JP2000343316A - Throwaway type spherical surface cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform accurate work of spherical spot facing by positioning the cutting edge of a spherical cutter accurately on a spherical surface having its center on the axis of the tool body while adopting the throwaway system on the spherical cutter. SOLUTION: A throwaway tip 17 having a cutting edge 19 in the form of circular arc is mounted on a tip mounting seat 16 formed on the end face 14 facing in the axial O direction of the tool body 11 rotated round the axis O removable in such an arrangement that the cutting edge 19 is positioned on the spherical surface R having its center P on the axis O. The tool body 11 is equipped with an adjusting mechanism 20 to make fine adjustment of the position of the cutting edge 19 of a throwaway tip 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away type spherical cutter used for forming a spherical spot facing portion on a workpiece.

[0002]

2. Description of the Related Art Conventionally, as a spherical cutter for forming such a spherical counterbore portion on the inner periphery of a hollow portion of a workpiece, those shown in FIGS. 9 and 10 have been conventionally used. That is, in the spherical cutter shown in these figures, both end surfaces 2, 2 of a substantially cylindrical tool body 1 having a central portion depressed by one step are formed in a convex spherical shape, and these end surfaces 2, 2 are respectively formed on the end surfaces 2, 2. Three chip pockets 3 are formed at intervals in the circumferential direction. Further, on the surface of these chip pockets 3 facing the tool rotation direction T, the cutting edge chips 4 respectively move the cutting edges 5 from the end surfaces 2. It is brazed to protrude. Here, the cutting edges 5 are brazed on the cutting edges 4 and then polished together for each end face 2 so that the center faces P on the center axis O of the tool body 1 for each end face 2. And is formed so as to be located on one spherical surface R slightly larger in radius than the end face 2. The tool body 1 has a mounting hole 6 along the axis O.
Are formed so as to open to both end surfaces 2 and 2. The inner side of the mounting hole 6 in the direction of the axis O has a cross section of the axis O.
Are formed in a square with the center as the center.

[0003] Such a spherical cutter, when housed in the above-mentioned cavity of a workpiece, has a pair of insertion holes formed coaxially with the above-mentioned workpiece so as to communicate with the above-mentioned cavity, from the outside of the machine tool. By inserting a pair of arbors and attaching the tips of the arbors to the mounting holes 6 from both sides in the axis O direction, the arbors can be rotated in the tool rotation direction T about the axis O via the arbors. By rotating the tool main body 1 and reciprocating the arbor together with the tool main body 1 on both sides in the direction of the axis O while feeding the tool main body 1 as described above, feed is performed around the insertion hole on the inner periphery of the hollow portion of the workpiece. A concave spherical counterbore portion having a center on the axis O is formed by the cutting blades 5 on the end faces 2 and 2 of the tool body 1 facing the insertion holes. Therefore, by adjusting the feed amount by the arbor and making the centers of the concave spheres formed by the counterbores formed on both sides of the cavity coincide with each other, the counterbore that is concavely curved along one sphere is formed in the cavity. It can be formed on both sides.

[0004]

By the way, in the spherical cutter having the above-mentioned structure, the cutting edge tip 4 is brazed and joined to the tool body 1, but when the cutting edge 5 is worn, a normal cutting edge is used. Even if the cutting blade 5 is polished again like a brazing tool, if the cutting blade 5 is polished again in an arc shape centered on the center P of the end face 2 as described above, the radius of the cutting blade 5 becomes larger than the initial radius. Therefore, it becomes impossible to form a spherical countersunk portion having a predetermined diameter in the cavity of the workpiece. Therefore, in the case of such a conventional spherical cutter, if the cutting blade 5 is worn to some extent, the tool body 1 must be discarded, which is extremely uneconomical. On the other hand, for example, an attempt has been made to make the cutting edge tip 4 detachable from the tool main body 1 so as to allow a throwaway, but in this case, after brazing the cutting edge tips 4.
Since it is impossible to grind the cutting edges 5 collectively for each case, it is extremely difficult to accurately arrange the cutting edges 5 on the spherical surface R centered on the center P.

