JP4186795B2 - Pin mirror cutter and throw-away tip attached to it - Google Patents

Description

  The present invention relates to a pin mirror cutter for processing a crankshaft used in, for example, a reciprocating internal combustion engine, and a throw-away tip (hereinafter referred to as a tip) attached to the pin mirror cutter.

Conventionally, a so-called internal type pin mirror cutter as disclosed in, for example, Patent Document 1 is known.
This pin mirror cutter has a plurality of first tip mounting seats formed on the inner peripheral surface of a substantially annular cutter body that rotates about an axis, and a second tip on both end faces of the cutter body. A plurality of mounting seats are formed, and the same type of chip is mounted on each of the first chip mounting seat and the second chip mounting seat.

  In this chip, a total of eight cutting edges are formed at the intersection ridge line portion between a pair of side surfaces opposed to each other of the chip body having a substantially parallelogram flat plate shape and the upper and lower surfaces of the chip body. In the other pair of side surfaces different from the side surfaces, the region on the obtuse corner portion side of the chip body is cut off so as to increase the corner angle, so that the other pair of side surfaces is composed of two wall surfaces. In this way, it has a chevron shape that protrudes outward from the chip body. Further, each of the connecting portions to the other pair of side surfaces on the upper and lower surfaces of the chip body is chamfered into a convex curved surface.

The tip mounted on the first tip mounting seat has an axial rake (axial rake angle): positive, radial, with a sharp edge formed on the sharp corner of the tip body that is a substantially parallelogram flat plate. Rake (radial rake angle): It is a pin blade that protrudes from the inner peripheral surface of the cutter body so as to be negative, and processes the outer peripheral surface of the pin portion (shaft portion) of the crankshaft.
The tip mounted on the second tip mounting seat has an axial rake (axial rake angle): negative, with one cutting edge formed at the obtuse corner of the tip body having a substantially parallelogram flat plate shape. Radial rake (radial rake angle): A wave blade that is projected from the end face of the cutter body so as to be negative and that processes the side face of the counterweight portion of the crankshaft.

In such a pin mirror cutter, by attaching the same type of chip to the first and second chip mounting seats, the cutting blades formed in a total of 8 locations with one chip are each subjected to cutting, Tool costs can be reduced. Then, by using a chip having a substantially parallelogram flat plate chip body having the other pair of side surfaces as described above, the chip mounted on the first chip mounting seat is the pin blade. The axial rake given to the cutting blade is set to a positive value to reduce cutting resistance.
JP 2002-46009 A

However, in the pin mirror cutter disclosed in Patent Document 1, a cutting blade as a pin blade whose axial rake is set to be positive is formed at an acute corner portion of a chip body having a substantially parallelogram flat plate shape. Since the tip body has the other pair of side surfaces from which the region on the obtuse corner portion side is cut off as described above, the radial of the cutting blade as a wave blade formed in the obtuse corner portion of the tip body. The rake inevitably becomes very large toward the negative angle side. Therefore, the pin mirror cutter disclosed in Patent Document 1 cannot be an effective solution for reducing cutting resistance.
In addition, the tip body of such a tip is provided with the other pair of side surfaces from which the obtuse corner portion is cut off as described above, so that the length of the tip body is not increased by the amount of the cut-off. A sufficient length cannot be secured, and the space occupied by the chip mounting seat formed on the cutter body is increased, thereby reducing the strength of the cutter body. In addition, since the shape of the chip body is complicated, it is difficult to manufacture the chip body, resulting in an increase in processing cost.

  The present invention has been made in view of the above problems, and a pin mirror cutter capable of effectively reducing cutting resistance, maintaining a high strength of the cutter body, and being easy to manufacture, and the pin mirror cutter. It aims at providing the chip | tip mounted | worn with.

