JP2008000830A - Insert for spherical surface cutter and insert detachable type spherical surface cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert for a spherical surface cutter which can smoothly adjust the position of a cutting blade by a position adjustment mechanism and accurately dispose the cutting blade on a spherical surface with a point on the axis line of a tool body as a center by securing an adjustment amount. <P>SOLUTION: The insert 20 for the spherical surface cutter is mounted to the spherical surface cutter which has a circular-arc shaped cutting blade 23, and a spherical surface shape counter part is formed on a cavity formed on a workpiece. The insert 20 for the spherical surface cutter has a polygonal surface 21 where at least one side is swollen in a circular-arc shape toward the outside, and the cutting blade 23 is provided on the side swollen in the circular-arc shape. An insertion hole 26 where a clamp screw having a shaft and an abutting surface orthogonal to the shaft is inserted is formed, and a clamp surface 27 on which the abutted surface is abutted is formed on the polygonal surface 21. The clamp surface 27 is inclined so as to be gradually retreated as approaching to the cutter blade 23 with respect to a plane orthogonal to an axis line L of the insertion hole 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spherical cutter insert and an insert detachable spherical cutter to be attached to a spherical cutter used when a spherical counterbore portion is formed on a workpiece.

  Conventionally, as a spherical cutter that forms a spherical counterbore on the inner surface of a cavity formed in a workpiece, both end surfaces in the direction of the axis O of the tool body having a substantially cylindrical shape extending along the axis O are convex curved surfaces. A plurality of recesses are formed on both end surfaces of the recesses at intervals in the circumferential direction, and a cutting edge tip having an arcuate cutting edge is provided on a wall surface facing the front side in the tool rotation direction T of the recesses. What was brazed in the state which protruded the cutting edge from the end surface is widely provided.

Here, these cutting blades are polished for each end face in a state where the cutting edge chips are brazed, so that each end face has a center on the axis of the tool body and is slightly radiused than the end face. It is formed so as to be located on a large spherical surface.
Further, the tool body is formed with mounting holes extending along the axis so as to open on both end faces, and the axially inner portion of the mounting hole has a square cross section centered on the axis. Is formed.

  Such a spherical cutter is accommodated in a cavity formed in the workpiece, and a pair of machine tools from the outside through a pair of insertion holes formed coaxially in the workpiece so as to communicate with the cavity. Each arbor is inserted, and the tips of these arbors are rotated around the axis O through the arbor by attaching them to the mounting holes from both sides in the direction of the axis O. Then, by rotating the tool body and feeding the arbor so as to reciprocate integrally with the tool body on both sides in the direction of the axis O, each insertion is made around the insertion hole on the inner surface of the cavity portion. A concave counterbore part having a center on the axis O is formed by the cutting edge of the cutting edge tip brazed to the end face of the tool body facing the hole side. Here, by adjusting the feed amount by the arbor, by matching the center of the concave spherical surface formed by the counterbore portion formed on the inner surface of the hollow portion, the counterbore portion that is concavely curved along one spherical surface is formed. It is formed at both ends of the inner surface.

  However, in the spherical cutter of this configuration, the cutting edge tip is brazed to the tool body, so that when the cutting edge is worn, the cutting edge is re-polished like a normal brazing tool. . Here, if the cutting edge is repolished while keeping the diameter of the arc formed by the cutting edge constant, the center P point of the arc is shifted outward in the axis O direction. It is necessary to change the feed amount in the direction of the axis O. Therefore, there is a possibility that the spherical counterbore cannot be formed with high accuracy due to a feed amount setting error, a measurement error of the cutting edge position, or the like. In addition, since the tool body and the cutting blade are integrally formed by brazing, when the material of the cutting blade is to be changed depending on the material to be cut, the spherical cutter itself must be replaced. Therefore, it is necessary to prepare many spherical cutters in accordance with the above, and the use cost of the spherical cutter is increased.

Therefore, as shown in Patent Document 1, for example, there is provided an insert detachable spherical cutter in which a mounting seat is formed on an end surface of a tool body, and an insert having a cutting edge is detachably mounted on the mounting seat.
The insert detachable spherical cutter has a tool body that rotates about an axis, and a plurality of recesses are formed on both end surfaces in the axial direction of the tool body, and a mounting seat is provided on the rear side of the tool rotation direction T in the recesses. Is provided.

An accommodation hole extending in a direction perpendicular to the wall surface is formed in the axially inner portion of the wall surface facing the front side in the tool rotation direction of the mounting seat, and the position of the cutting edge of the insert is adjusted in the accommodation hole. As the position adjusting mechanism, a pressing pin and an adjusting screw for pressing the pressing pin are accommodated.
A clamp screw hole extending in a direction orthogonal to the wall surface is formed in the wall surface facing the front side in the tool rotation direction of the mounting seat.