The present invention has been made in view of such a background, and while making the above-mentioned spherical cutter into a throw-away, the cutting edge is formed on a spherical surface having a center on the axis of the tool body. It is an object of the present invention to provide a spherical cutter capable of performing high-precision spherical spot facing by accurately arranging a spherical cutter.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve such an object, the present invention provides a chip mounting member formed on an axially facing end face of a tool body rotated about an axis. A throw-away tip (hereinafter, referred to as a tip) having an arc-shaped cutting edge is detachably mounted on the seat such that the cutting edge is positioned on a spherical surface having a center on the axis. The tool body is provided with an adjusting mechanism for finely adjusting the position of the cutting edge of the tip. Therefore, according to the spherical cutter configured as described above, the insert can be attached to and detached from the tool main body, and the insert can be throw-away. Therefore, when the cutting edge becomes worn, the cutting edge is replaced to replace the cutting edge. On the other hand, when such a tip is exchanged, the position of the cutting edge can be finely adjusted by the adjusting mechanism provided in the tool body, so that the cutting edge is accurately arranged on the spherical surface. It is possible to do.

Here, more specifically, the chip is formed in a substantially flat plate shape, and the cutting edge is formed at a side edge of one flat plate surface which is a rake face, and the chip is formed from the rake face side. On the other hand, the adjusting mechanism includes a pair of pressing members that abut on the side surface of the chip opposite to the cutting blade and press the side surface, and the pair of pressing members are mounted on the chip mounting seat by a clamp screw to be screwed. When the members are arranged in a substantially isosceles triangular shape with the clamp screw at the apex when viewed from the direction facing the rake face, by appropriately adjusting the pressing amount between the pair of pressing members, The position can be finely adjusted in the pressing direction by the pressing member, and also can be finely adjusted in the rotation direction around the clamp screw, so that the cutting blade can be more accurately arranged on the spherical surface. . On the other hand, a chip mounting seat is formed on both end surfaces of the tool body, the chip is mounted, and a center of the both end surfaces is mounted on an arbor of a machine tool for rotating the tool body around the axis. In the case where the respective parts are provided, especially when forming the spherical counterbore part in the cavity of the workpiece as described above, the tool body is reciprocated in the axial direction while rotating the tool body around the axis by the arbor. , A pair of spot facing portions on a spherical surface having a center on the axis can be accurately formed on the inner periphery of the hollow portion.

[0008]

1 to 4 show a first embodiment of the present invention.
1 shows an embodiment of the present invention. In the present embodiment, the tool main body 11 has a substantially cylindrical shape centered on the axis O, and feed is given in the direction of the axis O while being rotated around the axis O in the tool rotation direction indicated by the symbol T in the drawing. As a result, the spherical counterbored portion is formed as described above. Here, in the present embodiment, the tool main body 11 is formed so as to be symmetrical with respect to an imaginary plane Q which is orthogonal to the axis O and located in the center of the tool main body 11 in the axis O direction. The center of the tool main body 11 in the direction of the axis O along the virtual plane Q is formed so as to be constricted one step over the entire circumference to form a concave portion 12.
Has a flat surface 12A for gripping the tool body 11,
12A are formed parallel to each other.

Further, both end portions 13, 13 of the tool main body 11 sandwiching the concave portion 12 are formed in a convex spherical shape having center P on the axis O, respectively. And these both ends 13, 13
Are formed on the outer peripheral surface of the pair of flat surfaces 13A, which are parallel to the flat surfaces 12A. The centers P, P of the spherical surfaces formed by the end faces 14, 14 are:
The center P of the end face 14 facing one side in the direction of the axis O is arranged so as to be located on the other side opposite to the end face 14 with the virtual plane Q interposed therebetween. The total length of the eleventh axis 11 in the direction of the axis O is set smaller than the diameter of the spherical surface formed by the end face 14.

Then, both ends 13,
13, a pair of chip pockets 15, 15 respectively opening to the end face 14 are formed symmetrically with respect to the axis O, and a chip mounting seat is provided on a bottom surface 15A of each chip pocket 15 facing the tool rotation direction T side. A chip 17 is seated on each of the chip mounting seats 16 and is detachably attached by a clamp screw 18. Here, the tip pocket 15 is
It is formed so as to be cut out in an L-shape when viewed from the direction opposite to the end surface 14 in the direction of the axis O from the end surface 14 to the middle of the end portion 13 in the direction of the axis O. Each of the chip pockets 1 is defined by the bottom surface 15A where the seat 16 is formed, the wall surface 15B facing the tool outer peripheral side, and the wall surface 15C facing the outside in the axis O direction.
5, the wall surface 15B is disposed at a position spaced from the axis O toward the radially outer side.

