JP4797462B2 - Rotating tool - Google Patents

Description

The present invention relates to a rotary tool such as a face mill and an end mill, and more particularly to a rotary tool that improves the accuracy of a machining wall surface.

Conventionally, the throw-away rotary tool forms an arc-shaped convex curved surface in machining a right-angle wall surface when the axial rake angle is set to positive or negative while the outer peripheral cutting edge is a straight ridge. This is because the cutting trajectory of the straight ridge is excessively cut at both ends with respect to the cutting trajectory of the twisting blade. In particular, as the absolute value of the axial rake angle increases, the amount of protrusion of the arc-shaped convex curved surface increases.

FIGS. 8 and 9 illustrate a throw-away end mill that improves the arc-shaped convex curved surface in the processing of the right-angle wall surface. In this end mill, a flute groove 3 is formed in a cylindrical tool body 1, and a positive tip 4 having a substantially parallelogram plate shape is mounted in a tip seat 5 provided on the bottom side thereof. In addition, a large positive rake angle α is formed in the axial direction of the tool body 1 where the long side is located, and the tip 4 has a clearance angle in the tip seat 5 of the tool body 1. The short side and long side inclined side surfaces 8a and 8b having θ1 are screwed by using the center mounting hole 6 so as to abut on the two inclined support surfaces 17a, and on the long side side, The outer peripheral cutting edge ridge 10 is formed by the band-shaped surface 9 having a large curvature radius R set with a clearance angle θ2 smaller than the clearance angle θ1, and a small connecting ridge is formed at a diagonal corner portion constituting an acute angle. Inclined surface 12 forming 11 In addition, a quadrilateral inclined surface 14 that forms the horizontal blade edge 13 is formed, and an inclined surface 16 that forms a small connecting edge 15 is formed in a diagonal corner portion that forms an obtuse angle. Yes.

The end mill is such that an outer peripheral cutting edge ridge formed from a band-shaped surface having a large curvature radius R brings the wall surface processing shape close to a right angle (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 4-45617

However, in the above-mentioned conventional end mill, since the accuracy of the outer peripheral cutting edge of the tip mounted on the tool body is reduced due to the accumulation of machining errors of the tip seat and the tip of the tool body, the perpendicularity of the machining wall surface is stable. It was difficult to maintain high accuracy. Although the above-mentioned problem can be solved if the chip seat and the chip are formed with high accuracy, other problems such as deterioration of the defect rate of the tool body and the chip and an increase in manufacturing cost may occur.

The present invention has been made in view of the above-described problems, and its purpose is to maintain the perpendicularity of the machining wall surface with high accuracy and stability and to suppress the flash of the machining wall surface to form a highly accurate machining wall surface. An object of the present invention is to provide a rotary tool that can be used.

In order to solve the above-described problems, the present invention provides that one or more tip mounting grooves extending in the axial direction of the tool body are formed on the outer peripheral portion of the cylindrical tool body, Is a chip having a substantially polygonal plate shape, the rake face formed on at least one of the opposing polygonal faces is directed forward in the direction of tool rotation, and the bottom face facing the rake face is defined by the tip mounting groove. The outer peripheral cutting edge ridge formed on the side ridge located on the tool outer peripheral side of the rake face is placed so as to protrude from the outer peripheral face of the tool main body, and is normal to the rake face. In the rotary tool fixed to the tool body by screwing a clamp screw inserted in the direction into the seating surface, the outer peripheral cutting edge ridge is given a positive or negative axial rake angle, and the outer A convex curved outer flank surface that curves in the direction of the outer peripheral cutting edge is formed on the side surface that continues to the cutting edge, and the tip can be rotated around the axis of the clamp screw by fine adjustment means. It is a rotary tool characterized by being said.