  The conventional insert mounted on this mounting seat is made of a hard material such as cemented carbide, for example, and has an outer shape of a substantially rectangular flat plate, two rectangular surfaces and four side surfaces intersecting these rectangular surfaces. Have One square surface is a rake face that faces the front side of the tool rotation direction, and one side of the rake face is projected in an arc shape toward the outside, and an arc-shaped cutting blade is provided. Yes. Further, an insertion hole penetrating in the thickness direction of the insert is provided so as to open in a quadrangular surface.

  A state in which such an insert is placed such that one rectangular surface that is a rake face faces the front side in the tool rotation direction, and the arc-shaped cutting blade faces the outer side in the axial direction from the end face of the tool body. Thus, the clamp screw inserted into the insertion hole is fixed to the mounting seat by being screwed into the clamp screw hole, and the insert detachable spherical cutter is configured.

In such a spherical cutter, even if the cutting blade is worn, the insert can be replaced and used, so the center P point of the arc formed by the cutting blade can be made constant, and the feed amount needs to be adjusted for each spherical cutter There is no. Furthermore, when it is desired to change the material of the cutting blade depending on the material to be cut, it can be dealt with by simply replacing the insert, and it is not necessary to prepare many tool bodies, and the cost of using the spherical cutter can be greatly reduced. Further, since the position of the cutting blade can be adjusted by pressing the insert, the cutting blade is positioned on a spherical surface centered on the axis O of the tool body even when the cutting blade is worn and the insert is replaced. Can be arranged to do.
JP 2000-343316 A

  By the way, in the above-mentioned spherical cutter, when the position of the cutting blade is adjusted, the insert is pressed with a pressing pin while the insert is fixed with a clamp screw, and the insert is moved by deforming the clamp screw to bend. become. Here, when the clamp screw is in close contact with the insert, the clamp screw is not easily deformed even when the insert is pressed by the frictional force between the insert and the clamp screw, and when a certain pressing force is applied. Will greatly deform.

  Therefore, in the above spherical cutter and insert, the position of the cutting edge cannot be adjusted smoothly, and the position of the cutting edge of the insert is arranged on a spherical surface centered on one point on the axis of the tool body. It took a lot of time and effort. In addition, the amount of movement of the insert is determined by the amount of deformation of the clamp screw. However, when the clamp screw is in close contact with the insert as described above, the amount of deformation of the clamp screw is reduced and the insert The amount of movement is limited, and the cutting edge cannot be adjusted with high accuracy.

  The present invention has been made in view of the above-described circumstances, and the position of the cutting blade can be adjusted smoothly by the position adjusting mechanism, and the amount of adjustment can be ensured so that the cutting blade is placed on the axis of the tool body. It is an object of the present invention to provide a spherical cutter insert that can be accurately arranged on a spherical surface centered on one point, and an insert detachable spherical cutter to which the spherical cutter insert is attached.

  In order to solve this problem, the insert for a spherical cutter according to the present invention is mounted on a spherical cutter having an arcuate cutting edge and forming a spherical counterbore in a cavity provided in the workpiece. It is an insert for a spherical cutter, and has a polygonal surface that swells in an arc shape with at least one side facing outward, and the cutting edge is provided on the one side that swells in this arc shape, An insertion hole into which a clamp screw having a shaft portion and a contact surface orthogonal to the shaft portion is inserted is opened, and a clamp surface with which the contact surface is contacted is formed. In addition, it is characterized in that it is inclined with respect to a plane perpendicular to the axis of the insertion hole so as to gradually recede as it approaches the cutting edge.

  Further, an insert detachable spherical cutter according to the present invention is provided with the above-described spherical cutter insert, and the insert detachable which forms a spherical counterbore in a cavity provided in the workpiece by the arc-shaped cutting blade. A spherical cutter that has a tool body that rotates about an axis, the tool body having a mounting seat on an end surface facing the axial direction, and the spherical surface mounted on the mounting seat A position adjusting mechanism is provided for adjusting the position of the cutting blade by pressing the cutter insert in the adjusting direction, and the mounting seat has an arc formed by the cutting blade on the axis. The clamp surface is disposed so as to be positioned on a spherical surface having a center and gradually retreats in the adjustment direction.

  According to the spherical cutter insert and the insert detachable spherical cutter of this configuration, a clamp screw having a shaft portion and a contact surface orthogonal to the shaft portion is inserted into a polygonal surface having a cutting edge formed on one side. And a clamping surface with which the abutting surface of the clamping screw abuts is formed, and the clamping surface approaches the cutting edge with respect to a plane perpendicular to the axis of the insertion hole. Accordingly, since it is inclined so as to gradually retreat from the polygonal surface, the contact surface of the clamp screw and the clamp surface are not in close contact with each other, and a slight gap is formed in the cutting blade side portion.

The clamp surface is arranged on the mounting seat so as to gradually recede in the direction of adjustment of the insert, so that when the insert is pressed by the position adjustment mechanism, the clamp screw is deformed so that only the gap portion is bent. The insert can be moved reliably even with a small pressing force, and the position of the cutting blade can be adjusted smoothly.
Further, since the amount of deformation of the clamp screw is secured by the gap, the amount of movement of the insert is larger than in the conventional case, and the position adjustment width of the cutting blade can be secured.

