JP3118956B2 - Indexable tip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away insert mounted on various throw-away tools.

[0002]

2. Description of the Related Art As a throw-away type tool to which such a throw-away tip (hereinafter referred to as a tip) is mounted, for example, a throw-away type end mill as shown in FIG. 10 to FIG. Are known.

In this end mill, the thickness of the distal end portion 2 is gradually increased from the distal end in the direction of the tool axis C to the proximal end side of the distal end portion 2 of the tool body 1 having a multi-stage cylindrical shape whose diameter is reduced toward the distal end. The chip pocket 3 is formed so as to be large. A tip mounting seat 5 is formed on the bottom surface 4 of the tip pocket 3 on the tip side in the direction of the tool axis C and on the side of the side facing the tool rotation direction. Thus, the chip 7 is fixed.

The chip 7 is a plate-shaped positive chip in which one end face 9 of a chip body 8 serving as a rake face forms a substantially parallelogram in plan view. The other end surface 10 of the chip body 8 which is a seating surface in contact with is formed so as to be parallel to each other. The nose portions 11 of the chip 7 are formed at a pair of acute angles located on one diagonal line of the parallelogram forming the one end surface 9. Then, the side surfaces 12 adjacent to each other across the nose portion 11 of the chip body 8,
13 and the one end face 9 form an intersection ridge line 14,
15, that is, cutting edges 16 and 17 are formed on two sides of the parallelogram nose portion 11 forming the one end surface 9 so as to be continuous with the nose portion 11. It is a cutting blade and a bottom cutting blade. Further, the chip body 8 is located at the center of the chip body 8.
A mounting hole 18 penetrating in the thickness direction is formed.

On the other hand, the tip mounting seat 5 on which the tip 7 is mounted is such that the cutting blades 16 and 17 respectively protrude from the outer peripheral surface and the distal end surface of the tip 2 of the tool body 1 when the tip 7 is attached. It is formed into a shape that engages with the outer shape of the chip body 8. Further, the other end surface 10 of the chip body 8
The bottom surface 19 of the tip mounting seat 5 on which the tool body 1 is seated, as in the bottom surface 4 of the tip pocket 3, is such that the thickness H of the distal end portion 2 of the tool main body 1 gradually increases from the distal end to the proximal end side of the tool main body 1. In addition, a flat surface is formed by being inclined in a direction oblique to the tool axis C.

Further, a screw hole (not shown) is provided at the center of the bottom surface 19 of the chip mounting seat 5, and the axis of the screw hole is aligned with the chip body 8 when the chip 7 is mounted on the chip mounting seat 5. The tip mounting seat 5 is slightly eccentric toward the base end side corner in the tool axis direction from the axis of the mounting hole 18 formed in the center of the chip mounting seat 5. An oval recess 20 is formed at a corner of the tip mounting seat 5 on the base end side in the tool axis direction in plan view.

In the throw-away type end mill having such a configuration, the tip 7 is mounted on the tip mounting seat 5 of the tool body 1 and the clamp screw 6 is tightened. The chip 7 is seated and fixed by being pressed against the bottom surface 19 of the chip. At the same time, the eccentricity between the axis of the screw hole of the chip mounting seat 5 and the axis of the mounting hole 18 of the chip body 8 pushes the chip body 8 against the corner of the chip mounting seat 5, whereby the chip body 8 is pressed. Side 1 located on the base end side of the tool body 1
2 and the side 1 adjacent to the side 12 with the nose 11 interposed therebetween
3 is brought into contact with the wall portions 21 and 22 of the tip mounting seat 5 to protrude from the outer peripheral surface of the distal end portion 2 of the tool body 1 and the distal end surface, and the outer peripheral side cutting edge and the bottom cutting edge of the end mill. The positions of the cutting blades 16 and 17 are accurately determined. Further, in the end mill of this example, the recesses 20 formed in the corners of the chip mounting seat 5 prevent the vicinity of the nose portion 11 of the chip 7 from contacting the chip mounting seat 5, so that the cutting edges 16, 17 are used. This has the advantage that the positioning accuracy can be maintained, and the molding of the tip mounting seat 5 itself can be facilitated.

