JP2014014926A - Tool holder and shank structure for cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool for chucking which is improved as compared with before.SOLUTION: A tool holder (10) includes a cylindrical tool attachment/detachment part (12); centering and gripping means (31) provided to an axially tip part of the tool attachment/detachment part, and centering and gripping a shank part (60) of a cutting tool inserted into a tool holding hole; and first and second side-lock bolts (23a, 23b) which threadably engage first and second through holes (22a, 22b) extending obliquely from an outer peripheral surface to an inner peripheral surface of the tool attachment/detachment part at peripherally different places more on a rear-end side than the centering and gripping means. The first and second side-lock bolts are fastened and rotated while the shank part of the cutting tool is centered and gripped by the centering and gripping means to chuck the shank part of the cutting tool.

Description

  The present invention relates to a shank portion of a cutter such as an end mill or a reamer and a tool holder that chucks the shank portion of the cutter.

  Conventionally, as a shank portion of a blade and a tool holder for chucking the same, for example, Japanese Patent Application Laid-Open No. 2002-346864 (Patent Document 1), Japanese Patent Application Laid-Open No. 2001-87969 (Patent Document 2), and Japanese Utility Model Laid-Open No. 6-80509. The thing of the gazette gazette (patent document 3) is known. Such a conventional tool holder includes two side lock bolts. In addition, the shank portion of the blade is basically a circular cross section, and two flat surfaces are formed on the outer periphery thereof. Then, by tightening the two side lock bolts, the tip of each side lock bolt comes into contact with each flat surface to chuck the shank portion of the blade.

JP 2002-346864 A JP 2001-87969 A Japanese Utility Model Publication No. 6-80509

  However, the present inventors have found that there is room for further improvement in the shank portion of the conventional blade. That is, since two flat surfaces formed on the outer periphery of the shank portion are provided in alignment with predetermined positions in the circumferential direction, the shank portion receives a specific radial pressing force from the side lock bolt. Since the shank portion is pressed in a specific radial direction by the side lock bolt in this way, there is room for improvement in chucking. In addition, there is a concern of so-called runout that the axis of the shank portion is displaced from the normal position.

  In view of the above circumstances, an object of the present invention is to provide a cutting tool for chucking which is improved as compared with the related art.

  For this purpose, the shank structure of the cutter according to the first aspect of the present invention is provided in the shank portion of the cutter to be chucked on the tool holder so that the outer periphery of the shank portion is in contact with a side lock bolt attached to the main body of the tool holder. The first and second flat surfaces are formed at different locations in the circumferential direction.

  According to this 1st invention, since a flat surface is formed in several different places in the circumferential direction of a shank part, a shank part receives several radial direction pressing force from a mutually different direction. Therefore, the shank part does not receive a specific radial direction pressing force from the side lock bolt, and a side lock bolt type chucking mechanism improved compared to the conventional one can be provided. The first invention does not exclude the formation of additional flat surfaces at different locations in the circumferential direction in addition to the first and second flat surfaces.

  As a preferred embodiment of the first invention, at least one of the first and second flat surfaces is a surface inclined at a predetermined angle of not less than 1 degree and not more than 10 degrees with respect to the axis of the shank portion so as to be directed to the tip side of the blade. is there. According to this embodiment, the pressing force from the side lock bolt received by the flat surface of the shank part includes a component toward the rear end side in the axial direction, and urges the shank part to be inserted into the tool holder. Therefore, the shank portion can be chucked more reliably. As a more preferred embodiment, the flat surface is a surface inclined by 5 degrees with respect to the axis of the shank so as to be directed toward the tip side of the blade.

  In addition, when the first and second flat surfaces are inclined at less than 1 degree with respect to the axis of the shank portion, the force for urging the shank portion to be inserted into the tool holder is weakened. Moreover, when the 1st and 2nd flat surface inclines more than 10 degree | times with respect to the axis line of a shank part, the force which presses a shank part to radial direction will become weak. As another embodiment, the flat surface of the shank portion may be parallel to the axis.

  As a preferred embodiment of the first invention, the first flat surface is provided at a position away from the second flat surface by a predetermined angle of 60 degrees or more and 120 degrees or less around the axis of the shank portion. According to this embodiment, since the pressing force received by the first flat surface and the pressing force received by the second flat surface intersect each other, the shank portion is preferably pressed against the inner peripheral surface of the tool holder to improve chucking. . As a more preferred embodiment, the first flat surface is provided at a position separated from the second flat surface by a predetermined angle of 80 degrees or more and 100 degrees or less around the axis of the shank portion. In a more preferred embodiment, the first flat surface is provided at a position 90 degrees away from the second flat surface about the axis of the shank portion.

  In addition, when the angle between the first flat surface and the second flat surface is less than 60 degrees, the force for pressing the shank portion in a specific radial direction is increased. Further, when the angle between the first flat surface and the second flat surface exceeds 120 degrees, the resultant force of the force that the first flat surface receives from the side lock bolt and the force that the second flat surface receives from the side lock bolt is The ratio which cancels increases and the force which presses a shank part in a radial direction toward a tool holder will become weak.

  As a preferred embodiment, at least one of the first and second flat surfaces is surface-treated so as to have a high friction coefficient. According to this embodiment, when the surface-treated flat surface comes into contact with the side lock bolt, both of them do not slide easily, and the side lock bolt can reliably press the flat surface. Therefore, it becomes more difficult for the shank part to come out of the tool holder. Examples of such surface treatment include shot peening treatment and plating treatment. Alternatively, other physical treatment or chemical treatment may be used.

  As one embodiment of the first invention, the shank structure of the blade includes a liquid passage extending from the shank portion toward the tip of the blade. According to this embodiment, a liquid such as a cutting fluid or a cleaning fluid can be supplied from the tool holder to the cutting tool, and the liquid can be directly ejected from the cutting edge of the cutting tool to the workpiece. As another embodiment, the liquid may be ejected from the tool holder toward the cutting edge without going through the blade.

