JP5515958B2 - Coolant supply hole structure for cutting tools - Google Patents

Description

  The present invention relates to a coolant supply hole structure for a cutting tool.

  2. Description of the Related Art Conventionally, a cutting tool that is attached to a machine tool and performs cutting on a work material made of a metal material is known. As this type of cutting tool, for example, a tool body having an axial shape and a plate-shaped cutting insert that is detachably attached to the tip or outer periphery of the tool body are provided. There is an edge-changing type rolling tool configured to roll a work material with a cutting edge of a cutting insert by being rotated about an axis).

  For example, in the cutting edge exchange type rolling tool shown in Patent Documents 1 and 2, a plurality of insert mounting seats are formed on the outer periphery of the tip of the tool body, and cutting inserts are respectively mounted on these insert mounting seats. ing. These cutting inserts are arranged in a row so as to be aligned in the tool axis direction, and the entire row is formed in a spiral step shape so as to be twisted in the tool rotation direction. Moreover, a plurality of such rows of cutting inserts are formed at intervals in the circumferential direction at the outer peripheral portion of the tip.

  The cutting edge exchange type turning tool has a coolant supply hole structure that allows coolant such as cutting fluid to flow through the inside of the tool body and to be ejected toward the vicinity of the cutting edge. Specifically, the coolant supply hole structure communicates with the first supply hole (supply hole, cooling medium passage) extending along the tool axis of the tool body, and the cutting insert at the outer periphery of the tip. And a second supply hole (spout hole, branch passage) extending toward the end, and the second supply hole is opened to a chip discharge groove (chip groove). At the time of cutting, coolant is supplied to the first supply hole of the tool body from the spindle of the machine tool that supports the rear end of the tool body, and the coolant is directed to the tip side of the tool body through the first supply hole. Then, it flows out through the second supply hole toward the vicinity of the cutting edge of the cutting insert.

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

However, the coolant supply hole structure of this type of cutting tool has the following problems.
In general, one first supply hole is formed along the tool axis, whereas the second supply hole is spaced circumferentially around the tool axis so as to correspond to the arrangement of cutting edges of the cutting insert. A plurality of holes are formed at intervals in the tool axis direction. In this case, the coolant may not be easily ejected from a part of the holes (second supply holes) due to the arrangement of the second supply holes. That is, it has been difficult to set the flow rate and supply amount of the coolant ejected through the second supply holes evenly.

  Specifically, for example, when a plurality of cutting inserts are arranged along the tool axial direction as in the cutting tools described in Patent Documents 1 and 2, the second supply holes are formed by cutting edges of the cutting inserts. Corresponding to the arrangement, a plurality are formed at intervals in the tool axis direction. Of these second supply holes, the rear end side of the tool body with respect to the flow rate and supply amount of the coolant ejected through the second supply hole located on the front end side of the tool body with respect to the second supply hole. In some cases, the flow rate and the supply amount of the coolant ejected from the other second supply hole located in the lower position are reduced.

  If there is a difference in the coolant flow rate or the supply amount between the second supply holes, the sharpness of the cutting edge and the chip dischargeability will not be stable as a whole tool, and the machining accuracy cannot be ensured. In addition, the cutting insert disposed in a region where the coolant is not sufficiently supplied becomes difficult to obtain the cooling / lubricating effect of the cutting edge by the coolant, and is liable to be welded or broken, thereby shortening the tool life.

  The present invention has been made in view of such circumstances, and the flow rate and supply amount of the coolant sprayed toward the vicinity of the cutting edge can be made uniform over the entire tool, and the sharpness of the cutting edge and the dischargeability of chips can be reduced. An object of the present invention is to provide a coolant supply hole structure for a cutting tool that can be stably increased, ensure machining accuracy, and extend tool life.

In order to achieve the above object, the present invention proposes the following means.
That is, the present invention is a coolant supply hole structure of a cutting tool that is formed inside a shaft-shaped tool body provided with a cutting edge and supplies coolant toward the cutting edge, and is along the tool axis of the tool body. A first supply hole extending in the direction of the first supply hole, a recess formed in the inner surface of the first supply hole and recessed toward the opposite side of the tool axis, and an opening in the inner surface of the recess. A second supply hole extending toward the blade, and the recess is formed to be inclined so as to gradually approach the axis of the second supply hole from the inner surface of the first supply hole toward the back surface. It is characterized by being.
Moreover, this invention is a coolant supply hole structure of the cutting tool which is formed in the inside of the shaft-shaped tool main body provided with a cutting edge, and supplies a coolant toward the said cutting edge, Comprising: The tool axis line of the said tool main body is followed. A first supply hole extending in the direction of the first supply hole, a recess formed in the inner surface of the first supply hole and recessed toward the opposite side of the tool axis, and an opening in the inner surface of the recess. A second supply hole extending toward the blade, and a plurality of the recesses are formed at intervals in the tool axis direction, and an inner surface of the first supply hole is formed along the tool axis. It is formed so as to be inclined so as to gradually approach the tool axis line from the end side toward the tip side.