[0008]

However, in such a throw-away type tool, a large cutting resistance acts on the chip 7 which comes into contact with and cuts the work material. It is desirable that the distal end portion 2 of the main body 1 be designed to have sufficient rigidity. Therefore, in the end mill shown in FIGS. 10 to 12, as described above, the tip pocket 3 is formed so that the thickness of the distal end portion 2 gradually increases from the distal end of the tool axis C toward the proximal end side. A flat surface whose bottom surface 19 is inclined in a direction oblique to the tool axis C so that the thickness H of the tip end portion 2 also becomes gradually larger toward the base end of the tool axis C in the same manner. It is molded as

However, when the chip 7 whose rake face and seating face are parallel to each other is mounted on the chip mounting seat 5 whose bottom 19 is inclined in this way, the rake face is also attached to the chip mounting seat 5. The inclined surface is parallel to the bottom surface 19. That is, when the angle formed between the bottom surface 19 of the chip mounting seat 5 and the tool axis C is to θ, as shown in FIG. 11,
The axial rake angle γa1 of the mounted chip 7 is a negative angle whose absolute value is equal to θ, and it is inevitable that the machinability deteriorates.

Also, the radial rake angle γr of the one rake face
₁ is determined by the thickness H of the tip 2 and the thickness of the tip body 8 when the outer diameter of the tip 2 of the tool body 1 is equal. However, in order to impart sufficient rigidity to the tip 2 of the tool body 1 as described above, the thickness H of the tip 2 cannot be made too small. It is also difficult to reduce the thickness of No. 8 and consequently the radial rake angle γr ₁
Has to be increased toward the negative angle side, which further deteriorates the machinability.

In view of the above circumstances, the applicant has filed Japanese Patent Application No.
No. 052 proposed a throwaway tip. This throw-away tip has an inclined surface inclined in a direction in which the thickness decreases as the distance from the nose portion increases, so that the upper surface of the throw-away tip having a polygonal shape in plan view is inclined in either the axial direction or the radial direction. The thickness of the tool body is ensured while securing the rake angle in the positive direction. An object of the present invention is to further improve the indexable insert to realize the securing of the rake angle and the securing of the thickness of the tool main body while preserving the compatibility of the attachment to the tool main body. .

[0012]

According to a first aspect of the present invention, a nose portion is formed at a corner of a chip body having a polygonal flat plate shape, and the nose portion is sandwiched between the nose portion. A throwaway in which a cutting edge is formed on at least one of two intersecting ridges formed by each of a pair of adjacent side surfaces of the chip body and one end surface of the chip body connected to the nose portion, the cutting edge being formed on the nose portion. In the chip, the one end surface has an inclined surface gradually approaching the other end surface of the chip body as being separated from the nose portion, and the two intersecting ridge lines are also separated from the nose portion by this inclined surface. wherein is slant to face the other end face side, each side, the crossing ridge
A first side surface that is continuous with the line, and an end surface side other than the first side surface
And a second side located on the tool body.
With a clearance angle that matches the reference mounting surface of
One side forms a clearance angle smaller than the clearance angle of the second side
As described above, the configuration has a two-step relief angle .

[0013] The invention according to claim 2 is the invention according to claim 1.
For clarity, a breaker is formed on each of the inclined surfaces along a ridge line formed by each of the inclined surfaces and each of the side surfaces.

[0014]

According to the above construction, the one end surface, which is the rake surface of the chip, has an inclined surface toward the other end surface side of the chip body, that is, the seating surface side, as the chip surface is separated from the nose portion. The two intersecting ridges formed by each of the two side surfaces sandwiching the nose portion and the one end surface also incline toward the seating surface as the distance from the nose portion increases. Therefore, when such a tip is mounted on a throw-away type tool that is inclined such that the thickness of the tip portion gradually increases as the bottom surface of the above-mentioned tip mounting seat moves toward the base end side of the tool body, By making the inclination of the cross ridge line located on the outer peripheral side of the tool among the cross ridge lines larger than the inclination of the bottom surface of the chip mounting seat, the inclination of the bottom surface of the chip mounting seat is offset, and as a result, the axial rake of the chip rake surface is obtained. The corner can be set to a regular angle. Also, in this case, of the two crossing ridge lines, the crossing ridge line located on the tool tip side is also inclined from the nose portion to the seating surface side of the tool body, so that the rake angle in the radial direction of the rake face is more regular than before. Can be set to the side.

