JP5310191B2 - Insert detachable cutting tool - Google Patents

Description

  The present invention relates to an insert detachable cutting tool in which a coolant hole for supplying and ejecting coolant toward a cutting insert attached to an insert mounting seat formed in a tool body is formed.

  Among such insert detachable cutting tools, Patent Documents 1 to 3 describe a row in which a plurality of insert mounting seats are arranged in the axial direction on the outer periphery of the tip of a cylindrical tool body rotated around the axis. None, a plurality of rows of such insert mounting seats are formed at intervals in the circumferential direction, and the cutting inserts are respectively attached to these insert mounting seats so that the cutting blades of these cutting inserts are arranged around the axis of the cutting edge. An insert detachable long-blade end mill whose rotation trajectory is continuous in the axial direction has been proposed in which the coolant holes as described above are formed.

Japanese Utility Model Publication No. 63-53613 Japanese Utility Model Publication No. 3-15017 Japanese Patent Laid-Open No. 7-60528

  However, all of the insert detachable cutting tools described in Patent Documents 1 to 3 branch the coolant ejection holes from the coolant supply holes formed along the axis of the tool body toward the insert mounting seats. Therefore, the direction of the ejection hole must be limited to the radial direction with respect to the axis. For this reason, coolant is surely supplied and ejected toward the periphery of the cutting edge used for cutting located on the outermost periphery with respect to the above-mentioned axis of the rake face of the cutting insert oriented in the rotation direction of the tool body. It has been difficult to achieve efficient cooling and lubrication.

  Here, in such an insert detachable cutting tool described in Patent Documents 1 to 3, in order to efficiently cool and lubricate the periphery of the cutting blade, the rake face of the cutting insert directed in the rotational direction is used. On the other hand, in order to eject the coolant from the rotation direction side, the coolant supply hole formed along the axis is increased in diameter, and the spray hole extends from the inner peripheral surface toward the tangential direction. It is conceivable to install. However, if such a supply hole with a large inner diameter is formed, the rigidity and strength of the tool main body are reduced, and stable cutting cannot be performed.

  The present invention has been made under such a background, and without damaging the strength and rigidity of the tool body, the coolant is surely ejected toward the cutting edge used for cutting of the cutting insert to efficiently perform the operation. An object of the present invention is to provide an insert detachable cutting tool that can be cooled and lubricated.

In order to solve the above problems and achieve such an object, according to the present invention, a cutting insert seated on an insert mounting seat formed on a tool body is detachable by a clamp screw screwed into the tool body. An insert detachable cutting tool to be attached to the tool body , wherein the tool body has an outer cylindrical shape or an outer disk shape centered on an axis, and a plurality of the insert mounting seats are formed on the outer periphery thereof at intervals in the circumferential direction. are a supply hole coolant is supplied to the tool body, the coolant with the ejection hole for ejecting toward the cutting insert is formed, and these supply holes and ejection hole, the tool body is formed has been communicated with the screw under hole extending from the mounting screw hole which the clamping screw is screwed into the insert mounting seat circumferentially adjacent An ejection hole for ejecting the coolant toward the cutting insert attached to one insert mounting seat communicates with the screw under hole extending from the mounting screw hole for attaching the cutting insert to the other insert mounting seat. It is characterized by being.

  In the insert detachable cutting tool configured as described above, the coolant injection hole is formed toward the cutting edge used for cutting on the rake face of the cutting insert, and the coolant is supplied to the spray hole. Even if the direction and position of the hole must be restricted, the coolant is supplied to the ejection hole through the lower screw hole by connecting the supply hole and the ejection hole to the lower screw hole. Can be ejected.

  This screw hole extends from a mounting screw hole into which a clamp screw for mounting the cutting insert to the insert mounting seat is screwed, that is, a screw thread formed in the tool body to form a female screw in the mounting screw hole. Since the hole can be formed by extending the hole, the thickness of the tool body is not cut more than necessary in order to connect the supply hole and the ejection hole, and the strength and rigidity can be secured. .

