JP2014108474A - Drilling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling tool that is excellent in dischargeability of swarf and that facilitates working.SOLUTION: A drilling tool includes: an approximately cylindrical tool body 2 that is rotatively driven around an axis line; a swarf discharge groove 3 that is elongated toward a base end 2b of the tool body 2 from a tip 2a thereof; a cutting blade 4 that is provided at the tip 2a of the tool body 2; a division groove 5 that divides the cutting blade 4 into a plurality of areas; and a coolant discharge port 7 that is opened on a wall surface of the swarf discharge groove 3 and that discharges a coolant toward the area, except the division groove 5, of the cutting blade 4.

Description

  The present invention relates to a drilling tool.

  A drilling tool is widely used when drilling a work material in production of engine parts or molds. It has been found that the chip discharging performance of this drilling tool has a great influence on the machining accuracy of the cutting hole of the work material.

  For example, the drill described in the following Patent Document 1 shows a drill in which chips are generated by being cut in the width direction by forming a concave nick in the cutting edge. In this case, since chips are generated for each short range between nicks, it is difficult to sufficiently curl the chips and divide them in the length direction. Therefore, the invention described in this document attempts to divide the chips in the length direction by forming honing (chamfering) on the cutting edge.

JP 2007-50477 A

  However, in the configuration in which the honing is provided on the cutting edge as described above, it cannot be said that the chips can be curled reliably in the length direction, and the chip dischargeability may not be sufficiently improved.

  Moreover, the drill of the said patent document 1 is provided with the oil groove in the rake face on the extension of the oil hole formed in the chip breaker surface. In this case, the oil hole needs to be provided at a position that opens to the chip breaker surface and a part of the oil hole overlaps the rake face (that is, the oil hole partially protrudes from the chip breaker surface. (See FIG. 2 in the literature). For this reason, it is necessary to set the position of the oil hole with respect to the cemented carbide head with high accuracy, and the difficulty of processing increases. In particular, when the diameter of the oil hole is reduced and the discharge pressure of the cutting oil is increased, the position setting of the oil hole becomes very difficult.

  This invention is made | formed in view of the above point, and makes it the technical subject which should be solved to provide the drilling tool excellent in the discharge | emission property of a chip.

  In order to solve the above-described problems, the present invention has a substantially cylindrical shape, a tool body that is driven to rotate around an axis, a chip discharge groove that extends from the distal end to the proximal end of the tool body, and the tool body. A cutting edge provided at the tip of the cutting edge, a dividing groove for dividing the cutting edge into a plurality of areas, and a wall surface of the chip discharge groove, and coolant is directed toward the area of the cutting edge excluding the dividing grooves. A drilling tool having a coolant discharge port for discharging is provided.

  As described above, the drilling tool of the present invention subdivides the chips in the width direction by the dividing grooves provided on the rake face of the cutting blade during the cutting process, and further coolants toward the region excluding the dividing grooves from the coolant discharge port. By discharging the coolant, the coolant can be applied to the chips generated by the cutting blade to curl the chips in the length direction. By curling the chips with the coolant discharge force in this way, the curl diameter of the chips can be reduced and the chips are easily divided in the length direction, so that the chips are refined and the chips are discharged. Can increase the sex.

  In the above drilling tool, if the coolant discharge port is oriented in a direction substantially perpendicular to the extending direction of the cutting blade, the coolant can be applied almost vertically to the chips generated by the cutting blade. The pressure is efficiently transmitted to the chips, and the chips can be curled more reliably.

The drilling tool is formed, for example, in a tool body, and extends in a first coolant path extending in the axial direction and the first coolant path, and opens on the wall surface of the chip discharge groove to form a coolant discharge port. It can be set as the structure provided with 2 coolant paths. Thus, the freedom degree of design is raised by comprising the coolant path | route formed in a tool main body by a 1st coolant path | route and a 2nd coolant path | route. For example, if the first coolant path is offset from the axial center and passes through a relatively thick part of the tool body, the strength of the tool body can be ensured. By branching the second coolant path from the first coolant path, the coolant discharge port can be formed at an arbitrary position.

  In this case, if the second coolant path is formed at a plurality of locations separated in the axial direction, the coolant always hits the cutting blade even when the cutting blade is re-polished and the axial position of the cutting blade is retracted. Design becomes possible. For example, what is necessary is just to make the space | interval of the some 2nd coolant path | route in the extension direction of a cutting blade narrower than the extension direction dimension of each area | region of the cutting blade divided | segmented by the dividing groove. Thereby, the refinement | miniaturization effect of a chip can be maintained over a long period of time.

