JPH11197935A - Pin mirror cutter and tip for cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the cutting life by increasing the number of effective edges of a cutting edge. SOLUTION: A first tip 22 is installed with a cutting edge projected from the peripheral surface on the inner peripheral surface of a cutter main body 21 formed like a ring, and similarly a second tip 23 is installed with a cutting edge projected from the peripheral surface. A cutting edge part 25a having the locus of rotation repeating that of the end part 24a of the cutting edge in the first tip 22 is formed on a cutting edge of the second tip 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pin mirror cutter for machining a crankshaft of a reciprocating internal combustion engine and a tip for the cutter, and more particularly to a technique effective for extending the life of a cutting blade. .

[0002]

2. Description of the Related Art Conventionally, as a tool for machining a crankshaft of a reciprocating internal combustion engine, there is, for example, an internal pin mirror cutter as shown in FIG. The pin mirror cutter 1 has a plurality of chips 3, 4 on the inner peripheral portion of a cutter main body 2 forming an internal annular shape, with the respective cutting edges 5, 6 projecting from the inner peripheral surface of the cutter main body 2. It is detachably attached by a clamp screw 7.

As shown in FIG. 12, the pin mirror cutter 1 is mounted on a cutter mounting portion 9 provided on a processing machine 8 so that its axis coincides with a main shaft (not shown). A crankshaft (not shown), which is a work material, is bridged through the chuck 10 provided through the inner space of the pin mirror cutter 1.

At the time of driving, the pin mirror cutter 1
Is rotated around its own axis by a main shaft in a fixed direction (the direction of arrow A in FIG. 11), and revolves around the fixedly held crankshaft while rotating and moves appropriately in a direction perpendicular to the axis. Let me do.

As a result, the pin mirror cutter 1 is
As shown in FIG. 3, the side surface 11a of the counterweight portion 11 of the crankshaft is machined by the cutting blades 5 and 6, and the outer peripheral surface 12a of the shaft portion 12 is formed.
To process.

[0006]

In the pin mirror cutter 1, as shown in FIGS. 11 and 13,
With respect to the cutting edge 5 formed on the tip 3, the cutting edge 6 formed on the tip 4 is disposed so as to be retracted on the radially outer side of the cutter body 2.

[0007] For this reason, the rotation locus of the cutting edge 5 and the cutting edge 6 is different, and each of them independently cuts a separate portion, so that the cutting load applied to the cutting edge 5 and the cutting edge 6 during cutting is large. There were drawbacks.

In particular, regarding the end 5a of the cutting blade 5, FIG.
As shown in FIG. 3, the outer peripheral surface 12a of the shaft portion 12
And the counterweight portion 11 with a large cutting volume
Since both of the side surfaces 11a are used for cutting, there is a problem that they are liable to be worn or chipped easily at an early stage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a pin mirror cutter capable of extending the life of a cutting blade by increasing the number of effective blades at the cutting edge, and a tip for the pin mirror. The purpose is to provide.

[0010]

The present invention has the following features to attain the object mentioned above. The invention according to claim 1 is characterized in that a first tip is mounted on an inner peripheral portion or an outer peripheral portion of an annular cutter main body, the first tip being mounted on a peripheral surface of the cutter main body with a cutting blade protruding from the peripheral surface. In a pin mirror cutter, a second tip that is alternately mounted on one side surface and the other side surface of the cutter body in a state where a cutting edge is protruded from the peripheral surface is arranged alternately in a circumferential direction. The cutting edge of the second tip is formed with a cutting edge part whose rotation locus overlaps with the end of the cutting edge of the first tip.

According to such a configuration, the portion to be cut by the cutting edge of the first tip is also cut by the cutting edge of the second tip. For this reason,
The number of effective blades provided for cutting such a machined part increases,
The cutting load acting on the cutting edge of the first insert can be reduced, and early wear and chipping can be suppressed.

According to a second aspect of the present invention, there is provided a throw-away chip in which a side surface of a chip body having a substantially rectangular plate shape is a rake face, and a cutting edge is formed on a ridge of the rake face. An end portion of the cutting edge is provided with a cutting edge portion formed by lowering one step from one of the upper surface and the lower surface of the chip body toward the other surface.

When the chip having such a configuration is used for the pin mirror cutter according to the first aspect, for example, like the second chip in the pin mirror cutter, the cutting edge portion is the cutting edge end of the first chip. Can be overlapped with the rotation locus.
Therefore, it is possible to increase the number of effective blades at the end of the cutting edge of the first tip mounted on the pin mirror cutter, and to suppress early wear and chipping of the cutting edge as described above.

Here, the cutting edge portion may be formed at both ends of the cutting edge connected to either the upper surface or the lower surface (the invention according to claim 3), or may be formed at one end portion of the cutting blade connected to the upper surface. It may be formed at the other end of the cutting blade connected to the lower surface (the invention according to claim 4). In these cases, four cutting edges are formed on one chip, so even if the cutting edges are worn or broken, the other cutting edges can be reused. One chip can be used efficiently.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a pin mirror cutter and a chip according to the present invention will be described with reference to FIGS. FIG. 1 is a front view of a pin mirror cutter, in which reference numeral 21 indicates a cutter body.