According to the rotary tool of the present invention, since the positive or negative axial rake angle is given to the outer peripheral cutting edge, the cutting resistance during cutting is reduced and the sharpness is improved. Since it flows out toward the rear end side of the tool, the flash at the upper end portion or the lower end portion of the processing wall surface is suppressed. Furthermore, since the outer peripheral relief surface of the curved surface shape curved in the direction of the outer peripheral cutting edge ridge is formed on the side surface connected to the outer peripheral cutting edge ridge of the chip, the arc-shaped convex curved surface in the wall surface processing shape can be reduced. . In addition, the squareness in the wall surface processing shape can be maintained with high accuracy and stability by appropriately rotating the tip around the axis of the clamp screw by the fine adjustment means. From the above, it is possible to maintain the perpendicularity of the machining wall surface with high accuracy and stability and suppress the flash of the machining wall surface to form a machining wall surface with high accuracy.

In the rotary tool of the present invention, the fine adjustment means includes a tip end side in a tool axis direction and a tool on a radial direction constraining surface formed on a side surface of the tip facing the tool inner peripheral side with the axis of the clamp screw interposed therebetween. It consists of fine adjustment screw members that respectively support the position of the rear end side in the axial direction and urge toward the outer periphery of the tool, and the tip is rotated around the axis of the clamp screw by the cooperation of the fine adjustment screw members. When the rotation is made possible, the tip can be circularly moved in the forward and reverse directions around the axis of the clamp screw, and fine adjustment can be performed very easily and accurately.

In the rotary tool described above, a curved axial restraint surface that forms a convex arc centering on the axis of the clamp screw with a cross section parallel to the rake face is formed on the side face of the tip facing the tool rear end side. When the tip is supported by an axial support member that is slidable on the axial restraint surface, the tip is rotated around the axis of the clamp screw by fine adjustment means. Nevertheless, since the axial direction restraint surface and the radial direction restraint surface are stably supported at three points by the axial direction support member and the fine adjustment means, respectively, deterioration of accuracy of the machining wall surface is prevented.

Further, when at least one wedge member that presses the rake face toward the seating surface side is provided, the clamping force of the chip is improved and the resistance force against the rotation of the chip during fine adjustment is moderate. This makes it easy to make fine adjustments.

Further, each of the opposing polygonal faces of the chip is a rake face having a point-symmetrical shape, and an outer peripheral cutting edge ridge is formed at a side ridge portion arranged on the outermost tool outer side of each rake face. In this case, the front and back of the chip can be used, and the economy is improved.

Next, an embodiment to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a front view of a throw-away end mill according to an embodiment of the present invention viewed from a direction perpendicular to the axis. 2 is a partial sectional front view of the throw-away end mill shown in FIG. FIG. 3 is a bottom view of the throw-away end mill shown in FIG. 4 is a cross-sectional view taken along line S1-S1 in FIG. FIG. 5 is a front view of a tip mounted on the throw-away end mill shown in FIG. FIG. 6 is a right side view of the chip shown in FIG. FIG. 7 is a bottom view of the chip shown in FIG. FIG. 8 is a front view of a conventional throw-away end mill. FIG. 9 is a front view of a tip mounted on the throw-away end mill shown in FIG.

As shown in FIGS. 1 to 3, three tip mounting grooves 3 are provided on the outer peripheral portion of the cylindrical tool body 2 so as to extend in the tool axis direction substantially evenly along the circumferential direction. Yes. These tip mounting grooves 3 have a tip opening on the tip surface 2b of the tool body 2, and gradually move forward in the tool rotation direction K from the tip opening toward the rear end side in the tool axis direction. It is inclined and its inclination angle is 10 °.

A tip pocket 5 is formed on the front side in the tool rotation direction K of the tip attachment groove 3 so as to continue to the tip attachment groove 3. Furthermore, wedge insertion grooves 4 are formed in the wall surface of the chip pocket 5 at two locations separated in the tool axis direction.

At the rear end portion of the tool body 2, there are formed an attachment end surface 2 a that is in close contact with an end surface of a holder (not shown) and a connection portion 9 that is a recess provided on the attachment end surface 2 a. An oil hole 8A extending toward the tip side along the axis of the tool body 2 and an injection hole 8B branched from the oil hole and opened to the wall surface of each chip pocket 5 are formed on the bottom surface of the connection portion 9. And the cutting oil supplied to the oil hole 8A is supplied from the opening of the injection hole 8B to be supplied to the vicinity of the rake face 11 and the peripheral cutting edge ridge 13 of the chip.

