JP2005081469A - Throwaway tip and pin mirror cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the securement of the profile irregularity on the side face at a pin part in a throwaway tip and a pin mirror cutter for working a crankshaft. <P>SOLUTION: The throwaway tip has the following characteristics. A cutting edge 25B is formed to at least one crossing ridge line part of the upper face 21 or the lower face 22 and the side face 24 of a tip body 20 in a nearly quadrangle flat plate shape. The upper face 21 or the lower face 22, which is one face for forming the crossing ridge line part, is made as a flank. A first side face 24, which is the other face for forming the crossing ridge line part, is made as a rake face. A sub-cutting edge 30 is formed at the crossing ridge line part of the first side face 24 made as the rake face and a second side face 23 adjacent to the first side face 24. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a throw-away tip and a pin mirror cutter suitable for use in processing a crankshaft or the like used in a reciprocating internal combustion engine.

As is well known, as a tool for processing a crankshaft or the like of a reciprocating internal combustion engine, an annular cutter body having an annular shape, a mounting portion to which the cutter body is attached, an inner peripheral surface and both end surfaces of the cutter body, A pin mirror cutter generally composed of a plurality of chips mounted in a removable state is used (see Patent Document 1). FIG. 6 shows an example of this pin mirror cutter. The pin mirror cutter shown in FIG. 6 includes a cutter body 1 having a substantially annular shape that is rotated around an axis O, and a mounting portion 1A to which the cutter body 1 is attached. A plurality of first tip mounting seats 3A are formed on the peripheral surface 2A, and a plurality of tip mounting seats 3B are formed on both end surfaces 2B and 2B of the cutter body. These first tip mounting seat 3A and the second tip A throw-away tip 50 is attached to the mounting seat 3B.
As shown in FIG. 7, the throw-away tip 50 used for the pin mirror cutter is a substantially rectangular flat plate, upper and lower surfaces 51 and 52 at both ends in the thickness direction, and one side surface 53 that is a rake face. The two side surfaces 54 adjacent to the one side surface are formed, and curved surface portions 59 and 60 formed in a convex shape are formed at both ends in the thickness direction of the second side surface 54.

The angle θ3 formed by the extension line of the straight part 54a of the second side surface 54 and the extension line of the straight part 51a of the upper surface 51 is an acute angle, and a curved surface part 59 is formed in this part. A curved blade 55 is formed at the intersecting ridge line portion between the curved surface portion 59 and the one side surface 53.
In addition, an angle θ4 formed by an extension line of the straight part 54a of the second side surface 54 and an extension line of the straight part 52a of the lower surface 52 is an obtuse angle, and a curved surface part 60 is formed in this part. A curved blade 56 is formed at the intersecting ridge line portion between the curved surface portion 60 and the one side surface 53.
Further, a straight blade 58 is formed at the intersection ridge line portion between the one side surface 53 and the upper surface 51 which are rake faces. Here, the curved blade 55 and the straight blade 58 are pin blades for processing the pin portion of the crankshaft. The curved blade 56 is a wave blade that processes the side surface of the counterweight portion of the crankshaft.
Furthermore, an inclined portion 57 that is gradually inclined toward the tip body side is formed at the intersecting ridge line portion between the one side surface 53 and the second side surface 54 from the end portion of the curved blade 55 toward the end portion of the curved blade 56. Has been.

The pin mirror cutter thus configured revolves while the cutter body 1 rotates to process the crankshaft.
In this case, as shown in FIG. 8, the straight blade 58 processes the bottom portion 70 of the pin portion in the process of processing the pin portion of the crankshaft by the throw-away tip 50 mounted on the first tip mounting seat 3A. .
On the other hand, the intersecting ridge line portion between the one side surface 53 and the second side surface 54 of the throwaway tip 50 is inclined toward the main body side of the throwaway tip 50 from the end of the curved blade 55 toward the curved blade 56 side. An inclined portion 57 is formed, and the side surface 71 of the pin portion is processed by the inclined portion 57.
For this reason, the protrusion part 80 whose cross-sectional shape is substantially triangular shape is formed in the side surface 71 of a pin part.
JP-A-1-252302 (page 1-3)

By the way, the conventional throw-away tip and the pin mirror cutter have a problem that the surface accuracy of the side surface of the pin portion after processing cannot be secured.
That is, when the tip cuts the pin portion of the crankshaft, a certain interval occurs in the cutting operation, while the tip is sent to the processing surface during that time, so the inclined portion of the tip body is the side surface of the pin portion. Thus, the projecting portion 80 having a substantially triangular cross section is formed on the side surface 71 of the pin portion.
Therefore, there is a problem that the surface accuracy of the side surface of the pin portion after processing cannot be secured.
Furthermore, in order to ensure the surface accuracy of the side surface of the pin portion, there has been a problem that it is necessary to polish the side surface portion of the pin portion with a grindstone.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pin mirror cutter and a throw-away tip capable of ensuring the surface accuracy of the side surface of the pin portion in the processing of the crankshaft. To do.

