WO2013021856A1

WO2013021856A1 - Cutting tool with coolant hole

Info

Publication number: WO2013021856A1
Application number: PCT/JP2012/069414
Authority: WO
Inventors: 阿部　太郎; 貴行畔上
Original assignee: 三菱マテリアル株式会社
Priority date: 2011-08-05
Filing date: 2012-07-31
Publication date: 2013-02-14
Also published as: JP2013035094A

Abstract

Provided is a cutting tool with a coolant hole, which has different cutting blades such as an outer circumferential blade and a bottom blade and in which a coolant hole having a plurality of branch holes corresponding to the different cutting blades is formed and even when one of the cutting blades is solely used, coolant is not uselessly used and supply pressure is not required more than necessary. A coolant hole (17) is formed in a tool main body and branched into a plurality of branch holes (18a, 18b) in a blade portion (11) of the tool main body. In addition, the coolant hole (17) is equipped with a switching means (3) that makes it possible to select, among the branch holes (18a, 18b), a branch hole (18) for supplying coolant.

Description

Cutting tool with coolant hole

The present invention relates to a cutting tool with a coolant hole in which a coolant hole for supplying coolant for cooling and lubrication is formed on a blade portion of a tool body.

As such a cutting tool with a coolant hole, in Patent Document 1, a cutting oil (coolant) supply port is formed at one end, and the other end is drilled in the direction of the central axis that opens to the center of the edge of the end mill (bottom blade center). An end mill with a coolant hole is proposed which is provided with a hollow shaft oil pipe and a hollow cutting oil jet port which communicates with the shaft pipe in the end mill shaft and has an end opening in the groove of the outer peripheral blade outside the end mill. Yes.

Similarly, Patent Document 2 includes an axial coolant hole that opens to the center of the tip of the end mill, and a branch hole that branches from the axial coolant hole and opens into the blade groove of the outer peripheral blade. An end mill with a coolant hole has been proposed in which the end of the axial coolant hole is closed with a plug during cutting, and the plug is removed during front cutting with a bottom blade.

Japanese Utility Model Publication No.2-100728 US Pat. No. 3,037,264

However, among these end mills with coolant holes described in Patent Document 1, even in the case of side cutting using only the outer peripheral edge of the end mill, the coolant is ejected from the shaft tube opened at the center of the end mill edge. Even in the case of groove cutting with a shallow cutting depth that uses only the bottom blade at the end of the end mill, the coolant will be ejected from the outlet opening in the edge groove of the outer peripheral blade. Of course, it is consumed wastefully, and coolant must be supplied at a supply pressure higher than necessary to supply coolant toward the cutting blade used for cutting. An extra burden will be imposed on the supply means.

In this respect, in the end mill with a coolant hole described in Patent Document 2 in which the tip of the axial coolant hole is closed with a plug during side cutting, the coolant is wasted in this side cutting or more coolant than necessary. It does not require supply pressure, but in the case of groove cutting that uses only the bottom blade exclusively, coolant continues to be ejected from the branch hole that opens to the blade groove of the outer peripheral blade that is not used for cutting. Again, the coolant is wasted and the coolant must be supplied at a supply pressure higher than necessary.

The present invention has been made under such a background, and as described above, a plurality of end mills such as an end mill having a branch hole toward the bottom blade at the end mill tip and a branch hole toward the outer peripheral blade at the outer periphery of the end mill as described above. In coolant tool with coolant hole with branch hole formed, coolant that does not waste coolant or require excessive supply pressure even when only one of the cutting edges is used It aims to provide a cutting tool with a hole.

In order to solve the above problems and achieve such an object, according to the present invention, a coolant hole is formed in the tool body, and the coolant hole is branched into a plurality of branch holes in the blade portion of the tool body. In addition, the coolant hole is provided with switching means for selecting a branch hole for supplying the coolant among the plurality of branch holes.

Therefore, in such a cutting tool with a coolant hole, when the plurality of branch holes are opened toward different cutting edges as described above, when using only one of the cutting edges, By selecting the branch hole by the switching means so that the coolant is supplied to the branch hole that opens toward the cutting blade to be used, the coolant supply to the other branch hole is stopped and the coolant is wasted. It is possible to prevent excessive coolant supply pressure from being required.

