JP4844210B2 - Method for correcting protrusion amount of cutting tool and finish cutting blade - Google Patents

Description

  The present invention relates to a cutting tool such as a boring bar used when cutting an inner wall surface of a pilot hole provided in advance in a workpiece, and a method for correcting a protrusion amount of a finishing cutting edge provided in the cutting tool.

In recent years, as a cutting tool used for machining a cylinder bore of an engine or the like, for example, as shown in Patent Document 1, a cutting blade is provided on the outer periphery of a tool body, and a cutting blade for finishing work separately from this cutting blade. There is known a boring bar or the like arranged so as to be able to appear and retract in the tool body radial direction.
FIG. 7 shows an example of a conventional boring bar. The boring bar 1 has a substantially cylindrical tool body 2, and a first cutting edge 3 is provided on the outer peripheral surface of the tool body 2.

A piston chamber 4 is provided inside the tool body 2, and a wall surface of the piston chamber 4 on the tip side (lower side in FIG. 7) of the tool body 2 serves as a stopper wall 4A. A piston 5 that can move in the direction of the axis O is disposed inside the piston chamber 4. The piston chamber 4 is divided by the piston 5, and the rear end side portion of the tool body 2 from the piston 5 serves as a first space 6. The tip of the tool body 2 from the piston 5 is a second space 7.
A rod-like member 8 is connected to the tip end side of the tool body 2 of the piston 5 and is arranged so as to be movable in the direction of the axis O as the piston 5 moves. A slide member 9 is arranged on the tip end side of the rod-shaped member 8 so as to intersect the rod-shaped member 8, and the slide member 9 is provided with a second cutting edge 10 for finishing.

A serration groove 8 </ b> A that is inclined in the protruding direction of the second cutting edge 10 is formed at the front end side portion of the tool body 2 of the rod-shaped member 8 toward the rear end side of the tool body 2. The slide member 9 is provided with a serration groove 9A that can be fitted into the serration groove 8A. The serration groove 8A of the rod-like member 8 and the serration groove 9A of the slide member 9 are slidably fitted. Yes.
A cap 11 is provided on the distal end surface of the tool body 2, and a recess 12 into which the rod-like member 8 can be inserted is formed on the tool body 2 side of the cap 11.

In the boring bar 1, the second cutting edge 10 is projected and retracted in the radial direction of the tool body 2 as follows.
When coolant is supplied into the tool body 2 and this coolant flows into the first space 6 of the piston chamber 4, the piston 5 is moved to the tip end side of the tool body 2 by the pressure of the coolant, and the stopper wall 4 </ b> A of the piston chamber 4. The piston 5 is brought into contact with. As the piston 5 moves, the rod-shaped member 8 is moved toward the tip end side of the tool body 2, so that the slide member 9 is moved by being guided by the serration groove 8 </ b> A of the rod-shaped member 8, and the second cutting edge 10 is moved to the tool body. It protrudes outward in the two radial directions. On the other hand, when the coolant flows into the second space 7 of the piston chamber 4, the piston 5 is moved to the rear end side of the tool body 2 by the pressure of the coolant, and the rod-shaped member 8 is moved to the rear end side of the tool body 2, The slide member 9 is guided by the serration groove 8A of the rod-shaped member 8 and the second cutting edge 10 is retracted inward in the tool body 2 radial direction.

In the boring bar 1 having such a configuration, the tool body 2 is rotated at a high speed around the axis O of the tool body 2 and is fed in the direction of the axis O of the tool body 2, and is prepared in a prepared hole provided in advance in the workpiece W. After the inner wall surface of the prepared hole is finished by the first cutting edge 3 inserted and provided on the outer periphery of the tool body 2 to form a machining hole having a predetermined inner diameter, the second cutting edge 10 is moved to the diameter of the tool body 2. It protrudes outward in the direction, and the boring hole is back-bored by the second cutting edge 10 to finish the inner wall surface of the boring hole.
JP 2003-266216 A

By the way, in the boring bar 1 described above, the projecting amount in the radial direction of the tool main body 2 of the second cutting edge 10 for finishing is such that when the rod-shaped member 8 is moved to the tip end side of the tool main body 2, the piston 5 is a stopper. Since it is determined by the position of the slide member 9 in a state where it cannot be moved to the tip side of the tool body 2 due to contact with the wall 4A, the amount of protrusion of the second cutting blade 10 in the radial direction of the tool body 2 can be easily adjusted. It was something that could not be done.
Here, the wear of the cutting edge is large at the initial stage of use, and the position of the second cutting edge 10 in the radial direction of the tool body 2 changes during the use of the boring bar 1. There has been a problem that variations in dimensions occur.

