Long rod polishing device

First Embodiment

[0053]FIG. 1 is a perspective view when a dry wall sander 1 according to the first embodiment of the disclosure is viewed from a left side. FIG. 2 is a perspective view when the dry wall sander 1 is viewed from a right side. FIG. 3 is a right side view of the dry wall sander 1. FIG. 4 is a front view of the dry wall sander 1. FIG. 5 is a center vertical cross-sectional view of a front of a rear portion of the dry wall sander 1. FIG. 6 is a center vertical cross-sectional view of a rear of the rear portion of the dry wall sander 1. FIG. 7 is a center vertical cross-sectional view of a front portion of the dry wall sander 1. FIG. 8 is a cross-sectional view taken along a line B-B in FIG. 6. FIG. 9 is a cross-sectional view taken along a line A-A in FIG. 3. FIG. 10 is a drawing equivalent to FIG. 1 and illustrates the dry wall sander in a state where the rod portion 2 is at its shortest length.

[0054]The dry wall sander 1 includes a rod portion 2, a handle portion 4, which is disposed at the rear portion (second end portion) of the rod portion 2, and a head portion 8, which is coupled to the front end portion (first end portion) of the rod portion 2 via a suspension frame portion 6.

[0055]The rod portion 2 extends back and forth and includes a large-diameter pipe 10 as a first rod body and a small-diameter pipe 12 as a second rod body that slidably enters into the large-diameter pipe 10. Sliding of one of the large-diameter pipe 10 and the small-diameter pipe 12 to the other provides the rod portion 2 with a telescopic mechanism, making the rod portion 2 telescopic.

[0056]The small-diameter pipe 12 has a cylindrical shape and is mounted to a handle housing 14 as an outer wall of the handle portion 4. A flange tube 16 is fixed to the front end portion of the small-diameter pipe 12. The flange tube 16 has a flange portion on its front portion protruding from the front end of the small-diameter pipe 12 and contacting the inner surface of the large-diameter pipe 10. Meanwhile, an outer surface of a part other than the flange portion in the flange tube 16 contacts the inner surface of the small-diameter pipe 12. A hole radially inside the flange portion in the flange tube 16 expands forward.

[0057]The large-diameter pipe 10 is a pipe with two holes having a cylindrical first hollow portion 20 through which the small-diameter pipe 12 passes and a second hollow portion 22 having a “U” shape in cross section along the lower portion of the first hollow portion 20. The large-diameter pipe 10 is formed by extrusion of an aluminum material. Large-diameter pipe guide grooves 23 are formed on an outer surface (an adjacent portion of a partition wall separating the first hollow portion 20 from the second hollow portion 22) of the large-diameter pipe 10. The large-diameter pipe guide grooves 23 guide the sliding of the large-diameter pipe 10 in the front-rear direction or position the large-diameter pipe 10 in the up, down, right, and left directions.

[0058]To the rear end portion of the first hollow portion 20 in the large-diameter pipe 10, a cylindrical stop ring 24 in contact with or close to the outer surface of the small-diameter pipe 12 is fixed. The rear end of the second hollow portion 22 in the large-diameter pipe 10 is located forward with respect to the rear end of the first hollow portion 20. A lead wire guide 26 having a “U” shape in cross section is mounted to the lower side of the rear end portion of the first hollow portion 20 and on the rear side of the rear end of the second hollow portion 22.

[0059]The handle housing 14 is laterally halved and formed by fastening the left portion and the right portion combined with one another with screws 28.

[0060]The handle housing 14 includes a rod housing portion 30, a hump grip base portion 32, a grip portion 34, a battery mounting portion 36, and a joint holding portion 38. The rod housing portion 30 extends back and forth and houses the rod portion 2. The grip base portion 32 is located at the upper rear portion of the rod housing portion 30. The grip portion 34 having a “T” shape when viewed from the upper side projects rearward from the rear upper portion of the grip base portion 32. The battery mounting portion 36 is located at the rear of the rod housing portion 30. The joint holding portion 38 is located at the lower front side of the battery mounting portion 36 and expands toward the rear.

[0061]The grip portion 34 includes a grip portion main body 34a extending in the front-rear direction and an auxiliary grip portion 34b extending in both of the right and left sides at the rear end portion of the grip portion main body 34a.

[0062]To the joint holding portion 38, a tubular joint 40 is held. The joint 40 includes a space having an “S” shape in side view, and the space runs from between the rod housing portion 30 and the battery mounting portion 36 to the lower side of the battery mounting portion 36. The joint 40 is laterally halved and combined by causing screws 41 to pass through the left portion and the right portion combined with one another. The rear end portion of the small-diameter pipe 12 is coupled to the upper end portion, which opens forward, of the joint 40. To the lower end portion, which opens rearward, of the joint 40, a dust collection hose 42 (only the distal end portion is illustrated in FIG. 3 and FIG. 6) of a dust collector is coupled (dust collection hose coupling portion, dust collector coupling portion).

[0063]The front portion of the rod housing portion 30 is formed into a cylindrical shape and exposed outside (see FIG. 5). At a boundary between an upper surface of the rear portion of the rod housing portion 30 and a lower surface of the grip base portion 32, upper rod housing portion ribs 44, which project inward from both of the right and left sides and extend in the front-rear direction, are stood (see FIG. 6 and FIG. 8). Both upper rod housing portion ribs 44 are positioned above the rod portion 2 and have distal ends in contact with one another. The rear end portion of the upper rod housing portion rib 44 is formed into a “7” shape in cross section, and a band 46 that holds the rear end portion of the small-diameter pipe 12 is mounted to the inside of the upper rod housing portion ribs 44. The rear upper portion of the band 46 is in contact with or adjacent to the front upper portion of the joint 40. Lower rod housing portion ribs 48, which project inward from both of the right and left sides and extend in the front-rear direction, are stood at the lower portion of the rod housing portion 30 and the side portions at the lower end portion of the rod portion 2 (see FIG. 8). The distal end portions of both of the lower rod housing portion ribs 48 enter into the corresponding large-diameter pipe guide grooves 23 on the rod portion 2. A rod housing portion bottom portion 49 is located under the lower rod housing portion ribs 48 and on the upper side of the lower screw 28.