In order to solve the above-described problems and achieve such an object, the pin mirror cutter according to the present invention has a first tip mounting seat on the peripheral surface of a substantially annular cutter body rotated about an axis. A second tip mounting seat is formed on an end surface of the cutter body, and the first tip mounting seat has a pair of long side surfaces in which a tip body having a substantially trapezoidal flat plate shape is disposed opposite to the first tip mounting seat; The upper and lower surfaces opposed to each other at both ends in the thickness direction of the chip body and the pair of parallel short sides facing each other at both ends in the longitudinal direction of the chip body, the pair of long side surfaces and the upper and lower surfaces, and a pair of obtuse corner portion having the same identical corner angle with one another and a pair of sharp corner portions having a corner angle of substantially equal to each other when viewed along the cutting edge is formed Rutotomoni the thickness direction intersecting edge line region of the The That chip, as well as the rake face toward the one of the pair of long side to the cutter rotational direction front side, substantially aligned with the thickness direction of the chip body in the radial direction of the cutter body, said chip A cutting edge formed at an acute corner portion of the main body is mounted to be used for cutting, and the second tip mounting seat has a throw-away tip of the same type as the throw-away tip out of the pair of long side surfaces. A cutting edge formed at an obtuse corner portion of the chip body, with one of the rake surfaces facing the front side of the cutter rotation direction and the thickness direction of the chip body substantially matching the axial direction of the cutter body Is mounted so as to be used for cutting.
The chip according to the present invention is a chip mounted on the pin mirror cutter according to the present invention, and is formed at a pair of long side surfaces in which a substantially trapezoidal plate-shaped chip body is disposed opposite to each other at both ends in the thickness direction of the chip body. A pair of parallel short side surfaces disposed opposite to each other at both ends in the longitudinal direction of the chip body, and the pair of long side surfaces and the top and bottom surfaces at the intersection ridge line portion. and a pair of obtuse corner portion having the same identical corner angle with one another and a pair of sharp corners cutting edge having a look along are formed Rutotomoni the thickness direction substantially the same corner angle with one another to the side surface of the rake face and it is characterized in that it comprises.

According to the present invention, the chip body of the same type of chip mounted on the first and second chip mounting seats has a substantially trapezoidal flat plate shape as described above, and the first chip mounting seat. The tip mounted on the chip body was subjected to cutting using the cutting edge formed at the acute corner portion of the chip body as a pin blade, and the chip mounted on the second chip mounting seat was formed at the obtuse corner portion of the chip body. Since the cutting blade is used as a wave blade for cutting, the axial rake can be set positive for the cutting blade as the pin blade in the tip mounted on the first tip mounting seat. In addition, the chip body has a substantially trapezoidal flat plate shape, and each of the other side surfaces different from the pair of side surfaces is composed of one wall surface, so that the wave in the chip mounted on the second chip mounting seat is provided. Regarding the cutting blade as the blade, the radial rake is set to be negative, but does not increase significantly toward the negative angle side. Therefore, in the present invention, cutting resistance can be effectively reduced, and high-precision and stable crankshaft machining can be continued.
In addition, since each of the other pair of side surfaces of the chip body is constituted by one wall surface, a sufficient cutting edge length can be ensured without increasing the length of the chip body. The space occupied by the formed chip mounting seat can be reduced, and the strength of the cutter body can be kept high.
Furthermore, since the chip body has a simple shape, its manufacture can be facilitated, and the processing cost can be reduced.

Hereinafter, a pin mirror cutter according to an embodiment of the present invention will be described with reference to FIGS.
The cutter main body 10 of the pin mirror cutter according to the present embodiment has a substantially annular shape centering on the axis O rotated about the axis O as shown in the enlarged view of the main part in FIGS.
In the cutter body 10, a plurality of first tip mounting seats 13 are formed on the inner circumferential surface 11 facing the radially inner circumferential side at substantially equal intervals along the circumferential direction of the cutter body 10. A plurality of second tip mounting seats 14 are formed at substantially equal intervals along the circumferential direction of the cutter body 10 on the inner peripheral surface 11 side of the both end surfaces 12A and 12B facing outward in the direction. Yes.

The plurality of first tip mounting seats 13 formed on the inner peripheral surface 11 of the cutter body 10 are arranged near one end surface 12A of the both end surfaces 12A and 12B of the cutter body 10 in the circumferential direction. And those arranged closer to the other end face 12B are arranged alternately in the circumferential direction of the cutter body 10.
A plurality of second chip mounting seats 14 formed on one end surface 12A of the cutter body 10 are respectively a plurality of first chip mounting seats 13 formed on the inner peripheral surface 11 near the other end surface 12B. A plurality of second chip mounting seats 14 arranged on the other end surface 12B of the cutter body 10 are also arranged near the one end surface 12A. Are arranged in the circumferential direction so that each of the plurality of first chip mounting seats 13 formed on the inner circumferential surface 11 is slightly behind the cutter rotation direction T.

