CN102076450A - Cutting insert and method of manufacturing same - Google Patents

Abstract

A cutting insert includes a top surface, a bottom surface, a major side connecting the top and bottom surfaces, and a minor side connecting adjacent major sides. The top surface includes: a main top surface adjacent to the main side surface; a subtop surface adjacent to the sub-side surface, the sub-top surface is connected to the adjacent main top surface and formed to be higher than the main top surface; and surrounded by the main top surface and the sub-top surface center plane. The major top and major sides are unground surfaces, while the minor top and minor sides are ground surfaces. The main cutting edge is formed between the main top surface and the main side surface, which are unground surfaces. The secondary cutting edge is formed between the secondary top surface and the secondary side surface, which are ground surfaces.

Description

Cutting insert and manufacturing method thereof

technical field

The present invention relates to a cutting insert and a method of manufacturing the same. In particular, the present invention relates to cutting inserts that minimize the grinding process on the surface of the cutting insert and maintain the surface roughness of the surface of the workpiece.

Background technique

Generally, cutting inserts mounted on milling tools are manufactured by pressing a powder, such as tungsten carbide, into a predetermined shape of the cutting insert. The cutting insert is then sintered at a temperature between about 1300 and 1400 degrees Celsius. The cutting inserts produced through the above process have large manufacturing errors. Thus, the surfaces of the cutting inserts are ground after the pressing and sintering steps, thereby reducing the position difference of the individual cutting inserts. Such a cutting insert is disclosed in US Patent Application Publication No. 2007/183858. In such cutting inserts, all surfaces of the cutting insert are ground except for the top surface adjacent to the main cutting edge.

However, since the sanding step typically takes a long time, it is necessary to minimize the time for such a step as much as possible.

Figure 1 shows a conventional milling tool and Figure 2 shows a conventional cutting insert (10) mounted on the milling tool. The cutting insert (10) comprises: a top surface (12); a bottom surface (14); a major side surface (16) connecting the top surface (12) and the bottom surface (14); a secondary side surface (18) connecting adjacent major sides (16) ); a major cutting edge (20) is formed between the top surface (12) and the major side surface (16); and a minor cutting edge (22) is formed between the top surface (12) and the minor side surface (18).

Figure 3 shows the process of cutting a workpiece with a conventional cutting insert (10) mounted on a milling tool. Fig. 4 shows an enlarged view of the cutting insert (10) shown in Fig. 3 . As shown in Figures 3 and 4, the main cutting edge (20) of the cutting insert (10) initially cuts the workpiece along the feed direction of the milling tool. Subsequently, the secondary cutting edge (22) smoothes the workpiece that has been cut by the primary cutting edge (20). Therefore, although there is a certain degree of positional difference between the major cutting edges (20) on the milling tool, the surface roughness of the surface of the workpiece can be maintained as long as the positions of the minor cutting edges (22) are consistent with respect to each other.

Assuming that the surface roughness of the surface of the workpiece is controlled by the position difference between the minor cutting edges (22), it may be considered to grind only the bottom surface (14), the bottom surface (14) and the seating surface of the milling tool and the adjacent minor cutting edge (22) ) in contact with the secondary side (18).

However, in this case, since the top surface (12) of the cutting insert (10) is not ground, as shown in Figure 5, there may be an error (M) in the position of the minor cutting edge (22) on the milling tool , which is caused by manufacturing errors along the thickness direction from the top surface (12) to the bottom surface (14). Therefore, in the case where the surface of the workpiece is cut by a milling tool on which a plurality of such cutting inserts (10) are seated, the surface roughness of the surface of the workpiece may be deteriorated compared with when all surfaces of the cutting inserts are ground. worse.

Contents of the invention

technical problem:

The present invention seeks to provide a solution to the aforementioned disadvantages of conventional cutting inserts. Specifically, the present invention provides a cutting insert that can make the surface roughness of a workpiece as in the case of a workpiece being cut by a cutting insert whose surface is entirely ground while minimizing the grinding process on the surface of the cutting insert.

Technical solutions:

The cutting insert of the present invention includes a top surface, a bottom surface, major sides connecting the top and bottom surfaces, and minor sides connecting adjacent major sides. The top surface includes: a main top surface adjacent to the main side surface; a subtop surface adjacent to the sub-side surface, the sub-top surface is connected to the adjacent main top surface and formed to be higher than the main top surface; and surrounded by the main top surface and the sub-top surface center plane. The major top and major sides are unground surfaces, while the minor top and minor sides are ground surfaces. The main cutting edge is formed between the main top surface and the main side surface, which are unground surfaces. The secondary cutting edge is formed between the secondary top surface and the secondary side surface, which are ground surfaces.