  Here, by setting the crossing angle θ between the plane perpendicular to the axis of the insertion hole and the clamp surface within a range of 0 ° 10 ′ ≦ θ ≦ 15 °, the deformation amount of the clamp screw is secured. The insert can be reliably moved and the insert can be securely fixed. That is, if the crossing angle θ is smaller than 0 ° 10 ′, the gap between the contact surface of the clamp screw and the clamp surface of the insert becomes small, and the amount of movement of the insert becomes small. On the other hand, if the intersecting angle θ is larger than 15 °, the gap between the contact surface of the clamp screw and the clamp surface of the insert becomes too large, and there is a possibility that the fixing of the insert by the clamp screw becomes insufficient. Therefore, the crossing angle θ is preferably set within the range of 0 ° 10 ′ ≦ θ ≦ 15 °.

  According to the present invention, the position of the cutting blade can be smoothly adjusted by the position adjusting mechanism, and the amount of adjustment is secured, and the cutting blade is accurately placed on a spherical surface centered on one point on the axis of the tool body. It is possible to provide a spherical cutter insert that can be disposed, and an insert detachable spherical cutter to which the spherical cutter insert is attached.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 and 2 show a spherical cutter insert according to an embodiment of the present invention, and FIGS. 3 to 8 show an insert detachable spherical cutter to which the spherical cutter insert is attached.
The spherical cutter insert 20 according to the present embodiment is made of a hard material such as cemented carbide, and the outer shape thereof is a substantially rectangular flat plate shape. In this embodiment, as shown in FIGS. The plate has a substantially square quadrilateral plate shape.

The spherical cutter insert 20 has two parallelogram surfaces 21 and four side surfaces 22, and one parallelogram surface 21 is formed on a wall surface 44 c facing the tool rotation direction T front side of the mounting seat 44. The mounting surface 21a is mounted, and the other parallelogram surface 21 is directed to the front side in the tool rotation direction T to be a rake surface 21b.
One long side of the parallelogram surface 21, which is the rake face 21 b, has a convex arc shape that is convex outward, and this long side portion is an arc-shaped cutting edge 23. The side surface 22 connected to the arcuate cutting edge 23 is a flank 22a, forms a convex curved surface projecting outward, and retreats to the inner side of the spherical cutter insert 20 as it approaches the mounting surface 21a. It is inclined like so.

As shown in FIG. 7, the inner periphery of the parallelogram surface 21 is gradually formed on the side surface 22 connected to the short side that intersects with the long side provided with the arcuate cutting edge 23 as shown in FIG. An inclined plane is formed so as to recede to the side, and this inclined plane is the first pressed surface 24.
Further, on the side surface 22 arranged opposite to the side surface 22 which is the flank 22a, that is, the side surface 22 connected to the other long side of the parallelogram surface 21, as shown in FIGS. An inclined plane that gradually recedes toward the inner peripheral side of the parallelogram surface 21 as it approaches 21a is formed in parallel to the other long side, and this inclined plane serves as the second pressed surface 25. ing.

  An insertion hole 26 that penetrates in the thickness direction of the spherical cutter insert 20 and extends along the central axis L is formed in the central portion of the parallelogram surface 21. As shown in FIG. 1, a clamp surface 27 having a substantially square shape is formed in the vicinity of the opening portion on the rake face 21 b side of the insertion hole 26, as shown in FIG. 1, and the clamp surface 27 is a parallelogram surface 21. In a direction orthogonal to the side surface 22 connected to the other long side, as it approaches the arcuate cutting edge 23, it is inclined so as to gradually retreat from the rake face 21b. In this embodiment, the clamp surface 27 is formed so as to intersect with a plane orthogonal to the central axis L of the insertion hole 26 at an intersection angle θ, and the intersection angle θ is 0 ° 10 ′ ≦ θ. ≦ 15 ° is set, and more specifically, θ = 3 ° is set.

  The insert detachable spherical cutter 30 to which the above-described spherical cutter insert 20 is mounted has a tool body 31 having a substantially cylindrical shape extending along the axis O. At the center of the tool body 31 in the direction of the axis O, a groove 32 that is recessed one step radially inward is formed over the entire circumference of the tool body 31, and a pair of grooves extending in parallel with the axis O is formed in the groove 32. The flat surfaces 33 and 33 are arranged in parallel to each other. Here, in the present embodiment, the tool body 31 is formed so as to be symmetric with respect to the virtual plane Q that is orthogonal to the axis O and is located in the center of the axis O direction.

Both end portions 34, 34 of the tool main body 31 sandwiching the concave groove 32 are formed in a convex curved surface having end surfaces 35, 35 having a center P (P ') on the axis O, respectively. A pair of flat portions 36 and 36 parallel to the flat surface 33 are also formed on the outer peripheral surfaces 34 and 34, respectively.
The center P of the spherical surface formed by the end surface 35 facing one side (right side in FIG. 3) is located on the other side of the virtual plane Q, and the spherical surface formed by the end surface 35 facing the other side (left side in FIG. 3). The center P ′ is located on one side of the virtual plane Q, and the length of the tool body 31 in the axis O direction is set smaller than the diameter of the spherical surface formed by the end face 35.