The cutter body 21 is formed in an annular shape, and a plurality of chips 22 and 23 have cutting edges 24 and 25 (hereinafter referred to as pin blades 24 and wave blades 25) on the inner periphery thereof. It is detachably attached by a clamp screw 26 so as to protrude from the inner peripheral surface of the cutter body 21.

As shown in FIGS. 5 and 6, the chip 22 (first chip) has a substantially rectangular plate shape, and has a rake face 22a having a side face connected to a long side thereof, and the rake face 22a. Of the rake face 22a and the arc-shaped intersection ridge line 24b of the rake face 22a and the convex face 22b formed continuously with the short side of the chip 22.
4 are formed.

As shown in FIG. 1, the tip 22 has a predetermined spacing on the inner peripheral surface of the cutter body 21 with the rake face 22a facing forward in the rotational direction (the direction of arrow A in FIG. 1). In a state where the pin blades 24 are inclined at a predetermined angle with respect to the width direction of the cutter body 21 as shown in FIG. End 24 of pin blade 24 located
a is displaced rearward (downward in the drawing) in the rotational direction of the cutter body 21 from the end 24b located inward in the width direction.

The ends 24a of the pin blades 24 are alternately provided on one side and the other side of the cutter body 21 and slightly project outward from the side surfaces in the width direction. I have.

On the other hand, as shown in FIGS. 7 and 8, the chip 23 (second chip) protrudes in the direction of extension of the long side on the side surface connected to the short side of the chip body having a substantially rectangular plate shape. And a schematic configuration including a projecting portion 23A. The upper surface of the projecting portion 23A is formed as a convex surface, and the uppermost portion thereof is one step lower than the upper surface 23a of the chip body toward the lower surface 23b.

The chip 23 has a rake surface 23c facing forward in the rotation direction when the chip 23 is mounted on the cutter body 21, and the rake surface 23c, the protrusion 23A, A wave blade 25 is formed at an intersection ridge line between the projecting portion 23A and the convex surface 23B continuing to the upper surface 23a.

That is, the chip 23 in the present embodiment
As shown in FIG. 7, a wave blade 25 is formed at each of the four corners. For this reason, even when the wave blade 25 is worn or damaged, the pair of wave blades 25 arranged diagonally on one side of the cutter body 21 can be used without replacing the tip 23. Twice,
In addition, the tip 23 can be changed to the other side surface side, and the remaining pair of wave blades 25 can be used twice, respectively, and the wave blades 25 can be reused a total of four times.

Then, as shown in FIG. 1, the tip 23 extends along the circumferential direction of the
1 are alternately arranged on one side surface and the other side surface, and are mounted so as to be alternately arranged on the chip 22 as well.

At this time, the chip 23 corresponds to FIGS.
As shown in FIG.
A toward the inner space 27 of the cutter body 21 so that the rotation locus of the intersection ridge line (cutting edge portion 25a) between the A and the rake face 23c overlaps with the rotation locus of the end portion 24a of the pin blade 24. It is mounted in a protruding state.

The pin mirror cutter having the above configuration is mounted in a processing machine, and in a state in which a crankshaft is penetrated through the inner space 27, in a fixed direction around its own axis (in the direction of arrow A in FIG. 1). While being rotated, the crankshaft, which is fixed and held, revolves while rotating and is appropriately moved in a direction orthogonal to the axis of the pin mirror cutter.

As a result, the pin mirror cutter processes the side surface 51a of the counterweight portion 51 of the crankshaft with the pin blade 24 and the wave blade 25 as shown by the two-dot chain line in FIG. The surface 52a is processed.

At this time, the rotation locus of the cutting blade portion 25a of the wave blade 25 corresponds to the end portion 24a of the pin blade 24.
, The end 24a and the cutting edge 25a are alternately subjected to cutting. That is, when the same number of chips 22 and 23 are arranged, the number of effective blades is doubled.

This makes it possible to reduce the cutting load acting on the end portions 24a of the individual pin blades 24 in such a portion to be cut, thereby suppressing early wear and chipping of the end portions 24a and shortening the life of the cutting edge. Can be extended.

Next, a second embodiment of the chip according to the present invention will be described with reference to FIGS. 9 and 10 are a front view and a side view, respectively, of the chip in the present embodiment.

The chip 31 is similar to the chip 23 described above.
It has a schematic configuration including a protruding portion 32 protruding in a direction in which the long side portion extends in a side surface connected to the short side portion of the chip body.
However, in the present embodiment, for one of the protrusions 32,
One end of the chip body in the longitudinal direction (the right end in FIG. 10) is connected to the upper surface 31a, and the other protrusion 32 is the other end of the chip body in the longitudinal direction (FIG. 1).
The configuration of the chip 23 is different from that of the chip 23 in that it is connected to the lower surface 31b at the left end portion at 0).

