Design and Development of Drilling Jig for Spinning Rings used in Textile Industry

Transcription

1 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Design and Development of Drilling Jig for Spinning Rings used in Textile Industry Dr. Rajendra K. Patil Professor: Dept. of Mechanical Engineering TSSM s PadmabhooshanVasantdadaPatil Institute of Technology Bavdhan, Pune, India rkpvpit@gmail.com Shivam C. Shinde Student: BE Mechanical Engineering shivam.shinde54@gmail.com Suraj Madhukar Takale Bhawarlal Choudhary Surajtakale777@gmail.com bhawar1976@gmail.com Abstract The target of the mass production is to increase the productivity and increase the accuracy. This is done by reducing the set up cost and manual fatigue. Thus mass production can be achieved by the use of jigs. For large scale production of different materials a lot of time is wasted in set up of the device and clamping the device. Trial and error method is usually practiced until the axis of the hole is properly aligned with the axis of the drill. In such a situation a lot of time is being wasted to maintain the accuracy. Eventually it increases the operator s fatigue. Thus drill jig increases productivity by eliminating individual positioning, marking and frequent checking. The main advantage of the jigs is interchangeability. The need of selective assembly is eliminated. The parts of the jig will fit properly and in the assembly and all similar components are interchangeable. Also a jig reduces the repetitive nature required for drilling holes, because the locating, clamping and guiding of the tool is done by the jig itself. The tool guiding element is used whose chief work is to guide the tool in to the correct position. Hence the requirement of skilled labor is eliminated. Keywords productivity; accuracy; jig; interchangeability; locating; clamping; guiding. I. INTRODUCTION UnitechTexmechPvt. Ltd. is a manufacturer of spinning rings used in textile industry. Therefore,spinning rings are mass produced in this organization. Drilling operation is a vital operation carried out during the production of these rings. The unique features of the machined holes are 1) the holes have to be drilled 15 degrees inclined to the vertical, into the ring body from the top surface, 2) the hole should be drilled exactly between two milling cuts present horizontally on the ring body and should be equidistant, 3) the diameter of the machined holes is 1.0 mm, 1.1mm or 1.2 mm based of the buyer s requirement, 4) if the angle of the machined holes is incorrect, the ring is rejected. The drill machines used in the organization are standard radial arm drills. Previously, the drill operator would place half of the ring on a step of certain height so that the required angle is achieved and would hold the ring manually and perform the operation, which was unethical and unsafe. After noticing and understanding the problem, development of a drilling jig was proposed. The proposed jig not only optimized the accuracy of the machined holes but it also reduced the rejection rate, along with making it a safe operation for the drill operator. The jig has a universal design so that it can be used to operate spinning rings with variable diameters and heights. II. DESIGN METHODOLOGY A. Development of an Inclined Platform The previously used step to achieve the required angle to drill holes into the ring body had to be considered in the drill jig. The top surface of the ring is tapered at an angle of 15 degrees from the horizontal. Therefore by using the alternate angles phenomenon an inclined platform was developed which had an angle on 15 degrees from the horizontal. Therefore when the ring was placed on the platform one end of the ring would be parallel to the horizontal. B. Design of the Ring Assembly A jig is used to locate and clamp the workpiece and to guide a tool onto the workpiece. An octagonal disc was manufactured on which the ring could be mounted. The disc has a stepped hole in the centre. A stub locator was used to locate the ring concentrically. It is manufactured with an outer diameter equal to that of the inner diameter of the ring. The stub locator has a boss that fits in the stepped hole of the disc. Therefore after placing the ring and the stub on the octagonal disc, 3067