  The both end portions 34 and 34 are formed with attachment holes 37 extending along the axis O so as to open toward the respective end surfaces 35 and 35. The mounting hole 37 is formed with a tapered hole portion 38 that gradually decreases in diameter about the axis O as it goes inward in the direction of the axis O in the opening portion on the end surface 35 side, A large-diameter hole 39 having a one-step large diameter is formed along the virtual plane Q, and square holes 40 having a square cross section are formed on both sides of the large-diameter hole 39. In addition, the opening edge of the mounting hole 37 on the end surface 35, that is, the intersecting ridge line portion between the end surface 35 having a spherical shape and the tapered hole portion 38 of the mounting hole 37 is chamfered perpendicularly to the axis O to form an annular shape. A flat portion 41 is formed.

  In addition, a pair of concave portions 42 and 42 that open toward the end surface 35 are formed at both end portions 34 and 34 so as to be 180 ° rotationally symmetric about the axis O. As shown in FIG. 3, the recess 42 has a substantially L-shape with a wall surface 42 a facing outward in the axis O direction and a wall surface 42 b facing outward in the radial direction of the tool body 31, as seen from the front side in the tool rotation direction T. As shown in FIGS. 6 and 7 when viewed from the O direction, the wall surface 42b facing the radially outer side of the tool body 31 and the wall surface 42c facing the front side in the tool rotation direction T form a substantially L shape.

  A wall surface 42 a facing the outside in the direction of the axis O of the recess 42 is formed to extend in a direction perpendicular to the axis O, and a wall surface 42 b of the recess 42 facing the outside in the radial direction of the tool body 31 is formed to extend in parallel to the axis O. These wall surfaces 42a and 42b are connected via a concave curved surface. Further, as shown in FIGS. 6 and 7, a coolant supply hole 43 communicating with the large-diameter hole 39 of the mounting hole 37 is opened on the wall surface 42 a facing the outside in the axis O direction of the recess 42.

  A mounting seat 44 for mounting the spherical cutter insert 20 is formed on the wall surface 42c of the recess 42 facing the front side in the tool rotation direction T. The mounting seat 44 is recessed by one step from the wall surface 42c facing the front side in the tool rotation direction T of the recess 42 toward the rear side in the tool rotation direction T, and is opened toward the outer side in the radial direction of the tool body 31 and the outer side in the axis O direction. Yes. In this embodiment, as shown in FIGS. 6 and 7, the wall surface 44 b facing the tool body 31 in the radial direction of the mounting seat 44 and the wall surface 42 b facing the tool body 31 in the radial direction of the recess 42 are formed in the mounting holes 37. It is formed so as to intersect with the annular flat surface portion 41 formed at the opening edge.

  Here, as shown in FIG. 4, a clamp screw hole 45 extending perpendicular to the wall surface 44c is formed in the wall surface 44c facing the front side in the tool rotation direction T of the mounting seat 44. Further, as shown in FIG. 3, the wall surface 44 a facing the outer side of the mounting seat 44 in the axis O direction is positioned on the outer side in the axis O direction than the wall surface 42 a facing the outer side of the recess 42 in the axis O direction. As it goes outward in the direction, it is inclined so as to recede toward the inside in the direction of the axis O gradually. A wall surface 44b of the mounting seat 44 facing the tool body 31 in the radial direction is formed to extend parallel to the axis O.

  And as shown in FIG.3 and FIG.7, the tool main body 31 radial direction inner side of this attachment seat 44 is 1st extended in the direction which cross | intersects with the wall surface 44c which faces the tool rotation direction T front side of the attachment seat 44. As shown in FIG. A receiving hole 50 is formed. In the present embodiment, the first accommodation hole 50 extends in a direction orthogonal to the wall surface 44 c facing the tool rotation direction T front side of the mounting seat 44, and the wall surface 44 c facing the tool rotation direction T front side of the mounting seat 44. To the outer peripheral surface of the tool main body 31.

  A first pressing pin 51 is disposed on the mounting seat 44 side of the first accommodation hole 50, and a first adjustment screw 52 is screwed on the rear end side of the first pressing pin 51. The rear end face 35 of the first adjustment screw 52 in which an engagement hole with which the work tool is engaged is formed is exposed toward the outer peripheral side of the tool body 31. An inclined plane inclined with respect to the axis of the first pressing pin 51 is formed at the tip of the first pressing pin 51, and this inclined plane contacts a first pressed surface 24 of a spherical cutter insert 20 described later. The first pressing surface 51a is in contact. The first pressing pin 51 and the first adjusting screw 52 are the first adjusting mechanism 53 in the present embodiment.