  The coolant supply hole structure for a cutting tool according to the present invention is arranged on a shaft-shaped tool body and a tip portion or / and an outer peripheral portion (hereinafter abbreviated as a tip outer peripheral portion) of the tool body to cut a work material. It is used for a cutting tool provided with a cutting edge to supply coolant such as cutting fluid to the vicinity of the cutting edge. For example, the cutting tool is rotated around the tool axis in a state where the rear end of the tool body is supported by the spindle of the machine tool, etc., thereby cutting the work material with the cutting edge (rolling processing). To do. A first supply hole is formed in the tool body of the cutting tool along the center axis (tool axis). The first supply hole is formed in, for example, a cylindrical hole shape, and a recess that is recessed toward the side opposite to the tool axis is formed on the inner surface thereof. The recess is formed in, for example, an annular shape extending in the circumferential direction around the tool axis, or a concave curved surface shape partially recessed from the inner surface, and the inner surface (radially outward in the recess). A second supply hole is opened in a surface (ie, a bottom surface) that is disposed on the surface and faces the tool axis side. The second supply hole is formed, for example, in a cylindrical hole shape having a smaller diameter than the first supply hole, and extends toward the cutting edge.

Here, in the conventional configuration, the second supply hole is simply opened on the inner surface of the first supply hole, and the first and second supply holes are communicated with each other. However, since the first supply hole and the second supply hole have different inner diameters and different extending directions, the flow rate of the coolant flowing from the first supply hole to the second supply hole has a frictional resistance. Therefore, the coolant could not be ejected vigorously toward the vicinity of the cutting edge.
On the other hand, according to the coolant supply hole structure of the cutting tool of the present invention, when coolant is supplied to the first supply hole of the tool body from the spindle or the like of the machine tool, the coolant accumulates in the recess of the first supply hole. Then, the inside of the recess flows toward the side opposite to the tool axis so as to follow the shape of the recess, and is smoothly guided into the second supply hole opened in the inner surface of the recess. That is, the coolant flows from the first supply hole into the second supply hole through the recess, so that the flow rate of the coolant is prevented from being reduced and the supply amount is secured, so that the coolant is cut off. It is ejected vigorously toward the vicinity of the blade.

In addition, for example, in the tool body of a cutting tool, when a plurality of cutting edges are provided at intervals in the tool axis direction or the circumferential direction, or when extending along the tool axis line and formed into a long blade, A plurality of second supply holes are formed corresponding to the cutting edges. In such a case, in the above-described conventional configuration, the coolant may be difficult to be ejected from some holes (second supply holes) due to the arrangement of the second supply holes, and the like. It was difficult to set the flow rate and the supply amount of the injected coolant evenly.
On the other hand, according to the coolant supply hole structure of the cutting tool according to the present invention, the flow rate and supply amount of the coolant ejected through the respective second supply holes are sufficiently ensured. The difference in the flow rate and the supply amount is less likely to occur, and the coolant is evenly ejected as a whole tool.

  Therefore, the sharpness of the cutting edge and the chip dischargeability are stably improved as a whole tool, and the processing accuracy is ensured. Further, since the cooling and lubrication effect of the cutting edge can be reliably obtained, the cutting edge is prevented from being welded or broken, and the tool life is extended.

Further , the recess is formed so as to gradually approach the axis of the second supply hole as it goes from the inner surface of the first supply hole to the inner surface, so that the frictional resistance of the coolant flowing in the recess is reduced. In addition to being reduced, the coolant flow rate is gradually increased toward the inner surface. Thereby, the momentum of the coolant ejected through the second supply hole is increased.

In general, the amount of coolant required for the part on the rear end side in the tool axis direction in the first supply hole is larger than the amount of coolant required for the part on the front end side in the tool axis direction. That is, the amount of coolant required for the part on the rear end side in the tool axis direction in the first supply hole is only the amount of coolant that is ejected from the part on the rear end side to the vicinity of the cutting edge through the second supply hole. In addition, it also includes the amount of coolant that flows from the rear end portion to the tip end portion in the tool axis direction and is ejected from the front end portion through the second supply hole toward the vicinity of the cutting edge. Therefore, the inner surface of the first supply hole is from the rear end side along the tool axis by being formed to be inclined gradually to approach the tool axis as it goes toward the distal end, and the coolant amount is more necessary The capacity | capacitance in the site | part of the rear-end side of the tool axial direction in 1 supply hole is fully ensured.

Further, with such a configuration, the coolant flows substantially evenly into the plurality of recesses arranged at intervals in the tool axis direction. Then, the coolant is uniformly ejected toward the vicinity of the cutting edge through the respective second supply holes that open in these recesses, and the sharpness of the cutting edge and the chip dischargeability are stably improved as a whole tool. It is done.
Further, in the coolant supply hole structure for a cutting tool according to the present invention, the tool body may be rotated around the tool axis and the work material may be rolled by the cutting edge.
According to the coolant supply hole structure for a cutting tool according to the present invention, since the work material is rolled by the cutting edge by rotating the tool body around the tool axis, the centrifugal force generated when the tool body rotates. This makes it easy for the coolant to collect in the recess. Further, the coolant accumulated in the recesses easily flows toward the inner surface opposite to the tool axis, and easily flows into the second supply hole opened in the inner surface. Thereby, the flow velocity and supply amount of the coolant sprayed to the vicinity of the cutting edge are reliably increased.

  In the coolant supply hole structure for a cutting tool according to the present invention, the angle α at which the inner surface of the first supply hole is inclined with respect to the tool axis is set within a range of 0 ° <α ≦ 20 °. It is good.

