Sumitomo Electric Carbide Manufacturing, Inc. ~ Master Tool Division

Transcription

1 MASTER TOOLING S P E C Sumitomo Electric Carbide Manufacturing, Inc. I A L I S T S T O O L Sumitomo Electric Carbide Manufacturing, Inc. ~ Master Tool Division MASTER TOOLING Sumitomo Electric Carbide Manufacturing, Inc. S P E C I A L T O O L I S T S ASTER TOOLING P E C I A L I S T S T O O L ric Carbide Manufacturing, Inc. MAS TOOLI Sumitomo Electric Carbide Manufact S P E C I A L T O O L I S T S MASTER TOOLING Sumitomo Electric Carbide Manufacturing, Inc. S P E C I A L T O O L I S T S MASTER TOOLING S P E C Sumitomo Electric Carbide Manufacturing, Inc. I A L I S T S T O O L MASTER TOOLING MASTER TOOLING Sumitomo Electric Carbide Manufacturing, Inc. S P E C I A L I S T S T O O L

2 Table of Contents

3 BBR1-85 Master Tool suggested a broach design that consisted of fixed pocket inserts in the leading pockets with adjustment only in the last two (2) pockets on each side of the broach. The adjustable pockets utilized a simple cam adjustment for the insert. These last few finishing inserts are mounted to quick change blocks with a DIN HSK connection and are presettable off-line with a pre-set gage. A few months ago, Master Tool was asked by General Motors de Mexico to provide a simpler solution for their existing bearing cap broaching operation at their Toluca plant. Their existing broach consisted of 28 individually adjusted triangle inserts. These inserts sat in an angled pocket with a wedge clamp. Among the many problems with this style included the fact that when adjustment was made in one direction ( ie. radially) movement was also automatically made in the axial direction - even though no movement was necessary axially. This new concept broach block is currently running production parts in Mexico with great success. It now takes less than one (1) hour to preset the tools. It is also possible to make minor adjustments on-line to adjust the finishing inserts for tool wear. The tool life projection is far greater than the old competitor's design. If you are currently broaching with either brazed or antiquated insert designs, contact Master Tool for a solution. Tool life on the existing broach was not bad (approximately 10,000 hits) but when new inserts were changed or indexed to a new edge a minimum of hours was necessary to set the broach. Any adjustment on-line to adjust for tool wear was virtually impossible. February-99

4 DUST COVER- Protects Arbor & Bayonet threads from dirt and lubricants DRIVE KEY- Insures proper positioning of cutters HELICAL KEYWAY ARBOR- Staggers common cutters to eliminate multi-insert stepping BAYONET ADAPTER- Releases arbor within a 60 degree rotation ERROR PROOF PIN- Eliminates cutter mounting errors ARBOR LOADED AND UNLOADED WITHIN.31 AXIAL MOVEMENT ALLOWING YOU THE QUICKEST ARBOR CHANGE POSSIBLE! M Master Tool was recently contacted by one of our Canadian customers to review their arbor milling process on their cast iron engine block bulkhead. They were currently performing the bulkhead milling in two separate machine stations (every other journal in each station) with adjustable pocket half side mill cutters from one of our competitors. They problems consisted of low tool life (only 1600 hits) and long tool setting time trying to adjust all of the insert cartridges. Addressing the tool life issue was relatively easy. We suggested fixed insert pocket (no adjustment) cutters. This permitted doubling the number of inserts. It also dramatically reduced the tool setting problem since no tool setting was required. We also used an arbor with a helical rather than straight keyway (a Master Tool exclusive feature). This helical keyway staggers the common cutters into the workpiece to eliminate multi-insert stepping. The effect is a dramatically reduction in tool pressure and the potential for chatter. Lastly, we suggested cutting all of the journals in one station rather than two. The machine builder advised the customer that this was not possible because of horsepower restrictions. Our calculations showed otherwise and we guaranteed the success of the operation. When the bulkhead arbor was installed (on one station only) there was no noticeable difference in horsepower. Tool life went from 1600 hits to 4800 hits dramatically reducing the cost per piece on this operation. In addition, the customer loaded a full set of arbors in both stations - run for a week on one station (with the other station off) and then switches stations. This means he has zero downtime for tool changes. The next step is to gradually increase the chip load (because of the higher density of inserts) which will increase the tool life even further. July-00

