JP4781224B2 - Reamer - Google Patents

Description

  The present invention relates to a reamer for finishing a hole in a non-ferrous metal such as aluminum die casting.

  The valve body, which is one of the key parts of automobiles, is made of materials such as aluminum die-casting, but the structure has become more complex as the parts are consolidated, and the holes for hydraulic control have become multi-stage shapes. It is made up of a number of holes with a general shape. In order to perform such hole finishing, for example, a reamer using a diamond sintered body for a cutting edge is used. When processing with this reamer, chips may be wound around the reamer depending on the processing form, and problems such as reduced work efficiency and scratches on the processed surface are likely to occur. In particular, when the shape of the processed part is not a through hole but a blind hole, the chip discharge property is deteriorated, and the chip is easily wound around the cutting edge. As a countermeasure, a countermeasure may be taken at the cutting edge for the purpose of dividing chips, and as one typical example, a break function is given to the cutting edge tip. As a method of providing a break function, a chip is divided by providing a step in a part of the chip.

As an example of a reamer having such a break function, there is a reamer in which a notch is provided on a rake face of a corner portion of a cutting edge tip as shown in FIG. 2 to form a step on the rake face, and this is used as a breaker ( For example, see Patent Document 1).
JP 2001-322029 A (page 5, FIG. 3)

  However, if the reamer is made of a chip having a step as described in Patent Document 1 in order to have a break function, the accuracy of the processed surface is worse than that of a reamer made of a chip without a step, and gloss is obtained. It is easy for problems to occur or quality to deteriorate. In addition, since the performance depends on the shape of the breaker, it is not easy to determine the appropriate shape, and the breaker is generally formed on all the blades, and the manufacturing cost is also increased. . Further, depending on the shape of the breaker, the area in which the chip can be effectively used is narrowed, and there is a problem that the number of times the chip can be corrected for reuse when the cutting edge is worn is reduced. In view of the above, the present invention provides a reamer in which chips are less likely to be wound during processing, the accuracy of the processed surface is good, and the manufacturing cost can be reduced.

  A feature of the reamer of the present invention is a reamer having a plurality of chips each having a cutting edge, wherein the plurality of chips includes a first chip having a break function and a second chip having no break function. And having

  When the reamer having such a configuration is used, the first tip having a break function cuts the workpiece as a leading edge, and since the frictional resistance is large, the elastic recovery amount of the workpiece is increased, resulting in uncut portions. . Further, since the cutting amount of the first chip is increased, cutting is performed while cutting off chips by the break function. Then, the uncut portion of the first chip is cut by the second chip having no break function as a finishing blade, and the accuracy of the processed surface is improved.

  As a preferable means for providing a break function, a breaker having a step is provided on the rake face of the first chip.

  If a breaker having such a shape is provided, chips can be efficiently divided.

  Another suitable means for providing a break function is to make the surface roughness of the rake face of the first chip rougher than the surface roughness of the rake face of the second chip.

  If the breaker having such a shape is provided, it is easy to form the breaker, and the breaker can be formed even after the chip is attached to the tool body.

  In order to effectively operate the first tip as a roughing leading edge, the rotation radius of the outer peripheral cutting edge of the first tip is 0.001 than the rotation radius of the outer peripheral cutting edge of the second tip. It is preferable to be larger by .about.0.003 mm.

  With such a configuration, after cutting with the first tip, the amount of the workpiece that has been elastically recovered is cut with the second tip, and an appropriate finishing process becomes possible. In addition, in such a configuration, it is very difficult to accurately adjust the turning radius of the outer peripheral cutting edge of the chip, but if the surface roughness of the rake face is roughened as a breaker, such a configuration It becomes easy to make. First, a chip on which a breaker is not formed is joined to a tool body, and a chip having a large rotation radius of an outer peripheral cutting edge among a plurality of chips is used as a first chip to roughen the surface roughness of the rake face of the chip. This is because it is easy to adjust the bonding position of the chip if the processing is performed.

  In the above reamer, it is preferable that one each of the first chip and the second chip is provided.

  This is because when three or more chips are provided, it takes a lot of work to arrange the chip for roughing and the chip for finishing, and to adjust the rotation radius of the outer peripheral cutting edge. This is because if one is provided, positioning can be facilitated by relatively adjusting the joining position of both chips.

  According to the reamer of the present invention, roughing and finishing can be performed at once, it is difficult for chips to be wound during processing, the accuracy of the processed surface is good, the accuracy of the cutting edge position is easy to adjust, and the manufacturing cost is reduced can do.

  As a reamer of the present invention, a diamond reamer having a chip made of a sintered diamond will be described as an example. 1A and 1B are views showing a reamer according to the present invention, in which FIG. 1A is a front view and FIG. 1B is a right side view. 2, 3 and 4 are perspective views of the periphery of the chip. As a first embodiment of the reamer of the present invention, a reamer in which a shank for attaching a chip is provided on one end side of a shaft-shaped main body 1, and one chip 2 and 22 are provided in the part of the shank. There is. The main body 1 is made of cemented carbide or the like, and the chip 2 is made of a cemented carbide 2b on which a sintered diamond 2a is formed, and is fixed to the main body 1 by brazing or the like.