The tip end of the tool body holding the insert can be designed so that its thickness gradually increases toward the base end side of the tool axis, as in the prior art, so that the rigidity of this portion is impaired. There is nothing. Therefore, according to the present invention, the axial rake angle and the radial rake angle of the rake face are set on the regular angle side while the one end face serving as the rake face of the tip maintains the rigidity of the tip end portion of the tool body holding the chip. Therefore, the machinability can be improved.

Further, the side surface of the chip body is formed at the intersection ridge line.
A continuous first side surface and a position located on the other end side relative to the first side surface.
And a second side surface. Here, the second aspect
On the side of the tip body for cutting regardless of the shape of the cutting edge.
Contact with the mounting surface of the tool body.
This is the side surface that is attached and serves as a reference for positioning. Also,
One side is related to the shape of the cutting edge of the side of the tip body.
Within the range, independently of the second side, the cutting edge
It is inclined so as to reduce the clearance angle.

Here, the mounting surface of the tool body is at the position of the chip.
It is the basis of the decision, and its shape (inclination angle)
It is predetermined. And the side of the chip body
That is, the second side, which is the reference for positioning, is
Same shape as the surface (same inclination angle), related to the shape of the cutting edge
Adjusting the tilt angle of the first side, which is the range,
When ensuring compatibility when attaching the main body to the tool body
In both cases, the clearance angle of the first side leading to the cutting edge is greater than the second side
The angle of the rake face can be adjusted by setting a small appropriate angle.
Any angle greater than the second side without changing the tool angle
Angle can be changed. With this, the cutting edge shape
It can be set freely according to cutting conditions and the like. Soshi
Tilt the first side in a direction to reduce the clearance angle of the cutting blade.
By tilting, the angle of the cutting edge is increased and its strength is increased.
And increase the life of the chip.
Wear.

In addition, since the breaker is formed along the cutting edge, the rake angle of the cutting edge is set in the forward direction by the breaker, and the action of improving the cutting performance and the rigidity of the tool body is improved. It gets even bigger. Further, since the valley line of the breaker is inclined with respect to the cutting edge, the interval between the breaker and the cutting edge is optimally set at each of the cutting edges having different cutting conditions.

[0019]

1 to 9 show an embodiment of the present invention. As shown in these figures, the chip 31 of the present embodiment has a positive type in which one end face 33 of a chip body 32 which is a rake face of the chip 31 forms a parallelogram in plan view as shown in FIG. Noses 34, 34 are formed at a pair of acute angles located on one diagonal of the parallelogram. Further, a pair of side surfaces 35, 36 adjacent to each other with the nose portions 34, 34 interposed therebetween.
The intersection ridges 37 and 38 formed by the one end face 33 and the two sides sandwiching the acute angle portion of the parallelogram are formed by the nose portion 34.
In the case where the insert 31 is attached to the above-mentioned throw-away type tool,
7 and the cutting edge 38 serving as the cutting edge 38 at the bottom.

One end surface 33 of the chip body 32
The other end surface 3 of the chip main body 32 which becomes a seating surface of the chip 31 as it goes away from the nose portions 34 and 34 to the other diagonal side connecting the obtuse portions of the parallelogram.
9 so that the two intersecting ridge lines 37 and 38 are also inclined toward the other end surface 39 as the distance from the nose portion 34 increases. Is formed in a V-shape when viewed from the side along the other diagonal as shown in FIG. In this embodiment, the other end surface 39 of the tip main body 32 is a flat surface perpendicular to the thickness direction of the tip main body 32 as shown in FIG. .

The parallelogram forming the contour of the chip 31 is shown in FIG. 1 along the inclination of the side surfaces 35 and 36 of the chip main body 32 along the inclination of the side surface 35 and 36 of the chip main body 32 as shown by a broken line in the figure. It substantially matches the shape in plan view when enlarged in the direction perpendicular to the paper surface. And the chip body 32
The cutting edges 37, 38 of the tip body 32
From the sides s1 and s2 of the parallelogram indicated by the two-dot chain line in the figure, θ1 (θ1 = 1 ° in the example) and θ2 (θ2 = 2 ゜ 30 ′ in the example), respectively.
It will be formed at a position shifted only by. The cutting blades 37 and 38 are formed between the one end surface 37 of the chip main body 32 and the side surface 35 or 36, and these surfaces are all formed with respect to the end surface or the side surface of the chip 31. It is formed by repeating the process of moving the grinding wheel within a two-dimensional plane set at a predetermined angle once or while changing the feed direction as needed. Therefore, for example, the cutting edge 37 on the outer peripheral side, which is the intersection line between the plane of the one end surface 33 and the plane of the side surface 35, becomes linear.