[0064]At the front end portion of the rod housing portion 30, a screw groove portion 52 including a first screw groove 50 is located on the outer surface of the rod housing portion 30. A fixing pipe 54 is located inside the screw groove portion 52. The outer surface at the rear portion of the fixing pipe 54 contacts the inner surface of the screw groove portion 52, and the inner surface of the fixing pipe 54 contacts the outer surface of the large-diameter pipe 10. A ring-shaped fixing pipe projecting portion 56 projecting radially outward with respect to the other part is formed on the front portion of the fixing pipe 54. The fixing pipe projecting portion 56 has a first tapered surface 58 expanding rearward on its front portion. An outer pipe 60 is located outside the screw groove portion 52. On the inner surface of the outer pipe 60, a second screw groove 62 that enters into the first screw groove 50 on the screw groove portion 52, and a second tapered surface 64 located into a ring shape at the front of the second screw groove 62 so as to be tapered forward are formed.

[0065]When a user rotates the outer pipe 60 in a direction of the forward movement of the outer pipe 60, the second tapered surface 64 is away from the first tapered surface 58 of the fixing pipe 54, thus releasing the press of the fixing pipe 54 against the large-diameter pipe 10. The large-diameter pipe 10 in this state is relatively movable back and forth with respect to the small-diameter pipe 12, and the length of the rod portion 2 is changeable. When a desired length of the rod portion 2 is obtained, the user rotates the outer pipe 60 in the retreat direction. Then, the second tapered surface 64 contacts the first tapered surface 58 of the fixing pipe 54 and presses the fixing pipe 54 radially inward. The fixing pipe 54 presses against the large-diameter pipe 10 inside the fixing pipe 54 to fix the large-diameter pipe 10. Thus, the outer pipe 60 and the fixing pipe 54 (and the screw groove portion 52) can fix the rod portion 2 at any given expansion/contraction position.

[0066]When the rod portion 2 is at its short length position, the large-diameter pipe 10 passes through between the handle housing 14 (rod housing portion 30) and the small-diameter pipe 12.

[0067]When the rod portion 2 is at its longest length position, the stop ring 24 on the large-diameter pipe 10 abuts on the flange portion at the flange tube 16 of the small-diameter pipe 12. At this time, the rear end portion of the large-diameter pipe 10 is positioned inside the outer pipe 60.

[0068]Meanwhile, when the rod portion 2 is at its shortest length position (FIG. 10), the rear end of the large-diameter pipe 10 abuts on the rear end portion of the upper rod housing portion ribs 44. At this time, the suspension frame portion 6 is positioned on the front side of the outer pipe 60.

[0069]The handle portion 4 includes the above-described handle housing 14 and joint 40, a terminal base plate 70, a switch 72, a trigger 74, a lock-on member 76, a trigger lock member 78, a speed adjustment dial 80, a controller 82, and a wireless communication adapter insertion portion 84. The terminal base plate 70 is held to the battery mounting portion 36 of the handle housing 14. The switch 72 is held into the front end portion of the grip portion 34. The trigger 74 extends back and forth and is located under the switch 72 with the rear portion exposed. The lock-on member 76 is located on the upper side of the trigger 74. The trigger lock member 78 is located on the front side of the trigger 74. The speed adjustment dial 80 is held to the upper portion of the grip base portion 32. The controller 82 is held to the front portion of the grip base portion 32. The wireless communication adapter insertion portion 84 is formed in the grip base portion 32.

[0070]To the terminal base plate 70, a battery 86 as an electric power supply source having a rectangular parallelepiped (quadrangular prism) shape rechargeable by a charger (not illustrated) is mountable.

[0071]The terminal base plate 70 includes a pair of respective power supply terminals 88, which project rearward and extend in the right-left direction, and a communication terminal 90.

[0072]Meanwhile, the battery 86 includes battery power supply terminals 92 and a battery communication terminal 94 located corresponding to these power supply terminals 88 and communication terminal 90. The battery power supply terminals 92 and the battery communication terminal 94 are located in terminal grooves formed in a direction similar to a longest side J of the battery 86.

[0073]The battery 86 includes a battery button 95 used to remove the battery 86. The battery button 95 is integrated with a battery nail (not illustrated) lockable to the battery mounting portion 36. The battery button 95 is slidable from a state of this battery nail projecting outward to a state of the battery nail retreating inside and is biased by an elastic body (not illustrated) such that this battery nail enters the projecting state.

[0074]The battery 86 has the longest side J in the right-left direction, and sliding the battery 86 leftward from the right side of the battery mounting portion 36 with the battery button 95 on the right side mounts the battery 86 to the battery mounting portion 36. At this time, the projecting battery nail locks to the battery mounting portion 36. The power supply terminals 88 are coupled to the battery power supply terminals 92.

[0075]Further, the communication terminal 90 is coupled to the battery communication terminal 94.

[0076]The mounted battery 86 is slid rightward to be removed in a state where the slide operation is performed such that the battery button 95 moves rearward and the lock of the mounted battery 86 to the battery mounting portion 36 is released.

[0077]The battery 86 is an 18 V-output lithium-ion battery for general purpose usable for another electric power tool and a similar tool.

[0078]The switch 72 changes its switching state by entering a plunger 97 into a switch main body 96 to be returnable by an elastic force and is installed such that the plunger 97 is disposed on the lower side. When the plunger 97 (exceeding a backlash) enters the switch main body 96, the switching state of the switch 72 turns from off to on.

[0079]By supporting a shaft (not illustrated) in the right-left direction disposed at a center trigger shaft portion 98 with the handle housing 14, the trigger 74 is configured to be swingable. A spring 99 is bridged between the top surface of the trigger 74 and the handle housing 14. When the spring 99 has a natural length or is in a stretched state close to the natural length, the rear portion of the top surface of the trigger 74 is adjacent to the plunger 97 of the switch 72. When the trigger 74 is pulled upward, the spring 99 enters a compressed state, the rear portion of the top surface of the trigger 74 contacts the plunger 97 and presses the plunger 97.

