JP5809344B1 - Extra fine drill - Google Patents

Abstract

An extremely fine drill capable of effectively discharging chips when a hole having a small diameter is formed in a workpiece. A drill shaft portion is configured to include a regular quadrangular prism-shaped shaft portion main body and a regular quadrangular pyramid-shaped cutting edge portion integrally provided at the tip of the shaft portion main body. A ridge line 17 that functions as a cutting edge is formed at each corner between the triangular side faces 15 adjacent in the circumferential direction of the cutting edge 13. A pair of side surface portions 15a of the four side surface portions 15 of the cutting edge portion 13 is used as an opening side surface portion, and coolant holes extending from the shank portion to the cutting edge portion 13 through the shaft body 9 are formed in the respective opening side surface portions 15a. Configure to open. [Selection] Figure 1

Description

  The present invention relates to an extremely fine drill suitable for making a very small diameter hole in a silicon wafer, glass, ceramics, or a hard and brittle material product such as silicon.

  As a drill for making a hole in a workpiece (workpiece), a spiral blade groove is formed from the tip end of the drill shaft portion to the base end portion, and is generated by the rotation of the cutting edge provided at the tip end of the drill shaft portion. What is comprised so that the chip of a workpiece can be discharged | emitted through this blade groove is used (for example, refer FIG. 4 of patent document 1). Such a drill having a helical blade groove is made of, for example, a metal material and relatively soft, and when the chips generated during drilling are continuous, the continuous chips are spirally formed. Can be efficiently discharged along the blade groove of the glass, but when the workpiece is relatively brittle, for example made of glass, and the chips generated during drilling are in the form of powder, it exhibits a particularly effective chip discharging function. Therefore, even if such a drill is used, chips tend to accumulate in the processing hole. In addition, when the hole to be formed in the workpiece is an extremely fine hole having a diameter of about 0.3 mm to 1.0 mm, for example, and the drill shaft portion is extremely thin, the drill shaft portion is formed by forming a spiral blade groove. Since the strength is significantly reduced, if the workpiece is made of silicon and is hard, for example, the drill may be easily damaged by accumulated chips.

  Therefore, a regular quadrangular pyramid-shaped cutting blade is formed at the tip of the main body of a regular quadrangular prism as an ultra-thin drill shaft used for drilling ultra-fine diameter holes in hard brittle materials such as glass, ceramics, or silicon. Moreover, the thing which does not have a helical blade groove is also disclosed (for example, refer FIG. 1 of patent document 1).

JP 2001-179517 A

  The drill shaft portion as shown in FIG. 1 of Patent Document 1 has high strength because it does not have a spiral blade groove, and is formed in the square outline of the shaft portion main body and the workpiece when drilling. Since a gap is formed between the round processing hole or the grinding hole, when the chip of the workpiece is powdery, the chip can be discharged through this gap.

  However, the gap between the square outline of the shaft body and the circular grinding hole of the workpiece does not act to forcibly eject the chip of the workpiece, so that the chips are removed as the grinding hole becomes deeper. It becomes difficult to discharge out of the grinding hole. Therefore, when drilling deep holes, grinding cycles such as grinding with a drill-extracting a drill from a grinding hole-discharging chips by supplying coolant to the grinding hole-inserting a drill into the grinding hole are frequently used. Therefore, it takes a long time for drilling. Moreover, if the grinding hole is deepened, the chips accumulated at the bottom of the grinding hole cannot be sufficiently discharged even if the coolant is supplied.

  Therefore, an object of the present invention is to provide an ultrafine drill capable of effectively discharging chips when a hole having a fine diameter or an ultrafine diameter is formed in a workpiece.

  To achieve this object, an ultrafine drill of the present invention is an ultrafine drill for making an ultrafine hole, and includes a shank portion and a drill shaft portion provided in the shank portion, The drill shaft portion has a prismatic shaft portion main body extending from the tip of the shank portion, and a pyramid-like or substantially pyramid-shaped cutting edge portion provided integrally at the tip of the shaft portion main body, for example. The cutting edge portion is a plurality of triangular or substantially triangular side portions, and a ridge line as a cutting edge formed at at least one corner between the side portions adjacent to each other in the circumferential direction, or An opening surface portion is provided in the cutting edge portion, and a coolant hole is formed in the shank portion and in the drill shaft portion, and the coolant hole is formed in the opening surface portion of the cutting blade portion. It is an opening. The coolant is supplied from the opening of the opening surface to the tip of the cutting edge, and the cutting edge is cooled. Is forcibly discharged. For example, it is configured such that the cross-sectional shape or the tip surface shape of the tip of the shaft main body matches the bottom shape of the cutting edge. For example, when the shaft body is quadrangular or hexagonal, the cutting edge is formed into a quadrangular pyramid or hexagonal pyramid. It is comprised so that a side part may correspond.

