JP6569403B2 - Replaceable cutting tool - Google Patents

Description

  The present invention relates to a cutting edge-exchangeable cutting tool in which a cutting insert having an insert body formed with a cutting blade is detachably attached to an insert mounting seat formed on the tool body.

  In such a blade-tip-exchange-type cutting tool, for example, the one described in Patent Document 1 is known as having a coolant supply path for cooling the cutting region of the cutting insert. In the cutting edge-exchangeable cutting tool described in Patent Document 1, an insert mounting seat is formed in which a cutting insert having a circular cutting edge is fitted and fixed at the tip of a shaft-shaped tool holder. A through hole is formed along the central axis to open to the insert mounting seat, and the cutting insert is also formed to have a through hole communicating with the through hole and open to the top surface on which the cutting blade is formed. The coolant can be supplied through these through holes.

Special table 2011-506111 gazette

  However, in the cutting edge-exchangeable cutting tool described in Patent Document 1, the coolant is discharged perpendicularly to the top surface (rake surface) of the cutting insert having a cutting edge formed on the peripheral edge. It has been difficult to efficiently supply coolant to the cutting site of the work material. Also, if the cutting insert is tried to be firmly fixed by inserting a clamp screw into the through hole of the cutting insert and screwing it into the through hole of the tool holder, the coolant supply path is blocked and the coolant itself is supplied. become unable.

  The present invention has been made under such a background, and it is possible to supply the coolant even when the cutting insert is fixed by the clamp screw, and the supplied coolant can be efficiently used for the cutting blade and the cutting site. It aims at providing the cutting-edge-exchange-type cutting tool which can be discharged | emitted in the middle.

In order to solve the above problems and achieve such an object, the present invention provides, as a first invention , a cutting insert having an insert body in which a cutting blade is formed on an insert mounting seat formed in a tool body. Is a detachable cutting tool with a detachable attachment, wherein the insert body has a through-hole through which a clamp screw is inserted, and the insert mounting seat is screwed with the clamp screw A hole is formed, and the through hole opens in the pressed surface of the insert body, and the cutting blade is formed in a side ridge portion on the upper surface of the insert body on the side where the pressed surface is provided. The cutting insert is configured such that the pressed surface is a pressing surface of the washer by a washer interposed between the head of the clamp screw and the insert body. Therefore, it is pressed and attached to the insert mounting seat, and the through hole communicates with a coolant supply hole formed in the tool body, and the pressing surface of the washer communicates with the through hole and communicates with the through hole. A coolant discharge groove for discharging the coolant is formed on the upper surface of the insert body, and the plurality of coolant discharge grooves are formed radially on the pressing surface of the washer, and the groove width becomes wider toward the outer peripheral side. It is characterized by that.
Moreover, this invention is a blade-tip-exchange-type cutting tool in which the cutting insert which has the insert main body in which the cutting blade was formed was detachably attached to the insert mounting seat formed in the tool main body as 2nd invention. The insert body has a through hole into which a clamp screw is inserted, and the insert mounting seat has a clamp screw hole into which the clamp screw is screwed, and the through hole is formed in the insert body. The cutting blade is formed in a side ridge portion of the upper surface of the insert body on the side where the pressed surface is provided, and the cutting insert is a head of the clamp screw. Is attached to the insert mounting seat by the washer interposed between the insert body and the insert body. The through hole communicates with a coolant supply hole formed in the tool body, and a coolant that discharges coolant to the upper surface of the insert body communicates with the through hole on the pressing surface of the washer. A discharge groove is formed, and a recess is formed on the upper surface of the insert body on which the cutting blade is formed. The bottom surface of the recess is the pressed surface, and the washer is a protruding end. A convex portion that is the pressing surface and is accommodated in the recess; and a flange portion that projects on the upper surface of the insert body; and an inner peripheral surface of the recess and an outer peripheral surface of the convex portion. A space is provided over the entire circumference between the gap and the upper surface of the insert main body on which the cutting edge is formed and the side surface of the flange portion facing the upper surface.
Furthermore, the present invention provides, as a third invention, a cutting edge-exchangeable cutting tool in which a cutting insert having an insert body formed with a cutting blade is detachably attached to an insert mounting seat formed on the tool body. The insert body has a through hole into which a clamp screw is inserted, and the insert mounting seat has a clamp screw hole into which the clamp screw is screwed, and the through hole is formed in the insert body. The cutting blade is formed in a side ridge portion of the upper surface of the insert body on the side where the pressed surface is provided, and the cutting insert is a head of the clamp screw. And the insert body, the pressed surface is pressed by the pressing surface of the washer and is attached to the insert mounting seat. The through hole communicates with a coolant supply hole formed in the tool body, and the pressure surface of the washer communicates with the through hole to discharge the coolant to the upper surface of the insert body. A coolant discharge groove is formed, and a plurality of the coolant discharge grooves are formed radially on the pressing surface of the washer, and the groove width becomes wider toward the outer peripheral side, and the cutting blade is formed. A recess is formed in the upper surface of the insert body, and the bottom surface of the recess is used as the pressed surface, and the washer is received in the recess with the protruding end surface serving as the pressing surface. An upper surface of the insert main body, which includes a convex portion and a flange portion projecting on the upper surface of the insert main body, between the inner peripheral surface of the recess and the outer peripheral surface of the convex portion, and on which the cutting blade is formed. And this top Between the side surface of the flange portion opposite to it, characterized in that it spaced over the entire circumference.

