Low Cost Automation(LCA): A Case Study

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1 Low Cost Automation(LCA): A Case Study Sameer S. Gajmal 1, Prof. Sudhir.G Bhatwadekar 2 1 Assistant Professor, Department of Mechanical Engineering, Gharda Institute of Technology, Lavel 2 Associate Professor, Department of Production Engineering, K.I. T. s college of Engineering, Kolhapur. 1 sameergajmal@git-india.edu.in ABSTRACT Automation is the creation and application of technology to monitor and control the production and delivery of products and services. In today s world for any industry to survive in the competitive market, must go for automation. Automation demands huge capital investment which requires mass production for quick return on investment. Hence Large Scale Industries can afforded and opt the option of automation, whereas medium and small scale industries find it very difficult adopt automation. Low cost automation (LCA) is one solution especially for medium and small scale industries. Automation demands replacement of conventional machines by CNC, VMC, SPM s, etc, manual material handling by conveyor s, AGV s and many more things. In the present paper a case study is discussed which includes application of Low cost automation concept by replacing conventional Radial Drilling Machine by Special Purpose Horizontal Multi Spindle Drilling Machine. This SPM was in-house designed and developed by using the spare parts of old machines which were declared as scrap by other industries. Due this there was a huge saving in the manufacturing cost of this SPM. This newly developed SPM not only increased the production rate by about 85% but also made it possible the machine operator to operate another machine along with it with no compromise in quality requirements. Keywords: Automation, SPM, LCA. 1.INTRODUCTION: Automation is a set of technologies that results in operation of machines and systems without significant human intervention and achieves performance superior to manual operation. In today s world for any industry to survive in the competitive market, must go for automation. Automation demands huge capital investment for replacing the conventional machines by CNC, VMC, SPM s, etc, manual material handling by automated material handling systems like conveyor s, AGV s and many more things. Large Scale industries which do have huge production afford to go for huge capital investment and opt automation at various levels. But medium and small scale industries mostly do not go for automation due to huge capital investment. That means even though medium and small scale industries desires to go for automation are unable adopt it. Low cost Automation (LCA) is one solution to medium and small scale industries. Various Special Purpose Machines, Jigs, Fixtures, material handling systems can be designed and developed by using the concept of LCA. As per the design requirement choose the spare parts from the old, unutilized and scrapped machines, mechanisms. Inspect those spare parts for the requirements and use them for developing new SPM s, Jigs. Fixtures, etc. This will reduce down the manufacturing cost to almost 50-70%. Thus medium and small scale industries can also 172

2 afford to have automation in their organization at low cost. 2.LOW COST AUTOMATION (LCA): Automation is a very vast topic which can be briefly defined as Automation is using set of all measures aiming at replacing human work through machines and using technology for this purpose This includes automation in Storage Systems, Handling Systems, Assembly Lines,Production Lines, Production Cells, Machines, Computers, Controllers, Software,etc. This requires huge capital investment. Only national and multinational companies can afford to opt automation. These companies do have mass production which balance the huge capital investment and provide quick return on investment. On the other hand small & medium scale industries do not afford such huge capital investment and generally avoid automation. But this leads to lower growth of such industries. Low Cost Automation is a concept of developing new automated machines, mechanisms, systems, etc by making use of parts, sub-assemblies, etc of old unutilized machines, mechanisms, systems which are available free or at very lower cost. 1. Design the machine, system, mechanism as per the requirement. 2. Decide upon the parts, sub-assemblies, sub-systems required. 3. Check for the above requirements from old unutilized machines, mechanisms, systems, if they are available. 4. Inspect the parts, sub-assemblies, subsystems available and see that they meet the design requirements. 5. Use them for developing new machine, system, mechanism. 6. Due to use of parts of old unutilized machines, mechanisms, systems which are available free or at very lower cost, there is no need to purchase new parts, systems and hence,the overall cost of development new machines, systems will be very low. Thus automation is possible at lower cost. 3. CASE STUDY: The Case Study discussed is from a Company named Menon and Menon Pvt. Ltd. Vikaramnagar, Kolhapur manufacturing 2, 3 & 4 cylinders Engine Block for SAME Tractors, Italy. The component under consideration was 4 cylinders Engine Block for SAME Tractors, Italy. Actual demand for this component from SAME was 600 blocks per month 25 blocks per day). But the supply was only about 264 blocks per month 11 blocks per day). Therefore increasing the rate of production of this particular block was the problem. Out of total 17 Nos. of operations one operation was MOG Hole Drilling Operation. The Details of MOG drilling bare as follows: Component under consideration: TABLE- I Sr. No Name of Component SAME 2-Cylinder Engine Block SAME 3-Cylinder Engine Block SAME 4-Cylinder Engine Block Designation of Component Job I Job II Job III 173

