REDUCING THE REJECTION RATE OF PISTONS DURING MACHINING

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 9, September 207, pp , Article ID: IJMET_08_09_024 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed REDUCING THE REJECTION RATE OF PISTONS DURING MACHINING Navinesh BC, Dr. Somasundar B School of Mechanical Engineering, REVA University, Bengaluru, Karnataka, India B Nitya Aparna, Pramod S N Department of Mechanical Engineering SKIT, Bengaluru, Karnataka, India ABSTRACT Productivity is the measure of extent to which a rated output can be extracted from a given input. Productivity improvement deals with achieving more output for the same input within the specified time. Rejection or scarp is a threat to organization. Eliminating or minimizing the scrap is the main aim of any manufacturing unit The existing methods and procedure are improved by DEMAIC approach of six sigma methodology to improve the quality of the product and the rework and rejections are reduced by set of lean principles. The outcomes of this project being suggestion to improve and change certain procedure in the process and also to improve certain process, which are causing bottle necks in the line. By implementing certain changes in the process the productivity is observed to be increased from less units per shift to Maximum units per shift, the scarp % is observed to reduce. Key words: Piston defects, analysis criteria, FMEA, DOE, and 7QC Tools. Cite this Article: Navinesh BC, Dr.Somasundar B, B Nitya Aparna, Pramod S N, Reducing the Rejection Rate of Pistons During Machining, International Journal of Mechanical Engineering and Technology 8(9), 207, pp INTRODUCTION The last two decades has witnessed an increased pressure from customers and competitors for greater value from their purchase whether based on quality, faster delivery, or lower cost (or combination of both) in both manufacturing and service sector. Productivity is the measure of extent to which a rated output can be extracted from giving input. Productivity improvement deals with achieving the more output for the same output achieving the same output from the less input within the specified time. This can be done basically by improving basic process by R&D and by improving the existing methods and procedure and also by controlling rework and rejections. Rejection or scarp is a threat to organization. Eliminating or minimizing the scrap is the main aim of any manufacturing unit editor@iaeme.com

2 Navinesh BC, Dr.Somasundar B, B Nitya Aparna, Pramod S N The project is carried out to minimize the number of defective pistons produced in the piston machine shop. Processes involved in the processes are properly evaluated, analyzed and the root cause behind the rejection is evaluated with help of 7QC (Quality Control) tools, Statistical process control charts and DOE techniques. Detailed observation and data gathering is done for data collection, the raw data is then processed into relevant information to assess the present capacity and manpower. The project is carried out with view of purging all the non valued activity. Necessary steps are carried out to identify and eliminate all the non valued activity. The outcomes of this project being suggestion to improve and change certain procedure in the process and also to improve certain process, which are causing bottle necks in the line. By implementing certain changes in the process the productivity can be increased by reducing the scrap percentage during manufacturing for best output. 2. PROBLEM FORMULATION 2.. Problem Definition Rejection or the scrap is a threat to any manufacturing industries. In a mass production company which aims to produce around 800 per shift per line every single rejection accounts to the loss of efficiency. As all products cannot be thrown out as scarp they are inspected again and rework is carried out to bring about difference in number of scrap thus bringing down of the quality of the product manufactured, consuming extra man and machine time. [0]. Figure Shows the final component to be produced in the line 3. OBJECTIVES The main objectives of our research is Balancing the product line. Better utilization of resources. Lead time reduction. Reduce rejection. Productivity improvement. Standardization of the output 4. DATA COLLECTION Data collection approach allows us to systematically collect information about various object of the study i.e. people, objects and phenomenon for the purpose of the further analysis. Data regarding the number of operations in the 6M line, the number of workers working in the line, editor@iaeme.com