  In the blade replacement type cutting tool configured in this way, the coolant supplied from the coolant supply hole of the tool body passes between the screw shaft portion of the clamp screw screwed into the clamp screw hole and the through hole of the insert body, It is supplied between the pressed surface of the insert body in which the through hole is opened and the pressing surface of the washer that presses the pressed surface, and is discharged from a coolant discharge groove formed on the pressing surface. The pressed surface is provided on the upper surface side where the cutting edge of the insert body is formed, and the pressed surface presses the pressed surface so as to face the pressed surface, so that the discharged surface is discharged from the coolant discharge groove. The applied coolant is efficiently supplied toward the cutting edge and the cutting site by the cutting edge.

Here, when the coolant supply hole includes one or a plurality of branch holes communicating with the through hole, the sum of the minimum cross-sectional areas of the coolant discharge grooves is equal to or greater than the sum of the minimum cross-sectional areas of the branch holes. By doing so, it is possible to prevent the resistance when the coolant is discharged from the coolant discharge groove from being increased. For this reason, even when supplying coolant to the coolant supply hole of the tool body, supply pressure higher than necessary is not required, and it is also efficient. In the case Edaana is one, the sum of the minimum cross-sectional area is the smallest cross-sectional area of the one Edaana, when the coolant discharge groove and Edaana is plural, the sum of the minimum cross-sectional area The sum of the minimum cross-sectional areas of the plurality of coolant discharge grooves and branch holes.

Further, for example, when the cutting insert has a circular cutting edge as described in Patent Document 1, as in the first and third inventions, a plurality of the coolant discharge grooves, By forming a radial shape on the pressing surface of the washer and increasing the groove width toward the outer peripheral side, the coolant can be uniformly supplied to such a circular cutting edge, and the cutting site Of course, not only the cutting edge part in the part but also the cutting edge in the part away from the cutting part can be cooled efficiently.

On the other hand, in the first invention, the pressing surface of the washer may be pressed directly with the upper surface of the insert body on which the cutting blade is formed as the pressed surface, but as in the second and third inventions. In addition, a recess is formed on the upper surface of the insert body, and the bottom surface of the recess is used as the pressed surface, and the washer has a protruding end surface as the pressing surface and is accommodated in the recess. A flange portion projecting on the upper surface of the insert body, and between the inner peripheral surface of the recess and the outer peripheral surface of the convex portion, and the upper surface of the insert main body on which the cutting blade is formed. A space may be provided over the entire periphery between the side surface of the flange portion facing the upper surface.

  When configured in this way, the coolant is discharged from between the coolant discharge groove formed on the protruding end surface of the convex portion that is the pressing surface of the washer and the bottom surface of the recess that is the pressed surface of the insert body, It passes through the gap between the outer peripheral surface of the convex portion and the inner peripheral surface of the recess, and further passes through the gap between the upper surface on which the cutting edge of the insert body is formed and the side surface of the flange portion facing it. It is discharged towards. And since a turbulent flow arises in the coolant discharged | emitted when passing through these space | interval parts, a coolant can be discharged | emitted toward a cutting blade more uniformly and efficiently.

  Further, in order to prevent the clamp screw from being worn and damaged by scraping of chips generated by the cutting blade during cutting, the head of the clamp screw is provided with the washer in which the head is accommodated. It is desirable to be buried so as not to protrude from the receiving hole. In particular, in the case of such a configuration, the washer is made of a material having a hardness higher than that of the clamp screw, thereby preventing damage to the washer together with the clamp screw, thereby providing a long-life blade-replaceable cutting tool. Can be provided.

  As described above, according to the present invention, the coolant can be supplied even when the cutting insert is fixed to the insert mounting seat by the clamp screw, and the coolant thus supplied can be efficiently applied to the cutting blade and the cutting site. It becomes possible to discharge and to cool and lubricate.

It is a perspective view which shows one Embodiment of this invention. It is the top view which looked at embodiment shown in FIG. 1 from the front end side. It is a side view of embodiment shown in FIG. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is a disassembled perspective view of embodiment shown in FIG. It is a perspective view of the tool main body of embodiment shown in FIG. It is the top view which looked at the tool main body shown in FIG. 7 from the front end side. It is a side view of the tool main body shown in FIG. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. 1A is a perspective view as viewed from the front end side, (b) is a perspective view as viewed from the rear end side, (c) is a plan view as viewed from the front end side, and (d) is a rear end side. It is the bottom view seen from, (e) side view, (f) ZZ sectional drawing in figure (c). 1 is a perspective view of the washer in the embodiment shown in FIG. 1 as viewed from the front end side, (b) a perspective view from the rear end side, (c) a plan view from the front end side, and (d) from the rear end side. It is the bottom view seen, (e) Side view, (f) ZZ sectional drawing in figure (c).

