WO2008140191A1

WO2008140191A1 - Insert for parting and chamfering

Info

Publication number: WO2008140191A1
Application number: PCT/KR2008/002007
Authority: WO
Inventors: Hong Sik Park; Sung Hyup Park
Original assignee: Taegutec Ltd.
Priority date: 2007-05-09
Filing date: 2008-04-10
Publication date: 2008-11-20
Also published as: CN101678464A; SE0901530L; SE535067C2; KR20080099471A; CN101678464B

Abstract

The present invention discloses an insert being capable of performing successively a cutting process and a chamfering process after mounting to the tool holder. An insert according to the present invention comprises a parting section for cutting a rotating work-piece; and a chamfering section having a width larger than that of the parting section, the chamfering section being formed integrally with the parting section at a rear side of the parting section to chamfer the work-piece cut by the parting section. A cutting edge to be contacted with the work-piece is formed at an upper edge of a front end surface of the parting section for cutting the work-piece, and the chamfering section has a step on at least one lateral side, and the forward surface of the step is formed of a curved surface to make an upper edge to chamfer an edge portion of a cut surface of the work-piece.

Description

INSERT FOR PARTING AND CHAMFERING

Technical Field

[I] The present invention relates to a tool, more particularly, to an insert being capable of performing successively a parting process and a chamfering process.

[2]

Background Art

[3] In general, a cutting tool is used in the field of cutting machining such as drilling, milling, and turning. Within the fields of drilling and milling, a tool having a rotary character is useful for machining a fixed and movable work-piece. And, a tool for turning machining is fixed and has the purpose of machining work-piece which is rotating.

[4] For example, for manufacturing a bearing cap, a process for parting a work-piece is performed, a process for chamfering an edge portion of the work-piece is then carried out. Accordingly, the inserts having specific shapes for the parting process and the chamfering process should be separately prepared, and the insert is selected and utilized according to the process to be performed.

[5] In general, the insert is fixed to a mounting surface of a tool holder through a clamping means, and so a machining tool is assembled. Accordingly, in order to perform the chamfering process after the parting process, the insert for the parting process is dismounted from the tool holder and the insert for the chamfering process should be mounted to the tool holder.

[6]

Disclosure of Invention

[7] Accordingly, the present invention is conceived to solve the aforementioned problems in a process of manufacturing an article requiring both parting and chamfering processes, and an object of the present invention is to provide an insert being capable of performing successively a parting process and a chamfering process.

[8]

[9] An insert according to the present invention comprises a parting section for cutting a rotating work-piece; and a chamfering section having a width larger than that of the parting section, the chamfering section being formed integrally with the parting section at a rear side of the parting section to chamfer the work-piece cut by the parting section.

[10]

[I I] A cutting edge to be contacted with the work-piece is formed at an upper edge of a front end surface of the parting section for cutting the work-piece, and the chamfering section with a larger width has a step on at least one lateral side, and the forward surface of the step is formed of a curved surface to make an upper edge to chamfer an edge portion of a cut surface of the work-piece.

[12]

[13] The parting section comprises a groove formed on an upper surface of a front part thereof in a longitudinal direction, and the front end of the groove corresponds to a cutting edge. Also, the parting section comprises a protrusion formed at the rear of the groove, and the front surface of the protrusion is formed of an upward inclined surface.

[14]

[15] Advantageeous Effects

[16] The insert according to the present invention having the structure and function as described above has the advantages as follows.

[17] Since the single insert is used for performing the parting process as well as the chamfering process, there is no need to dismount the insert for the parting process from the tool holder after the parting process and to mount the insert for the chamfering process. That is, after the parting process for a work-piece is completed, the chamfering process can be immediately performed without replacing the insert, and so the total processing time can be considerably reduced.

[18] In addition, since the insert for the parting process and the insert for the chamfering process are manufactured as a single insert, a cost and a time for manufacturing the insert can be remarkably saved.

[19]

Brief Description of the Drawings

[20] FIG. 1 is a perspective view of an insert according to the present invention;

[21] FIG. 2 and FIG. 3 are side view and plane view of an insert according to the present invention;

[22] FIG. 4 is a sectional view taken along the line A-A in FIG. 3; and

[23] FIG. 5 and FIG. 6 are plane views illustrating a process for machining a work-piece using an insert according to the present invention.