Further, in the insert detachable cutting tool , like the above-described end mill , the tool body has an outer cylindrical shape or an outer disk shape centered on the axis, and a plurality of circumferentially spaced outer peripheries thereof. The above-mentioned insert mounting seat is formed , whereas an ejection hole for ejecting the coolant toward the cutting insert attached to one of the circumferentially adjacent insert mounting seats, By configuring the other insert mounting seat so as to communicate with the screw lower hole extending from the mounting screw hole for mounting the cutting insert, the length of the jet hole extending can be shortened to increase the strength of the tool body. While ensuring rigidity more reliably, it can also prevent that the pressure of the coolant ejected from an ejection hole reduces.

  In particular, such an end mill has a long blade, that is, a plurality of rows of the insert mounting seats formed in a row in the axial direction are formed on the outer periphery of the tool body at intervals in the circumferential direction. In this case, the ejection holes of the one insert mounting seat are communicated with the threaded holes of the other insert mounting seat shifted in the axial direction in a row adjacent in the circumferential direction. Also in the tool main body in which the insert mounting seat is formed, the ejection hole can be formed so as to be surely directed to the cutting edge of the cutting insert attached to each insert mounting seat.

  Furthermore, by forming a through hole in the clamp screw that communicates with the screw hole, coolant can be ejected through the through hole from the screw hole that communicates with the supply hole. It is possible to achieve more effective cooling and lubrication without impairing.

  As described above, according to the present invention, while enabling stable cutting without impairing the strength and rigidity of the tool body, the coolant is raked around the cutting edge used for cutting. It can be reliably ejected, the cutting part of the cutting edge and work material can be effectively cooled and lubricated, and the cutting insert can be prevented from being damaged by the heat during cutting, and smooth machining can be achieved. it can.

1 is a side view of an insert detachable cutting tool (end mill) showing an embodiment of the present invention. It is the top view which looked at embodiment shown in FIG. 1 from the axial direction rear end side. It is a fragmentary sectional view of embodiment shown in FIG. It is an enlarged view of sectional drawing shown in FIG. It is another fragmentary sectional view of the embodiment shown in FIG. It is a partial expanded sectional view which shows the modification of embodiment shown in FIG.

  The insert detachable cutting tool of one embodiment of the present invention shown in FIGS. 1 to 5 is an application of the present invention to an insert detachable end mill. That is, in the insert detachable cutting tool of the present embodiment, the tool body 1 has a substantially cylindrical shape with the axis O as the center, and the rear end portion (the upper portion in FIGS. 1, 3, and 5). By being attached to the main spindle side of the machine tool and rotated in the tool rotation direction T around the axis O, it is used for cutting work (rolling work) of the work material.

  A mounting hole 2 is formed in the tool body 1 so as to penetrate the tool body 1 along the axis O, and the mounting hole 2 extends from the rear end side in the axis O direction to the front end side (FIGS. 1 and 3). , In the order toward the lower side in FIG. 5, the large-diameter portion 2A having the largest inner diameter, the small-diameter portion 2B having the smallest inner diameter, and the medium-diameter portion 2C having an inner diameter between the large-diameter portion 2A and the small-diameter portion 2B. Are arranged coaxially. An annular groove 2D is formed on the distal end side of the small diameter portion 2B, and an O-ring 3 is fitted in the annular groove 2D. Further, a key groove 4 is formed on the rear end surface of the tool body 1 so as to extend in the diameter direction with respect to the axis O.

  On the other hand, on the outer peripheral surface of the tool body 1, a plurality of chip discharge grooves 5 that are twisted to the rear side in the tool rotation direction T around the axis O from the front end toward the rear end are formed at equal intervals in the circumferential direction. The chip discharge grooves 5 are provided with a plurality of insert mounting seats 6 (four in this embodiment) that open to the wall surface facing the tool rotation direction T and the outer peripheral surface. The cutting inserts 8 are detachably attached to the insert mounting seats 6 by the clamp screws 7 respectively.