  Although at least one side surface portion of the cutting edge portion can be configured to form an opening surface portion (opening side surface portion), in this case, the bulging portion is formed on the outer surface portion corresponding to the opening surface portion at least on the tip side of the shaft body. Alternatively, it is preferable that an overhang portion is formed and the coolant hole is formed so as to be hooked on the bulge portion or the bulge portion or open at the opening surface portion in close contact with or in contact with the bulge portion or the bulge portion. The outer surface of such a bulging portion or overhanging portion can be positioned in or on a circle whose diameter is the diagonal end surface of the shaft body or the diagonal line of the rectangular cross section. By configuring in this way, the strength of the shaft body or the drill shaft is not greatly reduced even if the coolant hole has a large diameter. More specifically, the front end surface of the bulging portion or the overhanging portion is inclined obliquely outward from the bottom side portion of the opening surface portion (triangular or substantially triangular opening surface portion) toward the base end portion side of the shaft body. In this way, the coolant hole is opened at the opening surface portion so as to hang on the tip surface or approach or contact the tip surface. It is preferable that the front end surface of the bulging portion or the overhanging portion is formed so as to be inclined at the same angle as the opening surface portion (or the base portion side of the opening surface portion when the opening surface portion is bent). Here, it is preferable that a plurality of side surface portions of the cutting edge portion include a non-opening surface portion, and the coolant hole is not opened in the non-opening surface portion of the cutting edge portion, and the outer surface portion corresponding to the non-opening surface portion of the shaft portion main body It is effective that neither the bulging part nor the overhanging part is formed. For example, the side surface portion of the cutting edge portion includes an opening surface portion and a non-opening surface portion. Chips of the object to be processed are discharged from between the outer surface portion of the shaft body corresponding to the non-opening surface portion and the processing hole or the grinding hole, for example.

  A ridge line as a cutting edge is formed at a corner between adjacent side portions in the circumferential direction of the cutting edge, but a chamfered portion is provided at at least one corner to eliminate or almost eliminate the ridge. . The cutting edge portion can be formed in multiple stages so that the inclination becomes gentler from the base side toward the tip side. That is, the cutting edge portion may be bent in a line extending from the apex or the tip to the outer edge of the bottom surface portion along the outer surface to form a multistage pyramid shape. That is, the side surface portion of the cutting edge portion may be bent and formed. Or each side part of a cutting-blade part can be expanded so that it may become convex outside. When a chamfer is provided at the corner of the cutting edge, this chamfer can be used as an opening surface.

  By using the ultrafine drill according to the present invention, for example, it is possible to process an ultrafine deep hole in a short time, and it is possible to reliably prevent chips from being discharged efficiently and damaging the ultrafine drill. .

It is a figure which shows the whole shape of the ultra fine drill which concerns on this invention. It is a perspective view which shows a 1st drill axial part. It is a top view of the 1st drill axis part. It is a side view of the front end side of a 1st drill axial part. It is a figure which shows another shape of a coolant hole. It is a figure which shows the modification of a 1st drill axial part. It is a perspective view of the 2nd drill axis part. It is a top view of the 2nd drill axis part. It is a side view of the front end side of a 2nd drill axial part. It is a perspective view of the 3rd drill axis part. It is a top view of the 3rd drill axis part. It is a side view of the front end side of a 3rd drill axial part. It is a figure which shows the modification of a 3rd drill axial part. It is a perspective view of the 4th drill axis part. It is a top view of the 4th drill axis part. It is a side view of the front end side of a 4th drill axial part. It is a figure which shows the example of a change of a 4th drill axial part. It is a perspective view of a 5th drill axial part. It is a top view of the 5th drill axis part. It is a side view of the front end side of a 5th drill axial part. It is a figure which shows the example of a change of a 5th drill axial part. It is a perspective view of the 6th drill axis part. It is a top view of the 6th drill axis part. It is a side view by the side of the tip of the 6th drill axis part. It is another side view of the front end side of a 6th drill axial part. It is a perspective view of the example of a change of the cutting-blade part of a 6th drill axial part. It is a top view of the example of a change of the cutting-blade part of a 6th drill axial part. It is a figure explaining a hole processing state.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the overall shape of an ultrafine drill according to the present invention will be described with reference to FIG.

