MXPA06005003A - Spade drill insert having helical margins - Google Patents

Abstract

A spade drill insert and drilling tool assembly is provided wherein the lands of the spade drill insert have helical margins which provide increased stability during cutting operations. The margin may have a helical trailing side or leading side, a parallel helical margin, or may also include a gullet or flute adjacent the helical margin.

Description

BIT INSERT THAT HAS HELICAL MARGINS TECHNICAL FIELD The invention relates, in general, to a drill insert to be placed in a tool holder for drilling holes in metals. More specifically, the invention relates to a drill insert having helical margins which provide greater stability during cutting operations.

BACKGROUND OF THE INVENTION Drilling systems are often used to provide cylindrical orifices in metal workpieces. The cutting or drilling action of the drilling system can be carried out by a substantially cylindrical, elongated drilling tool, such as a combination of a tool holder and a drill insert, which is selectively attached thereto.

That arrangement can then be used in an application where one end of the toolholder is securely mounted in a motor apparatus, which rotates the fastener about its longitudinal axis. At the opposite end of the elongated toolholder, the cutting insert engages the material to be cut. Alternatively, the workpiece can be rotated relative to the fastener and cutting insert, such as by placing the fastener on the mandrel of a lathe or the like. In addition, the tool and the workpiece can be rotated one relative to the other. The use of drill bit inserts allows the insert to be quickly changed after the wear of the cutting surfaces instead of the entire tool, and allows a tool to be used for a variety of different drilling applications, simply by changing the insert and not all the drilling assembly. The drill inserts are characterized in that they are generally flat and have a pair of surfaces or connecting faces on the opposite sides of the insert which are parallel to each other and provide a registration surface for the fastening arms of the fastener. The front end of the drill typically has a pair of transverse cutting edges in the form of an obtuse V. The rear end or base of the drill insert is typically flat and perpendicular to the pair of connection surfaces and engages the bottom of the fastener groove. The sides across the width of the insert, typically referred to as the surface between grooves, comprise the margin adjacent to the front connection surface and a space adjacent to the rear connection surface of the insert. The margin is formed cylindrically around the rotational axis of the bit and engages the sides of a hole that is being cut. The margin width is typically about one-quarter to one-third the width of the insert and is formed parallel to the rotational axis of the bit on the side of the cutting edge of the width. The rest of each side ... is the empty surface that is radially inward from the margin so that it does not come into contact with the hole that is being machined. A problem with the prior art bit inserts is that only a small radial portion of the side widthwise is in contact with the hole, which reduces the stability of the bit and can produce excessive output vibration when cut. Selected materials. Another problem with some prior art bit inserts that have large margins is that the surface area of the margin rubs against the side of the hole when the bit rotates, which causes additional heat buildup on the insert and may require high speeds. Reduced cutting and can also shorten the life of the insert.