  Further, the tool holder according to the second aspect of the present invention is a cylindrical tool attaching / detaching portion having a tool holding hole extending from the axial front end toward the axial rear end side, and an outer peripheral surface of the tool attaching / detaching portion at different locations in the circumferential direction. First and second side lock bolts screwed into first and second through holes extending to the inner peripheral surface, respectively, and the first and second side lock bolts are tightened and rotated to rotate the first and second side lock bolts. A flat front end surface formed at the front end of each side lock bolt is brought into contact with the shank portion of the cutter to chuck the shank portion of the cutter. According to the second invention, the flat tip surfaces of the first and second side lock bolt tips are opposed to the first and second flat surfaces formed in the shank portion, and the shank structure of the first invention is preferably chucked. Can be king. The second invention does not exclude the formation of additional side lock bolts at different locations in the circumferential direction in addition to the first and second side lock bolts.

  As a preferred embodiment, the tool attaching / detaching portion further includes centering grasping means for centering and grasping the shank portion of the cutter provided at the tip in the axial direction of the tool attaching / detaching portion, and the first and second side locks. The bolt chucks the shank portion of the blade with the shank portion of the blade centered and grasped by the centering grasping means.

  According to this embodiment, since the shank part of a cutter is centered, the front-end | tip part of a tool attaching / detaching part can grasp | ascertain the shank part of a cutter equally in the circumferential direction. Therefore, the axis of the tool holder coincides with the axis of the cutter, and the cutter can be grasped with high accuracy. Thereafter, the plurality of side lock bolts prevent the shank portion of the blade from rotating as a final tightening function. The centering grasping means and the plurality of side lock bolts prevent the chucking from loosening even for long-time cutting.

  The grasping means for centering is not particularly limited. As one embodiment, the centering grasping means is formed on the outer peripheral surface of the tool attaching / detaching portion and becomes tapered toward the tip end side in the axial direction, and the inner peripheral surface is formed into a taper having the same angle as the outer peripheral surface of the tool attaching / detaching portion. An annular space between the cylindrical fastening member that surrounds the outer peripheral surface of the tool attaching / detaching portion on the tip end side in the axial direction with respect to the side lock bolt, and the inner peripheral surface of the tightening member and the outer peripheral surface of the tool attaching / detaching portion And a retainer that holds the needle rollers so as to be inclined at a predetermined angle in the circumferential direction with respect to the axis. Then, by rotating the fastening member, the needle roller is rotated and revolved spirally to reduce or restore the tool holding hole.

  According to this embodiment, when the tightening member is rotated in the tightening direction, the tool holding hole is reduced in diameter by a taper action over a predetermined dimension in the axial direction, the axis line of the tool holder and the axis line of the blade are aligned, and the shank portion is entirely moved. It can be grasped by tightening with a uniform force over the circumference. Therefore, the centering grasping means can be suitably realized.

  As one embodiment, the side lock bolt is attached so that the bolt body that is screwed into the through hole and the pressing surface that comes into contact with the shank portion of the cutter are formed so that the direction of the pressing surface can be freely changed at the tip of the bolt body. A pressed member. According to this embodiment, even if the flat surface of the shank portion is not orthogonal to the advancing direction of the side lock bolt, when the side lock bolt is rotated in the tightening direction, the press surface of the side lock bolt tip is flat with the shank portion. The direction is changed following the surface, and the flat surface is brought into surface contact. Therefore, the side lock bolt firmly presses the flat surface of the shank portion, and the shank portion can be chucked more reliably.

  As a preferred embodiment, the flat front end surface of the side lock bolt may be surface-treated so as to increase the friction coefficient. According to this embodiment, when the front end surface of the surface-treated side lock bolt comes into contact with the flat surface of the shank portion, both of them are difficult to slip, and the side lock bolt can reliably press the flat surface. Therefore, it becomes more difficult for the shank part to come out of the tool holder. Examples of such surface treatment include shot peening treatment and plating treatment. Alternatively, other physical treatment or chemical treatment may be used. In addition, the side lock bolt surface-treated so that a friction coefficient becomes high is at least one of the 1st and 2nd side lock bolt. The flat surface of the shank portion that contacts the tip surface of the side lock bolt may be at least one of the first flat surface and the second flat surface described above.

  As a more preferred embodiment, the tool holder of the present invention may further include a stopper member that is provided on the bottom side of the tool holding hole and that defines the axial position of the shank portion of the cutter inserted into the tool holding hole.

  As a further preferred embodiment, the stopper member has a communication passage penetrating in the axial direction, and the front end side opening of the communication passage may be configured to be connected to the rear end opening of the liquid passage provided in the shank portion of the blade. .

  As described above, the shank structure of the present invention provides improved chucking without the shank portion of the blade being subjected to a specific radial pressing force.

It is a side view which shows the cutter which becomes one Embodiment of this invention. It is a general view which shows the cutter and tool holder which become one Embodiment of this invention. FIG. 3 is a transverse sectional view taken along the line III-III in FIG. 2. It is a front view which shows the axial direction front-end | tip part of a tool holder. It is a front view which shows the axial direction front-end | tip part which removed the cover member from the tool holder. It is a general view which shows the groove | channel formed in the tool peripheral part internal peripheral surface of a tool holder. It is a general view which shows the tool holder before the chucking which has not grasped | ascertained the shank part of the blade. It is a side view which shows the cutter which becomes other embodiment of this invention. It is a general view which shows the tool holder which becomes other embodiment of this invention. It is a longitudinal cross-sectional view which shows the side lock type chucking structure used as the modification of this invention. It is a longitudinal cross-sectional view which shows the side lock type chucking structure which becomes the other modification of this invention. It is a perspective view which shows the shank part of the cutter which becomes a modification of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a cutter according to an embodiment of the present invention. FIG. 2 is an overall view showing a tool holder according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a state in which the tool holder and the cutter of the embodiment are cut along the line III-III in FIG. 2 and viewed in the direction of the arrow. FIG. 4 is a front view showing an axial tip portion of the same embodiment. FIG. 5 is a front view showing an axial tip portion with the lid member removed from the embodiment. FIG. 6 is an overall view showing the groove formed on the inner peripheral surface of the tool attaching / detaching portion of the embodiment, and FIG. 7 is an overall view showing the embodiment before chucking in which the shank portion of the cutter is not grasped. It is. 2, 6, and 7, the upper half is a longitudinal sectional view and the lower half is a side view. In FIG. 4, the cross section representing FIG. 2 and the cross section representing FIG. 6 are indicated by alternate long and short dash lines II-II and VI-VI.