[0080]The lock-on member 76 extends in the right-left direction and has respective right and left end portions exposed as lock-on buttons 100. When the user pushes (turns on) any of the right and left lock-on buttons 100 while pulling the trigger 74, the moved lock-on member 76 hangs to the center of the trigger 74 and stops the trigger 74 attempting to return downward when the pulling is stopped, thus maintaining the pulling state. Accordingly, during the on operation of the lock-on button 100, the switch 72 is maintained on. When the user further pulls the trigger 74 upward, the lock-on member 76 returns to the original position and the maintained pulling state of the trigger 74 is released; therefore, the maintained on-state of the switch 72 is released.

[0081]The trigger lock member 78 extends in the right-left direction and both of the right and left end portions are exposed as trigger lock buttons 101. When the user pushes (turns on) the left trigger lock button 101 while not pulling the trigger 74, the trigger lock member 78 hangs to the front end portion of the trigger 74 and stops the trigger 74 whose rear portion attempts to move up (the front portion moves down) by being pulled, thus restricting the pulling operation of the trigger 74. Meanwhile, when the user pushes (turns off) the right trigger lock button 101, the trigger lock button 101 that has returned leftward releases the restriction of the pulling operation on the trigger 74.

[0082]The speed adjustment dial 80 is disposed such that an upper portion of a curved surface in a disc-shaped dial portion 102 is exposed. The user can change the switching state of the speed adjustment dial 80 by the operation of the dial portion 102. The switching state of the speed adjustment dial 80 corresponds to a speed setting.

[0083]The controller 82 includes a controller case 104 having an open lid box shape opening upward and a control circuit board 106 held at the upper portion of the controller case 104.

[0084]The controller 82 is held by a forward first rib 108 having a “J” shape in cross section and a rearward second rib 110 having an inverted “J” shape in cross section integrally formed with the upper rod housing portion ribs 44. A wiring slit 112 is disposed at a part at the rear of the second rib 110 in the upper rod housing portion ribs 44. A wiring groove 114 having a “C” shape in side view is formed at a part from the lower side of the front end portions of the upper rod housing portion ribs 44 to the wiring slit 112 on the left inner wall of the handle housing 14. Further, slit-shaped ventholes 116 are formed on parts on both side portions of the controller 82 in the handle housing 14.

[0085]The control circuit board 106 is electrically coupled to the terminal base plate 70 (communication terminal 90) of the battery mounting portion 36, the switch 72, and the speed adjustment dial 80 with a lead wire (not illustrated).

[0086]The control circuit board 106 includes a display unit 118 having the upper portion (including four LEDs) exposed from the top surface of the handle housing 14. The control circuit board 106 causes the display unit 118 to display a remaining amount of the battery 86 coupled to the terminal base plate 70 and a magnitude of a motor load.

[0087]Further, rod portion lead wires 120 extending to the head portion 8 are coupled to the control circuit board 106. The rod portion lead wires 120 are formed of a bundle of a plurality of single lead wires (see FIG. 9), and a part of the single lead wires (control lead wires) are coupled to the control circuit board 106. Another part of the single lead wires (power supply lead wires) are coupled to the terminal base plate 70 (power supply terminals 88). That is, the rod portion lead wires 120 are coupled to the handle portion 4. The rod portion lead wires 120 are bundled as one just before the wiring slit 112, pass through the wiring slit 112 and the wiring groove 114. The rod portion lead wires 120 enter a lead wire housing portion P which is a space between the lower portions of both of the lower rod housing portion ribs 48 and the small-diameter pipe 12 and the rod housing portion bottom portion 49. The rod portion lead wires 120 make a U-turn (bend) after once heading toward the rear and head toward the front, and then enter the second hollow portion 22 (lead wire housing space) in the large-diameter pipe 10 via the lead wire guide 26. Note that the illustrations of the rear end portions (branches of the control lead wires and the power supply lead wires) of the rod portion lead wires 120 are omitted.

[0088]The lead wire housing portion P houses the rear portions of the rod portion lead wires 120. The lead wire housing portion P is located radially outside (lower side) of the rod housing portion 30 and the rod portion 2 (small-diameter pipe 12). The lead wire housing portion P has a wall portion Q as a part of the front wall of the joint 40 at its rear end portion. The wall portion Q is located away rearward with respect to the rear end of the large-diameter pipe 10 when the rod portion 2 is in a contracted state where the rod portion 2 is shortest and the large-diameter pipe 10 is fully housed in the rod housing portion 30. The lead wire housing portion P has a width (a size in the right-left direction) larger than a thickness (diameter) of the rod portion 2 (large-diameter pipe 10).

[0089]The wireless communication adapter insertion portion 84 is formed so as to be depressed in a box shape inward from the outer surface on the right portion of the handle housing 14, and a wireless communication adapter 122 (illustrated only in FIG. 3) is insertable into the wireless communication adapter insertion portion 84. When inserted, the wireless communication adapter 122 is electrically coupled to a controller for wireless communications (not illustrated) mounted on the control circuit board 106 in the controller 82.

[0090]The wireless communication adapter 122 performs wireless communications with the above-described dust collector as another accessory facility. The wireless communications coordinate a start operation and a stop operation of the dust collector with a start operation and a stop operation of the dry wall sander 1.

[0091]An association (pairing) for allowing the wireless communications is preliminarily performed between the wireless communication adapter 122 and a dust collector side wireless communication adapter mounted to the dust collector. The user pushes a button on the dust collector side wireless communication adapter and operates a button (not illustrated) on the wireless communication adapter 122 within a predetermined period for pairing.