Here, as such a switching means, for example, when the branch hole is plugged with a plug like the cutting tool with a coolant hole described in Patent Document 2, when the number of branch holes is large, many switching operations are performed. It takes time and the management of the plug becomes complicated. Accordingly, the plurality of branch holes are branched while being shifted in at least one of the circumferential direction and the axial direction of the coolant hole, and the switching means is slidably contacted with the inner peripheral surface of the coolant hole and rotatably accommodated therein. When a plurality of through holes are formed in the cylindrical member and the plurality of through holes communicate with each other, some of the through holes communicate with some of the plurality of branch holes. By forming the remaining through holes so as to be offset from the remaining branch holes, the branch holes can be switched easily and in a short time only by rotating the cylindrical member.

Here, in order to rotatably accommodate the switching means made of such a cylindrical member in sliding contact with the inner peripheral surface of the coolant hole as described above, the tool body is formed of a hard material and the cylindrical shape is formed. The member is made of a metal material whose hardness is lower than that of the hard material, an annular groove is formed on the inner peripheral surface of the coolant hole, and the outer peripheral surface of the cylindrical member is formed on the inner peripheral surface of the coolant hole. What is necessary is just to be able to rotate in contact with this internal peripheral surface by closely_contact | adhering and engaging with the said annular groove. Since the outer peripheral surface of the cylindrical member is engaged with the annular groove on the inner peripheral surface of the coolant hole, the cylindrical member is allowed to rotate and the movement in the axial direction can be restrained and prevented from coming off. In addition to this annular groove, the outer circumferential surface of the cylindrical member is in close contact with the inner circumferential surface of the coolant hole so as to be slidable, thereby preventing leakage of the coolant.

In particular, the present invention is suitable for application to an end mill with a coolant hole as in the inventions described in

Patent Documents

1 and 2, that is, an end mill in which the tool body has a bottom blade and an outer peripheral blade on the blade portion. A tool body in which the blade portion is formed, and when the plurality of branch holes are respectively opened to supply the coolant to the bottom blade and the outer peripheral blade, the switching means is By making it possible to select a branch hole for supplying coolant between a bottom blade branch hole for supplying the coolant to the blade and an outer blade branch hole for supplying the coolant to the outer peripheral blade, the bottom blade and the outer blade can be selected. Even when only one of the cutting blades is used, it is possible to reliably prevent the coolant from being consumed wastefully or requiring an excessive supply pressure.

As described above, according to the present invention, it is possible to stop the supply of the coolant toward the cutting blade that is not used to prevent wasteful consumption of the coolant and to reduce the supply pressure of the coolant. It is possible to promote efficient cutting.

It is a perspective view which shows the head exchange type end mill with a coolant hole to which the cutting head which is the 1st Embodiment of this invention was attached. It is the (a) perspective view, (b) side view, (c) front view of the cutting head of embodiment shown in FIG. In the cutting head shown in FIG. 2 (the head main body 1 is the head main body material 1A), (a) YY sectional view in FIG. 2 (c) when the coolant hole communicates with the outer peripheral edge branch hole, (b) FIG. It is ZZ sectional drawing in 2 (c). In the cutting head shown in FIG. 2 (the head main body 1 is the head main body material 1A), (a) YY sectional view in FIG. 2 (c) when the coolant hole communicates with the bottom blade branch hole, (b) FIG. It is ZZ sectional drawing in 2 (c). It is (a) perspective view, (b) front view, (c) side view, (d) rear view, and (e) side sectional view of the head main body material 1A of the cutting head shown in FIG. (A) perspective view, (b) front view, (c) side view, (d) rear view, (a) of a cylindrical member material 3A that is a material of the switching means (cylindrical member 3) of the cutting head shown in FIG. e) Side sectional view. 6 is a cross-sectional view showing a state in which the switching means (cylindrical member 3) shown in FIG. 6 is attached to the head main body material 1A shown in FIG. It is a side view which shows the solid end mill with a coolant hole which is the 2nd Embodiment of this invention. It is a sectional side view of the end mill main body raw material of embodiment shown in FIG.