In order to achieve the above object, the present invention proposes the following means.
In the throw-away tip mounted on the tip mounting seat formed on the inner peripheral surface of the cutter main body of the pin mirror cutter, the upper or lower surface and the side surface of the tip main body having a substantially rectangular flat plate shape are provided. A cutting edge is formed in at least one intersecting ridge line portion, and an upper surface or a lower surface as one surface forming the intersecting ridge line portion is a flank surface, and one side surface as the other surface is a rake surface. And a corner blade is formed at the corner portion of the one side surface which is the rake face, and is continuous with the end portion of the corner blade among the intersecting ridge line portions of the one side surface and the two side surfaces. The secondary cutting edge is formed.

  According to the throw-away tip for the pin mirror cutter according to the present invention, the cutting edge formed at the crossing ridge line portion between the one side face that is the rake face and the top face or the bottom face, and the cross ridge line between the rake face and the two side faces. When machining using the curved blade formed on the top, the secondary cutting edge cuts the machining side surface formed substantially perpendicular to the machining surface to be machined by the above cutting blade, and the machining side surface is machined flat. Will be.

  According to a second aspect of the present invention, in the throw-away tip for the pin mirror cutter according to the first or second aspect, the length in the thickness direction of the tip body of the auxiliary cutting blade is 0.2 mm or more 3 It is characterized by being formed to 0.0 mm or less.

According to the throw-away tip for a pin mirror cutter according to the present invention, the processing side surface is processed flat even when the tip is fed and processed.
In other words, if the width in the thickness direction of the auxiliary cutting edge is narrower than 0.2 mm, a protrusion is formed on the processed side surface when the cutting edge of the next chip further processes the processed surface that has already been processed. In addition, if the width in the thickness direction of the secondary cutting edge is larger than 3.0 mm, the cutting resistance between the secondary cutting edge and the processing side surface becomes excessive.

  According to a third aspect of the present invention, in the throw away tip for a pin mirror cutter according to the first or second aspect, the auxiliary cutting edge is located from the end side continuous with the curved blade to the other end side. It is formed to be inclined from 0 degree 50 minutes to 3 degrees 50 degrees so as to gradually deviate from the axis parallel to the thickness direction toward the chip body side as it goes.

  According to the throw-away tip for the pin mirror cutter according to the present invention, the processing side surface is formed substantially flat, while the cutting resistance generated in the auxiliary cutting edge does not become excessive.

  Invention of Claim 4 is equipped with the annular cutter main body rotated about an axis line, and the attaching part of this cutter main body, The pin in any one of Claim 1 to 3 in the said cutter main body A throwaway tip for a mirror cutter is mounted.

  According to the pin mirror cutter according to the present invention, the processing side surface is processed flat by the auxiliary cutting blade formed on the throw-away tip for the pin mirror cutter attached to the pin mirror cutter.

  According to a fifth aspect of the present invention, in the pin mirror cutter according to the fourth aspect, the cutter body has a first tip mounting seat formed on the inner peripheral surface thereof and a second mounting surface on the end surface thereof. A seat is formed, and the throwaway tip for a pin mirror cutter according to any one of claims 1 to 3 is mounted on the first and second tip mounting seats.

  According to the pin mirror cutter according to the present invention, when the pin mirror cutter throw-away tip mounted on the first tip mounting seat is processed, the processing side surface is formed by the auxiliary cutting edge of the pin mirror cutter throw-away tip. Processed flat.

  According to a sixth aspect of the present invention, in the pin mirror cutter according to the fourth or fifth aspect, the angle formed between the radial axis of the cutter body and the auxiliary cutting edge is 0 degree or more and 3 degrees or less. It is characterized by.

According to the pin mirror cutter according to the present invention, cutting resistance generated during processing is reduced.
That is, if the angle formed between the radial axis of the cutter body and the auxiliary cutting edge is smaller than 0 degrees, the cutting resistance is excessive, and if it is larger than 3 degrees, the processed side surface is formed flat. It will not be done.