[0092]When the switch 72 turns on at the completion of pairing and the dry wall sander 1 starts, start information indicative of the start is transmitted from the wireless communication adapter 122 to the dust collector. Accordingly, the dust collector automatically starts based on the reception of this start information by the dust collector side wireless communication adapter. The wireless communication state is notified to the user by a lighting state of a lamp disposed on the wireless communication adapter 122.

[0093]The suspension frame portion 6 includes an outer frame 124 and an inner frame 126. The outer frame 124 is branched into two to the right and left mounted to the distal end portion of the large-diameter pipe 10. The inner frame 126 has a rectangular shape in top view coupled into the distal end portions of the outer frame 124 to be rotatable around an axis in the right-left direction.

[0094]The inner frame 126 has a “V” shape both in front view and rear view, and the head portion 8 is located between the respective lowest positions of the inner frame 126. The head portion 8 is coupled to the inner frame 126 to be rotatable around the axis in the front-rear direction.

[0095]The head portion 8 can change the posture around two axes in total in the right-left direction and the front-rear direction with the suspension frame portion 6. The head portion 8 changes the posture mainly around the axis in the right-left direction with the comparatively large outer frame 124, and supplementarily changes the posture around the axis in the front-rear direction with the comparatively small inner frame 126.

[0096]The head portion 8 includes a bell-shaped head portion outer housing 130, a motor housing 132 located inside the head portion outer housing 130, a gear housing 134 mounted to the lower side of the motor housing 132 having a tubular upper portion and a disc-shaped lower portion, a ring-shaped bumper 136 mounted outside the lower end portion of the gear housing 134, an electric motor 138 as a driving source held to the motor housing 132, a planetary gear mechanism 140 held to the upper portion of the gear housing 134, a spindle 142 located at the lower portion of the gear housing 134, and a disc-shaped pad 146 mounted to the spindle 142 with a screw 144 and having the upper portion located in the bumper 136.

[0097]The head portion outer housing 130, the motor housing 132, and the gear housing 134 constitute a head portion housing 147.

[0098]Boss portions 148 are formed at the front and rear of the head portion outer housing 130. The suspension frame portion 6 (inner frame 126) is coupled to the respective boss portions 148 to be relatively rotatable via bolts 150.

[0099]At the front upper portion of the head portion outer housing 130, a first hose coupling portion 152 projecting into a cylindrical shape upward with respect to the other parts is formed. A front end portion of a first hose 154 is coupled to the first hose coupling portion 152 such that the first hose 154 is coupled to the rear upper portion of the suspension frame portion 6 to communicate with the first hollow portion 20 in the large-diameter pipe 10. The first hose 154 is laid out so as to maintain an inverted “U” shape in side view.

[0100]An opening is provided under the boss portion 148 at the rear of the head portion outer housing 130.

[0101]The motor housing 132 is laterally halved and is combined with a plurality of (seven) screws 156.

[0102]The motor housing 132 includes a cylindrical motor housing main body 158 and a tubular portion 160 projecting into a “J” shape in side view rearward and downward from the rear portion of the motor housing main body 158.

[0103]The tubular portion 160 comes out from the opening at the rear of the head portion outer housing 130.

[0104]A second hose 162 has a front end portion coupled to the rear upper end portion of the tubular portion 160. The second hose 162 is coupled to the rear lower portion of the suspension frame portion 6 in a state of communicating with the second hollow portion 22 in the large-diameter pipe 10. The second hose 162 is laid out so as to maintain an inverted “J” shape in side view. The front portions of the rod portion lead wires 120, which come out from the controller 82 of the handle portion 4 and pass through the rod portion 2, are located inside the second hollow portion 22 in the large-diameter pipe 10, the second hose 162, and the tubular portion 160. At a part of the rod portion lead wires 120 located in the tubular portion 160, a pair of (male and female) connectors 164 that are freely coupled and separated through attachment and removal are interposed.

[0105]The lower end portion of the motor housing main body 158 is fitted to an opening on the upper end portion of the gear housing 134. Entering a top surface side edge of the lower portion of the gear housing 134 into an opening on the lower end portion of the head portion outer housing 130 mounts the gear housing 134 to the head portion outer housing 130 together with the motor housing 132.

[0106]The electric motor 138 is a DC-driven brushless motor and is held into the upper portion of the motor housing main body 158.

[0107]The electric motor 138 includes a stator 166 and a rotor 168. The controller 82 controls the electric motor 138.

[0108]The stator 166 includes a stator core 170, an upper insulating member 172 and a lower insulating member 174 disposed at the front and rear of the stator core 170, a plurality of (here, six) drive coils 176 each wound around the stator core 170 via the upper insulating member 172 and the lower insulating member 174, and a ring-shaped short-circuit member 177 that short-circuits the mutual drive coils 176 in a predetermined coupling aspect and is electrically coupled to the rod portion lead wires 120 (power supply lead wires). A sensor circuit board 178 is fixed to the upper insulating member 172.

[0109]The rotor 168 is located inside the stator 166 (inner rotor type). The rotor 168 includes a motor shaft 180 as a rotation drive shaft, a tubular rotor core 182 located at the peripheral area of the motor shaft 180, a plurality of (four) permanent magnets 184, and a plurality of sensor permanent-magnets (not illustrated). The permanent magnets 184 are located inside the rotor core 182, has a plate shape extending up and down, and are arranged whose polarities are changed in alternation in the circumstantial direction. The plurality of sensor permanent-magnets (not illustrated) are radially located on the upper side (sensor circuit board 178 side) of these members. A pinion 185 is mounted to the lower end portion of the motor shaft 180. The rotor core 182, the permanent magnets 184, and the sensor permanent-magnets constitute a rotor assembly.

[0110]The sensor circuit board 178 includes a plurality of (three) sensors (rotation detecting elements) (not illustrated) that detect a rotation angle (rotation position) of the rotor 168 (motor shaft 180) with the sensor permanent-magnets. The sensor circuit board 178 is electrically coupled to the controller 82 with the rod portion lead wires 120 (signal lead wires) entered from the tubular portion 160 in the motor housing main body 158. The controller 82 (control circuit board 106) includes six switching elements (not illustrated). The respective switching elements are disposed corresponding to any of the drive coils 176 for switching of the corresponding drive coils 176. The controller 82 (control circuit board 106) includes a microcomputer (not illustrated) that controls the switching of the switching elements. The control circuit board 106 includes various elements controlling the electric motor 138.