  The drill 1 is an ultra-fine micro drill for making an extremely fine hole having a diameter of 0.3 mm to 1.0 mm in a hard and brittle material product such as glass, ceramics, or silicon, and the shank portion 3 and the shank portion 3 For example, a drill shaft portion 7 to which the base end portion 5 is fixed by brazing is provided. The material of the shank part 3 can be ultrafine particle cemented carbide, ultrafine particle cemented carbide, high speed steel or stainless steel, and the material of the drill shaft part 7 is ultrafine particle cemented carbide or ultrafine particle cemented carbide. An alloy obtained by applying a diamond coating, a single crystal diamond, a PCD diamond, an ultrafine particle cemented carbide or an ultra ultrafine particle cemented carbide can be used.

  A first embodiment of the drill shaft 7 will be described with reference to FIGS.

  The first drill shaft portion 7 includes a base portion 5 having a base end portion 5 fixed to the distal end of the shank portion 3 and extending from the shank portion 3, and a shaft portion main body 9 extending from the shank portion 3. A regular quadrangular pyramid-shaped cutting blade portion 13 having a square bottom surface portion coinciding with the tip surface 11 or the tip cross-section of the shaft body 9, and the cutting blade portions 13 are triangular triangles adjacent in the circumferential direction. It has four ridgelines 17 formed at each of the four corners between the side portions 15 of the shape, and each ridgeline 17 is formed to function as a cutting edge. Of the four side surface portions 15 of the cutting edge portion 13, the first pair of side surface portions 15a positioned so as to face each other is an opening side surface portion that forms the opening surface portion, and the first pair of side surface portions 15a positioned so as to face each other. The pair of side surface portions 15b is a non-opening side surface portion that forms a non-opening surface portion, and a coolant hole 19 extending from the shank portion 3 through the shaft body 9 to the cutting edge portion 13 is formed at each opening side surface portion 15a. An opening (see reference numeral 21) is formed in an elliptical shape or an oval shape. The coolant hole 19 is formed from a hole body 23 that passes through the center of the shaft body 9 and a branch portion 25 that bifurcates from the hole body 23 near the tip of the shaft body 9 and opens at the opening side surface 15a. However, as shown in FIG. 5, it may be formed so as to have two hole portions 27 that extend through the shaft main body 9 and open at the opening side surface portion 15a to the separate straight portions. As shown in FIG. 6, an undercut 28 and a margin (chamfer) 30 can be formed on the shaft body 9. The first drill shaft portion 7 may be formed integrally as a whole, or, for example, a distal end member having a base portion and a cutting edge portion 13 that forms the distal end portion of the shaft portion main body 9 and the distal end portion of the shaft portion main body 9. It can form by adhere | attaching the main body member which forms other than.

  A second embodiment of the drill shaft 7 will be described with reference to FIGS.

