BORER MULTICANNELE AND CUTTING PLATE FOR THIS ONE

The cutting tools rotatable perform reaming operations typically include a cutting head with an axis of rotation, The cutting head has a front end and a peripheral surface extending rearward from the same, The peripheral surface includes at least two cutting inserts or scan ranges extending rearwardly from the front end and a chip flute for the removal of chips produced during the cutting operation.

A drawback of conventional reamers is that chips produced during a cutting operation flow directly into the chip flute, cannot be control the shape and the removal of chips during the cutting operation. Therefore, the chips at risk of becoming entangled on the tool shank and/or remaining in the holes of the machine during the cutting operation.

The problem of controlling the formation of chips into a treamer multicannelé is solved by including a cutting insert with a rounded bevel and a chip breaking along the rake face of the cutting insert, and by widening the rear side of the chip discharge groove.

According to one aspect of the invention, a reamer multicannelé comprises a cutting portion having a front end and a rear end and a peripheral surface therebetween. The cutting section has a chip flute which extends rearwardly from the front end. One cutting insert is mounted on the cutting portion. The cutting insert has an upper surface with a chip breaking member extending over the entire length L of the cutting insert. The breaking element is formed with a lower surface of radius R. The chip breaking extends in the direction of a central longitudinal axis of the cutting portion.

According to another aspect of the invention, a reamer multicannelé comprises a cutting portion having a front end and a rear end and a peripheral surface therebetween, The cutting section has a chip flute which extends rearwardly from the front end, the chip flute having a chip-receiving opening extending from the rear end toward the front end of the cutting portion, and the chip-receiving opening being defined by a receding lower surface, a front wall formed with a radius R2, and opposite side walls.

According to another aspect of the invention, a reamer multicannelé comprises a cutting portion having a front end and a rear end and a peripheral surface therebetween, The cutting section has a chip flute which extends rearwardly from the front end, The chip flute has a chip-receiving opening extending from the rear end toward the front end of the cutting portion, the chip-receiving opening being defined by a receding lower surface, a front wall formed with a radius R2, and opposite side walls. One cutting insert is mounted on the cutting portion. The cutting insert has a front side surface, a bottom surface, a surface radially inner side, a forward side surface, a surface radially outer side and a rear side surface, a leading edge being formed at an intersection between the top surface and the surface radially outer side, and a front edge being formed at an intersection between the top surface and the front side surface, and the cutting insert further comprising a leading cutting edge rounded having a radius RI, at the intersection between the leading edge and the leading edge, and the top surface has a chip-breaking element having a bottom surface formed with a radius R,

In some embodiments, the cutting insert further comprises a bottom surface, a radially inner lateral surface, a forward side surface, a radially outer lateral surface and a rear side surface.

In some embodiments, the cutting insert further includes a forward edge formed at an intersection between the top surface and the front side surface.

In some embodiments, the reamer further comprises a leading edge formed at the intersection between the top surface and the radially outer lateral surface.

In some embodiments, the upper surface of the cutter insert also has a cutting surface extending between the leading edge and the chip breaking.

In some embodiments, the cutting insert has a leading cutting edge formed with a rounded radius RI, at the intersection between the leading edge and the leading edge.

In some embodiments, the cutting insert further comprises a primary surface, and a secondary surface, the primary clearance surface extending between the leading cutting edge rounded and the secondary surface, and the secondary surface extending from the bottom surface up to the primary surface.

In some embodiments, a portion of the bottom surface of the breaking member includes a surface land in t.

In some embodiments, the chip flute has a chip-receiving opening extending from the rear end toward the front end of the cutting portion.

In some embodiments, the chip-receiving opening is defined by a bottom surface recessed, a front wall formed with a radius R2 and opposite side walls.

Although various embodiments of the present invention have been illustrated, the particular embodiments shown should not be regarded as limiting the claims. It is anticipated that changes and modifications can be made without departing from the scope of the present invention.

Figure 1 is a perspective view of a reamer multicannelé with a rupture element according to one example embodiment of the invention;

figure 2 is a side view of the reamer multicanneié with the chip breaking of Figure 1;

figure 3 is an end view of the reamer multicanneié with the chip breaking of Figure 1;

figure 4 is a perspective view enlarged of the cutting insert with the breaking member according to one embodiment of the invention;

figure 5 is a cross-sectional view of the reamer multicanneié and of the cutting insert along the line 5-5 of Figure 2;

figure 6 is a cross-sectional view enlarged of the failure element the cutting insert;

figure 7 is a magnified view of the rounded cutting edge of the cutting insert according to the invention;

figure 8 is a cross-sectional view of the leading cutting edge rounded along the line 8-8 of Figure 7 ; and

figure 9 is a cross-sectional view of the reamer multicanneié and the chip-receiving opening along the line 9-9 of Figure 2.

