Dust collection system for power tool

Abstract

To provide a dust collection system for a power tool that prevents transmission of noise occurring from a DC motor of a dust collection attachment to a power supply path of a power tool which is an AC machine.SOLUTION: A dust collection system S for a power tool includes: a hammer drill 1 which is supplied with a commercial power supply and includes a motor 7 which is driven or stopped in conjunction with on / off operation of a main switch 21; and a dust collection attachment 60 including a duct 80, a dust box 65, a dust collection fan 94, a dust collection motor 92, and a battery pack 101. A tool body side power supply path extending from a power cord 20 to the motor 7 is electrically separated from a dust collection side power supply path extending from the battery pack 101 to the dust collection motor 92. Further, the dust collection system S is provided with linking means (a sub switch 22, a sub lead wire 27, and a signal lead wire 97) which drives / stops the dust collection motor 92 in conjunction with the on / off operation of the main switch 21 when electrically separated from a signal path of the main switch 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a dust collection system for a power tool that includes a power tool and a dust collection attachment that is attached to the power tool to collect dust generated during use of the power tool. [Background technology]

[0002] When a power tool such as a hammer drill is used to process a workpiece such as concrete or stone, a dust collection attachment is attached to the power tool to prevent dust generated from the workpiece from scattering. As disclosed in Patent Document 1, this dust collection attachment includes a suction section that sucks in dust, a dust collection section that stores the sucked dust, and a dust collection motor equipped with a fan that generates suction force. The dust collection attachment is attached to the power tool by, for example, sliding the casing of the dust collection attachment onto the main body of the power tool from below. In the attached state, the male plug of the dust collection attachment is inserted into the female connector of the power tool to electrically connect them. The power tool is supplied with commercial power via a power cord, and when the trigger is operated to turn the switch ON, the drive motor is driven and the commercial power is also supplied to the controller of the dust collection attachment. The controller converts the supplied commercial power into direct current and supplies it to the dust collection motor, which is a DC motor, to drive the dust collection motor. When the switch is turned OFF, the power supply from the power tool to the controller is stopped and the dust collection motor is also stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6211433 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional dust collection system for power tools, the power tool and the dust collection attachment are electrically connected, and the DC motor of the dust collection attachment is linked to the ON / OFF switch of the power tool. Therefore, there is a risk that noise generated by the DC motor will reach the commercial power supply through the power path of the power tool. As a result, it will fail the EMI (Electromagnetic Interference) standard test, and noise countermeasures will be required.

[0005] Therefore, an object of the present disclosure is to provide a dust collection system for a power tool that can prevent noise generated in a DC motor of a dust collection attachment from being propagated to the power path of the power tool, which is an AC machine. [Means for solving the problem]

[0006] In order to achieve the above object, the present disclosure provides an electric tool including an AC motor that is supplied with commercial power and is driven / stopped in response to an ON / OFF operation of a switch; The dust collection system for power tools includes a dust collection attachment that is attached to the power tool to collect dust generated when the power tool is used, and that includes a suction unit, a dust collection unit that captures dust sucked through the suction unit, a fan that generates suction force in the suction unit, a DC motor that rotates the fan, and a battery pack that serves as a power source for the DC motor. When the dust collection attachment is attached to the power tool, the power path on the power tool side from the commercial power source to the AC motor is electrically separated from the power path on the dust collection side from the battery pack to the DC motor. The device is characterized by being provided with a linkage means for driving / stopping the DC motor in conjunction with the ON / OFF operation of the switch while being electrically separated from the signal path of the switch. Effect of the Invention

[0007] According to the present disclosure, it is possible to prevent noise generated in a DC motor of a dust collection attachment from propagating to the power supply path of a power tool, thereby passing EMI standard tests and eliminating the need for noise countermeasures. [Brief description of the drawings]

[0008] [Figure 1] 1 is a central vertical cross-sectional view of a dust collection system for a power tool; [Diagram 2] FIG. 2 is an enlarged view of the left half of the portion taken along line AA in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one embodiment of the present disclosure, the power tool is provided with a main unit controller that controls the AC motor in response to ON / OFF operation of a switch, and the power supply path from the commercial power source via the main unit controller to the AC motor may be electrically separated from the power supply path from the battery pack to the DC motor. According to this configuration, even if there is a main unit controller, it is possible to prevent noise generated in the DC motor from being transmitted to the power supply path of the power tool. In one embodiment of the present disclosure, the interlocking means may include a second switch that is provided on the power tool separately from the switch and that is turned ON / OFF in conjunction with the ON / OFF operation of the switch, and a second signal path that electrically connects the second switch and the DC motor when the dust collection attachment is attached to the power tool. According to this configuration, the DC motor can be linked to the ON / OFF operation of the switch while being securely separated from the signal path of the switch.

