JP2006321040A - Cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool of structure that a finish cutting blade can easily appear/disappear in the radial direction of a tool body and that position of the finish cutting blade in the radial direction of the tool body can be corrected in the condition wherein the cutting tool is fitted to a machine tool. <P>SOLUTION: This cutting tool 21 has the finish cutting blade 44 arranged freely to appear/disappear in the radial direction of the tool body 22. A piston 26 is arranged inside the tool body 22 freely to move in the axial direction O, and a rod-like member 41 is connected to the piston 26 on a tip side of the tool body 22. A slide member 43 is arranged to cross the rod-like member 41 and to be moved in a direction crossing the axial direction O with movement of the rod-like member 41 in the axial direction O. The slide member 43 is provided with the finish cutting blade 44, and an adjustment screw 51, on which a tip face of the rod-like member 41 abuts, is provided in the rod-like member 41 on a tip side of the tool body 22. The tip face of the tool body 22 is provided with a turning member 55 for adjusting position of the adjustment screw 51 in the axial direction O. <P>COPYRIGHT: (C)2007,JPO&INPIT

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.

  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. It aims at providing the cutting tool which can correct | amend the position of the tool main body radial direction of a finishing cutting blade in the state still attached to.

  In order to achieve the above object, the present invention includes a tool main body that is rotated around an axis, a cutting blade is provided on the outer periphery of the tool main body, and a finishing cutting blade for finishing work separately from the cutting blade. Is a cutting tool disposed so as to be able to appear and retract in the radial direction of the tool body, and 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 tool body rear end side of the piston chamber is a first space with respect to the piston, and the tool body front end side is a second space with respect to the piston, and fluid is supplied to the piston chamber in the tool body. A fluid supply device to supply, and a switching device for selectively supplying 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, The stick A slide member that is arranged so as to intersect with the rod-shaped member and moves in the direction intersecting the axial direction when the rod-shaped member moves in the axial direction at the tip end portion of the tool body of the member. A state in which the finishing 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. And an adjustment screw with which the tip surface of the rod-shaped member comes into contact is provided, and the tool main body tip surface is rotated to adjust the axial position of the adjustment screw by rotating the adjustment screw. A member is provided.

In the cutting tool having the above-described configuration, the piston chamber is provided with a piston, the tool body rear end side is defined as the first space with respect to the piston, and the tool body front end side is defined as the second space with respect to the piston. The piston can be moved in the tool body axial direction by selectively allowing fluid to flow into the 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.
And since the rotation member which rotates an adjustment screw and adjusts the axial direction position of an adjustment screw is provided in the tool body tip side, in the state where this cutting tool was attached to a machine tool, it is from a tool body tip side. 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.

  Further, when the rotary member is an adjustment nut having a disk-shaped head, the adjustment nut is provided when an automatic adjustment machine having a nut gripping part such as a collet chuck is provided on the machine tool side such as a machining center. Since the adjustment nut can be gripped without rotating the nut gripping part, the amount of rotation of the adjustment nut can be adjusted accurately, and the axial position of the adjustment screw can be adjusted accurately. The amount of protrusion can be adjusted with high accuracy.

  Further, a guide portion that is inclined with respect to the axis line is provided on the tip end side of the tool body of the bar-like member so as to gradually go to the side opposite to the projecting direction of the finishing cutting edge portion toward the tip end side of the tool body, By forming a guided portion to be fitted to the guide portion, the slide member moves in the axial direction so that the slide member is surely crossed with the axis along the guide portion of the rod-shaped member. The finishing cutting edge can be made to appear and disappear in the tool body radial direction.

  In addition, since the guide portion and the guided portion are configured by serration grooves that can be fitted to each other, the rod-like member and the slide member are slidably disposed, and the slide member accompanying the movement of the rod-like member. Is stable, and the finishing cutting edge can be reliably projected and retracted in the radial direction of the tool body.