  1 to 13 show an embodiment of the present invention. The cutting edge replacement type cutting tool of the present embodiment is such that a cylindrical shaft-shaped tool body 1 is attached to a machine tool such as a multi-tasking machine and is driven to rotate around an axis O, while the tip of the tool body 1 (FIG. 1). 6 and 7, by a circumferential cutting blade centering on the axis O of the cutting insert 2 detachably attached to the upper left part in FIGS. 6 and 7 and the upper part in FIGS. 3 to 5 and 9 to 11. The present invention is applied to a so-called drive type rotary tool for turning a work material.

  The tool main body 1 according to the present embodiment is such that the tip end portion is centered on the axis O with a metal material such as a steel material, and the tip end portion is a rear end portion (lower right portion in FIGS. 1, 6, and 7, FIGS. 3 to 5, 9). To FIG. 11 is formed in a multistage outer cylindrical shape having an outer diameter larger than that of the lower portion), and the rear end portion is gripped by the machine tool and rotated. An insert mounting seat 3 on which the cutting insert 2 is seated is formed on the front end surface of the tool body 1, and the cutting insert 2 seated on the insert mounting seat 3 in this way includes a clamp screw 4 and a washer 5. Is attached to the tool body 1 in a detachable manner.

  The cutting insert 2 has a positive type round shape in which the insert body 2A is formed of a hard material such as cemented carbide in a multi-stage (two-stage) truncated cone shape with the axis O as the center as shown in FIG. It is a piece insert. One circular surface having a large diameter of the insert main body 2A is a rake surface, and a cutting edge 2B is formed on the peripheral edge thereof. That is, the upper surface 2C on which the cutting edge 2B of the insert body 2A is formed is the one circular surface. In the present embodiment, the upper surface 2C is a flat surface perpendicular to the axis O, and the diameter thereof, that is, the diameter of the cutting edge 2B is larger than the outer diameter of the tip portion of the tool body 1.

  Further, the insert body 2A is formed with a through-hole 2D having a circular cross section around the axis O having a constant inner diameter along the axis O. A recess 6 having an inner diameter slightly larger than that of the through hole 2D and having a circular cross section around the axis O is formed in the opening on the upper surface 2C side of the through hole 2D. Is the pressed surface 6A in the present embodiment. The pressed surface 6A is also a flat surface perpendicular to the axis O, and the inner peripheral surface 6B of the recess 6 is formed in a tapered surface shape that slightly increases in diameter toward the upper surface 2C side.

  The other circular surface having a small diameter of the insert body 2A opposite to the upper surface 2C is a seating surface 2E for the insert mounting seat 3. Here, in the present embodiment, the opening of the through hole 2D toward the seating surface 2E is also provided with an annular groove 7A that circulates around the opening of the through hole 2D around the axis O, and the annular groove 7A. A recess 7 having a plurality of grooves 7B extending radially outward with respect to the axis O in a bottom view is formed. The annular groove 7A and the recessed groove 7B are equal in depth to each other and shallower than the recessed part 7 on the upper surface 2C side, and in the present embodiment, four recessed grooves 7B are formed at equal intervals in the circumferential direction. The end does not reach the outer peripheral surface of the insert body 2A and is closed in a semicircular shape when viewed from the bottom as shown in FIG.

  The insert mounting seat 3 on which such a cutting insert 2 is seated includes a circular bottom surface 3A perpendicular to the axis O to which the seating surface 2E of the insert body 2A is in close contact, and the tip surface of the tool body 1 from the bottom surface 3A. And a peripheral wall surface 3 </ b> B extending to the center. The peripheral wall surface 3B is formed in a cylindrical surface shape with the rear end side (bottom surface 3A side) centering on the axis O having the same inner diameter as the diameter of the bottom surface 3A, while the inner diameter gradually increases toward the front end side. When the seating surface 2E of the insert main body 2A is seated in close contact with the bottom surface 3A, it is slidably contacted with the outer peripheral surface of the insert main body 2A on the seating surface 2E side. It is possible.

  A clamp screw hole 3C into which the clamp screw 4 is screwed is formed along the axis O from the center of the bottom surface 3A toward the rear end side. A screw hole 3D having a smaller diameter than the clamp screw hole 3C is formed in parallel to the axis O at a position spaced from the clamp screw hole 3C on the bottom surface 3A to the outer peripheral side. The part-attached screw 8 is screwed in, and its head 8A protrudes as a protrusion from the bottom surface 3A. When the cutting insert 2 is seated on the insert mounting seat 3 as described above, the protruding head portion 8A is inserted into a part (one in this embodiment) of the concave grooves 7B among the plural concave grooves 7B. It can be accommodated.

