Dust collecting attachment

Abstract

To make powder dust less likely to be deposited in a dust suction portion.SOLUTION: A dust collecting attachment 1 includes: a dust suction portion 2 which faces a surface of a workpiece W and through which a tip tool T may penetrate; and a body portion 3 having a dust collection passage 36 communicating with the dust suction portion 2 and connectable to an external hose. A suction force is exerted from the hose to the dust collection passage 36 to create a negative pressure in the dust suction portion 2. The dust suction portion 2 has: an inner cylinder 5 through which the tip tool T penetrates; a front dust suction passage 20 including a front suction port 22 which is open to the front at the radial outer side of the inner cylinder 5 and communicates with the dust collection passage 36; and a rear dust suction passage 21 which includes a rear suction port 23 which is open to the rear at the radial outer side of the inner cylinder 5 and communicates with the dust collection passage 36.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present disclosure relates to a dust collection attachment used to collect dust generated from a workpiece during work using a power tool. [Background technology]

[0002] For example, when drilling holes with a tool tip using a hammer drill, a dust collection attachment may be used to collect dust generated from the workpiece at the processing position without scattering it. Patent Document 1 (U.S. Patent Application Publication No. 2011 / 0142561) discloses an example of such a dust collection attachment. The dust collection attachment disclosed therein has a housing that extends to the left and right, and a cylindrical dust collection section at the top, through which the tool tip passes, and a cylindrical handle on the front side of the housing, which has a dust collection passage that communicates with the dust collection section. Meanwhile, a sealant or pad is provided on the back side of the housing to form a suction space where the suction port opens. This dust collection attachment is used by connecting an external dust collector to the handle via a hose. When the dust collector is operated and the suction nozzle is brought into contact with the surface of the workpiece, negative pressure is created in the handle and dust collection unit, which are connected to the hose, and also in the suction space connected to the handle. As a result, the suction nozzle is directly sucked into the workpiece and positioned there. When the tip of the power tool is inserted into the dust collection unit and processing is performed, the generated dust is sucked directly into the dust collection unit and collected in the dust collector via the handle and hose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2011 / 0142561 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional dust collection attachment, the dust collection part is located at the top of the housing, so when used with the dust collection part and the housing lined up one above the other, the dust sucked into the dust collection part flows downward and is smoothly sucked into the dust collection passage. However, when used in a horizontal position with the suction unit and housing lined up, there is a risk that dust will remain on the inner surface of the lower suction unit without being sucked into the dust collection passage.In particular, the opening on the front side of the suction unit (the side facing the operator) is often fitted with a rubber cap through which the tool insert passes to improve sealing, which creates a space between the inner surface of the suction unit and the rubber cap through which air cannot flow, and when working in a horizontal position, dust is likely to accumulate in this space.

[0005] Therefore, an object of the present disclosure is to provide a dust collection attachment in which dust is less likely to accumulate in the dust collection section. [Means for solving the problem]

[0006] In order to achieve the above object, the present disclosure provides a dust collection attachment, comprising: It includes a dust collection section that faces the surface of the workpiece and can be penetrated by a tip tool, and a main body section that has a dust collection passage that communicates with the dust collection section and to which an external hose can be connected, and the dust collection section becomes negative pressure by applying suction force from the hose to the dust collection passage. The dust suction unit includes an inner tube through which the tool bit passes, a first dust suction flow path that opens a first suction port on the workpiece side at the radially outer side of the inner tube and communicates with the dust collection path, The dust collecting passage has a second suction port that opens on the radially outer side of the inner cylinder on the opposite side of the workpiece and communicates with the dust collecting passage. [Effects of the Invention]