3 TABLE-II Specification Component Job-I Job-II Job-III Hole - A Diameter of Hole Ø15.00 mm Ø15.00 mm Ø15.00 mm Length of Hole 330 mm(thro) 462 mm(thro) 592 mm (Thro) Hole - B Diameter of Hole Ø11.40 mm Ø11.40 mm Ø11.40 mm Length of Hole 330 mm(thro) 462 mm(thro) 592 mm(thro) Hole - C Diameter of Hole Ø15.00 mm Length of Hole mm (Blind) The block was having one operation of Main Oil Gallery (MOG) Hole Drilling. (MOG) hole drilling (3 Nos.) which are through & 592 mm long. Machine used is Radial Drilling with Drilling Jig. For getting these holes produced half of the drilling length is achieved by drilling from one (Rear) side & remaining by drilling from opposite (Front) side. Drills used are extra long (450 mm), H.S.S., taper shank, twist drills. Clamping of the job is done manually; & location is by using dowel pins. Presently the number of jobs (4Cylinder) produced per shift is 11(very less). Reason: drilling very long length holes (592mm) with wood pecking action in two set-ups. Frequent problem of drill breakage. Fig.1 SAME 4-Cylinder Engine Block TABLE-III Total Time Required To Complete MOG Hole Drilling Operation On One Job = Total Time available per shift = 8 x 60 = 480 minutes Production Rate per Shift = 480/ 43 = Jobs

4 As mentioned above by using radial drilling machine the production rate was only11 Jobs/ shifts. Other problems which were frequently observed were: High Tooling Cost: As the drills used were extra long drills, frequent breakage of drills was resulting into high tooling cost. High Fatigue to the Operators: Due to frequent change of drills, drilling speeds, spindle (drill) positions, loading unloading of jig plates the operator was feeling high amount of fatigue. Also due to manual wood pecking action. Expected Production Rate: As per the demand from SAME TRACTORS, ITALY, the production rate expected was 600 Jobs/ month i.e. about 25 Jobs/ day. Quality: As far as quality was concerned, the present set up was capable enough to satisfy the quality requirements in the MOG drilling operation. As the holes being drilled were used just to carry the lubricating oil (as per the name; Main Oil Gallery Hole) 1.5 mm drill-shift was allowed and the present set-up was giving acceptable results (About 0-1% rejection) 5-10 % rework during the final inspection was one of the major problem being observed. 3.1 COMPANY S REQUIREMENT: 1. Increased Production Rate: As mentioned above company s requirement was to satisfy the demand of 600 Jobs/Month i.e. about 25 Jobs/ day. 2. Consistent Quality: As far as quality was concerned the company s expectation was to achieve the same quality level as that of the present set-up i.e. with radial drilling machine with 0% rejection combined with 0% rework. 3. Low Cost Automation: To achieve the above two targets it was clear that the modified new set-up was going to be very costly. Company s expectation was to Enhance Quality as well as Production rate with low cost automation. Therefore increasing the rate of production of this particular block was the Company s Requirement being identified. 3.2 BRIEF ABOUT DESIGN AND DEVELOPMENT OF SPM TABLE-IV List of Operations OP.NO. OPERATION MACHINE TOOLING 01 Top- Bottom Milling SPM Milling Fixture 02 Front- Rear side Milling SPM Milling Fixture 03 Dowel Hole Drilling Radial Drilling M/c Drilling Jig 04 LH-RH Side Pad Milling SPM Milling Fixture 05 FIP Pad Milling Vertical Milling M/c Milling Fixture 06 Cap seat Milling Vertical Milling M/c Milling Fixture 07 MOG Hole Drilling Radial Drilling M/c Drilling Jigs 08 Front & Rear Side Drilling SPM Drilling Jig 09 Front & Rear Side Tapping Radial Drilling M/c Top Drilling Radial Drilling M/c Drilling Jig 175