The tip mounting seat 16 is formed so as to be recessed one step further from the bottom surface 15A of the tip pocket 15 in the tool rotation direction T, and is opened at the outer peripheral surfaces of the end surfaces 14 and 13. Like the tip pocket 15, the bottom surface 16A faces the tool rotation direction T, the wall surface 16B faces the tool outer peripheral side, and the wall surface 16C faces the outside in the direction of the axis O. Here, the wall 16
C is formed in a direction perpendicular to the axis O, and is disposed so as to protrude slightly slightly outward in the direction of the axis O from the wall 15C of the chip pocket 15, while a wall 16B is perpendicular to the wall 16C and It is formed in a direction parallel to the axis O, and is arranged so as to protrude slightly more toward the outer peripheral side of the tool than the wall surface 15B of the chip pocket 15. Further, the bottom surface 16A of the chip mounting seat 16 is aligned with the axis O
And is disposed at a position retracted one step parallel to the rear side in the tool rotation direction T with respect to an imaginary plane S orthogonal to the wall surfaces 16B and 16C, and formed so as to be orthogonal to the wall surfaces 16B and 16C. A screw hole (not shown) into which the clamp screw 18 is screwed is formed perpendicularly to the bottom surface 16A at the center of the bottom surface 16A.

On the other hand, the chip 17 mounted on the chip mounting seat 16 thus formed is formed of a hard material such as cemented carbide in the present embodiment, and has a flat plate shape. In the embodiment, the bottom surface 16A of the tip mounting seat 16 is in the tool rotation direction T with respect to the virtual plane S.
Is set to be equal to the amount of retreat backward. Further, the chip 17 has two long and short sides parallel to each other when viewed from above when viewed from the upper surface side, which is the rake face 17A.
An outline composed of a vertical side perpendicular to the two long sides and an oblique side located on the opposite side of the vertical side and intersecting the long side at an acute angle and the short side at an obtuse angle. The oblique side is not a straight line but a convex arc bulging outward, and the cutting edge 19 is formed on the arcuate oblique side.

In the tip 17 of the present embodiment, the side of the flank 17B connected to the cutting edge 19 moves from the side of the rake face 17A to the bottom side of the seating face 17C. The chip 17 is a so-called positive chip that is inclined toward the side surface 17D of the chip 17 connected to the vertical side of 17A. Also, this side face 17D,
The portion on the seating surface 17C side is an inclined surface 17E inclined toward the flank 17B side as it goes toward the seating surface 17C side, and the side surfaces 17F and 17G of the chip 17 connected to the long and short sides of the rake surface 17A are raked. It is formed so as to be orthogonal to the surface 17A and the seating surface 17C.

Further, in the center of the rake face 17A and the seating face 17C, a mounting hole 1 through which the clamp screw 18 is inserted through the chip 17 in the thickness direction.
7H is formed and opened.
H attaches the side surface 17D and the side surface 17F to the tip mounting seat 1.
6 in contact with the wall surface 16C and the wall surface 16B, respectively, and the seating surface 17C is seated on the bottom surface 16A, and is slightly slightly outside the tool hole and outside in the direction of the axis O with respect to the screw hole formed on the bottom surface 16A. It is formed so as to be disposed at a position eccentric with respect to. The portion of the mounting hole 17H on the rake face 17A side is formed in a tapered shape whose diameter gradually increases toward the rake face 17A side, and the head of the clamp screw 18 faces the screw part side. It is formed in a dish head shape having a tapered surface whose diameter gradually decreases.

The chip 17 thus configured is seated on the chip mounting seat 16 as described above, and the clamp screw 18 is inserted into the mounting hole 17H and screwed into the screw hole. Mounting hole 1 for screw hole
With the eccentricity of 7H, the tapered surface of the mounting hole 17H is pressed against the tapered surface of the head of the clamp screw 18 so as to be pressed against the corner portion formed by the wall surfaces 16B and 16C of the chip mounting seat 16. It is fixed to the mounting seat 16 and attached to the tool body 11. Here, in this mounting state, the cutting edge 19 of the tip 17
The thickness of the bottom surface 1 of the chip mounting seat 16 from the virtual plane S
By being equal to the retreat amount up to 6A, it is located on the imaginary plane S including the axis O, and around the axis O of the cutting edges 19, 19 of the chips 17, 17 attached to the same end surface 14 side. The rotation trajectory is arranged so as to form one spherical surface R having a radius slightly larger than the end face 14 about the center P.

The tool body 11 to which the chip 17 is mounted is provided with an adjusting mechanism 20 for finely adjusting the position of the cutting edge 19 of the chip 17 for each chip mounting seat 16. Here, the adjusting mechanism 20 of the present embodiment is provided with the bottom surface 16 of the tip mounting seat 16 as shown in FIG.
The wall surface 16C from the rear side in the tool rotation direction T perpendicular to A
Is formed in the end portion 13 so as to extend along
An adjustment pin 22 as a pressing member according to the present embodiment is fitted into the mounting hole 21 on the side of the chip mounting seat 16 so that a tip end portion of the adjustment pin 22 projects from the bottom surface 16A.
A female screw portion 21A is formed on the outer peripheral surface of the end portion 13 of the mounting hole 21, and an adjusting screw 23 is screwed into the female screw portion 21A.