  In recent years, computer-controlled machining by machining centers has been widely performed. Therefore, a cutting tool that can correct the radial position of the finishing cutting blade that performs finishing machining with the cutting tool attached to the machining center. Is required.

  The present invention has been made in view of the above-described circumstances, and after finishing the inner wall surface of the pilot hole provided in advance in the workpiece with a cutting blade provided on the outer periphery of the tool body, it is used for finishing. This is a cutting tool that finishes a machining hole by projecting the finishing cutting edge outward in the tool body radial direction. It can easily make the finishing cutting edge appear and disappear in the tool body radial direction, and is a general machine tool such as a machining center. An object of the present invention is to provide a cutting tool capable of easily correcting the position of the finish cutting blade in the radial direction of the tool body and the method of correcting the protrusion amount of the finishing cutting edge.

  In order to achieve the above object, a cutting tool of the present invention has a tool main body rotated around an axis, a cutting blade is provided on the outer periphery of the tool main body, and is used for finishing work separately from the cutting blade. A finishing cutting blade is a cutting tool arranged so as to be able to protrude and retract in the radial direction of the tool body, and a piston chamber is formed inside the tool body, and a piston is movable in the axial direction in the piston chamber. The tool body rear end side of the piston chamber in the piston chamber is a first space, the tool body front end side of the piston is a second space, and fluid is supplied to the tool body. A fluid supply device that supplies the piston chamber; and a switching device that selectively supplies the fluid to the first space or the second space. A rod-like member is connected to the tip of the tool body of the piston. Wait The rod-shaped member is arranged at the tip end portion of the tool body so as to intersect the rod-shaped member, and the rod-shaped member is moved in the direction intersecting the axial direction by moving in the axial direction. A slide member is provided, and the finish cutting blade is provided on the outer peripheral side of the tool body of the slide member, and the rod-like member is moved to the tip side of the tool body by the piston on the tip side of the tool body of the rod-like member. In this state, an adjustment screw with which the tip end surface of the rod-shaped member comes into contact is provided, and the adjustment screw is rotated on the tip end surface of the tool body to adjust the axial position of the adjustment screw. The rotating member is provided, and an inclined groove that is recessed radially inward and inclined with respect to the axis is formed on the outer periphery of the rotating member.

  Further, the method for correcting the protrusion amount of the finishing cutting edge according to the present invention is a method for correcting the protrusion amount of the finishing cutting edge for adjusting the protrusion amount of the finishing cutting edge provided in the above-described cutting tool to the outside in the radial direction of the tool body. , By disposing an engaging pin slidable in the inclined groove, and moving the tool main body in the axial direction with the engaging pin inserted in the inclined groove, The axial position of the adjustment screw is moved by relatively rotating the adjustment screw.

According to the method for correcting the amount of projection of the cutting tool and the finishing cutting blade having the above-described configuration, the piston chamber is provided with the piston, the tool body rear end side is the first space from the piston, and the tool body front end side is the first space from the piston. There are two spaces, and the piston can be moved in the axial direction of the tool body by selectively allowing fluid to flow into the first space and the second space. A rod-like member is connected to the tool body tip side of the piston, and the rod-like member is also moved in the tool body axis direction as the piston moves.
Since the rod-shaped member is moved in the direction intersecting the axial direction by moving the rod-shaped member in the axial direction at the tip portion of the rod-shaped member, and the slide member provided with the finishing cutting edge is provided, the rod-shaped member is By moving in the direction, the finishing cutting edge can be made to appear and disappear in the radial direction of the tool body.