  According to the coolant supply hole structure of the cutting tool according to the present invention, the angle α at which the inner surface of the first supply hole is inclined with respect to the tool axis is set within a range of 0 ° <α ≦ 20 °. When a plurality of recesses are formed along the tool axis direction, the coolant flows into these recesses substantially uniformly, and the rigidity of the tool body is ensured. That is, when the angle α is set to exceed 20 °, it is difficult to secure the thickness of the part located on the rear end side in the tool axis direction in the tool body, and the rigidity of the tool body is reduced. There is.

  Further, in the coolant supply hole structure for a cutting tool according to the present invention, an axis of the second supply hole extends toward a front side in a tool rotation direction in which the tool main body rotates with respect to the cutting edge. 2 The distance between the axis of the supply hole and the cutting edge may be set within a range of 0.5 mm to 3 mm.

  According to the coolant supply hole structure of the cutting tool according to the present invention, the axis of the second supply hole extends toward the front side in the tool rotation direction from the cutting edge, and the distance between the axis and the cutting edge is It is set within a range of 0.5 mm to 3 mm. That is, the coolant flowing through the second supply hole is ejected toward the chips generated by cutting the cutting edge, and in detail, it is ejected toward the base of the chips.

  Here, the chip is generated by curling so as to go to the tool axis side of the tool main body and then to the front side in the tool rotation direction by being scraped off by the cutting edge and being scooped by the rake face ( For example, see FIG. Therefore, after cooling the chip, the coolant sprayed near the root of the chip flows toward the cutting edge between the chip and the rake face or around the chip so as to follow the curl of the chip. As a result, the coolant is efficiently and stably supplied to the chips and the cutting edge, and the chip dischargeability and the sharpness of the cutting edge are stably increased, thereby ensuring machining accuracy.

  Further, in the coolant supply hole structure for a cutting tool according to the present invention, the second supply hole has a circular cross section perpendicular to the axis of the second supply hole, and is formed on the cutting edge side of the second supply hole. In communication, the cross-section is circular and a third supply hole having a smaller diameter than the second supply hole is formed. Between the second and third supply holes, the second supply hole is formed between the second supply hole and the third supply hole. A taper surface that gradually decreases in diameter as it goes toward the cutting edge along the axis may be formed.

  According to the coolant supply hole structure for a cutting tool according to the present invention, the third supply hole having a smaller diameter than the second supply hole is formed in communication with the cutting edge side of the second supply hole. And between these 2nd and 3rd supply holes, the taper surface which diameter is gradually reduced as it goes to the cutting-blade side along the axis line of a 2nd supply hole is formed. By forming such a tapered surface, the frictional resistance of the coolant flowing into the third supply hole from the second supply hole is reduced, and the flow velocity of the coolant is increased. Therefore, the momentum of the coolant that is ejected to the vicinity of the cutting edge through the third supply hole is sufficiently ensured.

  In the coolant supply hole structure for a cutting tool according to the present invention, the inner diameter of the third supply hole may be set in a range of 0.5 mm to 1.6 mm.

  According to the coolant supply hole structure of the cutting tool according to the present invention, the inner diameter of the third supply hole is set in the range of 0.5 mm to 1.6 mm, so that the coolant is clogged in the third supply hole. Is prevented, and the jetting power of the coolant is sufficiently secured. That is, when the inner diameter is set to be smaller than 0.5 mm, the coolant may be clogged in the third supply hole due to adhesion or the like. Further, when the inner diameter is set to exceed 1.6 mm, the flow rate of the coolant flowing from the second supply hole to the third supply hole cannot be sufficiently increased, and the momentum of ejection may not be ensured.

  According to the coolant supply hole structure of the cutting tool according to the present invention, the flow rate and supply amount of the coolant sprayed toward the vicinity of the cutting edge can be made uniform over the entire tool, and the sharpness of the cutting edge and the discharge of chips can be stabilized. While being able to raise, processing accuracy is ensured and a tool life can be extended.

It is a side view which shows the blade-tip-exchange-type rolling tool using the coolant supply hole structure of the cutting tool which concerns on one Embodiment of this invention. FIG. 2 is a side cross-sectional view showing a part of the cutting edge-replaceable type rolling tool of FIG. 1 in a simplified manner, illustrating a coolant supply hole structure of a cutting tool according to an embodiment of the present invention. It is a figure which shows the AA cross section of FIG. It is a sectional side view explaining the principal part of the coolant supply hole structure of the cutting tool which concerns on one Embodiment of this invention. It is a sectional side view explaining the principal part of the coolant supply hole structure of the cutting tool which concerns on one Embodiment of this invention.

As shown in FIGS. 1 and 2, a coolant supply hole structure 10 for a cutting tool according to an embodiment of the present invention is formed in a cutting edge-replaceable rolling tool 1 that is a cutting tool. The cutting edge-exchangeable cutting tool 1 is composed of a shaft-shaped tool body 2 made of steel or the like and a hard material such as cemented carbide, and is detachably attached to the outer periphery of the tip of the tool body 2 from the tool body 2. A plate-like cutting insert 4 for projecting the cutting edge 3. Specifically, the tool body 2 has a cylindrical shape, and the cutting edge-replaceable rolling tool 1 has a rear end portion (the upper end in FIGS. 1 and 2) in the central axis (tool axis) O1 direction of the tool body 2. Is cut in the tool rotation direction T around the tool axis O1 while being supported by the spindle of the machine tool, etc., thereby cutting the work material made of a metal material with the cutting edge 3 (Turning process) To do.
The coolant supply hole structure 10 of the cutting tool is formed inside the tool main body 2 and supplies coolant made of a cutting oil or the like toward the cutting edge 3.