At the tip of the mounting hole 21, a half of a circle formed by the cross section of the mounting hole 21 extends along the wall surface 16C as shown in FIG.
5A, while the other half of the circle is formed to open at the edge of the bottom surface 16A of the chip mounting seat 16 on the wall surface 16C side. On the other hand, the tip of the adjustment pin 22 protruding from the bottom surface 16A has a portion facing outward in the direction of the axis O at an angle of 45 ° from the outer periphery of the adjustment pin 22 toward the central axis toward the tip. An inclined surface 22A that is inclined at a small inclination angle is formed, and the inclination angle of the inclined surface 22A with respect to the central axis is:
The inclined surface 17E of the side surface 17D of the tip 17 is set to be equal to the inclined angle formed with respect to the direction perpendicular to the seating surface 17C, and these inclined surfaces 17E and 22A can be brought into close contact with each other and contact. I have.

Further, in the present embodiment, such an adjusting mechanism 20 is provided with a pair of the adjusting pins 22 and the adjusting screws 23 for each one chip mounting seat 16 on the tool inner peripheral side and the outer peripheral side of the wall surface 16C. These adjustment pins 2
2 and 22, the chip 1 is mounted on the chip mounting seat 16 as described above.
In a state where the rake face 7 is attached, when viewed from the direction opposite to the rake face 17A, as shown in FIG. The adjustment pins 22 are arranged at both ends of the bottom side so as to form an approximately isosceles triangle. In the adjusting mechanism 20 configured as described above, the two adjusting pins 22 and 22
Female threads 21A, 21 of mounting holes 21, 21 into which are inserted.
As shown in FIG. 2, the adjusting screws 23 screwed into the A are caused by a difference in depth due to a difference in a radial position of the mounting holes 21 and 21 from the axis O, and as shown in FIG. The adjustment screw 23 on the outer peripheral side is shorter than the above.

On the other hand, a mounting hole 24 is formed in the tool main body 11 at the center of both end surfaces 14 thereof and penetrates the tool main body 11 along the axis O as a mounting portion in the present embodiment. The tool body 11 is rotated in the tool rotation direction T around the axis O as described above by inserting and attaching a pair of shaft-shaped arbors on the machine tool side from both ends to the mounting holes 24. And the cutting edge 19 of the tip 17
Are used to form a spherical spot facing portion. here,
The mounting hole 24 is formed with tapered portions 24A, 24A whose diameters gradually decrease about the axis O toward the inside in the direction of the axis O toward the inner side in the direction of the axis O at the opening sides of both ends, and the virtual plane Enlarged portion 24 that expands one step along Q
B is formed, and square holes 24C, 24C having a square cross section are formed on both sides of the enlarged diameter portion 24B.

The mounting holes 2 on both end faces 14,
4, that is, the spherical end surface 14 and the mounting hole 2
4 is chamfered perpendicularly to the axis O at the intersection ridge line portion with the tapered portion 24A so that the annular flat surface 2 is formed.
4D are formed, and the wall surfaces 15B and 15C of the tip pocket 15 and the tip mounting seat 16 facing the tool outer peripheral side.
Are formed so as to intersect with the flat surface 24D. A small-diameter hole 24E for supplying a cutting oil or the like from the enlarged diameter portion 24B toward the cutting edge 19 of each tip 17.
Are formed, and these small-diameter holes 24E are formed on the wall surface 15C facing outward in the direction of the axis O of each chip pocket 15.
An opening is formed so as to extend in a direction passing directly above the clamp screw 18 along the rake face 17 </ b> A of the chip 17.

Further, in the present embodiment, a chamfering chip 25 for chamfering an opening edge of an insertion hole of a workpiece into which the arbor is inserted can be attached to both end surfaces 14, 14 of the tool body 11. . This chamfered chip 25 is also formed in a cylindrical axis shape from a hard material such as a cemented carbide, and its tip is cut off in a semicircular cross section perpendicular to the center line of the cylindrical axis. The notch surface 25A is a rake face, and its leading edge is cut so as to be inclined at 45 ° to the center line when viewed from the direction facing the notch surface 25A, and the leading edge is cut by a cutting blade 25B. It has been. In addition, the rear end of the chamfering chip 25 extends in a direction perpendicular to the notch surface 25A, and is opposite to the cutting blade 25B with respect to the center line when viewed from the direction facing the notch surface 25A. Is formed, and a flat surface 25D extending in a direction perpendicular to the cutout surface 25A and parallel to the center line is formed on the outer peripheral surface of the chamfering chip 25. , The cutting blade 2
5B and the inclined surface 25C are formed on the side approaching each other.