  Further, a control device that controls a fluid supply amount per unit time of the fluid supply unit is provided, and the switching device performs a switching operation according to the fluid supply amount per unit time of the fluid supply unit. Thereby, the switching operation of the switching device can be performed by controlling the liquid supply amount by the control device, and the finish cutting blade can be easily moved up and down.

  The switching unit includes a main channel connected to the fluid supply unit, a first channel branched from the main channel and connected to the first space, and a second channel connected to the second space. By providing a device at the branching portion and switching and supplying the fluid from the main channel to the first channel and the second channel, the fluid switching operation can be performed with a simple structure. The finishing cutting edge can be easily and reliably raised and lowered.

  In addition, the switching device includes a second piston provided so as to be movable in the axial direction, and an internal flow path is provided in the second piston, and the second piston is disposed on the distal end side of the tool body. The main flow path and the first flow path are connected when moved, and the main flow path and the second flow path pass through the internal flow path when the second piston moves to the rear end side of the tool body. Since the fluid flow path can be switched simply by moving the second piston in the axial direction by adopting the connected configuration, the switching device can be simplified.

  And a biasing member that biases the second piston toward the rear end side of the tool body, the rear end surface of the second piston facing the main flow path, and per unit time from the main flow path. When the second piston moves to the tip end side of the tool body according to the fluid supply amount of the tool and the fluid supply amount per unit time becomes a predetermined value or less, the biasing member causes the second piston to move the tool. With the configuration of moving to the rear end side of the main body, the second piston can be moved in the axial direction depending on the amount of fluid supplied from the fluid supply unit, and the switching device can be further simplified.

  Therefore, according to the present invention, after the inner wall surface of the prepared hole provided in the work material is cut with the cutting blade provided on the outer periphery of the tool body, the finishing cutting blade for finishing is moved radially outward of the tool body. This is a cutting tool that finishes the machined hole by projecting it to the tool body, and can easily make the finish cutting blade appear and disappear in the radial direction of the tool body, and remains attached to a general machine tool such as a machining center. The cutting tool which can correct | amend the position of the tool main body radial direction of a finishing cutting blade in a state can be provided.

A first embodiment 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 the first embodiment of the present invention.
The boring bar 21 has a multi-stage cylindrical tool body 22 extending in the direction of the axis O, and on the rear end side (the upper side in FIGS. 1 and 2) of the tool body 22, the tool body 22 is used as the spindle end of the machine tool. A mounting portion 23 for mounting is provided.
As shown in FIG. 3, the tool body 22 is provided with a first cutting edge 24 protruding outward in the radial direction of the tool body 22, and in this embodiment, two axial lines are provided in the circumferential direction. They are arranged at positions facing each other across O.

A piston chamber 25 having a circular cross section extending along the axis O is provided inside the tool body 22, and a piston 26 that can reciprocate in the direction of the axis O is disposed in the piston chamber 25. An O-ring 27 that is in sliding contact with the side wall of the piston chamber 25 is provided on the outer peripheral surface.
The piston chamber 25 is divided by the piston 26, and the rear end side of the tool body 22 from the piston 26 in the piston chamber 25 is defined as a first space 28, and the tip end side of the tool body 22 from the piston 26 in the piston chamber 25 is a second space. 29. The first space 28 and the second space 29 are blocked by an O-ring 27 provided on the outer peripheral surface of the piston 26.

  A coolant hole 30 extending along the axis O is formed in the tool main body 22, and the rear end side of the tool main body 22 of the coolant hole 30 is opened in the mounting portion 23, and the coolant that supplies the coolant as the fluid in the present embodiment. A supply device 31 and a control device 32 that adjusts the supply amount of coolant per unit time are connected. On the distal end side of the tool body 22 of the coolant hole 30, there are a first flow path 33 that communicates the coolant hole 30 and the first space 28, and a second flow path 34 that communicates the coolant hole 30 and the second space 29. A branching portion that branches off is formed, and a second piston chamber 35 is formed in the branching portion.