3 Reducing the Rejection Rate of Pistons During Machining cycle time of the individual operation, hourly output, WIP between the operation and the number of rejections are collected. Table. shows the operation being performed 6M line and the manpower for each operation. [2] 4.. Operations and Man Power 4.2. Codes Codes given for different types of scrap 4.3. Scrap codes for the piston Table Number of operation and operator OPERATION NO OPERATION MANPOWER 0 Rough OD turning & crown step finishing 02 Finish fixture seat boring & crown centering 03 Rough pinhole boring 04 OD turning & finishing, CI groove, Skirt end & crown chamfer. 05 Finish OD profile turning, First groove edge chamfer, 06 First pinhole boring 07 Crown facing, Cavity finishing, 08 Circlip grooving, 09 Outside chamfering, Table 2 Different scraps codes CODE DEFECTS CODE DEFECTS Crown P Porosity 2 Ring Zone B Blow Hole 3 Skirt D Defective 4 Pin hole Si Silicon 5 Inside RZD2 C.I.Ring shift S Shrinkage Table 3 Scrap codes for piston CODES A A3 A4 A5 A6 A7 A8 A9 A0 A A3 A4 A5 PARAMETER Crown finish Groove finish Lock pin position Chamfer Slot Oil Hole position O.D. Unclear Pin hole Unclear Wall Thickness Eye distance Surface treatment Damage Crack editor@iaeme.com

4 Navinesh BC, Dr.Somasundar B, B Nitya Aparna, Pramod S N A6 A25 A26 A3 A32 A33 A46 A36 A37 A38 A39 A4 A42 Cavity Finish Bonding Cavity depth Groove Diameter Groove Width Groove position Outer Diameter Pin Hole diameter Pin Hole Ovality Pin Hole alignment Circlip Groove Distance Compression Height less Pinhole squareness 5. PROCESS OF REJECTIONS In the past two years automobile industry is progressing fast. There are a lot of many new vehicles coming to the market and for existing models demand is increased. When the demand is increased suddenly for expansion needs money and lot of lead time so, to meet the customer demand better option is to make use of existing facilities, improving OEE, productivity. Management was considering the many options to improve productivity. In this direction reduction of rejections are being considered. So, we have taken quality improvement (reducing the rejection). To understand where high machining rejections are occurring we collected the data and arranged in the descending order. Data regarding the number of operations in the 6M line, the number of workers working in the line, cycle time of the individual operation, hourly output, WIP between the operation and the number of rejections are collected. Table shows the operation being performed 6M line and the manpower for each operation. It is the way of collecting and classifying data so that it can be easily presented or analyzed. It is particularly useful at the start of the problemsolving process for data gathering. It can also be used for monitoring performance once change has been implemented. This logical point is to start in most problem solving cycles to detect problems and carry out further analysis. The recommendations for the process improved were submitted to the company and they were implemented by production department at FMGIL during the project work. The rejection details have been collected as shown in below graph. [2] 5.. Line Selection in the Machine Shop Table 4 Percentage of rejections in each line Line Percentage Of Rejection 6M MLVD 8.7 CNC CNC2 7.3 LVD A 5.5 NBL 4.7 NHL editor@iaeme.com

5 Skirt diameter Pin hole dia Damages Pin hole finish Coating OD fins Crown finish Others Bond Hps Pinhole Ovality Cavity fin Marking Comperssion Oil hole Pin hole angle Valve pocket 6M 5 MLVD CNC 4 CNC2 LVD 3 5A NBL NHL Reducing the Rejection Rate of Pistons During Machining Line Wise Comparative Machining Rejection % of Rejection 5 0 Line Name Figure 2 Area of line selection 5.2. Different Defects and its Rejection Rate Table 5 Different defects in 6M line and its rejection percentage Defectives Percentage Of Rejection Skirt diameter.4 Pin hole dia 0.96 Damages 0.8 Pin hole finish 0.76 Coating 0.64 OD finish 0.6 Crown finish 0.55 Others 0.48 Bond 045 Hps 0.43 Pin hole Ovality 0.4 Cavity finish 0.4 Marking 0.38 Compression height 0.3 Oil hole 0.29 Pin hole angle 0.28 Valve pocket Percentage of Rejection % of Rejection. DEFECTIVES Figure 3 Different types of defective found in 6M line 24 editor@iaeme.com

