JP2004261896A - Boring tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boring tool capable of finishing the inner diameter and chamfering at the same time with one tool in relation to various holes H to be bored with a different inner diameter and a different chamfering angle. <P>SOLUTION: An inner diameter machining throw-away tip 5 having an inner diameter machining cutting blade 5B in nearly parallel with the axis O is removably fitted to a tip of a tool main body 1 to be rotated around the axis O. A chamfering throw-away tip 6 having a chamfering cutting blade 6B inclined toward the peripheral side more as it comes close to a rear end is fitted to the tip of the tool main body 1 on the rear end side of the inner diameter machining tip 5. About these tips 5 and 6, adjusting mechanisms 8 and 8 respectively provided in the tool main body 1 adjust diameter of the rotation of the inner diameter cutting blade 5B from the axis O in the inner diameter cutting tip 5, and adjust the angle of inclination of the chamfering cutting blade 6B in the chamfering tip 6. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool capable of performing chamfering on an opening of a pilot hole formed at the same time as finishing the inner diameter of the pilot hole formed in a workpiece.
[0002]
[Prior art]
Usually, a reamer is used to finish a prepared hole formed in a workpiece to a predetermined inner diameter.In other words, a reamer having a predetermined cutting edge diameter corresponding to the inner diameter to be finished is inserted into the prepared hole while rotating. Then, the inner periphery of the prepared hole is cut by the cutting blade to finish a processed hole having a predetermined diameter (for example, see Patent Document 1). Further, in order to perform chamfering on the opening of the formed hole, a chamfering tool having a chamfered cutting edge having an inclination angle corresponding to the inclination of the chamfer is used, and the chamfered hole finished by the reamer is used. Then, the chamfering tool is inserted while being rotated, and the opening of the machining hole is cut by the chamfering cutting blade to perform chamfering at a predetermined inclination.
[0003]
[Patent Document 1]
JP-A-6-170640
[Problems to be solved by the invention]
However, the inner diameter and the angle of the chamfered hole with the chamfer in this manner often differ slightly depending on the hole to be finally finished. It is necessary to prepare different tools for different bore diameters and different angles of chamfering, and to perform the inner diameter processing and chamfering processing in order, which makes the work extremely complicated and lowers the processing efficiency. That was inevitable. Further, in such a tool, when wear occurs on the cutting edge, re-polishing or re-coating of the coating is performed to reuse the tool, but such re-polishing and re-coating require time and cost. Therefore, economical efficiency is not so high, and especially in the case of reamers, such re-polishing reduces the cutting edge diameter, so it is used to finish a hole with the same inner diameter as the finish processing before re-polishing. There is also the problem that you cannot do that.
[0005]
The present invention has been made under such a background, and it is possible to simultaneously perform finishing processing of an inner diameter of a prepared hole formed in a workpiece and chamfering processing of an opening of the prepared hole. It is an object of the present invention to provide a drilling tool that can perform drilling with a single tool on various types of drilled holes having different bore diameters and chamfer angles.
[0006]
[Means for Solving the Problems]
In order to solve the above problems and achieve such an object, the present invention provides an inner diameter machining throw having an inner diameter machining cutting blade substantially parallel to the axis at a tip end of a tool body rotated around an axis. An away tip (hereinafter, referred to as an inner diameter processing chip) is detachably attached, and a chamfering cut is formed on a rear end side of the inner diameter processing tip, which is inclined toward an outer peripheral side toward a rear end side. A throw-away insert for chamfering having a blade (hereinafter, referred to as a chamfering insert) is detachably attached, and these chips are attached to the insert for inner diameter processing by an adjusting mechanism provided on the tool body. The rotation diameter from the axis of the inside diameter machining cutting blade, and the inclination angle of the chamfering cutting edge in the chamfering tip can be adjusted, respectively. To. Therefore, according to the drilling tool having such a configuration, since one tool body is provided with the inner diameter processing cutting edge and the chamfering processing cutting edge, the inner diameter finishing processing of the prepared hole and the opening thereof are performed in one processing. Can be performed simultaneously with the chamfering of the part, and even if the inside diameter of the machining hole and the inclination angle of the chamfered part are different, the rotation diameter of the inside diameter machining cutting blade and the inclination angle of the chamfering cutting blade are appropriately adjusted by the above adjustment mechanism By doing so, it is possible to easily cope with the situation without preparing a plurality of types of tools.
