JP2024109138A - Turning tools - Google Patents

Abstract

To provide a rolling tool which can suppress positional deviation of a cutting insert and can easily attach the cutting insert to a tool body.SOLUTION: A rolling tool comprises: a tool body rotated around a central axis; a cutting insert which is attached to an inserting attachment seat formed on a tip outer peripheral part of the tool body; and a clamp screw which detachably fixes the cutting insert to the insert attachment seat. The cutting insert comprises an insert body, a cutting blade provided on the insert body, and a planar seating face which is provided on the insert body and with which a tip of the clamp screw is brought into contact. The clamp screw is so provided as to be inclined with respect to a direction orthogonal to the seating face.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cutting tool.

Conventionally, the indexable milling cutter described in Patent Document 1 is known. The indexable milling cutter includes a tool body that can be rotated about an axis, and multiple cutting inserts. The tool body has an insert mounting seat on the outer periphery of the tip. The cutting insert is removably attached to the insert mounting seat by a clamp screw. The clamp screw is fastened to a screw hole formed in the insert mounting seat.

JP 2015-27707 A

In the above configuration, when the clamp screw is fastened, the tip of the clamp screw comes into surface contact with the insert clamping seat surface. Therefore, when the clamp screw is tightened into the screw hole to attach the cutting insert to the tool body, the frictional force generated between the tip of the clamp screw and the insert clamping seat surface may cause the turning insert to inadvertently shift in position in an unintended direction. If the cutting insert shifts in position, the position of the cutting insert must be adjusted to correct the shift. For this reason, attaching the cutting insert to the tool body is a laborious task.

In view of the above circumstances, one of the objects of the present invention is to provide a milling tool that can reduce the positional deviation of the cutting insert and facilitate the attachment of the cutting insert to the tool body.

One embodiment of the cutting tool of the present invention comprises a tool body that is rotated around a central axis, a cutting insert that is attached to an insert mounting seat formed on the outer periphery of the tip of the tool body, and a clamp screw that detachably fixes the cutting insert to the insert mounting seat, the cutting insert comprising an insert body, a cutting edge provided on the insert body, and a planar seat provided on the insert body with which the tip of the clamp screw comes into contact, and the clamp screw is inclined relative to a direction perpendicular to the seat.

According to one aspect of the milling tool of the present invention, the clamp screw that fixes the cutting insert to the insert mounting seat is inclined with respect to a direction perpendicular to the seat surface of the insert body. Therefore, when the clamp screw is tightened to fix the cutting insert to the insert mounting seat, a pressing force acts on the seat surface from the tip of the clamp screw in a direction inclined with respect to the direction perpendicular to the seat surface. The component force of this pressing force acts in a desired direction corresponding to the inclination direction of the clamp screw. This prevents the cutting insert from being pressed in the desired direction and being displaced in an inadvertent direction. Therefore, the need to correct the positional displacement of the cutting insert in an inadvertent direction is reduced. As a result, the positional displacement of the cutting insert is reduced, and the cutting insert can be easily attached to the tool body.

In the above-mentioned cutting tool, the clamp screw has an axis of the clamp screw having an inclination angle θ with respect to a direction perpendicular to the seat surface,
1°≦θ≦3°
The position may be set so that

In this case, when the clamp screw is tightened, an appropriate pressing force acts from the tip of the clamp screw against the seat surface in the desired direction, effectively preventing the cutting insert from shifting out of position.

In the above-mentioned cutting tool, when viewed from a direction perpendicular to the seating surface, in a circumferential direction around an orthogonal axis perpendicular to the seating surface, the clamp screw is arranged on the tightening side of the clamp screw in the circumferential direction with respect to a direction facing the tip side of the tool body in an axial direction along the central axis,
0°<δ<180°
The angle δ may be inclined in the direction such that

In this case, when the clamp screw is tightened, the force acting on the seat from the tip of the clamp screw presses the cutting insert along the central axis toward the rear end of the tool body. This prevents the cutting insert from protruding toward the tip of the tool body.

In the above turning tool, the clamp screw may be inclined relative to a direction perpendicular to the seat surface so that the cutting insert is pressed toward the rear end of the tool body by the frictional force generated between the clamp screw and the seat surface when the clamp screw is tightened.

In this case, the cutting insert is pressed toward the rear end of the tool body by the frictional force generated between the clamp screw and the seat when the clamp screw is tightened. This prevents the cutting insert from protruding toward the tip of the tool body.

In the above-mentioned milling tool, only a portion of the tip of the clamp screw in the circumferential direction around the axis of the clamp screw may be in contact with the seat surface.

