DESIGN AND OPTIMIZATION OF CRITICAL PART OF A ROTARY TABLE USED IN HORIZONTAL MACHINING CENTRE

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 6, Issue 11, Nov 2015, pp , Article ID: IJMET_06_11_019 Available online at ISSN Print: and ISSN Online: IAEME Publication DESIGN AND OPTIMIZATION OF CRITICAL PART OF A ROTARY TABLE USED IN HORIZONTAL MACHINING CENTRE Mr. Kadam Pradip Vasantrao PG Student, M.E.Design, P.V/P.I.T. Budhgaon , Sangli-Tasgaon Road, Maharashtra India Prof. N. V. Hargude, Associate Prof. Dean R and D, P.V/P.I.T. Budhgaon , Sangli-Tasgaon Road, Maharashtra India ABSTRACT Growing industry demands low manufacturing cost, saving of material, low cost material, ease of transportation etc. This demand leads to use different type of material and various techniques to increase productivity. The time factor is very important during loading and unloading of job/pallet. In this research critical parts like Pallet considering machining force taking weight of the work piece into the account. Analysis of pallet is carried out by using finite element package. Key words: Rotary Table, Pallet, Horizontal Machining Centre. Cite this Article: Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude. Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre. International Journal of Mechanical Engineering and Technology, 6(11), 2015, pp INTRODUCTION CNC rotary table is a work holding device used on machining centers to position the component in desired angle to do multi-face operation in one setup. The table can also be interpolated as a 4th axis with machines X, Y, Z axes to enable machining of profiles such as cam, which is out of reach with only 3 axes of the machining centers. Rotary axis is essential for machining the complex jobs where the machining forces are not at 90 or 180 degree to each other. Even if the jobs are rectangular, these can be machined in one setup using rotary table to improve the accuracy and productivity. Rotary table is designed with heavy duty axial radial roller bearing to take heavy editor@iaeme.com

2 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude loads. Rotary tables with dual lead worm and worm wheel with from correction are widely used for longer life and sustained accuracy as shown in Fig.1.1 Figure 1.1 Rotary Table with worm screw and worm wheel device 2. LITERATURE REVIEW Fred M plus et al [1], this paper which describes the pallet loading conditions and pallet operation for the IBM R 8/1 are developed and also a systematic algorithm is invented. Michael wang, suresh sethi et al [2], this paper represents the computational complexity of the problem of minimizing make span in a flow shop, where each jobs requires a pallet the entire time, from the start of its first operation until the completion of the last operation. Hence it is prove that the problem is NP-hard in the strong sense for m > 2 and k > 3, and for, m> 3 and k> 2, where m is the number of machines and k is the number of pallets in the system. Terry D. Gerhardt et al [3],This paper focuses on the effect of notches on the on pallet stringers such as stiffness and strength of pallet by changing the notch depth and radius of the stringers of pallet and also developed the design equations for conventional double notched oak pallet stringers by using the experimental method and finite element approach. H. Weule1, J. Fleischer1 W et al [4], In this paper which explained the topology method for optimizing the machine tools by using numerical methods such as finite element method (FEM) and multi-body simulation (MBS) and coupled each other, for this critical workspace positions, loading conditions are considered. Carsten Daub et al [5],in this a cast model is developed to enhance the effectiveness of machining centers with multi pallet changers, further a heuristic scheduling algorithm is developed to minimize the total weighted tardiness. Juan Pablo Leiva, Brian C at al [6],this paper which explains the difference between the topology and topometry methods when employed to the structural components such as what element types are available for each method and what types of analysis and responses can be used for each method are presented in the genesis program also explained the concepts that help solve larger problems in a reduced number of cycles. LubomírNovotný, JiříMarek et al [7],In this paper a detail study on pallet of size 800 mm is studied which covers the modeling of the. Component then the loading carrying capacity (deformation) is checked by using numerical methods considering load, machining operations and high speed of 600 min editor@iaeme.com