Ci below is shown and described a version of a reamer multicanneié and a cutting insert therefor. However, is that the reamer multicanneié and the cutting insert may be configured to suit the specific application and are not limited only to the example shown in the drawings.

With reference to Figures 1 to 3, in which identical digital references represent the like, a reamer multicanneié is generally designated by 10 according to an embodiment of the invention. In general, the reamer multicanneié 10 includes a cutting portion 12 and a mounting portion 14. The cutting portion 12 has a forward end 16 and a rear end 18. The cutting portion 12 rotates about a central longitudinal axis 20 and according to a given direction of rotation 22.

The cutting portion 12 has a peripheral side surface 24 extends between the front end 16 and the rear end 18. The peripheral side surface 24 includes a plurality of cutting inserts 26 mounted thereon, which extend from the front end 16 towards the rear end 18. In the illustrated embodiment, the reamer 10 includes six cutting plates 26. However, it will be appreciated that the invention is not limited by the number of cutting inserts, and that the invention may be implemented with a number of cutting inserts any desirable, based on the design parameters, as the cutting diameter of the reamer, andc. A chip flute or groove chip space 28 extends to the rear from the front end 16 towards the rear end 18 of the cutting portion 12. The chip flute 28 extends rearwardly beyond the cutting insert 26 and allows the chips formed by the cutting insert 26 out of the cutting portion 12 of the reamer 10 during a cutting operation.

With reference to present in Figure 4, each cutting insert 26 is generally rectangular and includes an upper surface 30, a bottom surface 32 opposite the top surface 30, inner radîalement a side surface 34, a forward side surface 36, a radially outer lateral surface 38 and a rear side surface 40. A leading edge 42 with an angled rear is formed at the intersection between the upper surface 30 and the radially outer lateral surface 38. The radially outer lateral surface 38 may include a first faceted surface 48 extending from the leading edge 42 to a faceted second surface 49. The width of the first faceted surface 48 may lie in the range of about 0.1 mm to about 0.4 mm. In the illustrated embodiment, the faceted second surface 49 extends from the first faceted surface 49 to the bottom surface 32.

A leading edge 56 is formed at the intersection of the upper surface 30 and the front side surface 36. When the leading edge 56 is used, the front side surface 36 provides a relief for the cutting insert 26. Furthermore, the front end 16 of the reamer 10 has a clearance surface 15 adjacent to the cutting insert 26 and a rounded end surface 17 adjacent to the peripheral side surface 24 in providing clearance suitable for the cutting insert 26, The relief surface 15 defines a clearance angle 19 which should be greater than or equal to a clearance angle (not shown) formed by the front side surface 36 relative to the forward end 16 of the reamer 10.

One aspect of the invention provides that the upper surface 30 has a chip breaking surface 44 extending from the front side 36 to the rear side surface 40, The chip breaking 44 is provided for controlling the shape of the chip during a cutting operation. In the illustrated embodiment, the breaking member chips 44 extends over the entire length L of the cutting insert 26 from the front side surface 36 to the rear side surface 40, That is, the breaking member chips 44 extends in the same direction as the central longitudinal axis 20 of the cutting portion 12 of the reamer 10. However, it will be appreciated that the invention may be implemented with the chip breaking 44 extending partially along the length L of the cutting insert 26. The upper surface 30 also includes a cutting surface 46 extending between the leading edge 42 and the breaking member 44 chips. Since the element chip-breaking 44 extends over the entire length of the cutting insert 26, the cutting surface 46 also extends over the entire length from the front side surface 36 to the rear side surface 40.

With reference to present in Figures 5 and 6, the chip breaking 44 is formed with a lower surface 58 of radius R, and with a width W land. The bottom surface 58 is bent such that a depth before DI (i.e. radially outward) relative to the top surface 30 is less than a depth D2 rear (i.e. radially inwardly) of the element chip-breaking 44. For example, the depth D2 of the rear element chip-breaking 44 may be about 0,135 mm more than the depth before Dl. However, the width of land W has a greater dimension than the depths Dl and D2 of the chip breaking 44. For example, the width of land W may be about 0.50 mm and the depth before Dl may be about 0.10 mm, and the depth D2 may be about 0,235 mm rear.

The chip breaking 44 forming an intersecting angle cutting insert 60 positive in the range of about 1° to about 15 °, and in particular about 7°.