  The steel blade 60 has a blade portion 60b of a super steel alloy in the front end region of the axis O direction and a shank portion 61 in the rear end region of the axial direction. The shank portion 61 is basically a cylindrical portion having a circular cross section with a constant radius. However, two flat surfaces (hereinafter referred to as a first flat surface 62 and a second flat surface 63) are formed on the outer periphery of the shank portion 61 by cutting.

  As shown in FIG. 1, the first flat surface 62 and the second flat surface 63 are disposed at the rear end portion in the axial direction of the shank portion 61. As shown in FIG. 2, the first flat surface 62 is not parallel to the axis O of the shank portion 61 but is slightly inclined so as to be directed toward the tip side of the blade 60. The inclination angle is 5 degrees with respect to the axis O. Alternatively, the first flat surface 62 is a surface inclined within a range of 1 degree to 10 degrees. The same applies to the second flat surface 63.

  As shown in FIG. 3, the first flat surface 62 is provided at a position 90 degrees away from the second flat surface 63 about the axis O of the shank portion 61. Alternatively, the first flat surface 62 is provided at a position separated within a range of 80 to 100 degrees. 3 is an angle from the center of the first flat surface 62 in the circumferential direction to the center of the second flat surface 63 in the circumferential direction.

  The tool holder 10 includes a holder main body 11, first and second side lock bolts 23a and 23b, and a fastening member 32 as main components.

  The metal holder main body 11 extends along the axis O indicated by the alternate long and short dash line, and is attached to the main axis of the machine tool in the axial direction rear end region and the tool attaching / detaching portion 12 for chucking the blade 60 in the axial direction front end region. Each has a mounting portion 13. A large-diameter flange portion 14 is formed in the center portion of the holder main body 11 in the direction of the axis O so as to protrude from the tool attaching / detaching portion 12 and the mounting portion 13 in the outer diameter direction. A V-shaped groove 142 extending in the circumferential direction is formed on the outer peripheral edge of the flange portion 14. A drive key groove 143 extending in the axial direction is formed on the outer peripheral edge of the flange portion 14.

  The mounting portion 13 has a shape that fits into a main shaft of a machine tool (not shown), and the outer peripheral surface of the mounting portion 13 of this embodiment is formed in a taper that decreases in radius toward the rear end in the axial direction. The mounting portion 13 is formed with a central hole 132 extending along the axis O that becomes the center of the holder main body 11. The central hole 132 extends from the rear end in the axial direction of the holder body 11 to the front end in the axial direction, and is formed with several different inner diameters at a midway position in the axial direction. And it is made into the central small hole 133 with the small diameter at the innermost part toward the front end side. A main shaft side member (not shown) is fitted to the rear end portion in the axial direction of the central hole 132, and the mounting portion 13 is securely mounted to the center through coolant main shaft of the machine tool by being pulled backward by the main shaft side member. Then, cutting fluid or cleaning fluid flows into the center hole 132 from the center through coolant main shaft. Accordingly, the central hole 132 becomes a liquid passage.

  The tool attaching / detaching portion 12 has a cylindrical shape with an opening in the axial direction, and has an outer peripheral surface and an inner peripheral surface. The inner peripheral surface 12h defines a tool holding hole 122 that extends along the axis O from the axial front end toward the axial rear end. The tool holding hole 122 has a constant inner diameter and has a hole bottom 123. The tool holding hole 122 is connected to the central small hole 133 formed in the hole bottom 123. As a result, the cutting fluid flows from the center hole 132 to the hole bottom of the tool holding hole 122.

  As shown in FIG. 2, a circumferential groove 124 is formed on the inner peripheral surface 12 h of the tool attaching / detaching portion 12. Further, as shown in FIG. 6, the inner circumferential surface 12 h of the tool attaching / detaching portion 12 extends from the axial front end surface 125 of the tool attaching / detaching portion 12 toward the rear end side in the axial direction and is connected to the circumferential groove 124. Is formed. The cutting fluid that has flowed into the bottom of the tool holding hole 122 from the central small hole 133 flows along the groove 126 through the circumferential groove 124, and travels toward the axial front end surface 125. As a modification, the circumferential groove 124 may not be formed on the inner circumferential surface 12h.

  Strictly speaking, the groove 126 does not extend in parallel with the axis O, but is inclined in the circumferential direction as shown by a solid line in FIG. 2 and by a broken line in FIG. The total length of the groove 126 of the book is shown, and the other grooves 126 are omitted.

  The axial end surface 125 is covered with the lid member 41. The lid member 41 is a ring-shaped plate member as shown in FIG. 4, and has end faces on both sides in the axis O direction of the tool holder 10. Further, the outer peripheral edge of the lid member 41 protrudes in the outer diameter direction from the front end surface 125 in the axial direction. A plurality of through holes 414 are formed in the lid member 41 at predetermined intervals in the circumferential direction. A bolt 44 is passed through the through-hole 414 from the axial front end side, and the front end of the bolt 44 is screwed into a bolt hole 127 (FIGS. 2 and 5) drilled in the axial front end surface 125, whereby the lid member 41 is engaged. Is fixedly attached to the tip of the tool attaching / detaching portion 12 in the axial direction.

