JP2015213968A - Play regulation mechanism for drilling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly perform play regulation of a drilling tool in a simplified manner.SOLUTION: A play regulation mechanism is for a shaft-shaped drilling tool 11 inserted and mounted into a mounting hole 2, the mounting hole 2 being formed along an axis O at the tip of a tool body 1 which is rotated about the axis O. The drilling tool 11 has an annular regulation member 21 fitted thereto rotatably around the axis O so that the annular member 21 contacts a tip end surface 1A of the tool body 1 around the opening of the mounting hole 2, where regulation screws 22 are screwed into the regulation member 21 in a radial direction relative to the axis O in such a manner as to be contactable to an outer peripheral surface of the drilling tool 11.

Description

  The present invention relates to a runout adjustment mechanism for a drilling tool that adjusts radial runout of a drilling tool such as a reamer attached to a tool body rotated around an axis with respect to the axis.

  As a cutting tool provided with such a deflection adjustment mechanism, for example, in Patent Document 1, a valve hole in a cylinder head of an engine is finished and an opening (valve seat) of the valve hole is processed into a predetermined shape. As an object, a hole machining tool such as a reamer for machining the valve hole is mounted on the mounting hole formed along the axis from the tip surface of the tool body rotated about the axis, and the tip of the tool body An outer peripheral portion is disclosed which is provided with a cutting blade for processing the opening.

  Here, in the cutting tool described in Patent Document 1, a collet chuck for holding the hole machining tool is provided on the rear end side of the mounting hole of the tool body, and the deflection adjusting mechanism described in Patent Document 1 is The hole drilling tool held in this way is adjusted for runout by a plurality of adjustment screws that are arranged at equal intervals in the circumferential direction on a plane orthogonal to the axis and screwed so as to protrude into the mounting hole of the tool body. ing.

  In such a run-out adjusting mechanism, by adjusting the screwing amount of the plurality of adjusting screws screwed so as to protrude into the mounting hole, the hole machining tool is pressed to the side opposite to the direction in which the run-out occurs, Adjust the runout in the radial direction of the drilling tool so that the drilling blade formed at the tip of this drilling tool is positioned on the axis of the tool body, and adjust the valve hole to a predetermined inner diameter along this axis. In addition, the opening can be precisely coaxially processed with the valve hole by the cutting blade.

JP 2008-049434 A

  However, in such a deflection adjusting mechanism described in Patent Document 1, in particular, the radial deflection of the drilling tool is intermediate between the positions where a plurality of adjustment screws are screwed in the circumferential direction on a plane perpendicular to the axis. If this occurs at the position, the drilling cutting edge at the tip of the drilling tool must be accurately positioned on the axis of the tool body unless the two drilling screws sandwiching the intermediate position are screwed in a well-balanced manner to press the drilling tool. Can not be located in. As a result, skill is required for shake adjustment and a lot of time is spent.

  The present invention has been made under such a background, and it is an object of the present invention to provide a drilling adjustment mechanism for a drilling tool that can easily and quickly adjust the runout of such a drilling tool. Yes.

  In order to solve the above problems and achieve such an object, according to the present invention, a mounting hole is formed along the axis at the tip of the tool body rotated around the axis, and is inserted into the mounting hole. A shaft-shaped hole machining tool run-out adjustment mechanism, wherein an annular or cylindrical adjustment member is rotatably fitted around the axis so as to open the mounting hole. An adjustment screw is screwed into the adjustment member so as to be able to contact the outer peripheral surface of the drilling tool in the radial direction with respect to the axis. Features.

  In order to perform radial runout adjustment of the drilling tool with respect to the above-mentioned axis by such runout adjustment mechanism, first, the runout in the radial direction is measured in a state where the drilling tool is inserted into the mounting hole and attached to the tool body. Next, the adjustment member is inserted into the drilling tool and brought into contact with the tip of the tool body around the opening of the mounting hole, and the adjustment screw is positioned at a position where the radial deflection has occurred in the drilling tool. Tighten temporarily. When the adjustment screw is further screwed in from this state, the drilling tool is pressed and slightly bent while the adjustment member is supported by friction caused by contact with the tool body tip surface, and the hole at the tip of the hole machining tool is bent. The runout is adjusted so that the working cutting edge is positioned on the axis of the tool body.

