WO2009107235A1

WO2009107235A1 - Chip suction drill

Info

Publication number: WO2009107235A1
Application number: PCT/JP2008/053658
Authority: WO
Inventors: 誠司大橋; 実朗伊藤; ナーウィンブアカウ; 秀通高橋
Original assignee: オーエスジー株式会社
Priority date: 2008-02-29
Filing date: 2008-02-29
Publication date: 2009-09-03
Also published as: CN101959634A; JPWO2009107235A1; JP4996739B2; KR20100119772A; KR101455582B1; CN101959634B

Abstract

A chip suction drill (10) performs a hole making process to a material to be ground (42) such as a casting using a cutting blade (24). A chip generated is suctioned in a chip suction path (18) from a chip intaking hole (30) formed in a cutting blade groove (22) and ejected to a shank (16) side. In this case, since an air introduction groove (32) is provided in the outer periphery surface of a blade (12), air is excellently introduced into the leading end of a tool at which the chip is generated by the cutting blade (24) and the air introduced into the leading end of the tool upon the suction of air by the chip suction path (18) is excellently suctioned in the chip intaking hole (30) together with the chip. Particularly, since only one chip suction path (18) is provided in the tool, its cross section area can be sufficiently secured and the chip intaking hole (30) can be enlarged along with the enlargement of the chip suction path (18). Thus, the generation of chip packing can be suppressed and excellent chip suction performance can be obtained.

Description

Chip suction drill

The present invention relates to a drill, and more particularly to a chip suction drill that forcibly sucks and discharges chips in order to prevent environmental pollution and simplify cleaning operations.

(a) a cutting edge groove formed on the outer peripheral surface, and a cutting edge provided with a cutting edge for drilling on the edge where the cutting edge groove opens on the tool tip side; and (b) a tool A chip suction passage provided along the axis and formed with a chip take-in hole opened in the groove for the cutting edge, and (c) a tool while being driven to rotate around the axis. Drilling is performed by the cutting blade by being advanced toward the tip side, and chips generated by the drilling are sucked into the chip suction passage from the chip intake hole and discharged to the shank side. A chip suction drill has been proposed (see Patent Document 1). According to such a chip suction drill, chips generated by drilling are sucked into the chip suction passage from the chip intake hole and discharged to the shank side. Thus, the cleaning of the chip becomes easier and the cleaning work is simplified, and the deterioration of the working environment due to the scattering of the chip is greatly improved.
Japanese Patent Publication No.44-13745

By the way, in the chip suction drill described in the above cited reference 1, an air introduction passage is provided inside the tool separately from the chip suction passage, and air is drawn from the air introduction passage along with suction by the chip suction passage. Since it is introduced to the tip, it is difficult to secure a sufficient cross-sectional area of the chip suction passage, chip clogging is likely to occur, and the chip intake hole is small, so that chip suction is possible. There was a problem that the effect could not be obtained sufficiently. Since the opening of the air introduction passage, that is, the air introduction site is also in front of the cutting edge, the chips generated by the cutting edge cannot always be efficiently guided to the chip intake hole. Further, since the spiral groove is continuously provided in the axial direction continuously to the cutting edge groove for forming the cutting edge, air is also introduced from the spiral groove to the tool tip side. Therefore, there is a possibility that the chip suction passage sucks only air and the chips cannot be sucked well. Furthermore, since air is introduced into the air introduction passage only by the negative pressure of the chip suction passage, it is difficult to generate a sufficient air flow. It may not be possible.

The present invention has been made in the background of the above circumstances, and the object of the present invention is that the chips generated by the cutting blade are sucked well into the chip suction passage by a high suction action, and chip clogging is caused. It is to ensure that the chips are discharged well through the chip suction passage without being generated.

In order to achieve such an object, according to the first aspect of the present invention, (a) a cutting edge groove is formed on the outer peripheral surface of the rod, and the cutting edge groove is formed at the edge of the tool leading end. A blade portion provided with a blade; and (b) a chip suction passage provided along the axis O inside the scissors tool and having a chip intake hole opened in the groove for the cutting edge. And (c) drilling is performed by the cutting edge while being driven to rotate toward the tool tip while being rotationally driven around the shaft axis O, and the chips generated by the drilling are cut into the chip-taking hole. In the chip suction drill for sucking into the chip suction passage and discharging to the shank side, (d) An air introduction groove is provided on the outer peripheral surface of the blade portion so as to reach the flank face of the cutting blade. It is characterized by.