  As shown in FIG. 4, a triangular groove-shaped injection port 415 extending from the front end surface to the rear end surface of the lid member 41 is formed on the inner peripheral edge of the lid member 41. When the lid member 41 is fixed to the tip end in the axial direction of the tool attaching / detaching portion 12, the injection port 415 coincides with the tip end in the axial direction of the groove 126 as shown in FIG. When the shank part 61 of the blade 60 is inserted into the tool holding hole 122 and the shank part 61 formed in a circular cross section is chucked to the tool attaching / detaching part 12, the groove 126 and the injection port 415 constitute a continuous liquid passage. To do. The cutting fluid flowing along the groove 126 is ejected from the ejection port 415 toward the tip of the blade 60 and reaches a workpiece (workpiece) (not shown). Thus, the groove 126 functions as a cutting fluid passage. The groove 126 facilitates elastic deformation of the tool attaching / detaching portion 12 in the diameter reducing direction. A plurality of grooves 126 may be provided, and more grooves may be provided than in the present embodiment shown in FIG.

  The tool holder 10 has a side lock chucking structure 21 and a roll lock chucking structure 31 in the tool attaching / detaching part 12 as a structure for chucking the shank part 61 of the blade 60 such as an end mill or a reamer. The roll-lock chucking structure 31 corresponds to centering grasping means for centering and grasping the shank portion 61 of the blade 60. The side lock chucking structure 21 performs a final tightening function for centering and chucking the shank portion 61 of the grasped cutter 60.

  First, the side lock chucking structure 21 will be described. In the tool attaching / detaching portion 12, the outer peripheral surface 12a of the front end side portion is made smaller in diameter, and the outer peripheral surface 12b of the rear end side portion is made larger in diameter. Surface 12c is formed. Two through holes 22 a and 22 b are formed on the rear side of the tool attaching / detaching portion 12. The first through hole 22 a penetrates from the rear end side outer peripheral surface 12 b of the tool attaching / detaching portion 12 to the inner peripheral surface 12 h of the tool attaching / detaching portion 12 and is connected to the tool holding hole 122. The through hole 22a extends substantially in the radial direction of the tool attaching / detaching portion 12, but is slightly inclined so that the outer diameter side is closer to the front end side in the axial direction than the inner diameter side as shown in FIG. This inclination angle is 5 degrees with respect to the direction perpendicular to the axis of the holder body 11. Alternatively, the inclination angle is set within a range of 1 degree to 10 degrees so as to correspond to the inclination angle of the first flat surface 62.

  The second through-hole 22b is also provided in the same manner, and extends in a substantially radial direction of the tool attaching / detaching portion 12, but is slightly inclined so that the outer diameter side is closer to the front end side in the axial direction than the inner diameter side. This inclination angle is 5 degrees with respect to the direction perpendicular to the axis. Alternatively, this inclination angle is set within a range of 1 degree to 10 degrees so as to correspond to the inclination angle of the second flat surface 63. The through hole 22a and the through hole 22b are arranged at the same position in the direction of the axis O, and the circumferential groove 124 described above is formed at the position of the through holes 22a and 22b in the axial direction.

  The through hole 22a is provided 90 degrees away from the through hole 22b around the axis O of the holder body 11. Alternatively, the angle from the through hole 22a to the through hole 22b is set within a range of 80 degrees to 100 degrees so as to correspond to the angle from the first flat surface 62 to the second flat surface 63.

  A female screw 22 s is formed in a portion of the through hole 22 a close to the tool holding hole 122. The outer diameter side portion 22m far from the tool holding hole 122 in the through hole 22a has a larger inner diameter than the female screw 22s. A first side lock bolt 23a is screwed into the first through hole 22a from the outer diameter side. The second through hole 22b is configured in the same manner as the through hole 22a, and the second side lock bolt 23b is screwed into the through hole 22b from the outer diameter side.

  The side lock bolt 23a has a large-diameter head portion 23m at the rear end portion in the longitudinal direction and a small-diameter male screw 23s in the central region in the longitudinal direction. The front end portion of the side lock bolt 23a in the longitudinal direction has a smaller diameter than the male screw 23s, and the front end surface 23t is formed in a plane perpendicular to the longitudinal direction of the side lock bolt 23a. The head 23m is accommodated in the outer diameter side portion 22m, and the male screw 23s is screwed into the female screw 22s. And the front-end | tip part of the side lock bolt 23a protrudes from the through-hole 22a, and advances to the tool holding hole 122. FIG.

  An annular groove is formed on the outer periphery of the head 23m of the side lock bolt 23a, and an O-ring 24, which is an annular seal member, engages with the annular groove. The O-ring 24 contacts the outer diameter side portion 22m of the through hole 22a over the entire circumference. Thereby, the O-ring 24 seals the annular gap between the through hole 22a and the side lock bolt 23a.

  The second side lock bolt 23b is also configured similarly to the first side lock bolt 23a described above.

  On the rear end side outer peripheral surface 12b of the tool attaching / detaching portion 12, a concave portion 25a is provided at a circumferential position different from the through hole 22a. The concave portion 25a prevents the center of gravity of the holder body 11 from being eccentric from the axis O due to the formation of the through hole 22a. As shown in FIG. It is formed at a position 180 ° different in the circumferential direction. Thereby, the center of gravity of the holder body 11 coincides with the axis O, and a mass balance around the axis O can be achieved. Similarly, a recess 25b is provided on the outer peripheral surface 12b on the rear end side of the tool attaching / detaching portion 12 at a circumferential position different from the through hole 22b. As another embodiment, a mass adjusting portion including a recess or a mass body is formed at another position other than 180 ° in the circumferential direction with respect to the through hole 22a and the through hole 22b.

  The recesses 25a and 25b provide a mass balance around the axis of the holder body 11 and the side lock bolts 23a and 23b in a state where the shank portion 61 of the blade 60 inserted into the tool holding hole 122 is fixed by the side lock bolts 23a and 23b. It is good to be provided. As a result, the center of gravity of the assembly of the side lock bolts 23a and 23b rotated in the tightening direction until the shank portion 61 of the blade 60 is fixed and the holder main body 11 in which the through holes 22a and 22b are formed is set to the axis O. Can be approximated or matched. Therefore, it is possible to prevent the runout of the blade 60b at the tip of the blade 60 and to process the workpiece with high accuracy.