  On the other hand, from the rear end surface of the tool body 1 toward the front end side, a coolant supply hole 9 having a circular cross section having a larger diameter and a constant inner diameter than the clamp screw hole 3C is formed along the axis O, and this coolant supply hole. In this embodiment, 9 communicates with the clamp screw hole 3C. Accordingly, a step surface 9A having a smaller inner diameter toward the tip side of the tool body 1 is formed between the coolant supply hole 9 and the clamp screw hole 3C. The step surface 9A is formed on the tip side. It is formed in a tapered surface shape whose inner diameter is reduced as it goes.

  Further, from the step surface 9A toward the bottom surface 3A of the insert mounting seat 3, a branch hole 9B having a constant cross-sectional diameter smaller than the coolant supply hole 9 and the clamp screw hole 3C is formed as a part of the coolant supply hole 9. It is formed and opens to the bottom surface 3A with a gap from the clamp screw hole 3C. This branch hole 9B is inclined and extended toward the outer peripheral side with respect to the axis O as it goes to the bottom surface 3A side (tip side), and such branch holes 9B are the plurality of grooves in the cutting insert 2 described above. The number of differences between the total number of 7B and the number of the concave grooves 7B (three in this embodiment) is formed. Note that the sum of the cross-sectional areas of these branch holes 9B in the cross section perpendicular to the axis O is set to be smaller than the cross-sectional area of the coolant supply hole 9 in the large diameter portion. The sum of the cross-sectional areas in the holes 9B is the sum of the minimum cross-sectional areas of the coolant supply holes 9.

  Further, the openings in the bottom surface 3A of these branch holes 9B are straight lines connecting the centers of the openings of these branch holes 9B and the axis O when viewed from the front side in the direction of the axis O as shown in FIG. The straight line connecting the center of the screw hole 3D and the axis O is formed so as to be arranged at equal intervals in the circumferential direction, and the interval from the axis O is the groove 7B from the axis O in the cutting insert 2. It is formed so as to be smaller than the distance to the outer peripheral end of the. Accordingly, in the state where the head 8A of the screw 8 with the head is accommodated in the part of the concave groove 7B and the cutting insert 2 is seated on the insert mounting seat 3 as described above, the part of the concave groove 7B is formed. The branch hole 9B opens so as to face the remaining concave groove 7B.

  Further, the clamp screw 4 is formed of a steel material or the like as in the tool body 1, and includes a screw shaft portion 4A that is screwed into the clamp screw hole 3C and a head portion 4B having a larger diameter than the screw shaft portion 4A. Yes. The screw shaft portion 4A is formed such that a screw thread spirally wound around the axis O is continuously formed over the entire circumference, and the outer diameter of the screw shaft portion 4A is the insert body 2A. This is made slightly smaller than the inner diameter of the through hole 2D, and a space is provided between the two in a state where the screw shaft portion 4A is inserted into the through hole 2D. An engagement hole 4C that engages with a work tool such as a wrench is formed in the distal end surface of the head 4B, and the rear end surface of the head 4B opposite to the distal end surface faces the screw shaft portion 4A side. Accordingly, the outer diameter is formed in a tapered surface shape that gradually decreases.

  On the other hand, the washer 5 is formed in an annular shape from, for example, maraging steel having a hardness higher than that of the clamp screw 4, or the same cemented carbide as the insert body 2A, and the tip portion is a large-diameter flange portion 5A. In addition, the rear end portion is a convex portion 5B having a smaller diameter than the flange portion 5A. The flange portion 5A has an outer diameter larger than the inner diameter of the recess 6 in the insert main body 2A of the cutting insert 2 and smaller than the diameter of the cutting edge 2B, and around the inner peripheral portion of the tip surface and the convex portion 5B. The extending rear end surface is a flat surface perpendicular to the axis O, while the outer peripheral portion of the front end surface is formed in a tapered surface extending toward the rear end side toward the outer peripheral side.

  Further, the convex portion 5B is formed in a tapered surface shape whose outer diameter gradually decreases as the outer peripheral surface thereof moves toward the rear end side, and the taper angle formed by the outer peripheral surface is formed by the inner peripheral surface 6B of the recess 6. It is set approximately equal to the taper angle. Furthermore, the protrusion height of the convex portion 5B from the rear end surface of the flange portion 5A is made larger than the depth of the recess 6 from the upper surface 2C of the insert body 2A to the pressed surface 6A, and the rear end surface of the convex portion 5B. The outer diameter of the protruding end surface 5C is smaller than the inner diameter of the pressed surface 6A, which is the bottom surface of the recess 6.

