JP2012148375A - Dust collection cover for grinding and power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust collection cover for grinding more efficiently sucking dust, and a power tool provided with the dust collection cover for grinding.SOLUTION: There are provided a dust collection cover 10 for grinding including a ring-like peripheral wall 21 disposed around a grinding blade 9 with one end facing a surface to be worked opened; an end wall 22 located at the other end of the peripheral wall 21 and demarcating a housing space 20a together with the peripheral wall 21; a fan 30 making the inside pressure of the housing space 20a negative in relation to the atmosphere; and a sealing part 42 attached to the opening of the peripheral wall 21 and cutting off the inside and the outside of the housing space 20, and the power tool 1. In the sealing part 42, a communication path 43a making the inside communicate with the outside of the containing space 20a is formed. The communication path 43 is formed in a section orthogonal to the rotary shaft of the grinding blade 9 with the path direction formed in the direction crossing the radial direction having the rotary shaft as a starting point and directed toward the rotary shaft along the rotary direction of the grinding blade 9, and with the outside of the sealing part 42 invisible in an arrow view from the rotary shaft.

Description

  The present invention relates to a dust collecting cover for grinding and a power tool including the dust collecting cover for grinding.

  In power tools that grind disc grinders, etc., a dust collection cover is provided around the grinding blade to collect chips, dust, etc. generated when a grinding blade with a chip on the side grinds the surface to be ground. Is provided. As shown in Patent Document 1, a brush that comes into contact with the surface to be ground is provided on the edge of the dust collecting cover that faces the surface to be ground.

  When grinding with a grinding blade, the disc grinder is moved back and forth and left and right while the brush is in contact with the surface to be ground. At this time, the brush is pressed against the surface to be ground to block the inside and outside of the dust collecting cover. Chips and dust generated by grinding are subjected to the rotational centrifugal force of the grinding blade, once hit the brush, and then sucked by the rotation of the fan that is mounted integrally with the shaft that rotates the grinding blade. It is discharged from the outlet provided in the cover to the outside. In this way, the brush prevents chips and the like from leaking out of the dust collection cover due to centrifugal force, but in the space between the grinding wheel outer periphery and the brush inside, suction force by the dust collection fan also acts. Yes.

Japanese Utility Model Publication No. 55-103143

  In the space between the outer periphery of the grinding wheel and the inner side of the brush, the air current state is very disturbed by the dust blown by the rotating centrifugal force of the grinding blade or the dust colliding with the inner side of the brush. Therefore, the suction of the chip dust by the fan is unstable, and unsucked material may be generated or the unsucked material may leak to the outside of the brush, leading to deterioration of the working environment. Accordingly, an object of the present invention is to provide a dust collection cover for grinding capable of efficiently sucking chips and dust generated by grinding and a power tool including the dust collection cover for grinding.

  In order to solve the above-described problems, the present invention provides an annular peripheral wall portion that is disposed around a grinding blade that is driven to rotate and cuts a processing surface, and that has one end that is opposed to the processing surface, and other peripheral wall portions. A housing space for housing the grinding blade is formed together with the peripheral wall portion located on the end side, an end wall portion mounted on a power tool that rotationally drives the grinding blade, and the interior of the housing space with respect to the outside air A suction mechanism that creates a negative pressure, and is attached to the opening of the peripheral wall portion on the other end side so that one end side projects from the opening position of the peripheral wall portion toward the processed surface side along the peripheral wall portion. A seal portion that defines the accommodation space together with the peripheral wall portion and the end wall portion and blocks the inside and outside of the accommodation space, and a communication path that communicates the inside and outside of the accommodation space is formed in the seal portion, In the cross-section orthogonal to the rotation axis of the grinding blade, the communication path is a half whose path direction starts from the rotation axis. Providing grinding dust cover along the rotation direction of intersecting the direction 該研 Kezuha are formed in the direction toward the said rotating shaft.