1 Head body (tool body)
1A Head body material 2 Connecting member 3 Cylindrical member (switching means)
3A Cylindrical member material 4 Holder 11 Blade portion 12 Engagement portion 13 Tapered shaft portion 15a Peripheral blade 15b Bottom blade 16 Connecting member mounting hole (coolant hole)
16a, 17a annular groove 17 cylindrical member mounting hole (coolant hole)
18 branch hole 18a outer peripheral blade branch hole 18b bottom blade branch hole 21 male screw part 31 bottom blade side through hole 32 outer peripheral blade side through hole 33 engagement hole part 41 end mill main body (tool main body)
42 End mill body material 43 Coolant hole O Axis of head body 1 and end mill body 41 T End mill rotation direction

FIGS. 1 to 7 show a first embodiment of the present invention. This first embodiment is an application of the present invention to a cutting head of a head replaceable end mill with a coolant hole. . This cutting head includes a head body 1 as a tool body in the present embodiment integrally formed of a hard material such as cemented carbide, cermet, ceramics, etc., and stainless steel having a hardness lower than that of the hard material forming the head body 1. It comprises a connecting member 2 made of a plastically deformable metal material such as a steel material such as steel or die steel, and a cylindrical member 3 as switching means in the present embodiment. Such a cutting head is attached to the tip of a cylindrical shaft-shaped holder 4 as shown in FIG. 1 via the connecting member 2, and this holder 4 is attached to the main shaft of the machine tool to be the center of the head body 1. The workpiece is cut by being fed in a direction intersecting the axis O while being rotated in the end mill rotation direction T around the axis O.

As shown in FIG. 2, the head body 1 includes a blade portion 11 on which cutting edges are formed in order from the front end side (left side in FIG. 2B) to the rear end side (right side in FIG. 2B). The engaging portion 12 with which a wrench or the like is engaged when exchanging the cutting head, and the outer diameter of the engaging portion 12 are smaller than those of the blade portion 11 and the engaging portion 12, and the outer diameter gradually increases toward the rear end side. A truncated cone-shaped tapered shaft portion 13 centering on the axis O that is made smaller is formed. The inclination angle formed by the outer peripheral surface of the taper shaft portion 13 with respect to the axis O is preferably in the range of 1 ° to 20 °, more preferably in the range of 1 ° to 5 °, and still more preferably. It is set within a range of 1 ° to 3 °, and in this embodiment, 2 °.

On the outer periphery of the blade portion 11, a plurality of chip discharge grooves 14 twisted toward the rear side in the end mill rotation direction T around the axis O from the front end to the rear end side of the head body 1 at equal intervals in the circumferential direction (this embodiment) In the form, four strips) are formed, and an outer peripheral edge 15a is formed as the cutting edge on the outer peripheral side ridge portion of the chip discharge groove 14, and a bottom blade 15b is also formed as a cutting edge on the distal end side ridge portion. Yes. The head replaceable end mill of the present embodiment is a radius end mill, and a corner blade 15c having a convex curve shape such as a quarter arc is formed at a corner portion where the outer peripheral blade 15a and the bottom blade 15b intersect. Has been.

FIG. 5 shows a head body material 1A that is a material of the head body 1 before the chip discharge groove 14, the outer peripheral edge 15a, the bottom edge 15b, and the corner edge 15c are formed. After connecting the connecting member 2 and the cylindrical member 3 shown in FIG. 6 to the head body material 1A manufactured by sintering or the like, as shown in FIGS. 2, 3 and 7, The chip discharge groove 14, the outer peripheral blade 15 a, the bottom blade 15 b, the corner blade 15 c, and the engagement portion 12 are formed in the blade body 11 and manufactured in the head body 1.

As shown in FIG. 5 (e), the head body material 1 </ b> A has a connecting member mounting hole 16 that opens to the rear end surface of the tapered shaft portion 13 and extends to the front end side, and further to the front end side of the connecting member mounting hole 16. A bottomed cylindrical member mounting hole 17 communicating with the connecting member mounting hole 16 and having a diameter smaller than that of the connecting member mounting hole 16 is formed along the axis O. The connecting member mounting hole 16 and the cylindrical member mounting hole 17 As a result, a coolant hole is formed. Therefore, in this embodiment, the axis of the coolant hole is coaxial with the axis O that is the center of the head body 1. Of these, a plurality of branch holes 18 having a smaller diameter than the cylindrical member mounting hole 17 are formed from the cylindrical member mounting hole 17.

Further, an annular groove 16 a that has a cross-section along the axis O that forms a concave curve such as an arc and circulates around the axis O is formed on the inner peripheral surface of the connecting member mounting hole 16 with the rear end surface of the tapered shaft portion 13. A plurality of strips (three strips in this embodiment) are formed at intervals from the boundary portion between the connecting member mounting hole 16 and the cylindrical member mounting hole 17. Further, an annular groove 17a that also has a concave curved cross-sectional shape and circulates around the axis O on the inner peripheral surface of the cylindrical member mounting hole 17 is formed between the boundary portion with the connecting member mounting hole 16 and the opening portion of the branch hole 18. One strip is formed with a gap between them.