  Therefore, when the protrusion 5B is accommodated in the recess 6 so that the protruding end surface 5C is brought into contact with the pressed surface 6A and the insert body 2A and the washer 5 are arranged coaxially, the recess 6 of the insert body 2A Between the inner peripheral surface 6B and the outer peripheral surface of the convex portion 5B of the washer 5, and between the upper surface 2C of the insert body 2A and the rear end surface which is the side surface of the flange portion 5A facing the upper surface 2C, FIG. As shown in FIG. 4 and FIG. The protruding end surface 5C of the convex portion 5B is a pressing surface that presses the pressed surface 6A in the present embodiment, and a coolant discharge groove 5D is formed on the protruding end surface 5C.

  The coolant discharge groove 5D is formed so that a cross section along the circumferential direction of the washer 5 forms a rectangular shape flattened in the direction of the axis O, and the coolant discharge groove 5D having the same shape and the same size is formed in the circumferential direction. A plurality of strips (six strips in this embodiment) are formed at intervals equal to, and are formed from the inner periphery to the outer periphery of the protruding end surface 5C. Further, these coolant discharge grooves 5D are radially formed so that the groove width becomes wider toward the outer peripheral side, and the projecting end face 5C portion which is left between the adjacent coolant discharge grooves 5D and serves as a pressing surface is formed. As seen from the rear end side of the washer 5, it is formed in a rectangular shape extending in the radial direction as shown in FIG.

  As the coolant discharge groove 5D becomes wider toward the outer peripheral side in this way, the cross-sectional area of the coolant discharge groove 5D becomes minimum on the inner periphery of the projecting end face 5C. However, the sum of the minimum cross-sectional areas of the plurality of coolant discharge grooves 5D that is minimum on the inner periphery of the protruding end surface 5C is the sum of the minimum cross-sectional areas of the coolant supply holes 9 that is minimum in the branch hole 9B as described above. As described above, in the present embodiment, the coolant supply hole 9 is set to be larger than the sum of the minimum cross-sectional areas.

  Further, the inner peripheral portion of the washer 5 is a receiving hole 5E in which the head 4B of the clamp screw 4 is received, and the opening on the protruding end surface 5C side of the receiving hole 5E is formed by the rear end surface of the head 4B. It is formed in a tapered surface shape whose inner diameter is gradually reduced toward the protruding end surface 5C side at a taper angle equal to that of the tapered surface, and the rear end surface of the head 4B can be brought into contact therewith. Then, with the rear end surface of the head 4B in contact with the opening on the protruding end surface 5C side of the receiving hole 5E, the head 4B of the clamp screw 4 has a front end surface as shown in FIGS. The thickness in the direction of the axis O is set so as not to protrude from the accommodation hole 5E but to be buried in the accommodation hole 5E.

  Such a blade-tip-exchangeable cutting tool accommodates the cutting insert 2 by inserting the head 8A of the screw 8 with the head, which is a protrusion of the insert mounting seat 3, into a part of the concave groove 7B as described above. 3, a convex portion 5B is accommodated in the recess 6 of the insert body 2A, a washer 5 is disposed, and the screw of the clamp screw 4 inserted through the accommodation hole 5E of the washer 5 and the through hole 2D of the insert body 2A. By screwing the shaft portion 4A into the clamp screw hole 3C of the tool body 1, the washer 5 is pressed by the rear end surface of the head 4B of the clamp screw 4, and the cutting end 2 of the cutting insert 2 is further pressed by the protruding end surface 5C which is the pressing surface of the washer 5. The pressed surface 6 </ b> A is pressed toward the rear end side in the direction of the axis O, and the cutting insert 2 is attached to the tool body 1. Therefore, stable cutting can be performed by firmly fixing the cutting insert 2 to the tool body 1.

  At this time, the cutting insert 2 is positioned in the radial direction with respect to the axis O when the outer peripheral surface of the insert body 2A is in sliding contact with the tapered peripheral wall surface 3B of the insert mounting seat 3, and the circumference around the axis O is In the direction, the head 8A of the head-attached screw 8 which is a protrusion protruding from the bottom surface 3A is prevented from rotating by engaging with the part of the concave groove 7B. Accordingly, the circumferential cutting edge 2B of the cutting insert 2 can be accurately arranged coaxially with the axis O of the tool body 1, and high-precision cutting can be performed.

  In this cutting process, when coolant (fluid) such as cutting fluid, mist, or air is supplied from the machine tool to the coolant supply hole 9 of the tool body 1, the coolant is branched from the coolant supply hole 9 tip side. Through the hole 9B, the remaining groove 7B of the seating surface 2E of the insert body 2A facing the opening enters the remaining groove 7B from the opening in the bottom surface 3A of the insert mounting seat 3, and then the annular shape of the recess 7 on the seating surface 2E side. In this embodiment, the groove 7A is supplied to the recess 6 on the top surface 2C on the distal end side of the insert body 2A through the space between the through hole 2D of the insert body 2A and the screw shaft portion 4A of the clamp screw 4.