3 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre ParagVichare, AydinNassehi et al [8], In this a detail study is done on the fixture used in the universal vises, chucks, pallets, auxiliary rotary tables when used in CNC machining center for Unified Manufacturing Resource Model. S. Pellegrinellia, A. Valentea et al [9], this research work proposes an integrated methodology and a software infrastructure to support the process planning and pallet configuration solutions whose major goal is to minimizing production costs including costs for energy consumption and cutting tool wear - while maximizing the number of finished work pieces per pallet. Abdullah Waseem, Ahmad Nawaz et al [10],In this a PVC made pallet are developed and analyzed for the uniformly distributed static load on pallet by using the Pro-E and ANSYS packages further deformation and stress developed in the pallet are compared with the other material pallet. Mohit Law, Yusuf Altintas[11],In this optimization of machine tools is carried out by using the position-dependent stability. For this identified weak machine component is modified based on reduced model sub structural synthesis and the complete dynamics are rapidly analyzed by virtually re-assembling the machine using reduced order models. S. Pellegrinellia,n, T.Tolio a, [12],This paper studied the pallet sequencing based on the network part program logic. Part program of non-production movements for each possible sequence of two operations are automatically generated at the shop floor level are simulated to obtain the non-production time. 3. STATIC STRUCTURAL ANALYSIS A static structural analysis determines the displacements, stresses, strains, and forces in structures or components caused by loads that do not induce significant inertia and damping effects. Steady loading and response conditions are assumed; that is, the loads and the structure's response are assumed to vary slowly with respect to time. 4. STATIC STRUCTURAL ANALYSIS OF EXISTING PALLET: Figure 4.1 Drawing of Existing Pallet editor@iaeme.com

4 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Figure 4.2 Existing Pallet With Applied Pressure Figure 4.3 Meshed Model of Existing Pallet Figure 4.4 Total Deformation of Existing Pallet Figure 4.5 Von Mises Stress in Existing pallet

5 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre 5. STATIC STRUCTURAL ANALYSIS OF FINAL MODIFIED PALLET Figure 5.1 Drawing of Final Modified Pallet Figure 5.2 Final Modified Pallet Figure 5.3 Meshed Model of Final Modified Pallet editor@iaeme.com

6 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Figure 5.4 Total Deformation of Final Modified Pallet Figure 5.5 Von Mises Stress In Final Modified Pallet Particular Existing Model Final Modified 1. Stress (MPa) Deflection (micron) Discussion on Results Obtained: From above table we found that the final modified pallet has less deflection as micron and Von mises stress as Mpa as compared to existing pallet. Therefore, modified pallet is safe under static conditions. 6. EXPERIMENTATION ON UTM 6.1. Procedure 1. Fix the pallet in the jaws of UTM 2. Then move the upper jaw in downward direction to fix the pallet and set zero reading on display. 3. Then adjust the dial gauge of least count 1 micron as shown in photo when reading on display for offline load is exactly zero. 4. Then gradually apply the load with fixed feeding rate. 5. Stop the machine when it crosses 16 kn. 6. Then note down the reading on display and dial gauge indicator editor@iaeme.com

7 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre Plate 6.1 Plate Plate 6.2 Reading of Plate on Display Plate 6.3 Reading of Dial Gauge Indicator For Plate editor@iaeme.com

8 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Plate 6.4 Existing Pallet Plate 6.5 Reading of Existing Pallet on Display Plate 6.6 Reading of Dial Gauge Indicator For Existing Pallet

9 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre Plate 6.7 Final Modified Pallet Plate 6.8 Reading of Final Modified Pallet on Display Plate 6.9 Reading of Dial Gauge Indicator For Final Modified Pallet Particular Plate Existing Pallet Modified Pallet Load Applied (kn) Offline Test Reading (mm) Dial Guage Reading (micron) From above table we found that the deformation of existing pallet is 6 micron and deformation of final modified pallet is 4.5 micron. So the deformation of final editor@iaeme.com

10 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude modified pallet is less than the existing pallet. So our design for final modified pallet is safe. Owing to this, the plate used for application of load over the entire surface of pallet has no any deformation up to load kn. So the plate has no any combine effect on results obtained for existing pallet and final modified pallet. The UTM has least count of 10 micron that s why the deformation on display of UTM shows zero reading and dial guage indicator used has least count 1 micron so we get the reading on dial guage indicator as shown in above plates. Particular Existing Pallet Modified Pallet Percentage Weight Difference In Existing And Modified Pallet Theoretical wt. (kg) Actual wt (kg) From above table, we note that there is reduction in weight by 23.33% of final modified pallet as compared to existing pallet in FEA. In actual case, reduction in weight of final modified pallet is % as compared to actual wt of existing pallet. Here we note that there are differences in actual and theoretical weights for both Existing Pallet and final Modified Pallet. This is due to rated material properties used during casting. So that much difference is negligible. Particular Existing Pallet Modified Pallet Deformation In FEA (micron) 4 3 Deformation On UTM (micron) From above table, we note that there is a very slight difference in readings of FEA and UTM test. This difference is negligible. 7. MODAL ANALYSIS OF FINAL MODIFIED PALLET: Figure 7.1 Mode 1 of Final Modified Pallet editor@iaeme.com

