Tool and dust collector

Abstract

To reduce an amount of chips flying from a gap between a dust collector and a work-piece when forming a hole in the work-piece.SOLUTION: A tool comprises: a tool body part; a blade part; and a dust collector which has a device body part that is detachably fixed to the tool body part and is located on an outer side in a radial direction of the blade part in such a mode that a tip of the blade part is not covered and is projected when the device body part is fixed to the tool body part. The device body part has: a first base end part fixed to the tool body part and a first tip positioned on a side opposite to the first base end part; a suction port which is provided at the first tip, is so located on the outer side in the radial direction of the blade part as to surround the blade part, and sucks chips, which are generated when cutting a work-piece to form a hole therein, by a negative pressure; one or more injection ports which are provided at the first tip, are annularly located on an outer side in a radial direction of the suction port so as to surround the suction port, and inject a gas to form air flow for trapping chips in a prescribed space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tool equipped with a dust collection device and capable of forming a hole in a workpiece, and a dust collection device that is detachable from a tool body of a tool having a cylindrical cutting portion and that sucks up chips generated when forming a hole in the workpiece. [Background technology]

[0002] When drilling holes using a drill bit (i.e., drill blade) in a workpiece made of a metal such as an aluminum alloy or a material such as ceramics, there is a problem that the work site is contaminated by flying chips.

[0003] In order to solve this problem, a dust collecting device that is attached to a processing tool has been proposed (see, for example, Patent Document 1). Note that the dust collecting device described in Patent Document 1 is referred to as a dust collecting attachment in the detailed description of the invention.

[0004] The dust collecting device described in Patent Document 1 has a cylindrical, bellows-shaped cover that surrounds the drill bit, and an intake pipe is provided on the side of the cover. During machining of the workpiece, chips are sucked in through an opening located at the bottom end of the cover, reducing the scattering of chips. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-306212 Summary of the Invention [Problem to be solved by the invention]

[0006] However, depending on the size and shape of the workpiece and the cutting method, there is a problem that chips fly out from the gap between the dust collector and the workpiece. The present invention has been made in consideration of such problems, and its object is to reduce the amount of chips that fly out from the gap between the dust collector and the workpiece when a hole is formed in the workpiece. [Means for solving the problem]

[0007] According to one aspect of the present invention, a tool capable of forming a hole in a workpiece includes a tool body, a cylindrical blade portion that is rotatably attached to the tool body and is capable of cutting the workpiece, and a dust collector having a device body that is detachably fixed to the tool body, the device body being disposed radially outside the blade portion in a manner that the tip end of the blade portion protrudes without covering it when the device body is fixed to the tool body, and the device body of the dust collector includes a first base end fixed to the tool body, and a second base end of the device body. a suction port provided at the first tip portion and arranged radially outside the cutting portion so as to surround the cutting portion, for sucking, by negative pressure, chips generated when the workpiece is cut to form the hole; and one or more injection ports provided at the first tip portion and arranged annularly radially outside the suction port so as to surround the suction port, for injecting gas to form an air current for confining the chips in a predetermined space.

[0008] According to another aspect of the present invention, there is provided a dust collection device that is detachably attached to a tool body of a tool having a cylindrical cutting portion and that sucks up chips generated when a hole is formed in a workpiece, the dust collection device comprising: a device body that is detachably fixed to the tool body; a first base end that is detachably fixed to the tool body; a first tip end that is located on the opposite side of the device body from the first base end in the longitudinal direction of the device body; a suction port that is provided at the first tip end and is positioned radially outside the blade portion so as to surround the blade portion, and that uses negative pressure to suck up the chips that are generated when the workpiece is cut to form a hole; and one or more injection ports that are provided at the first tip end and are positioned radially outside the suction port so as to surround the suction port, and that inject gas to form an airflow that confines the chips in a predetermined space; and when the first base end is fixed to the tool body, the device body is positioned radially outside the blade portion so as to protrude without covering the tip end of the blade portion. [Effects of the Invention]

[0009] When a workpiece is machined with a tool according to one aspect of the present invention, gas is injected from one or more nozzles of the dust collector, and the airflow confines chips in a predetermined space. This reduces the amount of chips that fly out from the gap between the dust collector and the workpiece, and the chips that are trapped in the predetermined space can be sucked in through the suction port. Therefore, the amount of chips that fly out from the gap between the dust collector and the workpiece can be reduced.