  Also, an adjustment screw is provided on the tool body tip side of the rod-shaped member, and when the rod-shaped member is moved to the tool body tip side, the tip surface of the rod-shaped member comes into contact with the adjustment screw. The position in the axial direction when moving to the tip side is positioned by the adjustment screw, the position of the slide member as the rod-shaped member moves is determined, and the amount of protrusion of the finish cutting blade to the outside of the tool body in the radial direction is stabilized. Can be determined.

  In addition, there is a rotating member that adjusts the axial position of the adjusting screw by rotating the adjusting screw on the tip of the tool body. The position of the adjusting screw in the axial direction can be adjusted by rotating the rotating member, and the amount of protrusion of the finish cutting blade to the outside in the radial direction of the tool body can be corrected. Therefore, by correcting the radial position by the amount of wear of the cutting blade, it is possible to prevent dimensional variations in the processed hole.

And since the inclined groove inclined to the axis is formed on the outer periphery of the rotating member, for example, by providing an engagement pin slidable in the inclined groove on the machine table side, the cutting tool of the cutting tool By moving the cutting tool in the axial direction with the engagement pin inserted in the inclined groove, the rotating member can be easily rotated to adjust the axial position of the adjusting screw.
Therefore, by controlling the operation of the cutting tool without providing a rotating mechanism for the rotating member on the machine side, it is possible to easily and accurately correct the protruding amount of the finish cutting blade to the outside in the tool body radial direction. Can do.

  According to the present invention, after cutting the inner wall surface of the prepared hole provided in advance in the workpiece with the cutting blade provided on the outer periphery of the tool body, the finishing cutting blade for finishing is projected outward in the tool body radial direction. This is a cutting tool that finishes machining holes, and can easily make the finish cutting blades protrude and retract in the radial direction of the tool body, while still attached to a general machine tool such as a machining center. It is possible to provide a cutting tool capable of easily correcting the position of the finishing cutting edge in the radial direction of the tool body and a method of correcting the protrusion amount of the finishing cutting edge.

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4 show a boring bar as a cutting tool according to an embodiment of the present invention.
The boring bar 20 includes a multi-stage cylindrical tool body 21 extending in the direction of the axis O, and the tool body 21 is used as a spindle end of the machine tool on the rear end side (the upper side in FIGS. 1 and 2) of the tool body 21. A mounting portion 22 for mounting is provided.
The tool body 21 is divided into a first member 21 A located on the rear end side and a second member 21 B located on the distal end side, and these are coupled by a plurality of coupling bolts 23.

  The outer periphery of the tool body 21 is provided with a first cutting edge 24 protruding outward in the radial direction of the tool body 21. In the present embodiment, as shown in FIG. Two in the circumferential direction are arranged at positions facing each other across the axis O. In the present embodiment, a first insert 25 having a cutting edge is mounted as the first cutting edge 24. This first insert 25 is a so-called vertical blade insert, and is arranged so that the first cutting blade 24 protrudes outward in the radial direction of the tool body 21 as it goes toward the tip side of the tool body 21.

The first member 21A is formed with a piston hole having a circular cross section that opens largely toward the tip end side of the tool body 21 and extends along the axis O, and the rear of the second member 21B is formed in the opening of the piston hole. A projecting portion formed in the end portion is inserted, and a piston chamber having a circular cross section extending along the axis O in the tool body 21 by the piston hole and the rear end surface of the projecting portion 26 (second member 21B). 27 is defined.
The piston chamber 27 is provided with a piston 28 that can reciprocate in the direction of the axis O, and an outer surface of the piston 28 is provided with an O-ring 29 that is in sliding contact with the side wall of the piston chamber 27.

  The piston chamber 27 is divided by the piston 28, the rear end side of the tool body 21 from the piston 28 in the piston chamber 27 is defined as a first space 27 </ b> A, and the tip end side of the tool body 21 from the piston 28 in the piston chamber 27 is second. The first space 27 </ b> A and the second space 27 </ b> B are liquid-tightly blocked by an O-ring 29 provided on the outer peripheral surface of the piston 28. The tool body 21 (first member 21A) communicates with the first space 27A and communicates with the second coolant space 27B and the first coolant hole 30 opened in the outer peripheral surface of the tool body 21 and the tool body 21. A second coolant hole 31 opened in the outer peripheral surface is formed, and a pressure valve is arranged in the first and second coolant holes 31 so that the coolant is not discharged below a certain pressure.