  Furthermore, in this embodiment, the convex part 5B of the washer 5 is accommodated in the recess 6, and the protruding end surface 5C that is a pressing surface of the washer 5 that presses the pressed surface 6A that is the bottom surface of the recess 6. The coolant discharge groove 5D is formed in the coolant, and the coolant supplied to the recess 6 is the interval between the coolant discharge groove 5D and the outer peripheral surface of the convex portion 5B and the inner peripheral surface 6B of the recess 6, and the insert body. 2A passes through the space between the upper surface 2C of 2A and the rear end surface, which is the side surface of the flange portion 5A facing the upper surface 2C, and is discharged along the upper surface 2C. And since the cutting edge 2B is formed in the peripheral part which is a side ridge part of this upper surface 2C in the side by which the to-be-pressed surface 6A was provided in 2A of insert bodies, according to the blade-tip-exchange-type cutting tool of the said structure. The coolant can be efficiently and surely supplied to the cutting blade 2B and the cutting portion of the work material by the cutting blade 2B for cooling and lubrication.

  Further, in particular, in the present embodiment, the cutting insert 2 is a circular piece insert as described above having a circumferential cutting edge 2B, whereas a plurality of coolant discharge grooves 5D are radially formed on the protruding end surface 5C. Since it is formed, not only the cutting edge 2B portion actually cut into the work material and the cutting site of the work material, but also the tool body 1 is driven away from the cutting site by the rotational drive, and the temperature becomes high due to the cutting. The coolant can also be supplied to the cutting blade 2B portion to cool it. Moreover, since these coolant discharge grooves 5D are formed so as to become wider toward the outer peripheral side, the coolant can be evenly distributed over the entire periphery of the cutting blade 2B.

Further, in the present embodiment, the sum of the minimum cross-sectional areas of the coolant discharge grooves 5D of the washer 5 is the sum of the minimum cross-sectional areas of the coolant supply holes 9 of the tool body 1 where the sum of the minimum cross-sectional areas of the branch holes 9B as described above. In particular, it is set to be larger than the sum of the minimum sectional areas of the coolant supply holes 9. For this reason, it is possible to reduce the pressure loss by preventing the resistance when the coolant is discharged from the coolant discharge groove 5D, and to reduce the coolant supply pressure to the coolant supply hole 9 of the tool body 1 more than necessary. Efficient coolant supply can be achieved without increasing the cost. In the present embodiment, a plurality of coolant discharge grooves 5D and branch holes 9B are formed, but one branch hole 9B may be provided. In this case, the sum of the minimum cross-sectional areas is the cross-sectional area of this one branch hole 9B.

  In the present embodiment, the recess 6 is formed on the upper surface 2C where the cutting blade 2B of the insert body 2A is formed, and the washer 5 is formed with a convex portion 5B accommodated in the recess 6; The protruding end surface 5C of the convex portion 5B is used as a pressing surface to form a coolant discharge groove 5D and press the bottom surface of the recess 6 which is the pressed surface 6A. For example, the upper surface 2C of the insert body 2A is A cutting insert having a through-hole 2D opened without forming a recess 6 and a washer 5 also having a coolant discharge groove 5D without forming a convex portion 5B and a rear end surface formed as a pressing surface. It is also possible to attach the coolant and supply the coolant. However, in this case, since the coolant discharged from the coolant discharge groove 5D is straightly injected to the cutting blade 2B, even if the coolant discharge groove 5D becomes wider toward the outer peripheral side, There is a risk that the coolant supply will be partially uneven.

  On the other hand, in the present embodiment, the convex portion 5B of the washer 5 is accommodated in the concave portion 6 thus formed on the upper surface 2C, and the outer peripheral surface of the convex portion 5B and the inner periphery of the concave portion 6 as described above. Since there is a space over the entire circumference between the surface 6B and between the upper surface 2C of the insert main body 2A and the rear end surface of the flange portion 5A projecting on the upper surface 2C opposite thereto, the coolant While the coolant discharged from the discharge groove 5D is blown toward the cutting edge 2B from between the upper surface 2C and the rear end surface of the flange portion 5A, turbulent flow is generated in these gap portions. For this reason, the coolant supply to the cutting blade 2B does not become uneven, and cooling and lubrication of the cutting blade 2B and the cutting site can be performed more efficiently.

  Further, in the present embodiment, the rear end surface of the head 4B of the clamp screw 4 comes into contact with the reduced diameter portion of the receiving hole 2E of the washer 5 on the seating surface 2E side in the insert body 2A, so that the cutting insert 2 is inserted into the insert mounting seat 3. The head 4 </ b> B is buried in the accommodation hole so as not to protrude from the front end surface of the washer 5. For this reason, even if the chips generated by the cutting blade 2B flow out from the upper surface 2C of the insert body 2A, which is the rake face, to the front end surface of the flange portion 5A of the washer 5, the head 4B of the clamp screw 4 is scratched. Therefore, it is possible to prevent the head 4B from being worn and damaged by such scraping of chips.