Furthermore, the plurality of branch holes 18 extend to the outer peripheral side from the inner peripheral surface of the cylindrical member mounting hole 17 toward the distal end side and open to the outer peripheral surface of the head main body material 1A, and a cylindrical shape. A bottom blade branch hole 18b that extends to the outer peripheral side from the bottom surface of the member mounting hole 17 toward the front end side and opens at the front end surface of the head main body material 1A is formed. Here, in the present embodiment, the four outer peripheral edge branch holes 18a and the lower edge branch holes 18b are branched at equal intervals in the circumferential direction and alternately spaced apart from each other in the circumferential direction. It is formed to do. The bottom blade branch hole 18b has a slightly smaller diameter than the outer blade branch hole 18a.

FIG. 6 shows a cylindrical member material 3A as a material of the cylindrical member 3 mounted in the cylindrical member mounting hole 17, and this cylindrical member material 3A is similar to the connecting member 2 in the head main body. 1 is formed of a metal material that can be plastically deformed, such as a steel material such as stainless steel or die steel having a lower hardness than the above-described hard material, and has a substantially bottomed cylindrical shape. However, the bottom of the cylindrical member material 3A having a bottom is parallel to the axis O at a position where the radius from the axis O is equal to the opening at the bottom surface of the cylindrical member mounting hole 17 of the bottom blade branch hole 18b. The same number of bottom blade side through holes 31 extending through the bottom portion as the bottom blade branch holes 18b are formed at equal intervals in the circumferential direction. Here, the shortest distance between the inner peripheral surfaces of the two bottom blade side through holes 31 adjacent in the circumferential direction around the axis O is the circumference of the opening of the bottom blade branch hole 18b on the bottom surface of the cylindrical member mounting hole 17. The shortest distance between the openings on the bottom surface of the cylindrical member mounting hole 17 of the two bottom blade branch holes 18b that are also adjacent to each other in the circumferential direction around the axis O is the circumference of the bottom blade side through hole 31. It is made larger than the width in the direction, that is, the inner diameter.

Further, the position of the cylindrical member material 3A in the direction of the axis O is also branched at the outer peripheral edge of the cylindrical member material 3A in a state where the bottom end surface of the cylindrical member material 3A is in contact with the bottom surface of the cylindrical member mounting hole 17. At the same position as the hole 18a, the outer peripheral blade side through holes 32 penetrating the cylindrical wall portion perpendicularly to the axis O are formed in the same number as the outer peripheral blade branch hole 18a at equal intervals in the circumferential direction. Here, the outer peripheral blade side through hole 32 and the bottom blade side through hole 31 are formed so as to be slightly shifted in the circumferential direction in the present embodiment, and the shift amount, that is, the outer peripheral blade side adjacent in the circumferential direction. The angles formed by the straight lines connecting the centers of the through hole 32 and the bottom blade side through hole 31 and the axis O when viewed in the direction of the axis O are the outer peripheral blade branch hole 18a and the outer blade side through hole 32 and the bottom as in this embodiment. When the same number of blade branch holes 18b and bottom blade side through holes 31 are formed at equal intervals, the outer peripheral blade branch holes 18a and the outer blade side through holes 32 are aligned in the circumferential direction. When the cylindrical member 3 is rotated by an angle (360 ° / 8 = 45 ° in the present embodiment) obtained by dividing 360 ° by the total number of the peripheral blade branch hole 18a and the bottom blade branch hole 18b, the bottom blade side Through hole 31 and bottom blade branch hole 18b It is an angle that matches the circumferential direction.

Note that the inner peripheral surface of the cylindrical member material 3A has a circular shape in the most part on the rear end side, whereas the tip side (bottom side) has a cross section perpendicular to the axis O in FIG. ) As shown in FIG. 5, the cross-section is a regular hexagonal shape that is substantially inscribed in a circle formed by the rear end side portion, and is an engagement hole portion 33 that can be engaged with a hexagonal bar wrench. The hole 31 is formed so as to partially open in the engagement hole 33. Further, the length of the cylindrical member material 3A in the direction of the axis O is slightly shorter than the length (depth) of the cylindrical member mounting hole 17, provided that the bottom end surface of the cylindrical member material 3A is attached to the cylindrical member. The cylindrical wall portion of the cylindrical member material 3 </ b> A extends to the rear end side with respect to the annular groove 17 a of the cylindrical member mounting hole 17 in a state where it is in contact with the bottom surface of the hole 17.