[0111]An upper bearing 192 that rotatably supports the motor shaft 180 is disposed on the upper side of the sensor circuit board 178. The upper bearing 192 is held to the motor housing 132.

[0112]A lower bearing 194 that rotatably supports the motor shaft 180 is disposed on the upper side of the pinion 185. The lower bearing 194 is fixed at the lower center of the motor housing 132.

[0113]Between the lower bearing 194 and the rotor core 182 of the motor shaft 180, a cooling fan 196 is located. The fan 196 is fixed to the motor shaft 180 to feed air in a centrifugal direction by its rotation (centrifugal fan). The fan 196 is located in the center of the motor housing 132. Inner exhaust ports (not illustrated) are formed at centers on the right and left of the motor housing 132. Outer exhaust ports 198 are formed at centers on the right and left of the head portion outer housing 130 and outside the respective inner exhaust ports. The inner exhaust ports and the outer exhaust ports 198 are positioned radially outward from the fan 196, and the airflow from the fan 196 is efficiently discharged.

[0114]Meanwhile, intake ports 199 (FIG. 7) are formed on the lower portion of the tubular portion 160 of the motor housing 132.

[0115]The planetary gear mechanism 140 has the gear housing 134 as an outer wall and includes two-staged planetary gear trains where respective axes in the up-down direction (including a center axis of the motor shaft 180 and a center axis of the spindle 142) are located at the center. The planetary gear mechanism 140 decelerates the rotation of the motor shaft 180 and transmits the rotation to the spindle 142. That is, the planetary gear mechanism 140 includes an upper planetary gear train 200 (a deceleration mechanism on the first stage), a lower planetary gear train 210 (a deceleration mechanism on the second stage), and an internal gear 220 shared by the upper planetary gear train 200 and the lower planetary gear train 210.

[0116]The upper planetary gear train 200 includes a plurality of (three) respective planetary gears 202 meshing with the pinion 185 and the internal gear 220 and one carrier 204 that rotatably supports all of the planetary gears 202 via a pin 203.

[0117]The lower planetary gear train 210 includes a plurality of (three) planetary gears 212, which each mesh with a diameter-reduced lower portion (sun gear) of the carrier 204 on the first stage and the internal gear 220, pins 213 of the planetary gears 212, and a carrier 214.

[0118]The rear end portion of the spindle 142 is mounted to the center of the carrier 214.

[0119]The spindle 142 is rotatably supported by a spindle upper bearing 222 and a spindle lower bearing 224. The spindle upper bearing 222 and the spindle lower bearing 224 are held to the gear housing 134.

[0120]The pad 146 is located below the motor housing 132.

[0121]A tip tool (not illustrated) such as a sandpaper is mounted to the lower surface of the pad 146. The lower surface of the pad 146 is configured as a polishing surface S where polishing is performed on a workpiece by a contact via the tip tool.

[0122]The pad 146 has a plurality of pad holes 230 in the up-down direction such that the pad holes 230 are arranged along an imaginary circle having a center identical to that of the pad 146. These pad holes 230 are aligned at equal intervals in the circumferential direction. The tip tool includes tip tool holes similar to the pad holes 230.

[0123]A gear housing hole 232 in the up-down direction is formed at the front lower portion of the gear housing 134. A space is positioned above the gear housing hole 232 between the front portion of the head portion outer housing 130 and the front portion of the motor housing 132, and the first hose coupling portion 152 is positioned upward with respect to the space.

[0124]With the dry wall sander 1, the longest side J of the battery 86 mounted to the battery mounting portion 36 has the direction, as illustrated mainly in FIG. 6 and FIG. 10, so as to form an angle with respect to a second imaginary straight line K (up-down direction). The second imaginary straight line K is perpendicular to a center axis M (an imaginary axis in the front-rear direction and including a part coming out from the rod portion 2) of the rod portion 2 and a first imaginary straight line L (right-left direction) perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0125]More specifically, the direction of the longest side J of the battery 86 has the angle of 90° with respect to the second imaginary straight line K and is in the right-left direction.

[0126]The direction of the polishing surface S of the pad 146 changes according to the posture change of the head portion 8 by the suspension frame portion 6. When not in contact with the workpiece, the posture of the head portion 8 with respect to the rod portion 2 is determined by a gravitation acting on the head portion 8. As long as the axis in the right-left direction is horizontal, the inner frame 126 is horizontally positioned and the polishing surface S of the pad 146 is also horizontally positioned. The posture change of the head portion 8 is mainly around the axis in the right-left direction. Accordingly, to determine the first imaginary straight line L, the posture change of the head portion 8 around the axis in the subsidiary front-rear direction needs not to be considered. Then, whichever the direction of the polishing surface S of the pad 146 is, the first imaginary straight line L parallel to the polishing surface S of the pad 146 extends in the right-left direction.

[0127]Additionally, the mounted battery 86 intersects with the center axis M of the rod portion 2, in more detail, the center of the battery 86 in the up-down direction intersects with the center axis M.

[0128]Further, the center of the battery 86 mounted to the battery mounting portion 36 in the second imaginary straight line K direction (up-down direction) overlaps with the center axis M of the rod portion 2 when viewed from leftward or rightward and overlaps in the first imaginary straight line L direction (right-left direction).

[0129]In addition, the mounted battery 86 is located between the grip portion 34 on the upper side and the joint 40 on the lower side in the up-down direction.

[0130]The dry wall sander 1 operates, for example, as follows.

[0131]That is, the user slides the charged battery 86 with the longest side J in the right-left direction leftward from the right side of the battery mounting portion 36 to mount the battery 86 to the battery mounting portion 36. The longest side J of the mounted battery 86 runs in the right-left direction, the direction perpendicular to the second imaginary straight line K.