The second invention is the chip suction drill of the first invention, wherein (a) the cutting edge groove is a straight groove parallel to the axis O or a twist groove twisted in the same direction as the tool rotation direction as viewed from the shank side. (B) The air introduction groove is a straight groove parallel to the shaft center O or a twist groove twisted in the direction opposite to the tool rotation direction as viewed from the shank side, and is axially closer to the shank than the cutting edge groove. It is provided so that it may extend long.

According to a third invention, in the chip suction drill of the first invention or the second invention, the axial length L3 of the blade portion with respect to the drill diameter D is in the range of 1.0D to 2.0D. Features. In addition, a blade part is the range in which the said groove | channel for cutting edges is formed.

According to a fourth aspect of the present invention, in the chip suction drill of any one of the first to third aspects, the axial length L1 of the chip take-in hole with respect to the drill diameter D is in the range of 0.3D to 1.0D. Among them, the width dimension L2 which is the maximum dimension in the width direction perpendicular to the axial direction is 0.15D or more.

A fifth aspect of the present invention is the chip suction drill according to any one of the first to fourth aspects of the present invention, wherein air introduced through the air introduction groove is formed on the flank of the cutting edge. A predetermined relief is provided so as to flow into the cutting edge groove through a gap between the bottom surface and the bottom surface.

According to a sixth aspect of the present invention, in the chip suction drill according to any one of the first to fifth aspects of the invention, the cutting edge of the edge where the groove for the cutting edge opens on the tool tip side is formed on the flank of the cutting edge. A communication groove is provided so as to connect a portion located on the opposite side to the air introduction groove.

According to a seventh aspect of the present invention, in the chip suction drill according to any one of the first to sixth aspects of the invention, (a) a pair of the cutting edge groove and the cutting edge are provided symmetrically with respect to the axis O. On the other hand, (b) the chip suction passage is a single circular hole formed concentrically with the axial center O of the tool, and (c) the pair of the pair of chip suction passages so as to partially intersect the tip of the chip suction passage. By providing the cutting edge groove, a pair of chip taking holes each opening in the cutting edge groove is formed.

An eighth invention is the chip suction drill according to any one of the first to seventh inventions, wherein (a) the blade has a neck portion that is continuous with the blade portion and has a smaller diameter than the blade portion; The cutting edge groove is provided in a range that does not reach the step at the boundary between the blade part and the neck part. (C) The air introduction groove includes a step at the boundary between the blade part and the neck part. Is provided.

A ninth aspect of the present invention is the chip suction drill according to the eighth aspect of the present invention, wherein the diameter d1 of the neck portion is equal to or larger than the cross-sectional area of the chip suction passage between the inner peripheral surface of the machining hole. It is defined that an annular space is formed.

In such a chip suction drill, since an air introduction groove is provided on the outer peripheral surface of the blade portion so as to reach the flank surface of the cutting blade, air is generated at the tip of the tool where chips are generated by the cutting blade. As the air is sucked in through the chip suction passage, the air introduced from the air introduction groove to the tool tip is sucked into the chip take-in hole together with the chips, and the chips are sucked. It will be discharged well to the shank side through the passage. In that case, by providing an air introduction groove on the outer peripheral surface of the blade portion, only a chip suction passage is provided in the tool, so that a sufficient cross-sectional area of the chip suction passage is ensured. As the chip suction passage is enlarged, the chip take-in hole can be enlarged, so that the occurrence of chip clogging is suppressed and excellent chip suction performance can be obtained. In addition, as compared with the case where an air introduction passage is provided inside the tool, the air introduction portion is closer to the cutting edge that generates chips, so that the chips are more effectively guided into the chip intake hole. And the chip suction performance is further improved.

In addition, if the blade portion provided with the cutting edge groove enters the machining hole as the drilling progresses, air flow from the cutting edge groove is restricted. Is introduced into the tip end of the tool, and the chip is more satisfactorily sucked into the chip suction passage when sucked into the chip take-in hole from the tip end side of the tool.

In the second invention, the air introduction groove is a straight groove parallel to the axis O or a twisted groove twisted in the direction opposite to the tool rotation direction, and in the case of the twisted groove, the tool is rotated during drilling. Along with this, air is introduced better to the tool tip side through the air introduction groove, coupled with the suction of air by the chip suction passage, the air flowing from the air introduction groove to the chip intake hole through the tool tip part. The flow is well formed and the air flow allows the chips to be sucked better into the chip suction passage. Further, since the air introduction groove is provided so as to extend longer in the axial direction to the shank side than the cutting edge groove, after the cutting edge groove has completely entered the machining hole, the air introduction groove is provided. Air is introduced into the tool tip as a center, and excellent chip suction performance can be obtained.