[0010] A dust collector according to another aspect of the present invention injects gas from one or more nozzles during machining of a workpiece, thereby forming an airflow for confining chips in a predetermined space. This reduces the amount of chips that fly out from the gap between the dust collector and the workpiece, and allows the chips that are confined in the predetermined space to be sucked in through the suction port. Therefore, the amount of chips that fly out from the gap between the dust collector and the workpiece can be reduced. [Brief explanation of the drawings]

[0011] [Figure 1]1 is an exploded perspective view of a tool according to a first embodiment. [Figure 2] FIG. 1 is a perspective view of a tool according to a first embodiment. [Figure 3] 1 is a cross-sectional view of the tool of the first embodiment when machining a workpiece. FIG. [Figure 4] FIG. 4(A) is a cross-sectional view of the tool of the first embodiment, FIG. 4(B) is a cross-sectional view of the tool at AA in FIG. 4(A), and FIG. 4(C) is a cross-sectional view of the tool at BB in FIG. 4(A). [Figure 5] FIG. 10 is an exploded perspective view of a tool according to a second embodiment. [Figure 6] FIG. 10 is a perspective view of a tool according to a second embodiment. [Figure 7] FIG. 7(A) is a cross-sectional view of the tool of the second embodiment, FIG. 7(B) is a cross-sectional view of the tool at CC in FIG. 7(A), and FIG. 7(C) is a cross-sectional view of the tool at DD in FIG. 7(A). DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is an exploded perspective view of a tool 2 according to a first embodiment. The tool 2 of this embodiment has a power tool main body 4 and a dust collecting device 20 fixed to the power tool main body 4.

[0013] First, the power tool body 4 will be described. The power tool body 4 has a substantially cylindrical grip 6. The grip 6 is held by an operator when the operator holds the tool 2 by hand. An electric circuit including an AC-DC converter (not shown) is provided inside the grip 6.

[0014] An electric wire (not shown) is fixed to the lower end of the grip portion 6. The above-mentioned electric circuit is electrically connected to one end of the electric wire, and an attachment plug (not shown) is fixed to the other end of the electric wire and is electrically connected to the electric wire.

[0015] The attachment plug is electrically connected to an AC power supply (for example, a wiring connector, socket, or outlet) that is supplied to factories, ordinary homes, and the like.

[0016] Instead of the AC-DC converter, a battery storage section into which a rechargeable battery (not shown) is inserted may be formed inside the grip section 6. In this case, the electric wires and the plug are omitted from the power tool body 4, and the battery placed in the battery storage section functions as the power source.

[0017] A cylindrical body 8 is connected to the top of the grip 6 in a manner perpendicular to the longitudinal direction of the grip 6. A motor 10 is provided inside the body 8 and fixed to the body 8.

[0018] A trigger switch (not shown) is provided on the grip 6 or the body 8. When the operator presses the trigger switch once, the motor 10 is driven by a DC voltage supplied from an AC power supply via an AC-DC converter, for example. When the operator presses the trigger switch again, the motor 10 stops.

[0019] An output shaft 10a of the motor 10 is directly or indirectly connected to the rotation shaft of a cylindrical drill chuck 12. A shank of a cylindrical drill bit (cutting part) 14 having a predetermined diameter (e.g., 5 mm) is fixed to the rotation shaft of the drill chuck 12.

[0020] That is, the drill bit 14 is mounted so as to be rotatable relative to the power tool body 4. When the motor 10 is operated, the drill bit 14 is driven to rotate, and when the operation of the motor 10 is stopped, the drill bit 14 comes to a standstill.

[0021] The drill bit 14 is made of, for example, high-speed steel (HSS), cemented carbide, cubic boron nitride (cBN) sintered body, cermet, diamond, or the like.

[0022] The drill bit 14 may be a straight fluted drill (also called a straight drill) or a twist drill (also called a twist drill).

[0023] 3, when the tip of the rotating drill bit 14 is pressed into a workpiece 11 made of metal, ceramics, plastic, wood, or the like, the workpiece 11 is cut. This allows a hole 11a, such as a through hole or a blind hole, to be formed in the workpiece 11.

[0024] Returning to Fig. 1, a dust collecting device 20 is attached to the tip of the power tool body 4. The dust collecting device 20 has a cylindrical device body 22. The device body 22 is made of hard resin.