  As described above, according to the deflection adjusting mechanism for a hole drilling tool having the above-described configuration, the adjustment member into which the adjustment screw is screwed is separated from the tool main body, and can be rotated around the axis of the tool main body. Since it is inserted and inserted, the position of the adjusting screw can be adjusted to the position where the hole machining tool has been shaken. For this reason, without adjusting the two adjustment screws in a well-balanced manner as in the prior art, only the adjustment screw that matches the position of the runout is screwed in so that it can be easily done in a short time without requiring skill. It is possible to adjust the runout of the drilling tool.

  Here, in order to reliably adjust the runout of the drilling tool by screwing in the adjusting screw while stably supporting the adjusting member by friction caused by contact with the tip surface of the tool body as described above, the adjusting screw It is desirable that the center line is positioned in the range of 1/2 or more of the length of the adjustment member in the central axis direction on the tip side of the tool body. By setting the position of the center line of the adjustment screw in this way, when the adjustment screw at the position where radial runout occurs is screwed in, the adjustment member strongly presses against the tool body tip surface due to slight deflection of the drilling tool. As a result, the frictional force can be increased to stably support the adjustment member and to perform accurate shake adjustment.

  In addition, the adjustment member includes an adjustment screw that receives the pressing force of the adjustment screw on the side opposite to the adjustment screw that presses and slightly deflects the hole drilling tool by screwing as described above, and further the vibration of the hole drilling tool. It is desirable to provide an adjustment screw that limits the deflection of the drilling tool in the radial direction perpendicular to the direction. For this reason, it is desirable that three or four adjustment screws are screwed into the adjustment member at equal intervals in the circumferential direction.

  When there are three adjustment screws, one adjustment screw adjusts the radial runout and the remaining two center lines are arranged so that the center line of the adjustment screw is a bisector. The adjustment screw can limit the bending in the direction orthogonal to the receiving of the pressing force and the direction of deflection. When there are four adjustment screws, the adjustment screw facing the adjustment screw that adjusts the shake receives a pressing force, and the remaining two adjustment screws limit the deflection in the direction perpendicular to the direction of the shake. be able to.

  As described above, according to the present invention, it is possible to easily adjust the deflection of the drilling tool in a short time without requiring skill.

It is a sectional side view which shows the front-end | tip part of the cutting tool provided with the run-out adjustment mechanism of the drilling tool of one Embodiment of this invention. It is a partially broken front view of the adjustment member used for the shake adjustment mechanism of embodiment shown in FIG. It is ZZ sectional drawing in FIG.

  FIG. 1 shows a tip portion of a cutting tool provided with a deflection adjusting mechanism for a hole machining tool according to one embodiment of the present invention. FIGS. 2 and 3 show adjustments used in the deflection adjusting mechanism of this embodiment. The member is shown. The cutting tool provided with the runout adjustment mechanism of the present embodiment finishes the valve hole in the cylinder head of the engine to a predetermined inner diameter with a hole machining tool, as with the cutting tool described in Patent Document 1, and this valve The opening of the hole is cut coaxially.

  The tool body 1 of the cutting tool has a substantially cylindrical shape with an axis O as the center, and a rear end (not shown) (right side in FIG. 1) is gripped by the spindle of the machine tool and rotates around the axis O. While being driven, the valve hole and its opening are cut by being sent to the front end side in the axis O direction (left side in FIG. 1). At the tip of the tool body 1, a mounting hole 2 having a circular cross section to which the drilling tool is attached is formed so as to open along the axis O to the tip surface 1 </ b> A of the tool body 1. The tip surface 1A is formed as an annular flat surface located on a plane perpendicular to the axis O.

  In the present embodiment, a plurality of (for example, three) cartridges 4 each having a cutting edge 3 for cutting the opening of the valve hole are attached to the outer periphery of the tip of the tool body 1 at intervals in the circumferential direction. . These cartridges 4 are formed in a prismatic shape having a longitudinal direction in a direction parallel to the axis O, and a cutting edge tip 3A is attached to the tip of the cartridge 4, and the cutting edge 3 is formed on the cutting edge tip 3A. Has been.

  Here, the cutting blades 3 provided in the plurality of cartridges 4 are inclined with respect to the axis O so as to go to the outer peripheral side toward the rear end side of the tool body 1, but the inclination angle with respect to the axis O Are different in size from each other, and the rotation trajectories around the axis O are overlapped so as to be positioned from the inner peripheral side of the front end to the outer peripheral side of the rear end of the tool main body 1 in order of increasing inclination angle. Therefore, a multi-step taper surface in which the inclination with respect to the axis O increases from the inner peripheral side toward the outer peripheral side is formed by the cutting blades 3 at the opening of the valve hole.

