Presentation on theme: "Common Problems and Solutions in Cutting Tools Implementation Practice in the Setting of Automotive Powertrain Plant: System Outlook Viktor P. Astakhov."— Presentation transcript:
Common Problems and Solutions in Cutting Tools Implementation Practice in the Setting of Automotive Powertrain Plant: System Outlook Viktor P. Astakhov
Viktor P. Astakhov IMTS Introduction What is a Tool Commodity Management (TCM) Company? The basic objectives of a TCM company set by the automotive industry are: 1.To keep production lines running while meeting quality requirements. 2.To meet a cost per unit (CPU) target set by the customer. 3.To assure direct tooling cost savings per year as required.
Viktor P. Astakhov IMTS Introduction Virtuality vs. Reality In the ideal world, these three objectives are the parts or facets of the tool management continuous process, which can be run by business management-type personnel with some engineering training. Any practical tool management process is a discrete process consisting of a great number of Problem Occurrence-Problem Solving dyads (couples). A problem occurrence can be thought of as failure, referred as tool failure. The tool management process runs smoothly if and only if each and every dyad Problem Occurrence-Problem Solving is completed, i.e. when for each problem that occurs on the daily basis, a proper, timely solution is provided. To accomplish that, a fast-respond problem solution system established by of any modern TCM company.
Viktor P. Astakhov IMTS Introduction Example of the machining system (drilling)
Viktor P. Astakhov IMTS Introduction Right Tool at Right Time at Rite Price Right time is when the customer needs the tool to keep its production running. Right cost calculates through CPU for a given application. The term Right tool is totally illusive. The right tool can be thought of as that one made to the print approved by the customer (an automotive company) and thus posted in the corresponding tooling database system. However, if this tool does not work properly, the blame goes to a TCM company, which has little to do with its design and approval. Moreover, a TCM company is responsible for the investigation of the tool failure.
Viktor P. Astakhov IMTS Introduction Tool Problem As seen As it is Simple questions 1.System coherence who is responsible? 2.What resources has a TCM company to investigate a tool failure? 3.What recourses has a tool manufacturer to investigate a tool failure? 4.Have you ever seen a 5Why analysis that point the root cause for the tool failure problem?
Viktor P. Astakhov IMTS Some Common Problems and Solutions
Viktor P. Astakhov IMTS Veins Cutting Through the Veins
Viktor P. Astakhov IMTS Veins Cutting Through the Veins Common drill and its geometryA reason for high point angle
Viktor P. Astakhov IMTS Veins Cutting Through the Veins Sladge
Viktor P. Astakhov IMTS Veins Cutting Through the Veins Improved drill geometry
Viktor P. Astakhov IMTS HSS HSS Tools Following tested possibilities to decrease CPU with HSS tools are most feasible: 1.Application of the advanced application-specific tool coatings 2.Optimization of the finish grinding and re-grinding practices 3.Use Diffusion process 4.Optimization of the tool geometry 5.Use the advanced tool materials as REX 121 and ASP developed for dry applications 6.Optimization of the metallurgical properties of the workpiece prior gear machining to achieve its maximum machinability.
Viktor P. Astakhov IMTS HSS Sharpening flaws Grinding Burr Burns
Viktor P. Astakhov IMTS Carbide Tool In the authors opinion, the following tested possibilities to decrease CPU with carbide tools are most feasible: 1.Application of the advanced application-specific tool coatings combined with high polish of substrates and airlapping after the coating. 2.Utilization of the application-specific carbide grades developed for machining aluminum. 3.Optimization of the tool design and geometry. 4.Synchronization and optimization of drill-rougher-finisher operations including the use of combined tools.
Viktor P. Astakhov IMTS Carbide Tool Common flaws Improper carbide grade + incorrect geometry Coarse grind Improper carbide grade
Viktor P. Astakhov IMTS Carbide Tool Example of Case Studies Upper Valve Body, aluminum alloy 380 Carbide straight flute combined drill –new coating for Al applications A regular tool design with a new coating has been tested using the same machining regime, tool material and other machining conditions (2 tools were tested). The analysis of the test results shows: 1.Tool life tripled 2.Average tool life – 2,500 cycles 3.Tool life of the tested tool – 7,500 cycles 4.Tool wear type is normal for the work material 5.Both margins do not show any excessive wear as with the regular tool. No wear marks were found on the additional supporting areas made on the heels. This shows that the tool maintained its working integrity during the whole tool life 6.All the cutting edges (drill, reamer and chamfer) have uniform wear.