The chip body 20 of the chip mounted on the first chip mounting seat 13 and the second chip mounting seat 14 as described above has a substantially trapezoidal flat plate shape as shown in FIG. The upper and lower surfaces 21 and 21 parallel to each other disposed at both ends in the thickness direction of the chip body 20 and a pair of long side surfaces 22 and 22 disposed at both ends in the short direction of the chip body 20 (one pair of Side surface) and a pair of parallel short side surfaces 23 and 23 (the other pair of side surfaces) arranged opposite to each other at both ends in the longitudinal direction of the chip body 20. Therefore, the chip body 20 has a pair of acute corner portions 24A and 24A having substantially the same corner angle as shown in FIG. 3A when viewed from above (as viewed along the thickness direction of the chip body 20). And a pair of obtuse corner portions 24B, 24B having the same corner angle.
Here, an insertion hole 20A through which a clamp screw used when the chip is screwed is inserted in a substantially central portion of the chip body 20 in the thickness direction of the chip body 20 (left and right in FIG. 3B). Direction, a direction substantially orthogonal to the upper and lower surfaces 21).

The pair of long side surfaces 22, 22 of the chip body 20 is composed of one substantially flat surface that is substantially parallel to the thickness direction of the chip body 20, and the pair of short side surfaces 23, 23 of the chip body 20 are also Each is constituted by one substantially flat surface which is substantially parallel to the thickness direction of the chip body 20.
The upper and lower surfaces 21 and 21 of the chip body 20 respectively intersect the pair of short side surfaces 23 and 23 of the chip body 20 at both end portions in the longitudinal direction of the chip body 20 (left and right direction in FIG. 3A). However, as shown in FIG. 3C, both end portions of the upper and lower surfaces 21 and 21 in the longitudinal direction are processed into convex curved surfaces.
In the upper and lower surfaces 21, a connecting portion to one short side surface 23 connecting the pair of acute corner portions 24A, 24A is smoothly connected to the short side surface 23 as shown in the left region of FIG. As shown in the right region of FIG. 3C, the connecting portion to the other short side surface 23, which is a curved surface portion 21A and connects the pair of obtuse corner portions 24B, 24B, is smooth with respect to the short side surface 23. Is a curved surface portion 21B that is not connected.

In the chip body 20, cutting edges are formed at intersection ridges between the pair of long side surfaces 22, 22 and the upper and lower surfaces 21, 21.
More specifically, a curved blade 25A having a substantially convex curve shape is formed at the intersecting ridge line portion between the curved surface portions 21A, 21A, 21B, and 21B and the pair of long side surfaces 22 and 22 on the upper and lower surfaces 21 and 21, respectively. A total of eight are formed, and the portions of the upper and lower surfaces 21 and 21 excluding the curved surface portions 21A, 21A, 21B, and 21B and the intersecting ridge line portions of the pair of long side surfaces 22 and 22 are substantially linear. A total of four straight blades 25B are formed, and a total of eight curved blades 25A... And a total of four straight blades 25B.

  The chip configured as described above has the thickness direction of the chip main body 20 substantially coincided with the radial direction of the cutter main body 10 with respect to the first chip mounting seat 13, and is formed of the pair of long side surfaces 22, 22. One is made to be a rake face toward the front side of the cutter rotation direction T, and is screwed and attached by a clamp screw 15 inserted into the insertion hole 20A of the chip body 20.

The tip mounted on the first tip mounting seat 13 has one curved blade 25A (especially, the upper and lower surfaces 21 and 21 and short ones) formed at the acute corner portion 24A of the eight curved blades 25A. One of the four curved blades 25A ... formed in the intersecting ridge line portion of the curved surface portion 21A and the long side surface 22 constituting the portion where the side surfaces 23 and 23 intersect each other is used as the cutter body 10 Is projected from the end surface 12A (12B) of the cutter body 10 to the outer side in the axis O direction, and the straight blade 25B connected to the curved blade 25A is connected to the cutter body 10. It protrudes from the inner peripheral surface 11 to the radially inner peripheral side.
The curved blade 25A and the straight blade 25B arranged in such a protruding state serve as pin blades for processing the outer peripheral surface of the pin portion (shaft portion) in the crankshaft.