  In FIG. 2, the tool body 2 is formed with a multi-stage cylindrical hole-shaped mounting hole 5 that penetrates the tool body 2 in the direction of the tool axis O1. The mounting hole 5 opens to the rear end surface 2A of the tool body 2 and has a large diameter portion 5A having the largest inner diameter, and opens to the tip surface 2B of the tool body 2 and has a smaller diameter than the large diameter portion 5A. The small diameter portion 5B and the first supply hole 6 that is arranged between the large diameter portion 5A and the small diameter portion 5B and has the smallest diameter are arranged coaxially. Further, the tool body 2 is formed with a key groove 7 that opens in the rear end surface 2A of the tool body 2 and extends in the diameter direction with respect to the tool axis O1.

  The cutting edge-replaceable rolling tool 1 has a mounting shaft on a main shaft of a machine tool fitted into a large diameter portion 5A of the mounting hole 5 from the rear end side (upper side in FIG. 2) of the tool body 2 and is attached to the main shaft. The provided key can be fitted in the key groove 7. In this state, the mounting bolt inserted into the mounting hole 5 from the front end side (the lower side in FIG. 2) of the tool body 2 is screwed into the bolt hole of the mounting shaft, so that the head of the mounting bolt is attached to the mounting hole 5. By pressing the step portion 5C between the small diameter portion 5B and the first supply hole 6, the rear end surface 2A of the tool main body 2 is pressed against the main shaft and attached to the main shaft. A space is provided around the mounting bolt between the inner surface 6A of the first supply hole 6 and coolant is supplied to the space from the spindle side of the machine tool.

  In FIG. 1, a chip discharge groove 8 is formed on the outer peripheral surface of the tool body 2 so as to gradually twist toward the rear side in the tool rotation direction T from the front end surface 2 </ b> B toward the rear end side. A plurality of chip discharge grooves 8 are formed on the outer peripheral surface of the tool body 2 at intervals in the circumferential direction.

  A plurality of concave insert mounting seats 9 (four in this embodiment) are formed in the chip discharge groove 8 along the chip discharge groove 8. The insert mounting seat 9 includes a wall surface facing the front side in the tool rotation direction T and a bottom surface facing the radial direction outward of the tool body 2. When viewed from the direction facing the outer peripheral surface of the tool body 2, the wall surface of the insert mounting seat 9 is formed in a concave V shape. Further, the bottom surface of the insert mounting seat 9 is formed in a substantially pentagonal shape, and a mounting screw hole is formed at a substantially center of the bottom surface so as to extend in the radial direction of the tool body 2.

  The cutting insert 4 is formed in a polygonal flat plate shape by a hard sintered body such as cemented carbide. Specifically, the cutting insert 4 includes a pair of polygonal surfaces and side surfaces arranged around the pair of polygonal surfaces, and in a state where one of these side surfaces is a rake face toward the front side in the tool rotation direction T, It is attached to the insert mounting seat 9. Specifically, the cutting insert 4 of the present embodiment has a substantially pentagonal flat plate shape, and includes a pair of pentagonal surfaces 12 and side surfaces 13 arranged around these pentagonal surfaces 12.

  Of the side surface 13 of the cutting insert 4, a surface facing the front side in the tool rotation direction T is a scoop surface 13A, and a surface facing the rear side in the tool rotation direction T is a seating surface 13B. The cutting insert 4 has a pentagonal shape when the seating surface 13B has a convex V shape when viewed from the direction facing the pentagonal surface 12. Further, the cutting insert 4 is formed with an attachment hole 14 penetrating between the pair of pentagonal surfaces 12 so as to open substantially at the center of both pentagonal surfaces 12.

  A cutting edge 3 is formed in the cutting insert 4, and the cutting edge 3 includes a main cutting edge 3 </ b> A that protrudes radially outward from the outer peripheral surface of the tool body 2, and a tip surface 2 </ b> B of the tool body 2. It has a secondary cutting edge 3B that protrudes toward the distal end side, and a convex curved corner blade that connects the main cutting edge 3A and the secondary cutting edge 3B.

  Specifically, the rake face 13 </ b> A of the cutting insert 4 is formed in a substantially parallelogram shape, and the sides and corners of the parallelogram are the cutting edges 3. And the intersection ridgeline part of the scoop surface 13A and the pentagonal surface 12 is made into the main cutting edge 3A among the said side parts. In addition, among the side portions, the intersecting ridge line portion between the rake face 13A and the other side face 13 adjacent to the rake face 13A is defined as the auxiliary cutting edge 3B. The corner portion is the corner blade.

  The cutting insert 4 is seated on the insert mounting seat 9 by bringing one of a pair of pentagonal surfaces 12 into contact with the bottom surface of the insert mounting seat 9 and having the seating surface 13B in contact with the wall surface of the insert mounting seat 9. Be made. In this state, the clamp screw 11 is inserted into the mounting hole 14 of the cutting insert 4 and screwed into the mounting screw hole of the insert mounting seat 9, so that the cutting insert 4 has the bottom surface and the wall surface of the insert mounting seat 9. In a state of being pressed against the insert mounting seat 9, the insert mounting seat 9 is detachably attached.