  In addition, in the present embodiment, the washer 5 itself is formed of a material such as maraging steel or cemented carbide having a hardness higher than that of the clamp screw 4 or the tool body 1, so that the wear of the washer 5 due to scraping of the chips is reduced. Damage can also be suppressed. Therefore, according to the present embodiment, it is possible to use the washer 5 and the clamp screw 4 for a long period of time, and by extension, it is possible to extend the life of the cutting edge-exchangeable cutting tool.

  On the other hand, in this embodiment, the seating surface 2E side provided with a plurality of concave grooves 7B extending radially outward from the through hole 2D on the seating surface 2E of the insert body 2A facing the bottom surface 3A of the insert mounting seat 3. The tool body 1 has a coolant supply hole 9 extending toward the insert mounting seat 3 and a branch hole 9B extending from the coolant supply hole 9 toward the bottom surface A of the insert mounting seat 3. Is formed. The bottom surface 3A of the insert mounting seat 3 is provided with a head 8A of a screw 8 with a head accommodated in the part of the recessed grooves 7B as a protrusion, and at a position facing the remaining recessed grooves 7B. The branch hole 9B is opened.

  For this reason, even if the coolant supply hole 9 and the clamp screw hole 3C extending from the rear end surface of the tool body 1 are arranged coaxially about the axis O as in the tool body 1 of the present embodiment, as described above. The coolant is supplied from the opening of the bottom surface 3A through the branch hole 9B to the remaining concave groove 7B facing the opening, and through the space between the through hole 2D of the insert body 2A and the screw shaft 4A of the clamp screw 4. It can be reliably supplied to the upper surface 2C side where the cutting blade 2B is formed. Therefore, a good rotation balance can be ensured particularly in the drive type rotary tool as in this embodiment.

  In the present embodiment, the annular groove 7A is formed between the concave groove 7B and the through hole 2D so as to go around the opening of the through hole 2D, and the coolant supplied from the branch hole 9B is It is supplied to the upper surface 2C side on which the cutting blade 2B is formed through the recess 7 on the seating surface 2E side provided with the annular groove 7A and the recessed groove 7B. For this reason, especially when the coolant is a liquid such as a cutting fluid, the recess 7 acts as a liquid reservoir, so that it is possible to stably supply the coolant even when the coolant supply amount fluctuates. It becomes.

  Furthermore, since the plurality of grooves 7B of the recess 7 are formed at equal intervals in the circumferential direction in the present embodiment, when the insert body 2A is seated on the insert mounting seat 3, any groove 7B is formed. Even when the head portion 8A of the head-attached screw 8 which is a protrusion is accommodated, the opening portion of the branch hole 9B can be opposed to and communicate with the remaining concave groove 7B. In addition, since the head 8A is housed in a part of the concave grooves 7B and engages with the insert main body 2A, the cutting insert 2 can be prevented from rotating, so that stable cutting can be performed.

  Furthermore, in the present embodiment, the coolant supplied to the recess 7 passes through the interval portion between the through hole 2D of the insert body 2A and the screw shaft portion 4A of the clamp screw 4 that clamps the cutting insert 2. It is supplied to the upper surface 2C side. For this reason, in this embodiment, the insert body 2A can be cooled also from the inner peripheral through-hole 2D side, and the insert body 2A can be reliably prevented from becoming hot due to cutting heat, and the cutting heat can be reduced. Is transmitted and the clamp screw 4 is heated to a high temperature to prevent the mounting stability of the cutting insert 2 from being impaired.

  In addition, in this embodiment, the coolant supply hole 9 communicates with the clamp screw hole 3C, so that the clamp screw 4 can be cooled from the end of the screw shaft portion 4A, and the cutting insert 2 can be more stably provided. It can be attached. However, for example, when the clamp screw 4 can be sufficiently cooled by supplying coolant to the through-hole 2D, the coolant supply hole 9 and the clamp screw hole 3C are not communicated with each other, and are formed in a blind hole shape. May be.

  In the present embodiment, the branch hole 9 </ b> B extends toward the outer peripheral side from the tip of the coolant supply hole 9 toward the bottom surface 3 </ b> A of the insert mounting seat 3. For this reason, not only when the coolant supply hole 9 has a larger diameter than the clamp screw hole 3C as in the present embodiment, but also when the coolant supply hole 9 has the same diameter or a small diameter, it is sufficient between the clamp screw hole 3C. The branch hole 9B can be formed with a sufficient interval, and the coolant can be reliably supplied while ensuring the mounting stability of the cutting insert 2. However, when the coolant supply hole 9 has a sufficiently larger diameter than the clamp screw hole 3C, the branch hole 9B may extend in parallel to the axis O, for example.