Technical effect:

According to the present invention, since the minor top surface and the minor side surfaces forming the minor cutting edge are ground, manufacturing errors in the thickness direction from the minor top surface to the bottom surface are reduced. In addition, the position of the secondary cutting edge on the milling tool has been made consistent. In addition, since the main top surface and the main side surface forming the main cutting edge having no influence on the surface roughness of the workpiece are not ground, time and cost spent on the grinding step can be reduced. Therefore, according to the present invention, while minimizing the grinding process on the surface of the cutting insert, the surface roughness of the workpiece can be made as in the case of the workpiece being cut by the cutting insert whose surface is entirely ground.

Description of drawings

Figure 1 shows a milling tool on which a number of cutting inserts are seated.

Fig. 2 is a perspective view of a conventional cutting insert.

Figure 3 shows the cutting of the surface of a workpiece with a milling tool on which a plurality of cutting inserts are seated.

FIG. 4 is an enlarged view of the cutting insert of FIG. 3 .

Fig. 5 is a sectional view of a minor cutting edge of the cutting insert shown in Fig. 2 .

Figure 6 shows a perspective view of a cutting insert according to one embodiment of the invention.

Fig. 7 shows a perspective view of a cutting insert according to another embodiment of the invention.

Fig. 8 shows a perspective view of a cutting insert according to another embodiment of the invention.

Fig. 9 shows a perspective view of a top-up oriented cutting insert according to yet another embodiment of the present invention.

Figure 10 shows a perspective view of a bottom-up oriented cutting insert according to yet another embodiment of the present invention.

Detailed ways

The present invention will now be described in detail with reference to examples of the invention.

Figure 6 shows a perspective view of a cutting insert (100) according to the invention. The cutting insert (100) includes a top surface (120) and a bottom surface (140). The top (120) and bottom (140) surfaces are connected by a major side (161). Adjacent major sides (161) are connected by minor sides (162). The top surface (120) includes: the main top surface (121) adjacent to the main side surface (161), the secondary top surface (122) connecting the adjacent main top surface (121), and the secondary top surface (122) adjacent to the secondary side surface (162 ), and formed to be higher than the main top surface (121), and a central surface (123) surrounded by the main top surface (121) and the sub-top surface (122). The major top (121) and major sides (161) are unground surfaces, while the minor top (122) and minor sides (162) are ground surfaces. The main cutting edge (181) is formed between the main top surface (121) and the main side surface (161), which are unground surfaces. The minor cutting edge (182) is formed between the minor top surface (122) and the minor side surface (162), which are ground surfaces.

Since the minor top surface (122) and the minor side surface (162) forming the minor cutting edge (182) are ground to ensure positional accuracy and reduce positional errors, along the thickness from the minor top surface (122) to the bottom surface (140), Manufacturing errors in direction are reduced and the position of the minor cutting edge (182) on the milling tool is made consistent. In addition, since the main top surface (121) and the main side surface (161) forming the main cutting edge (181) which has no influence on the surface roughness of the workpiece are not ground, the time spent on the grinding process can be reduced. and cost. Therefore, according to the present invention, while minimizing the grinding process on the surface of the cutting insert, the surface roughness of the workpiece can be made as in the case of the workpiece being cut by the cutting insert whose surface is entirely ground.

For a more consistent position of the minor cutting edge (182) on the milling tool, the bottom surface (140), which contacts the seating surface of the milling tool, is preferably ground. In addition, the central surface (123) is preferably ground and formed to be coplanar with the secondary top surface (122). This is because the center face (123) comes into contact with the wedge when the cutting insert (100) is seated on the milling tool.

A method of manufacturing a cutting insert according to the present invention will be explained below.

First, the dried raw powder is compacted to form a green body having the aforementioned shape of the cutting insert. The green body is sintered to form a sintered body. The sintered body is then ground. When grinding the sintered body, only the minor top surface (122) and the minor side surface (162) are ground, and the main top surface (121) and the main side surface (161) of the sintered body are not ground.

During the grinding step of the sintered body, preferably also the bottom surface (140) is ground. In addition, in the grinding step, it is preferable to grind the auxiliary top surface (122) together with the central surface (123).

In addition, the main top surface (121) of the raw body formed by compacting the raw material powder is preferably formed to be at least 0.1mm lower than the sub top surface (122). Otherwise, after sintering the green body, the height of the secondary top surface (122) becomes the same as or lower than that of the main top surface (121). Thus, during grinding of the minor top surface (121) of the sintered body, the main top surface (12) of the sintered body may also be undesirably ground.

While the invention will now be described with reference to its embodiments, such embodiments of the invention are exemplary only. It should be understood by those skilled in the art that various modifications of the embodiments may also be applied without departing from the scope of the present invention.

