Dust box and belt sander

Abstract

To provide technique for improving dust collection efficiency in a dust box that can be attached to and detached from a belt sander.SOLUTION: A dust box attachable to and detachable form a belt sander including a discharge nozzle that discharges dust generated in processing work from a housing, and a suction nozzle that sucks air in the dust box into the housing, comprise: a first nozzle that can be connected to the discharge nozzle; a second nozzle that can be connected to the suction nozzle; a container portion made of a synthetic resin and connected to the first nozzle and the second nozzle; and a filtering member. The filtering member separates air and dust. The filtering member is provided in the container portion and divides a space in the container portion into a first space being communicated with the first nozzle and a second space being communicated with the second nozzle.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a dust box that can be attached to a belt sander, and a belt sander that includes a dust box. [Background technology]

[0002] Patent Document 1 describes a belt sander capable of collecting dust generated during machining operations in a dust collection bag. This belt sander includes a dust collection port located behind a drive roller in the lower part of the housing, a dust collection path provided within the housing and communicating with the dust collection port, a discharge tube communicating with the dust collection path, and a dust bag attached to the discharge tube via a cuff. The dust collection path is formed to revolve around the motor shaft, and a dust collection fan is provided in the dust collection path. Dust is sucked through the dust collection port by the rotation of the dust collection fan, passes through the dust collection path, the discharge tube, and the cuff, and is collected in the dust bag. The belt sander also includes an earth plate configured to be electrically connected to the internal body when the cuff is attached, thereby suppressing the buildup of static electricity on the dust during dust collection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-291170 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there was a demand for improved dust collection efficiency in the dust box that can be attached to the belt sander. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, a dust box detachable from a belt sander is provided. The belt sander includes a belt drive unit configured to rotate an endless sanding belt, and a housing that accommodates a dust collection fan and an electric motor that drives the belt drive unit. The housing has an exhaust nozzle that exhausts dust generated during processing operations from the housing by rotation of the dust collection fan, and a suction nozzle that sucks air from the dust box into the housing. The dust box includes a first nozzle connectable to the exhaust nozzle, a second nozzle connectable to the suction nozzle, a synthetic resin container connected to the first and second nozzles, and a filter member that separates air and dust. The filter member is provided within the container unit so as to divide the space within the container unit into a first space communicating with the first nozzle and a second space communicating with the second nozzle.

[0006] According to this aspect, the first and second nozzles of the dust box are connected to the discharge nozzle and suction nozzle of the belt sander, respectively. When the dust collection fan rotates, air inside the dust box is sucked into the suction nozzle via the second nozzle. Dust generated during processing is discharged from the discharge nozzle of the belt sander through the first nozzle into the dust box. Since negative pressure is created inside the dust box as a result of the air being sucked in, the dust box of the first aspect can improve dust collection efficiency. Furthermore, the filter member divides the space inside the container into a first space connected to the first nozzle and a second space connected to the second nozzle, thereby collecting dust inside the dust box and preventing dust from flowing into the housing from the second nozzle.

[0007] According to a second aspect of the present disclosure, there is provided a belt sander to which the dust box is detachably attached. According to this aspect, the dust collection efficiency can be improved in a belt sander to which a dust box is detachably attached. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a belt sander equipped with a battery and a dust box. [Figure 2] FIG. [Figure 3] FIG. 2 is a left side view of the belt sander with the battery and dust box attached, showing the rotation range of the front handle. [Figure 4] FIG. 1 is a top view of a belt sander with a battery and dust box attached. [Figure 5] FIG. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. 4. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 4. [Figure 8] FIG. [Figure 9] 7 is a cross-sectional view showing the dust box taken along arrows VII-VII in FIG. 4. [Figure 10] FIG. 2 is a top view of the dust box, and a cross-sectional view showing the interior thereof with a dashed line. [Figure 11] FIG. 2 is a view showing a filter member and a frame. [Figure 12] FIG. 7 is a partially enlarged view of FIG. 6, showing a switch mechanism. [Figure 13] FIG. 10 is a right side view with the right main body housing open, showing an enlarged view of the first switch and the first lock switch. [Figure 14] 14 is a cross-sectional view of the first lock switch and the first switch operating portion, taken along the line XIV-XIV in FIG. 12, illustrating an unlocked state. [Figure 15] FIG. 15 is a cross-sectional view corresponding to FIG. 14, showing a state in which the first lock switch has been moved to a first lock-on position. [Figure 16] FIG. 15 is a cross-sectional view corresponding to FIG. 14, showing a state in which the first lock switch has been moved to a second lock-on position. [Figure 17]FIG. 10 is a right side view with the right main body housing open, showing an enlarged view of the second switch and the second lock switch. [Figure 18] 18 is a cross-sectional view of the second switch and the second lock switch taken along the arrows XVIII-XVIII in FIG. 5. [Figure 19] FIG. 19 is a cross-sectional view corresponding to FIG. 18, showing a state in which the second lock switch has been moved to a lock-on position. [Figure 20] This is an example of a battery that can be attached to or detached from a belt sander. DETAILED DESCRIPTION OF THE INVENTION

[0009] In one non-limiting embodiment of the present disclosure, the filtering member may be provided in the container at a position closer to the second nozzle than to the first nozzle. According to this aspect, it is possible to prevent dust from flowing into the housing from the second nozzle, while ensuring that the first space in which dust is stored is large relative to the second space that is in communication with the second nozzle.

[0010] In addition to or instead of the above embodiment, the belt drive unit may include a drive roller rotated by the motor and a driven roller. If the direction in which the rotation axis of the drive roller and the rotation axis of the driven roller extend is defined as the left-right direction, the direction in which the driven roller and the drive roller are aligned is defined as the front-rear direction, and the direction perpendicular to the left-right direction and the front-rear direction is defined as the up-down direction, the abrasive surface of the belt sander may be defined by the underside of the sanding belt. The dust box may be configured such that the first nozzle is located below the second nozzle when attached to the belt sander. The first space may be a lower space within the container. According to this embodiment, the first nozzle is located below the second nozzle, and the first space is provided at the bottom inside the container, so the path from the bottom surface (abrasive surface) of the sanding belt to the inside of the container can be shortened, thereby improving dust collection efficiency.

[0011] In addition to or instead of the above embodiment, the first nozzle and the second nozzle may open in the same direction. According to this embodiment, the airflow inside the container can be straightened, compared to a configuration in which the first nozzle and the second nozzle open in different directions, and therefore the dust collection efficiency can be further improved.

[0012] In addition to or instead of the above embodiment, the filtering member may be a bag-shaped air filter having one open end. According to this embodiment, the filter member can efficiently separate dust from air.

[0013] In addition to or instead of the above embodiment, the container may include a nozzle connector connected to the first nozzle and the second nozzle, and a main body detachably attached to the nozzle connector. The filtering member may be provided in the nozzle connector. According to this embodiment, dust accumulated in the container can be removed by removing the main body from the nozzle connection part.

[0014] In addition to or instead of the above embodiment, a detachable portion for attaching and detaching the container body to the nozzle connecting portion may be further provided. According to this embodiment, the user does not need to prepare a separate tool for attaching or detaching the container body to or from the nozzle connecting portion, thereby improving the convenience of using the dust box.

[0015] In addition to or instead of the above embodiment, At least a portion of the dust box may be made of a conductive synthetic resin. According to this embodiment, the dust collection efficiency can be improved in a dust box at least a part of which is made of conductive synthetic resin.

[0016] In addition to or instead of the above embodiment, when the up-down direction of the belt sander is defined with the side on which the belt drive unit is provided as the lower side and the opposite side as the upper side, when the dust box is attached to the belt sander, at least a portion of the container unit below the midpoint in the up-down direction may be formed from the conductive synthetic resin. According to this embodiment, the dust collection efficiency can be improved in a dust box at least a part of which is made of conductive synthetic resin.

[0017] In addition to or instead of the above embodiment, the dust box may include a grounding member, which may be provided on the dust box such that one end is connected to the portion formed of the conductive synthetic resin and the other end is exposed to the outside of the dust box. According to this embodiment, the electric charge stored in the dust box can be discharged by the earth member, which prevents the dust box from becoming electrically charged and causing dust to adhere to specific locations on the dust box, thereby improving dust collection efficiency.

[0018] In addition to or instead of the above embodiment, a belt sander having the dust box detachably attached thereto may be provided. The belt sander may include an electric motor, a dust collection fan, a housing that accommodates the motor and the dust collection fan, and a belt drive unit. The belt drive unit may include a drive roller rotated by the motor and a driven roller, and be configured to drive an endless sanding belt stretched between the drive roller and the driven roller. When the direction in which the rotation axes of the drive roller and the driven roller extend is defined as the left-right direction, the direction in which the driven roller and the drive roller are aligned is defined as the front-rear direction, and the direction perpendicular to the left-right direction and the front-rear direction is defined as the up-down direction, the belt drive unit may be disposed below the housing. The housing may include an exhaust nozzle and a suction nozzle. The exhaust nozzle may be configured to exhaust dust generated by the machining operation from within the housing. The suction nozzle may be configured to draw air into the housing. The housing may further have a dust collection port, an air discharge port, a first flow path connecting the dust collection port and the discharge nozzle, and a second flow path connecting the suction nozzle and the air discharge port. The dust collection port may be provided rearward of the belt drive unit. The air discharge port may be provided in the housing so as to communicate with a space in which the dust collection fan is accommodated. The first flow path may be provided to separate a space in the housing in which the motor and the dust collection fan are accommodated from the second flow path. The second flow path may be communicated with the space in which the dust collection fan is accommodated. The dust collection fan may be configured to generate, by rotation, an airflow from the dust collection port through the first flow path toward the discharge nozzle, and an airflow from the suction nozzle through the second flow path toward the air discharge port. According to this embodiment, when the dust collection fan rotates, dust generated during machining operations is transferred along with air through the dust collection port, first flow path, discharge nozzle, first nozzle, and container in this order. Because a filter is provided inside the container of the dust box, the dust does not pass through the filter and is instead stored in the first space inside the container. After the air inside the container is separated from the dust by the filter, it travels through the second nozzle, suction nozzle, and second flow path before being discharged from the belt sander's air outlet. Furthermore, because the first flow path is separated from the space housing the motor and dust collection fan and the second flow path, dust adhesion to the motor and dust collection fan is suppressed. This improves dust collection efficiency and extends the life of the belt sander.

[0019] In addition to or instead of the above embodiment, the suction nozzle and the discharge nozzle may be open facing rearward. The discharge nozzle may be provided below the suction nozzle. According to this embodiment, the dust collection port is provided behind the belt drive unit, and the discharge nozzle is provided below the suction nozzle, so the first flow path from the dust collection port to the discharge nozzle can be made relatively short, thereby further improving dust collection efficiency.

[0020] <Overall structure of the belt sander> A belt sander 1 will be described as one embodiment of the present disclosure. The belt sander 1 is a tool that can perform processing work by driving a belt drive unit 6 that holds an endless sanding belt B with a motor 2 and bringing the sanding belt B into contact (pressing) with a workpiece. The belt sander 1 of this embodiment is equipped with a handle 14. A user can process a desired location by holding the handle 14 and moving the belt sander 1 while bringing the sanding belt B into contact with the workpiece. The belt sander 1 described in this embodiment is also called an "up-handle type belt sander." An up-handle type belt sander is a type of belt sander in which the handle 14 and the motor 2 are located on the side opposite the sanding surface of the sanding belt B.

[0021] First, the overall configuration of the belt sander 1 will be described with reference to Figures 1 to 7. The belt sander 1 mainly comprises a housing 10, an electric motor 2, a fan 3, a power transmission unit 35, a belt drive unit 6, a battery mounting unit 4, and a switch mechanism 8.

[0022] The belt drive unit 6 includes a drive roller 61, a driven roller 62 disposed on one side of the drive roller 61, and a support frame 64 (see FIG. 6) that supports these rollers rotatably around their axes. The drive roller 61 and driven roller 62 are disposed parallel to each other. An endless sanding belt B is stretched between the drive roller 61 and the driven roller 62. A plate that presses the sanding belt B against the workpiece is provided on a predetermined surface of the support frame 64. The drive roller 61 is rotated by the motor 2 in the direction of arrow D (see FIG. 1).

[0023] For ease of explanation, the direction in which the drive roller 61 and the driven roller 62 are aligned is defined as the front-rear direction of the belt sander 1, and the side of the belt drive unit 6 where the drive roller 61 is provided is defined as the rear side, and the side where the driven roller 62 is provided is defined as the front side. The direction that intersects with the front-rear direction and in which the rotation axes A1, A2 of the drive roller 61 and the driven roller 62 extend is defined as the left-right direction of the belt sander 1. The direction perpendicular to the front-rear direction and the left-right direction is defined as the up-down direction of the belt sander 1. In the up-down direction, the side of the belt sander 1 where the belt drive unit 6 is provided is defined as the lower side, and the opposite side is defined as the upper side. The portion of the sanding belt B exposed from the housing 10 functions as a polishing surface (sanding surface B1) for polishing the workpiece.