DESCRIPTION OF SYMBOLS 1 Tool main body 2 Cutting insert 2A Insert main body 2B Cutting blade 2C Upper surface of insert main body 2A in which cutting blade 2B was formed 2D Through-hole 2E Seating surface 3 Insert mounting seat 3A Bottom surface of insert mounting seat 3 3B Circumferential wall surface of insert mounting seat 3 3C Clamp screw hole 4 Clamp screw 4A Screw shaft part 4B Clamp screw 4 head part 5 Clamp screw 4 head part 5 Washer 5A Flange part 5B Convex part 5C Convex end face (pressing surface)
5D coolant discharge groove 6 recess on the upper surface 2C side of the insert body 2A 6A pressed surface 6B inner peripheral surface of the recess 6 7 recess on the seating surface 2E side of the insert body 2A 7A annular groove 7B recess groove 8 screw with head 8A Head of screw 8 with head (protrusion of bottom surface 3A)
9 Coolant supply hole 9B Branch hole of coolant supply hole 9 Axis of tool body 1

Claims (6)

A cutting edge exchangeable cutting tool in which a cutting insert having an insert body formed with a cutting blade is detachably attached to an insert mounting seat formed on the tool body,
The insert body has a through hole through which a clamp screw is inserted, and the insert mounting seat has a clamp screw hole into which the clamp screw is screwed.
The through hole is opened in the pressed surface of the insert body, and the cutting blade is formed in a side ridge portion on the upper surface of the insert body on the side where the pressed surface is provided,
The cutting insert is attached to the insert mounting seat by the washer interposed between the head of the clamp screw and the insert body, the pressed surface being pressed by the pressing surface of the washer,
The through hole communicates with a coolant supply hole formed in the tool main body, and a coolant discharge groove that discharges the coolant to the upper surface of the insert main body is formed on the pressing surface of the washer in communication with the through hole. Has been
A plurality of the coolant discharge grooves are formed radially on the pressing surface of the washer, and the groove width becomes wider toward the outer peripheral side . A cutting edge exchangeable cutting tool in which a cutting insert having an insert body formed with a cutting blade is detachably attached to an insert mounting seat formed on the tool body,
The insert body has a through hole through which a clamp screw is inserted, and the insert mounting seat has a clamp screw hole into which the clamp screw is screwed.
The through hole is opened in the pressed surface of the insert body, and the cutting blade is formed in a side ridge portion on the upper surface of the insert body on the side where the pressed surface is provided,
The cutting insert is attached to the insert mounting seat by the washer interposed between the head of the clamp screw and the insert body, the pressed surface being pressed by the pressing surface of the washer,
The through hole communicates with a coolant supply hole formed in the tool main body, and a coolant discharge groove that discharges the coolant to the upper surface of the insert main body is formed on the pressing surface of the washer in communication with the through hole. Has been
A recess is formed on the upper surface of the insert body on which the cutting edge is formed, and the bottom surface of the recess is the pressed surface, and the washer has a protruding end surface as the pressing surface. The cutting edge is formed between the inner peripheral surface of the concave portion and the outer peripheral surface of the convex portion. A cutting edge exchangeable cutting tool characterized in that a space is provided over the entire circumference between the upper surface of the inserted insert body and the side surface of the flange portion facing the upper surface. A cutting edge exchangeable cutting tool in which a cutting insert having an insert body formed with a cutting blade is detachably attached to an insert mounting seat formed on the tool body,
The insert body has a through hole through which a clamp screw is inserted, and the insert mounting seat has a clamp screw hole into which the clamp screw is screwed.
The through hole is opened in the pressed surface of the insert body, and the cutting blade is formed in a side ridge portion on the upper surface of the insert body on the side where the pressed surface is provided,
The cutting insert is attached to the insert mounting seat by the washer interposed between the head of the clamp screw and the insert body, the pressed surface being pressed by the pressing surface of the washer,
The through hole communicates with a coolant supply hole formed in the tool main body, and a coolant discharge groove that discharges the coolant to the upper surface of the insert main body is formed on the pressing surface of the washer in communication with the through hole. Has been
A plurality of the coolant discharge grooves are formed radially on the pressing surface of the washer, and the groove width becomes wider toward the outer peripheral side,
A recess is formed on the upper surface of the insert body on which the cutting edge is formed, and the bottom surface of the recess is the pressed surface, and the washer has a protruding end surface as the pressing surface. The cutting edge is formed between the inner peripheral surface of the concave portion and the outer peripheral surface of the convex portion. A cutting edge exchangeable cutting tool characterized in that a space is provided over the entire circumference between the upper surface of the inserted insert body and the side surface of the flange portion facing the upper surface. The coolant supply hole includes one or a plurality of branch holes communicating with the through hole,
The cutting edge exchangeable cutting tool according to any one of claims 1 to 3, wherein the sum of the minimum cross-sectional areas of the coolant discharge grooves is equal to or greater than the sum of the minimum cross-sectional areas of the branch holes. .   5. The head of the clamp screw is buried so as not to protrude from an accommodation hole of the washer in which the head is accommodated. 6. Replaceable cutting tool.   The blade washer replaceable cutting tool according to any one of claims 1 to 5, wherein the washer is formed of a material having a hardness higher than that of the clamp screw.

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