JP4127617B2 - Internal machining tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an inner diameter composed of an attachment portion to a tool holder and a small-diameter bar-like portion in which a part of a cutting edge ridge provided on the tip end side of a cylindrical shank continuous with the attachment portion is projected to the side of the shank. The present invention relates to a machining tool, particularly to an inner diameter machining tool suitable for extremely small inner diameter machining for OA equipment parts, electronic parts, small diameter bearings and the like.
[0002]
[Prior art]
Conventionally, such inner diameter machining tools have a narrow gap between the small-diameter rod-shaped portion and the inner wall of the workpiece, and it is difficult to apply cutting oil to the edge of the cutting edge and it is difficult to discharge the chip. As shown in FIG. 3 (a), a cylindrical shank peripheral surface 31 with a relief groove 32 dug, or as shown in FIG. 3 (b), on the shank peripheral surface 34 on the upper side in the figure. There was a thing of the shape which provided the notch plane 35. FIG.
[0003]
[Problems to be solved by the invention]
By the way, the inner diameter machining tool cuts a part of the small-diameter rod-like portion so that a passage for cutting oil or chips can be secured in the inner diameter machining. This passage is one end of the cutting edge ridge. The part is integrated with a passage formed on the flank side formed by projecting to the side of the peripheral surface of the shank. Therefore, there is only one passage that leads to the outside of the workpiece hole during the inner diameter machining, and there is a problem that it is difficult to smoothly circulate the cutting oil and discharge chips.
[0004]
Hereinafter, this problem will be described in detail.
[0005]
As shown in FIGS. 3 (a) and 3 (b), the passage formed by the relief groove 32 or the notch plane 35 provided in the peripheral surface of the shank of the small-diameter bar-shaped part during the inner diameter machining is a part of the cutting edge. Is integrated with the escape portions 33 and 36, which are generated by protruding to the side of the shank. In this configuration, there is only one entrance and exit for the cutting oil and chips leading to the outside of the workpiece hole.
[0006]
As a result, as shown in FIG. 4, when cutting oil is injected into the workpiece hole from the passage (relief portion), at the same time, the tip blade tip portion will be discharged from the passage having only one location together with chips generated during machining. However, there is a problem in that it is not smoothly discharged because it is obstructed by the injected cutting oil.
[0007]
Moreover, if it is going to improve the circulation of a cutting oil and the discharge | emission property of a chip, it is necessary to enlarge the escape groove 31 and the notch plane 35, and will reduce the cross-sectional area of a shank greatly. As described above, the shank in which the cross-sectional area of the small-diameter bar-shaped portion is greatly reduced has a problem that rigidity is insufficient and chatter vibration is likely to occur during processing.
[0008]
In view of the above-described problems of the prior art, the present invention secures two passages for cutting oil or chips to improve the discharge performance or flowability of these, and does not reduce the rigidity of the small-diameter rod-shaped portion as much as possible. An object is to provide an inner diameter machining tool.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, the inner diameter machining tool of the present invention is an inner diameter machining tool including an attachment portion to a tool holder and a small diameter rod-shaped portion continuous to the attachment portion, and the small diameter rod-shaped portion includes: A columnar shank provided on the attachment portion side and a cutting edge portion provided at the tip of the shank are provided, and the cutting edge portion is provided with one end projecting to the side of the shank. A cutting edge and a rake face composed of a plurality of faces, and the face continuous with the cutting edge among the plurality of faces of the rake face protrudes one end of the cutting edge. is formed to extend on the peripheral surface opposite to the side with the peripheral surface of the opposite side with respect to the said small diameter rod portion, the side that is projected one end portion of the cutting edge with notched plane extending in the longitudinal direction of the small diameter rod portion is formed, cutout plane, or the plurality of surfaces It characterized in that it is formed so as to intersect with the at least one face of the rake surface formed.
[0010]
According to this configuration, in the inner diameter processing, two passages of cutting oil or chips can be generated around the shank provided in the small-diameter rod-like portion. Then, either one of the passages can be used as a cutting oil introduction path, and the other can be used as a cutting oil and chip discharge path, thereby enabling smooth cutting oil circulation and chip discharge.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 (a) shows a throw-away tip (hereinafter abbreviated as a tip) 1 as an inner diameter machining tool of the present invention, and FIG. 1 (b) is a view in the direction of arrow X in FIG. c) It is AA sectional drawing of the small diameter rod-shaped part 3. FIG.
[0013]
As shown in FIG. 1, in the tip 1, a small-diameter bar-like portion 3 is integrally projected from the peripheral surface of a flat plate-like base portion 2, and a cutting edge portion 4 is provided at the tip of a cylindrical shank 3 a provided in the small-diameter rod-like portion 3. Is provided. A rake face 6 is formed on the cutting edge portion 4, and one end of a cutting edge ridge 7 provided on the cutting edge portion 4 protrudes to the side of the shank 3 a of the small-diameter bar-shaped portion 3.