  In addition, the insert mounting seats 9 formed in plural along one chip discharge groove 8 have a spiral staircase shape in which each wall surface facing the front side in the tool rotation direction T follows the twist of the chip discharge groove 8. Is arranged. That is, the wall surface of the other insert mounting seat 9 adjacent to the rear end side thereof is shifted by one step toward the rear side in the tool rotation direction T with respect to the wall surface of the insert mounting seat 9 on the distal end side of the tool body 2. It is arranged like that.

  In FIG. 1, a plurality of (four in this embodiment) cutting inserts 4 mounted on the insert mounting seat 9 along one chip discharge groove 8 are arranged in a spiral staircase as a whole, and the tool body 2 A plurality of such rows are formed on the outer peripheral surface of the tool body 2 at intervals in the circumferential direction. In addition, as shown in FIG. 2, in the plurality of cutting inserts 4 attached to the insert mounting seat 9 along one chip discharge groove 8, the tool cutting lines 4 around the tool axis O <b> 1 between the main cutting edges 3 </ b> A of the cutting inserts 4. The rotation locus is arranged so as to form a long blade continuously in the direction of the tool axis O1.

  Further, in the chip discharge groove 8, a portion of the insert mounting seat 9 located on the front side in the tool rotation direction T with respect to the bottom surface is formed in a concave curved shape that is recessed toward the tool axis O1 side from the bottom surface. The groove bottom surface 8A.

  The coolant supply hole structure 10 of the cutting tool is formed in the first supply hole 6 extending along the tool axis O1 of the tool body 2 and the inner surface 6A of the first supply hole 6, and is opposite to the tool axis O1. A recess 15 that is recessed toward the side (radially outward of the tool body 2), a second supply hole 16 that opens to the back surface (bottom surface) 15 </ b> A of the recess 15 and extends toward the cutting edge 3, A third supply hole 17 communicating with the second supply hole 16 on the side of the cutting edge 3 via a tapered surface 18 is provided.

  As shown in FIG. 2, the first supply hole 6 is formed in a cylindrical hole shape or a truncated conical hole shape with the tool axis O1 of the tool body 2 as the center, and a cross section perpendicular to the tool axis O1 is a circle. It has a shape. Specifically, the first supply hole 6 is formed so as to be inclined so that the inner surface 6A gradually approaches the tool axis O1 as it goes from the rear end side along the tool axis O1 toward the front end side, and the front end portion has the smallest diameter. It is said that. In addition, an angle α at which the inner surface 6A of the first supply hole 6 is inclined with respect to the tool axis O1 is set within a range of 0 ° <α ≦ 20 °.

  A plurality of recesses 15 are formed in the inner surface 6 </ b> A of the first supply hole 6. In the present embodiment, two recesses 15 are formed at an interval in the direction of the tool axis O1, and these recesses 15 are each formed in an annular shape extending along the circumferential direction around the tool axis O1. Yes. Of these recesses 15, the recess 15 located on the rear end side in the tool axis O1 direction is formed to have a larger diameter than the recess 15 located on the tip side in the tool axis O1 direction. The recess 15 is formed with a back surface 15A that is arranged radially outward in the recess 15 and faces the tool axis O1 side (radially inward of the tool body 2). Moreover, the depth X of these recesses 15 (the distance from the inner surface 6A to the inner surface 15A of the first supply hole 6) is set to the same value, and this depth X is, for example, 0.5 mm to It is set within a range of 2.5 mm.

  The recess 15 is formed to be inclined so as to gradually approach the axis O2 of the second supply hole 16 from the inner surface 6A of the first supply hole 6 toward the inner surface 15A. As shown in the side sectional view of FIG. 4A, in the recess 15 of the present embodiment, a portion located on the tool axis O1 side and continuing to the inner surface 6A has a convex cross-sectional shape, and the tool is more than the portion. A portion on the back surface 15A side located radially outward of the main body 2 has a concave cross-sectional shape.

  In addition, second supply holes 16 are formed in the back surface 15A of each recess 15 so as to open. The second supply hole 16 is formed in a cylindrical hole shape having a smaller diameter than the first supply hole 6, and a cross section perpendicular to the axis O <b> 2 of the second supply hole 16 has a circular shape. Further, of the two recesses 15, a plurality of second supply holes 16 are formed in the back surface 15 </ b> A of the recess 15 located on the distal end side in the tool axis O <b> 1 direction. The second supply hole 16 extends from the inner surface 15 </ b> A of the recess 15 toward the chip discharge groove 8 of the tool body 2. In the present embodiment, the second supply hole 16 is also formed so as to open at the connecting portion between the large diameter portion 5 </ b> A of the mounting hole 5 and the first supply hole 6. In the side sectional view of FIG. 2, for convenience of explanation, it is described that the plurality of second supply holes 16 are arranged in the same side cross section of the tool body 2. 16 is arranged at intervals in the circumferential direction around the tool axis O <b> 1 so as to correspond to the shape of the chip discharge groove 8. In addition, these 2nd supply holes 16 may be arrange | positioned in the said same side cross section.