  Next, the roll lock chucking structure 31 will be described. The outer peripheral surface 12a on the distal end side of the tool attaching / detaching portion 12 has a circular cross section centered on the axis O, and is formed into a tapered taper (for example, 1/32 taper) whose diameter decreases toward the distal end in the axial direction. Surrounded by the attachment member 32.

  The tightening member 32 reduces the diameter of the tool attaching / detaching portion 12 and closely grasps the entire outer periphery of the shank portion 61 of the blade 60 so as to be in close contact with the entire periphery of the inner peripheral surface 12h. The inner peripheral surface 32a is formed in a taper (for example, 1/32 taper) that tapers at the same angle as the front end side outer peripheral surface 12a, and faces the front end side outer peripheral surface 12a. A retaining ring 36 is attached to the inner peripheral surface of the rear end portion of the tightening member 32. When the fastening member 32 moves to the distal end side in the axial direction, the inner peripheral edge of the retaining ring 36 comes into contact with the engaging portion formed on the outer peripheral surface 12a on the distal end side, and further movement to the distal end side in the axial direction is restricted. The This prevents the fastening member 32 from coming off from the tool attaching / detaching portion 12.

  In the annular space 33 formed between the inner peripheral surface 32a of the fastening member 32 and the distal end side outer peripheral surface 12a of the tool attaching / detaching portion 12, a plurality of needle rollers 34 and a retainer 35 for aligning these needle rollers 34 are provided. Is placed. The retainer 35 is formed in a cylindrical body that tapers at the same angle as the front end side outer peripheral surface 12a, and is loosely fitted to the front end side outer peripheral surface 12a.

  The thickness of the retainer 35 is made thinner than the distance between the inner peripheral surface 32a and the distal end outer peripheral surface 12a, that is, the diameter of the needle roller 34. The retainer 35 is formed with a plurality of pockets for holding one or a plurality of needle rollers 34 at predetermined intervals in the circumferential direction and at predetermined intervals in the axial direction. The pocket is a rectangular hole penetrating the retainer 35 in the radial direction, and the rolling surface of the needle roller 34 protrudes inward in the radial direction of the retainer 35 from the pocket and comes into contact with the outer peripheral surface 12a. It also protrudes outward in the direction and comes into contact with the inner peripheral surface 32a.

  The pocket of the retainer 35 is inclined at a predetermined angle in the circumferential direction with respect to the central axis. Accordingly, the needle roller 34 held in the pocket is inclined at a predetermined angle in the circumferential direction with respect to the axis O, and rolls while drawing a spiral locus on the distal end side outer peripheral surface 12a.

  The fastening member 32 is made of metal, and its axial tip edge protrudes beyond the axial tip face 125 of the tool attaching / detaching portion 12 toward the axial tip side. Then, it faces the outer peripheral edge of the lid member 41. The outer diameter dimension of the lid member 41 is larger than the outer diameter dimension of the axial front end surface 125 and covers the axial front end opening of the annular space 33 between the fastening member 32 and the tool attaching / detaching portion 12. Therefore, the movement of the retainer 35 toward the distal end side in the axial direction is restricted by the outer peripheral edge of the lid member 41, so that the retainer 35 does not come out of the tool attaching / detaching portion 12.

  An O-ring 42, which is an annular outer peripheral seal member, is attached to the outer peripheral edge of the lid member 41. The O-ring 42 seals between the lid member 41 and the fastening member 32. This prevents foreign matter from entering the annular space 33.

  The rear end edge in the axial direction of the tightening member 32 is formed on an annular flat surface 32 c perpendicular to the axis O and faces the annular step surface 12 c of the holder body 11. The tightening member 32 can move in the axial direction on the front end side of the annular step surface 12c, but the annular step surface 12c does not move to the rear end side beyond the annular step surface 12c. Regulates backward movement in the direction. An annular groove is formed in the annular plane 32c, and an O-ring 37, which is an annular seal member, is attached to the annular groove.

  An annular groove 12d centering on the axis O is formed on the inner diameter side of the annular step surface 12c. The inner diameter side surface of the annular groove 12d has an outer diameter equal to that of the distal end outer peripheral surface 12a and is continuous, thereby increasing the axial dimension of the distal end outer peripheral surface 12a. Therefore, the effective grasping length L1 of the roll lock chucking structure 31 can be increased without increasing the length of the holder body 11.

  For the chucking operation of the blade 60, first, the shank portion 61 of the blade 60 is inserted into the tool holding hole 122, and then the shank portion 61 is grasped with high accuracy by the roll-lock chucking structure 31, and then the side-lock chuck chuck. The shank portion 61 is prevented from rotating by the king structure 21. According to this embodiment, by rotating the fastening member 32 in the previous operation to reduce the diameter of the tool holding hole 122 and grasp the shank portion 61 of the blade 60, the axis of the blade 60 is aligned with the axis of the holder body 11. The shank part 61 of the blade 60 can be grasped with high accuracy by the tool attaching / detaching part 12. Further, since the two side lock bolts 23a and 23b are tightened in the subsequent operation, the shank portion 61 of the cutter 60 grasped with high accuracy so as to coincide with the axis O is prevented from being displaced from the coincident axis O. can do. In addition, if the previous work and the subsequent work described above are reversed, the shank portion of the blade cannot be grasped with high accuracy by the tool attaching / detaching portion.

  The chucking operation will be described in detail. As shown in FIG. 10, the side lock bolts 23 a and 23 b are rotated in the loosening direction in advance, and the front ends of the side lock bolts 23 a and 23 b are retracted from the tool holding hole 122. Further, the tightening member 32 is rotated in the loosening direction, the tool attaching / detaching portion 12 is restored in the outer diameter direction, and the inner diameter dimension of the tool holding hole 122 is increased. Next, the shank part 61 of the blade 60 is inserted into the tool holding hole 122 from the axial front end side. Since the outer periphery of the shank portion 61 is partly cut and two first and second flat surfaces 62 and 63 having a 90-degree phase difference are formed, the blade 60 is rotated to change the first flat surface 62. It faces the through hole 22a. Accordingly, the second flat surface 63 also faces the through hole 22b.