  Further, as shown in FIGS. 3 and 6, two second housings extending in a direction intersecting with the wall surface 44 c facing the front side in the tool rotation direction T of the mounting seat 44, on the inner side in the axis O direction of the mounting seat 44. The holes 54 are formed so that they are arranged in parallel. In the present embodiment, these second receiving holes 54, 54 extend in a direction perpendicular to the wall surface 44 c facing the tool rotation direction T front side of the mounting seat 44, and the tool rotation direction T front side of the mounting seat 44 is extended to the front side. It is drilled so as to penetrate from the facing wall surface 44 c to the outer peripheral surface of the tool body 31. One of the two second receiving holes 54, 54 is disposed in the vicinity of the wall surface 44 b facing the tool body 31 radially outward of the mounting seat 44, and the other is disposed in the tool body 31 radially outer portion of the mounting seat 44. Thus, the clamp screw hole 45 is positioned between the two second accommodation holes 54 in the radial direction of the tool body 31.

As shown in FIGS. 5 and 6, the second receiving hole 54 is provided with a second pressing pin 55 on the mounting seat 44 side, and a second adjustment screw 56 at the rear end of the second pressing pin 55. Are screwed, and the rear end surface of the second adjustment screw 56 in which an engagement hole with which a work tool such as a wrench is engaged is formed is exposed toward the outer peripheral side of the tool body 31. An inclined plane that is inclined with respect to the axis of the second pressing pin 55 is formed at the tip of the second pressing pin 55, and this inclined plane contacts the second pressed surface 25 of the spherical cutter insert 20 described later. The second pressing surface 55a is in contact. The second pressing pin 55 and the second adjusting screw 56 are the second adjusting mechanism 57 in the present embodiment.
Therefore, the tool body 31 includes a first adjusting mechanism 53 that adjusts the position of the spherical cutter insert 20 in one direction (radial direction) intersecting each other when viewed from the front side of the tool rotation direction T and the other direction. 2 adjustment mechanism 57 is provided.

  Further, as shown in FIG. 8, fitting holes 60 extending in parallel with the axis O and opened at the outer peripheral end portion of the annular flat surface portion 41 are formed in both end faces 35, 35 of the tool body 31. Yes. A fixing screw hole 61 communicating with the insertion hole 60 and extending in a direction perpendicular to the insertion hole 60 is formed in the center part of the insertion hole 60 in the axis O direction. In addition, a positioning screw hole 62 communicating with the insertion hole 60 and extending in a direction orthogonal to the insertion hole 60 is formed in the inner portion of the insertion hole 60 in the axis O direction. In the present embodiment, the fixing screw hole 61 and the positioning screw hole 62 are arranged in parallel with each other and in parallel with the second accommodation hole 54. A fixing screw 63 having a substantially cylindrical shape is screwed into the fixing screw hole 61, and the front end surface of the fixing screw 63 has a planar shape extending perpendicular to the axis of the cylinder formed by the fixing screw 63. Is formed. On the other hand, a positioning screw 64 having a tapered tip is screwed into the positioning screw hole 62.

  A chamfering tip 65 made of a hard material such as cemented carbide and having an outer shape that is substantially cylindrical is inserted into the insertion hole 60. The front end of the chamfered tip 65 is cut into a semicircular cross section perpendicular to the center axis of the cylinder formed by the chamfered tip 65, and the cutout surface 66 is a scooping surface, and the side facing the cutout surface 66. The tip edge is cut out so as to intersect the central axis at about 45 ° when viewed from the side, and a chamfered cutting edge 67 is formed at the tip edge.

  Further, the rear end portion of the chamfered tip 65 extends in a direction perpendicular to the notch surface 66 and is opposite to the chamfered cutting edge 67 when viewed from the direction facing the notch surface 66 with respect to the central axis. In addition, an inclined surface portion 68 is formed, and a flat surface portion 69 that extends in a direction orthogonal to the notch surface 66 and is parallel to the central axis is formed on the outer peripheral surface of the chamfered tip 65. The chamfered cutting edge 67 and the inclined surface portion 68 are formed on the side approaching each other.

  Such a chamfered chip 65 is inserted into the fitting hole 60 with the chamfered cutting edge 67 facing outward in the axis O direction, and the flat surface portion 69 is disposed so as to face the side where the fixing screw hole 61 is opened. Here, the taper angle at the tip of the positioning screw 64 is the same as the inclination angle of the inclined surface portion 68 formed at the rear end portion of the chamfered chip 65, and the chamfered chip 65 is screwed by screwing the positioning screw 64. Can be moved outward in the direction of the axis O. After adjusting the position in the direction of the axis O, the chamfered tip 65 is pressed and fixed inward in the radial direction of the tool body 31 by screwing a fixing screw 45 whose tip is in contact with the flat surface portion 69.