2 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 the ring is located concentrically to the disc. A circular disc called star plate was used to clamp the disc. The disc is called star plate because of the Fig. 1. Computer Aided Design of Star Plate top surface it has 24 grooves at 15 degrees intervals. Fig. 1 shows the computer aided design of the Star Plate. Based on the requirement of the holes to be drilled on the spinning rings (3 or 4 holes) there are slots cut on the stepped surface of the star plate at 120 degrees interval and 90 degrees interval through various number of equidistant holes can be drilled. There is a slot cut at 45 degrees to locate the milling cut groove on the ring for 4 equidistant holes and at 60 degrees to locate the milling cut groove on the ring for 3 equidistant holes. Therefore the star plate serves the purpose of indexing in the jig but it is also used to clamp the ring. The star plate has a boss at its lower surface which fits inside the top surface of the stub locator. The octagonal disc, stub locator and star plate are assembled together with a washer and a screw. The washer is used for easy and faster loading and unloading of the spinning ring. This is the ring assembly. The octagonal disc is the base of the ring assembly and has a boss which slides through the slot located centrally on the inclined platform. The shape of the disc is octagonal rather than circular for easy gripping during indexing. C. Need for Stopper Plate When the ring assembly slides freely inside the slot of the inclined platform it should be stopped at a correct distance sothat the ring is located perfectly for the drilling operation. Hence a stopper plate is used to prevent this sliding. D. Design of the Tool Guide A tool guide is required when manufacturing a jig. The proposed jig had a tool guide plate called as jig plate placed on various packing plates. Depending on the varying ring heights the height of the jig plate could be adjusted. Fig. 2 represents a computer aided design of the jig plate. The jig plate has a tapered edge which is used to match the grooves on the star plate and through the holes the drill tool is guided on the ring. Since the diameters of the rings vary the jig plate can be slid in the slot it is placed in. It consists of various holes on its body so when the first is eroded due to continuous use it can be cut and new hole can be used for tool guidance. III. DESIGN RESULT A. Working of the Jig The jig, Fig. 3, is placed on the machine table of the drilling machine. Consider a drilling operation to be performed on the spinning ring with a requirement of 3 holes, it is placed on the octagonal disc with the corresponding stub locator. After locating the milling cut groove on the ring body on the star plate slot located at 60 degrees the assembly is fastened with a screw and the washer. When the edge of the jig plate is matched with the groove on the 0 degree slot a hole is drilled on the ring. The ring assembly is rotated to the second slot on the star plate at 120 degree groove and the hole is drilled. Similarly for the third hole at 240 degree slot. Hence, all three holes are drilled equidistantly. Fig. 2. Computer Aided Design of Jig Plate /16/$ IEEE 3068

3 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 B. Problems faced during development Due to large number of parts the jig consists the jig had become heavy and sturdy. To reduce the weight of the jig many grooves and slot were cut on the base plate, inclined plate and packing plates. The loading and unloading of rings is time consuming. The stress, strain and displacement analysis of cantilever plate has been carried out. Fig 4 shows Stress analysis of the cantilever plate, Fig 5 shows the Strain analysis of the cantilever plate and Fig 6 shows the Displacement analysis of the cantilever plate. C. Part list Table 1 includes the number and name of the parts of the jig. TABLE I. PART LIST Component Serial No. Name Material Quantity Base Plate 02 Inclined Plate 03 Thrust Plate 04 Support for Inclined Plate 05 Packing Plate for Stopper Plate 06 Semi-Circular Plate 07 Stopper Plate 08 Octagonal Disc 09 Stub Locator EN Star Plate EN Washer EN Packing Plate 1 13 Packing Plate 2 14 Cantilever Plate for Jig Plate 15 Jig Plate 16 Allen Screw Countersunk (M6) 17 Allen Screw(M8) 18 Clamping Plate for Jig plate 19 Allen Screw(M6)

4 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Fig. 3. Computer Aided Design of Jig D. Effectiveness of the Jig Table II shows the trial of using the Jig for continuous 6 hours. TABLE II. EFFECTIVENESS OF JIG Time (is seconds) Loading Time (S) Drilling Time (S) Unloading Time (S) Cycle Time (S) Actual Time (S) [+ Marking Time Of 2 Seconds] Ring No. Remark 11:36 AM Initiated 25 Mins For CClamp Setting 3070

5 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Time (is seconds) Loading Time (S) Drilling Time (S) Unloading Time (S) Cycle Time (S) Actual Time (S) [+ Marking Time Of 2 Seconds] Ring No. Remark 12:58 PM Stopped 1:28 PM Initiated Drill Bit Failure 2 Mins 3071