[0007] According to the present disclosure, the flow paths are dispersed in the dust suction unit, and no spaces are created on either the workpiece side or the opposite side within the dust suction unit where air cannot easily flow. This makes it difficult for dust to accumulate within the dust suction unit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a rear perspective view of the dust collection attachment. [Figure 2] FIG. 2 is a front perspective view of the dust collection attachment. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 10 is a front perspective view of the dust collection unit with the rubber cap removed. [Figure 6] This is a rear perspective view of the dust collection unit with the rubber cap removed. [Figure 7] FIG. 2 is a front view of the dust collection unit with the rubber cap removed. [Figure 8] FIG. 10 is a rear view of the dust collection unit with the rubber cap removed. [Figure 9] FIG. 4 is an enlarged cross-sectional view taken along the line AA in FIG. 3. [Figure 10] FIG. 4 is an enlarged cross-sectional view taken along the line BB in FIG. 3. [Figure 11] FIG. 5 is an enlarged cross-sectional view of the CC line portion of FIG. [Figure 12] FIG. 10 is a rear view of the dust collection attachment with small diameter cuffs connected thereto. [Figure 13] FIG. 10 is a rear view of the dust collection attachment with large diameter cuffs connected thereto. [Figure 14] FIG. 13 is an enlarged cross-sectional view of the portion of line DD in FIG. [Figure 15] FIG. 14 is an enlarged cross-sectional view of the portion of line EE in FIG. [Figure 16] 4 is an explanatory diagram showing the air flow in an enlarged cross section of the portion of line AA in FIG. 3 in a state of use. FIG. [Figure 17] 17 is an enlarged cross-sectional view of the portion of line FF in FIG. 16 when used in a horizontal position. DETAILED DESCRIPTION OF THE INVENTION

[0009] In one embodiment of the present disclosure, the first dust suction passage and the second dust suction passage may join together in the dust collection passage. According to this configuration, even if two dust suction passages are provided in the dust suction unit, dust can be efficiently guided to the dust collection passage. In one embodiment of the present disclosure, the first dust suction passage and the second dust suction passage may be provided in at least a region on the dust collection passage side of the dust suction part. According to this configuration, both dust suction passages can be brought closer to the dust collection passage, making it possible to shorten the passages, thereby suppressing pressure loss and preventing a decrease in dust collection efficiency. In one embodiment of the present disclosure, the first suction port may be formed larger than the second suction port in the circumferential direction of the inner cylinder. This configuration allows for efficient collection of dust generated from the workpiece. In one embodiment of the present disclosure, the first air inlet and the second air inlet may be formed at an angle of 180° or more in the circumferential direction. With this configuration, even when the dust collection attachment is used in a position where the dust collection passage is sideways, both suction ports are positioned below the tool tip, allowing dust to be collected, which is effective in preventing dust from accumulating in the dust collection section.

[0010] In one embodiment of the present disclosure, the second suction port may be formed between the inner cylinder and an outer cylinder provided outside the inner cylinder, and a rib may be provided between the inner cylinder and the outer cylinder. According to this configuration, the second suction port is reinforced between the inner cylinder and the outer cylinder, and the shape can be maintained. In one embodiment of the present disclosure, a cap may be removably provided on the opposite side of the dust suction part from the workpiece, for sealing between the penetrating tool bit and the dust suction part. According to this configuration, the second dust collection passage can be formed by utilizing the cap. In one embodiment of the present disclosure, the second suction port includes an opposite side opening that opens to the opposite side of the workpiece, and an inner opening that communicates with the opposite side opening and opens toward the inner surface of the inner tube, and the cap may block the opposite side opening when attached. With this configuration, dust that tends to accumulate inside the cap can be efficiently sucked in through the inner opening. [Example]

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view from the rear showing an example of a dust collection attachment, FIG. 2 is a perspective view from the front, FIG. 3 is a rear view, and FIG. 4 is a front view. The dust collection attachment 1 has a dust suction unit 2, a main body 3, and a flexible hose 4. For convenience, the dust suction unit 2 side will be referred to as the upper side, and the side of the dust suction unit 2 and main body 3 where a suction port 48 (described later) is located will be referred to as the front side. The dust collection unit 2 is cylindrical with an axis extending in the front-to-rear direction. The dust collection unit 2 is a double cylinder having an inner cylinder 5 and an outer cylinder 6. The front end of the inner cylinder 5 is located rearward of the front end of the outer cylinder 6, and the inner cylinder 5 has a shorter axial length than the outer cylinder 6. As shown in Figures 5 and 6, a small-diameter cover portion 7 is coaxially formed at the rear end of the outer tube 6. A rubber cap 8 is detachably fitted onto the cover portion 7. The rubber cap 8 has a through-hole 9 located at the center and a plurality of notches 10, 10 extending radially from the through-hole 9. The rubber cap 8 is an example of a cap of the present disclosure.