[24]

Best Mode for Carrying Out the Invention

[25] Hereinafter, the present invention is described in detail with reference with the accompanying drawings.

[26]

[27] FIG. 1 is a perspective view of an insert according to the present invention, and FIG.

2 and FIG. 3 are side view and plane view of an insert according to the present invention. An insert 100 according to the present invention is a single body made of hardmetal cemented carbide material and manufactured through a powder metallurgy process such as a shaping process, a sintering process, a grinding process and a coating process. The insert 100 according to the present invention may be divided into a parting section 10 formed at a front side and a chamfering section 20 formed at a rear side and having a height that is the substantially same as that of the parting section 10.

[28]

[29] The structure and function of each section constituting the insert 100 are described in detail below.

[30]

[31] Parting section 10

[32] The parting section 10 having a certain width and height is a section provided for cutting a work-piece. A cutting edge 11 is formed at an upper edge of a front end surface of the parting section 10, and this cutting edge is contacted with a rotating work-piece and cuts the rotating work-piece.

[33]

[34] A groove 12 having a certain depth is formed on an upper surface of a front part of the parting section 10 in the lengthwise direction. The front end of the groove 12 corresponds to the cutting edge 11. A protrusion 13 having a certain height is formed at a rear side of the groove 12 along the entire width of the parting section 10. A front surface 13A of the protrusion is formed of an upward inclined surface.

[35]

[36] In this structure of the parting section 10, a chip generated when a work-piece is machined by the cutting edge 11 is guided along the groove 12, and the chip is then moved upward along the inclined surface 13A of the protrusion 13, and so a contact between the chip and a tool holder (not shown) is prevented. In addition, the chip discharged from the groove 12 gets bent and is then broken while the chip is moved along the front inclined surface 13A of the protrusion 13.

[37]

[38] Chamfering section 20

[39] The chamfering section 20 formed integrally with a rear side of the parting section 10 has a width that is larger than that of the parting section 10. The chamfering section 20 having a larger width than that of the parting section 10 has a step on at least one lateral side, the forward surface made by the step is preferably formed as curved surfaces 21 A and 2 IB having some curvature. The curvature of each of the curved surfaces 21 A and 2 IB corresponds to a designed curvature of an edge portion of the work-piece to be chamfered. Although, according to the desired edge shape of the work-piece, the forward surface of the step may take a slanted plane surface or a com- bination of slanted plane and curved surface, an example of curved forward surfaces formed on both lateral sides of the chamfering section 20 is explained hereinafter.

[40]

[41] Upper edges of the curved surfaces 21 A and 2 IB act as the chamfering edges which contact with edge portions of cutting surface of the work-piece and chamfer the edge portions of the work-piece.

[42]

[43] Here, as shown in FIG. 3, it is preferred that the curved surfaces 21A and 21B of the chamfering section 20 are inclined toward the parting section 10 with respect to the vertical line. Due to such structure, upper edges of the curved surfaces 21 A and 2 IB are provided with a more acute angle of the cutting edges against the edge portion of the work-piece.

[44]

[45] An upper surface of the chamfering section 20, preferably, upper surfaces of both lateral sides, that is, upper sides of the portions below which the curved forward surfaces 21 A and 21B are formed are formed of inclined surfaces 21A- 1 and 21B-2 which are inclined upward-rearward. In the structure of the chamfering section 20 as described above, a chip generated when the work-piece is machined by the cutting edges of the upper ends of the curved surfaces 21 A and 2 IB is moved upward along the inclined surfaces 2 IA-I and 2 IB-I.

[46]

[47] On the other hand, a plurality of serrations 22 may be formed on an entire bottom surface of the chambering section 20 and the parting section 10 or/and a portion of upper surface of the chamfering section 20 (i.e., an upper surface behind the protrusion 13) in the longitudinal direction. The serrations 22 provide a secure grip between the insert 100 having a narrow width and long length and the tool holder.

[48]

[49] On the other hand, FIG. 4 is a sectional view taken along the line A-A in FIG. 3 and shows the insert according to the present invention along with upper and lower grippers.

