A Real Time Design and Development of Fixture for Unloading of Control Assembly in an Industry

IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 11, 2016 | ISSN (online): 2321-0613

A Real Time Design and Development of Fixture for Unloading of Control Assembly in an Industry Harshal A.Dalvi1 Dr. C.C.Handa2 1 P.G. Student 2Professor & Head 1,2 Department of Mechanical Engineering 1,2 KDK College of Engineering, Nagpur, R.T.M. Nagpur University, Maharashtra Abstract— Fixture is most important equipment used in mechanical industries to hold, locate and support the work piece during the operation. This project is developed to handle the control valve assembly on assembly line in an industry and the purpose of the project is to reduce the human effort require to unload the valve assembly from assembly line which is much heavier in weight. This project has been selected as an issue of safety and fatigue of the worker in an industry. The completion of the project will drastically reduce fatigue of the worker and also provide safe working conditions to worker at shop floor. This fixture works automatically with the help of some mechanical and electronic components such as Pneumatic Cylinder, Solenoid valve, Direction Control Valve, Switch Mode Power Supply (SMPS) etc. These all will make the machine efficient and on the completion of project one may gain the knowledge of design, fabrication and also about the pneumatic systems. Also this can be use where valves like components are handling manually.

Key words: Pneumatic Cylinders, Direction Control Valve, Switch Mode Power Supply (SMPS), Solenoid Valve, Valve Assembly I. INTRODUCTION The fixture is a special tool for holding a work piece in proper position during manufacturing operation. For supporting and clamping the work piece, device is provided.

Frequent checking, positioning, individual marking and nonuniform quality in manufacturing process are eliminated by fixture. This increase productivity and reduce operation time. Fixture is widely used in the industry practical production because of features and advantages. To locate and immobilize work pieces for machining, inspection, assembly and other operations fixtures are used. [1]A fixture consists of a set of locators and clamps. Locators are used to determine the position and orientation of a work piece, whereas clamps exert clamping forces so that the work piece is pressed firmly against locators. Clamping has to be appropriately planned at the stage of machining fixture design. The design of a fixture is a highly complex and intuitive process, which require knowledge. Fixture design plays an important role at the setup planning phase. Proper fixture design is crucial for developing product quality in different terms of accuracy, surface finish and precision of the machined parts. In existing design the fixture set up is done manually, so the aim of this project is to replace with pneumatic fixture to save time for loading and unloading of component. Pneumatic fixture provides the manufacturer for flexibility in holding forces and to optimize design for machine operation as well as process function ability.

Control valve assembly is part of a tractor which is fixed in the engine of tractor. Control valve assembly is made by assembling the different small parts. Weight of

control valve assembly is in the range of 20 kg to 60 kg depending upon the engine of a tractor. Control valve assembly made on assembly line and this heavy control valve assembly is unloading from assembly line manually.

Due to heavy weight of this control valve assembly this is the hazardous job for operator to unloading this control valve assembly. So there is a requirement of some automatic unloading fixtures which will pick this control valve assembly from assembly line and place on the outside assembly line. This project involves the design and development of the fixture to unload the control valve from assembly line solely for the purpose of safety of the operator and to reduce the human fatigue. This project is about designing and development of fixture carrying valve assembly. After the design has completed, it was transformed to its real product where the design is used for guideline.

II. BACKGROUND [2]This machine is basically works on the principle of pneumatic cylinder in which translatory movement of cylinder is converted into an oscillatory movement of valve assembly carrying platform. In this, for longer life of fixture, the machine has to be developed according to the design and the human fatigue for unloading the valve assembly will completely be eliminated, this can be possible with the help of some mechanical and electronic components such as Pneumatic Cylinder, Solenoid Valve, Flow Control Valve, SMPS (Switch Mode Power Supply) etc. The fixture is so design that at the end, valve assembly will be collected at the control valves collector bin without any damage to the valve assembly.