  These cartridges 4 are attached to the tool body 1 so that they can be slightly advanced and retracted in the direction of the axis O by a clamp screw 5 inserted into a long hole formed in the cartridge 4 extending in the direction of the axis O and screwed into the tool body 1. It is attached. In addition, an inclined surface 4 </ b> A is formed on the rear end surface of the cartridge 4 so as to be inclined slightly toward the front end side toward the outer peripheral side of the tool body 1.

  On the other hand, a wedge member 6 having a wedge surface 6A that is similarly inclined on the rear end side of the cartridge 4 is attached to the tool body 1 by attachment screws 7 having screw portions at both ends. Accordingly, the wedge surface 6A and the inclined surface 4A are brought into contact with each other, and the wedge member 6 is pushed into the inner peripheral side of the tool body 1 by the mounting screw 7, whereby the cartridge 4 is advanced and the cutting blade 3 is positioned in the direction of the axis O. Can be fine-tuned.

  In this embodiment, the hole machining tool attached to the attachment hole 2 is a reamer, and includes a multi-stage cylindrical shaft-like reamer body 11 that gradually increases in diameter from the front end toward the rear end. The rear end portion of the reamer body 11 having a large diameter is a shank portion 12, and the shank portion 12 is inserted into the mounting hole 2, and is formed on the inner wall surface of the mounting hole 2 in the radial direction with respect to the axis O by, for example, a clamp screw (not shown). By being pressed and fixed, the reamer is attached to the tool body 1 with its central axis along the axis O. Note that the tip of the shank portion 12 thus fixed protrudes from the tip surface 1A of the tool body 1.

  The most advanced small-diameter portion of the reamer body 11 is a pilot portion 13, and the outer periphery of the reamer body 11 from the pilot portion 13 to the medium-diameter cutting blade portion 14 between the shank portion 12 is A chip discharge groove 15 extending in parallel to the central axis direction (axis O direction) of the reamer body 11 is formed so as to cut out the reamer body 11 in an L shape in a cross section orthogonal to the central axis. Further, on the wall surface of the chip discharge groove 15 facing the rotation direction of the tool body 1 at the time of drilling, a drilling cutting edge tip 16A in which a drilling cutting edge 16 is formed is disposed.

  As shown in FIGS. 2 and 3, the runout adjustment mechanism of the present embodiment for adjusting the runout of the drilling tool (reamer) attached in this manner is provided with an annular or tubular adjustment member 21 and the adjustment member 21. And an adjusting screw 22 to be screwed in. The adjusting member 21 of the present embodiment has an annular shape or a cylindrical shape with the central axis C as the center, and the inner diameter of the adjusting member 21 is such that the shank portion 12 of the reamer body 11 is rotatably inserted. The outer diameter is slightly larger than the diameter, and the outer diameter is substantially equal to or slightly smaller than the outer diameter of the ring formed by the front end surface 1A of the tool body 1.

  Further, the adjustment member 21 is formed in a rectangular shape having a longitudinal section in the direction of the central axis C as shown in FIG. An adjustment screw hole 21A is formed in the adjustment member 21 so as to penetrate in the radial direction with respect to the central axis C, and the adjustment screw 22 is screwed into the adjustment screw hole 21A. Therefore, the adjustment screw 22 is screwed in the radial direction with respect to the axis O in a state where the adjustment member 21 is fitted into the shank portion 12 of the drilling tool (reamer) attached to the tool body 1 as described above. Become.

  Furthermore, in the present embodiment, the adjustment screw hole 21A has a center line orthogonal to the central axis C of the adjustment member 21, and the adjustment member 21 is inserted into the reamer main body 11 as described above. As shown in FIG. 2, the range from the end surface 21B to the front end side is at least ½ of the length L in the central axis C direction of the adjustment member 21 from the end surface 21B facing the rear end side to the end surface 21C facing the front end side. It is formed so that it may be located in. Accordingly, the center line of the adjustment screw 22 is also located on the tip side of the adjustment member 21 from the end face 21B of the adjustment member 21 at least ½ of the length L.