  A chip having no breaker function has a shape shown in FIG. 4 and is provided with a flat rake face 23 and two flank faces 24a and 24b, and a cross ridge line between the rake face 23 and the flank face 24a is provided. The outer peripheral cutting edge 26 is formed with a bottom cutting edge 25 at the intersecting ridge line between the rake face 23 and the flank 24b. Further, a chamfered surface 27 obtained by chamfering is formed at the intersection of the flank surfaces 24a and 24b, and an oblique cutting edge 28 is formed at the intersection ridgeline between the rake surface 23 and the chamfered surface 27. Yes.

  A chip having a breaker function has the shape shown in FIG. 2, and is provided with a flat rake face 3 and two flank faces 4a and 4b, and a step 9 is formed at the corner of the tip, which is formed as a chip breaker. It is said. The step 9 is formed by electric discharge machining, grinding, or the like, and a rake face 9a is provided at a portion where the step 9 is formed. A chamfered surface 7 obtained by chamfering is formed at the intersection of the flank surfaces 4a and 4b in the same manner as the above chip having no breaker function. An outer peripheral cutting edge 6 is formed on the crossing ridgeline between the rake face 9a and the flank 4a, a bottom cutting edge 5 is formed on the crossing ridgeline between the rake face 9a and the flank 4b, and an oblique ridgeline is formed on the crossing ridgeline between the rake face 9a and the chamfered face 7 A cutting edge 8 is provided.

  The rotation radius of the outer peripheral cutting edge 6 of the chip 2 having the breaker function is larger by 0.001 to 0.003 mm than the rotation radius of the outer peripheral cutting edge 26 of the chip 22 having no breaker function.

  As a second embodiment of the reamer of the present invention, a reamer for providing a tip is provided on one end side of the shaft-shaped main body 1, and a reamer is provided with one each of chips 12 and 22 at the portion of the sag. There is. Like the reamer of the first embodiment, the main body 1 is made of cemented carbide or the like, and the chip 2 is made of a sintered diamond 2a formed on the base of the cemented carbide 2b, brazed or the like. It is fixed to the main body 1 by the above.

  The chip 12 having a breaker function has the shape shown in FIG. 3 and is provided with a flat rake face 13 and two flank faces 14a and 14b, and the rake face 13 has a surface roughness Rz of 1 to 3 μm. It has become. The rake face 13 is formed to have the above-described roughness by electric discharge machining or the like. A chamfered surface 17 obtained by chamfering is formed at the intersection of the flank surfaces 14a and 14b. An outer peripheral cutting edge 16 is formed on the crossing ridgeline between the rake face 13 and the flank 14a, a bottom cutting edge 15 is formed on the crossing ridgeline between the rake face 13 and the flank 14b, and an oblique ridgeline is formed on the crossing ridgeline between the rake face 13 and the chamfering face 17 A cutting edge 18 is provided.

  A chip having no breaker function has a shape shown in FIG. 4 and is provided with a flat rake face 23 and two flank faces 24a and 24b, and a cross ridge line between the rake face 23 and the flank face 24a is provided. The outer peripheral cutting edge 26 is formed with a bottom cutting edge 25 at the intersecting ridge line between the rake face 23 and the flank 24b. Further, a chamfered surface 27 obtained by chamfering is formed at the intersection of the flank surfaces 24a and 24b, and an oblique cutting edge 28 is formed at the intersection ridgeline between the rake surface 23 and the chamfered surface 27. Yes. The surface roughness of the rake face 23 is 0.1 μm in Rz.

  The rotation radius of the outer peripheral cutting edge 16 of the chip 12 having the breaker function is larger by 0.001 to 0.003 mm than the rotation radius of the outer peripheral cutting edge 26 of the chip 22 having no breaker function.

  As the diamond reamer according to the present invention, one chip shown in FIG. 3 and one chip shown in FIG. 4 are provided (present inventions 1 to 4), one chip shown in FIG. 2 and one chip shown in FIG. 4 are provided. (5-8 of the present invention) were produced. The chip 22 having no breaker function is obtained by cutting a PCD blank having a sintered diamond 22a formed on a cemented carbide 22b into a predetermined shape, lapping the rake face 23, and then forming a flank face 24a. 24b and the chamfered surface 27 were lapped to form an outer peripheral cutting edge 26, a bottom cutting edge 25, and an oblique cutting edge 28. The surface roughness of the rake face 23 is 0.1 μm in Rz.

  The chip 2 having the shape shown in FIG. 2 used in the present invention 5 to 8 is manufactured in the same manner as the chip having no breaker, and then the rake face 3 at the corner portion of the chip is ground and the breaker 9 is cut. Formed. Thereby, the outer peripheral cutting edge 6, the bottom cutting edge 5, and the diagonal cutting edge 8 are newly formed. The chip 2 and the chip 22 manufactured as described above were brazed and fixed to the main body 1. At the time of brazing, the rotational radius of the outer peripheral cutting edge of each chip is adjusted, the rotational radius of the chip 2 is larger than the rotational radius of the chip 22, and the rotational radius difference is different (Invention 5-7) And vice versa (Invention 8). However, this position adjustment took a very long time.