In this case, only a portion of the tip of the clamp screw in the circumferential direction around the axis of the clamp screw contacts the seating surface, so that when the clamp screw is tightened, a pressing force acts on the cutting insert from the portion where the tip of the clamp screw contacts the seating surface, along the seating surface, in the direction in which the clamp screw is tightened. This allows the cutting insert to be efficiently pressed in the desired direction.

In the above-mentioned turning tool, the insert body may be restricted from moving beyond a specified distance in a direction along the central axis toward the rear end side of the tool body opposite the tip end side.

In this case, if the cutting insert is pressed toward the rear end of the tool body due to the frictional force generated between the clamp screw and the seating surface when the clamp screw is tightened, the insert body can be prevented from moving excessively toward the rear end of the tool body.

According to one embodiment of the cutting tool of the present invention, it is possible to prevent the cutting insert from shifting out of position and to easily attach the cutting insert to the tool body.

FIG. 2 is a side view showing a milling tool according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line AA in FIG. 1 , showing the milling tool of the embodiment of the present invention; 2 is a cross-sectional view taken along the line BB in FIG. 1 , showing the milling tool of the embodiment of the present invention; FIG. 1 is a perspective view showing a cutting insert according to an embodiment of the present invention. 5 is a cross-sectional view taken along the line CC in FIG. 4, showing the cutting insert of the embodiment of the present invention. 1 is a cross-sectional view showing an inclination angle θ of a clamp screw with respect to a direction perpendicular to a bottom surface in a cutting insert according to an embodiment of the present invention. FIG. 1 is a diagram showing the inclination direction of the axis of a clamp screw as viewed from a direction perpendicular to the bottom surface in a cutting insert according to an embodiment of the present invention. FIG.

Below, an indexable milling cutter 1, which is an example of a milling tool according to an embodiment of the present invention, and a cutting insert (hereinafter, simply referred to as an insert) 30 provided in this indexable milling cutter 1 will be described with reference to the drawings.

[Outline of the configuration of indexable milling cutter and insert]
The indexable milling cutter 1 of this embodiment is a milling tool (cutting tool) that performs milling on a workpiece such as a metal material. The indexable milling cutter 1 mainly performs milling (cutting) such as face milling on the workpiece. Face milling is a milling method that forms a machined surface perpendicular to the central axis O of the tool body 2 on the workpiece.

As shown in Figures 1 to 3, the indexable milling cutter 1 includes a tool body 2, multiple inserts 30, and multiple adjustment units 50 (see Figures 1 and 2).

The tool body 2 has a substantially cylindrical shape centered on a central axis O. The tool body 2 is attached to a spindle of a machine tool (not shown) and rotated about the central axis O by the spindle.
A plurality of inserts 30 are arranged at intervals from one another in the circumferential direction on the outer periphery of the tip of the tool body 2. In Figs. 1 and 2, only one of the plurality of inserts 30 arranged on the tool body 2 is shown. Each insert 30 is called a cutting insert or cutting tip. The insert 30 is removably attached to the outer periphery of the tip of the tool body 2. A plurality of insert mounting seats 4 are provided at intervals from one another in the circumferential direction on the outer periphery of the tip of the tool body 2. Each insert 30 is removably attached to each insert mounting seat 4.

1 and 4 , the insert 30 has a cutting edge 7. The insert 30 attached to the insert mounting seat 4 is disposed so that the cutting edge 7 protrudes further toward the tip side and radially outward than the tool body 2.
2 and 3, in the indexable milling cutter 1 of this embodiment, the insert mounting seats 4 are provided at multiple locations (e.g., four locations) spaced apart in the circumferential direction on the tool body 2, and multiple inserts 30 (e.g., four pieces) are provided, the same number as the number of the insert mounting seats 4. This indexable milling cutter 1 is a so-called multi-blade type milling cutter. Note that, in this embodiment, a multi-blade type milling tool is exemplified, but it is not necessarily limited to the multi-blade type.

The upper part of the tool body 2 of the indexable milling cutter 1 is attached to the spindle of the machine tool. The tool body 2 of the indexable milling cutter 1 is rotated by the spindle in the tool rotation direction T about the central axis O, while being moved in a direction intersecting the central axis O (e.g., a direction perpendicular to the central axis O). The cutting edges 7 of the multiple inserts 30 attached to the tool body 2 mill the workpiece.