  Further, in the present embodiment, as shown in FIG. 2, four adjustment screw holes 21 </ b> A having the same diameter in the adjustment member 21 are equally spaced in the circumferential direction, and the center line thereof is orthogonal to the central axis C of the adjustment member 21. The adjusting screws 22 are respectively screwed into the adjusting screw holes 21A. Accordingly, these adjustment screws 22 are similarly screwed into the adjustment member 21 at equal intervals in the circumferential direction, and the respective center lines are located on the one plane.

  The adjustment screw 22 is a so-called potato screw with no head formed. The tip of the adjustment member 21 directed toward the inner peripheral side is a flat surface perpendicular to the center line. Engagement portions such as a slot and a wrench hole are formed at the rear end portion directed toward the outer peripheral side to engage with the work tool that rotates the adjustment screw 22. The four adjustment screws 22 screwed into the four adjustment screw holes 21A have the same length.

  Here, the shank portion 12 of the drilling tool (reamer) inserted into the mounting hole 2 formed in the tool body 1 is inserted into the mounting hole 2 in the radial direction with respect to the axis O of the tool body 1 by the clamp screw as described above. When the reamer is attached to the tool body 1 by being pressed against the wall surface, it is inevitable that the center line of the reamer body 11 is slightly decentered from the axis O to cause radial deflection. Such a runout in the radial direction of the drilling tool impairs the finishing accuracy of the valve hole to be machined.

  Therefore, in order to adjust the radial runout of such a drilling tool by the runout adjustment mechanism having the above-described configuration, first, the drilling tool is attached to the tool body 1 as described above without attaching the adjustment member 21. The runout of the drilling tool is measured, and the position where the runout in the radial direction occurs (the position in the circumferential direction where the eccentricity from the axis O is the largest) is specified. Next, in this embodiment of the drilling tool, the adjustment member 21 is fitted and inserted into the shank portion 12 of the reamer main body 11 so that the end surface 21B abuts the front end surface 1A of the peripheral edge of the attachment hole 2 of the tool main body 1 and the adjustment member. 21 is rotated around the axis O, and one of the adjusting screws 22 is positioned at the position where the radial deflection is generated, and then all the adjusting screws 22 are screwed to the extent that they abut against the outer periphery of the shank portion 12. Then, the adjustment member 21 is temporarily fixed.

  When the adjustment screw 22 at the position where the radial deflection is generated is further screwed, the adjustment member 21 maintains the radial position with respect to the axis O by the frictional force of the end surface 21B in contact with the tip surface 1A. The portion protruding from the mounting hole 2 of the reamer main body 11 of the drilling tool (reamer) is pressed while being supported, and the position where the deflection is generated in the radial direction is on the opposite side across the axis O. Slightly bends. Therefore, the center line of the reamer body 11 coincides with the axis O of the tool body 1 at the position of the hole cutting edge 16 at the tip of the reamer body 11 only by adjusting the screwing amount of the adjustment screw 22 at the position where the deflection occurs. The radial runout can be adjusted to reduce or eliminate.

  Although depending on the clearance between the mounting hole 2 of the tool main body 1 and the shank portion 12 of the reamer main body 11, the deflection (eccentric amount) of the drilling tool is usually slight, and from the mounting hole 2 of the reamer main body 11. Since the reamer body 11 is largely bent at the position of the drilling cutting edge 16 at the tip end by pressing the protruding root portion, sufficient runout adjustment can be performed even with a pressing force enough to tighten and tighten the temporarily fixed adjustment screw 22. Is possible.

  Thus, according to the deflection adjusting mechanism of the drilling tool having the above-described configuration, the adjusting member 21 into which the adjusting screw 22 is screwed is separated from the tool body 1 and is fitted to the drilling tool so as to be rotatable around the axis O. The adjustment screw 22 is inserted, and the position of the adjustment screw 22 can be adjusted to the position where the hole machining tool has been shaken by rotating the adjustment member 21. Adjustments can be made. For this reason, no skill is required for the shake adjustment, and anyone can easily perform the shake adjustment in a short time, and high-precision drilling can be performed.

