JP3239770U - Drill - Google Patents

Abstract

[PROBLEMS] To prevent a work material from being lifted by a drill, to suppress damage to the work material and the occurrence of delamination, to be excellent in chip discharge efficiency of the drill, and to prevent clogging. provide a drill. A drill A has a shank part 2, and a core cutting edge 121, a body cutting edge 122, and a diameter substantially equal to the maximum diameter of the cutting edge 122 which are provided at the tip of the shank part 2 and which process a material to be processed in a rotating direction. A finishing blade 123 provided parallel to the direction of the rotation axis, flanks 126a, 126b, and 126c connected to the cutting edge of each blade in the direction of rotation, and connected in the direction opposite to the direction of rotation, so as to substantially follow the diameter line of itself, A drill bit 1 having a concave scooping surface 120 provided so as to overlap the rotation center axis. [Selection diagram] Fig. 1

Description

There is an application for exception to loss of novelty

The present invention relates to drills. Specifically, it is possible to prevent the work material from being lifted by the drill, suppress the damage of the work material and the occurrence of delamination, and improve the chip discharge efficiency of the drill to prevent clogging. about things.

2. Description of the Related Art A drill is used for processing such as drilling holes in materials to be processed such as wood and synthetic resin materials. As such a drill, for example, the drill described in Non-Patent Document 1 is common.

The conventional drill described in Non-Patent Document 1 has a helical groove formed in the body portion on the tip side, and a chisel formed with a plurality of flank faces is formed at the tip of the body portion. there is The grooves of the body portion are used to discharge chips generated when the material to be machined is cut by rotation to the outside.

Mitsubishi Materials, "Names of parts of drills, shape specifications and cutting characteristics", (searched on February 1, 2019), Internet <URL: https://carbide.mmc.co.jp/technical_information/tec_rotating_tools/drills /tec_drilling_technical/tec_drilling_terminology＞

However, the drill described in Non-Patent Document 1 has the following problems.
In other words, the rotation of the helical groove tends to lift the work material, which can damage the drill and the work material, and cause delamination (surface peeling and burrs) on the surface of the work material. there were.

Further, in the case of a small drill having a diameter of, for example, 6 mm or less, two helical grooves are provided in order to improve the chip discharge efficiency. In this structure, the width of the grooves must be made small, which causes chips to easily clog the grooves, resulting in a problem of poor discharge efficiency.

Furthermore, when the powdery chips pile up inside the groove and are compressed and hardened, the drill cannot cut at all, and the hardened chips inside the groove cannot be easily removed.

The present invention has been devised in view of the above points. To provide a drill excellent in waste discharge efficiency and capable of preventing clogging.

(1) In order to achieve the above object, the present invention provides a shank portion, a cutting blade provided at the tip of the shank portion and for processing a material to be processed in the rotational direction, and a maximum diameter of the cutting blade that is approximately the same as the maximum diameter of the cutting blade. A finishing edge provided parallel to the direction of the rotation axis with a diameter, a flank connecting the cutting edge of the cutting edge and the cutting edge of the finishing edge in the rotation direction, and a flank connecting in the opposite direction to the rotation direction and substantially along the diameter line. and a body portion having a concave scooping surface that overlaps with or is adjacent to the rotation center axis.

The drill of the present invention can apply a rotational force to the body by chucking the shank portion with the rotating portion. When the drill is rotated, the cutting edge at the tip of the body portion cuts the material to be drilled.

Moreover, according to the finishing blade, since the diameter is substantially the same as the maximum diameter of the cutting blade, the portion machined by the cutting blade can be subsequently finished. In such processing, unlike a conventional drill having a helical blade (groove), the workpiece does not rise due to rotation of the drill. As a result, it is possible to suppress the occurrence of damage and delamination of the material to be processed due to lifting of the material to be processed.

Moreover, chips generated by the rotation of the cutting blade and the finishing blade are guided to the scooping surface connected to the cutting blade and the finishing blade and discharged. Since the scooping surface is a concave surface that overlaps or is provided close to the center axis of rotation so as to substantially follow the diameter line of the body, the space where chips are guided after cutting is relatively wide. It's becoming As a result, the chips are smoothly discharged, the chips are less likely to adhere to the scooping surface, and clogging can be prevented.