In the third invention, since the axial length L3 of the blade portion provided with the cutting edge groove is relatively short within the range of 1.0D to 2.0D, the processing resistance due to the sliding contact between the processing hole and the blade portion When machining a hole deeper than the blade, air is introduced into the tool tip centering on the air introduction groove after the blade has completely entered the machining hole. Therefore, excellent chip suction performance can be obtained.

In the fourth invention, since the axial length L1 of the chip take-in hole is in the range of 0.3D to 1.0D and the width dimension L2 perpendicular to the axial direction is 0.15D or more, it is generated by the cutting edge. Chips are sucked well into the chip take-up hole. In particular, when a chip such as a casting that is relatively small and difficult to be entangled is generated, the chip can be satisfactorily sucked and removed.

In the fifth invention, a predetermined relief is provided on the flank face of the cutting edge, and the air introduced through the air introduction groove passes through the gap between the flank face and the bottom surface of the machining hole and enters the inside of the cutting edge groove. Therefore, the air introduced into the air introduction groove can be satisfactorily flowed into the cutting edge groove through the gap between the flank face of the cutting edge and the bottom surface of the machining hole, The air flow for sucking the chips into the chip taking-in holes is well formed.

In the sixth aspect of the present invention, since the communication groove is provided on the flank face of the cutting edge, and the cutting edge groove and the air introduction groove are connected, the air introduced into the air introduction groove is cut through the communication groove. A flow of air that is satisfactorily flowed into the blade groove and sucked into the chip take-in hole is well formed.

In the seventh invention, a pair of cutting edges are provided symmetrically with respect to the axis O, but since a single chip suction passage is provided concentrically with the axis O of the tool, there is a large flow interruption. The area can be secured, and chips generated by the pair of cutting edges can be discharged to the shank side satisfactorily while suppressing chip clogging. In addition, since a pair of cutting edge grooves are provided so as to partially intersect the tip of the chip suction passage and a pair of chip taking holes are formed, the cutting edge groove is formed by cutting or grinding. At the time of forming, a chip taking hole can be provided at the same time, and the shape and size of the chip taking hole can be easily adjusted, for example, by changing the gradient angle θ of the cutting edge groove.

According to an eighth aspect of the present invention, in the case where the blade portion has a neck portion having a diameter smaller than that of the blade portion and an air introduction groove is provided including a step at the boundary between the blade portion and the neck portion, Since air is satisfactorily introduced into the air introduction groove through the gap between the circumferential surface and the neck, the processing length of the air introduction groove is shortened, and the neck is processed by cylindrical cutting or grinding. Since it can be carried out relatively easily and quickly, the production costs are reduced.

In the ninth aspect of the invention, the diameter d1 of the neck is determined such that an annular space having a cross-sectional area equal to or greater than the cross-sectional area of the chip suction passage is formed between the inner peripheral surface of the machining hole. Therefore, a sufficient amount of air flows between the neck portion and the inner peripheral surface of the machining hole, and the air flow for sucking the chips into the chip taking-in holes is well formed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a two-blade chip suction drill according to an embodiment of the present invention, where (a) is a schematic front view, (b) is an enlarged view of a tip, and (c) is (b) An end view as viewed from the tip side, (d) is a view as seen from below (c), and (b) is a view as seen from a direction in which the phase around the axis O is 90 ° different from. It is sectional drawing which fractured | ruptured the front-end | tip part of the chip suction drill of FIG. 1 along the groove | channel for cutting edges. It is an enlarged view of the chip taking-in hole provided in the chip suction drill of FIG. It is sectional drawing explaining the flow of the air at the time of drilling using the chip suction drill of FIG. It is a figure explaining the result of having drilled using 4 types of test products including the product of the present invention and examining the chip suction performance. It is a figure explaining the other Example of this invention, and is an enlarged view of the front-end | tip part corresponding to (d) ridge of FIG. It is a front view explaining another Example of this invention.

Explanation of symbols

10, 50, 60: Chip suction drill 12, 62: Blade part 14: Neck part 16: Shank 18: Chip suction passage 20: Processing hole 22: Groove for cutting edge 24: Cutting edge 26: Flank 30: Chip Intake holes 32, 64: Air introduction groove 52: Communication groove O: Shaft center D: Drill diameter

The present invention is preferably applied to a two-blade drill, but can also be applied to a single-blade drill or a drill having three or more blades. As the material of the drill, various tool materials such as cemented carbide and high-speed tool steel can be used.