  Further, in the shake adjusting mechanism of the present embodiment, the center line of the adjusting screw 22 screwed into the adjusting member 21 is not less than 1/2 of the length L in the central axis C direction of the adjusting member 21 and the tip of the tool body 1. The tool body 1 is located on the tip side from the end face 21B that contacts the face 1A. Accordingly, when the reamer body 11 of the drilling tool (reamer) is bent by screwing the adjustment screw 22 in a state where the end surface 21B is in contact with the tip surface 1A in this way, the center line of the adjustment screw 22 becomes the length of the adjustment member 21. The end surface 21B is more strongly pressed against the front end surface 1A than in the case where it is located on the rear end side with respect to 1/2 of the length L. Accordingly, adjustment by friction between the end surface 21B and the front end surface 1A is performed. Since the support of the member 21 is also strong, the adjustment member 21 can be stably supported on the tool body 1 and a more accurate runout adjustment can be performed.

  In the present embodiment, four adjustment screws 22 are screwed into the adjustment member 21 at equal intervals in the circumferential direction. However, a portion where the inner peripheral portion of the adjustment member 21 and the adjustment member 21 of the reamer body 11 are inserted. If the clearance with (the shank portion 12 in this embodiment) is sufficiently small, only one adjusting screw 22 is screwed into the adjusting member 21, or the two adjusting screws 22 are symmetrically positioned with respect to the central axis C. It is possible to adjust the run-out even if it is screwed into the screw.

  However, in such a case, if the clearance is large, the drilling tool may bend in the radial direction perpendicular to the direction in which the adjusting screw 22 is screwed in the direction of the central axis C. On the other hand, if the clearance is too small, the adjustment member 21 inserted into the hole machining tool cannot be smoothly rotated, or the adjustment member 21 and the hole machining tool sometimes rotate together, There is a possibility that the adjusting screw 22 cannot be arranged at a position where the drilling tool has run out.

  On the other hand, the clearance between the inner diameter of the adjusting member 21 and the drilling tool is increased by screwing a plurality of (four) adjusting screws 22 into the adjusting member 21 at equal intervals in the circumferential direction as in this embodiment. However, by adjusting the screwing amount of these adjusting screws 22, it is possible to limit the deflection to the drilling tool in the direction perpendicular to the radial direction in which the deflection has occurred, and the adjusting member 21 can be rotated smoothly. However, high-precision drilling can be performed. However, if there are five or more adjusting screws 22, it may take time for screwing in temporarily fixing, or depending on the size of the adjusting member 21, the adjusting screw hole 21 </ b> A may not be formed. It is desirable that four or three adjustment screws 22 are screwed at equal intervals in the circumferential direction as in this embodiment.

  When the number of adjusting screws 22 is four as in the present embodiment, one of the pair of adjusting screws 22 facing each other performs shake adjustment, and the pressing force of the one adjusting screw 22 is received by the other adjusting screw 22. The bending of the drilling tool in the direction orthogonal to the radial direction in which the vibration occurs due to the other pair of adjustment screws 22 can be limited. In addition, when three adjustment screws 22 are screwed at equal intervals in the circumferential direction, while the vibration adjustment is performed by one adjustment screw 22, the pressing force is received by the one adjustment screw 22, The remaining two adjustment screws 22 can limit the deflection in the direction orthogonal to the direction in which the shake occurs.

DESCRIPTION OF SYMBOLS 1 Tool body 1A Front end surface of tool body 1 2 Mounting hole 11 Reamer body 12 Shank part 16 Hole processing cutting blade 21 Adjustment member 21A Adjustment screw hole 22 Adjustment screw O Axis of tool body 1 C Center axis of adjustment member 21 L Adjustment member 21 length in the direction of the central axis C

Claims (3)

  An attachment hole is formed along the axis line at the tip of the tool body rotated about the axis, and the shaft hole drilling tool is mounted and attached to the attachment hole. The annular or cylindrical adjustment member is rotatably fitted around the axis, and is brought into contact with the tip surface of the tool body around the opening of the mounting hole. And a boring tool runout adjustment mechanism, wherein an adjusting screw is screwed into the boring tool so as to be able to come into contact with an outer peripheral surface of the boring tool in a radial direction with respect to the axis.   2. The hole machining according to claim 1, wherein a center line of the adjustment screw is located in a range of ½ or more of a length of the adjustment member in a central axis direction on a distal end side of the tool main body. Tool run-out adjustment mechanism.   3. The runout adjustment mechanism for a hole machining tool according to claim 1, wherein three or four adjustment screws are screwed into the adjustment member at equal intervals in a circumferential direction.

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