[Definition of Orientation (Direction) Used in the Present Embodiment]
In this embodiment, the direction along the central axis O of the tool body 2 (the direction in which the central axis O extends) is referred to as the axial direction. As described below, the tool body 2 is cylindrical and extends in the axial direction. An insert 30 protrudes from one of two faces facing both sides of the tool body 2 in the axial direction. In the following description, the direction in which the face facing the axial direction of the tool body 2 from which the insert 30 protrudes is referred to as the tip side, and the opposite side is referred to as the rear end side.
A direction perpendicular to the central axis O is called a radial direction. Of the radial directions, a direction approaching the central axis O is called a radially inner direction, and a direction moving away from the central axis O is called a radially outer direction.
The direction rotating around the central axis O is called the circumferential direction. Among the circumferential directions, the direction in which the tool body 2 is rotated by the spindle of the machine tool during cutting is called the tool rotation direction T, and the opposite rotation direction is called the opposite direction to the tool rotation direction T (or counter tool rotation direction).

[Description of tool body 1]
The tool body 2 has a cylindrical shape extending in the axial direction. The tool body 2 is made of, for example, a steel material. As shown in Figures 1 and 2, the tool body 2 has a chip pocket 6, an insert mounting seat 4, a support portion 24, and a recessed portion 25.

As shown in Figures 2 and 3, the tool body 2 is formed with an attachment portion 5. The attachment portion 5 is a hole that opens on the rear end surface of the tool body 2 and recesses from this rear end surface toward the tip side. The spindle of the machine tool is inserted into the attachment portion 5.

1 and 2 , a plurality of chip pockets 6 are provided at intervals from one another in the circumferential direction on the outer periphery of the tip end of the tool body 2. The chip pockets 6 are formed in the outer periphery of the tip end of the tool body 2 so as to be recessed in a concave shape.
The insert mounting seat 4 is disposed adjacent to the chip pocket 6 in the opposite direction to the tool rotation direction T on the outer periphery of the tip of the tool body 2. In other words, the chip pocket 6 is disposed adjacent to the insert mounting seat 4 in the tool rotation direction T. The insert mounting seat 4 has a rectangular hole or groove shape corresponding to the shape of the insert 30.
A detailed description of the insert mounting seat 4 and the other parts of the tool body 2 than those described above will be given later.

〔insert〕
4, the insert 30 is a face milling insert used, for example, in face milling (face cutting). The insert 30 is attached to the tool body 2 with the tip 31t facing the axial tip side. As the multiple inserts 30 attached to the tool body 2, only one type of inserts having the same shape of cutting edge 7 may be used, or multiple types of inserts having different shapes of cutting edge 7 may be used.
The insert 30 has an insert body 31 that is attached to the insert mounting seat 4 of the tool body 2, a cutting edge 7 that extends along the intersecting ridge between the cutting face 32 and the relief face 33 of the insert body 31 and is positioned on the outer periphery of the tip of the insert body 31, and a clamp recess 37.

The insert body 31 is a polygonal plate. In this embodiment, the insert body 31 is a rectangular plate. When the insert 30 is attached to the insert mounting seat 4, the longitudinal direction of the rectangular surface (polygonal surface, main surface 31f and back surface 31g) of the insert body 31 is aligned along the axial direction of the tool body 2 (see FIG. 1). In addition, the lateral direction of the rectangular surface of the insert body 31 is aligned along the radial direction of the tool body 2 (see FIG. 3).

The insert body 31 has a rectangular plate-shaped base metal portion 34 and a triangular plate-shaped blade portion 35 joined to one corner of the base metal portion 34 and on which the cutting edge 7 is formed.
The base metal portion 34 is made of, for example, a cemented carbide. The cutting edge portion 35 is made of an ultra-high pressure sintered body such as a diamond sintered body or a cBN sintered body, which has a higher hardness than the base metal portion 34. However, the present invention is not limited to this, and the entire insert body 31 including the base metal portion 34 and the cutting edge portion 35 may be made of, for example, a cemented carbide, and may be integrally formed from a single member.

In this embodiment, the cutting edge 35 is disposed at one corner of one of a pair of polygonal surfaces (rectangular surfaces) constituting the main surface 31f and the back surface 31g of the insert body 31, the main surface 31f, and is joined to the base metal portion 34 by brazing, integral sintering, or the like. The above corner is a corner located at the outer periphery of the tip of the indexable milling cutter 1 when the insert 30 is attached to the insert mounting seat 4. Therefore, the above corner is a corner of the tip portion 31t.