The rear end side of the second piston chamber 35 communicates with the coolant hole 30, and the opening 33 </ b> A of the first flow path 33 is formed on the rear end side of the tool body 22 on the side wall surface of the second piston chamber 35. In the side wall surface of the two piston chamber 35, the opening 34 </ b> A of the second flow path 34 is formed on the tip side of the tool body 22 with respect to the opening 33 </ b> A of the first flow path 33.
The second piston 36 is arranged in the second piston chamber 35 so as to be able to reciprocate in the direction of the axis O, and the second piston 36 is directed toward the rear end side of the tool body 22 at the tip end side of the tool body 22 of the second piston 36. A coil spring 38 is disposed as an urging member that urges the arm.
The second piston 36 is provided with an internal flow path 37 that communicates with the coolant hole 30 and opens on the side surface of the second piston 36.

When the second piston 36 moves to the distal end side of the tool body 22, as shown in FIG. 1, the side surface of the second piston 36 closes the opening 34A of the second flow path 34, and the tool body of the second piston 36 The coolant hole 30 and the first flow path 33 communicate with each other through the space on the rear end side.
On the other hand, when the second piston 36 moves to the rear end side of the tool body 22, as shown in FIG. 2, the side surface of the second piston 36 closes the opening 33 </ b> A of the first flow path 33, and the second piston 36. The coolant hole 30 and the second flow path 34 are communicated with each other through the internal flow path 37.
As described above, the coolant flow path can be switched by the reciprocating movement of the second piston 36.

  In addition, a housing hole 39 having a circular cross section that extends along the axis O and communicates with the piston chamber 25 is formed on the distal end side of the tool body 22 of the piston chamber 25, and the tool of the piston 26 is formed in the housing hole 39. A rod-shaped member 41 that is integrally formed on the distal end side of the main body 22 and has a circular cross section disposed along the axis O is liquid-tightly inserted. The tip side of the tool body 22 of the rod-shaped member 41 is cut out so that a cross section perpendicular to the axis O forms a substantially semicircular shape, and a slidable contact surface 42 extending along the axis O is formed. As shown in FIG. 3, the sliding contact surface 42 is disposed so as to be perpendicular to a straight line passing through the axis O and connecting the two first cutting edges 24.

  A slide hole 40 extending in a radial direction perpendicular to a straight line passing through the axis O and connecting the two first cutting edges 24 passes through a portion of the tool body 22 where the sliding contact surface 42 is formed. A slide member 43 slidable in the radial direction is arranged in the slide hole 40 so as to intersect the rod-shaped member 41. At the outer peripheral end of the slide member 43 with respect to the tool main body 22, an insert having a cutting edge is provided as a second cutting edge 44 for finishing. As shown in FIG. The first cutting edge 24 is disposed at a position of 90 °.

  The tool body 22 includes a first coolant supply path (not shown) extending from the second space 29 and the second flow path 34 of the piston chamber 25 toward the first cutting edge 24, and a first of the piston chamber 25. A second coolant supply path (not shown) extending from the space 28 and the first flow path 33 toward the second cutting edge 44 is provided. Here, since the cross-sectional areas of the first coolant supply path and the second coolant supply path are very small compared to the cross-sectional areas of the first flow path 33 and the second flow path 34, the coolant is moved by the movement of the piston 26. The coolant flows only when the pressure increases.

  A concave portion 45 is formed at the center of the slide member 43 so that the tip end side of the rod-like member 41 is inserted, and the bottom surface of the concave portion 45 is a sliding contact surface 46. On the sliding contact surface 42 of the rod-shaped member 41, a serration groove 42A inclined with respect to the axis O is formed so as to gradually approach the second cutting edge 44 toward the rear end side of the tool body 22. Further, the sliding contact surface 46 of the slide member 43 is formed with a serration groove 46A that can be fitted into the serration groove 42A provided in the rod-like member 41. As shown in FIG. The serration groove 42A and the serration groove 46A of the slidable contact surface 46 are slidably contacted.