[0024] The housing 10 includes a main housing 11 and a side housing 16 .

[0025] The main body housing 11 holds the belt drive unit 6 with the lower end of the belt drive unit 6 exposed. The main body housing 11 covers the upper part of the belt drive unit 6 and the part rearward of the rear end of the belt drive unit 6, and extends generally in the front-to-rear direction as a whole. In this embodiment, as shown in FIG. 4, the main body housing 11 is formed by screwing together a left main body housing 11L and a right main body housing 11R, which are halves of the main body housing 11.

[0026] As shown in FIG. 2, the main housing 11 has a first portion 12 above the belt drive unit 6 and a second portion 13 located in front of the first portion 12.

[0027] The first section 12 is located above the belt drive unit 6 and rearward from approximately the middle position of the belt drive unit 6 in the front-to-rear direction. The first section 12 mainly houses the motor 2. The first section 12 is also referred to as the "motor housing section." The first section 12 is formed in a generally box-like shape including a top wall 121, a front wall 122, side walls 123, 123, and a rear wall 124. The top wall 121 is generally perpendicular to the up-down direction. The top wall 121 is generally parallel to the sanding surface B1. The front wall 122 and the rear wall 124 are generally perpendicular to the front-to-rear direction. The top wall 121 may have some irregularities as long as it can be placed on a desk or the like when the belt sander 1 is used in the second usage mode.

[0028] The second section 13 is provided above the belt drive unit 6 and forward of approximately the middle position of the belt drive unit 6 in the front-to-rear direction. A side wall 133 of the second section 13 is continuous with the side wall 123 of the first section 12. An upper wall 131 of the second section 13 is located lower than the upper wall 121 of the first section 12. Therefore, the portion of the main body housing 11 located above the belt drive unit 6 has a stepped shape. A battery attachment section 4 is provided in the second section 13.

[0029] The portion of the main body housing 11 rearward of the first portion 12 constitutes a handle 14 extending in the front-rear direction. The handle 14 is connected to the first portion 12 and extends in the front-rear direction. In this embodiment, the handle 14 is connected to an upper portion of the rear wall 124 of the first portion 12 and extends rearward and downward from the first portion 12. The upper end of the handle 14 does not protrude above the top wall 121 of the first portion 12. In this embodiment, the upper end of the handle 14 is located at approximately the same position as the top wall 121 in the vertical direction. The handle 14 is also referred to as the "first handle."

[0030] The rear end of the handle 14 is bent downward. The bent portion is connected to the rear lower portion of the first portion 12. As a result, the portion of the main body housing 11 rearward of the belt drive unit 6 has an annular shape.

[0031] The part of the main housing 11 where the rear end of the handle 14 and the rear of the belt drive unit 6 are connected and below the handle 14 constitutes a controller accommodating section 15. The front end of the controller accommodating section 15 (the part directly behind the belt drive unit 6) is curved along the outer edge of the drive roller 61. The main housing 11 has openings in the left and right directions directly behind the belt drive unit 6. These openings function as dust collection ports 19 for introducing dust generated during machining into a dust flow path (first flow path 191) provided within the housing 10.

[0032] As shown in Fig. 6, the switch mechanism 8 is provided in the main body housing 11 at the rear of the motor 2. The switch mechanism 8 includes a first switch 80, a second switch 90, a first lock switch 85, and a second lock switch 95 (see Fig. 4) that can be manually operated by the user. The switch mechanism 8 will be described in detail later.

[0033] A dial 39 for adjusting the rotation speed of the motor 2 is provided on the upper rear part of the motor 2 in the main body housing 11. The upper end of the dial 39 is exposed from the top wall 121 of the main body housing 11. The dial 39 is configured so that its position (rotation position) can be changed by manual operation by the user. The dial 39 is connected to the controller 5 via a wire. The controller 5 is configured to set the rotation speed of the motor 2 according to the rotation position of the dial 39.

[0034] As shown in FIG. 6 , the controller 5 is mounted on a main board disposed within the case of the controller housing 15. In this embodiment, the controller 5 is configured as a microcomputer including a CPU and memory. The controller 5 is configured to control various operations of the belt sander 1, such as driving the motor 2. The controller 5 is connected to the battery mounting section 4, the motor 2, and the first switch 80 and the second switch 90 of the switch mechanism 8 via wiring (not shown). The controller 5 is configured to supply power from the battery 300 mounted in the battery mounting section 4 to the motor 2 when the first switch 80 and the second switch 90 are in the on state. This causes the motor 2 to rotate, driving the belt drive section 6 via the power transmission section 35 and rotating the sanding belt B in the direction of arrow D. The controller 5 is also configured to not supply power to the motor 2 when at least one of the first switch 80 and the second switch 90 is in the off state.

[0035] A portion of the left side wall 123 of the first section 12 is open and is covered by the horizontal housing 16. As shown in Figures 3 and 4, the horizontal housing 16 includes a fan housing 161 that covers the left side of the fan 3, a gear cover 162 that covers part of the power transmission unit 35, and a belt cover 163 that covers the endless synchronous belt that is part of the power transmission unit 35. The horizontal housing 16 is screwed to the left main body housing 11L.

[0036] The motor 2 is driven by power supplied from a battery 300 mounted in the battery mounting portion 4. In this embodiment, a brushless direct current (DC) motor is used as the motor 2. As shown in FIG. 6, the motor 2 includes a motor body 21 having a stator and a rotor, and a shaft 22 extending from the rotor and rotating integrally with the rotor. The shaft 22 (rotation axis A3 of the shaft 22) extends in the left-right direction. The shaft 22 is supported by the main body housing 11 via a bearing.

[0037] 7, the power transmission unit 35 is held by the horizontal housing 16 and configured to transmit the rotation of the shaft 22 to the drive roller 61. The power transmission unit 35 includes a pulley unit including a pulley integrated with the left end of the shaft 22, an endless synchronous belt, a gear mechanism that reduces the speed of the rotation of the shaft 22, and the like.

[0038] The fan 3 is configured to perform the functions of cooling the motor 2 and also functioning as a dust collection fan. The fan 3 generates an airflow that cools the motor 2, and also generates an airflow that sucks dust generated by the machining operation into the housing 10 and discharges it into the dust box 200.

[0039] In this embodiment, the fan 3 is mainly housed in the first portion 12 of the main housing 11, on the left side of the motor body 21. The fan 3 is fixed to the shaft 22 between the motor body 21 and a bearing, and rotates integrally with the shaft 22. As described above, a portion of the left wall 123 of the first portion 12 is open, and the back surface of the fan 3 is covered by the side housing 16 (fan housing 161). The front portion of the fan housing 161 is curved along the outer edge of the fan 3. A plurality of small openings (air outlets 165) are provided in the curved portion of the fan housing 161 (see, for example, FIGS. 4 and 7).

[0040] The fan 3 of this embodiment is configured as a centrifugal fan. The fan 3 draws in air from its rear side (the left side of the belt sander 1) and discharges the drawn-in air radially in a direction intersecting the rotation axis A3 of the shaft 22. The discharged air is sent to the motor 2 by a plurality of small blades provided on the front side of the fan 3 (the right side of the belt sander 1) and a baffle plate 32 provided on the front side of the fan 3. A guide plate 31 connected to a suction nozzle 150 (described later) is provided on the rear side of the fan 3. As the fan 3 rotates, it draws in air from its rear side and discharges it radially. It then discharges the discharged air to the motor 2 and also discharges air from within the housing 10 to the air outlet 165.

[0041] <Configuration of dust box and belt sander for collecting dust in the dust box> The belt sander 1 of this embodiment is configured to allow a dust box 200 to be detachably attached. The configuration of the belt sander 1 for storing dust in the dust box 200 and the configuration of the dust box 200 will be described below.

[0042] As shown in Figures 3 and 7, the housing 10 of the belt sander 1 has two cylindrical portions (a discharge nozzle 140 and a suction nozzle 150). The discharge nozzle 140 and the suction nozzle 150 are provided at the upper rear portion of the horizontal housing 16 and extend in the front-to-rear direction. The discharge nozzle 140 and the suction nozzle 150 are aligned in the vertical direction, with the discharge nozzle 140 located below the suction nozzle 150. The discharge nozzle 140 and the suction nozzle 150 open to the rear.

[0043] As described above, the main housing 11 has the dust collection port 19 that opens in the left-right direction directly behind the belt drive unit 6. A first flow path 191 that connects the dust collection port 19 and the discharge nozzle 140 is formed within the housing 10. In this embodiment, the first flow path 191 is defined by a partition wall 101 within the housing 10 and the cylindrical wall of the discharge nozzle 140. The partition wall 101 is provided continuously from the lower rear portion of the main housing 11 to the rear portion of the gear cover 162 and the rear portion of the fan housing 161. The partition wall 101 and the cylindrical wall of the discharge nozzle 140 separate the first flow path 191 from the spaces that house the motor 2, fan 3, power transmission unit 35, and other components. Therefore, air and dust passing through the first flow path 191 do not flow into the compartments housing the motor 2, fan 3, power transmission unit 35, and other components.

[0044] 7, a second flow path 192 that connects the suction nozzle 150 and the air outlet 165 is provided inside the housing 10. The second flow path 192 communicates with the space in the housing 10 that accommodates the fan 3. The second flow path 192 is defined mainly by the cylindrical wall of the suction nozzle 150, the guide plate 31, and the wall portion 102 that constitutes the fan housing 161.

[0045] Next, the configuration of the dust box 200 will be described with reference to Figures 7 to 11. The dust box 200 is formed so as to extend in a predetermined direction as a whole. The dust box 200 includes a first nozzle 210 and a second nozzle 220 extending in the predetermined direction, a container portion 230 connected to the first nozzle 210 and the second nozzle 220, and a filter member 260 provided within the container portion 230. The first nozzle 210, the second nozzle 220, and the container portion 230 are formed from a material that is impermeable to air. In this embodiment, the first nozzle 210, the second nozzle 220, and the container portion 230 are formed from a conductive synthetic resin.

[0046] In FIG. 8, the up-down direction, front-back direction, and left-right direction are shown based on the position of the dust box 200 when attached to the belt sander 1. When attached to the belt sander 1, the dust box 200 extends in the front-back direction as a whole. The first nozzle 210 and the second nozzle 220 extend in the front-back direction and open forward. The first nozzle 210 and the second nozzle 220 are aligned vertically, with the first nozzle 210 positioned below the second nozzle 220. The dust box 200 is attached to the belt sander 1 by inserting the first nozzle 210 and the second nozzle 220 into the discharge nozzle 140 and the suction nozzle 150 of the belt sander 1, respectively. When the first nozzle 210 is inserted into the discharge nozzle 140, the first flow path 191 of the belt sander 1 and the inside of the first nozzle 210 (inside the dust box 200) are connected. Furthermore, when the second nozzle 220 is inserted into the suction nozzle 150, the second flow path 192 of the belt sander 1 and the inside of the second nozzle 220 (inside the dust box 200) are connected to each other. O-rings 212 and 222 are provided on the outer peripheral walls of the first nozzle 210 and the second nozzle 220, respectively. This ensures airtightness at the connection points of the nozzles.

[0047] The container 230 is formed in a generally box-like shape extending in the front-rear direction. The left-right length of the container 230 is shorter than the up-down and front-rear lengths of the container 230. The upper wall (upper surface 231) of the container 230 is generally perpendicular to the up-down direction. The lower wall (lower surface 234) of the container 230 is inclined rearward and upward. As shown in FIG. 4, when the dust box 200 is attached to the belt sander 1, the container 230 is located to the left of the handle 14 and the controller housing 15.

[0048] The dust box 200 is configured to fit within the vertical and horizontal widths of the housing 10 when attached to the belt sander 1. Furthermore, the dust box 200 is configured so that the bottom surface 234 is positioned above the sanding surface B1 in the vertical direction when attached to the belt sander 1. In this embodiment, as shown in FIG. 4, the left side surface 233 of the container portion 230 is positioned in the horizontal direction substantially at the same position as the left side surface of the housing 10 (the left side surface of the fan housing 161). Furthermore, as shown in FIG. 7, the top surface 231 of the container portion 230 is positioned in the vertical direction substantially at the same position as the upper end (upper wall 121) of the belt sander 1.