32 side surfaces 35 and 36 of the chip body
Are flank faces for the cutting edges 37 and 38, respectively.
And the upper side surfaces 35a and 36a, respectively.(First aspect)
And the lower side surfaces 35b and 36b(Second side)And composed from
Have been. That is, the chip body 32 is shown in FIG.
As shown in FIG. 2, a portion having a truncated pyramid shape (shown by a thickness t1 in FIG. 2)
Area), the upper surface (one end surface 33) is tapered triangular weight
On which a part (a range indicated by a thickness t2 in FIG. 2) is formed.
Can be analyzed. Here the upper side 35a, 3
6a is the lowest part of the tapered end face 33.
Above the minute (the diagonal line connecting the obtuse corners)
A portion forming a side surface of the triangular pyramid, a lower side surface 35b,
36b means a portion forming a side surface of the truncated pyramid.

Note that the other end surface 39 of the chip body 32 is
And the side surfaces 35a, 36a with respect to the vertical straight line S3.
Make an angle of 15 ° as shown in FIG.
Have been. In addition, the side surface 35 with respect to the straight line S3
b and 36b make an angle θ4 as shown in FIG.
Is set to 20 °. That is, the straight line S3 is
In the figure, if it is a work surfaceUpper side surface 35a, 36a
IsLower side 35b, 36bthansmallHave a clearance angle
Will be. And the lower side surfaces 35b, 36b
After machining the upper side surfaces 35a, 36a, the angle of the grinding tool
And then again grind the side surface of the tip body 32
Thus, it can be formed at a predetermined angle.

In the embodiment, the lower side surfaces 35b, 36b
By making the truncated pyramid-shaped portion surrounded by the same shape as a normal chip (not a shape in which one end face is tapered as in the present embodiment, but upper and lower end faces in a plate shape parallel to each other) Care is taken to have compatibility when attaching the tip body 32 to the tool body.

A breaker 40 is provided on one end surface 33 of the chip main body 33 along cutting edges 37, 37 on the outer peripheral side.
Are formed. These breakers 40 have a cross-sectional shape as shown in FIG. 5, and their valley lines 41 are inclined with respect to the outer cutting edge 37 as shown in FIG. In addition, the breaker 40 is provided, for example, in a tool grinder, by using a grinding tool in a plane parallel to the other end surface 39 and the valley line 41.
(In a direction inclined with respect to the cutting edge 37) in a straight line. Therefore,
The cut in the grinding process gradually changes based on the inclination of the one end surface 33, and the width and the depth gradually decrease from the distal end side to the proximal end side.

The breaker 40 is formed slightly inward with respect to the outer and bottom cutting blades 37 and 38, respectively, and the outer and bottom cutting blades 37 and 3 are formed.
8, planar land portions 42 and 43 are respectively formed. Thus, in the indexable insert 31 of the embodiment, the cutting edge 37 of the outer peripheral side 37
By reducing the land of the cutting edge 38 (almost zero in the embodiment) and enlarging the land of the cutting edge 38 at the bottom, chipping of the cutting edge 38 at the bottom having a large cutting resistance is prevented. Care is taken so that a good cutting surface can be obtained at the cutting edge 37 on the outer peripheral side.

One inner surface 44 of the breaker 40 is raked in a direction orthogonal to the outer peripheral cutting edge 37 and is a rake face that is raked in a forward direction with respect to the land portion 42. On the other hand, the other inner surface 45 is a wall surface that performs a braking action. In the case of the embodiment, the other inner surface 4
5, the depth from the nose 34 is set to 0.2 mm,
It is inclined by θ5 (θ5 = 12 ° in the embodiment) in the negative direction with respect to the one inner surface 44.

Reference numeral 46 denotes a through hole which is provided through the center of the chip body 32 and into which a screw for mounting the chip is inserted. As shown in FIGS. 1 and 4, the periphery of the through hole 46 is formed in a cylindrical shape as a whole and has a thickness greater than that of other portions so that the strength of the chip body 32 in this portion is ensured. Has become.