[0007]
Here, when the chip is mounted on the tool body by pressing a pressing portion substantially at the center of the rake face in the cutting blade length direction by a clamp mechanism, the tip is opposite to the cutting blade in the adjusting mechanism. By providing pressing means capable of independently pressing two points sandwiching the pressing portion in the length direction of the cutting edge on the side surface of the tip, these two parts are pressed by the pressing means in the case of the inner diameter machining tip. By pressing evenly, it is possible to adjust the rotation diameter of the inner diameter machining blade while keeping the cutting edge parallel to the axis of the tool main body, while in the case of the chamfering tip, the pressing means is used at these two points. By adjusting the pressing force, the tip for chamfering can be rotated about the pressing portion to adjust the inclination angle of the chamfering cutting blade. Further, if a supply hole for the cutting oil is drilled in the tool body toward the tip of the tool body and the supply hole is opened in the tip surface of the tip, the chip generated during machining can be smoothly removed. Efficient discharge and efficient cooling and lubrication of the processing part can be achieved. Furthermore, a guide pad for inner diameter machining extending substantially parallel to the axis is provided on the outer periphery of the tip end portion of the tool body, and a chamfering process is provided on the rear end side of the tip for inner diameter machining in accordance with the inclination of the chamfering cutting blade. The guide pads are provided so that the outer peripheral surfaces of these guide pads are respectively located on the inner peripheral side of the inner diameter processing cutting edge and the chamfering processing cutting edge on the rotation locus around the axis. Can be slid into contact with the inner periphery or chamfered portion of the prepared pilot hole to guide the tool body, thereby enabling more accurate processing.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 6 show one embodiment of the present invention. In this embodiment, the tool main body 1 has a substantially multi-stage cylindrical shape with an axis O as a center, and a rear end (right end in FIG. 1) is a shank portion 2. By being gripped by the main shaft, the workpiece is rotated in the tool rotation direction indicated by the reference symbol T in the drawing and used for machining. On the other hand, the tip of the tool body 1 is a cutting blade 3, and the cutting blade 3 has a truncated conical portion 3A whose diameter gradually decreases toward the tip (left side in FIGS. 1, 3, and 5). And a small-diameter cylindrical portion 3B provided at the tip of the truncated conical portion 3A. A cross section orthogonal to the axis O is substantially formed on the outer periphery of the cutting blade 3 as shown in FIGS. The L-shaped chip pocket 4 is continuous from the truncated cone portion 3A to the columnar portion 3B, is parallel to the axis O in the columnar portion 3B, and is a generatrix of the truncated cone in the truncated cone portion 3A. On the wall surface of the tip pocket 4 facing the tool rotation direction T, an inner diameter machining tip 5 is provided on the cylindrical portion 3B, and a chamfering tip 6 is provided on the frustoconical portion 3A. Is a chip formed so as to be recessed one step from the wall surface, respectively. Detachably attached to be seated in the attached seat. In the present embodiment, a small-diameter disk portion 3D is formed at the center of the front end surface 3C of the cutting blade portion 3, that is, the center of the front end surface of the columnar portion 3B so as to protrude further to the front end side. A ring 3E made of cemented carbide is attached to the outer peripheral edge of the distal end of the plate portion 3D.