[0049] The container portion 230 is configured to be separable into a nozzle connection portion 240 and a main body portion 250. The nozzle connection portion 240 is a front portion of the container portion 230, and is connected to the first nozzle 210 and the second nozzle 220. In this embodiment, the nozzle connection portion 240 is formed integrally with the first nozzle 210 and the second nozzle 220. As shown in FIG. 10 , the first nozzle 210, the second nozzle 220, and the nozzle connection portion 240 are formed by screwing together a left nozzle portion 240L and a right nozzle portion 240R, which are halves of each other. An O-ring 244 is provided on the outer periphery of a rear end portion 243 of the nozzle connection portion 240.

[0050] The main body 250 is the rear portion of the container 230. The main body 250 is formed in a generally box-like shape with an open front end. In this embodiment, the container 230 is formed from carbon resin. As shown in FIG. 9, the container 230 has a window 235 formed from a light-transmitting resin. A user can visually check the amount of dust inside the container 230 through the window 235.

[0051] 9, the dust box 200 further includes a detachable part 270 configured to attach and detach the main body part 250 to and from the nozzle connecting part 240. In this embodiment, the detachable part 270 includes a mounting screw 271 provided on the main body part 250 and an engaging part 245 provided on the nozzle connecting part 240. The mounting screw 271 has a knob 272 and a shaft 273. The engaging part 245 is configured to engage (fit) with a front end part 274 of the mounting screw 271.

[0052] A cylindrical portion 258 extending forward from the rear wall 232 of the container portion 230 is provided inside the main body portion 250. The rear end of the cylindrical portion forms an opening provided in the rear wall 232. A knob 272 is disposed on the rear surface side of the rear wall 232 and covers the opening. A shaft 273 is connected to the knob 272 and disposed inside the cylindrical portion 258. The nozzle connection portion 240 has a partition wall 241 disposed between the first nozzle 210 and the second nozzle 220 in the up-down direction, and the engagement portion 245 is constituted by an opening provided in the partition wall 241 and an engagement member such as a nut 246 disposed within the opening. The partition wall 241 divides the interior of the nozzle connection portion 240 into a space communicating with the first nozzle 210 and a space communicating with the second nozzle 220.

[0053] A method for attaching the main body part 250 to the nozzle connection part 240 will be described. The user aligns the main body part 250 and the nozzle connection part 240 so that the outer shapes (e.g., side surface 233) of the main body part 250, to which the mounting screw 271 is attached, and the nozzle connection part 240 are continuous. The user fits the front end part 253 of the main body part 250 into the rear end part 243 of the nozzle connection part 240, and inserts the front end part 274 of the shaft 273 into the opening of the engagement part 245. When the user manually operates (rotates) the knob 272, the front end part 274 of the shaft 273 is inserted into the opening of the engagement part 245 and engages (fits) with the engagement part 245. In this manner, the main body part 250 can be attached to the nozzle connection part 240.

[0054] The filtering member 260 is provided in the container portion 230 so as to divide the space within the container portion 230 into a first space 281 communicating with the first nozzle 210 and a second space 282 communicating with the second nozzle 220. The filtering member 260 is provided at a position closer to the second nozzle 220 than the first nozzle 210. The filtering member 260 is formed to allow air to pass through but not allow dust generated during processing operations to pass through. In this embodiment, a bag-shaped air filter having an opening 261 is used as the filtering member 260. The air filter is, for example, a coarse dust filter.

[0055] In this embodiment, a frame 262 is disposed inside the filtration member 260. The frame 262 is formed to expand the filtration member 260 and maintain its bag shape. As shown in FIG. 9 , a groove 242 for detachably fixing the frame 262 is provided on the inner wall of the nozzle connection portion 240, above the partition wall 241 and behind the first nozzle 210. The filtration member 260 is fixed to the groove 242 via the frame 262 so that the opening 261 faces the first nozzle 210 (front side). It can also be said that the filtration member 260 is attached to a portion of the nozzle connection portion 240 that connects to the second nozzle 220 (second nozzle connection portion). As shown in FIG. 10 , the lower end of the filtration member 260 is supported by a plate 247 extending rearward from the partition wall 241.

[0056] The dust box 200 further includes a string-like earth member 265. The earth member 265 is a member for equalizing the potential of the dust box 200 and the earth. One end of the earth member 265 contacts the container 230, and the other end is exposed from the container 230. The exposed length of the earth member 265 is a length that allows the other end of the earth member 265 to contact the workpiece or a member on the same plane as the workpiece when the sanding surface B1 is placed on the workpiece. In this embodiment, the earth member 265 is separated from the space (first space 281) within the container 230 and is provided at the lower end of the nozzle connection portion 240. The earth member 265 discharges electric charges accumulated in the dust box 200.

[0057] Hereinafter, the manner in which dust is stored in the dust box 200, as well as the effects of the dust box 200 of this embodiment and the effects of the belt sander 1 to which the dust box 200 is attached will be described.

[0058] When the first nozzle 210 and the second nozzle 220 of the dust box 200 are connected to the discharge nozzle 140 and the suction nozzle 150 of the belt sander 1, respectively, and the dust box 200 is attached to the belt sander 1, the first flow path 191 of the belt sander 1 communicates with the first space 281 in the dust box 200. Also, the second flow path 192 of the belt sander 1 communicates with the second space 282 in the dust box 200. As described above, the first space 281 and the second space 282 are separated by the filter member 260, so that air in the dust box 200 can move between the first space 281 and the second space 282.

[0059] When the belt sander 1 is driven, the fan 3 rotates and draws in air from the rear side. At this time, the air around the fan 3 is drawn from the suction nozzle 150 toward the air outlet 165. That is, the rotation of the fan 3 generates an airflow F2 that flows from the dust box 200 through the second flow path 192 toward the air outlet 165 (see FIG. 7). Furthermore, the air drawn by the fan 3 creates a negative pressure inside the dust box 200, generating an airflow F1 that flows from the dust collection port 19 provided behind the belt drive unit 6 through the first flow path 191 into the dust box 200. As a result, dust generated during the processing operation moves from the dust collection port 19 to the first flow path 191, the discharge nozzle 140, the first nozzle 210, and the first space 281 in the container unit 230, in this order. The dust that has flowed into the container portion 230 is prevented from moving to the second space 282 by the filtering member 260, and therefore remains in the first space 281. In this way, the dust is stored in the first space 281 of the dust box 200. Furthermore, the air inside the dust box 200 passes through the filtering member 260 and moves from the first space 281 to the second space 282, the second nozzle 220, the suction nozzle 150, the second flow path 192, and the air outlet 165 in this order, before being discharged to the outside of the belt sander 1.

[0060] As described above, according to this embodiment, by connecting the first nozzle 210 and the second nozzle 220 of the dust box 200 to the discharge nozzle 140 and the suction nozzle 150 of the belt sander 1, respectively, and rotating the fan 3, it is possible to generate a rectified air flow from the dust collection port 19 of the belt sander 1 through the dust box 200 and toward the air discharge port 165 of the belt sander 1. Furthermore, the filter member 260 divides the space within the container portion 230 into a first space 281 communicating with the first nozzle 210 and a second space 282 communicating with the second nozzle 220, thereby storing dust within the dust box 200 and preventing dust from flowing into the housing 10 from the second nozzle 220. Therefore, the dust box 200 of this embodiment and the belt sander 1 equipped with the dust box 200 can improve dust collection efficiency.

[0061] As described above, the first flow path 191 is separated from the spaces accommodating the motor 2, fan 3, power transmission unit 35, and other components by the partition wall 101 and the cylindrical wall of the discharge nozzle 140. Therefore, air and dust passing through the first flow path 191 do not flow into the compartments accommodating the motor 2, fan 3, power transmission unit 35, and other components. Although air flows into the second flow path 192 from the dust box 200, this air has had dust filtered out by the filter member 260. Therefore, dust generated during machining can be prevented from adhering to the motor 2, fan 3, and power transmission unit 35 inside the housing 10. As a result, the life of the belt sander 1 can be extended.

[0062] Furthermore, in the dust box 200, the first nozzle 210 through which the dust flows in is provided below the second nozzle 220 through which air is sucked in. Therefore, the dust does not need to be moved to the upper part of the container part 230, and the path for storing the dust in the container part 230 can be shortened, thereby improving the dust collection efficiency.

[0063] The filtering member 260 is fixed via a frame 262 to a groove 242 provided on the rear side of the second nozzle 220. In other words, the filtering member 260 is provided at a position closer to the second nozzle 220 than the first nozzle 210. Therefore, the first space 281 in which the dust is stored can be made larger than the second space 282 that is in communication with the second nozzle 220.

[0064] Furthermore, the first nozzle 210 and the second nozzle 220 are aligned in the vertical direction and open to the rear. Therefore, the first nozzle 210 and the second nozzle 220 opening in different directions can be prevented from causing the air flow inside the container portion 230 to become complicated. Therefore, the air flow inside the container portion 230 can be made more rectified, and the dust collection efficiency can be further improved.

[0065] Furthermore, the container part 230 includes a nozzle connector 240 connected to the first nozzle 210 and the second nozzle 220, and a main body part 250 detachably attached to the nozzle connector 240, and the filtering member 260 is provided on the nozzle connector 240. Therefore, by removing the main body part 250 from the nozzle connector 240, dust accumulated inside the container part 230 can be removed.

[0066] When air moves into the filter member 260 (second space 282), dust may adhere to the outer surface of the filter member 260 because the filter member 260 prevents the air from moving. However, in this embodiment, the filter member 260 is attached to the nozzle connector 240, so that the user can easily remove dust adhering to the outer surface of the filter member 260 when removing the main body 250 from the nozzle connector 240. This prevents the filter member 260 from becoming covered with dust, thereby further improving the dust collection efficiency.

[0067] The dust box 200 includes a detachable part 270 configured to attach and detach the main body part 250 to and from the nozzle connector 240. This eliminates the need for a user to prepare a separate tool for attaching and detaching the main body part 250 to and from the nozzle connector 240, thereby improving the convenience of using the dust box 200.

[0068] In the belt sander 1, dust passes through the first flow path 191 in the housing 10, and static electricity is easily generated due to friction between the dust and the housing 10. However, the dust box 200 of this embodiment is equipped with an earth member 265, one end of which contacts the container portion 230 made of conductive synthetic resin and the other end of which is exposed from the container portion 230. This allows generated static electricity to be discharged via the earth member 265. This prevents dust from accumulating in a predetermined location due to static electricity, further improving dust collection efficiency.

[0069] The dust box 200 is configured to fit within the vertical and horizontal widths of the housing 10 when attached to the belt sander 1. This prevents the dust box 200 from contacting walls or objects located on the left and right of the belt sander 1, thereby limiting the processing range of the belt sander 1. Furthermore, when the belt sander 1 is used in the second usage mode, the dust box 200 is prevented from contacting a desk or the like on which the belt sander 1 is placed.

[0070] <Other forms of dust box and other forms of belt sander for collecting dust in the dust box> The dust box 200 may have a shape, material, etc. other than those of the above embodiment as long as it includes the first nozzle 210 connectable to the discharge nozzle 140, the second nozzle 220 connectable to the suction nozzle 150, the container portion 230, and the filtering member 260. For example, the container portion 230 may be in the shape of a vinyl bag. The filtering member 260 may be configured to be permeable to air but not to allow the passage of dust generated during the processing of the belt sander 1.

[0071] In the above embodiment, the opening 261 of the filter member 260 was attached to the part of the nozzle connection portion 240 that connects to the second nozzle 220 (the second nozzle connection portion), but the filter member 260 may also be attached to the second nozzle 220.

[0072] <Switch mechanism configuration> Next, the overall configuration of the switch mechanism 8 will be described. The switch mechanism 8 is a mechanism for switching between driving and stopping the belt sander 1 by manually operating the motor 2. As shown in FIG. 6, the switch mechanism 8 includes a first switch 80, a second switch 90, a first lock switch 85, and a second lock switch 95. FIGS. 14 to 18 show a plane P1 that includes the major axis of the handle 14 and is perpendicular to the left-right direction as an imaginary plane for explaining the structure of the switch mechanism 8. FIG. 12 shows the switch mechanism 8 cut at the plane P1 when the belt sander 1 is stopped (normally).

[0073] As shown in FIG. 12 , a portion of the first switch 80 protrudes downward from an opening 144 provided in the front lower part of the handle 14. The first switch 80 is configured to be able to be pulled relative to the handle 14. The first switch 80 is also called a pull switch or a trigger switch. A portion of the second switch 90 protrudes upward from an opening 149 provided in the rear upper part of the handle 14. The second switch 90 is configured to be able to be pushed relative to the handle 14. The first switch 80 and the second switch 90 are configured as momentary switches.

[0074] As shown in FIGS. 4 and 12, the first lock switch 85 is provided on the front of the handlebar 14 so as to act on the first switch 80. The first lock switch 85 is configured to perform a function of restricting the first switch 80 from being turned on (a function of maintaining the off state of the first switch 80, a lock-off function). The first lock switch 85 is also configured to perform a function of maintaining the on state of the first switch 80 (a lock-on function). The first lock switch 85 is also called a lock-off / lock-on switch. The second lock switch 95 is provided on the left rear of the handlebar 14 so as to act on the second switch 90. The second lock switch 95 is configured to perform a function of maintaining the on state of the second switch 90 (a lock-on function). The second lock switch 95 is also called a lock-on switch.