11 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre Figure 7.2 Mode 2 of Final Modified Pallet Figure 7.3 Mode 3 of Final Modified Pallet Modal Analysis Existing Model Frequencies in Hz Final Modified Frequencies in Hz Mode Mode Mode Modal Frequency Comparison in Hz for fixed boundary conditions From the above table, it can be concluded that the model frequencies of the modified pallet is greater than the operating frequencies. Hence there is no any resonance. So, design of pallet is safe. The frequency occurred in the final model is greater than the existing designed pallet Modal Analysis For Free Condition Graph 7.1 Natural Frequencies In Hz of Existing Pallet For Free Condition editor@iaeme.com

12 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Figure 7.4 Mode 1 of Existing Pallet For Free Condition Figure 7.5 Mode 2 of Existing Pallet For Free Condition Figure 7.6 Mode 3 of Existing Pallet For Free Condition Modal Analysis From FEA Existing Pallet Frequencies in Hz From FEA Final Modified Pallet Frequencies in Hz From FEA Mode Mode Mode Modal Frequency Comparison in Hz for free boundary conditions. From above table we conclude that natural frequency from mode3 is increasing means modal frequencies of the modified pallet is greater than the operating editor@iaeme.com

13 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre frequencies. The frequencies occurred in the final model is greater than the existing pallet. Hence there is no any resonance. So, design of final modified pallet is safe. 8. EXPERIMENTATION USING FFT ANALYZER: Plate 8.1 Hanging of Modified Pallet Plate 8.2 Hanging of Existing Pallet Figure 8.1 Natural Frequency in Hz of existing pallet at Mode editor@iaeme.com

14 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Figure 8.2 Natural Frequency in Hz of existing pallet at Mode 2 Figure 8.3 Natural Frequency in Hz of existing pallet at Mode 3 Modal Analysis From FEA Existing Pallet Frequencies in Hz From FEA From FET Percentage difference in FEA and FFT Results of existing pallet Mode Mode Mode Comparison Table Of Natural Frequency In Hz From FEA And FFT Of Existing Pallet editor@iaeme.com

15 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre 8.1. Discussion from above Observation Table From above observation table, we note there is very small percentage difference in FEA and FFT results. This is less than 20%. This is acceptable. This variation may occur due to rated material properties, change in mass, change in geometry and increase or decrease in stiffness values of material Final Model Figure 8.4 Natural Frequency in Hz of final modified pallet at Mode 1 Figure 8.5 Natural Frequency in Hz of final modified pallet at Mode editor@iaeme.com

16 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Figure 8.6 Natural Frequency in Hz of final modified pallet at Mode 3 Modal Analysis From FEA Final Modified Pallet Frequencies in Hz From FEA From FET Percentage difference in FEA and FFT Results of final modified pallet Mode Mode Mode Comparison Table of Natural Frequency In Hz From FEA And FFT of Modified Pallet 8.3. Discussion From Observation Table: From above observation table, we note there is very small percentage difference in FEA and FFT results. This is less than 20%. This is acceptable. This variation may occur due to rated material properties, change in mass, change in geometry and increase or decrease in stiffness values of material [14, 15]. Modal Analysis From FFT Existing Pallet Frequencies In Hz From FFT Final Modified Pallet Frequencies In Hz From FFT Mode Mode Mode Comparison Table of Natural Frequency In Hz From FFT of Existing Pallet And Modified Pallet editor@iaeme.com