[0010] In one embodiment of the present disclosure, the interlocking means may include a second signal path that is provided separately from the signal path of the switch and electrically connects the switch and the DC motor when the dust collection attachment is attached to the power tool. According to this configuration, the DC motor can be linked to the ON / OFF operation of the switch while being securely separated from the signal path of the switch to the AC motor. In one embodiment of the present disclosure, when a switch is turned on, the DC motor may be driven first, and then the AC motor may be driven. According to this configuration, the dust collection attachment can be operated first to generate suction force, so that dust can be reliably sucked up at the same time as work is performed with the power tool. In one embodiment of the present disclosure, when the switch is turned OFF, the DC motor may stop driving after the AC motor stops driving. According to this configuration, dust can be collected in the dust collecting section without remaining in the dust collection path after the operation of the power tool is stopped.

[0011] In one embodiment of the present disclosure, the dust collection attachment can be attached to and detached from the power tool by moving it vertically relative to the power tool, and when the dust collection attachment is attached to the power tool, the dust collection attachment and the power tool are electrically connected to each other so that the interlocking means can be operated. According to this configuration, the dust collection attachment can be easily attached to and detached from the power tool, and when the dust collection attachment is attached, the dust collection attachment automatically operates by turning the switch ON / OFF, improving usability. In one embodiment of the present disclosure, a notification unit may be provided that notifies the user when the remaining capacity of the battery pack falls below a predetermined amount. This configuration allows the worker to quickly take action such as replacing or charging the battery pack. In one embodiment of the present disclosure, the notification means may be visual. With this configuration, the operator can easily grasp the decrease in remaining capacity. EXAMPLES

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a central vertical cross-sectional view showing an example of a dust collection system for a power tool (hereinafter simply referred to as a "dust collection system") S formed by attaching a dust collection attachment 60 to a hammer drill 1, which is an example of a power tool. First, the hammer drill 1 will be described. The hammer drill 1 has an inner housing 2, a motor housing 3, an upper outer housing 4, and a lower outer housing 5 as housings. The inner housing 2 houses a striking mechanism 6 extending in the front-rear direction. The motor housing 3 is connected to the lower side of the inner housing 2 and houses a motor 7. The motor 7 is held in the motor housing 3 with a rotating shaft 8 facing upward. An upper portion of the rotating shaft 8 is supported by a bearing 9 held in the inner housing 2, and a pinion 10 provided at the upper end thereof protrudes into the inner housing 2. The motor 7 is an example of an AC motor of the present disclosure. The upper outer housing 4 covers the outside of the inner housing 2 above the motor housing 3 .

[0013] The lower outer housing 5 has a front tube portion 11 and a handle portion 12. The front tube portion 11 covers the outside of the motor housing 3 from below. A main unit controller 13 equipped with a control circuit board (not shown) is housed in the front tube portion 11 in the vertical direction at the rear of the motor housing 3. A front guide groove 14 is formed in the vertical direction at the center in the left-right direction on the front surface of the front tube portion 11. An upper locking recess 15 for mounting the dust collection attachment 60 is formed in the front and rear of the front guide groove 14. As shown in FIG. 2, a lateral locking recess 16 for mounting the dust collection attachment 60 is formed on the left and right side surfaces of the front tube portion 11. A pair of lateral guide grooves 17, 17 extending upward from the lower end of the front tube portion 11 are formed in front and behind the lateral locking recess 16.

[0014] The handle portion 12 is connected to the lower portion of the front tubular portion 11 and extends rearward, and then extends upward to be connected to the rear end of the upper outer housing 4 . A power cord 20 is connected to the lower part of the handle part 12. The power cord 20 is electrically connected to the machine-side controller 13. A main switch 21 and a sub switch 22 are provided above the power cord 20 in the handle part 12. The main switch 21 has a plunger 23 protruding forward. A main lead wire 24 is connected to the main switch 21. The main lead wire 24 is electrically connected to the machine-side controller 13, and an ON signal can be input to the machine-side controller 13 when the plunger 23 is pressed. The main switch 21 is an example of a switch of the present disclosure. The main lead wire 24 is an example of a signal path of a switch of the present disclosure. The power path from the power cord 20 to the motor 7 via the machine-side controller 13 is an example of the machine-side power path from the commercial power source to the AC motor of the present disclosure and the machine-side power path from the commercial power source to the AC motor via the machine-side controller of the present disclosure.