(2) The drill of the present invention may be configured such that the body portion has the cutting edge and the finishing edge and is provided with a blade body formed of a polycrystalline sintered body.

In this case, since the blade body is formed of a polycrystalline sintered body (polycrystalline diamond: PCD), the structure is dense, extremely hard, and excellent in strength.

(3) The drill of the present invention may be configured such that the scooping surface is arcuate in the diametrical direction of the body portion.

In this case, a processing device (polishing device) having a rotor (rotating body) can be employed in processing the scooped surface, so processing work can be performed with high efficiency.

(4) The drill of the present invention may have a configuration in which a plurality of cutting edges are provided with increasing angles stepwise outward from the rotation center axis.

In this case, a plurality of cutting blades are formed so as to protrude outward, and as the cutting operation progresses, the angle of the cutting blades increases stepwise as the diameter to be processed by the cutting blades increases. As a result, the further the cutting edge is located, the more gradual the increase in the torque required for rotation as the cutting operation progresses, and the impact load is less likely to act on the drill.

(5) The drill of the present invention may be configured such that a dead edge whose distance from the rotation center axis is shorter than that of the finishing edge is formed on the opposite side of the cutting edge and the finishing edge.

In this case, in cutting, only the cutting edge and the finishing edge perform machining when the body portion rotates around the rotation center axis, and the dead edge does not contact the workpiece and does not perform machining. However, since the dead edge is provided on the opposite side of the cutting edge and the finishing edge, the balance during rotation can be kept in a good state, so vibration of the body is less likely to occur.

The drill of the present invention is made by fixing and integrating a blade made of a polycrystalline sintered body to the blade base that constitutes the body, making it easier to hold and machining the blade with a grinding device. It becomes easier. In addition, by forming a cutting blade for processing the material to be processed in the rotating direction and a finishing blade provided in parallel with the rotating shaft direction with a diameter approximately equal to the maximum diameter of the cutting blade on the blade body, After machining the material, it is possible to finish machine the machined portion with a finishing blade.

Further, by providing the cutting edge of the cutting edge and the cutting edge of the finishing edge with a flank that extends in the rotational direction, the cutting resistance of the cutting edge can be reduced. In addition, by forming a concave scooping surface that is connected in the opposite direction to the rotation direction and that overlaps or is provided close to the rotation center axis so as to substantially follow the diameter line of the body portion, Chips can be discharged along the scooping surface.

The present invention is a drill that prevents the work material from being lifted by the drill, suppresses damage to the work material and the occurrence of delamination, is excellent in discharging chips from the drill, and prevents clogging. can be provided.

1 is a perspective view of a first embodiment of the drill of the present invention; FIG. 2 is a front view of the drill shown in FIG. 1; FIG. Fig. 2 is a right side view of the drill shown in Fig. 1; It is a bottom view explanatory drawing of the drill shown in FIG. FIG. 2 is an explanatory diagram of a state in which the drill shown in FIG. 1 is drilling; FIG. 4 is an explanatory diagram showing another embodiment of the drill of the present invention;

Embodiments of the present invention will be described in more detail with reference to FIGS. 1 to 4. FIG.
A drill A has a drill bit 1 which is a body part and a shank part 2 which is chucked by a rotating part such as a drilling machine and transmits a rotational force to the drill bit 1. - 特許庁

A drill bit 1 is fixed to the tip of a shank part 2 in parallel with the shank part 2 . In this embodiment, the shank portion 2 is a straight shank formed in a round bar shape, but it is not limited to this, and for example, a tapered shank that is slightly narrowed in the proximal direction can also be adopted. .

Further, the drill bit 1 is composed of a blade base 11 and a blade body 12 . The blade base 11 and the blade body 12 are formed to have substantially the same length, and the blade body 12 is layered and fixed to the blade base 11 (see FIGS. 1, 3, and 4).

In this embodiment, the blade body 12 is formed of a polycrystalline sintered body (polycrystalline diamond: PCD), and has a dense structure, is extremely hard, and has excellent strength.

The material of the blade is not limited to the above-mentioned polycrystalline sintered body, and for example, an ultra-high pressure crystal body (CBN (Cubic Boron Nitride: cubic boron nitride)) can also be adopted. 2 and the blade base 11 are made of steel in this embodiment, but the material is not limited to this, and other materials can be adopted.