  Further, a coolant hole 32 extending along the axis O is formed in the first member 21A, and the rear end side of the coolant hole 32 is opened to the mounting portion 22 and supplies the coolant as the fluid in the present embodiment. A supply device 33 and a control device 34 for adjusting the supply amount of coolant per unit time are connected. On the distal end side of the tool body 21 of the coolant hole 32, a first flow path 35 that communicates the coolant hole 32 and the first space 27A, and a second flow path 36 that communicates the coolant hole 32 and the second space 27B. A branching portion that branches off is formed, and a second piston chamber 37 is formed in the branching portion.

More specifically, a second piston hole having a circular cross section extending along the axis O is formed in the rear end surface of the piston chamber 27, and a receiving member 38 is screwed into a front end side opening of the second piston hole. A second piston chamber 37 is defined by the receiving member 38 and the second piston hole, and the coolant hole 32 is opened on the rear end side of the tool body 21 of the second piston chamber 37.
The second piston chamber 37 is disposed so that the second piston 39 can reciprocate in the direction of the axis O, and the second piston 39 is disposed on the distal end side of the tool body 21 of the second piston 39. A coil spring 40 is disposed as a biasing member that biases toward the side, and one end of the coil spring 40 is accommodated in the receiving member 38.

Of the side wall surface of the second piston chamber 37, an opening portion of the first flow path 35 is formed in the rear end portion of the tool body 21, and the opening portion of the first flow path 35 is formed among the side wall surfaces of the second piston chamber 37. In addition, the opening of the second flow path 36 is formed on the distal end side of the tool main body 21.
Further, the second piston 39 is provided with an internal flow path 41 that communicates with the coolant hole 32 and that opens to the side surface of the second piston 39.

  When the second piston 39 moves to the front end side of the tool body 21, the side surface of the second piston 39 closes the opening of the second flow path 36, and the coolant passes through the space on the rear end side of the tool body 21 of the second piston 39. The hole 32 communicates with the first flow path 35. On the other hand, when the second piston 39 moves to the rear end side of the tool body 21, the side surface of the second piston 39 closes the opening of the first flow path 35, and the coolant hole passes through the internal flow path 41 of the second piston 39. 32 and the second flow path 36 communicate with each other. Thus, it is comprised so that the flow path of a coolant can be switched by the 2nd piston 39 reciprocatingly moving.

  The second member 21 </ b> B is formed with a through hole 42 that extends in the direction of the axis O and communicates with the distal end side of the tool body 21 of the piston chamber 27. A rod-shaped member 43 having a circular cross section, which is formed integrally with the tip end side of the tool body 21 of the piston 28 and is disposed along the axis O, is fitted in the through hole 42 in a liquid-tight manner. The tip side of the tool body 21 of the rod-shaped member 43 is cut out so that a cross section perpendicular to the axis O forms a substantially semicircular shape, and a slidable contact surface 44 extending along the axis O is formed. In the present embodiment, as shown in FIG. 2, the sliding contact surface 44 is disposed so as to be in a direction perpendicular to a straight line passing through the axis O and connecting the two first cutting edges 24.

In the portion of the tool body 21 (second member 21B) where the slidable contact surface 44 formed on the rod-shaped member 43 is located, the radial direction perpendicular to the straight line passing through the axis O and connecting the two first cutting edges 24 A slide member 45 extending in the radial direction is provided, and a slide member 46 slidable in the radial direction is disposed in the slide hole 45 so as to intersect the rod-like member 43. A second insert 48 having a cutting edge is provided as a second cutting edge 47 for finishing at the outer peripheral end of the slide member 46 with respect to the tool main body 21. As shown in FIG. Is disposed at a position rotated by 90 ° about the axis O with respect to the two first cutting edges 24. The second insert 48 is arranged so that the second cutting edge 47 gradually protrudes outward in the radial direction of the tool body 21 as it goes toward the rear end side of the tool body 21.
Further, an adjustment piece 49 for adjusting the protruding amount of the second insert 48 is disposed inside the tool insert 21 in the radial direction of the second insert 48. A slit 50 is formed in the adjustment piece 49, and a pressing screw 51 that presses the second insert 48 by expanding the slit 50 is screwed.