  As described above, according to the present invention, it is possible to provide a pin mirror cutter throw-away tip and a pin mirror cutter capable of ensuring the surface accuracy of the side surface of the pin portion in the processing of the crankshaft. .

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. First, a pin mirror cutter to which a throw-away tip is attached will be described. The pin mirror cutter is substantially composed of a cutter body 10 formed in a substantially annular shape around an axis O rotated around an axis O, a chuck on which a crankshaft is stretched, and an attachment portion of the cutter body 10. ing.

  As shown in FIGS. 1 and 2, a plurality of first tip mounting seats 13 are arranged at substantially equal intervals along the circumferential direction of the cutter body 10 on the inner circumferential surface 11 facing the radially inner side 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 end surfaces 12A and 12B facing outward in the axis O direction. Is formed.

A plurality of first tip mounting seats 13 formed on the inner peripheral surface 11 of the cutter body 10 are formed from one end face 12A of the both end faces 12A and 12B of the cutter body 10 and the other end face 12B. Further formed ones are alternately arranged in the circumferential direction of the cutter body 10.
Here, the chip body 20 mounted on the first chip mounting seat 13 and the second chip mounting seat 14 of the cutter body 10 will be described.
As shown in FIG. 3, the chip body 20 forms a substantially rectangular flat plate (substantially rectangular flat plate), and upper and lower parallel surfaces 21, 22 arranged opposite to each other at both ends in the thickness direction of the chip body 20. A pair of parallel short side surfaces (second side surfaces) 23 and 23 disposed opposite to each other at both ends in the longitudinal direction of the chip body 20 and a pair of long side surfaces disposed opposite to each other in the short direction of the chip body 20 ( One side) 24, 24 is provided.
Here, as shown in FIG. 3 (a), an insertion hole 26 for inserting a clamp screw used when the chip is screwed is provided in the upper and lower surfaces 21 at a substantially central portion of the chip body 20. , 22 so as to penetrate in a direction substantially orthogonal to the thickness of the chip body.
As shown in FIGS. 3B and 3C, the upper and lower surfaces 21 and 22 of the chip body 20 are at both ends in the longitudinal direction of the chip body 20 (direction orthogonal to the pair of short side surfaces 23 and 23). It is made to cross | intersect with respect to a pair of short side surfaces 23 and 23 of the chip | tip 20 main body, respectively, and the both ends side part of the said thickness direction in each of the short side surfaces 23 and 23 seems to connect smoothly with the upper and lower surfaces 21 and 22, respectively. The curved surface portions 23A1 and 23A2 are processed into a convex curved surface.

The short side surfaces 23 and 23 of the chip body 20 are slightly inclined (for example, about 5 degrees) with respect to the thickness direction of the chip body 20.
As shown in FIGS. 3B and 3C, the angle α formed by the extension line of the straight line portion 43 of one short side surface 23 and the extension line of the straight line portion 42 of the lower surface 22 is an acute angle (for example, 85 degrees). The curved surface portion 23A1 is formed in this portion, the angle β formed with the extension line of the straight portion 41 of the upper surface 21 is an obtuse angle (for example, about 95 degrees), and the curved surface portion 23A2 Is formed.
The angle β formed by the extension line of the straight line portion 43 of the other short side surface 23 and the extension line of the straight line portion 42 of the lower surface 22 is an obtuse angle (for example, about 95 degrees), and a curved surface portion 23A2 is formed in this portion. In addition, the angle α formed with the extended line of the linear portion 41 of the upper surface 21 is an acute angle (for example, about 85 degrees), and a curved surface portion 23A1 is formed in this portion.

Further, a curved blade 25A1 is formed at the intersecting ridge line portion between the curved surface portion 23A1 of the short side surface 23 and the long side surface 24, and further, at the intersecting ridge line portion between the curved surface portion 23A2 of the short side surface 23 and the long side surface 24. A curved blade 25A2 is formed.
In the chip body 20, a straight blade 25 </ b> B is formed on an intersecting ridge line between the pair of long side surfaces 24, 24 and the upper and lower surfaces 21, 22.
That is, four curved blades 25A1 and 25A2 each having a substantially convex curve shape are formed on the intersecting ridge line portions of the curved surface portions 23A1 and 23A2 of the pair of short side surfaces 23 and 23 and the pair of long side surfaces 24 and 24, respectively. In addition, a total of four straight blades 25 </ b> B that form a substantially straight line are formed at the intersecting ridge line portion between the upper and lower surfaces 21 and 22 and the pair of long side surfaces 24 and 24.