III. WORKING PRINCIPLE The most important part of a fixture machine is a Pneumatic Cylinder which provides an oscillatory moment to the platform about a pivoted point which carries the control valve assembly and dispatches it to the valve collector bin without any damage the to the valve. The pressure of the fluid is act on the face of the piston thus displacement of piston takes place and the force transmitted to the valve carrying platform through piston rod as per fig1.

Fig. 1: Designed Experimental Set Up

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A Real Time Design and Development of Fixture for Unloading of Control Assembly in an Industry (IJSRD/Vol. 3/Issue 11/2016/032)

The different components which help to make this machine human effort free are explained as follows: A. Pneumatic Cylinder Cylinders are linear actuator which converts the fluid energy into a mechanical energy with help of actuating device like piston. These cylinders can either be hydraulic operated or pneumatic operated. But hydraulic cylinders are generally used at high pressure and produce a large force. In this, there is no need of high force to handle the assembly of control valve. So, pneumatic cylinder has been chosen which can easily be operated at limited required pressure.[4] Pneumatic cylinders are sometimes known as air cylinders are mechanical device which use the power of compressed gas or air to produce a force in a reciprocating linear motion. In this, fluid pushes the piston thus movement of the piston takes place and force is produce.

Fig. 2: Pneumatic Cylinder As per fig 2. gas or air pressure, forces a piston to move in a particular direction. In other word, once actuated, compressed air enters into the tube at one end of the piston and, hence, imparts force on the piston. Consequently, the piston becomes displaced. The piston is a simple disc or cylinder, and the piston rod transfers all the force it develops to the object that is to be moved.

B. Directional Control Valves (DCVs): It determines the path through which a fluid transverses a given circuit. A valve is a device that receives an external signal (mechanical, fluid pilot signal, electrical or electronics) to release, stop or redirect the fluid that flows through it. The function of a DCV is to control the direction of fluid flow in any hydraulic system. A DCV does this by changing the position of internal movable parts. Directional control valves can control the start, stop and change in direction of flow of a pressure medium (i.e. hydraulic oil).

For this reason, they are also referred to as switching valves.

Directional control valves are available as spool valves, poppet valves or rotary slide valves. Rotary slide valves, however, are no longer commonly used due to low operating pressure (up to 70 bars).

Fig 3: Pilot Operated Direction Control Valve The function of a directional control valve is determined by the number of working ports (excluding control ports) and the number of spool positions. A directional control valve comprises at least two spool (switching) positions and two working ports. [5]Any valve contains ports that are external openings through which a fluid can enter and exit via connecting pipelines. The number of ports on a DCV is identified using the term

“way.” Thus, a valve with four ports is a four-way valve. A DCV consists of a valve body or valve housing and a valve mechanism usually mounted on a sub-plate. The ports of a sub-plate are threaded to hold the tube fittings which connect the valve to the fluid conductor lines. The valve mechanism directs the fluid to selected output ports or stops the fluid from passing through the valve. DCVs can be classified based on fluid path, design characteristics, control methods and construction.

C. Solenoid Valve A solenoid is a simple electromagnetic device that converts electrical energy directly into linear mechanical motion, but it has a very short stroke (length of movement), which limits its applications.

Fig 4: Principle of Solenoid [6] The solenoid consists of a coil of wire with an iron plunger that is allowed to move through the center of the coil. Above figure 4. shows the solenoid in the unenergized state. A solenoid valve is the combination of a basic solenoid and mechanical valve. So a solenoid valve has two parts namely- Electrical solenoid, mechanical valve.

Solenoid converts electrical energy to mechanical energy and this energy is used to operate a mechanical valve that is to open, close or to adjust in a position.