5 11 Bottom Drilling & Tapping Radial Drilling M/c Drilling Jig 12 LH-RH Drilling & Tapping Radial Drilling M/c Drilling Jig 13 Cap seat Drilling & Tapping Radial Drilling M/c Drilling Jig D9 hole Drilling Radial Drilling M/c Drilling Jig 15 Cam Boring Horizontal Boring Boring Fixture 16 Linear Boring Vertical Boring Boring Fixture 17 Top- Bottom Finish Milling CNC Milling Fixture After studying the entire operations and the MOG hole drilling operation sheet in detail it was decided to design & manufacture a Horizontal Multi-Spindle Drilling SPM for SAME 2,3 & 4 cylinder engine block. Also another engine block i.e. TATA 4 SP engine block was having similar kind of MOG hole ( X Thro). It was decided to design and manufacture SPM to cover the MOG hole drilling operation of TATA 4 SP. Only additional requirement was: Extra spindle in the gear box (front & rear both) & the necessary gearing, bearings, drills, bushes, etc. In the drilling jig one more pair of dowel pins at the positions corresponding to the positions of dowel holes of TATA 4 SP block. 3.3 DEVELOPMENT OF SPM: Once it was finalized to develop a multi-spindle drilling SPM we started working on it. First of all we set our objectives discussed earlier and then studied the requirements and constraints in the development of the SPM. One of the important consideration was to manufacture the SPM by using Low Cost Automation Concept i.e. by making use of the old (scrapped) machine so as to bring down the manufacturing cost as low as possible. The constraint was that the SPM should be capable of performing the drilling operation on SAME 2,3 & 4 cylinder block and also another block i.e. TATA 4 SP cylinder block. Another important consideration was to increase the production rate. Time Study: Requirements of Multi-Spindle Drilling SPM: - Following are the various arrangements to be designed to satisfy various requirements of the multi- spindle drilling SPM. Job Holding Arrangement: Tool Holding Arrangements: a) For SAME 2 & 3 cylinder there are 2 holes ( 15 & 11.40) from both sides. b) For SAME 4 cylinder engine block there are 3 holes ( 15, 2 Nos. & No.) from rear side and 2 holes ( 15 & 11.40) from front side. c) For TATA 4 SP engine block there is only one hole ( 14.25) from both sides. So there are total 4 holes on one side & 3 holes on the other to be drilled, seven spindles are required to be designed and manufactured. Adjustable adaptors were decided to be used. Use of Adjustable Adaptors: As per the name they used to alter the length of hole being drilled as per the requirement. Due to continuous usage the length of the drill gets reduced, hence the length of drilled hole becomes less to that much amount of length. If adaptors are used the length of drilled hole can be maintained constant by operating the Adjustable Nut of the Adjustable Adaptor. Guiding Elements: Bed Structure: Drives: 176

6 The total time required to complete MOG hole drilling operation with conventional Radial Drilling Machine is actually determined and tabulated as: TABLE-V Time Study with conventional Radial Drilling Machine Particular Action Time required in minutes Job 1 Job 2 Job 3 Average For Front side drilling Loading + Clamping Drilling Time Declamping +Unloading For Rear side drilling Loading + Clamping Declamping +Unloading Drilling Time Total time in Minutes minutes Total Time for MOG hole drilling on Radial drilling Machine = Min. 43minutes Similarly the time study was also conducted for 5 samples jobs by using newly developed SPM. The sequence of operation is as follows: i) Machine cleaning ii) Component loading. iii) Cycle starts i.e. locating + clamping + drilling from both LH & RH side simultaneously. iv) Unloading the component. The total time required in drilling the MOG holes by using Newly developed SPM is tabulated as follows: TABLE-VI Time Study with MOG SPM Particular Action Time required in seconds Front and Rear side Drilling Job1 Job2 Job3 Job4 Job5 Loading Drilling Unloading Total time Average minutes time It is seen that the total drilling time for MOG hole drilling operation with radial drilling machine is 43 minutes, whereas the time required for MOG hole drilling operation with newly developed SPM is equal to 5 minutes which is considerably lowered. Hence the % saving in machining time is as follows: Saving in machining time = [(43-5)/ 43] x 100 = 88% Hence with the newly developed drilling SPM, the machining time can be saved as much as by 88%. The next testing was for the accuracy of the holes drilled in the component by using the newly developed SPM