The cross-sectional shape of the blade base 11 is a shape composed of an arc portion and a straight portion shorter than the diameter line. The cross-sectional shape of the blade body 12 is formed by a portion curved in an arcuate direction in a recessed direction, curved portions on both sides of the curved portion, and a straight portion having the same length as the straight portion of the blade base 11 (see FIG. 4). .

A boundary portion 110 where the blade base 11 and the blade body 12 are joined together for integration has a longitudinal direction that is parallel to the rotation center axis 13 as a whole (see FIG. 4). A narrowed flank 111 is formed at the tip of the blade base 11 .

The overall cross-sectional shape of the drill bit 1 perpendicular to the longitudinal direction is formed in a substantially semicircular shape (see FIG. 4). In this cross-sectional shape, the bridging portion corresponding to the approximate diameter of the drill bit 1 is formed in an arc shape gently curved in the concave direction.

As a result, a concave scooping surface 120 is formed over the entire length of the drill bit 1 (see FIGS. 1 and 4). Note that the scooping surface 120 is formed on the blade body 12 that constitutes the drill bit 1 . Hereinafter, mainly the structure of the blade body 12 will be described in detail.

First, the rotation center axis 13 of the drill A is on the same axis as the center axis (reference numeral omitted) of the shank portion 2, and in the drill bit 1, it is at a substantially intermediate position in the width direction of the scooping surface 120 of the blade body 12. (Refer to FIG. 2, FIG. 4, FIG. 5, etc.).

A tip portion of the blade body 12 is provided with a sharp portion 12c. The sharp portion 12 c is located on the rotation center axis 13 , that is, at the same position as the surface of the scooping surface 120 . In addition, as described above, the scooping surface 120 is formed so that the curvature in the width direction is the same in the longitudinal direction of the blade body 12 (excluding the portion where the length in the width direction is shortened and missing). ing.

The radius R of the scooping surface 120, which is an arcuately curved concave surface, is the center C on the diameter line of the drill bit 1, which is perpendicular to the boundary 110 between the blade base 11 and the blade body 12 and passes through the rotation center axis 13. is the distance from Further, the scooping surface 120 is formed so as to overlap the rotation center axis 13 so as to be close to and substantially along the diameter line D (see FIGS. 4 and 5) of the drill bit 1 . Although the radius R is set to 7.90 mm in the present embodiment, it is not limited to this and can be set as appropriate.

On the side of the blade body 12 that becomes a cutting edge when the drill bit 1 rotates in the rotational direction F, a core edge 121, a body edge 122 and a finishing edge 123 are provided in order with the sharp portion 12c as the apex. (enlarged view of FIG. 2, see FIG. 4). The core blade 121 and the body blade 122 constitute cutting blades. It should be noted that the cutting edges (reference numerals omitted) of these blades are formed along the surface of the scooping surface 120 .

Refer mainly to the enlarged view of FIG.
The cutting edge of the core blade 121 continuing outward from the sharp portion 12c is formed linearly at an angle of 20° in a front view with respect to a reference line B1 perpendicular to the rotation center axis 13. As shown in FIG.

Next, the cutting edge of the core blade 122 continues outward from the core blade 121 and is linear with respect to the reference line B1 at an angle of 45° in a front view (an angle of 25° with respect to the core blade 121). is formed in The end of the cutting edge of the body cutting edge 122 reaches the cutting edge of the finishing edge 123 formed parallel to the rotation center axis 13 .

In the blade body 12, a portion continuous in the direction opposite to the core blade 121 and formed linearly at an angle of 55° with respect to the reference line B1, and a portion continuous with that portion and on the opposite side to the finishing blade 123 A portion located parallel to the rotation center axis 13 is a dead edge 129 that is not directly related to the machining of the workpiece 3 by the drill A.

Mainly refer to FIG.
The core blade 121, the body blade 122, and the finishing blade 123 are set with scooping angles based on the scooping surface 120 corresponding to each of them. 4, only the rake angle of the finishing blade 123 is shown for convenience of illustration.

In this embodiment, the rake angle of the finishing blade 123 is 18°, and the rake angles of the core blade 121 and the body blade 122 are also set to 18°. It should be noted that the rake angle is not limited to this, and can be set as appropriate.