[0012] An upper connecting part 11 is provided between the inner cylinder 5 and the outer cylinder 6 directly above the axis of the dust suction part 2. The upper connecting part 11 is a V-shaped rib when viewed from the front, which extends in the front-to-rear direction and connects the inner cylinder 5 and the outer cylinder 6. Between the inner tube 5 and the outer tube 6, behind the upper connecting portion 11, there is provided a rear connecting portion 12, which is arc-shaped in rear view and connects the upper portions of the two tubes at their rear ends. The rear end of the inner tube 5, excluding the rear connecting portion 12, is located forward of the rear end of the outer tube 6. A pair of ribs 13, 13 connecting the two tubes 5, 6 are formed symmetrically between the rear end of the inner tube 5, excluding the rear connecting portion 12, and the rear end of the outer tube 6. The inner surface of each rib 13 is a concave curved surface that extends rearward, continuing from the inner circumferential surface of the inner tube 5. The rear surface of each rib 13 is a flat surface that extends radially inward, continuing from the rear end surface of the outer tube 6. The rear surface of each rib 13 abuts against the front surface of the attached rubber cap 8. Therefore, as shown in Figures 7 and 8, the inner tube 5 and the outer tube 6 are coaxially connected to each other, forming a ring-shaped ventilation space 14 that is continuous in the circumferential direction between the two tubes, except for the upper connection part 11. A notch 15 is partially formed in the lower front side of the outer cylinder 6. In this notch 15, the upper end of a partition plate 16 that separates and forms a dust collection passage 36 (described later) is positioned.

[0013] A front dust suction passage 20 and a rear dust suction passage 21 are formed on the radially outer side of the inner cylinder 5. The front dust suction passage 20 is an example of a first dust suction passage of the present disclosure, and the rear dust suction passage 21 is an example of a second dust suction passage of the present disclosure. The front dust suction passage 20 has a front suction port 22 open at the front. The front suction port 22 is an example of a first suction port of the present disclosure. 5 and 7, front suction port 22 opens in a ring shape between the front ends of inner tube 5, outer tube 6, and the upper end of partition plate 16, excluding upper connecting portion 11. That is, front suction port 22 opens in a ring shape spanning from the lower half to the upper half of dust suction unit 2. The lower half of dust suction unit 2 is an example of the area on the dust collection passage side of the dust suction unit of the present disclosure. The front dust collection passage 20 is a passage that extends from the front suction port 22 through the ventilation space 14 to an intake port 36a of a dust collection passage 36, which will be described later.

[0014] The rear dust suction passage 21 has a rear suction port 23 opening at its rear. The rear suction port 23 is an example of a second suction port of the present disclosure. As shown in Figs. 6 and 8, the rear suction port 23 has a rear opening 24 that opens in an arc shape, excluding the rear connecting portion 12, between the rear end of the inner tube 5 and the rear end of the outer tube 6 when viewed from behind. The rear opening 24 is an example of an opposite side opening of the present disclosure. The rear suction port 23 also has an inner opening 25 that opens in a band shape in the circumferential direction across the ribs 13, 13, radially inward at the rear of the inner cylinder 5. The rear opening 24 and the inner opening 25 are in communication with each other. In this way, rear suction port 23, which includes rear opening 24 and inner opening 25, is formed to include the lower half of dust collection unit 2 and form an angle greater than 180° in the circumferential direction of inner cylinder 5. However, rear suction port 23 is smaller than front suction port 22 in the circumferential direction of inner cylinder 5. With the rubber cap 8 attached, the rear opening 24 of the rear suction port 23 is closed by the outer circumferential portion of the rubber cap 8. Therefore, only the inner opening 25 of the rear suction port 23 opens into the inner cylinder 5. The rear dust collection flow path 21 is a flow path that extends from the rear suction port 23 through the ventilation space 14 to the intake port 36a of the dust collection passage 36.

[0015] The main body 3 has a main body housing 30 , a pad 31 , an inner frame 32 , and an air vent lever 33 . The main body housing 30 has a circular shape when viewed from the rear. A connecting portion 34 for connecting to the dust collection unit 2 is provided in the vertical direction at the top of the main body housing 30. A strip-shaped skirt portion 35 is formed on the outer periphery of the main body housing 30, protruding forward along the entire periphery and opening at the front. As shown in Figures 9 and 10, a cylindrical dust collection passage 36 is formed in the vertical direction within the main housing 30. The dust collection passage 36 penetrates the connecting portion 34 at the left-right center of the main housing 30, and its upper end opens into an air intake port 36a on the lower inner surface of the outer cylinder 6 of the dust suction unit 2. The air intake port 36a communicates with the ventilation space 14. The lower portion of the dust collection passage 36 bulges rearward from the top to the bottom of the main housing 30, forming a handle portion 37 whose lower end opens at the back of the main housing 30. A recess 38 with a semicircular cross section is formed in the back of the main housing 30 and extends downward from the handle portion 37. The partition plate 16 is screwed to the main housing 30 at a position forward of the handle portion 37 and extending upward from the recess 38, forming the front wall of the dust collection passage 36.

