JP2018024029A - Edge replaceable cutting tool - Google Patents

Abstract

[PROBLEMS] To prevent winding and damage to an urging portion due to chips during cutting, as well as to ensure the rigidity of a tool body and the mounting stability of a cutting insert, thereby reliably improving machining accuracy. A cylindrical fitting member 3 is fitted on the outer periphery of a tip 1A of a cylindrical tool body 1 centering on an axis O so as to be movable in a direction along the axis O. The front end of the peripheral surface is a fitting surface 3A, and a cutting insert 2 having an annular or cylindrical insert body 2A is attached to and detached from an insert mounting seat 3B formed by the fitting surface 3A and the tip surface 1E of the tool body 1. The housing body 8 is formed with a housing hole 8 in which the urging member 9 is housed, and a through hole 10 is formed from the housing hole 8 to the front end side of the tool body 1. A pressing member 11 that presses the fitting member 3 toward the distal end side by being biased by the biasing member 9 is inserted into the through hole 10. [Selection] Figure 6

Description

  The present invention relates to a cutting edge-exchangeable cutting tool in which a cutting insert having an annular or cylindrical insert body is detachably attached to an insert mounting seat formed at the tip of a tool body.

  As such a blade-tip-exchange-type cutting tool, for example, Patent Document 1 discloses an annular or cylindrical cutting insert having a cutting edge and a shaft of a tool main body tip portion having a tip surface abutting against a seating surface of the cutting insert. And a fitting member (fastening member) having a fitting portion fitted to the shaft portion, and an urging force that can be elastically deformed and can urge the fitting portion toward the distal end side with respect to the shaft portion. And a screw member that is inserted into the through hole of the cutting insert and screwed into the screw hole of the shaft portion to removably fix the cutting insert to the shaft portion, and the outer peripheral surface of the cutting insert and the fitting member On the inner peripheral surface, a drive-type rotary tool is described in which a taper surface that gradually decreases in diameter toward the rear end side is formed.

  In such a blade-tip-exchange-type cutting tool, when the screw member is screwed into the screw hole while bringing the tapered surface of the cutting insert into sliding contact with the tapered surface of the fitting member, the cutting insert compresses the urging portion together with the fitting member. Then, it is centered on the shaft portion of the tool body through the fitting member, and is fixed when the seating surface comes into contact with the tip surface of the shaft portion. Therefore, in the case of the drive type rotary tool as described above, the cutting insert can be attached coaxially with the axis of the tool body, so that the machining accuracy can be improved.

JP 2013-198971 A

  However, in the blade-tip-exchangeable cutting tool described in Patent Document 1, the urging portion is provided by forming a plurality of slits extending in the circumferential direction at the rear end portion of the fitting member. The slit is exposed on the outer periphery of the fitting member. For this reason, there is a possibility that chips generated at the time of cutting are wound around the slit and entangled, or the urging portion is damaged due to scraping of the chips and the fitting member must be replaced at an early stage.

  Further, when the urging portion is provided at the rear end portion of the fitting member in this way, the shaft portion at the tip of the tool body to which the fitting member is fitted becomes longer, and the cutting insert is thus extended in the shaft. It will be attached to the tip of the part. For this reason, the rigidity of the tool body against the back force and feed force during cutting and the mounting stability of the cutting insert are impaired, and even if the cutting insert can be coaxially attached to the tool body by the tapered surface, There is also a possibility that the accuracy cannot be sufficiently improved.

  The present invention has been made under such a background, and can prevent winding and damage to the urging portion due to chips during cutting, as well as rigidity of the tool body and attachment of the cutting insert. An object of the present invention is to provide a cutting edge-exchangeable cutting tool capable of ensuring stability and improving machining accuracy with certainty.

  In order to solve the above-described problems and achieve such an object, the present invention provides a cylindrical fitting member centered on the axis on the outer periphery of a cylindrical tool body tip centered on the axis. It is fitted so that it can move in the direction along the axis, and the tip of the inner peripheral surface of the fitting member is a fitting surface whose inner diameter gradually increases toward the tip. A cutting insert having an annular or cylindrical insert body formed on the insert mounting seat formed by the surface and the tip surface of the tool body and having a cutting edge formed on the outer periphery is provided behind the outer peripheral surface of the insert body. A screw hole in which a clamp screw inserted in an inner peripheral portion of the insert body is formed in the tip surface with a rear end surface of the insert body abutting on the tip surface while an end portion is in close contact with the fitting surface Removable by screwing into In addition, the rear end of the tool body is formed with a receiving hole for receiving the biasing member, and a through hole is formed from the receiving hole toward the distal end side of the tool body. The through hole is inserted with a pressing member that presses the fitting member toward the distal end side by being biased by the biasing member.

  In the blade-exchange-type cutting tool configured as described above, the urging member is accommodated in the accommodation hole formed in the rear end portion of the tool body, and the fitting member is a through-hole extending from the accommodation hole to the front end side. It is urged | biased by the urging | biasing member through the press member inserted in the front end side, and a fitting surface closely_contact | adheres to the rear-end part of the outer peripheral surface of a cutting insert. Therefore, the cutting insert can be mounted coaxially with the axis of the tip of the tool body by the close contact of the fitting surface, and the urging member is not exposed and exposed on the outer periphery of the tool body. Further, the length of the tip end of the tool body to which the fitting member is fitted can be shortened, and the rigidity and the mounting stability of the cutting insert can be ensured.