[0075] The controller 5 is configured to rotate the motor 2 when both the first switch 80 and the second switch 90 are in an ON state. The controller 5 is configured to stop the rotation of the motor 2 when at least one of the first switch 80 and the second switch 90 is in an OFF state.

[0076] As described above, the user can use the belt sander 1 of this embodiment in a first usage mode and a second usage mode. The first usage mode is a normal usage mode in which the sanding surface B1 is placed on the workpiece, and the user grips the handle 14 to perform the processing. The second usage mode is a mode in which the belt sander 1 is inverted with the sanding surface B1 facing vertically upward, placed on a stand, desk, or the like, and the user grips the workpiece and presses it against the sanding belt B to perform the processing. The second lock switch 95 is a switch that is mainly used in the second usage mode.

[0077] <Configuration of the first switch> First, a description will be given of the first switch 80. As shown in Figures 12 and 13, the first switch 80 includes a first switch operating section 81 and a first main switch 82.

[0078] The first main switch 82 is held in the handle 14 of the main body housing 11. The first main switch 82 has a main body 821 electrically connected to the controller 5, and a plunger 822 exposed downward from the lower part of the main body 821 and movable substantially in the vertical direction. The first main switch 82 turns on (on state) when the length of the exposed portion of the plunger 822 becomes equal to or less than a predetermined threshold, and turns off (off state) when the length of the exposed portion of the plunger 822 exceeds the predetermined threshold. When the first main switch 82 is on, the main body 821 outputs an on signal to the controller 5.

[0079] The first switch operation unit 81 is configured to be manually operable by the user. The first switch operation unit 81 is movable between a first on position and a first off position. In FIG. 13 , the first switch operation unit 81 in the first on position is indicated by a solid line, and the first switch operation unit 81 in the first off position is indicated by a dashed line. The first on position is a position of the first switch operation unit 81 where the first switch operation unit 81 acts on the first main switch 82 to turn the first main switch 82 on. The first off position is a position of the first switch operation unit 81 where the first main switch 82 is turned off. The first switch operation unit 81 is normally in the first off position. The operations of moving the first switch operation unit 81 to the first on position and the first off position are also referred to as an on operation and an off operation, respectively. In this embodiment, the on operation of the first switch operation unit 81 is a pull operation. The off operation of the first switch operation unit 81 is a release of the pull operation.

[0080] The configuration of the first switch operation unit 81 will be described in detail. The first switch operation unit 81 has a base 811, a boss 814, and a protrusion 815. The base 811 is a portion that extends from the front of the first main switch 82 below the plunger 822. A portion of the base 811 protrudes downward from an opening 144 provided at the front lower portion of the handle 14. The protruding portion has an outer shape that fits the user's fingers. The base 811 has an abutment portion 812 (see FIG. 12) that abuts against the lower end of the plunger 822. The protrusion 815 is formed in a generally thick plate shape that protrudes upward from the front portion of the base 811. As shown in FIGS. 14 to 16, the protrusion 815 is located approximately at the center of the handle 14 in the left-right direction, and the plane P1 passes through the protrusion 815. The boss 814 extends in the left-right direction at the front of the base 811 and is supported by the handle 14. The boss portion 814 is rotatable relative to the handle 14 .

[0081] When the ON operation of the first switch operation unit 81 is not restricted by the first lock switch 85, the first switch operation unit 81 is pulled into the opening 144 by the user's pulling operation. At this time, the first switch operation unit 81 rotates clockwise around the boss portion 814. As a result, the first switch operation unit 81 transitions from the state shown by the dashed line in FIG. 13 to the state shown by the solid line, and the protrusion 815 moves forward. In addition, the abutting portion 812 pushes the plunger 822. As the abutting portion 812 pushes the plunger 822, the first main switch 82 (first switch 80) is turned ON. The first ON position is also the position of the first switch operation unit 81 where the length of the exposed portion of the plunger 822 is equal to or shorter than a predetermined threshold.

[0082] When the pulling operation of the first switch operating unit 81 is released, the first switch operating unit 81 rotates counterclockwise around the boss portion 814 and returns to its original position, and the protrusion portion 815 moves rearward. In addition, the abutment portion 812 releases the pressing of the plunger 822. This causes the first switch 80 to enter the OFF state. The first OFF position is also the position of the first switch operating unit 81 where the length of the exposed portion of the plunger 822 is greater than a predetermined threshold.

[0083] The first switch 80 further includes a biasing member 818 that biases the first switch operating unit 81 to the first OFF position. In this embodiment, a compression coil spring is used as the biasing member 818. As shown in FIG. 12 , one end of the biasing member 818 is supported on the base 811 at the rear of the boss portion 814 and in front of the abutment portion 812. The other end of the biasing member 818 is supported on the inner wall of the handle 14. When the first switch operating unit 81 is pulled against the biasing force of the biasing member 818 and positioned at the first ON position, the first switch 80 is turned ON. When the pulling operation of the first switch operating unit 81 is released, the biasing force of the biasing member 818 returns the first switch operating unit 81 to the first OFF position, and the first switch 80 is turned OFF.

[0084] <Configuration of the first lock switch> Next, the first lock switch 85 will be described. The first lock switch 85 is manually operated by the user and moves between an off-lock position that restricts the on operation of the first switch operation unit 81 and an off-lock release position that allows the on operation of the first switch operation unit 81. The off-lock release position includes a locked-on position that maintains the on operation of the first switch 80. The first lock switch 85 is normally positioned in the off-lock position. Figures 12 and 14 show a state in which the first lock switch 85 is positioned in the off-lock position (off-lock state), and Figures 15 and 16 show a state in which the first lock switch 85 is positioned in the on-lock position (on-lock state).

[0085] 14, the first lock switch 85 includes an operating shaft portion 851, a lock-off engaging portion 853, lock-on engaging portions 855L and 855R, and a biasing member 858. The first lock switch 85 is configured as a push-in operating portion that can be pushed into the handle 14.

[0086] The operating shaft 851 is a member extending generally in the left-right direction. As shown in FIG. 14 , in the unlocked state, an approximate center of the operating shaft 851 in the left-right direction appears on plane P1. Normally, the left and right ends of the operating shaft 851 protrude from openings 145L and 145R provided in the left side surface (left wall 14L) and right side surface (right wall 14R) of the handle 14, respectively. The left and right ends of the operating shaft 851 function as operating units 851L and 851R, respectively. The first lock switch 85 is disposed within reach of the user's fingers operating the first switch operating unit 81. Specifically, the operating unit 851R is disposed within reach of the user's right thumb when the user holds the handle 14 with his or her right hand so as to pull the first switch operating unit 81 with the fingers of his or her right hand. Furthermore, the operation unit 851L is arranged within reach of the user's left thumb when the user holds the handle 14 with his or her left hand so as to pull the first switch operation unit 81 with the fingers of his or her left hand.

[0087] The lock-off engaging portion 853 is configured to come into contact with the protrusion 815 of the first switch operating portion 81 and restrict the pulling operation of the first switch operating portion 81. In this embodiment, a recessed portion 854 recessed toward the rear is provided in the center in the left-right direction of the operating shaft portion 851. The lock-off engaging portion 853 is formed in the shape of a thick plate that protrudes toward the front and lower front from the front center of the recessed portion 854.

[0088] The on-lock engaging portions 855L and 855R are provided at the left and right ends of the recessed portion 854, respectively, at a distance from the off-lock engaging portion 853. The on-lock engaging portions 855L and 855R are located rearward of the off-lock engaging portion 853 in the front-rear direction. The on-lock engaging portions 855L and 855R are each formed in a thick plate shape that protrudes downward. The distance between the on-lock engaging portion 855L and the off-lock engaging portion 853 in the left-right direction, and the distance between the on-lock engaging portion 855R and the off-lock engaging portion 853 in the left-right direction, are each greater than the thickness of the protrusion 815 in the left-right direction. Therefore, when the protrusion 815 (first switch operating portion 81) is disengaged from the off-lock engaging portion 853, it becomes rotatable (off-lock released state). When the engagement is released, the first switch operation portion 81 can rotate in the front-rear direction until the rear wall (rear surface) of the protrusion portion 815 is positioned forward of the front wall (front surface) of the lock-on engaging portions 855L and 855R.

[0089] The operating shaft 851 further has restriction walls 854L and 854R. The restriction walls 854L and 854R define the left and right ends of the recess 854. The restriction wall 854L is provided on the left front side of the lock-on engaging portion 855L. When the first lock switch 85 is pushed to the right, the restriction wall 854L abuts against the left side surface of the protrusion 815. As a result, the restriction wall 854L restricts the rightward movement of the first lock switch 85 and positions the lock-on engaging portion 855L directly behind the protrusion 815. The restriction wall 854R is provided on the right front side of the lock-on engaging portion 855R. When the first lock switch 85 is pushed to the left, the restriction wall 854R abuts against the right side surface of the protrusion 815. As a result, the restricting wall 854R restricts the movement of the first lock switch 85 to the left, and also positions the lock-on engaging portion 855R directly behind the protrusion 815.

[0090] The biasing member 858 is provided behind the operating shaft portion 851. The biasing member 858 is arranged along the left-right direction. The biasing member 858 is configured to bias the first lock switch 85 to the lock-off position. In this embodiment, a compression coil spring is used as the biasing member 858.

[0091] In this embodiment, a holding portion 859 is provided at the rear of the operating shaft 851, and is integrally formed with the operating shaft 851. The left and right ends of the biasing member 858 are held by the left and right walls of the holding portion 859, respectively. The left and right walls of the holding portion 859 each have an opening. Protrusions 149L and 149R protruding from the left and right walls of the handle 14 abut against the left and right ends of the biasing member 858 through the openings in the holding portion 859. As shown in FIG. 15 , when the operating shaft 851 moves leftward, the biasing member 858 moves leftward together with the holding portion 859. At this time, the right end of the biasing member 858 is supported by the right wall of the holding portion 859, while the left end of the biasing member 858 is supported by the protrusion 149L, causing the biasing member 858 to contract. 16, when operating shaft 851 moves to the right, biasing member 858 moves to the right together with holding portion 859. At this time, the left end of biasing member 858 is supported by the left wall of holding portion 859, while the right end of biasing member 858 is supported by protrusion 149R, causing biasing member 858 to contract.

[0092] As described above, the first lock switch 85 is normally positioned in the unlocked position. As shown in FIG. 14 , the unlocked position is a position of the first lock switch 85 where the unlocked locking portion 853 is located directly behind the protrusion 815. In the unlocked position, the locked locking portion 853 is located on plane P1. The first lock switch 85 can be moved to the first locked-on position shown in FIG. 15 by being manually pushed to the right by the user. The first locked-on position is a position of the first lock switch 85 where the lock-on locking portion 855R is located directly behind the protrusion 815. In the first locked-on position, the lock-on locking portion 855R is located on plane P1. In addition, the first lock switch 85 can be moved to the second locked-on position shown in FIG. 16 by being manually pushed to the left by the user. The second lock-on position is a position of the first lock switch 85 where the lock-on engaging portion 855L is located directly behind the protrusion 815. In the second lock-on position, the lock-on engaging portion 855L is located on the plane P1.

[0093] <How to operate the first switch and first lock switch> 12 and 14, when the first lock switch 85 is in the unlocked position, the rear wall of the unlocked latch 853 abuts (engages, interferes with) the front wall of the protrusion 815 of the first switch operating unit 81. As a result, the unlocked latch 853 restricts the forward movement of the protrusion 815, that is, restricts the pulling operation of the first switch operating unit 81 (locked-off state).

[0094] When the user pushes the operation portion 851R into the handle 14, the first lock switch 85 moves to the left from the lock-off position. This releases the engagement between the lock-off engaging portion 853 and the protrusion 815 of the first switch operation portion 81 (lock-off released state). This allows the protrusion 815 to rotate clockwise, enabling the first switch operation portion 81 to be pulled (turned on). When the user pulls the first switch operation portion 81, the protrusion 815 rotates clockwise and can move forward in the front-to-rear direction beyond the lock-on engaging portion 855R.

[0095] 15, the first lock switch 85 moves to the left until the restriction wall 854R abuts against the right side of the protrusion 815. Because a lock-on engaging portion 855R is provided to the left rear of the restriction wall 854R, when the restriction wall 854R abuts against the right side of the protrusion 815, the lock-on engaging portion 855R is positioned directly behind the protrusion 815. In other words, the first lock switch 85 is positioned at the first lock-on position.

