By adopting a drill with a cutting edge optimally shaped for micro pecking to the drilling of a laminated sheet of CFRP and Ti alloy, the quality was improved while reducing the number of processes and substantially improving the processing efficiency.
Effect(s)
* Reduction of the number of pieces of equipment and types of tools
* Reduction of the drilling cost and the tool room inventory cost
* Extension of the drill life
* Improvement of the hole diameter tolerance and surface roughness
* Reduction of delamination and burr
Conventional Technology
The conventional technology has various problems in the drilling of a laminated sheet of CFRP and Ti alloy.
* Normally, 3 to 4 processes including pilot hole drilling and reaming are involved in many cases, requiring significant processing time.
* It is necessary to process different materials (CFRP and Ti alloy) using the same tool, making it necessary to set the cutting condition at a low level.
* The CFRP surface is damaged by chips of Ti alloy, making it difficult to secure quality of the processed surface.
Since the demand for the drilling of larger-diameter holes is becoming stronger, it is urgent to make improvement.
<Requests from customers>
* Reduce the number of tools to be used in order to shorten the cycle time
* Reduce the processing cost per hole
* Increase the processing efficiency while maintaining the product accuracy
New Technology
By adopting the micro-pecking process and a drill with a cutting edge optimally shaped for it to the drilling of a laminated sheet of CFRP and Ti alloy, it became possible to process the workpiece in a single step, and various effects were achieved.
Micro-pecking is a drilling method in which micro vibrations in the axial direction are applied several times per revolution of the drill in addition to ordinary cutting feed by mounting this mechanism’s attachment on a drilling unit such as a power feeder or CNC machine, and has the following features:
<Features and advantages of the processing>
* Since thin chips are partially generated, they are fragmented from that point.
* In metal parts such as titanium and aluminum, fine chips are generated, and discharged.
* Damage to the CFRP surface due to chips is reduced.
* Low-power processing is achievable.
* Lubricant is surely supplied to the cutting edge.
By developing a drill with a cutting edge optimally shaped for micro-pecking process and adopting it, chips are finely fragmented without breaking the PCD cutting edge, the efficiency in processing a laminated sheet of CFRP and Ti alloy is substantially improved, and the dimensional accuracy is improved.
PRECORP INC. (Sandvick Group, Utah, USA) (role: manufacture of PCD tool, product performance evaluation through element testing)
Example of Application
* Aircraft fuselage parts
Technical Problems
・The processing may be unstable due to the matching between the power feeder and a fixing jig or suction equipment, and lack of maintenance.
The installation of the power feeder, which is the micro-pecking mechanism’s attachment, has partially limitations, and its application requires a separate special adapter, etc.
・We intend to contribute to highly efficient processing at customers by proposing a cutting tool and an application technology at the same time.
Collaborator needed to Improve
・Companies that conduct composite processing or have such a plan in the future, and companies related to equipment
・Research institutes such as universities having evaluation technology/equipment for composite processing
PRECORP INC. (Sandvick Group, Utah, USA) (role: manufacture of PCD tool, product performance evaluation through element testing)
Example of Application
* Aircraft fuselage parts
Technical Problems
・The processing may be unstable due to the matching between the power feeder and a fixing jig or suction equipment, and lack of maintenance.
The installation of the power feeder, which is the micro-pecking mechanism’s attachment, has partially limitations, and its application requires a separate special adapter, etc.
・We intend to contribute to highly efficient processing at customers by proposing a cutting tool and an application technology at the same time.
Collaborator needed to Improve
・Companies that conduct composite processing or have such a plan in the future, and companies related to equipment
・Research institutes such as universities having evaluation technology/equipment for composite processing