  The plurality of chip discharge grooves 5 and the plurality of insert mounting seats 6 formed along the chip discharge grooves 5 are formed so as to be rotationally symmetrical about the axis O by a predetermined angle. In the illustrated insert detachable cutting tool, only two chip discharge grooves 5 and an insert mounting seat 6 formed along these are shown for explanation, but three or more chip discharge grooves 5 are formed. Of course, the insert mounting seat 6 may be provided.

  The cutting insert 8 in the present embodiment is formed in a polygonal flat plate shape by a hard sintered body such as a cemented carbide, that is, includes a pair of polygonal surfaces and side surfaces arranged around the polygonal surfaces, One of these side faces is attached to the insert mounting seat 6 in the tool rotation direction T as a rake face. Specifically, the cutting insert 8 of the present embodiment has a substantially pentagonal flat plate shape, a pair of pentagonal surfaces 9, a rake face 10 disposed around the pentagonal surfaces 9, a pair of side surfaces 11, and a seating. The seat 12 has a convex V shape when viewed from the direction facing the pentagonal surface 9 and has a substantially pentagonal shape.

  Further, the cutting insert 8 is formed with a mounting hole 13 penetrating between the pair of pentagonal surfaces 9 so as to open in the approximate center of both pentagonal surfaces 9. Thus, a reduced diameter portion 13A is formed in which the inner diameter gradually decreases toward the center portion in the center line direction. Further, the rake face 10 is formed in a substantially parallelogram shape, and among the four sides of the parallelogram, a main cutting edge 10 </ b> A is provided at the intersecting ridge line portion between the rake face 10 and the pentagonal face 9, and the rake face 10 and the side face. A secondary cutting edge 10 </ b> B is formed at the intersection ridge line with 11.

  The insert mounting seat 6 to which such a cutting insert 8 is mounted includes a bottom surface 6A facing the outer peripheral side of the tool body 1 and a wall surface 6B facing the tool rotation direction T as shown in FIG. Of these, the wall surface 6B has a concave V-shape with a narrow angle equal to the convex V-shape formed by the seating surface 12 of the cutting insert 8, and the bottom surface 6A has a planar shape with a tool in the approximate center. A mounting screw hole 6 </ b> C is formed so as to extend in the radial direction of the main body 1.

  The cutting insert 8 has one of a pair of pentagonal surfaces 9 in close contact with the bottom surface 6A, and the seating surface 12 is brought into contact with the wall surface 6B to be seated on the insert mounting seat 6, and then the mounting When the clamp screw 7 inserted through the hole 13 is screwed into the attachment screw hole 6C, the reduced diameter portion 13A of the attachment hole 13 is pressed by the head portion 7A of the clamp screw 7, and the bottom surface 6A side and the wall surface 6B side. It is attached to the insert attachment seat 6 in a state where it is pressed against.

  Therefore, the rake face 10 of the cutting insert 8 thus attached to the insert mounting seat 6 is oriented in the tool rotation direction T, and the rake face 10 is opposite to the pentagonal face 9 closely attached to the bottom face 6A. The main cutting edge 10 </ b> A formed at the intersection ridge line with the surface 9 is directed to the outer peripheral side of the tool body 1. Further, in the plurality of cutting inserts 8 attached to the insert mounting seat 6 formed along one chip discharge groove 5, the rotation trajectory around the axis O between the main cutting edges 10A directed to the outer peripheral side is A long blade is formed continuously in the direction of the axis O.

  In this embodiment, the plurality of insert mounting seats 6 formed for one chip discharge groove 5 are arranged so that each of the wall surfaces 6B forms a spiral step shape along the twist of the chip discharge groove 5 in this embodiment. ing. That is, the wall surface 6B of the next insert mounting seat 6 adjacent to the rear end side of the wall surface 6B of the insert mounting seat 6 on the front end side is arranged so as to be shifted by one step toward the rear side in the end mill rotation direction T. Has been.