  The second drill shaft portion 7 is provided integrally with the shaft portion main body 29 whose base end portion 5 is fixed to the distal end of the shank portion 3 and extends from the shank portion 3 and the distal end of the shaft portion main body 29, for example. The cutting blade part 31 and the bulging part 33 integrally formed in the axial part main body 29 are provided. Although the shaft main body 29 is formed as a regular quadrangular prism (refer to the one-dot chain line in FIG. 8), a pair of elongated rectangular outer surfaces positioned so as to oppose the regular quadratic columnar main body 29. The section is integrally provided with a pair of bulging portions 33 having an arc cross section, and the shaft body 29 and the bulging portion 33 have a cross-sectional shape in which a pair of opposing sides of a square are bulged into an arc shape. Have. The distal end surface portion 35 of the bulging portion 33 is formed so as to be inclined obliquely outward toward the base end portion 5 side of the shaft body 29. The cutting edge portion 31 is formed in a regular quadrangular pyramid shape having a square bottom surface portion that coincides with the distal end surface 37 or the distal end section of the shaft body 29, and a corner portion between the triangular side portions 39 adjacent in the circumferential direction. Each of the four ridge lines 41 is formed so as to function as a cutting edge. The outer surface of the bulging portion 33 is located in or on a circle whose diameter is a diagonal line of the square tip surface 37 of the shaft body 29. Of the four side surface portions 39 of the cutting edge portion 31, the pair of side surface portions 39 a corresponding to the pair of bulging portions 33 is an opening side surface portion that forms an opening surface portion, and is positioned between the pair of bulging portions 33. The pair of side surface portions 39b is a non-opening side surface portion forming a non-opening surface portion, and the coolant holes 43 extending from the shank portion 3 through the shaft body 29 to the cutting edge portion 31 are swelled at the respective opening side surface portions 39a. It hangs on the front end surface portion 35 of the protruding portion 33 and opens in an elliptical shape or an oval shape (see reference numeral 45). The front end surface portion 35 of the bulging portion 33 is continuous with the bottom side portion 47 of the opening side surface portion 39a and spreads so as to be inclined at the same inclination as the opening side surface portion 39a. The coolant hole 43 includes a hole body 49 that passes through the center of the shaft body 29, a bifurcated shape from the hole body 49 near the tip of the shaft body 29, and an opening side surface 39 a and a tip surface 35 of the bulging portion 33. The bifurcated portion 51 is formed to have two separate hole portions 53 that open through the shaft body 29 and open at the opening side surface portion 39a and the distal end surface portion 35 of the bulging portion 33. May be. In this case, each of the two hole portions 53 enters the inner portion of the bulging portion 33 and extends linearly within the shaft portion main body 29 until it is opened at the opening side surface portion 39a and the tip surface portion 35 of the bulging portion 33. Formed as follows. The second drill shaft portion 7 is formed integrally as a whole, for example, a distal end side member having a distal end portion (a portion including the distal end surface portion 35 as a whole) of the shaft main body 29 and a cutting edge portion 31. And a main member forming a portion other than the tip portion of the shaft portion main body 29 can be bonded together.

  A third embodiment of the drill shaft 7 will be described with reference to FIGS. 10 to 13.

  The third drill shaft portion 7 has a bulging portion or a bulging portion 55 having a shape different from that of the bulging portion 33, but the other points have the same configuration as the second drill shaft portion 7. Therefore, the same reference numerals are given to the same components, and the description thereof is basically omitted.

  The shaft portion main body 29 of the third drill shaft portion 7 is formed as a regular quadrangular prism shape (see the one-dot chain line in FIG. 11), but is positioned so as to oppose the regular quadrangular columnar shaft portion main body 29. A pair of elongated rectangular outer surface portions are integrally provided with a pair of bulging portions 55 having a triangular cross section, and the shaft body 29 and the bulging portion 55 have a pair of opposing sides of a square in a triangular shape. It has an expanded cross-sectional shape. The distal end surface portion 57 of the bulging portion or the overhanging portion 55 is formed so as to be inclined obliquely outward toward the base end portion 5 side of the shaft portion main body 29, and the bottom side portion 47 of the opening side surface portion 39 a of the cutting edge portion 31. It spreads so that it may incline with the same inclination as the opening side surface part 39a.

  As shown in FIG. 13, only one of the pair of side surface portions 39 corresponding to the pair of bulging portions or the overhanging portion 55 is an opening side surface portion 39a, and the coolant hole bulges at the opening side surface portion 39a. You may make it open so that the front end surface part 57 of the part 55 may be hung.

  A fourth embodiment of the drill shaft 7 will be described with reference to FIGS. 14 to 17.