On the distal end side of the tool body 22 further than the slide hole 40 of the accommodation hole 39 in which the rod-shaped member 41 is accommodated, a screw hole portion 47 having a circular cross section that communicates with the accommodation hole 39 and has an internal thread formed on the inner wall surface is formed. An adjustment screw 51 is screwed into the screw hole 47.
The adjustment screw 51 includes a screw main body 52 having a male screw formed on the outer peripheral surface thereof, and a square prism shape protruding from the screw main body 52 toward the distal end side of the tool main body 22 (in this embodiment, as shown in FIG. 4, a square pillar shape). ), And the rear end surface of the tool body 22 of the screw body 52 is a stopper surface 54 that comes into contact with the front end surface of the rod-shaped member 41. The stopper surface 54 is formed in a planar shape perpendicular to the axis O.

An adjustment nut 55 is rotatably disposed on the tip side of the tool body 22 of the adjustment screw 51, and the disk-shaped head portion 56 of the adjustment nut 55 is exposed so as to protrude from the tip surface of the tool body 22. Yes. Further, a concave groove 57 having a U-shaped cross section is formed in the portion of the adjustment nut 55 on the rear end side of the tool body 22 as shown in FIG. By inserting the shaft portion 53 of the adjustment screw 51, the adjustment nut 55 and the adjustment screw 51 can be rotated together, and the position of the stopper surface 54 in the direction of the axis O can be adjusted.
Here, an annular groove 48 that is recessed toward the outer peripheral side is formed on the distal end side of the tool body 22 of the screw hole portion 47, and a flange portion 58 provided on the rear end side of the adjustment nut 55 slides on the annular groove 48. By being engaged so as to be movable, the adjustment nut 55 can only be rotated without moving in the direction of the axis O. Further, an O-ring is fitted on the distal end side of the flange portion 58 and is sealed so that the coolant does not leak from between the outer peripheral surface of the adjustment nut 55 and the tool body 22.

  The boring bar 21 configured in this manner is attached to the spindle end of a machine tool such as a machining center through the attachment portion 23, rotated around the axis O, and sent to the tip side of the tool body 22 along the axis O direction. The second cutting edge 44 is inserted into a prepared hole formed in advance in the work material in a state where the second cutting edge 44 is retracted inward in the radial direction of the tool body 22, and is prepared by the first cutting edge 24 provided on the outer periphery of the tool body 22. After finishing the inner wall surface of the tool, the second cutting edge 44 is projected outward in the radial direction of the tool body 22, and the machining hole is back-bored by the second cutting edge 44 to finish the inner wall surface of the machining hole. is there.

In the boring bar 21, the second cutting blade 44 protrudes and protrudes outward in the radial direction of the tool body 22 as follows.
When the supply amount of the coolant supplied to the tool body 22 through the coolant hole 30 per unit time is increased, the coolant pressure increases and the second piston 36 is moved to the tip end side of the tool body 22 by the coolant pressure. The first flow path 33 communicates with the coolant and the coolant is supplied to the first space 28 of the piston chamber 25 through the first flow path 33. By supplying the coolant to the first space 28 on the rear end side of the tool body 22 relative to the piston 26, the piston 26 is moved to the tip side of the tool body 22 by the pressure of the coolant, and the second space 29 and the second flow are supplied. The coolant stored in the path 34 is supplied toward the first cutting edge 24 through the first coolant supply path extending from the second space 29 and the second flow path 34.

  As the piston 26 moves, the rod-shaped member 41 is moved toward the distal end side of the tool body 22, and the distal end portion of the rod-shaped member 41 is brought into contact with the stopper surface 54 of the adjustment screw 51. When the rod-shaped member 41 moves to the tip end side of the tool main body 22, the slide member 43 arranged so as to intersect the rod-shaped member 41 has the serration groove 42 </ b> A of the rod-shaped member 41 inclined with respect to the axis O and the slide member 43. The tool body 22 moves in the radial direction along the serration groove 46 </ b> A, and the second cutting edge 44 provided on the slide member 43 protrudes outward in the radial direction of the tool body 22.