  As described above, according to the drilling tool of the present invention, the chips generated at the time of cutting are subdivided in the width direction by the dividing grooves, and further, since the coolant is discharged to the chips, the chips are curled small, Divided along its length. Thereby, since chip | tips are refined | miniaturized, discharge | emission property is improved and the fall of the processing precision by chip | tip remaining on a workpiece can be prevented.

It is a top view of the drilling tool which concerns on embodiment of this invention. It is a front view of the drilling tool which concerns on FIG. It is a front view side view in FIG. It is a fragmentary sectional view in FIG. It is a front-end | tip part expanded sectional view in FIG. It is a fragmentary sectional view which shows the cutting aspect of the drilling tool shown in FIG. It is the elements on larger scale of the X area | region of FIG. FIG. 7 is an enlarged cross-sectional view of a front end side view of an X region in FIG.

  Hereinafter, an embodiment of a drilling tool according to the present invention will be described with reference to FIGS.

  The structure of the drilling tool according to the present invention will be described with reference to FIGS. A drilling tool 1 according to the present invention has a substantially cylindrical shape, is attached to a main shaft of a machine tool, and is rotated about an axis, and an axis line from a tip 2a to a base end 2b of the tool body 2 A pair of chip discharge grooves 3 having a substantially V-shaped cross section extending in the direction are provided (see FIG. 3). Further, a fixing groove 21 is provided on the base end 2b side of the tool body 2 for fixing to the spindle of the machine tool. Further, when the fixing groove 21 is not provided, a collet chuck or a milling chuck may be provided on the machine tool side, and the base end 2b of the tool body 2 may be inserted and fixed.

  The pair of chip discharge grooves 3 have two wall surfaces 31 and 32 parallel to the axis, and the tool main body 2 is rotated in the direction of the arrow in FIG. A cutting edge 4 is provided at the tip of the wall surface 32. Further, the cutting blade 4 provided on the wall surface 32 on the rear side in the rotation direction of each chip discharge groove 3 extends from the cutting edge of the cutting blade 4 toward the base end 2b side, and has a plurality of regions in the extending direction of the cutting blade 4. A dividing groove 5 is provided to divide into two.

  Further, as shown in FIG. 4, a first coolant path 6 through which a coolant for cooling the cutting blade 4 flows is provided in the tool body 2 along the axial direction of the tool body 2. The first coolant path 6 is provided by being offset from the axis of the tool body 2, and is formed in a region surrounded by wall surfaces 31 and 32 that form the chip discharge groove 3. The first coolant path 6 is provided with a second coolant path 8 having one end opened to the first coolant path 6 and the other end opened toward the wall surface 32 on the rear side in the rotational direction of the chip discharge groove 3. . The second coolant path 8 allows the coolant discharge port 7 that opens in the wall 31 on the rotational direction side of the chip discharge groove 3 to communicate with the first coolant path 6. The coolant discharge port 7 is open in the direction in which the cutting edge 4 is provided.

As shown in FIG. 5, the second coolant path 8 is provided so as to extend in a direction substantially orthogonal to the extending direction B of the cutting edge 4. That is, the second coolant path 8 and the coolant discharge port 7 are arranged so that the center line of the second coolant path 8 and the extending direction B of the cutting edge 4 intersect each other approximately vertically. Further, a plurality of second coolant paths 8 are arranged apart from each other in the axial direction. At this time, the interval between the plurality of second coolant paths 8 in the extending direction B of the cutting edge 4 is denoted by δ, and the interval of the dividing grooves 5 in the extending direction B of the cutting edge 4 is denoted by Δ. That is, the dimension in the extending direction of the cutting edge 4 divided by the dividing groove 5 is Δ. In the present invention, the relationship between the interval δ of the plurality of second coolant paths 8 and the interval Δ of the dividing grooves 5 in the extending direction B of the cutting blade is such that δ <Δ.
The coolant path 8 and the dividing groove 5 are respectively arranged.

  Next, the effect | action of the drilling tool which concerns on this invention is demonstrated based on FIGS.