  According to such a configuration, the air outside the seal member can be drawn in as a flow having the same direction as the rotation direction of the grinding blade by suction of the suction mechanism. Therefore, a vortex flow that flows in the rotation direction of the grinding blade can be formed in the accommodation space, and dust or the like can be sucked in preferably by the suction mechanism.

  Moreover, it is preferable that it is formed so that the outside of the seal portion cannot be visually recognized as viewed from the rotation shaft.

  According to such a structure, it can further suppress that the dust scattered by rotation of the grinding blade is discharged | emitted outside the seal | sticker part, and can improve sealing performance.

  In the dust collecting cover for grinding having the above-described configuration, the seal portion is configured by arranging a plurality of strip-shaped sheet materials along the peripheral wall portion, and the communication path is a sheet adjacent in the rotation direction of the grinding blade. A gap between the materials is preferable. Further, it is preferable that the downstream end portion of the sheet material positioned upstream in the rotation direction of the grinding blade is positioned inward in the radial direction from the upstream end portion of the sheet material positioned downstream. .

  Further, it is preferably configured to have an annular shape to hold the seal portion in an annular shape and to be attached to the peripheral wall portion, and the seal portion is preferably attached to the peripheral wall portion via the base portion. .

  According to such a structure, since the base part to which the seal part was previously attached can be attached to the peripheral wall part, the seal part can be easily attached to the peripheral wall part. In addition, since the rigidity of the seal portion can be maintained by the pedestal portion, the shape of the seal portion can be reliably maintained even when a load is applied to the seal portion due to contact between the surface to be ground and the seal portion.

  The pedestal portion is formed with a groove portion that extends along the circumferential direction of the ring and opens toward the surface to be processed, and the seal portion is fixed to the pedestal portion by inserting the other end side into the groove portion. It is preferable.

  According to such a configuration, the seal portion can be easily fixed to the pedestal portion.

  The pedestal portion may be provided with a latching portion that is disposed in the groove portion and is latched to the other end side of the seal portion that is inserted into the groove portion.

  According to such a structure, a seal part can be fixed to a base part more reliably.

  One of the pedestal portion and the peripheral wall portion is provided with a convex portion that projects in the direction intersecting with the direction from the one end toward the other end and toward the other, It is preferable that a concave portion into which the convex portion is inserted is formed on the other of the peripheral wall portion, and the pedestal portion is attached to the peripheral wall portion by engaging the convex portion and the concave portion.

  According to such a structure, a base part can be fixed to a surrounding wall part reliably and simply.

  Further, the seal portion may be made of any one of a cloth body, a resin sheet, a resin or a metal brush, or at least two of these composite materials.

  According to such a configuration, the strength and flexibility of the fabric ring can be set to desired characteristics.

  Further, the passage length of the communication passage, the passage cross-sectional area, and the angle between the axis along the communication direction and the axis along the radial direction depend on the grinding ability of the grinding blade and the suction ability of the suction mechanism. It is preferably set.

  In order to solve the above-described problems, the present invention provides a housing, an output unit built in the housing, an output shaft to which power is transmitted from the output unit and rotationally driven around the shaft and to which a cutting blade is mounted. A cover mounting portion disposed around the output shaft portion is defined in the housing, and the cover mounting portion includes the grinding according to any one of claims 1 to 9. A power tool equipped with a dust collection cover is provided.

  According to the dust collection cover for grinding and the dust collection cover for grinding of the present invention, chips and dust generated by grinding can be efficiently sucked.

Sectional drawing in the state which mounted | wore the power tool with the dust collection cover for grinding which concerns on this Embodiment. The bottom view in the state where the dust collection cover for grinding concerning this embodiment was equipped in the power tool. The partial side view which shows the recessed part in the surrounding wall part in the state which mounted | wore the power tool with the dust collection cover for grinding which concerns on this Embodiment. Sectional drawing which shows the ring part of the dust collection cover for grinding which concerns on this Embodiment. The partial bottom view which concerns on the 1st modification of the ring part of the dust collection cover for grinding which concerns on this Embodiment. The bottom view which concerns on the 2nd modification of the ring part of the dust collection cover for grinding which concerns on this Embodiment. The bottom view which concerns on the 3rd modification of the ring part of the dust collection cover for grinding which concerns on this Embodiment.