5 CBFL1-85 Cummins Engine Co. in Columbus, Indiana has recently introduced their new Signature 600 diesel engine. This new 600 horsepower engine has taken the diesel engine industry by storm. In development for over four years, Cummins marketing introduction and manufacturing processes have been unprecedented. At the early stages of the program, Master Tool was invited to review the processes on the machining of the six cylinder block. The finish cylinder boring was a main concern because the process called for a double transfer of the block to permit the cylinder bore tool to be advanced into the bore in a non-rotating condition. This was necessary because the finish diameters above and below the liner shelf were the same diameter. However, this also required the spindle to be stopped and started on each cycle. Not only was this time consuming but it added additional stress and wear on the spindle bearings - reducing the projected spindle life dramatically. Master Tool proposed a cylinder bore tool that did not have to be started and stopped on each cycle. Based on previously designed feed-out heads using helical spline, Master Tool was able to design a cylinder bore tool that could enter the bore in a rotating condition. Once inside the bore, a push on the single drawbar rotated the bottom bore diameter cutting head into position for finish machining of both the top and bottom diameters. Then a push on the drawbar feeds the cross slide out to machine the liner shelf (see illustration above). The system is then reversed to remove the cylinder bore tool from the finished bore. The cross slide used to machine the liner shelf is round, rather than the conventional square slides used by competitors. This permits the slide to be sealed with an O- Ring to eliminate outside contaminants from entering the head. This innovative design reduced the cycle time by not shutting the spindles off, reduced the machine cost by eliminating the double transfer and provides longer spindle life by reducing the wear on the spindle bearings. ###

6 CODE-85 Master Tool used their already proven helical spline feed-out mechanism in the flange mounted adapter to produce the movement required to position the finishing cartridge. The helical spline eliminates any possibility of backlash in the cut, producing excellent size control. Cylinder boring on engine blocks is one of the most critical stations on a block transfer line. Back in 1991, Master Tool was presented with a unique problem at Ford in Cleveland, Ohio. Ford was buying a transfer line to produce two (2) separate V-6 aluminum blocks (2.5 Liter & 3.0 Liter) on the same transfer line. Change over time from one block size to the other was critical to meet the projected production rates. Ford determined that a change over of one hour or less was needed The one area that produced their biggest concern was the finish cylinder bore station. Traditional flange mounted cylinder bore tools would take four to six hours to change over to another size. Master Tool was named as their tooling partner and was asked to provide a solution. Master Tool also designed a connection system to permit the use of a quick change nose piece to provide off-line presetting of the tool and the ability to change heads for each block size without removing the flange mounted adapter. Not only was Ford able to make block size change overs in less than one hour, they where also able to preset the heads off-line and get First Part --- Good Part. Because of the rigidity of the system and the no-backlash helical spline Ford has consistently produced over 2.5 CPK s and have averaged over 4000 hits on the CBN (Cubic Boron Nitride) tipped inserts. Master Tool currently has over nine different cylinder boring installations using this tool design all successful with CPK s of well over 2.5. This led to the development of Master Tool s unique cylinder boring system. The system provides for the traditional semi-finish on the in-stroke and finishing on the out-stroke by a draw bar pull, but with some unique differences. Jul-98

7 Fig. 1 Fig. 2 Fig. 3 Over a year ago, Don Bolton, the Sumitomo sales engineer in Oklahoma, had a customer that was buying a new machine to mill the weld preparation forms on the edges of heat exchanger panels (see Fig.1) These panels would be milled on a vertical, twin spindle, special rail type of machining center. The machine would have twin 100 Horsepower milling heads to machine both sides of the heat exchanger panels at the same time (see Fig. 2 & 3). The materials would range from Inconel to 300 series Stainless Steel. The competitors were Walter and Sandvik and the initial quote request called for 10 inch diameter cutters for two different forms. Over the next few months the cutters changed from 10 inch to 12 inch to 14 inch and finally to 16 inch diameters. The number of forms to be machined increased from two (2) to six (6). There was a lot of confusion and not a great deal of information from the customer. But with Don's diligence, a great deal of support from his manager, Jay Martin and a very good distributor relationship with the end user we were able to present a final design and price. It is also interesting to note that after Don received the order from the customer one of the questions that he asked was "why did you give the order to us?". The answer was very interesting and telling. The customer said that besides the fact that they liked our design - we treated them with respect. They said that during the year of changing things like the cutter diameters and part forms and all of the requotes - both of our competitors became very impatient with them. They felt that the competitor's sales people "talked down" to them and did not completely answer their questions. They also said that was never an issue with Sumitomo or Master Tool. We were always respectful and answered all of their questions. Even though this process took almost a year to complete, the result was a very large order for a number of special milling cutters. This also will result in a very high volume of standard insert business in the years to come. Congratulations must also go to the Master Tool design engineers. They developed a design that was very easy for the customer to understand and believe in. August-09