[0016] An inner rib 39, which is one size smaller than the skirt portion 35 and has the same shape as the skirt portion 35, is formed on the front surface of the main body housing 30. A suction space 40 is formed inside the inner rib 39. A plurality of connecting ribs 41, 41..., which protrude radially from the inner rib 39, are installed between the skirt portion 35 and the inner rib 39. A communication port 42, which communicates with the suction space 40, is formed between the partition plate 16 and the recess 38 at the front upper end of the handle portion 37. The pad 31 is made of an elastic material and has an outer shape similar to, but slightly larger than, the main housing 30 when viewed from the front. An opening 43 of the same shape is formed in the center of the pad 31 along the inner rib 39. The pad 31 is arranged on the front surface of the main housing 30, covering the area between the skirt portion 35 and the inner rib 39. The pad 31 has a shallow tapered shape, with the front surface receding from the outer periphery toward the opening 43. A thin-walled portion 44 that is recessed rearward is formed around the entire inner peripheral edge of the opening 43.

[0017] The inner frame 32 is ring-shaped and goes around the thin-walled portion 44 of the pad 31. The thin-walled portion 44 is fitted into the inner frame 32 from the rear. A pair of left and right screw fastening portions 45, 45 is formed on the upper and lower inner periphery of the inner frame 32. The screw fastening portions 45, 45 are fixed by screws 47, 47 to a pair of left and right screw bosses 46, 46 provided upright on the upper and lower sides of the front surface of the main housing 30. This fixes the pad 31, and suction ports 48 that communicate with the central suction space 40 are formed on the front surfaces of the pad 31 and the inner frame 32. As shown in FIGS. 2 and 4, the upper ends of the pad 31 and the inner frame 32 are chamfered to form straight lines in the left-right direction. Four abutment portions 49, 49... that protrude forward are formed on the top, bottom, left, and right sides of the front surface of the inner frame 32. The upper abutment portion 49 extends in the left-right direction to match the shape of the upper end of the inner frame 32. The other three abutment portions 49, 49... on the bottom and on the left and right extend in arc shapes in the circumferential direction of the inner frame 32. 9 and 10, before the workpiece is attracted to the abutment portion 49, the front surface of the abutment portion 49 is formed to a protruding height that is positioned slightly rearward of the front end surface of the pad 31. In this state, the tapered portion of the pad 31 is in a position that does not abut against the skirt portion 35 of the main body housing 30.

[0018] The main body housing 30 is formed with air vent holes 50, 50 facing the suction space 40. Each air vent hole 50 has a rectangular shape extending in the vertical direction, and as shown in Figures 2 and 4, is arranged side by side in the vertical direction on the right side between the upper left and right screw bosses 46, 46. The air vent holes 50, 50 are located on the right side of the handle portion 37 on the rear side. A notch 51 is formed on the right side of the handle portion 37, spanning from the side surface to the rear side. The notch 51 extends in the vertical direction in a rectangular area that includes the air vent holes 50, 50. The air vent holes 50, 50 penetrate the main housing 30 and communicate with the notch 51.

[0019] The air vent lever 33 is a square block that fits into the cutout 51 and spans from the side to the back of the handle portion 37. The air vent lever 33 is movable back and forth within the cutout 51. A pair of upper and lower closing portions 52, 52 protrude from the front of the air vent lever 33. As shown in Figure 11, the closing portions 52, 52 fit into the air vent holes 50, 50 when the air vent lever 33 is in the forward position abutting the bottom surface of the cutout 51, thereby closing the air vent holes 50, 50. In the forward position, the air vent lever 33 fits into the notch 51 and fits within the outline of the handle 37. However, a finger hook 53 that protrudes diagonally outward and rearward to the right is integrally formed in the vertical direction between the side surface and back surface of the air vent lever 33. A similar finger hook 53A is formed on the left side surface of the handle 37 in a position symmetrical to the finger hook 53 of the air vent lever 33 with respect to a vertical and front-to-rear plane that passes through the center line L of the handle 37.