  Hereinafter, a grinding dust collecting cover and a power tool equipped with the grinding dust collecting cover according to an embodiment of the present invention will be described with reference to FIGS. A disc grinder 1 shown in FIG. 1 is a tool for performing a grinding operation with a grinding blade 9 on a concrete surface W that is a surface to be ground, and is configured by attaching a dust collecting cover 10 around the grinding blade 9. . The disc grinder 1 has a housing 2 as an outer shell, and a motor (not shown) that is an output unit that outputs rotational force, and a gear mechanism (not shown) to which the rotational force from the motor (not shown) is transmitted. And an output shaft portion 2A that is a rotating shaft that is connected to the gear mechanism and is mounted so that the grinding blade 9 rotates coaxially and integrally.

  The output shaft portion 2A is mounted with a washer 2B that rotates in the direction of arrow A (counterclockwise on the paper surface) in FIG. 2 and serves as a seat for determining the rotation center of the grinding blade 9, and a nut 2C that is screwed. The grinding blade 9 is fixed to the output shaft portion 2A so as to rotate coaxially and integrally with the washer 2B and the nut 2C. Further, in the housing 2, a cover mounting portion 2D to which the dust collecting cover 10 is mounted is provided around the output shaft portion 2A.

  The grinding blade 9 has a disk shape with an open center, and a plurality of chips 9A are provided on one side of the disk. In order to attach the grinding blade 9 to the output shaft portion 2A, the output shaft portion 2A is passed through the central opening, the center axis of the disk is coaxial with the rotation shaft of the output shaft portion 2A, and the tip 9A is anti-housing. It arrange | positions so that it may be located in 2 side, and the grinding blade 9 is fixed to 2 A of output-shaft parts by tightening the nut 2C. In the following description, the vertical direction is defined with the rotation axis direction of the output shaft portion 2A and the direction from the grinding blade 9 toward the housing 2 as the upper side, and is parallel to the concrete surface W perpendicular to the vertical direction. The direction in which the housing 2 extends is defined as the front-rear direction. In the front-rear direction, the side on which the output shaft portion 2A is mounted in the housing 2 is defined as the front side.

  The dust collection cover 10 is mainly composed of a frame body 20, a fan 30, and a ring portion 40. The frame body 20 is made of resin, and is disposed around the grinding blade 9 and has an annular peripheral wall portion 21 that opens at the lower end facing the concrete surface W, and is positioned on the upper end side of the peripheral wall portion 21 and is integral with the peripheral wall portion 21. The housing 20 is mainly composed of the end wall 22, and a housing space 20 a that is mainly partitioned by the peripheral wall 21 and the end wall 22 is formed inside the frame 20.

  The peripheral wall portion 21 is provided with a rib portion 23 that bisects the accommodation space 20a in the vertical direction in the cylinder in the vertical direction. The rib portion 23 has a grinding blade at the center in the front-rear direction and the horizontal direction. A hole 23a having a diameter slightly smaller than the outer diameter of 9 is formed. In the accommodation space 20a, an upper space partitioned by the rib portion 23 is defined as an upper space 20b in which the fan 30 is accommodated, and a lower space is defined as a lower space 20c in which the grinding blade 9 is accommodated. Further, the lower end portion of the peripheral wall portion 21 is defined as a lower end edge 21A.

  An exhaust duct 24 is provided on a wall defining the upper space 20 b in the peripheral wall portion 21, and a dust collection bag 25 that collects dust and the like is connected to the exhaust duct 24. The exhaust duct 24 is formed therein with an exhaust passage 24a that communicates with the upper space 20b. The exhaust passage 24a communicates with the space in the dust bag 25. Further, as shown in FIG. 2, the exhaust duct 24 has an exhaust passage 24 a that is at the outermost peripheral position of the upper space 20 b and coincides with the tangential direction of the peripheral wall portion 21 with respect to the upper space 20 b. It arrange | positions so that it may be located in the downstream of the tangential direction in a rotation direction.