On the other hand, both end surfaces 14 of the tool body 11
14 is provided with a mounting hole 26 into which such a chamfering chip 25 can be inserted.
And a hole is opened on a plane orthogonal to the virtual plane S and extends so as to be parallel to the axis O. The chamfering chip 25 has a tip portion protruding from the end face 14 to form a rake face. The notch surface 25A is oriented toward the tool rotation direction T, and the rotation trajectory of the cutting edge 25B around the axis O overlaps with the inner peripheral end of the cutting edge 19 of the tip 17, so that the mounting hole 26 Is inserted. Further, a pair of mounting screw holes 27, 27 extending perpendicularly to the axis O from the outer peripheral surface thereof and communicating with the mounting hole 26 are formed in the end portion 13 of the tool body 11 so as to be aligned in the direction of the axis O. Of these, the mounting screw hole 27 on the inner side in the direction of the axis O is
A positioning screw 28 whose tip is formed in a conical shape is screwed into and brought into contact with the inclined surface 25C at the rear end of the chamfering chip 25.
Is positioned in the direction of the axis O, while the clamp screw 29 is screwed into the mounting screw hole 27 on the outer side in the direction of the axis O to abut the flat surface 25D of the chamfering chip 25, and the positioned chamfering chip 25 is used as a tool. The inner peripheral side is pressed and fixed.

In the throw-away type spherical cutter configured as described above, the tool main body 11 is housed in the hollow portion C of the workpiece W as shown in FIG. As described above, a pair of arbors A, A of the machine tool are inserted into a pair of insertion holes H, H formed coaxially with the workpiece W, and the ends of the arbors A, A are connected to the axis line as described above. It is supported by being attached to the attachment hole 24 from the outside in the O direction. Here, a drive section D having a square cross section to be fitted into the square hole section 24C of the mounting hole 24 is formed at the front end of the arbor A, and is equal to the tapered section 24A at the rear end side. A taper portion E is formed to taper toward the tip end at a taper angle, and the axis O of the tool body 11 is made to coincide with the rotation axis of the arbor A by bringing the taper portions 24A and E into close contact with each other. At the same time, the tool body 11 is rotated in the tool rotation direction T integrally with the arbor A, by fitting the square hole 24C and the drive part D.

According to the throw-away type spherical cutter, the tool body 11 is fed by being reciprocally moved to both sides in the direction of the axis O by the arbor A while rotating the tool body 11 in this manner. Around the insertion holes H on the inner periphery of the hollow portion C of the workpiece W, cutting edges 19, 19 on the side of the end face 14 facing the respective insertion holes H are the same as the spherical surface R having a center on the axis O. It is possible to form concave spots F, F having a concave spherical shape, and at the same time, chamfer the intersection ridge line between the spot facing F and the insertion hole H by the cutting blade 25B of the chamfering tip 25. Can be applied. Furthermore, a tool body 1 using arbor A, A
The feed amount of the one reciprocating movement is set such that the positions of the centers P of the spherical surfaces R formed by the rotation trajectories of the cutting edges 19, 19 of the end surfaces 14 when forming the individual spot facing portions F, F coincide with each other. With such a setting, the concave spherical surface formed by the spot facing portions F, F formed on both sides of the hollow portion C can be a concave spherical surface along one spherical surface R.

However, in the throw-away type spherical cutter having the above-described structure, first, the tips 17 having the arc-shaped cutting edge 19 and forming the spot facing portion F are formed by the tool body 1.
1 is detachably attached to the tip mounting seat 16 formed by the clamp screw 18, and if the cutting edge 19 of the tip 17 is worn due to the processing of the spot facing portion F, the tip 17 is removed. , The cutting blade 19 can be returned to the original state, and the formation of the spot facing portion F can be continued without discarding the tool body 11. On the other hand, when the tip 17 is replaced in this way, or when the tip 17 is first mounted on the tool body 11, the rotation locus of the cutting edge 19 of the tip 17 around the axis O is a predetermined spherical surface R. According to the spherical cutter having the above configuration, the tool main body 11 is provided with the adjusting mechanism 20 for finely adjusting the position of the cutting edge 19 of the tip 17 even when the cutting edge 19 does not exactly coincide with the cutting edge 19.
It is possible to perform high-precision machining by making the rotation trajectory coincide with the spherical surface R.