Further, the auxiliary cutting edge formed between the curved edge 25A1 and the curved edge 25A2 at the intersecting ridge line portion of the long side surface 24 and the short side surface 23 from the end of the curved edge 25A2 substantially in parallel with the thickness direction of the chip body 20. 30 is formed, and an inclined portion 31 is formed between the end of the auxiliary cutting blade 30 and the end of the curved blade 25A2.
The auxiliary cutting edge 30 formed at the intersecting ridge line portion of the long side surface 24 and the short side surface 23 is an axis parallel to the thickness direction of the chip body 10 as it goes from the end portion of the curved blade 25A1 toward the end portion side of the curved blade 25A2. It is formed to be inclined in a direction deviating from the chip body side. Specifically, the angle formed between the axis parallel to the thickness direction of the chip body 10 and the auxiliary cutting edge 30 is formed to be 0 ° 50 minutes or more and 3 ° 50 minutes or less.
That is, if the angle is smaller than 0 degrees and 50 minutes, the cutting resistance increases when the pin portion is machined. If the angle is set to be larger than 3 degrees and 50 minutes, the side surface 71 of the pin portion is machined flat. It will not be possible.

Moreover, the length L of the chip body 20 in the thickness direction of the sub-cutting blade 30 is formed to be 0.2 mm or more and 3.0 mm or less. In addition, the length L of the sub cutting edge 30 is preferably a value obtained by multiplying the feed amount sent to the processing surface by 1.5 when processing.
On the other hand, the inclined portion 31 is inclined so as to deviate from the axis parallel to the thickness direction of the chip body 20 toward the chip body 20 side as it goes from the end of the sub cutting edge 30 to the end of the curved blade 25A2. Is formed.
Here, the angle formed by the inclined portion 31 and the axis parallel to the thickness direction of the chip body 20 is about 5 degrees, and the chip body 20 side becomes closer to the end of the curved blade 25A2 from the end of the curved blade 25A1. It is formed to be inclined.
The chip body 20 formed in this way is mounted on the first chip mounting seat 13 and the second chip mounting seat 14 of the cutter body 10.

Here, as shown in FIG. 2, the chip body 20 mounted on the first chip mounting seat 13 cuts one curved blade 25 </ b> A <b> 1 among the four cutting blades of the curved blade 25 </ b> A <b> 1 formed on the chip body 20. While projecting from the inner peripheral surface 11 of the main body 10 to the radially inner peripheral side of the cutter main body 10 and projecting outward from the end surface 12A or the end surface 12B of the cutter main body 10 in the direction of the axis O, the curved blade 25A1 is connected. The straight blade 25B is projected from the inner peripheral surface of the cutter body. That is, the long side surface 24 of the chip body 20 is installed as a rake face.
The curved blade 25A1 and the straight blade 25B arranged in such a protruding state are pin blades for processing the outer peripheral surface of the pin portion of the crankshaft.

4A and 4B show the trajectory of the tip body 20 when the cutter body 10 rotates. The tip body 20 attached to the first tip mounting seat 13 is a cutter body. 10 is set so that the angle θ1 formed by the axis P parallel to the radial direction and the auxiliary cutting edge 30 is 0 degree or more and 3 degrees or less, and the auxiliary cutting edge 30 moves from the inside in the radial direction to the outside as described above. It is installed so as to face the outside in the direction of the axis O.
The angle θ1 formed between the auxiliary cutting edge 30 and the axis P parallel to the radial direction of the cutter body 10 is preferably set to 0 ° 15 minutes or more and 0 ° 20 minutes or less.
Further, the angle θ2 formed between the inclined portion 31 and the axis P parallel to the radial direction of the cutter body 10 is about 4 degrees and 10 minutes, and the axis O of the cutter body 10 increases from the radially inner side toward the outer side. It is installed so that it can be inclined from the outside to the inside.

Further, the chip body 20 mounted on the second chip mounting seat 14 has the thickness direction of the chip body 20 substantially coincided with the axial direction of the cutter body 10, and one of the pair of long side surfaces 24, 24 is rotated by the cutter. It is screwed and attached by a clamp screw 15 inserted through the insertion hole 20A of the chip body 20 so as to be a rake face toward the front side in the direction T.
Thus, the chip body 20 mounted on the second chip mounting seat 14 is installed so that the curved blade 25A2 protrudes from the end surface 12A of the cutter body 10.
The curved blade 25A2 arranged in such a protruding state is a wave blade for machining the side surface of the counterweight portion in the crankshaft.