[0096] When the user releases the pull operation (ON operation) of the first switch operation unit 81, a biasing force toward the first OFF position is applied to the first switch operation unit 81 by the biasing member 818 (see FIG. 12). However, the rear wall (rear surface) of the protrusion 815 engages with the front wall (front surface) of the lock-on engaging portion 855R, restricting the movement of the first switch operation unit 81 to the first OFF position. This maintains the first switch operation unit 81 in the first ON position. Therefore, even if the user releases the pull operation of the first switch operation unit 81, the ON operation is maintained (locked-on state). At this time, the biasing member 858 of the first lock switch 85 contracts as shown in FIG. 15, biasing the first lock switch 85 toward the lock-off position. However, the biasing member 818 of the first switch 80 biases the protrusion 815 of the first switch operating portion 81 (first switch operating portion 81) in a direction toward the first OFF position (a direction in which the protrusion 815 rotates counterclockwise). Therefore, the biasing force of the biasing member 818 acts on the lock-on engaging portion 855R via the protrusion 815, maintaining the engagement between the protrusion 815 and the lock-on engaging portion 855R. In this way, the first lock switch 85 remains in the first lock-on position.

[0097] As shown in FIG. 15, when the first lock switch 85 is positioned at the first lock-on position and the first switch operation unit 81 is maintained in the on position, if the user further pulls the first switch operation unit 81, the protrusion 815 rotates clockwise. This causes the protrusion 815 to move away from the lock-on engaging portion 855R, and the engagement between the protrusion 815 and the lock-on engaging portion 855R is released. Therefore, the first lock switch 85 returns to the lock-off position due to the biasing force of the biasing member 858 (see FIG. 14). Furthermore, the first switch operation unit 81 returns to the first off position due to the biasing force of the biasing member 818.

[0098] The manner in which the user moves the first lock switch 85 from the unlocked position to the second locked position is similar to that described above. That is, when the user pushes the operating portion 851L into the handle 14, the first lock switch 85 moves from the unlocked position to the right. This disengages the unlocked latch 853 from the protrusion 815 of the first switch operating portion 81. When the user pulls the first switch operating portion 81 (turns it on), the protrusion 815 can move forward in the front-to-rear direction beyond the lock-on latch 855L.

[0099] 16, the first lock switch 85 moves to the right until the restricting wall 854L abuts against the left side surface of the protrusion 815. Because a lock-on engaging portion 855L is provided to the right rear of the restricting wall 854L, when the restricting wall 854L abuts against the left side surface of the protrusion 815, the lock-on engaging portion 855L is positioned directly behind the protrusion 815. In other words, the first lock switch 85 is positioned at the second lock-on position.

[0100] When the user releases the pull operation (ON operation) of the first lock switch 85, the biasing member 818 applies a biasing force to the first switch operation unit 81 toward the first OFF position. However, the rear wall of the protrusion 815 abuts against the front wall of the lock-on engaging portion 855L, restricting the movement of the first switch operation unit 81 to the first OFF position. As a result, the first switch operation unit 81 is maintained in the first ON position, and even if the user releases the pull operation of the first lock switch 85, the ON operation of the first switch operation unit 81 is maintained (the locked-on state of the first switch 80). Note that the biasing force of the biasing member 818 is applied to the lock-on engaging portion 855L (first lock switch 85) via the protrusion 815. Due to the action of this biasing force, the first lock switch 85 remains in the second locked-on position.

[0101] As shown in Fig. 16, when the first lock switch 85 is positioned at the second lock-on position and the first switch operation unit 81 is maintained in the on position, if the user further pulls the first switch operation unit 81, the protrusion 815 rotates clockwise. This disengages the protrusion 815 from the lock-on engaging portion 855R. Therefore, the first lock switch 85 returns to the lock-off position due to the biasing force of the biasing member 858 (see Fig. 14). The first switch operation unit 81 also returns to the first off position due to the biasing force of the biasing member 818.

[0102] As described above, when the first switch 80 is in the locked-on state (see Figures 15 and 16), the user can turn the first switch 80 off and transition the first switch 80 to the locked-off state simply by pulling the first switch operating unit 81 and then releasing the pulling operation.

[0103] <Configuration of the second switch> Next, a description will be given of the second switch 90. As shown in FIG.

[0104] The second main switch 92 is held within the handle 14 of the main body housing 11, behind the first switch 80. The second main switch 92 includes a main body 921 electrically connected to the controller 5, and an actuator 922 protruding upward from an upper portion of the main body 921. The actuator 922 is pressed downward to be pushed into the main body 921. The second main switch 92 turns on (on state) when the amount of depression (pressure) of the actuator 922 against the main body 921 is equal to or greater than a predetermined threshold, and turns off (off state) when the amount of depression against the main body 921 is less than the predetermined threshold. When the second main switch 92 is on, the main body 921 outputs an on signal to the controller 5.

[0105] The second switch operation unit 91 is located rearward of the first switch operation unit 81 and the first lock switch 85. The second switch operation unit 91 is located below an imaginary plane P2 (see FIG. 6) including the upper wall 121 of the first section 12 (motor housing section). As shown in FIG. 12, the second switch operation unit 91 is disposed on the handle 14 so that a portion of the second switch operation unit 91 protrudes upward from an opening 149 provided at the upper rear portion of the handle 14, and moves substantially in the vertical direction. The second switch operation unit 91 is configured to be manually operable by a user. The second switch operation unit 91 is movable between a second ON position and a second OFF position. In FIG. 17, the second switch operation unit 91 in the second ON position is shown by a solid line, and the second switch operation unit 91 in the second OFF position is shown by a dashed line. The second ON position is a position of the second switch operation unit 91 where the second switch operation unit 91 acts on the second main switch 92 to drive the motor 2. The second off position is a position of the second switch operation unit 91 that stops the driving of the motor 2. The second switch operation unit 91 is normally in the second off position. The operations of moving the second switch operation unit 91 to the second on position and the second off position are also called the on operation and the off operation, respectively. In this embodiment, the on operation of the second switch operation unit 91 is a push operation. The off operation of the second switch operation unit 91 is the release of the push operation.

[0106] The configuration of the second switch operation unit 91 will be described in detail. The second switch operation unit 91 has a base 911, a rotating shaft 916 extending in the left-right direction and having its left and right ends supported by the handlebars 14, and a biasing member 918. The base 911 is disposed above and in front of the second main switch 92 and extends in the front-to-rear direction. The rear portion of the base 911 protrudes downward. A contact portion 912 that can contact the upper end of the actuator 922 is provided at the rear lower portion of the base 911.

[0107] Normally, a portion of the base 911 protrudes upward from an opening 149 provided at the upper rear portion of the handle 14 (see FIG. 12). The protruding portion has a dorsal fin shape. An axial hole 915 extending in the left-right direction is provided at the front end of the base 911. A rotating shaft 916 is inserted into the axial hole 915. The base 911 is rotatable around the rotating shaft 916. When the user presses the base 911, it rotates counterclockwise (downward) and is pushed into the opening 149.

[0108] The base 911 is formed in a block shape with an internal space. As shown in Fig. 12, an opening 917 is provided in a left wall 911L of the base 911. As will be described in detail later, the opening 917 is formed in a position and size that allows the latching portion 954 of the second lock switch 95 to be inserted and disposed in the internal space of the base 911.

[0109] The biasing member 918 is configured to bias the second switch operation unit 91 to the second OFF position. In this embodiment, a torsion spring is used as the biasing member 918. A coil portion of the torsion spring 918 is provided on the rotating shaft 916. A support wall 142 extending from the front to the rear lower portion of the base 911 is provided within the handle 14, and one arm 918f of the torsion spring 918 is fixed to the support wall 142. The other arm (not shown) of the torsion spring 918 is fixed to the base 911 and biases the base 911 upward (clockwise).

[0110] The second switch operation unit 91 is pushed into the opening 149 by the user's pressing operation. At this time, the second switch operation unit 91 rotates counterclockwise around the rotation shaft 916. As a result, the abutment portion 912 moves downward and presses the actuator 922, and the second main switch 92 (second switch 90) is turned on. The second on position is also the position of the second switch operation unit 91 where the amount of depression (pressure) of the actuator 922 is equal to or greater than a predetermined threshold.

[0111] When the pulling operation of the second switch operation unit 91 is released, the second switch operation unit 91 rotates clockwise around the rotating shaft 916 due to the biasing force of the torsion spring 918 and returns to its original position, and the abutment portion 912 releases the pressing of the actuator 922. This causes the second switch 90 to enter the OFF state. The second OFF position is also the position of the second switch operation unit 91 where the pressing amount (pressure) of the actuator 922 is less than a predetermined threshold.

[0112] <Configuration of the second lock switch> The second lock switch 95 is provided at the rear of the handlebar 14 so as to act on the second switch 90. The second lock switch 95 is located behind the first lock switch 85 in the front-to-rear direction and below the first lock switch 85 in the up-down direction. As shown in FIG. 18, a portion of the second lock switch 95 is exposed through an opening 147 provided in the left wall 14L of the handlebar 14. The second lock switch 95 is normally positioned in the OFF position (unlocked-on position) (see FIG. 18). The second lock switch 95 can be manually operated by the user to move to a locked-on position, which maintains the ON operation of the second switch operating unit 91 (see FIG. 19).

[0113] As shown in Figures 18 and 19, a recessed portion 146 recessed to the right is provided in the left wall 14L of the handle 14 at a position corresponding to the rear portion of the second switch operating portion 91. The second lock switch 95 is disposed in the recessed portion 146. The recessed portion 146 is formed in a multi-step circular shape with an inner diameter that decreases toward the right. An opening 147 is located in approximately the center of the recessed portion 146. The recessed portion 146 has a first flange 146a and a second flange 146b that are perpendicular to the left-right direction. The second flange 146b is an annular wall provided around the opening 147. The first flange 146a is on the left side of the second flange 146b and is an annular wall provided around the second flange 146b.

[0114] The second lock switch 95 has a stepped pin 953 , an operating portion 951 provided at the left end of the stepped pin 953 , and a biasing member 958 .

[0115] The stepped pin 953 extends generally in the left-right direction and is movable in the left-right direction. The stepped pin 953 is arranged on the handle 14 so as to be insertable into the opening 917 of the base 911 when the second switch operation unit 91 is pressed. The stepped pin 953 is inserted through the opening 147 with its right end located inside the handle 14 and its left end located inside the recess 146 (to the left of the opening 147). The outer diameter of the right end of the stepped pin 953 is larger than the diameter of the opening 147. This prevents the stepped pin 953 from coming off the handle 14. Furthermore, as will be described in detail later, the right end of the stepped pin 953 functions as a locking portion 954 that locks with the second switch operation unit 91 to maintain the second switch operation unit 91 in the second ON position.

[0116] The operating portion 951 is formed in a cap shape that fits onto the left end of the stepped pin 953. The operating portion 951 is movable in the left-right direction together with the stepped pin 953. The outer diameter of the operating portion 951 is larger than the second flange 146b and smaller than the first flange 146a. Therefore, movement of the operating portion 951 to the right is restricted by the first flange 146a. Unlike the first lock switch 85, the operating portion 951 of the second lock switch 95 does not protrude leftward beyond the left wall 14L around the recessed portion 146 in the left-right direction.

[0117] The biasing member 958 is configured to bias the second lock switch 95 toward the unlocked position. In this embodiment, a compression coil spring is used as the biasing member 958. The biasing member 958 is disposed on the stepped pin 953. The left end of the biasing member 958 is supported by the flange 952 of the operating portion 951, and the right end is supported by the second flange 146b.

[0118] <How to operate the second switch and second lock switch> 12 and 18, a part of the second switch operating unit 91 (base 911) normally protrudes from an opening 147 provided in the handle 14 and above the handle 14 (second off position). As described above, when the user presses the second switch operating unit 91, it is pushed into the opening 149 and moves to the second on position, and the second main switch 92 (second switch 90) is turned on.

[0119] When the user pushes the operation portion 951 of the second lock switch 95 into the handle 14 while the second switch operation portion 91 is being pressed, the locking portion 954 of the second lock switch 95 is inserted into the internal space of the base 911 through an opening 917 provided in the base 911 of the second switch operation portion 91. When the pressing operation of the second switch operation portion 91 is released, the second switch operation portion 91 is urged toward its original position (second OFF position) by the urging force of the torsion spring 918. However, before the second switch operation portion 91 moves away from the second ON position, the locking portion 954 of the stepped pin 953 engages with the left wall portion 911L of the base 911 around the opening 917 (see FIG. 19 ). As a result, the second switch operation portion 91 is maintained in the second ON position (locked ON state). Although the second lock switch 95 is biased to the unlocked position by the biasing member 958, it remains in the locked position due to the engagement between the latching portion 954 and the base 911. As a result, even if the user removes his or her fingers from the second switch operating portion 91 and the second lock switch 95, the on state of the second switch 90 is maintained.