  On the other hand, the present inventions 1 to 4 were manufactured as follows. The chip 22 having no breaker function is the same as described above. However, the chip 12 having the breaker function is processed in the same manner as the chip 22 having no breaker function, and the chips 22 and 12 are made of cemented carbide. It fixed to the main body 1 which consists of by brazing. At this point, chips 22 and 12 have the same configuration. After brazing the tips 22 and 12, the turning radii of both outer peripheral cutting edges were measured. Originally, it is fixed so that it has the same turning radius, but due to problems such as brazing accuracy, there is a slight difference in the turning radius. Therefore, measure the turning radius, and the outer peripheral cutting edge with the larger turning radius is the breaker. A chip 12 having a function, a difference in the rotation radius difference between the outer peripheral cutting edges 16 and 26 of the two chips (inventions 1 to 3), and a chip 12 having a breaker function on the outer peripheral cutting edge having a smaller rotation radius. (Invention 4) was produced. Then, the rake face 13 of the chip 12 having a breaker function was roughened by electric discharge machining so that the surface roughness Rz was 2 μm.

  For comparison, a reamer provided with two chips 22 having no breaker function (Comparative Example 1) and a reamer provided with two chips 12 having a breaker function (Comparative Example 2) were manufactured. The chip 22 having no breaker function is the same as the reamer chip 22 of the present invention, and the chip 12 having the breaker function is the same as the reamer chip 12 of the present invention.

Using these reamers, a deep hole of an aluminum die-cast valve body (hole φ10 mm, depth 100 mm) was finished. The processing conditions were a rotational speed S = 3000 min ⁻¹ and a feed speed F = 500 mm / min.

  Table 1 shows the specifications and test results of the reamer subjected to the above test.

  As a result of the test, among the reamers of the present invention, as for the breakers of the present invention 1 to 4, the rake face has a rough surface, the length of the chips is cut short to about 15 to 35 mm and entangled with the cutting edge. Nonetheless, the surface roughness of the processed surface was also good. Moreover, about what provided the level | step difference in the rake face as a breaker of this invention 5-6, the length of the chip was divided | segmented into about 10-25 mm, the break function was very favorable, and it did not get entangled with the blade edge | tip. However, the cutting resistance increased due to the shape of the breaker, and the surface roughness of the machined surface tended to be slightly worse.

  Regarding the difference in the radius of rotation between the outer peripheral cutting edges of the two chips, regardless of the shape of the breaker, there was a tendency for the cutting resistance to decrease as the rotation radius of the outer peripheral cutting edge of the chip with the breaker increased. This seems to be because the two chips are processed with a good balance between the roles of roughing and finishing.

  The reamer of Comparative Example 1 has a long chip length of 50 to 70 mm and a situation where the cutting edge is entangled with the cutting edge. The accuracy of the machined surface is about 10% worse due to the surface roughness, and moreover, the chip is wound and the processing is troublesome. And the entire processing time was increased by about 20%. In the reamer of Comparative Example 2, the chip length was not different from that of the reamer of the present invention, but the cutting resistance was high and the chip was easy to adhere to the rake face, so the accuracy of the machined surface was about 30% in terms of surface roughness. It got worse.

  As can be seen from the above examples, the reamer of the present invention can perform roughing and finishing at once, it is difficult for chips to be wound during processing, the accuracy of the processed surface is good, and the manufacturing cost can be reduced. .

It is a figure which shows the reamer of this invention, (a) is a front view, (b) is a right view. It is a perspective view which shows the example of the chip | tip which has a breaker function. It is a perspective view which shows another example of the chip | tip which has a breaker function. It is a perspective view which shows the example of the chip | tip which does not have a breaker function.

Explanation of symbols

1 Body 2, 12, 22 Chip 2a, 12a, 22a Sintered diamond 2b, 12b, 22b Cemented carbide 3, 13, 23 Rake face 4a, 14a, 24a Flank 4b, 14b, 24b Flank 5, 15, 25 Bottom cutting edge 6, 16, 26 Peripheral cutting edge 7, 17, 27 Chamfered surface 8, 18, 28 Diagonal cutting edge 9, 19, 29 Chip breaker

Claims (4)

A reamer having a plurality of chips the cutting edge is formed, the plurality of chips, possess a first chip having a break function, a second chip having no break function, the first The reaming radius of the outer peripheral cutting edge of the tip is 0.001 to 0.003 mm larger than the rotating radius of the outer peripheral cutting edge of the second tip .   The reamer according to claim 1, wherein a breaker having a step is provided on a rake face of the first chip.   The reamer according to claim 1, wherein a surface roughness of the rake face of the first chip is rougher than a surface roughness of the rake face of the second chip. It said first chip and said second chip, reamer according to any one of claims 1 to 3 provided respectively 1 month.

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