  On the other hand, when the supply amount of the coolant per unit time is reduced, the coolant pressure is lowered, the second piston 36 is moved to the rear end side of the tool body 22 by the coil spring 38, and the coolant hole 30 and the second flow path 34 communicate with each other. Then, the coolant is supplied to the second space 29 of the piston chamber 25 through the second flow path 34. When the coolant is supplied to the second space 29 on the tip side of the tool body 22 relative to the piston 26, the piston 26 is moved to the rear end side of the tool body 22 by the pressure of the coolant, and the first space 28 and the first flow are supplied. The coolant stored in the path 33 is supplied toward the second cutting edge 44 through the second coolant supply path extending from the first space 28 and the first flow path 33.

  As the piston 26 moves, the rod-shaped member 41 is moved to the rear end side of the tool main body 22, and the slide member 43 arranged so as to intersect the rod-shaped member 41 is connected to the serration groove 42 </ b> A of the rod-shaped member 41 and the slide member 43. The tool body 22 moves in the radial direction along the serration groove 46 </ b> A, and the second cutting edge 44 provided in the slide member 43 is retracted inward in the tool body 22 radial direction.

  In the boring bar 21, the amount of protrusion when the second cutting edge 44 protrudes outward in the radial direction of the tool body 22 is adjusted as follows. By rotating the adjustment nut 55 provided on the distal end side of the tool body 22 from the distal end side of the tool body 22, the position of the adjustment screw 51 in the axis O direction can be adjusted by rotating the adjustment screw 51. Since the movement of the rod-shaped member 41 toward the distal end side of the tool body 22 is restricted to the stopper surface 54 on the rear end surface of the adjustment screw 51, the position in the axis O direction when the rod-shaped member 41 is moved toward the distal end side of the tool body 22 Is determined, and the protrusion amount when the second cutting edge 44 protrudes radially outward of the tool body 22 is adjusted.

  Here, as described above, the slide member 43 is moved along the serration grooves 42 </ b> A and 46 </ b> A inclined with respect to the axis O when the rod-like member 41 is moved toward the distal end side of the tool body 22. Since the two cutting blades 44 protrude outward in the radial direction of the tool main body 22, the slide member 43 is limited by limiting the most advanced position of the bar-shaped member 41 in a state where the bar-shaped member 41 is moved to the distal end side of the tool main body 22. Therefore, the maximum protrusion amount when the second cutting blade 44 protrudes outward in the radial direction of the tool body 22 is determined.

  In the boring bar 21 configured as described above, the adjustment screw 51 is provided on the distal end side of the tool main body 22 of the rod-shaped member 41, and when the rod-shaped member 41 is moved to the distal end side of the tool main body 22, the distal end surface of the rod-shaped member 41 is the adjustment screw. 51, the position in the direction of the axis O when the rod-shaped member 41 is moved to the distal end side of the tool body 22 is positioned by the adjusting screw 51, and the slide member 43 accompanying the movement of the rod-shaped member 41 is provided. Thus, it is possible to stably determine the amount of protrusion of the second cutting edge 44 that performs finishing to the outside of the tool body 22 in the radial direction.

  Further, an adjustment nut 55 is provided on the tip surface of the tool body 22 to rotate the adjustment screw 51 to adjust the position of the adjustment screw 51 in the direction of the axis O, so that the boring bar 21 is attached to a machine tool such as a machining center. In this state, the adjustment nut 55 can be rotated from the distal end side of the tool body 22 to adjust the position of the adjustment screw 51 in the axis O direction, and the amount of protrusion of the second cutting blade 44 outward in the radial direction of the tool body 22 can be corrected. it can. Here, since the adjustment nut 55 has a disk-shaped head portion 56, when an automatic adjustment machine having a nut gripping portion such as a collet chuck is provided on the machine tool side such as a machining center, the adjustment nut 55 and the nut gripping The adjustment nut 55 can be gripped without rotating the part, and the amount of rotation of the adjustment nut 55 can be controlled with high accuracy, so that the position of the adjustment screw 51 in the direction of the axis O can be adjusted with high accuracy. Therefore, the protrusion amount of the second cutting edge 44 to the outside in the radial direction of the tool body 22 can be corrected with high accuracy.