6 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Time (is seconds) Loading Time (S) Drilling Time (S) Unloading Time (S) Cycle Time (S) Actual Time (S) [+ Marking Time Of 2 Seconds] Ring No. Remark 2:53 PM Stopped 2:56 PM Initiated Drill Bit Failure 2 Mins 3:24 PM Stopped 4:44 PM Initiated 3072

7 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Time (is seconds) Loading Time (S) Drilling Time (S) Unloading Time (S) Cycle Time (S) Actual Time (S) [+ Marking Time Of 2 Seconds] Ring No. Remark Drill Bit Failure 2 Mins 5:38 PM Stopped 3073

8 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 Fig. 4. Stress analysis of cantilever plate Fig. 5. Strain analysis of cantilever plate Fig. 6. Displacement analysis of cantilever plate 3074

9 Proceedings - International Conference on Industrial Engineering and Operations Management, Kuala Lumpur, Malaysia, March 8-10, 26 IV. CONCLUSION The simple design of the drilling jig is easy to use and it eliminates the process of punching, since indexing is used. The jig has improved the accuracy of the holes due to which the rejection rate of the rings has reduced. From Table II it can be seen, due to the tool guide used in the jig, life of the drill bit has improved, earlier the drill bit would fail after every rings. Though the loading and unloading process in this jig is time consuming the indexing makes drilling quicker and accurate operation and therefore the total cycle time has been reduced. Previously, the operator would rotate the ring manually which was an unsafe operation, due to the use of jig safety has been ensured. The jig is being used regularly in the organization and plans to develop more such jigs. Though there are so many advantages of using the jig there are some minor problems as well, the setting of the jig on the machine table requires time and has to be accurate. Swarf accumulation may decrease the accuracy of the machined holes, by accumulating under the ring assembly and varying the angle, if not removed regularly. ACKNOWLEDGMENT Any accomplishment requires the effort of many people and this work is no different. We find great pleasure in expressing our deep sense of gratitude towards all those who have made it possible for us to complete this project work. We would like to express our gratitude towards UnitechTexmechPvt. Ltd. for providing us with the best facilities and proper environment to work on our project. REFERENCES Mohsin Ali, Design and analysis of weight lever drilling jig, IJPRET, vol. 1(8), pp , April 23. Hamad Mohammed Abouhenidi, Jig and Fixture Design, IJSER, Vol. 5, Issue 2, pp ,ISSN , February 24. Charles Chikwendu Okpala, Ezeanyim Okechukwu C., The Design and Need for Jigs and Fixtures in Manufacturing, Science Research,Vol. 3, No. 4, pp doi: , 25. [4] Sawita D. Dongre, Prof. U. D. Gulhane, Harshal C. Kuttarmare, Design and Finite Element Analysis of Jigs and Fixtures for Manufacturing of Chassis Bracket, IJRAT, Vol. 2, No. 2, February 24. [5] Edward G. Hoffman, Jig and Fixture design, Edition 5, Cengage Learning, [6] Rajput, R.K, (2007), A Textbook of Manufacturing Technology, Laxmi Publications, 1st Edition, pp. 899, ISBN [1] [2] [3] BIOGRAPHY Dr. R. K. Patil is working as a Professor in Mechanical Engineering Dept. at TSSM s PVPIT, Bavdhan, Pune, India. He has 19 years of teaching experience to UG and PG program. He earned his Ph.D. and M.E.(Heat Power Engineering) from COEP,Pune under Savitribai Phule Pune University. He has more than 35 publications in reputed National/ International journal and conferences. Recently he received Best Teacher Award from Pune City Mayor, Pad. Manibhai Desai, Maniratna Shishak Gaurav Puraskar 25. He is the author of LapLambert Academic Publishing House, Germany. Shivam C. Shinde has recently graduated as Bachelor of Engineering in Mechanical concentration from TSSM s PVPIT, Bavdhan, Pune, India. He is currently completing a Post Graduate Diploma in Supply Chain Management from Symbiosis Centre for Distance Learning. He did an internship at TAL Manufacturing Solutions Ltd., a Tata Motors subsidary, studying various types of material handling systems. He participated in the SAE BAJA 25 event. Suraj Madhukar Takale and Bhawarlal Choudhary are the leading buisnessman in Pune Region. 3075