  Next, when the tightening member 32 is rotated in the tightening direction, the needle roller 34 in contact with the inner peripheral surface 32a of the tightening member 32 revolves spirally around the distal end outer peripheral surface 12a while rotating. Then, the tightening member 32 gradually moves together with the retainer 35 toward the rear end side in the axial direction. As a result, the outer peripheral surface 12a is strongly compressed in the inner diameter direction over the entire circumference by the wedge action of the inner peripheral surface 32a and the outer peripheral surface 12a, both of which are tapered. As a result, the tool holding hole 122 formed at the center of the tool attaching / detaching portion 12 is also reduced in diameter, and the cylindrical portion in front of the shank portion 61 inserted into the tool holding hole 122 has an effective grasping length L1 of the distal end side outer peripheral surface 12a. The inner peripheral surface 12h is tightened evenly over the entire circumference. Therefore, the tool attaching / detaching portion 12 grasps the outer peripheral surface of the shank portion 61 evenly in the circumferential direction. And the shank part 61 is hold | maintained tightly and firmly in the axial direction area | region of the tool attachment / detachment part 12, the axis line of the holder main body 11 and the axis line of the cutter 60 correspond, and the cutter 60 is grasped | ascertained along the axis O with high precision.

  Further, when the tightening member 32 is rotated in the tightening direction and the shank portion 61 is grasped, the annular flat surface 32c at the rear end in the axial direction of the tightening member 32 and the annular step surface 12c of the holder body 11 come into contact with each other, and the O-ring 37 is It is interposed between the axial rear end edge of the fastening member 32 and the annular step surface 12 c of the holder body 11. Thereby, the axial rear end opening of the annular space 33 between the tightening member 32 and the tool attaching / detaching portion 12 can be sealed, and foreign matter can be prevented from entering the annular space 33.

  Next, both side lock bolts 23a and 23b are rotated in the tightening direction so that the front end surface 23t of the side lock bolt 23a screwed into the through hole 22a is brought into contact with the first flat surface 62 and screwed into the through hole 22b. The front end surface 23t of the side lock bolt 23b is brought into contact with the second flat surface 63. The flat front end surface 23t of the side lock bolt 23a pushes the first flat surface 62 behind the shank portion 61 with a strong force, and the flat front end surface 23t of the side lock bolt 23b is a second flat surface behind the shank portion 61 with a strong force. 63 is pushed and the shank part 61 is fixed to the tool holding hole 122. Since the circumferential groove 124 is formed at the same axial position as the through holes 22a and 22b, the cutting fluid from the central hole 132 toward the distal end side in the axial direction is more axially rearward than the cylindrical portion in front of the shank portion 61. It flows into the circumferential groove 124 on the end side. Therefore, the cutting fluid flows into the groove 126 without any stagnation.

  As described so far, the shank portion 61 is first grasped by using the roll-lock chucking structure 31, and the shank portion 61 is later prevented from being rotated by using the side-lock chucking structure 21, and FIG. 3, the shank portion 61 is chucked to the tool attaching / detaching portion 12. The removal of the blade 60 is performed in the reverse procedure to the above-described operation.

  Next, another embodiment of the present invention will be described. FIG. 8 is a side view showing a cutter according to another embodiment of the present invention. FIG. 9 is a longitudinal sectional view showing a tool holder for chucking the blade of FIG. Regarding the other embodiments, the same components as those described above are denoted by the same reference numerals, description thereof is omitted, and different configurations will be described below.

  The cutter 65 according to another embodiment includes a liquid passage 66 extending from the shank portion 61 toward the tip of the cutter 65 in addition to the basic configuration of the cutter 60 described above.

  In addition, the tool holder 20 according to another embodiment includes the two side lock bolts 23 a and 23 b described above, and the outer peripheral surface of the shank portion 61 of the cutter 65 inserted into the inner peripheral edge of the lid member 41 and the tool holding hole 122. An O-ring 43 is further provided as an annular inner peripheral side sealing member that seals between the two. A liquid passage 66 extending in the axial direction from the rear end to the front end of the cutter 65 is formed in the shank portion 61 chucked by the tool holder 20. The tool holding hole 122 is formed from the central small hole 133. Via this, the cutting fluid is supplied to the rear end of the liquid passage 66. The cutting fluid flows through the liquid passage 66 and is ejected from the tip (not shown) of the blade 65 to reach the workpiece. According to the embodiment of FIG. 9, since the annular O-ring 43 that seals between the inner peripheral edge of the lid member 41 and the outer peripheral surface of the shank portion 61 is provided, it flows from the central small hole 133 to the tool holding hole 122. The cutting fluid can be prevented from leaking from the tip of the tool attaching / detaching portion 12. In particular, the O-ring 43 is effective when the above-described groove 126 is formed on the inner peripheral surface 12 h of the tool holder 20.

  In the tool holder 20 according to another embodiment, a stopper member 51 that is provided on the bottom side of the tool holding hole 122 and that defines the axial position of the shank portion 61 of the cutter 65 inserted into the tool holding hole 122 is further provided. Prepare.

  The stopper member 51 includes a fixing member 52 that is fixed to the inner peripheral surface 12 h of the tool attaching / detaching portion 12, and an adjuster member 53 that is supported by the fixing member 52 so as to be axially displaceable and contacts the shank portion 61 of the blade 65. . A male screw 522 is formed on the outer peripheral surface of the fixing member 52, and is screwed with a female screw 12 s formed on the inner peripheral surface 12 h of the tool attaching / detaching portion 12 near the bottom of the tool holding hole 122. As a result, the fixing member 52 is attached and fixed to the tool holding hole 122. An annular groove is formed on the outer peripheral surface of the fixing member 52 on the tip side of the male screw 522, and an O-ring 55 serving as an annular seal member is attached to the annular groove. The O-ring 55 is a first seal member that seals between the tool holding hole 122 and the fixing member 52.