In this way, in this boring bar 21, the position of the second cutting edge 44 that performs the finishing process while attached to the machine tool can be corrected. Therefore, by correcting the radial position as much as the cutting blade is worn, Dimensional variation can be prevented.
In addition, the machining center is provided with an adjustment mechanism for the second cutting edge 44, so that after finishing with the second cutting edge 44, the diameter of the machining hole is measured to adjust the position of the second cutting edge 44, and the next machining is performed. Therefore, it is possible to improve the dimensional accuracy of the machining hole formed by the machining center.

  Further, the piston chamber 25 is provided with a piston 26, the rear end side of the tool body 22 with respect to the piston 26 is a first space 28, and the front end side of the tool body 22 with respect to the piston 26 is a second space 29. The piston 26 can be moved in the direction of the axis O of the tool body 22 by selectively allowing fluid to flow into the first space 28 and the second space 29. A rod-like member 41 is connected to the tip end side of the tool body 22 of the piston 26, and the rod-like member 41 is also moved in the direction of the axis O of the tool body 22 as the piston 26 moves. At the tip end portion of the rod-shaped member 41, a slide member 43 provided with a second cutting edge 44 is provided, as the rod-shaped member 41 moves in the direction of the axis O and is moved in a direction crossing the axis O. Therefore, the 2nd cutting blade 44 can be made to appear in the tool body 22 radial direction outer side by moving the rod-shaped member 41 to the axis line O direction.

  Further, a serration groove 42A inclined with respect to the axis O is formed on the sliding contact surface 42 of the rod-shaped member 41, and a serration groove 46A is formed on the sliding contact surface 46 of the slide member 43, and the serration grooves 42A, 46A are connected to each other. Since the rod-shaped member 41 and the slide member 43 are securely slid and arranged so as to be fitted to each other, the slide member 43 moves in the radial direction of the tool body 22 along with the movement of the rod-shaped member 41 in the axis O direction. The movement is stable, and the second cutting edge 44 can be reliably projected and retracted in the radial direction of the tool body 22.

  Further, since the slide member 43 provided with the second cutting edge 44 and the rod-like member 41 are fitted in the serration grooves 42A, 46A, the cutting resistance at the time of cutting by the second cutting edge 44 is reduced to the serration groove 42A. , 46 </ b> A can be received by the fitting portion, and the insert made as the second cutting edge 44 is prevented from moving by the cutting resistance, and the processing accuracy can be improved.

  Moreover, since the supply device 31 for supplying the coolant to the coolant hole 30 and the control device 32 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. By adjusting the coolant supply amount, the movement of the second piston 36 in the direction of the axis O can be controlled, and the flow path can be easily switched. Therefore, the second cutting blade 44 can be easily moved in and out, and the flow path switching device can have a simple structure.

Next, a second embodiment of the present invention will be described. 5 and 6 show a boring bar as a cutting tool according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same member as 1st Embodiment, and description is abbreviate | omitted.
In the boring bar 21 according to the second embodiment, the tool body 22 includes a first member 22A located on the rear end side (upper side in FIG. 5) and a second member located on the front end side (lower side in FIG. 5). 22B, and these are joined by a plurality of joining bolts 61.