  Accordingly, a step surface 14 extending in the circumferential direction is formed between the wall surfaces 6B of the adjacent insert mounting seats 6 in one chip discharge groove 5, and the cutting insert 8 attached to the insert mounting seat 6 is formed. The side surface 11 facing the front end side of the tool body 1 is disposed so as to face the step surface 14. However, in this embodiment, the side surface 11 of the cutting insert 8 attached in this way is arranged with a slight gap without contacting the stepped surface 14.

  In addition, on the bottom surface 6A of the bottom surface 6A of each insert mounting seat 6 on the tool rotation direction T side, a recess 15 is formed on the bottom surface of the chip discharge groove 5 facing the outer periphery of the tool body 1 so as to be further recessed than the bottom surface. Yes. The recess 15 is recessed so as to form a smooth concave curve in both the cross section along the circumferential direction of the tool body 1 and the cross section along the axis O direction, and the tool rotation direction for each insert mounting seat 6. They are formed at a distance from each other so as to be positioned on the T side.

  In such an insert-detachable cutting tool, a mounting shaft (not shown) protruding from the end surface on the main shaft side of a machine tool is inserted into the large-diameter portion 2A of the mounting hole 2 and is also shown on the end surface. After the key not to be fitted is fitted in the key groove 4, a mounting bolt (not shown) inserted into the mounting hole 2 from the tip side of the tool body 1 is screwed into the bolt hole formed in the mounting shaft. The head of the mounting bolt presses the step between the small-diameter portion 2B and the medium-diameter portion 2C of the mounting hole 2, the rear end surface of the tool body 1 is pressed against the end surface on the main shaft side, and is attached to the main shaft side as described above. It is done.

  Here, the protruding length of the mounting shaft from the main shaft side end surface is made smaller than the depth from the rear end surface of the large-diameter portion 2A, whereby the front-end surface of the mounting shaft and the large-diameter portion of the mounting hole 2 A space is formed between the mounting bolt and a stepped portion 2E that forms an annular shape between 2A and the small-diameter portion 2B, and a cylindrical space is formed around the mounting bolt.

  This space is formed by fitting the O-ring 3 in close contact with the outer periphery of the mounting bolt on the front end side and fitting the mounting shaft in close contact with the large diameter portion 2A of the mounting hole 2 on the rear end side. It is possible to maintain a dense state. Furthermore, an introduction hole for introducing a high-pressure coolant (in this embodiment, a liquid cutting fluid) fed from the machine tool into the space is opened at the tip surface of the mounting shaft.

  Furthermore, a coolant supply hole 16 is formed in the tool body 1 so as to open to the stepped portion 2E so as to communicate with this space, and the coolant is directed to the outer peripheral side of the cutting insert 8. The ejection holes 17 that eject toward the main cutting edge 10 </ b> A are formed so as to open in the recesses 15 formed on the tool rotation direction T side of each insert mounting seat 6.

  The supply hole 16 and the ejection hole 17 are communicated with a screw lower hole 18 formed so as to extend from a mounting screw hole 6C into which the clamp screw 7 of each insert mounting seat 6 is screwed. That is, the screw lower hole 18 extends the lower hole before forming the female screw portion on the inner periphery of the mounting screw hole 6C from a depth necessary for the mounting screw hole 6C within a range not reaching the mounting hole 2. Therefore, it is coaxial with the mounting screw hole 6C, and extends in the radial direction of the tool body 1 in the same manner as the mounting screw hole 6C in this embodiment.

  The supply hole 16, the ejection hole 17, and the screw lower hole 18 are formed so as to extend linearly. Further, the supply hole 16 and the ejection hole 17 may be communicated at the same position in the extending direction of the screw lower hole 18 as shown in FIGS. 3 and 4, and this extension as shown in FIG. You may be made to communicate in a different position in the installation direction.