  Specifically, in FIG. 2, the second supply hole 16 extends so that its axis O2 gradually goes to the distal end side in the direction of the tool axis O1 as it goes radially outward from the inner surface 15A of the recess 15. As shown in FIG. 3, the axis O <b> 2 of the second supply hole 16 extends gradually from the back surface 15 </ b> A of the recess 15 toward the rear side in the tool rotation direction T as it goes radially outward.

  In FIG. 3, the axis O <b> 2 of the second supply hole 16 extends toward the vicinity of the cutting edge 3 of the cutting insert 4 through the groove bottom surface 8 </ b> A of the chip discharge groove 8. Specifically, the axis O2 of the second supply hole 16 extends slightly toward the front side in the tool rotation direction T with respect to the main cutting edge 3A (cutting edge 3) of the cutting insert 4, and the axis O2 and the main cutting edge. The distance L with the blade 3A is set within a range of 0.5 mm to 3 mm. That is, the axis O2 of the second supply hole 16 does not extend so as to intersect the surface 13A of the cutting insert 4 that is easy to cut, but the root of the chips W generated by cutting with the cutting edge 3. It is set to extend toward the vicinity.

  Further, in the chip discharge groove 8 of the tool body 2, a substantially cylindrical adjustment member 19 is disposed on the cutting blade 3 side of the second supply hole 16. Specifically, the adjustment member 19 is screwed or fitted into a hole 8B formed in the groove bottom surface 8A of the chip discharge groove 8, and is detachably attached to the tool body 2. The adjusting member 19 is coaxial with the second supply hole 16 and is formed in a cylindrical hole-shaped third supply hole 17 having a smaller diameter than the second supply hole 16, and on the tool axis O1 side of the third supply hole 17. And a tapered surface 18 that is located and connects the second and third supply holes.

Specifically, the third supply hole 17 has a multistage cylindrical hole shape, and a cross section perpendicular to the axis O2 of the second supply hole 16 is formed in a circular shape. The inner diameter of the third supply hole 17 is set in the range of 0.5 mm to 1.6 mm. A portion of the third supply hole 17 on the side of the cutting edge 3 along the axis O2 is formed to have a diameter larger than that of a portion on the side of the tapered surface 18 along the axis O2.
Further, the tapered surface 18 is formed with a diameter gradually reduced along the axis O2 of the second supply hole 16 toward the cutting edge 3 side.

  When coolant is supplied to the mounting hole 5 from the spindle side of the machine tool that supports the tool body 2 during cutting, the coolant is supplied to the large diameter portion 5A, the first supply hole 6, the second supply hole 16, and the third supply. It flows in the order of the holes 17 and flows out from the third supply holes 17 opening in the chip discharge groove 8 toward the vicinity of the cutting edge 3.

  As described above, according to the coolant supply hole structure 10 for a cutting tool of the present embodiment, when coolant is supplied from the spindle side of the machine tool to the first supply hole 6 of the tool body 2, the coolant is supplied first. The hole 6 accumulates in the recess 15 and flows in the recess 15 toward the side opposite to the tool axis O1 so as to follow the shape of the recess 15, and is opened in the inner surface 15A of the recess 15. 2 It is guided smoothly into the supply hole 16. That is, the coolant flows from the first supply hole 6 to the second supply hole 16 through the recess 15 to prevent the coolant flow rate from being reduced and to secure the supply amount. The coolant is ejected vigorously toward the vicinity of the cutting edge 3.

Like the cutting edge-replaceable rolling tool 1 described in the present embodiment, a plurality of rows of cutting inserts 4 are provided on the outer peripheral surface of the tool body 2 at intervals in the circumferential direction, or the cutting inserts 4 arranged in the same row. When the cutting edges 3 are formed so as to form the long blade as a whole, a plurality of second supply holes 16 are formed in the tool body 2 corresponding to the cutting edges 3 of each cutting insert 4. ing. In such a case, in the conventional configuration, the coolant may not be easily ejected from some of the holes (second supply holes 16) due to the arrangement of the second supply holes 16 or the like. It was difficult to set the flow rate and supply amount of the coolant jetted evenly.
On the other hand, according to the coolant supply hole structure 10 of the cutting tool according to the present embodiment, the flow rate and supply amount of the coolant ejected through the respective second supply holes 16 are sufficiently ensured. Differences in the flow rate and supply amount of the coolant between the 16 are less likely to occur, and the coolant is evenly ejected as a whole tool.

  Accordingly, the sharpness of the cutting edge 3 and the dischargeability of the chips W can be stably improved as a whole tool, and the processing accuracy is ensured. Further, since the cooling / lubricating effect of the cutting edge 3 can be reliably obtained, the cutting edge 3 is prevented from being welded or broken, and the tool life is extended.

  Further, the recess 15 is formed so as to be gradually inclined so as to approach the axis O2 of the second supply hole 16 from the inner surface 6A of the first supply hole 6 toward the inner surface 15A. The frictional resistance of the coolant flowing through the coolant is reduced, and the coolant flow rate is gradually increased toward the inner surface 15A. As a result, the momentum of the coolant ejected through the second supply hole 16 increases.