  Here, in order to further improve the machining accuracy and ensure the mounting stability of the cutting insert, a plurality of the through holes are formed at equal intervals in the circumferential direction in the tool body, and each of these through holes is provided. It is desirable to insert the pressing member. By pressing the fitting member toward the distal end side by the pressing members inserted into the plurality of through holes formed at equal intervals in the circumferential direction in this way, the fitting member is arranged coaxially with the axis with high accuracy. The cutting insert can be attached coaxially and the attachment stability is improved.

  Further, when the accommodation hole for accommodating the biasing member is formed in the rear end portion of the tool body as described above, the coolant hole for supplying the coolant to the cutting insert is provided in the tool body. Thus, the space in which the accommodation hole is formed can be used effectively, and cooling and lubrication of the cutting blade of the cutting insert can be promoted without impairing the rigidity of the tool body.

  As described above, according to the present invention, since the biasing member can be prevented from being exposed and exposed on the outer periphery of the tool body, chips generated during cutting work can be wound around the biasing member. The biasing member is not scratched and damaged, and the length of the tip of the tool body where the fitting member fits can be shortened, ensuring the rigidity of the tool body and the stability of mounting of the cutting insert. Thus, it becomes possible to perform cutting with higher accuracy.

It is a side view which shows the 1st Embodiment of this invention. It is a top view of embodiment shown in FIG. It is the front view which looked at the embodiment shown in Drawing 1 from the tip side. It is the rear view which looked at embodiment shown in FIG. 1 from the rear end side. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is XX sectional drawing in FIG. It is a disassembled perspective view of embodiment shown in FIG. 2A is a front view, FIG. 2B is a rear view, FIG. 2C is an XX sectional view in FIG. 1A, and FIG. 2D is a YY sectional view in FIG. 1A is a perspective view as viewed from the front end side, FIG. 1B is a perspective view as viewed from the rear end side, FIG. 1C is a front view as viewed from the front end side, and FIG. (E) Side view, (f) XX sectional view in FIG. (D), (g) YY sectional view in FIG. (D). (A) Front view seen from the front end side, (b) Rear view seen from the rear end side, (c) Plan view, (d) XX cross section in FIG. FIG. 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 as viewed from the rear end side, (c) a front view as viewed from the front end side, and (d) from the rear end side. Viewed rear view, (e) Side view in the direction of arrow X in FIG. (C), (f) Side view in the direction of arrow Y in FIG. (C), (g) XX sectional view in FIG. It is. It is the front view seen from the front end side of the press member of the embodiment shown in FIG. 1, (b) The side view, (c) The back view seen from the rear end side. It is the (a) front view seen from the front end side of the plunger of embodiment shown in FIG. 1, (b) The side view, (c) The back view seen from the rear end side. It is the front view seen from the front end side of the screw member of the embodiment shown in FIG. 1, (b) The side view, (c) The back view seen from the rear end side. It is (a) sectional side view before cutting insert attachment of embodiment shown in FIG. 1, (b) It is XX sectional drawing in figure (a). It is a figure which shows the state which cuts (turns) a work material by embodiment shown in FIG. It is a side view which shows the 2nd Embodiment of this invention. It is a top view of embodiment shown in FIG. It is the front view which looked at embodiment shown in FIG. 18 from the front end side. It is the rear view which looked at embodiment shown in FIG. 18 from the rear end side. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. It is XX sectional drawing in FIG. It is a disassembled perspective view of embodiment shown in FIG. FIG. 19 is a (a) front view, (b) rear view, (c) XX sectional view in FIG. (A), and (d) YY sectional view in FIG. 18A is a perspective view as viewed from the front end side, FIG. 18B is a perspective view as viewed from the rear end side, FIG. 18C is a front view as viewed from the front end side, and FIG. 18D is a rear end side. (E) Side view, (f) XX sectional view in FIG. (D), (g) YY sectional view in FIG. (D). It is the (a) front view seen from the front end side of the fitting member of embodiment shown in FIG. 18, (b) Top view, (c) It is XX sectional drawing in figure (a). 18A is a perspective view as viewed from the front end side, FIG. 18B is a perspective view as viewed from the rear end side, FIG. 18C is a rear view as viewed from the rear end side, and FIG. ) Side view in the direction of arrow W, (e) side view in direction of arrow X in FIG. (C), (f) YY sectional view in FIG. (C), (g) ZZ section in FIG. FIG. It is the front view seen from the front end side of the press member of the embodiment shown in FIG. 18, (b) The side view, (c) The back view seen from the rear end side. (A) Front view seen from the front end side of the plunger of the embodiment shown in FIG. 18, (b) XX sectional view in FIG. (A), (c) Rear view seen from the rear end side, (d) Side view It is. It is the (a) front view seen from the front end side of the screw member of the embodiment shown in FIG. 18, (b) the side view, and (c) the back view seen from the rear end side. It is the (a) sectional side view before the cutting insert attachment of embodiment shown in FIG. 18, (b) It is XX sectional drawing in figure (a). It is a figure which shows the state which cuts (turns) a work material by embodiment shown in FIG.