THE INVENTION The drill of the present invention provides greater stability during drilling operations. This and other advantages are provided by a piercing insert comprising a piercing insert body having a first end and a second opposite end, a first opposite front side and parallel to a second front side and a first side of the surface between grooves opposite a second side of the surface between grooves, the first and second sides of the surface between grooves formed between the ends and front sides; and a margin formed on a portion of each side of the surface between grooves, the margin having a front side and a back side, where at least one of the front side and the rear side is formed as a helix. These and other advantages are also provided by a drilling tool assembly comprising a fastener having a first end and a second end, wherein the second end comprises a shaft portion adapted to be fixedly attached in a drilling machine, where the The first end comprises a groove of the fastener having a bottom seating surface on at least a portion of the groove of the fastener and at least one linking arm positioned on each side of the fastener groove, wherein each joint arm has at least one. an opening formed in it; and a piercing insert comprising a piercing insert body having a first end opposite a second end, a first frontal side opposite and parallel to a second frontal side and a first side of the surrogate surface opposite a second side of the surface between grooves, the first and second sides of the surface between grooves formed between the ends of the front sides, where the first side of the drill body is a generally flat surface, where the second side comprises at least two sharp edges formed transverse to each other, at least two openings formed through each front side of the body of the piercing insert, and a margin formed on a portion of each side of the surface between grooves, the margin having a front side and a back side, where at least one of the front side and the rear side is formed as a helix. These and other advantages of the invention will be apparent when described below in relation to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention and the developments thereof will be described in more detail in the following by way of embodiments with reference to the drawings, in which: FIGURE 1 is an exploded view of the assembly of the tool assembly of FIG. perforation according to a first modality. FIGURE 2 is a partial perspective view of the fastener associated with the assembly. FIGURES 3A-3E are a variety of different views of an insert according to a first embodiment of the present invention having a helical margin; FIGURES 4A-4E'-are a variety of different views of an insert according to a second embodiment of the present invention having a parallel helical margin; FIGS. 5A-5E are a variety of different views of an insert according to a third embodiment of the present invention having a parallel helical margin with a free front tooth spacing; FIGURES 6A-6B are a partial plane view and a partial top view, respectively, of a corner space of the bottom corner of the cam associated with the present invention; and Figures 7A-7B are a partial plan view and a partial top view, respectively, of a corner space of the corner holding corner associated with the present invention.