4 and 5, the clamp recess 37 is formed on the main surface 31f, which is one of the polygonal surfaces of the base metal portion 34, and is recessed from the main surface 31f in the thickness direction. In the example of this embodiment, the clamp recess 37 is D-shaped in a plan view of the insert 30 seen from the thickness direction. However, the clamp recess 37 is not limited to being D-shaped in a plan view. The depth of the clamp recess 37 becomes deeper from the end opposite the blade portion 35 toward the blade portion 35 along the short direction of the insert body 31. In other words, the bottom surface 37b of the clamp recess 37 is inclined with respect to the main surface 31f. When the insert 30 is attached to the insert mounting seat 4, the bottom surface 37b of the clamp recess 37 extends in the opposite direction to the tool rotation direction T as it moves radially outward. When the insert 30 is attached to the tool body 2, the bottom surface 37b of the clamp recess 37 forms a planar shape that extends parallel to an imaginary plane (not shown) that includes the central axis O of the tool body 2.

As shown in FIG. 4, a rib 38 is formed on one of the polygonal faces of the base metal portion 34, in a portion located between the clamp recess 37 and the blade portion 35, protruding from the polygonal face in the thickness direction. In a plan view of the insert 30, the rib 38 extends linearly and approximately parallel to the hypotenuse of the blade portion 35, which is approximately a right-angled triangle. The rib 38 is arranged to face the blade portion 35 in the longitudinal and lateral directions of the insert body 31. Therefore, when the insert 30 is attached to the insert mounting seat 4, the rib 38 is arranged to face the cutting edge 7 from the rear end side in the axial direction and from the inside in the radial direction. The rib 38 comes into contact with chips generated when the cutting edge 7 cuts the workpiece.

The thickness of the insert 30 increases along the short side of the insert body 31 from the blade portion 35 to the end opposite the blade portion 35. That is, as shown in FIG. 3, when the insert 30 is attached to the insert mounting seat 4, the thickness of the insert 30 increases radially inward.

When the insert 30 is attached to the insert mounting seat 4, the axial rake angle of the cutting edge 7 is a positive angle.
In Fig. 4, the portion of the cutting edge 7 that extends in the short direction of the insert body 31 is the front edge 7a. The front edge 7a is linear. Note that the front edge 7a is not limited to being linear, and may be, for example, a convex curved shape having a large radius of curvature. When the insert 30 is attached to the insert mounting seat 4, the front edge 7a protrudes from the insert mounting seat 4 toward the tip side of the tool body 2.
The cutting edge 7 includes a peripheral edge 7b that extends in the longitudinal direction of the insert body 31. The peripheral edge 7b is linear. When the insert 30 is attached to the insert mounting seat 4, the peripheral edge 7b protrudes from the insert mounting seat 4 toward the radially outer side of the tool body 2.
The cutting edge 7 is located between the front edge 7a and the peripheral edge 7b and is a corner edge 7c. The corner edge 7c is a convex curve or a straight line. When the insert 30 is attached to the insert mounting seat 4, the corner edge 7c protrudes from the insert mounting seat 4 toward the outer periphery of the tip of the tool body 2.

As shown in FIG. 4, the rear end surface 30a of the insert 30 functions as a pressed surface that receives a pressing force from the adjustment unit 50, which will be described later, toward the axial tip side. This allows the pressing force from the adjustment unit 50 to be received over a wide range of the rear end surface 30a of the insert 30. The rear end surface 30a is flat and extends in a direction perpendicular to the center line C. Therefore, the balance of the pressing force from the nut member 52 to the insert 30 is stabilized.

[Description of tool body 2]
The insert mounting seat 4 of the tool body 2 will now be described in detail.
2 and 3 , the insert mounting seat 4 extends in the axial direction and opens to the tip surface and outer circumferential surface of the tool body 2. The insert mounting seat 4 has a first wall surface 8 facing the direction opposite to the tool rotation direction T, a second wall surface 9 facing the tool rotation direction T, and a third wall surface 10 located at a radially inner end of the insert mounting seat 4 and facing radially outward.

2 and 3, in this embodiment, the first wall surface 8 is a planar surface extending parallel to a virtual plane (not shown) including the central axis O of the tool body 2, and the third wall surface 10 is a planar surface substantially perpendicular to the first wall surface 8. The second wall surface 9 extends in the tool rotation direction T as it moves radially outward. Therefore, the distance between the second wall surface 9 and the first wall surface 8 (the circumferential width of the insert mounting seat 4) becomes smaller as it moves radially outward.

The insert 30 is inserted toward the rear end side in the axial direction into the insert mounting seat 4. When the insert 30 is inserted into the insert mounting seat 4, the main surface 31f facing the thickness direction of the insert 30 contacts the first wall surface 8. When the insert 30 is fixed with a clamp screw 19 as described below, a small gap is provided between the main surface 31f facing the thickness direction of the insert 30 and the first wall surface 8. The back surface 31g facing the thickness direction of the insert 30 contacts the second wall surface 9. The side surface 31h facing the short direction of the insert 30 contacts the third wall surface 10. The insert 30 is sandwiched between the first wall surface 8 and the second wall surface 9 in the circumferential direction.