  1 to 17 show a first 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). The left side portion in FIGS. 2, 5, 6, and 16) This is a so-called drive-type rotary tool in which the workpiece W is turned as shown in FIG. 17 by a cutting insert 2 that is detachably attached to 1A. The present invention is applied, and particularly suitable for turning a work material W having a relatively small diameter D as shown in FIG.

  In the tool main body 1 according to the present embodiment, the tip 1A is centered on the axis O by a metal material such as steel, and the tip end 1A is more than the rear end (right side in FIGS. 1, 2, 5, 6, and 16). It is formed in a multi-stage outer shape substantially cylindrical with a small outer diameter. The tool body 1 is driven to rotate as described above by gripping the rear end portion as the shank portion 1B by the machine tool.

  In addition, between the tip portion 1A and the shank portion 1B, there is formed a neck portion 1C having a conical outer peripheral surface with an axis O as the outer diameter gradually decreases toward the tip side. An annular surface 1D perpendicular to the axis O is formed between the tip of the neck 1C and the rear end of the tip. Further, the tip surface (tip surface of the tip portion 1A) 1E of the tool body 1 is a flat surface perpendicular to the axis O, and a screw hole 1F is formed along the axis O in the center.

  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, and a cutting edge 2B is formed at the peripheral edge of one circular surface having a large diameter of the insert body 2A. Therefore, this one circular surface is the rake face 2C of the cutting edge 2B, and this rake face 2C is formed as a flat face perpendicular to the axis O in this embodiment, and the diameter thereof, that is, the diameter of the cutting edge 2B is It is larger than the outer diameter of the front end portion 1A of the main body 1 and smaller than the outer diameter of the annular surface 1D.

  The insert main body 2A is formed with a mounting hole 2D having a circular cross section around the axis O having a constant inner diameter so as to penetrate the insert main body 2A along the axis O. Further, a recess 2E having a circular cross section centered on the axis O and having an inner diameter slightly larger than that of the mounting hole 2D is formed in the opening on the rake face 2C side of the mounting hole 2D. The bottom surface of the recess 2E facing the front end in the direction of the axis O is also a flat surface perpendicular to the axis O, and the inner peripheral surface of the recess 2E has a tapered surface that slightly increases in diameter toward the rake face 2C. Is formed.

  Furthermore, the other circular surface with a small diameter of the insert body 2A opposite to the rake surface 2C is a seating surface 2F. Here, in this embodiment, the recess 2G is also formed in the opening of the mounting hole 2D toward the seating surface 2F. The recess 2G on the seating surface 2F side includes an annular groove 2H that circulates around the opening of the mounting hole 2D around the axis O, and a plurality of strips extending radially outward from the annular groove 2H in the direction of the axis O. And a concave groove 2I. The annular groove 2H and the recessed groove 2I are equal in depth to each other and shallower than the recess 2E. In this embodiment, four recessed grooves 2I are formed at equal intervals in the circumferential direction. It does not reach the outer peripheral surface of each other and is closed in a semicircular shape as shown in FIG.

  On the other hand, the cylindrical fitting member 3 centered on the axis O is fitted into the outer periphery of the tip portion 1A having a columnar shape centered on the axis O as described above of the tool body 1 so that the axis O is aligned with the axis O. It is attached so as to be movable along the direction. The distal end portion of the inner peripheral surface of the fitting member 3 is a fitting surface 3A whose inner diameter gradually increases toward the distal end side, and is formed by the fitting surface 3A and the tip surface 1E of the tool body 1. The cutting insert 2 is brought into close contact with the fitting surface 3A and the seating surface 2F is brought into contact with the front end surface 1E to the insert mounting seat 3B. The clamp screw 4 is inserted through the washer 5 into the mounting hole 2D, which is the inner peripheral portion of 2A, and is screwed into the screw hole 1F formed in the distal end surface 1E, so that it can be detachably attached.

  The fitting member 3 has the largest outer diameter at the rear end portion in the direction of the axis O, and the intermediate portion has an outer diameter that is one step smaller than the rear end portion, and between the rear end portion and the intermediate portion. From the intermediate portion to the tip in the direction of the axis O, the outer diameter is formed so as to gradually decrease toward the tip. The outer diameter of the rear end portion is substantially equal to or slightly smaller than the outer diameter of the annular surface 1D of the tool body 1. Further, the inner diameter of the fitting member 3 is set to a size that allows the fitting member 3 to be fitted into the tip portion 1A of the tool body 1 as described above except for the fitting surface 3A at the tip portion.

  Further, a plurality of (two in the present embodiment) elongated holes 3C extending in the direction of the axis O are formed in the intermediate portion so as to penetrate in the radial direction, and the tip of the tool body 1 is formed. On the outer periphery of the part 1A, positioning screws 6 are screwed into positions corresponding to these long holes 3C. The heads of these positioning screws 6 are sized so as to be fitted into the elongated holes 3C. Thus, the fitting members 3 are fitted as described above by fitting the heads of the positioning screws 6 into the elongated holes 3C. In addition, it is positioned so as not to rotate in the circumferential direction while allowing movement in the axis O direction.

  A protrusion 1G is formed on the tip surface 1E of the tool body 1 at a position spaced from the screw hole 1F to the outer peripheral side. In this embodiment, the protrusion 1G is formed in a substantially semi-oval shape having an arc portion on the outer peripheral side as shown in FIG. 9A when viewed from the front end side in the axis O direction. The cutting insert 2 is seated on the insert mounting seat 3B as described above, and when the seating surface 2F of the insert main body 2A contacts the tip surface 1E, the seating surface 2F is formed. It is formed in a size that can be accommodated in a part (two in this embodiment) of the plurality of grooves 2I in the recess 2G on the side.