[0025] The device main body 22 can be formed by a 3D printer using a resin such as ABS resin (i.e., acrylonitrile-butadiene-styrene copolymer synthetic resin), PLA (Poly-Lactic Acid) resin (i.e., polylactic acid), etc. However, the device main body 22 may also be formed by other methods such as injection molding.

[0026] A base end (first base end) 22b in the longitudinal direction 22a of the device body 22 is attached to the tip end of the power tool body 4. At this time, the device body 22 covers the tip end of the trunk 8 of the power tool body 4, the entire drill chuck 12, and most of the drill bit 14.

[0027] A plurality of through holes 24 are formed at approximately equal intervals around the circumferential direction of the device body 22 in the vicinity of the base end 22b on the outer periphery of the device body 22. In this embodiment, four through holes 24 are formed. Note that two through holes 24 are shown in FIG. 1.

[0028] A bolt 26 is inserted into each through-hole 24. The shaft of the bolt 26 is fastened to a plurality of threaded holes 16 provided at approximately equal intervals around the circumference of the body 8. In this embodiment, four threaded holes 16 are formed in the body 8, but two threaded holes 16 are shown in FIG. 1.

[0029] The device body 22 is fixed to the power tool body 4 by fastening the shank of the bolt 26 into the threaded hole 16 of the trunk 8. Fig. 2 is a perspective view of the tool 2 of the first embodiment with the dust collecting device 20 attached to the tip of the power tool body 4.

[0030] By removing the bolts 26 from the screw holes 16, the device body 22 can be removed from the power tool body 4. In other words, the device body 22 is detachably fixed to the power tool body 4 using the bolts 26.

[0031] Near an annular tip portion (first tip portion) 22c located on the opposite side of the base end portion 22b in the longitudinal direction 22a of the device body portion 22, an annular slope 22d corresponding to the side surface of the truncated cone is formed.

[0032] The outer diameter of the small diameter portion of the annular inclined surface 22d is the same as the outer diameter of the tip end portion 22c, and the outer diameter of the large diameter portion of the annular inclined surface 22d is the same as the outer diameter of the base end portion 22b. In other words, the outer diameter of the tip end portion 22c is smaller than the outer diameter of the base end portion 22b.

[0033] As shown in Figure 3, a first cylindrical flow path 28 is formed between the intermediate position 22e in the longitudinal direction 22a of the device main body 22 and the tip 22c, along the radial direction 22f of the device main body 22, from the outer peripheral side surface of the device main body 22 to a predetermined depth.

[0034] One end of a flexible first connecting member 30 such as a hose or tube is fixed to the outer end of the first cylindrical flow path 28 in the radial direction 22f. The other end of the first connecting member 30 is connected to a gas supply source 32, and the first cylindrical flow path 28 is connected to the gas supply source 32 via the first connecting member 30.

[0035] The gas supply source 32 supplies a gas 40 such as nitrogen gas or air. Note that the gas supply source 32 is not a part of the tool 2. For example, the gas supply source 32 is a tank filled with compressed nitrogen gas, air, or the like, but may also be a facility device that produces compressed air by taking in air from the atmosphere.

[0036] The gas supply source 32 as equipment includes a compressor for compressing a gas 40 such as air, a dryer for drying the compressed gas 40, a tank for storing the compressed gas 40, a filter for removing dust contained in the gas 40 supplied from the tank to the first connecting member 30, and the like.

[0037] An annular flow path 34 arranged approximately concentrically with the base end 22b, the tip end 22c, and the inclined surface 22d is connected to the inner end of the first cylindrical flow path 28 in the radial direction 22f of the device main body 22. A plurality of linear flow paths 36 are formed between the annular flow path 34 and the tip end 22c, each extending along the longitudinal direction 22a.

[0038] The multiple straight flow paths 36 are arranged at approximately equal intervals along the circumferential direction of the annular flow path 34, and the opening exposed at the tip 22c of each straight flow path 36 serves as an injection port 38 for injecting gas 40 toward the outside of the dust collection device 20.

[0039] As shown in FIG. 1, in the device main body 22 of this embodiment, a plurality of injection ports 38 are arranged at approximately equal intervals around the circumferential direction of the tip portion 22c, and are arranged in a ring shape so as to surround the suction port 42c radially outside the suction port 42c described later.