D. Switch Mode Power Supply (SMPS)

Fig 5: Block Diagram of SMPS Working Principle Switch-mode power supplies are a generally used in DC-DC power conversion system. SMPS provides distinct benefits when compared to alternative methods of converting DC power. Switch mode regulator is used to overcome the drawbacks of linear regulators. Switched power supplies are more efficient and they tend to have an efficiency of around 80% more or less. They compact in the size than linear regulators. Switched power supplies can be used for stepping up or steeping down the input voltage.

Generally, switched mode power supply consists of five standard components:  A pulse-width modulating controller  A transistor switch  An inductor  A capacitor and  A diode.

DC-DC converters is also called as choppers earlier, before, SCRs were used but Nowadays, IGBTs and MOSFETs are used mostly for dc-dc conversion and these

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A Real Time Design and Development of Fixture for Unloading of Control Assembly in an Industry (IJSRD/Vol. 3/Issue 11/2016/032)

circuits can be classified as switch mode power supply circuits.  Step up or step down an unregulated dc input voltage to a regulated dc output voltage  Step up an unregulated dc input voltage to a regulated dc output voltage using a Boost Converter circuit or Step-Up SMPS  Step down an unregulated dc input voltage to a regulated dc output voltage using a Buck Converter circuit or Step-Down SMPS,  Invert the input dc voltage using usually a converter circuit, and  Produce multiple dc outputs using the fly-back converter circuit.

Switch mode power supply is a widely used in a system such as a computer, television receiver, battery charger etc. The switching frequency above than 20 kHz is used in SMPS, so noise produced is above the audio range.

It is used in high-frequency unity-power factor circuit. It is also used to produce a variable dc voltage to a dc motor armature in a variable speed drive.

978-1-4244-7939-9, INSPEC Accession Number: 11727523, Conference Location : Wuhan, DOI: 10.1109/ICIECS.2010.5678378, Publisher: IEEE. [5] Qingxi Hu, Ting Wen, Jing Yu, “Rapid Fixture oriented Automatic Planning Approach and Implementation of Auxiliary Chuck” Published in: Measuring Technology and Mechatronics Automation (ICMTMA), 2010 International Conference on (Volume:2 ), Date of Conference: 13-14 March 2010, Page(s): 977 – 980, EISBN : 978-1-4244-5739-7, Print ISBN: 978-1-42445001-5, INSPEC Accession Number: 11290548, Conference Location : Changsha City.

[6] Janninck, R.F., Heiden, C.R., Guttensohn, A.E., “A rapid loading and unloading coliseum type fixture for ion plating reedblade contacts”, Published in: Journal of Vacuum Science and Technology (Volume:11, Issue: 2 ), Date of Publication: Mar 1974, Page(s): 535 – 536, ISSN : 0022-5355, DOI: 10.1116/1.1317855, Date of Current Version: 18 June 2009, Issue Date: Mar 1974, Publisher: AVS.

IV. CONCLUSION From the above study, it is observed that by arranging different mechanical as well as electronics components in a proper way the machine can be made efficient and automatic one to handle that valve assembly, completely to reduce the human efforts as well as provides a human safety. The use of such a system at shop floor also prevents the assembly from damages.

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[3] Shen Xiao-hong Zhang Yan-ting, “ Notice of Retraction Research on intelligent design system of hole-series built-up fixture”, Consumer Electronics, Communications and Networks (CEC Net), 2011 International Conference on Date of Conference: 16-18 April 2011, Page(s): 2512 – 5217, Print ISBN: 978-161284-458-9 INSPEC, Accession Number: 12055546, Conference Location: Xian Ning, DOI: 10.1109/CECNET.2011.5768873, Publisher: IEEE. [4] Mingwang Dong, XuePing Wang, “Research on Configuration Optimization of Loading-and-Unloading Equipment at Bulk Terminal”, Published in: Information Engineering and Computer Science (ICIECS), 2010 2nd International Conference on, Date of Conference: 25-26 Dec. 2010, Page(s): 1 – 4, ISSN : 2156-7379, E-ISBN : 978-1-4244-7941-2, Print ISBN:

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