[50]

[51] As shown in FIG. 1 and FIG. 4, it is preferred that an upper gripping groove 25 is formed on a portion of an upper surface of the chamfering section 20, that is, an upper surface behind the protrusion 13 along a center line extended in the longitudinal direction and/or a lower gripping groove 26 is formed on an entire bottom surface of the chamfering section 20 and the parting section 10 along a center line extended in the longitudinal direction, respectively, so that the insert 100 can be more securely fixed to the tool holder by the upper holder Gl and the lower holder G2. Also, although not shown in the drawings, it is possible to form a plurality of serrations on surfaces of the upper and lower gripping grooves 25 and 26 so as to provide a more secure grip.

[52]

[53] It is preferred that each of the upper and lower gripping grooves 25 and 26 is formed of a dual groove formed by overlapping two grooves (as shown in FIG. 4) having different curvatures each other. In the dual groove, ridges are formed in the longitudinal direction at both border portions between two grooves with different curvatures, and the ridges act as contact surfaces with end portions of the grippers Gl and G2. This structure is described in more detail as follows.

[54]

[55] The upper gripping groove 25 comprises a first groove 25-1 and a second groove

25-2. The first groove 25-1 having a first curvature is formed on an upper surface of the chamfering section 20 in the longitudinal direction, and a second groove 25-2 having a second curvature which is lager than the first curvature of the first groove 25-1 is formed on a bottom surface of the first groove 25-1 along the first groove. Accordingly, ridges PI l and P 12 are formed on both border portions between the first groove 25-1 and the second groove 25-2 in the longitudinal direction.

[56]

[57] Also, the lower gripping groove 26 comprises a third groove 26-1 and a fourth groove 26-2. The third groove 26- 1 having a third curvature is formed on an entire bottom surface of the parting section 10 and the chamfering section 20 in the longitudinal direction, and the fourth groove 26-2 having a fourth curvature which is larger than the third curvature of the third groove 26-1 is formed on a upper surface of the third groove 26-1 along the third reversed groove 26-1. Accordingly, ridges P21 and P22 are formed on both border portions between the third groove 26-1 and the fourth groove 26-2 in the longitudinal direction.

[58]

[59] When the insert 100 is mounted to the tool holder, the upper gripper Gl and the lower gripper G2 of the tool holder come into contact with the upper and lower gripping grooves 25 and 26 formed on an upper surface and a lower surface of the insert 100, respectively, and then pressurize the insert 100. At this time, it is preferred that the upper gripper Gl is contacted with the ridges Pl 1, P 12 formed in the longitudinal direction on both border portions of the first groove 25-1 and the second groove 25-2 formed on an upper surface of the chamfering section 20 and the lower gripper G2 is contacted with the ridges P21 and P22 formed in the longitudinal direction on both border portions of the third groove 26-1 and the fourth groove 26-2 formed on a lower surface of the chamfering section 20. To obtain the above structure, it is preferred that a curvature of each end portion of the grippers Gl and G2 is larger than the first curvature and the third curvature, but smaller than the second curvature and the fourth curvature.

[60]

[61] As described above, since the grippers Gl and G2 are contacted with the insert 100 at two contact points (that is, is Pl 1, P12 and P21, P22), respectively, a variation of the contact points caused by a machining error can be prevented and it is possible to maintain the balance between forces exerted to a right side and to a left side of the insert 100, and so the insert 100 can be more securely and precisely mounted to the tool holder.

[62]

[63] Here, it is preferred that the first curvature is made same as the third curvature and the second curvature is made same as the fourth curvature in order to utilize the gripper end with a same specification for both the upper gripper Gl and the lower gripper G2.

[64]

[65] Functions of the insert having the structure as described above are illustrated with reference to FIG. 1 to FIG. 3, FIG. 5 and FIG. 6.

[66]

[67] FIG. 5 is a plane view for illustrating a process for cutting (parting) a work-piece 200 by means of the insert 100 according to the present invention and FIG. 6 is a plane view illustrating a chamfering process performed after the cutting process is completed. For the sake of simplicity, the holder supporting the insert is not shown in FIG. 5 and FIG. 6.