[0015] The sub-switch 22 also has a plunger 25 protruding forward and a lever 26 in front of it. A sub-lead wire 27 is connected to the sub-switch 22. The sub-lead wire 27 passes between the main switch 21 and the inner surface of the handle portion 12 and is drawn downward inside the handle portion 12. The sub-switch 22 is an example of a second switch of the present disclosure. A connection port 28 that opens downward is provided below the main controller 13 on the lower surface of the front cylindrical portion 11 of the lower outer housing 5. A female connector 29 is provided facing downward in the connection port 28. The sub-lead wire 27 is connected to the female connector 29.

[0016] A switch lever 30 is provided in front of the main switch 21 and the sub-switch 22. The switch lever 30 is provided on the handle portion 12 so as to be swingable back and forth around its lower end. In a normal state, the switch lever 30 is in a protruding position in which it is in contact with the plunger 23 of the main switch 21 and protrudes forward from the handle portion 12. A pressing portion 31 is provided on the switch lever 30 above the contact portion of the plunger 23, and is located in front of the lever 26 of the sub-switch 22. Therefore, when the switch lever 30 is pushed backward from the protruding position, the plunger 23 is pushed in to turn on the main switch 21, and the pressing portion 31 pushes the plunger 25 via the lever 26 to also turn on the sub-switch 22. However, due to the setting of the length of the pressing portion 31, the timing at which the sub-switch 22 turns on is earlier than the timing at which the main switch 21 turns on.

[0017] The striking mechanism 6 has a tool holder 35. The tool holder 35 is rotatably held at the front side of the inner housing 2 and is cylindrical extending in the front-rear direction. Within the inner housing 2, an intermediate shaft 36 is supported at the front side of the rotating shaft 8, and a crankshaft 37 is supported at the rear side in the vertical direction. A gear 38 and a gear 39 are provided on the intermediate shaft 36 and the crankshaft 37, respectively. The gear 38 and the gear 39 are engaged with the pinion 10 of the rotating shaft 8. The intermediate shaft 36 has a first bevel gear 40 at its upper end. A switching sleeve 41 is splined to the tool holder 35. A second bevel gear 42 is rotatably mounted on the rear end of the tool holder 35 behind the switching sleeve 41. The second bevel gear 42 meshes with the first bevel gear 40 of the intermediate shaft 36. The second bevel gear 42 transmits the rotation of the first bevel gear 40 to the tool holder 35 by engaging with the switching sleeve 41 in the retracted position. The forward / rearward position of the switching sleeve 41 can be switched by a switching knob 51 provided on the rear surface of the upper outer housing 4.

[0018] A cylinder 43 is held in the rear of the inner housing 2. The cylinder 43 is inserted coaxially into the rear of the tool holder 35. A piston 44 is housed in the cylinder 43 so as to be movable back and forth. An eccentric pin 45 protrudes from the upper part of the crankshaft 37. The piston 44 and the eccentric pin 45 are connected by a connecting rod 46. A striker 48 is housed in the cylinder 43 in front of the piston 44 via an air chamber 47 so as to be movable back and forth. An impact bolt 49 is provided in the tool holder 35 in front of the striker 48. A bit B inserted into the front end of the tool holder 35 abuts against the impact bolt 49. An operation sleeve 50 for attaching and detaching the bit B is fitted to the front of the tool holder 35.

[0019] In the hammer drill 1, when the switch lever 30 is pressed, the main switch 21 is turned ON. When the machine-side controller 13 receives an ON signal from the main switch 21 via the main lead wire 24, it supplies power to the motor 7 to rotate the rotating shaft 8. This rotates the crankshaft 37, which moves the piston 44 back and forth via the connecting rod 46. As a result, the linked striker 48 strikes the bit B via the impact bolt 49. When the switching sleeve 41 is switched to the backward position by operating the switching knob 51, the hammer drill mode is set in which rotation is transmitted from the intermediate shaft 36 to the tool holder 35 via the second bevel gear 42. When the switching sleeve 41 is switched to the forward position, the hammer mode is set in which only impact is performed without the tool holder 35 rotating.