  However, in this embodiment, this screw lower hole 18 is not formed in the insert mounting seat 6 on the most distal side among the plurality of insert mounting seats 6 formed along each chip discharge groove 5. That is, it is formed only in the mounting screw hole 6 </ b> C formed in the bottom surface 6 </ b> A of the insert mounting seat 6 excluding the most advanced insert mounting seat 6.

  The supply holes 16 are formed so as to communicate one by one with respect to one screw lower hole 18, and accordingly, a plurality of (four in the present embodiment) formed along one chip discharge groove 5. 2), the number of supply holes 16 (three in this embodiment) excluding the most advanced insert mounting seat 6 is formed as shown in FIG. These supply holes 16 correspond to the circumferential displacement of the plurality of insert mounting seats 6 along the twist of the chip discharge groove 5, and the insert mounting seats 6 (inserts positioned on the front end side) located on the rotation direction T side. In order from the one communicating with the screw lower hole 18 of the mounting seat 6), the stepped portion 2E is opened at intervals from the rotation direction T side, and the supply holes 16 are not crossed.

  Further, the ejection holes 17 are also formed so as to communicate one by one with respect to one screw hole 18, and in this embodiment, as shown in FIG. It extends toward the tangential direction of the circle centered on the axis, and extends toward the outer peripheral side toward the opening to the recess 15, and at the corner on the rear end side of the recess 15 in the axis O direction. It is open.

  In addition, the ejection holes 17 are inclined obliquely from the rotational direction T side to the rotational direction T rear side with respect to the rake face 10 of the cutting insert 8 attached to the insert mounting seat 6 connected to the recess 15. Coolant is provided near the corner of the main cutting edge 10A facing the outer peripheral side of the cutting insert 8 and the secondary cutting edge 10B along the diagonal direction of the parallelogram formed by the rake face 10. It is drilled so as to be ejected.

  Here, in the insert detachable cutting tool of the present embodiment in which a plurality of insert mounting seats 6 are formed on the outer periphery of the tool body 1 at intervals in the circumferential direction, one of a pair of insert mounting seats 6 adjacent in the circumferential direction is provided. With respect to the rake face 10 of the cutting insert 8 attached to the insert mounting seat 6, coolant is jetted from a jet hole 17 extending from a screw hole 18 formed in the other insert mounting seat 6. .

  Specifically, of the insert mounting seats 6 formed along the chip discharge grooves 5 adjacent in the circumferential direction, the insert mounting seat 6 is mounted on one insert mounting seat 6 along the chip discharge grooves 5 located on the rear side in the rotation direction T. The coolant is ejected from the ejection hole 17 communicating with the screw lower hole 18 of the other insert mounting seat 6 on the rotation direction T side with respect to the cutting insert 8 thus formed.

  Moreover, in the present embodiment in which the plurality of cutting inserts 6 are formed so as to form a line in the axis O direction along the chip discharge grooves 5, the ejection holes 17 of the one insert mounting seat 6 are adjacent in the circumferential direction. In the row to be connected, it is communicated with the screw lower hole 18 of the other insert mounting seat 6 shifted in the direction of the axis O.

  Specifically, among the chip discharge grooves 5 adjacent to each other in the circumferential direction, an ejection hole for ejecting coolant toward the cutting insert 8 attached to one insert mounting seat 6 along the chip discharge groove 5 on the rear side in the rotation direction T. 17 is communicated with the screw hole 18 of the other insert mounting seat 6 that is shifted by one to the rear end side in the axis O direction among the plurality of insert mounting seats 6 along the chip discharge groove 5 on the rotation direction T side. , Extending toward the distal end side toward the opening to the recess 15.