The chip suction drill of the present invention is basically suitably used for dry processing that does not use a cutting fluid, but uses a mist-like cutting fluid as long as the chip suction action can be appropriately obtained. There is no problem. In addition, it is suitably used for drilling a work material such as a casting or an aluminum casting that has fine chips and is not easily entangled.

The present invention is preferably applied to a drill having a neck portion having a diameter smaller than that of the blade portion. However, the diameter reaches a shank with substantially the same diameter as the drill diameter D, or the diameter dimension continuously increases toward the shank side. The present invention can be applied well to those provided with a small back taper. In that case, it is desirable to set the blade portion provided with the cutting edge groove in a relatively short range on the tip side (for example, axial length L3 = about 1.0D to 2.0D). It suffices to extend the blade portion toward the shank side.

The cutting edge groove may be parallel to the axis O, but on the shank side so that the chips generated by the cutting edge flow well toward the chip taking hole opening in the cutting edge groove. It is desirable to use a twisted groove that is twisted in the same direction as the tool rotation direction seen from above. Since this cutting edge groove may be short, it may be a linear inclined groove inclined with respect to the axis O, and such an inclined groove is also an embodiment of a twisted groove. Note that the cutting edge groove is relatively short and the chips are sucked in by suction of the chip suction passage, so that the cutting edge groove is twisted or inclined in the direction opposite to the tool rotation direction seen from the shank side. However, it can be sucked into the chip take-in hole.

The chip suction passage is preferably, for example, a linear circular hole provided concentrically with the axis O, but a twisted hole twisted around the axis O or a square hole having a triangular or quadrangular cross section may be employed. Various modes capable of distributing chips are possible. In the case of a chip suction passage having a circular hole, if the diameter d2 is too small, the flow of chips is hindered, and if it is too large, the rigidity of the tool is impaired. For example, the diameter d2 is within the range of 0.3D to 0.7D. Appropriate, about 0.5D to 0.7D is desirable. The chip suction passage is provided so as to reach the end face on the shank side, for example, and is configured to discharge the chip, but it is formed on the outer peripheral surface at the middle part of the shank or the boundary between the shank and the neck part. It is also possible to discharge chips by providing an open discharge hole or the like.

The air introduction groove may be parallel to the axis O, but may be a twist groove twisted in the direction opposite to the tool rotation direction seen from the shank side so that air flows in as the tool rotates. desirable. When the length dimension is short, such as when an air introduction groove is provided only in the blade portion with a small-diameter neck, it may be a linear inclined groove inclined with respect to the axis O. Such an inclined groove is also an embodiment of a twisted groove. In addition, since air flows into the air introduction groove even by negative pressure due to suction of the chip suction passage, an air introduction groove that is twisted or inclined in the same direction as the tool rotation direction seen from the shank side is adopted. You can also

The air introduction grooves are provided in the same number as the cutting edge grooves corresponding to the cutting edge grooves. The air introduction groove is, for example, an arc groove that is curved along the outer peripheral surface with a certain depth, and can be formed by cutting or grinding with a grindstone. It is desirable that the air introduction groove is provided so as not to cross or contact the cutting edge groove, and is completely separated so that air does not flow through each other except for the flow at the tool tip. May be connected to allow a small amount of air to circulate. For example, the tip of the air introduction groove may open at the boundary between the cutting edge flank and the cutting edge groove.

If the axial length L1 of the chip take-in hole is smaller than 0.3D, chip clogging is likely to occur and there is a high possibility of welding, while the axial length L1 is larger than 1.0D. Therefore, only air is easily sucked and the chip suction performance is deteriorated, so that the range of 0.3D to 1.0D is appropriate. Further, if the width dimension L2 of the chip take-in hole is smaller than 0.15D, chip clogging is likely to occur and the possibility of welding is increased. The upper limit of the width dimension L2 is determined by the size of the chip suction passage, the cross-sectional shape of the cutting edge groove, and the like.

The chip take-in hole is formed, for example, by providing a cutting edge groove so as to partially intersect the tip of the chip suction passage, but the hole formed by the intersection is not necessarily used as the chip take-in hole. It is not necessary to do so, and if necessary, the hole may be enlarged by grinding or the like to be used as a chip take-in hole. When the cutting edge groove and the chip suction passage do not intersect at all, various forms such as making a hole in the bottom of the cutting edge groove and communicating with the chip suction passage may be used. Is possible.

Since the blade portion only needs to be able to form the above-described chip taking-in hole, the length L3 is suitably in the range of 1.0D to 2.0D. The length L3 may be longer than 2.0D. However, for example, when a twisted groove is formed as the air introduction groove, the air introduction groove does not interfere (contact) with the cutting edge groove. The length L3 of the blade, that is, the length of the groove for the cutting edge is preferably as short as possible.