In the example of this embodiment, as described above, the circumferential width of the insert mounting seat 4 becomes smaller toward the radially outward direction, so that the insert 30 inserted into the insert mounting seat 4 is suppressed from moving radially outward relative to the insert mounting seat 4. In other words, the insert 30 is prevented from slipping out radially outward from the insert mounting seat 4.
The insert 30 slides in the axial direction relative to the insert mounting seat 4. That is, the insert 30 slides in the axial direction relative to the tool body 2.

The insert 30 is fixed to the tool body 2 by a clamp screw 19. The clamp screw 19 is screwed into a clamp screw hole 11 formed in the tool body 2. The clamp screw 19 is a so-called set screw, which is cylindrical and extends along the axis N, and has a male thread portion formed on its outer circumferential surface.
The clamp screw hole 11 opens to the outer circumferential surface of the tool body 2 and the first wall surface 8. A female thread is formed on the inner circumferential surface of the clamp screw hole 11. The clamp screw hole 11 extends radially outward in the tool rotation direction T.

The tip of the clamp screw 19 screwed into the clamp screw hole 11 comes into contact with the bottom surface (seat surface) 37b of the clamp recess 37 of the insert 30. When the clamp screw 19 is screwed into the clamp screw hole 11, the insert 30 is pressed against the second wall surface 9. As a result, the insert 30 is sandwiched between the tip of the clamp screw 19 and the second wall surface 9, and is fixed to the insert mounting seat 4 and is fixed so as not to move axially relative to the tool body 2.

6, the clamp screw 19 is inclined with respect to a direction perpendicular to the bottom surface 37b so that the insert 30 is pressed toward the rear end side of the tool body 2 by the frictional force generated between the clamp screw 19 and the bottom surface 37b when the clamp screw 19 is tightened. Therefore, the clamp screw hole 11 and the clamp screw 19 screwed into the clamp screw hole 11 are inclined with respect to a direction D1 perpendicular to the bottom surface 37b of the clamp recess 37 of the insert 30 attached to the insert mounting seat 4 (i.e., the normal direction of the bottom surface 37b). When screwed into the clamp screw hole 11, the clamp screw 19 is inclined so that the axis N of the clamp screw 19 moves away from the bottom surface 37b and moves away from the direction D1. In this embodiment, the direction D1 is perpendicular to the central axis O.

7, when viewed from a direction D1 perpendicular to the bottom surface 37b, in the circumferential direction about an axis extending in the direction D1 perpendicular to the bottom surface 37b (clockwise in FIG. 7), the tip side of the tool body 2 in the axial direction along the central axis O is set to 0°, and the rear end side of the tool body 2 in the axial direction is set to 180°.
0°<δ<180°
It is preferable that the light emitting diode is provided so as to be inclined in the direction of the angle δ.
In other words, the angle δ between the axial direction (0° direction) of the tool body 2 toward the tip side and the inclination direction of the clamp screw 19 is inclined toward the tightening side of the clamp screw 19 in the circumferential direction Dc.
0°<δ<180°
It is preferable that the angle δ is
0°<δ<90°
It is more preferable that the angle δ is:
It is particularly preferable that 30°<δ<90°.
In this embodiment, the clamp screw 19 is inclined with respect to a direction D1 perpendicular to the bottom surface 37b so that the angle δ is 35°.

In this way, since the clamp screw 19 is inclined with respect to the direction D1 perpendicular to the bottom surface 37b of the insert body 31, when the clamp screw 19 is tightened to fix the insert 30 to the insert mounting seat 4, a pressing force F acts from the tip of the clamp screw 19 on the bottom surface 37b from a direction inclined with respect to the direction D1 perpendicular to the bottom surface 37b.
6, by inclining the clamp screw 19, only a portion 19p of the tip of the clamp screw 19 in the circumferential direction around the axis N of the clamp screw 19 contacts the bottom surface 37b. When the clamp screw 19 is tightened, a pressing force F acts on the insert 30 from the portion 19p where the tip of the clamp screw 19 contacts the bottom surface 37b in a direction in which the clamp screw 19 is tightened along the bottom surface 37b. By inclining the clamp screw 19 in the direction of the angle δ, the pressing force F acting from the tip of the clamp screw 19 against the bottom surface 37b presses the insert 30 toward the rear end side of the tool body 2 along the central axis O.