[0009]
Each of the tips 5 and 6 is a positive tip formed in a substantially rectangular flat plate shape from a hard material such as a cemented carbide, and one of the rectangular faces serves as rake faces 5A and 6A, respectively. A pair of long sides of a rectangle formed by 5A and 6A are used as an inner diameter machining cutting edge 5B in the inner diameter machining tip 5 and as a chamfered cutting edge 6B in the chamfering tip 6. . At the center of the rectangle formed by the rake faces 5A and 6A, a mounting hole (not shown) that penetrates the chips 5 and 6 in the thickness direction is formed, and the cutting edges 5B and 6A of the rake faces 5A and 6A are formed. Breaker grooves 5C and 6C are formed at the edge on the 6B side. In the present embodiment, the length of the long side of the rectangle formed by the rake face 6A, that is, the length of the cutting edge 6B of the chamfering tip 6 is longer than that of the inner diameter processing tip 5.
[0010]
These chips 5, 6 have their rake faces 5A, 6A oriented in the tool rotation direction T, and one of the cutting edges 5B, 6B protrudes from the outer periphery of the cylindrical portion 3B and the outer periphery of the truncated cone portion 3A, respectively. After being seated on the chip mounting seat, the head is clamped by a clamp screw 7 having a head, which is inserted into the mounting hole and screwed into the bottom surface of the chip mounting seat, via a disc spring washer 7A. The cutting edge 5B of the inner diameter machining tip 5 extends substantially parallel to the axis O in this mounted state, and is located on the rear end side with respect to the inner diameter machining tip 5. The cutting edge 6B of the chamfering chip 6 to be disposed at the end of the cutting edge 6B in the direction of the axis O is positioned on the inner peripheral side with respect to the rotation diameter around the axis O of the inner diameter processing cutting blade 5B. From the tip to the back And thus it is substantially tilted as parallel toward the outer peripheral side to the generatrix of the frustoconical portion 3A toward the side. Therefore, in the present embodiment, the clamp screw 7 is used as a clamping means, and the periphery of the mounting hole opening of the rake faces 5A, 6A pressed by the head of the clamp screw 7 via the disc spring washer 7A is a pressing portion. Since the mounting hole is formed at the center of the rake faces 5A and 6A, the pressing portion is disposed at the center of the cutting blades 5B and 6B also in the cutting blade length direction.
[0011]
On the other hand, with respect to the chips 5 and 6 thus attached, the columnar portion 3B and the truncated conical portion 3A of the cutting blade 3 are provided with adjusting mechanisms 8, 8, respectively. Each of these adjusting mechanisms 8 is composed of a pair of pressing means 9, 9, and each pressing means 9 is directed from the outer periphery of the tool body 1 to the tool outer peripheral side of the tip mounting seat. An insertion hole 10 is formed so as to open at an acute angle to the wall surface, and a pin 11 is inserted therein. An outer opening side of the insertion hole 10 on the outer periphery of the tool body 1 is formed as a female screw portion 10A, and an adjustment screw 12 is formed. When the adjusting screw 12 is screwed in, the pin 11 is pushed out, and its tip protrudes from the wall surface of the chip mounting seat. The protruding one of the cutting blades 5B, 6B is in contact with the chip side surface (flank surface of the other cutting blades 5B, 6B) 5D, 6D opposite to the cutting edge 5B, 6B so that the side surfaces 5D, 6D can be pressed. The tip of the pin 11 is notched obliquely in accordance with the inclination of the side surfaces (flank surfaces) 5D, 6D of the chips 5, 6, which are positive chips, and the cutout surface is entirely formed of the side surfaces 5D, 6D. And the length of the pin 11 of the pressing means 9 in the adjusting mechanism 8 of the inner diameter machining tip 5 is determined by the difference in diameter between the cylindrical portion 3B and the truncated conical portion 3A. The length of the pin 11 of the adjustment mechanism is increased.
