Production figures for vehicles with internal combustion engines are declining, but with around 75 million cars built annually, they still remain at a very high level. This provides ample reason for the industry to continue searching for optimization opportunities in series production. MAPAL supports this with new tool solutions for modern combustion and hybrid engines.
The automotive industry is always focused on faster cycle times and lower costs per component. With two examples from crankshaft manufacturing and valve seat machining, MAPAL demonstrates how this can be achieved through the combination of machining steps and innovative tool technologies.
One-Shot Solution for drilling and deburring
The desire for weight reduction to save fuel with less moving mass does not spare a classic component like the crankshaft. To remove material, a central relief hole runs through the entire component. Due to the shape of the crankshaft, there are repeated entries and exits of the tool into the material during machining. The number of these depends on the cylinder count of the engine.
The length of the drill also depends on this. To machine the entire crankshaft in one pass, tools with lengths between 600 and 800 mm are required. MAPAL achieves this with a modular system. The drill body is a special exchangeable head holder with a TTS interface (Torque Transfer System), which guarantees an extremely stable connection. The MAPAL interface is characterized by optimal torque transmission as well as high exchange and runout accuracy. For the desired tool length, the holder is screwed onto an extension.
The TTD exchangeable drill head at the tip is available in different geometric designs depending on machine performance.
A challenge during machining is the burrs that form when the drill enters and exits the metal. Previously, these burrs were removed in a separate operation. MAPAL now offers a one-shot solution for simultaneous drilling and deburring. This is made possible by a modular combination tool, in which an additional chamfer cutting edge is integrated behind the drill head. This SNAP18 module is a miniaturized deburring system that has been individually designed by HEULE Precision Tools.
For process-safe forward and backward deburring, a small spring controls the cutting edge and ensures that the pre-drilled diameter is chamfered to a tenth of a millimeter and not damaged by the deburring.
With this tool solution, the user saves one work step and thus also a tool position in the magazine. The cycle time is reduced.
Twelve cutting edges for valve seats
To reduce costs in the fine machining of valve seats, MAPAL has developed an innovative HNHX indexable cutting insert. Like its predecessor model, the HNHX is hexagonal but has twelve usable cutting edges instead of the previous six. The negative installation position allows for the turning of this new cutting insert. A modified clamping star ensures maximum force transmission and precise positioning in the insert seat. For the finishing of the valve seat ring, highly precise machining is required regarding both the specified tolerances and the surface quality. With the HNHX, surface values of less than Ra 2.0 are achieved.
MAPAL recommends a combination tool for machining valve seats and valve guides. In one operation, the tool first machines the valve guide and finally the valve seat with the HNHX cutting insert.
Further efficiency increase possible with larger valve seat rings
Depending on the design of the valve seat, the HNHX cutting inserts can also be used significantly more than twelve times. Where constructively possible, such as with larger valve seat rings in the truck sector, each of these edges can be used twice, making 24 cutting edges usable. This is achieved by removing the cutting edge at the end of its service life and re-inserting it at a different angle position. The used cutting edges are easily identifiable for the user due to a corresponding coating.
This allows for uncomplicated repositioning in another insert seat and continuing work with an unused area of the cutting edge.
Doubling the number of cutting edges directly affects the production costs for users: The cost per part is halved as a result. Additionally, there is a gain in tool life through the use of PcBN high-performance cutting materials developed within the MAPAL group. The cutting materials are tailored to industry developments that aim to make valve seat rings more wear-resistant through the use of new materials. The robust clamping system results in maximum force transmission and thus a homogeneous force distribution in the insert seat.
The further development of internal combustion engines continues despite the clear trend towards electromobility. Not least to be used in modern hybrid vehicles. As a technology partner, MAPAL stands by the side of its customers and will contribute to further optimizing their production in the coming years.
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