Viktor P. Astakhov IMTS PCD PSD Tool Some most common flaws found in PCD tools Brazing
Viktor P. Astakhov IMTS PCD Some most common flaws found in PCD tools Gap between PCD inserts and the tool body
Viktor P. Astakhov IMTS PCD Some most common flaws found in PCD tools
Viktor P. Astakhov IMTS PCD Recommendations The following is recommended to both tool manufacturers and users to avoid the discussed and many other common and specific problems with PCD tools: 1.Use application-specific PCD grades 2.Specify, inspect and maintain surface roughness on the ground surfaces of PCD inserts 3.Specify brazing quality 4.Specify and inspect the backtaper 5.Use proper re-sharpening/re-tipping strategy 6.Use proper machining regimes for PCD tools 7.Pay particular attention to carbide grade selection for PCD-tipped drills 8.Design and manufacture tools with no gaps between PCD inserts and carbide bodies, with overhanging of PSD inserts, with coolant holes directed into the machining zone (not before and not after), with 5-10 microns radius of the cutting edge (edge preparation) etc. Note that the diameter of the coolant holes as well as the location of their outlets with respect to the PCD inserts should be specified on the tool drawings.
Viktor P. Astakhov IMTS PCD Importance of the backtaper
Viktor P. Astakhov IMTS PCD Proper wear pattern c of PCD insert
Viktor P. Astakhov IMTS Standard Tool Standards for indexable inserts: 1.ISO1832: ANSI B212-4 Standard for tool holder ISO 5608:1995
Viktor P. Astakhov IMTS Tools with indexable inserts Valenite in its catalog in the dimensions of tool holder lists without any explanations two parameters axial and radial having the angular dimension. Seco Tools in the list of its toolholder parameters provides two angles, namely o and p. no explanations and/or figure are given to explain the meaning of these two angles. According to Bohler turning catalog, practically all of its toolholders are suitable for neutral inserts (N). However, it is not mentioned how the flank angle (relief) is provided by these tool holders. The same can be said about Ingersoll turning tool catalog. Standard Tool Sandvik Kennametal (both)
Viktor P. Astakhov IMTS Proper tool geometry Standard Tool ExternalInternal ISCAR Cutting edge inclination angle Normal flank angle
Viktor P. Astakhov IMTS Consequences of insufficient flank angle Standard Tool
Viktor P. Astakhov IMTS Cracking due to high MRS Standard Tool Boring of the liners
Viktor P. Astakhov IMTS Incomplete Tool Drawings Drawings
Viktor P. Astakhov IMTS Drawings
Viktor P. Astakhov IMTS Drawings
Viktor P. Astakhov IMTS Common features Tool Drawings 1.No tool geometry is shown according to the ISO and/or ANSI standard for tool geometry. No edge preparation conditions vitally important fop PCD tools are mentioned (microgeometry parameters). 2.Although all the shown tools are assemblages, no any bill of material is provided. In other words, no indication of the tool, tool shank and brazing filler materials are mentioned. 3.No shape and location tolerances are indicated including the runout of the working part with respect to HSK holder as probably the most important shape tolerance. 4.No surface finish is mentioned. 5.No particular sizes of PCD inserts including its thickness as well as the thickness of the carbide substrate are shown. 6.There is no indication how the cutting inserts are secured in the body. Technically, a paper glue can be used and this would not violate the drawing requirements.
Viktor P. Astakhov IMTS Importance in-house testing and R&D facilities R&D If tool brakes or does not perform adequately first time you try it then you may lose the trust of the customer in your ability to solve their tooling problems. As the old saying goes, You Never Get a Second Chance to Make a First Impression. Nowadays, many automotive powertrain plants use modern sophisticated equipment with expensive high-speed spindles. A wreck such a spindle due to tool failure cost a lot. As a new tool is to produce real parts for real transmissions and engines, the quality procedures require to have a filled out and approved a process change request (PPCR) form before the cutting tool can ever been ordered. Real production lines and manufacturing cells are not playgrounds because the production time is expensive and limited.
Viktor P. Astakhov IMTS Thank You "In theory, there is no difference between theory and practice. But, in practice, there is." - Jan L.A. van de Snepscheut