[0120] In the above-described locked-on state, when the user presses the second switch operation unit 91, the second switch operation unit 91 rotates counterclockwise (downward), and the engagement between the locking portion 954 of the stepped pin 953 and the left wall portion 911L of the base 911 is released. As a result, the second lock switch 95 returns to the unlocked position due to the biasing force of the biasing member 958 (see FIG. 18 ). Furthermore, the second switch operation unit 91 returns to the second off position due to the biasing force of the biasing member 918. In other words, in the locked-on state, the user can set the second switch 90 to the off state simply by pressing the second switch operation unit 91 once and then releasing the pressing operation.

[0121] The switch mechanism 8 described above can be operated as follows in the first and second usage modes. In the first usage mode, the user presses the second switch operation unit 91 with, for example, the left hand. Then, while placing the right hand on the first switch operation unit 81, the user presses the operation unit 851R of the first lock switch 85 with the right thumb to release the first switch 80 from its locked-off state. Then, by pulling the first switch operation unit 81 with the right hand and further pressing the operation unit 851R of the first lock switch 85 with the right thumb, the first switch 80 can be maintained in its on state (locked-on state). Note that the user can also press the second switch operation unit 91 with the right hand, and while placing the left hand on the first switch operation unit 81, press the operation unit 851L of the first lock switch 85 with the left thumb to place the first switch 80 in the locked-on state. In this state, when the user releases the belt sander 1, the second switch operating unit 91 returns to the second OFF position, and the second switch 90 is turned OFF. Therefore, the user can stop the belt sander 1 simply by releasing the pressing operation of the second switch operating unit 91.

[0122] In the second usage mode, the user presses the second switch operation unit 91 (moving it to the second ON position) and presses the second lock switch 95 to lock the second switch 90. The user can lock the first switch 80 by operating the first switch operation unit 81 and the first lock switch 85 in the same manner as in the first usage mode. This allows the user to release the belt sander 1, grip the workpiece, and perform processing work. As described above, the user can press the second switch operation unit 91 once, and then simply release the pressing operation to switch the second switch 90 to the OFF state and stop the belt sander 1.

[0123] As described above, in the belt sander 1 of this embodiment, the first lock switch 85 maintains the first switch 80 in the on state, and the second lock switch 95 maintains the second switch 90 in the on state. Therefore, in the second usage mode, the belt sander 1 of this embodiment can continue to stably drive the motor 2 even when the belt sander 1 is placed on a slightly uneven surface.

[0124] In addition, in the unlocked state, the operating portions 851L and 851R of the first lock switch 85 protrude from the left and right walls 14L and 14R of the handle 14, respectively, and the operating portion 951 of the second lock switch 95 is disposed in a recess 146 provided in the left wall 14L of the handle 14. Therefore, in the second usage mode, it is easy to operate the first lock switch 85 and the second lock switch 95 consecutively. Therefore, in the second usage mode, the operability of driving the belt sander 1 can be further improved.

[0125] Furthermore, in the belt sander 1, the upper wall 121 of the portion (first portion 12) of the housing 10 that houses the motor 2 is substantially parallel to the sanding belt B, and the second switch operation unit 91 is provided below an imaginary plane P2 that includes the upper wall 121. Therefore, in the second usage mode, the posture of the belt sander 1 can be stabilized by placing the upper wall 121 on a desk, stand, or the like.

[0126] Furthermore, the first lock switch 85 can be configured to have a function of preventing the first switch 80 from being turned on (lock-off function) in addition to a function of maintaining the first switch 80 in the on state (lock-on function). Therefore, by providing a separate switch that performs the lock-off function, it is possible to prevent the operation of the switch mechanism from becoming complicated and the belt sander from becoming larger. In other words, according to this embodiment, it is possible to improve the operability of driving the belt sander 1 and to make the belt sander 1 more compact.

[0127] In addition, since the second switch operating portion 91 protrudes from above the handle 14, the user can turn on the second switch 90 by pressing the second switch operating portion 91 from above. Therefore, the operability of driving the belt sander 1 can be improved even in the first usage mode.

[0128] In addition, the second switch operating unit 91 returns to the second off position when the user releases the pressing operation, so in the first usage mode, even if the user takes their hands off the belt sander 1, the belt sander 1 can be prevented from moving on its own.

[0129] The second lock switch 95 moves in a left-right direction that intersects with the movement direction (substantially the up-down direction) of the second switch operation unit 91. Therefore, when a user operates the second switch operation unit 91, the second lock switch 95 can be prevented from being unintentionally operated by the user's fingers accidentally touching the second lock switch 95. In this embodiment, the second lock switch 95 is configured so as not to protrude outward beyond the handle 14 (to the left of the left wall 14L). This further prevents the second lock switch 95 from being unintentionally operated.

[0130] <Other forms of switch mechanism> The first switch 80 and the second switch 90 may have configurations other than those described above as long as they are configured as momentary switches. For example, the first switch operation unit 81 and the second switch operation unit 91 may be configured as slide operation units that are moved between first and second ON positions and first and second OFF positions by a user's slide operation. Similarly, the first lock switch 85 and the second lock switch 95 may have configurations other than those described above as long as they are configured to enable the first switch 80 and the second switch 90, respectively, to be continuously ON.

[0131] In the above-described embodiments, compression coil springs are used as the biasing members 818, 858, and 958, and a torsion spring is used as the biasing member 918. However, other biasing members (elastic bodies) may be used as the biasing members 818, 858, 918, and 958.

[0132] In the above embodiment, the second lock switch 95 is provided on the left wall 14L of the handlebar 14. However, the second lock switch 95 may be provided on the right wall 14R of the handlebar 14, or on each of the left and right walls 14L and 14R.

[0133] <Battery compartment configuration> Next, the configuration of the battery mounting section 4 will be described with reference to Figures 1 to 5 and 20. The battery mounting section 4 is provided on the belt drive section 6 (second section 13 of the main body housing 11). The battery mounting section 4 is configured so that a rechargeable battery 300 having a known configuration can be attached or detached by sliding the battery 300 in the sliding direction relative to the battery mounting section 4.

[0134] First, an example of a battery that can be attached to and detached from the battery attachment section 4 will be described. A battery 300 shown in FIG. 20 is an example of a battery pack that can be attached to the battery attachment section 4. In FIG. 20, the battery 300 includes a case 310 that houses multiple battery cells and an attachment section 320 that can be attached to and detached from the battery attachment section 4. The attachment section 320 has an attachment surface 321 that faces the attachment surface 41 of the battery attachment section 4 when the battery 300 is attached to the battery attachment section 4. In FIG. 20, the direction of the battery 300 where the attachment surface 321 is provided relative to the case 310 is defined as the lower side, and the opposite side is defined as the upper side. Furthermore, the direction in which the battery 300 slides, which intersects the up-down direction, is defined as the front-rear direction. In the front-rear direction, the side where a 305 (described later) is provided is defined as the front side, and the opposite side is defined as the rear side. Furthermore, the direction that intersects the up-down direction and the front-rear direction is defined as the left-right direction.

[0135] The mounting portion 320 has a mounting surface 321, a pair of rail receiving portions 322, a pair of power terminals 324, and a signal terminal 326. The mounting surface 321 is a surface that faces a mounting surface 41 (described in detail later) of the battery mounting portion 4 when the battery 300 is mounted in the battery mounting portion 4 of the belt sander 1. In this embodiment, the mounting surface 321 is the lower surface of the case 310 and includes the lower surface of a portion (protrusion 311) that protrudes downward from the front lower portion of the case 310. The mounting surface 321 is a surface that is approximately parallel in the front-rear and left-right directions. The battery 300 is formed in the shape of a rectangular box whose up-down width is smaller than its front-rear and left-right widths. The battery 300 (case 310) has a long side in the sliding direction. The surface opposite the mounting surface 321 (upper surface 312) has the largest area of ​​the battery 300. The pair of rail receiving portions 322 are provided on the left and right side surfaces of the protruding portion 311, and extend in the long side direction (front-rear direction) of the case 310. The pair of rail receiving portions 322 are configured to be able to engage with guide rails 42 (see FIG. 4) provided on the battery mounting portion 4.

[0136] The mounting section 320 further includes a locking member 305 provided on the front lower portion of the protrusion 311. The locking member 305 engages with a lock receiving portion provided on the battery mounting section 4 to fix (lock) the battery 300 to the battery mounting section 4. When the user presses an unlock button (not shown), the unlocking button releases the lock between the locking member 305 and the lock receiving portion.

[0137] As shown in FIGS. 2 and 5 , the battery attachment section 4 is provided in the second section 13 of the main body housing 11. The battery attachment section 4 is provided on the inner side of the top wall 131 and the side wall 133 and is configured to be able to receive the battery 300 from the front. As described above, the portion of the main body housing 11 located above the belt drive section 6 is formed in a stepped shape, with the top wall 131 of the second section 13 located lower than the top wall 121 of the first section 12. Because the first section 12 houses the motor 2, the battery attachment section 4 can also be said to be located in front of the motor 2 and above the belt drive section 6. The battery attachment section 4 overlaps with the belt drive section 6 when viewed from above, and overlaps with the motor 2 when viewed from the front.

[0138] As shown in FIG. 6, the battery mounting section 4 is configured so that, in a mounted state with the battery 300 mounted (hereinafter referred to as the battery mounted state), the battery 300 does not protrude upward from the top wall 121 of the housing 10 in the up-down direction. Furthermore, the battery mounting section 4 is configured so that, in a battery mounted state, the battery 300 does not protrude forward from the front end of the main body housing 11 in the front-to-rear direction. In this embodiment, as shown in FIG. 6, the surface (top surface 312) of the battery 300 opposite the mounting surface 321 is located at approximately the same position as the top wall 121 of the first portion 12 of the main body housing 11 in the up-down direction. Furthermore, in the front-to-rear direction, the front surface 314 of the battery 300 is located at approximately the same position as the front end of the main body housing 11. Furthermore, as shown in FIG. 4, the battery mounting section 4 is configured so that, in the left-to-right direction, the battery 300 does not protrude leftward from the left end of the left main body housing 11L and does not protrude rightward from the right main body housing 11R. In other words, the battery mounting section 4 is configured so that, in the battery mounted state, the left-right direction of the battery 300 is within the left-right width of the second portion 13 of the main body housing 11. In this embodiment, in the left-right direction, the right surface 313 of the battery 300 is located at approximately the same position as the side walls 123, 133 of the right main body housing 11R.

[0139] The battery mounting section 4 includes a mounting surface 41, a pair of guide rails 42, a pair of power terminals 44, and a signal terminal 46. In this embodiment, the sliding direction of the battery 300 relative to the battery mounting section 4 is the front-to-rear direction. Specifically, the mounting direction of the battery 300 relative to the battery mounting section 4 is from front to rear. The removal direction of the battery 300 mounted in the battery mounting section 4 is from rear to front.

[0140] The mounting surface 41 is a surface that faces one surface (mounting surface 321) of the battery 300 when the battery 300 is mounted in the battery mounting section 4. The mounting surface 41 is approximately parallel to the front-rear direction and the left-right direction. Guide rails 42 extending in the front-rear direction are provided on the inner sides of the side walls 133 of the second section 13. The pair of guide rails 42 are configured to engage with the rail receiving portions 322 of the battery 300. When the mounting section 320 of the battery 300 is mounted in the battery mounting section 4, the guide rails 42 guide the rail receiving portions 322 in the front-rear direction. It can also be said that the mounting surface 41 is approximately parallel to the sliding direction of the battery 300.

[0141] The pair of power supply terminals 44 are provided between the pair of guide rails 42. The pair of power supply terminals 44 are formed in the shape of a plate that protrudes upward from the mounting surface 41 and extends in the front-to-rear direction. The pair of power supply terminals 44 are configured to receive power from the battery 300 mounted in the battery mounting section 4. The signal terminal 46 is provided between the pair of power supply terminals 44, protrudes upward from the mounting surface 41, and extends in the front-to-rear direction. The signal terminal 46 is configured to send and receive signals to and from the battery 300 mounted in the battery mounting section 4.

[0142] As the mounting portion 320 of the battery 300 slides from front to rear relative to the battery mounting portion 4, the rail receiving portions 322 of the battery 300 engage with the guide rails 42 of the battery mounting portion 4, and the battery 300 is mounted in the battery mounting portion 4. At this time, the mounting surface 41 of the battery mounting portion 4 faces the mounting surface 321 of the battery 300. Furthermore, the pair of power supply terminals 44 of the battery mounting portion 4 are electrically connected to the pair of power supply terminals 324 of the battery 300, respectively. Furthermore, the signal terminal 46 of the battery mounting portion 4 is electrically connected to the signal terminal 326 of the battery 300.