Here, the outer diameter of the cylindrical member material 3A is made, for example, about 0.2 mm smaller than the inner diameter of the cylindrical member mounting hole 17 in the head main body material 1A. In this embodiment, the cylindrical member material 3A is attached as the cylindrical member 3 that is slidably contacted with the inner peripheral surface of the cylindrical member mounting hole 17 (coolant hole) and rotatably accommodated. As shown in FIG. 7, after inserting this cylindrical member material 3A into the cylindrical member mounting hole 17, a head H having an outer diameter slightly larger than the inner diameter is formed on the inner peripheral portion of the cylindrical member material 3A. The shaft-shaped punch P is driven from the rear end side and is press-fitted to the front of the engagement hole 33, so that the cylindrical wall portion of the cylindrical member material 3A is plastically deformed and expanded in diameter.

Therefore, the cylindrical member 3 plastically deformed in this manner is in a substantially liquid-tight sliding contact with the outer peripheral surface of the rear end side portion into which the punch P is inserted in close contact with the inner peripheral surface of the cylindrical member mounting hole 17. While being rotatable around the axis O, the outer peripheral surface that is plastically deformed also enters the annular groove 17a formed in the cylindrical member mounting hole 17, and engages with the annular groove 17a. Movement is restrained and it is prevented from coming off. Note that the inner diameter of the inner peripheral portion of the cylindrical member 3 that has been expanded in diameter by the press-fitting of the punch P is such that the hexagonal bar wrench can be inserted therethrough. In the cylindrical member 3 thus plastically deformed, the shortest distance between the inner surfaces of the two outer peripheral blade side through holes 32 adjacent to each other in the circumferential direction around the axis O is the outer periphery of the inner peripheral surface of the cylindrical member mounting hole 17. The shortest distance between the openings on the inner peripheral surface of the cylindrical member mounting hole 17 of the two outer peripheral blade branch holes 18a which is made larger than the circumferential width of the opening of the blade branch hole 18a and is also adjacent in the circumferential direction around the axis O. The interval is made larger than the circumferential width of the outer peripheral blade side through hole 32 of the cylindrical member 3.

Next, after the cylindrical member 3 is accommodated in the cylindrical member mounting hole 17 (coolant hole) in this way, the connecting member 2 is attached to the connecting member mounting hole 16. In this embodiment, the connecting member 2 is also cylindrical. Similar to the shaped member 3, a connecting member material (not shown) formed of a metal material as described above is plastically deformed and expanded in diameter to be attached to the connecting member mounting hole 16.

That is, the connecting member material has a front end portion that is cylindrical with an outer diameter slightly smaller than the inner diameter of the connecting member mounting hole 16, and a rear end side portion that is larger than the inner diameter of the connecting member mounting hole 16. A male screw portion 21 having an outer diameter smaller than the outer diameter of the rear end surface of the taper shaft portion 13 of the head body 1 is formed, and the inner peripheral portion of the tip side portion is extended to the male screw portion 21 to be a connecting member. It penetrates the material.

However, the inner diameter of the inner peripheral portion of the male screw portion 21 is slightly larger than that of the tip end portion so as not to be plastically deformed. In addition, the length of the tip side portion in the direction of the axis O is slightly shorter than the length (depth) of the connecting member mounting hole 16, except that the tip surface of the male screw portion 21 is formed on the taper shaft portion 13 of the head body material 1A. In a state of being in contact with the rear end surface, the tip end portion extends to the tip end side from the annular groove 16 a on the tip end side of the connecting member mounting hole 16.

And after inserting the front end side part of the connection member raw material comprised in this way into the connection member attachment hole 16, it is a male screw with the outer diameter larger than the internal diameter of the front end side part in the inner peripheral part of this connection member raw material. A shaft-shaped punch having a head having an outer diameter smaller than the inner diameter of the portion 21 is driven from the rear end side, and press-fitted into the connecting member mounting hole 16 to a position exceeding at least the annular groove 16a on the front end side. The distal end portion of the member material is plastically deformed to expand its diameter, and is attached to the connecting member mounting hole 16 as the connecting member 2.