For example, Figure 6 shows a cutting insert seated on a wedge milling tool. However, as shown in Figures 7 and 8, a person skilled in the art may consider cutting inserts seated on helical milling tools. In this case, as shown in Fig. 7, the center face (223) may be configured as an unground surface in the same manner as the main top face (221), in order to further reduce any material loss due to the grinding process. In addition, as shown in FIG. 8, the central plane (323) may be coplanar with the secondary top plane (322). Furthermore, when manufacturing the cutting insert shown in Fig. 7, the minor top surface (222) of the raw body is preferably formed to be at least 0.1 mm higher than any one of the main top surface (221) and the center surface (223). When manufacturing the cutting insert shown in Fig. 8, any one of the minor top surface (322) and the central surface (323) of the raw body is preferably formed at least 0.1 mm higher than the main top surface (321).

Figures 6 to 8 show cutting inserts using only the top surface during cutting. However, as shown in Figures 9 and 10, one skilled in the art would contemplate the use of top and bottom face cutting inserts during cutting. In this case, in a similar manner to the top surface (420), the bottom surface (440) includes a main bottom surface (441), a sub bottom surface (442), and a central bottom surface (443). Each side includes: a first minor side (462), which is adjacent to the minor bottom (442), and which together with the minor bottom (442) forms a minor bottom cutting edge (484); and a second minor side (463), which is adjacent to the minor top surface (422), and forms a secondary top cutting edge (482) together with the secondary top surface (422). The secondary top (422), secondary bottom (442) and first and second secondary sides (462, 463) are ground.

Claims (13)

1. A cutting insert comprising: top surface; bottom surface; a major side connecting said top surface and said bottom surface; and secondary sides connecting adjacent major sides; Wherein, the top surface includes: a main top surface adjacent to the main side surface; a secondary top surface adjacent to the secondary side surface, the secondary top surface is connected to the adjacent main top surface, and is formed to be higher than the main top surface ; and a central surface surrounded by said main top surface and said secondary top surface; wherein said major top surface and said major sides are unground surfaces and said minor top surface and said minor sides are ground surfaces; and wherein a major cutting edge is formed between said major top surface and said major side surface which is an unground surface, and a minor cutting edge is formed between said minor top surface and said minor side surface which is a ground surface between. 2. The cutting insert of claim 1, wherein the bottom surface is a ground surface. 3. The cutting insert of claim 1, wherein the central surface is a ground surface formed to be coplanar with the secondary top surface. 4. The cutting insert of claim 1, wherein the central surface is an unground surface. 5. A cutting insert comprising: top surface; bottom surface; a major side connecting said top surface and said bottom surface; and secondary sides connecting adjacent major sides, each secondary side having a first secondary side and a second secondary side; Wherein, the top surface includes a main top surface adjacent to the main side surface and the first secondary side surface, and a secondary top surface adjacent to the second secondary side surface, and the secondary top surface connects adjacent main top surfaces and forms is higher than said major top surface; Wherein, the bottom surface includes a main bottom surface adjacent to the main side surface and the second secondary side surface, and a secondary bottom surface adjacent to the first secondary side surface, the secondary bottom surface is connected to the adjacent main bottom surface, and is formed to be higher than the the main bottom surface; Wherein, the main top surface, the main bottom surface and the main side surface are unpolished surfaces, and the secondary top surface, secondary bottom surface and the first secondary side surface and the second secondary side surface are polished surfaces ; Wherein, main cutting edges are respectively formed between the main top surface, the main side surface and the first minor side surface, and between the main bottom surface, the main side surface and the second minor side surface; and Wherein, the secondary cutting edges are respectively formed between the secondary top surface and the second secondary side surface, and between the secondary bottom surface and the first secondary side surface. 6. A method of manufacturing the cutting insert of claim 1, said method comprising: Prepare raw material powder; compacting the raw powder to form a raw body; sintering the green body to form a sintered body; and The minor top and minor sides of the sintered body are ground. 7. The method of claim 6, wherein grinding the minor top and minor sides of the sintered body comprises grinding the bottom surface. 8. The method of claim 6, wherein grinding the minor top and minor sides of the sintered body comprises grinding a center surface. 9. The method of claim 6, wherein compacting the raw powder to form a green body includes forming the major top surface lower than the secondary top surface. 10. The method of claim 9, wherein compacting the raw powder to form the green body comprises forming the major top surface at least 0.1 mm lower than the secondary top surface. 11. A method of manufacturing the cutting insert of claim 5, said method comprising: Prepare raw material powder; compacting the raw powder to form a raw body; sintering the green body to form a sintered body; and Grinding the secondary top surface, secondary bottom surface, and first and second secondary sides of the sintered body. 12. The method of claim 11, wherein compacting the raw powder to form the raw body comprises forming the major top surface and the major bottom surface lower than the secondary top and bottom surfaces, respectively. The secondary bottom surface. 13. The method of claim 12, wherein compacting the raw powder to form the raw body comprises forming the major top surface and the major bottom surface to be smaller than the secondary top and secondary surfaces, respectively. The bottom surface is at least 0.1mm lower.

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