  A concave portion is formed at the center of the slide member 46 so that the tip end side of the rod-shaped member 43 is inserted, and the bottom surface of the concave portion is a sliding contact surface 53. On the sliding contact surface 44 of the rod-shaped member 43, a serration groove 44A inclined with respect to the axis O is formed so as to gradually approach the second cutting edge 47 as it goes toward the rear end side of the tool body 21. Further, the sliding contact surface 53 of the slide member 46 is formed with a serration groove 53A that can be fitted into the serration groove 44A provided in the rod-like member 43. As shown in FIG. The serration groove 44A and the serration groove 53A of the slidable contact surface 53 are slidably disposed.

Of the through hole 42 in which the rod-shaped member 43 is accommodated, a screw hole portion 54 having a circular cross section having a female screw formed on the inner wall surface and communicating with the through hole 42 at the tip end side of the tool body 21 further than the slide hole 45. An adjustment screw 55 is screwed into the screw hole portion 54.
An end surface of the adjustment screw 55 facing the rear end side of the tool body 21 is formed in a planar shape perpendicular to the axis O, and serves as a stopper surface 56 with which the tip surface of the rod-shaped member 43 abuts. Further, a chamfered portion 57 is formed at the tip of the adjustment screw 55 and is cut out in a planar shape parallel to the axis O.

Furthermore, a male screw portion 58 is formed on the outer peripheral portion on the tip end side of the tool main body 21 (second member 21 </ b> B), and a cylindrical member 59 is screwed to the male screw portion 58. A protruding portion 60 that protrudes radially inward from the inner peripheral surface of the cylindrical member 59 is formed on the distal end side of the cylindrical member 59, and the radially outer side is formed by the protruding portion 60 and the distal end surface of the second member 21B. An annular groove 61 that is recessed toward is formed.
On the further distal end side of the cylindrical member 59, a rotating member 62 is disposed so as to be rotatable about the axis O.

  Specifically, the rotating member 62 includes a cylindrical main body portion 63 and a shaft portion 64 that protrudes toward the distal end side of the main body portion 63 and is arranged coaxially with the main body portion 63. At the rear end of the portion 63, a flange portion 65 that protrudes radially outward and has a one-step large diameter is formed, and the flange portion 65 is slidably engaged with the annular groove 61. . The shaft portion 64 is disposed so as to protrude from the opening on the front end side of the cylindrical member 59.

Further, a concave groove having a U-shaped cross section is formed in the portion of the rotating member 62 on the rear end side of the tool body 21 so as to extend in the radial direction, and the chamfered portion 57 of the adjusting screw 55 is formed in the concave groove. Is inserted, the rotation member 62 and the adjustment screw 55 can be rotated integrally, and the position of the stopper surface 56 in the direction of the axis O can be adjusted.
Here, since the flange 65 is slidably engaged with the annular groove 61, the rotation member 62 can only rotate without moving in the axis O direction.

  Further, as shown in FIG. 3, the shaft portion 64 formed at the front end of the rotating member 62 has an axial line O so as to gradually retreat toward the rear end side toward the rear end side on the outer peripheral surface. A rotating member 67 having an inclined groove 66 that is inclined with respect to the rotating member 67 is mounted, and a stop pin 68 is inserted so that the shaft portion 64 and the rotating member 67 rotate together. The inclined groove 66 has a U-shaped cross section, and both ends in the axial direction are wide. In the present embodiment, a plurality of inclined grooves 66 inclined at equal inclination angles are formed on the outer peripheral surface of the rotating member 67 at equal intervals in the circumferential direction.

  The boring bar 20 configured in this manner is attached to the spindle end of a machine tool such as a machining center through the attachment portion 22, is rotated about the axis O, and is sent to the tip side of the tool body 21 along the axis O direction. The second cutting blade 47 is inserted into a prepared hole formed in the workpiece in advance in a state where the second cutting blade 47 is retracted inward in the radial direction of the tool body 21, and is prepared by the first cutting edge 24 provided on the outer periphery of the tool body 21. After finishing the inner wall surface of the tool, the second cutting edge 47 protrudes outward in the radial direction of the tool body 21, and the machining hole is back-bored by the second cutting edge 47 to finish the inner wall surface of the machining hole. is there.