  The wall defining the lower space 20c in the peripheral wall portion 21 is formed with a total of four concave portions 21a having the same shape at the front-rear position and the left-right position substantially orthogonal to the front-rear direction. As shown in FIG. 3, the recess 21 a includes a first recess 21 b that opens to the lower end edge 21 </ b> A of the peripheral wall portion 21, and a second recess that is disposed adjacent to the first recess 21 b and is closed at the upper end and the lower end. 21c and a connection passage 21d that connects the upper end of the first recess 21b and the upper end of the second recess 21c. In the second recess 21c, an upper end edge 21B and a lower end edge 21C are respectively defined.

  As shown in FIG. 1, the rib portion 23 is provided with a plurality of springs 23 </ b> A that protrude downward. The spring 23 </ b> A is interposed between the ring portion 40 and the rib portion 23 and urges the ring portion 40 downward with respect to the rib portion 23.

  The end wall portion 22 is located on the upper side of the frame body 20 and defines the accommodating space 20a (upper space 20b) together with the peripheral wall portion 21. In the center of the end wall portion 22, there is provided a housing connection portion 22A that defines an opening 22a and is connected to the cover mounting portion 2D within the opening 22a.

  The fan 30 is a centrifugal fan, is accommodated in the upper space 20b, and is configured to rotate coaxially with the output shaft portion 2A in a state where the dust collection cover 10 is mounted on the housing 2. When the fan 30 rotates coaxially with the output shaft portion 2A, an airflow that flows from the hole 23a and flows out from the exhaust passage 24a is generated in the accommodation space 20a. Due to the generation of this air flow, the inside of the accommodation space 20a can be set to a negative pressure. A discharge mechanism is defined from the configuration of the frame 30 that defines the fan 30 and the upper space 20b in which the fan 30 is accommodated.

  The ring part 40 is mainly composed of a pedestal part 41 and a seal part 42. The pedestal portion 41 is made of resin and has an annular shape whose outer diameter is slightly smaller than the inner diameter of the peripheral wall portion 21. As shown in FIG. 2 and FIG. Convex portions 41A that can be inserted into 21a are provided at front, rear, left and right positions, respectively. As shown in FIG. 2, in the ring portion 40, a plurality of groove portions 41 a that open toward the concrete surface W side are formed on the lower surface 41 </ b> B facing the concrete surface W. The grooves 41a are arranged at equal intervals and in the same shape in the circumferential direction of the ring portion 40, and downstream of one groove 41a in the rotation direction of the output shaft portion 2A (circumferential direction of the ring portion 40). The end portion is located on the output shaft portion 2A side (inward in the radial direction) from the upstream end portion of the other groove portion 41a located on the downstream side of the one groove portion 41a, and is formed so as to overlap in the radial direction. Here, the radial direction refers to a direction starting from the axis of the output shaft portion 2A in a cross section perpendicular to the vertical direction. Further, the width of the groove 41a is configured to be slightly smaller than the thickness of the cloth constituting the sheet material 43 described later. As shown in FIGS. 1 and 4, an engaging portion 41 </ b> C that engages with the spring 23 </ b> A is provided on the upper surface of the ring portion 40.

  The seal portion 42 is made of felt and is composed of a plurality of sheet materials 43 having the same shape. The sheet material 43 is configured in a strip shape in which the length in the width direction is substantially the same as the longitudinal direction of the groove portion 41a and the cloth thickness is larger than the groove width of the groove portion 41a. As shown, the groove portion 41a is mounted such that the width direction and the thickness direction are orthogonal to the vertical direction. Further, the sheet material 43 is configured such that the most downstream position is tapered in a cross section orthogonal to the vertical direction in a state where the sheet material 43 is mounted in the groove portion 41a. Further, the sheet material 43 is mounted with the longitudinal direction inclined with respect to the tangential direction of rotation about the output shaft portion 2A.