Accordingly, the distal end side portion of the connecting member 2 thus expanded in diameter has an outer peripheral surface that is in close contact with the inner peripheral surface of the connecting member mounting hole 16 and is also plastically deformed in the annular groove 16a, like the cylindrical member 3. The surfaces enter and engage, and the connecting member 2 is prevented from coming off in the direction of the axis O. However, the connecting member 2 does not rotate around the axis O with respect to the head body 1, and the outer peripheral surface of the tip side portion is firmly in close contact with the inner peripheral surface of the connecting member mounting hole 16. And the inner / outer diameter difference between the tip end portion and the inner / outer diameter difference between the inner peripheral portion of the connecting member material and the punch head. 3 and 4, the inner diameter of the tip side portion thus plastically deformed is made equal to the inner diameter of the male screw portion 21, and the inner diameter is set such that the above hexagonal bar wrench can be inserted.

In addition, instead of or in addition to forming the annular groove 16a in the connecting member mounting hole 16, the cemented carbide or the like that forms the head body 1 without polishing or the like on its inner peripheral surface is used. Surface roughness within the range of 5 μm to 200 μm with the maximum height roughness Rz specified in JIS B 0601: 2001 (ISO 4287: 1997), for example, as the sintered skin when the powder sintered material is sintered. (However, by making the uneven surface of the reference length 0.8 mm, cut-off value λs = 0.005 mm, λc = 0.8 mm) and inserting the plastically deformed outer peripheral surface of the tip side portion of the connecting member material into this The rotation around the axis O and the movement in the direction of the axis O may be constrained.

In this way, on the head body material 1A to which the connecting member 2 and the cylindrical member 3 (switching means) are attached, the chip discharge groove 14, the outer peripheral blade 15a, the bottom blade 15b, the corner blade 15c, and the engaging portion 12 are provided. Are formed into the head body 1. In the head body 1, of the plurality of branch holes 18, the outer peripheral blade branch hole 18a is opened to the groove bottom of the chip discharge groove 14 so as to supply coolant toward the outer peripheral blade 15a. The blade branch hole 18b is opened at a tip flank that continues to the rear of the bottom blade 15b in the end mill rotation direction T so as to supply coolant to the bottom blade 15b.

In the cutting head of the head-replaceable end mill with coolant hole according to the first embodiment configured as described above, the male threaded portion of the connecting member 2 is screwed into the female threaded portion provided in the holder 4, whereby the head body 1. The taper shaft portion 13 is attached to the tip end portion of the cylindrical shaft holder 4 in close contact with the taper hole portion of the holder 4 as described above. The coolant supplied from the machine tool side through the inner peripheral portion of the holder 4 is connected to the connection member 2 and the cylindrical member 3 attached to the connection member attachment hole 16 and the cylindrical member attachment hole 17 which are coolant holes. The bottom blade branch hole 18b or the outer blade branch hole 18a is supplied from the bottom blade side through hole 31 or the outer blade side through hole 32 of the cylindrical member 3 which is supplied to the tip of the head body 1 through the peripheral portion and is a switching means. Erupted through.

Here, the circumferential position of the bottom blade side through hole 31 and the outer peripheral blade side through hole 32 in the cylindrical member 3, and the cylindrical member mounting hole 17 of the outer peripheral blade branch hole 18 a and the bottom blade branch hole 18 b in the head body 1. From the state in which the outer circumferential edge branch hole 18a and the outer circumferential blade side through hole 32 coincide with each other in the circumferential direction as described above, the position of the inner opening in the circumferential direction is 360 ° from the outer circumferential edge branch hole 18a and the bottom edge branch hole. When the cylindrical member 3 is rotated by an angle divided by the total number of 18b, the bottom blade side through hole 31 and the bottom blade branch hole 18b are made to coincide with each other in the circumferential direction. When the cylindrical member 3 is at a rotational position where the outer peripheral blade side through hole 32 coincides with the outer peripheral blade branch hole 18a as shown in FIG. 3B, the bottom blade side through hole 31 and the bottom blade branch as shown in FIG. It does not communicate with the hole 18b, and no coolant is supplied to the bottom blade 15b side. . On the other hand, when the cylindrical member 3 is located at the rotational position where the bottom blade side through hole 31 and the bottom blade branch hole 18b coincide as shown in FIG. 4B, the outer peripheral blade as shown in FIG. 4A. The side through hole 32 does not communicate with the outer peripheral blade branch hole 18a, and no coolant is supplied to the outer peripheral blade 15a side.

Accordingly, when either one of the outer peripheral blade 15a and the bottom blade 15b is exclusively used for cutting, the hexagonal bar is passed through the inner peripheral portion of the connecting member 2 and the cylindrical member 3 before attaching the cutting head to the holder 4. A wrench is inserted and engaged with the engagement hole 33, and the rotation position of the cylindrical member 3 as the switching means is set so that the coolant is supplied toward one of the cutting blades to be used. By selecting, it is possible to avoid supplying the coolant toward the other cutting edge. For this reason, it is possible to prevent wasteful consumption of the coolant, and it is possible to perform efficient cutting without requiring excessive coolant supply pressure in the machine tool.