  As shown in FIG. 4, a clamp screw 70 for mounting the spherical cutter insert 20 on the mounting seat 44 is formed in a substantially cylindrical shape extending along the central axis M, and coaxial with the shaft portion 71. The head portion 72 is disposed, and a male screw is formed on the outer peripheral surface of the shaft portion 71. The surface of the head portion 72 on the shaft portion 71 side is formed in a planar shape extending in a direction orthogonal to the central axis M of the shaft portion 71 and is in contact with the spherical cutter insert 20. It is said that.

The spherical cutter insert 20 is mounted on the mounting seat 44 of the tool body 31 as follows. The spherical cutter insert 20 is mounted such that the mounting surface 21a of the spherical cutter insert 20 contacts the wall surface 44c of the mounting seat 44 facing the front side in the tool rotation direction T. Here, the first pressed surface 24 of the spherical cutter insert 20 is disposed to face the wall surface 44 b facing the outer side in the radial direction of the tool main body 31 of the mounting seat 44, and the second pressed surface 25 is formed of the mounting seat 44. Opposing to the wall surface 44a facing outward in the direction of the axis O. Then, the arcuate cutting edge 23 is arranged so as to face the outside in the direction of the axis O.
Further, in the state where the spherical cutter insert 20 is placed in this way, the center of the clamp screw hole 45 is located on the inner side of the insertion hole 26 in the axis O direction and the tool as viewed from the front side in the tool rotation direction T. The body 31 is slightly eccentric toward the inside in the radial direction.

The first pressed surface 24 of the spherical cutter insert 20 is in contact with the first pressed surface 51 a of the first pressing pin 51 disposed in the first receiving hole 50. 2 A second pressing surface 55 a of a second pressing pin 55 disposed in the second accommodation hole 54 is in contact with the pressed surface 25.
With the spherical cutter insert 20 placed on the mounting seat 44 as described above, the clamp screw 70 is inserted through the insertion hole 26 and is drilled in the wall surface 44c facing the front side in the tool rotation direction T of the mounting seat 44. Screw into the clamp screw hole 45. Then, the abutting surface 72 a of the clamp screw 70 is abutted against the clamping surface 27 of the spherical cutter insert 20 and pressed toward the mounting seat 44, and the spherical cutter insert 20 is fixed to the mounting seat 44.

Here, in this embodiment, the clamping surface 27 of the insert 20 for the spherical cutter gradually recedes from the parallelogram surface 21 which is a scooping surface 51a toward the outside of the tool body 31 in the adjustment direction of the second adjustment mechanism 57. Are arranged to be.
Therefore, when the abutting surface 72a of the clamp screw 70 is abutted against the clamp surface 27 of the spherical cutter insert 20 and is pressed toward the mounting seat 44, the clamp surface 27 of the spherical cutter insert 20 is inclined backward. The wall surface 44a facing the outer side in the axis O direction of the mounting seat 44 and the wall surface facing the outer side in the radial direction of the tool body 31 so as to be pulled inwardly in the radial direction of the tool body 31 and inward of the axis O direction. It is fixed so as to be pressed against 44b.

  Further, the spherical cutter insert 20 mounted on the two mounting seats 44 and 44 formed on the end surface 35 facing the same side is on the virtual plane S in which the rake face 21b of the mutual spherical cutter insert 20 passes the axis O. The rotation trajectory centered on the axis O of the arcuate cutting edge 23 formed in the spherical cutter insert 20 is centered on the center P (P ′) and is located on the end face 35. Are arranged so as to form one spherical surface R (R ′) having a large step radius.

  In the insert detachable spherical cutter 30 having such a configuration, when the first adjustment screw 52 is screwed, the first pressing pin 51 moves toward the mounting seat 44 side, and the first pressing surface 51a becomes the spherical cutter insert 20. When the first pressed surface 24 is pressed, the spherical cutter insert 20 moves outward in the radial direction of the tool body 31, and the radial position of the arcuate cutting edge 23 in the tool body 31 is adjusted. Further, when the second adjustment screw 56 is screwed in, the second pressing pin 55 moves toward the mounting seat 44, and the second pressing surface 55 a presses the second pressed surface 25 of the spherical cutter insert 20, thereby The position of the arcuate cutting edge 23 is adjusted by moving the cutter insert 20 toward the outer side in the axis O direction and the outer side in the radial direction of the tool body 31.

  In this insert detachable spherical cutter 30, the position of the arcuate cutting blade 23 is adjusted as described above, and the arcuate shapes of the two spherical cutter inserts 20 and 20 mounted on the mounting seat 44 on the same end face 35 side. The positions of the cutting blades 23 and 23 are adjusted so as to coincide with each other in the rotation trajectory centered on the axis O, that is, on the spherical surface R (R ′) centered on the center P (P ′). In this state, it is subjected to the cutting shown in FIG.