As with the chip 23, the chip 31 has a side face connected to the long side of the chip body as a rake face 31c facing forward in the rotation direction when the chip 31 is mounted on the cutter body 21, and the rake face 31c. A wave blade 34 is formed at the intersection ridge line between the protrusion 32 and the convex surface 33 that extends from the protrusion 32 to the upper surface 31a and the lower surface 31b.

That is, the chip 31 in the present embodiment
Also, as shown in FIG. 9, since the wave blade 34 is formed at each of the four corner portions, if the wave blade 34 is worn or chipped, the cutter 31 is not replaced without replacing the tip 31. Using a pair of wave blades 34 arranged diagonally on one side of the main body 21,
Twice, using the tip 31 on the other side, and using the remaining pair of wave blades 34, twice.
Each wave blade 34 can be reused a total of four times.

The tip 31 has, similarly to the tip 23, a rotation locus of an intersection ridge (a cutting edge 34 a) between the projecting portion 32 and the rake face 31 c of the wave blade 34. The cutter body 21 is mounted so as to protrude toward the inner space 27 of the cutter body 21 so as to overlap with the rotation locus of the section 24a.

Therefore, in the pin mirror cutter having the above configuration, the cutting blade portion 34 of the wave blade 34 is also used.
Since the rotation trajectory a overlaps with the rotation trajectory of the end 24a of the pin blade 24, the number of effective blades used for cutting the portion to be cut increases. Therefore, the end portion 24 of the pin blade 24
By reducing the cutting load acting on a, the occurrence of early wear and chipping is suppressed, and the life of the cutting edge can be extended.

In each of the embodiments described above, a so-called internal type pin mirror cutter in which a chip is mounted on the inner peripheral portion of the cutter main body 21 has been described. Needless to say, a so-called external type pin mirror cutter in which each chip is mounted with the blade protruding may be used.

[0036]

As is apparent from the above description, according to the pin mirror cutter of the present invention, the cutting edge of which the rotation locus overlaps the edge of the cutting edge of the first tip with the cutting edge of the second tip. By forming the portion, the portion to be cut by the cutting edge portion of the first tip will also be cut by the cutting portion, the number of effective blades used for cutting such a portion to be cut Increases, the cutting load acting on each cutting edge is reduced, and the occurrence of early wear and chipping can be suppressed.

In particular, if the tip of the present invention is used as the second tip in the pin mirror cutter, the number of effective cutting edges at the cutting edge of the first tip is increased, as described above, and the premature wear of the cutting edge is increased. And the occurrence of chipping can be suppressed, and four cutting edge portions are formed for one chip. Therefore, even if the cutting edge portion is worn or chipped, the other cutting edge portion is formed. By repeatedly using, one chip can be used efficiently.

[Brief description of the drawings]

FIG. 1 is a main part front view showing an embodiment of a pin mirror cutter according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is an enlarged view of a main part showing a part of an inner peripheral surface of the pin mirror cutter shown in FIG. 1;

FIG. 5 is a plan view showing a first chip mounted on the pin mirror cutter shown in FIG. 1;

FIG. 6 is a side view showing the chip shown in FIG. 5;

FIG. 7 is a plan view showing a first embodiment of a chip according to the present invention.

FIG. 8 is a side view showing the chip shown in FIG. 7;

FIG. 9 is a plan view showing a second embodiment of the chip according to the present invention.

FIG. 10 is a side view showing the chip shown in FIG. 9;

FIG. 11 is a main part front view showing an example of a conventional pin mirror cutter.

FIG. 12 is a front view showing an example of a processing machine to which a pin mirror cutter is attached.

FIG. 13 is a sectional view taken along line XX of FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 Cutter main body 22 Chip (first chip) 23 Chip (second chip) 23a, 31a Upper surface of chip main body 23b, 31b Lower surface of chip main body 24 Pin blade (cutting edge in first chip) 24a End of pin blade Portions (ends of cutting edge in first tip) 25, 34 Wave blades (cutting edge in first tip) 25a, 34a Cutting edge portions 23c, 31c Rake face

Claims (4)

[Claims] A first tip mounted on an inner peripheral portion or an outer peripheral portion of an annular cutter main body with a cutting edge protruding from the peripheral surface of the cutter main body; In a pin mirror cutter in which a second tip mounted alternately on one side surface and the other side surface of the cutter body in a state where the cutting blade is protruded from a surface is arranged alternately in a circumferential direction, A pin mirror cutter, characterized in that a cutting edge of the cutting edge of the first tip is formed with a cutting edge part whose rotation locus overlaps with the end of the cutting edge of the first tip. 2. A throw-away chip in which a side surface of a chip body having a substantially rectangular plate shape is a rake face, and a cutting edge is formed on a ridge of the rake face. A throw-away tip, comprising a cutting blade portion formed by lowering one step from either one of an upper surface or a lower surface of the tip body toward the other surface. 3. The indexable insert according to claim 2, wherein the cutting edge is formed at both ends of a cutting edge connected to one of the upper surface and the lower surface. 4. The throwaway according to claim 2, wherein the cutting edge is formed at one end of the cutting blade connected to the upper surface and at the other end of the cutting blade connected to the lower surface. Chips.