  The fourth drill shaft portion 7 is provided integrally with the shaft portion main body 59 having the base end portion 5 fixed to the tip of the shank portion 3 and extending from the shank portion 3 and the tip of the shaft portion main body 59, for example. The cutting edge part 61 and the bulging part 63 integrally formed in the axial part main body 59 are provided. The shaft body 59 is formed as a regular octagonal column (see the dashed line in FIG. 15), but the eight elongated outer surfaces of the regular octagonal shaft 59 are alternately expanded in the circumferential direction. The four bulging surface portions are integrally provided with a bulging portion 63 having an arcuate cross section, and the shaft main body 59 and the bulging portion 63 have regular octagonal sides. It has a cross-sectional shape bulging every other arc. Each of the distal end surface portions 65 of the bulging portion 63 is formed so as to be inclined obliquely outward toward the base end portion 5 side of the shaft portion main body 59. The cutting edge 61 is formed in a regular octagonal pyramid shape having a regular octagonal tip surface 67 of the shaft body 59 or a regular octagonal bottom surface coinciding with the tip cross section, and is adjacent to the triangular side surface 69 in the circumferential direction. There are eight ridge lines 71 formed at each of the corners between the two ridge lines 71, and each ridge line 71 is formed to function as a cutting edge. The outer surface of the bulging portion 63 is located in or on a circle whose diameter is a diagonal line of the regular octagonal tip surface 67 of the shaft body 59. Of the eight side surface portions 69 of the cutting edge portion 61, the side surface portion 69a corresponding to the bulging portion 63 is an opening side surface portion that forms an opening surface portion, and the side surface portion 69b between the opening side surface portions 69a is a non-opening surface portion. A coolant hole 73 that is a non-opening side surface portion to be formed and extends from the shank portion 3 through the shaft portion main body 59 to the cutting edge portion 61 is in contact with the bottom side portion 75 of the opening side surface portion 69a at each opening side surface portion 69a. Are opened in an elliptical or oval shape (see reference numeral 77). The front end surface portion 65 of the bulging portion 63 is connected to the bottom side portion 75 of the opening side surface portion 69a and spreads so as to be inclined at the same inclination as the opening side surface portion 69a. The coolant hole 73 is formed from a hole body 79 that passes through the center of the shaft body 59 and a branch portion 81 that branches from the hole body 79 near the tip of the shaft body 59 and opens at the opening side surface 69a. However, it may be formed so as to have four separate straight holes 83 (only two are indicated by virtual lines) that open through the shaft main body 59 at the opening side surface 69a. The fourth drill shaft portion 7 is formed integrally with the whole, or, for example, a tip side member and a shaft having a tip portion (a portion including the tip surface portion 65 as a whole) and a cutting edge portion 61 of the shaft portion main body 59. It can be formed by adhering a main member that forms other than the tip portion of the main part 59.

  In addition, as shown in FIG. 17, the axial part main body 59 is formed as a regular hexagonal column-shaped thing (refer the dashed-dotted line of FIG. 17), and the elongate position located so that this regular hexagonal column-shaped axial part main body 59 may oppose Two bulging portions 63 having a circular arc section are provided on a pair of rectangular outer surface portions, and the shaft main body 59 and the bulging portion 63 are bulged in a pair of opposite hexagonal sides in an arc shape. A pair of side surfaces 69 corresponding to the pair of bulging portions 63 is formed as an opening side surface portion 69a, and the coolant hole is in contact with the bottom side portion 75 of the opening side surface portion 69a. May be opened in an elliptical or oval shape (see reference numeral 77).

  A fifth embodiment of the drill shaft 7 will be described with reference to FIGS.

  The fifth drill shaft portion 7 is provided integrally with, for example, a shaft portion main body 85 whose base end portion 5 is fixed to the tip of the shank portion 3 and extends from the shank portion 3 and the tip of the shaft portion main body 85. The cutting edge part 87 and the bulging part or overhang | projection part 89 integrally formed in the axial part main body 85 are provided. The shaft main body 85 is formed as a regular quadrangular prism (see the alternate long and short dash lines in FIGS. 18 and 19). In addition, four bulging portions 89 having a triangular cross-section are integrally provided, and the shaft body 85 and the bulging portion 89 have a cross-sectional shape in which each side of the square bulges or projects in a triangular shape. ing. The distal end surface portion 91 of the bulging portion or the overhang portion 89 is formed so as to be inclined obliquely outward toward the base end portion 5 side of the shaft portion main body 85. The cutting edge portion 87 is formed in a square shape having a square bottom surface portion that coincides with the regular square tip surface 93 or the tip section of the shaft body 85, and between the triangular side surfaces 95 adjacent in the circumferential direction. Each of the four corners has four ridge lines 97, and each ridge line 97 is formed to function as a cutting edge. The apex portion 99 on the outer surface of the bulging portion or overhanging portion 89 is located in or on a circle whose diameter is the diagonal line of the square tip surface 93 of the shaft body 85. Each of the four side surface portions 95 of the cutting edge portion 87 is an opening side surface portion that forms an opening surface portion, and the coolant hole 101 extending from the shank portion 3 through the shaft body 85 to the cutting edge portion 87 is formed on each side surface portion. A rectangular shape or a rhombus-shaped opening (see reference numeral 103) is applied to the tip surface portion 91 of the bulging portion or the overhang portion 89 at 95. The leading end surface portion 91 of the bulging portion or the overhanging portion 89 is connected to the bottom side portion 105 of the side surface portion 95 and spreads so as to be inclined at the same inclination as the side surface portion 95. The coolant hole 101 is divided into a hole body 107 passing through the center of the shaft body 85, and four holes from the hole body 107 in the vicinity of the tip of the shaft body 85, and the tip of the side surface 95 and the bulging or overhanging portion 89. The four branch holes 109 are formed from the branch portion 109 that opens at the surface portion 91, and opens at the tip surface portion 91 of the side surface portion 95 and the bulging or overhanging portion 89 through the shaft body 85. 110 may be formed. Here, the gap between the shaft main body 85 and the machining hole is specifically a gap between the bulging part or the overhanging part 89 and the machining hole. The fifth drill shaft portion 7 is formed integrally with the whole, or, for example, a distal end side member having a distal end portion (a portion including the distal end surface portion 91 as a whole) and a cutting edge portion 87 of the shaft main body 85 and the shaft. It can be formed by adhering a main member that forms other than the tip portion of the main part 85.

