1 5 shuttle valve21 6 air pilot actuator 21 1 1 8 5 3 7 manual actuator 1 1 1 8 push button actuator2 9 volume chamber1 10 double acting cylinder Note: Actuator may already be assembled on a Valve