As shown in FIG. 6, the clamp screw 19 has an axis N of the clamp screw 19 at an inclination angle θ with respect to a direction D1 perpendicular to the bottom surface 37b.
1°≦θ≦3°
It is set so that:
When the inclination angle θ of the axis N of the clamp screw 19 with respect to the direction D1 perpendicular to the bottom surface 37b falls below 1°, the pressing force F by inclining the clamp screw 19 decreases, and the effect of pressing the insert 30 toward the rear end of the tool body 2 becomes less pronounced. For this reason, it is preferable that the inclination angle θ is 1° or more. In addition, the larger the inclination angle θ of the axis N of the clamp screw 19 with respect to the direction D1 perpendicular to the bottom surface 37b, the smaller the force that sandwiches the insert 30 between the tip of the clamp screw 19 and the second wall surface 9 becomes, so it is preferable that the inclination angle θ is 3° or less.

The insert body 31 is displaceable in the axial direction by the amount of backlash between the first screw shaft 53 and the screw hole 24a of the tool body 2 (see FIG. 2), which will be described later, and the backlash between the second screw shaft 54 and the nut member 52. Therefore, the insert body 31 is restricted from moving in the axial direction toward the rear end side opposite the tool body 2 by more than a specified amount. Therefore, even if the inclination angle θ of the axis N of the clamp screw 19 with respect to the direction D1 perpendicular to the bottom surface 37b exceeds 3°, if the backlash between the first screw shaft 53 and the screw hole 24a of the tool body 2, and the backlash between the second screw shaft 54 and the nut member 52 are absorbed, further axial movement of the insert body 31 toward the rear end side is restricted.

[Adjustment section]
4, a plurality of adjustment units 50 are arranged at intervals from one another in the circumferential direction on the outer periphery of the tool body 2. The adjustment units 50 press the insert 30 toward the axial tip side to adjust the axial position of the insert 30. The adjustment units 50 adjust the axial position of the cutting edge 7 by adjusting the axial position of the insert 30 relative to the tool body 2. The number of adjustment units 50 is the same as the number of inserts 30, and in the example of this embodiment, a plurality of adjustment units 50 (e.g., four) are provided on the outer periphery of the tool body 2.

The adjustment portion 50 has a shaft member 51 and a nut member 52 .
The shaft member 51 is supported by the tool body 2. The shaft member 51 is screwed into the tool body 2. The nut member 52 is screwed onto the shaft member 51 and comes into contact with the insert 30.

As shown in FIG. 4, the center line C of the shaft member 51 extends along the axial direction of the tool body 2. That is, the center line C of the adjustment unit 50 extends along the axial direction. The direction in which the center line C of the shaft member 51 extends corresponds to the axial direction of the tool body 2. The shaft member 51 is rotated around the center line C relative to the tool body 2 (support unit 24), and moves axially relative to the tool body 2 due to the action of the screw. The nut member 52 is rotated around the center line C relative to the shaft member 51 and the tool body 2, and moves axially relative to the shaft member 51 and the tool body 2 due to the action of the screw.

The shaft member 51 has a first screw shaft 53 located at the rear end of the shaft member 51, a second screw shaft 54 located at the tip end, and an operating portion 55 located between the first screw shaft 53 and the second screw shaft 54 along the axial direction.
The outer diameter of the first screw shaft 53 is larger than the outer diameter of the second screw shaft 54. Male threads are formed on the outer peripheral surfaces of the first screw shaft 53 and the second screw shaft 54. The male threads of the first screw shaft 53 and the male threads of the second screw shaft 54 have different thread pitches. Specifically, the male threads of the first screw shaft 53 have a larger thread pitch than the male threads of the second screw shaft 54.

The operating part 55 is cylindrical or disk-shaped. The outer diameter of the operating part 55 is larger than the outer diameter of the first screw shaft 53 and the outer diameter of the second screw shaft 54. An axis operating hole 55a opens on the outer circumferential surface of the operating part 55. The axis operating holes 55a are provided on the outer circumferential surface of the operating part 55 at intervals from each other (for example, four equally spaced holes). The axis operating holes 55a extend in a direction perpendicular to the center line C. A working tool such as a wrench (not shown) is inserted into the axis operating hole 55a.

The nut member 52 is cylindrical or circular ring plate shaped with the center line C as the center. The outer diameter of the nut member 52 is larger than the outer diameter of the shaft member 51. A female thread is formed on the inner peripheral surface of the nut member 52. The nut member 52 is screwed onto the second screw shaft 54. A nut operation hole 52a opens on the outer peripheral surface of the nut member 52. A plurality of nut operation holes 52a (e.g., five equally spaced holes) are provided on the outer peripheral surface of the nut member 52 at intervals around the center line C. The nut operation holes 52a extend in a direction perpendicular to the center line C. A working tool such as a wrench (not shown) is inserted into the nut operation hole 52a.