In the boring bar 20, the second cutting edge 47 protrudes and protrudes outward in the radial direction of the tool body 21 as follows.
When the supply amount of the coolant supplied through the coolant hole 32 into the tool body 21 per unit time is increased, the coolant pressure increases, and the second piston 39 is moved to the tip end side of the tool body 21 by the coolant pressure. The first flow path 35 communicates with the coolant and the coolant is supplied to the first space 27 </ b> A of the piston chamber 27 through the first flow path 35. By supplying the coolant to the first space 27A on the rear end side of the tool body 21 with respect to the piston 28, the piston 28 is moved to the tip side of the tool body 21 by the pressure of the coolant, and the second space 27B and the second flow The coolant stored in the passage 36 is discharged to the outside of the tool body 21 through the second coolant escape hole 31.

  As the piston 28 moves, the rod-shaped member 43 is moved toward the distal end side of the tool main body 21, and the distal end portion of the rod-shaped member 43 comes into contact with the stopper surface 56 of the adjustment screw 55. When the rod-shaped member 43 moves to the distal end side of the tool main body 21, the slide member 46 arranged so as to intersect the rod-shaped member 43 is formed with the serration groove 44 </ b> A of the rod-shaped member 43 inclined with respect to the axis O and the slide member 46. The tool body 21 moves in the radial direction along the serration groove 53A, and the second cutting edge 47 provided on the slide member 46 projects outward in the radial direction of the tool body 21.

  On the other hand, when the supply amount of the coolant per unit time is reduced, the coolant pressure is lowered, the second piston 39 is moved to the rear end side of the tool body 21 by the coil spring 40, and the coolant hole 32 and the second flow path 36 communicate with each other. Then, the coolant is supplied to the second space 27 </ b> B of the piston chamber 27 through the second flow path 36. By supplying the coolant to the second space 27B on the tip end side of the tool body 21 relative to the piston 28, the piston 28 is moved to the rear end side of the tool body 21 by the pressure of the coolant, and the first space 27A and the first flow The coolant stored in the passage 35 is discharged to the outside of the tool body 21 through the first coolant hole 30.

  As the piston 28 moves, the rod-shaped member 43 is moved to the rear end side of the tool main body 21, and the slide member 46 arranged so as to intersect the rod-shaped member 43 is connected to the serration groove 44 </ b> A of the rod-shaped member 43 and the slide member 46. The tool body 21 moves in the radial direction along the serration groove 53A, and the second cutting edge 47 provided on the slide member 46 is retracted inward in the radial direction of the tool body 21.

In the boring bar 20, the amount of protrusion when the second cutting edge 47 protrudes radially outward of the tool body 21 is adjusted as follows. By rotating the rotation member 62 provided on the distal end side of the tool body 21 from the distal end side of the tool body 21, the position of the adjustment screw 55 in the axis O direction is adjusted by rotating the adjustment screw 55. Since the movement of the rod-shaped member 43 toward the tip end side of the tool body 21 is restricted to the stopper surface 56 on the rear end face of the adjustment screw 55, the position in the axis O direction when the rod-shaped member 43 is moved toward the tip end side of the tool body 21. Is determined, and the protrusion amount when the second cutting edge 47 protrudes outward in the radial direction of the tool body 21 is adjusted.
In other words, the position when the rod-shaped member 43 is moved to the most distal end side of the tool body is limited by the adjusting screw 55 whose position in the axis O direction is adjusted by the rotating member 62, and accordingly, the movement limit of the slide member 46 is limited. Is determined, and the maximum protrusion amount when the second cutting edge 47 protrudes outward in the radial direction of the tool body 21 is determined.

  Here, in the present embodiment, a rotation member 67 is disposed on the outer periphery of the shaft portion 64 formed at the tip of the rotation member 62, and the rotation member 62 and the rotation member 67 are integrally rotated. Since the pin 68 is inserted and the inclined groove 66 inclined with respect to the axis O is formed on the outer peripheral surface of the rotating member 67, the machine tool is left attached to the machine tool such as a machining center. An engagement pin 70 fixed and installed on the machine table side so as to protrude along a plane perpendicular to the axis O is inserted into the inclined groove 66, and the boring bar is maintained while maintaining the posture of the tool body 21. By moving 20 in the direction of the axis O, the rotation member 62 can be rotated from the distal end side of the tool body 21. The amount of rotation of the rotating member 62 at this time is determined by the inclination angle of the inclined groove 66 and the amount of movement of the boring bar 20 in the axis O direction. Therefore, the position of the adjusting screw 55 in the direction of the axis O can be adjusted, and the amount of protrusion of the second cutting blade 47 outward in the radial direction of the tool body 21 can be corrected with high accuracy.

