Drilling tools and inserts with coolant relief and method
There is provided a drill insert for drilling metallic or other materials, comprising a drill insert body with first and second lands at the outside diameter of the body that interface with the wall of a drilled hole. There is provided a coolant relief arrangement at the outside diameter of the drill insert by a plurality of coolant supply channels extending between the leading edge and trailing edge of the interface, to provide coolant relief to the outside diameter of the drill insert at the interface with the drilled hole. The drill inserts of the invention provide reduced friction and heat generation while maintaining high stability, and operate to prevent accumulation of materials on surfaces of the drill inserts at the outside diameter of the drill insert. This enables higher penetration rates and operating speeds while maintaining integrity of the drill inserts.
1 . A drill insert comprising,
a drill insert body having a first cutting end opposite a second mounting end, first and second side locating surfaces and a first land surface opposite a second land surface at the outside diameter of the body and a rotational axis,
the first cutting end of the drill insert body having cutting edges associated therewith, and the first and second side locating surfaces together locating the drill insert body with respect to a drill insert holder,
a coolant supply to disperse coolant fluid directed at the bottom of the hole and cutting edges of the drill insert body when positioned in the drill insert holder, the first and second land surfaces each forming an interface with the side of a drilled hole over at least a portion thereof, the interfaces having leading and trailing edges, and wherein at least one coolant supply channel extends at a transverse angle toward the second mounting end from the leading edge to the trailing edge of the interfaces to allow coolant fluid to flow through the interfaces and adjacent the trailing edge of the interfaces at the outside diameter of the drill insert body to disrupt the adhesion of cut materials adjacent the trailing edge of the interfaces.
2 . The drill insert of claim 1 , wherein a plurality of spaced apart coolant supply channels are provided in spaced relation to one another.
3 . The drill insert of claim 1 , wherein a plurality of coolant supply channels are directed at an orientation angle between the leading and trailing edges with respect to the thickness of the drill insert and plane of the interface and the orientation angle of at least one of the plurality of coolant supply channels is different than the orientation angle of at least one other of the plurality of coolant supply channels.
4 . The drill insert of claim 1 , wherein the at least one coolant supply channel is directed at an inclination angle with respect to the interfaces.
5 . The drill insert of claim 1 , wherein a plurality of spaced apart coolant supply channels are provided and the spacing between the plurality of coolant supply channels on each land surface is uniform or non-uniform.
6 . The drill insert of claim 1 , wherein a plurality of spaced apart coolant supply channels are provided and the same or different number of coolant supply channels are provided on each land surface.
7 . The drill insert of claim 1 , wherein a plurality of spaced apart coolant supply channels are provided and the spacing between the first of the plurality of coolant supply channels from the cutting edge on each land surface is uniform or non-uniform.
8 . The drill insert of claim 1 , wherein the coolant supply from the at least one coolant supply channel disrupts the adhesion of cut materials adjacent the trailing edge of the interfaces.
9 . The drill insert of claim 1 , wherein the at least one coolant supply channel extends through a margin that forms the interface with the wall of a drilled hole on each land surface.
10 . The drill insert of claim 1 , wherein a plurality of coolant supply channels are formed as grooves that create multiple margin contact areas spaced across the entire margin region of the outside diameter.
11 . The drill insert of claim 1 , wherein the at least one coolant supply channel has a curved configuration.
12 . The drill insert of claim 1 , wherein the drill insert body is formed with a flute associated with each cutting edge and the at least one coolant supply channel extends between each flute through the interface.
13 . The drill insert of claim 1 , wherein a plurality of spaced apart coolant supply channels are provided and formed as grooves wherein the width and/or depth of at least one of the plurality of grooves varies from other grooves and/or between the leading edge to the trailing edge of the interface.
14 . The drill insert of claim 1 , wherein there is a cutting lip associated with the cutting edges that extends to the outside diameter of the drill insert, and the at least one coolant supply channel is positioned at substantially the interface of the cutting lip at the outside diameter of the drill insert.
15 . The drill insert of claim 1 , wherein the at least one coolant supply channel is formed as a groove at the interface or hole extending through the drill insert body.
16 . A drilling system comprising,
a holder having a rotational axis and drill insert mounting end, a shank and coolant delivery outlets,
a drill insert formed as a body with bottom, top, first and second side locating surfaces together locating the drill insert body with respect to the holder and land surfaces at the outside diameter, the top including a plurality of cutting edges,
wherein the land surfaces each form an interface with the side of a drilled hole over at least a portion thereof, the interfaces having leading and trailing edges, and wherein at least one coolant supply channel extends between the leading and trailing sides of the interfaces at an acute orientation angle with respect to the thickness of the drill insert and plane of the interface from the cutting edges toward the bottom of the drill insert for coolant to enter from the bottom of the drilled hole and be dispersed in the area adjacent the trailing side of the interfaces.
17 . A method of dispersing coolant in a drilling operation using a drilling tool comprising
a holder having first and second ends and a rotational axis, with a drill insert configured to be fixed in association with the first end and the second end of the holder, and wherein the drill insert includes bottom, top, first and second side locating surfaces together locating the drill insert body with respect to the holder, first and second cutting edges on the top extending from the rotational axis, and first and second land surfaces at the outside diameter of the drill insert with at least a portion of the land surfaces forming an interface with the wall of a drilled hole, wherein at least one coolant supply channel extends through the interfaces from the leading to the trailing edges of the interfaces at a transverse angle toward the second mounting end from the leading edge, and drilling a hole in a workpiece while directing an amount of coolant under pressure toward the bottom of a drilled hole, wherein the at least one coolant supply channel provides coolant to flow through the interfaces and adjacent the trailing edge of the interfaces at the outside diameter of the drill insert.
18 . The method of claim 17 , wherein the coolant supply from the at least one coolant supply channel disrupts the adhesion of cut materials adjacent the trailing edge of the interfaces.
19 . The method of claim 17 , wherein the at least one coolant supply is formed as a groove at the interface or hole through the body of the insert extending from the leading side to the trailing side through the interfaces with the hole.
20 . The method of claim 17 , wherein the interfaces of the insert are formed by at least one margin on the land surfaces of the drill insert and a plurality of spaced apart coolant supply channels are provided which extend between the leading and trailing sides of the at least one margin on each land surface.