  Since the adjacent groove 41a and the other groove 41a overlap in the radial direction as described above, the adjacent one sheet material 43 and the other sheet material 43 are located upstream. The sheet material 43 is disposed such that the downstream end of the sheet material 43 is positioned radially inward from the upstream end of the other sheet material 43 positioned on the downstream side, and adjacent sheet materials 43 overlap in the radial direction. Become.

  Moreover, since the space | interval of the adjacent groove part 41a is open, in the seal | sticker part 42, as FIG. 2 shows, the communicating path 43a which is a clearance gap between the adjacent sheet materials 43 is formed. Since the adjacent sheet materials 43 overlap each other as described above, the communication path 43a is formed in a direction orthogonal to the vertical direction in a direction in which the path direction intersects the radial direction toward the output shaft portion 2A along the rotation direction. In addition, it is formed so that the outside of the seal portion 42 is not visible in the radial direction from the output shaft portion 2A. Accordingly, it is possible to prevent dust and chips scattered in the seal portion 42 from being discharged in the radial direction or in the direction slightly rotating from the radial direction (the direction of arrow B in FIG. 2). Is done. The passage length of the communication passage 43a, the passage cross-sectional area, and the angle between the axis along the communication direction of the communication passage 43a and the axis along the radial direction are determined by the grinding ability of the grinding blade 9 and the suction mechanism such as the fan 30. It is set according to the suction capacity.

  As described above, since the groove width of the groove portion 41a is smaller than the cloth thickness of the sheet material 43, the sheet material 43 is fixed to the pedestal portion 41 by mounting the sheet material 43 in the groove portion 41a. Since only the sheet material 43 is mounted in the groove 41a, the mounting and fixing of the seal portion 42 to the pedestal portion 41 can be facilitated.

  Further, the distance in the vertical direction of the portion of the seal portion 42 that protrudes from the pedestal portion 41 when mounted on the pedestal portion 41 is lower than the lower surface of the grinding blade 9 when the ring portion 40 is mounted on the peripheral wall portion 21. It is comprised so that it may protrude to the side.

  The ring portion 40 is attached to the peripheral wall portion 21 in a state where the seal portion 42 is attached and fixed to the pedestal portion 41. In order to attach the ring portion 40 to the peripheral wall portion 21, first, the convex portion 41A is inserted from the opening of the lower end edge 21A of the first concave portion 21b. Next, in a state where the ring portion 40 is pushed upward with respect to the frame body 20, the ring portion 40 is placed in the frame so that the convex portion 41A is disposed in the second concave portion 21c from the first concave portion 21b through the connection passage 21d. Rotate around the body 20 around the circumference. By stopping pushing up the ring part 40 in this state, the ring part 40 is moved downward by the urging force of the spring 23A, and is moved to a position where the convex part 41A comes into contact with the lower end edge 21C. When the convex portion 41A is located in the second concave portion 21c, the ring portion 40 is prevented from being detached from the peripheral wall portion 21. Thus, the base part 41 can be fixed to the peripheral wall part 21 reliably and simply by the concave part 21a and the convex part 41A. Further, since the convex portion 41A is movable in the second concave portion 21c from the upper end edge 21B to the lower end edge 21C, the ring portion 40 moves up and down with respect to the frame body 20 while being biased by the spring 23A. be able to.

  When working with the disc grinder 1 equipped with the dust collecting cover 10 having the above configuration, the disc grinder 1 is held so that the lower surface of the grinding blade 9 provided with the tip 9A is in contact with the concrete surface W. At this time, since the lower end of the seal portion 42 protrudes from the tip 9A of the grinding blade 9, when the concrete surface W is ground with the grinding blade 9, the seal portion 42 is always pressed with an appropriate pressing force by the urging force of the spring 23A. It can be pressed against W, and the formation of a gap between the seal portion 42 and the concrete surface W is suppressed. In this state, a motor (not shown) is driven to rotate the grinding blade 9, and the disc grinder 1 is moved back and forth and left and right.