As shown in FIGS. 5 to 7, the chip 10 has a substantially rectangular plate shape, and each of the opposing rectangular surfaces is a rake surface 11 having a point-symmetric shape, and any one of the opposing rectangular surfaces is a rake surface 11. The two-corner type chip can be used selectively with the other side as the bottom surface 14 and the front and back sides as a scooping surface. A mounting hole 17 is formed in the center of the rake face 11 so as to penetrate the rake face 11 and the bottom face 14 facing the rake face 11.

As shown in FIGS. 1 to 3, the tip 10 has one rectangular surface that becomes the rake face 11 facing forward in the tool rotation direction K of the tool body 2, and the other rectangular surface that becomes the bottom surface 14 faces the tip mounting groove 3. Further, the seating is carried out by screwing a clamp screw 20 inserted into the mounting hole 17 into a female screw hole 6A provided in the seating surface 3a. The surface 3a is pressed and fixed.

An outer peripheral cutting edge ridge 13 is formed on a side ridge portion of the rake face 11 located closest to the outer periphery of the tool, and an outer peripheral flank 12 is formed on a side surface connected to the outer peripheral cutting edge ridge 13. The outer peripheral flank 12 has a convex curved shape that curves in the direction along the outer peripheral cutting edge ridge 13 and protrudes toward the outer peripheral side of the tool, and is inclined inward at an angle of 20 ° with respect to the normal line of the rake face 11. It is considered as a positive flank. On the lower side of the outer peripheral flank 12, there is a radial constraining surface 15 formed of a flat plane that is connected to the bottom surface 14 at an angle of 27 ° inward with respect to the normal line. Is formed. The outer peripheral cutting edge ridge 13 formed by the intersecting ridge line between the rake face 11 and the outer peripheral flank face 12 is formed in an arc shape having a radius of curvature R of about 1400 mm when viewed from a direction orthogonal to the rake face 11. Convex arcs having a radius of curvature r centered on the axis of the mounting hole 17 in a cross section parallel to the rake face 11 are formed on the side face of the rake face 11 that is continuous with the short side ridge located on the tool rear end side. A curved axial restraint surface 16 is formed and intersects the rake surface 11 and the bottom surface 14 at a right angle.

The tip 10 is fixed in a state where it is inclined with respect to the tool body 2 in the tool axis direction and the diameter direction, and the axial rake angle AR of the outer peripheral cutting edge ridge 13 is set to a negative angle of −10 °. The radial rake angle RR is a positive angle of 15 °. Furthermore, the two wedge members 40 inserted in the wedge insertion groove 4 adjacent to the rake face 11 on the front side in the tool rotation direction K sink to the axial center side of the tool body 2 by the action of the wedge tightening screw. The rake face 11 is pressed toward the seating surface 3 a side of the chip mounting groove 3.

The tip 10 can be circularly moved in the forward and reverse directions around the axis of the clamp screw 20 by the fine adjustment means 30 including the fine adjustment screw member 31. That is, as understood from FIG. 4, the tool body 2 is formed with a notch 7 having a wall surface facing the rake face 11 of the chip 10 with the chip pocket 5 interposed therebetween, A female screw hole 6B opened in the wall surface of the chip mounting groove 3 is provided so as to face the radial direction restraint surface 15 located on the inner peripheral side of the tool of the chip 10, and fine adjustment screwed into the female screw hole 6B is made. The screw member 31 is capable of urging the tip 10 toward the outer peripheral side of the tool along the seating surface 3a of the tip mounting groove 3 by pressing the radial direction restraint surface 15 with the tip portion thereof. . Further, the female screw hole 6B and the fine adjustment screw member 31 are provided at one position on the front end side in the tool axis direction with the clamp screw 20 for fixing the chip 10 as understood from FIGS. The tip 10 is provided at two locations, one on the rear end side in the central direction, and the tip 10 is rotated around the axis of the clamp screw 20 by the cooperative action of the fine adjustment screw member 31 and the clamp screw 20. The circular motion in the forward and reverse directions is possible.