[0020] The air vent lever 33 is equipped with a guide pin 54 that protrudes forward. The rear portion of the guide pin 54 is fixed integrally to the air vent lever 33 between the stopper portions 52, 52 by insert molding. A guide tube 55 that protrudes forward is formed between the upper and lower air vent holes 50, 50 in the main housing 30. The guide pin 54 passes through the guide tube 55 from the rear. A washer 56 is attached to the front end of the guide pin 54 in front of the guide tube 55 and is prevented from coming off by a circlip. A coil spring 57 is fitted to the front of guide pin 54 in front of guide tube 55. Coil spring 57 is interposed between a receiving recess 58 formed on the inner periphery of guide tube 55 and washer 56. Therefore, guide pin 54 is urged forward by coil spring 57, and air vent lever 33 is normally positioned in an advanced position where closing portions 52, 52 close air vent holes 50, 50. The upper end of the flexible hose 4 is connected to the handle portion 37 of the main body housing 30. The flexible hose 4 fits into a recess 38 of the main body housing 30 and extends downward. A cylindrical joint 60 is attached to the lower end of the flexible hose 4.

[0021] The joint 60 has a three-stage diameter, with a large diameter section 61 at the top, a medium diameter section 62 in the middle, and a small diameter section 63 at the bottom, which is the smallest diameter. A recessed groove is formed in the circumferential direction on the outer periphery of the medium diameter section 62. A plurality of ring-shaped outer ribs 64, 64... are formed in the axial direction on the outer periphery of the small diameter section 63. Therefore, the joint 60 can be connected to either a small diameter cuff 70 shown in FIG. 12 or a large diameter cuff 71 shown in FIG. As shown in Figure 14, small-diameter cuffs 70 can be connected by fitting their tips onto the small-diameter portion 63. A plurality of ring-shaped inner ribs 72, 72... are formed in the axial direction on the inner peripheral surface of the cuffs 70. When connected to the small-diameter portion 63, the inner ribs 72 engage with the outer ribs 64, 64 to prevent slipping. As shown in FIG. 15, the large diameter cuff 71 can be connected by inserting the tip thereof into the medium diameter portion 62 just before the large diameter portion 61. Therefore, the worker can use one joint 60 regardless of whether the tip of the external hose 73 is connected to the cuff 70 or the cuff 71, and there is no need to use different joints 60 depending on the cuffs 70 and 71.

[0022] When using the dust collection attachment 1 configured as above, the operator grasps the handle 37 of the main body 3, aligns the dust collection unit 2 with the processing position, positions the main body 3 vertically on the surface of the workpiece, and brings the suction port 48 into close contact with the workpiece. When the dust collector is operated in this state, a suction force is generated in the flexible hose 4 and dust collection passage 36 via the hose 73, and also in the intake port 36a of the dust collection unit 2. Since the suction space 40 of the main body 3 is connected to the dust collection passage 36 via the communication port 42, the air in the suction space 40 is sucked into the dust collection passage 36 via the communication port 42, creating a negative pressure in the suction space 40. Therefore, as shown in Figure 16, the suction port 48 is attracted to the surface of the workpiece W, and the dust collection attachment 1 is fixed to the surface of the workpiece W.

[0023] At this time, the front surfaces of the contact portions 49 of the inner frame 32 come into contact with the surface of the workpiece W, restricting further advancement of the main housing 30. As a result, the pad 31 is no longer crushed between the pad 31 and the skirt portion 35 of the main housing 30, and a non-contact state with the skirt portion 35 is maintained. When the pad 31 is in contact with the skirt portion 35, if the surface of the workpiece W has a convex shape, the skirt portion 35 will also ride up on the convex shape along with the pad 31, widening the gap between the pad 31 and the surface of the workpiece W, which may reduce the suction force. However, in this case, the abutment portion 49 restricts the forward position of the main housing 30, maintaining a non-contact state between the pad 31 and the skirt portion 35. Therefore, even if the surface of the workpiece W has a convex shape, only the pad 31 deforms, preventing the main housing 30 from floating up and preventing a decrease in suction force. In particular, when the suction port 48 is not suctioned to the workpiece W, the front surface of the contact portion 49 is located closer to the main body housing 30 than the front end surface of the pad 31 . Therefore, even if the contact portion 49 is provided, the pad 31 does not interfere with the close contact with the surface of the workpiece W.