  As the grinding blade 9 (output shaft portion 2A) rotates, the fan 30 mounted on the output shaft portion 2A so as to rotate coaxially and integrally also rotates, and the air in the upper space 20b is discharged into the exhaust passage 24a in the accommodating space 20a. And the inside of the upper space 20b becomes a negative pressure. Since a plurality of communication passages 43a are formed in the seal portion 42 as described above, the pressure difference and the rotation of the fan 30 and the grinding blade 9 cause the pressure difference and the arrow C shown in FIGS. An anti-clockwise swirl flow is generated in the lower space 20c through the communication passage 43a, and an airflow flowing to the exhaust passage 24a through the upper space 20b is generated. The dust generated at the time of grinding is taken into the dust bag 25 by the air flow indicated by the arrow C, and the dust can be prevented from leaking out of the dust cover 10. Further, since the suction efficiency by the fan 30 is increased by forming the communication path 43a, the air in the opening outside the seal portion 42 of the communication path 43a can be sucked in well. Therefore, the dust leaked out of the seal part 42 can also be sucked into the dust collection bag 25 from the outside of the seal part 42 of the communication passage 43a, and the deterioration of the working environment can be reduced.

  Coarse granular chips cannot be taken into the dust bag 25 due to their weight and may remain in the lower space 20c. In this case, the chips are bounced by the grinding blade 9 and scattered in the radial direction, tangential direction, and rotational direction. However, since the sheet material 43 is disposed so as to overlap as described above, It is possible to prevent the chips from being discharged, and to reduce the deterioration of the working environment.

  The dust collection cover and power tool for grinding according to the present invention are not limited to the above-described embodiments, and various improvements and modifications can be made within the scope described in the claims. The sheet material 43 is not limited to the felt described above, and may be another cloth body, a resin sheet, a resin, a metal brush, or the like. Further, as shown in FIG. 5, it may be a sheet material 143 obtained by simply cutting out felt. Further, as shown in FIG. 6, the sheet material 143 may be composed of a composite material. Examples of the material constituting the sheet material 143 include at least two composites of the above-described cloth body, resin sheet, resin, metal brush, and the like.

  Further, as shown in FIG. 7, communication passages 242 a may be formed in a series of seal members 242 in the circumferential direction, and a portion sandwiched between adjacent communication passages 242 a may be used as the sheet material 243. According to such a configuration, it is only necessary to attach a series of seal members 242 to the pedestal portion 41, and thus the ring portion 40 can be easily configured.

  In each of the above-described embodiments and modifications, the communication path is formed up to the lower end position in contact with the concrete surface W in the seal portion. However, the communication path may be a hole that passes through at least the inside and outside of the seal portion because the communication passage does not have to penetrate at least the inside and outside of the seal portion and the chips scattered in the radial direction and the tangential direction do not pass therethrough.

  In addition, as in the above-described embodiment, it is desirable that the adjacent sheet materials 43 are in positions that overlap in the radial direction, but may be configured to have a slight gap. Even in this case, dust scattered by the rotation of the grinding blade 9 is guided by the airflow flowing in the rotation direction through the communication path, and is prevented from being discharged out of the seal portion 42.

  Further, in this embodiment, the power tool is assumed to be a disc grinder. However, the present invention is not limited to this, and if the power tool can be equipped with a grinding blade and a dust collecting cover for grinding, the type of the power tool is limited. do not do. Further, the power is not limited to the electric motor, and can be applied to a power tool using compressed air.