In the first member 22A, a piston chamber 25 is formed so as to open greatly toward the front end side of the first member 22A, and a second piston chamber 35 is formed in the rear end surface of the piston chamber 25. . A second piston 36 is fitted in the second piston chamber 35, and a coil spring 38 and a receiving member 62 that accommodates the coil spring 38 are screwed onto the tip end side (lower side in FIG. 5) of the second piston 36. Has been.
A first flow path 33 and a first hole 63 are formed in the rear end portion of the piston chamber 25, and a second flow path 34 and a second hole 64 are formed in the front end portion. .

On the rear end side of the second member 22B, a convex portion 65 that can be fitted into an opening of the piston chamber 25 provided in the first member 22A is formed.
The second member 22 </ b> B is formed with a through-hole 66 that accommodates the rod-shaped member 41, a screw hole portion 47 is formed at the distal end side of the through-hole 66, and the adjustment screw 51 is connected to the screw hole portion 47. It is screwed. A chamfered portion 67 is provided on the tip side of the adjustment screw 51.

Further, a male screw portion 68 is formed on the distal end side of the second member 22B, and a tubular member 69 is screwed to the male screw portion 68. A protruding portion 70 protruding radially inward is formed on the distal end side of the cylindrical member 69, and an annular groove 48 is formed by the protruding portion 70 and the distal end surface of the second member 22B.
In addition, an adjustment nut 55 is rotatably disposed on the front end side of the cylindrical member 69, and a collar portion 58 provided on the rear end side of the adjustment nut 55 is slidably engaged with the annular groove 48. The disc-shaped head portion 56 of the adjustment nut 55 is exposed so as to protrude from the tip end surface of the cylindrical member 69. Further, a concave groove that can be engaged with a chamfered portion 67 formed on the adjustment screw 51 is formed on the rear end side of the adjustment nut 55, and the adjustment nut 55 and the adjustment screw 51 can be rotated together. Has been.

A first insert 71 is mounted on the outer periphery of the second member 22B as the first cutting blade 24. The first insert 71 is a so-called vertical blade insert, and the tool body 22 is moved toward the tip side. It arrange | positions so that it may protrude on a radial direction outer side.
Further, the slide member 43 is provided with a second insert 72 as the second cutting edge 44, and the second insert 72 projects outward in the radial direction of the tool body 22 toward the rear end side. Has been placed.

  Further, an adjustment piece 73 for adjusting a protruding amount of the second insert 72 to the outer side in the radial direction is arranged on the inner side in the radial direction of the second insert 72. The adjustment piece 73 is formed with a slit, and a pressing screw 74 is screwed so as to spread the slit.

  In the boring bar 21 configured as described above, the tool main body 22 is divided into the first member 22A and the second member 22B. Therefore, the piston chamber 25, the second piston chamber, the first flow path 33, the first member 22A are included in the first member 22A. The two flow paths 34 and the like can be provided relatively easily. When the adjustment nut 51 is mounted on the distal end side of the second member 22B, the tubular member 69 is fitted after the flange portion 58 of the adjustment nut 51 is disposed so as to contact the distal end surface of the second member 22B. As a result, the flange 58 is engaged with the annular groove 48, and the adjustment nut 51 is rotatably arranged. Thus, the boring bar 21 can be configured relatively easily, and the manufacturing cost of the boring bar 21 can be reduced.

Further, since the first insert 71 forming the first cutting edge 24 is arranged so as to protrude outward in the radial direction of the tool main body 22 as it goes toward the distal end side, the boring bar 21 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 72 forming the second cutting edge 44 is arranged so as to protrude outward in the radial direction of the tool body 22 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 21 to the rear end side of the axis O, relief is given to the second cutting edge 44 so that the cutting can be performed smoothly.

  In the present embodiment, the serration grooves 42A and 46A inclined with respect to the axis O are formed on the sliding contact surface 42 of the rod-shaped member 41 and the sliding contact surface 46 of the slide member 43. When 41 moves to the tool main body 22 front end side along the axis O, the slide member 43 moves to the direction which cross | intersects the axis O, and the 2nd cutting blade 44 protrudes the tool main body 22 radial direction outer side. What is necessary is just to have. However, it is preferable that the serration grooves 42A and 46A are formed and fitted as in this embodiment because the above-described effects can be obtained.