  As shown in FIG. 21, only a pair of side surface portions 95 positioned so as to face each other is used as an open side surface portion, and a coolant hole is formed in the open side surface portion 95 and the front end surface portion 91 of the corresponding bulging portion or overhang portion 89. May be opened in a square shape or a rhombus shape (see reference numeral 103).

  A sixth embodiment of the drill shaft portion 7 will be described with reference to FIGS.

  The sixth drill shaft portion 7 includes, for example, a monolithic prismatic shaft portion main body 111 whose base end portion 5 is fixed to the distal end of the shank portion 3 and extends from the shank portion 3. A regular quadrangular pyramid-shaped cutting edge portion 115 having a square bottom surface portion that coincides with the distal end surface 113 or the distal end cross section of the shaft main body 111, and the cutting edge portion 115 is a base side of a steep slope 117 and the tip portion 119 with a relatively gentle slope are integrally formed. However, a three-step configuration with the tip portion with a gentle slope further integrated may be employed. Between the substantially triangular side surfaces 123 adjacent to each other in the circumferential direction of the cutting edge portion 115 (the side surface portion 123 is substantially triangular but is bent in two steps), each of the corner portions (total of four corner portions). ) Are provided, and a ridge line 125 is formed at each of a pair of corner portions located along one diagonal line of the tip end surface 113 of the shaft body 111, and each ridge line 125 functions as a cutting edge. Each of the pair of ridge lines 125 extends from the apex of the cutting blade 115 to the corner of the bottom surface, but has a bending point 127 positioned outside the straight line connecting the apex of the cutting blade 115 and the corner of the bottom surface. It is formed so as to be bent at this bending point 127. More specifically, the ridge line 125 extends from the apex of the cutting edge 115 to the bending point 127 while being inclined relatively gently, and is bent at the bending point 127 to the corner of the bottom surface. It extends with a steep slope. In addition, a pair of corner portions located along the other diagonal line of the tip end surface 113 of the shaft main body 111 are chamfered to form a flat chamfer portion 131, and function as a cutting edge. Is hardly defined. The chamfered portion 131 extends from the base side slightly from the apex to the upper end portion of the shaft portion main body 111. Each of the four side surfaces 123 of the cutting edge portion 115 is a non-opening side surface portion that forms a non-opening surface portion, but the pair of chamfered portions 131 forms an opening surface portion, and the shaft portion main body 111 is moved from the shank portion 3. The coolant holes 133 that pass through and extend to the cutting edge portion 115 are opened in an elliptical shape or an oval shape at each chamfered portion 131 (see reference numeral 135). The coolant hole 133 is formed by a hole body 135 that passes through the center of the shaft body 111, and a branch portion 137 that bifurcates from the hole body 135 near the tip of the shaft body 111 and opens at the chamfer 131. However, you may form so that it may have the hole part 139 extended through the shaft part main body 111 at the chamfer part 131, and extending in two separate straights. The sixth drill shaft portion 7 is formed as a whole, or, for example, a main member that forms other than the tip portion of the shaft portion main body 111 and the tip side member having the cutting edge portion 115 and the tip portion of the shaft portion main body 111. Can be formed by adhering.