7 3.4 INSPECTION REPORT TABLE-VII Inspection Report Particular Dimensions from Bottom Side Hole Size Dim. As Side Job1 Job2 Job3 Job4 Job5 per control In mm Plan in mm Front Side Ø ± Ø ± Rear Side Ø ± Ø ± TABLE-VIII Inspection Report Particular Dimensions from Dowel Holes Hole Size Dim. as per Side Job1 Job2 Job3 Job4 Job5 control In mm Plan in mm Front Side Ø ± Ø ± Rear Side Ø ± Ø ± This drilling accuracy was checked by using Digital Height Gauge TRIMOS. It was very glad to found that the positional accuracy of all the three holes was within the accuracy limits of ±0.25 and with consistency. 4. RESULTS AND FINDINGS: The important findings with the use of this newly developed multi-spindle drilling SPM are: Productivity is increased by reducing the handling and machining (drilling) time as all the three holes are drilled at a time. This reduction in production time leads to reduction in the cost of production. As all the spindles are already fixed in position; the positional accuracy of these holes is ensured. This certainly reduces the inspection timing and percentages rejection, which leads to better quality production. The length of the ф15 X 327 blind hole can be very well controlled by means of adjustable adaptor. It is observed from the time study that there is substantial saving in production cycle time by 88%. The overall design of the SPM is such that it provides full rigidity and sufficient space for easy movements of the jobs and of the operator. The old scrapped machine was very effectively utilized. This SPM is a very good example of productivity and quality improvement by using. A SPM manufactured at very low cost. The other side is that ergonomic deals with operator s comfort reduction in the undue strain and fatigue through proper design of machine, location of controls and ease of operation, etc. Following are the finding in this regard:

8 I) Elimination of jig plate handling during the operation: In the earlier procedure, the operator has to lift the drilling jig plate and place it on the face of the engine block to be drilled. Then do the locating and clamping. This is a tedious work as he has handle approximately kg load every time for loading and unloading the jig plate on the engine block. In the newly developed SPM, the operator only has to push the job into the fixture base and position it properly (Dowel hole exactly above the locating pins) from the roller conveyor. Hence it becomes easier for the operator to load and unload the component and not necessary to handle the jig plates as they are fixed on the fixture column. II) Comfort during operation: As the SPM is hydraulically operated the operator has to load the job in the fixture base and start the cycle ON. So there is no other work. After the drilling is completed, Declamping is also automatic. Operator has to pull the job out of the fixture base. III) Lesser hand movements and reduced handling time: In the earlier case, the drilling jig plate was fixed on the face of the block. Here the worker was required to position the spindle of radial drilling machine above the particular drilling bush and then start the feed motion of the drill. Also when one side drilling length was completed, the job was required to be changed it s position, so that drilling can be done from the opposite face so as to produce through holes. This certainly has increased handling time which increase the production cycle time. The new SPM is designed in such a way that the spindles are already positioned and the job is resting on bottom face, hence the drilling proceeds from both (LH and RH) side simultaneously. Hence not necessary to change the position of block or change the jig plates. Operator has to just load and unload the block and start the switch ON. Thus definitely reduces the hand motion of the operator and the unproductive handling time. IV) Increase in production rate: In the previous case production rate of (SAME 4 Cylinder) block was 11 jobs/shift and in case of newly developed SPM it is 96 jobs/ shift. TABLE-IX Time Saving TABLE-X Increase in Production Rate Machine Used Radial Drill MOG-SPM Machine Used Radial Drill MOG-SPM (old Method) (old Method) Cycle Time minutes minutes Saving in Manufacturing time. 88% Production Rate 11 jobs/ Shift 96 jobs/ shifts Increase in Production rate = 85 jobs/ shift VII) Cost of development of MOG- SPM = 4.5 Lakhs. TABLE-XI Cost of Manufacturing Sr. Item/Part Name Amount in Remark No. Rupees 1 Front side (Right) gear box 35,000/- Casting + Machining (Both-Inhouse) 2. Rear side (left) gear box 35,000/- Casting + Machining 3. Fixture base 40,000/- Casting + Machining 4. Fixture column along with LH. And RH. 25,000/- Fabrication, Casting + Side Jig plates Machining+ Purchase 5. Hydraulic power Pack 40,000/- Bought Out 179