  In addition, since the tool tip 2 rotates the tool body 2 around the tool axis O1, the cutting edge 3 rolls the work material with the cutting edge 3 so that the tool body 2 rotates when the tool body 2 rotates. Due to the force, the coolant is easily collected in the recess 15. Furthermore, the coolant that has accumulated in the recess 15 can easily flow toward the back surface 15A on the side opposite to the tool axis O1 (outward in the radial direction of the tool body 2), and the second supply hole that opens in the back surface 15A. 16 easily flows into the interior. Thereby, the flow velocity and supply amount of the coolant sprayed to the vicinity of the cutting edge 3 are reliably increased.

  By the way, the amount of coolant required for the part on the rear end side in the tool axis O1 direction in the first supply hole 6 is larger than the amount of coolant required for the part on the front end side in the tool axis O1 direction. That is, the amount of coolant required for the rear end portion of the first supply hole 6 in the direction of the tool axis O1 is ejected from the rear end portion toward the vicinity of the cutting edge 3 through the second supply hole 16. The amount of coolant that flows from the rear end portion to the tip end portion in the direction of the tool axis O1 and is ejected from the tip end portion toward the vicinity of the cutting edge 3 through the second supply hole 16 Is included. According to the coolant supply hole structure 10 of the cutting tool of the present embodiment, the inner surface 6A of the first supply hole 6 is formed so as to gradually approach the tool axis O1 from the rear end side along the tool axis O1 toward the front end side. Has been. Accordingly, a sufficient capacity is ensured at a portion on the rear end side in the tool axis O1 direction in the first supply hole 6 where a large amount of coolant is required.

  Further, with such a configuration, the coolant flows substantially evenly into the plurality of recesses 15 arranged at intervals in the direction of the tool axis O1. Then, the coolant is uniformly ejected toward the vicinity of the cutting edge 3 through the respective second supply holes 16 opened in these recesses 15, and the sharpness of the cutting edge 3 and the chip dischargeability as a whole tool. It is raised stably.

  Further, since the angle α at which the inner surface 6A of the first supply hole 6 is inclined with respect to the tool axis O1 is set within a range of 0 ° <α ≦ 20 °, a plurality of concave portions are formed along the tool axis O1 direction. Even if the locations 15 are formed, the coolant flows into the recesses 15 substantially uniformly, and the rigidity of the tool body 2 is ensured. That is, when the angle α is set to exceed 20 °, it is difficult to secure the thickness of the part located on the rear end side in the tool axis O1 direction in the tool body 2, and the rigidity of the tool body 2 is reduced. There are things to do.

  Further, the axis O2 of the second supply hole 16 extends toward the front side in the tool rotation direction T from the cutting edge 3, and the distance L between the axis O2 and the cutting edge 3 is 0.5 mm to 3 mm. It is set within the range. That is, the coolant flowing in the second supply hole 16 is ejected toward the chip W generated by the cutting edge 3 being cut, and in detail, it is ejected toward the base of the chip W.

  As shown in FIG. 3, the chip W is scraped off by the main cutting edge 3 </ b> A (cutting edge 3) and scooped by the rake face 13 </ b> A, thereby moving toward the tool axis O <b> 1 side of the tool body 2, and then the tool rotation direction T It is generated by curling so that it goes to the front side. In the illustrated example, the chips W are formed in a spiral shape so as to curl in the direction opposite to the tool rotation direction T. Accordingly, the coolant sprayed to the vicinity of the root of the chip W cools the chip W, and then follows the curl near the root of the chip W between the chip W and the rake face 13A and around the main cutting edge. It flows toward the 3A side. As a result, the coolant is efficiently and stably supplied to the chips W and the cutting edges 3, and the dischargeability of the chips W and the sharpness of the cutting edges 3 are stably increased, and the processing accuracy is ensured.

  A third supply hole 17 having a smaller diameter than that of the second supply hole 16 is formed in communication with the cutting blade 3 side of the second supply hole 16. And between these 2nd and 3rd supply holes, the taper surface 18 which is gradually diameter-reduced as it goes to the cutting-blade 3 side along the axis line O2 of the 2nd supply hole 16 is formed. By forming such a tapered surface 18, the frictional resistance of the coolant flowing from the second supply hole 16 to the third supply hole 17 is reduced, and the coolant flow rate is increased. Therefore, the momentum of the coolant sprayed to the vicinity of the cutting edge 3 through the third supply hole 17 is sufficiently ensured.

  Further, since the inner diameter of the third supply hole 17 is set within a range of 0.5 mm to 1.6 mm, the coolant is prevented from being clogged in the third supply hole 17, and the coolant Is sufficiently secured. That is, when the inner diameter is set to be smaller than 0.5 mm, the coolant may be clogged in the third supply hole 17 due to adhesion or the like. In addition, when the inner diameter is set to exceed 1.6 mm, the flow rate of the coolant flowing from the second supply hole 16 to the third supply hole 17 is not sufficiently increased, and the momentum of ejection may not be ensured. .

  The third supply hole 17 is formed in the adjustment member 19, and the adjustment member 19 can be attached to and detached from the tool body 2. That is, by changing the adjustment member 19, the third supply hole 17 having a different inner diameter can be easily changed, so that the flow rate and supply amount of the coolant ejected through the third supply hole 17 can be adjusted more precisely. Is possible.