  Further, the tool body 1 has a number of coolant holes 7 (two in the present embodiment) obtained by subtracting the number of the protrusions 1G from the number of the grooves 2I in the recess 2G on the seating surface 2F side of the insert body 2A. When the seating surface 2F comes into contact with the front end surface 1E, the front end surface 1E is opened so as to communicate with the concave groove 2I in which the projection 1G is not accommodated. That is, these coolant holes 7 open to the tip surface 1E so as to form a circle having a center on a circle centering on an axis O passing through the center of the semicircular arc of the projection 1G in the tip view. In the circumferential direction, the two protrusions 1G are arranged at equal intervals from each other.

  The clamp screw 4 is formed of a steel material or the like, like the tool body 1, and includes a screw shaft portion 4A that is screwed into the screw hole 1F and a head portion 4B having a larger diameter than the screw shaft portion 4A. . The outer diameter of the screw shaft portion 4A is made slightly smaller than the inner diameter of the mounting hole 2D of the insert body 2A, and a space is provided between the two in a state where the screw shaft portion 4A is inserted into the mounting hole 2D. An engagement hole that engages with a work tool such as a wrench is formed on the front end surface of the head 4B, and the rear end surface of the head 4B opposite to the front end surface is directed toward the screw shaft portion 4A. It is formed in a tapered surface shape whose outer diameter gradually decreases.

  Further, the washer 5 is formed in an annular shape from, for example, maraging steel having a higher hardness than the clamp screw 4 or the same cemented carbide as the insert main body 2A, and the tip portion is formed with 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 2E on the rake face 2C side of the insert main body 2A 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 rear end surface extending in a straight line 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 a taper formed by the inner peripheral surface of the recess 2E. It is set approximately equal to the corner. Furthermore, the protrusion height of the convex part 5B from the rear end surface of the flange part 5A is made larger than the depth of the recess 2E from the rake face 2C of the insert body 2A to the bottom surface facing the front end side in the axis O direction of the recess 2E. In addition, the outer diameter of the projecting end surface 5C, which is the rear end surface of the convex portion 5B, is smaller than the inner diameter of the bottom surface of the recess 2E.

  Therefore, when the convex portion 5B is accommodated so that the protruding end surface 5C contacts the bottom surface of the recess 2E and the insert body 2A and the washer 5 are arranged coaxially, the inner peripheral surface of the recess 2E of the insert body 2A. 5 and FIG. 6 between the rim and the outer peripheral surface of the convex portion 5B of the washer 5, and between the rake face 2C of the insert body 2A and the rear end face of the flange portion 5A facing the rake face 2C. In this way, intervals are provided over the entire circumference. Further, a coolant discharge groove 5D is formed on the protruding end surface 5C of the convex portion 5B from the inner periphery to the outer periphery of 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 has a rectangular shape, and a plurality of such coolant discharge grooves 5D having the same shape and the same size are provided at equal intervals in the circumferential direction. A strip (six strips in this embodiment) is formed. In this embodiment, as shown in FIG. 12, these coolant discharge grooves 5D are formed to have a constant radial width from the inner periphery to the outer periphery of the projecting end surface 5C. The protruding end surface 5C portion remaining between the grooves 5D is formed so as to increase in width toward the outer periphery, but conversely, the groove width of the coolant discharge groove 5D increases so as to increase toward the outer periphery. Then, the protruding end surface 5C portion remaining between the adjacent coolant discharge grooves 5D may have a constant width.

  Further, the inner peripheral portion of the washer 5 is a housing portion 5E in which the head portion 4B of the clamp screw 4 is housed, and the rear end surface of the head portion 4B has an opening on the protruding end surface 5C side of the housing portion 5E. The taper surface has a taper angle equal to that of the taper surface formed, and is formed in a taper surface shape whose inner diameter is gradually reduced toward the projecting end surface 5C, so that the rear end surface of the head 4B can contact. Then, with the rear end surface of the head 4B in contact with the opening on the projecting end surface 5C side of the accommodating portion 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 flange portion 5A but to be buried in the inner peripheral portion of the washer 5.

  On the other hand, a receiving hole 8 centering on the axis O is formed at the rear end of the tool body 1 with a space in the direction of the axis O from the tip 1A. A biasing member 9 that biases the fitting member 3 toward the distal end side is accommodated. Further, a through hole 10 is formed from the front end of the accommodation hole 8 toward the front end side of the tool body 1. The through hole 10 is fitted by being biased by the biasing member 9. A pressing member 11 that presses the member 3 toward the distal end side is inserted.

  The housing hole 8 has a constant inner diameter except that a female screw portion 8A is formed on the inner periphery of the rear end portion thereof and the opening portion to the rear end face of the tool body 1 is a large diameter portion 8B having a larger inner diameter. The cross section is formed in a circular shape, and the tip thereof is located slightly on the tip side with respect to the boundary between the shank portion 1B and the neck portion 1C. Further, the through hole 10 is inclined and extended toward the outer peripheral side from the front end of the accommodation hole 8 so as to avoid the coolant hole 7 so as to avoid the coolant hole 7 and is open to the annular surface 1D of the tool body 1. In the present embodiment, a plurality (three) of through holes 10 are formed at equal intervals in the circumferential direction, and a pressing member 11 is inserted into each of these through holes 10. The coolant hole 7 also extends from the front end of the accommodation hole 8 to the front end side of the tool body 1 so as to avoid the through hole 10 and opens to the front end surface 1E.