[0143] The battery mounting section 4 further includes a lock receiving hole 47 with which the locking member 305 of the battery 300 engages. When the battery 300 is mounted in the battery mounting section 4, the locking member 305 engages with the lock receiving hole 47, and the battery 300 is fixed so that it cannot move in the front-to-rear direction. When the unlock button of the battery 300 is pressed, the engagement between the locking member 305 and the lock receiving hole 47 is released. In this disengaged state, the battery 300 can be removed from the battery mounting section 4 by sliding the battery 300 from the rear to the front relative to the battery mounting section 4.

[0144] The belt sander 1 of this embodiment further includes a front handle 17. The front handle 17 is connected to the housing 10 and is rotatable relative to the housing 10. As shown in FIG. 3, a rotation axis A4 of the front handle 17 extends in the left-right direction. The front handle 17 is also referred to as a "second handle."

[0145] The front handle 17 rotates about a rotation axis A4 extending in the left-right direction. The front handle 17 includes an arm 171 having a base end 172 and a tip end 173 and extending in a direction intersecting the rotation axis A4, and a grip 175 for the user to grip.

[0146] As shown in FIGS. 2 and 3, a base end 172 of the arm 171 is detachably attached to a rotating part 18 provided on the left side wall (fan housing 161) of the housing 10. The rotating part 18 is configured to engage with the base end 172 of the arm 171 and allow the arm 171 to rotate within a predetermined range around the rotation axis A4. The grip part 175 extends to the right from a tip end 173 of the arm 171. The grip part 175 is parallel to the left-right direction. The tip end (right end) of the grip part 175 is located to the left of the right end (right side walls 123, 133) of the housing 10. The left-right length of the grip part 175 is formed to fit within the left-right width of the housing 10. The length of the arm 171 and the position of the base end 172 of the arm 171 relative to the housing 10 are adjusted so that the gripping portion 175 of the front handle 17 does not come into contact with the housing 10 or the battery 300 attached to the battery attachment portion 4 when the front handle 17 is rotated.

[0147] A plurality of cam surfaces extending radially are provided on the rotating portion 18 and on a portion of the front handle 17 facing the rotating portion 18 (the right side surface of the base end 172 of the grip portion 175). The front handle 17 is configured to be positioned at a plurality of rotation positions by the plurality of cam surfaces of the front handle 17 meshing (engaging) with the cam surfaces of the rotating portion 18. In this embodiment, the front handle 17 is positioned at four rotation positions (angular positions). As shown in FIG. 3, as the arm 171 rotates around the rotation axis A4, the front handle 17 (grip portion 175) moves from bottom to top in the order of positions R1, R2, R3, and R4. The position of the grip portion 175 is fixed (positioned) at each of the rotation positions R1 to R4 by the base end 172 of the arm 171 engaging with the rotating portion 18.

[0148] At position R1, the grip portion 175 is located forward of the front end of the housing 10 (second portion 13) and below the mounting surface 41. At position R2, the grip portion 175 is located forward of the front end of the housing 10 and in front of (directly in front of) the battery 300 mounted in the battery mounting portion 4. In this embodiment, at position R2, as shown in FIG. 6 , the upper end of the grip portion 175 is located at approximately the same position in the up-down direction as the upper end of the housing 10 (upper wall 121 of the first portion 12) and the upper surface 312 of the battery mounted in the battery mounting portion 4. At position R2, a plane P2 including the upper wall 121 passes through the upper end of the grip portion 175 and the upper surface 312 of the battery 300. Position R2 is also referred to as the "first rotation position."

[0149] At positions R3 and R4, the grip portion 175 is located rearward of the front end of the housing 10 and above the top wall 121 of the housing 10 in the vertical direction. Position R3 is a position suitable for a user to grip the handle 14 with one hand and the grip portion 175 of the front handle 17 with the other hand to perform processing work in the first usage mode. Position R4 is a position suitable for a user to lift and move the belt sander 1. Note that at position R1, the grip portion 175 is located below the mounting surface 41. At positions R3 and R4, the grip portion 175 is located above the upper end of the housing 10 (the top wall 121 of the first section 12), i.e., above the battery 300 mounted in the battery mounting portion 4. Therefore, the user can mount or remove the battery 300 to or from the battery mounting portion 4 by rotating the front handle 17 to move the grip portion 175 to any of positions R1, R3, or R4. Positions R1, R3, and R4 are also called "second rotation positions."

[0150] The following describes the effects of the belt sander 1 equipped with the battery mounting unit 4 of this embodiment. The battery mounting unit 4 of this embodiment is located in a position that overlaps the belt drive unit 6 (sanding belt B, sanding surface B1) when viewed from above, and overlaps the motor 2 when viewed from the front. Therefore, when the belt sander 1 is driven, the weights of the motor 2 and the battery 300 mounted in the battery mounting unit 4 are applied to the sanding surface B1. Therefore, the masses of the motor 2 and the battery 300 can be utilized to perform processing work, improving the operational efficiency of the belt sander 1.

[0151] Furthermore, the battery attachment section 4 is configured such that, in the battery-attached state, the top surface 312 of the battery 300 is positioned approximately flush with the top wall 121 of the first section 12 of the main body housing 11 in the up-down direction. Furthermore, in the left-right direction, the right surface 313 of the battery 300 is positioned approximately flush with the side walls 123, 133 of the right main body housing 11R. Furthermore, in the front-rear direction, the front surface 314 of the battery 300 is positioned approximately flush with the front end of the main body housing 11. Therefore, the belt sander 1 in the battery-attached state can be made compact in the up-down, left-right, and front-rear directions, and the processing range of the belt sander can be prevented from being limited due to the battery 300 contacting walls or objects positioned in front of or on the left or right of the belt sander 1.

[0152] Furthermore, with the battery attached, the top surface 312 of the battery 300 is at approximately the same position in the vertical direction as the top wall 121 of the housing 10. Therefore, when the belt sander 1 is used in a second usage mode (in which the belt sander 1 is turned upside down with the sanding surface B1 facing vertically upward and the user grips the workpiece and presses it against the sanding belt B to perform processing), the top wall 121 of the housing 10 and the top surface 312 of the battery 300 come into contact with a desk or the like. This allows the belt sander 1 to maintain a stable posture in the second usage mode. Furthermore, the top surface 312 of the battery 300 has the largest surface area of ​​the battery 300, so a relatively large area comes into contact with a desk or the like. This allows the belt sander 1 to maintain a stable posture in the second usage mode.

[0153] Furthermore, in the belt sander 1, the battery 300 is attached to the battery attachment section 4 from front to back, which is the same direction as the extension of the handle 14. Therefore, when attaching a battery to the battery attachment section 4, the user is likely to apply force in the direction opposite to the attachment direction of the battery 300 (from back to front) with the hand holding the handle 14. Therefore, the belt sander 1 of this embodiment has the advantage that the battery 300 can be easily attached to the battery attachment section 4.

[0154] The belt sander 1 also includes a front handle 17 that is rotatable relative to the housing 10. As the front handle 17 rotates, the grip 175 moves vertically to position R1 (second rotation position) where the grip 175 is located lower than the battery 300 attached to the battery attachment portion 4, position R2 (first rotation position) where the upper end of the grip 175 is substantially flush with the top wall 121 of the housing 10, and positions R3 and R4 (second rotation positions) where the grip 175 is located higher than the battery 300 attached to the battery attachment portion 4. Therefore, when the front handle 17 is rotated so that the grip 175 moves to position R2 and the belt sander 1 is used in the second usage mode, the top wall 121 of the housing 10, the grip 175, and the top surface 312 of the battery 300 attached to the battery attachment portion 4 come into contact with a desk or the like on which the belt sander 1 is placed. Therefore, the posture of the belt sander 1 in the second usage mode can be further stabilized. Also, by rotating the front handle 17 so that the grip part 175 moves to any of positions R1, R3, and R4, the battery 300 can be attached to or detached from the battery attachment part 4.

[0155] Furthermore, in consideration of the spirit of the present disclosure and the above-described embodiments, the following aspects are constructed. At least one of the following aspects can be adopted in combination with the above-described embodiments and their modifications, and at least one of the configurations (features) described in each claim.

[0156] [Aspect 1-1] Belt sandals, An electric motor; a housing having a motor accommodating portion in which the motor is accommodated; a belt driving unit including a driving roller rotated by the motor and a driven roller, the belt driving unit configured to drive an endless sanding belt stretched between the driving roller and the driven roller, a belt drive unit provided below the motor, the sanding surface being defined by the underside of the sanding belt; and a belt drive unit, the belt drive unit being provided below the motor, the belt drive unit being provided below the motor, the sanding surface being defined by the underside of the sanding belt, the belt drive unit being provided below the motor ... a first handle provided on a rear side of the motor in the front-rear direction, extending in the front-rear direction, and to be gripped by a user; a battery mounting section in which a battery serving as a power source for the motor can be attached and detached by sliding the battery in a sliding direction; the battery mounting portion is provided at a position overlapping the polishing surface when viewed from above and at a position overlapping the motor when viewed from the front, The belt sander, wherein the sliding direction is a horizontal direction including the front-rear direction and the left-right direction. [Aspect 1-2] the motor housing portion has an upper wall that is substantially parallel to the polishing surface, The battery mounting portion is provided below the upper wall in the up-down direction. [Aspect 1-3] The battery mounting portion is configured so that, when the battery is mounted in the battery mounting portion, the battery does not protrude upward from the upper wall in the up-down direction. [Aspect 1-4] the battery mounting portion is configured such that, in a mounted state in which the battery is mounted in the battery mounting portion, the battery protrudes upward by a predetermined protrusion length beyond the upper wall in the up-down direction, The predetermined protruding length is 10% or less of the length of the battery in the up-down direction. [Aspect 1-5] The battery mounting portion is configured so that, when the battery is mounted in the battery mounting portion, the battery does not protrude from the front end of the housing in the front-rear direction. [Aspects 1-6] the battery mounting portion is configured such that, in a mounted state with the battery mounted on the battery mounting portion, the battery protrudes forward in the front-rear direction beyond a front end of the housing by a predetermined protrusion length, The predetermined protruding length is 10% or less of the length of the battery in the front-rear direction. [Aspect 1-7] The battery mounting portion is configured so that, when the battery is mounted in the battery mounting portion, the battery does not protrude from the left and right ends of the housing in the left-right direction. [Aspect 1-8] the battery mounting portion is configured such that, in a mounted state with the battery mounted in the battery mounting portion, the battery protrudes to the left or right of a left end or a right end of the housing in the left-right direction by a predetermined protrusion length, The predetermined protruding length is 10% or less of the length of the battery in the left-right direction. [Aspect 1-9] the sliding direction is the front-rear direction, The battery mounting section is configured so that the battery can be mounted by sliding the battery in a front-to-rear direction relative to the battery mounting section. [Aspect 1-10] The battery mounting section is configured so that the battery can be attached and detached by sliding the battery in the left-right direction. [Aspect 1-11] a second handle having an arm with a rotation axis extending in the left-right direction and connected to the housing, and a grip portion connected to the arm and to be held by a user, the second handle being rotatable relative to the housing; In response to the rotation of the second handle, the gripping portion a first rotation position in which an upper end of the grip portion is positioned substantially flush with an upper wall of the motor accommodating portion in the vertical direction; and a second rotation position where the grip portion is positioned below or above the battery in the up-down direction when the battery is mounted in the battery mounting portion. [Aspect 1-12] Belt sandals, An electric motor; a housing having a motor accommodating portion in which the motor is accommodated; a belt driving unit including a driving roller rotated by the motor and a driven roller, the belt driving unit configured to drive an endless sanding belt stretched between the driving roller and the driven roller, a belt drive unit provided below the motor, the sanding surface being defined by the underside of the sanding belt; and a belt drive unit, the belt drive unit being provided below the motor, the belt drive unit being provided below the motor, the sanding surface being defined by the underside of the sanding belt, the belt drive unit being provided below the motor ... a first handle provided on a rear side of the motor in the front-rear direction, extending in the front-rear direction, and to be gripped by a user; a second handle having an arm connected to the housing and having a rotation axis extending in the left-right direction and a grip portion connected to the arm and to be held by a user, the second handle being rotatable relative to the housing; a battery mounting section in which a battery serving as a power source for the motor can be attached and detached by sliding the battery in a sliding direction; The battery mounting section a position overlapping the grinding surface when viewed from above and a position overlapping the motor when viewed from the front; the battery mounting portion is configured so that, in a mounted state in which the battery is mounted in the battery mounting portion, the battery does not protrude from an upper wall of the motor accommodating portion in the up-down direction, In response to the rotation of the second handle, the gripping portion a first rotation position in which the upper end of the gripping portion is at substantially the same position as the upper wall in the vertical direction; a second rotation position in which the gripping portion is positioned below or above the battery in the vertical direction when the battery is mounted in the battery mounting portion; [Aspect 1-13] The battery mounting portion is configured so that, in a mounted state with the battery mounted in the battery mounting portion, the upper surface of the battery is at substantially the same position as the upper wall in the up-down direction. [Aspect 1-14] Belt sandals, An electric motor; a housing having a motor accommodating portion in which the motor is accommodated; a belt driving unit including a driving roller rotated by the motor and a driven roller, the belt driving unit configured to drive an endless sanding belt stretched between the driving roller and the driven roller, a belt drive unit provided below the motor, the sanding surface being defined by the underside of the sanding belt; and a belt drive unit, the belt drive unit being provided below the motor, the belt drive unit being provided below the motor, the sanding surface being defined by the underside of the sanding belt, the belt drive unit being provided below the motor ... a first handle provided on a rear side of the motor in the front-rear direction, extending in the front-rear direction, and to be gripped by a user; a battery mounting section in which a battery serving as a power source for the motor can be attached and detached by sliding the battery in a sliding direction; the battery mounting portion is provided on an upper wall of the motor accommodating portion so as to overlap with the motor and the polishing surface when viewed from above; The battery mounting section is configured so that the battery can be mounted by sliding the battery in a direction from rear to front relative to the battery mounting section. Belt sandals. [Aspect 1-15] A belt sander to which the battery is detachably attached. [Aspect 2-1] Belt sandals, An electric motor; a housing that accommodates the motor; a belt driving unit including a driving roller rotated by the motor and a driven roller, the belt driving unit configured to drive an endless sanding belt stretched between the driving roller and the driven roller, a belt drive unit provided below the motor, the sanding surface being defined by the underside of the sanding belt; and a belt drive unit, the belt drive unit being provided below the motor, the belt drive unit being provided below the motor, the sanding surface being defined by the underside of the sanding belt, the belt drive unit being provided below the motor ... a first switch disposed in the housing, the first switch being configured to be manually operable by a user and including a first switch operating portion movable between a first on position that turns the first switch on and a first off position that turns the first switch off; a second switch disposed in the housing, configured to be manually operable by a user, and including a second switch operating portion movable between a second on position that turns the second switch on and a second off position that turns the second switch off; the first switch and the second switch are momentary switches, The motor is configured to be driven when the first switch and the second switch are in an on state, and to be stopped when at least one of the first switch and the second switch is in an off state; and a first lock switch disposed on the housing and configured to maintain the first switch operating portion in the first on position; and a second lock switch disposed on the housing and configured to maintain the second switch operating portion in the second on position. [Aspect 2-2] the housing includes a motor accommodating portion that accommodates the motor, and a grip portion that is connected to the motor accommodating portion and extends rearward from the motor accommodating portion, The second switch operation unit is a grip portion provided with the gripping portion and having a shape that protrudes upward from the gripping portion when the gripping portion is in the second off position; The grip portion is configured to move from the second off position to the second on position when pressed against the grip portion. [Aspect 2-3] The second lock switch is provided on the housing so as to move in a direction intersecting with the moving direction of the second switch operating portion. [Aspect 2-4] The first lock switch and the second lock switch are provided on the same surface of the housing. [Aspect 2-5] The second lock switch is provided below the first lock switch. [Aspect 2-6] The first lock switch is a lock-off position that engages with the first switch operating part in the first off position and restricts the first switch operating part from moving to the first on position; The switch is configured to be movable to a locked-on position, and to engage with the first switch operating portion in the first on position to restrict the first switch operating portion from moving to the first off position. [Aspect 2-7] the first switch includes a first biasing member that biases the first switch operating portion, which has been moved to the first on position, so as to return the first switch operating portion to the first off position; The second switch includes a second biasing member that biases the second switch operating portion, which has been moved to the first on position, so as to return the second switch operating portion to the second off position. [Aspect 2-8] the grip portion extends rearward and downward from the motor housing portion, The first switch operation unit is the second switch is provided on the grip portion between the second switch and the motor accommodating portion, and has a shape that protrudes downward from the grip portion when the second switch is in the first off position; The grip portion is configured to move from the first off position to the first on position when pulled. [Aspect 2-9] an upper wall of the motor accommodating portion is substantially parallel to the polishing surface; The second switch operation portion is provided below an imaginary plane including the upper wall. [Explanation of symbols]