Further, in the present embodiment, the switching means for selecting the branch hole 18 for supplying the coolant is the cylindrical member 3 that is slidable in contact with the inner peripheral surface of the cylindrical member mounting hole 17 that is the coolant hole and is rotatable. By setting the rotational position of the cylindrical member 3 as described above, the cylindrical member 3 is shifted in the circumferential direction of the cylindrical member mounting hole 17 and branched into the branch hole 18 which is branched to the outer peripheral blade side or bottom. One of the through

holes

31 and 32 on the blade side is made to coincide so that the coolant is supplied to the cutting blade to be used. For this reason, for example, when a branch hole that is not used is closed with a plug, work does not become complicated when the number of branch holes 18 increases, and the branch hole 18 to be selected can be switched easily and quickly. In addition, there is no risk of losing the plug and management becomes easy.

Moreover, the cylindrical member 3 is a cylindrical member in which a cylindrical member material 3A formed of a metal material having a hardness lower than that of the head body 1 made of a hard material is plastically deformed, and an outer peripheral surface thereof is a coolant hole. Since it is in close contact with the inner peripheral surface of the mounting hole 17 and is engaged with the annular groove 17a, it can be slidably contacted with the inner peripheral surface and can be rotated. Therefore, the outer peripheral surface is engaged with the annular groove 17a. The cylindrical member 3 can be rotated while preventing the cylindrical member 3 from coming out of the cylindrical member mounting hole 17, and due to the close contact between the inner and outer peripheral surfaces, the coolant leaks from the gap and is supplied to a cutting blade that is not used for cutting. It is possible to prevent the cylindrical member 3 from rotating during the cutting process.

Further, in order to prevent leakage of the coolant in this way, a resin or rubber O-ring or the like is not required. Therefore, for example, the head main body 1 in which the chip discharge groove 14, the outer peripheral blade 15a, the bottom blade 15b, and the corner blade 15c are formed. Even when the surface of the blade portion 11 is coated with various coating films, even if the head main body 1 becomes hot, it is possible to reliably prevent the coolant leakage as described above.

On the other hand, in the present embodiment, the present invention is applied to an end mill in which an outer peripheral blade 15a and a bottom blade 15b are formed on a blade portion 11 of a cutting tool, and the cutting in the direction of the axis O is small and only the bottom blade 15b is exclusively used. Even when used for cutting, or conversely, when only the outer peripheral edge 15a is used for cutting with a small radial cut, the plurality of branch holes 18 are divided into the outer peripheral edge branch holes 18a and the bottom edge branch as described above. By using the holes 18b, it is possible to selectively supply coolant between the outer peripheral blade branch holes 18a and the bottom blade branch holes 18b reliably and easily, especially by the rotation of the cylindrical member 3 as the switching means. It becomes.

In the first embodiment, the case where the present invention is applied to such a head replaceable end mill has been described. However, as in the second embodiment shown in FIGS. 8 and 9, the head replaceable type is used. The present invention can also be applied to general solid end mills that are not. Here, in these FIG. 8 and FIG. 9, the same code | symbol is distribute | arranged to the part which is common in 1st Embodiment shown in FIG. 1 thru | or 7, and description is simplified.

That is, in the second embodiment, the entire end mill body 41 having a substantially cylindrical shape centering on the axis O is formed of the hard material such as cemented carbide, and the chip discharge groove 14 and the outer peripheral blade 15a, Like the end mill main body material 42 of the end mill main body 41 shown in FIG. 9 before the bottom blade 15b and the corner blade 15c are formed, a coolant hole 43 is formed along the axis O from the rear end toward the front end. The tip of the coolant hole 43 is a cylindrical member mounting hole 17.

Then, the cylindrical member 3 as a switching means similar to that of the first embodiment is attached to the cylindrical member attachment hole 17 so as to be rotatable and prevented from being detached, and the outer peripheral edge branches from the cylindrical member attachment hole 17. The hole 18a and the bottom blade branch hole 18b are branched as a branch hole 18, and as shown in FIG. 8, on the tip flank that continues to the groove bottom of the chip discharge groove 14 and the end mill rotation direction T rear side of the bottom blade 15b. The coolant that is opened and selectively supplied can be supplied to the outer peripheral blade 15a or the bottom blade 15b.