In addition, this invention is not limited to the above-mentioned embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the cutting edge replacement type rolling tool 1 is used as a cutting tool, but the present invention is not limited to this. That is, a turning tool other than the turning tool 1 may be used as the cutting tool. Further, the cutting edge 4 is not limited to the cutting edge exchange type cutting tool, and may be a solid type cutting tool in which the cutting edge 3 is directly formed on the outer periphery of the tip of the tool body 2.

  In addition, the angle α, the depth X, the distance L, and the inner diameter of the third supply hole 17 described in the present embodiment are not limited to the numerical values described above.

  In addition, the recess 15 has an annular shape extending in the circumferential direction around the tool axis O1, but is not limited thereto. For example, the recess 15 partially extends from the inner surface 6A. It may be formed in the shape of a concave curved surface or the like that is recessed. Further, although the plurality of recesses 15 are formed at intervals in the tool axis O1 direction, a plurality of recesses 15 may be formed at intervals in the circumferential direction around the tool axis O1. Further, the depths X of the plurality of recesses 15 may be set to different values. Moreover, although the plurality of recesses 15 are formed, a single recess 15 may be formed.

FIGS. 4B and 5A and 5B show a modification of the recess 15.
4B, the recess 15 is formed such that a back surface 15A facing the tool axis O1 side is parallel to the tool axis O1. The length along the tool axis O <b> 1 direction of the back surface 15 </ b> A is set to be substantially the same as the inner diameter of the second supply hole 16. In addition, a portion of the recess 15 that continues to the periphery of the back surface 15A is a tapered surface that is inclined so as to gradually approach the axis O2 from the inner surface 6A toward the back surface 15A.

Further, in the side sectional view of FIG. 5A, the recess 15 is formed in a concave curve shape as a whole.
5B, the recess 15 is formed such that a back surface 15A facing the tool axis O1 is parallel to the tool axis O1. In this modification, the length along the tool axis O <b> 1 direction of the back surface 15 </ b> A is set to be larger than the inner diameter of the second supply hole 16. In addition, a portion of the recess 15 that continues to the periphery of the back surface 15A is a tapered surface that is inclined so as to gradually approach the axis O2 from the inner surface 6A toward the back surface 15A.

1 Cutting edge exchangeable cutting tool (cutting tool)
2 Tool body 3 Cutting edge 6 First supply hole 6A Inner surface of first supply hole 10 Coolant supply hole structure of cutting tool 15 Recess 15A Recessed surface 16 Second supply hole 17 Third supply hole 18 Tapered surface L First 2 Distance between the axis of the supply hole and the cutting edge O1 Tool axis O2 Axis of the second supply hole T Tool rotation direction α Angle at which the inner surface of the first supply hole is inclined with respect to the tool axis O1

Claims (7)

A coolant supply hole structure of a cutting tool that is formed inside a shaft-shaped tool body including a cutting edge and supplies coolant toward the cutting edge,
A first supply hole extending along the tool axis of the tool body;
A recess formed on the inner surface of the first supply hole and recessed toward the opposite side of the tool axis;
A second supply hole that opens to the inner surface of the recess and extends toward the cutting edge, and
The coolant supply hole structure for a cutting tool , wherein the recess is formed to be inclined so as to gradually approach the axis of the second supply hole from the inner surface of the first supply hole toward the inner surface. .   A coolant supply hole structure of a cutting tool that is formed inside a shaft-shaped tool body including a cutting edge and supplies coolant toward the cutting edge,
  A first supply hole extending along the tool axis of the tool body;
  A recess formed on the inner surface of the first supply hole and recessed toward the opposite side of the tool axis;
  A second supply hole that opens to the inner surface of the recess and extends toward the cutting edge, and
  A plurality of the recesses are formed at intervals in the tool axis direction,
  A coolant supply hole structure for a cutting tool, wherein the inner surface of the first supply hole is formed so as to gradually approach the tool axis as it goes from the rear end side along the tool axis to the front end side. . The coolant supply hole structure for a cutting tool according to claim 1 or 2,
A coolant supply hole structure for a cutting tool, wherein the tool body is rotated about the tool axis and the workpiece is rolled by the cutting edge. A coolant supply hole structure for a cutting tool according to claim 2 or 3 ,
An angle α at which the inner surface of the first supply hole is inclined with respect to the tool axis is set in a range of 0 ° <α ≦ 20 °. The coolant supply hole structure for a cutting tool according to claim 3 or 4 ,
The axis of the second supply hole extends toward the front side in the tool rotation direction in which the tool main body rotates rather than the cutting edge,
A coolant supply hole structure for a cutting tool, wherein a distance between the axis of the second supply hole and the cutting edge is set within a range of 0.5 mm to 3 mm. It is the coolant supply hole structure of the cutting tool as described in any one of Claims 1-5 ,
The second supply hole has a circular cross section perpendicular to the axis of the second supply hole,
The second supply hole communicates with the cutting edge side, the cross section is circular and a third supply hole having a smaller diameter than the second supply hole is formed,
A coolant for a cutting tool, characterized in that a tapered surface is formed between the second and third supply holes, the diameter of which gradually decreases along the axis of the second supply hole toward the cutting edge. Supply hole structure. The coolant supply hole structure for a cutting tool according to claim 6 ,
The coolant supply hole structure for a cutting tool, wherein an inner diameter of the third supply hole is set in a range of 0.5 mm to 1.6 mm.

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