As described above, the boring bar 20 can correct the position of the second cutting edge 47 that performs finishing while attached to a machine tool such as a machining center, so that the radial position is corrected by the amount of wear of the cutting edge. Therefore, it is possible to prevent dimensional variations in the processed holes.
Further, since the stationary engaging pin 70 is installed on the machine table side and the boring bar 20 is moved in accordance with the engaging pin 70, the rotating member 62 can be rotated, so that the boring by the machining center can be performed. The position of the second cutting edge 47 can be corrected by the operation control of the bar 20. Therefore, it is possible to configure a machining program in which after finishing with the second cutting edge 47, the diameter of the machining hole is measured, the position of the second cutting edge 47 is automatically adjusted, and the next machining is performed, which is formed by the machining center. The dimensional accuracy of the processed hole can be improved.

  In addition, a plurality of inclined grooves 66 inclined at equal inclination angles are formed on the outer peripheral surface of the rotating member 67, and both ends in the axial direction of the inclined grooves 66 are wide. It can be inserted into the inclined groove 66 relatively easily, and the amount of protrusion of the finishing cutting edge can be corrected easily and reliably.

  Further, a serration groove 44A inclined with respect to the axis O is formed on the sliding contact surface 44 of the rod-shaped member 43, and a serration groove 53A is also formed on the sliding contact surface 53 of the slide member 46. The serration grooves 44A and 53A Are disposed so as to be fitted to each other, the rod-shaped member 43 and the slide member 46 are surely slid, and the tool body 21 radial direction of the slide member 46 accompanying the movement of the rod-shaped member 43 in the axis O direction. Is stable, and the second cutting edge 47 can be reliably projected and retracted in the radial direction of the tool body 21.

  Further, since the slide member 46 provided with the second cutting edge 47 and the rod-like member 43 are fitted in the serration grooves 44A and 53A, the cutting resistance at the time of cutting by the second cutting edge 47 is reduced to the serration groove 44A. , 53A can be received by the fitting portion, and the second insert 48, which is the second cutting edge 47, is prevented from moving by cutting resistance, and the processing accuracy can be improved.

  Moreover, since the supply device 33 for supplying the coolant to the coolant hole 32 and the control device 34 for controlling the supply amount of the coolant per unit time are provided, the supply amount of the coolant per unit time can be easily adjusted. Further, the movement of the second piston 39 in the direction of the axis O can be controlled by adjusting the coolant supply amount, and the flow path can be easily switched. Therefore, it is possible to easily control the appearance of the second cutting edge 47 and to make the flow path switching device have a simple structure.

  Moreover, since the tool main body 21 is divided into the first member 21A and the second member 21B, the piston chamber 27, the second piston chamber 37, the first flow path 35, the second flow path 36, etc. are added to the first member 21A. Can be provided relatively easily. Further, when the rotating member 62 is mounted on the distal end side of the second member 21B, the tubular member 59 is disposed after the flange portion 65 of the rotating member 62 is disposed so as to contact the distal end surface of the second member 21B. Is fitted into the annular groove 61, and the rotating member 62 is rotatably arranged. Thus, the boring bar 20 according to the present embodiment can be configured relatively easily, and the manufacturing cost of the boring bar 20 can be reduced.