Further, on the tool rear end side of the chip 10, there is provided an axial support means 50 including an axial support screw member 51 that can be slidably contacted with the axial restraint surface 16 of the chip. That is, a female screw hole 6C is provided in the wall surface on the tool rear end side of the chip mounting groove 3 so as to intersect the axial restraint surface 16 and face the axial restraint surface 16; The axial support screw member 51 screwed into the female screw hole 6C supports the tip 10 in the tool axial direction by making the hemispherical tip portion make point contact with the axial restraint surface 16, and A sliding contact with the axial direction restraint surface 16 is possible with respect to the rotation of the chip 10.

In the throw-away end mill 1 configured as described above, the axial rake angle AR of the outer peripheral cutting edge ridge 13 is −10 °, and the radial rake angle RR (at the tip of the outer peripheral cutting edge ridge 13) is 15 °. Therefore, cutting resistance during machining is reduced, and chips on the machining wall surface 61 are discharged downward and toward the inner peripheral side of the tool, so that the occurrence of flash at the upper end portion 61a of the machining wall surface 61 is prevented. Can be suppressed. Further, an outer peripheral cutting edge ridge 13 that is curved in the tool axis direction and formed on the intersecting ridge line between the outer peripheral flank 12 and the rake face 11 that is convex toward the outer periphery of the tool is orthogonal to the rake face 11. When viewed from the direction, the arcuate convex curved surface shape on the processed wall surface 61 can be reduced because the radius of curvature R is formed in an arc shape of about 1400 mm. In addition, the tip 10 is appropriately rotated around the axis of the clamp screw 20 by the fine adjustment means 30, so that the rotation locus of the outer peripheral cutting edge ridge 13 with the tool axis as the center of rotation is relative to the tool axis. Therefore, the perpendicularity of the processed wall surface 61 can be maintained with high accuracy and stability. The curvature radius R of the outer peripheral cutting edge ridge 13 is appropriately changed according to set values such as the axial rake angle AR, the radial rake angle RR, and the tool diameter. From the above, it is possible to maintain the perpendicularity of the machining wall surface with high accuracy and stability and suppress the flash of the machining wall surface to form a machining wall surface with high accuracy.

Even when the axial rake angle AR of the outer peripheral cutting edge ridge 13 is a positive angle, it is effective for suppressing flashes with improved cutting performance by reducing cutting resistance. When the absolute value of the axial rake angle AR is less than 2 °, it becomes difficult to obtain a flash suppression effect. When the absolute value of the rake angle AR exceeds 30 °, the length of the portion involved in the cutting of the outer peripheral edge 13 is increased. Since the effect of reducing the resistance is impaired, the absolute value is preferably in the range of 2 ° to 30 °. Further, if the rake angle RR in the radial direction becomes a negative angle, it becomes difficult to obtain the effect of reducing the cutting resistance. If the rake angle RR exceeds 30 °, the outer peripheral cutting edge ridge 13 becomes sharp, and chipping and chipping are likely to occur. It is preferable to be in the range of more than 30 ° and less.

In the present embodiment, the fine adjustment means 30 pushes the two radial restraint surfaces 15 at the positions deviated toward the tip end side in the tool axis direction and the rear end side in the tool axis direction with the clamp screw 20 of the tip 10 interposed therebetween. Since the fine adjustment screw member 31 is used, the tip 10 can be circularly moved in the forward and reverse directions around the axis of the clamp screw 20, and fine adjustment can be performed very easily and accurately.

Since the tip 10 is stably supported at three points of the axial support screw member 50 and the two fine adjustment screw members 31, and further firmly fixed to the tool body 2 by two wedge members, the machining wall surface The 61 accuracy deterioration is prevented. Furthermore, since the two wedge members 40 appropriately compensate for the resistance force against the rotation of the tip 10 during fine adjustment, the tip 10 is prevented from being rotated too much and a smooth fine adjustment operation is possible.

As mentioned above, although embodiment of this invention was described based on drawing, these are one embodiment to the last, and this invention can be implemented in the aspect which added the various change and improvement based on the knowledge of those skilled in the art. .