  Among the plurality of insert mounting seats 6 formed along one chip discharge groove 5, one of the insert mounting seats 6 on the rearmost end side is on the rotation direction T side and the rear end side in the axis O direction. Since there is no other displaced insert mounting seat 6, the ejection hole 17 is not shown in the recess 15 connected to the rearmost insert mounting seat 6, but for the rearmost insert mounting seat 6, The injection hole 17 may be formed in the stepped portion 2E or the like so as to directly communicate with the space, and the coolant may be injected toward the rake face 10 of the cutting insert 8.

  In the insert detachable cutting tool configured as described above, the coolant introduced into the space from the machine tool side as described above is ejected to the cutting insert 8 attached to the insert mounting seat 6 at the rearmost end. Cutting blades (main cutting blades 10A and 10A) used for cutting that are ejected from the ejection holes 17 from the supply holes 16 through the screw holes 18 and directed to the outer peripheral side of the rake face 10 of the cutting insert 8. Is supplied to the secondary cutting edge 10B).

  Here, in the present embodiment, the ejection hole 17 extends in the tangential direction of the circle centering on the axis O as described above, and toward the rear side in the rotational direction T toward the outer peripheral side with respect to the rake face 10. Since it is ejected obliquely, the coolant can be supplied to the cutting edge reliably and intensively, and effective cooling and lubrication of the cutting part of the cutting edge and the work material can be achieved.

  Furthermore, in order to form the ejection hole 17 through which the coolant can be ejected toward the cutting edge in this way, in the insert detachable cutting tool having the above-described configuration, a mounting screw hole used for mounting the cutting insert 8 to the insert mounting seat 6. The jet hole 17 and the coolant supply hole 16 are communicated with the screw hole 18 of 6C. Therefore, if communication is possible at any position within the range where the screw hole 18 extends, The ejection holes 17 can be formed in directions and positions where the coolant can be ejected effectively.

  The same applies to the supply hole 16, that is, the supply hole 16 only needs to be communicated at any position of the screw lower hole 18, and the supply hole 16 is located at a position where the supply holes 16 do not intersect with each other. It is easy to drill. That is, for example, the positions and orientations of the supply holes 16 and the ejection holes 17 are less restricted than when the supply holes 16 and the ejection holes 17 are formed so as to intersect and communicate directly with each other. .

  On the other hand, the screw hole 18 is an extension of the lower hole of the mounting screw hole 6C originally formed to attach the cutting insert 8 to the insert mounting seat 6, and is supplied separately from the screw hole 18. Compared to forming a hole communicating with the hole 16 and the ejection hole 17 in the tool body 1, it takes less time, and the opening to the outer peripheral side of the tool body 1 is screwed into the mounting screw hole 6C. Since it is sealed by the clamp screw 7, it is not necessary to attach a plug or the like to such an opening.

  And compared to forming such another hole, or increasing the diameter of the supply hole formed along the axis of the tool body as described above, and forming a jet hole extending in the tangential direction, Since the portion where the thickness of the tool body 1 is cut can be minimized, according to the insert detachable cutting tool having the above configuration, the strength and rigidity of the tool body 1 can be prevented from being damaged. Thus, the combination of ensuring the tool strength and rigidity and efficient cooling and lubrication makes it possible to promote stable cutting.

  On the other hand, in this embodiment, the tool body 1 has an external cylindrical shape centered on the axis O, and the cutting inserts 8 are attached to a plurality of insert mounting seats 6 formed on the outer periphery thereof at intervals in the circumferential direction. The present invention is applied to an insert detachable end mill that rotates the tool body 1 about the axis O and performs cutting with the cutting blades of these cutting inserts 8 (the main cutting blade 10A and the auxiliary cutting blade 10B). In particular, among the insert mounting seats 6 adjacent to each other in the circumferential direction, a jet hole 17 through which the coolant is jetted to one insert mounting seat 6 side communicates with a screw lower hole 18 extending from the mounting screw hole 6C of the other insert mounting seat 6. It has been.