DETAILED DESCRIPTION OF THE INVENTION Turning now to a first embodiment of the invention, FIGURE 1 illustrates a drill tool assembly 10, generally indicated. The drilling tool assembly 10 comprises a fastener 12, which has a body 14 and a head portion 16 associated therewith. In the first embodiment, the fastener 12 has, in general, a cylindrical shape with a first end 20 and a second end 22. As shown in FIGURE 2, the first end 20 of a fastener 12 has a fastening groove or fastener 30, which can extend across the entire diameter of the head portion 16 or, at least, over a central portion thereof at the general location of the axis of rotation 18 of the fastener 12. The groove of the fastener 30 has a bottom wall 32 placed in substantially perpendicular orientation relative to the axis of rotation 18 of the fastener 12. In the embodiment shown, the assembly 10 may further include a shoulder 24, which is positioned precisely with respect to the axis 18 and extends from the bottom wall 32 of the groove of the fastener 30. The bolt 24 can be positioned within a hole 26 extending downwardly from the bottom wall 32 of the groove 30 along the axis 18 of the body of the fastener e n a snap-fit relationship with the position bolt 24. Alternatively, the locating shoulder, which, in the embodiment shown, comprises the bolt 24, can be configured differently to achieve the corresponding functionality of the bolt 24 , as an integral member extending from the bottom wall 32. Within the slot of the fastener 30, a piercing insert 35 is accurately positioned with respect to the fastener 12 to effect the desired piercing function in conjunction therewith. As will be described here later in greater detail, the insert has a point geometry comprising a plurality of cutting surfaces, which are accurately positioned with respect to the axis 18 of the fastener 12 to minimize errors in a resulting drilling operation using the assembly 10. More particularly, the first embodiment of the fastener 12 is shown in FIGURE 2, and can be configured to include at its first end 20 a pair "of clamping arms 34, which extend around the groove of clamp 30. Clamping arms 34 preferably include openings 36. which accommodate screws 38 (see FIGURE 1) to secure the piercing insert 35 in position within the slot of the fastener 30. In the configuration shown, the holes 36 are threaded to engage the screws 38, and engage with the threaded holes formed in the piercing insert 35 in a predetermined manner to accurately locate the piercing insert at a predetermined location within the groove of the fastener 30, as will be described in more detail. Each of the clamping arms 34 may also include a lubrication hole 28, which allows the application and flow of lubrication adjacent to the cutting surfaces of the drilling insert to facilitate the drilling operation. The clamping arms 34 may also include angled or curved surfaces, which facilitates. the removal of fragments via fragment evacuation slots 37 on each side of the fastener 12. The seating surface 32 is also shown designed as a flat surface, which corresponds to the flat lower portion of the piercing insert 35, although it can be used another configuration of the lower surface 32 and is contemplated herein. It was contemplated that the drill insert 35 be made of hard sintered metal material such as carbide, cement, ceramic, monocrystalline and polycrystalline diamond or boron nitride. However, the piercing insert 35 may also be comprised of high speed steel. Turning now to FIGS. 3A-3F, a first embodiment of the drill insert 35 is shown. The drill insert 35 comprises cutting edges 64 on its obtuse V-shaped upper surface, with cutting edges 64 on each side of the bevel 62. and radially outwardly from a thin web 63. The cutting edges 64 may include a plurality of cutting components, such as disintegrators of fragments 66, which cooperate to provide the desired cutting surface for the material and / or application of perforation. The insert 35 further comprises a pair of connection front surfaces 68, on opposite sides of the insert 35 which are parallel to each other and provide a registration surface for the fastening arms 34 of the fastener 12. The bottom 72 of the insert 35 is generally flat and perpendicular to the connecting surfaces 68. The bottom 72 may also include positioning slots 74 which cooperate with the bolt 24 of the fastener 12. The piercing insert 35 may further comprise openings 70 through the connecting surfaces 68, which cooperate with the openings 36 in the clamping arms 34 for securing the insert 35 within the groove of the fastener 30 and sitting against the seating surface 32. Additionally, each of the openings 36 and 70 is preferably formed with countersunk portions. formed as a support surface adapted to be engaged by a corresponding tapered surface or the like on the screws or another clamping mechanism 38. The elongated clamping head of the screws 38 may be of any convenient shape, such as conical, spherical, or otherwise to correspond with similar surfaces in the tool holder 12 and the insert 35. In a typical manner, by diverting the axes of the openings 36 and 70, securing the insert 35 within the slot 30 by means of screws 38, the insert 35 will be forced down against