A drill includes a bar-shaped drill body, a major cutting edge which is located at a front end of the drill body and has a straight-line region in a front view, a rake surface located along the major cutting edge, and a chip discharge flute being extended spirally around a rotation axis of the drill body in a direction from the rake surface toward a rear end of the drill body. The rake surface has a flat region located along the straight-line region.

According to one implementation, a drill includes the first cutting edges, the second cutting edges and a deflection reducer. The first cutting edges drill a prepared hole to a workpiece. The first cutting edges are formed in a tip side of the drill. The first point angle and each first relief angle of the first cutting edges continuously or intermittently decrease from the tip side toward a rear end side of the drill. The second cutting edges finish the prepared hole. The second cutting edges are formed at positions away in the rear end side from the first cutting edges. The second cutting edges have the second relief angles at a maximum diameter position. The deflection reducer reduces deflection of the second cutting edges by being inserted into the prepared hole. The deflection reducer is formed between the first cutting edges and the second cutting edges.

A system and method for drilling a hole in a vehicle structure and installing a fastener in the hole. A drill plate having openings and associated machine-readable elements is positioned on the structure. A drill gun is positioned in a particular opening and reads hole information from the associated element, and a computer determines whether the drill gun is properly set-up to drill the hole. A fastener insertion gun is positioned in the particular opening and reads fastener information from the element, and the computer determines whether the hole has been drilled and, if so, whether the fastener insertion gun is properly set-up to insert the fastener. A fastener delivery subsystem stores, tracks, and delivers fasteners to the fastener insertion gun. A system computer monitors the drilling of every hole, the insertion of every fastener, and the overall operation of the fastener delivery subsystem.

A system and a method for measuring drilling damage in fiber reinforced plastic (FRP) composites is described. Multiple holes are drilled in the FRP composite using a drill having nominal diameter, and the FRP composite is separated into multiple drilled blocks. Each block, covered with the black substrate, is scanned on a scanner to generate a scanned image depicting a hole region, a background, and delamination damage peaks. For each scanned image, a maximum delamination damage peak and a maximum diameter of a first circle concentric with the drilled hole and passing through tip of the maximum delamination peak, are measured. Further, a delamination size and a delamination factor are calculated based on the maximum diameter of the first circle and the nominal diameter of the drill.

Provided herein is a drill having less possibility of cracks in an inner periphery of a drilled workpiece and deformation of a workpiece upon penetrating with a drill, as well as delamination. A drill according to the present invention comprises two cutting blades which are formed symmetrical about an axis of rotation, wherein each of the cutting blades has a main cutting blade formed from a drill tip toward a peripheral side of the drill to become a shape with curves, a thinning cutting blade in a shape with curves formed in closer to the drill tip than the main cutting blade, and an U-shaped cutting blade in a shape with curves formed in closer to the periphery of the drill than the thinning cutting blade.

A system and method for drilling a hole in a vehicle structure and installing a fastener in the hole. A drill plate having openings and associated machine-readable elements is positioned on the structure. A drill gun is positioned in a particular opening and reads hole information from the associated element, and a computer determines whether the drill gun is properly set-up to drill the hole. A fastener insertion gun is positioned in the particular opening and reads fastener information from the element, and the computer determines whether the hole has been drilled and, if so, whether the fastener insertion gun is properly set-up to insert the fastener. A fastener delivery subsystem stores, tracks, and delivers fasteners to the fastener insertion gun. A system computer monitors the drilling of every hole, the insertion of every fastener, and the overall operation of the fastener delivery subsystem.

An auxiliary material for fiber-reinforced composite material processing having a supporting material and an adhesive layer disposed on the supporting material, in which an elastic modulus at 23° C. of the supporting material is 0.1 to 30 GPa.

A drill includes a body. The body includes a first cutting edge, and a second cutting edge apart from the first cutting edge to the back end side relative to the first cutting edge and formed in a recess traversing an outer peripheral portion of the body. In a side view of the body in a first direction in which a distance between a center axis of the body and a first outer end of the first cutting edge is seen the longest, a second outer end of the second cutting edge is located at the center axis side relative to the first outer end of the first cutting edge.

A lubricant material for assisting machining process comprising fullerene.

A high frequency vibration spindle system with non-contact power transmission and a method for manufacturing a restraining member used therein are disclosed. The high frequency vibration spindle system comprises: an electric power transmission device including a first induction module and a second induction module, wherein the second induction module is disposed at either a spindle or a toolholder and is adapted to receive an electric power from the first induction module in a non-contact electromagnetic induction manner; a transducer adapted to vibrate the tool and disposed at the toolholder and electrically connected with the second induction module to receive the electric power; and-a restraining member located between the first induction module and the second induction module. With the restraining member, the structural strength and stability of the second induction module can be improved, thereby increasing the maximum rotational speed of the high frequency vibration spindle system.