[0040] The gas 40 jetted from the plurality of jet nozzles 38 forms a cylindrical air curtain. That is, the gas 40 jetted from the plurality of jet nozzles 38 forms an air flow 40a for confining chips 11b generated when cutting the workpiece 11 in a predetermined space (see FIG. 3).

[0041] The air flow 40a confines the chips 11b in a cylindrical or disk-shaped space having, for example, circles on the top and bottom surfaces with a diameter approximately equal to the outer diameter of the tip 22c, and a length (height) equal to the distance from the tip 22c to the workpiece surface of the workpiece 11.

[0042] The chips 11b trapped in the predetermined space in this manner are sucked into the dust collecting device 20 through the suction port 42c of the through-hole 42 that penetrates from the base end 22b to the tip end 22c. As shown in Fig. 3, the through-hole 42 is formed inside the annular flow path 34 and the plurality of linear flow paths 36 in the radial direction 22f of the device main body 22.

[0043] The through-hole 42 has a first annular step 42a near the base end 22b for positioning the cylindrical body 8. The diameter of the large diameter part of the first step 42a is approximately equal to the outer diameter of the body 8.

[0044] The through hole 42 further has an annular second step portion 42b having a large diameter portion smaller than the diameter of the large diameter portion of the first step portion 42a, located closer to the tip end 22c than the first step portion 42a in the longitudinal direction 22a of the device body 22. However, the diameter of the small diameter portion of the second step portion 42b is larger than the outer diameter of the drill chuck 12.

[0045] When the device main body 22 is fixed to the trunk 8, the drill chuck 12 is positioned inside the second step 42b in a manner that does not contact the inner wall of the device main body 22, and the entire drill chuck 12 and most of the drill bit 14 are covered by the device main body 22.

[0046] However, when the device main body 22 is fixed to the trunk 8, the dust collecting device 20 is positioned radially outside the drill bit 14, with the tip of the drill bit 14 protruding from the dust collecting device 20 without covering it.

[0047] At this time, the drill bit 14 is placed in the above-mentioned through hole 42, and the opening of the through hole 42 exposed at the tip 22c of the device main body 22 functions as a suction port 42c for sucking in chips 11b generated when cutting the workpiece 11 to form the hole 11a using negative pressure.

[0048] That is, with the device main body 22 fixed to the trunk 8, the suction port 42c of the dust collecting device 20 surrounds the drill bit 14 on the radially outer side of the drill bit 14. A second cylindrical flow path 44 is formed perpendicular to the through hole 42 at a position different from the first cylindrical flow path 28.

[0049] In this embodiment, the second cylindrical flow path 44 is provided on the opposite side of the first cylindrical flow path 28 in the radial direction 22f of the device main body 22, with the through hole 42 therebetween, and has an inner diameter larger than the inner diameter of the first cylindrical flow path 28.

[0050] In this embodiment, the inner diameter of the second cylindrical flow path 44 is approximately 16 times the inner diameter of the first cylindrical flow path 28. However, the position and inner diameter of the second cylindrical flow path 44 are not limited to this example.

[0051] One end of a flexible second connecting member 46 such as a hose or tube is fixed to the outer end of the second cylindrical flow path 44 in the radial direction 22f. The other end of the second connecting member 46 is connected to a suction source 48, and the second cylindrical flow path 44 is connected to the suction source 48 via the second connecting member 46.

[0052] The suction source 48 is not a part of the tool 2. For example, the suction source 48 is a facility device that generates negative pressure and has an ejector, a vacuum pump, a motor-driven blade (fan), or the like. A commercially available vacuum cleaner may be used as the suction source 48. The negative pressure generated by the suction source 48 is transmitted to the through-hole 42 via the second connecting member 46 and the second cylindrical flow path 44.

[0053] 3 is a cross-sectional view of the tool 2 of the first embodiment during machining of the workpiece 11. Chips 11b generated when the workpiece 11 is cut with the drill bit 14 are taken into the through-hole 42 via the suction port 42c, and are discharged from the dust collector 20 to the suction source 48 via the second cylindrical flow path 44 and the second connecting member 46.

[0054] When processing the workpiece 11, gas 40 is sprayed from the multiple spray ports 38 to form an airflow 40a for confining chips 11b in a predetermined space. This reduces the amount of chips 11b that fly out from the gap between the dust collector 20 and the workpiece 11, and also allows the chips 11b that are confined in the predetermined space to be sucked in through the suction port 42c.