the seating surface 32. The piercing insert 35 comprises also sides or surfaces between grooves 80 across the width of the insert 35, each side 80 comprising a helically extending margin 82 and an empty surface positioned radially inwardly 84. The surface of the margin 82 is cylindrically formed about the axis of rotation. of the insert 35 and comes into contact with the edges of the hole being drilled. However, in contrast to the prior art drill inserts, the back side of the margin 82 is helical, where the width of the margin increases helically from the cutting edge on one side of the insert. drill bit 35 towards the opposite side of the drill insert 35 as best shown in FIGURE 3C. The helical margin 82 results in that almost the entire radial width of the side 80 can come into contact with the hole as best shown in the top view of FIGURE 3B. The helically extending margin 82 increases the stability of the mounted tool 10 in operation and helps to avoid excessive vibration. Although the drill insert of the first mode provides more stability, the increase in surface area in contact with the orifice can provide greater heat due to friction in the margin and may not be adequate in some applications. Referring now to Figures 4A-4E, in a second embodiment of the invention the drill insert 35 'includes a parallel helical margin 82', where the front side of the margin is also helical. The parallel helical margin 82 'differs from the first embodiment in that the helical recess 82 has been added so that the width of the margin is maintained from the cutting edge on the side of the insert 35' to a later location on the other side of the insert 35 'as best shown in Figure 4C. The added helical recess 86 reduces the contact area between the insert 35 and the hole, which reduces the friction between the insert 35 'and the hole, thereby reducing the operating temperature and allowing higher speeds or penetration rates ( SFM), and an increase in the life of the tool. The parallel helical margin 82 'also results in almost the entire radial width of the side 80' being able to come into contact with the hole as best shown in the top view of Figure 4B. Therefore, the drill insert 35 'provides greater stability to that of the drill inserts of the prior art. In addition, the width of the margin may decrease with respect to the prior art, which will decrease the amount of heat generated on the sides 80 'of the insert which may further increase the life of the tool and / or allow the tool to function at a higher speed while maintaining the life of the tool. Referring now to Figures 5A-5E, in a third embodiment of the invention the drill insert 35"includes a parallel helical margin 82" having a helical tooth groove 88 adjacent the margin 82 '. The space between teeth 88 can help channel out fragments of the hole and can also assist in the formation of fragments. In addition, the tooth spacing 88 will prevent the fragments from being trapped on the leading edge side of the helical margin as may be possible in some machining applications with the insert 35 'of the second embodiment. The addition of the tooth spacing 88 does not prevent the parallel helical margin 82"from contacting the hole over almost the entire radial width of the side 80" as best shown in the top view of Figure 5B. This allows the insert 35"to retain the best stability provided by the above embodiments. The spaces 88 can be positioned radially outwardly of the openings 70, so that the standard connection is maintained. As with the previous embodiments, the width of the margin may also decrease with respect to the prior art, which will decrease the amount of heat due to the friction generated on the sides 80"of the insert 35, which may further increase the tool life and / or allow the tool to operate at higher speeds, while maintaining the life of the tool. It was contemplated that the helical margin in conjunction with a drill bit insert of the flat type is not limited to the features shown on the drill insert here and that the helical margin can be used in conjunction with other specific types of drill bit geometries. Consequently, the helical margin can be independent of the specific types of lips, point spaces, corner clamps, corner radii, etc., which can vary between the different bit inserts of the flat type. By. example, as shown in Figures 6A-7B, different types of corner treatments can be associated in a drill insert without limiting the helical margins. In Figure 6A a partial flat view of the corner of the insert, and in Figure 6B a partial top view of the corner of the insert, combine to show a cam bottom corner space 90 on an insert having a helical margin. In Figure 7A a partial flat view of the • corner of the insert, and in Figure 7B a partial top view of the corner of the insert, combine to show a second alternative corner space 90 'on an insert having a margin helical. Although the foregoing description has been presented with specific relation to particular embodiments of the invention, it should be understood that the claimed invention is not limited thereto and that certain changes can be made without departing from the scope of the invention with the foregoing description intended to be construed as illustrative and not limiting.

