Isa solution greatly improves crankshaft machining

In a large-scale engine manufacturing process, if the time spent on a single machining process is reduced by a few seconds, it means that the engine manufacturing company can save millions of dollars per year, get more profit from the price-sensitive market and have more Competitiveness. This has been verified by Japanese automakers and Brazilian off-road vehicle manufacturers.

Relevant examples: the support surface of the diesel engine crankshaft or the side of the balance block produced by the German company Cologne Deutz (GDR) (the leading supplier of German diesel engines). Although the surface of the counterweight does not come into contact with other metal parts of the engine, its dimensional accuracy directly affects the dynamic balance during engine operation. Deutz produces ten different types of crankshafts per year, with an annual production of 25,000 crankshafts per crankshaft.

Half of production beats

After Iskar's comprehensive update of the customer's tooling program, the production tact time was cut in half, from the original 69s to 38s. In addition, the new solution has greatly improved the service life of the tool, while being more stable, and the machining safety has been improved, which has fundamentally eliminated unplanned downtime due to tool factors. Power consumption has been reduced by 10% to 15%. In addition, a new type of ISCAR HELITURN LAYDOWN turning tool mounted on the turret eliminates the need for a second tool and leaves room for the turret.

The process consists of machining the crankshaft surfaces on the left and right sides (when the crankshaft rotates) and removing approximately 1.2 mm of allowance on each side of the counterweight. Deutz uses the CNC lathe made by Niles-Simmon with a three-jaw chuck, center frame and tailstock to perform the above process. Due to the asymmetry of the crankshaft, the surface to be machined is essentially a “moving surface”, so each process begins with an intermittent cutting state. In addition, all procedural problems are rotated along the eccentric path. The work surface is related.

Previously, complex machining requirements required separate processing of the left and right tools, using Iskar flat square CNMG series inserts. Due to the uneven cutting load and interrupted cutting in the process itself, unplanned tool failures often cause unplanned downtime, which is one of the reasons why Deutz's processing speed is low.

Turning another weight block

Deutz engineers asked Iskar to design this crankshaft machining solution for machining cycles. Isca gives a response: the new spiral blade mounted in a special double-knife holder allows a single tool to simultaneously machine both sides of the counterweight for a higher machining speed. The vertical orientation of the insert increases the strength along the cutting surface, making the cutting edge longer and more reliable. This also causes the main tool loss to come from the natural wear of the cutting edge, rather than an unpredictable break or chipping.

With the elimination of the threat of sudden blade failure, the machining speed can be reliably improved.

Close-up of a new type of tool

In addition to vertical inserts, HELINGO face milling cutters have many other advantages that contribute to machining. The large positive rake angle and the spiral edge make the cutting lighter, increasing the line speed, feed rate and depth of cut, while also ensuring safety. The large positive rake angle guarantees plunge cutting and avoids large cutting forces at smaller rake angles or zero rake angles. The spiral blade reduces the cutting force in different ways, making the cutting smoother, single and small, step by step. The helical cutting edge eliminates the cutting forces generated by the straight edge insert when it is cut into the workpiece. The top surface of the blade is provided with a chip breaking station to help form uniform ribbed chips. In addition, the strong side screw clamping method and the cutter body structure without the upper pressing plate at the top allow the iron filings to be discharged smoothly.

Establish partnerships that exceed expectations

Deutz and Isis collaborate on optimizing process parameters to achieve a balance between shorter production tempo and greater process safety. In the first attempt to use a single spiral blade, the production cycle was greatly reduced, the operating temperature was reduced, the spindle load was reduced, and the blade life was increased. Therefore, the cutting parameters are further improved in time to promote tool efficiency. Through the final parameter setting, not only the production cycle is shortened by more than 25%, but also the tool is fully protected to extend the life of the cutting edge and improve the processing safety. Through these tests and experiments, both parties realized that despite the increased cutting speed, the spindle load was still low compared to before.

At this point, Iskar recommends a second improvement: providing a lower spindle load. This involves installing a second tool at the turret turret and processing the two pairs of balance blocks simultaneously. If there is no lower cutting force from the spiral-blade tool, the above steps will be very dangerous. They tried and succeeded, further shortening the production cycle.

The concept is fully proven and is extending

Since the middle of 2009, the improved process has been produced around the clock, and about 20,000 special types of crankshafts have been machined. Production tacts have been cut in half, and unplanned downtime due to severe tool failures has become a thing of the past.

Based on the above successes, Deutz is currently extending this concept to the company's production lines. Deutz's ten crankshaft products are suitable for a wide range of equipment – ​​including industrial tractors, railway machinery and icebreakers. The company's history in diesel engines dates back to the world's first Otto four-stroke cycle internal combustion engine.

Success stories of rapid metal removal rate (FMR)

Iskar cited this success story as an example of Metal Removal Rate (FMR), which combines the world's top tool concepts with total application support to provide manufacturers with more beneficial processing. They note that current trends are tending to find solutions for suppliers rather than simply ordering tools through catalogs or websites. Iskar supports this trend as it provides customers with better and faster solutions.

To support this development, Iskar has recently launched an online tool search software, the Isca Tool Consultant (ITA), which takes computer-aided tools and machining options to a whole new level. The above search engine is freely available through the ISCAR.COM website. User-specific information is always secure. ITA's thoughtful "thinking" approach is comparable to process engineers, and the way it works is as simple as a normal computer or a Mac search engine, providing a solution that is workable and detailed. The software selects the most appropriate and correct tool for you by searching a large number of global best practice cases.