9 6. Machine Base 7. Guideways 8. Spindles, shafts 9. LH and RH side Hydraulic Feed Cylinders 10. Three clamping Cylinders 1,50,000/- Components already available in the company. (Spare parts of Old machine purchased from SAME Italy) 11. Assembly Cost 40,000/- Labour cost (5 persons) 12. Electric connection 85,0000/- On contract basis. TOTAL COST OF DEVELOPMENT Rs.4.5/- Lakhs TABLE-XII Saving in Cost Purchasing Cost In-house Manufacturing Cost Total Saving in Cost Rs.7 Lakhs Rs.4.5 Lakhs Rs.2.5 Lakhs 5. CONCLUSION: Interpretations of the results obtained, leads to know the important achievement and performance of the developed multiple spindle drilling SPM are: a) Increase in productivity with same quality standards. b) Reduction in production time. c) Reduction in cost of production. d) Operator (unskilled) can operate two more machines along with MOG SPM with Comfort and without Helper. e) Tremendous saving in the operational time of machining, with the newly developed multispindle drilling SPM. f) Saving in unproductive time. g) It can be seen that the loading and unloading time is also reduced. h) Proper arrangements for loading the job, location of machine controls and ease of operation reduces excessive strain on the operator and results into comfortable working conditions. i) Elimination of problems such as rejection, rework in MOG Hole Drilling operation Thus by adopting the concept of Low Cost Automation, the overall benefits of automation are achieved by replacing conventional Radial Drilling Machine by hydraulically operated automatic Horizontal Special Purpose Machine Multi Spindle Drilling Machine at lower cost. Total saving in the cost is Rs.2.5 Lakhs. 6. REFERENCES: [1] P.M. Singru & Anish Alias, Computer Aided Design of Machine(CADOM), Proceeding of International Conference on : Intelligent Flexible Autonomous Manufacturing Systems, IFAMS-2000, Institute of Technology, Coimbatore, 10 Jan.2000,PP [2] V.B. Bhandari, Design of Machine Elements Tata McGraw- Hill Publishing Co. Ltd. New Delhi, 25 th Reprint, PP [3] N.K. Metha, Machine Tool Design and Numerical Control, Tata McGraw- Hill Publishing Co. Ltd. New Delhi, Second Edition, PP [4] Tsung-Ming Lo and Jieh-Shian Young, Improvements of Productivity for PCB Drilling by Laser Driller Machine, International Journal of Precision Engineering and Manufacturing vol. 15, no. 8, August 2014, pp [5] Biman Das & Uday Venkatadri & Pankajkumar Pandey, Applying lean manufacturing system to improving productivity of air-conditioning coil manufacturing, International Journal of Advanced Manufacturing Technology, 24 November 2013,PP

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WELDING OF THREADED SPINDLES ONTO HOUSINGS

WELDING OF THREADED SPINDLES ONTO HOUSINGS 1 ARUN MARIBASHETTI, 2 B R NARENDRA BABU, 3 T.L RAMACHANDRA 1 Student, Production Technology, Mechanical Department, VVIET, Mysore, Karnataka, India 2 Associate