[0020] Next, the dust collecting attachment 60 will be described. The dust collection attachment 60 has a box-shaped casing 61. The casing 61 includes a main body 62, a front protruding portion 63, and a rear protruding portion 64. The main body 62 extends in the vertical direction, and the front protruding portion 63 extends forward from an upper portion of the main body 62. A dust box 65 is detachably attached to the front side of the main body 62 and the lower side of the front protruding portion 63. The rear protruding portion 64 extends rearward from a lower portion of the main body 62. The main body 62 and the rear protruding portion 64 are attachable to the hammer drill 1. An upper locking protrusion 66 is formed facing upward on the upper surface of the main body 62. The upper locking protrusion 66 is capable of being inserted into an upper locking recess 15 provided in the front cylindrical portion 11 of the hammer drill 1. A locking plate 67 is provided in the vertical direction on the upper rear surface of the main body 62. The locking plate 67 is capable of being locked in a front guide groove 14 provided on the front surface of the front tube portion 11.

[0021] A pair of side plates 68, 68 are provided on both the left and right sides from the rear surface of the main body 62 to the upper surface of the rear protruding portion 64. The front cylindrical portion 11 of the hammer drill 1 can be fitted between the side plates 68, 68 from above. A pair of front and rear protrusions 69, 69 are formed on the inner surface of each side plate 68. The protrusions 69, 69 can be fitted into lateral guide grooves 17, 17 provided on the side surface of the front cylindrical portion 11. A vertically extending recess 70 is formed on the outer surface of each side plate 68. A hook plate 71 is housed in the recess 70. The hook plate 71 is a strip-shaped plate that fits into the recess 70 and extends vertically. As shown in FIG. 2, the inside of the middle part is connected to the recess 70 so as to be rotatable around a shaft 72 in the front-rear direction. The lower part of the hook plate 71 is pressed outward to the left and right by a coil spring 73 provided between the hook plate 71 and the inner surface of the recess 70. Thus, the hook plate 71 is in a locked position in which the upper part is biased inward to the left and right as shown by the solid line in FIG. 2. A locking claw 74 that protrudes inward is provided on the upper end of the hook plate 71. In the locked position, the locking claw 74 protrudes inward of the side plate 68 through a through hole 75 provided in the recess 70. The locking claw 74 can be locked to the horizontal locking recess 16 of the front tube part 11 at the attachment position of the dust collection attachment 60 to the hammer drill 1. When the lower portion of the hook plate 71 is pressed toward the recess 70, the hook plate 71 tilts to an unlocked position in which the locking claws 74 are separated from the lateral locking recesses 16 as shown by the two-dot chain lines in FIG.

[0022] A receiving portion 76 is provided on the upper surface of the rear protruding portion 64. The receiving portion 76 abuts against the lower surface of the front tubular portion 11 at the attachment position of the dust collection attachment 60. A connecting tube 77 is provided on the upper surface of the rear protruding portion 64 behind the receiving portion 76 and protrudes upward. The connecting tube 77 is located in the center of the rear protruding portion 64 in the left-right direction and holds a male connector 78 facing upward. The connecting tube 77 is connected to the connecting port 28 on the lower surface of the front tubular portion 11 at the attachment position of the dust collection attachment 60, and connects the male connector 78 to the female connector 29 of the connecting port 28.

[0023] A duct 80 is provided in the front protruding portion 63. The front end of the duct 80 opens forward at the front surface of the front protruding portion 63. The duct 80 is routed rearward within the front protruding portion 63 and makes a U-turn within the main body portion 62, with the lower end opening at the front surface of the main body portion 62 below the front protruding portion 63. The front end of the duct 80 is an example of a suction portion of the present disclosure. The dust box 65 is a box-shaped body that is attached to the casing 61 from the front below the front protrusion 63. The dust box 65 is formed by hingedly connecting a lid 81 and a box body 82 at their lower ends. The lid 81 has a filter 83 on its front inner surface, and the box body 82 covers the filter 83 from the front. The dust box 65 is an example of a dust collection section of the present disclosure. A locking shaft 84 is provided in the left-right direction at the lower end of the front surface of the main body 62. A receiving recess 85 is formed in the left-right direction on the lower surface of the box main body 82. The dust box 65 is detachably attached to the casing 61 by engaging the receiving recess 85 with the locking shaft 84 and locking an elastic piece 86 provided on the upper end of the lid 81 to the lower surface of the front protrusion 63. The lid 81 is provided with an inlet 87 on the upper side and an outlet 88 on the lower side. The inlet 87 is connected to the lower end of the duct 80. The outlet 88 is provided on the rear side of the filter 83.