[0132]Additionally, the user loosens the outer pipe 60 to change the expansion/contraction state of the rod portion 2 and fastens the outer pipe 60 with the rod portion 2 having a desired length, thus adjusting the length of the rod portion 2.

[0133]When the user pulls trigger 74 with the trigger lock member 78 off to turn on the switch 72, the control circuit board 106 in the controller 82 supplies the electric power from the battery 86 to the electric motor 138 via the battery power supply terminals 92 and the power supply terminals 88 and the rod portion lead wires 120 (power supply lead wires), thus rotatably driving the motor shaft 180. Hence, the trigger 74 switches the electric motor 138 between on and off via the switch 72 and is a switch operating unit that operates the electric motor 138 between on and off, and the trigger 74 and the switch 72 constitute main switches of the electric motor 138.

[0134]According to the rotation position of the rotor 168 obtained by a magnetic sensor of the sensor circuit board 178, the switching elements in the controller 82 (control circuit board 106) switch the respective drive coils 176 to rotate the rotor 168 (motor shaft 180).

[0135]There may be a case where the control on the electric motor 138 causes the control circuit board 106 to emit heat. The heat is transmitted to the controller case 104 and dissipated, or the control circuit board 106 is cooled by external air introduced from the ventholes 116 by natural convection.

[0136]The rotational force of the motor shaft 180 is decelerated by the planetary gear mechanism 140 and transmitted to the spindle 142, thus moving (rotating) the pad 146 at the distal end of the spindle 142.

[0137]Gripping the grip portion 34 and the rod portion 2 causes the thus moving pad 146 to be pressed against the workpiece and move for a machining such as the polishing on the surface of the workpiece.

[0138]The workpiece is, for example, a dry wall (plaster board) applied on a wall or a ceiling of an architectural structure, and in more detail, a putty used to fill a screw-hole and a seam during a construction of the dry wall. The putty coming out from another part in the dry wall is flattened by polishing.

[0139]To polish a low position of a wall, the user orients the rod portion 2 in the right-left direction of the user. The user holds the auxiliary grip portion 34b extending in the up-down direction viewed from the user, and the large-diameter pipe 10 or the front portion of the rod housing portion 30 with the pad 146 orienting the wall on the side apart from the user.

[0140]To polish a high position of a wall or a ceiling, the user orients the rod portion 2 in the up-down direction of the user. The user holds the grip portion 34 (the grip portion main body 34a in the up-down direction of the user or the auxiliary grip portion 34b in the right-left direction of the user) and the large-diameter pipe 10 or the front portion of the rod housing portion 30 with the pad 146 orienting the wall or the ceiling on the side apart from the user.

[0141]In both cases, the suspension frame portion 6 adjusts the direction of the head portion 8 with respect to the rod portion 2, that is, the direction of the pad 146 in a predetermined range.

[0142]The rotation of the motor shaft 180 rotates the fan 196 and exhausts the air from the inner exhaust ports and the outer exhaust ports 198, thus forming an airflow (wind) from the intake ports 199 to the outer exhaust ports 198. This airflow moves up inside the rear portion of the motor housing main body 158 and reaches the fan 196 in the center through the inside of the upper portion of the motor housing main body 158.

[0143]This airflow cools an internal mechanism of the head portion 8 such as the electric motor 138.

[0144]Especially, the airflow moving down from the inside of the upper portion of the motor housing main body 158 passes through the lower side of the sensor circuit board 178 of the electric motor 138 and between the stator 166 and the rotor 168, thus efficiently cooling the electric motor 138.

[0145]Further, when the switch 72 turns on, the controller for wireless communications mounted to the control circuit board 106 in the controller 82 controls the wireless communication adapter 122, and the wireless communications with the dust collector side wireless communication adapter start the dust collector.

[0146]The dust collector suctions the air to collect the dust as follows. That is, dust occurred around the pad 146 and the tip tool that appropriately rotate during a machining is introduced from the tip tool holes and the pad holes 230 to the first hose 154 through the gear housing hole 232, between the head portion outer housing 130 and the gear housing 134, and between the head portion outer housing 130 and the motor housing 132 (see the arrow G1 in FIG. 7). The dust introduced to the first hose 154 reaches the small-diameter pipe 12 from the first hollow portion 20 (dust passage) in the large-diameter pipe 10 (see the arrow G2 in FIG. 5). The dust that has reached the small-diameter pipe 12 is suctioned with the dust collection hose 42 via the joint 40 (see the arrow G3 in FIG. 6).

[0147]The above-described dry wall sander 1 includes the prismatic battery 86, the battery mounting portion 36 to which the battery 86 is mountable, the electric motor 138 driven by the electric power from the battery 86, the pad 146 having the polishing surface S and moved by the driving force from the electric motor 138, and the rod portion 2 having the front end portion to which the pad 146 is coupled via the spindle 142, the gear housing 134, the head portion outer housing 130, and the suspension frame portion 6. The longest side J of the battery 86 mounted to the battery mounting portion 36 has a direction so as to form an angle with respect to the second imaginary straight line K. The second imaginary straight line K is perpendicular to both of the center axis M of the rod portion 2 and the first imaginary straight line L perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0148]Accordingly, the battery 86 lies down with respect to the second imaginary straight line K projecting outward and therefore the dry wall sander 1 becomes further compact while the battery 86 is mounted. Thus, the battery 86 is less likely to hinder.

[0149]The direction of the longest side J of the battery 86 mounted to the battery mounting portion 36 is identical to the direction of the first imaginary straight line L. Accordingly, the battery 86 runs along the first imaginary straight line L and the dry wall sander 1 to which the battery 86 is mounted becomes further compact.