[0024] The worker then performs the drilling operation by inserting the tip tool T of a power tool (not shown) into the rear of the dust suction unit 2. As a result, air outside the dust suction unit 2 is sucked into the inner tube 5 from between the rubber cap 8 and the tip tool T, as shown by the dotted arrow a in Figure 16. Some of the air sucked into the inner tube 5 moves forward within the inner tube 5 and enters the front dust suction flow path 20 from the front suction port 22. This part of the air then enters the dust collection passage 36 through the intake port 36a, and flows from the dust collection passage 36 to the dust collector via the flexible hose 4 and hose 73. Meanwhile, another portion of the air sucked into inner cylinder 5 flows radially outward within inner cylinder 5, as shown by dashed-dotted arrow b, and enters rear dust collection passage 21 from inner opening 25 of rear suction port 23. This other portion of the air then merges with a portion of the air flowing in front dust collection passage 20 within ventilation space 14, enters dust collection passage 36 from intake port 36a, and then travels from dust collection passage 36 to the dust collector via flexible hose 4 and hose 73. Therefore, the dust generated from the workpiece W is sucked in together with air through either the front suction port 22 or the rear suction port 23, enters the dust collection passage 36 through the front dust collection flow path 20 or the rear dust collection flow path 21, and is collected in the dust collector via the flexible hose 4 and hose 73.

[0025] Here, the inner opening 25 of the rear suction port 23 is open over a range exceeding 180° inside the outer periphery of the rubber cap 8. Therefore, dust inside the inner tube 5 is sucked through the rear suction port 23 without being trapped between the inner tube 5 and the rubber cap 8. Even when the dust collection attachment 1 is in a horizontal position, as shown in FIG. 17 , the inner opening 25 is located in the lower region of the inner tube 5 inside the rubber cap 8. Therefore, dust is sucked directly from the inner opening 25 through the rear dust suction flow path 21 into the dust collection passage 36. This makes it difficult for dust to accumulate on the inner circumferential surface of the inner tube 5 inside the outer periphery of the rubber cap 8.

[0026] When removing the dust collection attachment 1 from the workpiece W, for example, to change the processing position, the operator hooks his or her fingers from the front of the air vent lever 33 on the handle portion 37 between the finger hook 53 and the left finger hook 53A and pulls it backward. As a result, as shown by the two-dot chain line in FIG. 10 , the air vent lever 33 moves backward against the bias of the coil spring 57, opening the notches 51 and the air vent holes 50, 50. This allows outside air to flow into the suction space 40 through the air vent holes 50, reducing the suction force. The dust collection attachment 1 can then be removed backward from the workpiece W. This removal can be performed consecutively with the operation of pulling the air vent lever 33 backward via the finger hooks 53, 53A. In other words, air venting using the air vent lever 33 and removing the dust collection attachment 1 are not separate operations. Therefore, the dust collection attachment 1 can be removed with a simple operation, and it is also possible to effectively prevent the attachment from accidentally dropping when being removed. When the dust collecting attachment 1 is removed and the air vent lever 33 is released, the air vent lever 33 moves to the forward position due to the bias of the coil spring 57. Therefore, the air vent holes 50 are closed again by the closing portions 52.

[0027] The dust collection attachment 1 of the above embodiment includes a dust collection section 2 that faces the surface of the workpiece W and can be penetrated by a cutting tool T, and a main body section 3 that has a dust collection passage 36 that communicates with the dust collection section 2 and to which an external hose can be connected, and by applying suction force from the hose 73 to the dust collection passage 36, negative pressure is created in the dust collection section 2. The dust collection section 2 has an inner tube 5 through which the tip tool T passes, a front dust collection flow path 20 which opens a front suction port 22 forward on the radial outside of the inner tube 5 and communicates with the dust collection passage 36, and a rear dust collection flow path 21 which opens a rear suction port 23 backward on the radial outside of the inner tube 5 and communicates with the dust collection passage 36. According to this configuration, the flow paths are dispersed in the dust suction part 2, and no spaces where air cannot flow easily are created on either the front or rear sides of the dust suction part 2. Therefore, dust is less likely to accumulate in the dust suction part 2.