[0055] This reduces the amount of chips 11b that fly from the gap between the dust collecting device 20 and the workpiece 11. The device main body 22 is made of hard resin and does not have a bellows-shaped cover portion (see Patent Document 1 mentioned above) that is expandable and contractable along the longitudinal direction 22a, but instead the airflow 40a can function as a cover portion that comes into contact with the workpiece 11 and reduces the scattering of chips 11b.

[0056] Next, an example of dimensions of the dust collecting device 20 will be described with reference to Figures 4(A) to 4(C). Figure 4(A) is a cross-sectional view of the tool 2 of the first embodiment, Figure 4(B) is a cross-sectional view of the tool 2 taken along line AA in Figure 4(A), and Figure 4(C) is a cross-sectional view of the tool 2 taken along line BB in Figure 4(A).

[0057] 4(A), the length 22g in the longitudinal direction 22a of the device body 22 is 113 mm, and the amount of protrusion 14a of the drill bit 14 from the tip end 22c is 8 mm when the dust collecting device 20 is fixed to the power tool body 4. The inner diameter of the first connecting member 30 is 2.5 mm, and the inner diameter of the second connecting member 46 is 31.5 mm.

[0058] 4(B) is 60 mm, the outer diameter 22h of the annular flow path 34 is 33 mm, and the inner diameter 34b of the annular flow path 34 is 27 mm. The outer diameter 42d of the through-hole 42 is 24 mm. A cylindrical partition wall 22i is present between the inner diameter 34b of the annular flow path 34 and the outer diameter 42d of the through-hole 42.

[0059] The outer diameter 36a of the straight flow path 36 of the dust collector 20 shown in Fig. 4(C) is 3 mm, and although not shown in Fig. 4(C), the outer diameter of the injection port 38 is also 3 mm. The outer diameter of the drill bit 14 is 5 mm as described above.

[0060] When using the tool 2 to form a hole 11a in the workpiece 11, the operator presses the trigger switch to rotate the drill bit 14 at high speed, and then presses the tip of the drill bit 14 against the workpiece 11. This cuts the workpiece 11, and a hole 11a having a diameter of, for example, 5 mm is formed in the workpiece 11.

[0061] During cutting, for example, air is supplied from the gas supply source 32 to the dust collector 20 via the first connecting member 30 at a flow rate of 10 L / min, and the gauge pressure inside the second connecting member 46 is set to -76.8 kPa by the negative pressure transmitted from the suction source 48.

[0062] This confines the chips 11b in a predetermined space formed by the airflow 40a, reducing the scattering of the chips 11b, and also allows the chips 11b to be sucked through the suction port 42c. Therefore, the amount of chips 11b that scatters from the gap between the dust collector 20 and the workpiece 11 can be reduced.

[0063] Second Embodiment Next, a tool 50 according to a second embodiment will be described with reference to Fig. 5 to Fig. 7(C). Fig. 5 is an exploded perspective view of the tool 50 according to the second embodiment, and Fig. 6 is a perspective view of the tool 50 of the second embodiment.

[0064] The tool 50 of the second embodiment has a dust collector 52 having a different structure from the dust collector 20 of the first embodiment. More specifically, as shown in Fig. 7(A), a single cylindrical flow path 54 is connected to the first cylindrical flow path 28 of the dust collector 52, instead of the annular flow path 34 and the multiple linear flow paths 36 (see Fig. 4(A)). The cylindrical flow path 54 is approximately perpendicular to the first cylindrical flow path 28.

[0065] Therefore, the tip end 22c of the dust collecting device 52 is provided with a single annular injection port 56 instead of multiple injection ports 38. The dust collecting device 52 of the second embodiment differs from the dust collecting device 20 of the first embodiment in this respect, but is otherwise the same. Therefore, in Figures 5 to 7(C), the same reference numerals are used for the same elements as in the first embodiment.

[0066] Figure 7(A) is a cross-sectional view of the tool 50 of the second embodiment, Figure 7(B) is a cross-sectional view of the tool 50 at CC in Figure 7(A), and Figure 7(C) is a cross-sectional view of the tool 50 at DD in Figure 7(A). The characteristics of the cylindrical channel 54 are clearly shown in Figures 7(A) and 7(C).