In addition, the second piston 36 is described as the switching device for the flow paths 33 and 34 from the coolant hole to the first space 28 or the second space 29, but the present invention is not limited to this, and the flow path switching is not limited thereto. What is necessary is just to have the mechanism which can perform. However, it is preferable to adopt a configuration in which the second piston 36 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.

In the boring bar which is 1st Embodiment, it is side surface sectional drawing of the state which protruded the 2nd cutting blade (finishing cutting blade) to the tool main body radial direction outer side. In the boring bar of FIG. 1, it is side sectional drawing of the state which retracted the 2nd cutting blade (finishing cutting blade) to the tool main body radial direction inner side. It is XX sectional drawing in FIG. It is YY sectional drawing in FIG. In the boring bar which is 2nd Embodiment, it is side surface sectional drawing of the state which protruded the 2nd cutting blade (finishing cutting blade) to the tool main body radial direction outer side. It is ZZ sectional drawing in FIG. It is side surface sectional drawing of the conventional boring bar.

Explanation of symbols

21 Boring bar (cutting tool)
22 Tool body 24 First cutting edge (cutting edge)
25 Piston chamber 26 Piston 28 First space 29 Second space 30 Coolant hole (main flow path)
31 Supply device (fluid supply device)
32 control device 33 first flow path 34 second flow path 35 second piston (switching device)
38 Coil spring (biasing member)
41 Rod-shaped member 42A Serration groove (guide part)
43 Slide member 46A Serration groove (guided part)
44 2nd cutting edge (finishing cutting edge)
51 Adjustment screw 55 Adjustment nut (rotating member)
56 heads

Claims (8)

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 slide member that is moved in a direction that intersects the axial direction by moving in the direction is provided, and the finish cutting blade is provided on the outer peripheral side of the tool body of the slide 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.
A cutting tool characterized in that a turning member for turning the adjustment screw to adjust the position in the axial direction of the adjustment screw is provided on the tip surface of the tool body.   The cutting tool according to claim 1, wherein the rotating member is an adjustment nut having a disk-shaped head.   A guide portion that is inclined with respect to the axis line is provided on the tip side of the tool body of the rod-shaped member so as to gradually go to the side opposite to the protruding direction of the finishing cutting edge portion as it goes to the tip side of the tool body. The cutting tool according to claim 1, wherein a guided portion that is fitted to the guide portion is formed on the slide member.   The cutting tool according to claim 3, wherein the guide portion and the guided portion are formed of serration grooves that can be fitted to each other.   A control device that controls a fluid supply amount per unit time of the fluid supply unit is provided, and the switching device performs a switching operation according to the fluid supply amount per unit time of the fluid supply unit. The cutting tool according to any one of claims 1 to 4. A main channel connected to the fluid supply unit; a first channel branched from the main channel and connected to the first space; and a second channel connected to the second space;
6. The switching device according to claim 1, wherein the switching device is provided in the branch portion and supplies the fluid from the main flow channel to the first flow channel and the second flow channel in a switched manner. The cutting tool in any one. The switching device includes a second piston provided to be movable in the axial direction, and an internal flow path is provided in the second piston.
The main flow path and the first flow path are connected when the second piston moves to the tool body front end side, and the main flow path and the first flow path when the second piston moves to the tool body rear end side. The cutting tool according to claim 6, wherein the second flow path is connected through the internal flow path. An urging member that urges the second piston toward the rear end side of the tool body, and a rear end surface of the second piston faces the main flow path;
The biasing member when the second piston moves to the tip end side of the tool body according to the fluid supply amount per unit time from the main flow path and the fluid supply amount per unit time becomes a predetermined value or less. The cutting tool according to claim 7, wherein the second piston moves toward the rear end side of the tool body.

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