  As shown in FIGS. 26 and 27, even if each side surface portion 123 is curved outward, the cutting edge has a steep slope on the base side and a gentle or relatively gentle slope on the tip side. The portion 115 can be formed. Also here, a ridge line 125 is formed in each of the pair of corners located along one diagonal line of the tip surface 113 of the shaft body 111, and each ridge line 125 functions as a cutting edge. Each of the pair of ridge lines 125 extends from the apex of the cutting blade 115 to the corner of the bottom surface, but is circular so as to protrude outward from a straight line connecting the apex of the cutting blade 115 and the corner of the bottom surface. It swells in an arc. Further, a pair of corner portions located along the other diagonal line of the tip end surface 113 of the shaft portion main body 111 are chamfered to form a planar chamfered portion 131, which functions as a cutting edge. Is hardly defined. The chamfer 131 extends from the base side to the upper end of the shaft body 111 slightly from the apex of the cutting blade 115. Each of the four side surfaces 123 of the cutting edge portion 115 is a non-opening side surface portion that forms a non-opening surface portion, but the pair of chamfered portions 131 forms an opening surface portion, and the shaft portion main body 111 is moved from the shank portion 3. The coolant holes 133 (see FIG. 25) extending through the cutting edge 115 through the chamfered portions 131 are opened in an elliptical shape or an oval shape (see reference numeral 135).

  When the drill shaft 7 as described above is used, it is not necessary to perform drilling while repeating the cleaning and cooling step operations as shown in FIG. 28a, and continuous drilling as shown in FIG. 28b is possible.

  The ultrafine drill of the present invention can be used, for example, for drilling parts of semiconductor manufacturing equipment.

DESCRIPTION OF SYMBOLS 1 Drill 3 Shank part 7 Drill axial part 9, 29, 59, 85, 111 Shaft part main body 13, 31, 61, 87, 115 Cutting edge part 15, 39, 69, 95, 123 Side surface part 17, 41, 71, 97, 125 Ridge lines 15a, 39a, 69a, 95, 131 Opening surface portions 23, 43, 73, 101, 133 Coolant holes

Claims (5)

An ultra-fine drill for drilling ultra-fine holes,
A shank portion, and a drill shaft portion provided in the shank portion,
The drill shaft portion includes a shaft portion main body extending from the tip of the shank portion, and a pyramid-shaped cutting edge provided at the tip of the shaft portion main body. The cutting edge part is formed such that chips are discharged from the plurality of triangular side surfaces, and a ridge line as a cutting edge formed at at least one corner between the adjacent side surface parts, Have
A coolant hole is formed in the shank portion and the drill shaft portion, and the coolant hole opens at the side portion of the cutting edge portion,
The shaft main body is a bulge formed integrally on the outer side of the main body so as to correspond to the main body having an angular cross section and the side surface at least on the distal end side of the main body. An ultrafine drill, characterized in that the coolant hole has an opening at the side surface so as to hang on or come into contact with the bulging portion.   The distal end surface of the bulging portion is formed to be inclined obliquely outward from the bottom side portion of the side surface portion where the coolant hole is opened toward the base end portion side of the shaft portion main body, and the coolant hole is 2. The ultrafine drill according to claim 1, wherein the side surface portion is opened so as to be hooked on or in contact with the tip surface.   The ultrathin drill according to claim 2, wherein a tip surface of the bulging portion is formed so as to be inclined at the same angle as the side surface portion where the coolant hole is opened.   The plurality of side surface portions of the cutting edge portion include a non-opening surface portion, and the coolant hole does not open at the non-opening surface portion of the cutting edge portion, and is outside the main body portion corresponding to the non-opening surface portion. The ultra-thin drill according to claim 1, wherein the bulging portion is not formed. An ultra-fine drill for drilling ultra-fine holes,
A shank portion, and a drill shaft portion provided in the shank portion,
The drill shaft portion includes a prismatic shaft portion main body extending from the tip of the shank portion, and a pyramid-shaped cutting edge portion provided at the tip of the shaft portion main body. The cutting edge is formed as a cutting edge formed at a plurality of triangular side faces and at least one corner between the adjacent side faces. A ridgeline,
The cutting edge portion is provided with an opening surface portion, a coolant hole is formed in the shank portion and the drill shaft portion, and the coolant hole opens at the opening surface portion of the cutting edge portion,
A chamfered portion is formed in at least one corner between the side surface portions adjacent to the cutting edge portion so that a ridge line disappears,
The ultra-thin drill characterized in that the chamfered portion forms the opening surface portion.

Images