  That is, the ejection hole 17 communicating with the screw lower hole 18 of the other insert mounting seat 6 ejects the coolant to the cutting insert 8 attached to one of the adjacent insert mounting seats 6 adjacent in the circumferential direction. Therefore, the extended length of the ejection hole 17 can be shortened, and the pressure of the ejected coolant can be suppressed from being reduced by the frictional resistance with the ejection hole 17. Moreover, in the present embodiment, the ejection holes 17 extend toward the outer peripheral side in the radial direction toward the rear side in the rotation direction T of the tool body 1 during the rolling process as it goes toward the opening to the recess 15. Therefore, it becomes possible to supply the coolant more efficiently by the centrifugal force generated by the rotation of the tool body 1.

  Further, in the insert detachable cutting tool of the present embodiment, even in such an end mill, the chip discharge grooves 5 so that the insert mounting seats 6 spaced in the circumferential direction form a row in the direction of the axis O of the tool body 1. In this embodiment, of the insert mounting seats 6 adjacent to each other in the circumferential direction, the ejection hole 17 opened on the one insert mounting seat 6 side is the one of the insert mounting seats. The seat 6 is communicated with a screw lower hole 18 of the other insert mounting seat 6 shifted in the axis O direction.

  Accordingly, the ejection hole 17 is, for example, along the diagonal direction of the parallelogram formed by the rake face 10 as described above with respect to the rake face 10 of the cutting insert 8 attached to one insert mounting seat 6. It is formed so as to extend also in the direction of the axis O. For this reason, in the cutting edge (main cutting edge 10A) directed to the outer peripheral side, it is surely applied to a portion where a particularly high load acts (in this embodiment, around the corner portion with the auxiliary cutting edge 10b on the tip side in the axis O direction). In addition, it becomes possible to supply coolant in a concentrated manner, and it is possible to prevent damage to the cutting insert 8 due to heat generated during cutting in such a portion, thereby achieving smoother processing.

  In addition, in this embodiment, one insert mounting seat 6 in which the ejection hole 17 is opened is the tip in the axis O direction with respect to the other insert mounting seat 6 in which the screw lower hole 18 in communication with the ejection hole 17 is formed. The coolant which is shifted to the side and is fed at a high pressure from the machine tool side is ejected from the supply hole 16 which also extends toward the front end side in the direction of the axis O without passing through the screw lower hole 18 without greatly reducing the pressure. 17 is ejected. For this reason, according to the present embodiment, even in the case of a long-blade end mill having a large number of insert mounting seats 6 and cutting inserts 8 arranged along one chip discharge groove 5, the centrifugal force as described above. In combination with this, it is possible to more efficiently supply the coolant to a portion having a high cutting load.

  However, in this embodiment, the case where the present invention is applied to an end mill in which a plurality of insert mounting seats 6 arranged in a row in the axis O direction are formed in a plurality of rows at intervals in the circumferential direction has been described. Mainly used for insert detachable cutting tools such as external cylindrical end mills and external disk-shaped face mills, in which multiple insert mounting seats are formed on the outer periphery of the tip of the main body at intervals in the circumferential direction. The invention can also be applied. In such a case, of the insert mounting seats adjacent to each other in the circumferential direction, the ejection hole that opens to one insert mounting seat side is, for example, the other insert mounting seat that is not shifted in the axial direction located on the tool rotation direction side. What is necessary is just to form so that it may communicate with this screw under hole.

  Furthermore, in this embodiment, the mounting screw hole 6C is formed in the bottom surface 6A of the insert mounting seat 6, and the clamp screw 7 is inserted into the mounting hole 13 formed in the cutting insert 8 and screwed into the mounting screw hole 6C. Accordingly, the cutting insert 8 is directly attached to the insert mounting seat 6. However, in an insert detachable cutting tool such as the above-described face milling cutter, the wedge is tightened by a clamp screw screwed into the tool body. There are some which are detachably attached to the insert mounting seat by pressing the cutting insert, and the present invention can be applied to such an insert detachable cutting tool. In other words, in such an insert-detachable cutting tool, a screw hole for connecting the coolant supply hole and the ejection hole may be formed in the mounting screw hole into which the clamp screw for tightening the wedge is screwed.