[68]

[69] The insert 100 according to the present invention is mounted to the tool holder (not shown) through a clamping means and the tool is then approached to the work-piece 200 which is rotating. Then the tool is moved to the work-piece 200, and so the cutting edge 11 formed at a front end of the parting section 10 of the insert 100 cuts the work- piece 200 (a state of FIG. 5).

[70]

[71] A chip generated from the work-piece 200 by the cutting edge 11 of the parting section 10 is guided in the groove 12 formed on an upper surface of the front part of the parting section 10, the chip is then discharged from the groove 12 and contacted with the inclined surface 13A of the protrusion 13. The chip is broken while being moved along the inclined surface 13A of the protrusion 13.

[72]

[73] As the parting process as described above is continued, the work-piece 200 is completely cut by the insert 100. And, the curved surfaces 21 A and 2 IB formed at front surfaces of both sides of the chamfering section 20 are then contacted with edge portions of cut surfaces of the work-piece 200 (a state in FIG. 6).

[74]

[75] In this state, the working-piece 20 is continuously rotated, edges of both cut surfaces of the work-piece 200 are contacted with upper end edges (chamfering edges) of the curved surfaces 21 A and 2 IB of the chamfering section 20 and then machined. Accordingly, edges of both cut surfaces of the work-piece 200 are machined (chamfered) to the shape having the same curvature as that of the curved surfaces 21 A and 2 IB.

[76]

[77] The chip generated by the chamfering edges of the chamfering section 20 is guided along the inclined surfaces 2 IA-I and 2 IB-I formed above the curved surfaces 21 A and 2 IB and then discharged out of the insert 100.

[78]

[79] Due to such inclined surfaces 21A-1 and 21B-1, the chip generated in the chamfering process does not enter between the work-piece 200 and the insert 100 (in particular, the chamfering section 20). Accordingly, the machining process is not disadvantageously affected by chip-caused problems (for example, a generation of defect on cut surfaces of the work-piece).

[80]

[81] Although embodiments have been described with reference to the preferred embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

[I] An insert, comprising; a parting section for cutting a rotating work-piece; and a chamfering section having a width larger than that of the parting section, the chamfering section being formed integrally with the parting section at a rear side of the parting section to chamfer the work-piece cut by the parting section, wherein, a cutting edge to be contacted with the work-piece is formed at an upper edge of a front end surface of the parting section for cutting the work-piece, and the chamfering section with a larger width has a step on at least one lateral side thereof, and the forward surface of the step has an upper edge to chamfer an edge portion of a cut surface of the work-piece .

[2] The insert according to claim 1, wherein the forward surface of the step is a curved surface.

[3] The insert according to claim 1, wherein the parting section comprises a groove formed on an upper surface of a front part thereof in a longitudinal direction, and the front end of the groove corresponds to a cutting edge.

[4] The insert according to claim 1, wherein the parting section comprises a protrusion formed at the rear of the groove, and the front surface of the protrusion is formed of an upward inclined surface.

[5] The insert according to any one of claims 1 to 4, wherein the chamfering section has an upper surface which is inclined upward-rearward.

[6] The insert according to any one of claims 1 to 4, wherein the chamfering section has a gripping groove formed on an upper surface thereof along the center line extended in the longitudinal direction thereof.

[7] The insert according to claim 6, wherein the gripping groove has a plurality of serrations formed on an inner surface thereof.

[8] The insert according to claim 6, wherein the gripping groove is formed of a dual groove formed by overlapping two grooves with different curvatures and formed with ridges at both border portions between two grooves in the longitudinal direction.

[9] The insert according to any one of claims 1 to 4, wherein the chamfering section and the parting section has a gripping groove formed on a lower surface thereof along the center line extended in the longitudinal direction thereof.

[10] The insert according to claim 9, wherein the gripping groove has a plurality of serrations formed on an inner surface thereof.

[I I] The insert according to claim 9, wherein the gripping groove is formed of a dual groove formed by overlapping two grooves with different curvatures and formed with ridges formed at both border portions between two grooves in the longitudinal direction.

[12] The insert according to any one of claims 1 to 4, wherein the forward surface of the step is inclined toward the parting section with respect to a vertical line.