Further, a chamfered portion 47 is formed at a corner portion on the obtuse angle side of the chip body 32. The chamfered portion serves as an escape for avoiding interference with the surface to be machined when the indexable insert is used for an end mill to carry out a lifting process toward the base end in the axial direction.

FIGS. 10 to 12 show a state in which the indexable insert 31 having the above-described configuration is attached to the tip mounting seat 5 in the tip pocket 3 of the tool body 1 of the end mill.
In this end mill, a tip pocket 3 is formed at a tip portion 2 of a tool body 1 whose diameter gradually decreases toward the tip side in the tool axis C direction, and a tip side of the bottom surface 4 of the tip pocket 3 in the tool axis C direction and the tool rotation direction. The clamp screw 6 is attached to the tip mounting seat 5 formed at a position facing the corner on the side facing
Thus, the chip 31 is fixed.

When the chip 31 is mounted, the chip mounting seat 5 has a side surface 35 sandwiching one nose portion 34 of the chip body 32,
36 (specifically, lower side portions 35b, 36b) are brought into contact with the wall portions 21, 22 of the chip mounting seat 5, respectively, and the cutting blades 37, 38 connected to the other nose portion 34 are tooled, respectively. It is formed into a shape and dimensions protruding from the outer peripheral surface and the distal end surface of the distal end portion 2 of the main body 1. Also, at the corner of the chip mounting seat 5 where these walls 21 and 22 intersect,
When the tip 31 is mounted, the one nose portion 34 is
Oval recesses 2 in plan view so as not to contact
0 is formed.

The bottom surface 19 of the tip mounting seat 5 on which the other end surface 42 of the tip main body 32 is seated has a thickness H of the tip end portion 2 of the tool main body 1 from the tip end of the tool main body 1 toward the base end side. It has a gradually decreasing flat surface. Therefore, in the embodiment, a required rake angle can be obtained with a rake angle larger than the rake angle of the indexable insert 31 itself while minimizing the decrease in the rigidity of the tool body 1.

A screw hole (not shown) is provided at the center of the bottom surface 19, and the axis of the screw hole is set so that when the chip 31 is mounted on the chip mounting seat 5, the chip body 32
Are slightly offset from the axis of the mounting hole 46 toward the corner of the chip mounting seat 5.

In the throw-away type end mill having such a structure, the tip 31 is mounted on the chip mounting seat 5 and the other end surface 42 of the chip main body 32 is pressed against the bottom surface 19 of the chip mounting seat 5 by tightening the clamp screw 6. Then, the chip 31 is seated and the chip mounting seat 5 is seated.
The eccentricity between the axis of the screw hole and the axis of the mounting hole 41 of the chip body 32 pushes the chip body 32 against the corner of the chip mounting seat. Then, the side surfaces 35 and 36 sandwiching the one nose portion 34 of the chip body 32 are thereby formed.
Are brought into contact with the wall portions 21 and 22, and protrude from the outer peripheral surface and the distal end surface of the distal end portion 2 of the tool main body 1, and serve as the outer peripheral side cutting edge and the bottom cutting edge of the end mill.
Is positioned accurately. Further, the truncated square pyramid-shaped portion surrounded by the lower side surfaces 35b and 36b (second side surface) is not a normal (one end surface is tapered as in this embodiment), and the upper and lower end surfaces are parallel to each other. since the plate-like) has become a chip in the same shape, compatibility for mounting the chip body 32 to the tool body is ensured.

In this embodiment, the recess 20 formed in the corner of the chip mounting seat 5 prevents the vicinity of the nose portion 34 of the chip 31 from contacting the chip mounting seat 5 as in the conventional example. Therefore, the positioning accuracy of the cutting blades 37 and 38 can be maintained, and the tip mounting seat itself can be easily formed.

In the end mill, as described above, the one end face 33 is inclined with respect to the other end face 39 at an angle of α, so that the end mill 33 has an axial direction and a diameter smaller than the case where it is not inclined. A large rake angle in the direction can be secured. In addition, the rake angle can be set more positively by the inner surface 44 of the breaker 40.