8 CODE-85 This design also helps to eliminate any transfer error of the machine - ensuring that the finish insert machines the exact same amount of material on all sides of the crank bore. The end result was an increase of tool life from 80 parts per corner to over 280 parts per corner. This 250% increase in tool life dramatically increased the line s uptime due to less insert changing. Part quality was maintained (actually improved) and the cost per piece was noticeably reduced. Master Tool was recently presented with an opportunity to replace a competitor s Crank Line Boring Bar at General Motors in Romulus, Michigan. The dedicated Ingersoll transfer line to produce General Motor s GEN 3 Engine Block was delivered with the competitor s Line Bars on the crank boring station. The GEN 3 engine block is a cast iron block with a powdered metal girdle requiring bi-metal machining of the crank bore. The line went through run-off at Ingersoll with reasonable success on the crank bore, however, tool life never became an issue until installation at the Romulus plant. Once the installation was up and running, the fact that the best tool life achieved was only 80 parts per cutting edge became a major issue. The competitor was permitted to try various grades of carbide and insert geometries with limited success. This result was achieved by replacing only the finish competitors crank bar. The Ingersoll Line was a traditional three (3) station crank bore operation (roughing, semi-finishing and finishing). The Master Tool double cartridge design actually eliminates the need for three (3) station boring. If the double cartridge design is used in the roughing station, only two (2) stations are necessary to produce perfect crank bores. This is a potential $500,000 savings on a block line in addition to the savings on the cost of the tooling and back-up tooling. If part quality and tool life are important to you on your line boring operations, contact Master Tool for an engineered solution. Master Tool offered to build a test bar for the finish station only, using our proven double cartridge technology. The double cartridge design permits semi-finishing and finishing on the same feed stroke. Jan-98

9 ( Patent Pending ) Figure 1 ( Patent Pending ) Figure 2 T he number one criteria for a line boring bar is while there is face contact, there is only line to be straight and true. If the bar is bent the contact on the shank, permitting movement and resulting holes being machined will not be round vibration. nor will they be in line. The basic problems only begin with the manufacturing of the bar. Since the line bar must be machined and then heat treated (to as much as 60 Rc) keeping the bar straight is a big issue. In fact, it is impossible to machine a bar 2 or 3 inches in diameter and over 30 inches long - heat treat the bar - and not have the bar bent from heat treatment. Therefore, line bars are generally stress relieved and straightened after heat treatment. Although some of our competitor's have made attempts at manufacturing line bars in short segments, Master Tool has perfected the practice. The basic reason Master Tool has succeeded while others have failed is because of the joint used to hold the segments together. Our competitors attempts have used a straight shank style of connection to join the segments. The problem with this connection is two fold. First, a straight shank in a straight hole has an obvious run-out problem because of the manufacturing tolerances between the two. Secondly, this joint lacks strength because Master Tool has chosen a solid, stub tapered joint. This joint is patterned after the hollow DIN HSK joint we commonly use in industry as a quick change connection. The joint provides full face contact and a minimum of 80% surface contact on the taper (see Figure 1). The joints in the split bar consist of matching internal and external tapers in the center portion of the bar and a flat annular portion near the outside. The joint is held together by three set screws with conical ends. Tightening the screws provides a force, which draws the joints together until the flat annular portions are in contact (see Figure 2). It is possible to heat treat segments up to 20 inches in length without going through a straightening process. Because the run-out of this tapered joint is less than ( 1 micron ) the bars are perfectly straight when they are joined together. Now other features such as through coolant holes are much easier to manufacture. Master Tool was originally concerned about the bending strength of a pieced line bar. The difficulties of other manufacturers using