[0024] A motor housing chamber 90 is formed as a partition within the main body 62 behind the outlet 88. When the dust box 65 is attached, the outlet 88 abuts against an opening 91 provided on the front side of the motor housing chamber 90 and is connected to the motor housing chamber 90. A dust collection motor 92 is accommodated in the motor housing chamber 90. The dust collection motor 92 is held in a position with a rotating shaft 93 facing downward. A dust collection fan 94 is fixed to the rotating shaft 93. Exhaust ports (not shown) are formed on the left and right side surfaces of the main body 62 that are radially outward of the dust collection fan 94. The dust collection fan 94 is an example of a fan of the present disclosure. The dust collection motor 92 is an example of a DC motor of the present disclosure. Positive and negative lead wires 95, 95 connected to the dust collection motor 92 pass through the partition between the main body 62 and the rear protruding portion 64 and are drawn into the rear protruding portion 64. A dust collection side controller 96 equipped with a control circuit board (not shown) is provided inside the rear protruding portion 64. The lead wires 95, 95 are electrically connected to the dust collection side controller 96. The dust collection side controller 96 is electrically connected to the male connector 78 via a signal lead wire 97.

[0025] A battery mounting section 100 is provided on the rear protrusion 64. A battery pack 101, which serves as a power source for the dust collection attachment 60, can be slidably mounted from the rear into the battery mounting section 100. A terminal block 102 that electrically connects to the mounted battery pack 101 is provided inside the battery mounting section 100. The terminal block 102 is electrically connected to the dust collection side controller 96 via a power supply lead wire 103. The power supply path from the battery pack 101 through the dust collection side controller 96 to the dust collection motor 92 is an example of a dust collection side power supply path from the battery pack to the DC motor of the present disclosure. The dust collection side controller 96 is provided with a notification lamp 98 exposed on a side surface of the rear protrusion 64. For example, an LED is used for the notification lamp 98. When the battery pack 101 is attached to the battery attachment section 100, the dust collection side controller 96 monitors the remaining capacity of the battery pack 101. When the remaining capacity of the battery pack 101 falls below a predetermined threshold, the dust collection side controller 96 lights or blinks the notification lamp 98 to notify the user of the decrease in remaining capacity. The notification lamp 98 is an example of a notification means of the present disclosure.

[0026] In the dust collection system S configured as described above, with the rear protrusion 64 positioned below the front cylindrical portion 11 of the hammer drill 1, the dust collection attachment 60 vertically moves relative to the hammer drill 1 with the protrusions 69,69 of the side plates 68,68 aligned vertically with the lateral guide grooves 17,17 of the front cylindrical portion 11. Then, the protrusions 69,69 fit into the lateral guide grooves 17,17 from below, and the upper locking protrusions 66 of the main body 62 are inserted into the upper locking recesses 15 of the front cylindrical portion 11 from below. Also, the locking plate 67 of the main body 62 locks into the front guide groove 14 of the front cylindrical portion 11 from below. At this time, the hook plates 71, 71 of the side plates 68, 68 interfere with the front tubular portion 11 moving downward relatively, and swing from the locked position to the unlocked position, allowing the relative movement of the dust collection attachment 60. Then, when the dust collection attachment 60 is in the attachment position, the locking claws 74 of each hook plate 71, which has returned to the locked position, are locked into the lateral locking recesses 16 of the front tubular portion 11. Thus, downward movement of the dust collection attachment 60 relative to the hammer drill 1 is restricted, and attachment of the dust collection attachment 60 is completed. At the same time as this attachment is completed, the connection tube 77 of the rear protrusion 64 is connected to the connection port 28 of the front tube portion 11, and the male connector 78 is connected to the female connector 29. Thus, the sub-switch 22 is electrically connected to the dust-collection side controller 96 via the sub-lead wire 27 and the signal lead wire 97.

[0027] The bit B attached to the hammer drill 1 is a dust-suction bit having a dust-suction passage with a suction port opening at the front end at its axis and a hose attachment part (not shown) attached to its outer periphery. Therefore, a flexible hose is connected between the front end of the duct 80, where suction force is generated in the dust collection attachment 60, and the hose attachment part. By connecting the flexible hose 105, a dust collection path R is formed through which air flows across the bit B and the dust collection attachment 60. As shown by the dotted arrow in Fig. 1, this dust collection path R is a path that leads from the bit B through the flexible hose 105, the duct 80, the dust box 65, and the motor housing chamber 90 to the exhaust port.