Further, the breaker 40 and the outer peripheral cutting edge 3
7 and a land portion 4 between each of the bottom cutting edges 38.
Since the ridges 2 and 43 are provided, chipping of the cutting edge can be prevented while securing a rake angle in the forward direction. Further, in consideration of the fact that the cutting load of the bottom cutting edge 38 is higher than that of the cutting edge 37 on the outer peripheral side, the width of the land portion 43 of the bottom cutting edge 38 is set larger in the land portions 42 and 43. ing. Further, since the land portion 43 of the lower cutting edge 38 is relatively wide, it guides the chip straight as it is,
On the other hand, since the land portion 43 of the cutting edge 38 on the outer peripheral side is relatively narrow, the chips can be guided to the breaker 40 immediately.

Further, since the width of the breaker 40 gradually decreases from the distal end side to the proximal end side of the cutting edge 37 on the outer peripheral side,
The strength can be maintained in the proximal portion where the strength tends to be insufficient due to the small thickness of the chip body 32.

Further, the axial rake angle of the cutting edge 37 on the outer peripheral side in the axial direction becomes relatively smaller on the distal end side of the tool than on the proximal end side of the tool. Is likely to collide with the other inner surface 45 of the breaker 40 earlier than the tip side of the cutting blade 37 and is broken. On the other hand, on the tip side of the cutting blade 37, the chips can be guided to a place away from the cutting portion by the inner surfaces 44 and 45 of the breaker 40. In addition, the width and the depth of the breaker 40 are ensured to be sufficiently large at the tip portion where chips are generated from both the cutting blades 37 and 38, so that the chip discharge property at this portion is ensured.

In this embodiment, the present invention is applied to the cutting blades 37, 3
Although the description has been given of the case where the present invention is applied to a so-called positive type chip in which the clearance angle is formed in the nose portion 8 and the nose portion 34, the present invention can be applied to a so-called negative type chip.

By the way, the inclination angle α (not shown) of the one end face in the present invention, that is, the one end face 3 in the above embodiment is used.
3 and the other end surface 39, and the inclination angles β and δ between the cutting edges 37 and 38 and the other end surface 39 due to the inclination of the one end surface 33, the size and shape of the tip 31, or Needless to say, it should be set appropriately according to the cutting conditions and the like. However, for example, a chip having a parallelogram shape in a plan view as in the above embodiment, and the angle of the acute angle portion of the parallelogram is 85 ° to 70 °
In the case of a chip which is frequently used, the inclination angle α of the one end face 33 is preferably set to about 3 ° to 20 °, and the inclination angle formed by the cutting blades 37 and 38 which are inclined together with the inclination angle α. Angles β and δ are 3
It is preferable that the angle is about 15 to 15 degrees and about 3 to 20 degrees.
Incidentally, in the embodiment, the narrow angle of the parallelogram is approximately 85 °, and the inclination angle α of the one end face 33 is approximately 13 °.
As a result, the inclination angles β and δ of the crossing ridge lines 37 and 38 are set to approximately 5 ° and 12 °, respectively.

Here, when these inclination angles α, β, δ become smaller than the above-mentioned range, that is, when the one end face 33
Is too gentle, the axial rake angle and the radial rake angle are not arranged on the regular angle side when the insert is mounted on a throw-away tool such as an end mill, and the effect is not sufficiently exhibited. There is a risk. Conversely,
If the inclination angles α, β, and δ are larger than the above ranges, that is, if the inclination of the one end surface 33 is too steep, the thickness of the central portion of the chip main body 32 becomes too small, and the rigidity and strength of the chip itself are reduced. Risk of adverse effects.

As described above, this embodiment is an example in which the present invention is applied to a chip having a parallelogram shape in plan view. However, the present invention is not limited to this. The present invention can be applied to other quadrangular or triangular chips such as a square or a rhombus, or polygonal chips such as a pentagon or more. The appropriate ranges of the inclination angles α, β, and δ are examples in which the present invention is applied to a chip having a parallelogram shape in a plan view. May be different. further,
Needless to say, these ranges may change depending on differences in various cutting conditions during cutting.

The shape of the cross section of the breaker may of course be other shapes without departing from the spirit of the present invention. Further, in the above-described embodiment, the case where the present invention is applied to a milling tool such as a throw-away type end mill has been described. However, it is needless to say that the present invention can be applied to a cutting tool and a boring bar.