  Further, a central hole 523 penetrating in the axial direction is formed in the fixing member 52, and an adjuster member 53 is attached and fixed to the central hole 523. The rear end side of the central hole 523 has a smaller diameter than the front end side, and a female screw portion 524 is formed on the rear end side.

  The adjuster member 53 includes a large-diameter front end portion 531, a central portion 534 having a smaller diameter than the front end portion 531, and a rear end portion 535 having a smaller diameter than the central portion 534, and has a shape in which three columns are coupled in series. is there. A communication passage 532 that penetrates in the axial direction is formed at the center of the adjuster member 53. The rear end side opening of the communication passage 532 is connected to the central small hole 133. The front end opening of the communication passage 532 is connected to the rear end opening of the liquid passage 66 of the shank portion 61.

  The large-diameter leading end surface 533 of the adjuster member 53 formed on the large-diameter leading end portion 531 comes into contact with the rear end of the shank portion 61 of the cutter 65 inserted into the tool holding hole 122, and the shank portion 61 Define the axial position. A ring groove centered on the axis O is formed in the large-diameter tip surface 533, and an annular O-ring 57 is attached to the ring groove. The O-ring 57 is a third seal member that contacts the rear end surface of the shank portion 61 without a gap and seals between the large-diameter front end surface 533 and the shank portion 61. Thereby, the front end opening of the communication passage 532 provided at the center of the large diameter front end surface 533 is connected in a sealed state to the rear end opening of the liquid passage 66 provided at the center of the rear end surface of the shank portion 61.

  The rear end portion 535 of the adjuster member 53 has a male screw portion formed on the outer peripheral surface thereof, and is screwed with the female screw portion 524 of the fixing member 52. When the adjuster member 53 is rotated by such screwing, the position of the adjuster member 53 in the axial direction is adjusted as indicated by a broken line in FIG.

  The central portion 534 of the adjuster member 53 is received on the distal end side of the central hole 523 of the fixing member 52. An annular groove is formed on the outer peripheral surface of the central portion 534 of the adjuster member 53, and an O-ring 56 serving as an annular seal member is attached to the annular groove. The O-ring 56 is a second seal member that seals between the inner peripheral surface of the fixing member 52 and the outer peripheral surface of the adjuster member 53.

  According to the embodiment shown in FIG. 9, the central hole 132 and the central small hole 133 that are liquid passages through which the cutting fluid flows extend from the mounting portion 13 of the holder body 11 to the hole bottom 123 of the tool holding hole 122. The adjuster member 53 is attached and fixed to a central hole 523 formed in the fixing member 52 that penetrates in the axial direction, and communicates with the hole bottom 123 side of the tool holding hole 122 and the opening side of the tool holding hole 122. 532 and an annular O-ring 57 that seals between the large-diameter front end surface 533 that is the front end side end surface in the axial direction and the rear end surface of the shank portion 61 of the cutter 65. Thereby, the central small hole 133 of the holder main body 11 and the liquid passage 66 of the blade 65 can be reliably communicated with each other via the communication passage 532.

  The fixing member 52 has an annular O-ring 55 that seals between the fixing member 52 and the tool holding hole 122, and the adjuster member 53 seals between the peripheral wall surface of the central hole 523 and the adjuster member 53. Therefore, the cutting fluid can be prevented from flowing out toward the through holes 22a and 22b.

  Next, a modification of the side lock chucking structure will be described with reference to the longitudinal sectional view of FIG. In the modification, an annular groove is formed in the outer diameter side portion 22m of the through hole 22a, and the snap ring 26 is attached and fixed to the annular groove. The snap ring 26 is C-shaped, is located on the outer diameter side of the side lock bolt 23a, and prevents the side lock bolt 23a from coming out from the through hole 22a to the outside (outer diameter side). It is. Thereby, even if the side lock bolt 23a is loosened during the high-speed rotation of the tool holder 10, it is possible to prevent the side lock bolt 23a from coming out. The snap ring 26 is similarly provided in the through hole 22b.

  FIG. 10 shows a state in which the side lock bolt 23 a is rotated in the loosening direction and the head 23 m of the side lock bolt 23 a is brought into contact with the snap ring 26. When the side lock bolt 23 a is moved to the outer diameter side in this way, the tip end surface 23 t of the side lock bolt 23 a moves out of the tool holding hole 122. According to such a modification, it is possible to insert the columnar shank portion 61 that is not formed so that the flat contact plane is notched. The shank portion 61 can be grasped by the roll lock chucking structure 31.

  Next, another modification of the side lock chucking structure will be described with reference to the longitudinal sectional view of FIG. In the modification shown in FIG. 11, the side lock bolt 23 a includes a bolt main body 231 and a pressing member 232. The bolt body 231 has a large-diameter head portion 23m at the rear end portion in the longitudinal direction, and a small-diameter male screw 23s in the central region in the longitudinal direction. A spherical recess is formed at the front end of the bolt body 231 in the longitudinal direction, and a ball-shaped pressing member 232 is fitted into the recess. The pressing member 232 has a flat pressing surface 23t at its tip. Thus, since the pressing member 232 is supported by the bolt body 231 on the spherical surface, the pressing surface 23t can rotate around the central axis of the bolt main body 231 and be inclined with respect to the central axis of the bolt main body 231. Can do. Therefore, the direction of the pressing member 232 can be freely changed with respect to the bolt main body 231. Further, the pressing member 232 may be attached to the bolt main body 231 as long as the direction can be freely changed like a universal joint in addition to the modification of FIG.

  When the bolt main body 231 is screwed into the female screw 22s of the through hole 22a and rotated in the tightening direction, the side lock bolt 23a advances into the tool holding hole 122, and the pressing surface 23t of the side lock bolt 23a is the first flat surface. 62 abuts. When the bolt body 231 is continuously rotated in the tightening direction, the holding surface 23t changes its direction following the first flat surface 62 and comes into surface contact with the first flat surface 62.