[0157] 1: belt sander, 10: housing, 11: main body housing, 11L: left main body housing, 11R: right main body housing, 12: first part, 121: top wall, 122: front wall, 123: side wall, 124: rear wall, 13: second part, 131: top wall, 133: side wall, 14: handle, 14L: left wall, 14R: right wall, 142: support wall, 144: opening, 145L: opening, 145R: opening, 146: recess, 146a: first flange, 146b: second flange, 147: opening, 149: opening, 149L: protrusion, 149R: protrusion, 15: controller housing, 16: side Housing, 161: Fan housing, 162: Gear cover, 163: Belt cover, 165: Air outlet, 140: Exhaust nozzle, 150: Suction nozzle, 17: Front handle, 171: Arm, 172: Base end, 173: Tip, 175: Grip, A4: Rotating shaft, 18: Rotating part, 19: Dust collection port, 2: Motor, 21: Motor body, 22: Shaft, A3: Rotating shaft, 3: Fan, 31: Guide plate, 32: Baffle plate, 4: Battery mounting part, 41: Mounting surface, 42: Guide rail, 44: Power terminal, 46: Signal terminal, 47: Lock receiving hole, 5: Controller, 6: Belt drive unit, 61: Drive roller, 62: Driven roller, A1, A2: Rotating shaft, 64: Support frame, 8: Switch mechanism, 80: First switch, 81: First switch operating unit, 811: Base, 812: Contact portion, 814: Boss portion, 815: Protrusion portion, 818: Urging member, 82: First main switch, 821: Main body portion, 822: Plunger, 85: First lock switch, 851: Operating shaft portion, 851L, 851R: Operating portion, 853: Lock-off engaging portion, 854: Recessed portion, 854L, 854R: Restricting wall, 855L, 855R: Lock-on engaging portion, 85 8: biasing member, 859: holding portion, 90: second switch, 91: second switch operating portion, 911: base portion, 911L: left wall portion, 912: abutment portion, 915: shaft hole, 916: rotating shaft, 917: opening, 918: torsion spring, 918f: arm, 92: second main switch, 921: main body portion, 922: actuator, 95: second lock switch, 951: operating portion, 952: flange portion, 953: stepped pin, 954: locking portion, 958: biasing member, 35: power transmission portion, 39: dial, 101: partition wall, 102: wall portion, 191: first flow path, 192: second flow path,200: dust box, 210: first nozzle, 212: O-ring, 220: second nozzle, 222: O-ring, 230: container part, 231: upper surface, 232: rear wall, 233: side, 234: lower surface, 235: window part, 240: nozzle connection part, 240L: left nozzle part, 240R: right nozzle part, 241: partition wall, 242: groove part, 243: rear end part, 244: O-ring, 245: engagement part, 246: nut, 247: plate, 250: main body part, 253: front end part, 258: cylindrical part, 260: filtering member, 261: opening, 262: frame, 265: Grounding member, 270: Detachable part, 271: Mounting screw, 272: Knob, 273: Shaft, 274: Front end, 281: First space, 282: Second space, 300: Battery, 305: Locking member, 310: Case, 311: Protrusion, 312: Top surface, 313: Side surface, 314: Front surface, 320: Mounting part, 321: Mounting surface, 322: Rail receiving part, 324: Power terminal, 326: Signal terminal, B: Sanding belt, B1: Sanding surface, F1, F2: Air flow, P1, P2: Virtual plane, R1, R2, R3, R4: Rotation position,

Claims

1. A dust box detachable from a belt sander, the dust box comprising: a belt drive unit configured to rotate an endless sanding belt; and a housing accommodating a dust collection fan and an electric motor that drives the belt drive unit, wherein the housing has an exhaust nozzle that exhausts dust generated by a processing operation from inside the housing by rotation of the dust collection fan; and a suction nozzle that sucks air from the dust box into the housing; The dust box is a first nozzle connectable to the discharge nozzle; a second nozzle connectable to the suction nozzle; a synthetic resin container portion connected to the first nozzle and the second nozzle; a filter member that separates air and dust, the filter member being provided within the container portion and dividing a space within the container portion into a first space communicating with the first nozzle and a second space communicating with the second nozzle; the container portion includes a nozzle connector connected to the first nozzle and the second nozzle, and a main body portion detachably attached to the nozzle connector, The filtering member is provided at the nozzle connection portion. Dustbin.

2. 2. The dust box according to claim 1, The filter member is provided in the container portion at a position closer to the second nozzle than to the first nozzle.

3. The dust box according to claim 1 or claim 2, the belt drive unit includes a drive roller rotated by the motor and a driven roller, and when the direction in which the rotation axis of the drive roller and the rotation axis of the driven roller extend is defined as the left-right direction, the direction in which the driven roller and the drive roller are aligned is defined as the front-rear direction, and the direction perpendicular to the left-right direction and the front-rear direction is defined as the up-down direction, a polishing surface is defined by the underside of the sanding belt; The dust box is When the belt sander is attached to the belt sander, the first nozzle is located below the second nozzle, The first space is a lower space within the container portion.

4. A dust box according to any one of claims 1 to 3, A dust box, wherein the first nozzle and the second nozzle open in the same direction.

5. A dust box according to any one of claims 1 to 4, The dust box, wherein the filtering member is a bag-shaped air filter having one open end.

6. 2. The dust box of claim 1, further comprising: The dust box includes a detachable portion for attaching and detaching the main body portion to the nozzle connecting portion.

7. A dust box according to any one of claims 1 to 6, At least a portion of the dust box is made of a conductive synthetic resin.

8. 8. The dust box according to claim 7, When the up-down direction is defined as the side of the belt sander where the belt drive unit is provided being the lower side and the opposite side being the upper side, When the dust box is attached to the belt sander, at least a portion of the container portion below the middle position in the up-down direction is formed from the conductive synthetic resin.

9. The dust box according to claim 7 or claim 8, further comprising: A dust box having an earthing member, one end of which is connected to the portion formed from the conductive synthetic resin and the other end of which is exposed to the outside of the dust box.

10. A belt sander to which the dust box according to any one of claims 1 to 9 is detachably attached.

11. 11. The belt sander of claim 10, An electric motor; Dust collection fan and a housing that accommodates the motor and the dust collection fan; a belt drive unit including a drive roller rotated by the motor and a driven roller, and configured to drive an endless sanding belt stretched between the drive roller and the driven roller; When the direction in which the rotation axis of the drive roller and the rotation axis of the driven roller extend is defined as the left-right direction, the direction in which the driven roller and the drive roller are aligned is defined as the front-rear direction, and the direction perpendicular to the left-right direction and the front-rear direction is defined as the up-down direction, the belt drive unit is disposed below the housing, The housing includes: an exhaust nozzle for exhausting dust generated by the processing operation from inside the housing; and a suction nozzle for sucking air from the dust box into the housing; a dust collection port provided behind the belt drive unit; an air outlet communicating with a space in which the dust collection fan is accommodated; a first flow path connecting the dust collection port and the discharge nozzle; a second flow path connecting the suction nozzle and the air outlet, the first flow path is provided to separate a space in the housing in which the motor and the dust collection fan are accommodated, and the second flow path, the second flow path communicates with a space in which the dust collection fan is accommodated, The dust collection fan rotates to generate an airflow that passes from the dust collection port through the first flow path to the discharge nozzle, and an airflow that passes from the suction nozzle through the second flow path to the air discharge port.

12. 12. The belt sander of claim 11, The suction nozzle and the discharge nozzle open rearward, The belt sander, wherein the discharge nozzle is provided below the suction nozzle.

13. A dust box detachable from a belt sander, comprising a belt drive unit configured to rotate an endless sanding belt, and a housing containing a dust collection fan and an electric motor that drives the belt drive unit, wherein the housing has an exhaust nozzle that exhausts dust generated by processing operations from within the housing by rotation of the dust collection fan, and a suction nozzle that sucks air from the dust box into the housing; The dust box is a first nozzle connectable to the discharge nozzle; a second nozzle connectable to the suction nozzle; a synthetic resin container portion connected to the first nozzle and the second nozzle; a filter member that separates air and dust, the filter member being provided within the container portion and dividing a space within the container portion into a first space communicating with the first nozzle and a second space communicating with the second nozzle; At least a part of the dust box is made of conductive synthetic resin. When the up-down direction is defined as the side of the belt sander where the belt drive unit is provided being the lower side and the opposite side being the upper side, When the dust box is attached to the belt sander, at least a portion of the container portion below a middle position in the up-down direction is formed of the conductive synthetic resin. Dustbin.

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