That is, in this embodiment, the clamp screw 18 is inserted through the mounting hole 17H through the chip 17 which is seated on the chip mounting seat 16 with the side surfaces 17D and 17F abutting on the wall surfaces 16C and 16B. Tip mounting seat 16
When the screw 17 is screwed into the screw hole of the bottom surface 16A of the mounting hole 17H, the mounting hole 17H is pressed against the tapered surface of the head of the clamp screw 18 as described above. It is attached to the tool main body 11 while being pressed against the part side. Then
In the adjusting mechanism 20 of the present embodiment, the tip mounting seat 16
An adjustment pin 22 and an adjustment screw 23 as a pressing member are attached to a mounting hole 21 formed facing the wall surface 16C of the chip 17, and the inclined surface 22 A at the tip of the adjustment pin 22 is inclined with the inclined surface 17 E of the side surface 17 D of the chip 17. Since the adjusting screw 23 is screwed or loosened, the inclined surface 22A of the adjusting pin 22 is opposed to the pressing force of the clamp screw 18 so that the inclined surface 22A of the tip 17 is inclined.
Is pressed to slightly protrude the tip 17 outward in the direction of the axis O, or the protruding tip 17 is
By the pressing force of 8, the blade is slightly retracted, so that the position of the cutting blade 19 can be finely adjusted.

Moreover, in the present embodiment, the adjusting mechanism 2
0 has a pair of adjusting pins 22 as a pressing member, and these adjusting pins 22 are viewed from a direction facing the rake face 17 </ b> A of the chip 17.
Since the tips 17 are arranged in a substantially isosceles triangular shape with the apex 8 as a vertex, the tip 17 is moved in the direction of the axis O by appropriately adjusting the screwing amounts of the adjusting screws 23, 23 for projecting the adjusting pins 22, 22. In addition to finely adjusting the position of the cutting blade 19 by moving it forward and backward, it is also possible to finely adjust the rotational position of the tip 17 about the clamp screw 18 as viewed from the above-described facing direction. That is, for example, in the adjusting mechanism 20 for the tip 17 at the lower right in FIG. 1, the adjusting screw 23 on the tool inner peripheral side is screwed deeply so that the adjusting pin 22 protrudes greatly, and the adjusting screw 23 on the tool outer peripheral side is When the protrusion of the adjustment pin 22 is also reduced by reducing the screwing amount of the screw, the tip 17 and its cutting edge 19 rotate clockwise around the clamp screw 18 in FIG. If the screwing amount is reversed, the tip 17 also rotates in the opposite counterclockwise direction.

Therefore, according to the spherical cutter of the present embodiment, as described above, the tip 17
In addition to being able to finely adjust the position of the cutting edge 19 in the direction of the axis O, it is also possible to finely adjust the rotational position of the tip 17 around the clamp screw 18 as described above.
If the radius of the arc formed by the cutting edge 9 is formed so as to be equal to the radius of the spherical surface R, the cutting edge 9 can be arranged so that its rotation locus is positioned on the spherical surface R more accurately.
It is possible to form the spot facing portion F with higher precision. In addition, the inclined surface 22A of the tip of the adjustment pin 22 which is in close contact with the inclined surface 17E of the chip 17 is inclined at an inclination angle smaller than 45 ° with respect to the center axis of the adjustment pin 22, so that the adjustment can be performed. The amount of advance and retreat of the tip 17 with respect to the screwing amount of the screw 23 is small, and the cutting edge 1 with higher accuracy
There is also obtained an advantage that the position of No. 9 can be finely adjusted.

On the other hand, in the spherical cutter of the present embodiment, the tip mounting seats 16 are formed on both end faces 14 of the tool body 11, and the tips 17 are mounted by the adjusting mechanism 20 so as to be finely adjustable. And these two end faces 1
A mounting hole 24 as a mounting portion in the present embodiment is opened at the center of each of the mounting holes 4 and 14.
Then, while rotating the tool body 11 around the axis O,
The above-mentioned arbor A, A of a machine tool for reciprocating in the direction to give a feed is attachable. Therefore, when forming the spot facing portions F, F in the hollow portion C of the workpiece W,
Since the tool body 11 is mounted with both ends supported by the arbor A, the mounting rigidity is higher than that of a general cantilever type shank type cutter, and the tool main body 11 may be bent with respect to the axis O. Instead, it is possible to more accurately form concave spherical spots F, F having centers on the axis O on both sides of the cavity C.