[0028] The front dust suction passage 20 and the rear dust suction passage 21 join together at a dust collection passage 36 . Therefore, even if two dust collection passages 20, 21 are provided in the dust collection unit 2, dust can be efficiently guided to the dust collection passage . The front dust suction passage 20 and the rear dust suction passage 21 are provided in at least the lower half region of the dust suction section 2. Therefore, both dust collection passages 20, 21 can be brought closer to the dust collection passage 36, thereby shortening the passages, suppressing pressure loss and preventing a decrease in dust collection efficiency. The front suction port 22 is formed larger than the rear suction port 23 in the circumferential direction of the inner cylinder 5 . Therefore, the dust generated from the workpiece W can be efficiently collected. The front air inlet 22 and the rear air inlet 23 are formed at an angle of 180° or more in the circumferential direction. Therefore, even when the dust collection attachment 1 is used in a position where the dust collection passage 36 is horizontal, both suction ports 22, 23 are positioned below the tool tip T, allowing dust to be collected, which is effective in preventing dust from accumulating in the dust collection section 2.

[0029] The rear suction port 23 is formed between the inner cylinder 5 and the outer cylinder 6 provided outside the inner cylinder 5, and ribs 13, 13 are provided between the inner cylinder 5 and the outer cylinder 6. Therefore, rear suction port 23 is reinforced between inner cylinder 5 and outer cylinder 6, and the shape can be maintained. In addition, rib 13 prevents rubber cap 8 from excessively deforming forward. A detachable rubber cap 8 is provided on the rear side of the dust suction unit 2 to seal the space between the inserted tool tip T and the dust suction unit 2. Therefore, the rear dust collection passage 21 can be formed by utilizing the rubber cap 8. The rear suction port 23 includes a rear opening 24 that opens to the rear side and an inner opening 25 that communicates with the rear opening 24 and opens toward the inner surface of the inner tube 5, and the rubber cap 8 closes the rear opening 24 when installed. Therefore, dust that tends to accumulate inside the rubber cap 8 can be efficiently sucked in through the inner opening 25.

[0030] The above embodiment can be modified as follows. The first suction port is not limited to the form of the front suction port in the above example. The length of the first suction port in the circumferential direction of the dust suction part may be shorter than in the above example, or if possible, the first suction port may be open around the entire circumference. The radial opening width of the first suction port may also be larger or smaller than in the above example, or the opening width may vary in the circumferential direction.The first suction port may be formed by positioning the front end of the inner cylinder at the same front-to-rear position as the front end of the outer cylinder. The second suction port is not limited to the rear suction port configuration described above. The second suction port may be longer in the circumferential direction of the dust suction unit than in the above example, or may be open around the entire circumference if possible. The second suction port may be formed short, with an angle of less than 180° in the circumferential direction. The second suction port may be formed continuously in the circumferential direction without the rib connecting the inner cylinder and the outer cylinder. The first and second suction ports may have the same length in the circumferential direction. Conversely to the above example, the second suction port may be longer than the first suction port. The first and second dust suction passages are not limited to the front and rear dust suction passages in the above example. The first and second dust suction passages may be formed so that the ventilation space between the inner and outer cylinders is not ring-shaped. The first and second dust suction passages may not join together inside the dust suction unit, but may each communicate independently with the dust collection passage. The cap is not limited to the rubber cap in the above example, but may be made of other resins. The cap may also be omitted.

[0031] The structure for closing the air vent hole with the air vent lever is not limited to the above example. For example, the air vent lever may have two guide pins, one above the other, instead of one, and a plug may be formed between the guide pins to close one air vent hole in the main housing. The guide for the air vent lever is not limited to a guide pin, and a plate-shaped guide may be provided on the air vent lever. The guide may also be formed integrally with the air vent lever. The shapes of the air vent hole and the stopper portion can also be changed as appropriate, and the air vent hole and the stopper portion may be square or circular instead of rectangular. The shape of the air vent operating part is not limited to the square block-shaped air vent lever in the above example, and the air vent operating part may be a semicircular block or a rod. The finger hook portion does not have to be formed with the same amount of protrusion in the vertical direction as the finger hook piece in the above example. For example, the finger hook portion may be semicircular in rear view with a larger amount of protrusion in the vertical center. The finger hook does not have to be a structure that protrudes from the air vent operating part like the finger hook piece in the above example. For example, the finger hook may be a recess formed in the air vent lever. In the above example, the air vent lever is provided on the right side, but it may also be provided on the left side, or a pair of levers may be provided on the left and right sides of the handle portion. In the present disclosure, the structure for closing the air vent hole with the air vent lever may be omitted.