Further, since the first insert 25 forming the first cutting edge 24 is arranged so as to protrude outward in the radial direction of the tool body 21 as it goes toward the tip end, the boring bar 20 is rotated around the axis O. When cutting the inner wall surface of the pilot hole by sending it to the tip side of the axis O and inserting it into the pilot hole, the first cutting edge 24 is given relief so that the cutting process can be performed smoothly.
Further, since the second insert 48 forming the second cutting edge 47 is arranged so as to protrude outward in the radial direction of the tool body 21 as it goes toward the rear end side, this boring is performed after cutting with the first cutting edge 24. When cutting is performed by sending the bar 20 to the rear end side of the axis O, relief is given to the second cutting edge 47 so that the cutting can be performed smoothly.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, in the present embodiment, it has been described that serration grooves that are inclined with respect to the axis O are formed on the sliding contact surface of the rod-shaped member and the sliding contact surface of the slide member, but the rod-shaped member is a tool along the axis O. What is necessary is just to have a mechanism by which the slide member moves in the direction intersecting the axis O and the second cutting blade protrudes outward in the radial direction of the tool body when moved to the tip side of the body. However, it is preferable to form serration grooves and fit them as in the present embodiment because the above-described effects can be obtained.

In addition, although the second piston is described as the switching device for the flow path from the coolant hole to the first space or the second space, the mechanism is not limited to this and can switch the flow path. What is necessary is just to have. However, it is preferable to adopt a configuration in which the second piston is moved in the direction of the axis O as in the present embodiment, since the flow path switching device can have a simple structure.
In addition, although the description has been given on the case where two first cutting edges are provided on the outer periphery of the tool body, the number of the first cutting edges is not limited, and a second cutting edge (finishing) for finishing work separately from the first cutting edges. Any cutting edge may be used.

It is side surface sectional drawing of the boring bar which is embodiment of this invention. It is XX sectional drawing in FIG. It is a Y direction arrow directional view of the rotation member with which the boring bar shown in FIG. 1 was mounted | worn. It is ZZ sectional drawing in FIG. It is side surface sectional drawing of the conventional boring bar.

Explanation of symbols

20 Boring bar (cutting tool)
21 Tool body 24 First cutting edge (cutting edge)
27 Piston chamber 28 Piston 27A First space 27B Second space 32 Coolant hole (main flow path)
33 Supply device (fluid supply device)
34 control device 35 first flow path 36 second flow path 39 second piston (switching device)
40 Coil spring (biasing member)
43 Rod-shaped member 44A Serration groove (guide part)
46 Slide member 47 Second cutting edge (finishing cutting edge)
53A Serration groove (guided part)
55 Adjustment screw 62 Rotating member (Rotating member)
66 Inclined groove 67 Rotating member 70 Engaging pin

Claims (2)

It has a tool body that rotates around its axis, and a cutting edge is provided on the outer periphery of the tool body, and a finishing cutting edge for finishing is arranged separately from the cutting edge so that it can be projected and retracted in the radial direction of the tool body. A cutting tool,
A piston chamber is formed inside the tool body, and a piston is disposed in the piston chamber so as to be movable in the axial direction. The rear end side of the tool body in the piston chamber is a first space with respect to the piston. , The tool body tip side than the piston is the second space,
The tool body includes a fluid supply device that supplies fluid to the piston chamber, and a switching device that selectively supplies the fluid to the first space or the second space.
A rod-like member is connected to the tip end side of the tool body of the piston, and the rod-like member is arranged at the tip end portion of the tool body so as to intersect the rod-like member. A sliding member that is moved in a direction that intersects the axial direction by moving in the direction is provided, and the finishing cutting edge is provided on the outer peripheral side of the tool body of the sliding member,
An adjustment screw with which the tip surface of the rod-shaped member comes into contact with the rod-shaped member in a state where the rod-shaped member is moved to the tool body leading-end side by the piston is provided on the tip side of the tool body.
The tool body is provided with a rotating member that rotates the adjusting screw to adjust the axial position of the adjusting screw, and the outer periphery of the rotating member is recessed inward in the radial direction. A cutting tool characterized in that an inclined groove inclined with respect to an axis is formed. A method for correcting the amount of protrusion of the finishing cutting blade for adjusting the amount of protrusion of the finishing cutting blade provided in the cutting tool according to claim 1 to the outside in the radial direction of the tool body,
By disposing an engaging pin slidable in the inclined groove and moving the tool body in the axial direction with the engaging pin inserted in the inclined groove, the tool body and the adjustment are moved. A method for correcting a protrusion amount of a finishing cutting blade, wherein the axial position of the adjusting screw is moved by relatively rotating a screw.

Images