[0028] When performing work using the dust collection system S, the switch lever 30 of the hammer drill 1 is pressed while the tip of the bit B is pressed against the surface of the workpiece. Then, as described above, the sub-switch 22 is turned ON first. This ON signal is input to the dust collection side controller 96 via the sub-lead wire 27 and the signal lead wire 97. When the dust collection side controller 96 receives the ON signal, it supplies the power of the battery pack 101 obtained from the terminal block 102 via the power lead wire 103 to the dust collection motor 92 via the leads 95, 95. Thus, the dust collection motor 92 is driven to rotate the rotating shaft 93, which rotates the dust collection fan 94. Then, the dust collection path R becomes negative pressure, and a suction force is generated at the tip opening of the bit B. The sub-switch 22, the sub-lead wire 27, and the signal lead wire 97 are an example of the interlocking means of the present disclosure, and the sub-lead wire 27 and the signal lead wire 97 are an example of the second signal path of the present disclosure.

[0029] Following the sub-switch 22, the main switch 21 is turned ON. This ON signal is input to the machine-side controller 13 via the main lead wire 24. When the machine-side controller 13 receives the ON signal, it supplies operating power to the motor 7 from the commercial power source obtained from the power cord 20. This drives the motor 7 to rotate the rotating shaft 8, which in turn rotates the intermediate shaft 36 and the crankshaft 37. Here, regardless of whether the hammer drill mode or the hammer mode is selected, the piston 44 always reciprocates, so that the bit B is struck by the linked striker 48 via the impact bolt 49.

[0030] Dust generated from the workpiece is sucked into the dust suction passage in the bit B and enters the duct 80 via the flexible hose 105. The dust then passes through the dust collection path R into the dust box 65, where it is captured by the filter 83 and stored in the box body 82. Even if noise is generated by the dust collection motor 92 during this operation, the dust collection motor 92 is electrically isolated from the power supply path and signal path on the hammer drill 1 side, so there is no risk of the generated noise being transmitted to the power supply path of the hammer drill 1. When the work is completed, the pushing operation of the switch lever 30 is released and the main switch 21 is turned OFF. When the machine side controller 13 confirms that the main switch 21 is turned OFF, it stops the power supply to the motor 7 and stops the operation of the hammer drill 1. On the other hand, when the sub-switch 22 is turned OFF as a result of the release of the pressing operation of the switch lever 30, the dust-collection side controller 96 confirms that the sub-switch 22 is OFF, and then waits for a preset delay time of several seconds to elapse before stopping the supply of power to the dust collection motor 92. Thus, the dust remaining in the dust collection path R when the hammer drill 1 stops operating can be stored in the dust box 65.

[0031] When removing the dust collection attachment 60 from the hammer drill 1, the lower parts of the left and right hook plates 71, 71 are pushed in to move each hook plate 71 to the unlocked position. Then, each locking claw 74 is released from the lateral locking recess 16 of the front tubular part 11, allowing the dust collection attachment 60 to move relatively. Therefore, the dust collection attachment 60 is moved relatively away from the hammer drill 1 in the opposite direction to that during attachment. Then, the protrusions 69, 69 of the side plates 68, 68 are released from the lateral guide grooves 17, 17 of the front tubular part 11, and the locking plate 67 of the main body part 62 is moved downwardly away from the front guide groove 14. At the same time, the upper locking protrusion 66 of the main body part 62 is removed from the upper locking recess 15 of the front tubular part 11. In this manner, removal of the dust collection attachment 60 is completed. When disposing of the dust stored in the dust box 65, the elastic piece 86 is pushed down to release the engagement with the front protrusion 63. Then, the dust box 65 can be removed from the casing 61 by simply tipping the dust box 65 forward about the engagement shaft 84. When the lid 81 is opened, the dust stored inside the box body 82 can be disposed of.

[0032] The dust collection system S of the above embodiment includes the hammer drill 1 equipped with a motor 7 that is supplied with commercial power and is driven / stopped in response to ON / OFF operation of the main switch 21 by the switch lever 30. The dust collection system S also includes a dust collection attachment 60 that is attached to the hammer drill 1 to collect dust generated when the hammer drill 1 is in use, and includes a duct 80, a dust box 65 that captures dust sucked through the duct 80, a dust collection fan 94 that generates a suction force in the duct 80, a dust collection motor 92 that rotates the dust collection fan 94, and a battery pack 101 that serves as a power source for the dust collection motor 92. When the dust collection attachment 60 is attached to the hammer drill 1, the machine side power path from the power cord 20 to the motor 7 and the dust collection side power path from the battery pack 101 to the dust collection motor 92 are electrically separated, and a linkage means (sub-switch 22, sub-lead wire 27, signal lead wire 97) is provided which drives / stops the dust collection motor 92 in conjunction with the ON / OFF operation of the main switch 21 while being electrically separated from the signal path of the main switch 21. This configuration can prevent noise generated by the dust collection motor 92 from propagating to the power supply path of the hammer drill 1. As a result, the EMI standard test can be cleared, and noise countermeasures are not required.