  Here, in this embodiment, the biasing member 9 is a coil spring as shown in FIGS. 5, 6, and 8, and is accommodated in a compressed state in the accommodation hole 8 through the pressing member 11. The member 3 is biased. Further, the through hole 10 is a circular hole having a constant inner diameter, and the pressing member 11 is a small cylindrical pin (push rod) having an outer diameter as shown in FIG. 13 that can be fitted in sliding contact with the through hole 10. The rear end portion protrudes into the accommodation hole 8, and the front end portion of the pressing member 11 urged by the urging member 9 protrudes from the opening portion of the through hole 10 in the annular surface 1D. It abuts on the rear end surface and presses the fitting member 3 toward the front end side. In addition, the front end portion of the pressing member 11 that contacts the rear end surface of the fitting member 3 is formed in a hemispherical shape, and the rear end surface is a flat surface perpendicular to the center line of the cylindrical pressing member 11.

  Furthermore, in the present embodiment, a cylindrical plunger 12 is interposed between the front end of the biasing member 9 and the rear end of the pressing member 11 at the front end of the accommodation hole 8. The plunger 12 has an outer diameter that can be slidably fitted into the receiving hole 8 and an inner diameter that is substantially equal to or smaller than the inner diameter of the biasing member 9 that is a coil spring. The taper surface is inclined toward the rear end side toward the outer peripheral side at an angle at which the rear end surface of the pressing member 11 protruding into the housing hole 8 can contact. Accordingly, the pressing member 11 is urged toward the distal end side by the urging member 9 via the plunger 12 and presses the fitting member 3 toward the distal end side.

  Furthermore, a male screw portion 13A that can be screwed into the female screw portion 8A and a male screw portion 13A thus screwed into the female screw portion 8A are accommodated in the large-diameter portion 8B at the rear end portion of the receiving hole 8. A screw member 13 integrally formed with a flange portion 13B having a possible size is attached. An engagement hole 13C having a regular hexagonal cross section that can be engaged with a work tool such as a wrench is formed at the center of the rear end surface of the screw member 13, and the screw member extends from the bottom of the engagement hole 13C. A coolant supply hole 13 </ b> D having an inner diameter substantially equal to or smaller than the inner diameter of the urging member 9, which is a coil spring, is formed on the tip end surface of the coil spring 13, and opens in the accommodation hole 8.

  In such a blade-tip-exchangeable cutting tool, the pressing member 11 is inserted into the through hole 10, the plunger 12 and the biasing member 9 are inserted into the accommodation hole 8, and the fitting member is disposed on the outer periphery of the tip portion 1 </ b> A of the tool body 1. 3 is inserted and the positioning screw 6 is screwed to position in the circumferential direction, and then the male screw portion 13A is screwed into the female screw portion 8A of the receiving hole 8, and the screw member 13, the plunger 12, the pressing member 11, and the fitting By compressing the biasing member 9 with the joint member 3, the fitting member 3 is pressed and biased toward the distal end side via the plunger 12 and the pressing member 11. In this state, the fitting member 3 has the head of the positioning screw 6 in contact with the rear end of the long hole 3 </ b> C and protrudes toward the front end, and the rear end surface of the pressing member 11 contacts the front end surface of the plunger 12. By contacting, a space is provided between the plunger 12 and the hole bottom on the distal end side of the accommodation hole 8.

  Therefore, in this state, when the cutting insert 2 is placed with the rear end portion of the outer peripheral surface of the insert body 2A in close contact with the fitting surface 3A on the fitting surface 3A of the fitting member 3 forming the insert mounting seat 3B. 16, since the seating surface 2F of the insert body 2A is spaced from the tip surface 1E of the tool body 1 that also forms the insert mounting seat 3B, the insert body 2A is then attached via the washer 5. When the screw shaft portion 4A of the clamp screw 4 is inserted into the hole 2D and screwed into the screw hole 1F, the cutting insert 2 whose outer peripheral surface is in close contact with the fitting surface 3A is resistant to the urging force of the urging member 9. The fitting member 3, the pressing member 11, and the plunger 12 are moved to the rear end side, and are fixed when the seating surface 2F comes into contact with the front end surface 1E. At this time, the protrusion 1G is accommodated in the partial groove 2I among the plurality of grooves 2I in the recess 2G on the seating surface 2F side, and the cutting insert 2 is positioned in the circumferential direction, and the remaining grooves The groove 2I communicates with the coolant hole 7.

  In the blade-tip-exchangeable cutting tool configured as described above, the fitting member 3 on which the fitting surface 3A is formed is attached in such a manner that the cutting insert 2 abuts the seating surface 2F against the tip surface 1E by the clamp screw 4. In this state, the biasing member 9 is biased toward the distal end side of the tool main body 1 via the plunger 12 and the pressing member 11, and therefore the insert mounting seat formed by the fitting surface 3A and the distal end surface 1E. It becomes possible to attach the cutting insert 2 to 3B with high rigidity. Even if the forming accuracy of the cutting insert 2 is not so high, the annular or cylindrical insert body 2A is held by the fitting surface 3A of the fitting member 3 biased to the tip side in this manner, and the tool body 1 and Since it can be coaxially aligned, highly accurate and stable cutting can be performed.