Further, the curved surface portion 21A connected to the cutter rotation direction T rear side of the curved blade 25A, which is a pin blade, is inclined so as to go to the radially outer peripheral side toward the cutter rotation direction T rear side and the cutter rotation. As it goes to the rear side in the direction T, it is inclined so as to go inward in the direction of the axis O, and relief is given to this curved surface portion 21A that forms the flank of the curved blade 25A that is a pin blade. Yes.
Therefore, the radial rake R (radial rake angle) of the curved blade 25A, which is a pin blade, is inclined so that the curved blade 25A moves toward the front side in the cutter rotation direction T as it goes toward the outer peripheral side in the radial direction. Is set to be negative (for example, −8 °).

On the other hand, the axial rake A (axial rake angle) of the curved blade 25A that is a pin blade is such that the curved blade 25A moves toward the rear side in the cutter rotation direction T as it goes inward in the axis O direction. By being inclined, it is set to be positive (for example, 6 °).
In other words, since there is an acute corner portion 24A in which the long side surface 22 and the short side surface 23 that form a rake face intersect each other at an acute angle, the curved surface portion 21A that forms the flank of the curved blade 25A that is a pin blade. Even if escape is given, the axial rake of the curved blade 25A, which is a pin blade, can be set positively.

  Further, the chip configured as described above has a pair of long side surfaces 22, 22 with respect to the second chip mounting seat 14 such that the thickness direction of the chip body 20 is substantially aligned with the axis O direction of the cutter body 10. One of the two is raked with a clamp screw 15 inserted into the insertion hole 20A of the chip body 20 so as to be a rake face toward the front side in the cutter rotation direction T.

The tip mounted on the second tip mounting seat 14 has one curved blade 25A (especially, the upper and lower surfaces 21 and 21 and short ones) formed at the obtuse corner portion 24B of the eight curved blades 25A. One of the four curved blades 25A formed on the intersecting ridge line portion of the curved surface portion 21B and the long side surface 22 forming the portion where the side surfaces 23 and 23 intersect with each other is used as the cutter body 10 The end face 12A (12B) is projected outward in the axis O direction.
The curved blade 25A arranged in such a protruding state serves as a wave blade for machining the side surface of the counterweight portion of the crankshaft.
The curved blade 25A arranged in such a protruding state serves as a wave blade for machining the side surface of the counterweight portion of the crankshaft.

In addition, the curved surface portion 21B connected to the cutter rotation direction T rear side of the curved blade 25A, which is a wave blade, is inclined so as to go inward in the axis O direction as it goes to the cutter rotation direction T rear side. As the cutter rotates in the direction T rearward, it is inclined so as to go toward the outer periphery in the radial direction, and relief is given to the curved surface portion 21B that forms the flank of the curved blade 25A that is a wave blade. Yes.
For this reason, the axial rake A (axial rake angle) of the curved blade 25A, which is a wave blade, is inclined so that the curved blade 25A moves forward in the cutter rotation direction T as it goes inward in the axis O direction. Is set to be negative (for example, −6 °). Further, the radial rake R (radial rake angle) of the curved blade 25A, which is a wave blade, is inclined so that the curved blade 25A moves toward the cutter rotation direction T forward as the radial blade 25A moves toward the outer peripheral side in the radial direction. Is set to be negative (for example, −17 °).

  The pin mirror cutter having such a structure is attached to the cutter mounting portion of the processing machine so that the axis O of the cutter main body 10 coincides with the main axis, and the crankshaft spanned by the chuck is connected to the inside of the cutter main body 10. While rotating along the axis of the crankshaft (axis O of the cutter body 10) in a state of being penetrated through the hollow portion, it rotates around the axis O of the cutter body 10 and revolves around the axis of the crankshaft. Thus, the crankshaft is processed into a predetermined shape.

  As described above, in the pin mirror cutter according to the present embodiment, first, the same type as the chip to be mounted on the first chip mounting seat 13 ... and the second chip mounting seat 14 ... formed on the cutter body 10. Can be used for cutting as a pin blade or a wave blade, respectively, and the tool cost can be reduced. It has become.