[0014]
Further, in the small-diameter bar-shaped portion 3, a notch plane 8 extending in the longitudinal direction of the small-diameter rod-shaped portion 3 is formed on the peripheral surface 5 opposite to the side from which one end of the cutting edge ridge 7 is projected.
[0015]
With the above-described configuration, the small-diameter rod-like portion 3 can be inserted into the workpiece hole, and the inside of the extremely small-diameter hole can be processed like an earpick.
[0016]
The important point in the structure of the tip 1 is that the small-diameter rod-shaped portion 3 has a longitudinal direction on the circumferential surface 5 on the opposite side (back side) with respect to the side from which one end of the cutting edge ridge 7 protrudes. That is, a cut-out plane 8 extending in the direction is formed.
[0017]
This point will be described in detail with reference to FIG.
[0018]
As shown in FIG. 1 (c), the tip edge 7 protrudes from the peripheral surface 5 of the small-diameter bar-shaped part 3 between the peripheral surface 5 of the small-diameter bar-shaped part 3 of the chip 1 and the inner wall of the work hole. There are provided a passage 9a (hereinafter abbreviated as a blade edge side passage) and a passage 9b (hereinafter abbreviated as a back side passage) formed by a notch plane 8 provided on the back side from the center line C of the cross section. 2A, when cutting oil is injected into the workpiece hole from the cutting edge side passage 9a, the cutting oil passes through the cutting edge side passage 9a and is generated at the cutting edge. Are simultaneously discharged from the back edge 9b together with chips generated during machining from the cutting edge 7. Since the passages 9a and 9b (circulation paths) are located with the small-diameter rod-shaped portion 3 interposed therebetween, the cutting oil and chips are smoothly discharged without being interrupted by the injected cutting oil and discharged to the chips. Is possible. In addition, as shown in FIG.2 (b), when cutting oil is inject | poured in the workpiece | work hole from the said back side, it will become a circulation path opposite to the above.
[0019]
The shank 3a of the small-diameter rod-shaped portion 3 has a cylindrical shape. Here, a cross-sectional secondary moment is given as an index representing the rigidity of the shank 3a of the small-diameter rod-shaped portion 3.
[0020]
Although the tip 1 has a cut-out plane 8 formed on the peripheral surface 5 of the cylindrical shank 3a, the vertical direction of the cross-section (one end of the cutting edge ridge) is obtained when an approximately perfect elliptical cross-section second moment is used. The direction perpendicular to the direction in which the portion protrudes: the length in the vertical direction in FIG. 1C is 2 s, and the length in the horizontal direction (the direction in which one end of the cutting edge is protruded): FIG. ) The second moment of the cross section of the ellipse when 2t in the horizontal direction) is expressed as π · s ³ · t / 4. In other words, the length in the vertical direction is multiplied by the third power and the length in the horizontal direction is multiplied by the first power, contributing to the moment of inertia of the cross section. Increasing the length in the vertical direction increases the length in the horizontal direction. The cross-sectional secondary moment can be made larger than the increase.
[0021]
Therefore, by providing the notch plane 8 on the back side and increasing the length in the vertical direction, it is possible to minimize a decrease in the rigidity of the small-diameter bar-shaped portion 3 due to the provision of the notch plane 8. On the other hand, since the decrease in rigidity is small, the amount of notches (notch plane 8) can be increased, so that the flowability or dischargeability of cutting oil or chips can be improved.
[0022]
Next, in the cross section orthogonal to the longitudinal direction of the shank 3a, the ratio T2 / T1 between the width T1 in the direction in which one end of the cutting edge ridge 7 protrudes and the direction T2 orthogonal to this is 1.0-1. It is preferable to be within the range of 2. If this ratio T2 / T1 is less than 1.0, the discharge of cutting oil and chips may be deteriorated. On the other hand, if it exceeds 1.2, the cross-sectional area of the shank 3a may be reduced and the rigidity may be impaired.
[0023]
Similarly, the ratio S / T2 between the width S of the small-diameter bar-shaped portion 3 from which the cutting edge ridge 7 protrudes and the width T2 at which one end of the cutting edge ridge 7 protrudes to the side of the shank 3a is: It is preferable that it is 0.1-0.2.
[0024]
When this ratio S / T2 is less than 0.1, the discharge of cutting oil and chips may be deteriorated. On the other hand, when the ratio S / T2 is more than 0.2, the cross-sectional area of the shank 3a may be reduced and the rigidity may be impaired.
[0025]
Moreover, it is preferable that ratio F / T2 of the width | variety T2 of the direction orthogonal to the direction which protruded the width F of the said notch plane 8 and the one edge part of the said cutting-edge ridge 7 is 0.3-0.7. .