[0033] The hammer drill 1 is provided with a machine-side controller 13 that controls the motor 7 in response to ON / OFF operation of the main switch 21, and the power supply path from the commercial power source via the machine-side controller 13 to the motor 7 is also electrically separated from the power supply path from the battery pack 101 to the dust collection motor 92. Therefore, even if the machine-side controller 13 is provided, it is possible to prevent noise generated in the dust collection motor 92 from being transmitted to the power supply path of the hammer drill 1. The interlocking means includes a sub-switch 22 that is provided separately from the main switch 21 on the hammer drill 1 and is turned ON / OFF in conjunction with the ON / OFF operation of the main switch 21, and a sub-lead wire 27 and a signal lead wire 97 that electrically connect the sub-switch 22 and the dust collection motor 92 when the dust collection attachment 60 is attached to the hammer drill 1. Therefore, the dust collection motor 92 can be linked to the ON / OFF operation of the main switch 21 while being securely separated from the signal path of the main switch 21.

[0034] When the main switch 21 is turned on, the dust collection motor 92 is driven and then the motor 7 is driven. Therefore, the dust collecting attachment 60 can be operated first to generate suction force, and the suction of dust can be reliably performed simultaneously with the work by the hammer drill 1. When the main switch 21 is turned off, the motor 7 is stopped, and then the dust collection motor 92 is stopped. Therefore, dust can be collected in the dust box 65 without remaining in the dust collection path R after the operation of the hammer drill 1 is stopped.

[0035] The dust collection attachment 60 can be attached to and detached from the hammer drill 1 by moving it vertically relative to the hammer drill 1, and at the same time, the dust collection attachment 60 and the hammer drill 1 are electrically connected together, enabling the interlocking means to operate. Therefore, the dust collection attachment 60 can be easily attached to and detached from the hammer drill 1, and when the main switch 21 is turned ON / OFF with the attachment attached, the dust collection attachment 60 is automatically operated, improving usability. An alarm lamp 98 is provided to notify the user when the remaining capacity of the battery pack 101 falls below a predetermined level. Therefore, the worker can quickly take action such as replacing or charging the battery pack 101. The notification lamp 98 is visually appealing. Therefore, the operator can easily grasp the decrease in remaining capacity.

[0036] Modifications of the present disclosure will be described below. The sub-switch forming the interlocking means may be provided below or to the side of the main switch instead of above the main switch. The shape of the sub-switch may also be modified as appropriate. However, the interlocking means is not limited to a configuration using a sub-switch. For example, two electrically separated signal paths may be formed separately within one switch, one of the signal paths being connected to the main controller via a main lead wire, and the other of the signal paths being connected to the dust collection attachment via a sub-lead wire. In this way, even if the interlocking means is configured to include a second signal path that electrically connects the switch and the DC motor when the dust collection attachment is attached to the power tool, the DC motor can be interlocked with the ON / OFF operation of the switch while being securely separated from the switch's signal path to the AC motor.

[0037] In a hammer drill, the position and orientation of the motor, the position and orientation of the machine controller, and the connection position of the power cord are not limited to those in the above embodiment. For example, the motor may be oriented with the rotation shaft facing forward or diagonally forward, and the machine controller may be oriented sideways. The power cord may be connected to the rear surface of the handle. The machine controller may not be required. The structure of the striking mechanism is not limited to that of the above embodiment. The operation mode may be one in which a drill mode can be selected. The power tool is not limited to a hammer drill, but may be another power tool such as an electric hammer. In the above embodiment, a dust-collecting bit is used as the tip tool attached to the power tool, but the tip tool does not have to be a dust-collecting bit. In this case, a separate cylindrical attachment that covers the outside of the tip tool may be attached to the tip of the power tool, and a hose attachment part provided on the attachment and the suction part of the dust-collecting attachment may be connected by a flexible hose.