[0012]
Further, in the adjusting mechanism 8 of the inner diameter machining chip 5, the insertion holes 10, 10 of the pair of pressing means 9, 9 are respectively provided on a plane orthogonal to the one cutting edge 5B of the inner diameter machining chip 5, ie, The cutting blades 5B extend in a plane perpendicular to the axis O and are parallel to each other, and are positioned on the opposite side at equal intervals across the pressing portion in the cutting blade length direction (the direction of the axis O) of the cutting blade 5B. Therefore, the tip of the pin 11 of the pressing means 9, 9 is independent of the two portions of the inner surface machining tip 5 sandwiching the pressing portion in the cutting edge length direction on the tip side surface 5D. And can be pressed. Also, in the adjusting mechanism 8 of the chamfering chip 6, the insertion holes 10, 10 of the pressing means 9, 9 extend on a plane orthogonal to one of the cutting blades 6 </ b> B of the chamfering chip 6. In the longitudinal direction of the cutting edge 6B (in the direction of the generatrix of the truncated conical portion 3A), the cutting edge 6B is positioned on the opposite side at equal intervals with the pressing portion of the chamfering chip 6 interposed therebetween. The tip of each of the pins 9 and 9 is capable of independently pressing two portions sandwiching the pressing portion in the cutting edge length direction on the tip side surface 6D.
[0013]
Further, a cutting oil supply hole 13 is formed in the tool main body 1 along the axis O from the shank portion 2 at the rear end, and the cutting oil or its mist is supplied from the machine tool side during drilling. The supply hole 13 is bent to the outer peripheral side in the cutting edge portion 3 on the distal end side, and then is formed on the outer peripheral surface of the disk portion 3D on the distal end surface 3C of the cutting edge portion 3. It is opened sideways. In addition, on the outer periphery of the cylindrical portion 3B and the truncated conical portion 3A, there are three positions on the opposite side of the cutting edges 5B and 6B in the circumferential direction, and between this position and the cutting edges 5B and 6B. Guide pads 14 made of a hard material such as cemented carbide like the chips 5 and 6 are provided so as to extend in parallel to the axis O and the generatrix direction of the truncated conical portion 3A, respectively. These guide pads 14 are formed so that their outer peripheral surfaces form an arc shape centered on the axis O in a cross section orthogonal to the axis O, but their outer diameters are the cutting edges 5B, 6B in the same cross section. Of the guide pads 14 provided on the columnar portion 3B are disposed at positions slightly retreated from the distal end of the inner diameter processing cutting blade 5B.
[0014]
In the drilling tool configured as described above, the tool body 1 is advanced in the direction of the axis O while rotating in the tool rotation direction T, and the prepared hole H formed in the workpiece W as shown in FIG. , First, the inner diameter of the pilot hole H is finished to a predetermined diameter by the inner diameter processing cutting blade 5B of the inner diameter processing tip 5 attached to the cylindrical portion 3B at the tip of the cutting blade portion 3, and subsequently, A chamfered portion M is formed at the opening of the prepared hole H by the inclined chamfered cutting blade 6B of the insert 6 for the chamfered portion 6A of the truncated conical portion 3A. And the formation of the chamfered portion M can be performed at the same time, which is efficient, and the pilot hole H and the chamfered portion M can be formed with high coaxiality. Further, in the drilling tool having the above-described configuration, by appropriately operating the adjustment mechanism 8 for the inner diameter machining tip 5 and the adjusting means 8 for the chamfering tip 6, the inner diameter machining cutting edge of the inner diameter machining tip 5 is formed. The rotation diameter of 5B and the inclination angle of the chamfering cutting edge 6B of the chamfering tip 6 can be finely adjusted.