10 ( Patent Pending ) ( Patent Pending ) Figure 3 Figure 4 the straight shank connection has caused an industry perception that pieced bars are weaker than solid bars. In lieu of this, Master Tool contracted Cleveland State University to conduct a deflection analysis of our pieced bar. During their analysis, Cleveland State assumed the cutting forces to be 40 lbs. in the tangential direction and 20 lbs. in the radial direction (this is approximately three (3) times that of the actual cutting forces in cast iron). Their set screw calculations show that each screw contributes a force of 9000 lbs. to pull the tapers together and maintain contact between the annular potions of the joint. These calculations were based on an interference between the conical end of the set screw and the cone shaped depression in the tapered portion of the joint. The analysis also showed only 200 lbs. of force is needed to close the joint, even at maximum material condition. The remaining force from the set screws is available to prevent separation of the joint under load. Cleveland State calculated deflection amounts for both a solid and split line bar assembly of the same diameter and length. The split bar had three (3) joints. Both types of line bars show very small deformations under cutting forces, with the solid bar deflecting a maximum of of an inch near the center and the split bar having of an inch of maximum deflection. The conclusion of Cleveland State's analysis indicates that the split three-piece line bar has the same deflection performance under cutting loads as the solid one-piece bar. The joints remain in contact during cutting operations with significant residual clamping force. Another advantage of segmented bars is the ability to offer unique designs such as line bars with rotating bearings as a part of the bar (see Figure 3). In addition, line bars with feed-out and internal draw bars (see Figure 4) are now a real possibility. This type of line bar eliminates the tradition "lift and drop" process on crank bore machining on an engine block. By eliminating the "lift and drop" this station now becomes a direct transfer like any other station. This dramatically reduces the cost of the station and the cycle time - many times eliminating the need for a split (A and B) line for crank boring. For a complete copy of the Cleveland State University study please contact Master Tool Corporation. July-01

11 CODE-85 Rough cylinder boring on engine blocks can be one of the highest cost per stations on a block transfer line. Many transfer lines use either coated carbide or silicon nitride inserts in this application. Some use quick change tooling systems while others still use dedicated tooling bolted to the spindles. Almost all applications are in Cast Iron, whether it is a Cast Iron block or an Aluminum block with a Cast Iron sleeve. Master Tool s standard practice for rough cylinder boring is to use CBN inserts in fixed position (non-adjustable) cartridges that track within.001 (.025 mm). This tooling system also has an adapter bolted to the spindle with a quick change nose piece using only one screw to change tools. Recently, we had an opportunity to test our system against a competitive system at an automotive engine plant in Ontario, Canada. They were using a solid tool with a HSK- 100B quick change system built into the spindle. The cutting head used four (4) SNG543 inserts in a Silicon Nitride material with adjustable cartridges. They were using a solid tool with a HSK- 125B quick change system built into the spindle. The cutting head used four (4) SNG543 inserts in a Silicon Nitride material with adjustable cartridges. They were running at 1400 SFM with a chip load of.008 per insert. The depth of cut varied up to.250. With this setup their tool life was 800 parts per corner. The cost of a silicon nitride insert is not very high and with eight (8) cutting edges, the tool cost per piece was relatively low. However, at only 800 parts per corner and a very heavy tool, tool change time was high, resulting in a high total cost per piece. Master Tool built adapters using the HSK- 100B shank to mount and stay in the spindle with a quick change nose piece. Our design had fixed (non-adjustable) cartridges - so no preset adjustment was necessary. The nose piece utilized four (4) SNC422 inserts with a CBN top layer providing four (4) cutting edges. The end result was an increase in tool life to 4000 pieces (500%) with a dramatic reduction in tool change time. Insert cost per piece was increased by 4 times (because of the increase cost of CBN and only one half as many cutting edges). However, total cost per piece was decreased by over eight (8) times by the increased tool life and increased machine uptime. March-00