The tip surface of the nut member 52 contacts the rear end surface of the insert 30 from the rear end side. Therefore, when the clamp screw 19 is loosened or temporarily fastened, the axial position of the insert 30 is adjusted by adjusting either the amount of threading of the shaft member 51 into the tool body 2 or the amount of threading of the nut member 52 into the shaft member 51. That is, the axial positions of the insert 30 and the cutting edge 7 with respect to the insert mounting seat 4 can be adjusted by operating the work tool to rotate either the shaft member 51 or the nut member 52 around the center line C. After the position adjustment of the insert 30, the clamp screw 19 is screwed in and fully fastened, thereby fixing the insert 30 to the insert mounting seat 4.
In addition, when the clamp screw 19 is fully tightened, the axial position of the insert 30 may be fine-tuned by adjusting either the amount of threading of the shaft member 51 into the tool body 2 or the amount of threading of the nut member 52 into the shaft member 51.

[Description of tool body 3]
The remaining parts of the tool body 2 will now be described.
1 and 2 , the support portion 24 is disposed on the rear end side of the adjustment portion 50 in the axial direction, and supports the adjustment portion 50. A plurality of support portions 24 are disposed on the outer circumferential surface of the tool body 2 at intervals from one another in the circumferential direction. The number of support portions 24 is the same as the number of adjustment portions 50, and in this embodiment, a plurality of support portions 24 (e.g., four support portions 24) are provided on the outer periphery of the tool body 2. The support portion 24 is disposed on the rear end of the outer circumferential surface of the tool body 2.

2, the support portion 24 has a screw hole 24a extending in the axial direction. The screw hole 24a penetrates the support portion 24 in the axial direction and opens to the front end surface and the rear end surface of the support portion 24. A female thread is provided on the inner peripheral surface of the screw hole 24a. A first screw shaft 53 is screwed into the screw hole 24a.
When viewed from the axial direction, the support portion 24, the adjustment portion 50, the insert mounting seat 4, and the insert 30 are arranged to overlap one another.

1 and 2 , when viewed from the radial direction, the recessed portions 25 are disposed at positions on the outer circumferential surface of the tool body 2 that overlap with the adjustment portions 50, and are recessed radially inward. The number of recessed portions 25 is the same as the number of adjustment portions 50, and in this embodiment, a plurality of recessed portions 25 (e.g., four recessed portions 25) are provided on the outer periphery of the tool body 2. In this embodiment, the recessed portions 25 are rectangular hole-shaped. The recessed portions 25 extend in the axial direction.
In this embodiment, the portions 2b between the circumferentially adjacent recesses 25 are convex radially outward relative to the recesses 25. However, the recesses 25 may be a continuous cylindrical surface along the circumferential direction. In this case, the recesses 25 can be machined by a lathe.

A portion of the adjustment unit 50 is disposed within the recessed portion 25. In the illustrated example, a portion (radially inner end) of the operation unit 55 and a portion (radially inner end) of the nut member 52 of the adjustment unit 50 are located within the recessed portion 25. When viewed from the axial direction, the portion (radially inner end) of the operation unit 55, the portion (radially inner end) of the nut member 52, and the recessed portion 25 are disposed to overlap one another.

[Effects of this embodiment]
According to the replaceable cutting edge milling cutter 1 of the present embodiment described above, the clamp screw 19 for fixing the insert 30 to the insert mounting seat 4 is inclined with respect to the direction D1 perpendicular to the bottom surface 37b of the insert body 31. Therefore, when the clamp screw 19 is tightened to fix the insert 30 to the insert mounting seat 4, a pressing force F acts from the tip of the clamp screw 19 to the bottom surface 37b in a direction inclined with respect to the direction D1 perpendicular to the bottom surface 37b. The component force of this pressing force F acts in a direction along the bottom surface 37b. This prevents the insert 30 from being pressed in a direction along the bottom surface 37b and being displaced in an inadvertent direction. Therefore, the need to correct the positional displacement of the insert 30 in an inadvertent direction is reduced. As a result, the positional displacement of the insert 30 is reduced, and the insert 30 can be easily attached to the tool body 2.

In this embodiment, the inclination angle θ of the axis N of the clamp screw 19 is set to be 1°≦θ≦3°. As a result, when the clamp screw 19 is tightened, an appropriate pressing force F acts from the tip of the clamp screw 19 against the bottom surface 37b, effectively preventing the insert 30 from shifting out of position.