[0015]
That is, first, in the inner diameter machining chip 5, the adjusting screws 12, 12 of the pair of pressing means 9, 9 in the adjusting mechanism 8 are screwed in with the same screwing amount, so that the pins 13, 13 have the same amount of protrusion. And the side surface 5D of the tip 5 is evenly pressed in the cutting blade length direction by two portions sandwiching the pressing portion by the clamp screw 7, and resists the pressing force by the clamp screw 7. In some cases, the clamp screw 7 is bent to push the tip 5 to the outer peripheral side, and the rotating diameter of the cutting edge 5B is slightly increased while maintaining the parallel state with the axis O. Also, in the chamfering chip 6, the tip 6 is pushed out to the outer peripheral side by screwing the adjusting screws 12, 12 of the pair of pressing means 9, 9 of the adjusting mechanism 8. At this time, the pair of pressing means 9 , 9 are screwed with different screwing amounts from each other, so that the tip 6 has a larger outer periphery toward the pressing means 9 on which the adjusting screw 12 is screwed with a larger screwing amount in the longitudinal direction of the cutting edge with the pressing portion interposed therebetween. Since the tip 6 is pushed out to the side, the tip 6 can be slightly rotated around the pressed portion, and thereby the inclination angle of the cutting blade 6B can be slightly adjusted.
[0016]
Therefore, according to the drilling tool having the above-described configuration, the finishing hole H formed in the workpiece W has to be subjected to many types of finishing with slightly different inner diameters. Even when it is necessary to form many types of chamfered portions M with slightly different inclination angles, there is no need for a reamer or a chamfering tool corresponding to the type of the inner diameter and the inclination angle, and one hole machining is performed. It can be handled with tools, and efficient and economical work can be performed. Further, even if the cutting blades 5B, 6B are worn, for example, a certain amount of processing can be performed while maintaining the positions of the cutting blades 5B, 6B by projecting the tips 5, 6 to the outer peripheral side by the adjusting mechanism 8. If one of the cutting blades 5B, 6B becomes unusable, the chips 5, 6 are turned over, and the other cutting blades 5B, 6B can be used. The sharpness can be regained without the time and cost of repolishing or recoating.
[0017]
Further, in the present embodiment, as described above, the adjusting mechanism 8 for the chips 5 and 6 is configured such that the pressing portions of the chips 5 and 6 by the clamp screws 7 serving as the clamping means are sandwiched in the cutting edge length direction by two portions. Since it is provided with a pair of pressing means 9 and 9 for pressing 5D and 6D, by adjusting the respective pressing amounts, that is, the screwing amounts of the adjusting screws 12, the pressing as in the case of the inner diameter machining chip 5 is performed. By making the pressing amounts of the means 9 and 9 uniform, the rotating diameter is adjusted while the cutting edge 5B is kept parallel to the axis O, or the pressing of the pressing means 9 and 9 is performed as in the case of the chip 6 for chamfering. It is possible to adjust the inclination angle of the cutting blade 6B by rotating the tip 6 with different amounts, and it is possible to easily adjust such a rotation diameter and an inclination angle. For processing By changing the pressing amount of the pressing means 9,9 between the adjustment means 8-up 5, it is also possible to give them back taper on the cutting edge 5B. Moreover, in the present embodiment, since the chips 5 and 6 are pressed through the pins 11 by screwing the adjusting screws 12, the pressing amount can be more finely adjusted according to the screw pitch of the adjusting screws 12. Accordingly, highly accurate adjustment of the rotation diameter and the inclination angle can be performed.
[0018]
In the present embodiment, the supply hole 13 for the cutting oil is drilled in the tool body 1, and since the supply hole 13 is opened at the tip surface 3 </ b> C of the cutting blade 3 at the tip of the tool body 1. The cutting oil or the mist discharged from the supply hole 13 is discharged to the bottom of the pilot hole H, particularly when the pilot hole H is a blind hole, and discharged to the outside of the pilot hole H through the tip pocket 4. Become. When passing through the chip pocket 4, the chips generated by the cutting blades 5B and 6B are also discharged together with the cutting fluid, and the cooling and lubrication of the cutting blades 5B and 6B, the prepared hole H and the chamfer M by the cutting blades 5B and 6B. Therefore, according to the present embodiment, smooth processing can be performed while suppressing clogging of chips and increase in cutting resistance. When the mist of the cutting oil is supplied to the supply hole 13, the opening of the supply hole 13 in the front end surface 3 </ b> C has an inner diameter in order to secure the discharge pressure from the front end surface 3 </ b> C and to spread the mist evenly. It is desirable that the thickness be about 2 mm or less.