In the eighth aspect of the invention, the cutting edge groove is provided in a range that does not reach the step at the boundary between the blade part and the neck part. For example, it is difficult to sufficiently introduce air with only the air introduction groove. When it is difficult to form an air flow, the cutting edge groove is formed so as to reach the step at the boundary between the blade part and the neck part so that a predetermined amount of air flows into the cutting blade groove from the neck part. It is also possible to configure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing a chip suction drill 10 according to an embodiment of the present invention, where (a) is a schematic front view seen from a direction perpendicular to the axis O, and (b) is an enlarged view of a blade 12 at the tip. , (C) is an end view as viewed from the right side of (b), that is, from the front end side, and (d) is a view as viewed from below (c). The phase around the axis O is 90 ° compared to (b). It is the figure seen from the different direction. The chip suction drill 10 is made of a cemented carbide, has a blade portion 12 having the same diameter as the drill diameter D, a neck portion 14 having a smaller diameter than the blade portion 12 and a constant diameter d1, and a blade. A shank 16 having the same diameter as that of the portion 12 is provided continuously and integrally on the axis O. In this embodiment, the drill diameter D = 10 mm, the diameter dimension d1 of the neck portion 14 = 8 mm, and a constant diameter dimension d2 = 6 mm (0.6 D) from the end surface on the shank 16 side to the tip end on the axis O. A straight circular hole with a bottom is formed as the chip suction passage 18. The diameter d1 of the neck 14 is such that the annular gap 21 between the inner diameter of the machining hole 20 (see FIG. 4) is substantially the same as the cross-sectional area of the chip suction passage 18. = The drill diameter D is determined so as to satisfy the following formula (1).
D ² π-d1 ² π = d2 ² π (1)

A pair of cutting edge grooves 22 are provided symmetrically with respect to the axis O on the outer peripheral surface of the blade portion 12, and holes are formed in the edges of the cutting edge grooves 22 that open to the tool front end side. A cutting edge 24 for dawn is provided. The chip suction drill 10 of the present embodiment performs drilling by being rotated clockwise when viewed from the shank 16 side, and the cutting edge groove 22 has a predetermined twist angle (for example, about 20 °). ) To be twisted clockwise, strictly speaking, a linear inclined groove, and the chips generated by the cutting edge 24 are caused by the inclination of the cutting edge groove 22 as the tool rotates. A component force in the direction toward the neck 14 is applied. Further, the cutting edge 24 is formed with a flank 26 so as to escape in a circular arc shape with a predetermined clearance angle ρ. The clearance angle ρ is about 10 ° in this embodiment.

As shown in FIG. 2, the cutting edge groove 22 is inclined with respect to the axis O from the tip at a predetermined gradient angle θ with a core thickness of about 1.0 to 1.3 mm remaining at the tip. In this way, the chip is formed by grinding with a grindstone, and a chip take-in hole 30 is formed by a part of the groove bottom intersecting (interfering) with the chip suction passage 18. FIG. 3 is a front view showing the chip take-in hole 30, that is, an enlarged view of the shape corresponding to FIG. 1 (b), and the axial length L1 in the direction parallel to the axis O of the chip take-in hole 30 is Within the range of 0.3D to 1.0D, the width dimension L2 that is the maximum dimension in the width direction perpendicular to the axial direction is 0.15D or more. The shape and size of the chip take-in hole 30 are determined by the gradient angle θ and the cross-sectional shape of the cutting edge groove 22, and in this embodiment, the gradient angle θ≈20 ° and the axial length L1≈5.0 mm. (0.5D) and the width L2≈2.5 mm (0.25D). FIG. 2 is a cross-sectional view cut along the inclination (twist) of the cutting edge groove 22.

The blade portion 12 has an axial length L3 of 1. to prevent the cutting edge groove 22 from reaching the neck portion 14 and, strictly speaking, not to reach the step at the boundary between the neck portion 14 and the blade portion 12. It is set within the range of 0D to 2.0D, and in this embodiment, L3≈12 mm (1.2D).