[0067] The width 54a of the cylindrical flow path 54 shown in FIG. 7(C) (i.e., the difference between the outer diameter and the inner diameter) corresponds to the difference between the outer diameter 34a (33 mm) of the annular flow path 34 in the first embodiment and the inner diameter 34b (27 mm) of the annular flow path 34, and is 3 mm in the second embodiment.

[0068] In the second embodiment, when processing the workpiece 11, gas 40 is sprayed from one spray nozzle 56 to form an airflow 40a for confining chips 11b in a predetermined space. This reduces the amount of chips 11b that fly out from the gap between the dust collector 52 and the workpiece 11, and allows the chips 11b that are confined in the predetermined space to be sucked in through the suction port 42c. Therefore, the amount of chips 11b that fly out from the gap between the dust collector 52 and the workpiece 11 can be reduced.

[0069] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. For example, the dust collecting devices 20, 52 described above are not limited to the electric power tool body 4, but can also be applied to a manual tool body in which the drill bit 14 is rotated by the operator turning the handle by hand.

[0070] The above-described dust collecting devices 20, 52 can also be applied to an NC (Numerical Control) milling machine, a machining center, etc. Furthermore, instead of the drill bit 14, the drill chuck 12 may be fitted with a cutting part such as a Phillips or flat head screw tightening bit, a cylindrical grinding wheel, a cylindrical polishing wheel, or an end mill. [Explanation of symbols]

[0071] 2,50: Tool, 4: Power tool body (tool body) 6: gripping part, 8: body part, 10: motor, 10a: output shaft 11: Workpiece, 11a: Hole, 11b: Chips 12: Drill chuck, 14: Drill bit (blade), 14a: Protrusion, 16: Screw hole 20,52:Dust collector 22: device main body, 22a: longitudinal direction 22b: Proximal end (first proximal end), 22c: Distal end (first distal end) 22d: slope, 22e: intermediate position, 22f: radial direction 22g: length, 22h: outer diameter, 22i: bulkhead 24: Through hole, 26: Bolt 28: First cylindrical flow path, 30: First connecting member, 32: Gas supply source 34: Annular flow path, 34a: outer diameter, 34b: inner diameter 36: Straight channel, 36a: Outer diameter 38: Nozzle 40: gas, 40a: airflow 42: through hole, 42a: first step portion, 42b: second step portion 42c: Suction port, 42d: Outer diameter 44: second cylindrical flow path, 46: second connecting member, 48: suction source 54: Cylindrical flow path, 54a: Width, 56: Injection port

Claims

1. A tool capable of forming a hole in a workpiece, comprising: A tool body portion; a cylindrical blade portion that is attached to the tool body so as to be rotatable relative to the tool body and is capable of cutting the workpiece; a dust collecting device having a device body part that is detachably fixed to the tool body part, and that is disposed radially outside the blade part in a manner that the tip of the blade part is not covered but protrudes when the device body part is fixed to the tool body part; Equipped with The main body of the dust collecting device is a first base end portion fixed to the tool body portion; a first tip end portion located on the opposite side to the first base end portion in the longitudinal direction of the device body; a suction port provided at the first tip portion and disposed radially outside the blade portion so as to surround the blade portion, the suction port being for sucking, by negative pressure, chips generated when the workpiece is cut to form the hole; and one or more nozzles provided at the first tip portion, arranged in an annular shape radially outside the suction port so as to surround the suction port, and spraying gas to form an airflow for confining the cutting chips in a predetermined space.

2. A dust collection device that is detachable from a tool body of a tool having a cylindrical blade portion and that sucks up chips generated when a hole is formed in a workpiece, a device body portion detachably fixed to the tool body portion, The device main body includes: a first base end portion detachably fixed to the tool body portion; a first tip end portion located on the opposite side to the first base end portion in the longitudinal direction of the device body; a suction port provided at the first tip portion and disposed radially outside the blade portion so as to surround the blade portion, for sucking, by negative pressure, the chips generated when the workpiece is cut to form a hole; one or more jet ports provided at the first tip portion and arranged radially outside the suction port so as to surround the suction port, the jet ports forming an airflow for confining the chips in a predetermined space by jetting gas; having The dust collection device is characterized in that the device main body is positioned radially outside the blade portion in a manner that does not cover the tip of the blade portion but protrudes therefrom when the first base end is fixed to the tool main body.

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