[0150]Further, the center in the second imaginary straight line K direction (up-down direction) of the battery 86 mounted to the battery mounting portion 36 is on the center axis M of the rod portion 2 viewed from the first imaginary straight line L direction. Accordingly, the battery 86 is located so as not to project upward or downward so much with respect to the center axis M of the rod portion 2. The dry wall sander 1 is compact, and a weight balance with respect to the rod portion 2 is excellent, thereby further facilitating the handling.

[0151]Further, the handle portion 4 mounted to the end portion of the rod portion 2 on the side opposite to the pad 146 is provided. The handle portion 4 includes the grip portion 34 configured to be gripped by the user, and the joint 40 to which the dust collection hose 42 is couplable. The battery 86 mounted to the battery mounting portion 36 is located between the grip portion 34 and the joint 40 in the second imaginary straight line K direction (up-down direction). Accordingly, the battery 86 is mounted to the position where the battery 86 is less likely to interfere with the grip portion 34 and the dust collection hose 42.

[0152]The embodiment of this disclosure is not limited to the first embodiment, and the first embodiment appropriately includes, for example, the following modification examples.

[0153]The first imaginary straight line L (right-left direction) may be determined based on the grip portion 34 (auxiliary grip portion 34b).

[0154]The battery 86 may be mounted to the battery mounting portion 36 by sliding rightward from the left side.

[0155]The battery 86 may have a hexagonal prism shape or a similar shape.

[0156]Alternatively, the battery 86 may have a columnar shape. When a diameter of a bottom surface of the column is smaller than its height, the height of the column is defined as the longest side J of the battery 86. When the diameter of the bottom surface of the column is larger than its height, the diameter of the column is defined as the longest side J of the battery 86.

[0157]The number of stages of the planetary gear mechanism 140 may be one or may be three or more. Alternatively, a deceleration mechanism having another configuration may be used.

[0158]At least any of the number of installations, locations, sizes, and a similar specification of the venthole 116, the inner exhaust port, the outer exhaust port 198, and the intake port 199 are variously changeable.

[0159]As the fan 196, a fan having a configuration other than the centrifugal fan may be used.

[0160]The electric motor 138 may be an outer rotor type or may be a motor with brush.

[0161]The electric motor 138 may be located at the handle portion 4. In this case, the rotational force of the electric motor 138 may be passed through the inside of the rod portion 2 or may be mechanically transmitted with a shaft arranged with the rod portion 2.

[0162]The pad 146 may perform an eccentric motion via an eccentric spindle. The pad 146 may have a triangular shape.

[0163]At least any of a function, a location, a type, a configuration, and the number of various members or parts may be appropriately changed, for example, as follows. At least any of the battery nail and a dust collection nozzle is omitted, at least any of the numbers of various bearings, screws, and buttons is increased or decreased, a lever switch is used instead of the button, the pinion 185 is replaced by a belt and a pulley, the screw is configured as a rivet, the motor housing 132 and the gear housing 134 are integrated, the battery 86 is rechargeable in the battery mounting portion 36, and a disposable battery is used.

[0164]This disclosure is applicable to other long rod polishing devices such as a long rod polisher or a long rod grinder and a long rod concrete plane.

Second Embodiment

[0165]FIG. 11 is a drawing similar to FIG. 2 where a front portion is omitted in a dry wall sander 251 according to the second embodiment of the disclosure. FIG. 12 is a drawing similar to FIG. 3 where the front portion is omitted in the dry wall sander 251.

[0166]Excluding the number of and a location of battery mounting portions and the number of batteries, the dry wall sander 251 is configured similarly to the dry wall sander 1 according to the first embodiment. Hereinafter, identical reference numerals are given to parts configured similarly to those of the first embodiment and their descriptions are appropriately omitted.

[0167]The dry wall sander 251 includes a handle housing 264 that includes two battery mounting portions 286 in a handle portion 254.

[0168]The one battery mounting portion 286 is located on the right surface of the handle housing 264 and at the rear portion of the rod housing portion 30. The other battery mounting portion 286 is located on the left surface of the handle housing 264 and at the rear portion of the rod housing portion 30.

[0169]The batteries 86 are mountable to the respective battery mounting portions 286.

[0170]While the longest side J of the battery 86 is in the front-rear direction and the battery button 95 is on the front side, the battery 86 is mounted to the battery mounting portion 286 on the right side by sliding the battery 86 rearward from the front side of the battery mounting portion 286. At this time, a projecting battery nail locks to the battery mounting portion 286 on the right side.

[0171]Additionally, the battery power supply terminals 92 are coupled to the power supply terminals 88 located at the battery mounting portion 286 on the right side. Further, the communication terminal 90 located at the battery mounting portion 286 on the right side is coupled to the battery communication terminal 94.

[0172]While the battery mounting portion 286 on the right side is symmetrical to the battery mounting portion 286 on the left side with respect to the center axis M of the rod portion 2, the battery 86 is mounted to the battery mounting portion 286 on the left side by sliding the battery 86 rearward from the front side. The projecting battery nail locks to the battery mounting portion 286 on the left side, the power supply terminals 88 are coupled to the battery power supply terminals 92 located at the battery mounting portion 286 on the left side, and the communication terminal 90 located at the battery mounting portion 286 on the left side is coupled to the battery communication terminal 94.

[0173]With the two 18 V-batteries 86 mounted, the controller 82 can supply a 36 V-voltage to the electric motor 138 by series connection of the respective batteries 86.

[0174]With the dry wall sander 251, the longest sides J of the batteries 86 mounted to the battery mounting portions 286 have the direction so as to form an angle with respect to the second imaginary straight line K (up-down direction). The second imaginary straight line K is perpendicular to both of the center axis M of the rod portion 2 and the first imaginary straight line L (right-left direction) perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0175]More specifically, the direction of the longest sides J of the batteries 86 has the angle of 90° with respect to the second imaginary straight line K and is in the front-rear direction.

[0176]Further, the center of the battery 86 mounted to the battery mounting portion 286 in the second imaginary straight line K direction (up-down direction) overlaps with the center axis M of the rod portion 2 when viewed from leftward or rightward and overlaps in the first imaginary straight line L direction (right-left direction).