A pair of air introduction grooves 32 are provided symmetrically with respect to the axis O so as not to intersect with the cutting edge groove 22 on the outer peripheral surface of the blade portion 12. The air introduction groove 32 is a twist groove twisted at a predetermined twist angle (for example, about 30 °) in the direction opposite to the tool rotation direction as viewed from the shank 16 side, that is, counterclockwise, and the level difference at the boundary between the neck portion 14 and the blade portion 12. The external air is caused to flow along the air introduction groove 32 to the tip side of the tool as the tool rotates during drilling. The air introduction groove 32 has a predetermined width dimension (for example, about 2 to 3 mm) by grinding with a grindstone, and the groove bottom diameter is, for example, substantially the same as or smaller than the diameter dimension of the neck portion 14, and at least in the chip suction passage 18. It is formed so as not to reach. In the present embodiment, the air introduction groove 32 is provided completely separated without contacting the cutting edge groove 22 over its entire length.

As shown in FIG. 4, such a chip suction drill 10 has a suction device 40 connected to a rear end portion of the chip suction passage 18, that is, an opening on the shank 16 side. While suctioning air with the suction force of the tool, it is advanced to the tool tip side while being driven to rotate clockwise around the axis O as viewed from the shank 16 side by a processing machine (machining center or the like) (not shown), and a casting or the like by the cutting edge 24 Drilling is performed on the workpiece 42. In this case, chips generated by drilling are sucked into the chip suction passage 18 from the chip take-in hole 30 formed in the cutting edge groove 22 and discharged to the shank 16 side.

Here, in this embodiment, since the air introduction groove 32 is provided on the outer peripheral surface of the blade portion 12 so as to reach the flank 26 of the cutting blade 24, the cutting edge 24 generates a chip at the tip portion of the tool. Air is introduced well, and the air introduced from the air introduction groove 32 to the tip of the tool is sucked into the chip take-in hole 30 together with the chips as the air is sucked by the chip suction passage 18. Is done. In particular, since the air introduction groove 32 is provided on the outer peripheral surface of the blade portion 12, only one chip suction passage 18 is provided inside the tool, and therefore, the cross-sectional area of the chip suction passage 18 is determined. It is possible to ensure sufficient, and the chip take-in hole 30 can be enlarged as the chip suction passage 18 is enlarged, so that the occurrence of chip clogging is suppressed and excellent chip suction performance is achieved. Can be obtained.

Further, compared with the case where the air introduction passage is provided inside the tool, the air introduction portion is closer to the cutting edge 24 that generates chips, so that the chips are more effectively contained in the chip intake hole 30. The chip suction performance is further improved.

Further, when the blade portion 12 provided with the cutting edge groove 22 enters the processing hole 20 as the drilling progresses, air flow from the cutting edge groove 22 is restricted, so that air is introduced. Air is introduced into the tip of the tool centering on the groove 32, and when sucked into the chip take-in hole 30 from the tip of the tool, the chip is sucked into the chip suction passage 18 even better. It becomes like this. That is, the air introduction groove 32 is formed including a step at the boundary between the blade portion 12 and the neck portion 14, and extends toward the shank 16 rather than the cutting blade groove 22 provided so as not to reach the step at the boundary. Since the air introduction groove 32 and the cutting edge groove 22 are formed so as not to intersect each other, the blade portion provided with the cutting edge groove 22 is provided. After 12 completely enters the machining hole 20, air is introduced exclusively into the tool tip from the air introduction groove 32, and excellent chip suction performance can be obtained. The bold arrows in FIG. 4 indicate the air flow at this time.

Further, in this embodiment, since the air introduction groove 32 is a torsion groove twisted in the direction opposite to the tool rotation direction, the air is introduced to the tool tip side through the air introduction groove 32 as the tool rotates during drilling. The air flow from the air introduction groove 32 to the chip take-in hole 30 through the tool tip is well formed in combination with the suction of air by the chip suction passage 18, and the air As a result of this flow, the chips are better sucked into the chip suction passage 18.

In the present embodiment, the axial length L3 of the blade portion 12 provided with the cutting edge groove 22 is relatively short within the range of 1.0D to 2.0D. When the hole deeper than the blade portion 12 is machined, the neck portion 14 and the machining hole 20 are removed after the blade portion 12 completely enters the machining hole 20. Air is introduced into the tool tip through the gap 21 between the inner peripheral surface and the air introduction groove 32, and excellent chip suction performance is obtained.

In this embodiment, since the axial length L1 of the chip take-in hole 30 is in the range of 0.3D to 1.0D and the width dimension L2 perpendicular to the axial direction is 0.15D or more, the cutting edge The chips generated by 24 are satisfactorily sucked into the chip intake hole 30. In particular, when a chip such as a casting that is relatively small and difficult to be entangled is generated, the chip can be satisfactorily sucked and removed.