  Further, in the blade-tip-exchangeable cutting tool having the above-described configuration, the biasing member 9 that biases the fitting member 3 toward the distal end side of the tool main body 1 is formed in the accommodation hole formed in the rear end portion of the tool main body 1 as described above. 8 is not exposed and exposed to the outer periphery of the tool body 1. For this reason, the cutting generated by the cutting blade 2B of the cutting insert 2 during the cutting process is wound around the urging member 9 that is a coil spring as in the present embodiment, for example, so that the cutting process is interrupted. It is possible to prevent the urging member 9 from being damaged or damaged due to entangled chips, and a stable and smooth cutting operation can be performed.

  Further, in the blade-tip-exchangeable cutting tool in which the biasing member 9 is accommodated in the accommodation hole 8 in the rear end portion of the tool body 1 as described above, for example, a fitting member like the blade-tip-exchangeable cutting tool described in Patent Document 1 is used. The length of the front-end | tip part 1A of the tool main body 1 which the fitting member 3 fits can be shortened with respect to the case where the urging | biasing part is provided in the rear-end part. For this reason, the rigidity of the tool main body 1 and the mounting stability of the cutting insert 2 with respect to the back component force and feed component force at the time of cutting can be improved, and accordingly, high processing accuracy can be obtained.

  Furthermore, in the blade-tip-exchangeable cutting tool of the present embodiment, the annular surface 1D at the rear end of the tip 1A of the tool body 1 into which the fitting member 3 is fitted from the accommodation hole 8 that accommodates the biasing member 9 as described above. A plurality of through holes 10 are formed in the tool body 1 at equal intervals in the circumferential direction, and the fitting member 3 is pushed by the urging member 9 through the pressing members 11 respectively inserted into the through holes 10. Is biased to the side. Therefore, the cylindrical fitting member 3 can be arranged coaxially with the axis O of the tool main body 1 with high accuracy and urged toward the tip side, whereby the annular or cylindrical cutting insert 2 is also connected to the axis O. It can hold | maintain coaxially and can aim at the improvement of the further processing precision, and can also improve attachment stability.

  On the other hand, in the present embodiment, the tool body 1 is formed with a coolant hole 7 opened to the tip surface 1E through the housing hole 8, and the plunger 12 inserted into the tip of the housing hole 8 is The urging member 9 is a coil spring, and the portion along the axis O is hollow. Further, the screw member 13 in which the male screw portion 13A is screwed into the female screw portion 8A at the rear end portion of the accommodation hole 8 is also formed in the accommodation hole 8 with a coolant supply hole 13D formed from the bottom of the engagement hole 13C. Therefore, at the time of cutting, a coolant (fluid) such as cutting fluid, mist, or air is supplied from the machine tool to the coolant hole 7 through the coolant supply hole 13D, the biasing member 9 in the accommodation hole 8, and the hollow portion of the plunger 12. ) Can be supplied.

  In this embodiment, the coolant supplied to the coolant hole 7 from the remaining recess groove 2I of the recess 2G on the seating surface 2F side of the insert body 2A communicating with the coolant hole 7 in this embodiment is used as the recess 2G. Through the annular groove 2H, it passes through the space between the mounting hole 2D and the screw shaft 4A of the clamp screw 4, and is supplied to the recess 2E on the rake face 2C side. Further, the coolant supplied to the recess 2E is interposed between the protrusion 5B and the recess 2E from the coolant discharge groove 5D formed on the protruding end surface 5C of the protrusion 5B of the washer 5 accommodated in the recess 2E. Then, it is discharged along the rake face 2C from the space between the rake face 2C of the insert body 2A and the rear end face of the flange portion 5A and supplied to the cutting edge 2B. The cutting edge 2B and the cutting edge 2B Cools and lubricates the cutting part of the work material W.

  Therefore, according to such a blade-exchangeable cutting tool of this embodiment, the cutting edge of the cutting insert 2 can be effectively used by effectively utilizing the space of the accommodation hole 8 formed in the tool body 1 that accommodates the biasing member 9. The cutting site of 2B and the work material W can be reliably cooled and lubricated. For this reason, it is possible to prevent a situation in which the rigidity of the tool body 1 is unnecessarily impaired as compared with a case where a coolant supply path is formed separately from the housing hole 8, and the manufacturing cost of the tool body 1 is reduced. Reduction can be achieved.

  In this embodiment, in particular, the cutting insert 2 is a circular piece insert having a circumferential cutting edge 2B, whereas a plurality of coolant discharge grooves 5D are formed radially on the protruding end surface 5C of the washer 5. Therefore, the cutting blade 2B portion actually cut into the work material W and the cutting part of the work material W are separated from the cutting part by the rotational drive of the tool body 1 and become high temperature by cutting. The coolant can also be supplied to the cutting blade 2B portion to cool it. When the coolant discharge groove 5D is formed so as to become wider toward the outer peripheral side as described above, the coolant can be evenly distributed over the entire circumference of the circumferential cutting blade 2B.