In addition, in this embodiment, the clamp screw 19 is inclined in the direction of angle δ, where 0°<δ<180°, toward the tightening side of the clamp screw 19 in the circumferential direction, relative to the direction facing the tip side of the tool body 2 in the axial direction along the central axis O. As a result, when the clamp screw 19 is tightened, the force acting from the tip of the clamp screw 19 against the bottom surface 37b presses the insert 30 toward the rear end side of the tool body 2 along the central axis O. This prevents the insert 30 from protruding toward the tip side of the tool body 2.

In addition, in this embodiment, when the clamp screw 19 is tightened, the frictional force generated between the clamp screw 19 and the bottom surface 37b presses the insert 30 toward the rear end side of the tool body 2. This prevents the insert 30 from protruding toward the tip side of the tool body 2.

In addition, in this embodiment, only a portion of the tip of the clamp screw 19 in the circumferential direction around the axis N of the clamp screw 19 contacts the bottom surface 37b, so that when the clamp screw 19 is tightened, a pressing force F acts on the insert 30 from the portion where the tip of the clamp screw 19 contacts the bottom surface 37b in the direction of tightening the clamp screw 19 along the bottom surface 37b. This allows the insert 30 to be efficiently pressed in the desired direction.

In addition, in this embodiment, the insert body 31 is restricted from moving more than a specified distance toward the rear end side of the tool body 2, which is opposite the tip side, in the direction along the central axis O. Therefore, if the insert 30 is pressed toward the rear end side of the tool body 2 by the frictional force generated between the clamp screw 19 and the bottom surface 37b when the clamp screw 19 is tightened, the insert body 31 can be restricted from moving excessively toward the rear end side of the tool body 2.

[Other configurations included in the present invention]
The present invention is not limited to the above-described embodiment, and the configuration may be modified within the scope of the present invention, for example as described below.

In the above embodiment, an example was given in which the insert 30 is equipped with the adjustment portion 50, but this is not limited to the above. The insert 30 may be configured such that the axial position of the insert 30 relative to the tool body 2 cannot be adjusted by the adjustment portion 50.

In the above embodiment, the configuration of the insert body 31 of the insert 30 has been described, but the configuration can be appropriately changed.
In addition, in the above-described embodiment, the insert 30 is provided in the indexable milling cutter 1, but the cutting tool to which the present invention is applied is not limited to the indexable milling cutter 1 and may be another cutting tool.

In addition, the configurations (elements) described in the above-mentioned embodiments, modifications, and notes may be combined without departing from the spirit of the present invention, and additions, omissions, substitutions, and other modifications of the configurations are possible. Furthermore, the present invention is not limited to the above-mentioned embodiments, but is limited only by the claims.

1...Replaceable cutting edge milling cutter (milling tool)
2...Tool body 4...Insert mounting seat 7...Cutting edge 19...Clamp screw 30...Insert (cutting insert)
31: Insert body 37b: Bottom surface (seat surface)
N...Axis line O...Central axis δ...Angle θ...Inclination angle

Claims (6)

A tool body that can be rotated around a central axis;
a cutting insert attached to an insert mounting seat formed on an outer periphery of a tip of the tool body;
a clamp screw for removably fixing the cutting insert to the insert mounting seat,
The cutting insert comprises:
An insert body;
A cutting edge provided on the insert body;
A flat seat provided on the insert body and contacting the tip of the clamp screw;
The clamp screw is provided at an angle with respect to a direction perpendicular to the seat surface.
Turning tools. The clamp screw has an axis having an inclination angle θ of the clamp screw with respect to a direction perpendicular to the seat surface,
1°≦θ≦3°
It is set so that
A cutting tool according to claim 1. When viewed from a direction perpendicular to the seating surface, in a circumferential direction about an orthogonal axis perpendicular to the seating surface, the clamp screw is arranged such that, with respect to a direction facing the tip side of the tool body in an axial direction along the central axis, the clamp screw is arranged on the tightening side of the clamp screw in the circumferential direction,
0°<δ<180°
The angle δ is inclined in the direction such that
A cutting tool according to claim 1 or 2. The clamp screw is inclined with respect to a direction perpendicular to the seat surface so that the cutting insert is pressed toward the rear end side of the tool body by a frictional force generated between the clamp screw and the seat surface when the clamp screw is tightened.
A cutting tool according to claim 1 or 2. Only a portion of the tip of the clamp screw in a circumferential direction around the axis of the clamp screw contacts the seat surface.
A cutting tool according to claim 1 or 2. The insert body is restricted from moving beyond a predetermined dimension toward a rear end side of the tool body opposite to a front end side in a direction along the central axis.
A cutting tool according to claim 1 or 2.

Images