[0177]In addition, the mounted batteries 86 are located between the grip portion 34 on the upper side and the joint 40 on the lower side in the up-down direction.

[0178]The above-described dry wall sander 251 includes the prismatic batteries 86, the right and left battery mounting portions 286 to which the batteries 86 are mountable, the electric motor 138 driven by the electric power from the batteries 86, the pad 146 having the polishing surface S and moved by the driving force from the electric motor 138, and the rod portion 2 having the front end portion to which the pad 146 is coupled. The longest sides J of the batteries 86 mounted to the battery mounting portions286 have a direction so as to form an angle with respect to the second imaginary straight line K. The second imaginary straight line K is perpendicular to both of the center axis M of the rod portion 2 and the first imaginary straight line L perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0179]Accordingly, the batteries 86 lie down with respect to the second imaginary straight line K projecting outward and therefore the dry wall sander 251 becomes further compact while the batteries 86 are mounted. Thus, the batteries 86 are less likely to hinder.

[0180]The direction of the longest sides J of the batteries 86 mounted to the battery mounting portions 286 is identical to the direction of the center axis M of the rod portion 2. Accordingly, the batteries 86 run along the center axis M and the dry wall sander 251 to which the batteries 86 are mounted becomes further compact.

[0181]Further, the center in the second imaginary straight line K direction (up-down direction) of the batteries 86 mounted to the respective battery mounting portions 286 is on the center axis M of the rod portion 2 viewed from the first imaginary straight line L direction. Accordingly, the batteries 86 are located so as not to project upward or downward so much with respect to the center axis M of the rod portion 2, the dry wall sander 251 is compact, and a weight balance with respect to the rod portion 2 is excellent, thereby further facilitating the handling.

[0182]Further, the handle portion 254 mounted to the end portion of the rod portion 2 on the side opposite to the pad 146 is provided. The handle portion 254 includes the grip portion 34 configured to be gripped by the user, and the joint 40 to which the dust collection hose 42 is couplable. The batteries 86 mounted to the battery mounting portions 286 are located between the grip portion 34 and the joint 40 in the second imaginary straight line K direction (up-down direction). Accordingly, the batteries 86 are mounted to the positions where the batteries 86 are less likely to interfere with the grip portion 34 and the dust collection hose 42.

[0183]In addition, the batteries 86 two in total are mountable to the right and left battery mounting portions 286. Accordingly, compared with case where the one battery 86 is mounted, a higher voltage can be supplied, and this configuration allows the dry wall sander 251 to be driven at higher output.

[0184]Note that the second embodiment appropriately includes modification examples similar to those of the first embodiment.

[0185]With the two 18 V-batteries 86 mounted, the controller 82 may supply an 18 V-voltage to the electric motor 138 by parallel connection of the respective batteries 86. In this case, compared with the case where the one battery 86 is mounted, the capacity becomes double and the driving period becomes longer. Further, the controller 82 may switch a coupling aspect (series, parallel) of the respective batteries 86 based on a state of a dedicated switch.

[0186]In addition, the battery 86 may be mounted to at least one of the battery mounting portions 286 to be slid forward from the rear side.

Third Embodiment

[0187]FIG. 13 is a drawing similar to FIG. 2 where a front portion is omitted in a dry wall sander 301 according to the third embodiment of the disclosure. FIG. 14 is a drawing similar toFIG. 3 where the front portion is omitted in the dry wall sander 301.

[0188]Excluding a location of a battery mounting portion, the dry wall sander 301 is configured similarly to the dry wall sander 1 according to the first embodiment. Hereinafter, identical reference numerals are given to parts configured similarly to those of the first embodiment and their descriptions are appropriately omitted.

[0189]A battery mounting portion 336 is formed between the speed adjustment dial 80 and the display unit 118 at a top of a handle housing 314 in a handle portion 304 of the dry wall sander 301.

[0190]The battery 86 is mountable to the battery mounting portion 336. While the longest side J of the battery 86 is in the front-rear direction and the battery button 95 is on the front side, the battery 86 is mounted to the battery mounting portion 336 by sliding the battery 86 rearward from the front side of the battery mounting portion 336. At this time, a projecting battery nail locks to the battery mounting portion 336.

[0191]Additionally, the battery power supply terminals 92 are coupled to the power supply terminals 88 located at the battery mounting portion 336. Further, the communication terminal 90 located at the battery mounting portion 336 is coupled to the battery communication terminal 94.

[0192]With the dry wall sander 301, the longest side J of the battery 86 mounted to the battery mounting portion 336 has a direction so as to form an angle with respect to the second imaginary straight line K (up-down direction). The second imaginary straight line K is perpendicular to both of the center axis M of the rod portion 2 and the first imaginary straight line L (right-left direction) perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0193]More specifically, the direction of the longest side J of the battery 86 has the angle of around 60° with respect to the second imaginary straight line K and is in the front-rear direction.

[0194]The above-described dry wall sander 301 includes the prismatic battery 86, the battery mounting portion 336 to which the battery 86 is mountable, the electric motor 138 driven by the electric power from the battery 86, the pad 146 having the polishing surface S and moved by the driving force from the electric motor 138, and the rod portion 2 having the front end portion to which the pad 146 is coupled. The longest side J of the battery 86 mounted to the battery mounting portion 336 has a direction so as to form an angle with respect to the second imaginary straight line K. The second imaginary straight line K is perpendicular to both of the center axis M of the rod portion 2 and the first imaginary straight line L perpendicular to the center axis M and parallel to the polishing surface S of the pad 146.

[0195]Accordingly, the battery 86 lies down with respect to the second imaginary straight line K projecting outward and therefore the dry wall sander 301 becomes further compact while the battery 86 is mounted. Thus, the battery 86 is less likely to hinder.

[0196]Note that the third embodiment appropriately includes modification examples similar to those of the first embodiment or the second embodiment.

[0197]In the third embodiment, the battery 86 may be slid from the rear with respect to the battery mounting portion 336 to be mounted.