In the present embodiment, the flank 26 of the cutting edge 24 is provided with an arc-shaped flank with a predetermined clearance angle ρ, so that the air introduced into the air introduction groove 32 is flank 26 of the cutting edge 24. And the bottom surface of the machining hole 20 are satisfactorily flowed into the cutting edge groove 22, and a flow of air for sucking chips into the chip take-in hole 30 is well formed.

Further, in this embodiment, a pair of cutting edges 24 are provided symmetrically with respect to the axis O, but a single chip suction passage 18 is provided concentrically with the axis O of the tool. It is possible to secure a large flow cross-sectional area, and it is possible to discharge the chips generated by the pair of cutting edges 24 to the shank 16 side while suppressing chip clogging.

Further, since the pair of cutting edge grooves 22 are provided so as to partially intersect the tip of the chip suction passage 18 and the pair of chip taking holes 30 are formed, the cutting edge groove 22 is formed by grinding. The chip taking hole 30 can be provided simultaneously with the formation, and the shape and size of the chip taking hole 30 can be easily adjusted by changing the gradient angle θ of the groove 22 for the cutting edge. it can.

Further, in this embodiment, the blade portion 12 has a neck portion 14 having a diameter smaller than that of the blade portion 12 continuously, and the air introduction groove 32 is formed including a step at the boundary between the blade portion 12 and the neck portion 14. If provided, air is satisfactorily introduced into the air introduction groove 32 through the gap 21 between the inner peripheral surface of the machining hole 20 and the neck portion 14, so that the processing length of the air introduction groove 32 is shortened. Since the neck portion 14 can be processed relatively easily and quickly by cylindrical grinding or the like, the manufacturing cost is reduced.

In addition, since the diameter d1 of the neck portion 14 is determined so that an annular space having substantially the same cross-sectional area as the cross-sectional area of the chip suction passage 18 is formed with the inner peripheral surface of the processing hole 20, A sufficient amount of air flows between the neck portion 14 and the inner peripheral surface of the machining hole 20, and an air flow for sucking chips into the chip take-in hole 30 is well formed.

Next, as shown in FIG. 5 (b), four types of test pieces No1 to No4 having different sizes of the chip take-in holes 30 and the presence or absence of the air introduction grooves 32 are prepared, and the test conditions shown in (a) Explains the results of drilling and investigating chip suction performance. The basic shapes of the test pieces No1 to No4 are the same as those of the chip suction drill 10 of the above-described embodiment, are provided with a chip suction passage 18 having a diameter d2 = 6 mm, and the chips are formed by the gradient angle θ of the groove 22 for cutting edges. The shape of the intake hole 30 is changed. Test products No. 3 and No. 4 having the air introduction groove 32 are the products of the present invention, and the test product No. 3 among them is the same as that in the above-described embodiment.

Then, when the weight of the chips sucked through the chip suction passage 18 at the time of drilling with the test sample No. 3 was set to 100%, the amount of chip suction was compared, and the result shown in (b) b of FIG. 5 was obtained. It was. In the test sample No. 1 in which the chip take-in hole 30 is relatively small and does not have the air introduction groove 32, the chip is not sucked well, and the chip take-in hole 30 is clogged and welded to cause drilling. Was impossible. The test product No. 2 is provided with a chip take-in hole 30 having the same shape as the test product No. 3, but since the air introduction groove 32 is not provided, the air flow is not formed well, compared with the test product No. 3. The chip suction amount was about 85%. Test No. 4 is a case where the chip take-in hole 30 is large, and therefore the cutting edge groove 22 reaches the neck portion 14 beyond the blade portion 12, and the blade portion 12 has completely entered the machining hole 20. After that, since air is sucked into the chip take-in hole 30 through the cutting edge groove 22, the chip suction performance is impaired by that amount, and the chip suction amount is about 90% compared to the test sample No3. Met.

Next, another embodiment of the present invention will be described. In the following embodiments, parts that are substantially the same as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

The chip suction drill 50 of FIG. 6 is a case where the communication groove 52 is provided on the flank 26 of the cutting edge 24 so as to connect the air introduction groove 32 and the cutting edge groove 22 as compared with the above embodiment. is there. In this case, the air introduced into the air introduction groove 32 can be satisfactorily flowed into the cutting edge groove 22 through the communication groove 52, and the relief of the relief surface 26 due to the relief angle ρ. In combination, the air flow for sucking chips into the chip take-in hole 30 is well formed. Further, by providing the communication groove 52 as described above, the clearance angle ρ can be reduced, and the degree of freedom in design is increased.