The core cutting edge 121, the body cutting edge 122, and the finishing cutting edge 123 are provided with flanks 126a, 126b, and 126c (see FIGS. 1, 3, and 4).

In this embodiment, the clearance angle of the flank 126c of the finishing edge 123 is 15°, and the clearance angles of the flank 126a of the core edge 121 and the flank 126b of the body edge 122 are also set to 15°. . Note that the clearance angle is not limited to this, and can be set as appropriate.

Refer mainly to the enlarged view of FIG.
Further, the sharpened portion 12c of the blade body 12 is formed with a chisel edge 124 extending from the sharpened portion 12c toward the back (rightward in the enlarged view of FIG. 3). The chisel angle of the chisel edge 124 (the angle with respect to the reference line B1 in the axial direction) is 90° in the present embodiment (reference: enlarged views of FIGS. 1 and 3), but is not limited to this and may be changed as appropriate. Can be set.

A relief angle is set on the chisel edge 124 (see the enlarged view of FIG. 3). Although the clearance angle is set to 10° in the present embodiment, it is not limited to this, and can be appropriately set, for example, in the range of 5° to 45° or other angles.

In the present embodiment, the drill A is a drill with a φ5 (diameter of 5 mm) standard for the drill bit 1 . In the drill A, the radius from the rotation center axis 13 to the cutting edge of the finishing edge 123 is 2.5 mm (5/2 mm). Note that the drill A is not limited to the standard of Φ5, and can be manufactured (manufactured) with the standard of Φ3 to Φ7, or other standards, for example.

In addition, in the dead edge 129 opposite to the finishing edge 123, the radius to the portion parallel to the rotation center axis 13 is set to 2.34 mm, which is shorter than the radius from the rotation center axis 13 to the cutting edge of the finishing edge 123. there is Furthermore, the radius of the body portion of the blade rest 11 is also set to 2.34 mm (see FIG. 4).

In the drill A, since the sharp portion 12c is provided at the position of the rotation center axis 13 at the tip of the drill bit 1, it is not always necessary to perform thinning in order to improve the biting property to the material to be worked. However, this is not excluded and thinning can also be performed.

(Action)
Mainly referring to FIG. 5, the operation of drilling the material 3 with the drill A will be described.
(1) The tip of the drill bit 1 of the rotating drill A, which is chucked by a rotating part such as a drilling machine, is brought into contact with the surface of the material 3 to be processed, and the drill A is lowered.

(2) As the drill bit 1 rotates, the core edge 121 first cuts the material 3 to be processed, and then the body edge 122 cuts the material 3 to be processed. Thereby, the hole 30 can be drilled in the material 3 to be processed.

(3) After the processing by the body cutting edge 122, finishing processing by the finishing edge 123 is performed. Since the finishing blade 123 has substantially the same diameter as the maximum diameter of the body cutting edge 122, the portion machined by the body cutting edge 122 can be finished.

In such processing, unlike a conventional drill having a helical blade (groove), the workpiece 3 is not lifted by rotation of the drill. As a result, it is possible to suppress the occurrence of damage and delamination of the material to be processed 3 due to the lifting of the material to be processed 3 .

Chips generated by the rotation of the core blade 121, the body blade 122, and the finishing blade 123 are guided to the scooping surface 120 connected to each blade and discharged. The scooping surface 120 is a concave surface that overlaps the rotation center axis 13 so as to substantially follow the diameter line D of the drill bit 1, which is the body portion. relatively wide. As a result, the chips are smoothly discharged, and the chips are less likely to adhere to the scooping surface 120, thereby preventing clogging.

(Production method)
A method of manufacturing the drill A will be described below.
(1) A cutting edge 12 made of a polycrystalline sintered body is fixed to and integrated with a cutting edge 11 constituting the drill bit 1 . As a result, it becomes easy to hold the united body, and it is easy to process the blade body 12 with a polishing device or the like.

(2) The blade body 122 is formed with a core blade 121, a body blade 122, and a finishing blade 123 for processing the material to be processed in the rotating direction by using a polishing device or the like. As a result, after processing the material 3 to be processed with the body cutting edge 122 , it is possible to finish the processed portion with the finishing edge 123 .