  First, the base end 2b side of the tool body 2 is fixed to a spindle or the like of a machine tool (not shown). The tool body 2 is driven to rotate by rotating the main shaft or the like, and the cutting edge 4 provided at the tip 2a of the tool body 2 is brought into contact with the work material W to perform drilling. FIG. 6 is a partial cross-sectional view showing an aspect at the time of cutting the work material W by the cutting edge 4 provided at the tip 2 a of the drilling tool 1. The tool body 2 of the drilling tool 1 is moved in the direction of the arrow while rotating around the axis. As the cutting edge 4 advances while biting into the work material W, the cut chips are generated in a state of warping with respect to the cutting edge (see FIGS. 7 and 8).

  As shown in FIG. 7, the rake face 41 of the cutting edge 4 is provided with a dividing groove 5 that divides the cutting edge 4 in the extending direction B, and the chips cut by the cutting edge of the cutting edge 4 are divided. The grooves 5 are subdivided in the width direction by the uneven portions. The coolant discharged from the coolant discharge port 7 in the direction of the arrow is injected into a region excluding the dividing groove of the cutting blade 4, that is, a portion where chips are generated. As shown in FIGS. 7 and 8, the coolant discharged from the coolant discharge port 7 presses the W1 surface of the chips in the direction of the arrow. As a result, the chips are curled and refined in the direction in which the chips are pressed by the coolant. By providing the coolant discharge port so as to discharge the coolant in the region excluding the dividing groove 5, the rear side of the chips is pressed by the coolant.

Furthermore, since the second coolant path 8 is provided so as to extend in a direction substantially perpendicular to the extending direction B of the cutting blade 4, the discharge pressure of the discharged coolant is directly applied to the W1 surface of the chip, so that the chip is curled. The effect can be further enhanced. Thereby, since the curl diameter of the fragmented chip can be made smaller, the chip dischargeability can be improved. Furthermore, in addition to arranging a plurality of coolant discharge ports 7 in the axial direction of the tool body 2, the interval between the second coolant paths 8 is set smaller than the interval of the dividing grooves in the extending direction of the cutting blade. Thus, even if the position of the cutting edge changes due to wear of the cutting edge or the like, the coolant can always be discharged to the region excluding the dividing groove, and the chip refinement effect can be maintained for a long period of time.

  Although the description has been given of the case where the two chip discharge grooves 3 having a substantially V-shaped cross section extending in the axial direction from the distal end 2a to the proximal end 2b of the tool body 2 are provided, the present invention is not limited thereto. One or three or more may be provided. Moreover, you may change suitably the cutting edge 4 of the front-end | tip of the wall surface of the rotation direction of a tool main body on the wall surface of the chip discharge groove 3 according to the number of the chip discharge grooves 3.

  Further, in the above, as an example, two dividing grooves extending from the cutting edge of the cutting edge 4 toward the base end 2b side and dividing into a plurality of regions in the extending direction of the cutting edge 4 are provided. One or three or more may be provided.

  Further, in the above embodiment, the description has been given of the case where four second coolant paths 8 that are spaced apart from each other in the axial direction of the tool body 2 are disposed. The number may be changed as appropriate.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. The scope of the present invention is not limited to patents. It includes the equivalent meanings recited in the claims, and the equivalent meanings recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Drilling tool 2 Tool main body 21 Fixed groove | channel 2a Tip 2b Base end 3 Chip discharge groove 31 Wall surface (backward direction of rotation)
32 Wall surface (rotation direction side)
4 Cutting edge 41 Rake face 5 Dividing groove 6 First coolant path 7 Coolant discharge port 8 Second coolant path W Work material

Claims (3)

  A tool main body having a substantially cylindrical shape and driven to rotate around an axis, a chip discharge groove extending from the tip of the tool main body toward the base end, a cutting blade provided at the tip of the tool main body, and the cutting A drilling tool comprising: a dividing groove that divides the blade into a plurality of regions; and a coolant discharge port that opens on a wall surface of the chip discharge groove and discharges coolant toward the region of the cutting blade excluding the dividing groove.   The drilling tool according to claim 1, wherein the coolant discharge port faces a direction substantially orthogonal to the extending direction of the cutting blade.   A first coolant path that is formed inside the tool body and extends in the axial direction; a second coolant path that branches off from the first coolant path and opens in a wall surface of the chip discharge groove to form the coolant discharge port; The drilling tool according to claim 1, comprising:

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