A portion front of the chip breaking 44 has a surface land 64 of length T-L, T-The surface land 60 reduces the constraints on the cutting insert 26 during cutting operations and greatly improving the performance of the cutting insert 26. The surface land in T 64 forms a negative rake angle 66 in the range of about 0.25 to about 1.25 ° °. In one embodiment, the positive rake angle is about 0.65 66°.

When mounted on the cutting portion 12 of the reamer 10, the cutting surface 46 of the cutting insert 26 defines a radial rake angle 68 positive. The radial rake angle 68 may lie in the range of about 0° to about 12°. In one embodiment, the radial rake angle 68 is about 5°. The cutting insert 26 also defines a relief angle 70 (or clearance angle). The draft angle 70 may lie in the range of about 10° to about 25°. In one embodiment, the clearance angle 70 is about 16°.

With reference to present in Figures 7 and 8, another form of the present invention is that the cutting insert 26 includes a cutting edge rounded leading chamfer 50 rounded having a radius RI, with a radial offset 76. The leading cutting edge rounded 50 is provided for controlling the shape of the chips during a cutting operation. It will be appreciated that the invention is not limited by the magnitude of the radius RI, and that the invention can be implemented with a radius which is suitable for the particular type of cutting operation. For example, in one embodiment, the radius is about 0.4 mm RI.

In the illustrated embodiment, one end of the leading cutting edge rounded 50 is tangent to the front end 16 of the reamer 10, while the other end is not tangent to the leading edge 42. Therefore, the leading cutting edge rounded 50 is radially offset with respect to the leading edge 42 of a radial offset 76. The radial offset 76 provides a greater margin of correct positioning of the cutting insert 26 on the cutting portion 12 of the reamer 10. In one embodiment, the radial offset 76 is in the range of about 1% to about 15%. For example, the leading cutting edge rounded 50 can be formed with a radius of about 0.6 mm with a radial offset of about 0.06 mm (about 10% of the radius). In one embodiment, the distance is about 0.04 mm 76. For larger radii, the radial offset can be smaller, for example 5% or less for higher dimensional tolerance for the cutting insert 26. It will be appreciated that the invention is not limited by the amplitude of the radial offset 76, and that the invention may be implemented with a radial offset any desirable, depending on the cutting diameter of the reamer 10.

To provide clearance suitable for the leading cutting edge rounded 50, the cutting insert 26 comprises a primary clearance surface 52 and a secondary clearance surface 54. The primary relief surface 52 extends between the leading cutting edge rounded 50 and the secondary surface 54. In the illustrated embodiment, the secondary surface 54 extends from the bottom surface 32 to the primary relief surface 50. The primary relief surface 52 defines an angle primary clearance 72 between about 1° and about 10°. In one embodiment, the angle of primary clearance 72 is about 5°. Furthermore, the secondary surface 54 defines a secondary angle of clearance 74 between about 5° and about 25°. In one embodiment, the secondary angle of clearance 74 is about 16°.

With reference to Figures 2 and 9, another aspect of the invention is that the chip flute 28 (or groove chip space) of the reamer 10 includes a chip-receiving opening shown generally 78. The chip-receiving opening 78 facilitates the removal of chips from the chip flute 28 during the cutting operation. The chip-receiving opening 78 extends from the rear end 18 toward the front end 16 of the cutting portion 12. The chip-receiving opening 78 is defined by a receding lower surface 80, a front wall 82 formed with a radius R2, and opposing side walls 84, 86. Rounded The front wall 82 is located at a predetermined distance 88 of the rear end 18 of the cutting portion 12 of the reamer 10. The chip-receiving opening 78 90 has a depth relative to the peripheral side surface 24 of the cutting portion 12. The side wall 86 is located at a predetermined distance 92 a lower surface 94 of the chip flute 28. As seen in Figure 2, the chip-receiving opening 78 widens near the rear end 18 of the cutting portion 12 (i.e. tapers near the rear end 18 distal).

As described above, the reamer multicannelé 10 and the cutting insert according to the present invention provides for many distinct advantages over conventional rotary cutting tools. A distinct advantage is the ability to control the formation of chips during a cutting operation. This is achieved in that the chip breaking 44 has a rounded lower surface 58 which extends in the direction of the central longitudinal axis 20 of the cutting portion 12, and a rounded leading edge 74 formed at the intersection between the leading edge 42 and the front edge 56.

Another distinct advantage is the ability to remove shavings appropriately during a cutting operation. This is accomplished by the chip flute 28 which includes a chip-receiving opening 78 which expands in the vicinity of the rear end 18 of the cutting portion 12 of the reamer 10.

Having described currently preferred embodiments, the invention can be implemented in the frame of the appended claims.