  Here, the sum of the minimum cross-sectional areas of the coolant discharge grooves 5D of the washer 5 is preferably greater than or equal to the sum of the cross-sectional areas of the part of the tool body 1 where the cross-sectional area of the coolant supply path is minimum, for example, the part of the coolant hole 7. Is set to be larger than the total sum of the minimum cross-sectional areas, it is possible to prevent the resistance when the coolant is discharged from the coolant discharge groove 5D from being increased and to reduce the pressure loss. Therefore, the coolant supply pressure is not increased more than necessary, and the coolant can be supplied efficiently.

  Moreover, in this embodiment, while the convex part 5B of the washer 5 is accommodated in the recess 2E formed in the rake face 2C of the cutting insert 2, the outer peripheral surface of the convex part 5B and the inner peripheral surface of the recess 2E Between the rake face 2C of the insert body 2A and the rear end face of the flange portion 5A of the washer 5 opposite to the rim face 2C. While the coolant is blown out from between the rake face 2C and the rear end face of the flange portion 5A toward the cutting edge 2B, a 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 diameter-reduced portion on the seating surface 2F side of the insert body 2A of the receiving portion 5E of the washer 5, and the cutting insert 2 is inserted into the insert mounting seat 3B. The head 4 </ b> B is buried in the housing portion 5 </ b> E so as not to protrude from the front end surface of the washer 5. For this reason, even if chips generated by the cutting blade 2B flow out from the rake face 2C of the insert body 2A to the front end face of the flange portion 5A of the washer 5, the head 4B of the clamp screw 4 is not rubbed. 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 2F of the insert body 2A is formed with a recess 2G on the seating surface 2F side having a plurality of grooves 2I extending radially outward from the mounting hole 2D. On the tip surface 1E of the tool body 1 that forms the insert mounting seat 3B so as to face the seating surface 2F, a protrusion 1G that is accommodated in the partial concave groove 2I is formed, and the remaining concave groove 2I. The coolant hole 7 is inclined and extended toward the outer peripheral side as it goes to the front end side so as to communicate with the front end.

  For this reason, like the tool main body 1 of this embodiment, the accommodation hole 8 to which the coolant at the rear end of the tool main body 1 is supplied and the screw hole 1F into which the clamp screw 4 at the front end 1A is screwed are centered on the axis O. Even if arranged coaxially, the coolant can be supplied to the remaining concave groove 2I through the coolant hole 7 inclined as described above, and reliably supplied to the rake face 2C side on which the cutting blade 2B is formed. In addition, since these coolant holes 7 are formed at equal intervals in the circumferential direction, a good rotational balance can be ensured particularly in the drive type rotary tool as in this embodiment.

  In the present embodiment, an annular groove 2H is formed between the mounting hole 2D of the insert body 2A and the groove 2I of the recess 2G on the seating surface 2F side so as to go around the opening of the mounting hole 2D. The coolant supplied from the coolant hole 7 is supplied to the rake face 2C side through the recess 2G having the annular groove 2H and the recessed groove 2I. For this reason, especially when the coolant is a liquid such as a cutting fluid, the recess 2G acts as a liquid pool, so that it is possible to supply the coolant stably even when the coolant supply amount fluctuates. It becomes.

  Further, since the plurality of concave grooves 2I of the recess 2G are formed at equal intervals in the circumferential direction in the present embodiment, when the seating surface 2F of the insert body 2A is seated on the tip surface 1E, Even if the protrusion 1G is accommodated in the concave groove 2I, the coolant hole 7 can be communicated with the remaining concave groove 2I. In addition, since the protrusion 1G is housed in a part of the concave groove 2I and engages with the insert body 2A, the cutting insert 2 can be prevented from rotating, and therefore stable cutting can be performed.

  Furthermore, in the present embodiment, the coolant supplied to the recess 2G is supplied to the rake face 2C side through a gap portion between the mounting hole 2D of the insert body 2A and the screw shaft portion 4A of the clamp screw 4. Is done. For this reason, in the present embodiment, the insert body 2A can be cooled also from the mounting hole 2D side on the inner periphery, and the insert body 2A can be reliably prevented from becoming hot due to cutting heat, and this cutting heat can be prevented. 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.

  Next, FIGS. 18 to 34 show a second embodiment of the present invention. Elements common to the first embodiment shown in FIGS. 1 to 17 are assigned the same reference numerals. Description is omitted. Here, in the first embodiment described above, the present invention is applied to a drive rotary tool for turning a work material W having a relatively small diameter D, whereas this second embodiment. As shown in FIG. 34, there is no limitation on the diameter D of the work material W, and the rotary rotary tool that can be used for turning the work material W having a relatively small diameter D to a small diameter D. The present invention is applied to.

  That is, in the second embodiment, the diameter of the cutting edge 2B of the annular or cylindrical cutting insert 2 is made larger than the diameter of the shank portion 1B of the tool body 1, and the diameter D is as described above. It is possible to handle turning to a large work material W. Further, the neck portion 1C between the shank portion 1B and the tip portion 1A of the tool body 1 is slightly reduced in diameter at the tip portion of the shank portion 1B, and the outer diameter gradually increases toward the tip side of the tool body 1. After the diameter, the outer diameter becomes constant and reaches the annular surface 1D at the rear end of the front end 1A. Furthermore, the outer diameter of the fitting member 3 is constant, is approximately equal to the diameter of the constant outer diameter portion of the neck 1C, and is approximately equal to or slightly smaller than the diameter of the cutting edge 2B.