[0019]
Further, in the present embodiment, the guide pad 14 is attached to the outer periphery of the cylindrical portion 3B and the truncated cone portion 3A of the cutting blade 3, and the outer diameter of the outer peripheral surface thereof is the cutting blade 5B of the chips 5, 6. 6B, the inner diameter of the prepared hole H is processed without interfering with the inner periphery of the prepared hole H or the cutting of the chamfered portion M by the cutting blades 5B, 6B. The tool body 1 can be guided in sliding contact with the chamfered portion M, and more accurate machining can be performed. However, if the amount of retreat of the outer diameter of the outer peripheral surface of the guide pad 14 toward the inner peripheral side with respect to the rotational diameter of the cutting blades 5B, 6B is too large, the outer peripheral surface of the guide pad 14 will surely have the prepared hole H or the chamfered portion M. The retreat amount depends on the rotation diameter of the cutting blades 5B and 6B. It is desirable that the distance be at most about 0.01 mm.
[0020]
【The invention's effect】
As described above, according to the present invention, it is needless to say that the finishing process of the inner diameter of the prepared hole and the chamfering process of the opening thereof can be performed by one processing with one drilling tool. It is possible to cope with a plurality of types of holes having a finished inner diameter and a chamfer angle, and it is possible to perform economical and efficient hole processing.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of the present invention.
FIG. 2 is a front view of the embodiment shown in FIG. 1 as viewed from a distal end side.
FIG. 3 is a partially enlarged side view as viewed in a direction indicated by an arrow X in FIG. 1;
FIG. 4 is an enlarged sectional view taken along the line YY in FIG.
FIG. 5 is an enlarged side view showing the cutting blade portion 3 of the embodiment shown in FIG.
FIG. 6 is a sectional view taken along the line ZZ in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tool main body 3 Cutting blade part 5 Inner-diameter machining tip 5B Inner-diameter machining cutting blade 6 Tip for chamfering 6B Chamfering cutting blade 7 Clamp screw (clamp means)
8 Adjusting mechanism 9 Pressing means 11 Pin 12 Adjusting screw 13 Cutting oil supply hole 14 Guide pad O Axis line T of tool body 1 Tool rotation direction

Claims (4)

At the tip of the tool body that is rotated around the axis, an inner diameter machining throw-away tip having an inner diameter machining cutting blade substantially parallel to the axis is detachably attached, and the rear end is larger than the inner diameter machining throw-away tip. On the side, a chamfering indexable insert having a chamfered cutting edge inclined toward the outer peripheral side toward the rear end side is detachably attached, and these indexable inserts are respectively provided on the tool body. By the adjustment mechanism provided, the rotation diameter from the axis of the inner diameter processing cutting edge is adjusted in the inner diameter machining insert, and the inclination angle of the chamfering cutting edge is adjusted in the chamfering indexable insert. A drilling tool characterized by being made possible. The indexable insert is attached to the tool body by being pressed by a clamp mechanism at a pressing portion substantially at the center of the cutting edge length direction on the rake face, and the adjusting mechanism is mounted on a tip side opposite to the cutting edge. 2. The drilling tool according to claim 1, further comprising pressing means capable of independently pressing two portions sandwiching the pressing portion in the cutting edge length direction. A supply hole for cutting oil is drilled in the tool body toward the tip of the tool body, and the supply hole is opened at a tip surface of the tip. The drilling tool according to claim 1 or 2. A guide pad for inner diameter machining extending substantially parallel to the axis is provided on the outer periphery of the tip end of the tool body, and is inclined to the rear end side of the indexable insert for cutting in accordance with the inclination of the chamfering cutting blade. Guide pads for chamfering are provided respectively, and the outer peripheral surfaces of these guide pads are located on the inner peripheral side of the inner diameter processing cutting blade and the chamfering processing cutting blade, respectively, in the rotation trajectory around the axis. The drilling tool according to any one of claims 1 to 3, characterized in that:

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