12 CODE-85 Included in the many advantages of using a helical spline feed-out head rather than an eccentric spindle are: Five years ago Master Tool was chosen as the special tooling supplier for Ford Motor Company s Cleveland Engine Plant #2 on their new Giddings & Lewis transfer line installed to produce 2.5 & 3.0 Liter Aluminum engine blocks. Lower overall cost Ability to accurately pre-set the cutting tool Lower maintenance Higher part quality No backlash Sealed head Bearing encased No frictional (rubbing) wear Spindle quality manufacturing Balanced through the stroke First Part --- Good Part - Guaranteed For more information on helical spline feed-out heads contact Master Tool Corporation. One of the most critical stations on the line is machining the thrust face. The tooling must control both the width and location of the thrust wall. Traditionally, this operation is performed with expensive eccentric spindles. Eccentric spindles also have a high maintenance factor. Because of our successful history with helical spline style feed-out heads, Master Tool proposed performing this operation with a feedout head with a quick change cutting unit that could be preset off-line. This operation has been running over four years with absolutely no problems. The heads have produced over 500,000 engine blocks with little or no maintenance. The CPK values consistently produced in production are: Width Location CPK CPK February-98

13 FV1-85 For the past year, Navistar International in Indianapolis, Indiana has been making a strong effort to re-tool their Block and Head lines for their NGD Diesel truck engine to keep up with the increased demand on this engine. One area of particular interest was their finish valve seat operation on their transfer line. For many years, Navistar has been using generating heads to finish the valve seat. While producing a good seat, the generating heads proved to be costly to maintain and very time consuming to perform a tool change. Master Tool suggested that this might be a good place to improve the efficiency of the line by changing to plunge tooling rather than generating heads. Over the past four years, Master Tool has had tremendous success with a plunge valve seat tool design that eliminated all of the previous plunge tool problems. This design is so unique that it has received a US patent (No. 5,704,741) for it s design. Traditional plunge valve seat tooling using ISO style cartridges and straight shank quick change connections have some very obvious operational problems. The standard cartridge designs provide little stability in the cut, producing the potential for chatter on the seat. The existing straight shank quick change connections do not provide the concentricity necessary to correctly align the reamer to the centerline of the seat, producing off center guide holes. Master Tool s solid, tapered shank and captured cartridge design eliminated both of these problems and permitted accurate, off-line tool setting. The tapered shank provides concentricity of less than between the reamer and the tool, virtually assuring that the reamer is perfectly aligned with the stem hole. This provides round, accurately located stem holes (no leakers). The shank s repeatability (less than +/ ) permits fast and efficient tool setting and tool changing with the turn of one screw. By using this system, it is possible to increase the efficiency of the line by up to 20%. In addition, generating head valve seat tooling is up to 10 times the initial cost of plunge tooling, dramatically reducing the cost per piece.

14 Fig. 1 Fig. 2 Fig. 3 Brent Price, the Sumitomo sales engineer in the Detroit area, had an interesting application recently. One of his customers was struggling with rough boring on cast iron sleeves in an aluminum engine block. The operation was being performed on a dedicated transfer line using an adapter that was bolted to a dedicated spindle and an interchangeable nose piece holding the inserts (see Fig. 1). The nose piece held three (3) CBN tipped, fixed pocket, special screw down inserts (the customer had also tried five (5) screw down inserts). The cutting head was connected to the adapter using a shell mill (center bolt) mount (see Fig. 1). The customer had also tried a straight shank, ABS TM type connection to help reduce his run-out problem. The results of all of these different designs were poor at best. They had low tool life (2500 pieces, holes) and high cost per piece (cost per piece was approximately $0.40 per bore). Their hole quality was poor with high withdrawal marks due to a high cutting edge - resulting in additional tool life and quality problems when they finished the hole later. Brent convinced the customer that a whole different approach to this cut needed to be taken. He suggested to the customer that they needed to look at machining this hole from both the front and the back end of the tool. He convinced the customer that the low tool life was mainly due to the fact that all of the inserts were not tracking radially; therefore, adjustable pockets with cartridges were required. He further convinced the customer that the high withdrawal marks could be attributed to the lack of repeatability of the connection between the cutting head and the adapter. In this case, a tapered connection (HSK) was required so that when the tool was preset to the correct diameter it would repeat when placed onto the adapter. Brent added one additional offer that the customer could not refuse. He told the customer that we could provide all of these features and provide a standard, 8 cutting edge, solid CBN insert at approximately the same price as the current special single edged insert (see Figs. 2 &3). He guaranteed the customer that this would eliminate his issues. The customer placed the order and Master Tool Division manufactured the tools to our design standards. The end result was to double their current tool life. The customers cost per hole was reduced from $0.40 per hole to $0.04 per hole. Over 300,000 part per year added up to a huge cost savings for the customer. December-09