Since the chip body 20 of such a chip has a substantially trapezoidal flat plate shape with the pair of long side surfaces 22 and 22 and the pair of short side surfaces 23 and 23 as described above, the first chip mounting For the tip mounted on the seat 13, the axial rake A of the curved blade 25A, which is a pin blade, can be set positive. Moreover, since each of the short side surfaces 23, 23 of the chip body 20 is constituted by one substantially flat surface, the curved blade 25A as a wave blade in the chip mounted on the second chip mounting seat 14 Although the radial rake R is set to be negative, the radial rake R does not increase significantly toward the negative angle side.
Therefore, according to the present embodiment, the axial rake A of the curved blade 25A, which is a pin blade, can be positively set, and the cutting resistance can be effectively reduced. Accordingly, a highly accurate and stable crank It becomes possible to continue processing the shaft.

Furthermore, in this embodiment, since each of the short side surfaces 23 and 23 of the chip body 20 is constituted by one substantially flat surface, the cutting edge length can be sufficiently increased without increasing the length of the chip body 20. The space occupied by the chip mounting seat 13 formed on the cutter body 10 can be reduced, and the strength of the cutter body 10 can be kept high.
In addition, since the chip body 20 has a simple trapezoidal flat plate shape and a simple shape, the chip body 20 can be easily manufactured and the processing cost can be reduced.

  In each of the above-described embodiments, the present invention is described as being applied to a so-called internal-type pin mirror cutter. However, the present invention is not limited to this, and the cutter body faces the radially outer peripheral side. A plurality of first chip mounting seats are formed on the outer peripheral surface, and a plurality of second chip mounting seats are formed on each outer peripheral surface side of both end faces facing the axial direction. The present invention may be applied to a so-called external type pin mirror cutter in which a chip is mounted on each of the seat and the second chip mounting seat.

It is principal part expansion explanatory drawing of the end surface in the cutter main body of the pin mirror cutter by embodiment of this invention. It is principal part expansion explanatory drawing of the internal peripheral surface in the cutter main body of the pin mirror cutter by embodiment of this invention. (A) is a top view showing the chip body of the chip mounted on the pin mirror cutter according to the embodiment of the present invention, (b) is a side view of the chip in the A direction, and (c) is a view in the B direction of the chip. It is a C direction arrow directional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cutter main body 11 Inner peripheral surface 12A, 12B End surface 13 First chip mounting seat 14 Second chip mounting seat 20 Chip main body 21 Upper surface, lower surface 21A, 21B Curved portion 22 Long side surface 23 Short side surface 24A Sharp corner portion 24B Obtuse corner Part 25A Curved blade 25B Straight blade A Axial rake R Radial rake O Cutter body axis T Cutter rotation direction

Claims (2)

A first tip mounting seat is formed on the peripheral surface of the cutter body that rotates around the axis, and a second tip mounting seat is formed on the end surface of the cutter body,
Wherein the first chip mounting seat, the longitudinal direction of the chip body and the upper and lower surfaces of the chip body having a substantially trapezoidal flat plate shape is disposed opposite the ends of the oppositely disposed pair of longer sides and a thickness direction of the chip body and a short side of a pair of parallel disposed opposite at both ends of each other when viewed in the cutting edge is formed along Rutotomoni the thickness direction intersecting ridgeline portions between the pair of long side surfaces and the upper and lower surfaces A throw-away tip comprising a pair of acute corner portions having substantially the same corner angle and a pair of obtuse corner portions having the same corner angle, and one of the pair of long side surfaces in the direction of cutter rotation. The cutting edge formed at the acute corner portion of the chip body is cut with a rake face toward the front side and the thickness direction of the chip body substantially coincides with the radial direction of the cutter body. Is mounted so provide,
The second tip mounting seat has a throw-away tip of the same type as the throw-away tip as a rake face with one of the pair of long side faces facing forward in the cutter rotation direction, and the tip A pin mirror cutter, which is mounted so that a cutting edge formed at an obtuse corner portion of the chip body is used for cutting, with the thickness direction of the body being substantially coincident with the axial direction of the cutter body. A throw-away tip attached to the pin mirror cutter according to claim 1,
A pair of long side surfaces in which a chip body having a substantially trapezoidal flat plate shape is disposed opposite to each other, upper and lower surfaces opposed to each other at both ends in the thickness direction of the chip body, and opposite to each other in both longitudinal ends of the chip body. and a pair of short sides, said pair of each other when viewed along the longer sides and the cutting edge to the pair of face rake long sides intersecting ridgeline portion between the upper and lower surfaces are formed Rutotomoni the thickness direction A throw-away tip comprising a pair of acute corner portions having substantially the same corner angle and a pair of obtuse corner portions having the same corner angle .

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