  The insert detachable spherical cutter 30 is housed in a cavity C formed in the workpiece W, and is inserted into the pair of insertion holes H, H formed coaxially in the workpiece W so as to be inserted into the cavity C. A pair of arbors A and A (not shown) are respectively inserted, and the tips of these arbors A and A are supported by attaching them to the attachment holes 37 from the outside in the axis O direction. Here, the front end of the arbor A is formed with a drive section D having a square cross section that fits into the square hole portion 40 of the mounting hole 37, and the rear end side is equal to the tapered hole portion 38. A taper portion E that is reduced in diameter toward the tip side at a taper angle is formed, and the axis O of the tool body 31 is changed to the rotation axis by the arbors A and A by closely contacting the taper portion E and the taper hole 38. At the same time, the tool body 31 is rotated together with the arbors A and A toward the tool rotation direction T by fitting the square hole portion 40 and the drive portion D together.

  While the tool body 31 is rotated around the axis O, feed is performed by the arbors A and A so as to reciprocate in both directions in the direction of the axis O together with the arbors A and A. Around the holes H, the arcuate cutting edge 23 of the spherical cutter insert 20 mounted on the mounting seat 44 of the end surface 35 facing each insertion hole H side has a center P (P ′) on the axis O, respectively. Concave spherical counterbore portions F, F having the same diameter as the spherical surface R (R ′) are formed, and at the same time, the counterbore F and the insertion hole H intersect with the cutting edge of the chamfered tip 65. Chamfer the ridgeline.

  Furthermore, the feed amount of the reciprocating motion of the tool main body 31 by the arbor A, A is determined by the arcuate cutting edge 23 of the insert 20 for the spherical cutter mounted on the mounting seat 44 of each end face 35 that forms each counterbore F. By setting the positions of the centers P (P ′) of the spherical surface R (R ′) formed by the rotation trajectory to coincide with each other, the recesses formed by these counterbore portions F and F formed at both ends of the cavity C The spherical surface can be a concave spherical surface along one spherical surface R.

  In the spherical cutter insert 20 according to the present embodiment, the parallelogram surface 21 that is the rake face 21 b is inserted into the insertion hole 26 that penetrates in the thickness direction, and a plane that is orthogonal to the central axis L of the insertion hole 26. On the other hand, a clamp surface 27 that is inclined so as to gradually retreat from the parallelogram surface 21 (rake surface 21b) as it approaches the arcuate cutting edge 23 is provided. A clamp screw 70 having a shaft portion 71 having a substantially cylindrical shape extending along the head and a head portion 72 having a flat contact surface 72a extending in a direction orthogonal to the central axis M is inserted and fixed. Therefore, the contact surface 72a of the clamp screw 70 and the clamp surface 27 are not in close contact with each other, and a slight gap is formed in the arc-shaped cutting blade 23 side portion of the clamp surface 27.

The clamp surface 27 is gradually retracted from the scoop surface 21b in the direction in which the spherical cutter insert 20 is pressed by the second adjustment mechanism 57, that is, toward the outside of the tool body 31 in the adjustment direction by the second adjustment mechanism 57. Therefore, the gap is generated in the deformation direction of the clamp screw 70. Therefore, when the second adjustment screw 56 is screwed and the second pressing pin 55 is moved to the mounting seat 44 side and the second pressed surface 25 of the spherical cutter insert 20 is pressed by the second pressing surface 55a, the clamp is clamped. The screw 70 can be easily deformed so as to be bent even with a small pressing force, the spherical cutter insert 20 can be gradually pressed and moved, and the position of the arcuate cutting edge 23 can be adjusted smoothly.
Further, since the deformation amount of the clamp screw 70 is secured by the gap, the movement amount of the spherical cutter insert 20 is increased, and the position adjustment amount of the arcuate cutting blade 23 can be secured.

  Furthermore, in the present embodiment, the crossing angle θ between the plane orthogonal to the central axis L of the insertion hole 26 and the clamp surface 27 falls within the range of 0 ° 10 ′ ≦ θ ≦ 15 °, more specifically, Since θ = 3 ° is set, the gap between the abutting surface 72a of the clamp screw 70 and the clamp surface 27 is surely formed, the deformation amount of the clamp screw 70 is secured, and the arcuate cutting edge 23 is formed. Position adjustment can be performed smoothly, and it is possible to prevent the gap between the contact surface 72a and the clamp surface 27 from becoming too large and fixing the spherical cutter insert 20 to be insufficient.

  Further, according to the insert detachable spherical cutter 30 having this configuration, the radial position of the arcuate cutting blade 23 is adjusted by pressing the spherical cutter insert 20 toward the tool body 31 radially outward. The first pressing pin 51 and the first adjusting screw 52 (first adjusting mechanism 53), and the second pressing the spherical cutter insert 20 in a direction crossing the radial direction when viewed from the front side of the tool rotation direction T. Since the pressing pin 55 and the second adjustment screw 56 (second adjustment mechanism 57) are provided, the position of the arcuate cutting blade 23 can be adjusted by moving it in two directions. The position adjustment of the blade 23 can be performed easily and accurately.

  Therefore, even when the arcuate cutting edge 23 is worn due to use and the spherical cutter insert 20 is replaced, the position of the arcuate cutting edge 23 can be adjusted easily and accurately so that one point on the axis of the tool body 31 is centered. The spherical counterbore F having a predetermined diameter can be accurately formed on the inner surface of the cavity C of the workpiece W.