[0032] The number and shape of the contact portions of the inner frame can be changed as appropriate. For example, the contact portions may be elongated or shortened in the circumferential direction of the inner frame. In the above example, the front surface of the contact portion is positioned slightly rearward of the front end surface of the pad, but the front surface of the contact portion may also be positioned on the same plane as the front end surface of the pad (here, a plane defined by the up, down, left, and right directions). In the present disclosure, the abutting portion may be omitted. The joint can be modified as needed to fit the cuff shape of the dust collector hose. For example, the number of stages with different diameters can be increased to accommodate three or more types of cuffs. The connection between the joint and the cuff is not limited to rib engagement or push-fit connection. For example, screw connection or bayonet connection can also be used as the connection structure. The joint may be configured to accommodate only one cuff.

[0033] Furthermore, the main body is not limited to being circular when viewed from the rear, and may be other shapes when viewed from the rear, such as a polygon, square, rectangle, triangle, or oval. The shape of the suction port can also be changed as appropriate. The shape and mounting structure of the pad and inner frame can also be changed as appropriate to suit the main body. A suction port may be formed using a sealing member other than a pad. The flexible hose may be omitted. In this case, an external hose may be directly connected to the lower end of the handle portion. In the above example, the dust collection attachment is attached to a vertically oriented workpiece, but the dust collection attachment of the present disclosure can also be used when the workpiece is inclined or horizontal. [Explanation of symbols]

[0034] 1··Dust collection attachment, 2··Dust suction part, 3··Main body, 5··Inner tube, 6··Outer tube, 8··Rubber cap, 13··Rib, 14··Ventilation space, 20··Front dust suction passage, 21··Rear dust suction passage, 22··Front suction port, 23··Rear suction port, 30··Main body housing, 31··Pad, 32··Inner frame, 33··Air vent lever, 36··Dust collection passage, 36a··Air suction port, 37··Handle, 40··Suction space, 42··Communication port, 48··Suction port, 49··Abutment part, 50··Air vent hole, 52··Closure part, 53, 53A··Finger hook, 60··Joint, 70, 71··Cuffs, W··Workpiece.

Claims

1. A dust collection attachment including: a dust suction section that faces the surface of a workpiece and through which a tool tip can be passed; and a main body that has a dust collection passage that communicates with the dust suction section and to which an external hose can be connected; and a dust collection attachment that generates a negative pressure in the dust suction section by applying a suction force from the hose to the dust collection passage, The dust suction unit includes an inner tube through which the tool bit passes, a first dust collection passage having a first suction port that opens toward the workpiece on the radially outer side of the inner cylinder and communicates with the dust collection passage; a second dust collection passage having a second suction port opened on the radially outer side of the inner cylinder opposite to the workpiece and communicating with the dust collection passage; A dust collection attachment comprising:

2. The dust collection attachment according to claim 1 , wherein the first dust suction passage and the second dust suction passage join together at the dust collection passage.

3. 3. The dust collection attachment according to claim 1, wherein the first dust suction passage and the second dust suction passage are provided in at least a region of the dust suction part on the dust collection passage side.

4. 4. The dust collecting attachment according to claim 1, wherein the first suction port is larger than the second suction port in the circumferential direction of the inner cylinder.

5. 5. The dust collecting attachment according to claim 4, wherein the first suction port and the second suction port are formed at an angle of 180 degrees or more in the circumferential direction.

6. 6. The dust collecting attachment according to claim 5, wherein the second suction port is formed between the inner tube and an outer tube provided outside the inner tube, and a rib is provided between the inner tube and the outer tube.

7. A dust collection attachment as described in any one of claims 1 to 6, characterized in that a cap is removably provided on the opposite side of the dust collection section from the workpiece to seal the space between the penetrating tool tip and the dust collection section.

8. The dust collection attachment described in claim 7, characterized in that the second suction port includes an opposite side opening that opens to the opposite side of the workpiece, and an inner opening that communicates with the opposite side opening and opens toward the inner surface of the inner tube, and the cap closes the opposite side opening when attached.

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