In this embodiment, a tapered portion 24A and a square hole 24C are formed in the mounting hole 24, and the tapered portion E of the arbor A is brought into close contact with the tapered portion 24A. The tool body 11 is driven to rotate by fitting the square hole 24C and the drive part D of the arbor A after the rotation axes of the arbor A and the arbor A are matched. Therefore, by separately providing the part for rotating the tool body 11 and the part for aligning the axis of the tool body 11 according to the present embodiment, the tool body 1
1 is accurately rotated about its axis O to make the rotational trajectory of the cutting edge 19 of the tip 17 a spherical surface R having a center P on the axis O. F can be formed in the cavity C. Moreover, in the present embodiment, since the chamfering tip 25 is provided by projecting the cutting blade 25B so as to face the opening of the mounting hole 24, the intersection ridge portion between the spot facing portion F and the insertion hole H is provided. Can be chamfered exactly concentrically with the axis O.

Next, FIGS. 6 to 8 show a second embodiment of the present invention. The same reference numerals are used for the parts common to the first embodiment shown in FIGS. 1 to 5. The description is omitted. That is, in the adjusting mechanism 20 according to the first embodiment, the tool rotation direction T of the end portion 13 of the tool body 11 is adjusted.
Mounting hole 21 reaching the chip mounting seat 16 from the rear side of
On the other hand, the adjusting pin 22 and the adjusting screw 23 as the pressing member are attached to the
A mounting hole 31 of the adjusting mechanism 30 is formed so as to open to the outer peripheral surface of the end portion 13 on the tool rotation direction T side with respect to the chip mounting seat 16 and extend to the wall surface 16C. An adjustment pin 32 as a pressing member is provided on the 16C side.
And an adjusting screw 33 is attached to a female screw portion 31A formed on the opening side of the outer peripheral surface side of the end portion 13 of the mounting hole 31.

Here, in the present embodiment, the inclined surface 17E as in the first embodiment is not formed on the side surface 17D of the tip 17 on the side opposite to the cutting blade 19 side.
D is formed so as to be orthogonal to the rake face 17A and the seating face 17C, like the other side faces 17F and 17G. On the other hand, as the mounting hole 31 moves from the outer peripheral surface of the end portion 13 toward the wall surface 16C of the chip mounting seat 16, the tool rotation direction is along a plane perpendicular to the bottom surface 16A of the chip mounting seat 16 and parallel to the axis O. It extends rearward of T and outward in the direction of the axis O, intersects the wall surface 16C at an intersection angle smaller than 45 °, and opens toward the corner where the wall surface 16C intersects with the bottom surface 16A. Is formed. The tip of the adjusting pin 32 has an angle equal to the intersection angle of the mounting hole 31 with the wall surface 16C.
An inclined surface 32A is formed obliquely to the central axis of the second.

Further, also in the present embodiment, the adjusting mechanism 30 includes a pair of mounting holes 31, 31, adjusting pins 32, 32, and adjusting screw 3 for one chip mounting seat 16.
The mounting holes 31, 31 are formed in parallel with each other, and the inclined surfaces 32A, 32A of the adjusting pins 32, 32 projecting from the mounting holes 31, 31 and contacting the side surface 17D of the chip 17 are provided. 32A is arranged in a substantially isosceles triangular shape having the clamp screw 18 for fixing the chip 17 as a vertex at which the isosceles cross each other, as viewed from the direction facing the rake face 17A of the chip 17. In the second embodiment, the enlarged diameter portion 24B of the mounting hole 24 is used.
Small hole 24 for supplying cutting fluid etc.
E ... are one small-diameter holes 24 for each end 13 without opening to the chip pocket 15 as in the first embodiment.
E is opened in a recess 34 formed in the end face 14 so as to extend in the tool rotation direction T side of the mounting hole 26 in which the chamfering chip 25 is mounted, and the other small-diameter hole 2 is formed.
4E is opened on the end face 14 on the opposite side of the small diameter hole 24E and the axis O.

In the indexable spherical cutter according to the second embodiment, the arbor of the machine tool is inserted into the mounting hole 24 to machine the tool body 11 in the same manner as in the first embodiment. It is supported in the cavity of the object, and is reciprocated in the direction of the axis O while rotating in the tool rotation direction T around the axis O to give the feed. A concave spherical counterbore can be formed on both sides of the inside. Since the cutting edge 19 is formed on the tip 17 detachably attached to the tool body 11 by the clamp screw 18, even if the cutting edge 19 is worn, the tip 1
By exchanging 7, the tool body 11 can be kept as it is, and the formation of the concave spherical counterbore portion of a predetermined radius can be continued. Even when the tip 17 is exchanged in this way, the adjusting mechanism 30 can be used. By finely adjusting the position of the cutting edge 19, the rotation locus of the cutting edge can be accurately matched with the spherical surface R having the center P on the axis O to perform high-precision machining.