  Further, the center of the clamp screw hole 45 drilled in the mounting seat 44 is slightly inward of the tool body 31 in the radial direction and in the axis O direction with respect to the insertion hole 26 of the spherical cutter insert 20 placed on the mounting seat 44. The spherical cutter insert 20 is fixed by a clamp screw 70 so as to be pulled inwardly in the radial direction of the tool body 31 and inward of the axis O direction. When the spherical cutter insert 20 is not pressed by the second pressing pin 55, the arcuate cutting edge 23 is positioned inside the tool body 31 in the radial direction and inside the axis O. Therefore, by adjusting the screwing amounts of the first adjustment screw 52 and the second adjustment screw 56, the position of the arcuate cutting blade 23 can be adjusted so as to be able to advance and retract in the adjustment direction. It becomes even easier.

The spherical cutter insert and the insert detachable spherical cutter according to the embodiment of the present invention have been described above. However, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the present invention. It is.
For example, the clamp surface has been described as being recessed and inclined so as to recede from the rake face and the parallelogram surface as it goes toward the cutting edge, but the present invention is not limited to this. As shown, the clamp surface may protrude from the rake face, and the protrusion height may decrease as it goes toward the cutting edge.

In addition, although the description has been given with the clamp surface partially formed in the vicinity of the opening hole of the insertion hole, the present invention is not limited to this, and as shown in FIGS. 12 and 13, the part other than the vicinity of the inside of the cutting blade May be inclined.
Furthermore, although the shape of the spherical cutter insert has been described as a parallelogram flat plate shape, the shape of the insert is not limited, and any shape can be used as long as the arcuate cutting edge can be disposed toward the outside in the axis O direction.

In addition, the clamp screw has a hemispherical head, but the present invention is not limited to this, and the head may be formed in a flat plate shape and orthogonal to the axis of the shaft portion. As long as it has an abutting surface extending in a similar manner.
Furthermore, although the tool body has been described as an insert detachable spherical cutter provided with the first and second adjustment mechanisms, the tool body is not limited to this and may be provided with only one adjustment mechanism.

It is a top view of the insert for spherical cutters which is an embodiment of the present invention. It is WW sectional drawing in FIG. It is a side view of a detachable spherical cutter. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is an A direction arrow directional view in FIG. It is a B direction arrow line view in FIG. It is ZZ sectional drawing in FIG. It is explanatory drawing which shows the state which cuts a workpiece | work with the insert detachable spherical cutter shown in FIG. It is a top view of the insert for spherical cutters which is other embodiments of the present invention. It is WW sectional drawing in FIG. It is a top view of the insert for spherical cutters which is other embodiments of the present invention. It is WW sectional drawing in FIG.

Explanation of symbols

20 Insert 21 for spherical cutter Parallelogram surface (polygonal surface)
23 Arc-shaped cutting edge (cutting edge)
26 Insertion hole 27 Clamp surface 30 Insert detachable spherical cutter 31 Tool body 44 Mounting seat 53 First adjustment mechanism (position adjustment mechanism)
57 Second adjustment mechanism (position adjustment mechanism)
70 Clamp screw 71 Shaft 72a Contact surface

Claims (3)

An insert for a spherical cutter that has an arcuate cutting edge and is attached to a spherical cutter that forms a spherical counterbore in a cavity provided in the workpiece,
At least one side has a polygonal surface that swells in an arc shape toward the outside, and the cutting edge is provided on the one side that swells in this arc shape,
The polygonal surface is formed with an insertion hole into which a clamp screw having a shaft portion and a contact surface orthogonal to the shaft portion is inserted, and a clamp surface with which the contact surface is contacted. And
The spherical cutter insert according to claim 1, wherein the clamp surface is inclined with respect to a plane orthogonal to the axis of the insertion hole so as to gradually recede as the cutting edge is approached.   2. The spherical cutter according to claim 1, wherein an intersection angle θ between a plane perpendicular to the axis of the insertion hole and the clamp surface is set in a range of 0 ° 10 ′ ≦ θ ≦ 15 °. Insert for. An insert detachable spherical cutter in which the spherical cutter insert according to claim 1 or 2 is mounted, and a spherical counterbore portion is formed in a hollow portion provided in the workpiece by the arc-shaped cutting blade. And
A tool body that rotates about an axis, and a mounting seat is formed on an end surface facing the axial direction, and the insert for the spherical cutter mounted on the mounting seat is provided in an adjustment direction. A position adjusting mechanism for pressing and adjusting the position of the cutting blade is provided;
In the mounting seat, the spherical cutter insert is positioned on a spherical surface centered on the axis of the arc formed by the cutting blade, and the clamping surface is directed to the outside of the tool body in the adjustment direction. Accordingly, the insert detachable spherical cutter is arranged so as to gradually retreat from the polygonal surface.

Images