[0038] The attachment direction of the dust collection attachment to the power tool is not limited to the up-down direction, but may be, for example, the front-rear direction. In the dust collection attachment, the position and orientation of the DC motor and the position and structure of the dust box are not limited to those in the above embodiment. For example, the DC motor may be housed with the rotation shaft facing upward or sideways. The DC motor and the fan shaft may be separate, and the rotation may be transmitted from the rotation shaft of the DC motor to the shaft of the fan. The dust collecting section is not limited to a dust box, and may be a cyclone structure without a filter. Therefore, the dust collecting path can be changed as appropriate. The battery pack may be slid into the battery mounting portion from the side instead of from the rear. A plurality of battery packs may be mounted. In the dust collection attachment, the connection part of the flexible hose may be at another position such as the top surface or side surface instead of the front surface of the casing. However, the dust collection attachment may not use a flexible hose. For example, the dust collection attachment may have a cylindrical slide part that protrudes from the casing with a dust collection path provided therein, and a suction port through which a tool tip passes is provided at the tip of the slide part. The notification means is not limited to a lamp, and may be, for example, a display of letters or numbers, a sound such as an electronic tone, or a combination of a lamp and a sound. [Explanation of symbols]

[0039] 1 hammer drill, 2 inner housing, 3 motor housing, 4 upper outer housing, 5 lower outer housing, 6 striking mechanism, 7 motor, 8 rotating shaft, 11 front cylinder, 12 handle, 13 machine controller, 20 power cord, 21 main switch, 22 sub switch, 24 main lead wire, 27 sub lead wire, 29 female connector, 30 switch lever, 35 tool holder, 44 ·Piston, 48··Striker, 49··Impact bolt, 60··Dust collection attachment, 61··Casing, 62··Main body, 65··Dust box, 71··Hook plate, 78··Male connector, 83··Filter, 92··Dust collection motor, 94··Dust collection fan, 96··Dust collection side controller, 97··Signal lead wire, 101··Battery pack, 103··Power supply lead wire, B··Bit, R··Dust collection path, S··Dust collection system for power tools.

Claims

1. A power tool equipped with an AC motor that is supplied with commercial power and drives / stops in accordance with the ON / OFF operation of a switch, A dust collection system for power tools, comprising a dust collection attachment attached to the power tool for collecting dust generated when the power tool is used, the attachment comprising a suction unit, a dust collection unit for capturing dust sucked from the suction unit, a fan for generating suction force in the suction unit, a DC motor for rotating the fan, and a battery pack for powering the DC motor, With the dust collection attachment attached to the power tool, the power supply path on the main unit side from the commercial power supply to the AC motor and the power supply path on the dust collection side from the battery pack to the DC motor are electrically separated, A dust collection system for power tools is characterized by having an interlocking means that drives / stops the DC motor in conjunction with the ON / OFF operation of the switch, while being electrically isolated from the signal path of the switch.

2. The power tool is provided with a device-side controller that controls the AC motor in accordance with the ON / OFF operation of the switch, and the power supply path from the commercial power source to the AC motor via the device-side controller is electrically isolated from the power supply path from the battery pack to the DC motor, as described in claim 1.

3. The power tool dust collection system according to claim 1 or 2, characterized in that the interlocking means includes a second switch provided separately on the power tool from the switch and which is turned ON / OFF in accordance with the ON / OFF operation of the switch, and a second signal path that electrically connects the second switch and the DC motor when the dust collection attachment is attached to the power tool.

4. The power tool dust collection system according to claim 1 or 2, characterized in that the interlocking means includes a second signal path provided separately from the signal path of the switch, which electrically connects the switch and the DC motor when the dust collection attachment is attached to the power tool.

5. The dust collection system for power tools according to claim 1 or 2, characterized in that the DC motor is driven first, followed by the AC motor, in response to the ON operation of the switch.

6. The dust collection system for power tools according to claim 1 or 2, characterized in that the DC motor stops driving after the AC motor stops driving when the switch is turned OFF.

7. The dust collection attachment can be attached to and detached from the power tool by moving it relative to the power tool in the vertical direction. The dust collection system for power tools according to claim 1 or 2, characterized in that when the dust collection attachment is attached to the power tool, the dust collection attachment and the power tool are electrically connected, and the interlocking means becomes operable.

8. The dust collection system for power tools according to claim 1 or 2, characterized in that it is provided with a notification means for notifying when the remaining capacity of the battery pack falls below a predetermined amount.

9. The dust collection system for power tools according to claim 8, characterized in that the notification means is visually appealing.

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