1: Disc grinder 2: Housing 2A: Output shaft portion 2B: Washer 2C: Nut 2D: Cover mounting portion 9: Grinding blade 9A: Tip 10: Dust collecting cover 20: Frame body 20a: Storage space 20b: Upper space 20c: Lower portion Space 21: Peripheral wall 21A: Lower edge 21B: Upper edge 21C: Lower edge 21a: Recess 21b: First recess 21c: Second recess 21d: Connection passage 22: End wall 22A: Housing connection
22a: Opening 23: Rib part 23A: Spring 23a: Hole 24: Exhaust duct 24a: Exhaust passage 25: Dust collection bag 30: Fan 40: Ring part 41: Base part 41A: Convex part 41B: Lower surface 41C: Engaging part 41a : Groove part 42: Seal part 43: Sheet material 43a: Communication path 143: Sheet material 242: Seal member 242a: Communication path 243: Sheet material

Claims (11)

An annular peripheral wall portion that is arranged around a grinding blade that is driven to rotate and cuts the work surface, and that opens at one end facing the work surface;
An end wall portion that is located on the other end side of the peripheral wall portion and that defines an accommodation space in which the grinding blade is accommodated together with the peripheral wall portion, and is attached to a power tool that rotationally drives the grinding blade;
A suction mechanism that creates a negative pressure with respect to outside air in the housing space;
Along the peripheral wall portion, the one end side is attached to the opening of the peripheral wall portion on the other end side so as to protrude from the opening position of the peripheral wall portion toward the processed surface side, and the peripheral wall portion and the end wall portion And a seal portion that defines the accommodation space and blocks the inside and outside of the accommodation space, and
The seal portion is formed with a communication path communicating between the inside and outside of the housing space,
In the cross section orthogonal to the rotation axis of the grinding blade, the communication path is formed in a direction toward the rotation axis along the rotation direction of the grinding blade, with the passage direction intersecting the radial direction starting from the rotation axis. A dust collecting cover for grinding.   2. The dust collection cover for grinding according to claim 1, wherein the dust collection cover is formed so that the outside of the seal portion is invisible when viewed from the direction of the rotation shaft.   The seal portion is formed by arranging a plurality of strip-shaped sheet materials along the peripheral wall portion, and the communication path is a gap between adjacent sheet materials in the rotation direction of the grinding blade. The dust collection cover for grinding according to claim 1 or 2.   In the rotational direction of the grinding blade, the downstream end portion of the sheet material located upstream is located inward in the radial direction from the upstream end portion of the sheet material located downstream. The dust collection cover for grinding according to claim 3. A pedestal portion configured to be annular and configured to hold the seal portion in an annular shape and attached to the peripheral wall portion;
The dust collection cover for grinding according to any one of claims 1 to 4, wherein the seal portion is attached to the peripheral wall portion via the pedestal portion.   The pedestal portion is formed with a groove portion that extends along the circumferential direction of the ring and opens toward the surface to be processed, and the seal portion is fixed to the pedestal portion by inserting the other end side into the groove portion. The dust collection cover for grinding according to claim 5, wherein:   The pedestal portion is provided with a latching portion disposed in the groove portion and latched on the other end side of the seal portion inserted into the groove portion. Dust collecting cover for grinding. Either one of the pedestal portion and the peripheral wall portion is provided with a convex portion that protrudes toward the other side in a direction that intersects the direction from the one end toward the other end,
A concave portion into which the convex portion is inserted is formed on the other of the pedestal portion and the peripheral wall portion,
The dust collection cover for grinding according to any one of claims 3 to 7, wherein the convex portion and the concave portion are engaged with each other so that the pedestal portion is attached to the peripheral wall portion.   9. The seal part is configured by any one of a cloth body, a resin sheet, a resin or a metal brush or a composite material of at least two of them. The dust collection cover for grinding as described in any one of.   The passage length of the communication passage, the passage cross-sectional area, and the angle between the axis along the communication direction and the axis along the radial direction are set according to the grinding ability of the grinding blade and the suction ability of the suction mechanism. The dust collection cover for grinding according to any one of claims 1 to 9, wherein the dust collection cover is for grinding. A housing;
An output part built in the housing;
Power is transmitted from the output unit and rotated around the axis, and an output shaft unit to which a cutting blade is attached is provided,
The housing is provided with a cover mounting portion disposed around the output shaft portion,
A power tool, wherein the dust collecting cover for grinding according to any one of claims 1 to 10 is mounted on the cover mounting portion.

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