  As described above, according to the modification of FIG. 11, even if the first flat surface 62 of the shank portion 61 is not strictly orthogonal to the advancing direction of the side lock bolt 23 a, the pressing surface 23 t of the pressing member 232 is the shank portion. The first flat surface 62 is changed to follow the first flat surface 62 and comes into surface contact with the first flat surface 62. Therefore, the side lock bolt 23a firmly presses the first flat surface 62 of the shank portion 61, and the shank portion 61 can be chucked more reliably. The second side lock bolt 23b may be configured in the same manner as the first side lock bolt 23a.

  Next, referring to the perspective view of FIG. 12, a shank portion of a cutter according to a modification of the present invention will be described. In the modification shown in FIG. 12, the first flat surface 62 and the second flat surface 63 are surface-treated so as to increase the friction coefficient. Specifically, it has a fine uneven shape by shot peening.

  Shot peening is a cold working method in which a large number of particles are projected onto a work surface, and a large number of irregularities are formed on the work surface. Since the compressive stress remains on the first flat surface 62 and the second flat surface 63 subjected to the shot peening process, the fatigue life is improved.

  As described above, according to the modified example of FIG. 12, at least one of the first flat surface 62 and the second flat surface 63 is surface-treated so as to increase the friction coefficient. When coming into contact, the first flat surface 62 and the side lock bolt tip surface (pressing surface) 23t are difficult to slide with each other, and the side lock bolt 23a can reliably press the first flat surface 62. Therefore, the shank portion 61 is more difficult to remove from the tool holders 10 and 20.

  Further, instead of subjecting the first flat surface 62 and the second flat surface 63 to the surface treatment as described above, the front end surface (pressing surface) 23t of the side lock bolt 23a may be subjected to a surface treatment so as to increase the friction coefficient. . Also according to such a modified example, the first flat surface 62 and the side lock bolt front end surface (pressing surface) 23t are difficult to slide with each other, and the side lock bolt 23a can reliably press the first flat surface 62. Therefore, the shank portion 61 is more difficult to remove from the tool holders 10 and 20. Moreover, the processing becomes easier than the case where the first flat surface 62 and the second flat surface 63 are surface-treated as described above. The tip surface (pressing surface) of the side lock bolt 23b may also be surface-treated so as to increase the friction coefficient.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The blade shank structure and the tool holder according to the present invention are advantageously used in a machine tool.

  DESCRIPTION OF SYMBOLS 10 Tool holder, 11 Holder main body, 12 Tool attaching / detaching part, 13 Mounting part, 20 Tool holder, 21 Side lock type chucking structure, 22a, 22b Through hole, 22s Female thread, 23a, 23b Side lock bolt, 23t Surface), 24 O-ring, 25 recess, 31, roll lock chucking structure, 32 tightening member, 34 needle roller, 35 retainer, 37 O-ring, 41 lid member, 42, 43 O-ring, 51 stopper member, 52 Fixing member, 53 adjuster member 55, 56 O-ring, 57 O-ring, 60 blade, 61 shank, 62 first flat surface, 63 second flat surface, 65 blade, 66 liquid passage, 122 tool holding hole 126 groove, 231 bolt body, 232 presser member, 415 injection port.

Claims (6)

A cylindrical tool attaching / detaching portion centering on a tool holding hole extending from the front end in the axial direction toward the rear end side in the axial direction;
A centering grasping means for centering and grasping a shank portion of a cutter provided at the tip end in the axial direction of the tool attaching / detaching portion and inserted into the tool holding hole;
First and second side lock bolts respectively screwed into first and second through holes extending from the outer peripheral surface to the inner peripheral surface of the tool attaching / detaching portion at different locations in the circumferential direction,
At least one of the first and second through-holes is inclined and extended at a predetermined angle of 1 degree or more and 10 degrees or less with respect to the direction perpendicular to the axis so that the outer diameter side is closer to the front end side in the axial direction than the inner diameter side,
The first and second side lock bolts are tightened and rotated in a state where the shank portion of the cutter is centered and grasped by the centering grasping means, and are attached to the tips of the first and second side lock bolts. The tool holder comprised so that the formed flat front end surface may contact | abut to the shank part of the said cutter, respectively, and chuck the shank part of the said cutter. The centering grasping means includes a taper formed on the outer peripheral surface of the tool attaching / detaching portion and narrowing toward the tip end in the axial direction, and an inner peripheral surface formed with a taper having the same angle as the outer peripheral surface. A cylindrical fastening member that surrounds the outer peripheral surface of the tool attaching / detaching portion on the axial front end side with respect to the lock bolt, and an annular space between the inner peripheral surface of the fastening member and the outer peripheral surface of the tool attaching / detaching portion. A plurality of needle rollers disposed, and a retainer that holds these needle rollers so as to be inclined at a predetermined angle in the circumferential direction with respect to the axis,
2. The tool holder according to claim 1, wherein the tool holding hole is configured to be reduced in diameter or restored by rotating in a helical manner while rotating the needle roller by rotating the tightening member. The side lock bolt is
A bolt body screwed into the through hole;
The tool holder according to claim 1, further comprising a pressing member formed with a pressing surface that comes into contact with the shank portion of the cutter and attached to a tip portion of the bolt body so that the direction of the pressing surface can be changed. .   The tool holder according to any one of claims 1 to 3, wherein the flat front end surface of the side lock bolt is surface-treated so as to have a high friction coefficient.   The tool holder in any one of Claims 1-4 further provided with the stopper member which is provided in the hole bottom side of the said tool holding hole, and prescribes | regulates the axial direction position of the shank part of the cutter inserted in a tool holding hole. The stopper member has a communication passage penetrating in the axial direction,
The tool holder according to claim 5, wherein a front end side opening of the communication passage is configured to be connected to a rear end opening of a liquid passage provided in a shank portion of the blade.

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