17 Design and Optimization of Critical Part of A Rotary Table Used in Horizontal Machining Centre 8.4. Discussion On Result Obtained: From the above tables, it can be concluded that the modal frequencies of the final modified pallet is greater than the operating frequencies and also frequencies occurred in the final model is greater than the existing designed pallet. Hence there is no any resonance. So, design of pallet is safe. 9. CONCLUSIONS: 1. The weight of pallet is reduced, In final designed pallet compare to existing pallet by %. 2. From table 4.2, we found that the final modified pallet has less deflection as micron and Von mises stress as 30.8Mpa compared to existing pallet. Therefore, modified pallet is safe under static conditions. 3. From the above tables of natural frequencies, it can be concluded that the model frequencies of the modified pallet is greater than the operating frequencies. Hence there is no any resonance. So, design of final modified pallet is safe. The frequency occurred in the final model is greater than the existing pallet. 4. Due to reduction in weight this final modified pallet can be used as automatic pallet changer. 5. Reduction in weight of pallets results in to reduced material cost. 6. The provision of T slots in the final modified pallet leads to reduction in manufacturing complexity. REFERENCES [1] Fred M. Pulst and J.M.A.Tanchoco, Robotic Implementation of pallet loading patterns, International Journal of Prod.Res.1986, Vol.24, No.23, [2] MichaelWang, Suresh Sethi, ChelliahSriskandarajah, Steef Van De Velde, Minimizing MakespanInFlowshops with Pallet Requirements: Computational Complexity Infor vol. 35, no. 4, Nov [3] Terry D. Gerhardt, Strength and Stiffness Analysis of Notched, Green Oak Pallet Stringers United States Department of Agriculture Forest Service, Forest Products Laboratory Research Paper,FPL452. [4] H. Weule1, J. Fleischer W. Neithardt1, D. Emmrich, D. Just, Structural Optimization of Machine Tools including the static and dynamic Workspace Behavior The 36th CIRP-International Seminar on Manufacturing Systems, June 2003, Saarbruecken, Germany [5] Carsten Daub, A Model Of Enhance The Effectiveness Of Machining Centers With Automatic Multi-Pallet Changers : A Case Study May [6] Juan Pablo Leiva, Brian A Comparative Study of Topology and Topometry Structural Optimization Methods Within the Genesis Software LS-DYNA Anwender forum, Frankenthal 2007 [7] Lubomír Novotny, JiříMarek Numerical And Analytical Modelling Of A Pallet Used At A Machining Centre At High Speed Numerical and analytical modelling June /13 [8] Vichare, P., Nassehi, A. and Newman, S. T. (2011) Unified representation of fixtures: Clamping, locating and supporting elements in CNC manufacture International Journal of Production Research, 49 (16). pp ISSN [9] S. Pellegrinellia,*, A. Valentea, An Integrated Setup Planning and Pallet Configuration Approach for Highly Automated Production Systems with Energy editor@iaeme.com

18 Mr. Kadam Pradip Vasantrao and Prof. N. V. Hargude Modelling of Manufacturing Operations Tosattiaa Institute of Industrial Technology and Automation, National Research Council, ITLA-CNR, Via Bassini 15,20133 Milano. Italy. [10] Abdullah Waseem, Ahmad Nawaz, Comparative Analysis of different Materials for Pallet Design using ANSYS International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:13 No: IJMME-IJENS April 2013 IJENS [11] Mohit Law, Yusuf Altintas, Rapid evaluation and optimization of machine tools with position-dependent stability International Journal of Machine Tools & Manufacture 68 (2013) [12] S. Pellegrinellia,n, T.Tolio Pallet operation sequencing based on network part program logic Robotics and Computer-Integrated Manufacturing 29 (2013) [13] d+worm+wheel+device&biw=1242&bih=615&tbm=isch&tbo=u&source= univ&sa=x&ved=0cc8q7alqfqotcjoiw6ld7mccfq0ajgodmsupyg. [14] Ajeet Kumar Rai and Mustafa S Mahdi. A Practical Approach to Design and Optimization of Single Phase Liquid to Liquid Shell and Tube Heat Exchanger. International Journal of Mechanical Engineering and Technology, 3(3), 2012, pp [15] Mr. Abhijeet Rane, Gajendra V. Patil, Gajanan Thokal and Vinayak Khatwate. Design and Optimization of Electrostatic Precipitator Using Finite Element Analysis Tool. International Journal of Mechanical Engineering and Technology, 5(1), 2014, pp editor@iaeme.com