[0045]

As described above, according to the present invention, one end face of the chip, which is a rake face, has an inclined surface that faces the other end face side, which becomes a seating surface as the tip is separated from the nose portion. The intersection ridge line formed by the side surface of the tip body and the one end surface sandwiching the nose portion and having a cutting edge also inclines toward the other end surface side. Therefore, when such a tip is mounted on the tip mounting seat of the tool, the axial rake angle and the radial rake angle are shifted to the regular angle side while securing the thickness of the part holding the tool tip. This can be set to a large value, which makes it possible to improve the machinability while maintaining the rigidity of the tool portion that holds the chip body that receives the cutting resistance in contact with the work material.

[0046] In addition, the each side of the chip body, the exchange
A first side surface that is continuous with the difference ridge line, and the other end surface than the first side surface
And a second side located on the side. And a tool book
The second that is pressed against the mounting surface of the body and serves as a reference for positioning
The side surface can be any shape that matches the reference mounting surface on the tool body.
Independently of this, said first side relating to the shape of the cutting edge
The surface is inclined so as to reduce the clearance angle of the cutting blade.
You. Thus, mounting of the range not directly related to the cutting independent of the shape of the cutting edge, the tool body without giving a second side as a reference for positioning, the effect on the cutting geometry
Use any shape that matches the reference plane, and set the clearance angle on the first side
By setting an appropriate angle smaller than the second side surface, the blade angle is larger than the second side surface while maintaining the compatibility with the flat-shaped throw-away tip whose one end surface is not inclined.
It can be changed to any angle. With this the cutting edge
The shape can be set freely according to the cutting conditions, etc.
You. Then, reduce the clearance angle on the first side and increase the blade angle.
To increase the strength of the cutting edge,
Life can be extended.

Further, since the breaker is formed on the one end face along the cutting edge, the rake angle of the cutting edge is set to a more positive side, and the required rake angle can be easily secured. Therefore, the thickness of the seating surface of the tool main body can be secured and the rigidity thereof can be increased. Furthermore, the breaker can ensure good chip dischargeability.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view of the chip of FIG. 1 viewed from a direction along a ridgeline of a cutting blade 38.

FIG. 3 is an arrow view along the line III-III in FIG. 1;

FIG. 4 is an arrow view along one side surface 36 of FIG. 1;

FIG. 5 is an arrow view along the line VV in FIG. 1;

FIG. 6 is a view of the tip of FIG. 1 as viewed from a direction along a ridge line of the cutting blade 37;

FIG. 7 is a plan view showing a state where the chip of FIG. 1 is attached to a tool main body.

FIG. 8 is a side view showing a state in which the tip of FIG. 1 is attached to a tool main body.

FIG. 9 is a front view showing a state in which the tip of FIG. 1 is attached to a tool main body.

FIG. 10 is a plan view showing a case where a conventional tip 7 is mounted on a throw-away type end mill.

11 is a side view of the example in FIG. 10 as viewed in the direction A.

FIG. 12 is a front view of the example of FIG. 10 as viewed in the direction B.

[Description of Signs] 1 Tool main body 2 Tip 5 Chip mounting seat 31, Chip 8, 32 Chip main body 9, 33 One end face (rake face) 10, 39 Other end face (seating surface) 11, 34 Nose part 12, 13, 35,36 Side surface 35a, 36a Upper side surface 35b, 36b Lower side surface 16,17,37,38 Cutting edge C Tool axis α Incline angle of one end surface 33 β Incline angle of outer peripheral cutting edge 37 δ Bottom cutting edge 38 Tilt angle

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23C 5/20

Claims (2)

(57) [Claims] 1. A nose portion is formed at a corner of a chip body having a polygonal flat plate shape, and each of a pair of adjacent side surfaces of the chip body sandwiching the nose portion and the chip connected to the nose portion At least one of two intersecting ridges formed by one end surface of the main body, a throw-away chip in which a cutting edge is formed so as to be continuous with the nose portion, wherein the one end surface of the tip main body is separated from the nose portion. an inclined surface which gradually approaches the other end face, the inclined are allowed to face the second end face as the distance from both the nose portion also said two intersecting ridgeline by the inclined surface, wherein each side, the cross A first side surface continuing to the ridge line,
A second side located closer to the other end than the first side.
And the second side surface has a clearance angle adapted to a reference mounting surface on the tool body.
And the first side has a clearance angle of the second side.
Has a two-step clearance angle to form a smaller clearance angle
Indexable insert, characterized in that. Wherein said each inclined surface, the throw-away tip of claim 1, along the edge formed between each of the these inclined surfaces each side, characterized in that the breaker is formed.