Claims (23)

1. CLAIMS 1. Drill insert comprising: a drilling insert body having a first end opposite a second end, a first front side opposite and parallel to the second front side, and a first side of the furrow surface opposite a second end. second side of the surface between grooves, the first and second side of the surface between grooves formed between the ends and the front sides; and a margin formed on a portion of each side of the surface between grooves, the margin having a front side and a back side, where the front side of each margin is formed as a helix and a helical groove is formed adjacent to the front side of each margin. Drilling insert according to claim 1, wherein the margin is formed with a constant arc width between the front side and the rear side, so that both the front side and the rear side are formed as a helix. Drilling insert according to claim 1, wherein at least two openings are formed through each front side of the body of the piercing insert, and where the helical grooves are formed radially outwardly of the openings. 4. A piercing insert according to claim 1, wherein the first end of the body of the piercing insert is a generally planar surface having at least one cavity formed in the first side. 5. Drilling insert according to the claim 1, wherein the second end comprises at least two cutting edges formed transverse to each other. 6. The drill insert according to claim 1, wherein at least two cutting edges are curved. 7. Drilling insert according to the claim 5, further comprising a fragment disintegrant formed through each cutting edge. Drilling insert according to claim 1, wherein the body of the drilling insert is comprised of a hard sintered metal material. Drilling insert according to claim 1, wherein the body of the piercing insert is comprised of a material selected from the group consisting of carbide, cerametal, ceramic, monocrystalline and polycrystalline diamond and boron nitride. 10. The drill insert according to claim 1, wherein the body of the drill insert is comprised of high speed steel. A drilling insert comprising: a drilling insert body having a first end opposite a second end, a first front side opposite and parallel to a second front side, and a first side of the furrow surface opposite a second end. second side of the surface between grooves, the first and second side of the surface between grooves formed between the ends and the front sides; wherein the first end of the piercing body is a generally planar surface having at least one cavity formed in the first side; wherein the second end comprises at least two cutting edges formed transverse to each other; at least two openings formed through each front side of the body of the piercing insert; and a margin formed on a portion of each side of the surface between grooves, the margin having a front side and a back side, where the front side of each margin is formed as a helix and a helical groove is formed adjacent to the front side of each margin, where the helical grooves are formed radially outwardly of the openings. The drilling insert according to claim 11, wherein the margin is formed with a constant arc width between the front side and the rear side, so that both the front side and the rear side are formed as a helix. Drilling insert according to claim 11, wherein at least two cutting edges are curved. The piercing insert according to claim 11, further comprising a fragment disintegrator formed through each cutting edge. 15. Assembly of cutting tool, comprising: a fastener having a first end and a second end, wherein the second end comprises a shaft portion adapted to be fixedly attached to a drilling machine, wherein the first end comprises a fastener groove and having a surface of lower seat on at least a portion of the groove of the fastener and at least one joint arm placed on each side of the groove of the fastener, where each joint arm has at least one opening formed therein; piercing insert comprising a piercing insert body having a first end opposite a second end, a first frontal side opposite a second frontal side and a first side of the surrogate surface opposite a second side of the surface between grooves, the first and second sides of the surface between grooves formed between the ends and the front sides, where the first end of the drill body is a generally flat surface, where the second end comprises at least two cutting edges formed transverse to each other, at least two openings formed through each front side of the body of the piercing insert, and a margin formed on a portion of each side of the surface between grooves, the margin having a front side and a back side, wherein the front side of each margin is formed as a helix and a helical groove is formed adjacent to the front side of each margin. 16. Drilling tool assembly according to claim 15, wherein the margin of the drill insert is formed with a constant arc width between the front side and the rear side, so that both the front and the rear side are formed as a propeller 17. Drill tool assembly according to claim 15, wherein the helical grooves are formed radially outwardly from the openings. 18. Drill tool assembly according to claim 15, wherein the slot of the fastener includes a location shoulder extending from the bottom seat surface and the first end of the body of the drill insert has at least one cavity that cooperates with the location shoulder of the lower seat surface or the bottom to allow the insert to sit against the lower seat surface or bottom. 19. Drill tool assembly according to claim 15, wherein the fastener includes at least one level channel. 20. Drill tool assembly according to claim 15, wherein a clamping mechanism is coupled to each opening of at least two apertures of the piercing insert and a corresponding opening of the at least one opening in each clamping arm to secure the insert of the piercing insert. piercing in its position within the bracket slot. 21. Drill tool assembly according to claim 20, wherein at least one opening in each clamping arm is offset from the corresponding opening in the drilling insert at least to urge the drilling insert against the lower seating surface of the groove. of the bra. 22. Drill insert comprising: a drilling insert body having a first end opposite a second end, a first front side opposite and parallel to a second front side, and a first side of the furrow surface opposite a second end. second side of the surface between grooves, the first and second side of the surface between grooves formed between the ends and the front sides; and a margin formed on a portion of each side of the surface between grooves, the margin having a leading side and a trailing edge, where the leading side of each margin is formed as one. propeller; where at least a portion of each side of the groove surface extends from the front side of the margin to the corresponding front side of the body of the insert. 23. Drill insert comprising: a drilling insert body having a first end opposite a second end, a first front side opposite and parallel to a second front side, and a first side of the groove surface opposite a second end. second side of the surface between grooves, the first and second side of the surface between grooves formed between the ends and the front sides, and a rotational axis; and a margin formed on a portion of each side of the surface between grooves, the margin having a "front side and a back side, where the rear side of each margin is formed as a helix and the front side of the margin extends towards the front side of the body of the insert, so that the front side of the margin and the rear side of the margin form an acute angle equivalent to the angle of the helix.