Therefore, also in the solid end mill which is the cutting tool with a coolant hole of the second embodiment, when either one of the outer peripheral edge 15a and the bottom edge 15b is exclusively used for cutting, the rear end mill body 41 has a rear end. By inserting a hexagon wrench into the coolant hole 43 from the end side and rotating the cylindrical member 3, the coolant is supplied to one of the used cutting blades and the supply to the other cutting blade is stopped. It is possible to prevent the waste of coolant and the decrease in supply pressure.

In the first and second embodiments, the case where the present invention is applied to a head exchange type or a solid radius end mill has been described. However, other types of end mills such as a ball end mill and a square end mill, and other end mills may be used. It is also possible to apply to a cutting tool with a coolant hole. In the first and second embodiments, the plurality of branch holes 18 are selected by the switching means so that the coolant is supplied only to one of the outer peripheral edge 15a and the bottom edge 15b of the end mill. In addition to this, for example, when the cylindrical member 3 is rotated, a plurality of through holes 32 are formed so as to communicate with both the outer peripheral blade branch hole 18a and the bottom blade branch hole 18b, or the outer periphery is used for dry cutting. You may make it provide the rotational position of the cylindrical member 3 in which the through-hole 32 does not communicate with any of the blade branch hole 18a and the bottom blade branch hole 18b.

Further, in each of the above embodiments, the outer peripheral blade branch hole 18a and the bottom blade branch hole 18b, which are the plurality of branch holes 18, are shifted in the direction of the axis O on the inner surface of the cylindrical member mounting hole 17 which is a coolant hole. It is branched so as to open, and is also branched so as to be shifted in the circumferential direction. In particular, in a cutting tool such as an end mill having a twisted outer peripheral edge 15a, at any position in the axis O direction. Since the position of the opening to the coolant hole also changes depending on whether the outer peripheral blade branch hole 18a is opened, for example, the outer peripheral blade branch hole 18a and the bottom blade branch hole 18b may be branched at the same position in the circumferential direction. .

Further, in this way, the peripheral blade branch hole 18a and the bottom blade branch hole 18b are set as a plurality of branch holes 18, and not only the coolant supply is selected by the switching means, but also, for example, a plurality of branches branched in the direction of the axis O of the coolant hole. The branch hole for supplying coolant by the switching means is selected between the outer peripheral blade branch holes 18a, or the bottom blade branch hole 18b and the bottom blade 15b are opened from the bottom surface of the coolant hole to the tip clearance surface of the bottom blade 15b. The bottom blade branch holes that are open in the circumferential direction may be formed so as to be shifted in the circumferential direction, and a branch hole that supplies coolant between these bottom blade branch holes may be selected.

Claims

A coolant hole is formed in the tool body, and the coolant hole is branched into a plurality of branch holes at the blade portion of the tool body, and coolant is supplied to the coolant hole between the plurality of branch holes. A cutting tool with a coolant hole, characterized in that it is provided with a switching means that enables selection of a branch hole to be made.
The plurality of branch holes are shifted and branched in at least one of a circumferential direction and an axial direction of the coolant hole, and the switching means is slidably in contact with the inner peripheral surface of the coolant hole and accommodated rotatably. A plurality of through holes are formed in the cylindrical member, and the plurality of through holes are mutually connected, and some of the through holes are part of the plurality of branch holes. The cutting tool with a coolant hole according to claim 1, wherein the remaining through hole is formed so as to be offset from the remaining branch hole when communicating with the hole.
The tool body is formed of a hard material, the cylindrical member is formed of a metal material having a lower hardness than the hard material, and an annular groove is formed on the inner peripheral surface of the coolant hole. The cylindrical member has an outer peripheral surface that is brought into close contact with an inner peripheral surface of the coolant hole and is engaged with the annular groove so that the cylindrical member is slidably contacted with the inner peripheral surface and is rotatable. The cutting tool with a coolant hole according to claim 2.
The tool body is a tool body in which the blade portion of an end mill having a bottom blade and an outer peripheral blade is formed on the blade portion, and the plurality of branch holes supply the coolant to the bottom blade and the outer peripheral blade. The switching means is a branch that supplies coolant between a bottom blade branch hole that supplies the coolant to the bottom blade and an outer blade branch hole that supplies the coolant to the outer blade. The cutting tool with a coolant hole according to any one of claims 1 to 3, wherein a hole is selectable.