(3) Furthermore, flanks 126a, 126b, and 126c connecting in the rotational direction F to the cutting edges of the core cutting edge 121, the body cutting edge 122, and the finishing cutting edge 123 are machined. Further, it is connected to the cutting edge of the core cutting edge 121, the body cutting edge 122, and the finishing cutting edge 123 in the direction opposite to the rotation direction F, and is provided so as to overlap the rotation center axis 13 so as to substantially follow the diameter line D of the drill bit 1. It forms a concave scoop surface 120 that rests on it.

By providing the flanks 126a, 126b, and 126c in this way, the cutting resistance of the core cutting edge 121 and the body cutting edge 122 can be kept small. Furthermore, by forming the scooping surface 120 , chips generated by processing can be discharged along the scooping surface 120 .

Next, referring to FIG. 6, another embodiment of the drill is shown. In FIG. 6, the same parts as those of the drill A are indicated by the same reference numerals, and the description of the common structure is omitted.

The drill bit 1a of the drill shown in FIG. 6(a) is composed of one cutting edge 127. As shown in FIG. The cutting edge of the cutting blade 127 is formed linearly at an angle of 45° in front view from the sharp portion 12c with respect to the reference line B1.

The drill bit 1b of the drill shown in FIG. 6(b) has a core cutting edge 121, a body cutting edge 122, an outer cutting edge 125 and a finishing cutting edge 123 in order with a sharpened portion 12c as the apex in the blade body 12. . The cutting edge of the core blade 121 continuing from the sharp portion 12c is formed linearly at an angle of 20° in a front view with respect to the reference line B1.

The cutting edge of the body cutting edge 122 is continuous from the core cutting edge 121 and is formed linearly at an angle of 45° in a front view with respect to the reference line B1. , is formed linearly at an angle of 70° in a front view with respect to the reference line B1.

The drill provided with the drill edges 1a and 1b has substantially the same action as the drill A, but is characterized by variations in cutting resistance to the drill edges during cutting work due to the difference in the number of edges that constitute the cutting edges. There is

That is, when there are a plurality of cutting edges such as the drill edges 1 and 1b, unlike the drill edge 1a, the plurality of cutting edges bulge outward, and as the cutting operation progresses, the cutting edge becomes larger. The angle of the cutting edge increases stepwise as the diameter to be processed by the edge increases. As a result, the further the cutting edge is located, the slower the increase in the torque required for rotation as the cutting operation progresses, and the impact load is less likely to act on the drill during the cutting operation.

The terms and expressions used in the present specification and claims are for the purpose of description only and are not limiting in any way. There is no intention to exclude terms or expressions that are equivalent to features and portions thereof. Moreover, it goes without saying that various modifications are possible within the scope of the technical idea of the present invention.

A Drill 1 Drill edge 11 Tool post 110 Boundary part 111 Flank face 12 Blade body 120 Scooping face 121 Core edge 122 Body edge 123 Finishing edge 124 Chisel edge 129 Dead edge 12c Sharp part 13 Rotation center axis 2 Shank part R Radius C Center D Diameter Line B1 Reference line 3 Workpiece material 30 Hole 1a Drill edge 1b Drill edge 125 Outer edge 127 Cutting edge

Claims (5)

a shank portion;
A cutting blade that is provided at the tip of the shank portion and that processes the material to be processed in the direction of rotation, a finishing blade that has a diameter substantially equal to the maximum diameter of the cutting blade and is provided parallel to the direction of the rotation axis, and a cutting edge of the cutting blade. and a flank that connects to the cutting edge of the finishing blade in the direction of rotation, and a concave surface that connects in the direction opposite to the direction of rotation and is provided in close proximity to or overlaps the central axis of rotation so as to substantially follow its own diameter line. a body portion having a rake face of . 2. The drill according to claim 1, wherein the body portion has the cutting edge and the finishing edge, and includes a blade body formed of a polycrystalline sintered body. The drill according to claim 1 or 2, wherein the scooping surface is arcuate in the diametrical direction of the body portion. 4. The drill according to claim 1, 2 or 3, wherein a plurality of said cutting edges are provided with increasing angles stepwise outward from said central axis of rotation. 5. The drill according to claim 1, 2, 3 or 4, wherein a dead edge whose distance from said rotation center axis is shorter than said finishing edge is formed on the opposite side of said cutting edge and said finishing edge.

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