  Further, in the present embodiment, the accommodation hole 8 and the screw hole 1F communicate with each other through the communication hole 8C having an inner diameter smaller than the accommodation hole 8 with the axis O as the center, and the coolant hole 7 branches off from the communication hole 8C. The tool body 1 is inclined and extended toward the outer peripheral side as it goes toward the front end side of the tool body 1, and is open to the front end surface 1E. In the second embodiment, as shown in FIG. 28, the coolant discharge groove 5D in the washer 5 is formed so that the groove width becomes wider toward the outer peripheral side, and the coolant discharge groove adjacent in the circumferential direction is formed. The protruding end surface 5C portion remaining between 5D has a constant width.

  Furthermore, the plunger 12 has a plurality of branch holes 12A extending in the radial direction with respect to the axis O from the inner peripheral portion at the tip end portion thereof and opening in the outer peripheral surface of the plunger 12 at equal intervals in the circumferential direction (this embodiment). 4), and the concave groove 12B extends from the opening on the outer peripheral surface of the branch hole 12A to the distal end surface of the plunger 12, so as to avoid the portion of the distal end surface where the rear end surface of the pressing member 11 contacts. The coolant formed on the outer peripheral surface and supplied to the accommodation hole 8 flows from the branch hole 12A through the concave groove 12B into the communication hole 8C. The rear end portion of the pressing member 11 is formed in a truncated cone shape that gradually decreases in diameter toward the rear end side.

  Also in the cutting edge exchange type cutting tool of the second embodiment, the urging member 9 that is a coil spring is housed in the housing hole 8 formed in the rear end portion of the tool body 1 as in the first embodiment. Then, since the fitting member 3 is urged toward the distal end side of the tool body 1 via the pressing member 11, chips generated by the cutting blade 2 </ b> B during the cutting process are entangled with the urging member 9. It can prevent wrapping. Further, when the biasing portion is provided at the rear end portion of the fitting member, the length of the tip portion 1A of the tool body 1 can be shortened, and the rigidity of the tool body 1 and the cutting insert 2 can be reduced. It is possible to improve the mounting stability and perform highly accurate cutting.

  Furthermore, in this embodiment, since the screw hole 1F into which the clamp screw 4 is screwed is communicated with the accommodation hole 8 via the communication hole 8C, the clamp screw 4 is screwed to the screw shaft by the coolant supplied to the accommodation hole 8. It can cool also from the edge part of the part 4A. For this reason, expansion of the clamp screw 4 due to cutting heat can be prevented more reliably, and the cutting insert 2 can be attached more stably.

  In the second embodiment and the first embodiment, a coil spring is used as the urging member 9 having a hollow portion that allows the coolant to be supplied in the accommodation hole 8. You may make it urge | bias the fitting member 3 via the press member 11 or the plunger 12 by accommodating the disc spring in the accommodation hole 8 by alternating the direction of the large diameter part and the small diameter part. Moreover, in these 1st, 2nd embodiment, although the circular circular piece insert was attached to the insert attachment seat 3B as the cutting insert 2 so that attachment or detachment was possible, the cutting edge was formed in the front end surface or the outer peripheral surface, for example A cylindrical cutting insert for an end mill may be attached to constitute an end mill with a replaceable blade edge.

DESCRIPTION OF SYMBOLS 1 Tool main body 1A The front-end | tip part of the tool main body 1 1B Shank part (rear end part of the tool main body 1)
1E Tip surface of tool body 1 1F Screw hole 2 Cutting insert 2A Insert body 2B Cutting blade 2C Rake face 2D Mounting hole 2F Seating surface 3 Fitting member 3A Fitting surface 3B Insert mounting seat 4 Clamp screw 5 Washer 7 Coolant hole 8 Hole 9 Biasing member 10 Through-hole 11 Pressing member 12 Plunger 13 Screw member O Axis of tool body 1 W Work material

Claims (3)

A cylindrical fitting member centered on the axis is fitted on the outer periphery of the cylindrical tool body tip centered on the axis so as to be movable along the axis.
The tip of the inner peripheral surface of the fitting member is a fitting surface whose inner diameter gradually increases as it goes to the tip side,
A cutting insert having an annular or cylindrical insert body formed on the insert mounting seat formed by the fitting surface and the tip surface of the tool body and having a cutting edge formed on the outer periphery thereof is an outer periphery of the insert body. A clamp screw that is inserted through the inner peripheral portion of the insert body is formed on the distal end surface with the rear end surface of the insert body abutting against the distal end surface while the rear end portion of the surface is in close contact with the fitting surface. Removably attached by being screwed into the screw hole,
An accommodation hole for accommodating an urging member is formed at the rear end of the tool body,
A through hole is formed from the housing hole toward the tip side of the tool body,
A blade-tip-exchangeable cutting tool, wherein a pressing member that presses the fitting member toward the distal end side by being biased by the biasing member is inserted into the through hole.   2. The blade edge replacement according to claim 1, wherein a plurality of the through holes are formed in the tool body at equal intervals in the circumferential direction, and the pressing member is inserted into each of the through holes. Type cutting tool.   The cutting edge exchangeable cutting tool according to claim 1 or 2, wherein a coolant hole for supplying a coolant to the cutting insert is formed in the tool body via the receiving hole.

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