6 Navinesh BC, Dr.Somasundar B, B Nitya Aparna, Pramod S N 6. CORRECTIVE ACTION PLAN Implementation is carrying out, executing or practice of a plan a method, or any design for doing something. The corrective actions implemented to balance the line, standardize output and reduce the scrap and for better utilization of the resources. [6], [7], [9] 7. CONCLUSIONS The primary objective of the company was to increase the production rate of the Particular flow line. Through our study we found that the system before the implementation of corrective action was producing less output units/shift. After the implementation of the corrective actions the system showed up a daily production Maximum units/shift, with a considerable increase in the output of products. Present scarp percentage in the shop floor is more, by adopting the quality tools and DOE techniques should reduce the scrap percentage to minimum. The productivity of the piston in each shift is less and rejection rate is more. The main aim is to reduce the scrap and increase the productivity in each shift. By finding the gaps of productivity, can apply the quality tools and DOE techniques to reduce the scrap in each shift. REFERENCES [] S.Gobinath,D.Elangovan,S.Dharmalingam. Lean Manufacturing Issues and Challenges in Manufacturing Process A Review, International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN: , 205,Vol.8, No., pp [2] JatinTaneja, Dr.RajKumar, AnishTaneja, Kaizen Approach in Indian Industries, International Journal for Research in Technological Studies, June 204,Vol., Issue 7,ISSN(online): [3] Tejaskumar S. Parsana and Mihir T. Patel, A Case Study: A Process FMEA Tool to Enhance Quality and Efficiency of Manufacturing Industry, Bonfring International Journal of Industrial Engineering and Management Science, August 204Vol. 4, No. 3. [4] Fatma Pakdil & Karen Moustafa Leonard, Criteria for a lean organisation: development of a lean assessment tool. International Journal of Production Research, 204 Vol. 52, No. 5, [5] Mary IjeomaMarire, Barnabas EkpereNwankwoand NgoziSydneyAgbor, The Problems of Quality Control in the Manufacturing Sector, A Study of Nigeria Breweries Plc, Enugu, IOSR Journal of Business and Management, Dec. 204, ISSN: , p-issn: Volume 6, Issue 2.Ver.I,PP [6] E. A. Ogbonnaya, B. N. Nwankwojike,E. M. Adigio, J. A. Fadeyi, C. N. Nwogu, Development of CNC Program for Piston Production, West African Journal of Industrial & Academic Research, March 203,Vol.6. [7] MayankJha, R.K Tyagi, Gaurav Gupta. Reduction of rejected components in an automobile assembly line using quality tool, European Journal of Applied Engineering and Scientific Research,203,2 (3): 3-7. [8] Parikshit S. Patil, Sangappa P. Parit, Y.N. Burali, Poka Yoke.The Revolutionary Idea In Total Productive Management, Research Inventy International Journal Of Engineering And Science, February 203, Issn: , Vol. 2, Issue 4, Pp [9] Swapnil.B.Ambekar,AjinkyaEdlabadkar, VivekShrouty. Implementation of Failure Mode and Effect Analysis, IJEIT, February 203, Volume 2, Issue 8. [0] Neha Gupta, Dr.P.K.Bharti. Implementation of Six Sigma for Minimizing The Defects Rate At A Yarn Manufacturing Company. International Journal of Engineering Research and Applications (IJERA), 203 ISSN: editor@iaeme.com

7 Reducing the Rejection Rate of Pistons During Machining [] M. Dudek-Burlikowska, D. Szewieczek. Journal of Achievements in Materials and Manufacturing Engineering, October 2009, Volume 36 Issue. ArashShahin, Maryam Ghasemaghaei, Service Poka Yoke, International Journal of Marketing Studies Vol. 2, No. 2; November 200.p [2] J. Michalska, D. Szewieczek, The 5S methodology as a tool for improving the organization, Journal of Achievements in Materials and Manufacturing Engineering, Volume 24 Issue 2 October [3] S. Chiranjeeva Rao, A. Saravanakumar and G. Chandra Sekhar. Influence of Nano Added MME Blends on CI Engine Bas ed on DOE Concept. International Journal of Mechanical Engineering and Technology, 8(7), 207, pp [4] A.M. Senthil Anbazhagan and M. Dev Anand. Investigation and Modeling on Dynamic Failure Mode -I Type Crack Transitions in Pressure Vessel Geometry. International Journal of Mechanical Engineering and Technology, 8(5 ), 207, pp editor@iaeme.com