[0026]
If this ratio F / T2 is less than 0.3, the discharge of cutting oil and chips may be deteriorated. On the other hand, if it exceeds 0.7, the cross-sectional area of the shank 3a may be reduced and the rigidity may be impaired.
[0027]
As mentioned above, although embodiment of this invention was illustrated based on drawing, this invention is not limited to the said embodiment, It cannot be overemphasized that it can be set as arbitrary shapes unless it deviates from the objective of invention.
[0028]
For example, in this embodiment, a small-diameter bar-like portion 3 is integrally protruded from the peripheral surface of the flat-plate base 2, and a chip provided with the flat-plate base 2 as a fixing portion to a tool holder (not shown) is used. Although explained, the present invention is not limited to this, for example, a cylindrical mounting portion is provided as a fixing portion to the tool holder, and this mounting portion is inserted and fixed in the tool mounting hole of the tool holder provided with the tool mounting hole. The inner diameter machining tool may be used.
[0029]
【The invention's effect】
As described above, the inner diameter machining tool of the present invention is an inner diameter machining tool including an attachment portion to a tool holder and a small-diameter rod-like portion continuous with the attachment portion, and the small-diameter rod-like portion is the attachment tool. A cylindrical shank provided on the part side and a cutting edge part provided at the tip of the shank, the cutting edge part provided with one end projecting to the side of the shank A ridge and a rake face composed of a plurality of faces, and a face continuous with the cutting edge ridge among the plurality of faces of the rake face is a side where one end of the cutting edge is projected. the small diameter rod-shaped on the peripheral surface opposite to the side that is projected is formed to extend on the peripheral surface of the opposite side, in the small-diameter rod portion, one end portion of the cutting edge relative to with longitudinally extending notches plane is formed parts, cutout plane thumping comprising the plurality of surfaces By being formed so as to intersect at least one of the surfaces, the internal machining, the periphery of the shank including the small-diameter rod portion, the passage of the cutting oil or chips can cause passage of two places. Then, either one of the passages can be used as a cutting oil introduction path, and the other can be used as a cutting oil and chip discharge path, thereby enabling smooth cutting oil circulation and chip discharge.
[0030]
In the inner diameter machining tool, a ratio T2 / T1 between the width T1 of the shank in the direction in which one end portion of the cutting edge ridge protrudes and the direction T2 orthogonal thereto is 1.0 to 1.2. When it is within the range, cutting oil and chip discharge can be made very good without impairing the rigidity of the shank.
[Brief description of the drawings]
1A is a plan view of a chip as an inner diameter machining tool according to the present invention, FIG. 1B is a cross-sectional view taken along arrow X in FIG. 1A, and FIG. It is.
FIG. 2 is an explanatory diagram of cutting using the tip of FIG. 1;
FIG. 3 is a cross-sectional view of a small-diameter bar portion of a conventional inner diameter machining tool.
FIG. 4 is an explanatory diagram of cutting using the conventional inner diameter machining tool of FIG. 3;
[Explanation of symbols]
1: (Throw away) insert / Inner diameter machining tool 2: Flat base / Tool holder mounting part 3: Small diameter bar 3a: Shank 4: Cutting edge 5: Peripheral surface 6: Rake face 7: Cutting edge 8: Notch flat surface 9a: Cutting edge side passage 9b: Back side passage T1: Width in a direction in which one end portion of the cutting edge is protruded T2: In a direction orthogonal to a direction in which one end portion of the cutting edge is protruded Width S: One end of the cutting edge ridge projects to the side of the shank Width F: Length of the flat surface of the notch C: Center line of the cross section

Claims (2)

An inner diameter machining tool comprising an attachment part to a tool holder and a small-diameter bar-like part continuous to the attachment part,
The small-diameter rod-shaped portion includes a columnar shank provided on the attachment portion side and a cutting blade portion provided at the tip of the shank.
The cutting edge portion has a cutting edge ridge provided with one end protruding to the side of the shank, and a rake face composed of a plurality of surfaces.
Continuous surface to the cutting edge of the plurality of surfaces of said rake face is formed to extend in the peripheral surface opposite to the side that is projected one end portion of the cutting edge ,
A notch plane extending in the longitudinal direction of the small-diameter bar-shaped portion is formed on the circumferential surface opposite to the side where the one end portion of the cutting edge ridge is projected in the small-diameter bar-shaped portion ,
The inner diameter machining tool , wherein the notch plane is formed so as to intersect with at least one of the rake faces composed of the plurality of faces .   In the shank cross section orthogonal to the longitudinal direction of the shank, the ratio T2 / T1 of the width T1 in the direction in which one end portion of the cutting edge ridge protrudes and the width T2 in the direction orthogonal thereto is 1.0 to 1.2. The inner diameter machining tool according to claim 1, wherein the inner diameter machining tool is within the range.

Images