Here, the cutter body 10 to which the tip body 20 is mounted as described above is attached to the mounting portion 10A of the processing machine so that the axis O of the cutter body 10 coincides with the main axis, and the crank is stretched over the chuck. While rotating along the axial direction of the crankshaft with the shaft passing through the inner space of the cutter body 10, the shaft rotates about the axis O of the cutter body 10 and revolves around the axis of the crankshaft. The crankshaft is processed into a predetermined shape.
As shown in FIG. 5, when processing the pin portion of the crankshaft, the bottom portion 70 of the pin portion is processed by the straight blade 25 </ b> B formed at the intersecting ridge line portion between the lower surface 22 and the long side surface 24 of the chip body 20. The The curved surface portion 72 connecting the bottom portion 70 of the pin portion and the side surface portion 71 is processed by the curved blade 25A1, and the side surface portion 71 of the pin portion is processed by the sub cutting blade 30.
Here, after processing one pin body 20 after processing the pin portion, when processing the next chip body 20 that has already been processed, the chip body 20 is processed with a certain amount of feed. Become.
The direction in which the tip body 20 is fed is a direction substantially parallel to the radial direction of the cutter body 10. On the other hand, the auxiliary cutting edge 30 is mounted so as to be substantially parallel to the radial direction of the cutter body 10.
For this reason, after the one chip body 20 has processed the pin portion, when the next chip body 20 is further processed, the auxiliary cutting edge 30 installed substantially parallel to the processed side surface 71 is A processed side surface is newly formed from the curved surface portion 72 side of the processed side surface 71 already formed. The newly formed processed side surface 71 and the already formed processed side surface 71 are connected in a flat manner.
That is, the processed side surface 71 of the pin portion is formed flat by the auxiliary cutting edge 30 of the chip body 20.
Therefore, since the side surface of the pin portion is a flat surface, the surface accuracy of the side surface of the pin portion can be ensured.

  As described above, according to the present invention, it is possible to provide a throw-away tip and a pin mirror cutter that can ensure the surface accuracy of the side surface of the pin portion in the processing of the crankshaft.

It is a top view of the pin mirror cutter with which the throw away cutter is mounted. It is a figure which shows the internal peripheral surface of the pin mirror cutter of FIG. 1 is a top view, a side view, and a partially enlarged view of a side surface of a throw-away tip according to the present invention. It is the schematic which shows the locus | trajectory of the chip | tip main body when a cutter main body rotates. It is a figure showing the process in which the pin part of a crankshaft is processed. It is a top view of the conventional pin mirror cutter. It is a partial enlarged view of the side surface of the conventional throw-away tip. It is the figure which showed the manufacturing process of the pin part.

Explanation of symbols

10 Cutter body 11 Inner peripheral surface of cutter body 20 Tip body (throw away tip)
21 Upper surface 22 Lower surface 23 Short side surface (other side surface)
23A1, 23A2 Curved surface 24 Long side (One side)
25A1, 25A2 Curved blade 25B Straight blade (cutting blade)
30 Sub cutting edge

Claims (5)

In the throw-away tip attached to the tip mounting seat formed on the inner peripheral surface of the cutter body of the pin mirror cutter,
A cutting edge is formed in at least one intersecting ridge line portion between the upper surface or the lower surface and the side surface of the chip body having a substantially rectangular flat plate shape, and the upper surface or the lower surface, which is one surface forming the intersecting ridge line portion, is a flank. In addition, the one side which is the other side is a rake face, a corner blade is formed at the corner portion of the one side face which is the rake face, and the one side face and the second side face A throw-away tip, wherein a secondary cutting edge is formed continuously at an end of the corner blade in the intersecting ridge line portion. The throw-away tip according to claim 1,
A throw-away tip, wherein the length of the tip body of the sub-cutting blade in the thickness direction is 0.2 mm or more and 3.0 mm or less. The throw-away tip according to claim 1 or 2,
The sub cutting edge is formed to be inclined at 0 degree 50 minutes or more and 3 degrees 50 minutes or less so as to recede to the inside of the chip body from the end side continuous with the corner blade toward the other end side. Through-away chip, characterized by that. In a pin mirror cutter comprising an annular cutter body rotated around a central axis, and an attachment part of the cutter body,
A pin mirror cutter, characterized in that the throw-away tip according to any one of claims 1 to 3 is mounted on the tip mounting seat. In the pin mirror cutter according to claim 4,
A pin mirror cutter characterized in that an angle formed between the radial axis of the cutter body and the auxiliary cutting edge is set to 0 degrees or more and 3 degrees or less.

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