The chip suction drill 60 of FIG. 7 is provided with a back taper whose diameter is continuously reduced from the drill tip toward the shank 16 side, and the cutting edge groove 22 is the same as in the above embodiment. The range of the axial length L3 in which the cutting edge groove 22 is provided is the blade portion 62. On the other hand, the pair of air introduction grooves 64 provided so as to reach the flank 26 corresponding to the pair of cutting edge grooves 22 do not intersect the cutting edge groove 22 like the air introduction groove 32. However, the length dimension is sufficiently long and is provided in a spiral shape on the outer peripheral surface of the drill, and even when the blade portion 62 enters the processing hole 20 completely during drilling, External air can be introduced into the tool tip from the air introduction groove 64.

Also in this embodiment, the air introduction groove 64 is provided on the outer peripheral surface including the blade portion 62, and external air is favorably introduced into the tool tip through the air introduction groove 64. It is sufficient that only one chip suction passage 18 is provided, and a sufficient cross-sectional area of the chip suction passage 18 can be ensured. Since 30 can be increased, the same effects as those of the above-described embodiment can be obtained, for example, generation of chip clogging can be suppressed and excellent chip suction performance can be obtained.

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

The chip suction drill of the present invention is provided with an air introduction groove on the outer peripheral surface of the blade part, and external air is favorably introduced into the tool tip part through the air introduction groove. It is only necessary to provide a suction passage, it is possible to secure a sufficient cross-sectional area of the chip suction passage, and the chip intake hole can be enlarged with the enlargement of the chip suction passage. Occurrence of clogging is suppressed, and excellent chip suction performance can be obtained, which is suitably used for an environment-friendly drilling process that does not discharge chips.

Claims

A cutting edge groove formed on the outer peripheral surface, and a cutting edge provided with a cutting edge for drilling at the edge where the cutting edge groove opens on the tool tip side;
A chip suction passage provided inside the tool along the axis O and formed with a chip take-in hole that opens in the groove for the cutting edge;
And is drilled by the cutting blade by being advanced around the axis O while being driven to rotate, and the chips generated by the drilling are removed from the chip-taking hole. In the chip suction drill for sucking into the chip suction passage and discharging to the shank side,
A chip suction drill, wherein an air introduction groove is provided on an outer peripheral surface of the blade portion so as to reach a clearance surface of the cutting blade.
The cutting edge groove is a straight groove parallel to the axis O or a twisted groove twisted in the same direction as the tool rotation direction seen from the shank side.
The air introduction groove is a straight groove parallel to the axis O or a torsion groove twisted in a direction opposite to the tool rotation direction as viewed from the shank side, and extends in the axial direction to the shank side longer than the cutting edge groove. The chip suction drill according to claim 1, wherein the chip suction drill is provided.
The chip suction drill according to claim 1 or 2, wherein an axial length L3 of the blade portion is within a range of 1.0D to 2.0D with respect to a drill diameter D.
The axial length L1 of the chip take-in hole with respect to the drill diameter D is in the range of 0.3D to 1.0D, and the width dimension L2 which is the maximum dimension in the width direction perpendicular to the axial direction is 0.15D. The chip suction drill according to any one of claims 1 to 3, wherein the chip suction drill is as described above.
The flank of the cutting edge has a predetermined size so that air introduced through the air introduction groove can flow into the cutting edge groove through a gap between the flank and the bottom surface of the machining hole. The chip suction drill according to any one of claims 1 to 4, wherein a relief is provided.
The flank of the cutting edge is provided with a communication groove so as to connect the air introduction groove with a portion of the edge where the groove for the cutting edge is open on the tool tip side and located on the side opposite to the cutting edge. The chip suction drill according to any one of claims 1 to 5, wherein the chip suction drill is provided.
While the pair of the cutting edge groove and the cutting edge are provided symmetrically with respect to the axis O,
The chip suction passage is a single circular hole formed concentrically with the axis O of the tool,
The pair of cutting edge grooves are provided so as to partially intersect the tip of the chip suction passage, thereby forming a pair of chip taking holes each opening to the cutting edge groove. The chip suction drill according to any one of claims 1 to 6.
Having a neck that is continuous with the blade and smaller in diameter than the blade,
While the groove for the cutting edge is provided in a range that does not reach the step at the boundary between the blade part and the neck part,
The chip suction drill according to any one of claims 1 to 7, wherein the air introduction groove includes a step at a boundary between the blade portion and the neck portion.
The diameter d1 of the neck is determined such that an annular space having a cross-sectional area equal to or greater than the cross-sectional area of the chip suction passage is formed between the inner peripheral surface of the machining hole. A chip suction drill according to claim 8.