It is the front view which looked at the throw away type end mill which is an embodiment of the present invention from the direction perpendicular to an axis. It is a partial cross section front view of the throwaway type end mill shown in FIG. It is the bottom view seen from the tool front end side of the throw away type end mill shown in FIG. It is the S1-S1 sectional view taken on the line in FIG. It is a front view of the chip | tip with which the throwaway type end mill shown in FIG. 1 is mounted | worn. FIG. 6 is a right side view of the chip shown in FIG. 5. FIG. 6 is a bottom view of the chip shown in FIG. 5. It is a front view of the conventional throw away type end mill. It is a front view of the chip | tip with which the throwaway type end mill shown in FIG. 8 is mounted | worn.

Explanation of symbols

1 Throw-away end mill (rotary tool)
2 Tool body 3 Chip mounting groove 3a Seating surface 4 Wedge insertion groove 5 Chip pocket 6A, 6B, 6C Female thread hole 7 Notch 8A Oil hole 8B Injection hole 9 Connection 10 Tip 11 Rake face 12 Outer clearance face 13 Outer peripheral cutting edge Ridge 14 Bottom 15 Radial restraint surface 16 Axial restraint surface 17 Mounting hole 20 Clamp screw 30 Fine adjustment means 31 Fine adjustment screw member 40 Wedge member 50 Axial support means 51 Axial support screw member 60 Work material 61 Work wall surface 61a Upper end of machining wall

Claims (4)

One or a plurality of chip mounting grooves extending in the axial direction of the tool body are formed on the outer peripheral portion of the cylindrical tool body, and a chip having a substantially polygonal plate shape is formed in the chip mounting groove. The rake face formed on at least one of the opposing polygonal faces is directed forward in the tool rotation direction, the bottom face facing the rake face is in contact with the seating surface of the tip mounting groove, and the tool outer periphery of the rake face The outer peripheral cutting edge ridge formed on the side ridge located on the side is placed so as to protrude from the outer peripheral surface of the tool body, and a clamp screw inserted in the normal direction of the rake face is screwed into the seating surface In the rotary tool fixed to the tool body by
The outer peripheral cutting edge is provided with a positive or negative axial rake angle, and a convex curved outer peripheral flank curved in the outer peripheral cutting edge is formed on a side surface continuous with the outer peripheral cutting edge. Further, the tip can be rotated around the axis of the clamp screw by fine adjustment means, and the side of the tip facing the tool rear end side has a cross section parallel to the rake face of the clamp screw. A curved axial constraining surface having a convex arc centered on the shaft center is formed, and the tip is supported by an axial support member capable of sliding contact with the axial constraining surface. Rotary tool. One or a plurality of chip mounting grooves extending in the axial direction of the tool body are formed on the outer peripheral portion of the cylindrical tool body, and a chip having a substantially polygonal plate shape is formed in the chip mounting groove. The rake face formed on at least one of the opposing polygonal faces is directed forward in the tool rotation direction, the bottom face facing the rake face is in contact with the seating surface of the tip mounting groove, and the tool outer periphery of the rake face The outer peripheral cutting edge ridge formed on the side ridge located on the side is placed so as to protrude from the outer peripheral surface of the tool body, and a clamp screw inserted in the normal direction of the rake face is screwed into the seating surface In the rotary tool fixed to the tool body by
The outer peripheral cutting edge is provided with a positive or negative axial rake angle, and a convex curved outer peripheral flank curved in the outer peripheral cutting edge is formed on a side surface continuous with the outer peripheral cutting edge. Furthermore, the tip is provided with at least one wedge member that can be rotated around the axis of the clamp screw by fine adjustment means and presses the rake face toward the seating face. Rotating tool characterized by The fine adjustment means includes a radially constraining surface formed on a side of the tip facing the inner peripheral side of the tool, on the tip side in the tool axis direction and on the rear end side in the tool axis direction across the axis of the clamp screw. It consists of a fine adjustment screw member that supports the position and urges toward the outer periphery of the tool, and the tip can be rotated around the axis of the clamp screw by the cooperation of the fine adjustment screw members. The rotary tool according to claim 1, wherein the rotary tool is provided. Each of the opposing polygonal surfaces of the chip is a rake surface having a point-symmetric shape, and an outer peripheral cutting edge ridge is formed on a side ridge portion arranged on the outermost tool outer side of each rake surface. The rotary tool according to any one of claims 1 to 3, wherein

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