  On the other hand, in the present embodiment, the screw lower hole that continuously notifies the supply hole and the ejection hole is sealed with the solid clamp screw 7 as described above. Instead of such a solid clamp screw 7 as in the modification of the embodiment, a clamp screw 21 having a through hole 21B formed along the center line from the head 21A to the tip of the male screw is attached. The cutting insert 8 may be attached to the insert mounting seat 6 by screwing into the screw hole 6C. In this modification, the configuration other than the clamp screw 21 is the same as that of the above embodiment, and therefore the same reference numerals are assigned in FIG.

  Therefore, in such an insert-detachable cutting tool in which the clamp screw 21 is screwed into the attachment screw hole 6C and the cutting insert 8 is attached, the through-hole 21B of the clamp screw 21 communicates with the screw lower hole 18. The coolant supplied from the space to the screw lower hole 18 through the supply hole 16 is ejected from the ejection hole 17 toward the rake face 10 of the cutting insert 8, and a part thereof is also from the through hole 21B. It is made to erupt. Therefore, more effective cooling and lubrication can be achieved while maintaining the strength and rigidity of the tool body 1 without forming a new ejection hole.

  In particular, in the insert detachable cutting tool (end mill) of the above-described modification, the through hole 21B of the clamp screw 21 is connected to the cutting edge (main cutting edge 10A) directed to the outer peripheral side of the tool body 1 and the outer peripheral flank. When the coolant is fed at a high pressure as described above, the coolant is passed through the pentagonal surface 9 and the work surface of the work material as described above. Can be reached.

  Therefore, in the insert detachable cutting tool configured as described above, the coolant is ejected from the ejection hole 17 to the rake face 10 side, and from the pentagonal surface 9 side which is the outer peripheral flank through the through hole 21B. The coolant that can be reached can cool and lubricate the cutting edge and the cutting portion of the work material more reliably, and facilitate smooth and stable cutting.

DESCRIPTION OF SYMBOLS 1 Tool body 2 Mounting hole 5 Chip discharge groove 6 Insert mounting seat 6C Mounting screw hole 7, 21 Clamp screw 8 Cutting insert 10 Rake face 10A Main cutting edge 10B Sub cutting edge 15 Recess 16 Supply hole 17 Ejection hole 18 Screw lower hole 21B Through-hole of clamp screw 21 O Axis of tool body 1 T Rotation direction

Claims (3)

An insert detachable cutting tool in which a cutting insert seated on an insert mounting seat formed in a tool body is detachably attached by a clamp screw screwed into the tool body, and the tool body is centered on an axis. A plurality of insert mounting seats are formed on the outer periphery of the outer periphery of the tool body in a circumferential direction, and the tool body is provided with a supply hole for supplying coolant and the coolant. An ejection hole that ejects toward the cutting insert is formed, and the supply hole and the ejection hole are communicated with a screw hole extending from an attachment screw hole that is formed in the tool body and into which the clamp screw is screwed. It has been, in the cutting insert attached to one of the insert mounting seat of the insert attachment seat circumferentially adjacent direction Ejection hole for ejecting the coolant Te is insert-indexable tool, characterized by being communicated with the screw under hole extending from the mounting screw holes for mounting the cutting insert to the other of the insert mounting seat. In the outer periphery of the tool body, a plurality of insert mounting seats arranged in a row in the axial direction are formed in a plurality of rows at intervals in the circumferential direction, and the ejection holes of the one insert mounting seat are arranged in the circumferential direction. 2. The insert detachable cutting tool according to claim 1 , wherein the insert detachable cutting tool is communicated with the screw hole of the other insert mounting seat that is shifted in the axial direction in a row adjacent to. The insert detachable cutting tool according to claim 1 or 2 , wherein the clamp screw is formed with a through hole communicating with the screw hole.

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