Further, according to the second embodiment, the adjusting pin 32 serving as the pressing member of the adjusting mechanism 30 is inserted into the mounting hole 31 formed from the tip mounting seat 16 from the tool rotation direction T side. The above-described side surface 17D of the chip 17 being inserted and inserted.
The tip 17 is pressed by the adjusting screw 33 in a direction facing the bottom surface 16A of the tip mounting seat 16 to press the tip 17 outward in the direction of the axis O to perform fine adjustment. There is no force for lifting the chip 17 from the bottom surface 16A of the chip mounting seat 16 on the 17D side, so that the mounting rigidity of the chip 17 can be secured and more accurate fine adjustment can be performed. Moreover, in the present embodiment, the side surface 17D of the chip 17 and the inclined surface 32A of the adjustment pin 32 abutting on the side surface 17D are formed in a direction perpendicular to the seating surface 17C of the chip 17 and the bottom surface 16A of the chip mounting seat 16. Therefore, the pressing force due to the advance of the adjustment pin 32 is
Acting only in the direction along A, that is, in the direction of the axis O, it is possible to more reliably prevent the generation of a force that causes the tip 17 to float.

[0036]

As described above, according to the present invention,
By adopting a throwaway method in a spherical cutter, even if the cutting edge becomes worn, the tool body is not discarded, and the spherical counterbore portion of a predetermined diameter is processed again by exchanging the tip. On the other hand, even if the tip is changed in this way, the position of the cutting edge can be finely adjusted by the adjusting mechanism provided in the tool body, thereby performing high-precision spherical spot facing processing. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention as seen from a direction facing a rake face 17A of a throw-away tip 17. FIG.

FIG. 2 shows the embodiment shown in FIG.
FIG. 2 is a front view as viewed from a direction (right side in FIG. 1) facing.

FIG. 3 is a sectional view taken along the line XX in FIG.

FIG. 4 is a sectional view on the YY side in FIG. 2;

FIG. 5 is a view showing a case where concave spot-shaped spots F, F are formed in a hollow portion C of a workpiece W by a spherical cutter.

FIG. 6 is a plan view showing a second embodiment of the present invention.

7 is a front view of the embodiment shown in FIG. 6 (a view from the right side in FIG. 6).

8 is a sectional view taken along the line ZZ in FIG. 7;

FIG. 9 is a side sectional view showing a conventional spherical cutter.

10 is a front view of the spherical cutter shown in FIG. 9 (a view from the right side in FIG. 9).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Tool main body 14 End surface of tool main body 11 16 Tip mounting seat 17 Throw-away tip 18 Clamp screw 19 Cutting blade 20, 30 Adjusting mechanism 22, 32 Adjusting pin (pressing member) 23, 33 Adjusting screw 24 Mounting hole 25 Chamfering chip O Tool The center axis of the main body 11 T The tool rotation direction R The spherical surface formed by the rotation locus of the cutting edge 19 around the axis O The center of the spherical surface R W Workpiece A Arbor F Counterbore part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Akira Venus Inventor 1528 Nakashinda, Yokoi, Kobe-cho, Anpachi-gun, Gifu Prefecture F-term in Mitsubishi Materials Corporation Gifu Works (reference) 3C022 GG01 LL01 LL02 LL03 MM06 NN02

Claims (3)

[Claims] 1. A throw-away insert having an arc-shaped cutting edge is provided on a tip mounting seat formed on an end face of the tool body rotated around an axis which faces in the axial direction, the arc formed by the cutting edge is formed on the axis. The tool body is provided with an adjusting mechanism for finely adjusting the position of the cutting edge of the throw-away tip so as to be positioned on a spherical surface having a center. Indexable spherical cutter. 2. The indexable insert is formed in a substantially flat plate shape, and the cutting edge is formed on a side edge of one flat plate surface which is a rake face, and is screwed from the rake face side. While being attached to the tip mounting seat by a clamp screw, the adjusting mechanism includes a pair of pressing members that abut against and press against the side surface of the indexable tip opposite to the cutting blade, and The throw-away type spherical cutter according to claim 1, wherein the pressing members are arranged in a substantially isosceles triangle shape having the clamp screw as an apex as viewed from a direction facing the rake face. 3. The tool body has the tip mounting seats formed on both end faces thereof and the throw-away tips mounted thereon, and the tool body is disposed at the center of the both end faces around the axis. 3. The throw-away type spherical cutter according to claim 1, further comprising a mounting portion that can be mounted on an arbor of the machine tool to be rotated.